Compressor oil supply system

Abstract

This utility model relates to a compressor oil supply system, belonging to the field of compressor oil supply technology. The compressor oil supply system includes: a centrifugal compressor, a high-level oil tank, a main oil supply assembly, a first oil supply pipe, a second oil supply pipe, a first oil return pipe, and a second oil return pipe. The centrifugal compressor includes a volute, on which a first oil return port and a second oil return port are provided; the second oil return port is located at the bottom of the volute. The high-level oil tank has a first oil supply port and a second oil supply port. The first oil supply pipe is connected to the first oil supply port and the main oil supply assembly; the second oil supply pipe is connected to the second oil supply port and the main oil supply assembly; the first oil return pipe is connected to the first oil return port and the main oil supply assembly; the second oil return pipe is connected to the second oil return port and the main oil supply assembly; the main oil supply assembly supplies lubricating oil to the high-level oil tank through the first oil supply pipe and / or the second oil supply pipe; the volute returns lubricating oil to the main oil supply assembly through the first oil return pipe and / or the second oil return pipe.

Description

Technical Field

[0001] This application relates to the technical field of compressor oil supply, and more particularly to a compressor oil supply system. Background Technology

[0002] Centrifugal compressor systems are widely used in refrigeration equipment such as chillers. Their core components include the compressor, motor, lubrication system, and oil circulation loop. During operation, the compressor relies on the oil lubrication system to lubricate and cool the bearings, ensuring the stability and lifespan of the rotor during high-speed rotation.

[0003] In existing technology, the oil supply system of a compressor typically includes an external oil tank, an oil pump, a high-level oil tank, and oil supply and return pipelines connecting the various parts. The system uses the oil pump to transport lubricating oil from the external oil tank to the high-level oil tank, and then relies on gravity to supply oil to the front and rear bearings of the compressor. After lubrication, the oil returns to the external oil tank through the return pipeline, forming a closed loop.

[0004] However, the aforementioned existing technical solutions still have significant drawbacks in practical applications. Firstly, due to slight oil leakage at the compressor bearing shaft seal, lubricating oil gradually accumulates at the bottom of the volute, requiring periodic manual drainage or collection using an oil collection bottle. This is not only cumbersome but also increases maintenance costs and labor intensity. Secondly, when the unit experiences a sudden power outage or oil pump failure, the oil pump stops working, while the compressor remains in a high-speed coasting state due to inertia. In this situation, the bearings still require continuous lubrication. Traditional solutions rely on gravity-fed oil supply from a high-level oil tank, but a vacuum can easily form in the tank after the oil level drops, leading to reduced oil supply efficiency and an inability to achieve rapid and reliable emergency oil supply. This can potentially cause serious malfunctions such as poor bearing lubrication, wear, or even burnout, affecting the unit's operational safety and reliability. Utility Model Content

[0005] This utility model solves, to at least a certain extent, one of the technical problems in the related art.

[0006] Therefore, this application aims to provide a compressor oil supply system that, when the compressor unit stops, utilizes the pressure difference between the volute casing and the main oil supply assembly to discharge the lubricating oil at the bottom of the volute casing to the main oil supply assembly through the second oil return pipe, thus preventing oil accumulation in the volute casing and ensuring the oil level in the main oil supply assembly. When the compressor unit stops due to power failure, a certain pressure difference exists between the compressor volute casing and the high-level oil tank. This pressure difference is used to transport the lubricating oil in the main oil supply assembly to the high-level oil tank through the second oil supply pipeline, thereby replenishing the oil supply to the compressor unit.

[0007] To achieve the above objectives, this utility model provides a compressor oil supply system, comprising: A centrifugal compressor includes a volute casing, on which a first oil return port and a second oil return port are provided; wherein the second oil return port is located at the bottom of the volute casing. A high-level oil tank is used to replenish oil to the centrifugal compressor. The high-level oil tank is provided with a first oil supply port and a second oil supply port. Main oil supply components; The first oil supply pipe has its two ends connected to the first oil supply port and the input end of the main oil supply assembly, respectively. The second oil supply pipe has its two ends connected to the second oil supply port and the input end of the main oil supply assembly, respectively. The first return oil pipe has its two ends connected to the first return oil port and the output end of the main oil supply component, respectively. The second return oil pipe has its two ends connected to the second return oil port and the output end of the main oil supply assembly, respectively. The main oil supply assembly supplies lubricating oil to the high-level oil tank through the first oil supply pipe and / or the second oil supply pipe; The volute returns lubricating oil to the main oil supply assembly through the first return oil pipe and / or the second return oil pipe.

