首页 > 最新文献

International Journal of Air-conditioning and Refrigeration最新文献

英文 中文
A Study on the Combined Driven Refrigeration Cycle Using Ejector 喷射器联合驱动制冷循环的研究
IF 1 Q4 THERMODYNAMICS Pub Date : 2021-03-01 DOI: 10.1142/S2010132521500048
W. Raza, Gwang-Soo Ko, Youn Cheol Park
The rising need for thermal comfort has resulted in a rapid increase in refrigeration systems’ usage and, subsequently, the need for electricity for air-conditioning systems. The ejector system can be driven by a free or affordable low-temperature heat source such as waste heat as the primary source of energy instead of electricity. Heat-driven ejector refrigeration systems become a promising solution for reducing energy consumption to conventional compressor-based refrigeration technologies. An air-conditioning system that uses the ejector achieves better performance in terms of energy-saving. This paper presents a study on the combined driven refrigeration cycle based on ejectors to maximize cycle performance. The experimental setup is designed to determine the coefficient of performance (COP) with ejector nozzle sizes 1.8, 3.6, and 5.4[Formula: see text]mm, respectively. In this system, the R-134a refrigerant is considered as a working fluid. The results depict that the efficiency is higher than that of the conventional refrigeration method due to comparing the performance of the conventional refrigeration cycle and the combined driven refrigeration cycle. The modified cycle efficiency is better than the vapor compression cycle below 0∘C, which implies sustainability at low temperatures by using low-grade thermal energy. For the improvement of mechanical efficiency, proposed cycle can be easily used.
对热舒适的需求不断增加,导致制冷系统的使用迅速增加,随后,空调系统对电力的需求也随之增加。喷射系统可以由一个免费的或负担得起的低温热源驱动,如废热作为主要的能量来源,而不是电力。热驱动喷射器制冷系统是一种很有前途的解决方案,可以降低传统的基于压缩机的制冷技术的能耗。使用喷射器的空调系统在节能方面表现更好。本文研究了基于喷射器的联合驱动制冷循环,以实现循环性能的最大化。设计了实验装置,以确定分别为1.8、3.6和5.4 mm的引射喷嘴的性能系数(COP)。在这个系统中,R-134a制冷剂被认为是工作流体。通过对常规制冷循环和联合驱动制冷循环的性能进行比较,结果表明,联合驱动制冷循环的效率高于常规制冷方式。修改后的循环效率优于0°C以下的蒸汽压缩循环,这意味着使用低等级热能在低温下的可持续性。为了提高机械效率,所提出的循环可以方便地使用。
{"title":"A Study on the Combined Driven Refrigeration Cycle Using Ejector","authors":"W. Raza, Gwang-Soo Ko, Youn Cheol Park","doi":"10.1142/S2010132521500048","DOIUrl":"https://doi.org/10.1142/S2010132521500048","url":null,"abstract":"The rising need for thermal comfort has resulted in a rapid increase in refrigeration systems’ usage and, subsequently, the need for electricity for air-conditioning systems. The ejector system can be driven by a free or affordable low-temperature heat source such as waste heat as the primary source of energy instead of electricity. Heat-driven ejector refrigeration systems become a promising solution for reducing energy consumption to conventional compressor-based refrigeration technologies. An air-conditioning system that uses the ejector achieves better performance in terms of energy-saving. This paper presents a study on the combined driven refrigeration cycle based on ejectors to maximize cycle performance. The experimental setup is designed to determine the coefficient of performance (COP) with ejector nozzle sizes 1.8, 3.6, and 5.4[Formula: see text]mm, respectively. In this system, the R-134a refrigerant is considered as a working fluid. The results depict that the efficiency is higher than that of the conventional refrigeration method due to comparing the performance of the conventional refrigeration cycle and the combined driven refrigeration cycle. The modified cycle efficiency is better than the vapor compression cycle below 0∘C, which implies sustainability at low temperatures by using low-grade thermal energy. For the improvement of mechanical efficiency, proposed cycle can be easily used.","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"62 1","pages":"2150004"},"PeriodicalIF":1.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81953082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
