Oil supply system, air conditioning unit and control method of air conditioning unit

Abstract

The invention discloses an oil supply system, an air conditioning unit and a control method of the air conditioning unit, the oil supply system is used for supplying oil to an open-type screw compressor, and the open-type screw compressor comprises an exhaust pipeline and an oil return pipeline; the oil supply system comprises an oil-gas transmission system, the oil-gas transmission system comprises a gas driving pipeline, a transmission device and a lubricating oil driven pipeline, the gas driving pipeline is connected with an exhaust pipeline of the open-type screw compressor, one end of the transmission device is connected with the gas driving pipeline, and the other end of the transmission device is connected with the lubricating oil driven pipeline; and the oil-gas transmission system is used for driving the lubricating oil in the oil return pipeline to return by adopting the gaseous refrigerant in the exhaust pipeline. The problems that in the prior art, an oil supply oil pump of a semi-closed screw compressor needs to work continuously and is difficult to supply oil along with changes of working conditions are solved, the oil pump function is achieved, corresponding oil flow and oil pressure can be provided under different working conditions, and a unit can obtain sufficient lubricating, cooling and sealing effects under various working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an oil supply system, an air conditioning unit and a control method thereof. Background Art

[0002] For large open screw compressor refrigeration units, compared with semi-closed screw compressors, open compressors have higher requirements for lubrication, cooling, and sealing. If the compressor does not receive sufficient refrigeration oil supply during operation, it will cause problems such as excessively high compressor exhaust temperature and poor sealing, which will lead to reduced energy efficiency and even compressor damage. Therefore, common open screw compressor refrigeration units are equipped with oil supply measures - oil pumps, which continuously force oil supply to the compressor to maintain normal operation of the compressor.

[0003] However, existing oil pumps have many disadvantages: the oil pump needs to work continuously to maintain the normal operation of the compressor, which will shorten the service life of the oil pump. The oil pump is difficult to adapt to the different oil pressures required by the continuous changes in working conditions, and it is difficult to control the oil pressure to change with the working conditions, which is not conducive to the stable operation of the compressor.

[0004] With regard to the problem in the related art that the oil supply pump of the semi-hermetic screw compressor needs to work continuously and is difficult to supply oil as the working conditions change, no effective solution has been proposed so far. Summary of the invention

[0005] The present invention provides an oil supply system, an air conditioning unit and a control method thereof, so as to at least solve the problem in the prior art that the oil supply pump of a semi-hermetic screw compressor needs to work continuously and is difficult to supply oil with changes in working conditions.

[0006] To solve the above technical problems, according to one aspect of an embodiment of the present invention, there is provided an oil supply system for supplying oil to an open screw compressor, wherein the open screw compressor comprises an exhaust pipeline and an oil return pipeline; the oil supply system comprises: an oil-gas transmission system, comprising: a gas drive pipeline, a transmission device and a lubricating oil driven pipeline, the gas drive pipeline is connected to the exhaust pipeline of the open screw compressor, one end of the transmission device is connected to the gas drive pipeline, and the other end is connected to the lubricating oil driven pipeline, the oil-gas transmission system is used to use the gaseous refrigerant in the exhaust pipeline to drive the lubricating oil in the oil return pipeline for oil return.

[0007] Furthermore, the transmission device includes: a steam turbine, located on the gas driving pipeline, and the steam turbine is driven by the gaseous refrigerant in the exhaust pipeline to operate; a pump wheel, located on the lubricating oil driven pipeline, and used to drive the lubricating oil in the return oil pipeline to flow; a transmission shaft, one end of which is connected to the steam turbine and the other end of which is connected to the pump wheel, and is used to drive the pump wheel to operate using the steam turbine.

[0008] Furthermore, it also includes: a bypass solenoid valve, located on the exhaust pipeline; the air inlet end of the gas drive pipeline is connected to the air inlet end of the bypass solenoid valve, and the air outlet end of the gas drive pipeline is connected to the air outlet end of the bypass solenoid valve.

[0009] Furthermore, it also includes: an oil pump, located on the lubricating oil driven pipeline; the liquid inlet end of the lubricating oil driven pipeline is connected to the liquid inlet end of the oil pump, and the liquid outlet end of the lubricating oil driven pipeline is connected to the liquid outlet end of the oil pump.