[0008] In this technical solution, the compressor oil supply system achieves efficient lubricant circulation by setting up two return oil ports and two supply oil ports, and equipping it with a main oil supply component and multiple supply and return oil pipelines. During normal operation, the main oil supply component stably delivers lubricant to the high-level oil tank through the first supply oil pipe, ensuring sufficient lubrication of critical components such as compressor bearings and maintaining efficient unit operation. Simultaneously, lubricant flows back to the main oil supply component through the first return oil pipe, forming a closed loop. When the compressor unit stops, the pressure difference between the volute and the main oil supply component is used to discharge the lubricant at the bottom of the volute to the main oil supply component through the second return oil pipe, preventing oil accumulation in the volute and ensuring the oil level in the main oil supply component. When the compressor unit is powered off and shut down, a certain pressure difference exists between the compressor volute and the high-level oil tank. This pressure difference is used to transport the lubricant in the main oil supply component to the high-level oil tank through the second supply oil pipeline, thus replenishing the compressor unit's oil supply. This system design effectively solves the problems of insufficient oil supply and uneven distribution of lubricating oil that are prone to occur in traditional oil supply systems with a single oil supply path, thereby improving the operational stability and reliability of the unit and extending the service life of the equipment.

[0009] In some embodiments of this application, a normally closed solenoid valve is provided on the second return oil pipe; When the oil supply unit stops, the normally closed solenoid valve opens, and the lubricating oil at the bottom of the volute is discharged through the second return oil pipe.

[0010] In this technical solution, the normally closed solenoid valve remains closed during normal operation to ensure proper lubricating oil circulation and prevent excessive lubricating oil from being discharged through the second return oil pipe, which could lead to insufficient oil levels in the volute. The normally closed solenoid valve only opens when the compressor unit shuts down, allowing excess lubricating oil to drain from the volute. This changes the traditional passive method of relying on manual oil draining or oil bottles, achieving automated, timed, and metered oil return operation. This not only significantly reduces maintenance costs but also avoids compressor efficiency degradation or potential malfunctions caused by lubricating oil buildup. Furthermore, the normally closed design of this valve ensures it will not open accidentally during normal operation, guaranteeing system pressure stability.

[0011] In some embodiments of this application, a normally open solenoid valve is provided on the second oil supply pipe; When the oil supply unit is de-energized, the normally open solenoid valve opens, supplying lubricating oil from the main oil supply assembly into the high-level oil tank through the second oil supply pipe.

[0012] In this technical solution, when the unit experiences a sudden power outage, the normally open solenoid valve automatically opens due to the loss of power. Utilizing the pressure difference between the compressor casing and the high-level oil tank during compressor coasting, a "high-level oil tank pressurization" effect is created, forcing lubricating oil to flow rapidly into the bearing cavity within the casing, achieving emergency lubrication. This overcomes the shortcomings of traditional high-level oil tanks, which suffer from poor oil supply due to vacuum formation. This design requires no external power, is purely mechanical and pressure differential driven, has a fast response speed, and a simple and reliable structure, greatly improving the safety and reliability of the unit in the event of a sudden power outage.

[0013] In some embodiments of this application, a first shut-off valve is provided on the first oil supply pipe.

[0014] In this technical solution, the first shut-off valve can be used to cut off the connection between the high-level oil tank and the main oil supply circuit. It can be disconnected when lubrication of the compressor unit is not required, facilitating operations such as oil tank cleaning, oil pump maintenance, or lubricant replacement without affecting the operation of other parts of the system. Furthermore, during commissioning or in specific operating modes, the oil supply flow can be controlled by adjusting the opening of the first shut-off valve, enabling precise control of the lubrication system to adapt to lubrication requirements under different loads or speeds, thereby improving the system's adaptability and energy efficiency.

[0015] In some embodiments of this application, there are multiple first return oil lines, and the connection points between the different first return oil lines and the volute are at different locations.

[0016] In this technical solution, lubricating oil distribution at different locations may be uneven due to factors such as centrifugal force and airflow. The multi-path oil return design ensures that lubricating oil from the front bearing, rear bearing, and other parts can be effectively collected and returned to the main oil supply assembly, preventing localized oil accumulation or poor return flow. This improves lubricating oil utilization, reduces the risk of oil aging and contamination, helps maintain system pressure balance, and enhances overall operational stability and efficiency.

[0017] In some embodiments of this application, a second shut-off valve is provided on the first return oil pipe.

[0018] In the technical solution, the second shut-off valve can be used to regulate the return oil flow, preventing excessively rapid oil return from causing large fluctuations in the main oil tank level, and also avoiding insufficient lubricating oil in the volute casing, thus ensuring the compressor's lubrication effect. The second shut-off valve can also be used to cut off the return oil circuit during maintenance, facilitating maintenance of the compressor or return oil pipeline.