An Exergetic Model for the Ambient Air Temperature Impacts on the Combined Power Plants and its Management Using the Genetic Algorithm 基于遗传算法的环境气温对联合电厂影响的火用模型及其管理
IF 1 Q4 THERMODYNAMICS Pub Date : 2021-03-01 DOI: 10.1142/S2010132521500085
Hossein Khajehpour, N. Norouzi, M. Fani
4E analysis is used on a Brayton–Rankine combined cycle power plant (CCPP) with a dual pressure heat recovery steam generation (HRSG) system. A multi-objective genetic-based evolutionary optimization has been used to estimate the most optimal exergy efficiency status, exergy cost reduction, carbon emission reduction, and NOx emission reduction. For the validation of the data, the simulation results are compared with the plant’s data. This study investigates the effect of every decisive parameter on the objective performance parameters of the CCPP. The primary estimated results are the emission rates, efficiencies, and the exergoeconomic cost of the system. At the optimum operational state, the exergy efficiency may increase by 10%, while the total emissions may decrease by 14.6%. The conventional technical measures’ effectiveness to improve the combined cycle power plant’s energy performance is applied to the simulated case study. Results have shown that the main source of the exergy destruction in this system is the HRSG and the combustion chamber, and also the overall performance of the plant shows great sensitivity to the ambient air temperature. This fact has shown that climate change and global warming are effective in thermal power plants’ performance. Therefore, the effect of the climate change on the ambient air temperature impact on the power plant and the 4E performance of the simulated combined cycle power plant is also studied. The results show that, due to the global warming effect, the exergy efficiency of the CCPP unit is decreased by over 0.2% in the last two decades, which can be generalized to all thermal electricity generation units throughout the world based on the mean global temperature rise in the last decades.
采用4E分析方法对具有双压热回收蒸汽发生(HRSG)系统的Brayton-Rankine联合循环电厂(CCPP)进行了分析。采用多目标遗传进化优化方法,估算了最优的火用效率状态、降低火用成本、减少碳排放和减少NOx排放。为了验证数据,将模拟结果与工厂数据进行了比较。本研究探讨了各决定性参数对CCPP客观绩效参数的影响。初步估计的结果是排放率、效率和系统的消耗经济成本。在最佳运行状态下,能效可提高10%,总排放量可降低14.6%。将常规技术措施对提高联合循环电厂能源性能的有效性应用于模拟实例研究。结果表明,该系统的火用破坏的主要来源是余热sg和燃烧室,并且该装置的整体性能对周围空气温度表现出很大的敏感性。这一事实表明,气候变化和全球变暖对火电厂的性能是有效的。因此,还研究了气候变化对环境气温对电厂的影响以及模拟联合循环电厂4E性能的影响。结果表明:受全球变暖效应的影响,CCPP机组的火用效率在近20年下降了0.2%以上,基于近几十年全球平均温升,这可以推广到全球所有火力发电机组。
{"title":"An Exergetic Model for the Ambient Air Temperature Impacts on the Combined Power Plants and its Management Using the Genetic Algorithm","authors":"Hossein Khajehpour, N. Norouzi, M. Fani","doi":"10.1142/S2010132521500085","DOIUrl":"https://doi.org/10.1142/S2010132521500085","url":null,"abstract":"4E analysis is used on a Brayton–Rankine combined cycle power plant (CCPP) with a dual pressure heat recovery steam generation (HRSG) system. A multi-objective genetic-based evolutionary optimization has been used to estimate the most optimal exergy efficiency status, exergy cost reduction, carbon emission reduction, and NOx emission reduction. For the validation of the data, the simulation results are compared with the plant’s data. This study investigates the effect of every decisive parameter on the objective performance parameters of the CCPP. The primary estimated results are the emission rates, efficiencies, and the exergoeconomic cost of the system. At the optimum operational state, the exergy efficiency may increase by 10%, while the total emissions may decrease by 14.6%. The conventional technical measures’ effectiveness to improve the combined cycle power plant’s energy performance is applied to the simulated case study. Results have shown that