[0010] Furthermore, it also includes: a pressure sensor, located at the return oil port of the open screw compressor, for detecting the return oil pressure of the open screw compressor; a check valve, located at the liquid outlet end of the lubricating oil driven pipeline, for preventing the lubricating oil in the lubricating oil driven pipeline from flowing back.

[0011] According to another aspect of an embodiment of the present invention, there is provided an air conditioning unit, comprising the above-mentioned oil supply system and an open screw compressor.

[0012] Furthermore, the air-conditioning unit also includes: an oil separator, located at the exhaust port of the open screw compressor; wherein the bypass solenoid valve of the oil supply system is located on the pipeline between the oil separator and the condenser of the air-conditioning unit; an oil cooler, one end of which is connected to the lubricating oil outlet of the oil separator, and the other end is connected to the oil return port of the open screw compressor; wherein the oil pump of the oil supply system is located on the pipeline between the oil cooler and the oil return port of the open screw compressor.

[0013] According to another aspect of an embodiment of the present invention, a method for controlling an air-conditioning unit is provided, which is applied to an air-conditioning unit as described above, and the method includes: detecting a current return oil pressure of an open screw compressor; obtaining a preset range of the return oil pressure of the open screw compressor; and controlling the return oil system to return oil according to the current return oil pressure and the preset range of the return oil pressure.

[0014] Furthermore, before detecting the current return oil pressure of the open screw compressor, it also includes: after the air-conditioning unit is turned on, controlling the oil pump of the oil return system to start; after the oil pump is turned on for a preset time, controlling the open screw compressor to start; after the open screw compressor is turned on, triggering the detection of the current return oil pressure of the open screw compressor.

[0015] Furthermore, the oil return system is controlled to return oil according to the current oil return pressure and the preset range of oil return pressure, including: when the current oil return pressure is less than the minimum value of the preset range of oil return pressure, the oil pump is controlled to remain in an open state; when the current oil return pressure is greater than or equal to the minimum value of the preset range of oil return pressure and less than the maximum value of the preset range of oil return pressure, the oil pump is controlled to gradually unload; when the current oil return pressure is greater than the maximum value of the preset range of oil return pressure, it is detected whether the oil pump is shut down, and after the oil pump is shut down, the bypass solenoid valve of the oil return system is controlled to open.

[0016] According to another aspect of an embodiment of the present invention, there is provided a storage medium comprising computer executable instructions, wherein the computer executable instructions are used to execute the air conditioning unit control method as described above when executed by a computer processor.

[0017] In the present invention, an oil supply system with adaptive working conditions is provided to supply oil for an open screw compressor. The oil supply system includes an oil-gas transmission system for oil supply. The oil-gas transmission system includes: a gas driving pipeline, a transmission device and a lubricating oil driven pipeline. The gas driving pipeline is connected to the exhaust pipeline of the open screw compressor, one end of the transmission device is connected to the gas driving pipeline, and the other end is connected to the lubricating oil driven pipeline. The oil-gas transmission system is used to use the gaseous refrigerant in the exhaust pipeline to drive the lubricating oil in the return oil pipeline for oil return. The exhaust system uses the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow. The higher the compressor speed, the greater the amount of oil supplied, which just meets the situation that the higher the compressor speed, the greater the amount of refrigeration oil required. Therefore, the present invention uses the kinetic energy of the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow, which can provide corresponding oil flow and oil pressure under different working conditions, so that the unit can obtain sufficient lubrication, cooling and sealing effects under various working conditions. At the same time, under reasonable use, it can replace the oil pump function to avoid the loss of the oil pump caused by continuous operation of the oil pump, reduce the power consumption of the oil pump, lower the cost of use, increase the service life of the oil pump, and improve the energy efficiency and operating stability of the compressor, especially the open screw compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is an optional structural schematic diagram of an oil supply system according to an embodiment of the present invention;

[0019] Figure 2 is an optional flow chart of the air conditioning unit control method according to an embodiment of the present invention.

[0020] Description of reference numerals:

[0021] 1. Compressor; 2. Oil separator; 3. Condenser; 4. Oil cooler; 5. Steam turbine; 6. Drive shaft; 7. Pump wheel; 8. Bypass solenoid valve; 9. Oil pump; 10. Oil return port; 11. Check valve. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0024] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0025] It should be understood that although the terms first, second, third, etc. may be used to describe controllers in embodiments of the present invention, these controllers should not be limited to these terms. These terms are only used to distinguish controllers connected to different devices. For example, without departing from the scope of embodiments of the present invention, a first controller may also be referred to as a second controller, and similarly, a second controller may also be referred to as a first controller.

