JP2014047959A - Heat exchanger and refrigeration cycle device having the heat exchanger mounted thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat exchanging efficiency of a heat exchanger by a way of suppressing an increase in a cost without increasing a cubic volume of the heat exchanger.SOLUTION: A heat exchanger 20 comprise a heat transfer tube 23 through which a refrigerant is made to flow and heat radiation fins 24. A blower 16 for forming an air stream passing through the heat exchanger 20 is combined with the heat exchanger 20. In the heat exchanger 20, ventilation resistance at a region facing the blower 16 is larger than ventilation resistance at other regions. The fact that thickness of the fin 24 at the region facing the blower 16 is larger than thickness of the other regions or the fact that the size of the fin 24 at the region facing the blower 16 in a ventilation direction is larger than that of the other regions, becomes a primary factor of difference of ventilation resistance.

Description

  The present invention relates to a heat exchanger and a refrigeration cycle apparatus equipped with the heat exchanger.

  Refrigeration cycle apparatuses are widely put into practical use in the form of air conditioners, refrigerators, freezers, water heaters, and the like. A heat exchanger is an essential component of the refrigeration cycle apparatus.

  How the heat exchanger is incorporated in the refrigeration cycle apparatus will be described with reference to FIG. 6, taking an air conditioner as an example.

  The air conditioner 1 shown in FIG. 6 is configured as a separate type, and includes an indoor unit 2 and an outdoor unit 3. The indoor unit 2 includes an indoor heat exchanger 4, and the outdoor unit 3 includes a compressor 5, an outdoor heat exchanger 6, a receiver 7, and an expansion valve 8. The indoor heat exchanger 4, the compressor 5, the outdoor heat exchanger 6, the receiver 7, and the expansion valve 8 are connected as shown in FIG. 6 to constitute a refrigeration cycle.

  During cooling, the refrigerant is discharged from the discharge pipe of the compressor 5 as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant flows into the outdoor heat exchanger 6 and radiates heat to the outdoor air flowing outside the outdoor heat exchanger 6. When the heat is released, the gas refrigerant condenses. The condensed refrigerant is gas-liquid separated by the receiver 7 and then sent to the expansion valve 8. The refrigerant is throttled by the expansion valve 8 and becomes a low-temperature and low-pressure liquid refrigerant. The liquid refrigerant flows into the indoor heat exchanger 4, where it takes heat from the indoor air by being evaporated and vaporized. As a result, the room can be cooled.

  The general structure of the outdoor unit 3 is as shown in FIGS. The outdoor unit 2 houses a compressor 5, an outdoor heat exchanger 6, a receiver 7, and an expansion valve 8 inside a housing 10 composed of sheet metal parts and synthetic resin parts. Only 5 and the outdoor heat exchanger 6 are shown. The inside of the housing 10 is partitioned into a machine room 11 and a heat exchange chamber 12, the compressor 5 is housed in the machine room 11, and the outdoor heat exchanger 6 is housed in the heat exchange room 12.

  As shown in FIG. 7, the housing 10 has a rectangular planar shape, and of the long sides of the rectangle, the lower side in FIG. 7 is the front surface of the housing 10, and the upper side is the back surface of the housing 10. It becomes. The short side of the rectangle is the side of the housing. Here, the left hand side of the user facing the front of the housing 10 is the left side, and the right hand side is the right side.

  The outdoor heat exchanger 6 is formed in a planar shape L shape. The long side 6 a of the outdoor heat exchanger 6 faces the air intake 13 formed on the back surface of the housing 10, and the short side 6 b faces the air intake 14 formed on the right side of the housing 10.

  An air outlet 15 is formed on the front side of the heat exchange chamber 12, and a blower 16 is disposed between the air outlet 15 and the outdoor heat exchanger 6. The blower 16 includes a propeller fan 16a and a motor 16b that rotates the propeller fan 16a. The long side 6a of the outdoor heat exchanger 6 faces the propeller fan 16a from the front. That is, they face each other. The short side 6b of the outdoor heat exchanger 6 faces the side surface of the propeller fan 16a.

  When the blower 16 is driven, the air inside the housing 10 is blown out from the air outlet 15. Outside air flows into the housing 10 from the air intakes 13 and 14 in a form to make up for that. The outside air flowing in from the air intake 13 passes through the long side 6 of the outdoor heat exchanger 6 and exchanges heat with the long side 6a, and the outside air flowing in from the air intake 14 is mainly used in the outdoor heat exchanger. The heat exchange is performed with the short side 6b through the short side 6b.

  Various types of outdoor heat exchanger 6 can be used. Here, the parallel flow type heat exchanger 20 shown in FIGS. 10 to 12 is used as the outdoor heat exchanger 6.

  In FIG. 11, the upper side of the paper is the upper side of the heat exchanger 20, and the lower side of the paper is the lower side of the heat exchanger 20. The heat exchanger 20 has a configuration in which two vertical branch pipes 21 and 22 are arranged at intervals in the horizontal direction, and the branch pipes 21 and 22 are connected by a plurality of heat transfer pipes 23. The heat transfer tubes 23 are metal extrusion-molded products, and are arranged at predetermined intervals along the length direction of the flow dividing tubes 21 and 22.

