JP2013163440A - Heat medium heater and air conditioner for vehicle including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat medium heater capable of uniformly heating a heat medium not to generate imbalance and sharing a molding plate configuring a flat heat exchange tube and an inner fin, etc. and an air conditioner for a vehicle including the heat medium heater.SOLUTION: In a heat medium heater, a heat exchange element 12 configured by laminating a plurality of sheets of flat heat exchange tubes 13 and a plurality of pairs of PTC heaters 14 in a multilayer is stored and installed in a casing including outlet and inlet passages of a heat medium. An intermediate flat heat exchange tube 13B laminated in the middle of flat heat exchange tubes 13A, 13C on both sides of the flat exchange tubes 13 laminated in multilayer is constituted of a flat heat exchange tube in which two sheets of flat heat exchange tubes B1, B2 having substantially the same configurations with the flat heat exchange tubes 13A, 13C laminated on both the sides are arranged back-to-back and integrally joined.

Description

  The present invention relates to a heat medium heating device that heats a heat medium using a PTC heater, and a vehicle air conditioner including the heat medium heating device.

  In a vehicle air conditioner applied to an electric vehicle, a hybrid vehicle, or the like, a positive temperature coefficient thermistor element (hereinafter referred to as “Positive Temperature Coefficient”; hereinafter) A device using a PTC heater having a heat generating element as a PTC element) is known. In such a heat medium heating device, Patent Document 1 provides a plurality of partition walls that divide the inside of a housing having a heat medium outlet / inlet passage into a heating chamber and a heat medium circulation chamber, and the partition walls are provided on the heating chamber side. A PTC heater is inserted and installed in contact with the heating chamber to heat the heat medium flowing through the circulation chamber side, and a PTC heater control board is disposed at the upper position.

  Further, Patent Document 2 discloses a laminated structure heat medium in which a pair of heat medium circulation portions are stacked on both sides of a PTC heater and a substrate housing portion for housing a control substrate is provided on one surface side thereof. A heating device is disclosed. Furthermore, in Patent Document 3, a heat exchanging portion in which a large number of flat heat exchange tubes are provided between a pair of headers is provided in a casing having a heat medium outlet / inlet passage, and between the flat heat exchange tubes. A heat medium heating device is disclosed in which PTC heaters are installed and a control substrate for the PTC heaters is disposed at the upper position thereof.

  However, in Patent Documents 1 and 3, it is difficult to make the PTC heater and the partition wall or the flat heat exchanger tube serving as a heat transfer surface adhere to each other, the contact heat resistance between them increases, and the heat transfer efficiency decreases. have. On the other hand, since the thing of patent document 2 can laminate | stack and fix a PTC heater and a heat-medium distribution | circulation part, it can raise adhesiveness and can reduce contact thermal resistance, However, PTC heater is arrange | positioned in multiple layers. It is difficult to reduce the size and weight and the cost.

  Under such circumstances, by using a heat exchange tube with a flat structure, the flat heat exchange tube and the PTC heater are laminated in multiple layers to constitute a heat exchange element, and by tightening and fixing it in the casing, Development of a heat medium heating device that reduces contact thermal resistance and improves heat transfer efficiency and enables reduction in size and weight and cost.

JP 2008-7106 A JP 2011-16489 A JP 2011-79344 A

  However, as described above, when a heat exchange element is configured by laminating flat heat exchange tubes and PTC heaters in multiple layers, the flat heat exchange tubes laminated on both sides of the element are heated from only one side by the PTC heater. On the other hand, the middle (intermediate) flat heat exchanger tube to be laminated between the flat heat exchanger tubes on both sides is heated from both sides by the PTC heaters laminated on both sides thereof. become. For this reason, imbalance occurred in heating, and there was a possibility that temperature spots would occur in the heat medium.

  On the other hand, the middle (intermediate) flat heat exchanger tube is heated from both sides by the PTC heater as described above. Therefore, it is ideal to double the flow path height. However, if it does so, it becomes impossible to share the forming plate constituting the flat heat exchanger tube, the inner fin inserted into the flat heat exchanger tube, etc., which causes a decrease in productivity and an increase in cost. Such problems arise.

