Heat Exchanger, Intermediate Heat Exchanger, and Refrigeration Cycle

Abstract

A heat exchanger includes an outer tube and an inner tube having a plurality of fins for ed on an external periphery of the inner tube and disposed in the outer tube. The heat exchanger is designed to exchange heat between first fluid passing through the inner tube and second fluid passing in between the outer tube and the inner tube. A gap is formed between an internal periphery of the outer tube and a tip end of each of the plurality of fins of the inner tube. This structure can improve the heat exchanging performance and provide a heat exchanger excellent in vending workability.

1 . A heat exchanger, comprising:
 an outer tube;   an inner tube having a plurality of fins formed on an external periphery of the inner tube, the inner tube being disposed in the outer tube;   first fluid passing in the inner tube; and   second fluid passing in between the outer tube and the inner tube.   wherein the heat exchanger exchanges heat between the first fluid and the second fluid, and   wherein a gap is formed between an internal periphery of the outer tube and a tip end of each of the plurality of fins of the inner tube.   
   
   
       2 . The heat exchanger as recited in  claim 1 , wherein the plurality of fins extend along a longitudinal direction of the inner tube and are arranged in a circumferential direction thereof at certain intervals. 
   
   
       3 . The heat exchanger as recited in  claim 1 , wherein the gap is set to 0.2 to 1 mm. 
   
   
       4 . The heat exchanger as recited in  claim 15  wherein the plurality of fins are arranged along a circumferential direction of the inner tube and the number of fins is set to 13 to 18 
   
   
       5 . The heat exchanger as recited in  claim 1 , wherein a thickness of each of the plurality of fins is set to 0.3 to 1.3 mm. 
   
   
       6 . The heat exchanger as recited in  claim 1 , wherein an opening angle between adjacent fins is set to 15 to 30°. 
   
   
       7 . The heat exchanger as recited in  claim 1 , wherein the plurality of fins are integrally formed on the inner tube. 
   
   
       8 . The heat exchanger as recited in  claim 1 , wherein both the outer tube and the inner tube are bent by bending work. 
   
   
       9 . The heat exchanger as recited in  claim 1 , wherein the first fluid is high pressure heat medium and the second fluid is low pressure heat medium. 
   
   
       10 . The heat exchanger as recited in  claim 1 , wherein the inner tube is provided with a plurality of inner fins on an internal periphery thereof, 
   
   
       11 . An intermediate heat exchanger for exchanging heat between high pressure refrigerant and low pressure refrigerant among refrigerant circulating a refrigeration cycle,
 the inter-mediate heat exchanger, comprising:   an inner tube provided with a plurality of fins on an external periphery thereof and   an outer tube in which the inner tube is disposed in a manner such that a gap is formed between an internal periphery of the outer tube and a tip end of each of the plurality of fins of the inner tube,   wherein one of the high pressure refrigerant and the low pressure refrigerant passes through a first heat exchanging passage formed in the inner tube, and   wherein the other of the high pressure refrigerant and the low pressure refrigerant passes through a second heat exchanging passage between the outer tube and the inner tube,   
   
   
       12 . The heat exchanger as recited in  claim 11 , wherein the high pressure refrigerant passes through the first heat exchanging passage, and wherein the low pressure refrigerant passes through the second heat exchanging passage. 
   
   
       13 . The heat exchanger as recited in  claim 11 , wherein the refrigerant is carbon dioxide refrigerant. 
   
   
       14 . An intermediate heat exchanger for exchanging heat between high pressure refrigerant and low pressure refrigerant among refrigerant circulating a refrigeration cycle,
 the intermediate heat exchanger, comprising:   an inner tube provided with a plurality of fins on an external periphery thereof; and   an outer tube in which the inner tube is disposed in a manner such that a gap is formed between an internal periphery of the outer tube and the plurality of fins of the inner tube,   wherein one of the high pressure refrigerant and the low pressure refrigerant passes through a first heat exchanging passage formed in the inner tube and   wherein the other of the high pressure refrigerant and the low pressure refrigerant passes through a second heat exchanging passage between the outer tube and the inner tube.   
   
   
       15 . A refrigerant cycle in which refrigerant circulates such that the refrigerant passes through a compressor, a condenser, a decompressor and an evaporator, and then returns to the compressor.
 the refrigerant cycle, comprising:   an intermediate heat exchanger for exchanging heat between high pressure refrigerant passing through a high pressure circuit from the compressor to the decompressor and low pressure refrigerant passing through a low pressure circuit from the decompressor toward the compressor,   wherein the intermediate heat exchanger includes:   an inner tube provided with a plurality of fins on an external periphery thereof; and   an outer tube in which the inner tube is disposed in a manner such that a gap is formed between an internal periphery of the outer tube and a tip end of each of the plurality of fins of the inner tube,   wherein one of the high pressure refrigerant and the low pressure refrigerant passes through a first heat exchanging passage formed in the inner tube, and   wherein the other of the high pressure refrigerant and the low pressure refrigerant passes through a second heat exchanging passage between the outer tube and the inner tube.   
   
   
       16 . A refrigerant cycle in which refrigerant circulates such that the refrigerant passes through a compressor, a condenser, a decompressor and an evaporator and then returns to the compressor,
 the refrigerant cycles comprising:   an intermediate heat exchanger for exchanging heat between high pressure refrigerant passing through a circuit located between the condenser and the decompressor and low pressure refrigerant passing through a circuit located between the evaporator and the compressor,   wherein the intermediate heat exchanger includes:   an inner tube provided with a plurality of tins on an   external periphery thereof, and   an outer tube in which the inner tube is disposed in a manner such that a gap is for ed between an internal periphery of the outer tube and a tip end of each of the plurality of fins of the inner tube,   wherein one of the high pressure refrigerant and the low pressure refrigerant passes through a first heat exchanging passage for ed in the inner tube, and   wherein the other of the high pressure refrigerant and the low pressure refrigerant passes through a second heat exchanging passage between the outer tube and the inner tube.   
   
   
       17 . The refrigerant cycle as recited in  claim 6 , w herein the high pressure refrigerant passes through the first heat exchanging passage, and wherein the low pressure refrigerant passes through the second heat exchanging passage. 
   
   
       18 . The refrigerant cycle as recited in  claim 16 , wherein the condenser is a gas cooler. 
   
   
       19 . The refrigerant cycle as recited in  claim 12  , wherein the refrigerant is carbon dioxide refrigerant. 
   
   
       20 . The refrigerant cycle as recited in  claim 16 , wherein both the outer tube and the inner tube are bent by bending work.