A centrifugal unit oil circulation system and a circulating flushing method

Abstract

The present invention belongs to an oil circulation system and a circulating flushing method for a centrifugal unit; it includes a centrifugal unit body, and the centrifugal unit body is connected to a self-cleaning fuel tank unit through an oil circulation pipeline unit; the self-cleaning fuel tank unit includes a fuel tank, a gas distributor connected to a gas pipeline is provided at the inner bottom of the fuel tank, a circulating oil outlet is provided at the side of the fuel tank, and the circulating oil outlet is connected to a circulating oil inlet at the top of the fuel tank through a filtering device; it has the advantages of shortening the oil circulation time, eliminating the need to replace new lubricating oil, enabling the unit to enter the commissioning work in advance, shortening the project construction period, and ensuring the safe and stable operation of the unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil circulation of centrifugal units, and particularly relates to an oil circulation system and a circulation flushing method for centrifugal units. Background Art

[0002] Centrifugal units are key equipment with high rotational speeds in the petroleum, chemical, power, and steel industries. Their safe and stable operation is related to the normal operation of the entire system, and the oil system plays a crucial role in the reliable operation of centrifugal units. Therefore, doing a good job in the oil system circulation flushing of centrifugal units is precisely the primary task during the project construction period, directly affecting the commissioning of the system and the normal operation of the unit. Currently, the conventional oil circulation method not only has a long flushing time, with a cycle of 3 months, and requires multiple replacements of new lubricating oil during the process, incurring a large amount of labor costs and investment costs, but there are still impurities in the oil system, which affect the normal operation of the unit in the later stage. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects in the prior art, and provide an oil circulation system and a circulation flushing method for centrifugal units that are based on a self-cleaning type oil tank unit, cooperate with the entire system to remove impurities, achieve shortening the oil circulation time, and do not require replacement of new lubricating oil, enabling the unit to enter the commissioning work in advance, shortening the project construction period, and ensuring the safe and stable operation of the unit.

[0004] The purpose of the present invention is achieved as follows:

[0005] An oil circulation system for centrifugal units includes the main body of the centrifugal unit, and the main body of the centrifugal unit is connected to a self-cleaning type oil tank unit through an oil circulation pipeline unit; the self-cleaning type oil tank unit includes an oil tank, a gas distributor connected to a gas pipeline is provided at the inner bottom of the oil tank, a circulating oil outlet is provided at the side of the oil tank, and the circulating oil outlet is connected to a circulating oil inlet at the top of the oil tank through a filtering device.

[0006] Preferably, the gas distributor is connected to an air storage tank or a nitrogen storage tank through a gas pipeline; the gas distributor includes a central air inlet pipe and a plurality of annular pipes arranged outside the central air inlet pipe, and connecting pipes are respectively provided between the central air inlet pipe and the adjacent annular pipes and between two adjacent annular pipes; a plurality of groups of air outlet parts are evenly distributed on the annular pipes, each group of air outlet parts includes three air outlets, one of the air outlets is arranged at the top position of the annular pipe, and the other two air outlets are arranged on both sides of the air outlet at the top, the included angle between the air outlets on both sides and the air outlet at the top is 60°, and the diameter of the air outlet is 3 mm.

[0007] Preferably, there are two circulating oil outlets, one of which is arranged at the bottom side of the oil tank, and the other is arranged at the middle and lower part of the side of the oil tank; the circulating oil outlet at the bottom side of the oil tank is connected to the circulating oil inlet through a plate-frame oil filter; the circulating oil outlet at the middle and lower part of the side of the oil tank is connected to the circulating oil inlet through a vacuum oil filter.

[0008] Preferably, an oil inlet tee is provided between the circulating oil outlet at the middle and lower part of the side of the oil tank and the vacuum oil filter, the third end of the oil inlet tee is connected to an oil storage tank, a first cut-off valve is provided between the circulating oil outlet at the middle and lower part of the side of the oil tank and the oil inlet tee, and a second cut-off valve is provided between the third end of the oil inlet tee and the oil storage tank.

[0009] Preferably, an electric heater is provided inside the oil tank, and an exhaust air blower is provided on one side of the top of the oil tank.

