JP6102724B2 - Heat exchanger - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly to a heat exchanger in an outdoor unit.

  The air conditioner includes an indoor unit and an outdoor unit, and each includes a heat exchanger that exchanges heat between the air and the refrigerant.

  A heat exchanger in the outdoor unit (hereinafter referred to as an outdoor heat exchanger) is a finned tube heat exchanger provided with a heat transfer tube and fins orthogonal to the heat transfer tube. As shown in FIG. 5, in the conventional fin tube heat exchanger, the refrigerant pipe is connected to the outdoor heat exchanger 200 via the first flow divider 210 and the second flow divider 220. During the cooling operation, one of the refrigerants divided by the first flow divider 210 (refrigerant flowing through the upper flow path) flows from the heat transfer tube 230 in the central part on the leeward side of the outdoor heat exchanger 200, After sequentially passing through the heat transfer tubes (231 to 238) to the heat transfer tube 239 at the uppermost stage toward the upper side of the heat exchanger 200, the heat transfer tube 239 at the upper end on the leeward side is transferred to the heat transfer tube 240 at the upper end on the windward side. It flows in and flows through the heat transfer tubes (241 to 248) sequentially downward to the heat transfer tube 249 in the central part on the windward side. The remaining one (refrigerant flowing through the lower flow path) of the refrigerant diverted by the flow divider 210 flows in from the heat transfer tube 250 in the central part on the leeward side of the outdoor heat exchanger 200, and the outdoor heat exchanger 200. After flowing through the heat transfer tubes (251 to 258) sequentially to the lowermost heat transfer tube 259, the heat flows from the heat transfer tube 259 at the lower end on the leeward side to the heat transfer tube 260 at the lower end on the windward side. The heat transfer tubes (261 to 268) are circulated sequentially up to the heat transfer tube 269 in the upper central portion. And the refrigerant | coolant of both flow paths merges with the flow divider 220, and flows out from an outdoor heat exchanger.

  Since the outdoor heat exchanger 200 functions as a condenser during the cooling operation, the ratio of the liquid increases as the refrigerant exchanges heat with air. In the heat transfer tubes (260 to 269) on the windward side of the lower flow path, the refrigerant flows from the bottom to the top, so that the refrigerant tends to accumulate, and flows to the lower flow path as compared with the upper flow path. There was a problem that the flow rate of refrigerant decreased and the amount of heat exchange decreased.

  As a method for solving this problem, there is a technique disclosed in Patent Document 1. In Patent Document 1, as shown in FIG. 6, in addition to the leeward flow path of the lower flow path, the refrigerant also flows from the top to the bottom in the heat transfer tubes (360 to 369) on the windward side. A heat transfer tube 359 at the lower end on the leeward side and a heat transfer tube 369 at the center on the leeward side are connected by a pipe 370. Thereby, even if the ratio of the liquid of the refrigerant increases, the refrigerant flows down from the top to the bottom, so that it is difficult for the refrigerant to accumulate.

Japanese Patent No. 3888000

  However, in the outdoor heat exchanger 300 disclosed in Patent Document 1, during the heating operation, the heat transfer tube 360 at the lowermost end on the windward side on the lower flow path is a heat transfer tube into which the low-temperature refrigerant first flows, In addition, since the condensed water generated in the upper flow path of the outdoor heat exchanger 300 flows down, there is a problem that frost is likely to adhere as compared with other heat transfer tubes. In addition, during the defrosting operation, the heat transfer tube 360 at the lowermost end of the windward side on the lower flow path is the last to flow in high-temperature refrigerant despite the fact that a lot of frost is attached, so the heat transfer tube There was also a problem that it took time to remove the frost adhered to 360.

  Therefore, the present invention makes it difficult for refrigerant to accumulate in the heat exchanger during cooling operation, and makes it difficult for frost to adhere to the lower part of the windward side on the flow path below the outdoor heat exchanger during heating operation. The purpose is to shorten the driving time.

