JP2021072169A - Cooling device - Google Patents

Abstract

To provide a cooling device for batteries including a plurality of heat exchange units, in which a liquid refrigerant can be prevented from being sucked by a compressor by using fewer detectors than the heat exchange units.SOLUTION: A cooling device (10) connected to a refrigeration cycle (1) including a compressor (C) includes: an expansion device (14) to expand a refrigerant; a refrigerant distributor (16); a plurality of heat exchange units (30a, 30b); and a refrigerant merging device (24) to merge refrigerants flowing through the heat exchange units (30a, 30b). A valve opening degree of the expansion device (14) is controlled on the basis of a condition of refrigerants on a downstream side of the refrigerant merging device (24) and on an upstream side of the compressor (C) in a flow direction of a refrigerant.SELECTED DRAWING: Figure 4

Description

The present invention relates to a cooling device that cools a plurality of batteries for a vehicle.

Batteries mounted on vehicles generate heat when a relatively large amount of electric power is applied during charging. If the battery is thermally deteriorated due to this heat generation, the product life of the battery may be shortened. Therefore, the battery is cooled. Patent Document 1 discloses a cooling device for cooling a battery.

The cooling device of Patent Document 1 has a plurality of heat exchange units and can cool a plurality of batteries at the same time. The cooling device is connected to the refrigeration cycle, and when the battery is cooled, the refrigerant used in the refrigeration cycle flows into each heat exchange unit of the cooling device. The refrigerant that has exchanged heat with the battery in each heat exchange unit flows out of the cooling device and is directed to the refrigeration cycle.

In the case of a cooling device having a plurality of heat exchange units such as the cooling device described in Patent Document 1, the cooling device is from a distribution device that distributes the refrigerant toward the plurality of heat exchange units and a plurality of heat exchange units. It has a merging device for merging refrigerants. Then, the refrigerant flowing in from the refrigeration cycle is distributed to a plurality of heat exchange units by the distribution device, passes through the heat exchange units, merges with the confluence device, and is directed to the refrigeration cycle.

By the way, when the cooling device has a plurality of heat exchange units, it is desirable to suppress the degree of superheat of the refrigerant flowing out from each heat exchange unit to a certain value or less in order to suppress the variation in the cooling capacity among the plurality of heat exchange units. Is done. However, if the sensors are provided on the downstream side of each heat exchange unit, the manufacturing cost of the cooling device increases. If the number of sensors is simply reduced from that of the heat exchange unit, it is not possible to detect the degree of superheat in the heat exchange unit in which the corresponding sensor does not exist. If the flow rate of the refrigerant flowing through the heat exchange unit is suppressed so that the degree of overheating tends to increase in the heat exchange unit in which the corresponding sensor exists, the corresponding sensor exists by controlling the degree of overheating of the heat exchange unit. It is also possible to suppress an increase in the degree of overheating of the heat exchange unit. However, in this case, it is not possible to detect the wetness of the heat exchange unit in which the corresponding sensor does not exist. Therefore, even after the refrigerant having a high degree of wetness flows out and merges with the refrigerant flowing out from the heat exchange unit in which the corresponding sensor exists, the state of having a high degree of wetness may be maintained. That is, there is a risk that the compressor will inhale the liquid refrigerant.

European Patent Application Publication No. 2945219

The present invention provides a cooling device for a battery having a plurality of heat exchange units, which can prevent the compressor from sucking liquid refrigerant by using a smaller number of detection devices than the heat exchange units. The purpose is.

According to one preferred embodiment of the invention.
A cooling device that is connected to a refrigeration cycle that includes a compressor to cool multiple batteries for a vehicle.
A refrigerant introduction unit that introduces a refrigerant that exchanges heat with the battery,
An expansion device that expands the refrigerant introduced from the refrigerant introduction unit, and
A refrigerant distribution device having an expanded refrigerant inflow section into which the refrigerant expanded by the expansion device flows in and a plurality of distributed refrigerant outflow sections, and the refrigerant flowing in from the expanded refrigerant inflow section is distributed to the plurality of distributed refrigerant outflow sections. ,
A plurality of heat exchange units connected to each of the plurality of distributed refrigerant outflow portions, and a plurality of heat exchange units in which the refrigerant flowing through each heat exchange unit exchanges heat with the corresponding battery.
It has a plurality of merging refrigerant inflow portions connected to the plurality of heat exchange units to merge the refrigerants flowing through the plurality of heat exchange units, and the merging refrigerant flows out to the refrigeration cycle. Refrigerant merging device with a part and
With
Provided is a cooling device characterized in that the valve opening degree of the expansion device is controlled based on the state of the refrigerant on the downstream side of the refrigerant merging device and the upstream side of the compressor in the flow direction of the refrigerant.

