JP6179414B2 - Heat exchanger for heat source unit of refrigeration apparatus, and heat source unit including the same - Google Patents

Description

  The present invention relates to a heat exchanger for a heat source unit of a refrigeration apparatus, and a heat source unit including the heat exchanger.

  Conventionally, in a refrigeration apparatus such as an air conditioner or a water heater, a heat exchanger that performs heat exchange between air and a refrigerant has been used. In a heat exchanger including a large number of heat transfer tubes, it is common to arrange these heat transfer tubes in two rows on the windward side and the leeward side, but recently, there are also those in which three or more rows are arranged.

  For example, the heat exchanger shown in Patent Document 1 (Japanese Patent Laid-Open No. 2006-234264) has three rows.

  However, when a heat exchanger in which heat transfer tubes are arranged in three or more rows is used in the heat source unit of the refrigeration apparatus, if the refrigerant is flowed in the same manner as the two rows of heat exchangers, a part of the heat exchanger is transferred. It is assumed that the heat pipe does not sufficiently perform the function of heat exchange. In the heat source unit of a refrigeration system that draws heat from the outside air, the temperature difference between the refrigerant flowing inside the heat exchanger functioning as an evaporator and the outside air may be small. This is because the efficiency of heat exchange differs depending on whether the refrigerant flows.

  An object of the present invention is to provide a heat exchanger having three or more rows used in a heat source unit of a refrigeration apparatus and having excellent heat exchange efficiency. Another object of the present invention is to improve the energy saving performance of the heat source unit of the refrigeration apparatus.

  The heat exchanger of the heat source unit of the refrigeration apparatus according to the first aspect of the present invention causes heat exchange between the refrigerant flowing inside and the outside air to evaporate the refrigerant. The heat exchanger includes a plurality of first heat transfer tubes, a plurality of second heat transfer tubes, a plurality of third heat transfer tubes, a liquid side connection tube, a gas side connection tube, and a flow divider for diverting a refrigerant. I have. The liquid side connection pipe serves as an inlet for a liquid phase or gas-liquid two-phase refrigerant. The gas side connection pipe is an outlet for the gas phase refrigerant. The plurality of first heat transfer tubes form a first row that is aligned in the vertical direction and is located on the most upstream side of the flow of outside air. The plurality of third heat transfer tubes are arranged in the vertical direction and constitute a third row located on the most leeward side of the flow of outside air. The plurality of second heat transfer tubes are arranged in the vertical direction, and constitute a second row located on the leeward side from the first row and located on the leeward side from the third row. The first heat transfer tube, the second heat transfer tube, and the third heat transfer tube located below the first row, the second row, and the third row are connected to each other to form a first flow path. The liquid side connecting pipe communicates with the first flow path. The shunt diverts the refrigerant that has flowed from the liquid side connecting pipe into the first flow path and has exited the first flow path, into a plurality of branch pipes. The first heat transfer tube, the second heat transfer tube, and the third heat transfer tube other than the first heat transfer tube, the second heat transfer tube, and the third heat transfer tube forming the first flow path are refrigerants that have exited the plurality of branch tubes, respectively. Are formed. The plurality of branch channels are connected to each other so that the refrigerant flows in the order of the third heat transfer tube, the second heat transfer tube, and the first heat transfer tube. It is the made flow path. The plurality of branch channels are formed so that the refrigerant flows out from the first heat transfer tube to the gas side connection tube.

  Here, the liquid-phase or gas-liquid two-phase refrigerant first flows into the first flow path from the liquid side connecting pipe. Thereafter, the refrigerant exiting the first flow path passes through the flow divider and is divided into a plurality of branch flow paths, and flows through the respective branch flow paths. These branch flow paths are configured such that the refrigerant flows in the order of the third heat transfer tube, the second heat transfer tube, and the first heat transfer tube, and the refrigerant flows from the leeward side toward the windward side. . That is, the refrigerant flowing through the branch flow path flows in the direction opposite to the wind direction, and the refrigerant whose temperature is rising and flowing through the first heat transfer tube exchanges heat with the windward air having the highest temperature. The refrigerant flowing through the third heat transfer tube, which is not so hot, exchanges heat with the first and second heat transfer tubes to exchange heat with the air whose temperature has already decreased. The refrigerant flowing through these branch flow paths is a so-called counterflow with respect to the air flow, and the efficiency of heat exchange with air is improved. In addition, the refrigerant overheating region in the branch channel is reduced, and drift is also suppressed. The refrigerant that has evaporated heat from the air in the first flow path or the branch flow path flows out from the first heat transfer tubes of the plurality of branch flow paths to the gas side connection pipe.

  Note that the heat exchanger of the heat source unit of the refrigeration apparatus may be used not only as an evaporator but also as a condenser. However, even when used as the condenser, the first flow composed of the first heat transfer tube, the second heat transfer tube, and the third heat transfer tube located in the lower part of each of the first row, the second row, and the third row. Since the path and the liquid side connecting pipe communicate with each other, the refrigerant that has condensed into a liquid phase flows out from the liquid side connecting pipe without staying inside the heat exchanger.

