The direct contact condensation refrigeration cycle of high temperature gas discharged by compressor with super-cooled liquid is designed. Combined with the thermodynamic properties of natural refrigerant ammonia

the thermal performances of direct contact condensation refrigeration cycle are analyzed and compared with that of convention two stage compression refrigeration cycle and one stage compression refrigeration cycle. The following conclusions are obtained. With the increasing of saturated liquid temperature of main cycle

the coefficient of performance (COP) of direct contact condensation refrigeration cycle first increases

then decreases and has the maximum

the condenser heat load first decreases

then increases and has the minimum. The refrigerant mass flow rate in evaporator is gradually increasing. At the same evaporating and condensation temperature

when the super cooling degree of supercooled liquid is 20℃

compared with that of conventional two stage compression refrigeration cycle

the COP of direct contact condensation refrigeration cycle increases 4.92%

the condenser heat load reduces 6.65%

and the refrigerant mass flow rate in evaporator reduces 7.2%-7.9%. As well as when the super cooling degree of supercooled liquid is 5℃

compared with that of conventional one stage compression refrigeration cycle

the COP of direct contact condensation refrigeration cycle increases 6.52%

the condenser heat load reduces 3.32%

and refrigerant mass flow rate in the evaporator reduces 8.58%-8.91%. The results show that the ammonia direct contact condensation refrigeration cycle has obvious advantages over the conventional refrigeration cycle.