International Journal of Refrigeration-revue Internationale Du Froid最新文献

{"title":"Oil circulation ratio prediction in a vapor compression system using a discharge side oil separator and mass flow correction","authors":"Syed Angkan Haider ,&nbsp;Xin Wang ,&nbsp;Christopher Seeton ,&nbsp;Nenad Miljkovic ,&nbsp;Stefan Elbel","doi":"10.1016/j.ijrefrig.2024.09.026","DOIUrl":"10.1016/j.ijrefrig.2024.09.026","url":null,"abstract":"<div><div>Oil circulation ratio (<span><math><mrow><mi>O</mi><mi>C</mi><mi>R</mi></mrow></math></span>) is defined as the ratio of the mass flow rate of oil to the total mass flow rate of refrigerant-oil mixture in a vapor compression system. The standard method for measuring <span><math><mrow><mi>O</mi><mi>C</mi><mi>R</mi></mrow></math></span> uses liquid line sampling as described in ASHRAE Standard 41.4. Sampling is tedious, alters the steady state operation of the system, depends on different parameters, and only applies to miscible refrigerant-oil pairs. A potential method for measuring real-time <span><math><mrow><mi>O</mi><mi>C</mi><mi>R</mi></mrow></math></span> is by using an oil separator to separate the refrigerant flow from the oil flow and using the individual flow rates to calculate <span><math><mrow><mi>O</mi><mi>C</mi><mi>R</mi></mrow></math></span>. Neither a liquid line, nor refrigerant-oil miscibility are necessary for this separation-based method. No oil separator is perfect as some oil always escapes with the separated refrigerant, and some refrigerant, dissolved in oil, always escapes with the separated oil. This can significantly reduce the accuracy of the procedure. The present study investigates <span><math><mrow><mi>O</mi><mi>C</mi><mi>R</mi></mrow></math></span> measurements using an oil separator-based approach for a full vapor compression cycle working with R134a and PAG ISO 46 oil. A full cycle allows sampling to also be performed in parallel for validation. Mass flow corrections were performed to account for refrigerant dissolved in separated oil, and for oil entrained by separated refrigerant. <span><math><mrow><mi>O</mi><mi>C</mi><mi>R</mi></mrow></math></span> values from the oil separator-based approach, upon mass flow correction, were within 6 % of the sampling results. The usefulness of the oil separation efficiencies at the oil and vapor outlet ports for the oil separator-based approach is discussed.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"169 ","pages":"Pages 69-79"},"PeriodicalIF":3.5,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study of the performance of a water-to-water heat pump equipped with a liquid receiver with different charge levels","authors":"Chiara D’Ignazi,&nbsp;Luca Molinaroli,&nbsp;Carla Bongiorno","doi":"10.1016/j.ijrefrig.2024.09.022","DOIUrl":"10.1016/j.ijrefrig.2024.09.022","url":null,"abstract":"<div><div>This paper presents an experimental investigation of the effects of a decreasing refrigerant charge on the performance and operating conditions of an R513A water-to-water heat pump equipped with a large liquid receiver, an electronic expansion valve, and a vapor accumulator at the compressor inlet. The mass of the refrigerant inside the machine is progressively extracted to simulate refrigerant leakages occurring during the normal operation or in case of failures. The results show that the subcooling is the parameter mostly affected by a refrigerant charge variation since it rapidly collapses to 0 K with the charge reduction. Furthermore, it is possible to identify three different zones in which almost all the properties analyzed (COP, heating capacity, operating pressures and expansion valve opening) exhibit peculiar trends with the charge decrease: subcooling sensitivity zone, constant parameters zone, and compressor failure risk zone. The extension of these zones is determined by the size of the liquid receiver which is installed in the system and, for the heat pump under consideration, is between 100% and 95% of the initial charge for the first zone, between 95% and 40% for the second zone, and below 40% for the third zone.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 688-695"},"PeriodicalIF":3.5,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing the influence of refrigerant superheat on the cooperative thermal management system performance for the vehicle cabin and battery","authors":"Jiesong Jian,&nbsp;Yingchao Zhang,&nbsp;Guohua Wang,&nbsp;Qiankun Li","doi":"10.1016/j.ijrefrig.2024.09.013","DOIUrl":"10.1016/j.ijrefrig.2024.09.013","url":null,"abstract":"<div><div>The refrigerant superheat significantly impacts on the energy consumption of the vehicle cabin and battery collaborative thermal management system. The study investigates the problem using a genetic algorithm. Firstly, the model of collaborative thermal system is established and verified. Then, the coefficient of performance (COP) maximization is taken as the