Oil way system of air conditioning unit and air conditioning unit

Abstract

The utility model discloses an oil way system of an air conditioning unit and the air conditioning unit, and the oil way system specifically comprises an oil way pipeline which is connected between an oil separator and a compressor of the air conditioning unit; the oil pumps are arranged on the oil way pipeline; the valve assembly is arranged on the oil way pipeline and can switch the oil way pipeline to change the communication state of the oil pumps, so that the oil pumps are in a parallel connection state or a series connection state or a single-oil-pump communication state. The multiple oil pumps are used in the oil way system, the oil supply state of the oil way can be flexibly adjusted by adjusting the on-off state and the communication state of the oil pumps, the oil way can be matched with the operation working condition of the air conditioning unit, the operation requirement is accurately met, energy is saved, consumption is reduced, and the situation that the oil supply pressure is insufficient or the oil supply temperature is too high is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioning, in particular to an oil circuit system of an air conditioning unit and an air conditioning unit. Background Art

[0002] Ultra-low temperature open-type units play a vital role in the cooling process of cold storage warehouses. Compared with the relatively stable operating range of common air-conditioning units, the operating environment of ultra-low temperature open-type screw compressor units is more stringent. Specifically, some cold storage warehouses need to reduce the temperature from +16°C to -30°C. During the operation of the unit, the evaporation temperature also needs to be reduced from +5°C to -40°C. Taking the commonly used R507A refrigerant as an example, while keeping the condensing temperature at +30°C unchanged, as the evaporation temperature changes, the suction and exhaust pressure difference of the unit will increase significantly from 7.3bar to 13.2bar. This drastic change puts higher requirements on the performance and reliability of the equipment.

[0003] In order to improve the operational reliability of ultra-low temperature units, an oil pump is usually configured in the open type unit. When the oil supply pressure difference of the compressor does not meet the requirements, the oil pump will automatically turn on to ensure sufficient oil supply; when the demand is met, the oil pump will turn off. After the lubricating oil passes through the oil pump, it is sprayed into the compressor through the oil supply main pipe, which not only plays a role in cooling and lubrication, but also provides necessary support for the loading and unloading of the compressor.

[0004] However, this design of configuring a fixed-frequency oil pump has certain limitations in actual operation and cannot accurately adapt to the operation requirements of the cold storage. First, when the cold storage starts to cool down, due to the large gap with the target temperature, the compressor needs to load quickly to quickly reduce the temperature. At this time, the oil supply flow rate requirement is high. When the storage temperature is close to the target temperature, the compressor needs to load slowly, and the oil supply flow rate requirement is relatively low. In addition, changes in evaporation temperature and condensation temperature will also put forward different requirements for the oil supply system. When the unit is running for a long time, especially when the ambient temperature is low, the pressure drop of the oil system will change, thereby affecting the head requirement of the oil pump.

[0005] If you only choose a large flow and high head oil pump, although it can meet the needs under various working conditions, it will significantly increase the initial investment cost. In addition, such a high-specification oil pump may cause unnecessary energy consumption in daily operation, reducing the energy efficiency of the entire system. Utility Model Content

[0006] In order to solve the technical problem that only one fixed-frequency oil pump in the prior art cannot adapt to the variable oil supply demand of the unit, the utility model provides an oil circuit system of an air-conditioning unit and an air-conditioning unit.

[0007] The technical solution adopted by the utility model is:

[0008] The utility model proposes an oil circuit system of an air conditioning unit, comprising:

[0009] An oil pipeline connected between the oil separator and the compressor of the air conditioning unit;

[0010] A plurality of oil pumps are arranged on the oil pipeline;

[0011] The valve assembly is arranged on the oil pipeline, and can switch the oil pipeline to change the connection state of the multiple oil pumps, so that the multiple oil pumps are in a parallel state, a series state, or a single connection state.

[0012] Furthermore, the multiple oil pumps specifically include a first oil pump and a second oil pump.

