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chiller</title> <meta name="description" content="Search results for: air cooled chiller"> <meta name="keywords" content="air cooled chiller"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button class="d-block d-lg-none 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action="https://publications.waset.org/abstracts/search"> <div id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="air cooled chiller"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 204</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: air cooled chiller</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">204</span> Modeling and Performance Analysis of an Air-Cooled Absorption Chiller</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=A.%20Roukbi">A. Roukbi</a>, <a href="https://publications.waset.org/abstracts/search?q=B.%20Draoui"> B. Draoui</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Due to the high cost and the environmental problems caused by the conventional air-conditioning systems, various researches are being increasingly focused on thermal comfort in the building sector integrating renewable energy sources, particularly solar energy. For that purpose, this study aims to present a modeling and performance analysis of a direct air-cooled Water/LiBr absorption chiller. The chiller is considered to be coupled to a small residential building at an arid zone situated in south Algeria. The system is modeled with TRNSYS simulation program. The main objective is to study the feasibility of the chosen system in arid zones and to apply a simplified method to predict the performance of the system by mean of the characteristic equation approach tacking in account the influence of the climatic conditions of the considered site, the collector area and storage volume of the hot water tank on the performance of the installation. First, the results of the system modeling are compared with an experimental data from the open literature and the developed model is then validated. In another hand, a parametric study is performed to analyze the performance of the direct air-cooled absorption chiller at the operating conditions of interest for the present study. Thus, the obtained results has shown that the studied system can present a good alternative for cooling systems in arid zones since the cooling load is roughly in phase with solar availability. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=absorption%20chiller" title="absorption chiller">absorption chiller</a>, <a href="https://publications.waset.org/abstracts/search?q=air-cooled" title=" air-cooled"> air-cooled</a>, <a href="https://publications.waset.org/abstracts/search?q=arid%20zone" title=" arid zone"> arid zone</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20comfort" title=" thermal comfort"> thermal comfort</a> </p> <a href="https://publications.waset.org/abstracts/39302/modeling-and-performance-analysis-of-an-air-cooled-absorption-chiller" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/39302.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">230</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">203</span> Heat Recovery System from Air-Cooled Chillers in Iranian Hospitals</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Saeed%20Vahidifar">Saeed Vahidifar</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Nakhaee%20Sharif"> Mohammad Nakhaee Sharif</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Ghaffari"> Mohammad Ghaffari</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Few people would dispute the fact that one of the most common applications of energy is creating comfort in buildings, so it is probably true to say that management of energy consumption is required due to the environmental issues and increasing the efficiency of mechanical systems. From the geographical point of view, Iran is located in a warm and semi-arid region; therefore, air-cooled chillers are usually used for cooling residential buildings, commercial buildings, medical buildings, etc. In this study, a heat exchanger was designed for providing laundry hot water by utilizing condenser heat lost base on analytical results of a 540-bed hospital in the city of Mashhad in Iran. In this paper, by using the analytical method, energy consumption reduces about 13%, and coefficient of performance increases a bit. Results show that this method can help in the management of energy consumption a lot. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=air%20cooled%20chiller" title="air cooled chiller">air cooled chiller</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20management" title=" energy management"> energy management</a>, <a href="https://publications.waset.org/abstracts/search?q=environmental%20issues" title=" environmental issues"> environmental issues</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20exchanger" title=" heat exchanger"> heat exchanger</a>, <a href="https://publications.waset.org/abstracts/search?q=hospital%20laundry%20system" title=" hospital laundry system"> hospital laundry system</a> </p> <a href="https://publications.waset.org/abstracts/132496/heat-recovery-system-from-air-cooled-chillers-in-iranian-hospitals" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/132496.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">160</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">202</span> The Effect of Cooling Tower Fan on the Performance of the Chiller Plant</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ankitsinh%20Chauhan">Ankitsinh Chauhan</a>, <a href="https://publications.waset.org/abstracts/search?q=Vimal%20Patel"> Vimal Patel</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20D.%20Parekh"> A. D. Parekh</a>, <a href="https://publications.waset.org/abstracts/search?q=Ishant%20patil"> Ishant patil</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study delves into the crucial influence of cooling tower fan operation on the performance of a chiller plant, with a specific focus on the Chiller Plant at SVNIT. Continuous operation of the chiller plant led to unexpected damage to the cooling tower's belt drive, rendering the cooling tower fan non-operational. Consequently, the efficiency of heat transfer in the condenser was significantly impaired. In response, we analyzed and calculated several vital parameters, including the Coefficient of Performance (COP), heat rejection in the condenser (Qc), work required for the compressor (Wc), and heat absorbed by the refrigerant in the evaporator (Qe). Our findings revealed that in the absence of the cooling tower fan, relying solely on natural convection, the COP of the chiller plant reached a minimum value of 5.49. However, after implementing a belt drive to facilitate forced convection for the cooling tower fan, the COP of the chiller plant experienced a noteworthy improvement, reaching approximately 6.27. Additionally, the utilization of forced convection resulted in an impressive reduction of 8.9% in compressor work, signifying enhanced energy efficiency. This study underscores the critical role of cooling tower fan operation in optimizing chiller plant performance, with practical implications for energy-efficient HVAC systems. It highlights the potential benefits of employing forced convection mechanisms, such as belt drives, to ensure efficient heat transfer in the condenser, ultimately contributing to improved energy utilization and reduced operational costs in cooling. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cooling%20tower" title="cooling tower">cooling tower</a>, <a href="https://publications.waset.org/abstracts/search?q=chiller%20Plant" title=" chiller Plant"> chiller Plant</a>, <a href="https://publications.waset.org/abstracts/search?q=cooling%20tower%20fan" title=" cooling tower fan"> cooling tower fan</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20efficiency" title=" energy efficiency"> energy efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=VCRS." title=" VCRS."> VCRS.</a> </p> <a href="https://publications.waset.org/abstracts/186647/the-effect-of-cooling-tower-fan-on-the-performance-of-the-chiller-plant" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/186647.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">40</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">201</span> Effect of Cooling Approaches on Chemical Compositions, Phases, and Acidolysis of Panzhihua Titania Slag</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bing%20Song">Bing Song</a>, <a href="https://publications.waset.org/abstracts/search?q=Kexi%20Han"> Kexi Han</a>, <a href="https://publications.waset.org/abstracts/search?q=Xuewei%20Lv"> Xuewei Lv</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Titania slag is a high quality raw material containing titanium in the subsequent process of titanium pigment. The effects of cooling approaches of granulating, water cooling, and air cooling on chemical, phases, and acidolysis of Panzhihua titania slag were investigated. Compared to the original slag which was prepared by the conventional processing route, the results show that the titania slag undergoes oxidation of Ti<sup>3+</sup>during different cooling ways. The Ti<sub>2</sub>O<sub>3</sub> content is 17.50% in the original slag, but it is 16.55% and 16.84% in water cooled and air-cooled slag, respectively. Especially, the Ti<sub>2</sub>O<sub>3</sub> content in granulated slag is decreased about 27.6%. The content of Fe<sub>2</sub>O<sub>3</sub> in granulated slag is approximately 2.86% also obviously higher than water (<0.5%) or air-cooled slag (<0.5%). Rutile in cooled titania slag was formed because of the oxidation of Ti<sup>3</sup><sup>+</sup>. The rutile phase without a noticeable change in water cooled and air-cooled slag after the titania slag was cooled, but increased significantly in the granulated slag. The rate of sulfuric acid acidolysis of cooled slag is less than the original slag. The rate of acidolysis is 90.61% and 92.46% to the water-cooled slag and air-cooled slag, respectively. However, the rate of acidolysis of the granulated slag is less than that of industry slag about 20%, only 74.72%. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cooling%20approaches" title="cooling approaches">cooling approaches</a>, <a href="https://publications.waset.org/abstracts/search?q=titania%20slag" title=" titania slag"> titania slag</a>, <a href="https://publications.waset.org/abstracts/search?q=granulating" title=" granulating"> granulating</a>, <a href="https://publications.waset.org/abstracts/search?q=sulfuric%20acid%20acidolysis" title=" sulfuric acid acidolysis"> sulfuric acid acidolysis</a> </p> <a href="https://publications.waset.org/abstracts/62188/effect-of-cooling-approaches-on-chemical-compositions-phases-and-acidolysis-of-panzhihua-titania-slag" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/62188.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">238</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">200</span> Working Fluids in Absorption Chillers: Investigation of the Use of Deep Eutectic Solvents </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=L.%20Cesari">L. Cesari</a>, <a href="https://publications.waset.org/abstracts/search?q=D.%20Alonso"> D. Alonso</a>, <a href="https://publications.waset.org/abstracts/search?q=F.%20Mutelet"> F. Mutelet</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The interest in cold production has been on the increase in absorption chillers for many years. In fact, the absorption cycles replace the compressor and thus reduce electrical consumption. The devices also allow waste heat generated through industrial activities to be recovered and cooled to a moderate temperature in accordance with regulatory guidelines. Many working fluids were investigated but could not compete with the commonly used {H2O + LiBr} and {H2O + NH3} to author’s best knowledge. Yet, the corrosion, toxicity and crystallization phenomena of these mixtures prevent the development of the absorption technology. This work investigates the possible use of a glyceline deep eutectic solvent (DES) and CO2 as working fluid in an absorption chiller. To do so, good knowledge of the mixtures is required. Experimental measurements (vapor-liquid equilibria, density, and heat capacity) were performed to complete the data lacking in the literature. The performance of the mixtures was quantified by the calculation of the coefficient of performance (COP). The results show that working fluids containing DES + CO2 are an interesting alternative and lead to different trails of working mixtures for absorption and chiller. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=absorption%20devices" title="absorption devices">absorption devices</a>, <a href="https://publications.waset.org/abstracts/search?q=deep%20eutectic%20solvent" title=" deep eutectic solvent"> deep eutectic solvent</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20valorization" title=" energy valorization"> energy valorization</a>, <a href="https://publications.waset.org/abstracts/search?q=experimental%20data" title=" experimental data"> experimental data</a>, <a href="https://publications.waset.org/abstracts/search?q=simulation" title=" simulation"> simulation</a> </p> <a href="https://publications.waset.org/abstracts/106222/working-fluids-in-absorption-chillers-investigation-of-the-use-of-deep-eutectic-solvents" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/106222.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">110</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">199</span> Combining Chiller and Variable Frequency Drives</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Nasir%20Khalid">Nasir Khalid</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20Thirumalaichelvam"> S. Thirumalaichelvam</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In most buildings, according to US Department of Energy Data Book, the electrical consumption attributable to centralized heating and ventilation of air- condition (HVAC) component can be as high as 40-60% of the total electricity consumption for an entire building. To provide efficient energy management for the market today, researchers are finding new ways to develop a system that can save electrical consumption of buildings even more. In this concept paper, a system known as Intelligent Chiller Energy Efficiency (iCEE) System is being developed that is capable of saving up to 25% from the chiller’s existing electrical energy consumption. In variable frequency drives (VFDs), research has found significant savings up to 30% of electrical energy consumption. Together with the VFDs at specific Air Handling Unit (AHU) of HVAC component, this system will save even more electrical energy consumption. The iCEE System is compatible with any make, model or age of centrifugal, rotary or reciprocating chiller air-conditioning systems which are electrically driven. The iCEE system uses engineering principles of efficiency analysis, enthalpy analysis, heat transfer, mathematical prediction, modified genetic algorithm, psychometrics analysis, and optimization formulation to achieve true and tangible energy savings for consumers. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=variable%20frequency%20drives" title="variable frequency drives">variable frequency drives</a>, <a href="https://publications.waset.org/abstracts/search?q=adjustable%20speed%20drives" title=" adjustable speed drives"> adjustable speed drives</a>, <a href="https://publications.waset.org/abstracts/search?q=ac%20drives" title=" ac drives"> ac drives</a>, <a href="https://publications.waset.org/abstracts/search?q=chiller%20energy%20system" title=" chiller energy system"> chiller energy system</a> </p> <a href="https://publications.waset.org/abstracts/34795/combining-chiller-and-variable-frequency-drives" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/34795.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">558</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">198</span> Analysis and Optimized Design of a Packaged Liquid Chiller</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Saeed%20Farivar">Saeed Farivar</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohsen%20Kahrom"> Mohsen Kahrom</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The purpose of this work is to develop a physical simulation model for the purpose of studying the effect of various design parameters on the performance of packaged-liquid chillers. This paper presents a steady-state model for predicting the performance of package-Liquid chiller over a wide range of operation condition. The model inputs are inlet conditions; geometry and output of model include system performance variable such as power consumption, coefficient of performance (COP) and states of refrigerant through the refrigeration cycle. A computer model that simulates the steady-state cyclic performance of a vapor compression chiller is developed for the purpose of performing detailed physical design analysis of actual industrial chillers. The model can be used for optimizing design and for detailed energy efficiency analysis of packaged liquid chillers. The simulation model takes into account presence of all chiller components such as compressor, shell-and-tube condenser and evaporator heat exchangers, thermostatic expansion valve and connection pipes and tubing’s by thermo-hydraulic modeling of heat transfer, fluids flow and thermodynamics processes in each one of the mentioned components. To verify the validity of the developed model, a 7.5 USRT packaged-liquid chiller is used and a laboratory test stand for bringing the chiller to its standard steady-state performance condition is build. Experimental results obtained from testing the chiller in various load and temperature conditions is shown to be in good agreement with those obtained from simulating the performance of the chiller using the computer prediction model. An entropy-minimization-based optimization analysis is performed based on the developed analytical performance model of the chiller. The variation of design parameters in construction of shell-and-tube condenser and evaporator heat exchangers are studied using the developed performance and optimization analysis and simulation model and a best-match condition between the physical design and construction of chiller heat exchangers and its compressor is found to exist. It is expected that manufacturers of chillers and research organizations interested in developing energy-efficient design and analysis of compression chillers can take advantage of the presented study and its results. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=optimization" title="optimization">optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=packaged%20liquid%20chiller" title=" packaged liquid chiller"> packaged liquid chiller</a>, <a href="https://publications.waset.org/abstracts/search?q=performance" title=" performance"> performance</a>, <a href="https://publications.waset.org/abstracts/search?q=simulation" title=" simulation"> simulation</a> </p> <a href="https://publications.waset.org/abstracts/35728/analysis-and-optimized-design-of-a-packaged-liquid-chiller" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/35728.