WO2007013439A1

WO2007013439A1 - Heat exchanger

Info

Publication number: WO2007013439A1
Application number: PCT/JP2006/314643
Authority: WO
Inventors: Hironaka Sasaki
Original assignee: Showa Denko K.K.
Priority date: 2005-07-28
Filing date: 2006-07-25
Publication date: 2007-02-01
Also published as: JP2007032949A; DE112006001982T5

Abstract

A heat exchanger, comprising a heat exchanging part (10) having an outer tube (2), an inner tube (3), and a plurality of fins (4) integrally formed on the outer peripheral surface of the inner tube (3) extendedly in the longitudinal direction. The heat exchanging part (10) is bent at at least one position. In the cross section of the bent portion (10A) of the heat exchanging part (10), the tip parts of a part of the fins (4) are brought into contact with the inner peripheral surface of the bent inner portion (2a) and the inner peripheral surface of the bent outer portion (2b) of the outer tube (2), and the inner tube (3) is fixedly held by the bent inner portion (2a) and the bent outer portion (2b) of the outer tube (2) through the fins (4). In the cross section above, fluid mixing parts (20) having clearances between the tip parts of the fins (4) and the inner peripheral surface of the outer tube (2) are formed on the peripheral both sides of the portion where the tip parts of the part of fins (4) are brought into contact with the inner peripheral surface of the bent inner portion (2a) and the inner peripheral surface of the bent outer portion (2b) of the outer tube (2). Thus, an installation space for the heat exchanger can be rather reduced and the heat exchanging performance thereof can be increased.

Description

Specification

Heat exchanger

Technical field

[0001] The present invention relates to a heat exchanger, and more specifically, for example, a compressor, a gas cooler, an evaporator, a gas-liquid separator, a refrigerant that has come out of the gas cooler, and a refrigerant that has come out of the evaporator and has passed through the gas-liquid separator An intermediate heat exchanger for exchanging heat, and

In a supercritical refrigeration cycle using a supercritical refrigerant such as CO,

2

It is related to the heat exchange ^^ used suitably.

In this specification and claims, the term “aluminum” includes aluminum alloys in addition to pure aluminum. In this specification and claims, the term “supercritical refrigeration cycle” means a refrigeration cycle in which the refrigerant reaches a supercritical state exceeding the critical pressure on the high-pressure side. Means refrigerant used in the supercritical refrigeration cycle.

Background art

[0003] Conventionally, as a car air conditioner mounted on an automobile, a compressor, a condenser, an evaporator, a gas-liquid separator, a decompressor, and a refrigeration cycle that uses a fluorocarbon refrigerant have been widely used. .

[0004] However, in recent years, supercritical refrigerants such as CO have been used for environmental protection.

2

It is considered to install a supercritical refrigeration cycle in a car as a car air conditioner.

[0005] The supercritical refrigeration cycle has passed through the accumulator from the compressor, gas cooler, evaporator, accumulator as gas-liquid separator, expansion valve as decompressor, and high-temperature and high-pressure refrigerant and evaporator that came out of the gas cooler. It is equipped with an intermediate heat exchanger that exchanges heat with a low-temperature and low-pressure refrigerant.

[0006] By the way, the intermediate heat exchange in the supercritical refrigeration cycle is a heat exchanger that was not found in the conventional refrigeration cycle using a chlorofluorocarbon refrigerant, and the intermediate heat exchange is efficiently stored in the engine room of the automobile. However, it is currently considered to be placed in the engine room between the gas cooler and the evaporator. [0007] As the heat exchange ^^ used for the intermediate heat exchange ^^ in the supercritical refrigeration cycle described above, a straight outer pipe, a straight inner pipe arranged concentrically at intervals in the outer pipe, and It is fixed to both ends of the heat exchange part, which is made up of fins that are integrally formed so as to extend in the length direction of the inner pipe, with a space in the circumferential direction on the outer peripheral surface of the inner pipe, and both the inner and outer pipes of the heat exchange part. The gap between the outer and inner pipes of the heat exchange section is the first fluid passage and the inner pipe is the second fluid passage. A first flow path that communicates the first fluid passage of the heat exchange section to the outside, and a second flow path that is independent of the first flow path and communicates the second fluid path of the heat exchange section to the outside. It is known that the tip portions of all fins are in contact with the inner peripheral surface of the outer tube (see Patent Document 1).