[0013] Furthermore, the oil circuit pipeline includes: an oil circuit main pipe connected to the oil outlet side of the oil separator of the air-conditioning unit at one end, a first branch pipe and a second branch pipe in parallel at the other end of the oil circuit main pipe, a first branch pipe and a second branch pipe in parallel at the end of the second branch pipe, the end of the first branch pipe is connected to the first branch pipe, the first branch pipe and the second branch pipe are connected to the compressor side of the air-conditioning unit, the first oil pump is arranged on the first branch pipe, and the second oil pump is arranged on the second branch pipe.

[0014] Furthermore, the valve assembly specifically includes: a first solenoid valve arranged on the second branch pipe, and a second solenoid valve and a third solenoid valve arranged on the first branch pipe at intervals on both sides of the connection position of the end of the first branch pipe.

[0015] Furthermore, the oil pipeline also includes: a bypass oil circuit connected between the oil separator of the air-conditioning unit and the compressor and in parallel with the pipeline where the oil pump is set, and the valve assembly specifically includes a fourth solenoid valve set on the bypass oil circuit.

[0016] Furthermore, a one-way valve is provided on the first branch pipe.

[0017] Furthermore, it also includes: an oil cooler, which is arranged between the oil main pipe and the oil outlet side of the oil separator.

[0018] Furthermore, it also includes: an oil filter, which connects the first branch pipe and the second branch pipe and is used to filter the lubricating oil flowing to the compressor side.

[0019] Furthermore, it also includes: an oil supply main pipe connected between the oil filter and the compressor, and each oil supply branch pipe of the oil supply main pipe is connected to each oil supply port of the compressor.

[0020] The utility model also provides an air conditioning unit, comprising the above-mentioned oil circuit system.

[0021] Compared with the prior art, the oil circuit system of the utility model uses multiple oil pumps. By adjusting the on / off status and connectivity status of the oil pumps, the oil supply status of the oil circuit can be flexibly adjusted to match the operating conditions of the air-conditioning unit, accurately adapt to operating requirements, save energy and reduce consumption, and avoid insufficient oil supply pressure or excessive oil temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 It is a flow path structure diagram in an embodiment of the utility model;

[0024] Figure 2 It is a flow path structure diagram of the parallel state in the embodiment of the utility model;

[0025] Figure 3 This is a flow path structure diagram of a series connection state in an embodiment of the utility model;

[0026] Figure 4 It is a flow chart of an embodiment of the utility model;

[0027] 1. Compressor;

[0028] 2. Oil separator;

[0029] 3. Oil cooler;

[0030] 4. Oil filter;

[0031] 5. Oil supply main;

[0032] 61. Oil main pipe; 62. Converging pipe; 63. Bypass oil circuit;

[0033] 71, first division; 72, second division;

[0034] 81, first branch; 82, second branch;

[0035] 91. a first oil pump; 92. a second oil pump;

[0036] 101, first solenoid valve; 102, second solenoid valve; 103, third solenoid valve; 104, fourth solenoid valve; 105, one-way valve. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] The principle and structure of the present utility model are described in detail below with reference to the accompanying drawings and embodiments.

[0039] In order to improve the operational reliability of ultra-low temperature units, an oil pump is usually configured in the open type unit. When the oil supply pressure difference of the compressor does not meet the requirements, the oil pump will automatically turn on to ensure sufficient oil supply; when the demand is met, the oil pump will turn off. After the lubricating oil passes through the oil pump, it is sprayed into the compressor through the oil supply main pipe, which not only plays a role in cooling and lubrication, but also provides necessary support for the loading and unloading of the compressor.

