Cooling system and heat pump centrifuge unit

Abstract

This utility model discloses a cooling system and a heat pump centrifugal chiller unit, including a main circulation system formed by a main compressor, a main condenser, and a main evaporator; a first pipe connecting the motor cavity of the main compressor to the main condenser, and a second pipe connecting the motor cavity to the main evaporator; the first pipe is sequentially equipped with a subcooling device and a throttling device along the flow direction of refrigerant from the main condenser to the motor cavity; the subcooling device is used to extract liquid refrigerant from the main condenser and perform preliminary cooling; the throttling device is used to perform secondary cooling on the refrigerant flowing out of the subcooling device. In this way, the refrigerant flowing from the main condenser to the motor cavity is subjected to step cooling through the subcooling device and the throttling device, thereby effectively reducing the temperature of the refrigerant flowing to the motor cavity, significantly improving the cooling effect of the motor, extending the service life of the motor, avoiding motor overheating shutdown, and ensuring reliable system operation.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration technology, and in particular to a cooling system and a heat pump centrifugal chiller unit. Background Technology

[0002] In high-temperature heat pump centrifugal chillers, the operating temperature is quite high. The inlet and outlet water temperatures of the evaporator are approximately 80-90℃, while the inlet and outlet water temperatures of the condenser are approximately 120-130℃, or even higher. Because the unit is in a closed system, cooling components such as the motor within the unit presents a challenge.

[0003] The traditional solution is to take high-temperature, high-pressure liquid refrigerant from the condenser, cool it down through a throttling valve, and then enter the compressor's motor cavity. At this point, the liquid refrigerant absorbs heat and changes into gaseous refrigerant, thus carrying away the heat from the motor cavity and returning to the evaporator to cool the motor.

[0004] However, because the temperature of the high-temperature and high-pressure liquid refrigerant in the condenser is already very high (greater than 100°C), even after being throttled by the expansion valve, the refrigerant temperature is still high and cannot be significantly reduced. This makes it difficult to ensure that the motor temperature is reduced to a suitable range, which can easily lead to the motor overheating and shutdown, directly affecting the reliable operation of the system and / or the unit. Utility Model Content

[0005] This invention provides a cooling system and a heat pump centrifugal chiller unit to solve the problem in the prior art that the throttling valve cannot significantly reduce the temperature of the liquid refrigerant flowing from the condenser to the compressor motor cavity, which leads to the motor easily overheating and shutting down, directly affecting the reliable operation of the system / or unit.

[0006] The technical solution of this utility model is a cooling system, including a main circulation system formed by a main compressor, a main condenser, and a main evaporator; it also includes:

[0007] A first pipe connects the motor cavity of the main compressor to the main condenser, and a second pipe connects the motor cavity to the main evaporator;

[0008] The first pipe is provided with a subcooling device and a throttling device in sequence along the flow direction of the refrigerant from the main condenser to the motor cavity;

[0009] The subcooling device is used to extract the liquid refrigerant from the main condenser and perform initial cooling; the throttling device is used to perform secondary cooling on the refrigerant flowing out of the subcooling device.

[0010] Furthermore, the subcooling device includes:

[0011] The hollow housing has a cooling source inlet and a cooling source outlet; the cooling source inlet is configured to receive a cooling source from a heat dissipation system, and the cooling source flows out from the cooling source outlet after passing through the housing.

[0012] The tube bundle located within the housing has its two ends connected to the throttling device and the main condenser, respectively.

[0013] Furthermore, a pump structure is provided on the pipe between the tube bundle and the throttling device or between the tube bundle and the main condenser. The pump structure is used to draw liquid refrigerant from the main condenser and flow it to the motor cavity through the first pipe.

[0014] Furthermore, a flow guide baffle is also provided inside the housing, and the flow guide baffle is arranged intersecting with the tube bundle.

[0015] Furthermore, the heat dissipation system is a water supply system, which is used to transport liquid water into the housing to absorb the heat of the refrigerant in the tube bundle.

