An oil separator and oil return system, oil return control method and device

Abstract

This invention discloses an oil separator, an oil return system, an oil return control method, and an apparatus. The oil separator is divided into a high-pressure chamber and a low-pressure chamber. The high-pressure chamber is connected to the compressor's exhaust pipe, and the low-pressure chamber is connected to the compressor's suction pipe via an oil return pipe. The oil separator includes a first valve and a second valve, both used to control the connection between the high-pressure and low-pressure chambers. The first valve opens when the oil in the high-pressure chamber reaches a preset amount, allowing oil to flow into the low-pressure chamber. The second valve controls the pressure difference between the high-pressure and low-pressure chambers to maintain a set pressure difference, wherein the set pressure difference matches the required oil return amount of the compressor under the current operating conditions. This invention integrates the oil return control components into the oil separator, avoiding overly complex design of the oil return pipeline components, improving reliability, and enabling precise control of the oil return rate and amount through the second valve, ensuring a reasonable oil return amount under different operating conditions, while maintaining stable oil return pressure and reducing oil return pulsation.

Description

Technical Field

[0001] This invention relates to the field of oil return technology, and more specifically, to an oil separator and oil return system, an oil return control method and device. Background Technology

[0002] During the compressor's discharge process, some hydraulic oil is carried out. To prevent the compressor from running out of oil, an oil separator is usually installed after the discharge pipe to separate the oil in the refrigerant to the bottom of the oil separator. Then, through the oil return assembly, the oil at the bottom of the oil separator is pressed into the suction pipe and then enters the compressor, ensuring the compressor operates safely and efficiently.

[0003] Currently, the control of the oil return rate and volume of oil separators is mainly achieved through the design of the oil return pipeline, such as capillary tubes, solenoid valve switches, and parallel branches. The pipeline design is complex and has low reliability. Summary of the Invention

[0004] This invention provides an oil separator and oil return system, an oil return control method and device, to at least solve the problems of complex pipeline design and low reliability in the prior art for controlling the oil return rate and oil return volume.

[0005] To address the aforementioned technical problems, this invention provides an oil separator. The oil separator's cavity is divided into a high-pressure chamber and a low-pressure chamber. The high-pressure chamber is connected to the compressor's exhaust pipe, and the low-pressure chamber is connected to the compressor's suction pipe via an oil return pipe. The oil separator includes a first valve and a second valve, both used to control the connection between the high-pressure chamber and the low-pressure chamber. The first valve opens when the oil in the high-pressure chamber reaches a preset amount, allowing the oil in the high-pressure chamber to flow into the low-pressure chamber. The second valve controls the pressure difference between the high-pressure chamber and the low-pressure chamber to maintain a set pressure difference, wherein the set pressure difference matches the amount of oil return required by the compressor under the current operating conditions.

[0006] Optionally, a partition is provided inside the oil separator cavity to divide the oil separator cavity into a high-pressure cavity and a low-pressure cavity.

[0007] Optionally, the partition has a protruding portion that protrudes toward the low-pressure chamber relative to the other portions of the partition.

[0008] Optionally, the baffle is positioned at a height higher than the height corresponding to the maximum oil storage capacity of the oil separator.

[0009] Optionally, the first valve is mounted on the partition; if the partition has a protruding portion, the first valve is mounted at the most protruding part of the partition.

[0010] Optionally, the second valve is installed on other parts of the partition.

[0011] Optionally, the second valve is installed outside the cavity of the oil separator, and the second valve connects the high-pressure cavity and the low-pressure cavity through a pipeline.

[0012] Optionally, the first valve is a float valve, and the second valve is a differential pressure valve or a check valve.

[0013] Optionally, the return oil pipe is connected to the bottom of the low-pressure chamber; the high-pressure chamber is also connected to an oil outlet pipe.

[0014] This invention also provides an oil return system, including a compressor and the oil separator described in this invention.

