JP2013002775A - Parallel flow type heat exchanger and air conditioner with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parallel flow type heat exchanger of a side flow system in which a liquid refrigerant can be uniformly distributed to flat tubes at any height.SOLUTION: The parallel flow type heat exchanger 1 includes header pipes 2 and 3 arranged in the vertical direction, and a plurality of horizontal direction flat tubes 4 connecting the header pipes. A refrigerant pipe 9 is inserted in an inside of the header pipe 2 from a lower end to an upper end. A flow-down resistor 20 is arranged in a gap between an outer peripheral surface of the refrigerant pipe 9 and an inner peripheral surface of the header pipe 2. The flow-down resistor 20 is constituted by a resistance plate 21 arranged between the flat tubes 4. The resistance plate 21 has a refrigerant passage opening 22, and the flow-down resistance is set in accordance with the size of an area of the refrigerant passage opening 22.

Description

  The present invention relates to a side flow parallel flow heat exchanger and an air conditioner equipped with the heat exchanger.

  A parallel flow type heat exchange in which a plurality of flat tubes are arranged between two header pipes so that a refrigerant passage inside the flat tubes communicates with the header pipe, and fins such as corrugated fins are arranged between the flat tubes. The equipment is widely used in car air conditioners and building air conditioners.

  In a parallel flow type heat exchanger, it is an important design matter to improve heat exchange efficiency so that the refrigerant flows evenly through a plurality of flat tubes. Examples of parallel flow heat exchangers pursuing an even flow of refrigerant can be found in Patent Documents 1 to 3.

  The parallel flow heat exchanger described in Patent Document 1 has a flat tube having a plurality of refrigerant flow paths formed in a meandering shape, and an inlet header tube and an outlet header tube are attached to both ends of the flat tube. ing. In the inlet side header pipe, a plurality of partition plates having through holes are provided at appropriate intervals. Due to the orifice effect of the partition plate, the refrigerant can flow almost uniformly in each flow path in the flat tube.

  The parallel flow heat exchanger described in Patent Document 2 includes a cylindrical hollow header, a refrigerant inlet pipe connected to the refrigerant inflow chamber of the header, and a plurality of tubes connected to the refrigerant inflow chamber. Prepare. The refrigerant inflow chamber is divided into a plurality of inflow partition chambers, the refrigerant inlet pipe is branched into a corresponding number of branch pipes, and the branch pipes are connected to the inflow partition chambers so that the refrigerant is evenly divided into the tubes. Let

  The parallel flow heat exchanger described in Patent Document 3 has a configuration in which a vertical tube is combined with a horizontal header. In the lower header, a refrigerant dispersion pipe that communicates with the refrigerant inlet pipe is disposed along the length direction thereof. A plurality of refrigerant dispersion holes are provided in the peripheral wall of the refrigerant dispersion tube so that the liquid refrigerant flowing into the lower header through the refrigerant inlet pipe is evenly distributed to the tubes.

Japanese Utility Model Publication No. 1-102660 JP-A-6-74609 Japanese Patent Laid-Open No. 6-159983

  Patent Documents 1 and 3 describe a downflow parallel flow heat exchanger in which flat tubes are arranged in a vertical direction. Patent Document 2 describes a flat flow in which horizontal tubes are arranged in a horizontal direction. Side flow type parallel flow heat exchanger. In the side-flow parallel flow heat exchanger, liquid refrigerant tends to accumulate in the lower part of the header pipe, so a lot of liquid refrigerant flows in the lower flat tube. Causes a phenomenon that only a small amount of liquid refrigerant flows. For this reason, an amount of heat exchange can be increased in the lower region of the heat exchanger, but an imbalance occurs in which the amount of heat exchange cannot be increased in the upper region of the heat exchanger, making it difficult to improve heat exchange efficiency. Met.

  The present invention has been made in view of the above points, and in a side flow type parallel flow heat exchanger, even when it is used as an evaporator, a liquid refrigerant is applied to a flat tube at any height. The purpose is to be able to distribute evenly.

