JP6300915B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger in which lower end portions of a plurality of heat transfer tubes arranged in parallel at an interval and extending in the vertical direction are connected by a distribution header that distributes a refrigerant.

  Conventionally, a plurality of flat tubes arranged at intervals in the left-right direction so that the width direction faces the front-rear direction, corrugated fins arranged between adjacent flat tubes, and a lower end portion of each flat tube And a distribution header that communicates with each flat tube and distributes the refrigerant, and a heat exchange tube that exchanges heat between the refrigerant that flows through the flat tube and the air that flows through the corrugated fins by the rotation of the fan is known. (For example, refer to Patent Document 1).

JP 2006-170601 A (FIG. 1)

  In the above heat exchanger, when the frost generated in the flat tubes and corrugated fins flows down to the top surface of the distribution header, the top surface of the top surface is the highest portion in the front-rear direction, and from the highest portion toward the front and rear sides. Since the overall cross-sectional shape is gradually arc-shaped, water drops flowing down along the arc face the wind direction, and there is a problem that water is not smoothly drained from the distribution header.

  An object of the present invention is to solve such a problem, and an object of the present invention is to obtain a heat exchanger that has a simple structure, improves drainage at the distribution header, and prevents frost formation.

A heat exchanger according to the present invention includes a plurality of heat transfer tubes arranged in parallel at intervals, and
A distribution header that is connected at each lower end of the plurality of heat transfer tubes and communicates with the heat transfer tubes to distribute the refrigerant;
A plurality of fins provided in each air passage between the adjacent heat transfer tubes,
The distribution header has an upper surface inclined downward from the windward side to the leeward side.

  According to the heat exchanger according to the present invention, since the top surface of the distribution header is inclined downward from the windward side to the leeward side, water droplets on the top surface are more likely to flow down due to the force of gravity and wind. Therefore, drainage from the distribution header is improved, and the frosting resistance of the distribution header itself is improved.

It is a circuit diagram which shows the air conditioner with which the heat exchanger which concerns on Embodiment 1 of this invention was integrated. It is a figure when the heat exchanger of Embodiment 1 of this invention is seen from the windward side. It is a principal part perspective view which shows the heat exchanger of FIG. It is a figure which shows the internal structure of the distribution header of FIG. FIG. 3 is a cross-sectional plan view showing the folded header of FIG. 2. It is a figure which shows the state of the water drop in the distribution header of FIG. It is a principal part perspective view which shows the modification of the heat exchanger of Embodiment 1 of this invention. It is a principal part perspective view which shows the further modification of the heat exchanger of Embodiment 1 of this invention. It is a principal part side view which shows the behavior of the water droplet of the heat exchanger of FIG. It is a principal part side view which shows the heat exchanger of Embodiment 2 of this invention. It is a principal part side view which shows the heat exchanger of Embodiment 3 of this invention.

  Hereinafter, the heat exchanger according to each embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding members and parts will be described with the same reference numerals.

Embodiment 1 FIG.
FIG. 1 is a circuit diagram showing an air conditioner 51 in which the heat exchanger 1 of Embodiment 1 is incorporated.
In FIG. 1, the refrigerant flow during the cooling operation is indicated by a solid line arrow, the refrigerant flow during the heating operation is indicated by a dotted line, and the refrigerant flow during the defrosting operation is indicated by a dashed line arrow.
The air conditioner 51 includes a compressor 52, a four-way valve 53 connected to the compressor 52 via a first electromagnetic valve 60A, a throttle device 55 connected via a first electromagnetic valve 60C, and a four-way valve. 53 and the heat source side heat exchanger 54 connected via the first electromagnetic valve 60B, the expansion device 55 connected via the heat source side heat exchanger 54 and the first electromagnetic valve 60C, and the expansion device 55 A load-side heat exchanger 56 having one connected and the other connected to the four-way valve 53.
The air conditioner 51 includes a heat source side fan 57 provided to face the heat source side heat exchanger 54, a load side fan 58 provided to face the load side heat exchanger 56, and a second electromagnetic valve. 61 and a control device 59.
The compressor 52, the four-way valve 53, the heat source side heat exchanger 54, the expansion device 55, and the load side heat exchanger 56 are respectively connected via a refrigerant pipe to form a refrigerant circulation circuit.