[0015] This invention also provides an oil return control method applied to the oil separator described in this invention, comprising: determining the required pressure of the low-pressure chamber based on the current operating condition of the compressor; detecting the actual pressure of the high-pressure chamber; determining the set pressure difference of the second valve based on the required pressure of the low-pressure chamber and the actual pressure of the high-pressure chamber; and using the second valve to control the pressure difference between the high-pressure chamber and the low-pressure chamber to be maintained at the set pressure difference.

[0016] Optionally, determining the required pressure of the low-pressure chamber based on the current operating conditions of the compressor includes: calculating the theoretical pressure difference between the low-pressure chamber and the compressor's suction pipe based on the current operating conditions of the compressor; detecting the suction pressure of the compressor's suction pipe; and calculating the required pressure of the low-pressure chamber based on the theoretical pressure difference and the suction pressure.

[0017] Optionally, based on the current operating conditions of the compressor, the theoretical pressure difference between the low-pressure chamber and the compressor's suction pipe is calculated, including: calculating the required average oil return rate within time t under the current operating conditions based on the oil discharge rate of the compressor under the current operating conditions and the diameter of the oil return pipe; and calculating the total pressure loss of the oil return pipe under the current operating conditions as the theoretical pressure difference based on the average oil return rate, the height difference between the inlet and outlet ports of the oil return pipe, the diameter of the oil return pipe, the length of the oil return pipe, and the friction coefficient.

[0018] Optionally, using the second valve to control the pressure difference between the high-pressure chamber and the low-pressure chamber to maintain at the set pressure difference includes: if the actual pressure difference between the high-pressure chamber and the low-pressure chamber is less than the set pressure difference, then controlling the second valve to be in a closed state; if the actual pressure difference between the high-pressure chamber and the low-pressure chamber is greater than the set pressure difference, then controlling the second valve to be in an open state until the actual pressure difference is maintained at the set pressure difference.

[0019] This invention also provides an oil return control device applied to the oil separator described in this invention, comprising: a first determining module for determining the required pressure of the low-pressure chamber based on the current operating condition of the compressor; a detection module for detecting the actual pressure of the high-pressure chamber; a second determining module for determining a set pressure difference of a second valve based on the required pressure of the low-pressure chamber and the actual pressure of the high-pressure chamber; and a control module for using the second valve to control the pressure difference between the high-pressure chamber and the low-pressure chamber to be maintained at the set pressure difference.

[0020] This invention also provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described in this invention.

[0021] This invention also provides a non-volatile computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the method described in this invention.

[0022] Applying the technical solution of this invention, this embodiment divides the oil separator chamber into a high-pressure chamber and a low-pressure chamber. The high-pressure chamber is connected to the compressor exhaust pipe, and the low-pressure chamber is connected to the compressor suction pipe through a return oil pipe. A first valve automatically controls the flow of oil from the high-pressure chamber into the low-pressure chamber, and a second valve controls the pressure difference between the high-pressure and low-pressure chambers to maintain a set pressure difference that matches the required oil return volume under the current operating conditions of the compressor. Integrating the oil return control components into the oil separator avoids overly complex design of the oil return pipeline components, improves reliability, and allows for precise control of the oil return rate and volume through the second valve, ensuring a reasonable oil return volume under different operating conditions while maintaining stable oil return pressure and reducing oil return pulsation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the oil separator provided in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the oil return system provided in an embodiment of the present invention;

[0025] Figure 3 This is a flowchart of the oil return control method provided in the embodiments of the present invention;

[0026] Figure 4 This is a schematic diagram of the oil return control principle provided in an embodiment of the present invention;

[0027] Figure 5 This is a structural block diagram of the oil return control device provided in an embodiment of the present invention;

[0028] Explanation of reference numerals in the attached figures:

[0029] Oil separator 10, high pressure chamber 11, low pressure chamber 12, oil return pipe 13, first valve 14, second valve 15, baffle 16, oil separator outlet pipe 17, compressor 20, exhaust pipe 21, suction pipe 22. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0031] This invention provides an oil separator, such as... Figure 1 As shown, the oil separator 10 is divided into a high-pressure chamber 11 and a low-pressure chamber 12.

