Cooling system, cooling method and heat pump unit

Abstract

The invention provides a cooling system, a cooling method and a heat pump unit. The cooling system comprises a cooler, an oil circulation loop, a first motor cooling loop, a second motor cooling loop and a refrigerant purifier. Supplementary water enters the cooler to cool a heat exchange coil in the cooler, the heat exchange coil is connected into an oil circulation loop and a first motor cooling loop, and the oil circulation loop is used for circularly conveying lubricating oil to cool a compressor bearing. The first motor cooling loop is used for conveying a liquid refrigerant to cool a compressor motor; the supplemented water in the cooler continuously enters the refrigerant purifier and is used for condensing the refrigerant and separating non-condensable gas in the refrigerant; and the second motor cooling loop is connected with the refrigerant purifier and is used for conveying a refrigerant to cool the compressor motor. By arranging the cooling system, the problem that the high-temperature heat pump is not suitable for a conventional cooling system due to too high condensation temperature is solved, the heat exchange effect of the unit is guaranteed, and the reliability of the unit is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refrigeration, in particular to a cooling system, a cooling method and a heat pump unit. BACKGROUND

[0002] The refrigerant R134a used in large water chillers currently has a too high GWP (Global Warming Potential), and water chillers have begun to gradually eliminate the R134a refrigerant. In recent years, various manufacturers are also looking for a substitute for R134a, and the R1233zd refrigerant has gradually become a substitute for R134a due to its advantages of consuming ODP (Ozone Depletion Potential) and GWP, as well as high refrigeration efficiency, and has become a future development trend of water chillers.

[0003] At the same time, in recent years, under the background of carbon reduction and efficiency increase, heat pumps have gradually been applied. The current market demands higher grade and larger capacity heat pumps, and also considers the replacement of refrigerants. High-temperature heat pump units using R1233zd refrigerants have emerged as the times require. However, unlike the working conditions of water-source heat pumps, the outlet water temperature of high-temperature heat pumps is 90-140℃, while the cooling of general motors and bearings needs to be cooled to 50℃. Using a conventional cooling scheme, high-temperature and high-pressure refrigerant liquid is taken from the condenser, throttled, and the pressure difference between the condenser and the evaporator is used to provide cooling liquid to the motor and bearing. The cooling liquid temperature does not meet the existing cooling demand, and the high-temperature heat pump cooling problem cannot be solved, resulting in that the high-temperature heat pump unit cannot run stably and continuously. SUMMARY

[0004] To solve the problems in the prior art, the present application provides a cooling system, a cooling method and a heat pump unit suitable for a high-temperature heat pump unit, which can meet the current cooling demand.

[0005] The present application adopts the following technical solutions.

[0006] The first aspect of the present application provides a cooling system, comprising: a cooler, an oil circulation loop, a first motor cooling loop, a second motor cooling loop and a refrigerant purifier;

[0007] Water of the water supply system enters the cooler to cool the heat exchange coil in the cooler. The heat exchange coil is connected to the oil circulation loop and the first motor cooling loop, respectively. The oil circulation loop is used to circulate and deliver lubricating oil to cool the compressor bearing. The first motor cooling loop is used to deliver liquid refrigerant to cool the compressor motor.

[0008] The make-up water in the cooler continues to enter the refrigerant purifier to condense the refrigerant and separate the non-condensable gas in the refrigerant; the second motor cooling circuit is connected to the refrigerant purifier to transport refrigerant to cool the compressor motor.

[0009] Preferably, the oil circulation loop includes: an oil tank, an oil pump and an oil filter; the lubricating oil in the oil tank is pressurized by the oil pump, enters the compressor through the oil filter, lubricates the bearings and takes away the heat of the bearings, then leaves the compressor, enters the cooler for cooling, and then re-enters the oil tank.

[0010] Preferably, the first motor cooling circuit includes: a condenser, a first electronic expansion valve, a first solenoid valve and an evaporator; high-temperature and high-pressure liquid refrigerant is taken from the bottom of the condenser, enters the cooler through the first solenoid valve, the refrigerant heat exchange temperature is reduced, and is throttled to a low-temperature and low-pressure liquid refrigerant through the first electronic expansion valve, enters the compressor to surround the cooling motor, and the refrigerant absorbs heat and evaporates into a gaseous state and enters the evaporator.