[0016] Furthermore, the heat dissipation system is a refrigerant purification system, which is used to deliver low-temperature refrigerant into the housing to absorb the heat of the refrigerant in the tube bundle;

[0017] The temperature of the low-temperature refrigerant is lower than the temperature of the refrigerant flowing into the tube bundle.

[0018] Furthermore, the refrigerant purification system includes:

[0019] An auxiliary compressor, an auxiliary condenser, an expansion valve, and an auxiliary evaporator are connected in series to form a closed loop; the refrigerant discharged from the auxiliary compressor flows sequentially through the auxiliary condenser, expansion valve, and auxiliary evaporator before returning to the auxiliary compressor;

[0020] A first three-way valve is provided on the pipeline between the expansion valve and the auxiliary evaporator. Its first port is connected to the refrigerant outlet of the expansion valve, the second port is connected to the refrigerant inlet of the auxiliary evaporator, and the third port is connected to the cooling source inlet.

[0021] The cooling source outlet is connected to the refrigerant inlet of the auxiliary compressor.

[0022] Furthermore, a second three-way valve is provided on the pipeline between the auxiliary compressor and the auxiliary evaporator, with its fourth port connected to the refrigerant outlet of the auxiliary evaporator, its fifth port connected to the refrigerant inlet of the auxiliary compressor, and its sixth port connected to the cooling source outlet.

[0023] Furthermore, a temperature detection device is provided inside the motor cavity, which is used to detect the temperature inside the motor cavity.

[0024] This utility model also proposes a heat pump centrifuge unit, which includes the cooling system described above.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] This invention uses a subcooling device and a throttling device to perform stepped cooling of the refrigerant flowing from the main condenser to the motor cavity, thereby effectively reducing the temperature of the refrigerant flowing from the main condenser to the motor cavity. When the stepped-cooled refrigerant flows into the motor cavity, it can absorb more heat, thereby effectively removing the heat generated by the motor and ensuring that the motor temperature is reduced to a suitable range. This significantly improves the cooling effect of the motor, extends the service life of the motor, avoids motor overheating shutdown, and ensures the reliable operation of the system. Attached Figure Description

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this invention are used to distinguish different objects and not to describe a particular order.

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the first cooling system proposed in this utility model;

[0030] Figure 2 This is a schematic diagram of the fluid flow in the first cooling system proposed in this utility model;

[0031] Figure 3 This is a schematic diagram of the second cooling system proposed in this utility model;

[0032] Figure 4This is a schematic diagram of the fluid flow in the second cooling system proposed in this utility model;

[0033] Figure 5 This is a schematic diagram of the third cooling system proposed in this utility model;

[0034] Figure 6 This is a schematic diagram of the fluid flow in the third cooling system proposed in this utility model.

[0035] Figure label:

[0036] 10. Main compressor; 101. Motor cavity; 102. First pipe; 103. Second pipe;

[0037] 20. Main condenser;

[0038] 30. Main evaporator;

[0039] 40. Subcooling device; 401. Shell; 402. Tube bundle; 403. Pump body structure; 404. Baffle plate;

[0040] 50. Throttling device;

[0041] 60. Heat dissipation system; 601. Auxiliary compressor; 602. Auxiliary condenser; 603. Expansion valve; 604. Auxiliary evaporator; 605. First three-way valve; 606. Second three-way valve;

[0042] 70. Temperature detection device. Detailed Implementation

[0043] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the present utility model, and does not imply that every embodiment of the present utility model must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0044] The principle and structure of this utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0045] In high-temperature heat pump centrifugal chillers, the operating temperature is relatively high. The inlet and outlet water temperatures of the evaporator are approximately 80-90℃, while the inlet and outlet water temperatures of the condenser are approximately 120-130℃, or even higher. Because the unit is in a closed system, cooling of components such as the motor within the unit presents a challenge.