[0032] The high-pressure chamber 11 is connected to the compressor's discharge pipe (via position A in the diagram). The high-pressure chamber 11 is used to separate the oil carried in the refrigerant discharged from the compressor. Preferably, the compressor's discharge pipe is specifically connected to the upper middle part of the high-pressure chamber 11. The low-pressure chamber 12 is connected to the compressor's suction pipe via the oil return pipe 13. The low-pressure chamber 12 is used to return the separated oil to the compressor. The high-pressure chamber 11 is located above the low-pressure chamber 12.

[0033] The oil separator 10 includes a first valve 14 and a second valve 15, both of which are used to control the connection between the high-pressure chamber 11 and the low-pressure chamber 12.

[0034] The first valve 14 opens when the oil in the high-pressure chamber 11 reaches a preset amount, allowing the oil in the high-pressure chamber 11 to flow into the low-pressure chamber 12. The preset amount corresponds to the opening condition of the first valve 14, and the specific preset amount is determined by the specific specifications of the first valve 14. As the compressor runs, the oil in the high-pressure chamber 11 gradually accumulates. When the oil reaches the preset amount, the pressure or buoyancy applied to the first valve 14 reaches the opening condition of the first valve 14, and the first valve 14 automatically opens, allowing the oil in the high-pressure chamber 11 to flow into the low-pressure chamber 12, without air leakage between the high-pressure chamber 11 and the low-pressure chamber 12.

[0035] The second valve 15 controls the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 to be maintained at a set pressure difference, wherein the set pressure difference matches the amount of oil return required by the compressor under the current operating conditions.

[0036] The compressor's operating conditions include compressor frequency and ambient temperature. Compressor frequency affects the compressor's oil discharge rate, and the compressor's oil return rate should be equal to its discharge rate. Ambient temperature affects the viscosity of the lubricating oil, thus affecting the total pressure loss of the oil return pipe 13. Therefore, compressor frequency and ambient temperature affect the oil return rate and oil return volume, and the required oil return volume varies under different compressor operating conditions. Different oil return volume requirements correspond to different pressure differences between the low-pressure chamber 12 and the compressor's suction pipe (i.e., the pressure difference across the oil return pipe 13). Because the suction pressure is fixed, the required pressure of the low-pressure chamber 12 varies, thus requiring variations in the set pressure difference of the second valve 15. In this embodiment, the second valve 15 is controlled according to a set pressure difference matching the oil return volume required by the compressor under the current operating conditions, maintaining the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 at this set pressure difference. This controls the air pressure in the low-pressure chamber 12, thereby controlling the pressure difference between the low-pressure chamber 12 and the compressor's suction pipe, achieving precise control of the oil return rate and oil return volume. That is, by changing the set pressure difference of the second valve 15, the pressure of the low-pressure chamber 12 can be set, thereby meeting different oil return volume requirements.

[0037] In this embodiment, the oil separator 10 is divided into a high-pressure chamber 11 and a low-pressure chamber 12. The high-pressure chamber 11 is connected to the compressor exhaust pipe, and the low-pressure chamber 12 is connected to the compressor suction pipe through the oil return pipe 13. The first valve 14 automatically controls the flow of oil from the high-pressure chamber 11 into the low-pressure chamber 12, and the second valve 15 controls the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 to maintain a set pressure difference that matches the required oil return amount under the current operating conditions of the compressor. Integrating the oil return control components into the oil separator 10 avoids overly complex design of the oil return pipeline components, improves reliability, and allows for precise control of the oil return rate and amount through the second valve 15, ensuring a reasonable oil return amount under different operating conditions while maintaining stable oil return pressure and reducing oil return pulsation.

[0038] The oil separator 10 has a baffle 16 inside its cavity, which divides the cavity of the oil separator 10 into a high-pressure cavity 11 and a low-pressure cavity 12, resulting in a simple structure.