According to the present invention, a cooling device for a battery having a plurality of heat exchange units, which can prevent the compressor from sucking liquid refrigerant by using a smaller number of detection devices than the heat exchange units. Can be provided.

It is a perspective view of the cooling apparatus according to one Embodiment of this invention. It is a figure which shows schematic structure of the cooling apparatus shown in FIG. It is a schematic side view of the heat exchange unit shown in FIG. It is a circuit diagram which shows an example of the refrigeration cycle which connected the cooling device shown in FIG. It is a circuit diagram which shows an example of the refrigeration cycle which connected the cooling device by the modification. It is a circuit diagram which shows an example of the refrigeration cycle which connected the cooling device by another modification.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view of a cooling device according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing the configuration of the cooling device shown in FIG. FIG. 3 is a schematic side view of the heat exchange unit shown in FIG. FIG. 4 is a circuit diagram showing an example of a refrigeration cycle to which the cooling device shown in FIG. 1 is connected.

The arrows shown in FIGS. 1 to 4 and 5 and 6 which will be referred to later indicate the flow and state of the refrigerant. The terms "upstream side" and "downstream side" in the present specification shall mean "upstream side" and "downstream side" with respect to the flow direction of the refrigerant.

The cooling device 10 is a device that cools a plurality of batteries B for a vehicle. The cooling device 10 is connected to the refrigeration cycle 1 as shown in FIG. Then, the heat medium used in the refrigeration cycle 1 flows inside the cooling device 10 as a refrigerant. By exchanging heat with the battery B, the cooling device 10 can cool the battery B.

The refrigerant is a fluid that cools the object to be cooled by removing heat corresponding to the heat of vaporization at the time of phase change from the liquid phase to the gas phase from the object to be cooled. Specifically, as the refrigerant, a refrigerant for a vehicle air conditioner, for example, HFC-134a widely used conventionally, HFO-1234yf corresponding to recent EU regulations, and the like can be used.

The cooling device 10 includes a refrigerant introduction unit 12, an expansion device 14, an expansion refrigerant lead-out unit 15, a refrigerant distribution device 16, a plurality of upstream refrigerant passages 20a and 20b, and a plurality of heat exchange units 30a and 30b. The refrigerant introduced from the refrigerating cycle 1 includes a plurality of downstream refrigerant flow paths 22a and 22b, a refrigerant merging device 24, and a refrigerant lead-out unit 27, and flows in this order in the cooling device 10. Further, as shown in FIGS. 1 and 2, the cooling device 10 preferably includes a connector 28 including a refrigerant introduction unit 12 and a refrigerant outlet unit 27. The connection work to the refrigeration cycle 1 can be facilitated.

The refrigerant introduction unit 12 is a flow path of the refrigerant connected to the refrigeration cycle 1. In FIG. 2, the refrigerant introduction section 12 is shown as a pipeline, but the present invention is not limited to this. For example, when the connector 28 and the expansion device 14 are directly connected without passing through a pipeline, the through hole formed in the connector 28 becomes the refrigerant introduction portion 12. The refrigerant flowing through the refrigeration cycle 1 is introduced into the cooling device 10 through the refrigerant introduction unit 12.

The expansion device 14 is, for example, an electronic expansion valve. The expansion device 14 expands the refrigerant introduced from the refrigerant introduction unit 12. The valve opening degree of the expansion device 14 can be adjusted, and the refrigerant having a flow rate corresponding to the valve opening degree flows out from the expansion device 14 to the refrigerant distribution device 16. The valve opening degree of the expansion device 14 is controlled by an ECU (Electronic Control Unit) 60 as shown in FIG.

The expansion refrigerant lead-out unit 15 is a flow path of the refrigerant arranged between the expansion device 14 and the refrigerant distribution device 16. The refrigerant flowing out of the expansion device 14 flows into the refrigerant distribution device 16 through the expansion refrigerant lead-out unit 15. In FIG. 2, the expanded refrigerant lead-out unit 15 is shown as a pipeline. When the expansion device 14 and the refrigerant distribution device 16 are directly connected without passing through a pipeline, the expansion refrigerant lead-out unit 15 may not be provided. In this case, the expansion refrigerant inflow portion 17 of the refrigerant distribution device 16 described later is directly connected to the expansion device 14.