[0008] In the intermediate heat exchanger described in Patent Document 1, the heat exchange performance between the refrigerant flowing in the first fluid passage of the heat exchange section and the refrigerant flowing in the second fluid passage is made desired. It is necessary to increase the heat transfer area between the fluids flowing in both fluid passages. However, in this case, the length of both the inner and outer pipes must be increased, and since both the inner and outer pipes are straight pipes, the installation space for the intermediate heat exchange ^^ becomes relatively large. is there. In particular, when installed in an automobile, there is a limitation on the installation space in the engine room, so that it is impossible to efficiently store the intermediate heat exchange, and the feasibility is low.

[0009] Further, since the first fluid passage is divided into a plurality of passage portions by fins provided in the inner pipe, the refrigerant flowing through each passage portion can be efficiently mixed in both fluid passages. The heat exchange efficiency between the flowing refrigerants may be insufficient.

[0010] Furthermore, although the tips of all the fins of the inner tube are in contact with the inner peripheral surface of the outer tube, the fins are not fixed to the outer tube. There is a risk of rattling and abnormal noise due to vibration.

Patent Document 1: International Publication No. 03Z085344 Pamphlet

Disclosure of the invention

Problems to be solved by the invention

[0011] An object of the present invention is to provide a heat exchange that can solve the above-described problems and can reduce the installation space.

Means for solving the problem The present invention has the following aspect power to achieve the above object.

[0013] 1) An outer tube, an inner tube provided at an interval in the outer tube, and a heat exchange unit including fins provided between the outer tube and the inner tube, and both inner and outer tubes of the heat exchange unit The gap between the outer tube and the inner tube of the heat exchange section serves as the first fluid passage and the inside of the inner tube serves as the second fluid passage. The heat exchange is ^^ and the heat exchange part is bent at least in one place.

[0014] 2) The heat exchanger according to 1), wherein the fins are integrally formed so as to be spaced apart in the circumferential direction on the outer peripheral surface of the inner tube and extend in the length direction of the inner tube.

[0015] 3) In the cross section of the bent portion of the heat exchanging portion, the tips of some fins are in contact with the inner peripheral surface of the bent inner portion and the bent outer portion of the outer tube, The heat exchanger described in 2) above, in which the inner tube is sandwiched and fixed by the portion and the bent outer portion via the fin.

[0016] 4) In the cross section of the bent portion of the heat exchanging portion, the tips of some fins are in contact with the inner peripheral surfaces of the bent inner portion and the bent outer portion of the outer tube, and both sides in the circumferential direction of the bent portion. The heat exchange described in 3) above is provided with a fluid mixing portion in which a gap is formed between the tip of the fin and the inner peripheral surface of the outer tube.

[0017] 5) The heat exchanging portion has a plurality of bent portions, and includes a bent portion bent in one plane including the axes of both the inner and outer tubes and the axes of the inner and outer tubes, and the above The heat exchange as described in 1) above, in which a bent part bent in another plane intersecting the plane is mixed ^^

[0018] 6) A compressor, a gas cooler, an evaporator, a gas-liquid separator, a pressure reducer, and a gas cooler force are provided, and an intermediate heat exchanger ^^ that exchanges heat between the refrigerant that has come out and the refrigerant that has come out of the evaporator A refrigeration cycle using a supercritical refrigerant, wherein the intermediate heat exchange ^^ is the heat exchange described in 1) above.

[0019] 7) The low-pressure refrigerant coming out of the evaporator flow in the first fluid passage of the intermediate heat exchanger, and the high-pressure refrigerant coming out of the gas cooler also flows in the second fluid passage. 6) The refrigeration cycle described.

[0020] 8) The refrigeration cycle according to 6) above, wherein the supercritical refrigerant comprises carbon dioxide. [0021] 9) A vehicle in which the refrigeration cycle described in 6) above is mounted as a car air conditioner.