the main source of the exergy destruction in this system is the HRSG and the combustion chamber, and also the overall performance of the plant shows great sensitivity to the ambient air temperature. This fact has shown that climate change and global warming are effective in thermal power plants’ performance. Therefore, the effect of the climate change on the ambient air temperature impact on the power plant and the 4E performance of the simulated combined cycle power plant is also studied. The results show that, due to the global warming effect, the exergy efficiency of the CCPP unit is decreased by over 0.2% in the last two decades, which can be generalized to all thermal electricity generation units throughout the world based on the mean global temperature rise in the last decades.","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"11 1","pages":"2150008"},"PeriodicalIF":1.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89722459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Performance Enhancement in LiCl–H2O and LiBr–H2O Absorption Cooling Systems Through an Advanced Exergy Analysis 通过先进的火用分析提高LiCl-H2O和lib - h2o吸收式冷却系统的性能
IF 1 Q4 THERMODYNAMICS Pub Date : 2021-02-20 DOI: 10.1142/S2010132521500073
Parth Mody, J. Patel, Nishant Modi, Bhargav Pandya
This research study compares the thermodynamic performance of 10kW lithium chloride–water (LiCl–H2O) and lithium bromide–water (LiBr–H2O) absorption cooling systems through first and second law of ...
本研究通过热力学第一定律和第二定律,比较了10kW氯化锂-水(LiCl-H2O)和溴化锂-水(lib - h2o)吸收式冷却系统的热力学性能。
{"title":"Performance Enhancement in LiCl–H2O and LiBr–H2O Absorption Cooling Systems Through an Advanced Exergy Analysis","authors":"Parth Mody, J. Patel, Nishant Modi, Bhargav Pandya","doi":"10.1142/S2010132521500073","DOIUrl":"https://doi.org/10.1142/S2010132521500073","url":null,"abstract":"This research study compares the thermodynamic performance of 10kW lithium chloride–water (LiCl–H2O) and lithium bromide–water (LiBr–H2O) absorption cooling systems through first and second law of ...","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"57 1","pages":"2150007"},"PeriodicalIF":1.0,"publicationDate":"2021-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80840430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Modified Chilled Coil Model Development and Application to Turbine Inlet Air Cooling 改进冷却盘管模型的开发及其在汽轮机进气冷却中的应用
IF 1 Q4 THERMODYNAMICS Pub Date : 2021-02-10 DOI: 10.1142/S2010132521500061
G. Anand, E. Makar
A Turbine Inlet Air Conditioning (TIAC) system can chill the inlet air of the turbine to maintain maximum turbine performance at all ambient temperatures. However, turbine characteristics, performa...
涡轮进气空调(TIAC)系统可以冷却涡轮的进气,以在所有环境温度下保持最大的涡轮性能。然而,涡轮特性,性能…
{"title":"Modified Chilled Coil Model Development and Application to Turbine Inlet Air Cooling","authors":"G. Anand, E. Makar","doi":"10.1142/S2010132521500061","DOIUrl":"https://doi.org/10.1142/S2010132521500061","url":null,"abstract":"A Turbine Inlet Air Conditioning (TIAC) system can chill the inlet air of the turbine to maintain maximum turbine performance at all ambient temperatures. However, turbine characteristics, performa...","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"94 1","pages":"2150006"},"PeriodicalIF":1.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87675812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Exergy Analysis and Optimization of Natural Gas Liquids Recovery Unit 天然气液回收装置的火用分析与优化
IF 1 Q4 THERMODYNAMICS Pub Date : 2021-02-01 DOI: 10.1142/s201013252150005x
Hossein Khajehpour, N. Norouzi, N. Shiva, Reza Mahmoodi Folourdi, Ehsan Hashemi Bahremani
The Natural Gas Liquids (NGL) recovery unit is one of the processes that requires cooling. The sweetened gas enters this unit after the dehydration stage, and the final product called NGL Product i...