  The parallel flow type heat exchanger according to the present invention includes two vertical header pipes and a plurality of horizontal flat tubes connecting the two header pipes, and the header pipe has an inlet at the inlet of the flat tubes. A flow resistor for extending the refrigerant residence time is arranged.

  In the parallel flow heat exchanger having the above-described configuration, it is preferable that a resistance plate disposed between the flat tubes constitutes the flow-down resistor.

  In the parallel flow heat exchanger configured as described above, it is preferable that the resistance plate includes a refrigerant passage opening, and the flow resistance is set according to the area of the refrigerant passage opening.

  In the parallel flow heat exchanger configured as described above, it is preferable that the resistance plate has a lower flow resistance as the upper plate and a larger flow resistance as the lower plate.

  In the parallel flow heat exchanger configured as described above, it is preferable that an aggregate of fibrous substances constitute the flow-down resistor.

  In the parallel flow type heat exchanger having the above configuration, a refrigerant pipe is inserted into the header pipe from the lower end toward the upper end, and the gap between the outer peripheral surface of the refrigerant pipe and the inner peripheral surface of the header pipe, It is preferable that the flow-down resistor is disposed.

  According to the present invention, the parallel flow heat exchanger configured as described above is mounted on an indoor unit or an outdoor unit of an air conditioner.

  A flow resistor that extends the refrigerant residence time at the flat tube inlet is arranged inside the header pipe, so that even if it is a liquid refrigerant, it does not flow down rapidly, and the liquid refrigerant flows into the flat tube from top to bottom. Can be evenly distributed. This reduces the drift of the liquid refrigerant and improves the heat exchange efficiency.

It is a principal part sectional front view of the heat exchanger concerning a 1st embodiment of the present invention. FIG. 2 is a vertical cross-sectional view of a heat exchanger cut along a line II-II in FIG. 1. It is an expanded horizontal sectional view of the header pipe of the heat exchanger which concerns on 1st Embodiment. It is an expanded horizontal sectional view in the other site | part of the header pipe of the heat exchanger which concerns on 1st Embodiment. It is an expanded horizontal sectional view of the header pipe of a heat exchanger, Comprising: The deformation | transformation embodiment of a resistance board is shown. It is a partial expanded vertical sectional view of the heat exchanger which concerns on 2nd Embodiment of this invention. It is an expanded sectional view of the heat exchanger concerning a 3rd embodiment of the present invention. It is a top view in the state where the heat exchanger concerning a 3rd embodiment is not developed. It is an expanded horizontal sectional view of the header pipe of the heat exchanger which concerns on 3rd Embodiment. It is a schematic block diagram of the air conditioner carrying the heat exchanger which concerns on this invention, and shows the state at the time of heating operation. It is a schematic block diagram of the air conditioner carrying the heat exchanger which concerns on this invention, and shows the state at the time of air_conditionaing | cooling operation.

  The structure of the side flow parallel flow heat exchanger according to the first embodiment of the present invention will be described with reference to FIG. In FIG. 1, the upper side of the paper is the upper side in the vertical direction, and the lower side of the paper is the lower side in the vertical direction.

  A heat exchanger 1 which is a side flow type parallel flow heat exchanger according to the first embodiment includes two vertical header pipes 2 and 3 and a plurality of horizontal flat tubes 4 arranged therebetween. The header pipes 2 and 3 are arranged in parallel in the horizontal direction at intervals, and the flat tubes 4 are arranged at a predetermined pitch in the vertical direction. Since the parallel flow type heat exchanger 1 is installed at various angles according to design requirements at the stage of actually mounting on equipment, “vertical direction” and “horizontal direction” in this specification should not be strictly interpreted. Absent. It should be understood as a mere measure of direction.

  When used as an evaporator (for example, an indoor unit during cooling operation or an outdoor unit during heating operation), the header pipe 2 serves as a refrigerant inflow header pipe, and the header pipe 3 serves as a refrigerant outflow header pipe. Hereinafter, in the first embodiment, the description will proceed with the header pipe 2 as the refrigerant inflow side header pipe and the header pipe 3 as the refrigerant outflow side header pipe.

