Cooling system for compressor lubricating oil, control method of cooling system and compressor

Abstract

The invention discloses a cooling system for compressor lubricating oil, a control method of the cooling system and a compressor. The cooling system for the lubricating oil of the compressor comprises an oil tank provided with a first temperature sensor, the oil tank is connected with a high-level oil tank of the compressor, the top of the oil tank is communicated with the bottom of a condenser through a cold oil electronic expansion valve, an atomizing nozzle is arranged on the inner wall of a refrigerant inlet in the top of the oil tank, and a pre-cooling container is arranged below the atomizing nozzle; and an oil discharge port of the compressor is communicated with the pre-cooling container through an oil return electromagnetic valve. Oil recovered from a compressor is firstly input into the pre-cooling container, a liquid refrigerant is atomized into tiny liquid beads through the atomizing nozzle arranged in the oil tank, and the tiny liquid beads are uniformly sprayed into the oil in the pre-cooling container, so that lubricating oil overflows into the oil tank after sufficient and uniform heat exchange and cooling are carried out. And the refrigerant atomized into tiny liquid beads is uniformly dispersed and completely covered, so that the problems of insufficient and non-uniform cooling of the lubricating oil are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration compressors, and in particular to a cooling system for compressor lubricating oil and a control method thereof, and a compressor having the lubricating oil cooling system. Background Art

[0002] The centrifuge in the refrigeration unit needs to use lubricating oil to reduce the friction and wear of its internal bearings and other moving parts during operation to ensure the smooth operation of the unit. However, the high temperature generated by friction during operation will affect the viscosity of the lubricating oil, thereby accelerating the oxidation and deterioration of the oil, and ultimately affecting the normal operation of the unit. Therefore, conventional centrifuges need to use heat exchange cooling for the lubricating oil to ensure that the lubricating oil is at a suitable temperature for circulating lubrication and cooling.

[0003] A common method of cooling the lubricating oil in a centrifugal heat pump unit is to first discharge the lubricating oil in the compressor after absorbing heat into an external oil tank, then introduce the high-pressure liquid refrigerant at the bottom of the condenser into the oil tank to perform heat exchange cooling on the high-temperature lubricating oil inside, and then input the cooled lubricating oil into the compressor, thereby cooling and recycling the lubricating oil.

[0004] However, under the influence of the large pressure difference between the condenser and the oil tank, most of the liquid refrigerant entering the oil tank will quickly transform into low-temperature and low-pressure gaseous refrigerant. These gaseous refrigerants entering the oil tank will contact the upper surface of the high-temperature lubricating oil recovered from the compressor and absorb heat. The gaseous refrigerant after absorbing heat is sent back to the evaporator through the balance pipe, while taking away part of the heat of the lubricating oil. In this way, the heat exchange achieves the effect of cooling the lubricating oil. The small amount of liquid refrigerant that has not been vaporized flows into the lubricating oil in the oil tank and is then input into the high-level oil tank in the compressor through the oil pump.

[0005] However, when the above method is used to cool the lubricating oil, since the gaseous refrigerant will float above the surface of the lubricating oil in the oil tank, it can only cool the upper surface of the oil it contacts, and the middle and lower layers of the lubricating oil are not in contact. Therefore, this method is not efficient in absorbing the heat of the lubricating oil, and the remaining small amount of liquid refrigerant can only rely on gravity potential energy to flow into the local area of ​​the lubricating oil, which cannot ensure that the liquid refrigerant diffuses and mixes evenly with the lubricating oil for heat exchange, which ultimately leads to insufficient subsequent cooling of the lubricating oil.

[0006] Therefore, the prior art actually mainly uses gaseous refrigerant to cool the lubricating oil of the compressor, which leads to technical problems of insufficient cooling and poor cooling efficiency. Summary of the invention

[0007] In order to solve the problem of insufficient cooling and poor cooling efficiency of compressor lubricating oil in the prior art, the present invention proposes a cooling system for compressor lubricating oil and a control method thereof, and also includes a compressor having the lubricating oil cooling system. The cooling system sets relevant parameters so that lubricating oil and refrigerant enter the oil tank at a certain rate, so that the pressure difference between the oil tank and the condenser becomes small, thereby achieving sufficient and efficient heat exchange cooling of the lubricating oil and recycling it.

