JP6237068B2 - Heat exchanger and air conditioner - Google Patents

Description

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

  Conventionally, a refrigerant that includes a plurality of flat tubes, fins joined to the plurality of flat tubes, and header collecting tubes respectively connected to one end side and the other end side of the plurality of flat tubes, and flows inside the flat tubes A heat exchanger that exchanges heat with air flowing outside the flat tube is known.

  For example, in the heat exchanger described in Patent Document 1, both ends of a plurality of outflow pipes extending in the horizontal direction are connected to header collecting pipes extending in the vertical direction.

  In the heat exchanger described in Patent Document 1, in the header collecting pipe extending in the up-down direction, a liquid phase refrigerant having a large specific gravity is gathered downward and a gas phase refrigerant having a small specific gravity is gathered upward, thereby causing a drift. In order to solve this problem, it is proposed to form a restriction inside the header collecting pipe.

By passing the throttle formed in this way, it is easy to mix the gas-phase refrigerant and the liquid-phase refrigerant, while improving the flow rate of the refrigerant to easily reach the upper part of the header collecting pipe, It is trying to suppress drift.
JP-A-2-219966

  However, the heat exchanger shown in Patent Document 1 as described above is not assumed at all for suppression of drift in a situation where the circulation amount of the refrigerant changes, and is a case of a low circulation amount. However, no study has been made on a structure that can provide a drifting suppression effect regardless of whether the circulation rate is high or not.

  That is, in the case of a low circulation amount, it is possible to suppress the drift by increasing the flow velocity by forming a throttle and reaching the upper part in the header collecting pipe, but in the case of a high circulation amount, The flow velocity is excessively increased by the restriction, and the liquid phase refrigerant having a large specific gravity collects too much upward, resulting in a drift.

  On the other hand, even if it is possible to suppress uneven flow by providing a throttle that is adjusted to some extent so that the flow rate does not increase too much in the case of a high circulation amount, the refrigerant should be allowed to reach upward when the circulation amount is low. May become difficult and drift may occur.

  The present invention has been made in view of the above-described points, and an object of the present invention is heat exchange capable of suppressing refrigerant drift even when used under conditions where the amount of circulation changes. And providing an air conditioner.

The heat exchanger according to the first aspect includes a plurality of flat tubes, a header collecting tube, and a plurality of fins. The plurality of flat tubes are arranged side by side. The header collecting pipe is connected to one end of a flat pipe and extends along the vertical direction. The plurality of fins are joined to the flat tube. When this heat exchanger functions as a refrigerant evaporator, an inflow port through which the refrigerant flows is provided so that an upward flow is generated in the internal space of the header collecting pipe. A communication pipe for supplying a refrigerant to a space below the inflow port in the header collecting pipe is further provided, and the connecting pipe is connected to a side of the header collecting pipe opposite to the side to which the flat pipe is connected. In this heat exchanger, the overlapping portion in the top view of the flat tube located at the lowermost position among the flat tubes located above the inlet and the inlet is formed in the inlet. It is arrange | positioned so that it may become wider than the non-overlapping part which is parts other than the overlapping part.

  In this heat exchanger, when the flow rate of the refrigerant that has passed through the inlet is high as in the case of a high circulation rate, the refrigerant can be applied to the flat tube vigorously. Can be stirred. For this reason, it becomes possible to supply a refrigerant | coolant more equally with respect to the flat tube located in the upper direction, and the flat tube located in the downward direction.

  In addition, when the flow rate of the refrigerant that has passed through the inlet is slow as in the case of a low circulation amount, the refrigerant is more gently applied to the flat tube, so that the upward force in the header collecting pipe is not greatly lost It becomes easy to make the refrigerant reach up to. For this reason, it becomes possible to supply a refrigerant | coolant more equally with respect to the flat tube located in the upper direction, and the flat tube located in the downward direction.

  As described above, the drift of the refrigerant flowing through the plurality of flat tubes can be suppressed to a small level regardless of whether the circulation rate is high or low.

  The heat exchanger according to the second aspect is a heat exchanger according to the first aspect, and further includes a partition member. The partition member partitions the internal space of the header collecting pipe into a first space and a second space. The first space is a space in which an upward flow of the refrigerant occurs when functioning as an evaporator of the refrigerant, and is a space on the side where the inflow port is provided and the flat tube is connected. The second space is a space on the opposite side to the side where the flat tube is connected to the first space.

  In this heat exchanger, the internal space of the header collecting pipe is partitioned into a first space and a second space by a partition member. For this reason, compared with the case where the partition member is not provided, it can be narrowed by making only the 1st space the area through which the refrigerant | coolant which goes up through an inflow port passes. For this reason, the fall of the flow velocity of the refrigerant | coolant which raises 1st space can be suppressed. Therefore, even when the flow rate of the refrigerant that has passed through the inlet is slow as in the case of a low circulation amount and the refrigerant that has passed through the inlet hits the flat tube and the rising speed is reduced, the refrigerant is moved to the upper part in the header collecting pipe. It will be easier to reach.

  The heat exchanger according to the third aspect is a heat exchanger according to the second aspect, and further includes an upper communication path and a lower communication path. The upper communication path is located in the upper part of the first space and the second space, and communicates the upper part of the first space and the second space to guide the refrigerant that has risen in the first space to the second space. The lower communication path is located below the first space and the second space, and communicates the lower portion of the first space and the second space, so that the lower communication passage is guided from the first space to the second space and descends in the second space. The returned refrigerant is returned from the second space to the first space.

  In this heat exchanger, when functioning as an evaporator of the refrigerant, the flow rate of the refrigerant that has passed through the inlet as in the case of a high circulation amount is merely a liquid-phase refrigerant when the refrigerant is vigorously applied to the flat tube. Even when it is so early that it is biased, it is possible to reduce this bias by further providing an upper communication path and a lower communication path. That is, in this heat exchanger, the liquid-phase refrigerant that has reached the upper part of the first space after striking the flat tube with a strong force is guided to the second space via the upper communication path, and the second space is lowered. Thereafter, it is possible to return to the first space via the lower communication path. Therefore, even when the flow rate of the refrigerant that has passed through the inlet is high, such as in the case of a high circulation amount, and the refrigerant that has passed through the inlet hits the flat tube, the liquid phase refrigerant is likely to be biased upward, It is possible to suppress the drift of the refrigerant flowing through the plurality of flat tubes.

  The heat exchanger which concerns on a 4th viewpoint is a heat exchanger which concerns on a 2nd viewpoint or a 3rd viewpoint, Comprising: The rectification | straightening space is formed below 1st space and 2nd space among internal space. . The first space, the second space, and the rectifying space are partitioned by a rectifying member. The inflow port is provided in the rectifying member so that the passage cross-sectional area of the refrigerant from the rectifying space toward the first space can be reduced.

  In this heat exchanger, the refrigerant traveling from the lower rectifying space to the upper first space can be led to the inflow port provided so that the passage cross-sectional area is reduced. Thereby, the flow velocity of the refrigerant flowing so as to pass through the inlet from the rectifying space toward the first space can be increased, and the rising flow of the refrigerant in the first space can be easily generated. Since the first space, the second space, and the rectifying space are provided in the header collecting pipe, it is not necessary to provide a configuration that causes the rising flow of the refrigerant in the first space other than the header collecting pipe.

  The heat exchanger which concerns on a 5th viewpoint is a heat exchanger which concerns on either of the 1st viewpoint to the 4th viewpoint, Comprising: The some flat tube is arrange | positioned at predetermined intervals in the perpendicular direction. The vertical interval between the inflow port and the directly above flat tube is arranged to be shorter than a predetermined interval.

  In this heat exchanger, it is possible to apply a refrigerant having a high rising speed immediately after passing through the inlet to the flat tube directly above. For this reason, the rising speed of the refrigerant immediately after passing through the inflow port can be sufficiently suppressed. For this reason, even when the flow rate of the refrigerant that has passed through the inlet is high as in the case of a high circulation amount, it is possible to effectively improve the upward bias of the liquid-phase refrigerant in the header collecting pipe. Become.

  The air conditioning apparatus according to the sixth aspect includes a refrigerant circuit. The refrigerant circuit is configured by connecting a heat exchanger according to any one of the first to fifth aspects and a variable capacity compressor.