[0039] Considering that the oil separator 10 has a maximum oil storage capacity in practical applications, the baffle 16 is positioned at a height higher than the height corresponding to the maximum oil storage capacity of the oil separator 10, so as to avoid insufficient oil storage space in the low-pressure chamber 12.

[0040] The baffle 16 can be set horizontally or slightly tilted within the cavity of the oil separator 10.

[0041] The partition 16 can be flat or convex (e.g., U-shaped). Figure 1As shown, the partition 16 has a protruding portion that protrudes towards the low-pressure chamber 12 relative to the rest of the partition 16. Within the high-pressure chamber 11, the protruding portion is more conducive to oil accumulation.

[0042] The first valve 14 can be installed on the partition 16. Preferably, when the partition 16 has a protruding portion, such as... Figure 1 As shown, the first valve 14 is installed at the most protruding part of the partition 16, making it easier to open the first valve 14 and thus ensuring timely oil return.

[0043] The second valve 15 can be installed on the partition 16. Specifically, if the partition 16 has a protruding portion, the second valve 15 can be installed on other parts of the partition 16, preferably at a higher position, to avoid the second valve 15 being submerged in oil and unable to control the pressure difference. That is, if both the first valve 14 and the second valve 15 are installed on the partition 16, the first valve 14 is installed at a lower position on the partition 16 to facilitate oil flow into the low-pressure chamber 12, and the second valve 15 is installed at a higher position on the partition 16 to facilitate control of the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12.

[0044] The second valve 15 can also be installed outside the cavity of the oil separator 10, such as... Figure 1 As shown, the second valve 15 connects the high-pressure chamber 11 and the low-pressure chamber 12 through a pipeline. Preferably, the second valve 15 is connected to the upper middle part of the high-pressure chamber 11 through the first pipeline and to the upper part of the low-pressure chamber 12 through the second pipeline, thereby ensuring that the second valve 15 can effectively control the pressure difference.

[0045] The first valve 14 can be a float valve. When the lubricating oil separated in the high-pressure chamber 11 accumulates to a certain amount, the valve body opens due to buoyancy, and the oil flows into the low-pressure chamber 12 without leakage, ensuring that the lubricating oil flows smoothly from the high-pressure chamber 11 to the low-pressure chamber 12.

[0046] The second valve 15 can be a differential pressure valve or a check valve. When the opening pressure (also known as resistance) of the check valve is reached, the check valve opens; that is, the opening pressure of the check valve is equivalent to the differential pressure maintained by the check valve. The differential pressure valve or check valve is used to adjust the differential pressure between the high-pressure chamber 11 and the low-pressure chamber 12, thereby controlling the pressure in the low-pressure chamber 12 to the required pressure corresponding to the current operating condition.

[0047] If the compressor's operating environment is relatively stable, i.e., the ambient temperature and compressor frequency are basically constant (the lubricating oil viscosity and discharge volume do not change much), a differential pressure valve or a check valve with a fixed differential pressure can be used as the second valve 15. Before selecting a specific valve, the required fixed differential pressure can be calculated based on the compressor's operating conditions. Please refer to the description in the subsequent oil return control method for specific calculations.

[0048] Preferably, the oil return pipe 13 is connected to the bottom of the low-pressure chamber 12, so that the separated oil can be returned to the compressor through the oil return pipe 13.

[0049] like Figure 1 As shown, the high-pressure chamber 11 is also connected to an oil separator outlet pipe 17, which is used to discharge the separated gaseous refrigerant into relevant pipelines for condensation. Preferably, the oil separator outlet pipe 17 can be specifically connected to the top of the high-pressure chamber 11 to facilitate the discharge of gaseous refrigerant.

[0050] A support bracket can be installed below the oil separator 10 for support purposes.

[0051] This invention also provides an oil return system, such as... Figure 2 As shown, the oil return system includes an oil separator 10 and a compressor 20. The structure of the oil separator 10 is as described in the above embodiment. The high-pressure chamber 11 is connected to the exhaust pipe 21 of the compressor 20, and the low-pressure chamber 12 is connected to the suction pipe 22 of the compressor 20 through the oil return pipe 13.