  The heat exchanger of the heat source unit of the refrigeration apparatus according to the second aspect of the present invention is the heat exchanger according to the first aspect, and the liquid side connecting pipe is provided at the lower part of the first row forming the first flow path. It communicates with the first heat transfer tube.

  When the heat exchanger is used as a condenser, the refrigerant flows from the first flow path to the liquid side connection pipe, and then flows out from the liquid side connection pipe. Here, the first flow path forming the first flow path The liquid side connection pipe is connected to the first heat transfer pipe at the bottom of the row. That is, the liquid refrigerant passes through the liquid side connection pipe from the first heat transfer pipe arranged on the windward side among the first heat transfer pipe, the second heat transfer pipe and the third heat transfer pipe constituting the first flow path. It will flow out. Thereby, the supercooling region of the refrigerant in the heat exchanger when used as a condenser can be kept small, and a decrease in the capacity of the heat exchanger is suppressed.

  The heat exchanger of the heat source unit of the refrigeration apparatus according to the third aspect of the present invention is the heat exchanger according to the first aspect or the second aspect, and further includes a gas side header. The gas side header is arrange | positioned between the 1st heat exchanger tube of each of several branch flow paths, and a gas side connection pipe.

  Here, the refrigerant evaporated through each branch flow path flows and gathers in the gas-side header and flows to the gas-side connection pipe.

  The heat source unit according to the present invention includes a heat exchanger according to a third aspect, a first flow path switching mechanism, and a second flow path switching mechanism. The first flow path switching mechanism is disposed between the first flow path and the flow divider. The second flow path switching mechanism is disposed between the gas side header and the gas side connection pipe. The first flow path switching mechanism can switch between a first state in which the first flow path and the flow divider communicate with each other and a second state in which the first flow path and the gas side header communicate with each other. The second flow path switching mechanism includes a third state in which the gas side header and the gas side connection pipe communicate with each other, and a fourth state in which the gas side connection pipe and the first flow path switching mechanism side of the flow divider communicate with each other. Can be switched.

  In this heat source unit, by switching between the first flow path switching mechanism and the second flow path switching mechanism, the heat exchanger can function as an evaporator or a condenser while maintaining a counter flow. . When a heat exchanger is used as an evaporator, the refrigerant flow and the air flow in each branch flow path are obtained by setting the first flow path switching mechanism to the first state and the second flow path switching mechanism to the third state. Can be made countercurrent. Also, when using a heat exchanger as a condenser, the refrigerant flow in each branch flow path can be reduced by setting the first flow path switching mechanism to the second state and the second flow path switching mechanism to the fourth state. The air flow can be counterflowed.

  According to the heat exchanger of the heat source unit according to the first aspect of the present invention, the refrigerant flowing through the branch flow path becomes a so-called counterflow with respect to the air flow, and the efficiency of heat exchange with air is improved.

  According to the heat exchanger of the heat source unit according to the second aspect of the present invention, the refrigerant subcooling region in the heat exchanger when used as a condenser can be kept small, and a decrease in the capacity of the heat exchanger is suppressed. The

  According to the heat exchanger of the heat source unit according to the third aspect of the present invention, the refrigerant branched by the flow divider can be collected by the gas side header.

  According to the heat source unit of the present invention, the heat exchanger can function as an evaporator or a condenser while maintaining a counter flow.

The refrigerant circuit of the air conditioning apparatus which is a refrigeration apparatus which concerns on one Embodiment of this invention. The perspective view of the outdoor heat source unit which concerns on one Embodiment of this invention. The perspective view which shows the outdoor heat source unit from which the right side board and the port casing were removed. The figure which shows the flow of the refrigerant | coolant of an outdoor heat exchanger when functioning as an evaporator. The figure which shows the flow of the refrigerant | coolant of an outdoor heat exchanger when functioning as a condenser. The figure which shows the flow of the refrigerant | coolant around the outdoor heat exchanger which concerns on the modification B when functioning as an evaporator. The figure which shows the flow of the refrigerant | coolant around the outdoor heat exchanger which concerns on the modification B when functioning as a condenser.

(1) Configuration of Air Conditioner An outdoor heat source unit of an air conditioner installed outdoors will be described as an example of the heat source unit of the refrigeration apparatus according to the present invention. FIG. 1 is a refrigerant circuit of an air conditioner 10 according to an embodiment of the present invention. The air conditioner 10 is a multi-type air conditioner, and is configured such that five indoor use units 30 are connected in parallel to one outdoor heat source unit 20.

(1-1) Refrigerant circuit The refrigerant circuit 11 of the air conditioner 10 mainly includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an electric valve 24 for a high-pressure receiver, a high-pressure receiver 27, and five chambers. The motor-operated valve 25, the indoor heat exchanger 31, the accumulator 26, and the compressor gas-liquid separator 21a are sequentially connected. In the refrigerant circuit 11, a vapor compression refrigeration cycle is performed. The refrigerant circuit 11 has a configuration in which an outdoor refrigerant circuit 12 formed in the outdoor heat source unit 20 and an indoor refrigerant circuit 13 formed in the indoor use unit 30 are connected. The outdoor refrigerant circuit 12 includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an electric valve 24 for a high pressure receiver, five electric valves 25 for each chamber, a gas-liquid separator 21a for a compressor, and an accumulator. 26 and the high-pressure receiver 27, and the indoor refrigerant circuit 13 includes an indoor heat exchanger 31.