[0019] In some embodiments of this application, the main oil supply assembly includes: Main oil tank, the interior of which is used to hold lubricating oil; An oil supply pump is connected to the inside of the main oil tank and is used to output lubricating oil to the first oil supply pipe. The first return oil pipe and the second return oil pipe are connected to the main oil tank.

[0020] In this technical solution, the main oil tank stores lubricating oil, while the oil supply pump delivers stable oil pressure and flow to the high-level oil tank via the first oil supply pipe. This structural design is mature and highly reliable, providing a stable and reliable foundation for the entire lubrication system.

[0021] In addition, this application also provides a compressor oil supply system, which includes: A centrifugal compressor includes a volute casing, on which a first oil return port and a second oil return port are provided; wherein the second oil return port is located at the bottom of the volute casing. A high-level oil tank is used to replenish oil to the centrifugal compressor. The high-level oil tank is provided with a first oil supply port and a second oil supply port. Main oil supply components; The first oil supply pipe has its two ends connected to the first oil supply port and the input end of the main oil supply assembly, respectively. The second oil supply pipe has its two ends connected to the second oil supply port and the input end of the main oil supply assembly, respectively. The first return oil pipe has its two ends connected to the first return oil port and the output end of the main oil supply component, respectively. The second return oil pipe has its two ends connected to the second return oil port and the first return oil pipe, respectively. The main oil supply assembly supplies lubricating oil to the high-level oil tank through the first oil supply pipe and / or the second oil supply pipe; The volute returns lubricating oil to the main oil supply assembly through the first return oil pipe.

[0022] In this technical solution, the volute casing returns lubricating oil to the main oil supply assembly via the first return oil pipe, forming a closed loop. When the compressor unit stops, the pressure difference between the volute casing and the main oil supply assembly is used to output lubricating oil from the bottom of the volute casing to the second return oil pipe. The lubricating oil in the second return oil pipe is then fed into the first return oil pipe and discharged to the main oil supply assembly, preventing oil accumulation in the volute casing and ensuring the oil level in the main oil supply assembly. When the compressor unit stops due to power failure, a certain pressure difference exists between the compressor volute casing and the high-level oil tank. This pressure difference is used to transport lubricating oil from the main oil supply assembly to the high-level oil tank through the second oil supply pipeline, thus replenishing the compressor unit's oil supply. This system design effectively solves the problems of insufficient oil supply and uneven lubricating oil distribution that easily occur in traditional oil supply systems with a single oil supply path, improving the unit's operational stability and reliability, and extending the equipment's service life.

[0023] In some embodiments of this application, a second shut-off valve is provided on the first return oil pipe, and a section of the first return oil pipe located between the second shut-off valve and the main oil supply assembly is a connecting section, and the second return oil pipe is connected to the connecting section.

[0024] The technical solution ensures that the lubricating oil in the second return oil pipe can be output to the main oil supply component through the first return oil pipe, avoiding blockage of the second shut-off valve and ensuring smooth oil return.

[0025] In some embodiments of this application, a normally closed solenoid valve is provided on the second return oil pipe; A normally open solenoid valve is installed on the second oil supply pipe.

[0026] In this technical solution, the normally closed solenoid valve remains closed during normal use to ensure proper lubricating oil circulation and prevent excessive lubricating oil from being discharged through the second return oil pipe, which could lead to insufficient oil levels in the volute. The normally closed solenoid valve only opens when the compressor unit stops, allowing excess lubricating oil to drain from the volute. In the event of a sudden power outage, the normally open solenoid valve automatically opens due to the loss of power. Utilizing the pressure difference between the volute and the high-level oil tank during compressor coasting, a "high-level oil tank pressurization" effect is created, forcing lubricating oil to flow rapidly into the bearing cavity within the volute, achieving emergency lubrication. This overcomes the shortcomings of traditional high-level oil tanks, which suffer from poor oil supply due to vacuum formation.

[0027] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a compressor oil supply system in the prior art; Figure 2 This is one of the overall structural schematic diagrams of the compressor oil supply system according to an embodiment of this application; Figure 3 This is the second schematic diagram of the overall structure of the compressor oil supply system according to the embodiments of this application; Figure 4 This is the third schematic diagram of the overall structure of the compressor oil supply system according to the embodiments of this application; Figure 5 This is the fourth schematic diagram of the overall structure of the compressor oil supply system according to the embodiments of this application; Figure 6 This is a control flowchart of the controller of the compressor oil supply system according to an embodiment of this application; Figure 7 This is a control flowchart of the controller of the compressor oil supply system according to an embodiment of this application; Figure 8 This is a control flowchart of the controller of the compressor oil supply system according to an embodiment of this application; Figure 9 This is a control flowchart of the controller of the compressor oil supply system according to an embodiment of this application; Figure 10 This is a control flowchart of the controller of the compressor oil supply system according to an embodiment of this application.