[0026] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0027] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0028] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] Example 1

[0030] As mentioned above, the existing oil pump has many disadvantages: the oil pump needs to work continuously to maintain the normal operation of the compressor, which will shorten the service life of the oil pump. The oil pump is difficult to adapt to the different oil pressures required for the continuous changes in working conditions, and it is difficult to control the oil pressure to change with the working conditions, which is not conducive to the stable operation of the compressor.

[0031] Based on the problem that the oil supply pump of the semi-closed screw compressor needs to work continuously and is difficult to supply oil as the working conditions change, an oil supply system is provided in a preferred embodiment 1 of the present invention for supplying oil to an open screw compressor, and the open screw compressor includes an exhaust pipeline and an oil return pipeline.

[0032] Specifically, Figure 1 An optional structural diagram of the oil supply system is shown in FIG. Figure 1 As shown, the oil supply system includes an oil-gas transmission system, and the oil-gas transmission system includes:

[0033] Gas drive pipeline;

[0034] Transmission device;

[0035] The lubricating oil is driven into the pipeline;

[0036] Among them, the gas driving pipeline is connected to the exhaust pipeline of the open screw compressor 1, one end of the transmission device is connected to the gas driving pipeline, and the other end is connected to the lubricating oil driven pipeline, and the oil-gas transmission system is used to use the gaseous refrigerant in the exhaust pipeline to drive the lubricating oil in the return oil pipeline for oil return.

[0037] In the above embodiment, an oil supply system with adaptive working conditions is provided to supply oil for an open screw compressor. The oil supply system includes an oil-gas transmission system for oil supply. The oil-gas transmission system includes: a gas drive pipeline, a transmission device and a lubricating oil driven pipeline. The gas drive pipeline is connected to the exhaust pipeline of the open screw compressor, one end of the transmission device is connected to the gas drive pipeline, and the other end is connected to the lubricating oil driven pipeline. The oil-gas transmission system is used to use the gaseous refrigerant in the exhaust pipeline to drive the lubricating oil in the return oil pipeline for oil return. The exhaust system uses the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow. The higher the compressor speed, the greater the amount of oil supplied, which just meets the situation that the higher the compressor speed, the greater the amount of refrigeration oil required. Therefore, the present invention uses the kinetic energy of the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow, which can provide corresponding oil flow and oil pressure under different working conditions, so that the unit can obtain sufficient lubrication, cooling and sealing effects under various working conditions. At the same time, under reasonable use, it can replace the oil pump function to avoid the loss of the oil pump caused by continuous operation of the oil pump, reduce the power consumption of the oil pump, lower the cost of use, increase the service life of the oil pump, and improve the energy efficiency and operating stability of the compressor, especially the open screw compressor.

[0038] like Figure 1 As shown, the transmission device includes: a steam turbine 5, which is located on the gas driving pipeline and is driven by the gaseous refrigerant in the exhaust pipeline to operate; a pump wheel 7, which is located on the lubricating oil driven pipeline and is used to drive the lubricating oil in the return oil pipeline to flow; a transmission shaft 6, which is connected to the steam turbine 5 at one end and to the pump wheel 7 at the other end, and is used to drive the pump wheel 7 to operate by the steam turbine 5. Optionally, the transmission shaft 6 is a sealed transmission shaft to improve the transmission effect.

[0039] In addition, it also includes a sealed casing, that is, the transmission device is composed of a steam turbine 5, a sealed transmission shaft 6, a pump wheel 7 and a sealed casing. The number and size of blades of the oil pump 9, the steam turbine 5 and the pump wheel 7 are designed according to the required oil supply of the unit. The high-temperature and high-pressure refrigerant exhausted by the compressor is fully utilized to drive the lubricating oil to return to the oil return port 10 of the compressor, and it is adapted to the load and working conditions of the compressor to maintain the operating stability of the compressor and the oil supply system.