The control device 59 is connected with a compressor 52, a four-way valve 53, a throttle device 55, a heat source side fan 57, a load side fan 58, first electromagnetic valves 60A to 60C, a second electromagnetic valve 61, various sensors, and the like.
By switching the flow path of the four-way valve 53 by the control device 59, the cooling operation and the heating operation are switched. The heat source side heat exchanger 54 acts as a condenser during the cooling operation, and acts as an evaporator during the heating operation.
The load side heat exchanger 56 acts as an evaporator during the cooling operation, and acts as a condenser during the heating operation.
The first solenoid valves 60A to 60C are open during the cooling operation and the heating operation, and are closed during the defrosting operation. The second solenoid valve 61 is closed during the cooling operation and the heating operation, and is open during the defrosting operation.

Next, the flow of the refrigerant during the cooling operation in the air conditioner 51 will be described.
The high-pressure and high-temperature gas refrigerant discharged from the compressor 52 flows into the heat source side heat exchanger 54 via the first electromagnetic valve 60A, the four-way valve 53, and the first electromagnetic valve 60B, and is supplied by the heat source side fan 57. The refrigerant is condensed by heat exchange with the outside air and becomes a high-pressure liquid refrigerant, and flows out of the heat source side heat exchanger 54.
The high-pressure liquid refrigerant flowing out of the heat source side heat exchanger 54 flows into the expansion device 55 via the first electromagnetic valve 60C, and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant flowing out of the expansion device 55 flows into the load-side heat exchanger 56 and evaporates by heat exchange with the indoor air supplied by the load-side fan 58, thereby causing a low-pressure gas state. And flows out of the load-side heat exchanger 56. The low-pressure gaseous refrigerant flowing out from the load-side heat exchanger 56 is sucked into the compressor 52 through the four-way valve 53.

Next, the flow of the refrigerant during the heating operation will be described.
The high-pressure and high-temperature gas refrigerant discharged from the compressor 52 flows into the load-side heat exchanger 56 via the first electromagnetic valve 60A and the four-way valve 53, and the indoor air supplied by the load-side fan 58 By condensing by heat exchange, it becomes a high-pressure liquid refrigerant and flows out of the load-side heat exchanger 56. The high-pressure liquid refrigerant flowing out of the load-side heat exchanger 56 flows into the expansion device 55 and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant flowing out of the expansion device 55 flows into the heat source side heat exchanger 54 via the first electromagnetic valve 60C and evaporates by heat exchange with the outside air supplied by the heat source side fan 57. As a result, the refrigerant is in a low-pressure gas state and flows out of the heat source side heat exchanger 54. The low-pressure gas refrigerant flowing out of the heat source side heat exchanger 54 is sucked into the compressor 52 through the first electromagnetic valve 60B and the four-way valve 53.

Next, the flow of the refrigerant during the defrosting operation will be described.
The high-pressure and high-temperature gas refrigerant discharged from the compressor 52 flows into the heat source side heat exchanger 54 via the second electromagnetic valve 61, and heats while melting the frost attached to the heat source side heat exchanger 54. By exchanging, the gas-liquid two-phase or gas state refrigerant flows out from the heat source side heat exchanger 54. The high-pressure gas-liquid two-phase or gas refrigerant flowing out of the heat source side heat exchanger 54 flows into the expansion device 55 and becomes a low-pressure gas-liquid two-phase or gas refrigerant. The low-pressure gas-liquid two-phase or gas refrigerant flowing out of the expansion device 55 passes through the load-side heat exchanger 56. The low-pressure gas-liquid two-phase or gas-state refrigerant that has passed through the load-side heat exchanger 56 is sucked into the compressor 52 via the four-way valve 53.

  Frost adheres to the heat source side heat exchanger 54 from the flow direction of the refrigerant during heating operation, and the frost grows. When the air conditioner defrosts, the refrigerant is performed in the flow direction during the cooling operation, so that defrosting of the portion where the frost is growing is delayed. On the other hand, if the refrigerant is flown in the flow direction during the heating operation as described above, the defrosting efficiency can be improved and the defrosting time can be shortened because high-temperature gas can flow from the growing part.