[0046] The traditional solution is to take high-temperature, high-pressure liquid refrigerant from the condenser, cool it down through a throttling valve, and then enter the compressor's motor cavity. At this point, the liquid refrigerant absorbs heat and changes into gaseous refrigerant, thus carrying away the heat from the motor cavity and returning to the evaporator to cool the motor.

[0047] However, because the temperature of the high-temperature and high-pressure liquid refrigerant in the condenser is already very high (greater than 100°C), even after being throttled by the expansion valve, the refrigerant temperature is still high and cannot be significantly reduced. This makes it difficult to ensure that the motor temperature is reduced to a suitable range, which can easily lead to the motor overheating and shutdown, directly affecting the reliable operation of the system and / or the unit.

[0048] Therefore, to solve the above problems, in some embodiments, such as Figures 1-2 As shown, this utility model proposes a cooling system, including a main circulation system formed by a main compressor 10, a main condenser 20, and a main evaporator 30; and further including:

[0049] A first pipe 102 connects the motor cavity 101 of the main compressor 10 to the main condenser 20, and a second pipe 103 connects the motor cavity 101 to the main evaporator 30;

[0050] The first pipe 102 is provided with a subcooling device 40 and a throttling device 50 in sequence along the flow direction of the refrigerant from the main condenser 20 to the motor cavity 101;

[0051] The subcooling device 40 is used to extract the liquid refrigerant from the main condenser 20 and perform initial cooling; the throttling device 50 is used to perform secondary cooling on the refrigerant flowing out of the subcooling device 40.

[0052] It should be noted that the throttling device 50 proposed in this embodiment is preferably a throttling valve. Furthermore, the cooling system proposed in this embodiment also includes a control unit, which is electrically connected to both the subcooling device 40 and the throttling device 50.

[0053] Thus, when it is necessary to lower the temperature of the motor cavity 101 of the main compressor 10, the control unit activates the subcooling device 40. At this time, the subcooling device 40 will extract the high-temperature and high-pressure liquid refrigerant from the main condenser 20 and pass it through the first pipe 102. The subcooling device 40 will first perform preliminary cooling on the high-temperature and high-pressure liquid refrigerant. Then, the pre-cooled liquid refrigerant will flow into the throttling device 50 for secondary cooling. After secondary cooling, the refrigerant will flow into the motor cavity 101. The refrigerant flowing into the motor cavity 101 will absorb the heat in the motor cavity 101 to remove the heat generated by the motor of the main compressor 10. Then, the refrigerant in the motor cavity 101 that has absorbed the heat will flow to the main evaporator 30 through the second pipe 103 so that the refrigerant that cooled the motor of the main compressor 10 will flow back to the main circulation system.

[0054] Therefore, this invention uses a subcooling device 40 and a throttling device 50 to perform stepped cooling on the refrigerant flowing from the main condenser 20 to the motor cavity 101, thereby effectively reducing the temperature of the refrigerant flowing from the main condenser 20 to the motor cavity 101. When the stepped-cooled refrigerant flows into the motor cavity 101, it can absorb more heat, thereby effectively removing the heat generated by the motor of the main compressor 10, ensuring that the motor temperature is reduced to a suitable range, thus significantly improving the cooling effect of the motor, extending the service life of the motor, avoiding the motor from overheating and shutting down, and ensuring the reliable operation of the system.

[0055] It is understandable that the throttling device 50 can drastically reduce the pressure of the high-pressure liquid refrigerant, causing some of the liquid refrigerant to evaporate and absorb heat instantly (called flash evaporation), forming a mist-like fluid in which gas and liquid coexist. The flash evaporation process absorbs the heat of the refrigerant itself, making its temperature significantly lower than before throttling (the greater the subcooling, the lower the temperature after throttling).

[0056] In some embodiments, such as Figure 3 As shown, this embodiment presents the composition of a subcooling device 40:

[0057] The subcooling device 40 includes:

[0058] The hollow housing 401 has a cooling source inlet (not shown, same throughout) and a cooling source outlet (not shown, same throughout); the cooling source inlet is configured to receive a cooling source from the heat dissipation system 60, so that the cooling source flows out from the cooling source outlet after passing through the housing 401;

[0059] The tube bundle 402 is located inside the housing 401, and its two ends are respectively connected to the throttling device 50 and the main condenser 20.

