Abstract: In order to improve high temperature heat pumps (HTHP), firstly it is presented that incomplete condensation of non-azeotropic working fluids is possible in condenser of HTHP, after theoretical analysis is carried out about heat transfer of non-azeotropic working fluids in condenser. Secondly, a experimental plan is designed to study the phenomenon, and many working conditions experiments (flow rate, temperature and frequency are changed) are done on a water-water heat pump unit. Finally, the incomplete condensation is found and some relationships are presented between the phenomenon and parameters, those are helpful to improve control strategy of HTHP.

Key words: High temperature heat pump, Incomplete condensation Experimental research, Non-azeotropic working fluids, Experiment, Grinding force, Modeling, Ultrasonic vibration