10) Coolant heating heat exchanger that exchanges heat between the high-temperature and high-pressure heat medium compressed by the compressor, outdoor heat exchanger, gas-liquid separator, decompressor, and engine power and engine coolant sent to the heater core And a heating cycle using a supercritical heat medium, wherein the heat exchange for heating the coolant is the heat exchange described in 1) above.

[0022] 11) The engine coolant flows in the first fluid passage of the heat exchanger for heating the coolant, and the high-temperature and high-pressure heat medium compressed by the compressor also flows in the second fluid passage. The heating cycle described in 10) above.

[0023] 12) The heating cycle as described in 10) above, wherein the supercritical heat medium is composed of carbon dioxide and carbon dioxide.

[0024] 13) A vehicle in which the heating cycle described in 10) above is mounted as a car air conditioner.

The invention's effect

[0025] According to the heat exchange ^ of 1) above, since the heat exchange section is bent at at least one location, the total heat transfer between the fluids flowing in the first and second fluid passages of the heat exchange section. Even if the area is made as large as necessary to obtain the desired heat exchange performance, the linear spacing between the two connectors is shorter than the intermediate heat exchange described in Patent Document 1. Therefore, the linear length of the installation space for heat exchange can be made smaller than that of the heat exchanger described in Patent Document 1. For example, when it is mounted on an automobile, it can be bent into an arbitrary shape according to the empty space of the automobile, and the space in the engine room of the automobile can be used effectively.

[0026] According to the heat exchanger 2), the heat transfer area between the fluids flowing in the first and second fluid passages is increased, and the heat exchange efficiency is improved. Also, since the fins are formed integrally with the inner tube, the number of parts is reduced.

[0027] According to the heat exchange of 3) above, the inner tube is fixed to the outer tube, and the generation of abnormal noise due to vibration can be prevented.

[0028] According to the heat exchanger of 4) above, when a fluid is caused to flow in the first fluid passage, the fluid is mixed efficiently in the fluid mixing portion in combination with the inertial force when passing through the bent portion. Therefore, compared to the intermediate heat exchanger described in Patent Document 1, due to the turbulent flow effect and the fluid temperature equalizing effect, Thus, the heat exchange performance between the fluids flowing in both fluid passages is improved.

[0029] When the heat exchanger of 5) above is mounted on a car, for example, it can be bent into any shape according to the free space of the car, making space in the engine room of the car effective. It can be used and the realization becomes high.

[0030] In the heat exchanger of 5) above, in the cross section of the bent portion of the heat exchanging portion, the tip end portions of some fins contact the inner peripheral surface of the bent inner portion and the bent outer portion of the outer tube. If the inner tube is sandwiched and fixed by the bent inner part and the bent outer part of the outer tube through the fins, the effect of preventing the generation of noise due to the inner tube being fixed to the outer tube is obtained. Further improvement.

[0031] Further, in the heat exchanger of the above 5), in the cross section of the bent portion of the heat exchanging portion, the tip of one fin is in contact with the inner peripheral surface of the bent inner portion and the bent outer portion of the outer tube. If there is a fluid mixing part with a gap formed between the tip of the fin and the inner peripheral surface of the outer pipe on both sides in the circumferential direction, the axis of both the inner and outer pipes are included. The bent portion bent in one plane and the bent portion bent in the other plane including the axis of both the inner and outer tubes and intersecting the plane are both the inner and outer tubes of the fluid mixing portion. The positions in the circumferential direction are different. Therefore, the fluid flowing in the first fluid passage is

In combination with the inertial force when passing through each bending part, the fluid mixing part will mix more efficiently, and the fluid flowing in both fluid passages due to the turbulent flow effect and the fluid temperature equalizing effect The effect of improving the heat exchange performance between the two becomes remarkable.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0033] In the following description, the top and bottom and the left and right in FIG.

