JP2018080857A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger reduced in its weight and improved in its anticorrosion characteristic.SOLUTION: A heating heat exchanger 22 and a cooling heat exchanger 23 are provided with a corrosion-proof layer 70 made of a material having a high anticorrosion characteristic. This can prevent the generation of a hole due to corrosion without increasing a plate thickness of a refrigerant flowing unit 50 and heat medium flowing unit 60, thereby reducing the weight and improving the anticorrosion characteristic.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat exchanger applied to, for example, a vehicle air conditioner.

  A conventional heat exchanger for exchanging heat between water and a refrigerant improves corrosion resistance by being formed of a metal such as stainless steel. However, since the heat exchanger mounted in the vehicle is required to be light, it is considered that the heat exchanger is formed of an aluminum alloy (for example, see Patent Document 1).

  Aluminum alloy heat exchangers have lower corrosion resistance than stainless steel heat exchangers, and therefore, measures to improve corrosion resistance are required.

  Therefore, when the fin tube type heat exchanger that exchanges heat between the refrigerant and air is formed of an aluminum alloy, the fin is formed of an aluminum alloy having a lower potential than the aluminum alloy that forms the tube. It is considered to improve the corrosion resistance.

JP 2012-67957 A

  On the other hand, a water-refrigerant heat exchanger that exchanges heat between a liquid heat medium such as water and a refrigerant, for example, has a refrigerant flow path through which the refrigerant flows and a heat medium flow path through which the heat medium flows adjacent to each other. Heat exchange with the heat medium is performed. For this reason, in a water refrigerant heat exchanger, there is no part using a member with low potential unlike a fin tube type heat exchanger, and it is difficult to improve corrosion resistance by using a potential difference. Therefore, in the water refrigerant heat exchanger, in order to satisfy the required corrosion resistance, the thickness of the aluminum alloy must be increased, which may hinder weight reduction.

  An object of the present invention is to provide a heat exchanger capable of reducing the weight and improving the corrosion resistance.

  In order to achieve the above object, the present invention is connected to a refrigerant circuit provided outside the passenger compartment of a vehicle, and exchanges heat between a carbon dioxide refrigerant, a flammable refrigerant, or a toxic refrigerant and a liquid heat medium. The heat exchanger is made of aluminum or aluminum alloy, and an anticorrosion layer made of a highly corrosion-resistant material is formed on the outer surface side.

  As a result, the outer surface side of the heat exchanger that exchanges heat between the refrigerant and the liquid refrigerant is covered with the anticorrosion layer, so that opening of holes due to corrosion is suppressed without increasing the thickness of the members constituting the heat exchanger. Is done.

  According to the present invention, since it is possible to suppress the opening of holes due to corrosion without increasing the plate thickness of the members constituting the heat exchanger, the weight can be reduced and the corrosion resistance can be improved. Is possible.

1 is a schematic configuration diagram of a vehicle air conditioner showing an embodiment of the present invention. It is the whole heat exchanger perspective view. It is a top view of a heat exchanger. It is A1-A1 sectional drawing in FIG. It is A2-A2 sectional drawing in FIG. It is A3-A3 sectional drawing in FIG.

  1 to 6 show an embodiment of the present invention.

  As shown in FIG. 1, a vehicle air conditioner 1 including a heat exchanger according to the present invention includes an air conditioning unit 10 provided in a vehicle compartment A and a refrigerant circuit 20 provided outside the vehicle compartment A. And a heating heat medium circuit 30 and a cooling heat medium circuit 40 which are configured in the passenger compartment A and outside the passenger compartment A.

  The air conditioning unit 10 has an air flow passage 11 for circulating air to be supplied into the passenger compartment A, an air suction port 11 a is provided on one end side of the air flow passage 11, and the other end side of the air flow passage 11. Is provided with an air discharge port 11b. A blower 12 such as a sirocco fan is provided on one end side of the air flow passage 11. The blower 12 allows one or both of the air outside the passenger compartment A and the air inside the passenger compartment A to flow in from the air suction port 11a, and directs the air flowing through the air flow passage 11 from the air discharge port 11b into the passenger compartment A. And let it flow.

  A cooler 13 for cooling the air flowing through the air flow passage 11 is provided on the downstream side of the air flow passage 11 in the air flow direction of the blower 12. Furthermore, a heater 14 for heating the air flowing through the air flow passage 11 is provided downstream of the cooler 13 in the air flow passage 11 in the air flow direction. The cooler 13 and the heater 14 are respectively a fin and a tube for exchanging heat between the heat medium flowing through the heating heat medium circuit 30 and the cooling heat medium circuit 40 and the air flowing through the air flow passage 11. It is a heat exchanger which consists of.