[0029] In the above diagrams: 100, centrifugal compressor; 200, main oil supply assembly; 201, main oil tank; 202, oil supply pump; 300, first oil supply pipe; 400, first shut-off valve; 500, second oil supply pipe; 600, normally open solenoid valve; 700, first return oil pipe; 800, second shut-off valve; 900, second return oil pipe; 110, normally closed solenoid valve; 102, high-level oil tank. Detailed Implementation

[0030] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature. In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0031] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments. In this application, the compressor oil supply system includes a volute, a main oil supply assembly, and a high-level oil tank. Lubricating oil from the main oil supply assembly is supplied to the high-level oil tank via an oil supply pipe, and the high-level oil tank then supplies lubricating oil to the volute for lubrication. The lubricating oil in the volute flows back to the main oil supply assembly via a return oil pipe, completing the circulation.

[0032] In the following, embodiments of this application will be described in detail with reference to the accompanying drawings. Referring to all the accompanying drawings, in an illustrative embodiment of the compressor oil supply system of this utility model, the compressor oil supply system includes a centrifugal compressor 100. The centrifugal compressor 100 is a device that uses rotating blades to compress and increase the pressure of gas. It draws in gas through a high-speed rotating impeller, uses centrifugal force to accelerate the gas radially, and then converts kinetic energy into pressure energy through a diffuser, ultimately achieving the purpose of increasing gas pressure. The centrifugal compressor 100 is widely used in chemical, energy, and metallurgical industries. In this application, the centrifugal compressor 100 is mainly used in air conditioning units.

[0033] In some embodiments, the centrifugal compressor 100 includes a volute, on which a first oil return port and a second oil return port are provided; wherein, the second oil return port is located at the bottom of the volute. Lubricating oil inside the volute is discharged through the first and second oil return ports.

[0034] In some embodiments, the compressor oil supply assembly further includes an elevated oil tank 102 for replenishing oil to the centrifugal compressor 100. The elevated oil tank 102 is located above the centrifugal compressor 100 and can automatically provide a continuous flow of lubricating oil to the centrifugal compressor 100 by gravity.

[0035] In some embodiments, the high-level oil tank 102 is provided with a first oil supply port and a second oil supply port. The compressor oil supply assembly also includes a main oil supply assembly 200. The main oil supply assembly 200 is used to supply lubricating oil to the high-level oil tank 102 and to recover the lubricating oil after the centrifugal compressor 100 has circulated.

[0036] In some embodiments, the compressor oil supply assembly further includes a first oil supply pipe 300, the two ends of which are connected to a first oil supply port and the input end of the main oil supply assembly 200, respectively. The oil supply assembly delivers lubricating oil to the high-level oil tank 102 via the first oil supply pipe 300.

[0037] In some embodiments, the compressor oil supply assembly further includes a second oil supply pipe 500, the two ends of which are connected to a second oil supply port and the input end of the main oil supply assembly 200, respectively. Under normal circumstances, the first oil supply pipe 300 remains open. When the compressor unit is powered off, the first oil supply pipe 300 will close due to the power failure. At this time, there is a certain pressure difference between the volute and the high-level oil tank 102, causing the volute to draw lubricating oil from the high-level oil tank 102 into the volute. Since the high-level oil tank 102 is a closed space, it will draw lubricating oil from the main oil supply assembly 200 through the second oil supply pipe 500 to replenish the oil level in the high-level oil tank 102, ensuring sufficient lubricating oil is supplied to the volute.

[0038] In some embodiments, the compressor oil supply assembly further includes a first oil return pipe 700, the two ends of which are connected to a first oil return port and the output end of the main oil supply assembly 200, respectively. During normal operation, the lubricating oil in the volute flows back to the main oil supply assembly 200 through the first oil return pipe 700, completing the circulation of the lubricating oil and achieving lubrication of the centrifugal compressor 100.

[0039] In some embodiments, the compressor oil supply assembly further includes a second oil return pipe 900, the two ends of which are connected to a second oil return port and the output end of the main oil supply assembly 200, respectively. Because the second oil return port is located below the volute, when the compressor unit stops, the lubricating oil circulating to the main oil supply assembly 200 through the first oil return pipe 700 cannot discharge the lubricating oil at the bottom of the volute. At this time, the lubricating oil at the bottom of the volute can be transported to the main oil supply assembly 200 through the second oil return pipe 900.