[0034] In addition, throughout the drawings, the same parts and the same parts are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 shows the overall configuration of a first embodiment of a heat exchanger according to the present invention, and FIGS. 2 to 4 show the configuration of the main part thereof. Fig. 5 shows a supercritical refrigeration cycle using the heat exchanger of Fig. 1 as an intermediate heat exchanger. In FIGS. 1 to 4, the heat exchanger (1) has an outer tube (2) having a circular cross section and an inner tube having a circular cross section inserted concentrically into the outer tube (2) at intervals. The heat exchange section (10) consisting of fins (4) provided on the outer peripheral surface of the pipe (3) and the inner pipe (3), and both pipes (2) and (3) of the heat exchange section (10) With a fixed connector (5) and the heat exchanger (10), i.e. both pipes (2) (3) contain at least one axis, here the axis of both pipes (2) (3) It is bent at two points in one horizontal plane (P). The bent part is indicated by (10A).

[0037] The outer tube (2) is also a metal, in this case, an aluminum extruded profile. The inner tube (3) is also a metal, here an aluminum extruded profile, and has a plurality of fins (4) force circumferentially spaced on its outer peripheral surface and in the length direction of the inner tube (3). It is integrally formed to extend. In the linear part (10B) of the heat exchange part (10) excluding the bent part (10 A), there is a slight gap between the tip of the fin (4) and the outer peripheral surface of the outer pipe (2). Exists (see Figure 2). Both ends of the inner tube (3) protrude outward from the outer tube (2), and the fin (4) is cut off over the entire outer protruding portion (3a), and the finless portion (8) is removed. Is provided. Further, a plurality of inner fins (9) extending over the entire length are integrally formed on the inner peripheral surface of the inner pipe (3) at intervals in the circumferential direction (see FIGS. 2 and 3). The gap between the outer pipe (2) and the inner pipe (3) is the first fluid passage (6), and the inner pipe (3) is the second fluid passage (7). It has become.

[0038] The heat exchanging section (10) is formed by inserting a straight inner pipe (3) into a straight outer pipe (2) and then applying bending calorie. This bending cache is applied either before or after fixing the connector (5) to both pipes (2) and (3). As shown in FIG. 3, in the bent portion (10A) of the heat exchange section (10), the outer pipe (2) is placed on the plane (P) with the bending center and the axis of the outer pipe (2). Slightly crushed in the direction of connecting. Then, in the cross section of the bent portion (10A) of the heat exchange section (10), that is, the cross section orthogonal to the plane (P) (corresponding to the cross section along line B-B in FIG. 1), The tip of the fin (4) is in contact with the inner peripheral surface of the bent inner part (2a) and outer bent part (2b) of the outer pipe (2), and the inner bent part ( The inner pipe (3) is clamped and fixed via the fin (4) by the bent outer part (2b) and 2a). In addition, in the cross section of the bent portion (10A) of the heat exchange section (10), the tips of some fins (4) are bent inner portions (2a) and outer bent portions (2) of the outer tube (2). On both sides in the circumferential direction of the part in contact with 2b) (upper and lower sides in Fig. 3), the gap between the tip of the fin (4) and the outer tube (2) inner circumferential surface is linear. Part (10B ) Between the front end of the fin (4) and the outer peripheral surface of the outer tube (2), and the fluid mixing part (20) is formed there.

[0039] As shown in FIG. 4, the connector (5) has a blocking force made of metal, here aluminum, and has a horizontal cylindrical part (5a) and a rectangular parallelepiped part connected to the upper end of the cylindrical part (5a). (5b). Hereinafter, the left connector (5) will be described. On the right end surface of the cylindrical part (5a) of the connector (5), an annular wall (11) is integrally formed so as to protrude rightward, so that the outer pipe fits into the end of the outer pipe (2). A recess (12) is formed. Then, the end of the outer tube (2) is fitted into the outer tube fitting recess (12) of the connector (5), and the outer tube (2) outer peripheral surface and the tip of the annular wall (11) That is, the opening periphery of the recess (12) is joined. This joining is performed by brazing, here torch brazing.