  The flat tube 4 is an elongated molded product obtained by extruding a metal, and as shown in FIG. 2, a refrigerant passage 5 through which a refrigerant flows is formed. Since the flat tube 4 is disposed so that the extrusion direction, which is the longitudinal direction, is horizontal, the refrigerant flow direction of the refrigerant passage 5 is also horizontal. A plurality of refrigerant passages 4 having the same cross-sectional shape and cross-sectional area are arranged in the left-right direction in FIG. 2, and therefore the vertical cross section of the flat tube 4 has a harmonica shape. Each refrigerant passage 5 communicates with the inside of the refrigerant inflow side header pipe 2 and the refrigerant outflow side header pipe 3.

  Corrugated fins 6 are arranged between the adjacent flat tubes 4. Of the corrugated fins 6 arranged in the vertical direction, side plates 7 are arranged outside the uppermost and lowermost ones.

  The header pipe 2 on the refrigerant inflow side, the header pipe 3 on the refrigerant outflow side, the flat tubes 4, the corrugated fins 6, and the side plates 7 are all made of a metal having good heat conductivity such as aluminum. On the other hand, the corrugated fin 6 is fixed to the flat tube 4 and the side plate 7 is fixed to the corrugated fin 6 by brazing or welding.

  One refrigerant pipe 8 is connected to the header pipe 3. A refrigerant pipe 9 is inserted into the header pipe 2 from the lower end toward the upper end. As shown in FIG. 3, the header pipe 2 and the refrigerant pipe 9 are both circular in cross section and are arranged coaxially. The refrigerant pipe 9 is made of the same material as the header pipe 2 and is fixed to the end plate 10 forming the lower end of the header pipe 2 by brazing or welding.

  The upper end, that is, the tip of the refrigerant pipe 9 faces the end plate 11 forming the upper end of the header pipe 2 with a predetermined interval. The refrigerant pipe 9 has a discharge port 12 only at the tip. The refrigerant discharged from the discharge port 12 collides with the lower surface of the end plate 11.

  A flow-down resistor 20 is disposed inside the header pipe 2. In the first embodiment, the resistance plate 21 disposed between the flat tubes 4 becomes the flow-down resistor 20. The resistance plate 21 has a shape that fills the gap between the outer peripheral surface of the refrigerant pipe 9 and the inner peripheral surface of the header pipe 2, that is, a donut shape. The resistance plate 21 is made of the same material as the refrigerant pipe 9 and the header pipe 2 and is fixed to one or both of the refrigerant pipe 9 and the header pipe 2 by brazing or welding.

  The resistance plate 21 includes a refrigerant passage opening 22. In the resistance plate 21 of the first embodiment, a total of eight circular through holes arranged so as to surround the refrigerant pipe 9 constitute the refrigerant passage opening 22. The number “8” is merely an example, and does not limit the invention.

  The resistance plate 21 has a flow resistance set by the size of the area of the refrigerant passage opening 22. The upper resistance plate 21 has a lower flow resistance, and the lower resistance plate 21 has a lower flow resistance. FIG. 3 shows a resistance plate 21 at a relatively higher position, and a through hole having a large diameter is opened. FIG. 4 shows a relatively low-order resistor plate 21 with a through hole having a small diameter.

  The function of the heat exchanger 1 is as follows. When the refrigerant is fed into the refrigerant pipe 9, the refrigerant is discharged from the discharge port 12. The discharged refrigerant collides with the end plate 11 and changes its direction, and flows down inside the header pipe 2. If the flow-down resistor 20 does not exist, the liquid refrigerant flows down at a high speed and accumulates in the lower part of the header pipe 2, but there is a resistance plate 21 that is the flow-down resistor 20 between the flat tubes 4. Therefore, the refrigerant residence time at the inlet of each flat tube 4 is extended, and the liquid refrigerant also enters the upper flat tube 4.

  Since the resistance plate 21 has a lower flow resistance as the upper plate and a larger flow resistance as the lower plate, the lower flat tube 4 has a liquid refrigerant even though the refrigerant amount decreases as it flows down. Is allocated without shortage. Thereby, from the top to the bottom of the heat exchanger 1, the drift of the liquid refrigerant is reduced, and the heat exchange efficiency is improved.