  In this air conditioner, when the capacity variable compressor is driven, the circulation amount of the refrigerant flowing through the refrigerant circuit varies, and the amount of refrigerant passing through the heat exchanger varies. Here, when the heat exchanger functions as an evaporator, even if the amount of refrigerant passing therethrough increases the mixing ratio of the liquid-phase refrigerant or the flow rate increases, the refrigerant in the heat exchanger It is possible to suppress the drift of the flow.

  In the heat exchanger according to the first aspect, it is possible to suppress the drift of the refrigerant flowing through the plurality of flat tubes to a small value regardless of whether the circulation rate is high or low.

  In the heat exchanger according to the second aspect, even when the flow rate of the refrigerant that has passed through the inflow port is slow as in the case of a low circulation amount, the rising rate is weakened when the refrigerant that has passed through the inflow port hits the flat tube, It becomes easy for the refrigerant to reach the upper part in the header collecting pipe.

  In the heat exchanger according to the third aspect, the flow rate of the refrigerant that has passed through the inlet is high as in the case of a high circulation rate, and the liquid-phase refrigerant is likely to be biased upward even if the refrigerant that has passed through the inlet hits the flat tube Even if it becomes, it becomes possible to suppress the drift of the refrigerant | coolant which flows into a some flat tube small.

  In the heat exchanger according to the fourth aspect, the upward flow of the refrigerant in the first space can be easily generated only by the header collecting pipe.

  In the heat exchanger according to the fifth aspect, even when the flow rate of the refrigerant that has passed through the inlet is high as in the case of a high circulation amount, the upward bias of the liquid-phase refrigerant in the header collecting pipe is effective. It becomes possible to improve.

  In the air conditioner according to the sixth aspect, even when the heat exchanger functions as an evaporator, the amount of refrigerant passing therethrough increases and the mixing ratio of the liquid-phase refrigerant increases or the flow velocity increases. In addition, it is possible to reduce the drift of the refrigerant in the heat exchanger.

The circuit diagram for demonstrating the outline | summary of a structure of the air conditioning apparatus which concerns on one Embodiment. The perspective view which shows the external appearance of an air-conditioning outdoor unit. Typical sectional drawing for demonstrating the outline | summary of arrangement | positioning of each apparatus of an air-conditioning outdoor unit. The external appearance schematic perspective view which shows an outdoor heat exchanger, gas refrigerant | coolant piping, and liquid refrigerant | coolant piping. The typical rear view which shows schematic structure of an outdoor heat exchanger. The schematic rear view for demonstrating the structure of an outdoor heat exchanger. The partial expanded sectional view for demonstrating the structure of the heat exchange part of an outdoor heat exchanger. The schematic perspective view which shows the attachment state of the heat-transfer fin in an outdoor heat exchanger. The schematic structure perspective view of the upper part vicinity of a return header collecting pipe. FIG. 3 is a schematic cross-sectional view of the vicinity of a first internal space of a folded header collecting pipe. The top view schematic diagram of 1st internal space vicinity of the return header collection pipe. The schematic sectional drawing of the 2nd interior space vicinity of a return header collection pipe. FIG. 6 is a schematic cross-sectional view of the vicinity of a third internal space of the folded header collecting pipe. Explanatory drawing which shows the refrigerant | coolant distribution condition at the time of the low circulation amount as a reference example. Explanatory drawing which shows the refrigerant | coolant distribution condition at the time of the intermediate | middle circulation amount as a reference example. Explanatory drawing which shows the refrigerant | coolant distribution condition at the time of the high circulation amount as a reference example. The schematic structure perspective view of the upper part vicinity of the turn-up header collection pipe concerning other embodiments D. The schematic structure perspective view of the upper vicinity part of the folding header collection pipe concerning other embodiments E.

(1) Overall Configuration of Air Conditioner 1 FIG. 1 is a circuit diagram showing an outline of a configuration of an air conditioner 1 according to an embodiment of the present invention.

  The air conditioner 1 is an apparatus used for air conditioning in a building in which the air conditioning indoor unit 3 is installed by performing a vapor compression refrigeration cycle operation, and uses the air conditioning outdoor unit 2 as a heat source side unit, The air conditioning indoor unit 3 as a side unit is connected by refrigerant communication pipes 6 and 7.

  The refrigerant circuit configured by connecting the air-conditioning outdoor unit 2, the air-conditioning indoor unit 3, and the refrigerant communication pipes 6 and 7 includes a compressor 91, a four-way switching valve 92, an outdoor heat exchanger 20, an expansion valve 33, and indoor heat. The exchanger 4 and the accumulator 93 are connected by a refrigerant pipe. A refrigerant is sealed in the refrigerant circuit, and a refrigeration cycle operation is performed in which the refrigerant is compressed, cooled, decompressed, heated and evaporated, and then compressed again. As the refrigerant, for example, one selected from R410A, R32, R407C, R22, R134a, carbon dioxide, and the like is used.

(2) Detailed configuration of air conditioner 1 (2-1) Air conditioning indoor unit 3
The air conditioning indoor unit 3 is installed on the wall surface of the room by wall hanging or the like, or embedded or suspended in the ceiling of a room such as a building. The air conditioning indoor unit 3 has an indoor heat exchanger 4 and an indoor fan 5. The indoor heat exchanger 4 is, for example, a cross fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of fins, and functions as a refrigerant evaporator during cooling operation to cool indoor air. In the heating operation, the heat exchanger functions as a refrigerant condenser and heats indoor air.

(2-2) Air conditioning outdoor unit 2
The air conditioning outdoor unit 2 is installed outside a building or the like, and is connected to the air conditioning indoor unit 3 via the refrigerant communication pipes 6 and 7. As shown in FIGS. 2 and 3, the air-conditioning outdoor unit 2 has a substantially rectangular parallelepiped unit casing 10.

  As shown in FIG. 3, the air conditioner outdoor unit 2 has a structure in which the blower chamber S <b> 1 and the machine chamber S <b> 2 are formed by dividing the internal space of the unit casing 10 into two by a partition plate 18 extending in the vertical direction. (So-called trunk type structure). The air conditioner outdoor unit 2 includes an outdoor heat exchanger 20 and an outdoor fan 95 disposed in the blower chamber S1 of the unit casing 10, and includes a compressor 91 and four compressors disposed in the machine chamber S2 of the unit casing 10. A path switching valve 92, an accumulator 93, an expansion valve 33, a gas refrigerant pipe 31, and a liquid refrigerant pipe 32 are provided.

  The unit casing 10 includes a bottom plate 12, a top plate 11, a side plate 13 on the blower chamber side, a side plate 14 on the machine chamber side, a front plate 15 on the blower chamber side, and a front plate 16 on the machine chamber side. Make up body.

The air conditioner outdoor unit 2 is configured to suck outdoor air into the blower chamber S <b> 1 in the unit casing 10 from a part of the back surface and side surface of the unit casing 10, and blow out the sucked outdoor air from the front surface of the unit casing 10. . Specifically, suction plug mouth 10a and inlet 10b for the blower chamber S1 of the unit casing 10, the rear side of the end portion and the end of the blower chamber S1 side of the side plate 14 of the machine chamber side of the blower chamber side of the side plate 13 It is formed over the part. Moreover, the blower outlet 10c is provided in the fan chamber side front board 15, The front side is covered with the fan grill 15a.

  The compressor 91 is a hermetic compressor driven by, for example, a compressor motor, and is configured to be able to change the operation capacity by inverter control.

  The four-way switching valve 92 is a mechanism for switching the direction of refrigerant flow. During the cooling operation, the four-way switching valve 92 connects the refrigerant pipe on the discharge side of the compressor 91 and the gas refrigerant pipe 31 extending from one end (gas side end) of the outdoor heat exchanger 20, and via the accumulator 93. Then, the refrigerant communication pipe 7 for the gas refrigerant and the refrigerant pipe on the suction side of the compressor 91 are connected (see the solid line of the four-way switching valve 92 in FIG. 1). During the heating operation, the four-way switching valve 92 connects the refrigerant pipe on the discharge side of the compressor 91 and the refrigerant communication pipe 7 for the gas refrigerant, and also connects the suction side and the outdoor heat of the compressor 91 via the accumulator 93. A gas refrigerant pipe 31 extending from one end (gas side end) of the exchanger 20 is connected (see the broken line of the four-way switching valve 92 in FIG. 1).