[0011] Preferably, the heat exchange coil in the cooler that is connected to the oil circulation circuit is arranged above the heat exchange coil that is connected to the first motor cooling circuit.

[0012] Preferably, the make-up water in the cooler flows into the heat exchange coil of the refrigerant purifier, and the refrigerant purifier is connected to the high-temperature and high-pressure gaseous refrigerant of the condenser. The gaseous refrigerant exchanges heat with the make-up water in the heat exchange coil, and the gaseous refrigerant condenses into liquid refrigerant and gathers at the bottom of the refrigerant purifier. The non-condensable gas gathers at the top of the refrigerant purifier and is discharged through the filter.

[0013] Preferably, a one-way valve is provided between the refrigerant purifier and the condenser to prevent backflow of the replenishing water.

[0014] Preferably, the non-condensable gas gathers at the top of the refrigerant purifier, passes through the filter and the second solenoid valve, is drawn out by the vacuum pump, and is discharged into the atmosphere.

[0015] Preferably, the liquid refrigerant is collected at the bottom of the refrigerant purifier and then divided into two paths, including: a second motor cooling circuit and an inverter cooling circuit;

[0016] In the second motor cooling circuit, the cold refrigerant is throttled by the second electronic expansion valve, enters the compressor and surrounds the compressor motor to cool it, and after heat exchange, it turns into gaseous refrigerant and returns to the evaporator;

[0017] In the inverter cooling circuit, the refrigerant is throttled by the third electronic expansion valve and then enters the inverter to cool the inverter module. After heat exchange, it turns into gaseous refrigerant and returns to the evaporator.

[0018] Preferably, the second motor cooling circuit and the first motor cooling circuit protect each other, and the two circuits can cool the motor at the same time. When one of the cooling circuits fails, the other circuit can ensure the cooling of the motor.

[0019] A second aspect of the present invention provides a cooling method for a cooling system, based on the cooling system of the first aspect, comprising cooling of an oil circulation circuit and cooling of a motor cooling circuit;

[0020] The cooling of the oil circulation loop, the heat exchange coil is connected to the oil circulation loop, the water of the water supply system cools the lubricating oil entering the heat exchange coil, and the cooled lubricating oil re-enters the oil circulation loop to complete the cooling;

[0021] The cooling of the motor cooling circuit includes: cooling of the first motor cooling circuit and the second motor cooling circuit. The heat exchange coil is connected to the first motor cooling circuit and the second motor cooling circuit respectively. The water from the water supply system cools the high-temperature and high-pressure liquid refrigerant entering the heat exchange coil. The cooled liquid refrigerant surrounds the compressor motor for cooling.

[0022] A third aspect of the present invention provides a heat pump unit, comprising a cooling system according to the first aspect.

[0023] Compared with the prior art, the beneficial effects of the present invention include at least:

[0024] The present invention solves the problem of high-temperature heat pumps being unsuitable for conventional cooling systems due to their excessively high condensing temperatures by providing a cooler and refrigerant purifier. By utilizing the cooler, water-based cooling refrigerant and lubricating oil as the primary circuit for motor cooling, this solves the motor and bearing cooling issues of the compressor.

[0025] At the same time, the refrigerant is condensed by adding water, and the refrigerant purifier is used to achieve the separation of negative pressure refrigerant and non-condensable gas to ensure the heat exchange effect of the unit. The separated refrigerant is throttled by the electronic expansion valve and then used to cool the inverter and motor. This cooling circuit for cooling the motor serves as the second circuit for motor cooling. While optimizing the cooling effect of the motor, it can also ensure the cooling of the motor when one of the cooling circuits fails, reduce the risk of motor overheating, and improve the reliability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the cooling system of the present invention;

[0027] Figure 2 It is a schematic diagram of the purification and cooling system of the present invention;

[0028] In the figure: 1-compressor; 101-bearing; 102-motor; 2-evaporator; 3-condenser; 4-oil tank; 5-oil pump; 6-oil filter; 7-cooler; 8-first electronic expansion valve; 9-first solenoid valve; 10-inverter; 11-refrigerant purifier; 12-filter; 13-second solenoid valve; 14-vacuum pump; 15-refrigerant leakage sensor; 16-check valve; 17-third solenoid valve; 18-second electronic expansion valve; 19-third electronic expansion valve. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0032] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the descriptions with reference to the terms "one scheme", "some schemes", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the scheme or example are included in at least one scheme or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same scheme or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more schemes or examples.