  The resistance plate 21 does not necessarily need to be arranged as one sheet for one flat tube 4. The configuration may be such that one resistive plate 21 is provided for each of the plurality of flat tubes 4. The coolant passage opening 22 is not limited to the through hole. A notch or a notch may be formed in the outer edge or inner edge of the resistance plate 21, and this may be used as the coolant passage opening 22.

  As shown in FIG. 5, the resistance plate 21 may be formed in a U shape instead of a donut shape by forming a notch 21 a through which the refrigerant pipe 9 is passed through the resistance plate 21. If it does in this way, the resistance board 21 can be inserted into the header pipe 2 containing the refrigerant pipe 9 from a horizontal direction, and attachment of the resistance board 21 becomes easy.

  FIG. 6 shows a second embodiment. Components that are functionally common to the first embodiment are denoted by the same reference numerals used in the description of the first embodiment, and description thereof is omitted. This handling is the same in the third embodiment.

  The second embodiment differs from the first embodiment in the configuration of the flow-down resistor 20. Here, the flow-down resistor 20 is an aggregate 23 of fibrous substances. As the aggregate 23 of fibrous materials, for example, steel wool can be used. Even with this type of flow-down resistor 20, the refrigerant residence time at the inlet of each flat tube 4 is extended, and the liquid refrigerant is evenly distributed to each flat tube 4.

  7 to 9 show a third embodiment. The heat exchanger 1 of the third embodiment is characterized by a structure in which heat exchangers 1A and 1B, which are side flow parallel flow type heat exchangers, are combined. As shown in FIG. 8, the heat exchangers 1 </ b> A and 1 </ b> B are arranged so as to overlap each other when viewed from above. FIG. 7 shows this in an expanded state. The heat exchanger 1A is on the windward side, and the heat exchanger 1B is on the leeward side.

  In the heat exchanger 1A, one header pipe is 2A, and the other header pipe is 3A. In the heat exchanger 1B, one header pipe is 2B, and the other header pipe is 3B.

  The interior of the header pipe 2A is partitioned into two sections S1 and S3 by a single partition plate P1. The partition plate P1 also divides the plurality of flat tubes 4 into a plurality of groups. A total of 24 flat tubes 4 are connected to each of the sections S1 and S3, twelve.

  There is no partition plate inside the header pipe 3A, and the whole is a single section S2.

  The interior of the header pipe 2B is partitioned into two sections S4 and S6 by a single partition plate P2. The partition plate P2 also divides the plurality of flat tubes 4 into a plurality of groups. A total of 24 flat tubes 4 are connected to each of the sections S4 and S6, twelve.

  There is no partition plate inside the header pipe 3B, and the whole is a single section S5.

  The total number of the flat tubes 4 described above, the number of partition plates inside each header pipe and the number of partitions partitioned thereby, and the number of flat tubes 4 for each flat tube group divided by the partition plates are merely examples. Yes, it does not limit the invention.

  A refrigerant pipe 9 extending in the horizontal direction is connected to the compartment S1. A refrigerant pipe 8 extending in the horizontal direction is connected to the compartment S6. The “horizontal direction” of the refrigerant pipe 9 and the refrigerant pipe 8 is also used in the same meaning as the “horizontal direction” of the flat tube 4.

  The section S3 and the section S4 are connected by a connecting pipe 13. As shown in FIG. 8, the connection pipe 13 is bent in a U shape when viewed from above.

  A flow-down resistor 20 is disposed inside the header pipe 3B of the heat exchanger 1B. A resistance plate 24 having the same structure as the resistance plate 21 of the first embodiment constitutes the falling resistor 20. However, as shown in FIG. 9, the resistance plate 24 does not have a central hole for passing the refrigerant pipe, and has a simple disk shape. The resistance plate 24 has a plurality of circular through holes formed on the same circumference, and constitutes a refrigerant passage opening 25. A cutout or a notch may be formed in the outer edge of the resistance plate 24 and used as the coolant passage opening 25.