optimization target during steady-state conditions. The results show that the optimal refrigerant superheat at the evaporator outlet (S_Eva) is very low for different heat dissipation of the battery (H_Bat) as well as ambient temperature, while the optimal refrigerant superheat at the chiller outlet (S_Chi) is affected by the H_Bat as well as ambient temperature. Finally, according to conclusions under the steady state, the S_Eva is set to 1 K and taking the energy consumption (EC) as the response under transient condition, the S_Chi is determined. The results indicate that when the S_Chi is decided by single-point optimization, the optimal S_Chi is 18 K, and the EC is 1490 kJ, which is 2.3 % energy saving compared to the basic condition. When the S_Chi is decided by two-point optimization, the optimal two superheats are 12 K and 37 K and the EC is 1460 kJ, which is 4.3 % energy saving compared to the basic condition.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 364-375"},"PeriodicalIF":3.5,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive review of low dew-point desiccant wheel system: Mechanisms, configuration, and optimization","authors":"Yujie Xu,&nbsp;Liu Chen","doi":"10.1016/j.ijrefrig.2024.09.006","DOIUrl":"10.1016/j.ijrefrig.2024.09.006","url":null,"abstract":"<div><div>Humidity control is very important in production and life, especially in low dew-point industries where the dew-point temperature is less than 0 °C. A low dew-point desiccant wheel system (LDDWS) can meet the ambient humidity ratio required for production well. The mechanisms, configuration, and optimization of the LDDWS are comprehensively reviewed. The air heat-moisture handling processes of the LDDWS are initially introduced. The influence of the cold and heat source configurations on the dehumidification capacity and energy consumption is illustrated. Free cold sources, renewable heat sources, and heat pump technology can effectively increase energy utilization, thereby reducing refrigeration consumption and promoting energy savings. The optimization measures of system performance, including efficient desiccant materials, desiccant wheel partitioning, heat recovery technology, and low dew-point return air recycling, are presented. These optimization measures can effectively improve the dehumidification capacity and reduce the consumption of primary energy. In addition, to enhance the further development of LDDWS, this paper presents prospects for future developments in terms of industrial demand, dehumidification capacity, thermodynamic cycle and energy utilization.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 345-363"},"PeriodicalIF":3.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A method to calculate the two-phase distribution in a microchannel heat exchanger","authors":"Chao Yuan ,&nbsp;Hequn Liu ,&nbsp;Jinqing Peng ,&nbsp;Zhongbing Liu ,&nbsp;Houpei Li","doi":"10.1016/j.ijrefrig.2024.09.027","DOIUrl":"10.1016/j.ijrefrig.2024.09.027","url":null,"abstract":"<div><div>Maldistribution seriously impacts the heat transfer performance of the microchannel heat exchanger (MCHX). Fully understanding the two-phase distribution in the heat exchanger is important for advancing academic research and engineering applications. This study introduces a novel method for quantifying two-phase distribution in a microchannel heat exchanger. An experimental setup was developed to measure the local vapor mass fraction in the heat exchanger header. Capacitance signals were measured under inlet vapor mass fractions from 0 to 1, and inlet flow rates of 10, 15, and 25 g s⁻¹ corresponding to a mass flux of 17.47, 26.2, and 43.66 kg m⁻²s⁻¹, respectively. The local vapor mass fraction in the header was estimated using the capacitance measurements. The mass flow rate in the header, the microchannel tube, and the vapor mass fraction in the tube were calculated using the proposed model. The calculation model was validated against literature data, and the results were analyzed. The analysis reveals the characteristics of vapor mass fraction and mass flow rate distribution in the MCHX and further elaborates on the effects of phase separation, entrainment ratio, and pressure drop balance on the distribution. The proposed method can evaluate distribution in the header and tubes of microchannel heat exchangers, and it is also applicable to other types of two-phase flow devices.