[0034] Embodiment 1 of the present invention provides a cooling system comprising: a cooler 7, an oil circulation circuit, a first motor cooling circuit, and a refrigerant purifier 11;

[0035] The normal temperature water of the water supply system enters the cooler 7 to cool the heat exchange coil in the cooler 7. The first layer of heat exchange coil is connected to the oil circulation circuit for circulating lubricating oil to cool the compressor bearing 101; the second layer of heat exchange coil is connected to the first motor cooling circuit for conveying liquid refrigerant to cool the compressor motor 102; the make-up water in the cooler flows into the refrigerant purifier 11 after the above-mentioned heat exchange, which is used to condense the refrigerant and separate the non-condensable gas in the refrigerant. The refrigerant is used to cool the compressor motor and the inverter 10.

[0036] In a preferred but non-limiting embodiment of the present invention, softened room temperature water in the water supply system is taken, connected to the top of the cooler 7, and sprayed evenly. Two layers of heat exchange coils are arranged in the cooler 7. The first layer of heat exchange coils is connected to the oil circulation loop. The lubricating oil flowing out of the compressor 1 absorbs the heat of the lubricating oil inside the coil through the water on the outer surface of the first layer of heat exchange coils. After the lubricating oil is cooled, it re-enters the compressor 1 to cool the bearing 101; the second layer of heat exchange coils is connected to the first motor cooling circuit, and the liquid refrigerant taken from the condenser 3 enters the compressor 1 after being cooled by water in the second layer of heat exchange coils, surrounds the cooling motor 102, and then enters the evaporator 2.

[0037] Further preferably, the make-up water in the cooler 7 absorbs heat after passing through the above-mentioned cooling lubricant and cooling refrigerant, completing the first step of preheating, and the make-up water enters the heat exchange coil of the refrigerant purifier 11. The middle part of the refrigerant purifier 11 is connected to the high-temperature and high-pressure gaseous refrigerant from the condenser 3. The gaseous refrigerant exchanges heat with the make-up water in the coil and absorbs heat. The gaseous refrigerant condenses into liquid and gathers at the bottom of the refrigerant purifier 11. The non-condensable gas gathers at the top of the refrigerant purifier 11 and is discharged through the filter 12.

[0038] In a preferred but non-limiting embodiment of the present invention, the liquid refrigerant is divided into two paths after leaving the refrigerant purifier 11. One path enters the compressor 1 after being throttled by the electronic expansion valve, and surrounds the cooling motor 102. The other path enters the inverter 10 after being cooled by the electronic expansion valve, cools the inverter module and dehumidifies the inside of the inverter cabinet.

[0039] Further preferably, the make-up water passes through the coil of the refrigerant purifier 11 to complete the second step of preheating and enters the condenser 3.

[0040] Embodiment 2 of the present invention provides a cooling system, which provides a cooling system suitable for a high-temperature heat pump unit based on embodiment 1.

[0041] like Figures 1-2 As shown, the cooling system includes: a cooler 7, an oil circulation circuit, a first motor cooling circuit and a refrigerant purifier 11;

[0042] The oil circulation loop includes: an oil tank 4, an oil pump 5 and an oil filter 6. The lubricating oil in the oil tank 4 is pressurized by the oil pump 5, passes through the oil filter 6, enters the compressor 1, lubricates the bearing 101 and removes the heat of the bearing. The lubricating oil leaves the compressor 1, enters the cooler 7 for cooling, and then re-enters the oil tank 4.

[0043] Figure 1 In the cooler 7, two layers of heat exchange coils are provided, and room temperature softened water from the water supply system is connected to the top. The softened water is evenly sprayed on the surface of the heat exchange coils, and the lubricating oil that takes away the heat of the bearing 101 enters the first layer of heat exchange coils of the cooler 7. The softened water and the high-temperature lubricating oil exchange heat through the heat exchange coils. The softened water is heated and the lubricating oil is cooled. The cooled lubricating oil leaves the cooler 7 coils and returns to the oil tank 4.