  In order to achieve the above object, the present invention provides a plurality of fins that are laminated with a predetermined gap, and that circulates air through the gap, and that passes through the fins in the laminating direction and has two rows in the direction of circulating air. A finned tube type heat exchanger having a heat transfer tube arranged in a plurality of stages in the vertical direction intersecting with the direction of circulation, and circulating the refrigerant through a refrigerant flow path formed by sequentially connecting the heat transfer tubes. When the condenser is used as a condenser, an upper inlet and a lower inlet into which the refrigerant flows are provided vertically adjacent to a row on the leeward side with respect to the direction in which the air flows, and the upper side from which the refrigerant flows out The outlet and the lower outlet are provided in the windward row with respect to the direction in which the air flows, and the refrigerant flowing in from the upper inlet sequentially moves up the upper row to the uppermost heat transfer tube. In the uppermost row on the windward side after flowing through The heat flows into the heat pipe and flows through the heat transfer pipes sequentially toward the bottom of the leeward row, and the upper flow path that flows out from the upper outlet and the refrigerant that flows in from the lower inlet reach the lower side of the leeward row. After sequentially flowing through the heat transfer tubes to the lower heat transfer tubes, the air flows into the heat transfer tubes in the lowermost row of the windward row and flows through the at least two heat transfer tubes toward the upper side of the windward row. The heat transfer tubes are sequentially flowed downward to the heat transfer tubes that flow into the heat transfer tubes adjacent to the upper outlet and flow before flowing into the heat transfer tubes adjacent to the upper outlet. And a lower flow path that flows out from the lower flow outlet.

  According to the heat exchanger as described above, it is possible to make it difficult for frost to adhere to the lower part on the windward side of the heat exchanger and to shorten the time required for the defrosting operation.

It is sectional drawing which shows the outdoor heat exchanger of a 1st Example. It is a figure which shows the refrigerating cycle of a 1st Example. It is sectional drawing which shows the outdoor heat exchanger of a 2nd Example. It is sectional drawing which shows the outdoor heat exchanger of a 3rd Example. It is sectional drawing which shows the conventional outdoor heat exchanger. It is sectional drawing which shows the outdoor heat exchanger of patent document 1.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a heat exchanger according to the present invention will be described with reference to the accompanying drawings based on an embodiment when used in an air conditioner.

  A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2, the air conditioner according to the present embodiment sequentially connects the compressor 10, the four-way valve 20, the outdoor heat exchanger 100, the expansion valve 30, and the indoor heat exchanger 40 with refrigerant piping. Thus, the refrigeration cycle 1 is configured and the refrigerant is circulated. During the cooling operation, the outdoor heat exchanger 100 functions as a condenser, and the indoor heat exchanger 40 functions as an evaporator. On the other hand, during the heating operation, the outdoor heat exchanger 100 functions as an evaporator, and the indoor heat exchanger 40 functions as a condenser.

The outdoor heat exchanger 100 will be described in detail below.
The outdoor heat exchanger 100 is a finned tube heat exchanger. The outdoor heat exchanger 100 includes a plurality of fins that are stacked with a predetermined gap and allow air to flow through the gap. In addition, it has two rows in the direction of circulating air and two rows of heat transfer tubes in the vertical direction intersecting with the direction of air circulation, and is formed by sequentially connecting the heat transfer tubes The refrigerant is circulated through the refrigerant flow path. When the outdoor heat exchanger 100 functions as a condenser, as shown in FIG. 1, before the refrigerant flows into the outdoor heat exchanger 100, the refrigerant is divided into the upper flow path and the lower flow path by the first flow divider 110. Is done. The separated refrigerant in the upper flow path flows into the heat transfer tube 130 serving as the upper inlet at the center of the outdoor heat exchanger 100 in the leeward row, and the refrigerant flowing out of the heat transfer tube 130 flows in the leeward row. The refrigerant flowing out from the heat transfer tube 139 in the uppermost flow path in the upper flow path in the upper flow path 139 is sequentially circulated through the heat transfer tubes (131 to 138) in the upper flow path. The refrigerant flowing into the uppermost heat transfer tube 140 in the upper flow path in the windward row and flowing out of the heat transfer tube 140 sequentially reaches the heat transfer tube 149 in the center of the outdoor heat exchanger 100 in the windward row. After flowing through the heat transfer tubes (141 to 148), the heat flows out from the outdoor heat exchanger 100 and flows into the second flow divider 120.

