JP6332991B2 - Heat exchange unit for direct expansion cooler of refrigeration air conditioner - Google Patents

Description

  The present invention relates to a heat exchange unit for a direct expansion cooler of a refrigeration air conditioner.

  As a conventional refrigeration air conditioner, for example, as shown in Patent Document 1 below, a large flat plate heat exchanger and a large-capacity fan are installed in a refrigerated warehouse to cool the refrigerated warehouse. Things are known.

Japanese Patent Laying-Open No. 2013-040694 (page 6, FIG. 1)

  However, since the conventional refrigerating and air-conditioning apparatus is a large flat plate heat exchanger, the resistance to air flow is large and a large capacity fan is required. For this reason, conventionally, power consumption for driving the fan has increased. Furthermore, in the conventional refrigeration air conditioner, the cooling load in the refrigerated warehouse is increased due to heat generated when the fan is driven. As a result, the conventional refrigeration air-conditioning apparatus has a problem that power consumption increases.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a heat exchange unit for a direct expansion cooler of a refrigeration air conditioner in which energy saving is achieved.

The direct expansion type cooler heat exchange unit of the refrigeration air conditioner according to the present invention includes a plurality of U-shaped heat exchangers including a flat plate portion and inclined portions formed on both sides of the flat plate portion, and the plurality of heat exchange units. And a plurality of fans that supply air that has undergone heat exchange in the plurality of heat exchangers in a first axial direction, the first axial direction facing upward The plurality of heat exchangers are installed such that each of the flat plate portions is disposed on a plane intersecting the first axis, and each of the plurality of heat exchangers has a first A plurality of switching means for switching to supply a refrigerant having a temperature or a refrigerant having a second temperature higher than the first temperature, and each of the plurality of switching means is directly connected to the output side of the compressor; Directly connected to the output side of the solenoid valve and condenser One of the plurality of switching means is configured by controlling opening and closing of the electromagnetic valve that is configured by a magnetic valve and is directly connected to the compressor and the electromagnetic valve that is directly connected to the condenser. When the refrigerant having the second temperature is supplied to one of the plurality of heat exchangers, the other switching means supplies the refrigerant having the first temperature to the other heat exchanger. To do.

  According to this invention, it is possible to obtain a heat exchange unit for a direct expansion cooler of a refrigeration air conditioner that achieves energy saving.

1 is a schematic view of a refrigeration air conditioner according to Embodiment 1 of the present invention. It is the schematic of the heat exchange unit shown in FIG. It is the schematic of the comparative example of the heat exchange unit shown in FIG. It is a graph which compares the relationship between a front surface area and a heat exchange rate with the heat exchanger of Embodiment 1, and the heat exchanger of a comparative example. It is a graph which compares the relationship of the pressure loss, the air volume, and the characteristic of a fan with the heat exchange unit of Embodiment 1, and the heat exchange unit of a comparative example. 6 is a graph comparing the relationship between the motor capacity for driving the fan and the heat generation amount in the heat exchange unit of the first embodiment and the heat exchange unit of the comparative example. It is the schematic of the heat exchange unit which concerns on Embodiment 2 of this invention. It is the schematic which shows the application example of the heat exchange unit shown in FIG. It is the schematic which shows the other application example of the heat exchange unit shown in FIG. It is the schematic which shows the further another application example of the heat exchange unit shown in FIG. It is the schematic explaining the example of attachment of the fan to a housing | casing. It is the schematic of the refrigeration air conditioning apparatus which concerns on Embodiment 3 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is omitted or simplified as appropriate.

Embodiment 1 FIG.
The refrigerating and air-conditioning apparatus 1 according to this embodiment cools the inside of the warehouse 50 as shown in FIG. In the following description, the refrigerating and air-conditioning apparatus 1 will be described as cooling a relatively large space such as a refrigerated warehouse or a refrigerated warehouse. However, for example, it may be used for cooling a relatively small space such as a refrigerator. Can be applied.

  As shown in FIG. 1, the refrigeration air conditioner 1 includes a compressor 2, a check valve 4, a condensing unit 6, a solenoid valve 8, an expansion valve 10, and an evaporation unit (heat exchange unit) 100, which are connected by piping. Has been. The compressor 2, the check valve 4 and the condensation unit 6 are disposed outside the warehouse 50, and the electromagnetic valve 8, the expansion valve 10 and the evaporation unit 100 are disposed inside the warehouse 50.

