WO2018173356A1 - Heat exchanger and air conditioner using same - Google Patents

Abstract

A heat exchanger comprising a heat transfer tube inserted from the horizontal direction with respect to a vertical fin suffers from the problem of power consumption reduction being difficult because the heat transfer area of the entire heat exchanger is not utilized due to an unbalanced flow occurring in the flow of refrigerant from a header to a plurality of heat transfer tubes. In order to resolve this problem, provided is a heat exchanger comprising an inflow-side header, an outflow-side header, a plurality of heat transfer tubes connecting between the headers, and a fin that expands the heat transfer area of the heat transfer tubes, wherein: the inflow-side header comprises a gas-liquid mixing unit into which a gas-liquid two-phase refrigerant flows via an inlet pipe, a plurality of header spaces that are disposed in the upper part of the gas-liquid mixing unit and that are divided vertically by a partitioning plate, and a plurality of communication channels by which the gas-liquid mixing unit directly communicates with the header spaces; each header space is connected to at least one heat transfer tube; and each communication channel has at least one opening inside the gas-liquid mixing unit.

Description

Heat exchanger and air conditioner using the same

The present invention relates to an air conditioner equipped with a heat exchanger, and in particular, effectively uses the heat exchanger by optimizing the distribution amount of the gas-liquid two-phase refrigerant that flows to each of the plurality of heat transfer tubes connecting the headers. The present invention relates to an air conditioner that uses and reduces power consumption.

In many of the air conditioners that support air conditioning, a cross fin tube heat exchanger composed of circular copper heat transfer tubes and aluminum strip fins is currently used. This heat exchanger performs heat exchange between the refrigerant and air by flowing a fluorocarbon refrigerant in the copper heat transfer tube.

On the other hand, parallel flow type heat exchangers are widely used in automobile radiators and air conditioners for cooling to reduce size, weight, performance, and cost. This heat exchanger is provided with two header pipes at the openings of both ends of a plurality of flat heat transfer tubes brazed with aluminum fins on the outer surface, and from the inflow side header pipes to the outflow side via the respective flat heat transfer tubes. It is a heat exchanger of the form which makes a refrigerant flow toward a header pipe.

In the parallel flow type heat exchanger, in order to make all the fin areas work effectively, it is necessary to flow an appropriate amount of liquid refrigerant to each of a plurality of flat heat transfer tubes stacked vertically.

However, in the heat exchanger, the refrigerant flows as a refrigerant in a gas-liquid two-phase state while changing the phase of evaporation and condensation, so that it stands in the vertical direction under the condition that the flow rate of the refrigerant is small and the momentum is low. Since the liquid refrigerant in the header pipe on the inflow side stays downward due to the influence of gravity, there is a tendency that it is difficult to supply sufficient liquid refrigerant to the flat heat transfer pipe connected to the upper part of the header pipe on the inflow side.

As a result, when the parallel flow heat exchanger is used as an evaporator, the amount of liquid refrigerant to be supplied is reduced in the upper one of the stacked flat heat transfer tubes, and all of the liquid refrigerant is upstream of the flat heat transfer tubes. Since it evaporates, heat absorption due to the evaporation of the liquid refrigerant does not occur downstream from the middle stream. That is, in the upper flat heat transfer tube, there is a problem that the liquid component of the refrigerant is small and the degree of superheat increases from the middle flow to the downstream, and the heat transfer area in that portion is not effectively used.

On the other hand, in the laminated flat heat transfer tubes below, the amount of liquid refrigerant supplied is excessive, so that the liquid refrigerant remains even at the outlet of the flat heat transfer tubes. That is, from the flat heat transfer tube below, the liquid refrigerant that has left the heat absorption capacity flows out, which causes a problem that the efficiency of the entire heat exchanger is deteriorated.

In addition, if a “liquid return” occurs in which the liquid refrigerant flows from the lower flat heat transfer tube into the compressor downstream of the heat exchanger, the liquid refrigerant may damage the compression chamber of the compressor. In order to avoid this, it is necessary to evaporate the liquid refrigerant completely by the expansion valve upstream of the heat exchanger and reducing the evaporation pressure to reach the outlet of the heat exchanger. There is a problem that the energy consumption in the vessel is increased.

In order to avoid such problems, when using a parallel flow type heat exchanger as an evaporator, the liquid refrigerant in each flat heat transfer tube is completely eliminated at a substantially aligned position near the header tube on the outflow side. Desirable to maximize heat exchanger performance. In particular, when supplying air at a constant wind speed to a heat exchanger, such as an outdoor unit of an air conditioner, it is required that the refrigerant can be equally distributed to each flat heat transfer tube without drift.

Here, the refrigeration cycle of the heat pump type air conditioner will be described with reference to FIG. 22, taking the heating operation as an example. As shown here, the air conditioner includes a compressor 8, a four-way valve 9, an indoor heat exchanger 101, an expansion valve 103, an outdoor heat exchanger 106, and the like.