[0052] The gaseous refrigerant (carrying lubricating oil) discharged from the compressor 20 enters the high-pressure chamber 11 through the exhaust pipe 21 for separation. When the separated oil reaches the preset amount, it flows into the low-pressure chamber 12 through the first valve 14. Under the pressure difference regulation of the second valve 15, the oil in the low-pressure chamber 12 returns to the compressor 20 in sequence through the oil return pipe 13 and the suction pipe 22 according to the oil return rate and oil return amount required by the current working condition.

[0053] In this embodiment, the oil return system integrates the components for controlling the oil return into the oil separator 10, which avoids overly complex design of the oil return pipeline components, improves reliability, and can accurately control the oil return rate and oil return volume through the second valve 15, ensuring a reasonable oil return volume under different working conditions, while ensuring stable oil return pressure and reducing oil return pulsation.

[0054] This invention also provides an oil return control method, applied to the oil separator 10 described in the above embodiments. Figure 3 This is a flowchart of the oil return control method provided in the embodiments of the present invention, such as... Figure 3 As shown, the method includes the following steps:

[0055] S301, determine the required pressure of the low-pressure chamber 12 based on the current operating conditions of the compressor 20.

[0056] S302, detects the actual pressure in high-pressure chamber 11.

[0057] S303, determine the set pressure difference of the second valve 15 based on the required pressure of the low-pressure chamber 12 and the actual pressure of the high-pressure chamber 11.

[0058] S304, the second valve 15 is used to control the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 to be maintained at the set pressure difference.

[0059] The compressor's operating conditions include compressor frequency and ambient temperature. As mentioned earlier, compressor frequency and ambient temperature affect the oil return rate and oil return volume, and the required oil return volume varies under different compressor operating conditions. The pressure difference between the low-pressure chamber 12 and the compressor suction pipe (i.e., the pressure difference across the oil return pipe 13) corresponds to different oil return volume requirements. Because the suction pressure is fixed, the required pressure of the low-pressure chamber 12 varies, thus requiring changes in the set pressure difference of the second valve 15. In this embodiment, the pressure of the low-pressure chamber 12 is controlled by adjusting the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 using the second valve 15. That is, based on the oil return volume requirement corresponding to the compressor operating conditions, the required pressure of the low-pressure chamber 12 is determined, and the pressure of the low-pressure chamber 12 is adjusted by changing the set pressure difference of the second valve 15, thereby meeting different oil return volume requirements.

[0060] Specifically, a pressure sensor can be installed in the high-pressure chamber 11 to detect the pressure in the high-pressure chamber 11. The actual pressure in the high-pressure chamber 11 minus the required pressure in the low-pressure chamber 12 is calculated as the set pressure difference for the second valve 15.

[0061] This embodiment integrates the oil return control components into the oil separator 10, avoiding overly complex design of the oil return pipeline components and improving reliability. The required pressure of the low-pressure chamber 12 is determined based on the current operating conditions of the compressor 20. The set pressure difference of the second valve 15 is determined based on the required pressure of the low-pressure chamber 12 and the actual pressure of the high-pressure chamber 11. The second valve 15 is used to maintain the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 at this set pressure difference. By changing the set pressure difference of the second valve 15 based on the compressor's operating conditions, the oil return rate and amount can be precisely controlled, ensuring a reasonable oil return amount under different operating conditions, while also ensuring stable oil return pressure and reducing oil return pulsation.

[0062] In practical applications, the set differential pressure can be determined when the compressor operating conditions change, or it can be determined periodically.

[0063] In one embodiment, step S301 determines the required pressure of the low-pressure chamber 12 based on the current operating condition of the compressor 20, including: calculating the theoretical pressure difference between the low-pressure chamber 12 and the suction pipe 22 of the compressor 20 based on the current operating condition of the compressor 20; detecting the suction pressure of the suction pipe 22 of the compressor 20; and calculating the required pressure of the low-pressure chamber 12 based on the theoretical pressure difference and the suction pressure. Specifically, the sum of the suction pressure and the theoretical pressure difference is calculated as the required pressure of the low-pressure chamber 12. The low-pressure chamber required pressure calculated in this embodiment can meet the requirements of the oil return rate and oil return volume under the current operating condition of the compressor.