The refrigerant distribution device 16 distributes the refrigerant expanded by the expansion device 14 to the plurality of upstream refrigerant flow paths 20a and 20b. Specifically, as shown in FIG. 2, the refrigerant distribution device 16 has an expansion refrigerant inflow section 17 into which the refrigerant expanded by the expansion device 14 flows in, and a plurality of distribution refrigerant outflow sections 18a and 18b, and expands. The refrigerant flowing in from the refrigerant inflow section 17 is distributed to the plurality of distribution refrigerant outflow sections 18a and 18b. The expanded refrigerant inflow unit 17 is connected to the expanded refrigerant outlet unit 15. Further, a plurality of upstream refrigerant flow paths 20a and 20b are connected to the plurality of distributed refrigerant outflow portions 18a and 18b.

The plurality of upstream refrigerant flow paths 20a and 20b are arranged between the refrigerant distribution device 16 and the plurality of heat exchange units 30a and 30b. The upstream ends of the plurality of upstream refrigerant flow paths 20a and 20b are connected to each of the plurality of distribution refrigerant outflow portions 18a and 18b of the refrigerant distribution device 16. Further, the downstream ends of the plurality of upstream refrigerant flow paths 20a and 20b are connected to each of the plurality of heat exchange units 30a and 30b. In the illustrated example, the upstream side refrigerant flow paths 20a and 20b are the first upstream side refrigerant flow paths 20a and 20b1 in which the upstream side ends are connected to the distributed refrigerant outflow parts 18a and 18b, respectively, and the downstream side side. It has second upstream side refrigerant flow paths 20a2 and 20b2 whose ends are connected to the heat exchange units 30a and 30b. Then, by connecting the downstream end portion of the first upstream side refrigerant flow path 20a1, 20b1 and the upstream side end portion of the second upstream side refrigerant flow path 20a2, 20b2, the upstream side refrigerant flow path 20a, 20b Is formed.

The plurality of heat exchange units 30a and 30b are connected to the corresponding upstream refrigerant flow paths 20a and 20b, respectively. Each heat exchange unit 30a, 30b includes one or more (one in the illustrated example) heat exchanger 31. As is well shown in FIG. 3, the heat exchanger 31 includes a first header (manifold) 32 and a second header (manifold) 33, both of which are configured as hollow tubular members, and a first header 32 and a second header. It has a plurality of (three in the illustrated example) tubes 34 arranged between the 33 and the tube 34.

The plurality of tubes 34 are arranged in the vertical direction, and each tube extends in the horizontal direction. Preferably, the first tube 34A is above the second tube 34B. The first header 32 and the second header 33 are arranged parallel to each other and in the vertical direction.

The first header 32 includes a refrigerant inflow portion (inlet port) 35 through which the downstream ends of the corresponding upstream refrigerant flow paths 20a and 20b are connected to exchange heat with the battery B, and the battery B and heat. It has a refrigerant outflow portion (outlet port) 36 through which the exchanged refrigerant flows out. The inside of the first header 32 is divided into an upper space on the refrigerant inflow portion 35 side and a lower space on the refrigerant outflow portion 36 side by a partition wall 37.

The plurality of tubes 34 include one or more first tubes 34A for flowing the refrigerant from the first header 32 to the second header 33, and a plurality of tubes 34 for flowing the refrigerant from the second header 33 to the first header 32. Classified as one or more second tubes 34B. In the examples shown in FIGS. 1 to 3, each heat exchanger 31 is provided with two first tubes 34A and one second tube 34B. The end of the first tube 34A on the first header 32 side is connected to the upper space on the refrigerant inflow portion 35 side. Further, the end portion of the second tube 34B on the first header 32 side is connected to the lower space on the refrigerant outflow portion 36 side. In such a heat exchanger 31, the refrigerant that has flowed into the space above the first header 32 flows in parallel in the two first tubes 34A, flows into the second header 33, and then flows through the second tube 34B. It flows and flows into the space below the first header 32.

The tube 34, the first header 32 and the second header 33 of the heat exchanger 31 can be formed from a highly thermally conductive material such as an aluminum alloy. Further, it is preferable that the plurality of tubes 34 have the same shape and size as each other due to manufacturing technology reasons (extrusion mold cost, brazing uniformity, etc.). The side surface of each tube 34 is in direct or indirect (preferably direct) thermal contact with the surface of the corresponding battery B (battery module).

In FIG. 3, the area of the portion where each tube 34 (34A, 34B) and the battery B overlap (the portion of the battery B hidden behind the tube 34) is the heat exchange surface between the one tube 34 and the battery B. Area (hereinafter also referred to as "heat exchange area"). In FIG. 3, since the tubes 34 have the same shape and dimensions, the heat exchange areas of the tubes take equal values A (“A” is an appropriate positive number). The heat exchange area of the entire heat exchanger 31 is 3A.

