Heating performance enhancement of a CO2 heat pump system recovering stack exhaust thermal energy in fuel cell vehicles

2007 ◽  
Vol 30 (7) ◽  
pp. 1215-1226 ◽  
Author(s):  
Sung Chul Kim ◽  
Min Soo Kim ◽  
In Chul Hwang ◽  
Tae Won Lim
Keyword(s):  
Fuel Cell ◽  
Heat Pump ◽  
Thermal Energy ◽  
Performance Enhancement ◽  
Fuel Cell Vehicles ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Performance

scholarly journals Theoretical Analysis of a Single-Stage Gas-fired Ejector Heat Pump Water Heater

2021 ◽  
pp. 1-28
Author(s):  
Jeremy Spitzenberger ◽  
Pengtao Wang ◽  
Laith Ismael ◽  
Hongbin Ma ◽  
Ahmad Abuheiba ◽  
...  
Keyword(s):  
Heat Pump ◽  
Thermal Energy ◽  
Ambient Air ◽  
Single Stage ◽  
Coefficient Of Performance ◽  
Water Heater ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Capacity ◽  
Condenser Temperature

Abstract Ejector driven systems have the ability to operate at high efficiencies, utilizing recycled thermal energy as a power source. For a typical ejector heat pump system, the increase of the condenser temperature reduces the coefficient of performance (COP). In addition, if the condenser temperature is higher than the critical temperature, the ejector may not function. In this situation, the condenser temperature must be reduced, and an additional heater will be utilized to heat the production water from the condenser temperature to the desired temperature. In this investigation, a single-stage gas-fired ejector heat pump (EHP) is investigated and thermodynamically modeled in order to optimize the system COP for the purpose of heating water by utilizing the thermal energy from the ambient air. The effects of the high-temperature evaporator (HTE) and low-temperature evaporator (LTE) temperatures on the ejector critical back pressure and the EHP system performance are examined for a HTE temperature range of 120-180 °C and LTE temperatures of 15.5, 17.5, and 19.5 °C. Results show that an optimized COP of the EHP system exists which depends on HTE and LTE temperatures, primary nozzle throat diameters. In addition, it is found that the EHP COP is independent of the ejector COP. From this investigation a maximum EHP COP of 1.31 is able to be achieved for a HTE temperature of 160 °C and a LTE temperature of 19.5 °C with a total heating capacity of 15.98 kW.

Experimental Investigation on Heating Performance of Newly Designed Air Source Heat Pump System for Electric Vehicles

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Kang Li ◽  
Jun Yu ◽  
Rong Yu ◽  
Lin Su ◽  
Yidong Fang ◽  
...  
Keyword(s):  
Heat Pump ◽  
Electric Vehicles ◽  
Flow Characteristics ◽  
Cold Climate ◽  
Positive Temperature ◽  
Pump System ◽  
Cooling Performance ◽  
Heat Pump System ◽  
Heating Performance ◽  
Driving Range

Abstract Utilizing the heat from air source with heat pump system in electric vehicles shows a significant advantage from thermoelectric heat source for heat supply in cold climate. It could improve the driving range of electric vehicles considerably in winter and replace the positive temperature coefficient (PTC) heater with an acceptable cost and reliability. In this work, a newly designed heat pump system was first introduced with less components and cost. Second, experiments were conducted to investigate its cooling performance, and subsequent heating performance from −10 to 10 °C. The typical heat transfer and flow characteristics of refrigerant were recorded, and the behavior of each component including compressor, evaporator, condenser, and outside heat exchanger were analyzed and interpreted. The results showed that the heating and cooling performance of the new heat pump system could almost remain the same with traditional air-conditioning system in automobile and surely satisfy with the heat requirement of electric vehicles. In the heating mode, the maximum heating capacity increases by 13% at 400 m3/h air volume from 300 m3/h at the ambient temperature −10 °C, while the outlet air temperature decreases by 4–6%. In addition, using a heat pump system showed an increase in the driving range of electric vehicles by 25–31% as compared to PTC heaters.

Improvement of A Chemical Heat Pump System to Utilize Wasted Thermal Energy

2020 ◽  
Vol 2020.57 (0) ◽  
pp. Q031
Author(s):  
Fumikazu IWABUCHI ◽  
Takehide OKAMOTO ◽  
Masakazu OKAZAKI ◽  
Hitoshi TSUCHIDA
Keyword(s):  
Heat Pump ◽  
Thermal Energy ◽  
Chemical Heat ◽  
Pump System ◽  
Heat Pump System ◽  
Chemical Heat Pump
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