[0064] Furthermore, based on the current operating conditions of the compressor 20, the theoretical pressure difference between the low-pressure chamber 12 and the suction pipe 22 of the compressor 20 is calculated, including: calculating the required average oil return rate under the current operating conditions within time t based on the oil discharge rate of the compressor 20 under the current operating conditions and the diameter of the oil return pipe; and calculating the total pressure loss of the oil return pipe 13 under the current operating conditions as the theoretical pressure difference based on the average oil return rate, the height difference between the inlet and outlet ports of the oil return pipe, the diameter of the oil return pipe, the length of the oil return pipe, and the friction coefficient.

[0065] refer to Figure 4 The compressor's oil discharge rate varies with its frequency. To ensure a constant oil volume, the compressor's oil return rate should be the same as its discharge rate. With a fixed return pipe diameter, the return rate can be calculated using the following formula:

[0066] Q = πR 2 vt,

[0067] Where Q is the amount of oil discharged within time t under the current operating conditions of the compressor, which can be obtained through relevant compressor tests; R is the radius of the oil return pipe; and v is the average oil return rate required within time t under the current operating conditions of the compressor.

[0068] The viscosity of lubricating oil changes with temperature, and the temperature-lubricating oil viscosity curve can be obtained from the supplier. Based on parameters such as lubricating oil viscosity, return rate, return pipe diameter, and return pipe length, the friction loss (i.e., total pressure loss) of return pipe 13 can be calculated as the theoretical pressure difference between the two ends of the return pipe.

[0069] Specifically, the theoretical pressure difference across the two ends of return oil pipe 13 can be roughly divided into the following parts:

[0070] (1) Local pressure loss at inlet and outlet ΔP1:

[0071] Where ξ represents the local loss coefficient; ρ represents the oil density; and v represents the average oil return rate required within time t under the current operating conditions of the compressor.

[0072] (2) Gravity pressure loss ΔP2: ΔP2 = ρgh, where h represents the height difference between the inlet and outlet ends.

[0073] (3) Pipeline resistance loss ΔP3:

[0074] Where λ represents the friction coefficient, which is related to the Reynolds number when the lubricating oil flows in the pipe; d represents the diameter of the return pipe; and l represents the length of the return pipe.

[0075] The total pressure loss in the return oil pipe is: ΔP = ΔP1 + ΔP2 + ΔP3. In practical applications, the calculated total pressure loss can be compared with experimental results to correct the correlation coefficient and ensure accuracy.

[0076] Although the compressor's oil discharge and lubricating oil viscosity may change, these changes are constant with the compressor speed and ambient temperature, respectively. Therefore, the theoretical pressure difference between the low-pressure chamber 12 and the suction pipe 22 is also constantly changing and can be calculated.

[0077] Through the above steps, based on the current operating conditions of the compressor, the theoretical pressure difference between the low-pressure chamber 12 and the suction pipe 22 of the compressor 20 under the current operating conditions can be accurately calculated, which provides a guarantee for the precise control of the subsequent oil return rate and oil return volume.

[0078] Specifically, S304 uses the second valve 15 to control the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 to maintain at a set pressure difference, including: if the actual pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 is less than the set pressure difference, then control the second valve 15 to be in the closed state; if the actual pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 is greater than the set pressure difference, then control the second valve 15 to be in the open state until the actual pressure difference is maintained at the set pressure difference.

[0079] If the second valve 15 is open, the actual pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 will decrease; if the second valve 15 is closed, the actual pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 will gradually increase. This embodiment utilizes the working principle of the second valve 15 to maintain the set pressure difference between the two chambers.