2 shows the heat source side heat exchanger 54 shown in FIG. 1 when the heat exchanger 1 according to Embodiment 1 of the present invention is viewed from the windward side, and FIG. 3 shows the heat exchanger of FIG. 4 is a perspective view showing the internal structure of the distribution headers 2 and 7 shown in FIG. 3, and FIG. 5 is a plan sectional view showing the folded header shown in FIG. In FIG. 3, only the corrugated fins 5 sandwiched between the pair of flat tubes 4 and the corrugated fins 5 sandwiched between the pair of flat tubes 6 are shown, and the other flat tubes 4, 6 arranged in parallel. The corrugated fins 5 are omitted.
The heat exchanger 1 includes a first distribution header 2 disposed in a direction perpendicular to the air direction indicated by an arrow C as viewed from the vertical direction, and a second distribution header 7 arranged in parallel with the first distribution header 2. And a first flat tube 4 as a first heat transfer tube, the lower end of which is connected to the first distribution header 2 and the upper end extends in the vertical direction and is arranged at equal intervals, and the first distribution header 2 and The folded header 3 is provided opposite to the second distribution header 7 and connected to the upper part of each first flat tube 4, and the upper end is connected to the folded header 3 and the lower end is connected to the second distribution header 7. The second flat tubes 6 that are a plurality of second heat transfer tubes connected to each other at equal intervals, the adjacent first flat tubes 4, and the adjacent second flat tubes 6, respectively. And corrugated fins 5 provided on the road. .

The first distribution header 2 and the second distribution header 7 have the same shape and a rectangular cross section.
The first distribution header 2 has a refrigerant inflow portion 2A that extends in the horizontal direction and into which the refrigerant flows. A refrigerant pipe is connected to the refrigerant inflow portion 2A. The first distribution header 2 is provided with a distribution pipe 2B extending in the horizontal direction. The distribution pipe 2B is vertically connected to the leading end of the refrigerant inflow portion 2A.
The second distribution header 7 having a hollow inside has a refrigerant outflow portion 7A extending in the horizontal direction and flowing out of the refrigerant. A refrigerant pipe is connected to the refrigerant outflow portion 7A.
The first distribution header 2 is formed with a plurality of holes into which the lower ends of the first flat tubes 4 are inserted.
The second distribution header 7 is formed with a plurality of holes into which the lower ends of the second flat tubes 6 are inserted.
Each of the first distribution header 2 and the second distribution header 7 has inclined surfaces 10 and 11 whose top surfaces descend from the windward side along the leeward side. The starting points of the inclined surfaces 10 and 11 are higher than the connection point on the upper side of the first flat tube 4 extending in the vertical direction from the first distribution header 2.
In addition, you may make it provide the partition plate for adjusting each distribution ratio of the 1st flat tube 4 and the 2nd flat tube 6 in each distribution header 2 and 7. FIG.

The folded header 3 is formed with holes through which the upper ends of the first flat tube 4 and the second flat tube 6 are inserted. The first flat tube 4 and the second flat tube 6 are opposed to each other in the longitudinal direction. A partition wall 8 is provided between the pair of first flat tube 4 and second flat tube 6 adjacent to the pair of first flat tube 4 and second flat tube 6. The partition wall 8 restricts the refrigerant to flow in the direction of arrow A in FIG.
The 1st distribution header 2, the return header 3, the 2nd distribution header 7, the 1st flat tube 4, the 2nd flat tube 6, the corrugated fin 5, and the distribution pipe 2B are the products made from aluminum, for example. Further, the number of the refrigerant inflow portions 2A and the number of the refrigerant outflow portions 7A may be plural.

  The first flat tube 4 and the second flat tube 6 are flat tubes each having a plurality of flow paths 4a and 6a individually extending in the vertical direction. The first flat tube 4 and the second flat tube 6 having a rectangular shape have a longitudinal direction that is a vertical direction, and a short side that is disposed along the wind direction. The joining of the corrugated fin 5 and the first flat tube 4 and the joining of the corrugated fin 5 and the second flat tube 6 are preferably brazed. Of course, the number of the first flat tubes 4 and the second flat tubes 6 is not limited to the number shown in FIG.