The outdoor heat exchanger 20 is disposed upright in the vertical direction (vertical direction) to the blower chamber S1, and faces suction plug mouth 10a, to 10b. The outdoor heat exchanger 20 is an aluminum heat exchanger, and in the present embodiment, the one having a design pressure of about 3 MPa to 4 MPa is used. In the outdoor heat exchanger 20, the gas refrigerant pipe 31 extends from one end (gas side end) so as to be connected to the four-way switching valve 92. The liquid refrigerant pipe 32 extends from the other end (liquid side end) of the outdoor heat exchanger 20 so as to be connected to the expansion valve 33.

  The accumulator 93 is connected between the four-way switching valve 92 and the compressor 91. The accumulator 93 has a gas-liquid separation function that divides the refrigerant into a gas phase and a liquid phase. The refrigerant flowing into the accumulator 93 is divided into a liquid phase and a gas phase, and the gas phase refrigerant that collects in the upper space is supplied to the compressor 91.

  The outdoor fan 95 supplies outdoor air to the outdoor heat exchanger 20 for heat exchange with the refrigerant flowing through the outdoor heat exchanger 20.

  The expansion valve 33 is a mechanism for decompressing the refrigerant in the refrigerant circuit, and is an electric valve capable of adjusting the opening degree. The expansion valve 33 is provided between the outdoor heat exchanger 20 and the refrigerant communication pipe 6 for liquid refrigerant in order to adjust the refrigerant pressure and the refrigerant flow rate, and allows the refrigerant to be used in both the cooling operation and the heating operation. Has the function of expanding.

  The outdoor fan 95 is disposed in the blower chamber S1 so as to face the outdoor heat exchanger 20. The outdoor fan 95 sucks outdoor air into the unit, causes the outdoor heat exchanger 20 to perform heat exchange between the refrigerant and the outdoor air, and then discharges the air after heat exchange to the outside. The outdoor fan 95 is a fan capable of changing the air volume of air supplied to the outdoor heat exchanger 20, and is, for example, a propeller fan driven by a motor such as a DC fan motor.

(3) Operation of the Air Conditioner 1 (3-1) Cooling Operation During the cooling operation, the four-way switching valve 92 is in the state indicated by the solid line in FIG. 1, that is, the discharge side of the compressor 91 is connected via the gas refrigerant pipe 31. Connected to the gas side of the outdoor heat exchanger 20 and the suction side of the compressor 91 is connected to the gas side of the indoor heat exchanger 4 via the accumulator 93 and the refrigerant communication pipe 7. . The opening of the expansion valve 33 is adjusted so that the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger 4 (that is, the gas side of the indoor heat exchanger 4) is constant (superheat degree control). . When the compressor 91, the outdoor fan 95, and the indoor fan 5 are operated in the state of the refrigerant circuit, the low-pressure gas refrigerant is compressed by the compressor 91 to become a high-pressure gas refrigerant. This high-pressure gas refrigerant is sent to the outdoor heat exchanger 20 via the four-way switching valve 92. Thereafter, the high-pressure gas refrigerant is condensed in the outdoor heat exchanger 20 by exchanging heat with the outdoor air supplied by the outdoor fan 95 to become a high-pressure liquid refrigerant. Then, the high-pressure liquid refrigerant in a supercooled state is sent from the outdoor heat exchanger 20 to the expansion valve 33. The refrigerant that has been decompressed to near the suction pressure of the compressor 91 by the expansion valve 33 and is in a low-pressure gas-liquid two-phase state is sent to the indoor heat exchanger 4 and performs heat exchange with indoor air in the indoor heat exchanger 4. Evaporates into a low-pressure gas refrigerant.

  This low-pressure gas refrigerant is sent to the air-conditioning outdoor unit 2 via the refrigerant communication pipe 7 and again sucked into the compressor 91. As described above, in the cooling operation, the air conditioner 1 uses the outdoor heat exchanger 20 as the refrigerant condenser compressed in the compressor 91 and the indoor heat exchanger 4 as the refrigerant condensed in the outdoor heat exchanger 20. To function as an evaporator.

  In the refrigerant circuit during the cooling operation, the compressor 91 is inverter-controlled so as to reach the set temperature (so that the cooling load can be processed) while the superheat degree control of the expansion valve 33 is performed. There are cases where the circulation rate is high and the circulation rate is low.

(3-2) Heating Operation During the heating operation, the four-way switching valve 92 is in the state indicated by the broken line in FIG. 1, that is, the discharge side of the compressor 91 is on the gas side of the indoor heat exchanger 4 via the refrigerant communication pipe 7. And the suction side of the compressor 91 is connected to the gas side of the outdoor heat exchanger 20 via the gas refrigerant pipe 31. The opening of the expansion valve 33 is adjusted so that the degree of supercooling of the refrigerant at the outlet of the indoor heat exchanger 4 becomes constant at the target value of the degree of supercooling (supercooling degree control). When the compressor 91, the outdoor fan 95, and the indoor fan 5 are operated in the state of this refrigerant circuit, the low-pressure gas refrigerant is sucked into the compressor 91 and compressed to become a high-pressure gas refrigerant, and the four-way switching valve 92, And it is sent to the air conditioning indoor unit 3 via the refrigerant communication pipe 7.

  Then, the high-pressure gas refrigerant sent to the air conditioning indoor unit 3 undergoes heat exchange with the indoor air in the indoor heat exchanger 4 to condense into a high-pressure liquid refrigerant, and then passes through the expansion valve 33. Furthermore, the pressure is reduced according to the opening degree of the expansion valve 33. The refrigerant that has passed through the expansion valve 33 flows into the outdoor heat exchanger 20. The low-pressure gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 20 exchanges heat with the outdoor air supplied by the outdoor fan 95 to evaporate into a low-pressure gas refrigerant. Then, the air is sucked into the compressor 91 again. As described above, in the heating operation, the air conditioner 1 uses the indoor heat exchanger 4 as a refrigerant condenser compressed in the compressor 91 and the outdoor heat exchanger 20 as a refrigerant condensed in the indoor heat exchanger 4. To function as an evaporator.

  In the refrigerant circuit during the heating operation, the compressor 91 is inverter-controlled so that the set temperature is reached (so that the heating load can be processed) while the degree of supercooling of the expansion valve 33 is being controlled. There are cases where the circulation amount of the refrigerant becomes high and the circulation amount becomes low.

(4) Detailed configuration of outdoor heat exchanger 20 (4-1) Overall configuration of outdoor heat exchanger 20 Next, FIG. 4 showing a schematic external perspective view of the outdoor heat exchanger 20, and a schematic diagram of the outdoor heat exchanger The configuration of the outdoor heat exchanger 20 will be described in detail with reference to FIG. 5 showing a rear view and FIG. 6 which is a schematic rear view.

  The outdoor heat exchanger 20 includes a heat exchanging unit 21 that exchanges heat between outdoor air and refrigerant, an inlet / outlet header collecting pipe 22 provided on one end side of the heat exchanging unit 21, and other heat exchanging units 21. And a folded header collecting pipe 23 provided on the end side.

(4-2) Heat exchange unit 21
FIG. 7 is a partially enlarged view showing a cross-sectional structure in a plane perpendicular to the flat direction of the flat multi-hole tube 21b of the heat exchange section 21 of the outdoor heat exchanger 20. FIG. 8 is a schematic perspective view showing a mounting state of the heat transfer fins 21 a in the outdoor heat exchanger 20.

  The heat exchanging portion 21 includes a large number of heat transfer fins 21a and a large number of flat multi-hole tubes 21b. The heat transfer fins 21a and the flat multi-hole tube 21b are both made of aluminum or an aluminum alloy.

  The heat transfer fins 21a are flat plate members, and each heat transfer fin 21a is formed with a plurality of notches 21aa for inserting a flat tube extending in the horizontal direction in the vertical direction. The heat transfer fins 21a are attached so as to have countless portions protruding toward the upstream side of the air flow.

  The flat multi-hole tube 21b functions as a heat transfer tube, and transfers heat moving between the heat transfer fins 21a and outdoor air to the refrigerant flowing inside. The flat multi-hole tube 21b has upper and lower flat portions serving as heat transfer surfaces and a plurality of internal flow paths 21ba through which the refrigerant flows. The flat multi-hole tubes 21b that are slightly thicker than the upper and lower widths of the cutouts 21aa are arranged in a plurality of stages at intervals with the plane portion facing up and down, and are temporarily fixed in a state of being fitted into the cutouts 21aa. The Thus, the heat transfer fin 21a and the flat multi-hole tube 21b are brazed in a temporarily fixed state in which the flat multi-hole tube 21b is fitted in the notch 21aa of the heat transfer fin 21a. Further, both ends of each flat multi-hole pipe 21b are fitted into the inlet / outlet header collecting pipe 22 and the folded header collecting pipe 23 and brazed. Therefore, the upper and lower inner spaces 22a and 22b and the first to sixth inner spaces 23a, 23b, 23c, 23d, 23e, and 23f of the folded header collecting tube 23, which will be described later, are flat. The internal channel 21ba of the multi-hole tube 21b is connected. The plurality of flat multi-hole tubes 21b are arranged at predetermined intervals in the vertical direction.