  The outdoor refrigerant circuit 12 of the outdoor heat source unit 20 and the indoor refrigerant circuit 13 of the indoor use unit 30 are connected by five gas side refrigerant communication pipes 17a and five liquid side refrigerant communication pipes 17b. The five gas side refrigerant communication pipes 17 a are connected to the gas pipe connection port 14 of the outdoor heat source unit 20, and the five liquid side refrigerant communication pipes 17 b are connected to the liquid pipe connection port 15 of the outdoor heat source unit 20. . The gas pipe connection port 14 combines the five gas side refrigerant communication pipes 17 a into one, and is connected to the fourth port of the four-way switching valve 22 via the gas side closing valve 18. The second port of the four-way switching valve 22 is connected to the outdoor heat exchanger 23 via a gas refrigerant pipe 22a. In the liquid pipe connection port 15, five liquid side refrigerant communication pipes 17 b are connected to one end side of each of the five electric motor valves 25 for each chamber, and connected to the other end side of the five electric motor valves for each chamber 1. The main liquid pipe is connected to the high-pressure receiver 27 via the liquid-side closing valve 19. The high-pressure receiver 27 is connected to the other end side of the high-pressure receiver electric valve 24. One end of the high-pressure receiver motor-operated valve 24 is connected to the outdoor heat exchanger 23 via a liquid refrigerant pipe 24a. The discharge side of the compressor 21 is connected to the first port of the four-way switching valve 22, and the third port of the four-way switching valve 22 is connected to the accumulator 26. The accumulator 26 is connected to the suction side of the compressor 21 via the compressor gas-liquid separator 21a.

  The outdoor heat source unit 20 is provided with an outdoor control unit 29 for controlling the compressor 21, the four-way switching valve 22, the high-pressure receiver electric valve 24, the electric motor valves 25 for each room, the outdoor fan 28, and the like. . Each indoor use unit 30 is provided with an indoor control unit 33 for controlling the indoor fan 32 and the like. Further, a bypass path is provided from the high pressure receiver 27 to the accumulator 26 via the electric valve 27b.

(1-2) Structure of the outdoor heat source unit FIG. 2 is a perspective view showing an external appearance of the outdoor heat source unit 20 as viewed from the upper right side on the front side. The outdoor heat source unit 20 includes a main body casing 40 and a port casing 50. The main body casing 40 includes a front plate 41, a top plate 42, a right side plate 43, a bottom plate 46 (see FIG. 3), and the like. Further, a grill 44 for covering the propeller 28a of the outdoor fan 28 is attached to the front plate 41 of the main body casing 40 in front of the opening 41a.

  A port casing 50 is attached so as to protrude further rightward from the right side plate 43 of the main body casing 40. The port casing 50 is a resin casing for covering the gas pipe connection port 14, the liquid pipe connection port 15, and the like.

  FIG. 3 is a perspective view showing an appearance of the outdoor heat source unit 20 as viewed from the upper right side on the rear surface side. In FIG. 3, the right side plate 43 and the port casing 50 are removed, and the accumulator 26 and the high-pressure receiver 27 housed in the machine chamber S <b> 1 inside the main body casing 40 are exposed. The propeller 28a of the outdoor fan 28 shown in FIG. 2 and the outdoor heat exchanger 23 shown in FIG. 3 are arranged in the blower room partitioned from the machine room S1. The outdoor heat exchanger 23 has an L shape in plan view. One side of the L-shape of the outdoor heat exchanger 23 faces the rear surface side of the main body casing 40. On the rear surface side of the main casing 40, a lattice-shaped protection member 45 that covers the outdoor heat exchanger 23 is disposed. In addition, in FIG. 3, illustration of the compressor 21 arrange | positioned in machine room S1 is also abbreviate | omitted.

  The outdoor heat exchanger 23 of the outdoor heat source unit 20 will be described in detail later.

(2) Operation of Air Conditioner Next, the operation of the air conditioner 10 during the cooling operation and the heating operation will be described. In addition, although the following description demonstrates the case where all the five indoor use units 30 are operate | moving, each indoor use unit 30 operate | moves according to the setting and environmental condition of the air conditioning apparatus 10, or stops. It is something to do.

(2-1) Cooling Operation First, during the cooling operation, the four-way switching valve 22 is switched to the state shown by the solid line in FIG. 1 so that the first port and the second port are connected, and the third port and the fourth port are connected. Connected. That is, the discharge side of the compressor 21 is connected to the outdoor heat exchanger 23, and the suction side of the compressor 21 is connected to the gas side shut-off valve 18. With such a circuit configuration of the refrigerant circuit 11 during the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 flows into the outdoor heat exchanger 23 through the four-way switching valve 22 and the gas refrigerant pipe 22a. The heat is exchanged with outdoor air (outside air) in the outdoor heat exchanger 23 to condense and liquefy. The liquid refrigerant liquefied by the outdoor heat exchanger 23 flows into the high-pressure receiver 27 via the liquid refrigerant pipe 24a and the high-pressure receiver electric valve 24. The high-pressure liquid refrigerant temporarily stored in the high-pressure receiver 27 passes through the liquid-side shut-off valve 19 from the high-pressure receiver 27 and then is divided into five, and the five divided flows pass through the five motor-operated valves 25 for each chamber, respectively. pass. The liquid refrigerant that has passed through the five motor-operated valves 25 for each chamber of the liquid pipe connection port 15 expands by passing through the motor-operated valves 25 for each chamber, and passes through five liquid-side refrigerant communication pipes 17b. To the indoor use unit 30 of each.

