JP2013194968A - Heat exchanger and air conditioner mounted with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a thermosensitive device mounted to measure a temperature of a refrigerant flowing in a tube from affecting the tube.SOLUTION: A heat exchanger 1 includes: a tube 3 in which a refrigerant flows; and fins 2 mounted to the tube 3. A thermosensitive device 7 for sensing a refrigerant temperature is mounted to the tube 3. A component preventing the tube 3 from generating electrolytic corrosion is interposed between the tube 3 and the thermosensitive device 7. The component may be a component of an outer case 8 of the thermosensitive device 7 and may be a component of fixation members 10, 11 for mounting the thermosensitive device 7 to the tube 3.

Description

  The present invention relates to a heat exchanger and an air conditioner equipped with the heat exchanger.

  Most heat exchangers used in air conditioners exchange heat with ambient air by flowing a refrigerant through the tube. Heat exchangers used in air conditioners include fin and tube type, serpentine type, and parallel flow type. Patent Document 1 shows an example of a parallel flow heat exchanger.

  In the parallel flow heat exchanger described in Patent Document 1, the refrigerant temperature is measured and used for control. The temperature sensing element for detecting the refrigerant temperature is attached with a metal fitting at a location where the gas-liquid two-phase refrigerant flows in the header pipe on the refrigerant pipe connection side.

JP 2011-85368 A

  Even in a heat exchanger other than the parallel flow type, it may be necessary to know the temperature of the refrigerant flowing therethrough. The present invention has been made in view of this point, and an object thereof is to prevent the attachment of the temperature sensitive element from adversely affecting the tube.

  In order to achieve the above object, the present invention provides a heat exchanger having a tube through which a refrigerant flows and fins attached to the tube, and a temperature sensing element for detecting the refrigerant temperature is attached to the tube. A constituent material that does not cause electric corrosion in the tube is interposed between the tube and the temperature sensitive element.

  In the heat exchanger configured as described above, it is preferable that the tube is made of aluminum and the constituent material is also aluminum.

  In the heat exchanger configured as described above, the tube is preferably made of aluminum, and the constituent material is preferably a synthetic resin containing an aluminum filler.

  In the heat exchanger configured as described above, the synthetic resin containing the aluminum filler is preferably a heat conductive synthetic resin.

  In the heat exchanger configured as described above, the constituent material is preferably a synthetic resin.

  In the heat exchanger having the above configuration, the synthetic resin of the constituent material is preferably a heat conductive synthetic resin.

  In the heat exchanger configured as described above, it is preferable that the constituent material is a metal material that is baseless with respect to the tube.

  In the heat exchanger having the above configuration, the constituent material is preferably a constituent material of an outer case of the temperature sensitive element.

  In the heat exchanger configured as described above, the constituent material is preferably a constituent material of a fixing member for attaching the temperature sensing element to the tube.

  In the heat exchanger having the above configuration, it is preferable that a constituent material that can be brazed to the tube is used as a constituent material of the fixing member.

  Further, the present invention is an air conditioner in which the heat exchanger configured as described above is mounted on an indoor unit or an outdoor unit.

  ADVANTAGE OF THE INVENTION According to this invention, the heat exchanger which can measure a refrigerant | coolant temperature can be provided, without having a bad influence on the tube which flows a refrigerant | coolant.

It is a schematic block diagram of a fin and tube type heat exchanger. It is a 1st partial front view which shows the state which attached the temperature sensing element to the fin and tube type heat exchanger. It is a 2nd partial front view which shows the state which attached the temperature sensitive element to the fin and tube type heat exchanger. It is a partial top view which shows the condition which attaches a temperature sensing element to a tube via a fixing member. It is a partial top view which shows the state which attached the temperature sensitive element to the tube via the fixing member. It is a partial top view which shows the condition which attaches a temperature sensing element to a tube using the fixing member of a different shape. It is a schematic block diagram of the air conditioner carrying the heat exchanger which concerns on this invention, and shows the state at the time of air_conditionaing | cooling operation. It is a schematic block diagram of the air conditioner carrying the heat exchanger which concerns on this invention, and shows the state at the time of heating operation.

  The structure of the fin-and-tube heat exchanger that forms the basis of the embodiment of the present invention will be described with reference to FIG. In FIG. 1, the upper side of the paper is the upper side of the heat exchanger, and the lower side of the paper is the lower side of the heat exchanger. Further, the left side of the paper is the left side of the heat exchanger, and the right side of the paper is the right side of the heat exchanger.

