Composite heat exchanger

Abstract

A composite heat exchanger is used in a vapor compression refrigeration cycle. The vapor compression refrigeration cycle includes: a compressor; a decompressor configured to decompress a high-pressure refrigerant discharged from the compressor; and an evaporator configured to evaporate a low-pressure refrigerant decompressed at the decompressor by exchanging heat between the low-pressure refrigerant and a first heat medium. The composite heat exchanger includes a condenser unit, a liquid storage unit temporarily storing a high-pressure liquid refrigerant, a sub-cooler unit sub-cooling the high-pressure liquid refrigerant through heat exchange with a second heat medium, and an internal heat exchanger unit exchanging heat between the high-pressure liquid refrigerant passed through the sub-cooler unit and the low-pressure refrigerant. The condenser unit, the sub-cooler unit and the internal heat exchanger unit are joined together by a predetermined binding element and thereby form an integral structure.

What is claimed is: 
     
         1 . A composite heat exchanger configured to be used in a vapor compression refrigeration cycle that includes: a compressor; a decompressor configured to decompress a high-pressure refrigerant discharged from the compressor; and an evaporator configured to evaporate a low-pressure refrigerant decompressed at the decompressor by exchanging heat between the low-pressure refrigerant and a first heat medium, the composite heat exchanger comprising:
 a condenser unit configured to condense the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant and a second heat medium;   a liquid storage unit configured to temporarily store a high-pressure liquid refrigerant contained in the high-pressure refrigerant passed through the condenser unit;   a sub-cooler unit configured to sub-cool the high-pressure liquid refrigerant stored in and outputted from the liquid storage unit by exchanging heat between the high-pressure liquid refrigerant and the second heat medium; and   an internal heat exchanger unit configured to exchange heat between the high-pressure liquid refrigerant passed through the sub-cooler unit and the low-pressure refrigerant discharged from the evaporator, wherein:   the condenser unit, the sub-cooler unit and the internal heat exchanger unit are joined together by a predetermined binding element and thereby form an integral structure;   in the integral structure, the sub-cooler unit is placed between the condenser unit and the internal heat exchanger unit; and   the liquid storage unit is placed adjacent to a portion of the integral structure which forms the internal heat exchanger unit.   
     
     
         2 . The composite heat exchanger according to  claim 1 , wherein the integral structure is configured to limit heat transfer between the condenser unit and the internal heat exchanger unit. 
     
     
         3 . The composite heat exchanger according to  claim 1 , wherein:
 in the integral structure, a high-pressure inlet passage, which is configured to conduct the high-pressure refrigerant passed through the condenser unit to the liquid storage unit, extends through the sub-cooler unit and the internal heat exchanger unit, and a high-pressure outlet passage, which is configured to conduct the high-pressure liquid refrigerant stored in the liquid storage unit to the sub-cooler unit, extends through the internal heat exchanger unit; and   in the integral structure, a portion of the internal heat exchanger unit, which is adjacent to the liquid storage unit, is configured to conduct the high-pressure refrigerant flowing in the high-pressure inlet passage to the liquid storage unit and also conduct the high-pressure liquid refrigerant stored in the liquid storage unit to the high-pressure outlet passage.   
     
     
         4 . The composite heat exchanger according to  claim 1 , wherein the internal heat exchanger unit is coupled to one heat exchanger unit among the condenser unit and the sub-cooler unit through at least one coupler component in a state where the internal heat exchanger unit is spaced from the one heat exchanger unit. 
     
     
         5 . The composite heat exchanger according to  claim 4 , wherein:
 the internal heat exchanger unit is coupled to the sub-cooler unit in a state where the internal heat exchanger unit is spaced from the sub-cooler unit.   
     
     
         6 . The composite heat exchanger according to  claim 1 , wherein the liquid storage unit is directly joined to a portion of the integral structure which forms the internal heat exchanger unit. 
     
     
         7 . The composite heat exchanger according to  claim 1 , wherein the internal heat exchanger unit and at least one of the condenser unit and the sub-cooler unit are formed by a plurality of plate members which are stacked and joined together. 
     
     
         8 . The composite heat exchanger according to  claim 7 , wherein the plurality of plate members include a plurality of multi-hole members each of which has:
 at least two high-temperature side passage holes which are configured to conduct the high-pressure refrigerant that includes the high-pressure liquid refrigerant; and   at least one low-temperature side passage hole which is configured to conduct the second heat medium or the low-pressure refrigerant.   
     