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">278</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">197</span> Hybrid Adaptive Modeling to Enhance Robustness of Real-Time Optimization </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hussain%20Syed%20Asad">Hussain Syed Asad</a>, <a href="https://publications.waset.org/abstracts/search?q=Richard%20Kwok%20Kit%20Yuen"> Richard Kwok Kit Yuen</a>, <a href="https://publications.waset.org/abstracts/search?q=Gongsheng%20Huang"> Gongsheng Huang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Real-time optimization has been considered an effective approach for improving energy efficient operation of heating, ventilation, and air-conditioning (HVAC) systems. In model-based real-time optimization, model mismatches cannot be avoided. When model mismatches are significant, the performance of the real-time optimization will be impaired and hence the expected energy saving will be reduced. In this paper, the model mismatches for chiller plant on real-time optimization are considered. In the real-time optimization of the chiller plant, simplified semi-physical or grey box model of chiller is always used, which should be identified using available operation data. To overcome the model mismatches associated with the chiller model, hybrid Genetic Algorithms (HGAs) method is used for online real-time training of the chiller model. HGAs combines Genetic Algorithms (GAs) method (for global search) and traditional optimization method (i.e. faster and more efficient for local search) to avoid conventional hit and trial process of GAs. The identification of model parameters is synthesized as an optimization problem; and the objective function is the Least Square Error between the output from the model and the actual output from the chiller plant. A case study is used to illustrate the implementation of the proposed method. It has been shown that the proposed approach is able to provide reliability in decision making, enhance the robustness of the real-time optimization strategy and improve on energy performance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=energy%20performance" title="energy performance">energy performance</a>, <a href="https://publications.waset.org/abstracts/search?q=hybrid%20adaptive%20modeling" title=" hybrid adaptive modeling"> hybrid adaptive modeling</a>, <a href="https://publications.waset.org/abstracts/search?q=hybrid%20genetic%20algorithms" title=" hybrid genetic algorithms"> hybrid genetic algorithms</a>, <a href="https://publications.waset.org/abstracts/search?q=real-time%20optimization" title=" real-time optimization"> real-time optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=heating" title=" heating"> heating</a>, <a href="https://publications.waset.org/abstracts/search?q=ventilation" title=" ventilation"> ventilation</a>, <a href="https://publications.waset.org/abstracts/search?q=and%20air-conditioning" title=" and air-conditioning"> and air-conditioning</a> </p> <a href="https://publications.waset.org/abstracts/59904/hybrid-adaptive-modeling-to-enhance-robustness-of-real-time-optimization" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/59904.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">417</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">196</span> FC and ZFC Studies of Nickel Nano Ferrites and Ni Doped Lithium Nano Ferrites by Citrate-Gel Auto Combustion Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=D.%20Ravinder">D. Ravinder</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Nickel ferrites and Ni doped Lithium nano ferrites [Li0.5Fe0.5]1-xNixFe2O4 with x= 0.8 and 1.0 synthesized by citrate-gel auto combustion method. The broad peaks in the X-ray diffraction pattern (XRD) indicate a crystalline behavior of the prepared samples. Low temperature magnetization studies i,e Field Cooled (FC) and Zero Field Cooled (ZFC) magnetic studies of the investigated samples are measured by using vibrating sample magnetometer (VSM). The magnetization of the prepared samples as a function of an applied magnetic field 10 T was measured at two different temperatures 5 K and 310 K. Field Cooled (FC) and Zero Field Cooled (ZFC) magnetization measurements under an applied field of 100 Oe and 1000 Oe in the temperature range of 5–375 K were carried out. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ferro-spinels" title="ferro-spinels">ferro-spinels</a>, <a href="https://publications.waset.org/abstracts/search?q=field%20cooled%20%28FC%29" title=" field cooled (FC)"> field cooled (FC)</a>, <a href="https://publications.waset.org/abstracts/search?q=Zero%20Field%20Cooled%20%28ZFC%29%20and%20blocking%20temperature" title=" Zero Field Cooled (ZFC) and blocking temperature"> Zero Field Cooled (ZFC) and blocking temperature</a>, <a href="https://publications.waset.org/abstracts/search?q=superpara%20magnetism" title=" superpara magnetism"> superpara magnetism</a>, <a href="https://publications.waset.org/abstracts/search?q=drug%20delivery%20applications" title=" drug delivery applications"> drug delivery applications</a> </p> <a href="https://publications.waset.org/abstracts/36077/fc-and-zfc-studies-of-nickel-nano-ferrites-and-ni-doped-lithium-nano-ferrites-by-citrate-gel-auto-combustion-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/36077.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">557</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">195</span> Modelling of Air-Cooled Adiabatic Membrane-Based Absorber for Absorption Chillers Using Low Temperature Solar Heat</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20Venegas">M. Venegas</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20De%20Vega"> M. De Vega</a>, <a href="https://publications.waset.org/abstracts/search?q=N.%20Garc%C3%ADa-Hernando"> N. García-Hernando</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Absorption cooling chillers have received growing attention over the past few decades as they allow the use of low-grade heat to produce the cooling effect. The combination of this technology with solar thermal energy in the summer period can reduce the electricity consumption peak due to air-conditioning. One of the main components, the absorber, is designed for simultaneous heat and mass transfer. Usually, shell and tubes heat exchangers are used, which are large and heavy. Cooling water from a cooling tower is conventionally used to extract the heat released during the absorption and condensation processes. These are clear inconvenient for the generalization of the absorption technology use, limiting its benefits in the contribution to the reduction in CO2 emissions, particularly for the H2O-LiBr solution which can work with low heat temperature sources as provided by solar panels. In the present work a promising new technology is under study, consisting in the use of membrane contactors in adiabatic microchannel mass exchangers. The configuration here proposed consists in one or several modules (depending on the cooling capacity of the chiller) that contain two vapour channels, separated from the solution by adjacent microporous membranes. The solution is confined in rectangular microchannels. A plastic or synthetic wall separates the solution channels between them. The solution entering the absorber is previously subcooled using ambient air. In this way, the need for a cooling tower is avoided. A model of the configuration proposed is developed based on mass and energy balances and some correlations were selected to predict the heat and mass transfer coefficients. The concentration and temperatures along the channels cannot be explicitly determined from the set of equations obtained. For this reason, the equations were implemented in a computer code using Engineering Equation Solver software, EES™. With the aim of minimizing the absorber volume to reduce the size of absorption cooling chillers, the ratio between the cooling power of the chiller and the absorber volume (R) is calculated. Its variation is shown along the solution channels, allowing its optimization for selected operating conditions. For the case considered the solution channel length is recommended to be lower than 3 cm. Maximum values of R obtained in this work are higher than the ones found in optimized horizontal falling film absorbers using the same solution. Results obtained also show the variation of R and the chiller efficiency (COP) for different ambient temperatures and desorption temperatures typically obtained using flat plate solar collectors. The configuration proposed of adiabatic membrane-based absorber using ambient air to subcool the solution is a good technology to reduce the size of the absorption chillers, allowing the use of low temperature solar heat and avoiding the need for cooling towers. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=adiabatic%20absorption" title="adiabatic absorption">adiabatic absorption</a>, <a href="https://publications.waset.org/abstracts/search?q=air-cooled" title=" air-cooled"> air-cooled</a>, <a href="https://publications.waset.org/abstracts/search?q=membrane" title=" membrane"> membrane</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20thermal%20energy" title=" solar thermal energy"> solar thermal energy</a> </p> <a href="https://publications.waset.org/abstracts/67714/modelling-of-air-cooled-adiabatic-membrane-based-absorber-for-absorption-chillers-using-low-temperature-solar-heat" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/67714.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">285</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">194</span> Modeling and Analysis of Solar Assisted Adsorption Cooling System Using TRNSYS</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20Wajahat">M. Wajahat</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Shoaib"> M. Shoaib</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Waheed"> A. Waheed</a> </p> <p class="card-text"><strong>Abstract:</strong></p> As a result of increase in world energy demand as well as the demand for heating, refrigeration and air conditioning, energy engineers are now more inclined towards the renewable energy especially solar based thermal driven refrigeration and air conditioning systems. This research is emphasized on solar assisted adsorption refrigeration system to provide comfort conditions for a building in Islamabad. The adsorption chiller can be driven by low grade heat at low temperature range (50 -80 °C) which is lower than that required for generator in absorption refrigeration system which may be furnished with the help of common flat plate solar collectors (FPC). The aim is to offset the total energy required for building’s heating and cooling demand by using FPC’s thus reducing dependency on primary energy source hence saving energy. TRNSYS is a dynamic modeling and simulation tool which can be utilized to simulate the working of a complete solar based adsorption chiller to meet the desired cooling and heating demand during summer and winter seasons, respectively. Modeling and detailed parametric analysis of the whole system is to be carried out to determine the optimal system configuration keeping in view various design constraints. Main focus of the study is on solar thermal loop of the adsorption chiller to reduce the contribution from the auxiliary devices. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=flat%20plate%20collector" title="flat plate collector">flat plate collector</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20saving" title=" energy saving"> energy saving</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20assisted%20adsorption%20chiller" title=" solar assisted adsorption chiller"> solar assisted adsorption chiller</a>, <a href="https://publications.waset.org/abstracts/search?q=TRNSYS" title=" TRNSYS "> TRNSYS </a> </p> <a href="https://publications.waset.org/abstracts/29515/modeling-and-analysis-of-solar-assisted-adsorption-cooling-system-using-trnsys" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/29515.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">653</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">193</span> Control Strategy of Solar Thermal Cooling System under the Indonesia Climate</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Budihardjo%20Sarwo%20Sastrosudiro">Budihardjo Sarwo Sastrosudiro</a>, <a href="https://publications.waset.org/abstracts/search?q=Arnas%20Lubis"> Arnas Lubis</a>, <a href="https://publications.waset.org/abstracts/search?q=Muhammad%20Idrus%20Alhamid"> Muhammad Idrus Alhamid</a>, <a href="https://publications.waset.org/abstracts/search?q=Nasruddin%20Jusuf"> Nasruddin Jusuf</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Solar thermal cooling system was installed on Mechanical Research Center (MRC) Building that is located in Universitas Indonesia, Depok, Indonesia. It is the first cooling system in Indonesia that utilizes solar energy as energy input combined with natural gas; therefore, the control system must be appropriated with the climates. In order to stabilize the cooling capacity and also to maximize the use of solar energy, the system applies some controllers. Constant flow rate and on/off controller are applied for the hot water, chilled water and cooling water pumps. The hot water circulated by pump when the solar radiation is over than 400W/m<sup>2</sup>, and the chilled water is continually circulated by pump and its temperature is kept constant 7 °C by absorption chiller. The cooling water is also continually circulated until the outlet temperature of cooling tower below than 27 <sup>o</sup>C. Furthermore, the three-way valve is used to control the hot water for generate vapor on absorption chiller. The system performance using that control system is shown in this study results. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=absorption%20chiller" title="absorption chiller">absorption chiller</a>, <a href="https://publications.waset.org/abstracts/search?q=control%20system" title=" control system"> control system</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20cooling" title=" solar cooling"> solar cooling</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20energy" title=" solar energy"> solar energy</a> </p> <a href="https://publications.waset.org/abstracts/43453/control-strategy-of-solar-thermal-cooling-system-under-the-indonesia-climate" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/43453.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">274</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">192</span> Efficient Chiller Plant Control Using Modern Reinforcement Learning</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jingwei%20Du">Jingwei Du</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The need of optimizing air conditioning systems for existing buildings calls for control methods designed with energy-efficiency as a primary goal. The majority of current control methods boil down to two categories: empirical and model-based. To be effective, the former heavily relies on engineering expertise and the latter requires extensive historical data. Reinforcement Learning (RL), on the other hand, is a model-free approach that explores the environment to obtain an optimal control strategy often referred to as “policy”. This research adopts Proximal Policy Optimization (PPO) to improve chiller plant control, and enable the RL agent to collaborate with experienced engineers. It exploits the fact that while the industry lacks historical data, abundant operational data is available and allows the agent to learn and evolve safely under human supervision. Thanks to the development of language models, renewed interest in RL has led to modern, online, policy-based RL algorithms such as the PPO. This research took inspiration from “alignment”, a process that utilizes human feedback to finetune the pretrained model in case of unsafe content. The methodology can be summarized into three steps. First, an initial policy model is generated based on minimal prior knowledge. Next, the prepared PPO agent is deployed so feedback from both critic model and human experts can be collected for future finetuning. Finally, the agent learns and adapts itself to the specific chiller plant, updates the policy model and is ready for the next iteration. Besides the proposed approach, this study also used traditional RL methods to optimize the same simulated chiller plants for comparison, and it turns out that the proposed method is safe and effective at the same time and needs less to no historical data to start up. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=chiller%20plant" title="chiller plant">chiller plant</a>, <a href="https://publications.waset.org/abstracts/search?q=control%20methods" title=" control methods"> control methods</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20efficiency" title=" energy efficiency"> energy efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=proximal%20policy%20optimization" title=" proximal policy optimization"> proximal policy optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=reinforcement%20learning" title=" reinforcement learning"> reinforcement learning</a> </p> <a href="https://publications.waset.org/abstracts/191163/efficient-chiller-plant-control-using-modern-reinforcement-learning" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/191163.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">29</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">191</span> Performance Evaluation of Lithium Bromide Absorption Chiller</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Z.%20Neffah">Z. Neffah</a>, <a href="https://publications.waset.org/abstracts/search?q=L.%20Merabti"> L. Merabti</a>, <a href="https://publications.waset.org/abstracts/search?q=N.%20Hatraf"> N. Hatraf</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Absorption refrigeration technology has been used for cooling purposes over a hundred years. Today, the technology developments have made of the absorption refrigeration an economic and effective alternative to the vapour compression cooling cycle. A parametric study was conducted over the entire admissible ranges of the generator and absorber temperatures. On the other hand, simultaneously raising absorber temperatures was seen to result in deterioration of coefficient of performance. The influence of generator, absorber temperatures, as well as solution concentration on the different performance indicators was also calculated and examined. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=absorption%20system" title="absorption system">absorption system</a>, <a href="https://publications.waset.org/abstracts/search?q=Aqueous%20solution" title=" Aqueous solution"> Aqueous solution</a>, <a href="https://publications.waset.org/abstracts/search?q=chiller" title=" chiller"> chiller</a>, <a href="https://publications.waset.org/abstracts/search?q=water-lithium%20bromide" title=" water-lithium bromide"> water-lithium bromide</a> </p> <a href="https://publications.waset.org/abstracts/15199/performance-evaluation-of-lithium-bromide-absorption-chiller" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/15199.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">302</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">190</span> Effective Energy Saving of a Large Building through Multiple Approaches</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Choo%20Hong%20Ang">Choo Hong Ang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The most popular approach to save energy for large commercial buildings in Malaysia is to replace the existing chiller plant of high kW/ton to one of lower kW/ton. This approach, however, entails large capital outlay with a long payment period of up to 7 years. This paper shows that by using multiple approaches, other than replacing the existing chiller plant, an energy saving of up to 20 %, is possible. The main methodology adopted was to identify and then plugged all heat ingress paths into a building, including putting up glass structures to prevent mixing of internal air-conditioned air with the ambient environment, and replacing air curtains with glass doors. This methodology could save up to 10 % energy bill. Another methodology was to change fixed speed motors of air handling units (AHU) to variable speed drive (VSD) and changing escalators to motion-sensor type. Other methodologies included reducing heat load by blocking air supply to non-occupied parcels, rescheduling chiller plant operation, changing of fluorescent lights to LED lights, and conversion from tariff B to C1. A case example of Komtar, the tallest building in Penang, is given here. The total energy bill for Komtar was USD2,303,341 in 2016 but was reduced to USD 1,842,927.39 in 2018, a significant saving of USD460,413.86 or 20 %. In terms of kWh, there was a reduction from 18, 302,204.00 kWh in 2016 to 14,877,105.00 kWh in 2018, a reduction of 3,425,099.00 kWh or 18.71 %. These methodologies used were relatively low cost and the payback period was merely 24 months. With this achievement, the Komtar building was awarded champion of the Malaysian National Energy Award 2019 and second runner up of the Asean Energy Award. This experience shows that a strong commitment to energy saving is the key to effective energy saving. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=chiller%20plant" title="chiller plant">chiller plant</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20saving%20measures" title=" energy saving measures"> energy saving measures</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20ingress" title=" heat ingress"> heat ingress</a>, <a href="https://publications.waset.org/abstracts/search?q=large%20building" title=" large building"> large building</a> </p> <a href="https://publications.waset.org/abstracts/120869/effective-energy-saving-of-a-large-building-through-multiple-approaches" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/120869.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">105</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">189</span> Engineering Optimization Using Two-Stage Differential Evolution</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=K.%20Y.%20Tseng">K. Y. Tseng</a>, <a href="https://publications.waset.org/abstracts/search?q=C.%20Y.%20Wu"> C. Y. Wu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper employs a heuristic algorithm to solve engineering problems including truss structure optimization and optimal chiller loading (OCL) problems. Two different type algorithms, real-valued differential evolution (DE) and modified binary differential evolution (MBDE), are successfully integrated and then can obtain better performance in solving engineering problems. In order to demonstrate the performance of the proposed algorithm, this study adopts each one testing case of truss structure optimization and OCL problems to compare the results of other heuristic optimization methods. The result indicates that the proposed algorithm can obtain similar or better solution in comparing with previous studies. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=differential%20evolution" title="differential evolution">differential evolution</a>, <a href="https://publications.waset.org/abstracts/search?q=Truss%20structure%20optimization" title=" Truss structure optimization"> Truss structure optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=optimal%20chiller%20loading" title=" optimal chiller loading"> optimal chiller loading</a>, <a href="https://publications.waset.org/abstracts/search?q=modified%20binary%20differential%20evolution" title=" modified binary differential evolution"> modified binary differential evolution</a> </p> <a href="https://publications.waset.org/abstracts/109896/engineering-optimization-using-two-stage-differential-evolution" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/109896.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">168</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">188</span> A Cost-Effective Evaluation of Proper Control Process of Air-Cooled Heat Exchanger </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ali%20Ghobadi">Ali Ghobadi</a>, <a href="https://publications.waset.org/abstracts/search?q=Eisa%20Bakhoda"> Eisa Bakhoda</a>, <a href="https://publications.waset.org/abstracts/search?q=Hamid%20R.%20Javdan"> Hamid R. Javdan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> One of the key factors in air cooled heat exchangers operation is the proper control of process stream outlet temperature. In this study, performances of two different air cooled heat exchangers have been considered, one of them condenses Propane and the other one cools LPG streams. In order to predict operation of these air coolers at different operating conditions. The results of simulations were applied for both economical evaluations and operational considerations for using convenient air cooler control system. In this paper, using On-Off fans method and installing variable speed drivers have been studied. Finally, the appropriate methods for controlling outlet temperature of process fluid streams as well as saving energy consumption were proposed. Using On-Off method for controlling studied Propane condenser by multiple fans is proper; while controlling LPG air cooler with lesser fans by means of two variable speed drivers is economically convenient. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=air%20cooled%20heat%20exchanger" title="air cooled heat exchanger">air cooled heat exchanger</a>, <a href="https://publications.waset.org/abstracts/search?q=simulation" title=" simulation"> simulation</a>, <a href="https://publications.waset.org/abstracts/search?q=economical%20evaluation" title=" economical evaluation"> economical evaluation</a>, <a href="https://publications.waset.org/abstracts/search?q=energy" title=" energy"> energy</a>, <a href="https://publications.waset.org/abstracts/search?q=process%20control" title=" process control"> process control</a> </p> <a href="https://publications.waset.org/abstracts/30730/a-cost-effective-evaluation-of-proper-control-process-of-air-cooled-heat-exchanger" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/30730.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">411</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">187</span> Multi-Objective Optimization of a Solar-Powered Triple-Effect Absorption Chiller for Air-Conditioning Applications</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ali%20Shirazi">Ali Shirazi</a>, <a href="https://publications.waset.org/abstracts/search?q=Robert%20A.%20Taylor"> Robert A. Taylor</a>, <a href="https://publications.waset.org/abstracts/search?q=Stephen%20D.%20White"> Stephen D. White</a>, <a href="https://publications.waset.org/abstracts/search?q=Graham%20L.%20Morrison"> Graham L. Morrison</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, a detailed simulation model of a solar-powered triple-effect LiBr–H<sub>2</sub>O absorption chiller is developed to supply both cooling and heating demand of a large-scale building, aiming to reduce the fossil fuel consumption and greenhouse gas emissions in building sector. TRNSYS 17 is used to simulate the performance of the system over a typical year. A combined energetic-economic-environmental analysis is conducted to determine the system annual primary energy consumption and the total cost, which are considered as two conflicting objectives. A multi-objective optimization of the system is performed using a genetic algorithm to minimize these objectives simultaneously. The optimization results show that the final optimal design of the proposed plant has a solar fraction of 72% and leads to an annual primary energy saving of 0.69 GWh and annual CO<sub>2</sub> emissions reduction of ~166 tonnes, as compared to a conventional HVAC system. The economics of this design, however, is not appealing without public funding, which is often the case for many renewable energy systems. The results show that a good funding policy is required in order for these technologies to achieve satisfactory payback periods within the lifetime of the plant. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=economic" title="economic">economic</a>, <a href="https://publications.waset.org/abstracts/search?q=environmental" title=" environmental"> environmental</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-objective%20optimization" title=" multi-objective optimization"> multi-objective optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20air-conditioning" title=" solar air-conditioning"> solar air-conditioning</a>, <a href="https://publications.waset.org/abstracts/search?q=triple-effect%20absorption%20chiller" title=" triple-effect absorption chiller"> triple-effect absorption chiller</a> </p> <a href="https://publications.waset.org/abstracts/50914/multi-objective-optimization-of-a-solar-powered-triple-effect-absorption-chiller-for-air-conditioning-applications" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/50914.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">238</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">186</span> Type–2 Fuzzy Programming for Optimizing the Heat Rate of an Industrial Gas Turbine via Absorption Chiller Technology</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=T.%20Ganesan">T. Ganesan</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20S.%20Aris"> M. S. Aris</a>, <a href="https://publications.waset.org/abstracts/search?q=I.%20Elamvazuthi"> I. Elamvazuthi</a>, <a href="https://publications.waset.org/abstracts/search?q=Momen%20Kamal%20Tageldeen"> Momen Kamal Tageldeen</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Terms set in power purchase agreements (PPA) challenge power utility companies in balancing between the returns (from maximizing power production) and securing long term supply contracts at capped production. The production limitation set in the PPA has driven efforts to maximize profits through efficient and economic power production. In this paper, a combined industrial-scale gas turbine (GT) - absorption chiller (AC) system is considered to cool the GT air intake for reducing the plant’s heat rate (HR). This GT-AC system is optimized while considering power output limitations imposed by the PPA. In addition, the proposed formulation accounts for uncertainties in the ambient temperature using Type-2 fuzzy programming. Using the enhanced chaotic differential evolution (CEDE), the Pareto frontier was constructed and the optimization results are analyzed in detail. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=absorption%20chillers%20%28AC%29" title="absorption chillers (AC)">absorption chillers (AC)</a>, <a href="https://publications.waset.org/abstracts/search?q=turbine%20inlet%20air%20cooling%20%28TIC%29" title=" turbine inlet air cooling (TIC)"> turbine inlet air cooling (TIC)</a>, <a href="https://publications.waset.org/abstracts/search?q=power%20purchase%20agreement%20%28PPA%29" title=" power purchase agreement (PPA)"> power purchase agreement (PPA)</a>, <a href="https://publications.waset.org/abstracts/search?q=multiobjective%20optimization" title=" multiobjective optimization"> multiobjective optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=type-2%20fuzzy%20programming" title=" type-2 fuzzy programming"> type-2 fuzzy programming</a>, <a href="https://publications.waset.org/abstracts/search?q=chaotic%20differential%20evolution%20%28CDDE%29" title=" chaotic differential evolution (CDDE)"> chaotic differential evolution (CDDE)</a> </p> <a href="https://publications.waset.org/abstracts/64966/type-2-fuzzy-programming-for-optimizing-the-heat-rate-of-an-industrial-gas-turbine-via-absorption-chiller-technology" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/64966.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">310</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">185</span> The Experimental Measurement of the LiBr Concentration of a Solar Absorption Machine </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=N.%20Hatraf">N. Hatraf</a>, <a href="https://publications.waset.org/abstracts/search?q=L.%20Merabti"> L. Merabti</a>, <a href="https://publications.waset.org/abstracts/search?q=Z.%20Neffah"> Z. Neffah</a>, <a href="https://publications.waset.org/abstracts/search?q=W.%20Taane"> W. Taane</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The excessive consumption of fossil energies (electrical energy) during summer caused by the technological development involves more and more climate warming. In order to reduce the worst impact of gas emissions produced from classical air conditioning, heat driven solar absorption chiller is pretty promising; it consists on using solar as motive energy which is clean and environmentally friendly to provide cold. Solar absorption machine is composed by four components using Lithium Bromide /water as a refrigerating couple. LiBr- water is the most promising in chiller applications due to high safety, high volatility ratio, high affinity, high stability and its high latent heat. The lithium bromide solution is constitute by the salt lithium bromide which absorbs water under certain conditions of pressure and temperature however if the concentration of the solution is high in the absorption chillers; which exceed 70%, the solution will crystallize. The main aim of this article is to study the phenomena of the crystallization and to evaluate how the dependence between the electric conductivity and the concentration which should be controlled. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=absorption" title="absorption">absorption</a>, <a href="https://publications.waset.org/abstracts/search?q=crystallization" title=" crystallization"> crystallization</a>, <a href="https://publications.waset.org/abstracts/search?q=experimental%20results" title=" experimental results"> experimental results</a>, <a href="https://publications.waset.org/abstracts/search?q=lithium%20bromide%20solution" title=" lithium bromide solution "> lithium bromide solution </a> </p> <a href="https://publications.waset.org/abstracts/10868/the-experimental-measurement-of-the-libr-concentration-of-a-solar-absorption-machine" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/10868.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">310</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">184</span> Cryogenic Separation of CO2 from Molten Carbonate Fuel Cell Anode Outlet—Experimental Guidelines</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jaros%C5%82aw%C2%A0Milewski">Jarosław Milewski</a>, <a href="https://publications.waset.org/abstracts/search?q=Rafa%C5%82%C2%A0Bernat"> Rafał Bernat</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents an analysis of using cryogenic separation unit for recovering fuel from anode off gas of molten carbonate fuel cells (MCFCs) in order to upgrade the efficiently of the unit. In the proposed solution, the CSU is used for condensing water and carbon dioxide from anode off gas, and re-cycling the rest of the stream to the anode, saving certain amount of fuel (at least 30%). The resulting system efficiency is increased considerably. CSU, virtually consumes power, thus this solution has energy penalty as well, on the other hand, MCFC generates large amount of heat at elevated temperature, thus part of the CSU can be based on absorption chiller. In all cases, a high amount of fuel is obtained after condensation of water and carbon dioxide and re-cycled to the anode inlet. Based on mathematical modeling done previously, the concept and guidelines for forthcoming experimental investigations are presented in this paper. During planned experiments, an existing single cell laboratory stand will be equipped with re-cycle device (a fan, a peristaltic pump, etc.). Parallel, a mixture of anode off gas will be cooled down for determining the proper temperature for the separation of water and carbon dioxide. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cryogenic%20separation" title="cryogenic separation">cryogenic separation</a>, <a href="https://publications.waset.org/abstracts/search?q=experiments" title=" experiments"> experiments</a>, <a href="https://publications.waset.org/abstracts/search?q=fuel%20cells" title=" fuel cells"> fuel cells</a>, <a href="https://publications.waset.org/abstracts/search?q=molten%20carbonate%20fuel%20cells" title=" molten carbonate fuel cells"> molten carbonate fuel cells</a> </p> <a href="https://publications.waset.org/abstracts/41874/cryogenic-separation-of-co2-from-molten-carbonate-fuel-cell-anode-outlet-experimental-guidelines" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/41874.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">247</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">183</span> The Role of Poling Protocol on Augmentation of Magnetoelectricity in BCZT/NZFO Layered Composites</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Pankhuri%20Bansal">Pankhuri Bansal</a>, <a href="https://publications.waset.org/abstracts/search?q=Sanjeev%20Kumar"> Sanjeev Kumar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We examined the exotic role of electrical poling of layered BCZT-NZFO bulk composite for sustainable advancement of magnetoelectric (ME) technology. Practically, it seems quite difficult to access the full potential of ME composites due to their weak ME coupling performances. Using a standard poling protocol, we successfully deployed the coupling performance of laminated ME composite, comprised of a ferroelectric (FE) layer of BCZT and a ferrite layer of NZFO. However, the ME coupling constant of laminated composite is optimized by lowering the volume fraction of the FE component to strengthen the mechanical strain in the piezoelectric layer while fixing the thickness of the magnetostrictive ferrite layer. Here, we employed systematic zero field cooled (ZFC) and field cooled (FC) electrical poling protocol on morphotropic phase boundary (MPB) based BCZT composition, well-appreciated for it’s remarkable electromechanical activity. We report a record augmentation in magnetoelectric coupling as a consequence of a prudent field-cooled poling mechanism. On the basis of our findings, we emphasize that the degree of magnetoelectricity may be significantly improved for the miniaturization of efficient devices via proper execution of the poling technique. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=magnetoelectric" title="magnetoelectric">magnetoelectric</a>, <a href="https://publications.waset.org/abstracts/search?q=lead-free" title=" lead-free"> lead-free</a>, <a href="https://publications.waset.org/abstracts/search?q=ferroelctric" title=" ferroelctric"> ferroelctric</a>, <a href="https://publications.waset.org/abstracts/search?q=ferromagnetic" title=" ferromagnetic"> ferromagnetic</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20harvesting" title=" energy harvesting"> energy harvesting</a> </p> <a href="https://publications.waset.org/abstracts/185280/the-role-of-poling-protocol-on-augmentation-of-magnetoelectricity-in-bcztnzfo-layered-composites" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/185280.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">43</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">182</span> Comparative Analysis of Internal Combustion Engine Cooling Fins Using Ansys Software</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Aakash%20Kumar%20R.%20G.">Aakash Kumar R. G.</a>, <a href="https://publications.waset.org/abstracts/search?q=Anees%20K.%20Ahamed"> Anees K. Ahamed</a>, <a href="https://publications.waset.org/abstracts/search?q=Raj%20M.%20Mohan"> Raj M. Mohan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Effective engine cooling can improve the engine’s life and efficacy. The design of the fin of the cylinder head and block determines the cooling mechanism of air cooled engine. The heat conduction takes place through the engine parts and convection of heat from the surface of the fins takes place with air as the heat transferring medium. The air surrounding the cooling fins helps in removal of heat built up by the air cooled engine. If the heat removal rate is inadequate, it will result in lower engine efficiency and high thermal stresses in the engine. The main drawback of the air cooled engine is the low heat transfer rate of the cooling fins .This work is based on scrutiny of previous researches that involves enhancing of heat transfer rate of cooling fins. The current research is about augmentation of heat transfer rate of longitudinal rectangular fin profiles by varying the length of the fin and diameter of holes on the fins. Thermal and flow analysis is done for two different models of fins. One is simple fin without holes and the other is perforated (consist of holes). It can be inferred from the research that the fins with holes have a higher fin efficiency than the fins without holes. The geometry of the fin is done in CREO. The heat transfer analysis is done using ANSYS software. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fins" title="fins">fins</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20transfer" title=" heat transfer"> heat transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=perforated%20fins" title=" perforated fins"> perforated fins</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20analysis" title=" thermal analysis"> thermal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20flux" title=" thermal flux"> thermal flux</a> </p> <a href="https://publications.waset.org/abstracts/59711/comparative-analysis-of-internal-combustion-engine-cooling-fins-using-ansys-software" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/59711.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">373</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">181</span> Parametric Study of a Solar-Heating-And-Cooling System with Hybrid Photovoltaic/Thermal Collectors in North China</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ruobing%20Liang">Ruobing Liang</a>, <a href="https://publications.waset.org/abstracts/search?q=Jili%20Zhang"> Jili Zhang</a>, <a href="https://publications.waset.org/abstracts/search?q=Chao%20Zhou"> Chao Zhou</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A solar-heating-and-cooling (SHC) system, consisting of a hybrid photovoltaic/ thermal collector array, a hot water storage tank, and an absorption chiller unit is designed and modeled to satisfy thermal loads (space heating, domestic hot water, and space cooling). The system is applied for Dalian, China, a location with cold climate conditions, where cooling demand is moderate, while space heating demand is slightly high. The study investigates the potential of a solar system installed and operated onsite in a detached single-family household to satisfy all necessary thermal loads. The hot water storage tank is also connected to an auxiliary heater (electric boiler) to supplement solar heating, when needed. The main purpose of the study is to model the overall system and contact a parametric study that will determine the optimum economic system performance in terms of design parameters. The system is compared, through a cost analysis, to an electric heat pump (EHP) system. This paper will give the optimum system combination of solar collector area and volumetric capacity of the hot water storage tank, respectively. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=absorption%20chiller" title="absorption chiller">absorption chiller</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20PVT%20collector" title=" solar PVT collector"> solar PVT collector</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20heating%20and%20cooling" title=" solar heating and cooling"> solar heating and cooling</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20air-conditioning" title=" solar air-conditioning"> solar air-conditioning</a>, <a href="https://publications.waset.org/abstracts/search?q=parametric%20study" title=" parametric study"> parametric study</a>, <a href="https://publications.waset.org/abstracts/search?q=cost%20analysis" title=" cost analysis"> cost analysis</a> </p> <a href="https://publications.waset.org/abstracts/36328/parametric-study-of-a-solar-heating-and-cooling-system-with-hybrid-photovoltaicthermal-collectors-in-north-china" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/36328.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">422</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">180</span> Thermal Performance of Reheat, Regenerative, Inter-Cooled Gas Turbine Cycle</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Milind%20S.%20Patil">Milind S. Patil</a>, <a href="https://publications.waset.org/abstracts/search?q=Purushottam%20S.%20Desale"> Purushottam S. Desale</a>, <a href="https://publications.waset.org/abstracts/search?q=Eknath%20R.%20Deore"> Eknath R. Deore</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Thermal analysis of reheat, regenerative, inter-cooled gas turbine cycle is presented. Specific work output, thermal efficiency and SFC is simulated with respect to operating conditions. Analytical formulas were developed taking into account the effect of operational parameters like ambient temperature, compression ratio, compressor efficiency, turbine efficiency, regenerator effectiveness, pressure loss in inter cooling, reheating and regenerator. Calculations were made for wide range of parameters using engineering equation solver and the results were presented here. For pressure ratio of 12, regenerator effectiveness 0.95, and maximum turbine inlet temperature 1200 K, thermal efficiency decreases by 27% with increase in ambient temperature (278 K to 328 K). With decrease in regenerator effectiveness thermal efficiency decreases linearly. With increase in ambient temperature (278 K to 328 K) for the same maximum temperature and regenerator effectiveness SFC decreases up to a pressure ratio of 10 and then increases. Sharp rise in SFC is noted for higher ambient temperature. With increase in isentropic efficiency of compressor and turbine, thermal efficiency increases by about 40% for low ambient temperature (278 K to 298 K) however, for higher ambient temperature (308 K to 328 K) thermal efficiency increases by about 70%. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=gas%20turbine" title="gas turbine">gas turbine</a>, <a href="https://publications.waset.org/abstracts/search?q=reheating" title=" reheating"> reheating</a>, <a href="https://publications.waset.org/abstracts/search?q=regeneration" title=" regeneration"> regeneration</a>, <a href="https://publications.waset.org/abstracts/search?q=inter-cooled" title=" inter-cooled"> inter-cooled</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20analysis" title=" thermal analysis"> thermal analysis</a> </p> <a href="https://publications.waset.org/abstracts/3990/thermal-performance-of-reheat-regenerative-inter-cooled-gas-turbine-cycle" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/3990.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">337</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">179</span> Dynamic Compensation for Environmental Temperature Variation in the Coolant Refrigeration Cycle as a Means of Increasing Machine-Tool Precision</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Robbie%20C.%20Murchison">Robbie C. Murchison</a>, <a href="https://publications.waset.org/abstracts/search?q=Ibrahim%20K%C3%BC%C3%A7%C3%BCkdemiral"> Ibrahim Küçükdemiral</a>, <a href="https://publications.waset.org/abstracts/search?q=Andrew%20Cowell"> Andrew Cowell</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Thermal effects are the largest source of dimensional error in precision machining, and a major proportion is caused by ambient temperature variation. The use of coolant is a primary means of mitigating these effects, but there has been limited work on coolant temperature control. This research critically explored whether CNC-machine coolant refrigeration systems adapted to actively compensate for ambient temperature variation could increase machining accuracy. Accuracy data were collected from operators’ checklists for a CNC 5-axis mill and statistically reduced to bias and precision metrics for observations of one day over a sample period of 27 days. Temperature data were collected using three USB dataloggers in ambient air, the chiller inflow, and the chiller outflow. The accuracy and temperature data were analysed using Pearson correlation, then the thermodynamics of the system were described using system identification with MATLAB. It was found that 75% of thermal error is reflected in the hot coolant temperature but that this is negligibly dependent on ambient temperature. The effect of the coolant refrigeration process on hot coolant outflow temperature was also found to be negligible. Therefore, the evidence indicated that it would not be beneficial to adapt coolant chillers to compensate for ambient temperature variation. However, it is concluded that hot coolant outflow temperature is a robust and accessible source of thermal error data which could be used for prevention strategy evaluation or as the basis of other thermal error strategies. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=CNC%20manufacturing" title="CNC manufacturing">CNC manufacturing</a>, <a href="https://publications.waset.org/abstracts/search?q=machine-tool" title=" machine-tool"> machine-tool</a>, <a href="https://publications.waset.org/abstracts/search?q=precision%20machining" title=" precision machining"> precision machining</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20error" title=" thermal error"> thermal error</a> </p> <a href="https://publications.waset.org/abstracts/157403/dynamic-compensation-for-environmental-temperature-variation-in-the-coolant-refrigeration-cycle-as-a-means-of-increasing-machine-tool-precision" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/157403.