[0040] One end of the connector (5) opens to a portion surrounded by the annular wall (11) on the right end surface of the cylindrical portion (5a), and the other end opens to the upper surface of the rectangular parallelepiped portion (5b). A flow path (13) communicating with the first fluid path (6) is formed. Also, a through-hole extending in the left-right direction between the left end surface of the lateral portion present in the cylindrical portion (5a) in the flow path (13) of the connector (5) and the left end surface (outer surface) of the cylindrical portion (5a) A hole (14) is formed. The left side portion of the finless portion (8) of the inner pipe (3) is inserted into the through hole (14). The left end of the finless part (8) protrudes outward from the opening on the left end face side of the cylindrical part (5a) in the through hole (14), and the finless part (8) of the inner pipe (3) The outer peripheral surface is joined to the peripheral edge of the left end opening of the through hole (14) in the cylindrical portion (5a). This joining is performed by brazing, here torch brazing.

[0041] An annular wall (15) is integrally formed on the left end surface of the cylindrical portion (5a) of the connector (5) around the through hole (14) so as to protrude leftward. The left end of the fin-free part (8) of the inner pipe (3) protrudes to the left of the annular wall (15), and the part protruding from the annular wall (15) and the annular part of the fin-free part (8) A union screw (16) is arranged to cover the wall (15). The annular wall (15) is fitted into the large diameter part (17a) of the right end of the through hole (17) formed in the union screw (16), and the left end of the finless part (8) is the through hole (17). Is fitted into a small diameter portion (17b) connected to the right end large diameter portion (17a). The right end of the union screw (16) is fitted in an annular recess (18) formed in the peripheral portion of the annular wall (15) on the left end surface of the cylindrical portion (5a), and the union screw (16) The right end of the outer peripheral surface of the cylinder and the inner peripheral surface of the recess (18) in the cylindrical portion (5a) It is joined. This joining is performed by brazing, here torch brazing. The union screw (16) of one connector (5) is used to connect a pipe for supplying fluid into the second fluid passage (7), and the union screw (16 of the other connector (5) ) Is used to connect a pipe for draining fluid from the second fluid passage (7).

[0042] The connector (5) has a female screw hole (19) extending downward from the upper surface of the rectangular parallelepiped portion (5b). The female screw hole (19) of one connector (5) is used to connect a piping nove for supplying fluid into the first fluid passage (6), and the female screw of the other connector (5). The hole (19) is used to connect a piping pipe for discharging the fluid from the first fluid passage (6).

[0043] The right connector (5) is opposite to the left connector (5), and is fixed to the outer tube (2) and inner tube (3) in the same way as the left connector (5). ing.

[0044] FIG. 5 shows a supercritical refrigeration cycle using the heat exchange (l) described above as an intermediate heat exchange.

In FIG. 5, the supercritical refrigeration cycle uses CO as a supercritical refrigerant.

2

Refrigerant and evaporator from the compressor (21), gas cooler (22), evaporator (23), accumulator (24) as gas-liquid separator, expansion valve (25) as decompressor, and gas cooler (22) Provide intermediate heat exchange (l) to exchange heat with the refrigerant from (23)! The supercritical refrigeration cycle is mounted on a vehicle such as an automobile as a car air conditioner.

[0046] The low-pressure refrigerant that has flowed out of the evaporator (23) and passed through the accumulator (2 4) flows through the first fluid passage (6) of the intermediate heat exchanger (1), and the second fluid passage (7) The high-pressure refrigerant from the gas cooler (22) flows through the inside. Then, the refrigerant flowing in the first fluid passage (6) is mixed in the fluid mixing section (20) together with the inertial force when passing through each bending portion (10A), Due to the turbulent flow effect and fluid temperature equalizing effect, the heat exchange performance between the refrigerants flowing in both fluid passages (6) and (7) is improved.

[0047] Fig. 6 shows the same configuration as that of the heat exchanger (1) of the example except that the heat exchanger (1) of the first embodiment (1) (example) and a heat exchanger that is straight as a whole are provided. The heat exchange performance with heat exchange (comparative example) is shown. Here, the substantial length of the heat exchanging portion (10) including the bent portion (10A) in the heat exchanger of the embodiment is equal to the linear length of the heat exchanging portion of the heat exchanger of the comparative example. From the results shown in Fig. 6, the heat exchange performance of the heat exchange (l) of the example is superior to that of the comparative example ^^. I understand.

FIG. 7 shows a second embodiment of the heat exchanger according to the present invention.

