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

Effect of ultrasonic oscillation combined with atomization on enhancing ammonia-water falling film process and performance of absorption refrigeration system 超声振荡结合雾化对提高吸收式制冷系统氨-水降膜过程及性能的影响

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-21 DOI: 10.1016/j.ijrefrig.2025.06.021

Chuang Pan , Jinlei Li , Runfa Zhou , Shuhong Li , Yanjun Li , Jun Wu , Gui Li

{"title":"Effect of ultrasonic oscillation combined with atomization on enhancing ammonia-water falling film process and performance of absorption refrigeration system","authors":"Chuang Pan , Jinlei Li , Runfa Zhou , Shuhong Li , Yanjun Li , Jun Wu , Gui Li","doi":"10.1016/j.ijrefrig.2025.06.021","DOIUrl":"10.1016/j.ijrefrig.2025.06.021","url":null,"abstract":"<div><div>The ammonia-water absorption refrigeration system (AARS) can utilize low-grade heat sources to drive the generation of high-grade energy. The enhancement of the coupled heat and mass transfer is the key to improving the system performance, thereby reducing energy consumption and the size of components. High-frequency ultrasonic waves can generate fine droplets, increasing the mass transfer area of gas-liquid contact. Medium and low-frequency ultrasonic oscillations can enhance the disturbance and heat and mass transfer within the falling film solution, increasing the driving potential for mass transfer, and thus realizing the improvement of the system performance. Therefore, a thermodynamic mathematical model of the system was established, and the reliability of the model was verified through a constructed experimental system. The coefficient of performance (<em>COP</em>) and exergy efficiency (<em>COE</em>) were used to describe the system energy consumption and irreversible losses. The size reduction rate was used to measure the reduction of the system size, and economic evaluation indicators were used to assess the investment and operating costs of the system operation. The results show that the installation of atomizers and oscillators has a positive impact on the system performance, making the system more compact and efficient. The <em>COP</em> can be improved by up to 37.12 %, the irreversible losses can be reduced by up to 43.82 %, the size of the main components can be reduced by up to 39.5 %, and the annual operating cost can be reduced by up to 30.85 %, providing a strong basis for the practical application of ultrasonic waves in AARS.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 417-435"},"PeriodicalIF":3.5,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491104","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}

引用次数: 0

Employing cooling/power cycle in a sustainable geothermal scheme integrated desalinated water-based H2 production/liquefaction; AI-aided multi-facet optimization and economic examination 采用冷却/动力循环的可持续地热方案集成了脱盐水基制氢/液化；人工智能辅助的多方面优化和经济性检验

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-17 DOI: 10.1016/j.ijrefrig.2025.06.016

Tianwen Yin , LeI Chang , Sinan Q. Salih , Ahmad Almadhor , Mohamed Shaban , Essam R. El-Zahar , Ashit Kumar Dutta , Barno Abdullaeva , H. Elhosiny Ali , Hind Albalawi

{"title":"Employing cooling/power cycle in a sustainable geothermal scheme integrated desalinated water-based H2 production/liquefaction; AI-aided multi-facet optimization and economic examination","authors":"Tianwen Yin , LeI Chang , Sinan Q. Salih , Ahmad Almadhor , Mohamed Shaban , Essam R. El-Zahar , Ashit Kumar Dutta , Barno Abdullaeva , H. Elhosiny Ali , Hind Albalawi","doi":"10.1016/j.ijrefrig.2025.06.016","DOIUrl":"10.1016/j.ijrefrig.2025.06.016","url":null,"abstract":"<div><div>The sustainable nature of geothermal energy, combined with advances in power generation technologies, has allowed establishing sustainable energy supply programs. To respond to significant thermal losses, it is crucial to develop hybrid systems that minimize irreversibility through environmentally friendly methods, which is vital for the longevity of these energy conversion processes. Thus, this study introduces an innovative environmentally friendly thermal plan that identifies and addresses points of thermal losses in a geothermal power cycle. The process employs a multi-step approach for producing desalinated water, converting it into hydrogen, and subsequently liquefying hydrogen gas. The suggested scheme incorporates subsystems, encompassing a geothermal flash cycle, an organic flash cycle, a unit for thermally produced desalinated water, a combined cooling and power cycle, a water electrolysis module, and a Claude cycle. This research assesses the thermodynamic, cost, and sustainability viewpoints. The research’s primary aim is to optimize the system’s performance using an artificial intelligence-driven optimization algorithm. The optimization targets the cost of liquefied hydrogen and exergy efficiency as objective functions, employing artificial neural networks that achieve a regression coefficient of 1 to initiate the optimization process. Using the NSGA-II algorithm, four decision variables are utilized to map the Pareto front, revealing an optimum exergetic efficiency of 0.3208 and a liquefied hydrogen cost of 0.3676 $/lit. The hydrogen liquefaction rate is attained at 44.57 lit/h, resulting in a sustainability index of 1.472.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 436-455"},"PeriodicalIF":3.5,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490980","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}