  As shown in FIG. 7, since the heat transfer fins 21a are connected to each other in the vertical direction, the condensation generated in the heat transfer fins 21a and the flat multi-hole tubes 21b drops down along the heat transfer fins 21a. The liquid is discharged to the outside through a path formed in the bottom plate 12.

(4-3) Entrance / exit header collecting pipe 22
The entrance / exit header collecting pipe 22 is a tubular member made of aluminum or aluminum alloy that is provided on one end side of the heat exchange section 21 and extends in the vertical direction.

The entrance / exit header collecting pipe 22 has an upper entrance / exit internal space 22a and a lower entrance / exit internal space 22b partitioned in the vertical direction by a first baffle 22c. A gas refrigerant pipe 31 is connected to the upper upper inlet / outlet inner space 22a, and a liquid refrigerant pipe 32 is connected to the lower lower inlet / outlet inner space 22b.

  Note that one end of a plurality of flat multi-hole pipes 21b is connected to both the upper inlet / outlet inner space 22a at the upper part of the inlet / outlet header collecting pipe 22 and the lower lower inlet / outlet inner space 22b.

(4-4) Folded header collecting pipe 23
The folded header collecting pipe 23 is a tubular member made of aluminum or aluminum alloy that is provided on the other end side of the heat exchange section 21 and extends in the vertical direction.

  The inside of the folded header collecting pipe 23 is partitioned in a vertical direction by a second baffle 23g, a third baffle 23h, a third baffle plate 43, a fourth baffle 23i, and a fifth baffle 23j, and the first to sixth inner spaces 23a, 23b, 23c, 23d, 23e, and 23f are formed.

  Among these, the three first to third inner spaces 23 a, 23 b, 23 c of the folded header collecting pipe 23 have a large number of flattened one ends connected to the upper inlet / outlet inner space 22 a above the inlet / outlet header collecting pipe 22. The other end of the hole tube 21b is connected.

Further, the three fourth to sixth inner spaces 23d, 23e, and 23f of the folded header collecting pipe 23 have a large number of flat multi-hole pipes having one ends connected to the lower inlet / outlet inner space 22b below the inlet / outlet header collecting pipe 22. The other end of 21b is connected.

  The uppermost first internal space 23 a and the lowermost internal space 23 k of the folded header collecting pipe 23 are connected by a connecting pipe 24.

  The second internal space 23b in the second stage from the top and the fifth internal space 23e in the second stage from the bottom are connected by a communication pipe 25.

  The third internal space 23c at the third level from the top and the fourth internal space 23d at the third level from the bottom are partitioned by the third current plate 43, but the third internal space 23c provided at the third current plate 43 is provided. It has a part which communicated up and down via the inflow port 43x.

  Further, the number of flat multi-hole pipes 21 b into which the refrigerant flowing through the connecting pipe 24 in the first inner space 23 a of the folded header collecting pipe 23 is diverted is lower in the lower inlet / outlet inner space 22 b below the inlet / outlet header collecting pipe 22. The refrigerant flowing through the refrigerant pipe 32 is divided and is configured to be larger than the number of flat multi-hole tubes 21b that lead to the sixth internal space 23f (the flat inner spaces of the second internal space 23b and the fifth internal space 23e). The same applies to the relationship between the number of hole tubes 21b and the number of flat multi-hole tubes 21b in the third internal space 23c and the fourth internal space 23d).

(4-5) Loop structure of the folded header collecting pipe 23, etc. Among the folded header collecting pipe 23, the upper three first to third internal spaces 23a, 23b, 23c are provided with a loop structure and a rectifying structure. It has been.

  Hereinafter, the loop structure and the rectifying structure will be described for each of the first to third internal spaces 23a, 23b, and 23c.

(4-5-1) First internal space 23a
In the uppermost first internal space 23a of the folded header collecting pipe 23, as shown in FIG. 6, FIG. 9, a schematic perspective view, a schematic cross-sectional view of FIG. In addition, a first rectifying plate 41 and a first partition plate 51 are provided.

  The first rectifying plate 41 divides the first internal space 23a into a lower first rectifying space 41a, an upper first outflow space 51a, and a first loop space 51b. It is. Although not particularly limited, the first partition plate 51 in the present embodiment is provided at the center of the first internal space 23a, so that the space above the first rectifying space 41a is changed to the first outflow space 51a. And the first loop space 51b are partitioned so as to have the same size in a top view. The first partition plate 51 is fixed so that its side surface is in contact with the inner peripheral surface of the folded header collecting pipe 23. Here, the first rectifying plate 41 is arranged such that the vertical distance between the flat multi-hole tube 21b located closest to the upper side of the first rectifying plate 41 and the first rectifying plate 41 is aligned in the vertical direction. It arrange | positions so that it may become shorter than the predetermined space | interval of the flat multi-hole pipe 21b which is. The first rectifying space 41a is a space above the second baffle 23g that partitions the first internal space 23a and the second internal space 23b, and from the flat multi-hole tube 21b immediately above the second baffle 23g. Is a space below the first rectifying plate 41 provided at a lower position. The first rectifying space 41a communicates with a connecting pipe 24 extending from the lowermost sixth inner space 23f of the folded header collecting pipe 23.

  The first partition plate 51 partitions a space above the first rectifying space 41a in the first internal space 23a into a first outflow space 51a and a first loop space 51b, and is a substantially square plate shape. It is a member. The first outflow space 51a is a space on the side to which one end of the flat multi-hole tube 21b is connected in the first internal space 23a. The first loop space 51b is a space on the opposite side to the first outflow space 51a side with respect to the first partition plate 51 in the first internal space 23a.

  Above the first internal space 23a, there is provided a first upper communication path 51x configured by a vertical gap between the inner side of the upper end of the folded header collecting pipe 23 and the upper end portion of the first partition plate 51. It has been.

  Below the first internal space 23a, a first lower communication path 51y configured by a vertical gap between the upper surface of the first rectifying plate 41 and the lower end portion of the first partition plate 51 is provided. Yes. In the present embodiment, the first lower communication passage 51y extends in the horizontal direction from the first loop space 51b side toward the first outflow space 51a side. Further, the outlet of the first lower communication passage 51y on the first outflow space 51a side is located further below the lowermost one of the flat multi-hole tubes 21b connected to the first outflow space 51a. ing.

  As shown in FIG. 9, the first rectifying plate 41 is an opening provided in the first outflow space 51a, which is the space on the side where the flat multi-hole tube 21b extends out of the first internal space 23a. The first inflow port 41x, which is a circular opening communicating with the vertical direction, is provided. The first inflow port 41x is provided so that the vicinity of the center of the first outflow space 51a in the top view is a center. In addition, since the vertical distance between the first rectifying plate 41 and the flat multi-hole tube 21b directly above is shorter than a predetermined interval between the flat multi-hole tube 21b, the first rectifying plate 41 and the first inflow port 41x are closest to each other. It arrange | positions so that the distance of the up-down direction between these flat multi-hole pipes 21b may also become short.

  The first internal space 23a has a refrigerant passage area (horizontal area) at the first inlet 41x that is sufficiently smaller than the refrigerant passage area of the first rectification space 41a (horizontal area of the first rectification space 41a). It has a rectifying structure. With this rectifying structure, the refrigerant flow from the first rectifying space 41a toward the first outflow space 51a can be sufficiently narrowed, and the flow velocity of the refrigerant moving vertically upward can be increased.

  In addition, the space above the first rectifying plate 41 in the first internal space 23a is partitioned by the first partition plate 51, so that the refrigerant passage area on the first outflow space 51a side (inside the first outflow space 51a rises). The refrigerant flow passage area) can be made smaller than the total horizontal area of the first outflow space 51a and the first loop space 51b. Accordingly, it is possible to easily maintain the rising speed of the refrigerant that has flowed into the first outflow space 51a via the first inflow port 41x, and the refrigerant can reach the upper portion of the first outflow space 51a even under a low circulation amount. Make it easy to reach.