  The present invention has been made in view of such circumstances, and in a heat exchange element in which a flat heat exchange tube and a PTC heater are laminated in multiple layers, the heat medium is uniformly heated so as not to cause unbalance. Another object of the present invention is to provide a heat medium heating device that can share a forming plate, an inner fin, and the like constituting a flat heat exchanger tube, and a vehicle air conditioner including the heat medium heating device.

In order to solve the above-described problems, the heat medium heating device of the present invention and the vehicle air conditioner including the same employ the following means.
That is, the heat medium heating device according to the present invention includes a plurality of flat heat exchanger tubes that flow out from the outlet header portion after the heat medium flowing from the inlet header portion flows through the flat tube portion, and a plurality of the flat portions. A plurality of sets of PTC heaters incorporated between the flat tube portions of the heat exchange tube, and the heat exchange element formed by alternately laminating the flat heat exchange tubes and the PTC heaters is a heat medium. A heat medium heating device accommodated and installed in a casing having an inlet / outlet passage, wherein the intermediate portion of the flat heat exchange tubes laminated on both sides of the flat heat exchange tubes laminated in a multilayer of the heat exchange element Flat heat exchanger tube is laminated with two flat heat exchanger tubes of the same configuration as the flat heat exchanger tubes laminated on both sides. Characterized in that it is constituted by a tube.

  According to the present invention, in the heat exchange element configured by laminating a plurality of flat heat exchange tubes and a plurality of sets of PTC heaters in a multilayer manner, the flat heat exchange tubes on both sides of the flat heat exchange tubes laminated in a multilayer manner. An intermediate flat heat exchange tube laminated in the middle of the flat heat exchange tube is composed of two flat heat exchange tubes having substantially the same configuration as the flat heat exchange tubes laminated on both sides and joined together in a back-to-back manner. Therefore, since the intermediate flat heat exchanger tube to be heated from both sides by the PTC heater is a flat heat exchanger tube integrally joined with the two flat heat exchanger tubes back to back, The heat medium can be heated in the same manner as a flat heat exchanger tube having a flow path height of 2 times. Therefore, in all flat heat exchanger tubes including the flat heat exchanger tube and the intermediate flat heat exchanger tube arranged on both sides of the heat exchange element, the heat medium can be heated substantially uniformly and efficiently through the PTC heater, Generation of temperature spots can be suppressed. In addition, the intermediate flat heat exchanger tube can be configured with a tube having substantially the same configuration as the flat heat exchanger tube laminated on both sides, and all the flat heat exchanger tubes can be formed with substantially the same configuration. By sharing fins and the like, productivity reduction and cost increase can be prevented.

  Furthermore, the heat medium heating device of the present invention is the above-described heat medium heating device, wherein the flat heat exchanger tube has the same surface on the one side of the inlet header portion, the outlet header portion, and the flat tube portion. It is characterized by a flat surface configuration.

  According to the present invention, since the flat heat exchanger tube has a flat surface configuration in which the surfaces of the inlet header portion and the outlet header portion and the flat tube portion are flush with each other, the intermediate flat heat exchanger tube is Heat exchange elements can be easily integrated by joining the flat surfaces together and joined together, and the flat heat exchanger tubes on both sides are laminated with the flat surface configuration facing outward It is possible to make the both sides of the surface flat and clean. Accordingly, it is possible to easily integrate the intermediate flat heat exchanger tubes by joining, and also to easily incorporate the heat exchange element into the casing.

  Furthermore, the heating medium heating device of the present invention is the heating medium heating device according to any one of the above, wherein the flat heat exchanger tube is formed by laminating a pair of molded plates obtained by press-molding thin plates and brazing and joining them, One forming plate of the pair of forming plates has a flat surface configuration in which the surfaces of the inlet header portion, the outlet header portion, and the flat tube portion are flush with each other.

  According to the present invention, the flat heat exchanger tube is formed by laminating a pair of molding plates obtained by press-molding a thin plate and brazing and joining, and one molding plate of the pair of molding plates is an inlet header portion. And the outlet header portion and the flat tube portion have the same flat surface configuration, so that one of the press-molded plates is formed between the inlet header portion and the outlet header portion and the flat tube portion. It is not structurally different from the conventional flat heat exchanger tube except that it has a flat surface structure with the same surface, and can be manufactured by the same method. Therefore, it is possible to easily manufacture a flat heat exchanger tube having a flat surface on one side without causing a decrease in productivity or an increase in cost.