The compressor 8 compresses the gas refrigerant, and the refrigerant 60 that has been brought to a high temperature / high pressure state by the compressor 8 is led to the indoor heat exchanger 101 (condenser) in the indoor unit 100 via the four-way valve 9. It is burned. And the room | chamber interior is warmed because the high temperature refrigerant | coolant which flows through the inside of the flat heat exchanger tube of the indoor heat exchanger 101 dissipates to the indoor air supplied from the air blower 102. At this time, in the flat heat transfer tube, the gas refrigerant that has been deprived of heat gradually liquefies, and from the outlet of the indoor heat exchanger 101, the supercooled liquid refrigerant that is several degrees C lower than the saturation temperature flows out.

Thereafter, the liquid refrigerant that has flowed out of the indoor unit 100 becomes a gas-liquid two-phase refrigerant in a low-temperature and low-pressure state by an expansion action when passing through the expansion valve 103. This low-temperature, low-pressure gas-liquid two-phase refrigerant is guided to the outdoor heat exchanger 106 (evaporator) in the outdoor unit 105. And the low-temperature refrigerant | coolant which flows through the inside of the flat heat exchanger tube of the outdoor heat exchanger 106 absorbs heat from the external air supplied from the air blower 107, so that the dryness of the refrigerant (= mass velocity of gas / (mass velocity of liquid + gas) At the outlet of the outdoor heat exchanger 106, the refrigerant is gasified and returns to the compressor 8 with a degree of superheat of several degrees C. The refrigerant 60 circulates counterclockwise as described above. The heating operation of the air conditioner is realized by a series of refrigeration cycles.

On the other hand, during the cooling operation, the four-way valve 9 is switched to form a refrigeration cycle in which the refrigerant 61 circulates clockwise. In this case, the indoor heat exchanger 101 acts as an evaporator, and the outdoor heat exchanger 106 acts as a condenser.

Next, the state of refrigerant drift occurring in the evaporator when the indoor heat exchanger 101 or the outdoor heat exchanger 106 acts as an evaporator will be described with reference to FIG. FIG. 21 is a plan view schematically showing the evaporator, and a part of the evaporator is simplified, such as omitting the individual display of the flat heat transfer tube.

FIG. 21A is an explanatory diagram when there is a drift of liquid refrigerant, and FIG. 21B is an explanatory diagram when there is no drift of liquid refrigerant. As shown in these figures, the heat exchanger is provided with headers 3a and 3b that are substantially perpendicular to the left and right, and connected by a number of flat heat transfer tubes 1 that are stacked in the vertical direction therebetween. Each flat heat transfer tube 1 is brazed with a fin for enlarging the heat transfer area, but is not shown here. Further, in the flat heat transfer tube 1, the hatched portion is a two-phase region 90 through which the gas-liquid two-phase refrigerant flows, and the white portion is an overheat region 91 through which the gas refrigerant flows.

In the parallel flow type evaporator shown in FIG. 21, low-temperature and low-pressure gas-liquid two-phase refrigerant flows from the lower part of the header 3b. The refrigerant flowing in flows in the flat heat transfer tubes 1 in the order of the regions (A) → (B) → (C) → (D) while changing the flow direction, and exchanges heat with the air passing between the flat heat transfer tubes 1 ( After the heat absorption), the refrigerant is discharged from the upper portion of the header 3b as a medium temperature / low pressure refrigerant.

As shown in FIG. 21 (b), when the refrigerant knitting flow does not occur, that is, when the flow velocity of the refrigerant is large, and a substantially equal amount of gas-liquid two-phase refrigerant is supplied to each flat heat transfer tube 1 in the region (D). In any of the flat heat transfer tubes 1, since the two-phase region 90 becomes the superheated region 91 at the same distance from the inflow side, only the gas refrigerant that sufficiently absorbs heat from any flat heat transfer tube 1 is used. Leaked.

On the other hand, as shown in FIG. 21A, when the liquid refrigerant drifts, that is, gravity acts on the gas-liquid two-phase refrigerant having a low flow velocity in the header 3a, and the flat heat transfer tube 1 above the region (D) When there is little liquid refrigerant flowing into the lower part and more liquid refrigerant flows into the lower flat heat transfer tube 1, the lower part is the two-phase region 90 and the upper part is the superheated region 91 in the vicinity of the outlet of the region (D).

As described above, when the gas-liquid two-phase refrigerant containing a large amount of liquid refrigerant returns to the compressor 8, “liquid return” causes damage to the compression chamber. In order to avoid this, the expansion valve 103 upstream of the evaporator is throttled so that the liquid refrigerant is completely gasified in the vicinity of the outlet of the region (D) in FIG. It is necessary to lower. However, when the evaporation pressure is lowered, there is a problem that the compression work increases and the energy saving performance of the air conditioner is hindered.

Further, when refrigerant drift occurs, the two-phase region 90 is short and the superheat region 91 is long in the flat heat transfer tube 1 above the region (D), so that the two-phase region 90 greatly contributes to the heat absorption from the air. There is a problem that the heat transfer area decreases and the compression work increases.

