Refrigeration cycle apparatus

Abstract

A refrigeration cycle apparatus that can achieve both a reduction in a refrigerant charge amount and high operational efficiency is provided. The refrigeration cycle apparatus that performs a heating operation and a cooling operation, the refrigeration cycle apparatus including: a compressor; a radiator; an internal heat exchanger; and an evaporator, in which the internal heat exchanger includes: a first heat transfer tube through which a refrigerant that flows from the evaporator to the compressor passes; and a second heat transfer tube through which the refrigerant that flows from the radiator to the evaporator passes, causes heat exchange between the refrigerant passing through the first heat transfer tube and the refrigerant passing through the second heat transfer tube, and the refrigerant does not flow through the second heat transfer tube in the cooling operation.

1 . A refrigeration cycle apparatus that performs a heating operation and a cooling operation, the refrigeration cycle apparatus comprising:
 a compressor;   a radiator;   an internal heat exchanger; and   an evaporator,   wherein the internal heat exchanger includes:
 a first heat transfer tube through which a refrigerant that flows from the evaporator to the compressor passes; and 
 a second heat transfer tube through which the refrigerant that flows from the radiator to the evaporator passes, 
   wherein the internal heat exchanger is configured to cause heat exchange between the refrigerant passing through the first heat transfer tube and the refrigerant passing through the second heat transfer tube, and   wherein the refrigerant does not flow through the second heat transfer tube in the cooling operation.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , further comprising:
 a liquid refrigerant flow path that connects the evaporator to the radiator;   an injection flow path that branches from the liquid refrigerant flow path and joins the compressor;   a second decompressor that is configured to decompress the refrigerant passing through the injection flow path; and   an economizer heat exchanger that is configured to cause mutual heat exchange between the refrigerant decompressed by the second decompressor and the refrigerant flowing from the radiator to the evaporator.   
     
     
         3 . The refrigeration cycle apparatus according to  claim 2 , wherein the economizer heat exchanger is configured to not allow the refrigerant to flow in the cooling operation. 
     
     
         4 . The refrigeration cycle apparatus according to  claim 3 , wherein the internal heat exchanger and the economizer heat exchanger are configured to allow the refrigerant to flow in the heating operation. 
     
     
         5 . The refrigeration cycle apparatus according to  claim 2 , further comprising a first valve that is configured to regulate the flow of the refrigerant from the liquid refrigerant flow path to the economizer heat exchanger. 
     
     
         6 . The refrigeration cycle apparatus according to  claim 5 , wherein the first valve is a valve that is switchable between an open state and a closed state. 
     
     
         7 . The refrigeration cycle apparatus according to  claim 6 , wherein the first valve is in the closed state in the cooling operation. 
     
     
         8 . The refrigeration cycle apparatus according to  claim 2 , further comprising a second valve that is configured to regulate inflow of the refrigerant flowing through the injection flow path into the compressor. 
     
     
         9 . The refrigeration cycle apparatus according to  claim 8 , wherein the second valve is a valve that is switchable between an open state and a closed state. 
     
     
         10 . The refrigeration cycle apparatus according to  claim 8 , wherein the second valve is in an open state in the cooling operation. 
     
     
         11 . The refrigeration cycle apparatus according to  claim 8 , further comprising a first branch flow path and a second branch flow path that branch from the liquid refrigerant flow path,
 wherein a first end of the second heat transfer tube is connected to an end of the first branch flow path opposite to the liquid refrigerant flow path, and   wherein a second end of the second heat transfer tube is connected to an end of the second branch flow path opposite to the liquid refrigerant flow path.   
     
     
         12 . The refrigeration cycle apparatus according to  claim 11 , further comprising a third valve that is configured to regulate the flow of the refrigerant from the liquid refrigerant flow path to the second heat transfer tube in the second branch flow path. 
     
     
         13 . The refrigeration cycle apparatus according to  claim 12 , wherein the third valve is a check valve. 
     
     
         14 . The refrigeration cycle apparatus according to  claim 12 , further comprising a fourth valve that is a check valve that is configured to regulate the flow of the refrigerant from a first branch portion where the first branch flow path branches from the liquid refrigerant flow path to a second branch portion where the second branch flow path branches from the liquid refrigerant flow path. 
     
     
         15 . The refrigeration cycle apparatus according to  claim 14 , wherein the economizer heat exchanger is configured to cause mutual heat exchange between the refrigerant flowing through the injection flow path and the refrigerant flowing through the first branch flow path. 
     
     
         16 . The refrigeration cycle apparatus according to  claim 14 , further comprising:
 a first decompressor that is configured to decompress the refrigerant between the second branch portion and the third valve in the second branch flow path;   a third branch flow path that branches from the second branch flow path between the first decompressor and the third valve, and is connected to a portion of the liquid refrigerant flow path on an opposite side of the fourth valve with the second branch portion interposed;   a fifth valve that is configured to regulate the flow of the refrigerant from a connection part of the third branch flow path to the second branch portion in the liquid refrigerant flow path; and   a sixth valve that is configured to regulate the flow of the refrigerant from the second branch flow path to the liquid refrigerant flow path in the third branch flow path.   
     
     
         17 . The refrigeration cycle apparatus according to  claim 1 , wherein the refrigerant is flammable. 
     
     
         18 . The refrigeration cycle apparatus according to  claim 1 , wherein the refrigerant includes R1234yf, R1234ze, R32, or R290.