[0060] It should be noted that the heat dissipation system 60 proposed in this embodiment is electrically connected to the control unit. The tube bundle 402 proposed in this embodiment is preferably a coil structure. Furthermore, the connection between the cooling source inlet and outlet and the corresponding pipes proposed in this embodiment is a sealed connection to prevent leakage of the cooling source. The cooling source proposed in this embodiment is a fluid.

[0061] Thus, when it is necessary to lower the temperature of the motor cavity 101 of the main compressor 10, the control unit activates the subcooling device 40. At this time, the subcooling device 40 extracts the high-temperature, high-pressure liquid refrigerant from the main condenser 20 and enters the tube bundle 402 along the first pipe 102. Simultaneously, the control unit activates the heat dissipation system 60, so that the cooling source of the heat dissipation system 60 enters the housing 401 through the cooling source inlet, so that the cooling source in the housing 401 exchanges heat with the high-temperature, high-pressure refrigerant in the tube bundle 402, thereby lowering the temperature of the refrigerant in the tube bundle 402 and completing the initial cooling. Then, the liquid refrigerant after initial cooling flows into the throttling device 50 for secondary cooling. After secondary cooling, the refrigerant flows into the motor cavity 101, where it absorbs the heat generated by the motor of the main compressor 10, effectively removing the heat generated by the motor and ensuring that the motor temperature is lowered to a suitable range. This significantly improves the motor cooling effect, extends the motor's service life, prevents the motor from overheating and shutting down, and ensures the reliable operation of the system.

[0062] It is understood that the subcooling device 40 proposed in this embodiment is equivalent to a shell-and-tube heat exchanger, a tube-and-pipe heat exchanger, or other similar shell-and-tube or tube-and-pipe heat exchangers, and is not limited here. Of course, the cooling source inlet and cooling source outlet of the shell 401 can be connected to the throttling device 50 and the main condenser 20 respectively, so that high-temperature and high-pressure refrigerant flows inside the shell 401; and the two ends of the tube bundle 402 are connected to the heat dissipation system 60, so that the cooling source of the heat dissipation system 60 flows through the tube bundle 402, and is not limited here.

[0063] In a further embodiment, to ensure that the high-temperature, high-pressure liquid refrigerant in the main condenser 20 flows more effectively through the first pipe 102, sequentially through the tube bundle 402 and the throttling device 50, into the motor cavity 101, as follows: Figure 3 As shown, a pump structure 403 is provided on the pipe between the tube bundle 402 and the throttling device 50 or between the tube bundle 402 and the main condenser 20. The pump structure 403 is used to draw liquid refrigerant from the main condenser 20 and flow it to the motor cavity 101 through the first pipe 102.

[0064] It should be noted that the pump body structure 403 proposed in this embodiment is preferably a refrigerant pump, a pneumatic device used for long-distance transportation or pressurization of liquid refrigerant. Furthermore, the pump body structure 403 is electrically connected to the control unit.

[0065] In this embodiment, the pump body structure 403 is installed on the pipeline between the tube bundle 402 and the throttling device 50 as an example.

[0066] In a further embodiment, to improve the heat exchange effect of the subcooling device 40, such as... Figure 3 As shown, a flow guide baffle 404 is also provided inside the housing 401, and the flow guide baffle 404 is arranged intersectingly with the tube bundle 402.

[0067] In this way, the flow guide baffle 404 can guide the cooling source flowing into the housing 401 so that the cooling source can contact the tube bundle 402 to a greater extent, thereby improving the heat exchange efficiency between the cooling source and the refrigerant, and thus better reducing the temperature of the refrigerant in the tube bundle 402.

[0068] In some embodiments, such as Figures 3-4 As shown, this embodiment proposes one type of heat dissipation system 60:

[0069] The heat dissipation system 60 is a water supply system, which is used to transport liquid water into the housing 401 to absorb the heat of the refrigerant in the tube bundle 402.