[0049] In the case of the heat exchanger (30) of the embodiment shown in Fig. 7, the heat exchange section (10), that is, both pipes (2) (3) are bent at at least one place, here three places. . In each bent part (10A), the heat exchanging part (10) is the force bent in one plane (P1) (P2) (P3) including the axes of both pipes (2) (3). The planes (P1), (P2), and (P3) cross each other.

[0050] Although not shown, as in the case of the first embodiment described above, in each bent portion (10A), on the plane (P1XP2XP3), the outer tube (2) has a bending center. It is slightly crushed in the direction connecting the axis of the outer tube (2). Then, along the cross section of the bent portion (10A) of the heat exchange section (10), that is, the cross section orthogonal to the plane (P1XP2XP3), the tip of the fin (4) of a part of the inner pipe (3) is The inner side (2a) and the outer side (2b) of the outer pipe (2) are in contact with the inner peripheral surface of the outer side (2a) and the outer side (2b). Thus, the inner tube (3) is clamped and fixed via the fin (4). In addition, the end of some fins (4) are connected to the bent inner part (2a) and outer bent part of the outer tube (2) in the cross section of the bent part (10A) of the heat exchange part (10). The gap between the tip of the fin (4) and the outer tube (2) inner circumferential surface is the fin in the linear portion (10B) on both sides in the circumferential direction of the portion that abuts (2b). It is larger than the space between the tip of (4) and the outer pipe (2) and the inner peripheral surface, and a fluid mixing section (20) is formed here. Here, since the planes (P1), (P2), and (P3) cross each other, the position of the fluid mixing section (20) of each bending section (1 OA) is set to both pipes (2) (3 ) Is different in the circumferential direction.

[0051] Other configurations are the same as those of the heat exchanger (1) of the first embodiment, and are suitably used as intermediate heat exchange in the supercritical refrigeration cycle, as in the case of the first embodiment. When used as intermediate heat exchange, the position of the fluid mixing section (20) of each bending section (10A) differs in the circumferential direction of both pipes (2) and (3). ) The refrigerant flowing in the fluid is mixed more efficiently in the fluid mixing part (20) in combination with the inertial force when passing through each bending part (10A), and the turbulent flow effect and the uniform fluid temperature are obtained. The effect of improving the heat exchange performance between the refrigerants flowing in the two fluid passages (6) and (7) due to the crystallization effect is superior to the case of the first embodiment.

[0052] FIG.

And super 2 shows a heating cycle using a field heat medium.

[0053] In Fig. 8, the heating cycle uses CO as the supercritical heat medium, and

2

Heat exchanger (1X30) for heating the coolant that exchanges heat between the high-temperature and high-pressure heat medium compressed by the presser (50) and compressor (50) and the engine coolant sent from the engine (51) to the heater core (52) An expansion valve (53) as a pressure reducer for reducing the pressure of the heat medium that has passed through the coolant heating heat exchanger (1X30), and an outdoor heat exchanger (54) for evaporating the heat medium depressurized by the expansion valve (53) And an accumulator (55) as a gas-liquid separator for separating the liquid in the heat medium sent from the outdoor heat exchanger (54) to the compressor (50). The heating cycle is installed in a vehicle such as an automobile as a car air conditioner.

[0054] High-temperature and high-pressure, in which engine coolant flows in the first fluid passage (6) of the heat exchanger (1X30) for heating the coolant, and is compressed in the second fluid passage (7) by the compressor (50). The heat medium flows.

[0055] In this heating cycle, as the compressor (50), the expansion valve (53) and the accumulator (55), the compressor (21) of the supercritical refrigeration cycle shown in Fig. 5 and the expansion valve ( 25) and accumulator (24) as a gas-liquid separator are shared, and piping and switching valves may be installed so that the gas cooler (22) is shared as outdoor heat exchange (54) .

[0056] In the above, carbon dioxide is used as the supercritical refrigerant and supercritical heat medium, but is not limited to this, and ethylene, ethane, nitric oxide, and the like can also be used.