[0040] Through the above scheme, the compressor oil supply system achieves efficient circulation of lubricating oil by setting two return oil ports and two supply oil ports, and equipping it with a main oil supply component 200 and multiple supply and return oil pipelines. During normal operation, the main oil supply component 200 stably supplies lubricating oil to the high-level oil tank 102 through the first supply oil pipe 300, ensuring sufficient lubrication of key components such as compressor bearings and maintaining efficient unit operation. Simultaneously, lubricating oil returns to the main oil supply component 200 through the first return oil pipe 700, forming a closed loop. When the compressor unit stops, the pressure difference between the volute and the main oil supply component 200 is used to discharge the lubricating oil at the bottom of the volute to the main oil supply component 200 through the second return oil pipe 900, preventing oil accumulation in the volute and ensuring the oil level in the main oil supply component 200. When the compressor unit shuts down due to power failure, a certain pressure difference exists between the compressor casing and the high-level oil tank 102. This pressure difference is used to transport the lubricating oil in the main oil supply assembly 200 to the high-level oil tank 102 through the second oil supply pipe 500, thus replenishing the oil supply to the compressor unit. This system design effectively solves the problems of insufficient oil supply and uneven lubricating oil distribution that are prone to occur in traditional oil supply systems with a single oil supply path, improving the operational stability and reliability of the unit and extending the service life of the equipment.

[0041] Specifically, the main oil supply assembly 200 supplies lubricating oil to the high-level oil tank 102 via the first oil supply pipe 300. The second oil supply pipe 500 supplies lubricating oil to the high-level oil tank 102. The volute casing returns lubricating oil to the main oil supply assembly 200 via the first return oil pipe 700. The second return oil pipe 900 returns lubricating oil to the main oil supply assembly 200.

[0042] In some embodiments, a normally closed solenoid valve 110 is installed on the second oil return pipe 900. When the oil supply unit stops, the normally closed solenoid valve 110 opens, and the lubricating oil at the bottom of the volute is discharged through the second oil return pipe 900. During normal use, the normally closed solenoid valve 110 is in the closed state to ensure normal circulation of lubricating oil and prevent insufficient oil level in the volute due to excessive lubricating oil being discharged through the second oil return pipe 900. The normally closed solenoid valve 110 is only opened when the compressor unit stops to allow excess lubricating oil in the volute to be discharged. This changes the traditional passive method of relying on manual oil draining or oil bottles, realizing automated, timed, and quantitative oil return operation, which not only significantly reduces operation and maintenance costs but also avoids compressor efficiency reduction or potential failure risks caused by lubricating oil accumulation. At the same time, the normally closed design of the valve ensures that it will not be accidentally opened during normal operation, guaranteeing the stability of system pressure.

[0043] In some embodiments, a normally open solenoid valve 600 is provided on the second oil supply pipe 500. When the oil supply unit loses power, the normally open solenoid valve 600 is de-energized and opens, supplying lubricating oil from the main oil supply assembly 200 to the high-level oil tank 102 through the second oil supply pipe 500. When the unit suddenly loses power, the normally open solenoid valve 600 automatically opens due to power loss, utilizing the pressure difference between the volute and the high-level oil tank 102 during compressor coasting to create a "high-level oil tank 102 pressurization" effect, forcing the lubricating oil to flow rapidly into the bearing cavity inside the volute, achieving emergency lubrication. This overcomes the defect of poor oil supply caused by the vacuum formed in the traditional high-level oil tank 102. This design requires no external power, is purely mechanical and pressure differential driven, has a fast response speed, and a simple and reliable structure, greatly improving the safety and reliability of the unit in the event of a sudden power outage.

[0044] In some embodiments, a first shut-off valve 400 is provided on the first oil supply pipe 300. The first shut-off valve 400 can be used to cut off the connection between the high-level oil tank 102 and the main oil supply circuit. It can be disconnected when the compressor unit does not need lubrication, facilitating operations such as oil tank cleaning, oil pump maintenance, or lubricant replacement, without affecting the operation of other parts of the entire system. In addition, during commissioning or in specific operating modes, the oil supply flow can be controlled by adjusting the opening of the first shut-off valve 400, achieving fine control of the lubrication system, adapting to lubrication requirements under different loads or speeds, and improving the system's adaptability and energy efficiency.

[0045] In some embodiments, a second shut-off valve 800 is provided on the first oil return pipe 700. The second shut-off valve 800 can be used to regulate the oil return flow rate, prevent excessively fast oil return which could cause excessive fluctuations in the liquid level of the main oil tank 201, and also prevent insufficient lubricating oil in the volute casing, thus ensuring the lubrication effect of the compressor. The second shut-off valve 800 can also be used to cut off the oil return circuit during maintenance, facilitating maintenance of the compressor or the oil return pipeline.

[0046] In some embodiments, there are multiple first return oil pipes 700, and the connection points between the different first return oil pipes 700 and the volute housing are located at different positions. Lubricating oil at different locations may be unevenly distributed due to factors such as centrifugal force and airflow. The multi-path return oil design ensures that lubricating oil from the front bearing, rear bearing, or other parts can be effectively collected and returned to the main oil supply assembly 200, avoiding localized oil accumulation or poor return flow. This improves the utilization rate of lubricating oil, reduces the risk of oil aging and contamination, and also helps maintain system pressure balance, improving overall operational stability and efficiency.