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 673-687"},"PeriodicalIF":3.5,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation of ammonia boiling heat transfer in rectangular microchannel under high pressure","authors":"Chenbing Yang ,&nbsp;Liping Pang ,&nbsp;Yuandong Guo,&nbsp;Desheng Ma","doi":"10.1016/j.ijrefrig.2024.09.025","DOIUrl":"10.1016/j.ijrefrig.2024.09.025","url":null,"abstract":"<div><div>Ammonia boilers are commonly used as expendable radiators during the return phase of spacecraft. The aim of this study is to investigate the bubble behavior and heat transfer characteristics within a vertical rectangular microchannel of a plate-fin ammonia boiler under gravity at an absolute pressure of 354–615 kPa. In order to achieve this, a single rectangular microchannel unit was intercepted from the ammonia boiler structure to construct a simulation model, and the high-pressure boiling process of ammonia in the rectangular microchannel was numerically investigated using the VOF model. Good agreement was obtained by comparing the numerical results with the experimental data with the error within 8 %. The results show that the wake flow at the lower end of the primary bubbles has an enhanced effect on the heat transfer, which is about 50–60 %. The maximum horizontal dimension of primary bubbles increases with increasing superheat, and significant bubble coalescence occurs when 45 % of the rectangular microchannel spacing is exceeded. In addition, the effect of different saturation temperatures on the heat transfer performance on the hot high temperature wall was investigated. Significant heat transfer deterioration was found to occur at saturation temperatures below 4 °C (superheat above 15 °C). The reason found in this study was that bubble coalescence significantly increases the percentage of gas-phase contact area on the high-temperature wall (from 25 % to 54 %) and weakens the wake enhancement effect.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 607-619"},"PeriodicalIF":3.5,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating dehumidification and heating performance in a dual evaporator heat pump system for electric vehicles","authors":"Kang Li ,&nbsp;Mingfei Tan ,&nbsp;Yuan Man ,&nbsp;Hua Zhang ,&nbsp;Binlin Dou ,&nbsp;Ni Liu ,&nbsp;Tianjiao Zhang ,&nbsp;Qize He ,&nbsp;Lin Su ,&nbsp;Soheil Mohtaram","doi":"10.1016/j.ijrefrig.2024.09.024","DOIUrl":"10.1016/j.ijrefrig.2024.09.024","url":null,"abstract":"<div><div>In cold, moisture-rich winter environments, window fogging represents a substantial safety hazard for drivers. Electric vehicles often incorporate heat pump systems to address challenges such as dehumidification and heating specific to cold weather. Therefore, it is essential to evaluate the dehumidification and heating efficiency of these systems through focused research. This study presents a dual-evaporator heat pump system designed specifically for electric vehicles, equipped with two distinct modes for dehumidification and heating. The research examines how factors such as inlet air volume and the degree of opening of the electronic expansion valve affect the system's dehumidification and heating performance. Experimental analyses were conducted to explore the system's response under various conditions of inlet air humidity and compressor speed in both modes. Results suggest that increasing inlet air volume improves dehumidification effectiveness but may reduce heating performance. Likewise, a wider opening of the electronic expansion valve enhances heating but could decrease dehumidification efficiency. Importantly, the study indicates that when the relative humidity of the inlet air exceeds 70 %, a single evaporator mode is more effective for dehumidification. However, when the relative humidity is below 70 %, the dual evaporator mode is more advantageous, showing better heating performance.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 620-631"},"PeriodicalIF":3.5,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental performance comparison of various expansion devices for small-capacity subcritical R744 vapour-compression refrigeration units","authors":"Paride Gullo ,&nbsp;Martin Ryhl Kærn","doi":"10.1016/j.ijrefrig.2024.09.015","DOIUrl":"10.1016/j.ijrefrig.2024.09.015","url":null,"abstract":"<div><div>The target of this study is to experimentally compare the performance of three different expansion devices for small-capacity subcritical R744 vapour-compression refrigeration units. The first considered expansion device was the conventional high-pressure expansion valve, which was selected as the baseline. The second assessed expansion device was a two-phase ejector for expansion work recovery whose refrigerant flow was modulated via the pulse-width modulation (PWM) strategy. Finally, the PWM approach was employed for controlling the refrigerant flow of the ejector motive nozzle while the refrigerant was not permitted to be drawn by the ejector suction nozzle. The results showed that the motive nozzle controlled via PWM effect offers similar effectiveness to a conventional high-pressure expansion valve in the subcritical regime. Furthermore, it was observed that the PWM ejector is able to control the high pressure effectively while increasing the coefficient of performance (COP) by up to 5.3 % without and by up to 7.9 % with overfed evaporator compared to the baseline in the transition regime. The results also showed that the installation of the conventional high-pressure expansion valve is not necessary. Finally, the yearly performance of the aforementioned expansion devices was assessed in five different locations, i.e., Athens (Greece), Phoenix (USA), New Delhi (India), Riyadh (Saudi Arabia) and Bangkok (Thailand). The outcomes revealed that the PWM ejector allows for a higher in yearly average COP (COP_{yearly avg}) from 4.9 % (in Athens) to 11.8 % (in Bangkok) over the baseline.