Condensation and evaporation heat transfer characteristics of pure and binary-mixture HFO refrigerants inside a plate heat exchanger
Keishi Kariya1, Akio Miyara1.
1Saga university, Saga, Japan
In the present study, condensation and evaporation local heat transfer coefficients of the pure and binary-mixture HFO refrigerants inside a brazed plate heat exchanger were investigated by using a test section which is combined with two grooved stainless steel plates. In the test section, wall temperature distribution was measured. The test section consists of eight plates; two of them were processed herringbone for refrigerant flow channel other two flat plates are set for cooling plate for refrigerant, and another consist on cooling water flow channel. In order to measure local heat transfer and temperature distribution, five thermocouples were set on flow direction for each wall temperature measurement of the refrigerant side and heat source water side. Local heat transfer coefficient were calculated from local wall temperature of refrigerant side, saturation temperature and local heat flux obtained by temperature gradient between heat transfer surface of refrigerant side and heat source side.