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">89</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">178</span> Design and Optimization of Sustainable Buildings by Combined Cooling, Heating and Power System (CCHP) Based on Exergy Analysis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Saeed%20Karimi">Saeed Karimi</a>, <a href="https://publications.waset.org/abstracts/search?q=Ali%20Behbahaninia"> Ali Behbahaninia</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study, the design and optimization of combined cooling, heating, and power system (CCHP) for a sustainable building are dealt with. Sustainable buildings are environmentally responsible and help us to save energy also reducing waste, pollution and environmental degradation. CCHP systems are widely used to save energy sources. In these systems, electricity, cooling, and heating are generating using just one primary energy source. The selection of the size of components based on the maximum demand of users will lead to an increase in the total cost of energy and equipment for the building complex. For this purpose, a system was designed in which the prime mover (gas turbine), heat recovery boiler, and absorption chiller are lower than the needed maximum. The difference in months with peak consumption is supplied with the help of electrical absorption chiller and auxiliary boiler (and the national electricity network). In this study, the optimum capacities of each of the equipment are determined based on Thermo economic method, in a way that the annual capital cost and energy consumption will be the lowest. The design was done for a gas turbine prime mover, and finally, the optimum designs were investigated using exergy analysis and were compared with a traditional energy supply system. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=sustainable%20building" title="sustainable building">sustainable building</a>, <a href="https://publications.waset.org/abstracts/search?q=CCHP" title=" CCHP"> CCHP</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20optimization" title=" energy optimization"> energy optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=gas%20turbine" title=" gas turbine"> gas turbine</a>, <a href="https://publications.waset.org/abstracts/search?q=exergy" title=" exergy"> exergy</a>, <a href="https://publications.waset.org/abstracts/search?q=thermo-economic" title=" thermo-economic"> thermo-economic</a> </p> <a href="https://publications.waset.org/abstracts/155971/design-and-optimization-of-sustainable-buildings-by-combined-cooling-heating-and-power-system-cchp-based-on-exergy-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/155971.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">93</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">177</span> Approaches for Minimizing Radioactive Tritium and ¹⁴C in Advanced High Temperature Gas-Cooled Reactors</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Longkui%20Zhu">Longkui Zhu</a>, <a href="https://publications.waset.org/abstracts/search?q=Zhengcao%20Li"> Zhengcao Li</a> </p> <p class="card-text"><strong>Abstract:</strong></p> High temperature gas-cooled reactors (HTGRs) are considered as one of the next-generation advanced nuclear reactors, in which porous nuclear graphite is used as neutron moderators, reflectors, structure materials, and cooled by inert helium. Radioactive tritium and ¹⁴C are generated in terms of reactions of thermal neutrons and ⁶Li, ¹⁴N, ¹⁰B impurely within nuclear graphite and the coolant during HTGRs operation. Currently, hydrogen and nitrogen diffusion behavior together with nuclear graphite microstructure evolution were investigated to minimize the radioactive waste release, using thermogravimetric analysis, X-ray computed tomography, the BET and mercury standard porosimetry methods. It is found that the peak value of graphite weight loss emerged at 573-673 K owing to nitrogen diffusion from graphite pores to outside when the system was subjected to vacuum. Macropore volume became larger while porosity for mesopores was smaller with temperature ranging from ambient temperature to 1073 K, which was primarily induced by coalescence of the subscale pores. It is suggested that the porous nuclear graphite should be first subjected to vacuum at 573-673 K to minimize the nitrogen and the radioactive 14°C before operation in HTGRs. Then, results on hydrogen diffusion show that the diffusible hydrogen and tritium could permeate into the coolant with diffusion coefficients of > 0.5 × 10⁻⁴ cm²·s⁻¹ at 50 bar. As a consequence, the freshly-generated diffusible tritium could release quickly to outside once formed, and an effective approach for minimizing the amount of radioactive tritium is to make the impurity contents extremely low in nuclear graphite and the coolant. Besides, both two- and three-dimensional observations indicate that macro and mesopore volume along with total porosity decreased with temperature at 50 bar on account of synergistic effects of applied compression strain, sharpened pore morphology, and non-uniform temperature distribution. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=advanced%20high%20temperature%20gas-cooled%20reactor" title="advanced high temperature gas-cooled reactor">advanced high temperature gas-cooled reactor</a>, <a href="https://publications.waset.org/abstracts/search?q=hydrogen%20and%20nitrogen%20diffusion" title=" hydrogen and nitrogen diffusion"> hydrogen and nitrogen diffusion</a>, <a href="https://publications.waset.org/abstracts/search?q=microstructure%20evolution" title=" microstructure evolution"> microstructure evolution</a>, <a href="https://publications.waset.org/abstracts/search?q=nuclear%20graphite" title=" nuclear graphite"> nuclear graphite</a>, <a href="https://publications.waset.org/abstracts/search?q=radioactive%20waste%20management" title=" radioactive waste management"> radioactive waste management</a> </p> <a href="https://publications.waset.org/abstracts/70163/approaches-for-minimizing-radioactive-tritium-and-14c-in-advanced-high-temperature-gas-cooled-reactors" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/70163.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">311</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">176</span> Synthesis of Hard Magnetic Material from Secondary Resources</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20Bahgat">M. Bahgat</a>, <a href="https://publications.waset.org/abstracts/search?q=F.%20M.%20Awan"> F. M. Awan</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20A.%20Hanafy"> H. A. Hanafy</a>, <a href="https://publications.waset.org/abstracts/search?q=O.%20N.%20Alzeghaibi"> O. N. Alzeghaibi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Strontium hexaferrite (SrFe12O19; Sr-ferrite) is one of the well-known materials for permanent magnets. In this study, M-type strontium ferrite was prepared by following the conventional ceramic method from steelmaking by-product. Initial materials; SrCO3 and by-product, were mixed together in the composition of SrFe12O19 in different Sr/Fe ratios. The mixtures of these raw materials were dry-milled for 6h. The blended powder was pre-sintered (i.e. calcination) at 1000°C for different times periods, then cooled down to room temperature. These pre-sintered samples were re-milled in a dry atmosphere for 1h and then fired at different temperatures in atmospheric conditions, and cooled down to room temperature. The produced magnetic powder has a dense hexagonal grain shape structure. The calculated energy product values for the produced samples ranged from 0.3 to 2.4 MGOe. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=hard%20magnetic%20materials" title="hard magnetic materials">hard magnetic materials</a>, <a href="https://publications.waset.org/abstracts/search?q=ceramic%20route" title=" ceramic route"> ceramic route</a>, <a href="https://publications.waset.org/abstracts/search?q=strontium%20ferrite" title=" strontium ferrite"> strontium ferrite</a>, <a href="https://publications.waset.org/abstracts/search?q=synthesis" title=" synthesis"> synthesis</a> </p> <a href="https://publications.waset.org/abstracts/7644/synthesis-of-hard-magnetic-material-from-secondary-resources" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/7644.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">324</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">175</span> Second-Order Slip Flow and Heat Transfer in a Long Isothermal Microchannel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Huei%20Chu%20Weng">Huei Chu Weng</a>, <a href="https://publications.waset.org/abstracts/search?q=Chien-Hung%20Liu"> Chien-Hung Liu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents a study on the effect of second-order slip and jump on forced convection through a long isothermally heated or cooled planar microchannel. The fully developed solutions of thermal flow fields are analytically obtained on the basis of the second-order Maxwell-Burnett slip and Smoluchowski jump boundary conditions. Results reveal that the second-order term in the Karniadakis slip boundary condition is found to contribute a negative velocity slip and then to lead to a higher pressure drop as well as a higher fluid temperature for the heated-wall case or to a lower fluid temperature for the cooled-wall case. These findings are contrary to predictions made by the Deissler model. In addition, the role of second-order slip becomes more significant when the Knudsen number increases. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=microfluidics" title="microfluidics">microfluidics</a>, <a href="https://publications.waset.org/abstracts/search?q=forced%20convection" title=" forced convection"> forced convection</a>, <a href="https://publications.waset.org/abstracts/search?q=gas%20rarefaction" title=" gas rarefaction"> gas rarefaction</a>, <a href="https://publications.waset.org/abstracts/search?q=second-order%20boundary%20conditions" title=" second-order boundary conditions"> second-order boundary conditions</a> </p> <a href="https://publications.waset.org/abstracts/26201/second-order-slip-flow-and-heat-transfer-in-a-long-isothermal-microchannel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/26201.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> 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