[0040] However, this design of configuring a fixed-frequency oil pump has certain limitations in actual operation and cannot accurately adapt to the operation requirements of the cold storage. First, when the cold storage starts to cool down, due to the large gap with the target temperature, the compressor needs to load quickly to quickly reduce the temperature. At this time, the oil supply flow rate requirement is high. When the storage temperature is close to the target temperature, the compressor needs to load slowly, and the oil supply flow rate requirement is relatively low. In addition, changes in evaporation temperature and condensation temperature will also put forward different requirements for the oil supply system. When the unit is running for a long time, especially when the ambient temperature is low, the pressure drop of the oil system will change, thereby affecting the head requirement of the oil pump.

[0041] In this regard, Figures 1 to 3 As shown, the utility model proposes an oil circuit system of an air conditioning unit, and the specific air conditioning unit can be an ultra-low temperature open screw compressor unit, which is used to cool the cold storage warehouse. The air conditioning unit includes an air circuit system and an oil circuit system, and the air circuit system includes a compressor 1, an oil separator 2, an external evaporator, etc. After the refrigerant vapor is compressed by the compressor 1 from the external evaporator and mixed with the lubricating oil sprayed into the compressor 1, the high-pressure gas separated by the oil separator 2 is discharged into the external condenser through the exhaust stop valve.

[0042] The oil circuit system specifically includes: oil cooler 3, oil filter 4, oil pipeline, multiple oil pumps, valve assembly. The oil pipeline is set between the oil separator 2 and the compressor of the air conditioning unit, as the main circulation path of the lubricating oil, to ensure the efficient circulation of the oil in the system; multiple oil pumps are installed on the oil pipeline, responsible for providing the necessary lubricating oil flow and pressure under different operating conditions. By using multiple oil pumps, the system can adjust the oil supply capacity as needed; the valve assembly is set on the oil pipeline to control the connection state of the oil pump. The valve assembly can adjust the working state of the oil pump in the following three ways:

[0043] Parallel state: The pipelines corresponding to multiple oil pumps are in parallel state, providing the maximum oil flow, thereby increasing the oil side flow rate, which can be used specifically when the oil temperature is too high;

[0044] Series connection: The pipelines corresponding to multiple oil pumps are in series connection to increase the oil supply pressure of the system, i.e. the head;

[0045] Single connection state: a certain oil pump operates alone to meet the oil supply demand under specific working conditions.

[0046] Specifically, the valve assembly can be controlled by a controller to adjust the state of the valve assembly according to the evaporation temperature deviation value ΔQ of the air conditioning unit and the oil supply temperature of the oil supply main pipe. For example, the evaporation temperature is monitored in real time, compared with the target evaporation temperature, the evaporation temperature deviation value ΔQ is calculated, and the valve assembly is automatically adjusted according to the evaporation temperature deviation value ΔQ to change the connection state of multiple oil pumps.

[0047] The design of the oil system can flexibly adapt to different operating conditions. By changing the pipeline status of multiple oil pumps, the oil supply flow and pressure of the oil pipeline are adjusted to improve the operating efficiency and reliability of the ultra-low temperature open screw compressor unit, ensuring that the cold storage warehouse can be effectively cooled under various temperature requirements. At the same time, this configuration scheme can also optimize energy utilization, reduce the overall energy consumption of the system, and achieve the goal of energy saving and consumption reduction.

[0048] In a specific embodiment, the part associated with the air-conditioning unit and the oil circuit system specifically includes an oil separator 2 and a compressor 1. The oil separator 2 is connected to the refrigerant pipeline of the air-conditioning unit and can separate the lubricating oil mixed in the refrigerant in the refrigerant pipeline of the air-conditioning unit.

[0049] The oil circuit system specifically also includes an oil cooler 3, which is located between the oil separator 2 and the oil circuit main pipe of the oil circuit pipeline and can cool the lubricating oil separated by the oil separator 2 to prevent the lubricating oil from being too high in temperature.

[0050] The oil circuit system specifically also includes an oil supply main pipe 5, and various branch pipes of the oil supply main pipe 5 are connected to various oil supply ports of the compressor 1, such as loading and unloading oil ports, cooling lubricating oil ports, etc. The lubricating oil is reasonably distributed through the oil supply main pipe 5 to meet the needs of various oil ports of the compressor.