  The compressor 2 is, for example, a two-stage compressor having a front-stage compressor and a rear-stage compressor, and compresses the refrigerant. The compressor 2 includes mechanical capacity control means such as a slide valve, and can vary the operating capacity. The check valve 4 allows the refrigerant flow only in a certain direction. The condensing unit 6 includes, for example, a finned tube heat exchanger composed of a heat transfer tube and a large number of fins, and a fan that blows air to the heat exchanger, and heat of the refrigerant flowing in the heat transfer tube and the ambient air Exchange.

  The electromagnetic valve 8 is controlled by the control unit 16 and switches between an open state and a closed state. The expansion valve 10 is, for example, an electronically controlled expansion valve that is controlled by the control unit 16, and the opening degree thereof can be adjusted. The evaporating unit 100 includes, for example, a finned tube heat exchanger composed of a heat transfer tube and a large number of fins, and a fan that blows air to the heat exchanger, and heat of the refrigerant flowing through the heat transfer tube and the air in the warehouse 50 Exchange. A specific configuration of the evaporation unit 100 will be described later. The temperature sensor 14 detects the temperature in the warehouse 50.

  The refrigerating and air-conditioning apparatus 1 configured as described above operates as described below. That is, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the condensation unit 6. The gas refrigerant that has flowed into the condensing unit 6 undergoes heat exchange with outdoor air in the condensing unit 6 to condense and liquefy, and become high-pressure and low-temperature liquid refrigerant. The liquid refrigerant flowing out of the condensing unit 6 is expanded and decompressed by the expansion valve 10 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant undergoes heat exchange with the air in the warehouse 50 by the evaporation unit 100 to evaporate and vaporize. The gas refrigerant that has flowed out of the evaporation unit 100 is again sucked into the compressor 2 and discharged from the compressor 2 as a high-temperature and high-pressure gas refrigerant.

  Next, a specific configuration of the evaporation unit 100 according to this embodiment will be described with reference to FIG. As shown in FIG. 2, the evaporation unit 100 includes a plurality of U-shaped heat exchangers 102 and a plurality of fans 104 arranged to face the heat exchangers 102. In the following description, an example having three heat exchangers 102 and three fans 104 will be described based on the example shown in FIG. 2, but the number of heat exchangers 102 and fans 104 depends on the usage environment. It can be changed as appropriate. For example, the number of heat exchangers 102 may be two, or four or more. Further, for example, the number of fans 104 may be two, or four or more.

  As shown in FIG. 2, in this embodiment, all of the plurality of heat exchangers 102 are arranged in one housing 106. Each heat exchanger 102 has a flat plate portion 102a and inclined portions 102b formed on both sides of the flat plate portion 102a, and is substantially U-shaped. The U-shaped heat exchanger 102 is obtained, for example, by bending a heat exchanger formed in a flat plate shape. An expansion valve 10 and a distributor 12 are connected to each heat exchanger 102, and the gas-liquid two-phase refrigerant expanded by the expansion valve 10 and distributed by the distributor 12 is supplied.

  Each of the plurality of fans 104 is disposed so as to face the flat plate portion 102 a of the heat exchanger 102. Each fan 104 is, for example, an axial fan that generates an air flow along its axial direction. The housing 106 is formed with a supply port 108 for taking air into the housing 106 and an outlet 110 for blowing air from the housing 106 along the axial direction of each fan 104, and driving each fan 104. Thus, an air flow along the arrow direction shown in FIG. 2 is generated. That is, each fan 104 sucks air from a supply port 108 formed on the front side of each heat exchanger 102 and blows air from a blowout port 110 formed on the back side of each heat exchanger 102. Is generated.

  The air in the warehouse 50 sucked into the housing 106 is cooled by exchanging heat with the gas-liquid two-phase refrigerant flowing in the heat exchanger 102. The air cooled by the heat exchanger 102 is blown out from the housing 106 and blows air to the cooling target existing in the axial direction of each fan 104. The cooling target existing in the axial direction of each fan 104 may be a cooling target stored in the warehouse 50 or may be a cooling target area in the warehouse 50.