[0070] It is understood that the preferred cooling source in this embodiment is room temperature liquid water, that is, the temperature of room temperature liquid water is lower than the temperature of the refrigerant inside the tube bundle 402.

[0071] Therefore, when it is necessary to reduce the temperature of the motor cavity 101 of the main compressor 10, the control unit activates the subcooling device 40. At this time, the subcooling device 40 will extract the high-temperature and high-pressure liquid refrigerant from the main condenser 20 through the pump body structure 403 and enter the tube bundle 402 along the first pipe 102. At the same time, the control unit activates the water supply system so that the water supply system injects room temperature liquid water into the housing 401 through the cooling source inlet, so that the room temperature liquid water in the housing 401 can exchange heat with the high-temperature and high-pressure refrigerant in the tube bundle 402 to reduce the temperature of the refrigerant in the tube bundle 402, thereby completing the initial cooling. Then, the liquid water that has absorbed the heat of the refrigerant is discharged from the housing 401 through the cooling source outlet. In this way, the water supply system continuously provides room temperature liquid water to the housing 401 so that the liquid water can continuously exchange heat with the high-temperature and high-pressure refrigerant in the tube bundle 402.

[0072] The liquid water flowing out of the shell 401 flows out directly and does not flow back to the water supply system.

[0073] Of course, in other embodiments, the liquid water provided by the water supply system can be cooled first to form low-temperature liquid water. The temperature of the low-temperature liquid water is lower than the room temperature so that the low-temperature liquid water can absorb more heat from the refrigerant and improve the initial cooling effect of the subcooling device 40. At this time, the liquid water flowing out of the shell 401 can flow back to the water supply system to be cooled to form low-temperature water and then flow back into the shell 401 to form a cycle.

[0074] In some embodiments, such as Figures 5-6 As shown, this embodiment presents another composition of the subcooling device 40:

[0075] The heat dissipation system 60 is a refrigerant purification system, which is used to deliver low-temperature refrigerant into the housing 401 to absorb the heat of the refrigerant in the tube bundle 402.

[0076] The temperature of the low-temperature refrigerant is lower than the temperature of the refrigerant flowing into the tube bundle 402.

[0077] It should be noted that the temperature of the low-temperature refrigerant flowing to the casing 401 in the refrigerant purification system proposed in this embodiment is lower than the temperature of the high-temperature refrigerant flowing to the tube bundle 402 in the main condenser 20. Furthermore, the refrigeration principle of the refrigerant purification system proposed in this embodiment is equivalent to that of a household air conditioner.

[0078] Therefore, when it is necessary to reduce the temperature of the motor cavity 101 of the main compressor 10, the control unit activates the subcooling device 40. At this time, the subcooling device 40 will extract the high-temperature and high-pressure liquid refrigerant from the main condenser 20 through the pump body structure 403 and enter the tube bundle 402 along the first pipe 102. At the same time, the control unit activates the refrigerant purification system so that the refrigerant purification system injects low-temperature refrigerant into the housing 401 through the cooling source inlet, so that the low-temperature refrigerant in the housing 401 can exchange heat with the high-temperature and high-pressure refrigerant in the tube bundle 402 to reduce the temperature of the refrigerant in the tube bundle 402, thereby completing the initial cooling. Then, the low-temperature refrigerant that has absorbed the heat of the refrigerant flows back to the refrigerant purification system through the cooling source outlet. In this way, the refrigerant purification system continuously provides low-temperature refrigerant to the housing 401 so that the low-temperature refrigerant can continuously exchange heat with the high-temperature and high-pressure refrigerant in the tube bundle 402.

[0079] In this way, the refrigerant purification system does not need to be installed outside the unit with the cooling system. Instead, it is integrated into the main condenser 20 or the main evaporator 30, thereby reducing the external piping layout of the unit and optimizing the unit's spatial layout.