引用次数: 0

LSTM-Based Modeling and Cross-Correlation Sensitivity Analysis for Heat Pump Refrigerant Distribution 基于lstm的热泵制冷剂分布建模及相关灵敏度分析

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-16 DOI: 10.1016/j.ijrefrig.2025.06.006

Kosuke Miyawaki , Hongtao Qiao , Anna Sciazko , Naoki Shikazono

{"title":"LSTM-Based Modeling and Cross-Correlation Sensitivity Analysis for Heat Pump Refrigerant Distribution","authors":"Kosuke Miyawaki , Hongtao Qiao , Anna Sciazko , Naoki Shikazono","doi":"10.1016/j.ijrefrig.2025.06.006","DOIUrl":"10.1016/j.ijrefrig.2025.06.006","url":null,"abstract":"<div><div>This heat pump study introduces a Resonance-Based Sensitivity Analysis (RBSA) framework, which was inspired by the resonant characteristics of LSTM networks to visualize and interpret correlations between output features. First, we developed an LSTM network that predicts the time-series distribution of refrigerant within the system, focusing on refrigerant migration and its nonlinear dependency on the initial distribution in startup operation. A total of nine different datasets were employed, structured as a 3×3 matrix combining three levels of charged refrigerant, incrementing approximately 10wt% of system refrigerant, and three levels of initial refrigerant in evaporator from 30wt% to 70wt%. The prediction by the network achieved a coefficient of determination exceeding 95% in refrigerant distribution against validation data. Subsequently, targeted noise was applied to specific outputs of the trained network to analyze the intensity of inter-feature dependencies, demonstrating the utility of the RBSA approach in capturing causal relationships within the system. We investigated using both spike noise and persistent Gaussian noise in a comparative analysis to evaluate their distinct effects. During sensitivity evaluation with spike noise, we examined noise propagation between features using cross-correlation functions. The analysis revealed that the relationships between parameters maintained physical plausibility, even without an explicit physical model. We then introduced continuous white noise into the refrigerant distribution to examine its propagation effects and map how distribution fluctuations affected system operating parameters. The findings revealed that variations in refrigerant distribution substantially affect operating parameters such as mass flow rate, compressor input and condenser and evaporator capacity.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 351-363"},"PeriodicalIF":3.5,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470886","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}

引用次数: 0

Calorimetric determination of emissivity for metallic foils: An innovative approach for thermal analysis 金属箔发射率的量热测定：热分析的创新方法

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-15 DOI: 10.1016/j.ijrefrig.2025.06.018

Abdul Rehman Hashmi , Yunfei Gao , Jiahao Yu , Haoren Wang , Bo Wang , Fatima Saadat , Zhihua Gan

{"title":"Calorimetric determination of emissivity for metallic foils: An innovative approach for thermal analysis","authors":"Abdul Rehman Hashmi , Yunfei Gao , Jiahao Yu , Haoren Wang , Bo Wang , Fatima Saadat , Zhihua Gan","doi":"10.1016/j.ijrefrig.2025.06.018","DOIUrl":"10.1016/j.ijrefrig.2025.06.018","url":null,"abstract":"<div><div>In vacuum environments, thermal radiation significantly influences heat transfer, making accurate emissivity predictions crucial for improving the efficiency of refrigeration systems. However, emissivity is a highly sensitive parameter that is challenging to measure with precision due to the limited availability of reliable measurement methods. This paper introduces an innovative method for measuring the total hemispherical emissivity of metallic foils, specifically targeting highly reflective metals. In this study, the emissivity of the 99.9 % pure aluminum with a thickness of 25.4 μm was measured across a temperature range of 170.1 K to 283.8 K, varying from 0.0185 to 0.0205, with a comparative analysis revealing a 38.3 % difference between the shiny and matte sides of the foil. Additionally, the influence of absorber temperature was examined using an insulation layer. The experimental results were validated against published data within the same temperature range and further corroborated through simulations. This approach offers a reliable and precise method for measuring emissivity in highly reflective metals under low-temperature conditions.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 364-377"},"PeriodicalIF":3.5,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470887","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}