[0044] The first motor cooling circuit includes: a condenser 3, a first electronic expansion valve 8, a first solenoid valve 9 and an evaporator 2;

[0045] High-temperature, high-pressure liquid refrigerant is drawn from the bottom of condenser 3 and enters the second coil of cooler 7 through first solenoid valve 9. Softened water, having absorbed heat from the lubricating oil, passes through the heat exchange coil, absorbing heat from the liquid refrigerant, which is even hotter than the lubricating oil. This coolant's temperature drops, and upon leaving the cooler's heat exchange coil, it is throttled by first electronic expansion valve 8 to a low-temperature, low-pressure liquid refrigerant. It then enters compressor 1, flows around cooling motor 102, absorbs heat, and evaporates into a gaseous state. It then enters evaporator 2, returning the refrigerant to the refrigeration cycle. The first solenoid valve 9 controls the opening and closing of the first motor cooling circuit.

[0046] It is worth noting that the softened water is all the make-up water that needs to be added to the condenser 3. The softened water first absorbs the heat of the lubricating oil and then absorbs the heat of the refrigerant. The heat exchange coil adopts a copper tube. The lubricating oil runs in the first layer of heat exchange coil and the refrigerant runs in the second layer of heat exchange coil. The softened water is sprayed from the top and first falls on the surface of the first layer of heat exchange coil. It exchanges heat with the lubricating oil in the copper tube through the copper tube. The softened water continues to fall and then exchanges heat with the second layer of heat exchange coil. The order of heat exchange needs to be limited. Because the lubricating oil temperature is 50-60℃ and the refrigerant temperature is above 80℃, the lubricating oil temperature is lower than the refrigerant temperature, so the lubricating oil needs to be cooled first and then the refrigerant.

[0047] In order to achieve the heat exchange sequence, the first layer of heat exchange coil is set above the second layer of heat exchange coil. The sprayed softened water passes through the first layer of heat exchange coil and then passes through the second layer of heat exchange coil.

[0048] Further preferably, in order to enhance the heat exchange effect, an additional spraying device can be provided between the first layer of heat exchange coil and the second layer of heat exchange coil. After spraying the first layer of heat exchange coil, the softened water is collected and sprayed to the second layer of heat exchange coil through the middle sprayer.

[0049] The purpose of the two layers of heat exchange coils is to preheat the softened water. Softened water, or make-up water, is generally municipal water at around 25°C. The outlet water temperature of the high-temperature heat pump unit targeted by the present invention is above 120°C. Directly adding 25°C water will dissipate the heat generated by the high-temperature heat pump unit and cause a significant change in the pressure ratio of the high-temperature heat pump unit. Therefore, the make-up water needs to be preheated before it is added to the condenser 3. Therefore, the softened water is first heat-exchanged with lubricating oil at 50-60°C, and then with refrigerant above 80°C, narrowing the temperature difference with the outlet water of the high-temperature heat pump unit and reducing losses.

[0050] The softened water in the cooler is preheated after passing through the first and second heat exchange coils. The preheated softened water is collected at the bottom of the cooler 7 and enters the refrigerant purifier 11 .

[0051] Figure 2 In the process, the softened water preheated in the first step of the cooler 7 enters the heat exchange coil of the refrigerant purifier 11. The third solenoid valve 17 is opened, and the high-temperature and high-pressure gaseous refrigerant in the condenser 3 enters the refrigerant purifier 11. The gaseous refrigerant absorbs heat on the surface of the heat exchange coil and is condensed into liquid by the softened water. The gaseous refrigerant is collected at the bottom of the refrigerant purifier 11 and then divided into two paths, including: a second motor cooling circuit and an inverter cooling circuit;

[0052] In the second motor cooling circuit, the refrigerant is throttled by the second electronic expansion valve 18, enters the compressor 1 and surrounds the cooling motor 102, and after cooling, turns into gaseous refrigerant and returns to the evaporator 2;

[0053] It is worth noting that the second motor cooling circuit and the first motor cooling circuit protect each other, which can not only optimize the cooling effect of the motor, but also ensure the cooling of the motor when one of the cooling circuits fails.

