Refrigeration cycle apparatus

Abstract

A refrigeration cycle apparatus includes a refrigerant circuit and a controller for controlling the refrigerant circuit. The refrigerant circuit includes a compressor, a condenser, a pressure-reducing device and an evaporator. Refrigerant circulating through the refrigerant circuit contains propane or propylene. The controller sets a degree of superheat of refrigerant at an entrance port of the compressor to be a value greater than or equal to 10 degrees.

1 . A refrigeration cycle apparatus comprising:
 a refrigerant circuit including
 a compressor, 
 a condenser, 
 a pressure-reducing device, and 
 an evaporator; and 
   a controller configured to control the refrigerant circuit, wherein   refrigerant circulating through the refrigerant circuit is refrigerant containing propane or propylene,   the evaporator has a heat transfer pipe in which refrigerant flows,   a refrigerant port temperature sensor for detecting temperature of refrigerant is provided at an entrance port of the evaporator,   an inner temperature sensor for detecting temperature of refrigerant is provided in the heat transfer pipe of the evaporator,   in the evaporator, a length of the heat transfer pipe between the entrance port of the evaporator and the inner temperature sensor is greater than or equal to 66% of a length of the heat transfer pipe between the entrance port of the evaporator and an exit port of the evaporator, and less than or equal to 88% of the length of the heat transfer pipe between the entrance port and the exit port,   the controller sets a degree of superheat of refrigerant at an entrance port of the compressor to be a value greater than or equal to 10 degrees, and   the controller controls the refrigerant circuit so that the temperature of refrigerant detected by the inner temperature sensor is higher than the temperature of refrigerant detected by the refrigerant port temperature sensor.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , wherein the controller set the degree of superheat of refrigerant at the entrance port of the compressor to be a value greater than or equal to 15.4 degrees and less than or equal to 20.6 degrees. 
     
     
         3 . The refrigeration cycle apparatus according to  claim 1 , wherein the controller starts an operation of the refrigerant circuit in a state where an opening degree of the pressure-reducing device is smaller than an opening degree of the pressure-reducing device in a full open state. 
     
     
         4 . (canceled) 
     
     
         5 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the condenser has a heat transfer pipe in which refrigerant flows,   an inner diameter of the heat transfer pipe of each of the condenser and the evaporator is less than or equal to 5 mm.   
     
     
         6 . The refrigeration cycle apparatus according of  claim 1 , wherein
 each of the condenser and the evaporator is connected to the compressor via a gas-side refrigerant path,   each of the condenser and the evaporator is connected to the pressure-reducing device via a liquid-side refrigerant path,   an inner diameter of the gas-side refrigerant path is greater than or equal to 7.92 mm and less than or equal to 14.28 mm,   an inner diameter of the liquid-side refrigerant path is greater than or equal to 4.75 mm and less than or equal to 11.1 mm, and   a length of each of the gas-side refrigerant path and the liquid-side refrigerant path is less than or equal to 5 m.