引用次数: 0

Research and process optimization on frostless heat source tower heat pump system based on compound enthalpy enhancement 基于复合焓增强的无霜热源塔热泵系统研究与工艺优化

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-14 DOI: 10.1016/j.ijrefrig.2025.06.013

Lei Li , Huafu Zhang , Zhentao Zhang , Fuqiang Qi , Qiu Tu , Hongwei Wu , Junling Yang , Xuelai Zhang , Mingxin He

{"title":"Research and process optimization on frostless heat source tower heat pump system based on compound enthalpy enhancement","authors":"Lei Li , Huafu Zhang , Zhentao Zhang , Fuqiang Qi , Qiu Tu , Hongwei Wu , Junling Yang , Xuelai Zhang , Mingxin He","doi":"10.1016/j.ijrefrig.2025.06.013","DOIUrl":"10.1016/j.ijrefrig.2025.06.013","url":null,"abstract":"<div><div>Due to the problems of high pollution, strong corrosion and high regenerative energy consumption in traditional heat source tower, a compound enthalpy enhancement heat source tower heat pump system using potassium formate solution as antifreeze and integrated mechanical vapor compression solution regeneration system is propose. Using Aspen Plus simulations, this work systematically investigates the impacts of six key parameters: air inlet temperature, relative humidity, airflow velocity, solution-air temperature differential, antifreeze concentration, and spray density on heating performance and energy efficiency. The results demonstrate 15-20% efficiency improvements under elevated ambient temperatures (>15°C) and high humidity conditions (>70% RH). Optimal operational ranges are established as 1.9-2.3 m/s airflow velocity and 14-18 m³/(m²·h) spray density with >5°C thermal differential. The main contributions include developing an environmentally sustainable antifreeze solution implementation framework and establishing practical engineering guidelines for parameter optimization in cold climate applications. These findings provide critical insights for enhancing heat pump system efficiency while reducing corrosion risks and regeneration energy consumption by approximately 25-30% compared to conventional systems.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 320-337"},"PeriodicalIF":3.5,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330556","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}

引用次数: 0

Thermodynamic evaluation of advanced adsorbents for thermally-driven atmospheric water harvesting system in diverse climatic conditions 不同气候条件下热驱动大气集水系统高级吸附剂的热力学评价

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-10 DOI: 10.1016/j.ijrefrig.2025.06.012

Muhammad Sultan , Aïssa Rezzoug , Muhammad Aleem

{"title":"Thermodynamic evaluation of advanced adsorbents for thermally-driven atmospheric water harvesting system in diverse climatic conditions","authors":"Muhammad Sultan , Aïssa Rezzoug , Muhammad Aleem","doi":"10.1016/j.ijrefrig.2025.06.012","DOIUrl":"10.1016/j.ijrefrig.2025.06.012","url":null,"abstract":"<div><div>In the context of freshwater scarcity, the current research aims to evaluate silica-gel, zeolite, ionogel, and metal-organic framework (MOF) based four types of advanced adsorbents for thermally-driven adsorption-based atmospheric water harvesting (AWH) system. Thermodynamic modeling framework is executed for performance evaluation of studied adsorbents by means of water production potential (WPP), energy consumption (EC), and thermal efficiency (TE) with respect to different operating conditions like ambient/adsorption temperature (T<sub>amb/ads</sub>)/relative humidity (RH<sub>amb/ads</sub>) and desorption T (T<sub>des</sub>)/RH (RH<sub>des</sub>). According to results, ionogel and MOF-based adsorbents observed maximum WPP of 1.28 kg/kg/cycle and 0.95 kg/kg/cycle, respectively at T<sub>amb/ads</sub> of 25 °C, T<sub>des</sub> of 100 °C and RH<sub>des</sub> of 20 %. Consequently, the EC computed as 4350.91 kJ/kg/cycle and 4650.67 kJ/kg/cycle with TE of 0.52 and 0.49, respectively. Keeping in view optimized operating conditions, the studied adsorbents are further evaluated for five major cities of Pakistan and South Africa having diverse climatic conditions (arid, semi-arid and humid subtropical). Average WPP of 7.10 L/kg/day and 19.85 L/kg/day is observed by ionogel and MOF, respectively throughout the year with EC of 4647.49 kJ/kg/cycle, and 4331.86 kJ/kg/cycle as well as TE of 0.49 and 0.51, respectively. This research underscores feasibility of advanced adsorbents in diverse climatic conditions from thermodynamic point of view and presents valuable insights on integrating low-grade thermal energy options for the AWH systems. Moreover, the integration of AWH systems could be a potential option in building façades and green roofs for water-resilient urban development in water stressed regions.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 273-295"},"PeriodicalIF":3.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321215","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}