  The heat exchanger 1 includes a large number of fins 2 and one meandering tube 3. The individual fins 2 have a strip shape with the vertical direction as the longitudinal direction, and many fins 2 are arranged in the horizontal direction with a predetermined gap between each other. The tube 3 penetrates through the group of fins 2 so as to meander and sew. The inside of the tube 3 serves as a refrigerant passage 4 through which the refrigerant flows. The fin 2 and the tube 3 are made of a metal having good heat conductivity such as aluminum, and are fixed by, for example, brazing, welding, or tube expansion.

  Both ends of the tube 3 serve as refrigerant inlets and outlets 5 and 6, and refrigerant pipes of devices (for example, air conditioners) are connected thereto. The refrigerant may enter from the refrigerant inlet / outlet 5 as indicated by a solid line arrow and exit from the refrigerant inlet / outlet 6, or may enter from the refrigerant inlet / outlet 6 and exit from the refrigerant inlet / outlet 5 as indicated by a broken line arrow. When the heat exchanger 1 is used as a condenser, the refrigerant flow enters from the refrigerant inlet / outlet 5 and exits from the refrigerant inlet / outlet 6. When the heat exchanger 1 is used as an evaporator, the refrigerant flow enters from the refrigerant inlet / outlet 6 and exits from the refrigerant inlet / outlet 5. There are many cases.

  In the heat exchanger 1 of the fin-and-tube type, it is common that the fin 2 is made of aluminum and the tube 3 is made of copper. However, a configuration in which the tube 3 is made of aluminum is also possible.

  The temperature sensitive element 7 is used to measure the temperature of the refrigerant flowing inside the tube 3. The temperature sensitive element 7 is a thermistor (not shown) wrapped in an outer case 8.

  The temperature sensitive element 7 is attached to the tube 3. When attaching the temperature sensing element 7, as shown in FIGS. 2 and 3, a fixing method in which the temperature sensing element 7 is brought into direct contact with the outer surface of the tube 3 is possible. Alternatively, as shown in FIG. 6, a fixing method is also possible in which a fixing member is interposed between the tube 3 and the temperature sensing element 7 to avoid direct contact between the tube 3 and the temperature sensing element 7.

  In the configuration shown in FIG. 2, the temperature sensitive element 7 is fixed to the tube 3 by a binding band 9.

  In the configuration shown in FIG. 3, the temperature sensitive element 7 is fixed to the tube 3 by a fixing member 10. As shown in FIG. 4, the planar shape of the fixing member 10 is L-shaped, the longer side of the L-shape is pressed tightly against the tube 3, and the shorter side with the curved tip is bent by the tube 3. Stick out at right angles to the plane you want. When the temperature sensing element 7 is pushed in between the curved portion on the shorter side and the tube 3 as shown in FIG. 4, the temperature sensing element 7 is pushed against the tube 3 by the elasticity of the fixing member 10 as shown in FIG. 5.

In the configuration shown in FIG. 6, the temperature sensitive element 7 is fixed to the tube 3 by a fixing member 11. The fixing member 11 includes a bifurcated portion 11 a that sandwiches the tube 3 from both sides, and a bifurcated portion 11 b that sandwiches the temperature sensing element 7 from both sides, holds the tube 3 by its own elasticity, and holds the temperature sensing element 7. A fixing member 11 is interposed between the tube 3 and the temperature sensing element 7 so that the tube 3 and the temperature sensing element 7 do not come into direct contact with each other.

  The present invention is characterized in that a constituent material that does not cause electric corrosion in the tube 3 is interposed between the tube 3 and the temperature sensing element 7. In the case of the structure in which the temperature sensing element 7 is in direct contact with the tube 3 as in the configuration example of FIG. 2 and the configuration examples of FIG. 3 to FIG. In the case of the configuration example of FIG. 2, the binding band 9 is formed, and in the case of the configuration example of FIG. 3, the fixing member 10 is formed of such a configuration member.

  In the case of a structure in which the fixing member 11 is interposed between the tube 3 and the temperature sensitive element 7 as in the configuration example of FIG. In the configuration of FIG. 6, if not only the fixing member 11 but also the outer case 8 of the temperature sensing element 7 is formed of a constituent material that does not cause electrolytic corrosion in the tube 3, the possibility of electrolytic corrosion is further reduced.

  Examples of the constituent material that does not cause electrolytic corrosion in the tube 3 include the following.

  When the tube 3 is made of aluminum, the outer case 8, the fixing member 10, or the fixing member 11 can be formed of aluminum.

  When the tube 3 is made of aluminum, the outer case 8, the fixing member 10, or the fixing member 11 can be formed of a synthetic resin containing an aluminum filler. As the synthetic resin, a heat conductive synthetic resin can be used. When a heat conductive synthetic resin contains 50% of an aluminum filler by volume, the heat conductivity is 2.6 W / (m · k).