  In each indoor use unit 30, the liquid refrigerant evaporates by exchanging heat with indoor air in the indoor heat exchanger 31. The indoor air cooled by the evaporation of the refrigerant is blown out into the room by the indoor fan 32 to cool the room. The gas refrigerant evaporated and vaporized by the five indoor heat exchangers 31 returns to the outdoor refrigerant circuit 12 of the outdoor heat source unit 20 from the gas pipe connection port 14 through the five gas side refrigerant communication pipes 17a. . The gas refrigerant that has returned to the outdoor refrigerant circuit 12 is sucked into the compressor 21 from the four-way switching valve 22 via the accumulator 26 and the compressor gas-liquid separator 21a.

(2-2) Heating operation During the heating operation, the four-way switching valve 22 is switched to the state indicated by the broken line in FIG. 1, the first port and the fourth port are connected, and the second port and the third port are connected. It will be in the state. That is, the discharge side of the compressor 21 is connected to the gas side shut-off valve 18, and the suction side of the compressor 21 is connected to the outdoor heat exchanger 23. Due to the circuit configuration of the refrigerant circuit 11 during the heating operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 is supplied from the gas pipe connection port 14 via the four-way switching valve 22 and the gas-side closing valve 18. It flows out to the five gas side refrigerant communication pipes 17a. Then, the gas refrigerant flows into the indoor heat exchanger 31 of each indoor use unit 30 through the five gas side refrigerant communication pipes 17a, and is condensed by heat exchange with indoor air in the indoor heat exchanger 31. To liquefy. The indoor air heated by the condensation of the refrigerant is blown into the room by the indoor fan 32 to heat the room. The liquid refrigerant liquefied in the five indoor heat exchangers 31 returns to the outdoor refrigerant circuit 12 of the outdoor heat source unit 20 from the liquid pipe connection port 15 through the five liquid side refrigerant communication pipes 17b. The liquid refrigerant that has returned to the outdoor heat source unit 20 passes through the five motor-operated valves 25 for each chamber at the liquid pipe connection port 15. The liquid refrigerant that has passed through the five motor-operated valves 25 for each chamber joins, passes through the liquid-side closing valve 19, and flows into the high-pressure receiver 27. The liquid refrigerant that has been expanded by passing through the electric valve for each chamber 25 and temporarily accumulated in the high-pressure receiver 27 is further depressurized from the high-pressure receiver 27 through the electric valve for high-pressure receiver 24, and passes through the liquid refrigerant pipe 24 a. And flows into the outdoor exchanger 23. The liquid refrigerant that has flowed into the outdoor heat exchanger 23 evaporates by exchanging heat with the outside air in the outdoor heat exchanger 23. The gas refrigerant evaporated and vaporized in the outdoor heat exchanger 23 passes through the gas refrigerant pipe 22a, and is sucked into the compressor 21 from the four-way switching valve 22 via the accumulator 26 and the compressor gas-liquid separator 21a. .

(3) Detailed configuration and heat exchange operation of the outdoor heat exchanger of the outdoor heat source unit (3-1) Detailed configuration of the outdoor heat exchanger The outdoor heat exchanger 23 exchanges heat between the refrigerant flowing inside and the outside air. It is a device that evaporates or condenses the refrigerant. As shown in FIG. 4, the outdoor heat exchanger 23 includes a plurality of heat transfer fins 70, a plurality of first heat transfer tubes 71a, 71b, 71c, 71d, 71e, and a plurality of second heat transfer tubes 72a, 72b, 72c, 72d, 72e, a plurality of third heat transfer tubes 73a, 73b, 73c, 73d, 73e, a liquid side connection tube 75, a gas side connection tube 76, and a flow divider 78 for dividing the refrigerant. .

  The liquid side connection pipe 75 is connected to the high-pressure receiver motor-operated valve 24 via the liquid refrigerant pipe 24a. When the outdoor heat exchanger 23 functions as an evaporator, the liquid side connection pipe 75 serves as an inlet for a liquid-phase or gas-liquid two-phase refrigerant, When the outdoor heat exchanger 23 functions as a condenser, it serves as an outlet for liquid-phase refrigerant.

  The gas side connection pipe 76 is connected to the four-way switching valve 22 via the gas refrigerant pipe 22a, and when the outdoor heat exchanger 23 functions as an evaporator, it serves as an outlet for the gas phase refrigerant, and the outdoor heat exchanger 23 is When functioning as a condenser, it serves as an inlet for a gas-phase refrigerant.