  Furthermore, in the heat medium heating device of the present invention, in any one of the heat medium heating devices described above, the intermediate flat heat exchanger tube is a flat heat exchanger tube formed by brazing and joining two flat heat exchanger tubes back to back. It is configured.

  According to the present invention, since the intermediate flat heat exchange tube is constituted by the flat heat exchange tube in which two flat heat exchange tubes are joined by brazing back to back, the two flat heat exchange tubes are back to back. It is possible to produce an intermediate flat heat exchanger tube that integrally joins two flat heat exchanger tubes by simply attaching them. By brazing, the area around the communication holes in the inlet / outlet headers can be sealed and sealed. it can. Therefore, the intermediate flat heat exchanger tube can be easily manufactured, and the periphery of the communication hole of the outlet / inlet header portion of the intermediate flat heat exchanger tube can be surely sealed without using a sealing material.

  Furthermore, the heat medium heating device of the present invention has a flat surface configuration of the two flat heat exchanger tubes to be joined by brazing of the intermediate flat heat exchanger tube in any one of the heat medium heaters described above. The one forming plate is a thin plate material in which a brazing material is clad on both sides.

  According to the present invention, one of the flat plates of the two flat heat exchanger tubes to be brazed and joined to the intermediate flat heat exchanger tube is a thin plate member having a brazing material clad on both sides thereof. Therefore, when a tube is formed by brazing and joining a pair of press-molded molding plates with a brazing material clad on one side, they are joined together by a brazing material clad on the other side 2 The flat surfaces of the flat heat exchanger tubes can be joined together by brazing at the same time. Therefore, the intermediate flat heat exchanger tube can be manufactured by the same method as other flat heat exchanger tubes. In addition, one shaping | molding plate of other flat heat exchanger tubes may be a single-sided clad material, and the sticking countermeasure with respect to a brazing jig becomes unnecessary.

  Furthermore, the vehicle air conditioner according to the present invention is configured such that the heat medium heated by the heat medium heating device can be circulated with respect to the radiator disposed in the air flow passage. The heat medium heating device is any one of the above-described heat medium heating devices.

  According to the present invention, in a vehicle air conditioner configured such that the heat medium heated by the heat medium heating device can be circulated with respect to the radiator disposed in the air flow passage, the heat medium heating device Is one of the heat medium heating devices described above, the heat medium supplied to the radiator disposed in the air flow passage is heated substantially uniformly and efficiently through the PTC heater, and temperature fluctuations occur. It can be heated and supplied by the above-described heat medium heating device that can suppress the occurrence of the above. Therefore, the heating performance of the vehicle air conditioner can be stabilized and the reliability of the vehicle air conditioner can be improved.

  According to the heat medium heating device of the present invention, the intermediate flat heat exchanger tube to be heated from both sides by the PTC heater is a flat heat exchanger tube joined together with the two flat heat exchanger tubes back to back. Therefore, it is possible to heat the heat medium in the same way as a flat heat exchanger tube having a flow path height that is twice as high, so that the flat heat exchanger tube and the middle disposed on both sides of the heat exchange element In all the flat heat exchanger tubes including the flat heat exchanger tubes, the heat medium can be heated substantially uniformly and efficiently via the PTC heater, and the occurrence of temperature spots can be suppressed. In addition, the intermediate flat heat exchanger tube can be configured with a tube having substantially the same configuration as the flat heat exchanger tube laminated on both sides, and all the flat heat exchanger tubes can be formed with substantially the same configuration. By sharing fins and the like, productivity reduction and cost increase can be prevented.

  In addition, according to the vehicle air conditioner of the present invention, the heat medium supplied to the radiator disposed in the air flow passage is heated substantially uniformly and efficiently through the PTC heater, thereby generating temperature spots and the like. Since it can heat and supply with the above-mentioned heat-medium heating device which can be suppressed, the heating performance of a vehicle air conditioner can be stabilized and the reliability of a vehicle air conditioner can be improved.