     
         9 . The composite heat exchanger according to  claim 8 , wherein in each of the plurality of multi-hole members, one of the at least two high-temperature side passage holes is formed as a passage hole that is configured to conduct the high-pressure liquid refrigerant and is placed adjacent to a corresponding one of the at least one low-temperature side passage hole. 
     
     
         10 . The composite heat exchanger according to  claim 8 , wherein in each of the plurality of multi-hole members, the at least two high-temperature side passage holes include:
 a large-diameter hole that is configured to conduct the high-pressure refrigerant in a gas state or the high-pressure liquid refrigerant; and   a small-diameter hole that has a diameter smaller than a diameter of the large-diameter hole and is configured to conduct the high-pressure liquid refrigerant, wherein the small-diameter hole is placed adjacent to a corresponding one of the at least one low-temperature side passage hole.   
     
     
         11 . The composite heat exchanger according to  claim 7 , wherein:
 each of the plurality of plate members has a sacrificial layer at one surface and lacks the sacrificial layer at another surface opposite to the one surface;   the one surface having the sacrificial layer of each corresponding one of the plurality of plate members is opposed to and is joined to the one surface having the sacrificial layer of an adjacent one of the plurality of plate members, and the another surface lacking the sacrificial layer of each corresponding one of the plurality of plate members is opposed to and is joined to the another surface lacking the sacrificial layer of an adjacent one of the plurality of plate members;   each of a primary condenser passage configured to conduct the high-pressure refrigerant discharged from the compressor, a primary sub-cooler passage configured to conduct the high-pressure liquid refrigerant stored in the liquid storage unit, and a primary heat exchanger passage configured to conduct the high-pressure liquid refrigerant passed through the sub-cooler unit is formed between the another surface of each corresponding one of the plurality of plate members and the another surface of the adjacent one of the plurality of plate members; and   each of a secondary condenser passage configured to conduct the second heat medium, a secondary sub-cooler passage configured to conduct the second heat medium, and a secondary heat exchanger passage configured to conduct the low-pressure refrigerant is formed between the one surface of each corresponding one of the plurality of plate members and the one surface of the adjacent one of the plurality of plate members.   
     
     
         12 . The composite heat exchanger according to  claim 7 , wherein each of the condenser unit, the sub-cooler unit and the internal heat exchanger unit is formed by corresponding plate members among the plurality of plate members, and the plurality of plate members are made of a plurality of plate materials, respectively, each of which has at least a common plate thickness and common external dimensions. 
     
     
         13 . The composite heat exchanger according to  claim 1 , wherein:
 each of the condenser unit and the sub-cooler unit has a plurality of primary heat exchange fins which are configured to promote heat exchange between the high-pressure refrigerant and the second heat medium;   the internal heat exchanger unit has a plurality of secondary heat exchange fins which are configured to promote heat exchange between the high-pressure liquid refrigerant and the low-pressure refrigerant; and   each of the plurality of secondary heat exchange fins has a shape that is different from a shape of each of the plurality of primary heat exchange fins to reduce a refrigerant pressure loss at the internal heat exchanger unit.   
     
     
         14 . The composite heat exchanger according to  claim 1 , wherein the liquid storage unit is arranged such that a center position of the liquid storage unit does not overlap a center plane of the integral structure extending in a direction along which the condenser unit, the sub-cooler unit and the internal heat exchanger unit are arranged in a row. 
     