  The plurality of first heat transfer tubes 71 a, 71 b, 71 c, 71 d, 71 e are arranged in the vertical direction and constitute a first row R <b> 1 that is located on the furthest upstream side of the outdoor air flow W. Here, four first heat transfer tubes 71a, four first heat transfer tubes 71b disposed thereon, four first heat transfer tubes 71c disposed thereon, and four tubes disposed thereon. The first heat transfer tube 71d and the four first heat transfer tubes 71e arranged thereon constitute a first row R1.

  The plurality of third heat transfer tubes 73a, 73b, 73c, 73d, and 73e are arranged in the vertical direction and constitute a third row R3 that is located on the most leeward side of the flow W of outside air. Here, four third heat transfer tubes 73a, four third heat transfer tubes 73b disposed thereon, four third heat transfer tubes 73c disposed thereon, and four disposed thereon. The third heat transfer tube 73d and the four third heat transfer tubes 73e arranged thereon constitute a third row R3.

  The plurality of second heat transfer tubes 72a, 72b, 72c, 72d, 72e are arranged in the vertical direction and constitute a second row R2. The second row R2 is located on the leeward side with respect to the first row R1, and is located on the leeward side with respect to the third row R3. Here, four second heat transfer tubes 72a, four second heat transfer tubes 72b disposed thereon, four second heat transfer tubes 72c disposed thereon, and four disposed thereon. The second heat transfer tube 72d and the four second heat transfer tubes 72e arranged thereon constitute a second row R2.

  Each of the heat transfer tubes 71a, 71b, 71c, 71d, 71e, 72a, 72b, 72c, 72d, 72e, 73a, 73b, 73c, 73d, 73e is a copper tube, and many aluminum are arranged in parallel with a minute gap. It penetrates through a group of heat transfer fins 70 made.

  The first heat transfer tube 71a, the second heat transfer tube 72a, and the third heat transfer tube 73a located below the first row R1, the second row R2, and the third row R3 are connected to each other and pass through the first flow path P1. Forming. The liquid side connection pipe 75 is connected to the first heat transfer pipe 71a located at the bottom of the four first heat transfer pipes 71a of the first flow path P1.

  When the outdoor heat exchanger 23 functions as an evaporator, the flow divider 78 flows the refrigerant that flows from the liquid side connection pipe 75 into the first flow path P1 and exits the first flow path P1, and has four branch pipes 78b and 78c. , 78d, 78e. The first heat transfer tubes 71b, 71c, 71d, 71e other than the first heat transfer tube 71a, the second heat transfer tube 72a, and the third heat transfer tube 73a forming the first flow path P1, and the second heat transfer tubes 72b, 72c, 72d. , 72e and the third heat transfer tubes 73b, 73c, 73d, 73e form four branch flow paths P2, P3, P4, P5 through which the refrigerant exiting each of the plurality of branch tubes 78b, 78c, 78d, 78e flows. Yes.

  The branch flow path P2 includes the first heat transfer tube 71b, the second heat transfer tube 72b, and the second heat transfer tube 73b so that the refrigerant flows in the order of the four third heat transfer tubes 73b, the four second heat transfer tubes 72b, and the four first heat transfer tubes 71b. 3 heat transfer tubes 73b are connected to each other. The refrigerant flows out from the first heat transfer pipe 71b of the branch flow path P2 to the gas side connection pipe 76.

  The branch flow path P3 includes the first heat transfer tube 71c, the second heat transfer tube 72c, and the second heat transfer tube 73c so that the refrigerant flows in the order of the four third heat transfer tubes 73c, the four second heat transfer tubes 72c, and the four first heat transfer tubes 71c. 3 heat transfer tubes 73c are connected to each other. The refrigerant flows out from the first heat transfer pipe 71c of the branch flow path P3 to the gas side connection pipe 76.

  The branch flow path P4 includes the first heat transfer pipe 71d, the second heat transfer pipe 72d, and the second heat transfer pipe 73d so that the refrigerant flows in the order of the four third heat transfer pipes 73d, the four second heat transfer pipes 72d, and the four first heat transfer pipes 71d. This is a flow path in which three heat transfer tubes 73d are connected to each other. The refrigerant flows out from the first heat transfer pipe 71d of the branch flow path P4 to the gas side connection pipe 76.

  The branch flow path P5 includes the first heat transfer pipe 71e, the second heat transfer pipe 72e, and the second heat transfer pipe 72e so that the refrigerant flows in the order of the four third heat transfer pipes 73e, the four second heat transfer pipes 72e, and the four first heat transfer pipes 71e. 3 heat transfer tubes 73e are connected to each other. The refrigerant flows out from the first heat transfer pipe 71e of the branch flow path P5 to the gas side connection pipe 76.

  A gas side header 79 is provided between the four branch flow paths P2, P3, P4, P5 and the gas side connection pipe 76. Specifically, the gas side header 79 is disposed between the first heat transfer tubes 71b, 71c, 71d, 71e of the branch flow paths P2, P3, P4, P5 and the gas side connection tube 76. The refrigerant that has flowed out of the first heat transfer tubes 71b, 71c, 71d, 71e of the branch flow paths P2, P3, P4, P5 flows into the gas-side header 79 through the header connection tubes 79b, 79c, 79d, 79e, and gas. After gathering in the side header 79, it flows out to the gas side connection pipe 76 connected to the lower part of the gas side header 79.