  As shown in FIG. 2, the fan 104 is preferably disposed downstream of the heat exchanger 102 in the air flow. By disposing the fan 104 on the cooling target side in the downstream direction of the air flow from the heat exchanger 102, the air cooled by the heat exchanger 102 can be suitably supplied to the cooling target.

  The heat exchanger 102 is preferably arranged in parallel to a plane in which the flat plate portion 102 a intersects the axial direction of the fan 104. Thus, by installing the heat exchanger 102, the air taken into the housing 106 can be suitably cooled by the heat exchanger 102.

  The inclined portion 102b of the heat exchanger 102 is preferably arranged so as to protrude downstream of the air flow. That is, the inclined portion 102b of the heat exchanger 102 is disposed so as to protrude toward the cooling target side in the downstream direction of the air flow. As described above, by disposing the heat exchanger 102, the air taken into the housing 106 can be brought into contact with a wide area of the heat exchanger 102, and heat exchange can be suitably performed.

  The inclined portion 102b of the heat exchanger 102 is preferably formed by being bent at an acute angle of less than 90 degrees from both sides of the flat plate portion 102a. As described above, by forming the inclined portion 102b, the air taken into the housing 106 can be suitably brought into contact with the heat exchanger 102 to perform heat exchange.

  The supply port 108 for taking air into the housing 106 is preferably larger than the width of the flat plate portion 102a of the heat exchanger 102 (the horizontal direction in the drawing) and larger than the width of the heat exchanger 102 (the horizontal direction in the drawing). It is formed small. In addition, the outlet 110 for blowing air from the housing 106 is preferably formed smaller than the width of the heat exchanger 102. In this way, by forming the supply port 108 and the blowout port 110, the air taken into the housing 106 can be reliably and preferably brought into contact with the heat exchanger 102 to perform heat exchange. In addition, the heat exchanger 102 is larger than the supply port 108 and the blower port 110 in the height direction (direction intersecting with the air flow direction and the width direction of the heat exchanger 102).

  Next, the evaporation unit 100 according to this embodiment was evaluated. As a comparative example, a prior art evaporation unit 200 shown in FIG. 3 was prepared. As shown in FIG. 3, the evaporation unit 200 of the comparative example includes one large flat plate heat exchanger 202 and a large-capacity fan 204 disposed so as to face the heat exchanger 202. The heat exchanger 202 of the comparative example has 12 rows and 30 stages × 1 unit, and its product width is 2600 mm.

  Compared with the above comparative example, the evaporation unit 100 according to this embodiment has three U-shaped heat exchangers 102 as shown in FIG. It has three fans 104 arranged. Specifically, there are 4 rows and 30 stages × 3 heat exchangers 102, and the product width of each heat exchanger 102 is 2600 mm, as in the comparative example. In this embodiment, since each heat exchanger 102 is U-shaped, the installation dimension in the width direction of each heat exchanger 102 is reduced. The evaporation unit 100 according to this embodiment is configured to have the same dimension in the width direction as compared with the evaporation unit 200 of the comparative example. That is, each of the heat exchangers 102 according to this embodiment is formed in a U shape so that the dimension in the width direction is not more than one third of the product width.

  Since the evaporation unit 100 according to this embodiment includes three heat exchangers 102 formed in a U shape, the air suction front area (the contact area between the suction air and the heat exchanger 102) is large. That is, in the evaporation unit 200 of the comparative example, compared with the air suction front area corresponding to the product width of the heat exchanger 202 for one unit, the evaporation unit 200 of this embodiment has an amount for three units. It is an air suction front area corresponding to the product width of the heat exchanger 102. As described above, the heat exchanger 102 of this embodiment and the heat exchanger 202 of the comparative example have the same product width, so the air suction front area of the evaporation unit 100 according to this embodiment is compared. It is 3 times compared with the example. As shown in FIG. 4, the heat exchange rate improves as the air suction front area increases. As a result, in the evaporation unit 100 of this embodiment, the heat exchange rate is improved as compared with the evaporation unit 200 of the comparative example.

Furthermore, in this embodiment, since there are a plurality of U-shaped heat exchangers 102, the number of rows of each heat exchanger 102 can be reduced. Specifically, the number of columns of each heat exchanger 102 of this embodiment is four compared to the number of columns of the heat exchanger 202 of the comparative example being twelve. In other words, in this embodiment, the number of columns of the heat exchanger 102 is one third as compared with the comparative example.
As a result, in the evaporation unit 100 according to this embodiment, the resistance of the air flow in the heat exchanger 102 can be reduced. That is, in this embodiment, as shown in FIG. 5, the pressure loss in the heat exchanger 102 is small as compared with the comparative example. Therefore, in this embodiment, as shown in FIG. 5, in order to obtain the same air volume, it is possible to select the fan 104 having a smaller capacity compared to the comparative example.