[0040] In order to achieve accurate control of oil supply, the oil supply system also includes: a bypass solenoid valve 8, which is located on the exhaust pipeline; the air inlet end of the gas drive pipeline is connected to the air inlet end of the bypass solenoid valve 8, and the air outlet end of the gas drive pipeline is connected to the air outlet end of the bypass solenoid valve 8. When the main solenoid valve of the exhaust pipe is opened, the speed of the turbine 5 is reduced due to the exhaust bypass, thereby reducing the speed of the oil pump 9 and the oil pressure to prevent the compressor from running with liquid due to excessive oil supply.

[0041] Preferably, it also includes: an oil pump 9, which is located on the lubricating oil driven pipeline; the liquid inlet end of the lubricating oil driven pipeline is connected to the liquid inlet end of the oil pump 9, and the liquid outlet end of the lubricating oil driven pipeline is connected to the liquid outlet end of the oil pump 9.

[0042] The oil pump 9 and the oil-gas transmission system can supply oil separately or be used simultaneously. Optionally, before the open screw compressor 1 refrigeration unit is started, the oil pump 9 is started first to pre-lubricate the moving parts of the compressor 1 to reduce dry friction during startup and keep the unit running stably. After the compressor 1 is started, the low-pressure refrigerant enters the compressor 1 from the air intake port, and after being compressed, it forms a high-temperature and high-pressure gas and enters the oil separator to separate the refrigeration oil (lubricating oil) and the refrigerant. The solenoid valve is closed. After the refrigerant is separated, it enters the condenser 3 through the steam turbine 5 for cooling. The steam turbine 5 is driven by the high-pressure refrigerant and drives the pump wheel 7 through the sealed transmission shaft 6. After the refrigeration oil is separated, it flows from the oil separator to the oil cooler 4 and then flows into the oil supply port of the compressor 1 through the oil pump 9 or the pump wheel 7. Due to the drive of the steam turbine 5, the pump wheel 7 can pressurize the refrigeration oil on this road to increase the oil supply pressure or oil volume.

[0043] like Figure 1 As shown, it also includes: a pressure sensor, located at the return oil port 10 of the open screw compressor 1, for detecting the return oil pressure of the open screw compressor 1; a check valve 11, located at the liquid outlet end of the lubricating oil driven pipeline, for preventing the lubricating oil in the lubricating oil driven pipeline from flowing back.

[0044] In order to carry out precise control, a pressure sensor is added to detect the return oil pressure of the open screw compressor. As the compressor is loaded, the refrigerant flow and refrigerant pressure gradually increase, the speed of the steam turbine and the pump impeller also increase accordingly, and the pressure of the refrigeration oil supplied by the pump impeller gradually increases. The operation of the oil supply system can be adjusted according to the return oil pressure to avoid insufficient lubrication caused by insufficient oil supply, or excessive oil supply causing the compressor to run with liquid.

[0045] Example 2

[0046] Based on the oil supply system provided in the above-mentioned embodiment 1, in a preferred embodiment 2 of the present invention, an air-conditioning unit is further provided, comprising the above-mentioned oil supply system.

[0047] Figure 1 Also shown is an optional structural schematic diagram of the air conditioning unit where the oil supply system is located, such as Figure 1 As shown, the air conditioning unit includes the above-mentioned oil supply system and an open screw compressor.

[0048] In addition, the air conditioning unit also includes:

[0049] The oil separator 2 is located at the exhaust port of the open screw compressor 1; wherein the bypass solenoid valve 8 of the oil supply system is located on the pipeline between the oil separator 2 and the condenser 3 of the air conditioning unit;

[0050] The oil cooler 4 has one end connected to the lubricating oil outlet of the oil separator 2 and the other end connected to the oil return port 10 of the open screw compressor; wherein the oil pump 9 of the oil supply system is located on the pipeline between the oil cooler 4 and the oil return port 10 of the open screw compressor.

[0051] The refrigeration oil supply system of the air-conditioning unit where the open screw compressor is located is mainly composed of an oil pump, an oil-gas transmission system (consisting of a steam turbine, a sealed transmission shaft, a pump wheel and a sealed housing), a pressure sensor, a check valve, a solenoid valve, etc. The number and size of the oil pump, steam turbine and pump wheel blades are designed according to the required oil supply of the unit.

[0052] Before starting the open screw compressor refrigeration unit, the oil pump is started first to pre-lubricate the moving parts of the compressor to reduce dry friction during startup and keep the unit running stably.