[0051] The oil circuit system specifically includes an oil filter 4 , which is connected to the oil supply main pipe 5 , so that the lubricating oil is filtered before entering the oil supply main pipe 5 , thereby preventing impurities from entering the compressor 1 and affecting the operation of the compressor 1 .

[0052] In a specific embodiment, the oil pipeline specifically includes: an oil main pipe 61, a first branch pipe 71, a second branch pipe 72, a first branch pipe 81, and a second branch pipe 82. The left end of the oil main pipe 61 is connected to the oil cooler 3, and the right end is connected to the first branch pipe 71 and the second branch pipe 72 at the same time. The right end of the second branch pipe 72 is connected to the first branch pipe 81 and the second branch pipe 82 at the same time, and the right end of the first branch pipe 71 is connected to the first branch pipe 81. The right ends of the first branch pipe 81 and the second branch pipe 82 are connected to the oil filter 4 through the converging pipe 62.

[0053] The oil pipeline is arranged between the oil cooler 3 and the oil filter 4, and the original pipeline structure does not need to be changed on a large scale. At the same time, the switching of the two oil pumps can be achieved through the form of branch pipes and branch pipes in conjunction with the valve assembly.

[0054] The multiple oil pumps are specifically a first oil pump 91 and a second oil pump 92. The first oil pump 91 is arranged on the first branch pipe 71, and the second oil pump 92 is arranged on the second branch pipe 72. The two low-power oil pumps can realize the function of a high-power fixed-frequency oil pump, and at the same time have the flexibility that a high-power fixed-frequency oil pump does not have, effectively reducing the installation cost.

[0055] The valve assembly is specifically provided with a first solenoid valve 101 on the second branch pipe 72 , and a second solenoid valve 102 and a third solenoid valve 103 are provided at intervals on both sides of the connection position of the end of the first branch pipe 71 on the first branch pipe 81 .

[0056] By setting up a solenoid valve, the oil pipeline can be switched through the controller, so that corresponding switching can be carried out according to actual working conditions to meet the oil supply needs of the air-conditioning unit under various working conditions.

[0057] Specifically, the oil circuit pipeline also includes: a bypass oil circuit 63, the bypass oil circuit 63 is connected to the converging pipe 62 (equivalent to the compressor side), and the other end is connected to the oil separator 2. The valve assembly specifically also includes a fourth solenoid valve 104 arranged on the bypass oil circuit 63, which is used to open and close the bypass oil circuit 63. The bypass oil circuit 63 is opened when the oil supply pressure difference is low to avoid excessive supply pressure of the oil pump operation, and can dynamically meet the pressure difference demand.

[0058] Specifically, a one-way valve is provided on the first branch pipe to prevent lubricating oil from flowing back on the first oil pump side, thereby ensuring normal oil supply under low differential pressure conditions.

[0059] In other embodiments, more oil pumps may be provided as required, for example, four oil pumps or six oil pumps, and the oil pipelines may be adjusted accordingly.

[0060] For example, when there are four oil pumps, two groups of oil pipelines and two groups of valve assemblies are set up. The oil pipeline main pipes 61 of the two groups of oil pipelines are connected to the outlet side of the oil cooler 3. Two oil pumps are set up for each group of oil pipelines. The structure of each group of oil pipelines and valve assemblies is consistent with the structure of the previous embodiment.

[0061] By selecting to connect one of the groups of oil pipelines, the oil pumps can also be connected in series, in parallel or individually.

[0062] like Figure 4 As shown, the utility model also proposes a control method for an oil circuit system, using the oil circuit system of the air conditioning unit mentioned above, the control method can be implemented by the control mainboard of the air conditioning unit (the controller mentioned above is integrated in the control mainboard), and the implementation specifically includes the steps of:

[0063] Detect the actual evaporation temperature of the air conditioning unit (referring to the saturation temperature corresponding to the suction pressure), and calculate the evaporation temperature deviation value ΔQ by subtracting the target evaporation temperature from the actual evaporation temperature;

[0064] According to the comparison result between the evaporation temperature deviation value ΔQ of the air conditioning unit and the preset deviation value, the valve assembly is adjusted to change the connection state of the multiple oil pumps.