(3-2) Heat exchange operation of outdoor heat exchanger when functioning as an evaporator During the heating operation described above, the outdoor heat exchanger 23 functions as an evaporator. At this time, the liquid-phase or gas-liquid two-phase refrigerant that has been decompressed by the high-pressure receiver motor-operated valve 24 and flows through the liquid refrigerant pipe 24 a first flows into the first flow path P <b> 1 through the liquid-side connection pipe 75. Thereafter, the refrigerant exiting the first flow path P1 passes through the liquid side pipe 78a of the flow divider 78 and enters the flow divider 78, where it is divided into four branch pipes 78b, 78c, 78d and 78e, and further four branch flow paths. It flows through P2, P3, P4 and P5, respectively. These branch flow paths P2, P3, P4, P5 are the third heat transfer tubes 73b, 73c, 73d, 73e, the second heat transfer tubes 72b, 72c, 72d, 72e, and the first heat transfer tubes 71b, 71c, 71d, 71e. The refrigerant flows in order, and the refrigerant flows from the leeward side toward the windward side (see the white arrow in FIG. 4). That is, the refrigerant flowing through the branch flow paths P2, P3, P4, and P5 flows in the direction opposite to the outside air flow (wind direction) W, and the temperature has already risen, so that the first heat transfer tubes 71b, 71c, and 71d. , 71e exchange heat with the windward outside air having the highest temperature, and the refrigerant flowing through the third heat transfer tubes 73b, 73c, 73d, 73e, where the temperature is not so high, is already the first heat transfer tube. Heat exchange is performed with the outside air having a slightly lowered temperature by performing heat exchange with 71b, 71c, 71d, 71e and the second heat transfer tubes 72b, 72c, 72d, 72e. The refrigerant flowing through these branch flow paths P2, P3, P4 and P5 is a so-called counter flow with respect to the flow W of the outside air, and the efficiency of heat exchange with the outside air is improved. Moreover, the refrigerant | coolant overheating area in branch flow path P2, P3, P4, P5 becomes small, and a drift is also suppressed. In the first flow path P1 and the branch flow paths P2, P3, P4, and P5, the refrigerant that has evaporated from the outside air has evaporated the first heat transfer tubes 71b, 71c, The gas flows from 71d and 71e to the gas side connecting pipe 76 through the gas side header 79.

(3-3) Heat exchange operation of the outdoor heat exchanger when functioning as a condenser During the above-described cooling operation, the outdoor heat exchanger 23 functions as a condenser. At this time, the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 flows to the gas-side connecting pipe 76 via the four-way switching valve 22 and the gas refrigerant pipe 22a as shown in FIG. The gas refrigerant that has flowed from the gas side connection pipe 76 to the gas side header 79 is divided into branch flow paths P2, P3, P4, and P5, and flows from the windward side toward the leeward side (the white arrow in FIG. 5). See). The refrigerant flowing through these branch flow paths P2, P3, P4 and P5 is a so-called parallel flow with respect to the flow W of the outside air.

  The refrigerant that has exited the third heat transfer pipes 73b, 73c, 73d, and 73e of the branch flow paths P2, P3, P4, and P5 enters the flow divider 78 through the branch pipes 78b, 78c, 78d, and 78e. It flows into the 3rd heat exchanger tube 73a of the 1st flow path P1 from the liquid side piping 78a. Then, the refrigerant that flows through the first flow path P1 and exits the first heat transfer pipe 71a flows out from the liquid side connection pipe 75 to the liquid refrigerant pipe 24a.

(4) Features (4-1)
Generally, in a heat source unit of a refrigeration apparatus such as the air conditioner 10 that is often placed outdoors, the temperature difference between the refrigerant flowing inside the heat exchanger and the outside air may be small. In such a case, if the refrigerant flowing inside the heat exchanger drifts or the overheated area of the refrigerant flowing inside the heat exchanger is expanded, the efficiency of heat exchange decreases.

  However, in the outdoor heat exchanger 23 of the air conditioner 10 according to the embodiment of the present invention, when used as an evaporator, as indicated by the white arrows in FIG. 4, the branch flow paths P2, P3, P4 , P5 is a so-called counterflow with respect to the outside air flow W. Thereby, the outdoor heat exchanger 23 has improved the efficiency of heat exchange between the refrigerant flowing inside and the outside air. Moreover, the refrigerant | coolant overheating area in branch flow path P2, P3, P4, P5 becomes small, and a drift is also suppressed.