As a technique for improving the refrigerant drift that causes such a problem, there is a refrigerant distributor shown in Patent Document 1. As shown in FIG. 1a of the same document, this refrigerant flow divider has a single refrigerant inflow pipe and a plurality of refrigerant outflow pipes. The gas-liquid two-phase refrigerant that has entered the refrigerant distributor from the refrigerant inflow pipe is separated into the gas refrigerant and the liquid refrigerant when moving over the partition plate at the lower part of the refrigerant distributor, and the gas refrigerant that has accumulated in the upper part of the refrigerant distributor. The liquid refrigerant accumulated in the lower side of the refrigerant flow divider from the gas refrigerant outlet opening on the side of the refrigerant outlet pipe flows into the refrigerant outlet pipe from the refrigerant outlet at the lower end of the refrigerant outlet pipe, and the gas refrigerant and liquid refrigerant have a desired ratio. It becomes a gas-liquid two-phase refrigerant merged at, and flows out of the refrigerant distributor.

JP 2012-137223 A

In Patent Document 1, the diameter of the refrigerant outlet pipe, the installation position, size, and number of the refrigerant outlet and the gas refrigerant outlet opening are designed according to the rated load conditions of the air conditioner. Under the conditions, an appropriate amount of liquid refrigerant can be led to the refrigerant outlet pipe. However, when the air conditioner is operated under an intermediate load condition or a minimum load condition, the flow rate of the gas refrigerant is small, so that the static pressure necessary for sucking up the liquid refrigerant cannot be obtained, and a sufficient amount of liquid refrigerant is not supplied. There was a problem that it could not be lifted.

That is, the configuration of Patent Document 1 is effective for performance improvement under rated load conditions, but for performance improvement under intermediate load conditions or minimum load conditions frequently used in recent air conditioners. There was a problem that the same level of effect could not be obtained and the impact on the reduction of annual power consumption during actual operation was limited.

Therefore, in the present invention, even during operation under the intermediate load condition and the minimum load condition, the liquid refrigerant supply amount bias to each flat heat transfer tube in the parallel flow type evaporator is suppressed with a simple structure, It aims at providing the air conditioner provided with the heat exchanger which can improve the performance as an evaporator.

In order to solve the above problems, a heat exchanger according to the present invention includes an inflow header, an outflow header, a plurality of heat transfer tubes connecting the two headers, and a fin that expands the heat transfer area of the heat transfer tubes. The inflow-side header includes a gas-liquid mixing unit into which the gas-liquid two-phase refrigerant flows in via an inlet pipe, and a plurality of gas-liquid mixing units arranged above the gas-liquid mixing unit and partitioned in a vertical direction by a partition plate. And a plurality of communication passages that directly communicate with the gas-liquid mixing portion and each header inner space, and at least one heat transfer tube is connected to each header inner space. The flow path was a heat exchanger having at least one opening in the gas-liquid mixing part.

ADVANTAGE OF THE INVENTION According to this invention, the energy distribution of an air conditioner can be improved by equalizing the refrigerant | coolant distribution to each flat heat exchanger tube of a parallel flow type heat exchanger, and making a heat exchanger act efficiently. .

The longitudinal cross-sectional view of the header of the heat exchanger of Example 1 Cross-sectional view of header of heat exchanger of embodiment 1 The front view of the communicating tube of the heat exchanger of Example 1 The longitudinal cross-sectional view of the header of the heat exchanger of Example 2 Cross-sectional view of header of heat exchanger of embodiment 2 Front view of the heat exchanger of Example 4 Top view of heat exchanger of Example 4 Top view of heat exchanger of Example 4 Front view of the heat exchanger of Example 5 The longitudinal cross-sectional view of the header of the heat exchanger of Example 3 Cross-sectional view of header of heat exchanger of embodiment 3 Cross-sectional view of header of heat exchanger of embodiment 6 Cross-sectional view of header of heat exchanger of embodiment 6 Cross-sectional view of header of heat exchanger of embodiment 6 Cross-sectional view of header of heat exchanger of embodiment 6 The longitudinal cross-sectional view of the header of the heat exchanger of Example 7 The exploded perspective view of the header of the heat exchanger of Example 8 Cross-sectional view of header of heat exchanger of embodiment 8 Vertical sectional view of the header of the heat exchanger of Example 9 The longitudinal cross-sectional view of the header of the heat exchanger of Example 10 The figure explaining the superheat degree of the conventional heat exchanger The figure explaining the refrigerating cycle of Example 1.

Hereinafter, embodiments of the air conditioner of the present invention will be described in detail with reference to the drawings. Since the outline of the air conditioner described in the following embodiments is the same as that described in FIG. 22, repeated description will be omitted, and each embodiment will be described focusing on the differences.

First, the structure of the heat exchanger used in the air conditioner of Example 1 will be described. The heat exchanger of the present embodiment includes two substantially cylindrical headers 3 arranged substantially vertically on the upstream side and the downstream side, a plurality of flat heat transfer tubes 1 connecting between them, and the flat heat transfer tubes 1. It consists of a plurality of fins 2 that expand the heat transfer area.