天然气液体(NGL)回收装置是需要冷却的过程之一。加糖后的气体经过脱水阶段进入该装置,最终产品称为NGL产品。
{"title":"Exergy Analysis and Optimization of Natural Gas Liquids Recovery Unit","authors":"Hossein Khajehpour, N. Norouzi, N. Shiva, Reza Mahmoodi Folourdi, Ehsan Hashemi Bahremani","doi":"10.1142/s201013252150005x","DOIUrl":"https://doi.org/10.1142/s201013252150005x","url":null,"abstract":"The Natural Gas Liquids (NGL) recovery unit is one of the processes that requires cooling. The sweetened gas enters this unit after the dehydration stage, and the final product called NGL Product i...","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"8 1","pages":"2150005"},"PeriodicalIF":1.0,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90173119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
A Novel Technique for Improving the Performance of Ammonia Absorption Refrigeration Cycle 一种提高氨吸收式制冷循环性能的新技术
IF 1 Q4 THERMODYNAMICS Pub Date : 2021-01-18 DOI: 10.1142/s2010132521500036
M. Shaker, M. Abd-Elhady, M. A. Halim
The world is now living in an energy crisis. Refrigeration and air-conditioning systems have become the basics of daily life in various fields and accordingly, it cannot be dispensed. Refrigeration machines and air-conditioning systems are the most energy-consuming systems, independent on the application whether it is domestic, commercial, industrial or medical. Therefore, using cooling systems which are powered by thermal energy, e.g., solar energy, can save a lot of electrical energy. Absorption refrigeration system is an example of a refrigeration system powered by heat energy. However, the system problem here is that it has low coefficient of performance (COP). The objective of this research is to improve the COP of the ammonia absorption cycle. This is done in the absorber unit by improving the absorption of the refrigerant ammonia into the ammonia–water solution. The absorption efficiency is improved by using (1) a stirrer pump to improve mixing, (2) sprayers to increase the contact area between ammonia and ammonia–water solution and (3) continuous cooling of the solution during the absorption process via an external heat exchanger. The COP of the ammonia absorption cycle has increased from 0.48 to 0.715, i.e., by 49%. This is due to the improvement of the absorption of the ammonia into the ammonia–water solution.
世界正处于能源危机之中。制冷和空调系统已经成为各个领域日常生活的基础,因此,它是不可分割的。制冷机和空调系统是最耗能的系统,无论其应用是家庭、商业、工业还是医疗。因此,使用以热能(如太阳能)为动力的冷却系统可以节省大量电能。吸收式制冷系统是一种以热能为动力的制冷系统。然而,这里的系统问题是它的性能系数(COP)很低。本研究的目的是提高氨吸收循环的COP。这是在吸收装置中通过提高制冷剂氨进入氨-水溶液的吸收来完成的。通过使用(1)搅拌泵来改善混合,(2)喷雾器来增加氨与氨水溶液的接触面积,以及(3)在吸收过程中通过外部热交换器对溶液进行连续冷却来提高吸收效率。氨吸收循环的COP由0.48提高到0.715,即提高了49%。这是由于氨水溶液对氨水的吸收得到了改善。
{"title":"A Novel Technique for Improving the Performance of Ammonia Absorption Refrigeration Cycle","authors":"M. Shaker, M. Abd-Elhady, M. A. Halim","doi":"10.1142/s2010132521500036","DOIUrl":"https://doi.org/10.1142/s2010132521500036","url":null,"abstract":"The world is now living in an energy crisis. Refrigeration and air-conditioning systems have become the basics of daily life in various fields and accordingly, it cannot be dispensed. Refrigeration machines and air-conditioning systems are the most energy-consuming systems, independent on the application whether it is domestic, commercial, industrial or medical. Therefore, using cooling systems which are powered by thermal energy, e.g., solar energy, can save a lot of electrical energy. Absorption refrigeration system is an example of a refrigeration system powered by heat energy. However, the system problem here is that it has low coefficient of performance (COP). The objective of this research is to improve the COP of the ammonia absorption cycle. This is done in the absorber unit by improving the absorption of the refrigerant ammonia into the ammonia–water solution. The