(4-2)
In the outdoor heat exchanger 23 of the air conditioner 10 according to the embodiment of the present invention, when used as a condenser, as indicated by the white arrows in FIG. The liquid flows into the side connection pipe 75 and flows out from the liquid side connection pipe 75 to the liquid refrigerant pipe 24a. In view of such a refrigerant flow, in the outdoor heat exchanger 23, the liquid side connection pipe 75 is connected to the first heat transfer pipe 71a in the lower part of the first row R1 forming the first flow path P1. That is, of the first heat transfer tube 71a, the second heat transfer tube 72a, and the third heat transfer tube 73a that constitute the first flow path P1, the liquid side connection tube 75 extends from the first heat transfer tube 71a that is disposed on the most windward side. The liquid refrigerant will flow out through. Thereby, the refrigerant | coolant supercooling area in the outdoor heat exchanger 23 when using as a condenser can be suppressed small, and the capability of the outdoor heat exchanger 23 is ensured. Further, the refrigerant that has condensed into a liquid phase flows out from the liquid side connection pipe 75 without staying in the outdoor heat exchanger 23.

(5) Modification (5-1) Modification A
In the above-described embodiment, the multi-type air conditioner 10 in which five indoor use units 30 are connected to one outdoor heat source unit 20 has been described, but one indoor use is provided to one outdoor heat source unit 20. Even if it is an air conditioner of the type to which the unit 30 is connected, if the outdoor heat exchanger 23 which concerns on this invention is employ | adopted, the result of the improvement of a heat exchange efficiency and a capability improvement can be obtained.

  Moreover, in the said embodiment, although this invention is applied to the outdoor heat exchanger 23 of the outdoor heat source unit 20 of the air conditioning apparatus 10, this invention is applied to the heat source unit which comprises another refrigeration apparatus, for example, a heat pump type water heater. May be applied.

(5-2) Modification B
Instead of the outdoor heat exchanger 23 of the above embodiment, the outdoor heat exchanger 123, the first switching valve 81, and the second switching valve 82 shown in FIG. 6 are replaced with the four-way switching valve 22 of the outdoor heat source unit 20 and the high-pressure receiver. Incorporation between the motorized valve 24 is also useful. The outdoor heat source unit 20 according to the modified example B includes an outdoor heat exchanger 123 and a first switching valve provided between a gas refrigerant pipe 22 a extending from the four-way switching valve 22 and a liquid refrigerant pipe 24 a extending from the high-pressure receiver electric valve 24. Except for 81 and the second switching valve 82, other configurations are the same as in the above embodiment. Hereinafter, the outdoor heat exchanger 123, the first switching valve 81, and the second switching valve 82 will be described with reference to FIGS. In addition, about the member etc. which use the same code | symbol in FIG. 4 and FIG. 6, since it is a structure as above-mentioned, description is abbreviate | omitted.

  In the outdoor heat source unit 20 according to Modification B, an outdoor heat exchanger 123, a first switching valve 81, and a second switching valve 82 are incorporated between the gas refrigerant pipe 22a and the liquid refrigerant pipe 24a. The major difference between these and the above-described outdoor heat exchanger 23 is that a first switching valve 81 is disposed between the third heat transfer pipe 73a and the flow divider 78 in the first flow path P1, and the gas side header 79 The second switching valve 82 is disposed between the gas side connecting pipe 76 and the gas side connecting pipe 76.

  The first switching valve 81 is a two-way valve that can switch between two states. The first state (see FIG. 6) in which the first flow path P1 and the flow divider 78 communicate with each other, and the first flow path P1 The second state (see FIG. 7) in which the gas side header 79 communicates can be switched. The first switching valve 81 has a first port connected to the third heat transfer pipe 73a of the first flow path P1 by the refrigerant pipe 81a, and a second port connected to the flow divider 78 by the liquid side pipe 78a of the flow divider 78. The third port is connected to the outlet pipe 79a of the gas side header 79 by the refrigerant pipe 81b. In the first state, the first port and the second port of the first switching valve 81 are connected, and the first flow path P1 and the flow divider 78 communicate with each other. On the other hand, in the second state, the first port and the third port of the first switching valve 81 are connected, and the first flow path P1 and the gas side header 79 communicate with each other.

  The second switching valve 82 is a two-way valve that can switch between two states. The second state is such that the gas side header 79 and the gas side connection pipe 76 communicate with each other, and the gas side connection pipe 76. And a fourth state (see FIG. 7) in which the liquid side pipe 78a of the flow divider 78 communicates with the liquid side pipe 78a (the pipe on the first switching valve 81 side of the flow divider 78) can be switched. The second switching valve 82 has a first port connected to the gas side connecting pipe 76, a second port connected to the outlet pipe 79a of the gas side header 79, and a third port connected to the flow divider 78 by the refrigerant pipe 82a. The liquid side pipe 78a is connected. In the third state, the first port and the second port of the second switching valve 82 are connected, and the gas side header 79 and the gas side connection pipe 76 communicate with each other. On the other hand, in the fourth state, the first port and the third port of the second switching valve 82 are connected, and the gas side connection pipe 76 communicates with the liquid side pipe 78a of the flow divider 78 through the refrigerant pipe 82a.