  As described above, in this embodiment, since the fan 104 having a small capacity is selected, the power consumption for driving the fan 104 is reduced. As shown in FIG. 6, when the motor capacity (capacity of the fan 104) decreases, the amount of heat generated when the fan 104 is driven decreases. Therefore, in this embodiment, since the amount of heat generated when driving the fan 104 is reduced, an increase in the cooling load in the warehouse 50 is suppressed, and the cooling operation in the warehouse 50 can be performed efficiently. it can.

Embodiment 2. FIG.
In the first embodiment, the example in which all of the plurality of heat exchangers 102 are accommodated in one housing 106 has been described. Compared to this, in the second embodiment, as shown in FIGS. 7 to 10, each of the plurality of heat exchangers 102 is accommodated in the housing 106 and modularized. In the following description, the description overlapping with the first embodiment will be omitted.

  In this embodiment, as shown in FIG. 7 to FIG. Each housing 106 accommodates each of the plurality of heat exchangers 102 and is modularized. In this embodiment, as shown in FIGS. 7 to 10, the modularized housing 106 can be installed in various modes.

  For example, in the example shown in FIG. 7, a plurality of housings 106A are connected and installed by fastening members that are not shown. That is, in the example shown in FIG. 7, the evaporation unit 100 having a shape corresponding to the evaporation unit 100 of the first embodiment is obtained. Further, in the example shown in FIG. 8, the evaporation unit 100 in which a plurality of casings 106B are installed in a distributed manner is obtained. Furthermore, in the example shown in FIG. 9, the vertically installed evaporation unit 100 in which a plurality of casings 106C are installed in the vertical direction is obtained. Furthermore, as shown in FIG. 10, the suspension means 112 can be provided in each casing 106 </ b> D, and each casing 106 </ b> D can be hung and installed at a desired location in the warehouse 50.

  As described above, in this embodiment, each of the plurality of housings 106 is modularized, and these can be freely arranged according to the environment in which the evaporation unit 100 is installed. As a result, in this embodiment, the degree of freedom of installation work is expanded. Furthermore, space saving of the installation space of the evaporation unit 100 can be realized.

  In the example described in the first embodiment and the second embodiment, the fan 104 is installed so as to blow the air cooled by the heat exchanger 102 directly toward the cooling target. For example, as shown in FIG. 11, the fan 104 may be installed so as to blow the air cooled toward the upper side of the cooling target. The temperature in the warehouse 50 can be made uniform by blowing the cooled air toward the upper side of the object to be cooled.

Embodiment 3 FIG.
In the refrigerating and air-conditioning apparatus 1 according to Embodiment 3, pipes are connected so that the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 can be directly supplied to the evaporation unit 100, as shown in FIG. It is. In the following description, description of the same parts as those in Embodiment 1 or Embodiment 2 is omitted.

  Solenoid valves 18A to 18C are installed in the pipes connecting the compressor 2 and the heat exchangers 102A to 102C, respectively. Each of solenoid valves 18A-18C is controlled by control part 16 shown in Drawing 2, and changes between an open state and a closed state. When the solenoid valves 18A to 18C are opened, the high-temperature refrigerant discharged from the compressor 2 is supplied to the heat exchangers 102A to 102C. When supplying the high-temperature refrigerant from the compressor 2 to the heat exchangers 102A to 102C, the solenoid valves 8A to 8C are switched to the closed state, and the low-temperature refrigerant flowing out from the condensation unit 6 is converted into the heat exchanger. It does not flow into 102A to 102C.