[0008] The present invention provides a cooling system for compressor lubricating oil, comprising an oil tank provided with a first temperature sensor, the oil tank being connected to a high-position oil tank of the compressor, the top of the oil tank being communicated with the bottom of a condenser, an atomizing nozzle being provided on the inner wall of a refrigerant inlet at the top of the oil tank, a precooling container being provided below the atomizing nozzle; an oil discharge port of the compressor being communicated with the precooling container, an oil return solenoid valve being provided between the oil discharge port and the precooling container; and a cold oil electronic expansion valve being provided between the oil tank and the condenser.

[0009] The present invention sets an oil return solenoid valve between the oil discharge port of the compressor and the precooling container in the oil tank, and sets a cold oil electronic expansion valve between the oil tank and the condenser. Before the unit is operated, the relevant pressure parameters of the lubricating oil cooling system are set so that the lubricating oil and the refrigerant enter the oil tank at a certain rate, so that the pressure difference between the oil tank and the condenser becomes smaller, so as to ensure that the liquid refrigerant from the condenser will not be vaporized in advance after entering the oil tank and affect the heat exchange cooling efficiency. Then, an atomizing nozzle is set on the inner wall of the refrigerant inlet at the top of the oil tank and a precooling container is set below the atomizing nozzle, and the oil discharge port of the compressor is connected to the precooling container. The liquid refrigerant is atomized into tiny droplets by the atomizing nozzle and sprayed onto the lubricating oil in the precooling container below, and the lubricating oil is fully and evenly cooled by heat exchange, thereby improving the efficiency of heat exchange cooling of the lubricating oil for recycling.

[0010] Preferably, the top of the oil tank is connected to the evaporator through a return ball valve. The refrigerant gasifies after heat exchange with the lubricating oil and is concentrated above the inner cavity of the oil tank. Timely inputting the gaseous refrigerant into the evaporator can improve the refrigeration efficiency of the unit and maintain an ideal pressure difference between the oil tank and the condenser, so as to keep the lubricating oil cooling system running well.

[0011] Preferably, an oil pump and a filter are provided between the oil tank and the high-position oil tank of the compressor, so as to timely provide the compressor with clean, cooled lubricating oil, and timely lubricate and cool the compressor to ensure the normal operation of the unit.

[0012] Preferably, a one-way valve is provided between the oil discharge port and the oil return solenoid valve. This can prevent the lubricating oil in the oil tank from flowing back to the compressor when a special situation occurs in the system, thereby affecting the normal operation of the compressor unit. This also facilitates the maintenance and repair of the lubricating oil cooling system.

[0013] The present invention provides a compressor having the lubricating oil cooling system.

[0014] Preferably, the compressor is a large-capacity high-temperature heat pump centrifugal unit with two units connected in series, and the oil tank is connected to the high-level oil tank of the low-pressure compressor and the high-level oil tank of the high-pressure compressor of the unit respectively; the oil discharge ports of the high- and low-level compressors of the unit are both connected to the precooling container in the oil tank.

[0015] The lubricating oil cooling system provided by the present invention can be used for various compressor units whose internal parts generate frictional heat during operation, thereby expanding the application scope of the lubricating oil cooling system of the present invention.

[0016] Preferably, a first oil pump and a first filter are provided between the oil tank and the high-position oil tank of the low-pressure stage compressor; and a second oil pump and a second filter are provided between the oil tank and the high-position oil tank of the high-pressure stage compressor.

[0017] An oil pump and a filter are installed between the oil tank and the high-level oil tank of the compressor, which can quickly and efficiently provide the compressor with clean, heat-exchanged and cooled lubricating oil, so as to lubricate and cool the compressor in time to ensure the normal operation of the unit.

[0018] Preferably, a first one-way valve is provided between the oil discharge port of the low-pressure stage compressor and the oil return solenoid valve, and a second one-way valve is provided between the oil discharge port of the high-pressure stage compressor and the oil return solenoid valve.

[0019] It can prevent the lubricating oil in the oil tank from flowing back to the compressor when a special situation occurs in the system, thus affecting the normal operation of the compressor unit. It is also convenient for the maintenance and repair of the lubricating oil cooling system.