     
         15 . A composite heat exchanger configured to be used in a vapor compression refrigeration cycle that includes: a compressor; a decompressor configured to decompress a high-pressure refrigerant discharged from the compressor; and an evaporator configured to evaporate a low-pressure refrigerant decompressed at the decompressor by exchanging heat between the low-pressure refrigerant and a first heat medium, the composite heat exchanger comprising:
 a condenser unit configured to condense the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant and a second heat medium;   a liquid storage unit configured to temporarily store a high-pressure liquid refrigerant contained in the high-pressure refrigerant passed through the condenser unit;   a sub-cooler unit configured to sub-cool the high-pressure liquid refrigerant stored in and outputted from the liquid storage unit by exchanging heat between the high-pressure liquid refrigerant and the second heat medium; and   an internal heat exchanger unit configured to exchange heat between the high-pressure liquid refrigerant passed through the sub-cooler unit and the low-pressure refrigerant discharged from the evaporator, wherein:   the condenser unit, the sub-cooler unit and the internal heat exchanger unit are joined together by a predetermined binding element and thereby form an integral structure;   the internal heat exchanger unit is coupled to one heat exchanger unit among the condenser unit and the sub-cooler unit through at least one coupler component in a state where the internal heat exchanger unit is spaced from the one heat exchanger unit;   in the integral structure, the condenser unit is placed between the sub-cooler unit and the internal heat exchanger unit; and   the internal heat exchanger unit is coupled to the condenser unit in a state where the internal heat exchanger unit is spaced from the condenser unit.   
     
     
         16 . The composite heat exchanger according to  claim 15 , wherein the liquid storage unit is placed adjacent to a portion of the integral structure which forms the sub-cooler unit. 
     
     
         17 . The composite heat exchanger according to  claim 15 , wherein the liquid storage unit is directly joined to a portion of the integral structure which forms the sub-cooler unit. 
     
     
         18 . The composite heat exchanger according to  claim 15 , wherein one of a vertical dimension and a horizontal dimension of the internal heat exchanger unit measured at a front surface of the internal heat exchanger unit is smaller than both of:
 a larger one of a vertical dimension and a horizontal dimension of the condenser unit measured at a front surface of the condenser unit; and   a larger one of a vertical dimension and a horizontal dimension of the sub-cooler unit measured at a front surface of the sub-cooler unit.   
     
     
         19 . The composite heat exchanger according to  claim 15 , wherein a larger one of a vertical dimension and a horizontal dimension of the internal heat exchanger unit measured at a front surface of the internal heat exchanger unit is smaller than both of:
 a larger one of a vertical dimension and a horizontal dimension of the condenser unit measured at a front surface of the condenser unit; and   a larger one of a vertical dimension and a horizontal dimension of the sub-cooler unit measured at a front surface of the sub-cooler unit.   
     
     
         20 . The composite heat exchanger according to  claim 15 , wherein at least one heat exchanger unit among the condenser unit, the sub-cooler unit and the internal heat exchanger unit is configured such that one of a vertical dimension and a horizontal dimension of the at least one heat exchanger unit measured at a front surface of the at least one heat exchanger unit is smaller than a largest dimension among a vertical dimension and a horizontal dimension of remaining one or more heat exchanger units measured at a front surface of the remaining one or more heat exchanger units among the condenser unit, the sub-cooler unit and the internal heat exchanger unit. 
     
     
         21 . The composite heat exchanger according to  claim 15 , wherein the internal heat exchanger unit is coupled to the evaporator through at least one coupling connector. 
     
     
         22 . A composite heat exchanger configured to be used in a vapor compression refrigeration cycle that includes: a compressor; a decompressor configured to decompress a high-pressure refrigerant discharged from the compressor; and an evaporator configured to evaporate a low-pressure refrigerant decompressed at the decompressor by exchanging heat between the low-pressure refrigerant and a first heat medium, the composite heat exchanger comprising:
 a condenser unit configured to condense the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant and a second heat medium;   a liquid storage unit configured to temporarily store a high-pressure liquid refrigerant contained in the high-pressure refrigerant passed through the condenser unit;   a sub-cooler unit configured to sub-cool the high-pressure liquid refrigerant stored in and outputted from the liquid storage unit by exchanging heat between the high-pressure liquid refrigerant and the second heat medium; and   an internal heat exchanger unit configured to exchange heat between the high-pressure liquid refrigerant passed through the sub-cooler unit and the low-pressure refrigerant discharged from the evaporator, wherein:   the condenser unit, the sub-cooler unit and the internal heat exchanger unit are joined together by a predetermined binding element and thereby form an integral structure;   the internal heat exchanger unit and at least one of the condenser unit and the sub-cooler unit are formed by a plurality of plate members which are stacked and joined together;   the plurality of plate members include a plurality of multi-hole members each of which has:   at least two high-temperature side passage holes which are configured to conduct the high-pressure refrigerant that includes the high-pressure liquid refrigerant; and   at least one low-temperature side passage hole which is configured to conduct the second heat medium or the low-pressure refrigerant.