  In the outdoor heat source unit 20 including the outdoor heat exchanger 123, the first switching valve 81, and the second switching valve 82, while maintaining the counter flow by switching control of the first switching valve 81 and the second switching valve 82, The outdoor heat exchanger 123 can function as an evaporator or a condenser. Specifically, when used as an evaporator, the first switching valve 81 is set to the first state and the second switching valve 82 is set to the third state as shown in FIG. Generate a flow. And when using as a condenser, as shown in FIG. 7, each branch flow path P2, P3, P4 is made by setting the 1st switching valve 81 to a 2nd state, and setting the 2nd switching valve 82 to a 4th state. The flow of the P5 refrigerant and the flow W of the outside air are set to counterflow. Thus, when the outdoor heat exchanger 123 is used as an evaporator or a condenser, the flow of the refrigerants P2, P3, P4, and P5 and the flow W of the outside air are kept in counterflow. The heat exchange efficiency can be improved and the drift can be suppressed.

(5-3) Modification C
In the outdoor heat exchanger 23 of the above embodiment, the heat transfer tubes are arranged in three rows from the windward side to the leeward side, but the present invention is also applicable to a heat exchanger in which a large number of heat transfer tubes are arranged in four or more rows. It is possible to apply.

10 Air conditioning equipment (refrigeration equipment)
20 outdoor heat source units 23, 123 outdoor heat exchangers 71a, 71b, 71c, 71d, 71e first heat transfer tubes 72a, 72b, 72c, 72d, 72e second heat transfer tubes 73a, 73b, 73c, 73d, 73e third heat transfer tubes 75 Liquid side connection pipe 76 Gas side connection pipe 78 Divider 78b, 78c, 78d, 78e Branch pipe 79 Gas side header 81 First switching valve (first flow path switching mechanism)
82 Second switching valve (second flow path switching mechanism)
P1 1st flow path P2, P3, P4, P5 Branch flow path R1 1st row R2 2nd row R3 3rd row

JP 2006-234264 A

Claims (4)

A heat exchanger (23, 123) of the heat source unit (20) of the refrigeration apparatus (10) for exchanging heat between the refrigerant flowing inside and the outside air to evaporate the refrigerant,
A plurality of first heat transfer tubes (71a, 71b, 71c, 71d, 71e) that form a first row (R1) that is aligned in the vertical direction and is located on the most upstream side of the flow of outside air,
A plurality of third heat transfer tubes (73a, 73b, 73c, 73d, 73e) that constitute the third row (R3) that is arranged in the vertical direction and is located on the most leeward side of the flow of outside air,
A plurality of second heat transfer tubes (72 a, 72 b, 72 b, 72 b, 72 b, 72 b, 72, 72 b, 72, 72 b, 72 b, 72 b, 72c, 72d, 72e)
A liquid side connection pipe (75) serving as an inlet for a liquid phase or gas-liquid two-phase refrigerant;
A gas side connecting pipe (76) serving as an outlet for the gas phase refrigerant;
A flow divider (78) for diverting the refrigerant;
With
The first heat transfer tube (71a), the second heat transfer tube (72a), and the third heat transfer tube (73a) located below the first row, the second row, and the third row are connected to each other. To form the first flow path (P1),
The liquid side connection pipe communicates with the first flow path,
The flow divider causes the refrigerant flowing from the liquid side connection pipe to the first flow path and exiting the first flow path to be divided into a plurality of branch pipes (78b, 78c, 78d, 78e),
The first heat transfer tubes (71b, 71c, 71d, 71e) other than the first heat transfer tubes, the second heat transfer tubes, and the third heat transfer tubes forming the first flow path, the second heat transfer tubes ( 72b, 72c, 72d, 72e) and the third heat transfer tubes (73b, 73c, 73d, 73e) are a plurality of branch flow paths (P2, P3, P4, P5) through which the refrigerant exits the plurality of branch tubes, respectively. )
The plurality of branch flow paths are configured such that the refrigerant flows in the order of the third heat transfer tube, the second heat transfer tube, and the first heat transfer tube, respectively, the first heat transfer tube, the second heat transfer tube, and the third heat transfer tube. The heat transfer tubes are flow paths connected to each other, and are formed so that the refrigerant flows out from the first heat transfer tube to the gas side connection tube.
Heat exchanger for heat source unit of refrigeration equipment. The liquid side connection pipe (75) communicates with the first heat transfer pipe (71a) in the lower part of the first row (R1) forming the first flow path (P1).
The heat exchanger of the heat-source unit of the refrigeration apparatus of Claim 1. Gas disposed between the first heat transfer pipe (71b, 71c, 71d, 71e) of each of the plurality of branch flow paths (P2, P3, P4, P5) and the gas side connection pipe (76). Side header (79)
The heat exchanger of the heat source unit of the refrigeration apparatus according to claim 1, further comprising: A heat exchanger (123) according to claim 3,
A first flow path switching mechanism (81) disposed between the first flow path (P1) and the flow divider (78);
A second flow path switching mechanism (82) disposed between the gas side header (79) and the gas side connection pipe (76);
With
The first flow path switching mechanism switches between a first state where the first flow path and the flow divider communicate with each other and a second state where the first flow path and the gas side header communicate with each other. Can
In the second flow path switching mechanism, the third state in which the gas side header and the gas side connection pipe communicate with each other, and the gas side connection pipe and the first flow path switching mechanism side of the flow divider communicate with each other. The fourth state can be switched.
Heat source unit (20).

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