[0020] The present invention also provides a control method for a compressor lubricating oil cooling system, comprising the following steps:

[0021] First, set the relevant pressure parameters of the cold oil electronic expansion valve and the oil return solenoid valve of the cooling system so that the pressure of the condenser is close to that of the oil tank; then start the lubricating oil cooling system;

[0022] When it is detected that the oil temperature of the oil tank is within a preset temperature range, the current opening of the cold oil electronic expansion valve is maintained, and when a preset time is reached, the oil temperature in the oil tank is detected again;

[0023] If the oil temperature in the oil tank is detected to be lower than the lower limit of the preset temperature range, the opening of the cold oil electronic expansion valve is reduced, and when the preset time is reached, the oil temperature in the oil tank is continuously detected;

[0024] If it is detected that the oil temperature in the oil tank is greater than the upper limit of the preset temperature range but less than the protection temperature, the opening of the cold oil electronic expansion valve is increased, and when the preset time is reached, the oil temperature in the oil tank is continuously detected;

[0025] When it is detected that the oil temperature in the oil tank is higher than the protection temperature, stop the machine for inspection.

[0026] By setting the relevant pressure parameters of the lubricating oil cooling system, the pressure difference between the oil tank and the condenser is kept small to avoid premature gasification of the liquid refrigerant and the inability to fully and effectively heat exchange and cool the lubricating oil. According to the real-time detection and monitoring of the internal temperature of the oil tank, the opening of the cold oil electronic expansion valve is adjusted in time to input the appropriate amount of refrigerant into the oil tank, and the lubricating oil is accurately heat exchanged and cooled to meet the needs of lubrication and cooling of the unit operation.

[0027] Preferably, the preset temperature range is 40-50°C; the protection temperature is 55°C; and the preset time is 30 seconds.

[0028] According to the needs of testing and long-term unit operation, select the optimal control parameters and monitoring control time of the oil tank temperature to provide excellent oil temperature control effect.

[0029] Based on the conventional compressor lubricating oil cooling system, the present invention adds an atomizing nozzle on the inner wall of the top of the oil tank, and sets a precooling container below the atomizing nozzle. By setting the corresponding pressure parameters of the lubricating oil system, the oil return solenoid valve between the compressor and the oil tank and the cold oil electronic expansion valve between the oil tank and the condenser are adjusted, so that the lubricating oil and the refrigerant enter the oil tank at a certain rate, so that the internal pressure of the oil tank is maintained at a certain level, which is equivalent to setting a normal operating environment. Compared with conventional units, the parameter setting of the present invention has a smaller pressure difference between the oil tank and the condenser to avoid the liquid refrigerant from vaporizing in advance and failing to perform sufficient and effective heat exchange cooling on the lubricating oil. The lubricating oil recovered from the compressor is then input into the precooling container on the top of the oil tank, and the liquid refrigerant from the condenser is atomized into tiny liquid droplets by the atomizing nozzle, and evenly enters the lubricating oil in the precooling container. Since the tiny liquid droplets of refrigerant sprayed from the atomizing nozzle can cover the entire plane of the pre-cooling container, the total heat exchange area between the liquid refrigerant and the lubricating oil is large and uniform during spray cooling, and the liquid refrigerant absorbs a large amount of heat when evaporating, thereby fully and efficiently exchanging heat and cooling the lubricating oil that first enters the pre-cooling container. After the oil in the pre-cooling container is fully cooled, the slowly rising liquid level of the lubricating oil overflows from the periphery of the pre-cooling container and flows into the main storage space at the bottom of the oil tank. Since the refrigerant is evenly distributed and fully covered by the atomized tiny liquid droplets, the problem of insufficient and uneven cooling of the lubricating oil is effectively solved. In addition, the present invention improves the interior of the oil tank, and the unit itself only needs to add a few pipelines corresponding to the load and connection, without the need for new components, which has little impact on the spatial structure of the unit and is easy to install and arrange. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of a lubricating oil cooling system for a stand-alone compressor according to a first embodiment of the present invention;

[0031] Figure 2 It is a three-dimensional schematic diagram of a large-capacity high-temperature heat pump centrifuge with two machines in series in the second embodiment of the present invention;

[0032] Figure 3 for Figure 2 The main view of

[0033] Figure 4 for Figure 2 A top view of

[0034] Figure 5 for Figure 2 Right view of;

[0035] Figure 6 for Figure 2 Schematic diagram of the appearance of the middle fuel tank;

[0036] Figure 7 for Figure 6 A cross-sectional view of the fuel tank;

[0037] Figure 8 This is a schematic diagram of a lubricating oil cooling system of a large-capacity high-temperature heat pump centrifuge with two machines in series in the second embodiment of the present invention;

[0038] Fig. 9 It is a flow chart of the compressor lubricating oil cooling system control method of the present invention.