[0047] In some embodiments, multiple first oil return ports are also provided on the volute housing, and the number of first oil return pipes 700 is the same as the number of first oil return ports, with each first oil return pipe 700 corresponding to a first oil return port. This ensures that all lubricating oil passing through the first oil return ports can flow back to the main oil supply assembly 200.

[0048] In some embodiments, the height of all first return oil ports is higher than that of the second return oil ports. This ensures the normal and stable operation of the second return oil ports. Furthermore, in actual operation, because the bottom of the volute does not involve many structures, the industry does not typically choose to place the first return oil pipe 700 at the bottom of the volute.

[0049] In some embodiments, each first oil return pipe 700 is equipped with a second shut-off valve 800. Each first oil return pipe 700 can precisely regulate the oil return volume to meet the lubrication needs of different parts of the compressor and prevent local lubricant accumulation or poor oil return. The oil return rate can be flexibly adjusted according to the system operating conditions to ensure balanced pressure in the lubrication system.

[0050] In some embodiments, the main oil supply assembly 200 includes a main oil tank 201, which contains lubricating oil. A first return oil pipe 700 and a second return oil pipe 900 are connected to the main oil tank 201.

[0051] In some embodiments, the main oil supply assembly 200 includes an oil supply pump 202, which is internally connected to the main oil tank 201. The oil supply pump 202 is used to supply lubricating oil to the first oil supply pipe 300. The main oil tank 201 is used to store lubricating oil, while the oil supply pump 202 delivers stable oil pressure and flow to the high-level oil tank 102 through the first oil supply pipe 300. This structure is mature in design and highly reliable, providing a stable and reliable foundation for the entire lubrication system.

[0052] In some embodiments, the oil supply pump 202 can be located inside the main oil tank 201, and its output end can be directly connected to the first oil supply pipe 300. The lubricating oil inside the main oil tank 201 is directly output through the oil supply pipe.

[0053] In some embodiments, the oil supply pump 202 may be located outside the main oil tank 201, and the input end of the oil supply pump 202 is connected to the inside of the main oil tank 201.

[0054] It is worth noting that in the above scheme, the oil supply pump 202 is not connected to the second oil supply pipe 500. This is because if the power is cut off and the machine stops, the oil supply pump 202 will also stop outputting power. Therefore, even if the second oil supply pipe 500 is connected to the oil supply pump 202, the second oil supply pipe 500 cannot draw lubricating oil through the pressure difference. Therefore, the second oil supply pipe 500 is directly connected to the inside of the main oil tank 201, and when the power is cut off and the machine stops, lubricating oil is drawn in through the pressure difference between the high-level oil tank 102 and the volute.

[0055] Understandably, in order to ensure that the second oil supply pipe 500 can draw in lubricating oil, the main oil tank 201 is not sealed, ensuring that the pressure difference inside and outside the main oil tank 201 is the same, so that the suction of the volute and the high-level oil tank 102 can draw in lubricating oil.

[0056] In some embodiments, the compressor oil supply system further includes a controller configured to start the centrifugal compressor 100 upon receiving a start signal.

[0057] In some embodiments, the controller is configured to: upon receiving a start signal, determine whether the start conditions are met; if so, start the centrifugal compressor 100; otherwise, issue an alarm or perform no operation.

[0058] In some embodiments, an oil level sensor is provided in the main oil tank 201 to detect whether the lubricating oil in the main oil tank 201 has reached a preset oil level value. A first sensor is also provided to detect the voltage and / or current of the oil supply pump 202 and obtain the oil pump circuit value. A second sensor is provided to detect the voltage and / or current of the centrifugal compressor 100 and obtain the compressor circuit value.

[0059] The specific steps for determining whether the start-up conditions are met are as follows: The control oil level sensor, the first sensor, and the second sensor acquire preset oil level values, oil pump circuit values, and compressor circuit values, respectively. Each of these values ​​is then checked to see if it reaches a preset threshold. If so, the start-up conditions are determined to be met.

[0060] In some embodiments, the controller is configured to start the centrifugal compressor 100 while simultaneously controlling the main oil pump to start.

[0061] In some embodiments, the controller is configured to: after starting the centrifugal compressor 100, control the normally open solenoid valve 600 to close and control the normally closed solenoid valve 110 to close.

[0062] In some embodiments, the controller is configured to: after starting the centrifugal compressor 100, determine whether a shutdown signal has been received; if not, maintain the current state until the determination is yes; if yes, shut down the centrifugal compressor 100 and control the normally closed solenoid valve 110 to open.

