Refrigeration cycle

Abstract

It is an object of the invention to provide a refrigeration cycle which uses HFC-152a as refrigerant, and can be operated stably without hunting of the superheat degree. A charge amount of refrigerant is increased, and refrigerant at an inlet of an expansion device is placed in a state where the subcool degree is ensured to be at least 5 degrees such that the subcool degree does not become equal to zero by variation in pressure. This suppresses fluctuation in the superheat degree of refrigerant at an outlet of an evaporator to thereby stabilize the system. In this state, to enhance the efficiency of a compressor, the superheat degree can be increased by decreasing the set value of the expansion device.

1 . A refrigeration cycle comprising a compressor, a condenser, an expansion device, and an evaporator, and using HFC-152a as refrigerant circulating therethrough, 
 wherein the refrigerant at an inlet of the expansion device is necessarily placed in a state where a predetermined degree of subcool is ensured, whereby fluctuation in a degree of superheat of the refrigerant at an outlet of the evaporator is suppressed, for stabilization.    
   
   
       2 . The refrigeration cycle according to  claim 1 , wherein the degree of subcool is ensured to be at least 5 degrees.  
   
   
       3 . The refrigeration cycle according to  claim 1 , wherein a charge amount of the refrigerant is adjusted to ensure the degree of subcool.  
   
   
       4 . The refrigeration cycle according to  claim 1 , wherein the condenser is replaced by a subcool condenser to thereby ensure the degree of superheat.  
   
   
       5 . The refrigeration cycle according to  claim 1 , wherein the expansion device is replaced by a thermostatic expansion valve, and a set value of the thermostatic expansion valve is adjusted to provide the degree of subcool.