absorption efficiency is improved by using (1) a stirrer pump to improve mixing, (2) sprayers to increase the contact area between ammonia and ammonia–water solution and (3) continuous cooling of the solution during the absorption process via an external heat exchanger. The COP of the ammonia absorption cycle has increased from 0.48 to 0.715, i.e., by 49%. This is due to the improvement of the absorption of the ammonia into the ammonia–water solution.","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"26 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88591819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Performance of a Flat-Tube Louvered-Fin Automotive Condenser with R1234yf 采用R1234yf的平板管百叶式汽车冷凝器的性能
IF 1 Q4 THERMODYNAMICS Pub Date : 2020-12-08 DOI: 10.1142/s2010132521500024
H. M. Gurudatt, G. Narasimham, B. S. Gowda
Numerical simulation of a mini-channel, flat-tube, louvered fin, automotive condenser is performed to study the heat rejection rate, pressure drop and performance of the heat exchanger. The simulation study is carried out for the refrigerant R1234yf. The properties of R1234y are obtained from REFPROP software. The moist air properties are calculated from those of dry air and water vapor using suitable correlations. To select the input data, the cycle performance is carried out for a standard vapor compression refrigeration system working with R1234yf between the temperature limits of [Formula: see text]C on the low-pressure side and [Formula: see text]C on the high-pressure side. The condensation process is taken into account in three sections, namely, the superheated, two-phase and the subcooled regions. A custom code is prepared in MATLAB to solve the simultaneous equations of heat transfer from refrigerant to inside tube wall, inside tube wall to outside tube wall and outside tube wall to moist air. The simulation results show the sensible heat transfer during desuper heating to be very small compared to the condensing region. Results are reported for the pressure variation along the refrigerant flow passage in the desuper heating, two-phase and subcooling regions. The heat-transfer coefficient is found to be the highest in the two-phase region for higher dryness fractions. The effect of inlet air velocity is less compared to that of the inlet air temperature on the heat rejection rate.
对一种小型通道、平板管、百叶翅片的汽车冷凝器进行了数值模拟,研究了换热器的散热率、压降和性能。对制冷剂R1234yf进行了仿真研究。R1234y的性能是通过REFPROP软件获得的。湿空气的性质是由干空气和水蒸气的性质利用适当的相关性计算出来的。为了选择输入数据,在低压侧[公式:见文]C和高压侧[公式:见文]C的温度极限范围内,对使用R1234yf的标准蒸汽压缩制冷系统进行循环性能试验。冷凝过程分为过热区、两相区和过冷区三个部分。在MATLAB中编写了自定义代码,求解制冷剂到管内壁、管内壁到外壁、外壁到湿空气的传热联立方程。模拟结果表明,与冷凝区相比,减速加热区的显热传递很小。结果报告沿冷媒流动通道的压力变化在过热,两相和过冷区域。在高干燥分数的两相区,传热系数最高。与进口空气温度相比,进口空气速度对排热率的影响较小。
{"title":"Performance of a Flat-Tube Louvered-Fin Automotive Condenser with R1234yf","authors":"H. M. Gurudatt, G. Narasimham, B. S. Gowda","doi":"10.1142/s2010132521500024","DOIUrl":"https://doi.org/10.1142/s2010132521500024","url":null,"abstract":"Numerical simulation of a mini-channel, flat-tube, louvered fin, automotive condenser is performed to study the heat rejection rate, pressure drop and performance of the heat exchanger. The simulation study is carried out for the refrigerant R1234yf. The properties of R1234y are obtained from REFPROP software. The moist air properties are calculated from those of dry air and water vapor using suitable correlations. To select the input data, the cycle performance is carried out for a standard vapor compression refrigeration system working with R1234yf between the temperature limits of [Formula: see text]C on the low-pressure side and [Formula: see text]C on the high-pressure side. The condensation process is taken into account in three sections, namely, the superheated, two-phase and the subcooled regions. A custom