  As shown in FIG. 10, the heat transfer tube 23 is bent into a planar shape L-shaped, and a long side 23a and a short side 23b are connected to a curved portion 23c having a predetermined radius. The long side 23 a becomes the long side 6 a in the outdoor heat exchanger 6, and the short side 23 b becomes the short side 6 b in the outdoor heat exchanger 6.

  A large number of heat dissipating fins 24 are arranged at a predetermined pitch between the heat transfer tubes 23 adjacent in the vertical direction. Each fin 24 is disposed in a plane that intersects the axis of the heat transfer tube 23 at a right angle. Therefore, adjacent fins 24 have different angles in the curved portion 23c.

  When the heat exchanger 20 is used as the outdoor heat exchanger 6, the heat exchanger 20 becomes low temperature during heating operation and frost formation occurs. In order to suppress frost formation and facilitate the discharge of defrost water (drain) during the defrosting operation, the fin 24 is a straight fin type in which a louver is raised and not formed.

  The shunt pipes 21 and 22, the heat transfer pipes 23, and the fins 24 are all formed of a metal having good heat conductivity such as aluminum, and are fixed to each other by welding or brazing. Needless to say, the inside of the heat transfer tube 23 communicates with the inside of the flow dividing tubes 21 and 22.

  A refrigerant inlet 25 is formed in the upper part of the branch pipe 21, and a refrigerant outlet 26 is formed in the lower part of the branch pipe 22. The refrigerant that has flowed into the branch pipes 21 from the refrigerant inlet 25 is split into the heat transfer pipes 23, flows to the branch pipes 22 while releasing heat (or absorbing heat) from the heat transfer pipes 23 and the fins 24 outside thereof, and flows out from the refrigerant outlet 26. To do.

  As described above, when the blower 16 is driven, outside air flows into the housing 10 from the air intake ports 13 and 14, and blows through the heat exchanger 20 used as the outdoor heat exchanger 6 to pass through the inside of the heat exchanger 20. Exchanges heat with the flowing refrigerant. At this time, compared to the airflow passing through the long side 23a facing the blower 16, the airflow passing through the short side 23b and the curved portion 23c not facing the blower 16 is inevitably slowed. Therefore, a uniform wind speed distribution cannot be obtained over the entire width of the heat exchanger 20, and the heat transfer performance cannot be sufficiently exhibited in all parts of the heat exchanger 20.

  In order to deal with the above problem, in the heat exchanger described in Patent Document 1, the fin pitch is set densely in a portion where the passing wind speed is high, and the fin pitch is set sparsely in a portion where the wind speed is slow. The thermal performance is improved. When the idea is applied to the heat exchanger 20 shown in FIGS. 10 to 12, the shape shown in FIGS. 13 and 14 is obtained.

  Similarly, in order to cope with the above problem, in the heat exchanger described in Patent Document 2, each part of the heat exchanger is provided by installing the second heat exchanger in a part facing the blower and increasing the wind speed. The air velocity passing through the air is made uniform, improving the heat exchange efficiency. When the idea is applied to the heat exchanger 20 shown in FIGS. 10 to 12, the shape shown in FIG. 15 is obtained.

JP 7-198167 A Japanese Patent Publication No. 8-270985

  In the solution of Patent Document 1, it is required to perform processing while changing the density of the fins according to the part of the heat exchanger, so that the processing cost increases. Further, since the frost formation immediately impedes ventilation in the portion where the fin pitch is dense, the frequency of the defrosting operation becomes high and is not suitable for continuous operation for a long time.

  In the solution method of patent document 2, since a 2nd heat exchanger is used, a process process increases and a process cost also rises. Further, since the volume of the heat exchanger increases, it is not suitable for downsizing of the equipment.

  The present invention has been made to solve the above-described problems of the prior art, and it is possible to improve the heat exchange efficiency of the heat exchanger in a manner that can suppress the increase in cost without increasing the volume of the heat exchanger. With the goal.

  The heat exchanger according to the present invention is a heat exchanger provided with a heat transfer tube through which a refrigerant passes and fins for heat dissipation, combined with a blower that forms an airflow passing through the heat exchanger, and the heat exchanger is The ventilation resistance of the site | part facing the said air blower is made large compared with the ventilation resistance of the other site | part.

  In the heat exchanger configured as described above, it is preferable that the portion facing the blower has a larger thickness of the fin than the other portions as a factor of the difference in ventilation resistance.

  In the heat exchanger configured as described above, it is preferable that the portion facing the blower has a larger size of the fin in the ventilation direction than the other portions is a factor of the difference in the ventilation resistance.

  The present invention is also characterized in that it is a refrigeration cycle apparatus equipped with the heat exchanger.

  According to the present invention, the refrigeration cycle apparatus is configured as an air conditioner including an outdoor unit and an indoor unit, and the heat exchanger is mounted on the outdoor unit.

