The research on heat transfer pinch point (between refrigerant and heat-transfer fluid) was carried out in a condenser with airconditioning operation to investigate the change in temperature difference from condenser inlet to outlet and to avoid the occurrence of pinch pointFirstly

a model of refrigerants condensation was built

and the condition of pinch point occurrence was determinedThe condensation parameters of 15 commonly used refrigerants were decided for standard airconditioning operationSecondly

the equations of state of refrigerants were used to compute and obtain some relationships between temperature and enthalpy and the probability of pinch point occurrence of 15 refrigerants was obtainedLastly

the ranges of temperature difference from condenser inlet to outlet were recommended to avoid the occurrence of pinch point for 10 refrigerantsSuch information might be helpful to choosing refrigerants and adjusting the operation of condenser in airconditioner units.