引用次数: 0

Modeling of two-phase CO2 ejectors using an Eulerian–Eulerian two-fluid approach 采用欧拉-欧拉双流体方法的两相CO2喷射器建模

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-09 DOI: 10.1016/j.ijrefrig.2025.05.020

Negar Alvandifar , Ehsan Mahravan , Kim Gardø Christensen , Pourya Forooghi

{"title":"Modeling of two-phase CO2 ejectors using an Eulerian–Eulerian two-fluid approach","authors":"Negar Alvandifar , Ehsan Mahravan , Kim Gardø Christensen , Pourya Forooghi","doi":"10.1016/j.ijrefrig.2025.05.020","DOIUrl":"10.1016/j.ijrefrig.2025.05.020","url":null,"abstract":"<div><div>Ejector is a work recovery device that plays a critical role in increasing the overall efficiency of CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> heat pump systems. Despite extensive research, persistent challenges in the numerical modeling of these devices limit the effective use of simulations as reliable and cost-efficient tools for design and optimization. These challenges are linked to the complex non-equilibrium two-phase and turbulent flow, with the presence of flashing phenomenon, rapid phase changes and compressibility effects. This study introduces an open-source numerical model based on the Eulerian–Eulerian two-fluid framework within OpenFOAM, which captures the detailed phase interactions and non-equilibrium effects often overlooked in previous models. Moreover, the model incorporates polydispersity to more realistically simulate phase change during flashing in the motive nozzle—an aspect not considered in previous CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> ejector models. To ensure consistent performance of the model across a range of operating conditions, 19 different cases with both supercritical and subcritical (including subcooled) motive flows are simulated and compared to independent experimental data. The model shows consistent predictions with an average deviation of approximately 8%, 12%, and 6% in predicting motive mass flow rate, suction mass flow rates, and entrainment ratio, respectively. This open-source model is expected to contribute to better designs of CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> ejectors and improved operational efficiencies of CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> heat pumps.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 338-350"},"PeriodicalIF":3.5,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144366236","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}

引用次数: 0

Experimental study on the performance consistency diagnosis of split-type air conditioner based double colour ball matching rule 基于双色球匹配规则的分体式空调性能一致性诊断实验研究

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-06 DOI: 10.1016/j.ijrefrig.2025.06.010

Lulu Hu , Hui Chen , Yike Miao , Cunfei Chen , Yingwen Liu

{"title":"Experimental study on the performance consistency diagnosis of split-type air conditioner based double colour ball matching rule","authors":"Lulu Hu , Hui Chen , Yike Miao , Cunfei Chen , Yingwen Liu","doi":"10.1016/j.ijrefrig.2025.06.010","DOIUrl":"10.1016/j.ijrefrig.2025.06.010","url":null,"abstract":"<div><div>With the continuous improvement of consumer product quality and the increasing demand for energy conservation, the quality requirements for air conditioning products have evolved beyond merely meeting energy efficiency standards. There are now stringent demands for performance consistency among products of the same model but from different batches. However, in the actual sampling process, there are various sources of performance deviation. Therefore, there is an urgent need for a diagnostic mechanism and method to provide personalized optimization strategies for machines exhibiting performance deviations, to restore their annual energy consumption efficiency (APF) levels to normal. Based on comparative experiments, a database consisting of 6 sets of APF deviation prototypes and 18 sets of internal and external machine combination samples is constructed. A personalized diagnosis system for performance consistency issues of split air conditioners is established by combining the two colour ball parameter matching strategy and BP neural network algorithm. Twelve relevant parameters are selected and the deviation level value is set as the diagnostic basis for the expert system. After comprehensive working conditions, the diagnostic problems and problem weight proportion of the prototype are given, and the component optimization strategy for the prototype is proposed. The verification experiment shows that after optimizing the corresponding components, the APF of the two prototypes increased by 1.2 % and 1.3 % respectively, reaching the APF qualification standard. And the optimization results verify the technical feasibility of the expert system.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 305-319"},"PeriodicalIF":3.5,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321217","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}