code is prepared in MATLAB to solve the simultaneous equations of heat transfer from refrigerant to inside tube wall, inside tube wall to outside tube wall and outside tube wall to moist air. The simulation results show the sensible heat transfer during desuper heating to be very small compared to the condensing region. Results are reported for the pressure variation along the refrigerant flow passage in the desuper heating, two-phase and subcooling regions. The heat-transfer coefficient is found to be the highest in the two-phase region for higher dryness fractions. The effect of inlet air velocity is less compared to that of the inlet air temperature on the heat rejection rate.","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"73 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90398849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Miniaturized Traveling-Wave Thermoacoustic Refrigerator Driven by Loudspeaker: Numerical Design 扬声器驱动的小型化行波热声制冷机:数值设计
IF 1 Q4 THERMODYNAMICS Pub Date : 2020-12-05 DOI: 10.1142/s2010132520500352
Oday S. Mahmood, A. Karim, S. G. Yahya, Itimad D. J. Azzawi
Ordinary refrigeration systems such as vapor-compression refrigerators are the commonly used devices in industry, mostly for their high efficiencies. However, they make a significant contribution to the depletion of Ozone and global warming due to their operational refrigerants. Hence, thermoacoustic refrigeration can be a great alternative candidate which uses inert gases such as air, helium and nitrogen as the primary refrigerant. Thermoacoustic refrigerators convert the acoustic power (sound waves) into a thermal effect (cooling power). Thermoacoustics can be counted as a new technology that has a strong potential toward the development of the thermal applications. This study aims to design and fabricate miniaturized traveling wave thermoacoustic refrigerator which can be driven by an ordinary loudspeaker. The optimized numerical design of the refrigerator shows an overall efficiency (cooling power over input electricity) of nearly 66% at a temperature difference of 25[Formula: see text]K (between cold and ambient heat exchangers). The maximum estimated cooling power is 65[Formula: see text]W at coefficient of performance (COP) of 2.65.
普通的制冷系统,如蒸汽压缩冰箱,是工业上常用的设备,主要是因为它们的高效率。然而,由于它们的操作制冷剂,它们对臭氧的消耗和全球变暖做出了重大贡献。因此,热声制冷可以是一个很好的备选,它使用惰性气体,如空气,氦和氮作为主要制冷剂。热声制冷机将声功率(声波)转化为热效应(冷却功率)。热声学技术是一门在热应用领域具有巨大发展潜力的新技术。本研究旨在设计并制造一种可由普通扬声器驱动的小型化行波热声制冷机。制冷机的优化数值设计表明,在冷热交换器和环境热交换器之间的温差为25 K时,制冷机的总效率(冷却功率除以输入功率)接近66%。在性能系数(COP)为2.65时,最大估计冷却功率为65[公式:见文]。
{"title":"Miniaturized Traveling-Wave Thermoacoustic Refrigerator Driven by Loudspeaker: Numerical Design","authors":"Oday S. Mahmood, A. Karim, S. G. Yahya, Itimad D. J. Azzawi","doi":"10.1142/s2010132520500352","DOIUrl":"https://doi.org/10.1142/s2010132520500352","url":null,"abstract":"Ordinary refrigeration systems such as vapor-compression refrigerators are the commonly used devices in industry, mostly for their high efficiencies. However, they make a significant contribution to the depletion of Ozone and global warming due to their operational refrigerants. Hence, thermoacoustic refrigeration can be a great alternative candidate which uses inert gases such as air, helium and nitrogen as the primary refrigerant. Thermoacoustic refrigerators convert the acoustic power (sound waves) into a thermal effect (cooling power). Thermoacoustics can be counted as a new technology that has a strong potential toward the development of the thermal applications. This study aims to design and fabricate miniaturized traveling wave thermoacoustic refrigerator which can be driven by an ordinary loudspeaker. The optimized numerical design of the refrigerator shows an overall efficiency (cooling power over input electricity) of nearly 66% at a temperature difference of 25[Formula: see text]K (between cold and ambient heat exchangers). The maximum estimated cooling power is 65[Formula: see text]W at coefficient of performance (COP) of 2.65.","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"1 1","pages":"2050035"},"PeriodicalIF":1.0,"publicationDate":"2020-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89853768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