  On the other hand, the divided refrigerant in the lower flow path flows into the heat transfer pipe 150 serving as a lower inlet adjacent to the lower part of the heat transfer pipe 130 in the center of the outdoor heat exchanger 100 in the leeward row, The heat transfer tubes (151 to 158) are circulated sequentially from the heat transfer tube 150 to the heat transfer tube 159 in the lowermost flow path in the leeward row, and the lowermost row in the lower flow channel in the leeward row. The refrigerant flowing out from the heat transfer tube 159 flows into the heat transfer tube 160 at the lowest stage in the lower flow path in the windward row, and the refrigerant flowing out from the heat transfer tube 160 flows next to the heat transfer tube 160 above. The refrigerant flows through the heat pipe 161, passes through the pipe 170, flows into the heat transfer pipe 169 in the central portion of the outdoor heat exchanger 100 in a row on the windward side, and the refrigerant flowing out of the heat transfer pipe 169 sequentially heats down the heat transfer pipe ( 168 to 162) after flowing out of the outdoor heat exchanger 100, the second It flows into Nagareki 120, and merges with the refrigerant of the upper flow channel.

The operation of the refrigeration cycle 1 using the outdoor heat exchanger 100 configured as described above will be described below.
First, an operation during cooling operation in which the outdoor heat exchanger 100 acts as a condenser will be described. The refrigerant compressed to a high pressure by the compressor 10 passes through the four-way valve 20, flows into the outdoor heat exchanger 100, dissipates heat to the outdoor air, condenses, is decompressed to a low pressure by the expansion valve 30, and the indoor heat exchanger 40. Then, it absorbs heat from the room air and evaporates, returns to the compressor 10 through the four-way valve 20. In the general outdoor heat exchanger 100, the gas refrigerant that has flowed in is condensed into a two-phase refrigerant. As the refrigerant condenses, the ratio of the liquid refrigerant in the two-phase refrigerant increases. In the vicinity of the outlet of the outdoor heat exchanger 100 according to the present invention, the refrigerant sequentially flows through the heat transfer pipes (169 to 162) in the downward direction. There is nothing.

  Thereby, the fall of the heat exchange amount by a refrigerant | coolant stagnating in a heat exchanger tube at the time of air_conditionaing | cooling operation can be prevented. In addition, since the heat exchange portions of the two refrigerant flow paths after being divided by the first flow divider 110 have substantially the same length, there is no pressure loss difference between the refrigerant flow paths, and the pressure loss difference is generated. There is no imbalance in the refrigerant flow rate, preventing a reduction in heat exchange.

  Next, the operation | movement at the time of the heating operation in which the outdoor heat exchanger 100 acts as an evaporator is demonstrated. The refrigerant compressed to a high pressure by the compressor 10 passes through the four-way valve 20, flows into the indoor heat exchanger 40, dissipates heat to the indoor air, condenses, is decompressed to a low pressure by the expansion valve 30, and is supplied to the second shunt 120. And then flows into the outdoor heat exchanger 100, absorbs heat from the outdoor air by the outdoor heat exchanger 100, evaporates, flows out of the outdoor heat exchanger 100, and then joins at the first flow divider 110 to form a four-way valve. Return to the compressor 10 through 20. In the outdoor heat exchanger 100, as the refrigerant evaporates, the temperature of the outdoor heat exchanger 100 decreases and condensed water is generated. The generated condensed water slides down along the fins due to its own weight. However, the refrigerant having a temperature lower than that of the refrigerant flowing through the heat transfer tube 162 does not flow into the heat transfer tube 160 at the lowest level on the windward side in the lower flow path. Thereby, condensed water is cooled by the lower part of the outdoor heat exchanger 100, and the quantity which changes to frost can be decreased.

