Experimental study on the heating performance of a transcritical CO2 heat pump water heater under Multi-Parameter coordinated matching operation

IF 3.5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Refrigeration-revue Internationale Du Froid Pub Date : 2025-02-20 DOI:10.1016/j.ijrefrig.2025.02.019

Rusheng Hu , Xu Jin , Xiaoqiong Li , Youdong Wang , Zhentao Zhang , Zhongyan Liu , Xin Meng

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引用次数: 0

Abstract

In CO₂ heat pump (HP) water heaters, achieving optimal synergy among operating parameters is essential for maintaining high system performance under varying heating demands. This study investigates a CO₂ HP system equipped with an electronic expansion valve (EEV) and ejector throttling. The comprehensive effects of operating parameters—compressor frequency, EEV opening, inlet water flow rate (IWFR), and temperature—on system performance were quantified through the mean normalization method, along with a comparative analysis of the performance under EEV and ejector throttling modes. The results show that ejector throttling improves the coefficient of performance (COP) by 6.5 %. Within a specific range, reducing the EEV opening improves COP, particularly at lower inlet water temperatures and higher IWFRs, achieving a COP of 3.49 (30 Hz, 60 % EEV, 20 °C, 0.6 m³⸳h⁻¹). Compressor frequency, IWFR, and temperature are identified as the primary factors influencing heat transfer rate. The impact of compressor frequency and inlet water temperature on COP is more significant than that of IWFR and EEV opening. To meet hot water demand and maintain high system performance, the weighted influence of each parameter must be carefully evaluated during adjustments to ensure system stability and optimal performance. This study offers valuable insights for developing multi-parameter control strategies for CO₂ HP water heaters.

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来源期刊

International Journal of Refrigeration-revue Internationale Du Froid 工程技术-工程：机械

CiteScore

7.30

自引率

12.80%

发文量

363

审稿时长

3.7 months

期刊介绍： The International Journal of Refrigeration is published for the International Institute of Refrigeration (IIR) by Elsevier. It is essential reading for all those wishing to keep abreast of research and industrial news in refrigeration, air conditioning and associated fields. This is particularly important in these times of rapid introduction of alternative refrigerants and the emergence of new technology. The journal has published special issues on alternative refrigerants and novel topics in the field of boiling, condensation, heat pumps, food refrigeration, carbon dioxide, ammonia, hydrocarbons, magnetic refrigeration at room temperature, sorptive cooling, phase change materials and slurries, ejector technology, compressors, and solar cooling. As well as original research papers the International Journal of Refrigeration also includes review articles, papers presented at IIR conferences, short reports and letters describing preliminary results and experimental details, and letters to the Editor on recent areas of discussion and controversy. Other features include forthcoming events, conference reports and book reviews. Papers are published in either English or French with the IIR news section in both languages.