[0053] After the compressor is started, the low-pressure refrigerant enters the compressor from the air intake port, is compressed to form high-temperature and high-pressure gas, and enters the oil separator to separate the refrigeration oil and the refrigerant. The solenoid valve is closed, and the refrigerant enters the condenser through the steam turbine for cooling after separation. The steam turbine is driven by the high-pressure refrigerant and drives the pump impeller through the sealed transmission shaft.

[0054] After the refrigerant oil is separated, it flows to the oil cooler through the oil pump or pump wheel and then flows into the oil supply port of the compressor. The pump wheel can pressurize the refrigerant oil on this path due to the drive of the steam turbine.

[0055] In the above embodiment, an oil supply system with adaptive working conditions is provided to supply oil for an open screw compressor. The oil supply system includes an oil-gas transmission system for oil supply. The oil-gas transmission system includes: a gas drive pipeline, a transmission device and a lubricating oil driven pipeline. The gas drive pipeline is connected to the exhaust pipeline of the open screw compressor, one end of the transmission device is connected to the gas drive pipeline, and the other end is connected to the lubricating oil driven pipeline. The oil-gas transmission system is used to use the gaseous refrigerant in the exhaust pipeline to drive the lubricating oil in the return oil pipeline for oil return. The exhaust system uses the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow. The higher the compressor speed, the greater the amount of oil supplied, which just meets the situation that the higher the compressor speed, the greater the amount of refrigeration oil required. Therefore, the present invention uses the kinetic energy of the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow, which can provide corresponding oil flow and oil pressure under different working conditions, so that the unit can obtain sufficient lubrication, cooling and sealing effects under various working conditions. At the same time, under reasonable use, it can replace the oil pump function to avoid the loss of the oil pump caused by continuous operation of the oil pump, reduce the power consumption of the oil pump, lower the cost of use, increase the service life of the oil pump, and improve the energy efficiency and operating stability of the compressor, especially the open screw compressor.

[0056] Example 3

[0057] As shown above, the refrigeration oil supply system of the air-conditioning unit where the open screw compressor is located is mainly composed of an oil pump, an oil-gas transmission system (consisting of a steam turbine, a sealed transmission shaft, a pump wheel and a sealed housing), a pressure sensor, a check valve, a solenoid valve, etc. The number and size of the oil pump, steam turbine and pump wheel blades are designed according to the required oil supply of the unit.

[0058] Based on the above air conditioning unit, a preferred embodiment 3 of the present invention provides an air conditioning unit control method, which is applied to the air conditioning unit in the above embodiment 2.

[0059] Specifically, Figure 2 An optional flow chart of the method is shown as follows: Figure 2 As shown, the method includes the following steps S202-S206:

[0060] S202: Detecting the current oil return pressure of the open screw compressor;

[0061] S204: Obtaining a preset range of the return oil pressure of the open screw compressor;

[0062] S206: Control the oil return system to return oil according to the current oil return pressure and the preset oil return pressure range.

[0063] In the above embodiment, an oil supply system with adaptive working conditions is provided to supply oil for an open screw compressor. The oil supply system includes an oil-gas transmission system for oil supply. The oil-gas transmission system includes: a gas drive pipeline, a transmission device and a lubricating oil driven pipeline. The gas drive pipeline is connected to the exhaust pipeline of the open screw compressor, one end of the transmission device is connected to the gas drive pipeline, and the other end is connected to the lubricating oil driven pipeline. The oil-gas transmission system is used to use the gaseous refrigerant in the exhaust pipeline to drive the lubricating oil in the return oil pipeline for oil return. The exhaust system uses the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow. The higher the compressor speed, the greater the amount of oil supplied, which just meets the situation that the higher the compressor speed, the greater the amount of refrigeration oil required. Therefore, the present invention uses the kinetic energy of the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow, which can provide corresponding oil flow and oil pressure under different working conditions, so that the unit can obtain sufficient lubrication, cooling and sealing effects under various working conditions. At the same time, under reasonable use, it can replace the oil pump function to avoid the loss of the oil pump caused by continuous operation of the oil pump, reduce the power consumption of the oil pump, lower the cost of use, increase the service life of the oil pump, and improve the energy efficiency and operating stability of the compressor, especially the open screw compressor.

[0064] Preferably, before detecting the current return oil pressure of the open screw compressor, it also includes: after the air-conditioning unit is turned on, controlling the oil pump of the oil return system to start; after the oil pump is turned on for a preset time, controlling the open screw compressor to start; after the open screw compressor is turned on, triggering the detection of the current return oil pressure of the open screw compressor.