Next, the flow of the refrigerant in the heat exchanger 1 will be described.
The refrigerant flowing through the refrigerant pipe flows into the first distribution header 2 via the refrigerant inflow portion 2A and is distributed, and flows upward from the lower ends of the plurality of first flat tubes 4 through the flow paths 4a of the first flat tubes 4. It flows toward. This refrigerant exchanges heat with the air flowing through the corrugated fins 5 by the fan while flowing through the first flat tube 4.
The refrigerant flowing through the first flat tube 4 reaches the folded header 3, where it is folded and flows down through the flow paths 6 a of the second flat tube 6. This refrigerant exchanges heat with the air flowing through the corrugated fins 5 by the fan while flowing through the first flat tube 4.
The refrigerant flowing down the second flat tubes 6 joins at the second distribution header 7 and flows out into the refrigerant pipe via the refrigerant outflow portion 7A. It is also possible to reverse the flow direction of the refrigerant.

Next, the effect of the heat exchanger 1 having the above configuration will be described.
As shown in FIG. 6, the water droplets 12 drained to the first distribution header 2 and the second distribution header 7 are caused by the inclined surfaces 10 and 11 of the first distribution header 2 and the second distribution header 7 in the gravitational direction of the arrow B. To flow. Furthermore, since the wind flowing through the heat exchanger 1 flows along the inclined surfaces 10 and 11 of the distribution headers 2 and 7 as shown by the arrow C, the water droplets 12 are more likely to flow due to the force of gravity and wind. . Therefore, drainage is improved and the frosting resistance of the headers 2 and 7 themselves is improved.

FIG. 7 is a main part perspective view showing a modification of the heat exchanger 1 according to Embodiment 1 of the present invention.
In this modification, the inclined surfaces 10 and 11 have an arc shape that descends from the windward side toward the leeward side.
The starting point of the inclined surface 10 is higher than the connecting point on the upper side of the first flat tube 4 extending in the vertical direction from the first distribution header 2, and the starting point of the inclined surface 11 extends in the vertical direction from the second distribution header 7. It is higher than the connection point on the upper side of the second flat tube 6.
Other configurations are the same as those of the heat exchanger 1 of FIG.
In this modification, the water droplets 12 drained to the first distribution header 2 and the second distribution header 7 flow in the direction of gravity due to the inclination of the inclined surfaces 10 and 11. Furthermore, since the inclined surfaces 10 and 11 on the top surfaces of the distribution headers 2 and 7 are streamlined, the wind flowing through the heat exchanger 1 is more along the distribution headers 2 and 7 than in the linear shape. Since it flows, the water droplets 12 are more likely to flow due to the force of gravity and wind.
Therefore, the distribution headers 2 and 7 have improved drainage and improved frost resistance.

FIG. 8 is a perspective view of an essential part showing a further modification of the heat exchanger 1 according to Embodiment 1 of the present invention. In this modification, the inclined surfaces 10 and 11 on the top surface are the same as those in FIG. 3, but the opposing surface where the first distribution header 2 and the second distribution header 7 are opposed is along the lower side. The difference is that the inclined surfaces 13 and 14 have a large distance from each other.
Other configurations are the same as those of the heat exchanger 1 of FIG.

For example, the heat exchangers 1 may be arranged in a plurality of rows, and the distance between the first distribution header 2 and the second distribution header 7 may have to be shortened due to installation space restrictions.
In this case, water droplets 12 flowing down from the top surfaces of the first distribution header 2 and the second distribution header 7 bridge between the first distribution header 2 and the second distribution header 7 due to surface tension, and from the bridged portion. The frost grows.
On the other hand, the first distribution header 2 and the second distribution header 7 have inclined surfaces 13 and 14 inclined with respect to the vertical direction on the surfaces facing each other, and the lower side of the inclined surfaces 13 and 14. The distance from each other increases as heading toward.
Accordingly, as shown in FIG. 9, the water drops 12 are less likely to bridge between the first distribution header 2 and the second distribution header 7, and the frosting resistance of the first distribution header 2 and the second distribution header 7 is improved. To do.

Embodiment 2. FIG.
FIG. 10 is a perspective view showing a main part of the heat exchanger according to the second embodiment of the present invention.
In this embodiment, the corrugated fin 5 has a leading edge projecting to the windward side from the windward end surfaces of the first flat tube 4 and the second flat tube 6.
Further, the corrugated fin 5 is inclined downward as it goes from the windward side to the leeward side.
Other configurations are the same as those of the heat exchanger 1 of the first embodiment.