[0080] In a further embodiment, such as Figure 6 As shown, the refrigerant purification system includes:

[0081] An auxiliary compressor 601, an auxiliary condenser 602, an expansion valve 603, and an auxiliary evaporator 604 are connected in series to form a closed loop. The refrigerant discharged from the auxiliary compressor 601 flows sequentially through the auxiliary condenser 602, the expansion valve 603, and the auxiliary evaporator 604 before returning to the auxiliary compressor 601.

[0082] A first three-way valve 605 is provided on the pipeline between the expansion valve 603 and the auxiliary evaporator 604. Its first port is connected to the refrigerant outlet of the expansion valve 603, the second port is connected to the refrigerant inlet of the auxiliary evaporator 604, and the third port is connected to the cooling source inlet.

[0083] The cooling source outlet is connected to the refrigerant inlet of the auxiliary compressor 601.

[0084] It is understandable that the refrigerant flowing out of the auxiliary condenser 602 will form a low-temperature, low-pressure gas-liquid two-phase refrigerant after passing through the expansion valve 603. Furthermore, the first three-way valve 605 proposed in this embodiment is electrically connected to the control unit.

[0085] Thus, when it is necessary to lower the temperature of the motor cavity 101 of the main compressor 10, the control unit will control the first three-way valve 605 to switch, that is, connect the first interface and the third interface, so that the low-temperature and low-pressure gas-liquid two-phase refrigerant flowing out of the expansion valve 603 will flow into the housing 401 through the first three-way valve 605, so that the low-temperature and low-pressure gas-liquid two-phase refrigerant in the housing 401 can exchange heat with the high-temperature and high-pressure refrigerant in the tube bundle 402, thereby lowering the temperature of the refrigerant in the tube bundle 402 and completing the initial cooling; at the same time, the low-temperature and low-pressure gas-liquid two-phase refrigerant in the housing 401 will absorb the heat of the refrigerant in the tube bundle 402 and flow back to the auxiliary compressor 601, thereby continuously supplying the housing 401 with low-temperature and low-pressure gas-liquid two-phase refrigerant to exchange heat with the high-temperature and high-pressure refrigerant in the tube bundle 402.

[0086] Of course, when it is not necessary to lower the temperature of the motor cavity 101 of the main compressor 10, the control unit will connect the first and second ports of the first three-way valve 605 so that the low-temperature and low-pressure gas-liquid two-phase refrigerant flowing out of the expansion valve 603 flows to the auxiliary evaporator 604.

[0087] In a further embodiment, such as Figure 6 As shown, a second three-way valve 606 is provided on the pipeline between the auxiliary compressor 601 and the auxiliary evaporator 604. Its fourth port is connected to the refrigerant outlet of the auxiliary evaporator 604, its fifth port is connected to the refrigerant inlet of the auxiliary compressor 601, and its sixth port is connected to the cooling source outlet.

[0088] It is understood that the second three-way valve 606 proposed in this embodiment is electrically connected to the control unit.

[0089] Thus, when it is necessary to lower the temperature of the motor cavity 101 of the main compressor 10, the control unit will control the first three-way valve 605 and the second three-way valve 606 to switch, that is, connect the first interface and the third interface, and connect the fifth interface and the sixth interface, so that the low-temperature and low-pressure gas-liquid two-phase refrigerant flowing out of the expansion valve 603 will flow into the housing 401 through the first three-way valve 605, so that the low-temperature and low-pressure gas-liquid two-phase refrigerant in the housing 401 can exchange heat with the high-temperature and high-pressure refrigerant in the tube bundle 402, thereby lowering the temperature of the refrigerant in the tube bundle 402 and completing the initial cooling; at the same time, the low-temperature and low-pressure gas-liquid two-phase refrigerant in the housing 401 will absorb the heat of the refrigerant in the tube bundle 402 and flow back to the auxiliary compressor 601 through the second three-way valve 606, thereby continuously supplying the housing 401 with low-temperature and low-pressure gas-liquid two-phase refrigerant to exchange heat with the high-temperature and high-pressure refrigerant in the tube bundle 402.

