Influence of the Source and Sink Temperatures on the Experimental Research of a CO2 Trans-Critical Refrigeration and Heat Pump System

The performance of the CO2 trans-critical system is affected significantly not only by optimal system pressure but also by instantaneous ambient temperatures. This paper presents the results of a study carried out to elucidate the influence of the source and sink temperatures on the experimental research of a CO2 trans-critical refrigeration and heat pump system which used a new dual expansion valve and a balance CO2 liquid receiver adjustment device. The unit had been fully tested along a multistate experimental study, at various evaporating temperatures and different gas cooler outlet pressures. The results showed that: the source and sink temperatures rose from 15°C to 25°C, trans-critical CO2 systems COPH average increase of 4.4% each 5°C, but COP decrease of 6.8%. The influence of the source temperature on the chilled water outlet temperature which is less than the sink temperature. The effect of the source or sink temperature on the cooling water outlet temperature to average every 5°C to change the range of from 0.7°C to 1.9°C.

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Performance testing of a heat pump system with auxiliary hot water under different ambient temperatures

Energy and Built Environment ◽

10.1016/j.enbenv.2021.02.002 ◽

2021 ◽

Author(s):

Xuejuan Li ◽

Yunfeng Wang ◽

Ming Li ◽

Mengxiao Hang ◽

Wenkui Zhao ◽

...

Keyword(s):

Heat Pump ◽

Performance Testing ◽

Hot Water ◽

Pump System ◽

Heat Pump System ◽

Ambient Temperatures

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Performance Research of Air-Cooled Heat Pump for Small Residential

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.516-517.1180 ◽

2012 ◽

Vol 516-517 ◽

pp. 1180-1183

Author(s):

Hui Fan Zheng ◽

Chun Li Yang ◽

Yan Hua Li ◽

Yao Hua Liang

Keyword(s):

Experimental Data ◽

Heat Pump ◽

Cooling Water ◽

Cooling Capacity ◽

Least Square ◽

Outdoor Environment ◽

Experimental Setup ◽

Outlet Temperature ◽

Pump System ◽

Environment Temperature

An experimental setup is designed and built to study the operation characteristics of the air-cooled heat pump system for small residential in this paper. Based on the experimental setup, the characteristics of the energy efficiency ratio(EER) and cooling capacity have been researched when the outlet temperature of cooling water and outdoor environment temperature change. The experimental data demonstrate that the cooling capacity and EER of the system increases with increasing outlet cooling water temperatures and decreases with increasing outdoor environment temperatures. In addition, the correlation of the system EER is calculated by using the least square method based on the experimental data.

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Experimental research on LiBr refrigeration – Heat pump system applied in CCHP system

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2011.02.004 ◽

2011 ◽

Vol 31 (17-18) ◽

pp. 3706-3712 ◽

Cited By ~ 17

Author(s):

Cuizhen Zhang ◽

Mo Yang ◽

Mei Lu ◽

Yanguang Shan ◽

Jiaxian Zhu

Keyword(s):

Heat Pump ◽

Experimental Research ◽

Pump System ◽

Heat Pump System

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Experimental research and performance study of a coaxial hybrid-power gas engine heat pump system based on LiFePO4 battery

Energy and Buildings ◽

10.1016/j.enbuild.2015.12.034 ◽

2016 ◽

Vol 113 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Wenxiu Ji ◽

Liang Cai ◽

Qingkun Meng ◽

Jie Yan ◽

Xiaosong Zhang

Keyword(s):

Heat Pump ◽

Experimental Research ◽

Performance Study ◽

Pump System ◽

Heat Pump System ◽

Gas Engine ◽

Hybrid Power ◽

And Performance ◽

Lifepo4 Battery

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The Study of Cooling Water Waste Heat Recovery in Chemical Plant by Heat Pump System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.121-122.986 ◽

2010 ◽

Vol 121-122 ◽

pp. 986-991

Author(s):

Jing Gang Wang ◽

Xiao Xia Gao ◽

Bo Liang ◽

Hua Hui Zhou

Keyword(s):

Heat Pump ◽

Waste Heat ◽

Lithium Bromide ◽

Cooling Water ◽

Water Source ◽

Chemical Plant ◽

Pump System ◽

Absorption Heat Pump ◽

Heat Pump System ◽

Water Waste

A large number of cooling water exists in chemical plant, use water source heat pump and lithium bromide absorption heat pump system to achieve water cooling instead of cooling tower, at the same time, extract heat for building cooling and heating. Respectively introduced the summer cooling system and winter heating system, and a feasibility analysis was carried out. The conclusion is get: water source heat pump system and lithium bromide absorption heat pump system for cooling water waste heat recovery is certain feasibility; the environment optimization can be achieved in chemical plant, at the same time, energy conservation and emission reduction is realized.