[0065] Before starting the open screw compressor refrigeration unit, the oil pump is started first to pre-lubricate the moving parts of the compressor to reduce dry friction during startup and keep the unit running stably. After the compressor is started, the low-pressure refrigerant enters the compressor from the air intake port, and after being compressed, it forms high-temperature and high-pressure gas and enters the oil separator to separate the refrigeration oil and the refrigerant. The solenoid valve is closed, and the refrigerant enters the condenser through the steam turbine for cooling after separation. The steam turbine is driven by the high-pressure refrigerant and drives the pump wheel through the sealed transmission shaft.

[0066] After the open screw compressor is turned on, the oil return system is controlled to return oil according to the current return oil pressure and the preset range of the return oil pressure, including: when the current return oil pressure is less than the minimum value of the preset range of the return oil pressure, the oil pump is controlled to remain in the open state; when the current return oil pressure is greater than or equal to the minimum value of the preset range of the return oil pressure and less than the maximum value of the preset range of the return oil pressure, the oil pump is controlled to gradually unload; when the current return oil pressure is greater than the maximum value of the preset range of the return oil pressure, it is detected whether the oil pump is shut down, and the bypass solenoid valve of the oil return system is controlled to open after the oil pump is shut down.

[0067] In the unit control, the minimum oil pressure parameter Pl, that is, the minimum value of the return oil pressure preset range, and the maximum oil pressure parameter Ph, that is, the maximum value of the return oil pressure preset range, are added. As the compressor is loaded, the refrigerant flow and refrigerant pressure gradually increase, the turbine and pump wheel speeds also increase accordingly, and the pressure of the pump wheel on the refrigeration oil gradually increases.

[0068] At this time, if the compressor oil return port pressure P is less than Pl, the oil pump remains on and the compressor continues to load;

[0069] If Ph>P≥Pl, the oil pump begins to unload gradually from 100% to 0%;

[0070] If P>Ph and the oil pump is in the shutdown state, the main solenoid valve of the compressor exhaust pipe opens, and the turbine speed is reduced due to the exhaust bypass, thereby reducing the oil pump speed and the oil pressure to prevent excessive oil supply from causing liquid in the compressor.

[0071] The higher the compressor speed, the greater the amount of refrigeration oil required. This invention uses the kinetic energy of the exhaust high-temperature and high-pressure refrigerant gas to drive the oil flow. That is, the higher the compressor load, the greater the amount of oil supplied. Under a reasonable control method, it can replace part of the oil pump power consumption, with lower cost of use. It can provide corresponding oil flow and oil pressure under different working conditions, thereby improving the energy efficiency and stability of the system.

[0072] Example 4

[0073] Based on the air conditioning unit control method provided in the above-mentioned embodiment 3, a storage medium containing computer executable instructions is also provided in a preferred embodiment 4 of the present invention. When the computer executable instructions are executed by a computer processor, they are used to execute the air conditioning unit control method as described above.

[0074] In the above embodiment, an oil supply system with adaptive working conditions is provided to supply oil for an open screw compressor. The oil supply system includes an oil-gas transmission system for oil supply. The oil-gas transmission system includes: a gas drive pipeline, a transmission device and a lubricating oil driven pipeline. The gas drive pipeline is connected to the exhaust pipeline of the open screw compressor, one end of the transmission device is connected to the gas drive pipeline, and the other end is connected to the lubricating oil driven pipeline. The oil-gas transmission system is used to use the gaseous refrigerant in the exhaust pipeline to drive the lubricating oil in the return oil pipeline for oil return. The exhaust system uses the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow. The higher the compressor speed, the greater the amount of oil supplied, which just meets the situation that the higher the compressor speed, the greater the amount of refrigeration oil required. Therefore, the present invention uses the kinetic energy of the high-temperature and high-pressure refrigerant gas of the exhaust to drive the oil flow, which can provide corresponding oil flow and oil pressure under different working conditions, so that the unit can obtain sufficient lubrication, cooling and sealing effects under various working conditions. At the same time, under reasonable use, it can replace the oil pump function to avoid the loss of the oil pump caused by continuous operation of the oil pump, reduce the power consumption of the oil pump, lower the cost of use, increase the service life of the oil pump, and improve the energy efficiency and operating stability of the compressor, especially the open screw compressor.

