International Journal of Air-conditioning and Refrigeration最新文献_第9页

A Study on the Combined Driven Refrigeration Cycle Using Ejector 喷射器联合驱动制冷循环的研究

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International Journal of Air-conditioning and Refrigeration Pub Date : 2021-03-01 DOI: 10.1142/S2010132521500048

W. Raza, Gwang-Soo Ko, Youn Cheol Park

{"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

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International Journal of Air-conditioning and Refrigeration Pub Date : 2021-03-01 DOI: 10.1142/S2010132521500085

Hossein Khajehpour, N. Norouzi, M. Fani

{"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

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International Journal of Air-conditioning and Refrigeration Pub Date : 2021-02-20 DOI: 10.1142/S2010132521500073

Parth Mody, J. Patel, Nishant Modi, Bhargav Pandya

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

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International Journal of Air-conditioning and Refrigeration Pub Date : 2021-02-10 DOI: 10.1142/S2010132521500061

G. Anand, E. Makar

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

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International Journal of Air-conditioning and Refrigeration Pub Date : 2021-02-01 DOI: 10.1142/s201013252150005x

Hossein Khajehpour, N. Norouzi, N. Shiva, Reza Mahmoodi Folourdi, Ehsan Hashemi Bahremani

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

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International Journal of Air-conditioning and Refrigeration Pub Date : 2021-01-18 DOI: 10.1142/s2010132521500036

M. Shaker, M. Abd-Elhady, M. A. Halim

{"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

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International Journal of Air-conditioning and Refrigeration Pub Date : 2020-12-08 DOI: 10.1142/s2010132521500024

H. M. Gurudatt, G. Narasimham, B. S. Gowda

{"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

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International Journal of Air-conditioning and Refrigeration Pub Date : 2020-12-05 DOI: 10.1142/s2010132520500352

Oday S. Mahmood, A. Karim, S. G. Yahya, Itimad D. J. Azzawi

{"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

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International Journal of Air-conditioning and Refrigeration Pub Date : 2020-11-25 DOI: 10.1142/s2010132521300019

M. Rasti, J. Jeong

{"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

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International Journal of Air-conditioning and Refrigeration 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

{"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