FIG. 1 is a partial cross-sectional view of the vicinity of the upstream header 3, and as shown here, a plurality of substantially horizontal flat heat transfer tubes 1 are stacked in a vertical direction with a predetermined gap (step pitch Pd). A plurality of plate-like fins 2 are arranged with a predetermined gap (fin pitch Pf) in the left-right direction, and the flat heat transfer tubes 1 and the fins 2 are brazed so that heat can be transferred. Each flat heat transfer tube 1 is inserted into the header 3, and the refrigerant supplied via the header 3 flows into each flat heat transfer tube 1.

The header 3, the flat heat transfer tube 1, and the fin 2 will be described more specifically. On the side surface of the header 3, a plurality of holes for inserting the flat heat transfer tubes 1 are formed in advance at a step pitch. The flat heat transfer tube 1 is made of aluminum, and has a plurality of multi-hole flow paths formed by extrusion processing in a flat cross section. The fins 2 are made of aluminum, and cuts are made at equal intervals in the upper and lower longitudinal ends, and the flat heat transfer tubes 1 are inserted into the cuts, or through holes are formed in the fins themselves and the flat heat transfer tubes 1 are inserted. Thus, it is formed integrally with the flat heat transfer tube 1. At the time of manufacturing a heat exchanger combining these, first, the end of each flat heat transfer tube 1 is inserted into the hole of the header 3, and further, the fins 2 are attached to the flat heat transfer tube 1. A heat exchanger may be manufactured by brazing, or a heat exchanger may be manufactured by partially brazing with a torch.

Here, the flat heat transfer tube 1 and the fins 2 are joined to the flat heat transfer tube 1 by plastic deformation by pressurizing the inside of the multi-hole flow path with a hydraulic pressure or a gas pressure instead of the brazing described above. A method may be adopted. Further, instead of the plate-like fins 2 as shown in FIG. 1, a corrugated (corrugated) fin that is currently mainstream in a condenser of an automotive air conditioner may be inserted between the flat heat transfer tubes 1. good.

Next, characteristic parts of the heat exchanger of this embodiment will be described. As shown in FIG. 1, in the heat exchanger of this embodiment, the gas-liquid mixing unit 4 is integrally formed below the header 3, and the interior of the header 3 is separated by four partition plates 31 into the header inner space. 32 a to 32 d and the five compartments of the mixing chamber 41. An inlet pipe 36 serving as a refrigerant inlet is connected to the lower side of the mixing chamber 41, and a plurality (four in FIG. 1) of flat heat transfer pipes 1 are connected to each of the header inner spaces 32a to 32d. Has been. Further, four communication pipes 5 that directly connect the mixing chamber 41 and the header inner spaces 32a to 32d are provided. FIG. 1 is a diagram schematically showing that the plurality of communication pipes 5 communicate with different spaces, and the arrangement of the communication pipes 5 is not accurately shown.

When the gas-liquid two-phase refrigerant is supplied from the inlet pipe 36 to the mixing chamber 41, a gas-liquid interface 42 that is a boundary between the gas refrigerant and the gas-liquid two-phase refrigerant is formed in the mixing chamber 41. The liquid refrigerant accumulated in the lower portion of the mixing chamber 41 is directly supplied to each of the header inner spaces 32a to 32d through the communication pipe 5 together with the gas refrigerant, and finally the flat heat transfer tubes connected to the header inner spaces. Flows out of 1. At this time, since the amount of liquid refrigerant supplied to each of the header inner spaces 32a to 32d is substantially equal, a substantially equal amount of liquid refrigerant is also supplied to each flat heat transfer tube 1 connected to each header inner space. Is done.

FIG. 2 is a cross-sectional view of the mixing chamber 41 in the AA section of FIG. 1, and shows the arrangement of the communication pipes 5 in the mixing chamber 41 more accurately. In FIG. 2, 51 is a lower hole provided at the lower end of the communication pipe 5. That is, FIG. 2 shows that the outlet of the inlet pipe 36 and the inlet of the communication pipe 5 are installed at substantially the same height, and that the four communication pipes 5 are arranged in a straight line substantially perpendicular to the inlet pipe 36. It shows that.

FIG. 3 is a side view illustrating the detailed structure of the communication pipe 5. As shown here, the side surface of the communication pipe 5 has a plurality or a single opening at a height corresponding to the height of the mixing chamber 41. For example, in FIG. 3A, side round holes 52a are provided with a predetermined gap in the vertical direction, and in FIG. 3B, narrow side long holes 52b are provided. Moreover, in FIG.3 (c), in addition to the side long hole 52b of FIG.3 (b), the plug 53 which plugs up the lower hole 51 of the communicating pipe 5 is attached.

Which communication pipe 5 shown in FIG. 3 is used is determined according to the flow rate of the refrigerant and the dryness condition, and a plurality of communication pipes 5 having the same shape may be connected to the gas-liquid mixing unit 4. It is good also as a structure which connects the gas-liquid mixing part 4 combining the communication pipe 5 of a different shape. For example, by changing the dimensions of the side round hole 52a and the side long hole 52b for each communication pipe 5, the refrigerant amount of the communication pipe 5 having different heights can be finely adjusted. Also, the amount of liquid refrigerant sucked from the lower end of the communication pipe 5 and the amount of gas refrigerant sucked from the side hole can be changed depending on the presence or absence of the plug 53, and fine adjustment of the ratio of gas refrigerant to liquid refrigerant in the gas-liquid two-phase refrigerant Is possible.