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Feasibility Analysis and Performance Evaluation and Optimization of a DXSAHP Water Heater Based on the Thermal Capacity of the System: A Case Study

Energies ◽

10.3390/en12203883 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3883

Author(s):

Jorge E. De León-Ruiz ◽

Ignacio Carvajal-Mariscal ◽

Antonin Ponsich

Keyword(s):

Heat Transfer ◽

Flat Plate ◽

Heat Pump ◽

Thermal Capacity ◽

Hot Water ◽

Outlet Temperature ◽

Solar Collectors ◽

Pump System ◽

Heat Pump System

The present work conducts an evaluation of the feasibility and the overall performance and consequent optimization of a direct expansion solar assisted heat pump (DXSAHP) employed for domestic water heating. For the study conducted R134a, R404A, R407C and R410A working fluids were evaluated as well as the use of four, six and eight flat-plate solar collectors and a worktime ranging from 1 to 6 h. The case study is based in Mexico City with a 300 L container and a hot water outlet temperature of 51 °C. The paper introduces a new evaluation criterion based on the thermal capacity and all the evaluations conducted throughout this research revolve around this performance metric. The results show that, the system would require at least 4 h of operation to achieve the outlet temperature. Additionally, it was found that the R410A refrigerant has the best heat transfer properties; with an average condensation heat rate of 6.31 kW, followed by the R407C with 5.72 kW, the R404A with 5.42 kW and the R134a with 5.18 kW. Diversely, the R134a refrigerant requires 0.402 kW of compression work, 62% less than the R410A, which requires 1.06 kW. Consequently, R134a delivers the highest COP, which ranges from 7 to 14, followed by the R407C and R404A refrigerants, which present a similar behaviour between them, with COP ranging from 5 to 9 and 4 to 8, respectively, and finally the R410A, achieving the lowest COP, ranging from 3.5 to 6.5. Moreover, it was found that the R134a presents a higher dispersion regarding the energy exchange rate, which reveals that it is the fluid most susceptible to external factors, such as the weather. Contrarily, the remaining refrigerants present a more consistent performance. Finally, the optimization revealed that the R407C refrigerant is the most suitable given that it requires 20% less compression work than the R404A. This provides the heat pump system with a steadier behaviour, a COP ranging from 7 to 8, 30% higher than R410A, a worktime decrease of 1.5 h and heat transfer area of 5.5 flat-plate solar collectors, equivalent to a 31% reduction, both compared to R134a.

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Operating Modes of the Solar Assisted Drainwater System for Ground Source Heat Pump

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.171-172.67 ◽

2010 ◽

Vol 171-172 ◽

pp. 67-72

Author(s):

Yong Lan Yin ◽

Qing Gao ◽

Bai Fa Zhu ◽

Ming Li

Keyword(s):

Electric Power ◽

Heat Pump ◽

Distribution Ratio ◽

Water Distribution ◽

Operating Conditions ◽

Outlet Temperature ◽

Pump System ◽

Heat Pump System ◽

Operating Modes ◽

And Performance

To extend the area in applications of solar heat pump and drainwater heat recovery, the gravity film exchanger was employed to establish the solar assisted drainwater heat pump system. In this paper, two gravity film exchangers were assembled in the hybrid heat pump system to discuss the effect of water distribution ratio in two exchangers on the electric power complement and outlet water temperature of the condenser. The technology of Matlab/Simulink was used in modeling and simulations of the system by the performance curves and performance parameters of the corresponding system components. In the designing processes, the dynamic characteristics can be predicted, and the optimal operating conditions can also be concluded that appropriate water distribution ratio should be selected respectively for higher outlet temperature of the condenser or lower electric power complement.

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