It is a schematic block diagram of the vehicle air conditioner provided with the heat-medium heating device which concerns on 1st Embodiment of this invention. It is a disassembled perspective view of the heat carrier heating apparatus shown in FIG. It is the assembly | attachment state figure (A) of the heat exchange element which consists of a flat heat exchanger tube and a PTC heater built in the heat-medium heating apparatus shown in FIG. 2, and its exploded view (B).

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 shows a schematic configuration diagram of a vehicle air conditioner including a heat medium heating device according to an embodiment of the present invention.
The vehicle air conditioner 1 is provided with a casing 3 that forms an air flow passage 2 for taking outside air or vehicle interior air and adjusting the temperature thereof, and then guiding it to the vehicle interior.

  Inside the casing 3, a blower 4 that sucks and pressurizes outside air or passenger compartment air in order from the upstream side to the downstream side of the air flow passage 2 and pumps it to the downstream side, and is pumped by the blower 4. The flow rate ratio of the cooler 5 that cools the air to be cooled, the radiator 6 that heats the air that has passed through the cooler 5, and the amount of air that passes through the radiator 6 and the amount of air that bypasses the radiator 6 And an air mix damper 7 that adjusts the temperature of the temperature-controlled air by installing the air mix on the downstream side thereof.

The downstream side of the casing 3 is connected to a plurality of outlets for blowing out temperature-controlled air into the vehicle compartment via an outlet mode switching damper and a duct (not shown).
The cooler 5 constitutes a refrigerant circuit together with a compressor, a condenser, an expansion valve, etc., not shown, and cools the air passing therethrough by evaporating the refrigerant adiabatically expanded by the expansion valve. . The radiator 6 constitutes a heat medium circulation circuit 10A together with the tank 8, the pump 9 and the heat medium heating device 10, and a heat medium (for example, antifreeze liquid, hot water, etc.) heated to a high temperature by the heat medium heating device 10 is used. By circulating through the pump 9, the air passing therethrough is heated.

FIG. 2 shows an exploded perspective view of the heat medium heating device 10 shown in FIG. 1, and FIG. 3 shows a heat exchange comprising a flat heat exchanger tube incorporated in the heat medium heating device 10 and a PTC heater. A block diagram of the elements is shown.
As shown in FIG. 2, the heat medium heating device 10 includes a casing 11, a plurality of flat heat exchanger tubes 13 and a plurality of sets of PTC heaters 14 stacked in a multilayer structure incorporated in the casing 11. An element 12, a heat exchange pressing member 15 that presses and fixes the heat exchange element 12 to the casing 11, and a control board 16 that controls energization of the PTC heater 14 are provided.

  The casing 11 is formed of an upper casing (not shown) that constitutes the upper half of the casing 11 and a lower casing 11A that constitutes the upper half of the casing 11. It is tightened and fixed via the, and is integrated. The lower casing 11A is integrally formed with an inlet passage 11B and an outlet passage 11C for a heat medium, and a boss portion 11D for fastening and fixing the heat exchanger pressing member 15 is integrally formed with four corner portions.

  Moreover, the lower surface of the lower casing 11 </ b> A is provided with a power harness connecting portion and an LV harness connecting portion (both not shown) for penetrating the distal ends of the power harness 17 and the LV harness 18. The power supply harness 17 is for supplying power to the PTC heater 14 via a control board 16 on which a power transistor and a control circuit are mounted. The two power supply harness terminal blocks 16 </ b> A can be screwed via electrode harness connection screws 19. Further, the LV harness 18 transmits a control signal to the control board 16, and a tip portion thereof can be connected to the control board 16 via a connector.

  The heat exchange element 12 is configured by laminating a plurality of flat heat exchanger tubes 13 and a plurality of sets of PTC heaters 14 incorporated therebetween, and is laminated on the inner bottom surface of the lower casing 11A. On the other hand, the heat exchanger pressing member 15 is pressed and fixed from one side. The flat heat exchanger tube 13 includes an upper flat heat exchanger tube 13A and a lower flat heat exchanger tube 13C arranged on both sides when laminated, and a middle (intermediate) flat heat exchanger tube 13B arranged in the middle. The middle (intermediate) flat heat exchanger tube 13B is a flat heat exchanger tube 13B integrated by joining two flat heat exchanger tubes B1 and B2 back to back.