Industrial applicability

[0057] In the present invention, heat exchange is performed, for example, with a compressor, a gas cooler, an evaporator, a gas-liquid separator, and a gas cooler force. With intermediate heat exchange ^^ and CO

In the supercritical refrigeration cycle using a supercritical refrigerant such as 2, it can be used as intermediate heat exchange ^^

FIG. 1 is an overall perspective view showing a first embodiment of a heat exchanger according to the present invention. FIG. 2 is an enlarged sectional view taken along line AA in FIG.

FIG. 3 is an enlarged sectional view taken along line BB in FIG.

FIG. 4 is an enlarged sectional view taken along line CC in FIG.

V5] A diagram showing a supercritical refrigeration cycle using the heat exchanger of the first embodiment as an intermediate heat exchanger.

6] A graph showing an experimental example and a comparative example performed using the heat exchanger of the first embodiment.

[7] FIG. 7 is an overall perspective view showing a second embodiment of the heat exchange according to the present invention.

[8] FIG. 8 is a diagram showing a heating cycle in which the heat exchangers of the first and second embodiments are used as a heat exchanger for heating a coolant.

Claims

The scope of the claims

[1] A heat exchanging section consisting of an outer pipe, an inner pipe provided at intervals in the outer pipe, and fins provided between the outer pipe and the inner pipe, and both ends of the inner and outer pipes of the heat exchanging section And a connector between the outer tube and the inner tube of the heat exchanging portion serving as the first fluid passage and the inner tube serving as the second fluid passage. Heat exchange, where the heat exchanger is bent in at least one place.

[2] The heat exchanger according to claim 1, wherein the fins are integrally formed so as to be circumferentially spaced on the outer peripheral surface of the inner tube and extend in the length direction of the inner tube.

[3] In the cross section of the bent part of the heat exchange part, the tip of some fins is in contact with the inner peripheral surface of the inner bent part and the outer bent part of the outer pipe, and the bent inner part of the outer pipe The heat exchanger according to claim 2, wherein the inner pipe is sandwiched and fixed by a bent outer portion via a fin.

[4] In the cross section of the bent portion of the heat exchange part, the tip of some fins abuts the inner peripheral surface of the bent inner part and the outer bent part of the outer tube, 4. The heat exchange according to claim 3, wherein a fluid mixing portion is provided in which a gap is formed between the tip portion of the fin and the inner peripheral surface of the outer tube.

[5] The heat exchanging portion has a plurality of bent portions, and the bent portion is bent in one plane including the axes of both the inner and outer tubes, and the plane including the axes of both the inner and outer tubes and the plane. The heat exchange according to claim 1, wherein a bent portion bent in one other plane is mixed.

[6] Supercritical with compressor, gas cooler, evaporator, gas-liquid separator, decompressor, and intermediate heat exchange ^^ that exchanges heat between the refrigerant coming out of the gas cooler and the refrigerant coming out of the evaporator The refrigeration cycle using a refrigerant, wherein the intermediate heat exchanger has a heat exchange power according to claim 1.

[7] The low-pressure refrigerant coming out of the evaporator flow in the first fluid passage of the intermediate heat exchanger and the high-pressure refrigerant coming out of the gas cooler in the second fluid passage. The refrigeration cycle according to claim 6.

[8] The refrigeration cycle according to claim 6, wherein the supercritical refrigerant is carbon dioxide nitric acid.

[9] A vehicle in which the refrigeration cycle according to claim 6 is mounted as a car air conditioner.

[10] Coolant heating that exchanges heat between the high-temperature and high-pressure heat medium compressed by the compressor, outdoor heat exchanger, gas-liquid separator, decompressor, and compressor and the engine coolant sent from the engine to the heater core The heating cycle comprising a heat exchanger for heating and using a supercritical heat medium, wherein the heat exchanger for heating the coolant is the heat exchanger according to claim 1.

11. The engine coolant flows in the first fluid passage of the heat exchanger for heating the coolant, and the high-temperature and high-pressure heat medium compressed by the compressor flows in the second fluid passage as well. The heating cycle described.

12. The heating cycle according to claim 10, wherein the supercritical heat medium also has a diacid-carbon power.

[13] A vehicle on which the heating cycle according to claim 10 is mounted as a car air conditioner.