  Then, the operation | movement at the time of a defrost operation is demonstrated. The refrigerant compressed to high temperature and high pressure by the compressor 10 passes through the four-way valve 20, flows into the outdoor heat exchanger 100, melts frost adhering to the outdoor heat exchanger 100, and connects the expansion valve 30 and the indoor heat exchanger 40. Via, it passes through the four-way valve 20 and returns to the compressor 10. In the outdoor heat exchanger 100, frost and ice adhering to the outdoor heat exchanger 100 are thawed by the flow of high-temperature and high-pressure refrigerant. In particular, since the refrigerant after flowing through the leeward heat transfer tubes (150 to 159) flows into the heat transfer tube 160 at the lowermost stage on the leeward side in the lower flow path, the leeward side as in Patent Document 1. The refrigerant after flowing through the heat transfer tubes (350 to 359) has a higher temperature than the refrigerant flowing from the windward heat transfer tube 369 downward to the heat transfer tube 360, so that attached frost and the like can be removed quickly. I can do it.

  As described above, the liquid refrigerant is less likely to accumulate in the lower flow path in the windward row during the cooling operation. Further, during the heating operation, the refrigerant outlet in the lower flow path is a heat transfer tube located above the lowermost stage. This makes it difficult for frost to adhere to the lower part of the windward row in the lower channel. Furthermore, during the defrosting operation, the time required for the defrosting operation is shortened by flowing a high-temperature refrigerant early to the heat transfer tube that is adjacent to the heat transfer tube serving as the refrigerant outlet in the lower channel. I can do it.

  Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the heat exchanger is provided with a supercooling section below the heat transfer tubes (159, 160) which are the lowest stages in the heat exchanger described in the first embodiment. During the cooling operation, the refrigerant that has flowed through the upper flow path and the lower flow path merges in the heat transfer pipe 473 at the lower part of the leeward row of the outdoor heat exchanger 400, and the combined refrigerant passes through the pipe 483. The refrigerant flowing into the heat transfer tubes 475 in the windward row and flowing out from the heat transfer tubes 475 sequentially passes through the heat transfer tubes (476 to 477) up to the heat transfer tubes 478, and the refrigerant flowing out from the heat transfer tubes 478 is the outdoor heat exchanger. 400 is discharged. During the heating operation, the lower flow path is formed by setting the heat transfer tube 460 into which the refrigerant branched into the lower flow path first flows above the lowermost heat transfer pipe 458 on the lower flow path. In order to prevent frost from adhering to the lower part of the windward side of Further, during the defrosting operation, the heat transfer tubes 459 adjacent to the heat transfer tubes 460 in the downward direction are circulated through the heat transfer tubes (450 to 457) on the leeward side, and then the heat transfer tubes 458 in the leeward row are circulated. Since the refrigerant flows, the heat transfer tube 460 is also heated to easily remove frost, and the time required for the defrosting operation can be shortened. Thus, even when the supercooling section is provided at the lower part of the heat transfer tubes (457, 458) as the lowest stage in the outdoor heat exchanger 400, the effect of the supercooling section can be obtained and the same as in the first embodiment. The effect of can also be acquired.

  Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, heat having the same flow path as the heat exchanger described in the first embodiment above the heat transfer tubes (437, 438) which are the uppermost stage in the heat exchanger described in the second embodiment. It is a heat exchanger provided with an exchange part. When the heat exchanger of this embodiment is used as an evaporator, in order to improve the efficiency of the heat exchanger, a large number of refrigerants are branched so that each refrigerant flow path is not lengthened. In the present embodiment, a case where the refrigerant is branched into four and the refrigerant is caused to flow into the heat exchanger will be described. The refrigerant is divided into an upper flow path and a lower flow path in each of the first flow divider 510 and the second flow divider 511, and flows into the heat transfer tubes (530 and 540, 550 and 560) adjacent in the vertical direction. The During the cooling operation, the refrigerant flowing in the upper flow path extends from the heat transfer tubes (530, 550) in the leeward row to the uppermost heat transfer tubes (533, 553) in the leeward row on the upper flow path. The refrigerant that sequentially flows in the heat transfer tubes (531 to 532, 551 to 552) and flows out of the heat transfer tubes (533 and 553) flows into the heat transfer tubes (534 and 554) in the uppermost row of the windward side, and then moves downward. To the heat transfer tubes (535-537, 555-557) sequentially. On the other hand, during the cooling operation, the refrigerant flowing in the lower flow path is transferred from the heat transfer tubes (540, 560) in the leeward row to the heat transfer tubes (543, 563) sequentially flows in the heat transfer tubes (541 to 542, 561 to 562), and the refrigerant flowing out of the heat transfer tubes (543, 563) flows on the lower flow path, and the heat transfer tubes (544 in the lowermost row in the windward row). 564), the refrigerant flowing into the heat transfer tubes (545, 565) that are one stage higher than the heat transfer tubes (544, 564), and the refrigerant flowing out of the heat transfer tubes (545, 565) is further two steps higher. After flowing into a certain heat transfer tube (547, 567) through a pipe, the heat transfer tube (546, 566) flows downward. During the heating operation, the heat transfer tubes (546, 566) into which the refrigerant flowing in the lower flow path first flows are placed above the lowermost heat transfer tubes (544, 564) in the lower flow path. Thus, frost is less likely to adhere to the lower part of the windward side of the lower channel. In addition, the heat transfer tubes (540 to 543, 560 to 563) on the leeward side are circulated to the heat transfer tubes (545, 565) which are adjacent to the heat transfer tubes (546, 566) serving as the refrigerant outlet during the defrosting operation. However, the time taken for the defrosting operation can be shortened by flowing the refrigerant after passing through the heat transfer tubes (544, 564) in the lowermost stage in the lower flow path in the windward row. Thus, pressure loss is reduced by diverting the refrigerant flowing into the heat exchanger so as not to lengthen the refrigerant flow path in the heat exchanger. Even when there are four heat transfer tubes flowing into the outdoor heat exchanger 500 as in the heat exchanger of the present embodiment, the same effect as that of the first embodiment can be obtained. In the present invention, the number of heat transfer tubes flowing into the outdoor heat exchanger 500 is not limited to two or four, but the upper flow path and the lower flow path that are divided by the flow divider are adjacent in the vertical direction. There may be a plurality of things flowing into the heat pipe.

1 Refrigeration cycle 10 Compressor 20 Four-way valve 30 Expansion valve 40 Indoor heat exchanger 100 Outdoor heat exchanger

Claims (1)

A plurality of fins laminated with a predetermined gap, and air flowing through the gap;
Heat passing through the fins in the stacking direction, two rows in the direction of circulating air, and a plurality of heat transfer tubes arranged in the vertical direction intersecting the direction of circulating air,
A fin tube type heat exchanger that circulates a refrigerant in a refrigerant flow path formed by sequentially connecting the heat transfer tubes,
When the heat exchanger is used as a condenser, the upper inlet and the lower inlet into which the refrigerant flows are provided vertically adjacent to the leeward row with respect to the direction in which the air flows, and the refrigerant flows out. The upper outlet and the lower outlet are provided in a row on the windward side in the direction in which the air flows.
The refrigerant flowing in from the upper inflow port sequentially flows through the heat transfer tubes up to the uppermost heat transfer tube toward the upper side of the leeward row, and then flows into the uppermost heat transfer tube in the upper windward row. An upper flow path that sequentially flows through the heat transfer tubes downward and flows out of the upper outlet,
The refrigerant flowing in from the lower inflow port sequentially flows through the heat transfer tubes to the lowermost heat transfer tube toward the lower side of the leeward row and then flows into the lowermost heat transfer tube in the upper windward row. After flowing through at least two stages of heat transfer tubes toward the upper side, before flowing into the heat transfer tubes adjacent to the upper outlets in the row on the windward side and before flowing into the heat transfer tubes adjacent to the upper outlets A heat exchanger, comprising: a lower flow path that sequentially flows downward through a heat transfer tube to a heat transfer tube adjacent to the upper side of the flowing heat transfer tube and flows out from the lower outlet.

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