[0054] In the inverter cooling circuit, the refrigerant is throttled by the third electronic expansion valve 19 and then enters the inverter 10 to cool the inverter module and dehumidify. After cooling, it turns into gaseous refrigerant and returns to the evaporator 2.

[0055] Figure 2 In the process, the non-condensable gases in the gaseous refrigerant are not condensed by the heat exchange coils. Instead, they gather at the top of the refrigerant purifier 11, pass through the filter 12 and the second solenoid valve 13, and are extracted by the vacuum pump 14 and discharged into the atmosphere. The softened water from the cooler 7 passes through the heat exchange coils of the cooling purifier 11, undergoing a second preheating step, and finally enters the condenser 3.

[0056] In a preferred but non-limiting embodiment of the present invention, a baffle may be provided at the inlet of the refrigerant purifier 11 to prevent the high-temperature and high-pressure gaseous refrigerant in the condenser 3 from impacting the heat exchange coil in the refrigerant purifier 11 .

[0057] Further preferably, a refrigerant leakage sensor 15 is provided before the vacuum pump 14 to avoid abnormal discharge of the refrigerant.

[0058] Further preferably, a one-way valve 16 is provided between the refrigerant purifier 11 and the condenser 3 to prevent the preheated softened water from flowing back.

[0059] Embodiment 3 of the present invention provides a cooling method, which is implemented based on the cooling system described in embodiment 1 or 2, and includes: cooling of an oil circulation circuit and cooling of a motor cooling circuit;

[0060] The cooling of the oil circulation loop, the heat exchange coil is connected to the oil circulation loop, the water of the water supply system cools the lubricating oil entering the heat exchange coil, and the cooled lubricating oil re-enters the oil circulation loop to complete the cooling;

[0061] The cooling of the motor cooling circuit includes: cooling of the first motor cooling circuit and the second motor cooling circuit. The heat exchange coil is connected to the first motor cooling circuit and the second motor cooling circuit respectively. The water from the water supply system cools the high-temperature and high-pressure liquid refrigerant entering the heat exchange coil. The cooled liquid refrigerant surrounds the compressor motor for cooling.

[0062] Embodiment 4 of the present invention provides a heat pump unit, comprising a cooling system as described in embodiment 1 or 2.

[0063] Compared with the prior art, the beneficial effects of the present invention include at least:

[0064] The present invention solves the problem of high-temperature heat pumps being unsuitable for conventional cooling systems due to their excessively high condensing temperatures by providing a cooler and refrigerant purifier. By utilizing the cooler, water-based cooling refrigerant and lubricating oil as the primary circuit for motor cooling, this solves the motor and bearing cooling issues of the compressor.

[0065] At the same time, the refrigerant is condensed by adding water, and the refrigerant purifier is used to achieve the separation of negative pressure refrigerant and non-condensable gas to ensure the heat exchange effect of the unit. The separated refrigerant is throttled by the electronic expansion valve and then used to cool the inverter and motor. This cooling circuit for cooling the motor serves as the second circuit for motor cooling. While optimizing the cooling effect of the motor, it can also ensure the cooling of the motor when one of the cooling circuits fails, reduce the risk of motor overheating, and improve the reliability of the unit.

[0066] The present disclosure may be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0067] A computer-readable storage medium can be a tangible device that can hold and store instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination thereof. As used herein, a computer-readable storage medium is not to be construed as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through an electrical wire.

[0068] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in the computer-readable storage medium in each computing / processing device.

[0069] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and conventional procedural programming languages ​​such as "C" language or similar programming languages. Computer-readable program instructions may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., utilizing an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions. The electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A cooling system, characterized in that: include: A cooler (7), an oil circulation circuit, a first motor cooling circuit, a second motor cooling circuit and a refrigerant purifier (11); Water from the water supply system enters the cooler (7) to cool the heat exchange coil in the cooler (7), and the heat exchange coil is respectively connected to an oil circulation circuit and a first motor cooling circuit. The oil circulation circuit is used to circulate lubricating oil to cool the compressor bearing (101); the first motor cooling circuit is used to transport liquid refrigerant to cool the compressor motor (102); The replenishing water in the cooler (7) continues to enter the refrigerant purifier (11) to condense the refrigerant and separate the non-condensable gas in the refrigerant; the second motor cooling circuit is connected to the refrigerant purifier (11) to transport the refrigerant to cool the compressor motor (102).