  Each flat heat exchanger tube 13 is formed by press-molding a thin plate made of aluminum alloy with one side clad with a brazing material, and a pair of molded plates in which the flat tube portion 21, the inlet header portion 22, and the outlet header portion 23 are integrally formed. 20A and 20B are overlapped and joined by brazing. The inlet header portion 22 and the outlet header portion 23 are juxtaposed on one end side of the tube, and the flat tube portion 21 extends from the inlet header portion 22 and is folded back at the other end side to return to the outlet header portion 23. A flow path is formed. The U-turn flow path of the flat tube portion 21 may have a configuration in which an inner fin shaped in a waveform is inserted and installed.

  Of the pair of molding plates 20A and 20B, one molding plate 20A has a flat surface configuration in which the flat tube portion 21, the inlet header portion 22 and the outlet header portion 23 have the same surface, and the other. The forming plate 20B is configured such that the inlet header portion 22 and the outlet header portion 23 protrude from the flat tube portion 21 by a predetermined dimension. The flat heat exchanger tube 13B in the middle stage is integrated by brazing one of the two flat heat exchanger tubes B1 and B2 with one molding plate 20A being back to back. .

  In order to configure the middle (intermediate) flat heat exchanger tube 13B as described above, only two flat heat exchanger tubes B1 and B2 are used, using a thin plate material in which one molding plate 20A is clad with a brazing material on both sides. When a pair of molding plates 20A and 20B are brazed and joined into a tube shape, the two brazing plates 20A and 20B can be brazed at the same time.

  Of the flat heat exchanger tubes 13A, 13B, and 13C, the inlet header portion 22 and the outlet header portion 23 of the molded plates 20A and 20B of all tubes except the one molded plate 20A of the upper flat heat exchanger tube 13A are laminated. When this is done, a communication hole (not shown) is provided for communicating the inlet header portion 22 and the outlet header portion 23 of the adjacent tubes. It is necessary to seal the communication holes so that the heat medium flowing through the flat heat exchanger tubes 13A, 13B, and 13C does not leak.

  Since the two flat heat exchanger tubes B1 and B2 of the middle flat heat exchanger tube 13B are sealed by being brazed together, it is not necessary to put a sealing material, but the other flat heat exchanger tubes 13A , 13C around the communication hole requires a sealing means, and a sealing material 24 such as a liquid gasket or an O-ring is interposed at the time of stacking, and is tightly sealed to seal it. In the lower flat heat exchanger tube 13C, the inlet header portion 22 and the outlet header portion 23 communicate with the heat medium inlet passage 11B and the outlet passage 11C on the lower casing 11A side, and therefore a sealing material 24 is interposed at the communicating portion. There is a need to.

  As is well known, the PTC heater 14 is composed of a PTC element and a pair of electrode plates (both not shown) for supplying electric power thereto. Here, as shown in FIG. The plate-like PTC heater 14 has a rectangular shape and a certain thickness. In the present embodiment, the PTC heater 14 is formed between the flat tube portion 21 between the lower flat heat exchanger tube 13C and the middle flat heat exchanger tube 13B, and between the middle flat heat exchanger tube 13B and the upper flat heat exchanger tube 13A. Are stacked in multiple layers.

  Each of the pair of electrode plates is integrally provided with a terminal 25, and is extended from one side of the electrode plate to the side and then bent upward in an L shape. Each of the plurality of terminals 25 is configured to be directly connected via a screw 26 to a terminal block 16B provided on the control board 16 described later. The PTC heater 14 is interposed between the flat heat exchanger tubes 13 with both surfaces sandwiched between a thin insulating film and a heat conductive sheet (both not shown).