  The refrigerant circuit 20 includes a compressor 21 for compressing and discharging the refrigerant, a heating heat exchanger 22 for exchanging heat between the refrigerant and the heat medium flowing through the heating heat medium circuit 30, and refrigerant and cooling. Cooling heat exchanger 23 for exchanging heat with the heat medium flowing through the heating medium circuit 40, an outdoor heat exchanger 24 for exchanging heat between the refrigerant and the air outside the passenger compartment A, and cooling heat An internal heat exchanger 25 for exchanging heat between the refrigerant flowing into the exchanger 23 and the refrigerant flowing out of the cooling heat exchanger 23, a three-way valve 26 for switching the refrigerant flow path, and a plurality of electromagnetic valves 27 And a plurality of check valves 28 and a plurality of expansion valves 29, which are connected by a pipe made of aluminum or aluminum alloy.

  Here, the refrigerant circuit 20 is filled with carbon dioxide as a refrigerant. Since carbon dioxide as a refrigerant has a higher pressure (pressure on the high pressure side) when discharged from the compressor 21 than other refrigerants (for example, 7.5 MPa or more), the refrigerant circuit 20 is damaged. It may damage the human body. Further, when carbon dioxide leaked from the refrigerant circuit 20 enters the passenger compartment A, there is a possibility that the passenger's thinking ability in the passenger compartment A may be deteriorated or the health condition may be deteriorated. For this reason, the refrigerant circuit 20 is disposed outside the vehicle compartment A such as an engine room from the viewpoint of protecting passengers in the vehicle compartment A when the refrigerant circuit 20 is damaged or when carbon dioxide leaks.

  In the refrigerant circuit 20, the refrigerant flow path is set by switching the opening and closing of the flow path of the three-way valve 26 and the plurality of electromagnetic valves 27. The refrigerant circuit 20 can be switched between a cooling / dehumidifying cooling channel, a heating channel, a first dehumidifying / heating channel, and a second dehumidifying / heating channel. The cooling / dehumidifying cooling channel causes the refrigerant discharged from the compressor 21 to flow in the order of the heating heat exchanger 22, the outdoor heat exchanger 24, the expansion valve 29, and the cooling heat exchanger 23. 21 is a flow path for suction. The heating flow path is a flow path that causes the refrigerant discharged from the compressor 21 to flow through the heating heat exchanger 22, the expansion valve 29, and the outdoor heat exchanger 24 in this order and to be sucked into the compressor 21. The first dehumidifying and heating channel causes the refrigerant discharged from the compressor 21 to flow into the heating heat exchanger 22, and a part of the refrigerant flowing out of the heating heat exchanger 22 is transferred to the expansion valve 29 and outdoor heat. The refrigerant is circulated in the order of the exchanger 24 and sucked into the compressor 21, and the other refrigerant flowing out of the heating heat exchanger 22 is circulated in the order of the expansion valve 29 and the cooling heat exchanger 23 and sucked into the compressor 21. It is a flow path to be made. The second dehumidifying and heating channel is a channel that causes the refrigerant discharged from the compressor 21 to flow through the heating heat exchanger 22, the expansion valve 29, and the cooling heat exchanger 23 in this order and to be sucked into the compressor 21. is there.

  The heating heat medium circuit 30 is configured by connecting the heat medium flow path of the heater 14 and the heat medium flow path of the heating heat exchanger 22 by a tube made of aluminum or aluminum alloy. A first pump 31 for circulating the heat medium between the heater 14 and the heat exchanger 22 for heating is connected to the heat medium circuit 30 for heating. The heating heat medium circuit 30 is filled with, for example, an antifreeze such as ethylene glycol as a heat medium.

  The cooling heat medium circuit 40 is configured by connecting the heat medium flow path of the cooler 13 and the heat medium flow path of the cooling heat exchanger 23 by a pipe made of aluminum or aluminum alloy. The cooling heat medium circuit 40 is connected to a second pump 41 for circulating the heat medium between the cooler 13 and the cooling heat exchanger 23. The cooling heat medium circuit 40 is filled with, for example, an antifreeze such as ethylene glycol as a heat medium.