The heat exchange units 30a and 30b act as an evaporator when the refrigerant passes through the inside thereof. That is, when the refrigerant leaving the expansion device 14 flows into the upper space of the first header 32, it is in a liquid state or in a gas-liquid mixed state containing a sufficient amount of liquid, but the heat exchange unit 30a, When passing through 30b, it is vaporized by exchanging heat with the battery B, and the heat of vaporization removes heat from the battery B.

As shown in FIG. 2, the plurality of downstream refrigerant flow paths 22a and 22b are arranged between the plurality of heat exchange units 30a and 30b and the refrigerant merging device 24. The upstream ends of the plurality of downstream refrigerant flow paths 22a and 22b are connected to each of the plurality of heat exchange units 30a and 30b (specifically, to the refrigerant outflow portion 36 of the first header 32). Further, the downstream ends of the plurality of downstream refrigerant flow paths 22a and 22b are connected to the refrigerant merging device 24. In the illustrated example, each of the downstream side refrigerant flow paths 22a and 22b has the first downstream side refrigerant flow paths 22a1 and 22b1 whose upstream end portions are connected to the heat exchange units 30a and 30b, and the downstream side end portions. Has a second downstream side refrigerant flow path 22a2, 22b2 connected to the refrigerant merging device 24. Then, by connecting the downstream end of the first downstream refrigerant flow path 22a1,22b1 and the upstream end of the second downstream refrigerant flow path 22a2,22b2, the downstream refrigerant flow paths 22a, 22b Is formed.

The refrigerant merging device 24 merges the refrigerants that have flowed through the plurality of downstream refrigerant flow paths 22a and 22b, and discharges the merged refrigerant into the refrigeration cycle 1. Specifically, as shown in FIG. 2, the refrigerant merging device 24 includes a plurality of merging refrigerant inflow portions 25a and 25b, each of which is connected to the downstream end portions of the plurality of downstream side refrigerant flow paths 22a and 22b. It has a merging refrigerant outflow portion 26 that allows the merging refrigerant to flow out.

The refrigerant lead-out unit 27 is a flow path of the refrigerant connected to the refrigeration cycle 1. In FIG. 2, one end of the refrigerant lead-out portion 27 is shown as a pipeline connected to the merging refrigerant outflow portion 26 of the refrigerant merging device 24, but the present invention is not limited to this. For example, when the connector 28 and the expansion device 14 are directly connected without passing through a pipeline, the through hole formed in the connector 28 serves as the refrigerant lead-out portion 27. The refrigerants that have flowed through the plurality of heat exchange units 30a and 30b are merged by the refrigerant merging device 24 and then led out to the refrigeration cycle 1 through the refrigerant leading-out unit 27.

By the way, when the cooling device has a plurality of heat exchange units, it is desirable to suppress the degree of superheat of the refrigerant flowing out from each heat exchange unit to a certain value or less in order to suppress the variation in the cooling capacity among the plurality of heat exchange units. Is done. However, if the sensors are provided on the downstream side of each heat exchange unit, the manufacturing cost of the cooling device increases. If the number of sensors is simply reduced from that of the heat exchange unit, it is not possible to detect the degree of superheat in the heat exchange unit in which the corresponding sensor does not exist. If the flow rate of the refrigerant flowing through the heat exchange unit is suppressed so that the degree of overheating tends to increase in the heat exchange unit in which the corresponding sensor exists, the corresponding sensor exists by controlling the degree of overheating of the heat exchange unit. It is also possible to suppress an increase in the degree of overheating of the heat exchange unit. However, in this case, it is not possible to detect the wetness of the heat exchange unit in which the corresponding sensor does not exist. Therefore, even after the refrigerant having a high degree of wetness flows out and merges with the refrigerant flowing out from the heat exchange unit in which the corresponding sensor exists, the state of having a high degree of wetness may be maintained. That is, there is a risk that the compressor will inhale the liquid refrigerant.

Based on these points, the cooling device of the present embodiment is devised to prevent the compressor from sucking the liquid refrigerant even if a smaller number of detection devices than a plurality of heat exchange units are used. Has been made.

Specifically, in the present embodiment, the flow rate of the refrigerant flowing through the cooling device 10 is adjusted based on the state of the refrigerant sucked into the compressor C. More specifically, the valve opening degree of the expansion device 14 is controlled based on the state of the refrigerant on the downstream side of the refrigerant merging device 24 and the upstream side of the compressor C. As a result, it is possible to prevent the liquid refrigerant from being sucked into the compressor C and causing a problem in the compressor C.