  Whether the tube 3 is aluminum or a metal other than aluminum, the outer case 8, the fixing member 10, or the fixing member 11 can be formed of synthetic resin. As the synthetic resin, a heat conductive synthetic resin can be used.

  Whether the tube 3 is aluminum or a metal other than aluminum, the outer case 8, the fixing member 10, or the fixing member 11 can be formed of a metal material that is lower than the tube 3. When the tube 3 is formed of an NE alloy (composition: 0.05% Si, 0.18% Fe, 0.4% Cu, 0.02% Zn, 0.04% Zr) which is a kind of corrosion resistant alloy A Zn-added alloy can be used as the base metal material.

  As described above, if a “noble” material is used for the tube 3 and a “base” material is used for the outer case 8, the fixing member 10, or the fixing member 11, corrosion will occur. Under the environment, the corrosion of the “base” material has priority, so that the progress of the corrosion of the tube 3 is suppressed. This is a method called “sacrificial corrosion protection method”.

  According to the present invention, it is possible to use the heat exchanger 1 without suppressing electric corrosion of the tube 3 and worrying about refrigerant leakage from the tube 3.

  If a constituent material that can be brazed to the tube 3 is used as a constituent material of the fixing member 10 or 11, the temperature sensitive element 7 can be attached more firmly. For example, when the tube 3 is made of aluminum, brazing is possible if the fixing member 10 or 11 is also made of aluminum. The constituent material that can be brazed to the tube 3 is not limited to aluminum.

  7 and 8 show a schematic configuration of a separate air conditioner AC using the heat exchanger 1 as a component of the heat pump cycle. The air conditioner AC includes an outdoor unit 20 and an indoor unit 40.

  The outdoor unit 20 houses a compressor 22, a switching valve 23, an outdoor heat exchanger 24, an expansion valve 25, an outdoor blower 26, and the like in a housing 21 made of sheet metal parts and synthetic resin parts. doing. The switching valve 23 is a four-way valve. The heat exchanger 1 according to the present invention can be used as the outdoor heat exchanger 24. As the expansion valve 25, a valve whose opening degree can be controlled is used. The outdoor blower 26 is a combination of a propeller fan and a motor.

  The outdoor unit 20 is connected to the indoor unit 40 through two refrigerant pipes 27 and 28. The refrigerant pipe 27 is intended to flow a liquid refrigerant, and a thin pipe is used as compared with the refrigerant pipe 28. Therefore, the refrigerant pipe 27 may be referred to as “liquid pipe”, “narrow pipe”, or the like. The refrigerant pipe 28 is intended to flow a gaseous refrigerant, and is thicker than the refrigerant pipe 27. Therefore, the refrigerant pipe 28 is sometimes referred to as “gas pipe”, “thick pipe”, or the like. For example, HFC R410A or R32 is used as the refrigerant.

  In the refrigerant pipe inside the outdoor unit 20, a two-way valve 29 is provided in the refrigerant pipe connected to the refrigerant pipe 27, and a three-way valve 30 is provided in the refrigerant pipe connected to the refrigerant pipe 28. The two-way valve 29 and the three-way valve 30 are closed when the refrigerant pipes 27 and 28 are removed from the outdoor unit 20 to prevent the refrigerant from leaking from the outdoor unit 20 to the outside. When it is necessary to release the refrigerant from the outdoor unit 20 or from the entire refrigeration cycle including the indoor unit 40, the refrigerant is discharged through the three-way valve 30.

  The indoor unit 40 houses an indoor side heat exchanger 42, an indoor side blower 43, and the like inside a housing 41 made of synthetic resin parts. The indoor heat exchanger 42 is a combination of three heat exchangers 42 </ b> A, 42 </ b> B, 42 </ b> C like a roof that covers the indoor blower 43. Any or all of the heat exchangers 42A, 42B, and 42C can be configured by the heat exchanger 1 according to the present invention. The indoor blower 43 is a combination of a motor and a cross flow fan.

  In order to control the operation of the air conditioner AC, it is indispensable to know the temperature of each place. For this purpose, temperature detectors are arranged in the outdoor unit 20 and the indoor unit 40. In the outdoor unit 20, a temperature detector 31 is disposed in the outdoor heat exchanger 24, and a temperature detector 32 is disposed in a discharge pipe 22 a serving as a discharge unit of the compressor 22, and suction serving as a suction unit of the compressor 22. A temperature detector 33 is disposed in the pipe 22 b, a temperature detector 34 is disposed in the refrigerant pipe between the expansion valve 25 and the two-way valve 29, and a temperature detector for measuring the outside air temperature at a predetermined location inside the housing 21. 35 is arranged. If the outdoor heat exchanger 24 is configured by the heat exchanger 1 according to the present invention, the temperature detector 31 is configured by the temperature sensitive element 7. Note that the temperature detectors 32, 33, 35, and 35 are also configured by thermistors, similarly to the temperature detector 31 configured by the temperature sensitive element 7.