  As shown in the schematic top view of FIG. 11, the flat multi-hole tube 21b fills more than half of the horizontal area at the height position where the flat multi-hole tube 21b of the first outflow space 51a does not exist. It is embedded in the first outflow space 51a.

  However, from “the horizontal area of the first outflow space 51a at a height where the flat multi-hole tube 21b does not exist” to “the horizontal area of the portion of the flat multi-hole tube 21b extending into the first outflow space 51a”. The remaining area (the area of the portion where the refrigerant ascends avoiding the flat multi-hole tube 21b in the first outflow space 51a) is larger than the refrigerant passage area of the first lower communication passage 51y. Yes. Thus, the refrigerant that has flowed into the first outflow space 51a via the first inflow port 41x is not allowed to pass through the first lower communication path 51y, which is more difficult to pass through, toward the first loop space 51b side. It is possible to guide the first outflow space 51a, which is easy to pass widely, to the portion excluding the flat multi-hole tube 21b.

  In addition, as shown in FIG. 11, a first inflow port 41x provided in the first rectifying plate 41, and a flat portion directly above the first inflow port 41x that is located above the first inflow port 41x. The hole tube 21b is arranged so as to have an overlapping portion P that is an overlapping portion in a top view. Note that the overlapping portion P is disposed so as to be larger than the non-overlapping portion Q that is a portion that does not overlap in the top view of the first inflow port 41x and the flat multi-hole tube 21b directly above. Although not particularly limited, in the present embodiment, the first inflow port 41x is provided such that 70% or more of the first inflow port 41 is the overlapping portion P in a top view.

  The first internal space 23a has a loop structure including a first inflow port 41x, a first partition plate 51, a first upper communication path 51x, and a first lower communication path 51y. Therefore, the refrigerant that has reached the upper side without flowing into the flat multi-hole tube 21b in the first outflow space 51a passes through the first upper communication passage 51x above the first partition plate 51, as shown by the arrow in FIG. To the first loop space 51b, descends according to gravity in the first loop space 51b, and returns to the lower side of the first outflow space 51a via the first lower communication passage 51y below the first partition plate 51. In this way, the refrigerant that has reached the upper side of the first outflow space 51a can be looped in the first inner space 23a.

(4-5-2) Second internal space 23b
The second internal space 23b second from the top of the folded header collecting pipe 23 has the same configuration as that of the uppermost first internal space 23a, and is shown in FIGS. 6 and 12 respectively. Thus, the 2nd baffle plate 42 and the 2nd partition plate 52 are provided.

  The second rectifying plate 42 divides the second internal space 23b into a lower second rectifying space 42a, an upper second outflow space 52a, and a second loop space 52b. It is. The second rectifying space 42a is a space above the third baffle 23h that partitions the second internal space 23b and the third internal space 23c, and from the flat multi-hole tube 21b directly above the third baffle 23h. Is a space below the second rectifying plate 42 provided at a lower position. The second rectifying space 42a communicates with a communication pipe 25 extending from the second fifth inner space 23e from the bottom of the folded header collecting pipe 23.

  The second partition plate 52 divides a space above the second rectifying space 42a in the second internal space 23b into a second outflow space 52a and a second loop space 52b, and is a substantially square plate shape. It is a member. The second outflow space 52a is a space on the side to which one end of the flat multi-hole tube 21b is connected in the second internal space 23b. The second loop space 52b is a space on the opposite side to the second outflow space 52a side with respect to the second partition plate 52 in the second internal space 23b.

  Above the second internal space 23b, a second upper communication path 52x configured by a vertical gap between the lower surface of the second baffle 23g and the upper end portion of the second partition plate 52 is provided. .

  Below the second internal space 23b, a second lower communication passage 52y configured by a vertical gap between the upper surface of the second rectifying plate 42 and the lower end portion of the second partition plate 52 is provided. Yes. In the present embodiment, the second lower communication passage 52y extends in the horizontal direction from the second loop space 52b side toward the second outflow space 52a side. The outlet on the second outflow space 52a side of the second lower communication passage 52y is positioned further below the lowermost flat multi-hole tube 21b connected to the second outflow space 52a. .

  Similarly to the first rectifying plate 41, the second rectifying plate 42 is provided in a second outflow space 52a that is a space on the side where the flat multi-hole tube 21b extends out of the second internal space 23b. A second inflow port 42x which is a circular opening communicating with the vertical direction is provided. The second inflow port 42x is provided such that the vicinity of the center of the second outflow space 52a in the top view is a center. In addition, since the vertical distance between the second rectifying plate 42 and the flat multi-hole tube 21b directly above is shorter than a predetermined interval between the flat multi-hole tube 21b, the distance from the second inlet 42x of the second rectifying plate 42 is closest. It arrange | positions so that the distance of the up-down direction between these flat multi-hole pipes 21b may also become short.

Also, for the second internal space 23b, similarly to the first internal space 23a, the refrigerant passage area (horizontal area) at the second inlet 42x is set to the refrigerant passage area (first rectification space 4) of the second rectification space 42a. It has a sufficiently small to rectifying structure as compared with the 1 a area of the horizontal surface of).

  Further, the second outflow space 52a, which is a space where the refrigerant rises, is narrowed by the second partition plate 52, and the flat multi-hole tube 21b fills more than half of the horizontal area of the second outflow space 52a. It is embedded in the same manner as the first internal space 23a. Further, the horizontal area of the portion that rises away from the flat multi-hole tube 21b of the second outflow space 52a is made larger than the refrigerant passage area of the second lower communication passage 52y, and the second inlet 42x and the flat The overlapping relationship (the relationship between the overlapping portion P and the non-overlapping portion Q) in the top view of the multi-hole tube 21b is also the same as that of the first internal space 23a.

  Further, like the first internal space 23a, the second internal space 23b includes a second inlet 42x, a second partition plate 52, a second upper communication path 52x, and a second lower communication path 52y. It has a loop structure.

  The details of the other arrangement configuration are the same as those of the first internal space 23a, and thus are omitted.

(4-5-3) Third internal space 23c
In the third inner space 23c third from the top of the folded header collecting pipe 23, as shown in FIGS. 6 and 13, respectively, a third rectifying plate 43 and a third partition plate 53 are provided. Is provided.

  The third rectifying plate 43 divides the third inner space 23c into a third inner space 23d (a space located below) that is third from the bottom of the folded header collecting pipe 23, and a third located above. This is a substantially disk-shaped plate member that is partitioned into the outflow space 53a and the third loop space 53b.

  The third partition plate 53 partitions a space above the fourth internal space 23d in the third internal space 23c into a third outflow space 53a and a third loop space 53b, and is a substantially square plate shape. It is a member. The third outflow space 53a is a space on the side where one end of the flat multi-hole tube 21b is connected in the third internal space 23c. The third loop space 53b is a space on the opposite side to the third outflow space 53a side with respect to the third partition plate 53 in the third internal space 23c.

  Above the third internal space 23c, a third upper communication path 53x configured by a vertical gap between the lower surface of the third baffle 23h and the upper end portion of the third partition plate 53 is provided. .

  Below the third internal space 23c, a third lower communication path 53y configured by a vertical gap between the upper surface of the third rectifying plate 43 and the lower end portion of the third partition plate 53 is provided. Yes. In the present embodiment, the third lower communication passage 53y extends in the horizontal direction from the third loop space 53b side toward the third outflow space 53a side. The outlet on the third outflow space 53a side of the third lower communication passage 53y is located further below the lowermost one of the flat multi-hole tubes 21b connected to the third outflow space 53a. .

  Similar to the first rectifying plate 41 and the second rectifying plate 42, the third rectifying plate 43 has a third outflow space which is a space on the side where the flat multi-hole tube 21b extends out of the third internal space 23c. A third inflow port 43x, which is a circular opening provided in 53a and communicated in the vertical direction, is provided. The third inflow port 43x is provided such that the vicinity of the center of the third outflow space 53a is a center when viewed from above. Since the vertical distance between the third rectifying plate 43 and the flat multi-hole tube 21b directly above is shorter than the predetermined interval between the flat multi-hole tube 21b, the distance from the third inflow port 43x of the third rectifying plate 43 is closest. It arrange | positions so that the distance of the up-down direction between these flat multi-hole pipes 21b may also become short.