As shown in FIG. 1, the communication pipe 5 in the mixing chamber 41 has a substantially upper half located above the gas-liquid interface 42 and a substantially lower half located below the gas-liquid interface 42. Of the side round hole 52a and the side long hole 52b, the gas refrigerant can be sucked from the upper one, and the gas-liquid two-phase refrigerant can be sucked from the lower one. The height of the gas-liquid interface 42 varies depending on the environmental conditions of the air conditioner and the operating condition of the load, but the side round hole 52a and the side long hole 52b are provided over the entire height of the mixing chamber 41. Therefore, even when the height of the gas-liquid interface 42 changes, the communication pipe 5 can appropriately suck up the gas-liquid two-phase refrigerant.

Next, details of the operation of the evaporator according to the present embodiment will be described with reference to FIG. First, the gas-liquid two-phase refrigerant flows into the gas-liquid mixing unit 4 from the inlet pipe 36. The gas-liquid two-phase refrigerant releases part of the gas refrigerant in a relatively wide space called the mixing chamber 41. The gas-liquid two-phase refrigerant in which the ratio of the liquid refrigerant is increased by the release of the gas refrigerant accumulates in the lower part of the mixing chamber 41 due to the action of gravity, while the gas refrigerant separated from the gas-liquid two-phase refrigerant is above the mixing chamber 41. Moving. As a result, a gas-liquid interface 42 is formed between the gas refrigerant and the gas-liquid two-phase refrigerant.

The gas refrigerant in the upper part of the mixing chamber 41 flows into the communication pipe 5 at high speed from the opening (side round hole 52a, side long hole 52b) above the gas-liquid interface 42. At this time, negative pressure is generated by the high-speed gas refrigerant flowing in the communication pipe 5, and from the openings (lower hole 51, side round hole 52 a, side long hole 52 b) below the gas-liquid interface 42, Since the gas-liquid two-phase refrigerant accumulated in the lower part is sucked up, the gas refrigerant and the gas-liquid two-phase refrigerant are mixed in the communication pipe 5 at a predetermined ratio. This is a phenomenon that occurs in the same way in any of the four communication pipes 5 having different heights. Therefore, the ratio of the gas refrigerant to the liquid refrigerant in the gas-liquid two-phase refrigerant sucked up by the communication pipe 5 is four. In any of the communication pipes 5 of FIG.

After that, the gas-liquid two-phase refrigerant sucked up by the communication pipe 5 is directly supplied to each of the header inner spaces 32 a to 32 d stacked in the header 3. The refrigerant that has entered the header inner spaces 32a to 32d flows into each of the four flat heat transfer tubes 1 connected to the header inner spaces.

The substantially homogeneous gas-liquid two-phase refrigerant supplied to the header inner spaces 32a to 32d contains a large amount of gas refrigerant, and since the apparent density is small, the interior of each header inner space can be filled substantially evenly. As a result, the influence of the liquid head difference due to the difference in the height position of the flat heat transfer tubes 1 connected to the space in each header is reduced, and the substantially uniform gas-liquid two-phase is applied to each of the flat heat transfer tubes 1 having different heights. A refrigerant can be supplied.

As described above, according to the configuration of the present embodiment, the substantially homogeneous gas-liquid two-phase refrigerant is supplied to the plurality of header inner spaces having different heights in the header, and further, the plurality of headers connected to the header inner spaces. Since the substantially homogeneous gas-liquid two-phase refrigerant can be supplied to the flat heat transfer tube, the influence of the drift due to the height can be suppressed even in a heat exchanger having a height.

At the end of this embodiment, the situation where the heat exchanger of this embodiment is operated as a condenser will be briefly described. When used as a condenser, the refrigerant flows in the direction opposite to the arrow shown in FIG. That is, the refrigerant first flows from each flat heat transfer tube 1 into the header inner spaces 32 a to 32 d in the header 3, and then flows into the mixing chamber 41 from each header inner space through the communication tube 5. Finally, it flows out of the heat exchanger through the inlet pipe 36 connected to the lower part of the mixing chamber 41. Thus, since the refrigerant in the condenser sequentially moves in the header 3 from the high place to the low place, the liquid refrigerant does not move against the gravity, and the flow of the stable refrigerant without increasing the pressure loss. Can be maintained.

4 and 5 are diagrams for explaining the heat exchanger used in the second embodiment. In addition, about the structure equivalent to Example 1, duplication description is abbreviate | omitted. FIG. 4 is a partial cross-sectional view of the vicinity of the upstream header 3 in the present embodiment, and FIG. 5 is a cross-sectional view of the mixing chamber 41 in the AA portion of FIG. 4 to show the connection direction of the inlet pipe 36. Inlet pipes 36 at different heights are also shown.