  In the vehicle air conditioner 1, in the heating heat exchanger 22, the refrigerant flowing through the refrigerant circuit 20 dissipates heat, and the heat medium flowing through the heating heat medium circuit 30 is heated. The heat medium heated in the heating heat exchanger 22 radiates heat in the heater 14 and heats the air flowing through the air flow passage 11. Further, in the cooling heat exchanger 23, the refrigerant flowing through the refrigerant circuit 20 absorbs heat, and the heat medium flowing through the cooling heat medium circuit 40 is cooled. The heat medium cooled in the cooling heat exchanger 23 absorbs heat in the cooler 13 and cools the air flowing through the air flow passage 11. 1, the refrigerant circuit 20 is set as a cooling / dehumidifying cooling channel, and the compressor 21, the first pump 31, and the second pump 41 are driven to cool the air flowing through the air flow passage 11. The dehumidifying and cooling operation for dehumidifying, heating to the target temperature and supplying the passenger compartment A is shown.

  The heating heat exchanger 22 and the cooling heat exchanger 23 as the heat exchanger of the present invention are each made of a member made of aluminum or aluminum alloy. As shown in FIGS. 2 and 3, the heating heat exchanger 22 and the cooling heat exchanger 23 include a refrigerant circulation unit 50 through which a refrigerant circulates and a heat medium circulation unit 60 through which a heat medium circulates. ing.

  The refrigerant distribution unit 50 includes a refrigerant inflow header 51, a refrigerant outflow header 52, and a plurality of refrigerant tubes 53 that allow the refrigerant inflow header 51 and the refrigerant outflow header 52 to communicate with each other.

  Each of the refrigerant inflow header 51 and the refrigerant outflow header 52 is a member formed in a cylindrical shape by extrusion molding or an electric sewing tube, and closed at both ends. A refrigerant inflow pipe 51 a for allowing the refrigerant to flow into the refrigerant inflow header 51 is connected to one end of the refrigerant inflow header 51. Further, a refrigerant outflow pipe 52 a for allowing the refrigerant to flow out from the refrigerant outflow header 52 is connected to one end of the refrigerant outflow header 52. The refrigerant inflow header 51 and the refrigerant outflow header 52 are arranged with their central axes directed in the vertical direction, and are arranged at intervals.

  The refrigerant | coolant tube 53 is a member extended in the linear form formed in the flat shape by the extrusion molding or the bending of the board | plate material, and as shown to FIG. 4 thru | or FIG. 6, the some refrigerant | coolant flow path 53a is provided in the inside. The refrigerant tube 53 is provided with flat portions on both sides in the thickness direction. The plurality of refrigerant tubes 53 are arranged with their flat portions facing each other and spaced apart from each other, and one end is connected to the refrigerant inflow header 51 and the other end is connected to the refrigerant outflow header 52.

  As shown in FIGS. 2 and 5, the heat medium circulation unit 60 includes a pair of heat medium inflow header portions 60 a extending in the vertical direction on both outer sides in the width direction of the refrigerant tube 53 on the end portion side adjacent to the refrigerant outflow header 52. 2 and 6, a pair of heat medium outflow header portions 60b extending in the vertical direction on both outer sides in the width direction of the refrigerant tube 53 on the end side adjacent to the refrigerant inflow header 51, and FIGS. As shown in FIG. 4, between the pair of heat medium inflow header portions 60a and the pair of heat medium outflow header portions 60b, between the plurality of refrigerant tubes 53 and on both outer sides in the vertical direction of the plurality of refrigerant tubes 53 along the refrigerant tubes 53. And a heat medium flow part 60c as a plurality of heat medium flow paths extending.

  The heat medium circulation unit 60 includes a plurality of upper flow path forming plates 61 positioned above the plurality of heat medium circulation portions 60c and a plurality of lower flow paths positioned below the plurality of heat medium circulation portions 60c. And a heat transfer fin 63 disposed in the heat medium flow part 60 c formed between the upper flow path forming plate 61 and the lower flow path forming plate 62.

  The plurality of upper flow path forming plates 61, the plurality of lower flow path forming plates 62, and the plurality of heat transfer fins 63 are each formed by pressing a plate-like member.

  The upper flow path forming plate 61 and the lower flow path forming plate 62 are formed such that the width dimension at both ends in the longitudinal direction is larger than the width dimension of the refrigerant tube 53, and the width dimension of the portion excluding both ends in the longitudinal direction is the refrigerant tube. It is formed substantially the same as the width dimension of 53.

  A pair of communicating pipes 61 a in the width direction is formed on each of both ends in the longitudinal direction of the upper flow path forming plate 61 and is formed in a cylindrical shape extending upward and connected to the lower flow path forming plate 62 adjacent to the upper side. Has been.

  A pair of connecting holes 62a in the width direction are formed on both ends in the longitudinal direction of the lower flow path forming plate 62, to which the distal ends of the communication pipes 61a of the upper flow path forming plate 61 adjacent to the lower side are connected. Yes.

