COMPACT BRAZED PLATE HEAT EXCHANGERS FOR CO2 HEAT PUMP WATER HEATERS

2010 ◽  
Vol 18 (04) ◽  
pp. 289-295
Author(s):  
DANIEL LEIGHTON ◽  
YUNHO HWANG ◽  
REINHARD RADERMACHER
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Ambient Temperature ◽  
Heat Pump ◽  
Flow Rate ◽  
Operating Conditions ◽  
Test Facility ◽  
Water Heater ◽  
Heat Pump Water Heater ◽  
Plate Type

The plate-type heat exchanger is found to be well suited for the application of a transcritical CO2 heat pump water heater. A CO2 heat pump water heater test facility was used to evaluate the performance of a high-pressure plate-type heat exchanger. The performance characteristics of heat exchanger effectiveness, capacity, and pressure drop were evaluated over a range of CO2 gas cooler inlet pressures and temperatures. For the ambient temperature range of 10°C to 30°C, the maximum observed capacities ranged from 4.46 kW to 5.34 kW, with the capacity increasing approximately linearly with increasing ambient temperature. Over this maximum capacity range, the effectiveness of the gas cooler ranged from 98.7% to 99.4%, with the effectiveness increasing with decreasing ambient temperature. The largest gas cooler pressure drop was approximately 130 kPa at a volumetric flow rate of 128 cm3/s, which is the flow rate resulting from the optimum system operating conditions at an ambient temperature of 30°C.

scholarly journals Numerical study on the influence of internal heat exchanger in transcritical CO2 heat pumps under optimal pressure conditions

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
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Strong Influence ◽  
Numerical Study ◽  
Internal Heat ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Water Heater ◽  
Internal Heat Exchanger ◽  
Heat Pump Water Heater

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.

scholarly journals Analytical and Experimental Investigation of a Plate Fin Heat Exchanger at Cryogenics Temperature

2021 ◽  
Vol 39 (4) ◽  
pp. 1225-1235
Author(s):  
Ajay K. Gupta ◽  
Manoj Kumar ◽  
Ranjit K. Sahoo ◽  
Sunil K. Sarangi
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Cryogenic Temperature ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Compact Size

Plate-fin heat exchangers provide a broad range of applications in many cryogenic industries for liquefaction and separation of gasses because of their excellent technical advantages such as high effectiveness, compact size, etc. Correlations are available for the design of a plate-fin heat exchanger, but experimental investigations are few at cryogenic temperature. In the present study, a cryogenic heat exchanger test setup has been designed and fabricated to investigate the performance of plate-fin heat exchanger at cryogenic temperature. Major parameters (Colburn factor, Friction factor, etc.) that affect the performance of plate-fin heat exchangers are provided concisely. The effect of mass flow rate and inlet temperature on the effectiveness and pressure drop of the heat exchanger are investigated. It is observed that with an increase in mass flow rate effectiveness and pressure drop increases. The present setup emphasis the systematic procedure to perform the experiment based on cryogenic operating conditions and represent its uncertainties level.

scholarly journals Experimental Study of a Novel Direct-Expansion Variable Frequency Finned Solar/Air-Assisted Heat Pump Water Heater

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jing Qin ◽  
Jie Ji ◽  
Wenzhu Huang ◽  
Hong Qin ◽  
Mawufemo Modjinou ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Ambient Temperature ◽  
Heat Pump ◽  
Operating Mode ◽  
Heating Time ◽  
Solar Irradiation ◽  
Variable Frequency ◽  
Direct Expansion ◽  
Water Heater ◽  
Heat Pump Water Heater

A novel direct expansion variable frequency finned solar/air-assisted heat pump water heater was fabricated and tested in the enthalpy difference lab with a solar simulator. A solar/air source evaporator-collector with an automatic lifting glass cover plate was installed on the system. The system could be operated in three modes, namely, air, solar, and dual modes. The effects of the ambient temperature, solar irradiation, compressor frequency, and operating mode on the performance of this system were studied in this paper. The experimental results show that the ambient temperature, solar irradiation, and operating mode almost have no effect on the energy consumption of the compressor. When the ambient temperature and the solar irradiation were increased, the COP was found to increase with decreasing heating time. Also, when the compressor frequency was increased, an increase in the energy consumption of the compressor and the heat gain of the evaporator were noted with a decrease in the heating time.

scholarly journals Experimental Study of the Gas Engine Driven Heat Pump with Engine Heat Recovery

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Zhang ◽  
Tao Wang ◽  
Sulu Zheng ◽  
Xueyuan Peng ◽  
Xiaolin Wang
Keyword(s):  
Ambient Temperature ◽  
Water Flow ◽  
Heat Pump ◽  
Flow Rate ◽  
Heat Recovery ◽  
Engine Speed ◽  
Water Flow Rate ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Gas Engine

Gas engine driven heat pumps (GEHPs) represent one of practical solutions to effectively utilize fossil fuel energy and reduce environmental pollution. In this paper, the performance characteristics of the GEHP were investigated experimentally with engine heat recovery. A GEHP test facility was set up for this purpose. The effects of several important factors including engine speed, ambient temperature, condenser water flow rate, and condenser water inlet temperature on the system performance were studied over a wide range of operating conditions. The results showed that the engine waste heat accounted for about 40–50% of the total heat capacity over the studied operating conditions. It also showed that engine speed and ambient temperature had significant effects on the GEHP performance. The coefficient of performance (COP) and the primary energy ratio (PER) decreased by 14% and 12%, respectively, as engine speed increased from 1400 rpm to 2000 rpm. On the other hand, the COP and PER of the system increased by 22% and 16%, respectively, with the ambient temperature increasing from 3 to 12°C. Furthermore, it was demonstrated that the condenser water flow rate and condenser water inlet temperature had little influence on the COP of the heat pump and the PER of the GEHP system.

scholarly journals Performance evaluation of a plate type condenser for heat pump water heater

2015 ◽  
Vol 2 (1) ◽  
pp. 14-00338-14-00338
Author(s):  
Hitoshi ASANO ◽  
Kazuya HONDA ◽  
Nobuhiro TAKEDA ◽  
Masaki KONDO ◽  
Kazuhiro NISHIMURA
Keyword(s):  
Performance Evaluation ◽  
Heat Pump ◽  
Water Heater ◽  
Heat Pump Water Heater ◽  
Plate Type
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