A Review of Models for Estimation of Moisture Evaporation Rate from Clothes Inside a Clothes Dryer 干衣机内衣物水分蒸发速率估算模型综述
IF 1 Q4 THERMODYNAMICS Pub Date : 2020-11-25 DOI: 10.1142/s2010132521300019
M. Rasti, J. Jeong
Heat pump tumble dryers, air-vented dryers and condenser dryers are widely used as clothes dryers. Clothes dryers use hot air to absorb moisture from textiles to get them dry after a wash by passing drying air through the drum. To simulate the drying process of clothes in the drum and to obtain the moisture evaporation rate, it is necessary to use an accurate model to predict the moisture transfer coefficient from the textile to the air in the drum as well as the mass transfer area between the drying air and the textile. In this study, a comprehensive review of the literature on the prediction of the moisture evaporation rate inside the drum of a clothes dryers was conducted. It was found that researchers generally used constant values, fitting models, dimensionless correlations, and Chilton–Colburn analogy to predict the area–mass transfer coefficient. Moreover, few researchers used the effectiveness model for the prediction of moisture evaporation rate. The comprehensive review of the literature showed that all of the previous models for prediction of the moisture evaporation rate have some limitations in terms of generality or accuracy. Therefore, the development of a new accurate model for prediction of the moisture evaporation rate inside the drum of clothes dryers is crucial.
热泵滚筒式干衣机、通风式干衣机和冷凝器干衣机是目前广泛应用的干衣机。干衣机利用热风吸收纺织品中的水分,使衣物在洗涤后通过滚筒干燥。为了模拟衣物在滚筒内的干燥过程,获得水分蒸发速率,需要使用准确的模型来预测纺织品对滚筒内空气的水分传递系数以及干燥空气与纺织品之间的传质面积。在这项研究中,全面回顾了文献的预测在一个干衣机的滚筒内水分蒸发速率进行了。研究发现,研究人员一般采用定值、拟合模型、无因次相关性和Chilton-Colburn类比来预测面积-质量传递系数。此外,利用有效性模型预测水分蒸发速率的研究较少。综合文献分析表明,以往的水分蒸发速率预测模型在通用性和准确性上都存在一定的局限性。因此,建立一种新的准确的模型来预测干衣机滚筒内的水分蒸发速率是至关重要的。
{"title":"A Review of Models for Estimation of Moisture Evaporation Rate from Clothes Inside a Clothes Dryer","authors":"M. Rasti, J. Jeong","doi":"10.1142/s2010132521300019","DOIUrl":"https://doi.org/10.1142/s2010132521300019","url":null,"abstract":"Heat pump tumble dryers, air-vented dryers and condenser dryers are widely used as clothes dryers. Clothes dryers use hot air to absorb moisture from textiles to get them dry after a wash by passing drying air through the drum. To simulate the drying process of clothes in the drum and to obtain the moisture evaporation rate, it is necessary to use an accurate model to predict the moisture transfer coefficient from the textile to the air in the drum as well as the mass transfer area between the drying air and the textile. In this study, a comprehensive review of the literature on the prediction of the moisture evaporation rate inside the drum of a clothes dryers was conducted. It was found that researchers generally used constant values, fitting models, dimensionless correlations, and Chilton–Colburn analogy to predict the area–mass transfer coefficient. Moreover, few researchers used the effectiveness model for the prediction of moisture evaporation rate. The comprehensive review of the literature showed that all of the previous models for prediction of the moisture evaporation rate have some limitations in terms of generality or accuracy. Therefore, the development of a new accurate model for prediction of the moisture evaporation rate inside the drum of clothes dryers is crucial.","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"187 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77524252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Numerical Analysis of the Dynamic and Thermal Behavior of an Indirect Solar Dryer: Effect of the Outlet 间接太阳能干燥机动力和热特性的数值分析:出口的影响