[0075] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0076] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0077] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0078] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0079] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0080] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0081] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not invented by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0082] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. An oil supply system, characterized in that: Used to supply oil to an open screw compressor, wherein the open screw compressor comprises an exhaust pipeline and an oil return pipeline; The oil supply system comprises: The oil-gas transmission system comprises: a gas driving pipeline, a transmission device and a lubricating oil driven pipeline, wherein the gas driving pipeline is connected to the exhaust pipeline of the open screw compressor, one end of the transmission device is connected to the gas driving pipeline, and the other end is connected to the lubricating oil driven pipeline, and the oil-gas transmission system is used to use the gaseous refrigerant in the exhaust pipeline to drive the lubricating oil in the oil return pipeline for oil return.

2. The oil supply system according to claim 1, characterized in that: The transmission device comprises: A steam turbine, located on the gas drive pipeline, the steam turbine is driven by the gaseous refrigerant in the exhaust pipeline to operate; A pump wheel, located on the lubricating oil driven pipeline, used for driving the lubricating oil in the oil return pipeline to flow; A transmission shaft, one end of which is connected to the steam turbine and the other end of which is connected to the pump wheel, is used to drive the pump wheel to operate using the steam turbine.

3. The oil supply system according to claim 1, characterized in that: Also includes: A bypass solenoid valve is located on the exhaust pipeline; The air inlet end of the gas drive pipeline is connected to the air inlet end of the bypass solenoid valve, and the air outlet end of the gas drive pipeline is connected to the air outlet end of the bypass solenoid valve.

4. The oil supply system according to claim 1, characterized in that: Also includes: An oil pump, located on the lubricating oil driven pipeline; The liquid inlet end of the lubricating oil driven pipeline is connected to the liquid inlet end of the oil pump, and the liquid outlet end of the lubricating oil driven pipeline is connected to the liquid outlet end of the oil pump.

5. The oil supply system according to claim 4, characterized in that: Also includes: A pressure sensor, located at the oil return port of the open screw compressor, for detecting the oil return pressure of the open screw compressor; A check valve is located at the liquid outlet end of the lubricating oil driven pipeline and is used to prevent the lubricating oil in the lubricating oil driven pipeline from flowing back.

6. An air conditioning unit, characterized in that: It comprises an oil supply system and an open screw compressor as described in any one of claims 1 to 5.

7. The air conditioning unit according to claim 6, characterized in that: The air conditioning unit also includes: An oil separator is located at the exhaust port of the open screw compressor; wherein the bypass solenoid valve of the oil supply system is located on the pipeline between the oil separator and the condenser of the air conditioning unit; An oil cooler, one end of which is connected to the lubricating oil outlet of the oil separator, and the other end of which is connected to the oil return port of the open screw compressor; wherein the oil pump of the oil supply system is located on the pipeline between the oil cooler and the oil return port of the open screw compressor.

8. An air conditioning unit control method, applied to the air conditioning unit according to any one of claims 6 to 7, characterized in that: The method comprises: Detect the current return oil pressure of the open screw compressor; Obtaining a preset range of return oil pressure of the open screw compressor; The oil return system is controlled to return oil according to the current oil return pressure and the preset range of oil return pressure.

9. The method according to claim 8, characterized in that Before detecting the current oil return pressure of the open screw compressor, the method further includes: After the air conditioning unit is turned on, controlling the oil pump of the oil return system to start; After the oil pump is turned on for a preset time, controlling the open screw compressor to turn on; After the open screw compressor is turned on, the detection of the current oil return pressure of the open screw compressor is triggered.

10. The method according to claim 9, characterized in that Controlling the oil return system to return oil according to the current oil return pressure and the preset oil return pressure range includes: When the current oil return pressure is less than the minimum value of the preset range of oil return pressure, controlling the oil pump to remain in an on state; When the current oil return pressure is greater than or equal to the minimum value of the preset oil return pressure range and less than the maximum value of the preset oil return pressure range, controlling the oil pump to gradually unload; When the current oil return pressure is greater than the maximum value of the preset range of the oil return pressure, it is detected whether the oil pump is shut down, and after the oil pump is shut down, the bypass solenoid valve of the oil return system is controlled to open.

11. A storage medium containing computer executable instructions, characterized in that: The computer executable instructions are used to execute the air conditioning unit control method according to any one of claims 8 to 10 when executed by a computer processor.

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