[0063] In some embodiments, a pressure sensor is provided inside the volute housing to detect the pressure inside the volute housing and obtain the compressor pressure value. The controller is configured to: after the centrifugal compressor 100 is turned off, control the pressure sensor to obtain the compressor pressure value and determine whether the compressor pressure value is greater than a preset pressure value. If not, then wait for a first preset time and then turn off the oil supply pump 202. If yes, control the normally open solenoid valve 600 to open, wait for a second preset time, then turn off the oil supply pump 202 and disconnect the power supply to the normally open solenoid valve 600.

[0064] After normal operation is completed, open the second return oil pipe 900 to allow the lubricating oil accumulated at the bottom of the volute to flow back to the oil tank. Also, check if the pressure inside the volute is too high. If so, open the second return oil pipe 900 to replenish the oil in the volute.

[0065] In some embodiments, a sudden power outage may occur during operation. In this case, no controller intervention is required because the normally open solenoid valve 600 can automatically open when the power is off, enabling the second oil return pipe 900 to replenish oil to the centrifugal compressor 100. Therefore, no special control by the controller is required.

[0066] In some embodiments, a failure of the oil supply pump 202 may occur. The controller is configured to: control the centrifugal compressor 100 to shut down when the first sensor acquires the oil pump circuit value and the oil pump circuit value does not reach a preset threshold; cut off the power supply to the normally closed solenoid valve 110; control the pressure sensor to acquire the compressor pressure value and determine whether the compressor pressure value is greater than a preset pressure value; if not, cut off the power supply to the normally open solenoid valve 600; if so, control the normally open solenoid valve 600 to open. This design enables the centrifugal compressor 100 to be shut down in a timely manner and replenishes oil into the volute as needed, ensuring that the lubricating oil can lubricate the volute and preventing damage to the centrifugal compressor 100 due to insufficient oil.

[0067] In addition, this application also provides a compressor oil supply system, which includes a centrifugal compressor 100. The centrifugal compressor 100 includes a volute, and the volute has a first oil return port and a second oil return port; wherein the second oil return port is located at the bottom of the volute.

[0068] In some embodiments, the compressor oil supply system further includes a high-level oil tank 102, which is used to replenish oil to the centrifugal compressor 100. The high-level oil tank 102 is provided with a first oil supply port and a second oil supply port.

[0069] In some embodiments, the compressor oil supply system further includes a main oil supply assembly 200, which is used to supply oil to the centrifugal compressor 100.

[0070] In some embodiments, the main oil supply assembly 200 includes a first oil supply pipe 300, a second oil supply pipe 500, a first oil return pipe 700, and a second oil return pipe 900. The two ends of the first oil supply pipe 300 are connected to a first oil supply port and an input terminal of the main oil supply assembly 200, respectively. The two ends of the second oil supply pipe 500 are connected to a second oil supply port and an input terminal of the main oil supply assembly 200, respectively. The two ends of the first oil return pipe 700 are connected to a first oil return port and an output terminal of the main oil supply assembly 200, respectively. The two ends of the second oil return pipe 900 are connected to a second oil return port and the first oil return pipe 700, respectively. The main oil supply assembly 200 supplies lubricating oil to the high-level oil tank 102 through the first oil supply pipe 300 and / or the second oil supply pipe 500; the volute casing returns lubricating oil to the main oil supply assembly 200 through the first oil return pipe 700.

[0071] The volute casing returns lubricating oil to the main oil supply assembly 200 via the first return oil pipe 700, forming a closed loop. When the compressor unit stops, the pressure difference between the volute casing and the main oil supply assembly 200 is used to output lubricating oil from the bottom of the volute casing to the second return oil pipe 900. The lubricating oil in the second return oil pipe 900 is then fed back to the first return oil pipe 700 and discharged to the main oil supply assembly 200, preventing oil accumulation in the volute casing and ensuring the oil level in the main oil supply assembly 200. When the compressor unit stops due to power failure, a certain pressure difference exists between the compressor volute casing and the high-level oil tank 102. This pressure difference is used to transport the lubricating oil in the main oil supply assembly 200 to the high-level oil tank 102 via the second oil supply pipe 500, thus replenishing the compressor unit's oil supply. This system design effectively solves the problems of insufficient oil supply and uneven lubricating oil distribution that easily occur in traditional oil supply systems with a single oil supply path, improving the unit's operational stability and reliability, and extending the equipment's service life.

[0072] In some embodiments, a second shut-off valve 800 is provided on the first return oil pipe 700, and a section of the first return oil pipe 700 between the second shut-off valve 800 and the main oil supply assembly 200 is a connecting section, through which the second return oil pipe 900 is connected. This ensures that the lubricating oil in the second return oil pipe 900 can be output to the main oil supply assembly 200 through the first return oil pipe 700, preventing blockage of the second shut-off valve 800 and ensuring smooth oil return.