In the example shown in FIG. 4, the refrigeration cycle 1 includes a downstream detection device 40 for detecting the wetness and superheat degree of the refrigerant flowing out from the refrigerant lead-out unit 27. Then, the ECU 60 controls the valve opening degree of the expansion device 14 so that the wetness of the refrigerant detected by the downstream detection device 40 is 0% and the superheat degree is less than a predetermined value. This makes it possible to prevent the liquid refrigerant from being sucked into the compressor C. Further, since the flow rate of the refrigerant flowing through the cooling device 10 is adjusted by a number of detection devices 40 smaller than the plurality of heat exchange units 30a and 30b included in the cooling device 10, the outflow from the heat exchange units 30a and 30b. Compared with the case where a detection device for detecting the state of the refrigerant (wetness and overheating) is provided in each of the downstream side refrigerant flow paths 22a and 22b in order to detect the state of the refrigerant (wetness and overheating). , The flow rate of the refrigerant flowing through the cooling device 10 can be adjusted at low cost.

Even if the flow rate of the refrigerant is adjusted in this way, the plurality of batteries B having the same specifications are used, and the areas of the heat exchange surfaces of the plurality of heat exchange units 30a and 30b with the battery B are equal to each other. For example, since the difference in the amount of heat exchange between the plurality of heat exchange units 30a and 30b can be eliminated, the variation in the cooling capacity of the plurality of heat exchange units 30a and 30b can be suppressed. As a result, it is possible to sufficiently reduce the risk that a part of the battery B will be excessively heated and deteriorated.

In the example shown in FIG. 4, the downstream side detection device 40 measures the temperature of the refrigerant flowing out from the refrigerant lead-out unit 27 of the cooling device 10. Specifically, the downstream side detection device 40 is a pressure temperature sensor that detects the temperature and pressure of the refrigerant flowing through the conduit (second conduit 6b described later) that guides the refrigerant flowing out from the refrigerant lead-out unit 27 to the compressor C. Is. By inputting information on the temperature and pressure detected by the downstream detection device 40 into the ECU 60, the ECU 60 determines the wetness and superheat degree of the refrigerant flowing out from the cooling device 10 and opens the valve of the expansion device 14. Can be adjusted.

Hereinafter, the operation of the cooling device 10 connected to the refrigeration cycle 1 will be described with reference to FIG. FIG. 4 shows an example in which the above-mentioned cooling device 10 is connected to the refrigeration cycle 1 of the vehicle air conditioner. The refrigeration cycle 1 includes an outdoor heat exchanger 3 provided in the refrigerant circulation path 2, an indoor heat exchanger 4, a compressor C, and an expansion valve 5. The outdoor heat exchanger 3 is installed, for example, behind the front grill of the vehicle. The indoor heat exchanger 4 is installed, for example, in the air passage of the air conditioner. The vehicle air conditioner air-conditions the interior of the vehicle by a method well known to those skilled in the art.

The refrigerant introduction section 12 of the cooling device 10 is connected to the first pipeline 6a connected to the branch point 2a set on the refrigerant circulation path 2. Further, the refrigerant lead-out unit 27 of the cooling device 10 is connected to the second pipeline 6b connected to the confluence point 2b set on the refrigerant circulation path 2. The expansion valve 5 preferably has a function as a shutoff valve.

The quick charge of the battery B is usually performed while the vehicle is stopped (parked). When it is not necessary to flow the refrigerant to the indoor heat exchanger 4 during the rapid charging of the battery B, the expansion valve 5 acts as a shutoff valve. Therefore, at this time, a refrigeration cycle for cooling the battery B is configured from the outdoor heat exchanger 3, the cooling device 10, and the compressor C. When it is necessary to flow the refrigerant to the indoor heat exchanger 4 during the rapid charging of the battery B, the expansion valve 5 and the expansion device 14 of the cooling device 10 act as expansion valves. Therefore, at this time, the refrigerant discharged from the compressor C passes through the outdoor heat exchanger 3 and branches at the branch point 2a, one refrigerant flows to the expansion valve 5 and the indoor heat exchanger 4, and the other refrigerant flows. Flows to the cooling device 10. After that, the flows of the two refrigerants merge at the confluence point 2b and are sucked into the compressor C. Therefore, at this time as well, a refrigeration cycle for cooling the battery B is configured.