[0090] Of course, in other embodiments (not shown in the figure), a gas-liquid separator is also provided on the pipeline between the second three-way valve 606 and the refrigerant inlet of the auxiliary compressor 601. The gas-liquid separator separates residual droplets by gravity settling or baffles, allowing only gaseous refrigerant to enter the auxiliary compressor 601.

[0091] Of course, when it is not necessary to lower the temperature of the motor cavity 101 of the main compressor 10, the control unit will connect the first and second ports of the first three-way valve 605 and the fourth and fifth ports of the second three-way valve 606, so that the low-temperature and low-pressure gas-liquid two-phase refrigerant flowing out of the expansion valve 603 flows to the auxiliary evaporator 604, and the refrigerant flowing out of the auxiliary evaporator 604 flows to the auxiliary compressor 601.

[0092] In some embodiments, such as Figure 1 As shown, a temperature detection device 70 is provided inside the motor cavity 101, and the temperature detection device 70 is used to detect the temperature inside the motor cavity 101.

[0093] It should be noted that the temperature detection device 70 proposed in this embodiment is electrically connected to the control unit, and the temperature detection device 70 is preferably a temperature sensor.

[0094] In this way, the temperature detection device 70 monitors the temperature inside the motor cavity 101 in real time and uploads the monitored temperature data to the control unit so that the control unit can control the flow rate of the liquid refrigerant extracted by the pump body structure 403 according to the temperature inside the motor cavity 101.

[0095] If the temperature inside the motor cavity 101 received by the control unit is higher than or equal to the preset temperature value, it indicates that the motor temperature is too high. In this case, the control unit will increase the flow rate of liquid refrigerant pumped out by the pump body structure 403. If the temperature inside the motor cavity 101 received by the control unit is lower than the preset temperature value, it indicates that the motor temperature is too low. In this case, the control unit will reduce the flow rate of liquid refrigerant pumped out by the pump body structure 403. The two have a linear control relationship, ensuring that the motor operates under a suitable constant temperature condition. This allows the refrigerant purification system to better remove the heat generated by the motor, thereby significantly improving the motor's cooling effect, extending the motor's service life, preventing the motor from shutting down due to overheating, and ensuring the reliable operation of the system.

[0096] In some embodiments, the present invention also provides a heat pump centrifuge unit, the heat pump centrifuge unit including the cooling system described above.

[0097] It should be noted that the heat pump centrifugal chiller unit proposed in this embodiment is equipped with a main circulation system formed by a main compressor 10, a main condenser 20 and a main evaporator 30.

[0098] Thus, when it is necessary to lower the temperature of the motor cavity 101 of the main compressor 10, the control unit activates the subcooling device 40. At this time, the subcooling device 40 will extract the high-temperature and high-pressure liquid refrigerant from the main condenser 20 and pass it through the first pipe 102. The subcooling device 40 will first perform preliminary cooling on the high-temperature and high-pressure liquid refrigerant. Then, the pre-cooled liquid refrigerant will flow into the throttling device 50 for secondary cooling. After secondary cooling, the refrigerant will flow into the motor cavity 101. The refrigerant flowing into the motor cavity 101 will absorb the heat in the motor cavity 101 to remove the heat generated by the motor of the main compressor 10. Then, the refrigerant in the motor cavity 101 that has absorbed the heat will flow to the main evaporator 30 through the second pipe 103 so that the refrigerant that cooled the motor of the main compressor 10 will flow back to the main circulation system.

[0099] Therefore, this utility model uses a subcooling device 40 and a throttling device 50 to perform stepped cooling on the refrigerant flowing from the main condenser 20 to the motor cavity 101, thereby effectively reducing the temperature of the refrigerant flowing from the main condenser 20 to the motor cavity 101. When the stepped-cooled refrigerant flows into the motor cavity 101, it can absorb more heat, thereby effectively removing the heat generated by the motor of the main compressor 10, ensuring that the motor temperature is reduced to a suitable range, thus significantly improving the cooling effect of the motor, extending the service life of the motor, avoiding the motor from overheating and shutting down, and ensuring the reliable operation of the unit.