[0039] In the figure:

[0040] 1- Evaporator;

[0041] 2- Condenser;

[0042] 03-Compressor;

[0043] 3- Low pressure stage compressor;

[0044] 4- High pressure stage compressor;

[0045] 5-Fuel tank;

[0046] 6-First filter;

[0047] 7-First oil pump;

[0048] 8- Second filter;

[0049] 9- second oil pump;

[0050] 10- first one-way valve;

[0051] 11- second one-way valve;

[0052] 12-Return ball valve,

[0053] 13- atomizing nozzle;

[0054] 14- a first temperature sensor;

[0055] 15-cold oil electronic expansion valve;

[0056] 16-Oil return solenoid valve;

[0057] 17- second temperature sensor;

[0058] 18- Pre-cooling container;

[0059] 19-Gas-liquid separator. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and do not constitute a limitation to the present invention.

[0061] like Figure 1 As shown, a cooling system for lubricating oil of a single compressor of the first embodiment of the present invention comprises an oil tank 5, a first temperature sensor 14 is arranged below the oil tank 5, one side of the oil tank 5 is connected to the high-position oil tank of the compressor 03 through an oil pipe, and a first oil pump 7 and a first filter 6 are arranged on the oil pipe between the oil tank 5 and the high-position oil tank of the compressor 03. The top of the oil tank 5 is connected to the bottom of the condenser 2 through a refrigerant pipe, and a cold oil electronic expansion valve 15 is arranged on the refrigerant pipe. An atomizing nozzle 13 is arranged on the inner wall of the top inlet of the oil tank 5, and a precooling container 18 is arranged below the atomizing nozzle 13, and a second temperature sensor 17 is arranged on the precooling container 18. The liquid refrigerant from the condenser 2 is sprayed downward through the atomizing nozzle 13 to form tiny droplets, and the spraying area can cover the entire plane of the precooling container 18. The oil discharge port of the compressor 03 is connected to the precooling container 18 of the oil tank 5 through an oil pipe, and a first non-return valve 10 and an oil return solenoid valve 16 are sequentially arranged between the oil discharge port of the compressor 03 and the precooling container 18. The top of the oil tank 5 is connected to the evaporator 1 through a return ball valve 12. The condenser 2 is connected to the evaporator 1 through a throttling device.

[0062] The lubricating oil cooling system provided by the present invention can also be used for heat exchange cooling of lubricating oil of different types of refrigeration compressors. As long as there is friction heating during the operation of the compressor, the compressor lubricating oil cooling system provided by the present invention can be used. For example, it can be used for single-machine two-stage compressors or two-machine series compressors to provide heat exchange cooling of lubricating oil, etc. Please refer to Figure 8, a lubricating oil cooling system of a dual compressor unit in series, the unit includes a low-pressure compressor 3 and a high-pressure compressor 4. At this time, the lower two sides of the oil tank 5 are connected to the high-position oil tank of the low-pressure compressor 3 and the high-position oil tank of the high-pressure compressor 4 through oil pipes. The oil discharge port of the low-pressure compressor and the oil discharge port of the high-pressure compressor are both connected to the precooling container 18 in the oil tank 5.

[0063] The second embodiment provided by the present invention is a large-capacity high-temperature heat pump centrifugal machine unit with two machines in series and having the lubricating oil cooling system. Figure 2-Figure 8 As shown, the unit includes an oil tank 5 provided with a first temperature sensor 14, the left side of the lower part of the oil tank 5 is connected to the high-position oil tank of the low-pressure compressor 3 through an oil pipe, and the oil pipe between the oil tank 5 and the high-position oil tank of the low-pressure compressor 3 is provided with a first oil pump 7 and a first filter 6. The right side of the lower part of the oil tank 5 is connected to the high-position oil tank of the high-pressure compressor 4 through another oil pipe, and the oil pipe between the oil tank 5 and the high-position oil tank of the high-pressure compressor 4 is provided with a second oil pump 9 and a second filter 8.