  The resistance plate 24 has a flow resistance set by the size of the area of the refrigerant passage opening 25. The upper resistance plate 24 has a lower flow resistance, and the lower resistance plate 24 has a higher flow resistance. The size of the flow resistance can be set by making a difference in the size of the through hole, notch, notch, etc.

  The resistance plate 24 is not arranged for all of the flat tubes 4 connected to the section S5. It arrange | positions only with respect to the 12 flat tubes 4 connected to both division S5 and division S6. Further, the resistance plate 24 is not necessarily arranged in a single plate with respect to one flat tube 4. The configuration may be such that one resistive plate 24 is provided for each of a plurality of flat tubes 4.

  The twelve flat tubes 4 connecting the section S1 and the section S2 form the refrigerant flow path A. The twelve flat tubes 4 connecting the section S2 and the section S3 form a refrigerant flow path B. The twelve flat tubes 4 connecting the section S4 and the section S5 form a refrigerant flow path C. The twelve flat tubes 4 connecting the section S5 and the section S6 form a refrigerant flow path D.

  When the heat exchanger 1 is used as an evaporator, when the refrigerant is supplied to the section S1 through the refrigerant pipe 9, the refrigerant passes through the refrigerant flow path A toward the section S2. The refrigerant that has entered the section S2 is turned back through the refrigerant flow path B toward the section S3. The refrigerant that has entered the compartment S3 moves to the compartment S4 through the connecting pipe 13. The refrigerant that has entered the compartment S4 travels through the refrigerant flow path C to the compartment S5. The refrigerant that has entered the section S5 turns back there, and passes through the refrigerant flow path D toward the section S6. The refrigerant that has entered the compartment S6 flows out of the refrigerant pipe 8.

  The refrigerant that has entered the compartment S5 from the refrigerant flow path C travels to the flat tube 4 constituting the refrigerant flow path D. If the flow-down resistor 20 is not present, the liquid refrigerant flows down at a high speed and accumulates in the lower part of the header pipe 3B. However, the flow-down resistor 20 is provided for the flat tube 4 constituting the refrigerant flow path D. Since the resistance plate 24 is provided, the refrigerant residence time at the inlet of each flat tube 4 is extended, and the liquid refrigerant also enters the upper flat tube 4.

  Since the resistance plate 24 has a lower flow resistance as the upper plate and a larger flow resistance as the lower plate, the lower flat tube 4 has a liquid refrigerant even though the refrigerant amount decreases as it flows down. Is allocated without shortage. Thereby, the drift of the liquid refrigerant decreases from the top to the bottom of the refrigerant flow path D, and the heat exchange efficiency is improved.

  When the heat exchanger 1 is used as a condenser, the refrigerant pipe 9 is a pipe through which the refrigerant flows out. Since the refrigerant pipe 9 on the outlet side becomes the windward side, the outlet temperature of the refrigerant can be increased in the number of supercooling elements. If the relationship between the windward and leeward is reversed, the air passing through the heat exchanger 1 is heated in the heat exchanger 1B on the windward side and exchanges heat with the heat exchanger 1A on the leeward side. And the refrigerant outlet temperature rises. That is, supercooling cannot be performed and the amount of heat exchange is reduced. This is the reason why the heat exchanger 1A is on the leeward side and the heat exchanger 1B is on the leeward side.

  The heat exchanger 1 can be mounted on a separate type air conditioner. A separate type air conditioner is composed of an outdoor unit and an indoor unit. The outdoor unit includes a compressor, a four-way valve, an expansion valve, an outdoor heat exchanger, an outdoor fan, and the like. The indoor unit is an indoor heat exchanger, a room Includes an internal blower. The outdoor heat exchanger functions as an evaporator during heating operation and functions as a condenser during cooling operation. The indoor heat exchanger functions as a condenser during heating operation and functions as an evaporator during cooling operation.