  The heat exchange element 12 is incorporated into the inner bottom surface of the lower casing 11A while sequentially laminating the flat heat exchange tube 13 and the PTC heater 14 or in a state of being pre-assembled and laminated. Then, the heat exchanger pressing member 15 is stacked on the upper surface of the upper flat heat exchanger tube 13A, and the four corner portions of the heat exchanger pressing member 15 are fastened and fixed to the boss portion 11D of the lower casing 11A via screws 27, The sealing material 24 interposed between the flat heat exchanger tubes 13A, 13B, 13C and the PTC heater 14 and between the outlet / inlet header portions 22, 23 of the flat heat exchanger tubes 13A, 13B, 13C can be brought into close contact with each other. I have to.

  The heat exchanger pressing member 15 is made of an aluminum alloy material having good thermal conductivity, and its lower surface is configured to come into contact with the upper surface of the upper flat heat exchanger tube 13A. Thereby, the heat exchanger pressing member 15 uses a heat medium flowing in the flat heat exchanger tube 13 as a cooling source, and cools a power transistor (heat generating electrical component) such as an IGBT on the control board 16 installed on the upper surface thereof. It is designed to function as a heat sink. It is preferable that the heat exchanger pressing member 15 is fastened and fixed with the screw 27 on a line passing through the centers of the outlet / inlet header portions 22 and 23 of the flat heat exchanger tubes 13.

  As described above, the control board 16 is fixedly installed by screws 28 on the upper surface of the heat exchanger pressing member 15 with a heat conductive insulating sheet or the like interposed therebetween. The control board 16 is mounted with a control circuit that controls energization of a plurality of sets of PTC heaters 14 based on a command from a host control unit (ECU). For example, a plurality of power transistors such as IGBTs are mounted on the control board 16. Thus, the energization state of the plurality of sets of PTC heaters 14 can be switched.

  A power harness 17 is connected to the terminal board 16A of the control board 16, an LV harness 18 is connected via a connector, and a terminal 25 of the electrode plate is directly connected to the terminal board 16A. As a result, all electrical systems are connected. The heat medium heating device 10 is assembled by assembling the upper casing to the lower casing 11A after the incorporation of the internal device into the lower casing 11A is completed.

  In the heat medium heating device 10 described above, the heat medium flowing from the heat medium inlet passage 11 </ b> B of the casing 11 circulates through the inlet header portion 22 of each flat heat exchanger tube 13 to the flat tube portion 21, and While flowing through the U-turn flow path, it is heated and heated by the PTC heater 14, flows out to the outlet header portion 23, and then flows through the flow path that is sent to the outside through the heat medium outlet path 11C. ing. The heat medium flowing out from the heat medium heating device 10 is supplied to the radiator 6 through the heat medium circulation circuit 10A (see FIG. 1) and is used for heating.

  On the other hand, the power supplied from the power supply harness 17 is applied to the PTC heater 14 via the control board 16. The control board 16 is mounted with a control circuit for performing energization control for the plurality of sets of PTC heaters 14. For example, the energization state for the plurality of sets of PTC heaters 14 is switched and controlled via a plurality of power transistors such as IGBTs. The amount of heating is controlled. At this time, the heat generated in the power transistor is thermally conducted to the heat exchanger pressing member 16 made of an aluminum alloy material having good thermal conductivity. The heat exchanger pressing member 16 is used as a heat sink, and the flat heat exchanger tube 13 is used. The heat medium flowing inside is cooled by a cold heat source.

  The heat generated by the PTC heater 14 is transferred to a plurality of flat heat exchanger tubes 13 via a heat conductive sheet or the like, and used to heat the heat medium flowing through the inside. Here, each PTC heater 14 and the flat heat exchanger tube 13 are brought into close contact with each other by being pressed through the heat exchanger pressing member 16, so that the contact thermal resistance therebetween is reduced and the heat transfer efficiency is improved. . Accordingly, the heat medium can be efficiently heated, and the heat medium heating device 10 can be improved in performance and reduced in size and size. Further, by tightening the heat exchanger pressing member 16, the sealing material 24 such as an O-ring interposed around the communication holes of the outlet / inlet header portions 22 and 23 of each flat heat exchanger tube 13 can be surely adhered. Therefore, the sealing property can be secured and the reliability for preventing the heat medium from leaking can be improved.