[0064] The top of the oil tank 5 is connected to the bottom of the condenser 2 through a refrigerant pipe, and a refrigerant electronic expansion valve 15 is provided on the refrigerant pipe. Figure 6-Figure 8 As shown, an atomizing nozzle 13 is provided on the inner wall of the refrigerant inlet at the top of the oil tank 5, and a precooling container 18 is provided below the atomizing nozzle 13. The precooling container 18 is provided with a second temperature sensor 17. The liquid refrigerant from the condenser 2 is sprayed downward through the atomizing nozzle 13 to form tiny droplets, and the spray area can cover the entire plane of the precooling container 18.

[0065] The oil discharge port of the low-pressure compressor 3 is connected to a pipeline, and the oil discharge port of the high-pressure compressor 4 is connected to another pipeline. The two pipelines are connected in parallel and communicated with the precooling container 18 in the oil tank 5. The parallel pipeline is also provided with an oil return solenoid valve 16. A first check valve 10 is provided on the pipeline connected to the oil discharge port of the low-pressure compressor 3, and a second check valve 11 is provided on the pipeline connected to the oil discharge port of the high-pressure compressor 4. The top of the oil tank 5 is connected to the evaporator 1 through a gas-liquid separator 19 and a return ball valve 12. The condenser 2 is connected to the evaporator 1 through a throttling device.

[0066] like Figure 8 As shown, the working principle of the lubricating oil cooling system of the present invention is explained by taking the second embodiment as an example.

[0067] The unit starts, the first oil pump 7 and the second oil pump 9 are turned on, and the lubricating oil pumped out from the oil tank 5 respectively passes through the first filter 6 and the second filter 8. After filtering out the impurities in the oil, it is respectively input into the low-pressure stage compressor 3 and the high-pressure stage compressor 4 of the large-capacity high-temperature heat pump centrifuge with double machines in series. After the lubricating oil enters the low- and high-pressure stage compressors 3 and 4, it can lubricate the bearings and other components of the compressor, reduce friction and wear, and at the same time absorb the heat generated during the operation of the compressor, so that the compressor cools down, but the temperature of the lubricating oil rises. After the lubricating oil absorbs heat in the low-pressure stage compressor 3 and the high-pressure stage compressor 4, it flows out through the first check valve 10 and the second check valve 11 on the bottom oil discharge port pipelines of each of them respectively, and automatically flows into the pre-cooling container 18 in the oil tank 5 periodically through the oil return solenoid valve 16 and under the program control of on-off, and then exchanges heat and cools with the refrigerant from the condenser 2, and is recycled.

[0068] During this process, it is necessary to coordinately control the opening and closing of each valve in the pipeline according to the detected real-time oil temperature in the oil tank, so as to timely exchange heat and cool the lubricating oil in the oil tank and recycle it. The specific control method of the lubricating oil cooling system is as follows.

[0069] The control method of the compressor lubricating oil cooling system provided by the present invention includes the following control steps (please combine Figure 8 、 Fig. 9 ):

[0070] First, set the relevant pressure parameters of the cooling system. For example, set the pressure parameters of the cold oil electronic expansion valve 15 and the oil return solenoid valve 16. Reduce the pressure difference between the oil tank 5 and the condenser 2, that is, make the pressure difference between the oil tank 5 and the condenser 2 close to the pressure difference between the two in the existing compressor unit cooling system. Then start the oil return of the compressor unit and input the liquid refrigerant from the condenser, and implement the cooling and recycling of the compressor lubricating oil, so as to avoid the premature gasification of the liquid refrigerant entering the oil tank and affecting the heat exchange efficiency.

[0071] When the first temperature sensor 14 detects that the oil temperature T5 in the oil tank 5 is within the preset temperature range of 40 - 50 °C, that is, 40 °C < T5 < 50 °C, keep the current opening of the cold oil electronic expansion valve 15 running, that is, keep the current refrigerant flow rate. When the preset time is reached, that is, t = 30 seconds, the first temperature sensor 14 detects the oil temperature T5 in the oil tank again.

[0072] If it is detected that the oil temperature T5 in the oil tank is less than the lower limit value of the preset temperature range, that is, T5 < 40 °C, then reduce the opening of the cold oil electronic expansion valve 15 to run, reduce the refrigerant flow rate, reduce the cooling efficiency, until the oil temperature T5 in the oil tank rises back to the preset temperature range of 40 - 50 °C. And when the preset time is reached, that is, t = 30 seconds, the first temperature sensor 14 continues to detect the oil temperature T5 in the oil tank.

