Heat transfer characteristics of an expanded graphite/paraffin PCM-heat exchanger used in an instantaneous heat pump water heater

One CO2 heat pump water heater test apparatus was built in the paper. The heat transfer characteristics of CO2 in gas cooler with water in double-pipe heat exchanger was experimentally investigated. The effects of variation of cooling water flux on heat transfer characteristics, outlet temperature of water, COP and CO2 temperature were analyzed. The influences of cooling water flux to heat exchange about CO2 side, water side, and the CO2 and water temperature matching was analyzed. Experimental results showed that the supercritical CO2 heat pump water heater can acquire higher temperature of outlet water up to 80°C than those conventional Freon heat pump water heater, and the COP of the system increased with the increase of water flow rate through gas cooler. All the work was valuable for the application of CO2 heat pump water heater.

Download Full-text

Investigation on heat transfer characteristics of outside heat exchanger in an air conditioning heat pump system for electric vehicles

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2021.121040 ◽

2021 ◽

Vol 170 ◽

pp. 121040

Author(s):

Jun Yu ◽

Lin Su ◽

Kang Li ◽

Mingkang Liu ◽

Hua Zhang

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Heat Pump ◽

Electric Vehicles ◽

Air Conditioning ◽

Heat Transfer Characteristics ◽

Pump System ◽

Heat Pump System ◽

Transfer Characteristics

Download Full-text

Design and Experimental Research of Gas Cooler for CO2 Heat Pump Water Heater

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.156-157.1161 ◽

2010 ◽

Vol 156-157 ◽

pp. 1161-1164

Author(s):

Ye Feng Liu ◽

Guo Dong Gong ◽

Xi Chen

Keyword(s):

Heat Transfer ◽

Heat Pump ◽

Hot Water ◽

Global Environment ◽

Heat Transfer Characteristics ◽

Water Heater ◽

Working Pressure ◽

Heat Pump Water Heater ◽

Double Pipe ◽

Pipe Heat

The advantages of CO2 Heat Pump water heater include: CO2 is one of natural refrigerants and does not affect the global environment as many other HFCs refrigerants; CO2 heat pump water heater can produce hot water up to 90 ,which is higher than HFCs heat pump water heater(about 55 ).So the application of CO2 Heat Pump water heater is potential. But the Working pressure of CO2 Heat Pump Water Heater is about 9~12Mpa and is 3-5times of HFCs heat pump water heater’. Gas cooler is one of important part for CO2 heat pump water heater, and it must meet the needs of not only pressurization but also heat transfer. So it is important to design gas cooler correctly. In the paper, one system of CO2 Trans-critical Cycle Heat Pump Water Heater is designed, and double-pipe gas cooler is designed The heat transfer characteristics of CO2 in gas cooler with water in double-pipe heat exchanger was experimentally investigated. Experimental results showed that the gas cooler can meet the need of trans-critical CO2 cycle heat pump water heater. All the work is valuable for the application of CO2 heat pump water heater.

Download Full-text