IF 1 Q4 THERMODYNAMICS Pub Date : 2020-11-25 DOI: 10.1142/s2010132521500012
M. Salhi, Dounia Chaatouf, Benyounes Raillani, N. Dihmani, S. Amraqui, M. Moussaoui, A. Mezrhab, J. Fontaine
This work is a contribution to the improvement of the thermal and the dynamic fields of a natural convection indirect solar dryer, composed of a solar flat air heater and a drying chamber, intended for drying agricultural products and medicinal plants. We have studied the effects of size and position of the outlet on the distribution of air and temperature within the drying chamber, containing the figs as a product to be dried. To be more realistic, we have used a user defined function (UDF) subroutine written in [Formula: see text] to integrate the unsteady evolution of a day’s climate data in the Oujda region. This study was achieved by numerical simulations using the ANSYS FLUENT software, in order to optimize the distribution of air and temperature inside the drying chamber, and to choose the best outlet’s position and size for the best efficiency of the dryer. The results show that the optimal outlet position found is in the right corner with a size range of 0.07 to 0.15[Formula: see text]m. The effects of the position and size of the outlet on the air deflection along the trays were also presented and discussed.
本工作对自然对流间接太阳能干燥机的热场和动力场的改进做出了贡献,该干燥机由太阳能平板空气加热器和干燥室组成,用于干燥农产品和药用植物。我们研究了出口的大小和位置对干燥室内空气和温度分布的影响,其中包含无花果作为待干燥的产品。为了更实际,我们使用了用户定义函数(UDF)子程序来整合Oujda地区一天气候数据的不稳定演变。为了优化干燥室内的空气分布和温度分布,选择最佳的出口位置和尺寸,以达到干燥机的最佳效率,本研究利用ANSYS FLUENT软件进行了数值模拟。结果表明,找到的最佳出口位置为右下角,尺寸范围为0.07 ~ 0.15 m[公式:见文]m。此外,还讨论了出口的位置和尺寸对空气沿塔板偏转的影响。
{"title":"Numerical Analysis of the Dynamic and Thermal Behavior of an Indirect Solar Dryer: Effect of the Outlet","authors":"M. Salhi, Dounia Chaatouf, Benyounes Raillani, N. Dihmani, S. Amraqui, M. Moussaoui, A. Mezrhab, J. Fontaine","doi":"10.1142/s2010132521500012","DOIUrl":"https://doi.org/10.1142/s2010132521500012","url":null,"abstract":"This work is a contribution to the improvement of the thermal and the dynamic fields of a natural convection indirect solar dryer, composed of a solar flat air heater and a drying chamber, intended for drying agricultural products and medicinal plants. We have studied the effects of size and position of the outlet on the distribution of air and temperature within the drying chamber, containing the figs as a product to be dried. To be more realistic, we have used a user defined function (UDF) subroutine written in [Formula: see text] to integrate the unsteady evolution of a day’s climate data in the Oujda region. This study was achieved by numerical simulations using the ANSYS FLUENT software, in order to optimize the distribution of air and temperature inside the drying chamber, and to choose the best outlet’s position and size for the best efficiency of the dryer. The results show that the optimal outlet position found is in the right corner with a size range of 0.07 to 0.15[Formula: see text]m. The effects of the position and size of the outlet on the air deflection along the trays were also presented and discussed.","PeriodicalId":13757,"journal":{"name":"International Journal of Air-conditioning and Refrigeration","volume":"10 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87193178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
期刊
International Journal of Air-conditioning and Refrigeration
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1