Next, the defrosting operation of the refrigeration air conditioner 1 according to this embodiment will be described. In this embodiment, one of the plurality of heat exchangers 102A to 102C is selected to perform the defrosting operation. For example, when the defrosting operation of the first heat exchanger 102A is performed, the first electromagnetic valve 18A installed between the first heat exchanger 102A and the compressor 2 is switched to an open state. At this time, the first electromagnetic valve 8A installed between the first heat exchanger 102A and the condensing unit 6 is switched to the closed state. In this way, by switching the first switching means 300A having the first electromagnetic valve 8A and the first electromagnetic valve 18A, a high-temperature refrigerant having the second temperature is caused to flow through the first heat exchanger 102A. The defrosting operation is performed. At this time, the fan disposed opposite to the first heat exchanger 102A is stopped so that high-temperature air does not flow into the warehouse 50.
When the defrosting operation of the first heat exchanger 102A is performed, a normal cooling operation is performed in the second heat exchanger 102B and the third heat exchanger 102C. That is, when the defrosting operation of the first evaporation unit 100A is performed, the refrigerant having the first temperature lower than the second temperature is supplied to the second heat exchanger 102B and the third heat exchanger 102C. The second switching unit 300B and the third switching unit 300C are switched so as to flow. The second switching means 300B includes the second electromagnetic valve 8B and the second electromagnetic valve 18B, and the third switching means 300C includes the third electromagnetic valve 8C and the third electromagnetic valve 18C. It is what has.

  Thus, in this embodiment, for example, the first heat exchanger 102A is selected from the plurality of heat exchangers 102A to 102C, the defrosting operation is performed, and the other second heat exchanger 102B. In the third heat exchanger 102C, a normal cooling operation is performed. As a result, in this embodiment, the temperature rise in the warehouse 50 during the defrosting operation is suppressed, and the defrosting operation can be suitably performed.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. That is, the configuration of the above embodiment may be improved as appropriate, or at least a part of the configuration may be replaced with another configuration. Further, the configuration requirements that are not particularly limited with respect to the arrangement are not limited to the arrangement disclosed in the embodiment, and can be arranged at a position where the function can be achieved.

  DESCRIPTION OF SYMBOLS 1 Refrigeration air conditioner, 2 Compressor, 4 Check valve, 6 Condensing unit, 8 Solenoid valve, 10 Expansion valve, 12 Distributor, 14 Temperature sensor, 16 Control part, 18 Solenoid valve, 50 Warehouse, 100 Evaporation unit (heat Exchange unit), 102 heat exchanger, 102a flat plate portion, 102b inclined portion, 104 fan, 106 housing, 108 supply port, 110 outlet port, 112 suspension means.

Claims (6)

A plurality of U-shaped heat exchangers including a flat plate portion and inclined portions formed on both sides of the flat plate portion;
A plurality of fans that are arranged to face the plurality of heat exchangers, and that supply air that has undergone heat exchange in the plurality of heat exchangers in a first axial direction;
The first axial direction is inclined upward,
The plurality of heat exchangers are installed such that each flat plate portion is disposed on a plane intersecting the first axis,
Each of the plurality of heat exchangers further includes a plurality of switching means for switching to supply a refrigerant having a first temperature or a refrigerant having a second temperature higher than the first temperature,
The plurality of switching means are each composed of a solenoid valve directly connected to the output side of the compressor and a solenoid valve directly connected to the output side of the condenser,
By controlling the opening and closing of the solenoid valve directly connected to the compressor and the solenoid valve directly connected to the condenser, one of the plurality of switching means can be used as the plurality of heat exchangers. When the refrigerant having the second temperature is supplied to one of them, the other switching means supplies the refrigerant having the first temperature to the other heat exchanger. Heat exchange unit for air conditioner.   2. The heat exchange unit for a direct expansion cooler of a refrigeration air conditioner according to claim 1, wherein the plurality of fans are disposed closer to the cooling object than the plurality of heat exchangers.   The heat exchange unit for a direct expansion cooler of a refrigeration air conditioner according to claim 2, wherein the plurality of heat exchangers are arranged such that respective inclined portions protrude toward the cooling target.   4. The refrigerating and air-conditioning apparatus according to claim 1, wherein each of the plurality of fans is disposed so as to face the flat plate portion of the plurality of heat exchangers. 5. Heat exchange unit for direct expansion cooler.   The heat exchange unit for a direct expansion cooler of a refrigeration air conditioner according to any one of claims 1 to 4, further comprising a housing that accommodates all of the plurality of heat exchangers.   The heat exchange unit for a direct expansion type cooler of the refrigeration air conditioner according to any one of claims 1 to 4, further comprising a plurality of housings for accommodating the plurality of heat exchangers. .

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