The plurality of heat exchange units 30a and 30b of the cooling device 10 act as evaporators in the refrigerating cycle 1 for cooling the battery B. In the refrigeration cycle 1 shown in FIG. 4, the low-temperature low-pressure gaseous refrigerant flows into (sucks) into the compressor C and is compressed by the compressor C, so that the high-temperature and high-pressure gaseous state is obtained. Next, the refrigerant is cooled by exchanging heat with the ambient air (outside air) in the outdoor heat exchanger 3 that acts as a condenser, and becomes a medium-temperature and high-pressure liquid. The refrigerant then expands as it passes through the expansion device 14 of the cooling device 10 to become a low temperature, low pressure liquid or gas-liquid mixture fluid. Next, the refrigerant is distributed to the plurality of upstream refrigerant flow paths 20a and 20b by the refrigerant distribution device 16. The refrigerant then flows into the plurality of heat exchange units 30a, 30b that act as evaporators. When the refrigerant passes through the heat exchange units 30a and 30b, it vaporizes by exchanging heat with the battery B, and takes heat from the battery B by the heat of vaporization to become a low-temperature low-pressure gas. Next, the refrigerant flows into the plurality of downstream refrigerant flow paths 22a and 22b and merges at the refrigerant merging device 24. Next, the refrigerant flows from the refrigerant lead-out unit 27 into the second pipeline 6b, is returned to the compressor C again (inhaled), and is compressed.

The temperature and pressure of the refrigerant flowing out of the cooling device 10 are constantly detected by the downstream detection device 40, and information on the detected temperature and pressure is sent to the ECU 60. The EUC 60 determines the wetness and superheat degree of the refrigerant flowing out from the cooling device 10 based on the information acquired from the downstream detection device 40, and adjusts the valve opening degree of the expansion device 14 based on the determination result. Specifically, when the ECU 60 determines that the wetness of the refrigerant flowing out of the cooling device 10 is greater than 0%, the ECU 60 controls the expansion device 14 so as to further reduce the valve opening degree thereof. As a result, the flow rate of the refrigerant to the plurality of heat exchange units 30a and 30b is reduced, and the total amount of the liquid refrigerant contained in the refrigerant flowing out from the plurality of heat exchange units 30a and 30b is reduced (that is, the liquid flowing out from the cooling device 10). Reduce the amount of refrigerant) and avoid malfunction of compressor C. Further, the ECU 60 controls the expansion device 14 to expand the valve opening degree when it is determined that the superheat degree is equal to or higher than a predetermined value even if the wetness of the refrigerant flowing out from the cooling device 10 is 0%. .. As a result, the flow rate of the refrigerant to the plurality of heat exchange units 30a and 30b is increased, and the cooling capacity of the battery B by the heat exchange units 30a and 30b is improved. When it is determined that the wetness of the refrigerant flowing out of the cooling device 10 is 0% and the superheat degree is less than a predetermined value, the expansion device 14 is controlled so that the valve opening degree thereof is maintained.

Although the cooling device 10 according to the present embodiment has been described above with reference to FIGS. 1 to 4, the overall configuration of the cooling device 10 is not limited to that described above. Various changes can be made to the overall configuration of the cooling device 10 and the refrigeration cycle 1 shown in FIGS. 1 to 4.

For example, in the examples shown in FIGS. 1 to 4, the downstream detection device 40 is provided in the second pipeline 6b of the refrigeration cycle 1, and is not included in the cooling device 10, but is not limited to this. The downstream side detection device 40 may be provided on the downstream side of the refrigerant merging device 24 and on the upstream side of the compressor C. For example, as shown in FIG. 5, the downstream side detection device 40 may be provided in the refrigerant lead-out unit 27. In this case, the downstream detection device 40 is included in the cooling device 100.