  The pair of heat medium inflow header portions 60 a and the pair of heat medium outflow header portions 60 b are formed by alternately stacking the upper flow path forming plates 61 and the lower flow path forming plates 62 in the vertical direction. It is formed by connecting the pipe 61a to the connection hole 62a of the lower flow path forming plate 62 adjacent to the upper side. Upper portions of the pair of heat medium inflow header portions 60a and the pair of heat medium outflow header portions 60b are closed by an upper flow path forming plate 61 in which the communication pipe 61a is not provided. Lower portions of the pair of heat medium inflow header portions 60a and the pair of heat medium outflow header portions 60b are closed by a lower flow path forming plate 62 in which no connection hole 62a is provided. A heat medium inflow pipe 60d is connected to a portion located between the pair of heat medium inflow header portions 60a, and the upper flow path forming plate 61 located at the uppermost position is located between the pair of heat medium outflow header portions 60b. The heat medium outlet pipe 60e is connected to the part to be performed.

  The heat transfer fins 63 are plate-like members that are formed in a wave shape in the width direction of the heat medium circulation portion 60c, and the upper apex is connected to the upper flow path forming plate 61, and the lower apex is the lower Connected to the side flow path forming plate 62.

  The heating heat exchanger 22 and the cooling heat exchanger 23 include a refrigerant inflow header 51, a refrigerant outflow header 52, a plurality of refrigerant tubes 53 that constitute the refrigerant circulation unit 50, and a plurality of upper sides that constitute the heat medium circulation unit 60. The flow path forming plate 61, the plurality of lower flow path forming plates 62, and the plurality of heat transfer fins 63 are joined together by brazing in a state where they are assembled.

  Moreover, the heat exchanger 22 for heating and the heat exchanger 23 for cooling are formed with an anticorrosion layer 70 made of a highly corrosion-resistant material such as an acrylic resin or an epoxy resin on the outer surface side and the inner surface side of the heat medium circulation unit 60. Has been. The anticorrosion layer 70 is formed on the outer surface side of the heat exchanger 22 for heating and the heat exchanger 23 for cooling and the inner surface side of the heat medium circulation unit 60 by, for example, cationic electrodeposition coating.

  In the heating heat exchanger 22 and the cooling heat exchanger 23 as the heat exchangers configured as described above, the refrigerant flowing through the refrigerant circuit 20, the heating heat medium circuit 30, and the cooling heat medium circuit 40 are distributed. Heat exchange with the heating medium.

  As shown in FIG. 2, the refrigerant flowing through the refrigerant circuit 20 flows in the refrigerant distribution unit 50 in the order of the refrigerant inflow pipe 51a, the refrigerant inflow header 51, the plurality of refrigerant tubes 53, the refrigerant outflow header 52, and the refrigerant outflow pipe 52a. To do.

  Further, as shown in FIG. 2, the heat medium flowing through the heating heat medium circuit 30 (cooling heat medium circuit 40) is a heat medium inflow pipe 60d and a pair of heat medium inflow header sections in the heat medium distribution unit 60. It distribute | circulates in order of 60a, several heat-medium distribution | circulation part 60c, a pair of heat-medium outflow header part 60b, and the heat-medium outflow pipe | tube 60e.

  Thus, according to the heat exchanger of this embodiment, the anticorrosion layer 70 which consists of a highly corrosion-resistant substance is formed in the outer surface side of the heat exchanger 22 for heating, and the heat exchanger 23 for cooling.

  Thereby, since it can suppress that a hole opens by corrosion, without enlarging the plate | board thickness of the refrigerant | coolant distribution | circulation unit 50 and the heat medium distribution | circulation unit 60, while being able to achieve weight reduction and improving corrosion resistance. Is possible.

  An anticorrosion layer 70 is formed on the inner surface side of the heat medium distribution unit 60.

  Thereby, in the heat medium distribution unit 60, since corrosion due to the heat medium flowing inside can be reduced, the plate thickness of the heat medium distribution unit 60 can be reduced, and the weight can be reduced.

  Moreover, the refrigerant | coolant tube 53 of the refrigerant | coolant distribution unit 50 and the heat-medium distribution | circulation part 60c of the heat-medium distribution | circulation unit 60 are mutually laminated | stacked alternately.

  Thereby, the refrigerant | coolant distribution | circulation unit 50 and the heat-medium distribution | circulation unit are covered by covering the outer surface side of the heat exchanger 22 for heating which laminated | stacked the refrigerant | coolant tube 53 and the heat-medium distribution | circulation part 60c, or the heat exchanger 23 for cooling with the anticorrosion layer 70. The performance of blocking the heat transfer inside and outside 60 is improved, and the heat exchange efficiency in the heat exchanger 22 for heating and the heat exchanger 23 for cooling can be improved.

