The performance of a transcritical CO 2 heat pump system applied for hot water supply was experimentally investigated under various refrigerant charging conditions to clarify the effects of the heat transfer area of an internal heat exchanger (IHX) on the system performance. Experiments were conducted in the condition of constant heating capacity and evaporator outlet superheat by adjusting the compressor frequency and the opening of electronic expansion valve. Experimental results show that, at the optimum refrigerant charge, the compression ratio decreases while the discharge and suction temperatures increase with an increase in the IHX heat transfer area. Adopting an IHX can increase the maximum heating COP (coefficient of performance), and an improvement of about 3.2%-5.1% is obtained by using an IHX with a dimensionless heat transfer area of 0.2.
|Number of pages||5|
|Journal||Xinan Jiaotong Daxue Xuebao/Journal of Southwest Jiaotong University|
|Publication status||Published - Aug 2012|
All Science Journal Classification (ASJC) codes