Further, in the examples shown in FIGS. 1 to 5, the downstream side detection device 40 is a pressure temperature sensor, but the present invention is not limited to this. In the cooling device 200 shown in FIG. 6, the downstream side detection device 240 is a temperature sensor that detects the temperature of the refrigerant flowing on the downstream side of the refrigerant merging device 24 and on the upstream side of the compressor C. In the illustrated example, the downstream side detection device 240 is provided in the refrigerant lead-out unit 27, and detects the surface temperature of the refrigerant lead-out unit 27. The refrigerant lead-out unit 27 is formed of a highly thermally conductive material, for example, an aluminum alloy, so that the temperature of the refrigerant flowing inside the refrigerant lead-out unit 27 can be detected by detecting the surface temperature of the refrigerant lead-out unit 27. ing. By inputting information on the temperature detected by the downstream side detection device 240 into the ECU 60, the ECU 60 determines the wetness and superheat degree of the refrigerant flowing out from the refrigerant merging device 24, and determines the valve opening degree of the expansion device 14. Can be adjusted. In the illustrated example, the ECU 60 compares the temperature of the refrigerant after being expanded by the expansion device 14 and before flowing into the heat exchange units 30a and 30b with the temperature of the refrigerant flowing out of the refrigerant merging device 24. The wetness and superheat degree of the refrigerant flowing out from the refrigerant merging device 24 are determined. Therefore, in the example shown in FIG. 6, the cooling device 200 further includes an upstream detection device 250 that detects the temperature of the refrigerant after being expanded by the expansion device 14 and before flowing into the heat exchange units 30a and 30b. .. Specifically, the upstream side detection device 250 is a temperature sensor that detects the surface temperature of the expansion refrigerant lead-out unit 15. The expansion refrigerant lead-out unit 15 is made of a highly thermally conductive material, for example, an aluminum alloy, so that the temperature of the refrigerant flowing inside the expansion refrigerant lead-out unit 15 can be detected by detecting the surface temperature of the expansion refrigerant lead-out unit 15. Is formed from. By inputting information on the temperature detected by the upstream detection device 250 into the ECU 60, the ECU 60 combines the temperature of the refrigerant after expansion by the expansion device 14 and before flowing into the heat exchange units 30a and 30b, and the refrigerant merging device. The temperature of the refrigerant flowing out of 24 can be compared.

Even when the downstream side detection device 240 is a temperature sensor, the downstream side detection device 240 may be provided on the downstream side of the refrigerant merging device 24 and on the upstream side of the compressor C. That is, the downstream detection device 240 may not be included in the cooling device 200, and may be provided, for example, in the second pipeline 6a of the refrigeration cycle 1. Further, when the expansion device 14 or the refrigerant distribution device 16 itself has a function of detecting the temperature or pressure of the refrigerant after expansion by the expansion device 14, the cooling device 200 may not include the upstream side detection device 250. ..

Further, in the illustrated example, the cooling device 10 includes, but is not limited to, two heat exchange units 30a and 30b. The cooling device 10 may include three or more heat exchange units.

Further, in the illustrated example, each of the heat exchange units 30a and 30b includes, but is not limited to, a single heat exchanger 31. Each heat exchange unit 30a, 30b may include a plurality of heat exchangers 31 in which fluids are communicated with each other.

As described above, according to the present embodiment and its modification, the cooling devices 10, 100, 200 connected to the refrigeration cycle 1 including the compressor C and cooling the plurality of batteries B for the vehicle are
A refrigerant introduction unit 12 that introduces a refrigerant that exchanges heat with the battery B,
An expansion device 14 that expands the refrigerant introduced from the refrigerant introduction unit 12 and
It has an expanded refrigerant inflow section 17 into which the refrigerant expanded by the expansion device 14 flows in and a plurality of distributed refrigerant outflow sections 18a and 18b, and the refrigerant flowing in from the expanded refrigerant inflow section 17 is supplied to the plurality of distributed refrigerant outflow sections 18a and 18b. Refrigerant distributor 16 to distribute and
A plurality of heat exchange units 30a and 30b connected to each of the plurality of distributed refrigerant outflow portions 18a and 18b, and the refrigerant flowing through the heat exchange units 30a and 30b exchanges heat with the corresponding battery B. With a plurality of heat exchange units 30a and 30b,
It has a plurality of merging refrigerant inflow portions 25a and 25b, each of which is connected to a plurality of heat exchange units 30a and 30b, and merging the refrigerants flowing through the plurality of heat exchange units 30a and 30b, and refrigerating the combined refrigerants. A refrigerant merging device 24 having a merging refrigerant outflow portion 26 that flows out to 1 is provided.
The valve opening degree of the expansion device 14 is controlled based on the state of the refrigerant on the downstream side of the refrigerant merging device 24 and the upstream side of the compressor C in the flow direction of the refrigerant.

By configuring the cooling devices 10, 100, 200 in this way, the compressor C can be used even if a smaller number of detection devices 40 than the plurality of heat exchange units 30a, 30b are used for the cooling devices 10, 100, 200. Eliminates the risk of inhaling liquid refrigerant. Further, since the flow rate of the refrigerant flowing through the cooling device 10 is adjusted by a number of detection devices 40 smaller than the plurality of heat exchange units 30a and 30b included in the cooling device 10, the outflow from the heat exchange units 30a and 30b. Compared with the case where a detection device for detecting the state of the refrigerant is provided in each of the downstream side refrigerant flow paths 22a and 22b in order to detect the state of the refrigerant, the cooling devices 10, 100 and 200 pass through the refrigerant. The flow rate can be adjusted at low cost.