2. A cooling system according to claim 1, characterized in that: The oil circulation circuit comprises an oil tank (4), an oil pump (5) and an oil filter (6); the lubricating oil in the oil tank (4) is pressurized by the oil pump (5), enters the compressor (1) through the oil filter (6), lubricates the bearing (101) and takes away the heat of the bearing (101), then leaves the compressor (1), enters the cooler (7), cools, and then re-enters the oil tank (4).

3. A cooling system according to claim 1, characterized in that: The first motor cooling circuit comprises: a condenser (3), a first electronic expansion valve (8), a first solenoid valve (9) and an evaporator (2); a high-temperature and high-pressure liquid refrigerant is taken from the bottom of the condenser (3), enters the cooler (7) through the first solenoid valve (9), the refrigerant heat exchange temperature is reduced, and the refrigerant is throttled to a low-temperature and low-pressure liquid refrigerant through the first electronic expansion valve (8), enters the compressor (1) and surrounds the cooling motor (102), and the refrigerant absorbs heat and evaporates into a gaseous state and enters the evaporator (2).

4. A cooling system according to claim 1, characterized in that: The heat exchange coil in the cooler (7) is connected to the oil circulation circuit and is arranged above the heat exchange coil connected to the first motor cooling circuit.

5. A cooling system according to claim 1, characterized in that: The make-up water in the cooler (7) flows into the heat exchange coil of the refrigerant purifier (11), and the refrigerant purifier (11) is connected to the high-temperature and high-pressure gaseous refrigerant of the condenser (3). The gaseous refrigerant exchanges heat with the make-up water in the heat exchange coil, and the gaseous refrigerant condenses into liquid refrigerant and gathers at the bottom of the refrigerant purifier (11). The non-condensable gas gathers at the top of the refrigerant purifier (11) and is discharged through the filter (12).

6. A cooling system according to claim 5, characterized in that: A one-way valve (16) is provided between the refrigerant purifier (11) and the condenser (3) to prevent backflow of replenished water.

7. A cooling system according to claim 5, characterized in that: The non-condensable gas gathers at the top of the refrigerant purifier (11), passes through the filter (12) and the second solenoid valve (13), is drawn out by the vacuum pump (14), and is discharged into the atmosphere.

8. A cooling system according to claim 5, characterized in that: The liquid refrigerant is collected at the bottom of the refrigerant purifier (11) and is divided into two paths, including: a second motor cooling circuit and a frequency converter cooling circuit; In the second motor cooling circuit, the cold refrigerant is throttled by the second electronic expansion valve (18), enters the compressor (1), surrounds the cooling compressor motor (102), and after heat exchange, turns into gaseous refrigerant and returns to the evaporator (2); In the inverter cooling circuit, the refrigerant is throttled by the third electronic expansion valve (19) and then enters the inverter (10), cools the inverter module, and turns into gaseous refrigerant after heat exchange and returns to the evaporator (2).

9. A cooling system according to claim 8, characterized in that: The second motor cooling circuit and the first motor cooling circuit protect each other. The two circuits can cool the motor at the same time. When one of the cooling circuits fails, the other circuit can ensure the cooling of the motor.

10. A cooling method, based on a cooling system according to any one of claims 1 to 9, characterized in that: Including cooling of oil circulation circuit and motor cooling circuit; The cooling of the oil circulation loop, the heat exchange coil is connected to the oil circulation loop, the water of the water supply system cools the lubricating oil entering the heat exchange coil, and the cooled lubricating oil re-enters the oil circulation loop to complete the cooling; The cooling of the motor cooling circuit includes: cooling of the first motor cooling circuit and the second motor cooling circuit. The heat exchange coil is connected to the first motor cooling circuit and the second motor cooling circuit respectively. The water from the water supply system cools the high-temperature and high-pressure liquid refrigerant entering the heat exchange coil. The cooled liquid refrigerant surrounds the compressor motor for cooling.

11. A heat pump unit comprising a cooling system according to any one of claims 1 to 9.

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