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 768-776"},"PeriodicalIF":3.5,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical analysis of the optimal ejector operation and design within an ejector-based refrigeration system","authors":"Antoine Metsue ,&nbsp;Hakim Nesreddine ,&nbsp;Yann Bartosiewicz ,&nbsp;Sébastien Poncet","doi":"10.1016/j.ijrefrig.2024.09.020","DOIUrl":"10.1016/j.ijrefrig.2024.09.020","url":null,"abstract":"<div><div>Optimal operation and design of ejectors are the subject of recent concerns, especially for the enhancement of refrigeration and heat pump cycles based on natural refrigerants like carbon dioxide. In this study, a thermodynamic analysis of an ejector-based refrigeration cycle is performed to determine both what operating pressures lead to the highest physically possible performance depending on the ambient conditions, and what are the main dimensions of the ejector leading to the best performance at a given ambient temperature. A state-of-the-art thermodynamic model for the prediction of the ejector performance is for the first time utilized to generate reliable operation and performance maps of the ejector cycle. Most notably, it is found that the optimal coefficient of performance is not necessarily found when the ejector operates at critical conditions but mostly when the device is under off-design regime, depending on the ejector internal efficiency and the hot side temperature. In addition, the analysis reveals that the performance of the cycle is not highly sensitive to the throat area ratio of the ejector given that the latter lies within an acceptable range. Those findings contribute to getting a better understanding of how the cycle benefits from the ejector and define design and control strategies for the cycle.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 334-344"},"PeriodicalIF":3.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimisation of cooling performance and water consumption of a solid desiccant-assisted indirect evaporative cooling system using response surface methodology","authors":"Lanbo Lai ,&nbsp;Xiaolin Wang ,&nbsp;Gholamreza Kefayati ,&nbsp;Eric Hu ,&nbsp;Kim Choon Ng","doi":"10.1016/j.ijrefrig.2024.09.023","DOIUrl":"10.1016/j.ijrefrig.2024.09.023","url":null,"abstract":"<div><div>Solid desiccant-assisted dew-point indirect evaporative cooling (SD-DPIEC) systems have gained considerable attention as a potential eco-friendly alternative to vapour-compression cooling systems in building cooling applications. However, one major drawback of these systems is their substantial water consumption during evaporative cooling. To tackle this issue, this study aims to improve the cooling efficiency and water utilisation of an SD-DPIEC system using response surface methodology (RSM). This research focuses on optimising four key parameters: supply air temperature, humidity ratio, water consumption rate and coefficient of performance (COP). The independent variables encompass the ambient temperature, relative humidity, regeneration temperature, and recirculation air ratio. Employing a multi-objective optimisation approach via the desirability function, the optimised SD-DPIEC system is subsequently tested in two prevalent weather patterns in Australia. The results demonstrated that the regression models derived from RSM exhibited commendable predictive capability, with the determination coefficient <span><math><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup></math></span> and Adequate Precision exceeding 0.97 and 40.46, respectively. The outcomes revealed that the system attained its optimal performance with a supply air temperature of 20.36 °C, humidity ratio of 12.56 g kg^-1, a water consumption rate of 3.11 kg/hr, and COP of 2.03 under the ambient temperature of 33.79 °C, relative humidity of 68.48 %, regeneration temperature of 51.78 °C, and recirculation air ratio of 60 %. Based on the optimisation results, a case study was undertaken to evaluate the system's applicability in representative Australian climates. The results demonstrated that the system could uphold air conditions with the supply air temperature below 19 °C and humidity ratio below 11.51 g kg^-1 under the studied Australian climates.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"168 ","pages":"Pages 376-388"},"PeriodicalIF":3.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}