According to the modified examples shown in FIGS. 5 and 6, the cooling devices 100 and 200 further include downstream detection devices 40 and 240 for detecting the temperature or temperature and pressure of the refrigerant flowing out from the refrigerant merging device 24. The valve opening degree of the expansion device 14 is controlled based on the temperature or temperature and pressure detected by the downstream detection devices 40 and 240.

Further, according to the modification shown in FIG. 6, the cooling device 200 includes an upstream detection device 250 that detects the temperature or pressure of the refrigerant after being expanded by the expansion device 14 and before flowing into the heat exchange units 30a and 30b. Further prepare. In this case, by comparing the temperature or pressure of the refrigerant detected by the upstream side detection device 250 with the temperature or temperature and pressure detected by the downstream side detection devices 40 and 240, the downstream side and compression of the refrigerant merging device 24 The state of the refrigerant (wetness and superheat) on the upstream side of the machine C can be detected.

Further, according to the present embodiment and the modifications shown in FIGS. 5 and 6, the areas of the heat exchange surfaces of the plurality of heat exchange units 30a and 30b with the battery B are equal to each other. In this case, if the plurality of batteries B having the same specifications are used, the difference in the amount of heat exchange between the plurality of heat exchange units 30a and 30b can be eliminated, so that the cooling capacity of the plurality of heat exchange units 30a and 30b can be eliminated. Variations are also suppressed. As a result, it is possible to effectively reduce the risk that a part of the battery B will be excessively heated and deteriorated.

Since the air conditioner according to the present invention can be industrially manufactured and can be the subject of commercial transactions, it can be industrially used with economic value.

1 Refrigerant cycle 10,100,200 Cooling device 14 Expansion device 16 Refrigerant distribution device 20a, 20b Upstream side refrigerant flow path 22a, 22b Downstream side refrigerant flow path 24 Refrigerant merging device 30a, 30b Heat exchange unit 40, 240 Downstream side detection device 250 Upstream detector 60 ECU
C compressor

Claims (4)

A cooling device (10, 100, 200) connected to a refrigeration cycle (1) including a compressor (C) to cool a plurality of batteries (B) for a vehicle.
A refrigerant introduction unit (12) that introduces a refrigerant that exchanges heat with the battery (B),
An expansion device (14) that expands the refrigerant introduced from the refrigerant introduction unit (12), and
It has an expanded refrigerant inflow section (17) into which the refrigerant expanded by the expansion device (14) flows in, and a plurality of distributed refrigerant outflow sections (18a, 18b), and the refrigerant flowing in from the expanded refrigerant inflow section (17) is supplied. A refrigerant distribution device (16) that distributes to the plurality of distribution refrigerant outflow portions (18a, 18b), and a refrigerant distribution device (16).
A plurality of heat exchange units (30a, 30b) connected to each of the plurality of distributed refrigerant outflow portions (18a, 18b), and the refrigerant flowing through each heat exchange unit is connected to the corresponding battery (B). A plurality of heat exchange units (30a, 30b) for heat exchange, and
It has a plurality of merging refrigerant inflow portions (25a, 25b), each of which is connected to the plurality of heat exchange units (30a, 30b), and merges the refrigerants that have flowed through the plurality of heat exchange units (30a, 30b). At the same time, a refrigerant merging device (24) having a merging refrigerant outflow portion (26) that causes the merging refrigerant to flow out to the refrigeration cycle (1).
With
The valve opening degree of the expansion device (14) is controlled based on the state of the refrigerant on the downstream side of the refrigerant merging device (24) and on the upstream side of the compressor (C) in the flow direction of the refrigerant. Cooling device (10, 100, 200). A downstream side detection device (40, 240) for detecting the temperature or temperature and pressure of the refrigerant flowing out from the refrigerant merging device (24) is further provided.
The cooling device according to claim 1, wherein the valve opening degree of the expansion device (14) is controlled based on the temperature or temperature and pressure detected by the downstream detection device (40, 240). 100,200). A claim, further comprising an upstream detection device (250) for detecting the temperature or pressure of the refrigerant after expansion by the expansion device (14) and before flowing into the heat exchange units (30a, 30b). 2. The cooling device (200) according to 2. The cooling device (10) according to any one of claims 1 to 3, wherein the areas of the heat exchange surfaces of the plurality of heat exchange units (30a, 30b) with the battery (B) are equal to each other. , 100, 200).

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