Effects of input parameters on pressure loss in the evaporator.

Pressure loss in the evaporator of a CO2 water to water heat pump was monitored while input conditions were adjusted. Water inlet temperature, flow rate, refrigerant amount and throttle valve opening were varied according to an experimental design provided by a software known as design-expert®. In this study, it was observed that the pressure loss in the evaporator varied from 0.1 MPa to a maximum of 0.25 MPa. A linear model was suggested which provided an approximate linear polynomial equation to predict the relationship between pressure loss and the input variables. It was observed that refrigerant amount had the highest effect on pressure loss followed by throttle valve opening. Both water flow rates effects were not significant enough to be considered important. Kinetic models were also used to predict the pressure loss and their results compared to actual experimental results.