[0073] If it is detected that the oil temperature T5 in the fuel tank is greater than the upper limit value of the preset temperature range but less than the protection temperature, that is, when 50°C < T5 < 55°C, the opening of the cold oil electronic expansion valve 15 is increased for operation. This increases the circulation rate of the liquid refrigerant from the condenser 2 to improve the cooling efficiency until the oil temperature T5 in the fuel tank 5 drops back to the preset temperature range of 40 - 50°C. And when the preset time is reached, that is, when t = 30 seconds, the first temperature sensor 14 continues to detect the oil temperature T5 in the fuel tank.

[0074] When the first temperature sensor 14 detects that the oil temperature T5 in the fuel tank is greater than the protection temperature, that is, when 55°C < T5, the machine stops for inspection.

[0075] The specific values of the preset temperature range, protection temperature, and preset time can be selected according to different situations. The second temperature sensor 17 can assist in monitoring the oil temperature in the pre-cooling container 18.

[0076] When the cold oil electronic expansion valve 15 is opened, the lubricating oil cooling system transports an appropriate amount of liquid refrigerant from the bottom of the condenser 2, sprays it through the atomizing nozzle 13 in the fuel tank 5, so that the liquid refrigerant is converted into micron-sized tiny droplets and sprayed into the fuel tank 5, which can cool the lubricating oil in the upper layer of the pre-cooling container 18. Since the atomizing nozzle 13 is set at a certain height above the pre-cooling container 18, and the spraying area of the atomized refrigerant basically covers the entire plane of the pre-cooling container 18. The atomized liquid refrigerant is dispersed in the spraying area in the form of dense, small-volume, evenly distributed tiny droplets, and is evenly mixed with the lubricating oil for heat exchange and cooling. In this way, the tiny droplet form of the refrigerant can ensure that it has sufficient heat exchange area, improving the heat exchange and cooling efficiency between it and the lubricating oil. After a part of the atomized refrigerant exchanges heat with the upper-layer lubricating oil in the pre-cooling container 18, it evaporates and gasifies, and the remaining atomized refrigerant is evenly mixed with the lubricating oil in the form of tiny droplets and continues to exchange heat and cool, and the refrigerant evaporates and gasifies after absorbing heat. After the oil in the pre-cooling container 18 is cooled, the oil level rises and overflows to the lower fuel tank 5 for storage越过预冷容器18的侧板顶部溢流至下部的油箱5中储存。如此可以有效避免来自冷凝器2的液态冷媒直接注入油箱5润滑油的局部区域进行冷却,而出现的换热冷却不均匀、不充分的问题。从润滑油中吸收热量气化后的冷媒则通过油箱5的顶部的气液分离器19经由回气球阀12流入蒸发器1(如 Figure 6 、 Figure 7 所示)。

[0077] In the present invention, an atomizing nozzle and a pre-cooling container are added in the fuel tank. By setting the corresponding pressure parameters of the lubricating oil system, the oil return solenoid valve between the compressor and the fuel tank and the cold oil electronic expansion valve between the fuel tank and the condenser are adjusted, so that the pressure difference between the fuel tank and the condenser during operation is small, avoiding premature gasification of the refrigerant and ensuring sufficient and effective heat exchange and cooling of the lubricating oil.

[0078] The lubricating oil recovered from the compressor is input into the precooling container on the top of the oil tank, and then the liquid refrigerant from the condenser is atomized into tiny liquid droplets by the atomizing nozzle, and evenly enters the lubricating oil in the precooling container. Since the tiny liquid droplets of refrigerant sprayed by the atomizing nozzle can cover the entire surface of the precooling container, the total heat exchange area between the refrigerant and the lubricating oil is large and uniform during spray cooling, and the liquid refrigerant absorbs a large amount of heat when evaporating, thereby fully and efficiently exchanging heat and cooling the lubricating oil that first enters the precooling container. After the oil in the precooling container is fully cooled, the slowly rising liquid level of the lubricating oil overflows from the top of the periphery of the precooling container and flows into the main storage space at the bottom of the oil tank for recycling.

[0079] Since the refrigerant is evenly distributed and fully covered by atomized tiny liquid droplets, the problem of insufficient and uneven cooling of lubricating oil is effectively solved, thereby improving the heat exchange cooling efficiency. In addition, the present invention improves the internal part of the oil tank, and the unit itself only needs to add a few corresponding loads and connected pipelines, without adding new devices, which has little impact on the spatial structure of the unit and is easy to install and arrange.