  FIG. 9 shows a basic configuration of a separate type air conditioner that uses a heat pump cycle as a refrigeration cycle. The heat pump cycle 101 includes a compressor 102, a four-way valve 103, an outdoor heat exchanger 104, a decompression / expansion device 105, and an indoor heat exchanger 106 connected in a loop. The compressor 102, the four-way valve 103, the heat exchanger 104, and the decompression / expansion device 105 are accommodated in the casing of the outdoor unit, and the heat exchanger 106 is accommodated in the casing of the indoor unit. An outdoor fan 107 is combined with the heat exchanger 104, and an indoor fan 108 is combined with the heat exchanger 106. The blower 107 includes a propeller fan, and the blower 108 includes a cross flow fan.

  The heat exchanger 1 which concerns on this invention can be used as a component of the heat exchanger 106 of an indoor unit. The heat exchanger 106 is a combination of three heat exchangers 106A, 106B, and 106C like a roof that covers the blower 108, and one of the heat exchangers 106A, 106B, and 106C is combined with the heat exchanger 1. can do.

  FIG. 9 shows a state during heating operation. At this time, the high-temperature and high-pressure refrigerant discharged from the compressor 102 enters the indoor heat exchanger 106 where it dissipates heat and condenses. The refrigerant exiting the heat exchanger 106 enters the outdoor heat exchanger 104 from the decompression / expansion device 105 and expands there, takes heat from the outdoor air, and returns to the compressor 102. The airflow generated by the indoor fan 108 promotes heat dissipation from the heat exchanger 106, and the airflow generated by the outdoor fan 107 accelerates heat absorption of the heat exchanger 104.

  FIG. 10 shows a state during cooling operation or defrosting operation. At this time, the four-way valve 103 is switched so that the refrigerant flow is reversed from that during the heating operation. That is, the high-temperature and high-pressure refrigerant discharged from the compressor 102 enters the outdoor heat exchanger 104, where it dissipates heat and condenses. The refrigerant exiting the heat exchanger 104 enters the heat exchanger 106 on the indoor side from the decompression / expansion device 105 and expands there, takes heat from indoor air, and returns to the compressor 102. The airflow generated by the outdoor fan 107 promotes heat dissipation from the heat exchanger 104, and the airflow generated by the indoor fan 108 promotes heat absorption of the heat exchanger 106.

  The heat exchanger 1 can also be used as the heat exchanger 104 of the outdoor unit.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention is widely applicable to side flow parallel flow heat exchangers.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2, 3, 2A, 3A, 2B, 3B Header pipe 4 Flat tube 5 Refrigerant passage 6 Corrugated fin 7 Side plate 8 Refrigerant outflow pipe 9 Refrigerant pipe 20 Falling resistor 21 Resistor plate 22 Refrigerant passage opening 23 Fiber Aggregate of particulate matter 24 Resistance plate 25 Refrigerant passage opening

Claims (7)

In a parallel flow type heat exchanger of a side flow type comprising two vertical header pipes and a plurality of horizontal flat tubes connecting the two header pipes,
A parallel flow heat exchanger, wherein a flow resistor for extending the refrigerant residence time at the inlet of the flat tube is disposed inside the header pipe.   The parallel flow type heat exchanger according to claim 1, wherein a resistance plate disposed between the flat tubes constitutes the flow-down resistor.   The parallel flow heat exchanger according to claim 2, wherein the resistance plate includes a refrigerant passage opening, and a flow resistance is set according to a size of the area of the refrigerant passage opening.   4. The parallel flow heat exchanger according to claim 2, wherein the resistance plate has a lower flow resistance as the upper plate and a larger flow resistance as the lower plate. 5.   The parallel flow heat exchanger according to claim 1, wherein an aggregate of fibrous substances constitutes the flow-down resistor.   A refrigerant pipe is inserted into the header pipe from the lower end toward the upper end, and the flow resistor is disposed in a gap between the outer peripheral surface of the refrigerant pipe and the inner peripheral surface of the header pipe. The parallel flow heat exchanger according to any one of claims 1 to 5, wherein the heat exchanger is a parallel flow type heat exchanger.   An air conditioner in which the parallel flow heat exchanger according to any one of claims 1 to 6 is mounted on an indoor unit or an outdoor unit.

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