  As for the third internal space 23c, similarly to the first internal space 23a and the second internal space 23b, the refrigerant passage area (the area of the horizontal plane) at the third inlet 43x is set to the refrigerant passage area of the fourth internal space 23d. It has a rectifying structure that is sufficiently smaller than (the area of the horizontal plane of the fourth internal space 23d).

  Further, the third outflow space 53a, where the refrigerant rises, is narrowed by the third partition plate 53, and the flat multi-hole tube 21b fills more than half of the horizontal area of the third outflow space 53a. It is embedded in the same manner as the first internal space 23a and the second internal space 23b. Further, the horizontal area of the portion that rises away from the flat multi-hole tube 21b of the third outflow space 53a is made larger than the refrigerant passage area of the third lower communication passage 53y, and the third inflow port 43x and the flat The overlapping relationship (the relationship between the overlapping portion P and the non-overlapping portion Q) in the top view of the multi-hole tube 21b is also the same as the first internal space 23a and the second internal space 23b.

  Further, the third internal space 23c is, like the first internal space 23a and the second internal space 23b, the third inflow port 43x, the third partition plate 53, the third upper communication passage 53x, and the third lower connection. And a loop structure including the passage 53y.

  The details of the other arrangement configuration are the same as those of the first internal space 23a and the second internal space 23b, and thus will be omitted.

(5) Outline of Flow of Refrigerant During Heating Operation in Outdoor Heat Exchanger 20 Hereinafter, the flow of refrigerant in the outdoor heat exchanger 20 configured as described above will be described mainly during the heating operation.

  During the heating operation, as shown by the arrows in FIG. 5, the gas-liquid two-phase refrigerant is supplied to the lower inlet / outlet inner space 22 b below the inlet / outlet header collecting pipe 22 via the liquid refrigerant pipe 32.

The refrigerant supplied to the lower inlet / outlet inner space 22b at the lower part of the inlet / outlet header collecting pipe 22 passes through the plurality of flat multi-hole pipes 21b at the lower part of the heat exchanging part 21 connected to the lower inlet / outlet inner space 22b to return the header. These are supplied to the three fourth to sixth internal spaces 23d, 23e, and 23f below the collecting pipe 23, respectively. Note that the refrigerant supplied to the three fourth to sixth inner spaces 23d, 23e, and 23f below the folded header collecting pipe 23 passes through the flat multi-hole pipe 21b below the heat exchanging portion 21. A part of the liquid phase component of the refrigerant in the liquid two-phase state evaporates, so that the gas phase component is increased.

  The refrigerant supplied to the sixth inner space 23 f below the folded header collecting pipe 23 passes through the connecting pipe 24 and is supplied to the first inner space 23 a located above the folded header collecting pipe 23. The refrigerant supplied to the first internal space 23a flows into each of the plurality of flat multi-hole tubes 21b connected to the first internal space 23a (however, the refrigerant flows in the first internal space 23a). Will be described later.) The refrigerant that has flowed through the plurality of flat multi-hole tubes 21b is further evaporated to be in a gas phase state, and is supplied to the upper inlet / outlet inner space 22a above the inlet / outlet header collecting pipe 22.

  The refrigerant supplied to the fifth internal space 23 e below the folded header collecting pipe 23 passes through the connecting pipe 25 and is supplied to the second internal space 23 b above the folded header collecting pipe 23. The refrigerant supplied to the second internal space 23b flows into each of the plurality of flat multi-hole tubes 21b connected to the second internal space 23b (how to flow of the refrigerant in the second internal space 23b). Will be described later.) The refrigerant that has flowed through the plurality of flat multi-hole tubes 21b is further evaporated to be in a gas phase state, and is supplied to the upper inlet / outlet inner space 22a above the inlet / outlet header collecting pipe 22.

  The refrigerant supplied to the fourth inner space 23d below the folded header collecting pipe 23 passes through the third inlet 43x provided in the third rectifying plate 43 vertically upward, and the upper part of the folded header collecting pipe 23 To the internal space of the third internal space 23c. The refrigerant supplied to the third internal space 23c flows into each of the plurality of flat multi-hole tubes 21b connected to the third internal space 23c (how to flow of the refrigerant in the third internal space 23c). Will be described later.) The refrigerant that has flowed through the plurality of flat multi-hole tubes 21b is further evaporated to be in a gas phase state, and is supplied to the upper inlet / outlet inner space 22a above the inlet / outlet header collecting pipe 22.

  The refrigerant supplied from the first to third inner spaces 23a, 23b, 23c above the folded header collecting pipe 23 through the plurality of flat multi-hole pipes 21b to the upper inlet / outlet inner space 22a above the inlet / outlet header collecting pipe 22 is Then, they merge in the upper entrance / exit internal space 22a and flow out of the gas refrigerant pipe 31.

  In the cooling operation, the refrigerant flow is in the opposite direction to the flow indicated by the arrows in FIG.

(6) How refrigerant flows in the outdoor heat exchanger 20 in the case of a low circulation amount during heating operation Hereinafter, the flow of refrigerant in the outdoor heat exchanger 20 in the case of a low circulation amount during heating operation will be described below. The first internal space 23a of the tube 23 will be described as an example.

  The refrigerant flowing into the lower inlet / outlet inner space 22b of the inlet / outlet header collecting pipe 22 is decompressed by the expansion valve 33, and is in a gas-liquid two-phase state. A part of the liquid phase component of the gas-liquid two-phase refrigerant that has flowed into the first internal space 23 a of the folded header collecting pipe 23 is returned from the lower inlet / outlet inner space 22 b of the inlet / outlet header collecting pipe 22. It evaporates when it passes through the flat multi-hole tube 21b toward the sixth internal space 23f of 23. For this reason, the refrigerant that passes through the connecting pipe 24 and flows into the first internal space 23a of the folded header collecting pipe 23 is in a state where gas phase components and liquid phase components having different specific gravity are mixed.

  In the case of a low circulation amount, the amount of refrigerant per unit time flowing into the first rectifying space 41a via the connecting pipe 24 is small, and the flow rate of the refrigerant flowing through the outlet of the connecting pipe 24 is relatively slow. . For this reason, if it remains at this flow rate, the liquid phase component having a large specific gravity in the refrigerant is difficult to rise, so that it is positioned above the plurality of flat multi-hole tubes 21b connected to the first internal space 23a. It is difficult to reach what is being done, and in the plurality of flat multi-hole tubes 21b, the amount of passage becomes non-uniform depending on the height position, and there is a risk that drift will occur. Here, as shown in the explanatory diagram of the reference example at the time of the low circulation amount in FIG. 14, the gas phase component having a small specific gravity is contained in the refrigerant with respect to one end side of the flat multi-hole tube 21 b disposed relatively upward. When mainly flowing in, the refrigerant flowing out from the other end side of the flat multi-hole tube 21b has an excessively high degree of superheat, and no phase change occurs while passing through the flat multi-hole tube 21b. It will not be able to fully demonstrate. On the other hand, when a liquid phase component having a large specific gravity of the refrigerant mainly flows into one end side of the flat multi-hole tube 21b disposed relatively below, the refrigerant flows out from the other end side of the flat multi-hole tube 21b. Is less likely to be superheated and may reach the other end of the flat multi-hole tube 21b without evaporating, so that the ability of heat exchange cannot be fully exhibited.

  On the other hand, when the outdoor heat exchanger 20 of the present embodiment is used in a low circulation amount state, a liquid phase component having a large specific gravity among the refrigerant supplied to the first rectifying space 41a is larger than the conventional one. It has been experimentally confirmed that drift can be improved even when the amount of circulation is low.