[0080] It should be noted that the terms used in this specification are only for describing specific embodiments and are not intended to limit the present invention. Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the technical features and steps described in these embodiments do not limit the scope of protection of the present invention. For the technology, methods and equipment known to ordinary technicians in the relevant field, this specification is not discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of this specification. Any specific value in this specification should be interpreted as being merely exemplary and not constituting a limitation of the present invention.

[0081] For the convenience of description, the terms describing the position used in the specification, such as "above...", "to the left of...", "in front of...", etc., are only used to describe the spatial position relationship between a certain component and other components of the embodiment shown in the figure. When the position of the component is different, the relative position will change. Therefore, the position relationship of the embodiment of the drawing should not constitute a limitation to the present invention.

[0082] In addition, it should be noted that the words "first", "second" and the like used in the specification are only used to distinguish similar components, and there is no order of precedence, so they cannot be understood as limiting the scope of protection of the present invention. The above description is only a specific implementation of the present invention. It should be pointed out that any modification, equivalent substitution and change made within the spirit and framework of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cooling system for compressor lubricating oil, comprising an oil tank provided with a first temperature sensor, the oil tank being connected to a high-position oil tank of the compressor, characterized in that: The top of the oil tank is connected to the bottom of the condenser through a cold oil electronic expansion valve, an atomizing nozzle is provided on the inner wall of the refrigerant inlet at the top of the oil tank, a precooling container is provided below the atomizing nozzle, and the oil discharge port of the compressor is connected to the precooling container through an oil return solenoid valve.

2. The compressor lubricating oil cooling system according to claim 1, characterized in that: The top of the oil tank is communicated with the evaporator through a return ball valve.

3. The compressor lubricating oil cooling system according to claim 1, characterized in that: An oil pump and a filter are arranged between the oil tank and the high-position oil tank of the compressor.

4. The compressor lubricating oil cooling system according to claim 1, characterized in that: A one-way valve is provided between the oil discharge port and the oil return solenoid valve.

5. A compressor, characterized in that: A cooling system for compressor lubricating oil comprising the cooling system according to any one of claims 1 to 4.

6. The compressor according to claim 5, characterized in that The compressor is a large-capacity high-temperature heat pump centrifugal unit with two units connected in series. The oil tank is respectively connected to the high-level oil tank of the low-pressure compressor and the high-level oil tank of the high-pressure compressor of the unit; the oil discharge ports of the high and low-level compressors of the unit are both connected to the precooling container in the oil tank.

7. The compressor according to claim 6, characterized in that A first oil pump and a first filter are arranged between the oil tank and the high-position oil tank of the low-pressure compressor; a second oil pump and a second filter are arranged between the oil tank and the high-position oil tank of the high-pressure compressor.

8. The compressor according to claim 6, characterized in that A first one-way valve is provided between the oil discharge port of the low-pressure compressor and the oil return solenoid valve, and a second one-way valve is provided between the oil discharge port of the high-pressure compressor and the oil return solenoid valve.

9. A method for controlling a cooling system for a compressor lubricating oil according to any one of claims 1 to 4, comprising the following steps: First, set the relevant pressure parameters for the cold oil electronic expansion valve and oil return solenoid valve of the cooling system so that the pressure of the condenser is close to that of the oil tank, and then start the lubricating oil cooling system; When it is detected that the oil temperature of the oil tank is within a preset temperature range, the current opening of the cold oil electronic expansion valve is maintained, and when a preset time is reached, the oil temperature in the oil tank is detected again; If the oil temperature in the oil tank is detected to be lower than the lower limit of the preset temperature range, the opening of the cold oil electronic expansion valve is reduced, and when the preset time is reached, the oil temperature in the oil tank is continuously detected; If it is detected that the oil temperature in the oil tank is greater than the upper limit of the preset temperature range but less than the protection temperature, the opening of the cold oil electronic expansion valve is increased, and when the preset time is reached, the oil temperature in the oil tank is continuously detected; When it is detected that the oil temperature in the oil tank is higher than the protection temperature, stop the machine for inspection.

10. The control method of the compressor lubricating oil cooling system according to claim 9, characterized in that: The preset temperature range is 40-50°C; the protection temperature is 55°C; and the preset time is 30 seconds.

Images