Refrigeration cycle apparatus

Abstract

A refrigeration cycle apparatus according to the present invention performs cooling by circulation of refrigerant. The refrigeration cycle apparatus includes an evaporator, a condenser, a pump, a compressor, and a controller. The evaporator is arranged in a first space. The condenser is arranged in a second space. The pump is configured to compress refrigerant from the condenser and output the refrigerant to the evaporator. The compressor is configured to compress refrigerant from the evaporator and output the refrigerant to the condenser. The controller is configured to control the pump and the compressor to cool the first space. The controller is configured to turn on the pump after turn-on of the compressor while a temperature of the first space is higher than a temperature of the second space.

1 . A refrigeration cycle apparatus which performs cooling by circulation of refrigerant, the refrigeration cycle apparatus comprising:
 an evaporator arranged in a first space;   a condenser arranged in a second space;   a pump configured to compress the refrigerant from the condenser and output the refrigerant to the evaporator;   a compressor configured to compress the refrigerant from the evaporator and output the refrigerant to the condenser; and   a controller configured to control the pump and the compressor to cool the first space,   the controller being configured to   turn on the pump after turn-on of the compressor while a temperature of the first space is higher than a temperature of the second space and,   control the pump to gradually increase an amount of the refrigerant discharged per unit time by the pump during an elapsed time interval from time when the pump is turned on.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , further comprising a bypass flow path configured to
 connect a first flow path between the evaporator and the compressor and a second flow path between the compressor and the condenser to each other, and   allow the refrigerant to pass when a pressure of the refrigerant in the first flow path is higher than a pressure of the refrigerant in the second flow path.   
     
     
         3 . The refrigeration cycle apparatus according to  claim 2 , wherein
 the bypass flow path comprises a check valve configured to allow the refrigerant to pass when the pressure of the refrigerant in the first flow path is higher than the pressure of the refrigerant in the second flow path.   
     
     
         4 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the controller is configured to turn on the pump when a degree of supercooling of the refrigerant suctioned by the pump is higher than a reference value.   
     
     
         5 . The refrigeration cycle apparatus according to  claim 4 , further comprising a temperature sensor arranged in a third flow path between the condenser and the pump, the temperature sensor being configured to measure a temperature of the refrigerant in the third flow path, wherein
 the controller is configured to calculate the degree of supercooling by using the temperature.   
     
     
         6 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the controller is configured to turn on the pump in succession to an operation of the compressor which continues for a reference period of time.   
     
     
         7 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the controller controls the compressor to decrease an amount of the refrigerant discharged per unit time by the compressor with an elapsed time interval from time when the pump is turned on.   
     
     
         8 . The refrigeration cycle apparatus according to  claim 1 , further comprising:
 a first blower apparatus configured to send air to the evaporator; and   a second blower apparatus configured to send air to the condenser.   
     
     
         9 . The refrigeration cycle apparatus according to  claim 1 , further comprising a first pressure regulation valve connected between the evaporator and the pump, wherein
 a degree of opening of the first pressure regulation valve is larger after turn-on than before turn-on of the compressor.   
     
     
         10 . The refrigeration cycle apparatus according to  claim 9 , wherein
 the degree of opening of the first pressure regulation valve is set to a first reference degree of opening at turn-on of the compressor.   
     
     
         11 . The refrigeration cycle apparatus according to  claim 9 , further comprising a second pressure regulation valve connected between the compressor and the condenser, wherein
 a degree of opening of the second pressure regulation valve is larger after turn-on than before turn-on of the compressor.   
     
     
         12 . The refrigeration cycle apparatus according to  claim 11 , wherein
 the degree of opening of the second pressure regulation valve is set to a second reference degree of opening at turn-on of the compressor.   
     
     
         13 . The refrigeration cycle apparatus according to  claim 1 , further comprising a pressure regulation valve connected between the compressor and the condenser, wherein
 a degree of opening of the pressure regulation valve is larger after turn-on than before turn-on of the compressor.   
     
     
         14 . The refrigeration cycle apparatus according to  claim 13 , wherein
 the degree of opening of the pressure regulation valve is set to a reference degree of opening at turn-on of the compressor.   
     
     
         15 . A refrigeration cycle apparatus, comprising:
 a refrigerant circuit comprising a compressor, a first heat exchanger, a pump, and a second heat exchanger; and   a controller configured to perform a vapor compression cycle during a first period S 1  from a first time tm 1  to a second time tm 2 , a vapor-compression-and-liquid-pump cycle during a second period S 2  from the second time tm 2  to a third time tm 3 , and a liquid pump cycle during a third period S 3  starting at the third time tm 3 , wherein   in the first period S 1 , the controller is configured to turn on the compressor at the first time tm 1  and the pump is off during the first period S 1 ,   in the second period S 2 , the controller is configured to turn on the pump at the second time tm 2 , gradually increase a frequency of the pump from the second time tm 2  to the third time tm 3 , and gradually decrease a frequency of the compressor from the second time tm 2  to the third time tm 3  until the compressor turns off at the third time tm 3 , and   in the third period S 3 , the controller is configured to maintain the frequency of the pump at a constant frequency and the compressor is off during the third period S 3 .   
     
     
         16 . The refrigeration cycle apparatus according to  claim 15 , wherein
 the refrigerant circuit further comprises an expansion valve, and   in the first period S 1 , the controller is further configured to gradually increase an opening degree of the expansion valve starting at the first time period tm 1  from a reference opening degree until the opening degree reaches a fully-open opening degree.