  Further, in the present embodiment, among the plurality of flat heat exchanger tubes 13 stacked in multiple layers constituting the heat exchange element 12, the upper and lower flat heat exchanger tubes 13A and 13C stacked on both upper and lower sides are arranged. The middle (intermediate) flat heat exchanger tube 13B laminated in the middle is back-to-back with two flat heat exchanger tubes B1, B2 having substantially the same configuration as the upper and lower flat heat exchanger tubes 13A, 13C laminated on the upper and lower sides. Thus, a flat heat exchanger tube 13B having a structure joined integrally is formed.

  In this way, the middle flat heat exchanger tube 13B to be heated from both sides by the PTC heater 14 is combined with the flat heat exchanger tube 13B integrally joined with the two flat heat exchanger tubes B1 and B2 back to back. By doing so, it becomes possible to heat the heat medium in the same manner as a flat heat exchanger tube whose flow path height is substantially doubled. For this reason, in all the flat heat exchanger tubes 13 including the upper and lower flat heat exchanger tubes 13A and 13C disposed on both sides of the heat exchange element 12 and the middle (intermediate) flat heat exchanger tube 13B, the PTC heater 14 Thus, the heating medium can be heated substantially uniformly and efficiently, and the occurrence of temperature spots can be suppressed.

  Further, the middle (intermediate) flat heat exchanger tube 13B can also be composed of flat heat exchanger tubes B1, B2 having substantially the same configuration as the upper and lower flat heat exchanger tubes 13A, 13C laminated on both sides, and all the flat heat exchanger tubes Since the tube 13 can be a tube having substantially the same configuration, the molding plates 20A and 20B, the inner fins, and the like can be used in common, thereby preventing a reduction in productivity and an increase in cost.

  Further, each flat heat exchanger tube 13 has a flat surface structure in which the surfaces of the inlet header portion 22 and the outlet header portion 23 and the flat tube portion 21 are flush with each other. For this reason, the flat heat exchanger tubes 13B in the middle stage can be easily integrated by joining and joining the flat surfaces, and the flat heat exchanger tubes 13A and 13C in the upper and lower stages are flat surfaces. By laminating with the configured surfaces facing outside, the both sides of the heat exchange element 12 can be made flat and flat. Therefore, it is easy to integrate by joining the flat heat exchanger tube 13B in the middle stage, and it is also possible to facilitate the incorporation of the heat exchange element 12 into the casing 11.

  Further, the flat heat exchanger tube 13 is formed by laminating a pair of molding plates 20A and 20B obtained by press-molding a thin plate and brazing and joining, and one of the pair of molding plates 20A and 20B has a molding plate 20A. Since the surface of the inlet header portion 22 and the outlet header portion 23 and the flat tube portion 21 is a flat surface structure, one of the molding plates 20A to be press-molded includes the inlet header portion 22 and Except for the flat surface configuration in which the surfaces of the outlet header portion 23 and the flat tube portion 21 are made flush with each other, this is not structurally different from the conventional flat heat exchanger tube and is manufactured in the same manner. can do. Therefore, the flat heat exchanger tube 13 having a flat surface on one side can be easily manufactured without causing a decrease in productivity and an increase in cost.

  Further, the middle (intermediate) flat heat exchanger tube 13B is constituted by a flat heat exchanger tube 13B in which two flat heat exchanger tubes B1, B2 are brazed and joined back to back. For this reason, it is possible to manufacture a middle flat heat exchanger tube 13B in which the two flat heat exchanger tubes B1 and B2 are joined together by simply brazing the two flat heat exchanger tubes B1 and B2 back to back. It is possible to seal around the communication holes of the inlet / outlet header portions 22 and 23 by the brazing and seal them. Therefore, the middle flat heat exchanger tube 13 </ b> B can be easily manufactured, and the communication holes around the outlet / inlet header portions 22 and 23 can be reliably sealed without using the sealing material 24.