[0080] For example, differential pressure regulation can also be achieved by increasing or decreasing the opening of the second valve 15. If the actual differential pressure between the high-pressure chamber 11 and the low-pressure chamber 12 is less than the set differential pressure and the second valve 15 is already open, then the opening of the second valve 15 is decreased; if the actual differential pressure between the high-pressure chamber 11 and the low-pressure chamber 12 is greater than the set differential pressure and the second valve 15 is already open, then the opening of the second valve 15 is increased until the actual differential pressure is maintained at the set differential pressure.

[0081] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0082] Based on the same inventive concept, this embodiment of the invention also provides an oil return control device, applied to the oil separator 10 described in the above embodiments, which can be used to implement the oil return control method described in the above embodiments. This oil return control device can be implemented through software and / or hardware.

[0083] Figure 5 This is a structural block diagram of the oil return control device provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the device includes:

[0084] The first determining module 501 is used to determine the required pressure of the low-pressure chamber 12 based on the current operating conditions of the compressor 20.

[0085] Detection module 502 is used to detect the actual pressure in high-pressure chamber 11;

[0086] The second determining module 503 is used to determine the set pressure difference of the second valve 15 based on the required pressure of the low-pressure chamber 12 and the actual pressure of the high-pressure chamber 11.

[0087] The control module 504 is used to control the pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 to be maintained at the set pressure difference using the second valve 15.

[0088] Optionally, the first determining module 501 includes:

[0089] The first calculation unit is used to calculate the theoretical pressure difference between the low-pressure chamber 12 and the suction pipe 22 of the compressor 20 based on the current operating condition of the compressor 20.

[0090] The detection unit is used to detect the suction pressure of the suction pipe 22 of the compressor 20;

[0091] The second calculation unit is used to calculate the required pressure of the low-pressure chamber 12 based on the theoretical pressure difference and the intake pressure.

[0092] Optionally, the first calculation unit is specifically used to: calculate the required average return oil rate within time t under the current operating conditions based on the oil discharge volume of the compressor under the current operating conditions and the diameter of the return oil pipe; and calculate the total pressure loss of the return oil pipe 13 under the current operating conditions based on the average return oil rate, the height difference between the inlet and outlet ports of the return oil pipe, the diameter of the return oil pipe, the length of the return oil pipe, and the friction coefficient, as the theoretical pressure difference.

[0093] Optionally, the control module 504 is specifically configured to: control the second valve 15 to be in a closed state if the actual pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 is less than the set pressure difference; and control the second valve 15 to be in an open state if the actual pressure difference between the high-pressure chamber 11 and the low-pressure chamber 12 is greater than the set pressure difference, until the actual pressure difference is maintained at the set pressure difference.

[0094] The aforementioned oil return control device can execute the oil return control method provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects of the method. Technical details not described in detail in this embodiment can be found in the oil return control method provided in the embodiments of the present invention.

[0095] This invention also provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the oil return control method described in the above embodiments.

[0096] This invention also provides a non-volatile computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the oil return control method described in the above embodiments.

[0097] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0098] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An oil separator characterized by, The cavity of the oil separator is divided into a high-pressure cavity and a low-pressure cavity, the high-pressure cavity is communicated with the exhaust pipe of the compressor, and the low-pressure cavity is communicated with the suction pipe of the compressor through an oil return pipe; The oil separator comprises a first valve and a second valve, both of which are used for controlling the communication between the high-pressure cavity and the low-pressure cavity; The first valve is opened when the oil in the high-pressure cavity reaches a preset amount, so that the oil in the high-pressure cavity flows into the low-pressure cavity; The second valve controls the pressure difference between the high-pressure cavity and the low-pressure cavity to be maintained at a set pressure difference, wherein the set pressure difference matches the required oil return amount of the compressor under the current working condition; A partition plate is arranged in the cavity of the oil separator, and the cavity of the oil separator is divided into the high-pressure cavity and the low-pressure cavity by the partition plate; and the first valve is installed on the partition plate; The pressure difference between the low-pressure cavity and the suction pipe of the compressor is different for different oil return amount requirements; by changing the set pressure difference of the second valve, the pressure of the low-pressure cavity is set, and then the pressure difference between the low-pressure cavity and the suction pipe of the compressor is controlled to meet different oil return amount requirements.