In this embodiment, a perforated plate 43 is provided in the mixing chamber 41 in place of the side round hole 52a and the side long hole 52b of the communication pipe 5 in FIG. As shown in FIG. 4, the perforated plate 43 is not provided with a hole above the inlet pipe 36, and has a plurality of holes from the center to the bottom. The gas-liquid two-phase refrigerant flowing from the inlet pipe 36 collides with the flat portion of the perforated plate 43 and flows downward while releasing a part of the contained gas refrigerant. Thereby, since the direction of the main flow of the refrigerant is largely changed, the influence of the main flow on the subsequent flow of the refrigerant is suppressed. After that, in the gas-liquid two-phase refrigerant in which the ratio of the liquid refrigerant is increased, the bubbles of the gas refrigerant contained when passing through the holes below the perforated plate 43 are further subdivided and separated from the gas-liquid two-phase refrigerant. The gas refrigerant passes through the central hole and moves above the gas-liquid interface 42.

Due to the negative pressure generated when the communication pipe 5 sucks up the gas refrigerant at high speed, the gas refrigerant and the gas-liquid two-phase refrigerant are mixed in the upper part of the mixing chamber 41, and the header inner spaces 32 a to 32 d from the lower hole 51 of each communication pipe 5. A substantially homogeneous gas-liquid two-phase refrigerant is supplied to each of these. Even with such a simplified configuration of the communication pipe 5, an effect substantially equal to that of FIG. 1 can be obtained.

10 and 11 are diagrams for explaining the heat exchanger used in the third embodiment. In addition, about the structure equivalent to the above-mentioned Example, duplication description is abbreviate | omitted.

As shown in FIG. 10, the header 3 of this embodiment has an inlet pipe 36 connected to the lower surface of the mixing chamber 41 so that the refrigerant flows from below the gas-liquid mixing unit 4. FIG. 11 is a plan view showing the arrangement of the inlet pipe 36 and each communication pipe 5 in the mixing chamber 41. By arranging the communication pipe 5 so as to surround the inlet pipe 36 arranged at the center of the header 3 having a circular cross section. Since the distances from the inlet pipes 36 to the respective communication pipes 5 can be made equal, compared to the configuration in which the distances from the inlet pipes 36 to the respective communication pipes 5 as in the first embodiment are different, the refrigerant flow sucked up by the respective communication pipes 5 is further increased. Can be suppressed.

6 to 8 are diagrams for explaining the heat exchanger used in the fourth embodiment. In addition, about the structure equivalent to the above-mentioned Example, duplication description is abbreviate | omitted.

The heat exchanger of the present embodiment is divided into two in the vertical direction, and a header 3a using the refrigerant distribution structure of the above-described embodiment is provided between the lower heat exchanger 201 and the upper heat exchanger 202. Structure.

In this embodiment, as shown in FIG. 6, a lower heat exchanger 201 and an upper heat exchanger 202 are stacked one above the other in order to improve the drainage of the condensed water generated in the fins 2 of the heat exchanger. The gas-liquid mixing unit 4 is provided below the header 3a of the upper heat exchanger 202, which is disposed downstream of the header 3b of the lower heat exchanger 201. Since the header 3a protrudes downward by the amount of the gas-liquid mixing unit 4, the upper header 3a is arranged to be shifted outward by a predetermined distance D from the lower header 3b. When the heat exchanger shown in FIG. 6 is manufactured by the brazing method, if the furnace is small, the entire heat exchanger may not be brazed at once. In that case, the upper heat exchanger 202 and the lower heat exchanger 201 may be brazed separately and then combined to produce the heat exchanger of this embodiment.

FIG. 7 is a top view when FIG. 6 is observed from above, and shows a configuration in which the gas-liquid mixing unit 4 is mounted by shifting the header 3a to the outside of the header 3b.

FIG. 8 is a modification of FIG. Although FIG. 7 shows the positional relationship between the headers 3a and 3b in the planar heat exchanger, FIG. 8 shows the positional relationship between the headers 3a and 3b in the heat exchanger bent in an L shape with the curvature R. In a heat exchanger that is required to be downsized, such as a heat exchanger used in an outdoor unit of an air conditioner, the front surface area can be secured within the same unit size by the configuration as shown in FIG. A distribution structure can be realized.

FIG. 9 is a diagram for explaining a heat exchanger used in the fifth embodiment. In addition, about the structure equivalent to the above-mentioned Example, duplication description is abbreviate | omitted.

FIG. 9 shows a case where the heat exchanger is divided into three heat exchangers. With this configuration, a plurality of the refrigerant distribution structures of the above-described embodiments can be mounted. Specifically, a gas-liquid mixing unit 4a is provided at the lower part of the header 3 upstream of the middle heat exchanger, and a gas-liquid mixing unit 4b is provided at the lower part of the header 3 upstream of the upper heat exchanger.

When the configuration as shown in FIG. 9 is adopted, the liquid component in the gas-liquid two-phase refrigerant gradually decreases toward the downstream due to heat exchange. Therefore, the downstream gas is less than the gas-liquid mixing unit 4a on the upstream side. The liquid refrigerant that accumulates in the liquid mixing unit 4b decreases. For this reason, in the present embodiment, the volume of the downstream gas-liquid mixing unit 4b is smaller than the volume of the upstream gas-liquid mixing unit 4a (or the volume of the upstream gas-liquid mixing unit 4a is set downstream. By making it larger than the volume of the mixing portion 4b, the downstream header 3 is relatively miniaturized.