  In addition, one molding plate 20A having a flat surface configuration of the two flat heat exchanger tubes B1 and B2 to be brazed and joined to the middle (intermediate) flat heat exchanger tube 13B has a brazing material clad on both surfaces. It is a thin sheet material. For this reason, when a tube is formed by brazing and joining a pair of press-molded plates 20A and 20B with a brazing material clad on one surface, the tubes are joined together with a brazing material clad on the other surface. The flat surfaces of the two flat heat exchanger tubes B1 and B2 can be brazed together at the same time. Therefore, the middle flat heat exchanger tube 13B can be manufactured by the same method as the upper and lower flat heat exchanger tubes 13A and 13C.

  Furthermore, according to the vehicle air conditioner 1 of the present embodiment, the heat medium supplied to the radiator 6 disposed in the air flow passage 2 is heated substantially uniformly and efficiently via the PTC heater 14, Heating performance of the vehicle air conditioner 1 can be stabilized and the reliability of the vehicle air conditioner 2 can be improved because the heating medium heating device 10 capable of suppressing the occurrence of temperature spots can be heated and supplied. be able to.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above-described embodiment, the flat heat exchanger tubes 13A, 13B, and 13C are stacked in multiple layers, and the PTC heater 14 is incorporated between them. Of course, the number of laminated flat heat exchanger tubes 13B and PTC heaters 14 can be increased.

  Moreover, about each flat heat exchanger tube 13, although the inlet header part 22 and the outlet header part 23 were arranged in parallel at the one end side of the tube, and the U-turn flow path was formed in the meantime, Needless to say, the inlet header portion may be a tube provided with an outlet header portion on the other end side. Furthermore, the casing 11 may be made of a resin such as PPS or a metal such as an aluminum alloy.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 2 Air flow path 6 Radiator 10 Heat medium heating apparatus 10A Heat medium circulation circuit 11 Casing 11B Heat medium inlet path 11C Heat medium outlet path 12 Heat exchange element 13, B1, B2 Flat heat exchanger tube 13A Upper flat Heat exchanger tube 13B Middle (intermediate) flat heat exchanger tube 13C Lower flat heat exchanger tube 14 PTC heater 15 Heat exchanger presser member 16 Control board 20A, 20B Molding plate 21 Flat tube portion 22 Inlet header portion 23 Outlet header portion

Claims (6)

A plurality of flat heat exchanger tubes that flow out from the outlet header part after the heat medium flowing in from the inlet header part flows through the flat tube part,
A plurality of sets of PTC heaters incorporated between the flat tube portions of the plurality of flat heat exchanger tubes,
A heat medium heating device in which the heat exchange element configured by alternately laminating the flat heat exchange tubes and the PTC heaters is housed in a casing having a heat medium outlet / inlet passage. ,
An intermediate flat heat exchange tube laminated in the middle of the flat heat exchange tubes laminated on both sides of the flat heat exchange tubes laminated in multiple layers of the heat exchange element is substantially the same as the flat heat exchange tube laminated on both sides. A heat medium heating apparatus comprising a flat heat exchanger tube in which two flat heat exchanger tubes having a structure are joined back to back.   2. The flat heat exchanger tube according to claim 1, wherein one side of the flat heat exchanger tube has a flat surface configuration in which surfaces of the inlet header portion and the outlet header portion and the flat tube portion are flush with each other. Heat medium heating device.   The flat heat exchanger tube is formed by laminating a pair of molding plates obtained by press-molding a thin plate and brazing and joining, and one molding plate of the pair of molding plates includes the inlet header portion, the outlet header portion, and the The heat medium heating device according to claim 1, wherein the flat tube portion has a flat surface configuration in which a surface of the flat tube portion is flush with the surface.   The heat medium according to any one of claims 1 to 3, wherein the intermediate flat heat exchange tube is constituted by a flat heat exchange tube in which the two flat heat exchange tubes are joined by brazing back to back. Heating device.   The one molding plate having a flat surface configuration of the two flat heat exchanger tubes to be joined by brazing of the intermediate flat heat exchanger tube is a thin plate material in which a brazing material is clad on both surfaces. The heating medium heating device according to claim 3 or 4, wherein In the vehicle air conditioner configured such that the heat medium heated by the heat medium heating device can be circulated with respect to the radiator disposed in the air flow passage,
The vehicle air conditioner, wherein the heat medium heating device is the heat medium heating device according to any one of claims 1 to 5.

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