2. The oil separator of claim 1, wherein The partition plate has a protruding part, and the protruding part is protrudingly arranged towards the low-pressure cavity relative to other parts of the partition plate.

3. The oil separator of claim 1, wherein The partition plate is arranged at a position in the cavity of the oil separator, and the height of the position is higher than the height corresponding to the maximum oil storage amount of the oil separator.

4. The oil separator of claim 1, wherein In the case that the partition plate has a protruding part, the first valve is installed at the most protruding part of the partition plate.

5. The oil separator of claim 2, wherein The second valve is installed on other parts of the partition plate.

6. The oil separator of claim 1, wherein The second valve is installed outside the cavity of the oil separator, and the second valve communicates the high-pressure cavity and the low-pressure cavity through a pipeline.

7. The oil separator according to any one of claims 1 to 6, characterized in that The first valve is a float valve, and the second valve is a pressure difference valve or a one-way valve.

8. The oil separator according to any one of claims 1 to 6, characterized in that The oil return pipe is connected to the bottom of the low-pressure cavity; and the high-pressure cavity is also connected with an oil discharge gas pipe.

9. An oil return system characterized by, Comprise: The compressor and the oil separator according to any one of claims 1 to 8.

10. A method of controlling the return of oil to an oil separator as claimed in any one of claims 1 to 8, characterised in that, Comprise: Determine the required pressure of the low-pressure cavity according to the current working condition of the compressor; Detect the actual pressure of the high-pressure cavity; According to the required pressure of the low-pressure cavity and the actual pressure of the high-pressure cavity, determine the set pressure difference of the second valve; Use the second valve to control the pressure difference between the high-pressure cavity and the low-pressure cavity to be maintained at the set pressure difference.

11. The method of claim 10, wherein, Determine the required pressure of the low-pressure cavity according to the current working condition of the compressor, comprising: According to the current working condition of the compressor, calculate the theoretical pressure difference between the low-pressure cavity and the suction pipe of the compressor; Detect the suction pressure of the suction pipe of the compressor; According to the theoretical pressure difference and the suction pressure, calculate the required pressure of the low-pressure cavity.

12. The method of claim 11, wherein, According to the current working condition of the compressor, calculate the theoretical pressure difference between the low-pressure cavity and the suction pipe of the compressor, comprising: According to the oil discharge amount of the compressor within t time under the current working condition and the pipe diameter of the oil return pipe, calculate the required average oil return rate within t time under the current working condition; According to the oil return average rate, height difference of the inlet and outlet ports of the oil return pipe, oil return pipe diameter, oil return pipe length, and along the way resistance coefficient, the total pressure loss of the oil return pipe under the current working condition is calculated as the theoretical pressure difference.

13. The method according to any one of claims 10 to 12, characterized in that, The second valve is controlled to maintain the pressure difference between the high-pressure cavity and the low-pressure cavity at the set pressure difference, including: If the actual pressure difference between the high-pressure cavity and the low-pressure cavity is less than the set pressure difference, the second valve is controlled to be in a closed state; If the actual pressure difference between the high-pressure cavity and the low-pressure cavity is greater than the set pressure difference, the second valve is controlled to be in an open state until the actual pressure difference is maintained at the set pressure difference.

14. An oil return control device characterized by comprising: including: The oil separator of any one of claims 1 to 8; A first determination module is configured to determine a required pressure of the low-pressure cavity according to a current working condition of the compressor; A detection module is configured to detect an actual pressure of the high-pressure cavity; A second determination module is configured to determine a set pressure difference of the second valve according to the required pressure of the low-pressure cavity and the actual pressure of the high-pressure cavity; A control module is configured to control the second valve to maintain the pressure difference between the high-pressure cavity and the low-pressure cavity at the set pressure difference.

15. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method of any one of claims 10 to 13 when executing the computer program.

16. A non-transitory computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 10 to 13.

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