  According to the present invention, the wind speed of the airflow passing through each part of the heat exchanger is such that the ventilation resistance of the part facing the blower in the heat exchanger is larger than the ventilation resistance of the other part. Becomes uniform and heat exchange efficiency is improved.

It is a top view of the heat exchanger which concerns on 1st Embodiment of this invention. It is a front view of the heat exchanger which concerns on 1st Embodiment of this invention. It is a top view of the heat exchanger which concerns on 2nd Embodiment of this invention. It is a front view of the heat exchanger which concerns on 2nd Embodiment of this invention. It is a table | surface of the result obtained by simulation of a thermal fluid. It is a schematic block diagram of an air conditioner. It is a top view which shows schematic structure of the outdoor unit of an air conditioner. It is an elevation which shows schematic structure of the outdoor unit of an air conditioner. FIG. 9 is a partial elevation view showing a schematic configuration of an outdoor unit of an air conditioner, as viewed in a direction perpendicular to FIG. 9. It is a top view of the conventional heat exchanger. It is a front view of the heat exchanger of FIG. It is a fragmentary perspective view of the heat exchanger of FIG. It is a top view of another conventional heat exchanger. It is a front view of the heat exchanger of FIG. It is a top view of another conventional heat exchanger.

<First Embodiment>
Based on FIG.1 and FIG.2, the structure of the heat exchanger which concerns on this invention is demonstrated. In addition, the code | symbol used in FIGS. 10-12 is used for the component which is functionally common in the conventional heat exchanger shown in FIGS. 10-12, and description is abbreviate | omitted. The same applies to the description of the second embodiment.

  In the heat exchanger 20 according to the first embodiment, the thickness of the fin 24 is larger at the portion facing the blower 16, that is, the long side 23a than at the portion not facing the blower 16, that is, the short side 23b and the curved portion 23c. It is said that. Accordingly, the ventilation resistance of the long side 23a is larger than the ventilation resistance of the short side 23b and the curved portion 23c.

  By making a difference in ventilation resistance as described above, the difference between the wind speed of the airflow passing through the long side 23a and the wind speed of the airflow passing through the short side 23b and the curved portion 23c is reduced, and the heat exchanger 20 Heat exchange is performed evenly throughout. Thereby, the heat exchange efficiency of the heat exchanger 20 improves.

Second Embodiment
3 and 4 show a heat exchanger 20 according to a second embodiment of the present invention. In the heat exchanger 20 according to the second embodiment, the portion facing the blower 16, that is, the long side 23 a, the portion not facing the blower 16, that is, the short side 23 b and the curved portion 23 c are compared with the fin 24 in the ventilation direction. The dimensions are large. Accordingly, the ventilation resistance of the long side 23a is larger than the ventilation resistance of the short side 23b and the curved portion 23c.

  By making a difference in ventilation resistance as described above, the difference between the wind speed of the airflow passing through the long side 23a and the wind speed of the airflow passing through the short side 23b and the curved portion 23c is reduced, and the heat exchanger 20 Heat exchange is performed evenly throughout. Thereby, the heat exchange efficiency of the heat exchanger 20 improves.

<Simulation>
The effect of the present invention was confirmed using thermal fluid simulation software (trade name “STREAM”). The result is a table shown in FIG.

In the table of FIG. 5, “front flow rate” refers to the flow rate of the part facing the blower in the heat exchanger, and “side flow rate” refers to the flow rate of other parts. In the conventional heat exchanger, the side flow rate is 0.17 m ³ / s, whereas in the heat exchanger of the present invention, the side flow rate is 0.23 m ³ / s and the side flow rate is increased by 29%. Therefore, if the heat exchanger of this invention is used, the difference in the wind speed of the airflow in the whole heat exchanger will become small, and heat exchange efficiency will improve.

  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 a heat exchanger and a refrigeration cycle apparatus equipped with the heat exchanger.

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Indoor unit 3 Outdoor unit 4 Indoor heat exchanger 5 Compressor 6 Outdoor heat exchanger 7 Receiver 8 Expansion valve 10 Housing | casing 16 Blower 20 Heat exchanger 21, 22 Shunt pipe 23 Heat exchanger tube 23a Long side 23b Short side 23c bending portion 24 fin

Claims (5)

A heat exchanger having a heat transfer tube for passing a refrigerant and a fin for heat dissipation,
A blower that forms an airflow passing through the heat exchanger is combined,
The heat exchanger is characterized in that the ventilation resistance at a portion facing the blower is larger than the ventilation resistance at other portions.   2. The heat exchanger according to claim 1, wherein the portion facing the blower has a larger thickness of the fin than the other portions as a factor of the difference in the ventilation resistance.   2. The heat exchange according to claim 1, wherein the portion facing the blower has a larger size of the fin in the ventilation direction than the other portions, which is a factor of the difference in the ventilation resistance. vessel.   A refrigeration cycle apparatus comprising the heat exchanger according to any one of claims 1 to 3. It is configured as an air conditioner equipped with an outdoor unit and an indoor unit,
The refrigeration cycle apparatus according to claim 4, wherein the heat exchanger is mounted on the outdoor unit.

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