  Although the mechanism that can improve the drift is not necessarily clear, it can be considered, for example, for the following reasons. In other words, in the outdoor heat exchanger 20 of the present embodiment, more than half of the first inlet 41x is an overlapping portion P with the flat multi-hole tube 21b in the top view, and therefore the refrigerant that has passed through the first inlet 41x. Most of the upward flow collides with the overlapping portion P in the flat multi-hole tube 21b immediately above the first inlet 41x. Here, when the circulation rate is low, not only does the flow rate of the refrigerant slow, but also the flow rate of the refrigerant decreases by colliding with the overlapping portion P of the flat multi-hole tube 21b. It is considered difficult to ascend within 51a. A part of the refrigerant having no ascending force flows backward from the first outflow space 51a side to the first loop space 51b side through the first lower communication passage 51y, and the first loop space 51b has a flat multi-hole tube. It is considered that the destination is lost because 21b is not connected, and the refrigerant accumulates in the first loop space 51b. Thus, when a refrigerant | coolant accumulates in the 1st loop space 51b, the liquid phase component of a refrigerant | coolant will exist in column shape in the 1st loop space 51b. When the liquid phase component of the refrigerant exists in a columnar shape in the first loop space 51b, hydraulic head pressure is generated, and the first loop space 51b side is directed to the first outflow space 51a side via the first lower communication path 51y. Thus, a force for flowing the liquid phase component is generated. On the other hand, since there is also a flow from the first outflow space 51a side to the first loop space 51b side through the first lower communication passage 51y, there is a state in which both are balanced. Then, the height of the columnar liquid phase component existing in the first loop space 51b is maintained substantially constant, that is, the first internal space 23a apparently plugs into the first lower communication passage 51y. Thus, the refrigerant flowing in from the first inflow port 41x rises only in the first outflow space 51a in the first inner space 23a. That is, it is considered that the refrigerant rises only in the first internal space 23a which is partitioned and narrowed by the first partition plate 51 in the first internal space 23a.

  Further, in the case of the low circulation amount, the speed at which the refrigerant that has passed through the first inflow port 41x collides with the overlapping portion P of the flat multi-hole pipe 21b is smaller than in the case of the high circulation amount. Attenuation of the rising speed is small.

  From the above, it is considered that even in the case of a low circulation amount, the liquid phase component having a large specific gravity among the refrigerant can be easily guided to the upper side in the first outflow space 51a.

  Thereby, in the outdoor heat exchanger 20 of this embodiment, the state of the refrigerant flowing into the plurality of flat multi-hole pipes 21b arranged at different height positions is shown in FIG. It becomes possible to make it as close as possible to the state shown in the explanatory diagram of the reference example at the intermediate circulation amount.

  The second internal space 23b and the third internal space 23c of the folded header collecting pipe 23 are the same as the first internal space 23a, and thus the description thereof is omitted.

(7) How refrigerant flows in the outdoor heat exchanger 20 in the case of a high circulation amount during heating operation The refrigerant flow in the outdoor heat exchanger 20 in the case of a high circulation amount during heating operation is hereinafter referred to as a folded header set. The first internal space 23a of the tube 23 will be described as an example.

  Here, the refrigerant flowing into the first internal space 23a of the folded header collecting pipe 23 is in a state where gas phase components and liquid phase components having different specific gravities are mixed, as in the case of the low circulation amount. .

  In the case of a high circulation rate, the amount of refrigerant per unit time flowing into the first rectifying space 41a via the connecting pipe 24 is large, and the flow rate of the refrigerant flowing through the outlet of the connecting pipe 24 is relatively fast. Moreover, the flow velocity can be further increased by adopting the throttling function of the first inflow port 41x as a measure against the low circulation rate described above. Further, as a measure against the low circulation rate, the refrigerant rising speed is not easily reduced by the narrow refrigerant passage area of the first outflow space 51a in which the refrigerant passage cross-sectional area is narrowed by the first partition plate 51. For this reason, in the case of a high circulation rate, the liquid phase component having a large specific gravity among the refrigerant that has passed through the first inflow port 41x passes through the first outflow space 51a without flowing into the flat multi-hole tube 21b. They tend to tend to gather together. In this case, a liquid phase component having a large specific gravity tends to gather upward, and a gas phase component having a small specific gravity tends to gather downward, and the distribution is different from the case of the low circulation amount. As shown in the explanatory diagram of the reference example, a drift is also generated.

  On the other hand, in the outdoor heat exchanger 20 of the present embodiment, more than half of the first inlet 41x is an overlapping portion P with the flat multi-hole tube 21b in the top view, and therefore the first inlet 41x Most of the rising flow of the refrigerant that has passed through vigorously collides with the overlapping portion P in the flat multi-hole tube 21b immediately above the first inflow port 41x, and can greatly reduce the rising speed. In addition, since the refrigerant violently collides with the overlapping portion P in the flat multi-hole tube 21b, the uniformity of the mixed state of the gas phase component and the liquid phase component of the refrigerant can be improved. For this reason, it can suppress that only a liquid phase component with big specific gravity collects upwards. Moreover, since the loop structure is employed in the first internal space 23a, even if a large amount of the liquid phase component of the refrigerant reaches the upper end of the first outflow space 51a, the refrigerant passes through the first upper communication path 51x. After being guided to the first loop space 51b and lowered by gravity in the first loop space 51b, it can be returned again below the first outflow space 51a via the first lower communication passage 51y.

  The refrigerant returned to the first outflow space 51a through the first lower communication passage 51y is again dragged by the rising flow of the refrigerant that has passed through the first inflow port 41x, and then rises in the first outflow space 51a again. In some cases, after circulating in the first internal space 23a again, it can be caused to flow into the flat multi-hole tube 21b.

  Thereby, in the outdoor heat exchanger 20 of the present embodiment, the state of the refrigerant flowing into the plurality of flat multi-hole pipes 21b arranged at different height positions is shown in FIG. It becomes possible to make it as close as possible to the state shown in the explanatory diagram of the reference example at the intermediate circulation amount.

  The second internal space 23b and the third internal space 23c of the folded header collecting pipe 23 are the same as the first internal space 23a, and thus the description thereof is omitted.

(8) Features of the outdoor heat exchanger 20 of the air conditioner 1 (8-1)
The outdoor heat exchanger 20 of the present embodiment can cause the refrigerant that has passed through the first inlet 41x to collide with the overlapping portion P of the flat multi-hole tube 21b when the circulation amount is high. It is possible to prevent the rising speed of the from becoming too fast. In addition, since the refrigerant collides with the overlapping portion P of the flat multi-hole tube 21b vigorously, the gas phase component and the liquid phase component of the refrigerant can be mixed, and the deviation of the liquid phase component and the gas phase component is kept small and uniform. It becomes possible to make it. Moreover, even if the liquid phase component of the refrigerant reaches the upper side in the first outflow space 51a, the first internal space 23a is looped by the loop structure of the first internal space 23a, so that The refrigerant can be returned again from the first loop space 51b side to the first outflow space 51a side through the passage 51y and guided to the flat multi-hole tube 21b (second internal space 23b, third internal space 23c). The same).

  In the outdoor heat exchanger 20 of the present embodiment, when the amount of circulation is low, the liquid phase component of the refrigerant accumulates in the first loop space 51b, so that it passes through the first inflow port 41x and the folded header collecting pipe It is considered that the refrigerant that has flowed into the first internal space 23a of the 23 can make the narrow flow path substantially only the first outflow space 51a as the rising space. For this reason, it is considered that it is possible to suppress the decay of the rising speed of the refrigerant and to make it easier for the refrigerant to reach the upper part of the first outflow space 51a (the same applies to the second internal space 23b and the third internal space 23c). .

  As described above, the outdoor heat exchanger 20 of the present embodiment is arranged in a plurality in the vertical direction regardless of whether it is a low circulation amount or a high circulation amount. The drift of the refrigerant with respect to the flat multi-hole tube 21b can be kept small.

(8-2)
In the outdoor heat exchanger 20 of the present embodiment, the distance in the vertical direction between the first rectifying plate 41 and the flat multi-hole pipe 21b directly above is arranged to be shorter than a predetermined interval between the flat multi-hole pipe 21b. Yes. For this reason, since the vertical distance between the first inlet 41x of the first rectifying plate 41 and the nearest flat multi-hole tube 21b can be sufficiently shortened, immediately after passing through the first inlet 41x. It is possible to cause the refrigerant in the state of high flow velocity to collide with the flat multi-hole tube 21b directly above. Thereby, it is possible to suppress the excessive rising speed of the refrigerant.

  In addition, the above-mentioned point is the same also about the 2nd inflow port 42x of the 2nd rectifier plate 42, and the 3rd inflow port 43x of the 3rd rectifier plate 43. FIG.

(9) Other Embodiments In the above embodiment, an example of the embodiment of the present invention has been described. However, the above embodiment is not intended to limit the present invention, and is not limited to the above embodiment. The present invention naturally includes aspects appropriately modified without departing from the spirit of the present invention.

(9-1) Other embodiment A
In the above embodiment, an example is provided in which the first inlet 41x opened in the plate thickness direction is provided in the first rectifying plate 41 that is a plate-like member (the same applies to the second inlet 42x and the third inlet 43x). And explained.