In this embodiment, since the front edge portion of the fin 5 protrudes from the windward side of the flat tubes 4 and 6 to the windward side, the water droplet 12 at the front edge portion of the corrugated fin 5 drops when the flat tube 4 is dropped. , 6 is dropped without being transmitted to the corrugated fin 5 and the drainage performance is improved.
Further, since the corrugated fins 5 are inclined downward from the windward side to the leeward side, the corrugated fins 5 are drained by both forces of gravity and wind, and the drainage at the corrugated fins 5 is further improved.

Embodiment 3. FIG.
FIG. 11: is a side view which shows the principal part of the heat exchanger 1 of Embodiment 3 of this invention.
In this embodiment, the fins 5 whose both sides are brazed by the flat tubes 4 and 6 at the joint portion 15 are inclined downward from the windward to the windward.
Further, the flat tubes 4 and 6 are formed with drainage grooves 9 that are inclined along the joints 15 with the corrugated fins 5 and extend linearly.
Other configurations are the same as those of the heat exchanger 1 of the second embodiment.

  In this embodiment, the water droplet 12 from the corrugated fin 5 is transmitted to the first flat tube 4 and the second flat tube 6 and is accumulated in the drainage groove 9 by gravity. Since the water droplets 12 accumulated in the drainage groove 9 are pushed out by both gravity and wind forces, the drainage performance in the first flat tube 4 and the second flat tube 6 is improved.

In each of the above embodiments, the case where the heat exchanger is used in an air conditioner has been described. Of course, the use is not limited to the air conditioner, and other refrigeration cycles having a refrigerant circulation circuit, for example. It may be used in the device.
Moreover, although the case where an air conditioning apparatus switches between cooling operation and heating operation is demonstrated, it is not limited to such a case, You may perform only cooling operation or heating operation.
Moreover, the corrugated fin 5 is an example and is not limited to a corrugated shape.
The 1st flat tube 4 and the 2nd flat tube 6 are examples, and are not limited to flat shape.

  DESCRIPTION OF SYMBOLS 1 Heat exchanger, 2 1st distribution header, 2A Refrigerant inflow part, 2B Distribution pipe, 3 Folding header, 4 1st flat tube (1st heat transfer tube), 5 Corrugated fin, 6 2nd flat tube (2nd heat transfer tube) ), 7 Second distribution header, 7A Refrigerant outlet, 8 Partition wall, 9 Drain, 15 Joint, 51 Air conditioner, 52 Compressor, 53 Four-way valve, 54 Heat source side heat exchanger, 55 Throttle device, 56 Load side heat exchanger, 57 heat source side fan, 58 load side fan, 59 control device, 60A-C first solenoid valve, 61 second solenoid valve.

Claims (8)

A plurality of heat transfer tubes arranged in parallel at intervals, and
A distribution header that is connected at each lower end of the plurality of heat transfer tubes and communicates with the heat transfer tubes to distribute the refrigerant;
A plurality of fins provided in each air passage between the adjacent heat transfer tubes,
The distribution header has a top surface inclined downward from the leeward side to the leeward side ,
The distribution headers are arranged at least two rows apart in the direction of the wind;
The heat exchanger in which the opposing surfaces of the distribution header that face each other are spaced apart from each other toward the lower side . Sloped said top surface der Ru inclined slope has a heat exchanger according to claim 1 in the intermediate section is an arc protruding upward. 3. The heat exchanger according to claim 1, wherein an end surface on the windward side of the fin protrudes toward the windward side from an end surface on the windward side of the heat transfer tube. The fins, the heat exchanger according to any one of claim 1 to 3, from the windward is provided obliquely downwardly to the leeward side. The heat exchanger according to any one of claims 1 to 4 , wherein the heat transfer tube has a groove inclined downward from the windward side to the leeward side on a surface of a joint portion with the fin. The heat transfer tubes, the heat exchanger according to any one of claims 1 to 5 longitudinal direction is flat tube is vertical has a plurality of flow paths. The heat exchanger according to any one of claims 1 to 6 , wherein the fin is a corrugated fin. Said heat exchanger is a heat source-side heat exchanger of the air conditioner, the heat source-side heat exchanger, any claim 1-7 flow direction of the refrigerant is the same between the heating and defrosting The heat exchanger according to claim 1.

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