12 to 15 are diagrams for explaining the heat exchanger used in the sixth embodiment. In addition, about the structure equivalent to the above-mentioned Example, duplication description is abbreviate | omitted.

12 to 14 are modifications of the first embodiment and the second embodiment in which the inlet pipe 36 is connected to the side surface of the gas-liquid mixing section 4. FIG. 15 shows a modification of the third embodiment in which an inlet pipe is connected below.

12 has a side opening 52d of the communication pipe 5 provided in the direction opposite to the inlet pipe. With such a configuration, the influence of the main flow of the inlet pipe can be prevented, and a substantially equal amount of refrigerant can be supplied to each communication pipe 5. As the shape of the side opening 52d, the side round hole 52a described above may be adopted, or the side long hole 52b may be adopted.

In the structure of FIG. 13, a partition plate 37 is provided between the inlet pipe 36 and the communication pipe 5. That is, the perforated portion is omitted from the perforated plate 43 of the second embodiment. Even with such a configuration, similarly to the second embodiment, the influence of the refrigerant main flow from the inlet pipe can be suppressed.

In the structure of FIG. 14, the inlet pipe 36 is provided in the tangential direction of the inner surface of the header 3, and the four communication pipes 5 are collected and arranged at the center. With such a configuration, the fast flow from the inlet pipe 36 becomes a swirling flow in the header 3, and the communication pipe 5 sucks the refrigerant from the central region where the flow velocity is slow. Even with this configuration, the influence of the mainstream from the inlet pipe 36 can be suppressed.

FIG. 15 is a modification of FIG. 11 in which a connecting pipe is provided below, and a horizontal partition plate 38 is provided between the inlet pipe 36 and the communication pipe 5 to reduce the main flow speed of the refrigerant flowing from the inlet pipe 36. To do.

As described above, the configuration shown in FIGS. 12 to 15 also suppresses the influence of the high-speed refrigerant flowing from the inlet pipe 36 on the communication pipe 5, and each communication pipe 5 sucks up the substantially homogeneous gas-liquid two-phase refrigerant. Since it can distribute to each header inner space, a substantially homogeneous gas-liquid two-phase refrigerant can be supplied also to the flat heat exchanger tube 1 connected to each header inner space.

FIG. 16 is a diagram illustrating a heat exchanger used in Example 7. In addition, about the structure equivalent to the above-mentioned Example, duplication description is abbreviate | omitted.

In FIG. 1 to FIG. 15, four flat heat transfer tubes 1 are connected to the spaces in each header, that is, the refrigerant supplied from one communication tube 5 is branched into four flat heat transfer tubes 1. However, in the present embodiment, one flat heat transfer tube 1 is connected to each header space, that is, the refrigerant flows from one communication tube 5 to one flat heat transfer tube 1. Even if it is this structure, the effect of this invention that a substantially homogeneous refrigerant | coolant is supplied to each flat heat exchanger tube 1 can be acquired, and also by adjusting with the opening hole diameter etc. of the communication pipe 5, several flat heat exchangers can be obtained. It is also possible to perform a more homogeneous distribution to the heat tubes.

FIGS. 17 and 18 are diagrams for explaining a heat exchanger used in Example 8. FIG. In addition, about the structure equivalent to the above-mentioned Example, duplication description is abbreviate | omitted.

In FIG. 1 to FIG. 16, the communication pipe 5 is constituted by a pipe-shaped hollow pipe, but in this embodiment, a plurality of communication pipes 5 are formed by a substantially cylindrical core 5 a inserted into the circular groove-shaped header 3. It takes the form to do. As shown in FIG. 17, the core 5a is provided with partitioned header inner spaces 32a to 32d on the outer peripheral flat heat transfer tube 1 side, and on the opposite side is provided with a groove 5b for sucking the refrigerant. It has been. Each of the grooves 5b is provided with an opening indicated by hatching in the drawing, which communicates with the header inner spaces 32a to 32d. By configuring the core 5a and the header 3 with the same material and brazing both, a refrigerant flow path capable of obtaining the same effect as in the first embodiment can be formed. By adopting such a configuration, it is possible to obtain an effect equivalent to that of the above-described single command, relatively easily.

FIG. 19 is a diagram illustrating the heat exchanger used in Example 9. In addition, about the structure equivalent to the above-mentioned Example, duplication description is abbreviate | omitted.

1 to 18 show a configuration in which the gas-liquid mixing unit 4 is built in the lower part of the header 3, but in this embodiment, the two are separated and are connected using a plurality of communication pipes 5. . If such a separation configuration is used, only the gas-liquid mixing unit 4 can be installed perpendicular to the direction of gravity, and the header 3 can be inclined from the direction of gravity, which greatly increases the degree of freedom in designing the heat exchanger. Therefore, the effect equivalent to that of the above-described embodiment can be provided to a heat exchanger that requires space saving, such as a heat exchanger used in an indoor unit of an air conditioner.

