scholarly journals A water-to-water heat pump using hydrocarbon and hydrofluorocarbon zeotropic mixtures with and without an internal heat exchanger

2000 ◽  
Author(s):  
W Vance II Payne ◽  
Eric A Silk ◽  
Piotr A Domanski
2021 ◽  
Vol 2116 (1) ◽  
pp. 012098
Author(s):  
F Illán-Gómez ◽  
J R García-Cascales ◽  
F J Sánchez-Velasco ◽  
V Sena-Cuevas ◽  
R Otón-Martínez

Abstract This paper presents a numerical study on the influence of internal heat exchanger (IHX) exchanging surface in the performance of a transcritical CO2 heat pump water heater at different operating conditions. Five different IHX geometries and four different evaporation temperatures have been studied with water temperature ranging from 10 °C to 60 °C at the gas cooler inlet. The results show a strong influence of IHX characteristics on system’s performance.


2019 ◽  
Vol 158 ◽  
pp. 4147-4153 ◽  
Author(s):  
Xinxin Han ◽  
Huiming Zou ◽  
Hongbo Xu ◽  
Changqing Tian ◽  
Wei Kang

Author(s):  
Hee Jeong Kang ◽  
Zhen Huan Wang ◽  
Jun Son ◽  
Sun-Joon Byun ◽  
Young-Chul Kwon

Developing high performance HVAC system using natural refrigerants including carbon dioxide (CO2) has been important in respect of environmental preservation and associated technologies. Thus studies to optimize the HVAC (heating ventilation air conditioner) system using natural refrigerants through clarifying the cycle performance characteristics are necessary. The CO2 heat pump system using air and water sources was consisted to examine its performance characteristics, and by varying conditions of several factors that affect or characterize the system performance like the amount of refrigerant charge, EEV (electronic expansion valve) opening, and internal heat exchanger under cooling mode. The performance characteristics of CO2 heat pump system were tested by using an air enthalpy calorimeter. In the case of the CO2 heat pump system without internal heat exchanger, the opening of #3 EEV and #4 EEV was 60% and refrigerant charge amount was 5,600g. However, in the case of that with internal heat exchanger, the best performance was obtained when the opening of #2 EEV is 20%. From the present studies, it was observed that the performance variation and operational characteristics of the CO2 heat pump system were affected by design factors like refrigerant charge amount, EEV opening, and internal heat exchanger and thereby, the configuration on an optimal operation conditions of the system was enabled.


2017 ◽  
Vol 24 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Zhili Sun ◽  
Shengchun Liu ◽  
Youcai Liang ◽  
Mengjie Song ◽  
Jianghe Guo

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