[0065] The actual load-on / load-off condition of the unit can be determined by the evaporation temperature deviation value ΔQ, and the series, parallel, and single oil pump start / stop control of the oil pumps can be realized by controlling the start / stop of the oil pumps and the on / off of the solenoid valves of the oil circuit system. The unit's requirements for oil supply and oil supply pressure difference under different working conditions can be met, thereby meeting the operation requirements of the cold storage and saving energy and reducing consumption.

[0066] Specifically, when detecting the actual evaporation temperature of the air-conditioning unit, the oil supply temperature T of the oil supply main is also detected. When the oil supply temperature T is greater than or equal to the preset oil supply temperature upper limit, the control valve assembly switches the oil pipeline so that multiple oil pumps are in parallel.

[0067] Specifically, the comparison, judgment and control between the evaporation temperature deviation value ΔQ and the preset deviation value may be performed until the oil supply temperature T is less than the preset oil supply temperature upper limit value.

[0068] The above parallel state corresponds to the valves of the embodiment of two oil pumps and the opening of the oil pumps is specifically: opening the first oil pump and the second oil pump, opening the first solenoid valve and the third solenoid valve, and closing the second solenoid valve and the fourth solenoid valve.

[0069] When the oil supply temperature T of the oil supply main is too high, the inside of the compressor is in a high temperature state, and it is necessary to increase the flow rate in parallel as soon as possible, thereby increasing the flow rate on the oil side and improving the oil cooling heat exchange effect to avoid damage and failure that may cause the unit to shut down or affect the service life of the compressor.

[0070] Specifically, adjusting the valve assembly to change the connection state of multiple oil pumps according to the comparison result between the evaporation temperature deviation value ΔQ of the air conditioning unit and the preset deviation value specifically includes the following steps:

[0071] When the evaporation temperature deviation value ΔQ is greater than the preset load increase / decrease deviation value J corresponding to the rapid loading of the air-conditioning unit, or is less than the negative preset load increase / decrease deviation value J, the control valve assembly switches the oil pipeline so that the multiple oil pumps are in a series state;

[0072] The valves and the opening of the oil pumps in the embodiment of the series connection state corresponding to the two oil pumps are specifically as follows: opening the first oil pump and the second oil pump, opening the second solenoid valve, and closing the first, third and fourth solenoid valves.

[0073] When the evaporation temperature deviation value ΔQ is less than or equal to the preset load increase / decrease deviation value J, and greater than or equal to the dead zone deviation value S corresponding to the load maintained by the air conditioning unit, the oil pipeline is switched according to the oil supply pressure difference to change the connectivity of the multiple oil pumps.

[0074] That is, when the air-conditioning unit is in the fast loading and unloading control range, the unit operates at a high operating condition to make the cold storage temperature quickly reach the target temperature, requiring compressor 1 to quickly load and unload and cool down, and the required oil pressure is relatively high. At this time, turning on multiple oil pumps and switching them to a series state can increase the lubricating oil pressure and avoid insufficient oil supply; while the air-conditioning unit is in the process of slow loading and unloading, different loading speeds have different requirements for the oil supply flow rate, which is also related to the evaporation temperature and the oil supply pressure difference.