FIG. 20 is a diagram illustrating the heat exchanger used in Example 10. In addition, about the structure equivalent to the above-mentioned Example, duplication description is abbreviate | omitted.

1 to 19, the partition plate 31 is provided in the header 3. However, in FIG. 20, the partition 31 is removed and the upper openings of the communication pipes 5 are arranged at different heights. Even in such a configuration, the substantially homogeneous gas-liquid two-phase refrigerant can be guided to various heights of the header 3, so that the flat heat transfer tube 1 of any height connected to the header 3 can be used. In addition, a substantially homogeneous gas-liquid two-phase refrigerant can be supplied.

Note that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding by the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.

1 ... flat heat transfer tube,
2 ... Fins,
3, 3a, 3b ... header,
31, 37, 38 ... partition plates,
32, 32a to 32d ... space in header 36 ... inlet pipe,
4, 4a, 4b ... gas-liquid mixing section,
41 ... mixing chamber,
42 ... Gas-liquid interface,
43 ... Perforated plate 5 ... Communication pipe,
5a ...
5b ... groove,
51 ... bottom hole,
52a ... round hole on the side,
52b ... side oblong hole,
52d ... side opening,
53 ... stopper,
60, 61 ... direction of refrigerant flow,
7 ... Compressor,
8 ... Compressor,
9 ... Four-way valve,
90 ... two-phase (liquid) area,
91 ... Superheat (gas) area,
10 ... expansion valve,
100: indoor unit,
101 ... Indoor heat exchanger,
102 ... indoor blower,
103 ... expansion valve,
105: outdoor unit,
106: outdoor heat exchanger,
107: outdoor fan,
201 ... Lower heat exchanger,
202 ... upper heat exchanger,

Claims (11)

A heat exchanger comprising an inflow header, an outflow header, a plurality of heat transfer tubes connecting between both headers, and a fin for expanding the heat transfer area of the heat transfer tubes,
The inflow header is
A gas-liquid mixing section into which the gas-liquid two-phase refrigerant flows through the inlet pipe;
A plurality of header inner spaces arranged above the gas-liquid mixing section and partitioned in a vertical direction by a partition plate;
A plurality of communication channels that directly communicate with the gas-liquid mixing section and the space in each header,
At least one heat transfer tube is connected to each header inner space,
Each communication flow path has at least one opening in the gas-liquid mixing section. The heat exchanger according to claim 1,
The opening that the communication channel has in the gas-liquid mixing part is:
A plurality of side round holes provided on the side surface of the communication channel, or side long holes,
Or it is a lower hole provided in the lower end of this communicating flow path, The heat exchanger characterized by the above-mentioned. The heat exchanger according to claim 1,
The gas-liquid mixing part is provided with a perforated plate between the inlet pipe and the communication flow path, with no holes provided above the inlet pipe and a plurality of holes provided below the inlet pipe. A heat exchanger characterized by The heat exchanger according to claim 1,
The heat exchanger is divided into an upper heat exchanger and a lower heat exchanger,
The inflow header of the upper stage heat exchanger having the gas-liquid mixing part is arranged outside the outflow side header of the lower heat exchanger not having the gas-liquid mixing part. The heat exchanger according to claim 1,
The heat exchanger is divided into a plurality of heat exchangers,
A heat exchanger characterized in that the volume of the gas-liquid mixing section provided on the inflow side of the upstream heat exchanger is larger than the volume of the gas-liquid mixing section provided on the inflow side of the downstream heat exchanger. The heat exchanger according to claim 1,
The heat exchanger according to claim 1, wherein the inlet pipe is connected so that a gas-liquid two-phase refrigerant flows from below the gas-liquid mixing unit. The heat exchanger according to claim 1,
The heat exchanger according to claim 1, wherein the opening of the communication channel in the gas-liquid mixing unit is provided in a direction not facing the opening of the inlet pipe. The heat exchanger according to claim 1,
The plurality of communication channels are constituted by a plurality of grooves formed on the outer periphery of a substantially cylindrical core inserted into the inflow side header having a substantially circular tube shape. The heat exchanger according to claim 1,
The heat exchanger according to claim 1, wherein the gas-liquid mixing unit and the plurality of header inner spaces have separate structures and are connected by the communication flow path. A heat exchanger comprising an inflow header, an outflow header, a plurality of heat transfer tubes connecting between both headers, and a fin for expanding the heat transfer area of the heat transfer tubes,
The inflow header is
A gas-liquid mixing section into which the gas-liquid two-phase refrigerant flows through the inlet pipe;
A header internal space disposed above the gas-liquid mixing section;
A plurality of communication passages that directly communicate with the gas-liquid mixing portion and the space in the header,
Each of the plurality of communication channels is
Having at least one lower opening in the gas-liquid mixing section;
A heat exchanger having upper openings at different heights in the header space. An air conditioner including an outdoor heat exchanger, an indoor heat exchanger, a compressor, and an expansion valve,
The air conditioner according to any one of claims 1 to 10, wherein any one of the heat exchangers is the heat exchanger according to any one of claims 1 to 10.

Images