[0100] Obviously, the embodiments described above are only some embodiments of this utility model, not all embodiments. The accompanying drawings show preferred embodiments of this utility model, but do not limit the patent scope of this utility model. This utility model can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this utility model.

Claims

1. A cooling system comprising a main circulation system formed by a main compressor (10), a main condenser (20) and a main evaporator (30); characterized in that, Also includes: A first pipe (102) connecting the motor cavity (101) of the main compressor (10) to the main condenser (20), and a second pipe (103) connecting the motor cavity (101) to the main evaporator (30); The first pipe (102) is provided with a subcooling device (40) and a throttling device (50) in sequence along the flow direction of the refrigerant from the main condenser (20) to the motor cavity (101); The subcooling device (40) is used to extract the liquid refrigerant in the main condenser (20) and perform preliminary cooling; the throttling device (50) is used to perform secondary cooling on the refrigerant flowing out of the subcooling device (40).

2. The cooling system of claim 1, wherein, The subcooling device (40) includes: The hollow housing (401) has a cooling source inlet and a cooling source outlet; the cooling source inlet is configured to receive a cooling source from the heat dissipation system (60), and the cooling source flows out from the cooling source outlet after passing through the housing (401); The tube bundle (402) is located inside the housing (401), and the two ends of the tube bundle (402) are respectively connected to the throttling device (50) and the main condenser (20).

3. The cooling system of claim 2, wherein, A pump body structure (403) is provided on the pipe between the tube bundle (402) and the throttling device (50) or between the tube bundle (402) and the main condenser (20). The pump body structure (403) is used to draw liquid refrigerant from the main condenser (20) and flow it to the motor cavity (101) through the first pipe (102).

4. The cooling system of claim 2, wherein, The housing (401) is also provided with a flow guide baffle (404), which is arranged crosswise with the tube bundle (402).

5. The cooling system of claim 2, wherein, The heat dissipation system (60) is a water supply system, which is used to transport liquid water into the housing (401) to absorb the heat of the refrigerant in the tube bundle (402).

6. The cooling system according to claim 2, characterized in that, The heat dissipation system (60) is a refrigerant purification system, which is used to transport low-temperature refrigerant into the housing (401) to absorb the heat of the refrigerant in the tube bundle (402); The temperature of the low-temperature refrigerant is lower than the temperature of the refrigerant flowing into the tube bundle (402).

7. The cooling system of claim 6, wherein, The refrigerant purification system includes: An auxiliary compressor (601), an auxiliary condenser (602), an expansion valve (603), and an auxiliary evaporator (604) are connected in series to form a closed loop. The refrigerant discharged from the auxiliary compressor (601) flows sequentially through the auxiliary condenser (602), the expansion valve (603), and the auxiliary evaporator (604) before returning to the auxiliary compressor (601). A first three-way valve (605) is provided on the pipeline between the expansion valve (603) and the auxiliary evaporator (604). Its first port is connected to the refrigerant outlet of the expansion valve (603), the second port is connected to the refrigerant inlet of the auxiliary evaporator (604), and the third port is connected to the cooling source inlet. The cooling source outlet is connected to the refrigerant inlet of the auxiliary compressor (601).

8. The cooling system of claim 7, wherein, A second three-way valve (606) is provided on the pipeline between the auxiliary compressor (601) and the auxiliary evaporator (604). Its fourth port is connected to the refrigerant outlet of the auxiliary evaporator (604), its fifth port is connected to the refrigerant inlet of the auxiliary compressor (601), and its sixth port is connected to the cooling source outlet.

9. The cooling system of claim 1, wherein, A temperature detection device (70) is provided inside the motor cavity (101), and the temperature detection device (70) is used to detect the temperature inside the motor cavity (101).

10. A heat pump centrifugal unit, characterized by The heat pump centrifugal chiller unit includes the cooling system described in any one of claims 1 to 9.

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