曹锋

Date:

2025-04-30

Title of Paper:

Study on performance of a heat pump water heater using suction stream liquid injection

Journal:

Applied Thermal Engineering

Summary:

Liquid refrigerant injection into a suction line is an effective and practical method to reduce the discharge
temperature when a scroll compressor operates at high compression ratios. In the present study, correlations
among the compressor suction temperature, discharge temperature, heat pump heating capacity,
power consumption, coefficient of performance (COP) and the quantity of suction liquid injection are
established. The paper presents experimental analysis and a comparison with calculated results of the
heat pump water heater (HPWH) performance with suction liquid injection in different conditions. It
is found that the suction liquid injection explicitly lowers the discharge temperature of the compressor
and the heating capacity of the unit, but the power consumption increases with COP decreasing. In addition,
the highest injection ratio must be controlled fewer than 5%. The suction liquid injection has a better
effect on the HPWH at the temperature ranging from 15 C to 20 C. Within this temperature range, the
5% ratio suction liquid injection decreases the discharge temperature of the compressor by 10 C, while
the heating capacity of the HPWH decreases by less than 5%, power consumption increases by less than
1.5%, and COP decreases by less than 7%.

Co-author:

Feng Cao , Jiyou Fei, Ziwen Xing

Translation or Not:

No

Date of Publication:

2009-03-05