[0075] Specifically, switching the oil pipelines according to the oil supply pressure difference to change the connection state of the multiple oil pumps specifically includes:

[0076] When the oil supply pressure difference is greater than or equal to the sum of the preset minimum oil supply pressure difference and the preset compensation pressure, the control valve assembly connects the pipelines of the oil pipeline except the bypass oil pipeline, and shuts down all the oil pumps;

[0077] The opening of the oil pumps and valves corresponding to the above two oil pump embodiments is as follows: opening the first solenoid valve 101, the second solenoid valve 102 and the third solenoid valve 103, closing the fourth solenoid valve, and closing the first oil pump 91 and the second oil pump 92;

[0078] The air-conditioning unit is in the process of slow loading and unloading. At this time, the required oil pressure is lower. If the oil supply pressure difference is sufficient, there is no need to start the oil pump and the oil supply pipeline can be directly connected to automatically supply oil. The oil supply method can be flexibly selected through the oil supply pressure difference to suit the operating conditions and reduce ineffective work.

[0079] When the oil supply pressure difference is less than or equal to the preset minimum oil supply pressure difference, the oil pump with the shortest cumulative running time is turned on, and the valve assembly is controlled to connect the oil pump with the shortest cumulative running time alone.

[0080] The opening of the oil pump and the valve corresponding to the above two oil pump embodiments is as follows:

[0081] If the oil pump with the shortest running time is the first oil pump, the first oil pump is turned on, the second oil pump is turned off, the third solenoid valve and the fourth solenoid valve are turned on, and the first solenoid valve and the second solenoid valve are turned off.

[0082] If the oil pump with the shortest running time is the second oil pump, the second oil pump is turned on, the first oil pump is turned off, the first solenoid valve and the fourth solenoid valve are turned on, and the third solenoid valve and the second solenoid valve are turned off.

[0083] The air-conditioning unit is in the process of slow loading and unloading. At this time, the required oil pressure is relatively low. If the oil supply pressure difference is sufficient, there is no need to start the oil pump and directly connect the oil supply pipeline to automatically supply oil. If the oil supply pressure difference is low, some oil pumps need to be turned on for oil supply to avoid insufficient oil supply pressure. The oil supply method can be flexibly selected through the oil supply pressure difference to reduce ineffective work according to the operating conditions. At the same time, when turning on some oil pumps, the oil pump with the shortest running time is turned on first to balance the service life of the oil pumps and avoid failure of a single oil pump first.

[0084] Specifically, the control valve assembly is used to individually connect the oil pump with the shortest cumulative running time, and after running for the first preset time t1, if the oil supply pressure difference is still less than or equal to the preset minimum oil supply pressure difference, multiple oil pumps are turned on, and the oil pipelines are switched so that the multiple oil pumps are in series, until the oil supply pressure difference is detected to be greater than or equal to the sum of the preset minimum oil supply pressure difference and the preset compensation pressure for the second consecutive preset time t2, the control valve assembly switches the oil pipeline to individually connect the oil pump with the shortest cumulative running time, and shuts down other oil pumps.

[0085] Specifically, it is because the wet bulb temperature is low in winter, and the unit is cooled by the evaporative condenser. The low condensation temperature leads to low exhaust pressure and low pressure before the oil pump. At the same time, the oil viscosity increases, the oil line loss increases, and finally the oil supply pressure is low. The pressure on the evaporation side remains unchanged. Opening a single oil pump still cannot meet the minimum oil supply pressure difference requirement. Multiple oil pumps are turned on at the same time, and the head is increased in series to meet the required oil supply pressure.

[0086] The specific numerical values ​​are as follows:

[0087] The above-mentioned preset load-on / load-off deviation value J and dead zone deviation value S can be set to reasonable values ​​as needed. For example, the preset load-on / load-off deviation value J is set to 15°, and the dead zone deviation value S is set to 3°. When the calculated evaporation temperature deviation ΔQ is 8°, it is between the load-on / load-off deviation value J and the dead zone deviation value S. At this time, the unit operating condition is relatively low, and the oil pipeline is switched according to the oil supply pressure difference to change the connection state of the multiple oil pumps.

[0088] The calculation of the oil supply pressure difference is: the oil supply pressure difference is equal to the detected oil supply main pipe pressure minus the suction pressure. The preset compensation pressure can be set to 100kpa or other reasonable values.

