Piping structure with inner heat exchanger and refrigeration cycle device having the same

Abstract

A piping structure for a refrigerant cycle device includes an inner heat exchanger, and a bypass pipe through which refrigerant flows while bypassing the inner heat exchanger. The inner heat exchanger has a first flow passage in which high-pressure refrigerant before being decompressed flows and a second flow passage in which low-pressure refrigerant after being decompressed flows. The refrigerant cycle device includes plural low-pressure side heat exchangers, and the plural low-pressure side heat exchangers are located such that refrigerant from a part of the low-pressure side heat exchangers flows through the second flow passage of the inner heat exchanger, and refrigerant from the other part of the low-pressure side heat exchangers flows through the bypass pipe while bypassing the inner heat exchanger.

1 . A piping structure for a refrigerant cycle device that includes a compressor for compressing refrigerant, a high-pressure side heat exchanger for cooling high-pressure refrigerant discharged from the compressor, a decompression unit for decompressing the high-pressure refrigerant from the high-pressure side heat exchanger, and first and second low-pressure side heat exchangers for evaporating low-pressure refrigerant decompressed in the decompression unit, the piping structure comprising:
 an inner heat exchanger that has a first flow passage in which high-pressure refrigerant before being decompressed flows and a second flow passage in which low-pressure refrigerant after being decompressed by the decompression unit flows, the first and second flow passages being provided to exchange heat between the high-pressure refrigerant and the low-pressure refrigerant; and   a bypass pipe that defines a bypass flow passage through which the low-pressure refrigerant bypasses the inner heat exchanger,   wherein the first flow passage includes a first inlet-side connection part connected to a refrigerant outflow side of the high-pressure side heat exchanger on its one end side, and a first outlet-side connection part connected to a refrigerant inflow side of the decompression unit on its other end side,   wherein the second flow passage includes a second inlet-side connection part connected to a refrigerant outflow side of the first low-pressure side heat exchanger on its one end side and a second outlet-side connection part connected to a refrigerant suction side of the compressor on its other end side, and   wherein the bypass flow passage includes a bypass inlet-side connection part connected to a refrigerant outflow side of the second low-pressure side heat exchanger on its one end side and is joined to the second outlet-side connection part on its other end side.   
   
   
       2 . The piping structure according to  claim 1 ,
 wherein the first outlet-side connection part includes two outlet-side connection portions which are connected respectively to first and second decompression portions of the decompression unit.   
   
   
       3 . The piping structure according to  claim 1 ,
 wherein the inner heat exchanger is a double pipe part in which an inside pipe is passed through an outside pipe, and   wherein one of the first flow passage and the second flow passage is a flow passage between the outside pipe and the inside pipe, and another one thereof is a flow passage within the inside pipe.   
   
   
       4 . The piping structure according to  claim 3 ,
 wherein the double pipe part includes one or more bending portion, and   wherein a total bending angle of totalizing a bending angle of the bending portion is 160 degrees or more.   
   
   
       5 . The piping structure according to  claim 3 , wherein the double pipe part has a length of 600 mm or more. 
   
   
       6 . The piping structure according to  claim 3 , wherein the first flow passage is a flow passage between the outside pipe and the inside pipe, and wherein the second flow passage is a flow passage within the inside pipe. 
   
   
       7 . The piping structure according to  claim 3 , wherein the double pipe part has a groove provided on an outer surface of the inside pipe. 
   
   
       8 . A refrigeration cycle device comprising:
 a compressor for compressing refrigerant;   a high-pressure side heat exchanger for cooling high-pressure refrigerant discharged from the compressor;   a plurality of decompression units and low-pressure side heat exchangers, wherein the decompression units are located to decompress the high-pressure refrigerant to be low-pressure refrigerant, and the low-pressure side heat exchangers are located respectively downstream from the decompression units to evaporate the low-pressure refrigerant from the decompression units;   an inner heat exchanger that has a first flow passage in which high-pressure refrigerant before being decompressed flows and a second flow passage in which low-pressure refrigerant after being decompressed flows, the first and second flow passages being provided to exchange heat between the high-pressure refrigerant and the low-pressure refrigerant; and   a bypass pipe that defines a bypass flow passage through which the low-pressure refrigerant bypasses the inner heat exchanger,   wherein the first flow passage includes a first inlet-side connection part connected to a refrigerant outflow side of the high-pressure side heat exchanger on its one end side, and a first outlet-side connection part connected to a refrigerant inflow side of the decompression units on its other end side,   wherein the plurality of low-pressure side heat exchangers include at least a first low-pressure side heat exchanger and a second low-pressure side heat exchanger,   wherein the second flow passage includes a second inlet-side connection part connected to a refrigerant outflow side of the first low-pressure side heat exchanger on its one end side, and a second outlet-side connection part connected to a refrigerant suction side of the compressor on its other end side, and   wherein the bypass flow passage includes a bypass inlet-side connection part connected to a refrigerant outflow side of the second low-pressure side heat exchanger on its one end side, and is joined to the second outlet-side connection part on its other end side.   
   
   
       9 . The refrigeration cycle device according to  claim 8 ,
 wherein the plurality of low-pressure side heat exchangers further include a third low-pressure side heat exchanger, and   wherein a refrigerant outflow side of the third low-pressure side heat exchanger is connected to the bypass inlet-side connection part.   
   
   
       10 . The refrigeration cycle device according to  claim 8 ,
 wherein the plurality of low-pressure side heat exchangers further include a third low-pressure side heat exchanger, and   wherein a refrigerant outflow side of the third low-pressure side heat exchanger is connected to the second inlet-side connection part of the second flow passage of the inner heat exchanger.   
   
   
       11 . The refrigeration cycle device according to  claim 8 ,
 wherein the first outlet-side connection part includes two outlet-side connection portions, one of which is connected to a part of the plurality of the decompression units and the other one of which is connected to the other part of the plurality of the decompression units.   
   
   
       12 . The refrigeration cycle device according to  claim 8 ,
 wherein the inner heat exchanger is a double pipe part in which an inside pipe is passed through an outside pipe, and   wherein one of the first flow passage and the second flow passage is a flow passage between the outside pipe and the inside pipe, and another one thereof is a flow passage within the inside pipe.   
   
   
       13 . The refrigeration cycle device according to  claim 12 ,
 wherein the double pipe part includes one or more bending portion, and   wherein a total bending angle of totalizing a bending angle of the bending portion is 160 degrees or more.   
   
   
       14 . The refrigeration cycle device according to  claim 12 , wherein the double pipe part has a length of 600 mm or more. 
   
   
       15 . The refrigeration cycle device according to  claim 12 , wherein the first flow passage is a flow passage between the outside pipe and the inside pipe, and wherein the second flow passage is a flow passage within the inside pipe. 
   
   
       16 . The refrigeration cycle device according to  claim 8 , wherein at least one of the low-pressure side heat exchangers is used for cooling a compartment of a vehicle. 
   
   
       17 . The refrigeration cycle device according to  claim 8 , wherein refrigerant is HFC134a. 
   
   
       18 . A piping structure for a refrigerant cycle device, comprising:
 an inner heat exchanger that has a first flow passage in which high-pressure refrigerant before being decompressed flows and a second flow passage in which low-pressure refrigerant after being decompressed flows, the first and second flow passages being provided to exchange heat between the high-pressure refrigerant and the low-pressure refrigerant; and   a bypass pipe that defines a bypass flow passage through which a part of the low-pressure refrigerant flows while bypassing the inner heat exchanger.