  The anticorrosion layer 70 is made of an acrylic resin or an epoxy resin.

  Thereby, it becomes possible to form the anticorrosion layer 70 uniformly over the outer surface side of the heating heat exchanger 22 and the cooling heat exchanger 23 and the entire inner surface side of the heat medium circulation unit 60 by cationic electrodeposition coating or the like. .

  In the above embodiment, the antifreeze liquid is shown as the heat medium that exchanges heat with the refrigerant in the heat exchanger 22 for heating and the heat exchanger 23 for cooling. However, the present invention is not limited to this. A liquid such as water can be applied as the heat medium that exchanges heat with the refrigerant.

  Moreover, although the said embodiment showed the vehicle air conditioner 1 with which the refrigerant circuit 20 is filled with the carbon dioxide refrigerant | coolant from which the pressure of a high voltage | pressure side becomes high compared with another refrigerant | coolant, it is not restricted to this. For example, a flammable refrigerant or a toxic refrigerant such as ammonia gas may adversely affect the passengers in the passenger compartment A when leaked into the passenger compartment A. For this reason, it is desirable that the refrigerant circuit 20 be disposed outside the passenger compartment A such as an engine room from the viewpoint of protecting passengers in the passenger compartment A when the refrigerant leaks. Therefore, even in a vehicle air conditioner in which a refrigerant circuit is filled with a flammable refrigerant or a toxic refrigerant, the same effects as those of the above-described embodiment can be achieved by applying the present invention.

  Moreover, in the said embodiment, what formed the anticorrosion layer 70 which consists of a highly corrosion-resistant substance on the outer surface side in the heat exchanger 22 for heating and the heat exchanger 23 for cooling, and the inner surface side of the heat-medium distribution | circulation unit 60 is shown. Yes. When the highly corrosion-resistant substance of the above embodiment is filled in the gap between the outer peripheral portions of the pair of heat medium inflow header portions 60a and the pair of heat medium outflow header portions 60b of the heat medium circulation unit 60, only the corrosion resistance is improved. In addition, it is possible to prevent water from entering the gap. As a result, when the heat exchanger is used in a low temperature environment, it is possible to suppress damage to the heat exchanger due to freezing of water that has entered the gap and an increase in volume.

  Moreover, although the said embodiment showed what formed the anticorrosion layer 70 with respect to the heat exchanger 22 for a heating, and the heat exchanger 23 for a cooling, it is not restricted to this. If the anticorrosion layer 70 is formed on at least the heating heat exchanger 22 of the heating heat exchanger 22 and the cooling heat exchanger 23, the anticorrosion of the heating heat exchanger 22 on the high-pressure side in the refrigerant circuit 20. Therefore, durability of the refrigerant circuit 20 can be improved.

  DESCRIPTION OF SYMBOLS 20 ... Refrigerant circuit, 21 ... Compressor, 22 ... Heat exchanger for heating, 23 ... Heat exchanger for cooling, 29 ... Expansion valve, 50 ... Refrigerant distribution unit, 60 ... Heat medium distribution unit, 70 ... Anticorrosion layer.

Claims (5)

This is an aluminum or aluminum alloy heat exchanger that is connected to a refrigerant circuit provided outside the passenger compartment of the vehicle and exchanges heat between a carbon dioxide refrigerant, a flammable refrigerant, or a toxic refrigerant and a liquid heat medium. And
A heat exchanger in which an anti-corrosion layer made of a highly corrosion-resistant material is formed on the outer surface side. The heat exchanger according to claim 1, wherein an anticorrosion layer is formed on an inner surface side of the heat medium flow path through which the heat medium flows. A plurality of refrigerant flow paths through which the refrigerant flows;
A plurality of heat medium flow paths through which the heat medium flows,
The heat exchanger according to claim 1 or 2, wherein the plurality of refrigerant channels and the plurality of heat medium channels are alternately stacked. The heat exchanger according to any one of claims 1 to 3, wherein the anticorrosion layer is made of an acrylic resin or an epoxy resin. The refrigerant circuit includes a compressor that compresses and discharges the refrigerant, a heating heat exchanger that exchanges heat between the refrigerant discharged from the compressor and the heat medium, and an expansion that expands the refrigerant that has flowed out of the heating heat exchanger. A cooling heat exchanger for exchanging heat between the valve and the refrigerant expanded in the expansion valve and the heat medium,
The heat exchanger according to any one of claims 1 to 4, wherein the heat exchanger is used as at least a heating heat exchanger out of a heating heat exchanger and a cooling heat exchanger.