引用次数: 0

Effect of compressor speed on heat pump performance with climate-friendly refrigerants 压缩机转速对气候友好型制冷剂热泵性能的影响

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-05 DOI: 10.1016/j.ijrefrig.2025.05.027

Ali Khalid Shaker Al-Sayyab , Joaquín Navarro-Esbrí , Angel Barragán-Cervera , Adrián Mota-Babiloni

{"title":"Effect of compressor speed on heat pump performance with climate-friendly refrigerants","authors":"Ali Khalid Shaker Al-Sayyab , Joaquín Navarro-Esbrí , Angel Barragán-Cervera , Adrián Mota-Babiloni","doi":"10.1016/j.ijrefrig.2025.05.027","DOIUrl":"10.1016/j.ijrefrig.2025.05.027","url":null,"abstract":"<div><div>The sustainability of the Heating, Ventilation, and Air Conditioning (HVAC) system focuses on reducing energy consumption, improving efficiency, minimising environmental impact, and improving indoor air quality while maintaining comfort. Sustainable HVAC practices are critical in combating climate change and creating energy-efficient systems. A Variable Refrigerant Flow (VRF) is an HVAC technology that utilizes high-efficiency components of variable-speed compressors enabled by inverter technology. These compressors adjust cooling output to actual demand and contribute to the system's overall energy efficiency, unlike conventional systems that operate at full capacity and use more energy. Thus, VRFs are highly efficient, adaptable, and suitable for various building types. The current study compares climate-friendly refrigerants R1234yf and R515B under different compressor frequencies (35, 40, 45, and 50 Hz). The experiment was carried out under the secondary fluid inlet and outlet temperatures of (12 °C/6 °C in the case of glycol and 45 °C/50 °C in the case of water), respectively. While the degree of sub-cooling and superheat is maintained at 5 °C and 10 °C, respectively. R1234yf demonstrated the highest refrigerant mass flow rate under the tested frequency, increasing compressor power consumption. R515B presents the highest system COP over all tested compressor frequencies, which can be selected as a suitable, safe, and non-flammable alternative refrigerant in buildings.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 296-304"},"PeriodicalIF":3.5,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321216","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}

引用次数: 0

A novel on-board method for quantifying refrigerant charge in residential heat pumps 一种新型的机载定量住宅热泵制冷剂充注量方法

IF 3.5 2区工程技术

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-06-05 DOI: 10.1016/j.ijrefrig.2025.06.008

Maëlle Jounay , Odile Cauret , Cédric Teuillières , Cong Toan Tran

{"title":"A novel on-board method for quantifying refrigerant charge in residential heat pumps","authors":"Maëlle Jounay , Odile Cauret , Cédric Teuillières , Cong Toan Tran","doi":"10.1016/j.ijrefrig.2025.06.008","DOIUrl":"10.1016/j.ijrefrig.2025.06.008","url":null,"abstract":"<div><div>Heat pump performances may be dramatically impacted by refrigerant leakages, but only after a substantial loss of refrigerant. It is thus crucial to detect and quantify leakages during the initial phase of slight performance decline, to provide accurate information to maintainers and adapt the maintenance accordingly. Most existing refrigerant charge assessment methods rely on subcooling as main charge-sensitive parameter. However, in modern, well-optimized heat pumps, subcooling is minimal and quickly drops to zero after a small loss of refrigerant, rendering the methods ineffective. A new method for refrigerant charge assessment, well-suited for these contemporary heat pumps operating in heating mode, is thus proposed in this study, leveraging the evaporator inlet vapor quality as key charge-sensitive feature. Unlike conventional methods which directly predict the refrigerant charge, this new method is based on an indirect scheme where the developed correlation uses the refrigerant charge as input and the charge-sensitive parameter as output. This method was validated in climatic chambers, on a variable-speed air-to-water heat pump filled with R32. It was trained on stationary data with imposed operating conditions and then tested using a semivirtual setup where the heat pump operated autonomously and dynamically based on a heat curve to compensate for the heat losses of a virtual building. The method demonstrated high accuracy, with a 1.5–2.5 % error on charge assessment for charge levels between 70 % and 110 %. The calibration effort was minimized to 40 operating conditions distributed across three charge levels, including an overcharge one.</div></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":"177 ","pages":"Pages 263-272"},"PeriodicalIF":3.5,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312526","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}

引用次数: 0