  In the indoor unit 40, a temperature detector 44 is disposed in the indoor heat exchanger 42. If the heat exchanger 42A is constituted by the heat exchanger 1 according to the present invention among the heat exchangers 42A, 42B, 42C constituting the outdoor heat exchanger 42, the temperature detector 44 is constituted by the temperature sensitive element 7. Will be.

  FIG. 7 shows a state where the air conditioner AC is performing a cooling operation or a defrosting operation. At this time, the compressor 22 circulates the refrigerant in a cooling mode, that is, in a circulation mode in which the refrigerant discharged from the compressor 22 first enters the outdoor heat exchanger 24.

  The high-temperature and high-pressure refrigerant discharged from the compressor 22 enters the outdoor heat exchanger 24 where heat exchange with outdoor air is performed. The refrigerant dissipates heat to the outdoor air and condenses. The refrigerant that has been condensed to become liquid enters the expansion valve 25 from the outdoor heat exchanger 24 and is decompressed there. The decompressed refrigerant is sent to the indoor heat exchanger 42, expands to a low temperature and low pressure, and lowers the surface temperature of the indoor heat exchanger 42. The indoor side heat exchanger 42 whose surface temperature has dropped absorbs heat from the room air, whereby the room air is cooled. After absorbing heat, the low-temperature gaseous refrigerant returns to the compressor 22. The air flow generated by the outdoor blower 26 promotes heat radiation from the outdoor heat exchanger 24, and the air flow generated by the indoor blower 43 promotes heat absorption of the indoor heat exchanger 42.

  FIG. 8 shows a state in which the air conditioner AC is performing a heating operation. At this time, the switching valve 23 is switched, and the refrigerant flow is reversed from that during the cooling operation. The compressor 22 circulates the refrigerant in a circulation mode during heating, that is, in a circulation mode in which the refrigerant discharged from the compressor 22 first enters the indoor heat exchanger 42.

  The high-temperature and high-pressure refrigerant discharged from the compressor 22 enters the indoor heat exchanger 42 where heat exchange with the indoor air is performed. The refrigerant dissipates heat to the room air, and the room air is warmed. The refrigerant that has dissipated heat and is condensed to become liquid enters the expansion valve 25 from the indoor heat exchanger 42 and is decompressed there. The decompressed refrigerant is sent to the outdoor heat exchanger 24, expands to low temperature and low pressure, and lowers the surface temperature of the outdoor heat exchanger 24. The outdoor heat exchanger 24 whose surface temperature has dropped absorbs heat from the outdoor air. After absorbing heat, the low-temperature gaseous refrigerant returns to the compressor 22. The airflow generated by the indoor fan 43 promotes heat dissipation from the indoor heat exchanger 42, and the airflow generated by the outdoor fan 26 promotes heat absorption by the outdoor heat exchanger 24.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention is widely applicable to heat exchangers.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Fin 3 Tube 4 Refrigerant passage 7 Temperature sensing element 8 Exterior case 10, 11 Fixed member AC Air conditioner 20 Outdoor unit 40 Indoor unit

Claims (11)

In a heat exchanger having a tube through which refrigerant flows and fins attached to the tube,
A temperature sensing element for refrigerant temperature detection is attached to the tube,
A heat exchanger, wherein a constituent material that does not cause electric corrosion in the tube is interposed between the tube and the temperature sensing element.   The heat exchanger according to claim 1, wherein the tube is made of aluminum, and the constituent material is also aluminum.   The heat exchanger according to claim 1, wherein the tube is made of aluminum, and the constituent material is a synthetic resin containing an aluminum filler.   The heat exchanger according to claim 3, wherein the synthetic resin is a heat conductive synthetic resin.   The heat exchanger according to claim 1, wherein the constituent material is a synthetic resin.   The heat exchanger according to claim 5, wherein the synthetic resin is a heat conductive synthetic resin.   The heat exchanger according to claim 1, wherein the constituent material is a metal material that is baseless with respect to the tube.   The heat exchanger according to any one of claims 1 to 7, wherein the constituent material is a constituent material of an outer case of the temperature sensing element.   The heat exchanger according to any one of claims 1 to 8, wherein the constituent material is a constituent material of a fixing member for attaching the temperature sensing element to the tube.   The heat exchanger according to claim 9, wherein a constituent material that can be brazed to the tube is used as a constituent material of the fixing member.   An air conditioner in which the heat exchanger according to any one of claims 1 to 10 is mounted on an indoor unit or an outdoor unit.