[0089] The first preset time t1 and the second preset time t2 can be set to the same time or different times, and are adjusted according to the actual situation of the unit.

[0090] The utility model also proposes an air conditioning unit, specifically including the above-mentioned oil circuit system. The specific air conditioning unit can be an ultra-low temperature open screw compressor unit, which is used to cool the cold storage warehouse. The air conditioning unit includes an air circuit system and an oil circuit system. The air circuit system includes a compressor 1, an oil separator 2, an external evaporator, etc. The refrigerant vapor is compressed from the external evaporator by the compressor 1 and mixed with the lubricating oil sprayed into the compressor 1. The high-pressure gas separated by the oil separator 2 is discharged into the external condenser through the exhaust stop valve.

[0091] The air-conditioning unit adopts this oil circuit system to flexibly adjust the oil supply status of the oil circuit to match it with the operating conditions of the air-conditioning unit, accurately adapt to operating needs, save energy and reduce consumption, and avoid insufficient oil supply pressure or excessive oil temperature.

[0092] It should be noted that the terms used above are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0093] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps described in these embodiments do not limit the scope of the utility model. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0094] In the description of the present utility model, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present utility model; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0095] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0096] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the utility model.

[0097] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An oil circuit system of an air conditioning unit, characterized in that: include: An oil pipeline connected between the oil separator and the compressor of the air conditioning unit; A plurality of oil pumps are arranged on the oil pipeline; The valve assembly is arranged on the oil pipeline, and can switch the oil pipeline to change the connection state of the multiple oil pumps, so that the multiple oil pumps are in a parallel state, a series state, or a single connection state.

2. The oil circuit system of the air conditioning unit according to claim 1, characterized in that: The plurality of oil pumps specifically include a first oil pump and a second oil pump.

3. The oil circuit system of the air conditioning unit according to claim 2, characterized in that: The oil pipeline includes: an oil main pipe with one end connected to the oil outlet side of the oil separator of the air-conditioning unit, a first branch pipe and a second branch pipe connected in parallel to the other end of the oil main pipe, a first branch pipe and a second branch pipe connected in parallel to the end of the second branch pipe, the end of the first branch pipe is connected to the first branch pipe, the first branch pipe and the second branch pipe are connected to the compressor side of the air-conditioning unit, the first oil pump is arranged on the first branch pipe, and the second oil pump is arranged on the second branch pipe.

4. The oil circuit system of the air conditioning unit according to claim 3, characterized in that: The valve assembly specifically includes: a first solenoid valve arranged on the second branch pipe, and a second solenoid valve and a third solenoid valve arranged on the first branch pipe at intervals on both sides of the connection position of the end of the first branch pipe.

5. The oil circuit system of the air conditioning unit according to claim 1, characterized in that: The oil pipeline also includes: a bypass oil circuit connected between the oil separator of the air conditioning unit and the compressor and in parallel with the pipeline where the oil pump is set. The valve assembly specifically includes a fourth solenoid valve set on the bypass oil circuit.

6. The oil circuit system of the air conditioning unit according to claim 3, characterized in that: The first branch pipe is provided with a one-way valve.

7. The oil circuit system of the air conditioning unit according to claim 3, characterized in that: Also includes: An oil cooler is arranged between the oil main pipe and the oil outlet side of the oil separator.

8. The oil circuit system of the air conditioning unit according to claim 3, characterized in that: Also includes: An oil filter is connected to the first branch pipe and the second branch pipe, and is used for filtering lubricating oil flowing to the compressor side.

9. The oil circuit system of the air conditioning unit according to claim 8, characterized in that: Also includes: The oil supply main pipe is connected between the oil filter and the compressor, and each oil supply branch pipe of the oil supply main pipe is connected to each oil supply port of the compressor.

10. An air conditioning unit, characterized in that: Comprising the oil circuit system according to any one of claims 1 to 9.

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