  However, the present invention is not limited to this. For example, instead of forming an opening in a plate-like member and providing an inflow port, a cylindrical inflow passage extending in the vertical direction may be provided. In this case, when the refrigerant passes through the cylindrical inflow passage, it is possible to increase the speed of the refrigerant that flows out vertically upward.

  In addition, the point mentioned above is the same also in the 2nd inflow port 42x and the 3rd inflow port 43x.

(9-2) Other embodiment B
In the said embodiment, the exit by the side of the 1st outflow space 51a of the 1st lower communication path 51y is further more than what is located in the lowest among the some flat multi-hole pipes 21b connected to the 1st outflow space 51a. The case where it is positioned below (the same applies to the outlet of the second lower communication passage 52y and the outlet of the third lower communication passage 53y) has been described as an example.

  However, the present invention is not limited to this, and the outlet on the first outflow space 51a side of the first lower communication passage 51y is the most among the plurality of flat multi-hole tubes 21b connected to the first outflow space 51a. It may exist in the vicinity of what is located below, for example, may be the same height position as that located at the bottom.

  In addition, the point mentioned above is the same also at the exit of the 2nd lower communication path 52y, and the exit of the 3rd lower communication path 53y.

(9-3) Other embodiment C
In the above embodiment and other embodiments, the space above the first rectifying plate 41 in the first internal space 23a, the space above the second rectifying plate 42 in the second internal space 23b, and the third internal The case where the space above the third rectifying plate 43 in the space 23c has the same form has been described as an example.

  However, the present invention is not limited to this, and these forms may be different from each other.

(9-4) Other embodiment D
In the above embodiment, the first lower communication passage 51y (the same applies to the second lower communication passage 52y and the third lower communication passage 53y) constituted by the lower end portion of the first partition plate 51 and the upper surface portion of the first rectifying plate 41 is used. The folded header collecting pipe 23 has been described as an example.

  However, the present invention is not limited to this. For example, a folded header collecting pipe 123 as shown in FIG. 17 may be adopted instead of the folded header collecting pipe 23 of the above embodiment.

  The folded header collecting pipe 123 is provided with a first lower communication passage 151y penetrating in the thickness direction so as to connect the first outflow space 51a and the first loop space 51b below the first partition plate 151. The first partition plate 151 is supported by the entire lower end portion thereof being in contact with the upper surface of the first rectifying plate 41.

  In this case, it is not necessary to adjust the height position of the first partition plate 51 in order to adjust the refrigerant passage area of the first lower communication passage 51y as in the above embodiment, and the first partition plate 151 has the first position. Since the lower communication passage 151y may be designed in advance so as to have a desired refrigerant flow area, manufacturing can be facilitated.

(9-5) Other embodiment E
Further, instead of the folded header collecting pipe 23 of the above embodiment, for example, a folded header collecting pipe 223 as shown in FIG. 18 may be adopted.

  The folded header collecting pipe 223 is configured such that a part of the lower end portion of the first partition plate 251 is depressed upward. For this reason, with the first partition plate 251 installed on the upper surface of the first rectifying plate 41, the first partition plate 251 is depressed above the upper surface (plane) of the first rectifying plate 41 and the lower end portion of the first partition plate 251. The first lower communication passage 251y can be configured by the portion.

In this case, there is no need to adjust the height position of the first partition plate 51 in order to adjust the refrigerant passage area of the first lower communication passage 51y as in the above embodiment, and the lower end portion of the first partition plate 251 The size of the depressed portion may be designed in advance so as to be a desired refrigerant flow path area, and the manufacturing can be facilitated. In addition, it is possible to support the first partition plate 251 by disposing the non-recessed portion of the lower end portion so as to contact the upper surface of the first rectifying plate 41.

(9-6) Other embodiment F
In the said embodiment, the case where the flat plate member like the heat-transfer fin 21a as shown in FIG. 7, FIG. 8 was used as an example was demonstrated as a heat-transfer fin.

  However, the present invention is not limited to this. For example, the present invention can also be applied to a heat exchanger configured by using a corrugated heat transfer fin mainly used in an automobile heat exchanger. It is.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Air-conditioning outdoor unit 3 Air-conditioning indoor unit 10 Unit casing 20 Outdoor heat exchanger (heat exchanger)
21 Heat Exchanger 21a Heat Transfer Fin (Fin)
21b Flat multi-hole tube (flat tube)
22 Gateway header collecting pipe 23 Folding header collecting pipe (header collecting pipe)
22a Upper entrance / exit internal space 22b Lower entrance / exit internal space 23a, 23b, 23c, 23d, 23e, 23f First to sixth internal spaces (internal spaces)
31 Gas refrigerant piping 32 Liquid refrigerant piping 33 Expansion valve 41 First rectifying plate (rectifying member)
41a First rectification space (rectification space)
41x 1st inlet (inlet)
42 Second rectifying plate (rectifying member)
42a Second rectification space (rectification space)
42x 2nd inlet (inlet)
43 Third rectifying plate (rectifying member)
43a Third rectification space (rectification space)
43x 3rd inlet (inlet)
51 1st partition plate (partition member)
51a First outflow space (first space)
51b First loop space (second space)
51x First upper passage (upper passage)
51y First lower communication passage (lower communication passage)
52 Second partition plate (partition member)
52a Second outflow space (first space)
52b Second loop space (second space)
52x Second upper passage (upper passage)
52y Second lower communication path (lower communication path)
53 Third partition plate (partition member)
53a Third outflow space (first space)
53b Third loop space (second space)
53x Third upper passage (upper passage)
53y Third lower communication path (lower communication path)
91 Compressor 123 Folded header collecting pipe (header collecting pipe)
151 1st partition plate (partition member)
151y First lower communication path (lower communication path)
223 Folded header collecting pipe (header collecting pipe)
251 First partition plate (partition member)
251y First lower communication path (lower communication path)
P Overlapping part Q Non-overlapping part

JP-A-2-219966

Claims (6)

A plurality of flat tubes (21b) arranged side by side;
One end of the flat tube is connected, and a header collecting tube (23, 123, 223) extending in the vertical direction;
A plurality of fins (21a) joined to the flat tube;
A heat exchanger (20) comprising:
When functioning as a refrigerant evaporator, there are provided inlets (41x, 42x, 43x) through which the refrigerant flows so that an upward flow is generated in the internal space (23a, 23b, 23c) of the header collecting pipe,
The pipe further includes connecting pipes (24, 25) for supplying a refrigerant to the space (41a, 42a) below the inflow port in the header collecting pipe, and the connecting pipe is connected to the flat pipe in the header collecting pipe. Connected to the opposite side of the
An overlapping portion (P) in a top view of the flat tube located at the lowermost position among the flat tubes located above the inlet and the inlet is formed of the inlet. It is arranged to be wider than the non-overlapping part (Q) which is a part other than the overlapping part,
Heat exchanger (20). The internal space of the header collecting pipe is a space in which an upward flow of the refrigerant occurs when functioning as an evaporator of the refrigerant, and is a space on the side where the inflow port is provided and the flat tube is connected. Partition members (51, 52, 53, 151, 251) for partitioning the first space and the second space, which is the space opposite to the side where the flat tube is connected to the first space, are further provided. Prepared,
The heat exchanger according to claim 1. The upper space is located above the first space and the second space, and communicates the first space and the upper portion of the second space, thereby leading the refrigerant rising in the first space to the second space. Passages (51x, 52x, 53x),
It is located in the lower part of the first space and the second space, and communicates the lower part of the first space and the second space, so that it is guided from the first space to the second space and in the second space. Lower communication passages (51y, 52y, 53y, 151y, 251y) for returning the refrigerant having lowered to the first space from the second space;
Further equipped with,
The heat exchanger according to claim 2. Of the internal space, rectification spaces (41a, 42a, 43a) are formed below the first space and the second space,
The first space and the second space, and the rectifying space are partitioned by a rectifying member (41, 42, 43),
The inflow port is provided in the rectifying member so as to reduce a passage cross-sectional area of the refrigerant from the rectifying space toward the first space.
The heat exchanger according to claim 2 or 3. The plurality of flat tubes are arranged at predetermined intervals in the vertical direction,
The vertical interval between the inflow port and the directly above flat tube is arranged to be shorter than the predetermined interval.
The heat exchanger according to any one of claims 1 to 4.   An air conditioner (1) comprising a refrigerant circuit configured by connecting the heat exchanger (20) according to any one of claims 1 to 5 and a variable capacity compressor (91).

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