[0073] In some embodiments, a normally closed solenoid valve 110 is provided on the second return oil pipe 900; a normally open solenoid valve 600 is provided on the second supply oil pipe 500. During normal use, the normally closed solenoid valve 110 is in the closed state to ensure normal circulation of lubricating oil and prevent excessive lubricating oil from being discharged through the second return oil pipe 900, which could lead to insufficient oil in the volute. The normally closed solenoid valve 110 is only opened when the compressor unit stops to allow excess lubricating oil in the volute to be discharged. When the unit suddenly loses power, the normally open solenoid valve 600 automatically opens due to power failure. Utilizing the pressure difference between the volute and the high-level oil tank 102 during compressor coasting, a "high-level oil tank 102 pressurization" effect is created, forcing lubricating oil to flow rapidly into the bearing cavity within the volute, achieving emergency lubrication. This overcomes the defect of poor oil supply caused by a vacuum formed in the traditional high-level oil tank 102.

[0074] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A compressor oil supply system, characterized in that, It includes: A centrifugal compressor includes a volute casing, on which a first oil return port and a second oil return port are provided; wherein the second oil return port is located at the bottom of the volute casing. A high-level oil tank is used to replenish oil to the centrifugal compressor. The high-level oil tank is provided with a first oil supply port and a second oil supply port. Main oil supply components; The first oil supply pipe has its two ends connected to the first oil supply port and the input end of the main oil supply assembly, respectively. The second oil supply pipe has its two ends connected to the second oil supply port and the input end of the main oil supply assembly, respectively. The first return oil pipe has its two ends connected to the first return oil port and the output end of the main oil supply component, respectively. The second return oil pipe has its two ends connected to the second return oil port and the output end of the main oil supply assembly, respectively. The main oil supply assembly supplies lubricating oil to the high-level oil tank through the first oil supply pipe and / or the second oil supply pipe; The volute returns lubricating oil to the main oil supply assembly through the first return oil pipe and / or the second return oil pipe.

2. The compressor oil supply system according to claim 1, characterized in that, A normally closed solenoid valve is installed on the second return oil pipe; When the oil supply unit stops, the normally closed solenoid valve opens, and the lubricating oil at the bottom of the volute is discharged through the second return oil pipe.

3. The compressor oil supply system according to claim 1, characterized in that, A normally open solenoid valve is installed on the second oil supply pipe; When the oil supply unit is de-energized, the normally open solenoid valve is de-energized and opens, and the second oil supply pipe supplies the lubricating oil of the main oil supply component into the high-level oil tank.

4. The compressor oil supply system according to claim 1, characterized in that, A first shut-off valve is installed on the first oil supply pipe.

5. The compressor oil supply system according to claim 1, characterized in that, There are multiple first return oil pipes, and the connection points between the different first return oil pipes and the volute are at different locations.

6. The compressor oil supply system according to claim 1 or 5, characterized in that, A second shut-off valve is installed on the first return oil pipe.

7. The compressor oil supply system according to claim 1, characterized in that, The main oil supply component includes: Main oil tank, the interior of which is used to hold lubricating oil; An oil supply pump is connected to the inside of the main oil tank and is used to output lubricating oil to the first oil supply pipe. The first return oil pipe and the second return oil pipe are connected to the main oil tank.

8. A compressor oil supply system, characterized in that, It includes: A centrifugal compressor includes a volute casing, on which a first oil return port and a second oil return port are provided; wherein the second oil return port is located at the bottom of the volute casing. A high-level oil tank is used to replenish oil to the centrifugal compressor. The high-level oil tank is provided with a first oil supply port and a second oil supply port. Main oil supply components; The first oil supply pipe has its two ends connected to the first oil supply port and the input end of the main oil supply assembly, respectively. The second oil supply pipe has its two ends connected to the second oil supply port and the input end of the main oil supply assembly, respectively. The first return oil pipe has its two ends connected to the first return oil port and the output end of the main oil supply component, respectively. The second return oil pipe has its two ends connected to the second return oil port and the first return oil pipe, respectively. The main oil supply assembly supplies lubricating oil to the high-level oil tank through the first oil supply pipe and / or the second oil supply pipe; The volute returns lubricating oil to the main oil supply assembly through the first return oil pipe.

9. The compressor oil supply system according to claim 8, characterized in that, A second shut-off valve is provided on the first return oil pipe. A section of the first return oil pipe located between the second shut-off valve and the main oil supply assembly is a connecting section, and the second return oil pipe is connected to the connecting section.

10. The compressor oil supply system according to claim 9, characterized in that, A normally closed solenoid valve is installed on the second return oil pipe; A normally open solenoid valve is installed on the second oil supply pipe.

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