[0010] Preferably, the oil circulation pipeline unit includes a first basket filter connected to the oil outlet of the oil tank, the first basket filter is successively connected to an oil pump, an oil cooler, a duplex filter and a tee, the second end of the tee is respectively connected to a first bearing box of a centrifuge, a second bearing box of the centrifuge, a third bearing box of the centrifuge and a fourth bearing box of the centrifuge, and the first bearing box of the centrifuge, the second bearing box of the centrifuge, the third bearing box of the centrifuge and the fourth bearing box of the centrifuge are respectively connected to a return oil pipeline; the third end of the tee is connected to a four-way joint, the second end of the four-way joint is connected to the oil inlet of an electro-hydraulic conversion device, the third end of the four-way joint is connected to the return oil pipeline through the main air valve of the centrifuge unit, and the third end of the four-way joint is connected to the return oil pipeline through the emergency trip device of the centrifuge unit; a second basket filter is provided on the return oil pipeline, and the end of the return oil pipeline is connected to the oil return port of the oil tank.

[0011] Preferably, pipeline flushing units or system flushing units are provided at the oil circuits at both ends of the first bearing box, the oil circuits at both ends of the second bearing box of the centrifuge, the oil circuits at both ends of the third bearing box of the centrifuge, the oil circuits at both ends of the fourth bearing box of the centrifuge, the front end of the oil inlet of the electro-hydraulic conversion device, the front end and the rear end of the main air valve of the centrifuge unit, and the front end and the rear end of the emergency trip device of the centrifuge unit.

[0012] Preferably, the pipeline flushing unit includes detachable blind plates respectively provided on the oil circuits at both ends of the first bearing box, the oil circuits at both ends of the second bearing box of the centrifuge, the oil circuits at both ends of the third bearing box of the centrifuge, and the oil circuits at both ends of the fourth bearing box of the centrifuge, a temporary hose is provided between the outer sides of the detachable blind plates that can be opened on the same centrifuge bearing box, and first temporary filters are respectively provided at the inlet end and the outlet end of the temporary hose; second temporary filters are respectively provided at the front end of the oil inlet of the electro-hydraulic conversion device, the front end and the rear end of the main air valve of the centrifuge unit, and the front end and the rear end of the emergency trip device of the centrifuge unit.

[0013] Preferably, the system flushing unit includes an oil circuit at the inlet end of the first bearing box, an oil circuit at the inlet end of the second bearing box of the centrifuge, an oil circuit at the inlet end of the third bearing box of the centrifuge, and an oil circuit at the inlet end of the fourth bearing box of the centrifuge, and orifice plates are respectively arranged on them; check valves are respectively arranged on the oil circuit at the outlet end of the first bearing box, the oil circuit at the outlet end of the second bearing box of the centrifuge, the oil circuit at the outlet end of the third bearing box of the centrifuge, and the oil circuit at the outlet end of the fourth bearing box of the centrifuge; third temporary filters are respectively arranged at the front end of the oil inlet of the electro-hydraulic conversion device, at the front and rear ends of the main air valve of the centrifuge unit, and at the front and rear ends of the emergency governor of the centrifuge unit.

[0014] The present invention also provides a circulating flushing method for the oil circulation system of a centrifuge unit, which is characterized in that: the circulating flushing method includes preliminary preparation, pipeline flushing, and system flushing;

[0015] The preliminary preparation includes the following steps:

[0016] Step 1: Select stainless steel pipes for the pipelines, perform in-pipe polishing treatment on the pipelines, carry out the pipeline construction in a dust-free closed environment, and adopt mechanical cutting, argon arc welding for backing and segmented prefabrication for construction. After the pipeline construction, scrub the inside of the pipeline, and after scrubbing, blow it clean with clean compressed air, clean it with chemical acid, dry it after cleaning, and protect the seals at both ends after drying to ensure the cleanliness inside the pipeline;

[0017] Step 2: Remove the filter elements of the first basket filter, the second basket filter, the first temporary filter, the second temporary filter, the third temporary filter, the plate-frame oil filter, the vacuum oil filter, the orifice plate, the check valve, and the duplex filter in the system, check whether there are foreign objects inside; and clean them with kerosene, dry them with compressed air after cleaning and reinstall them;

[0018] Step 3: Assemble the system, connect the centrifuge unit body, the oil tank, the plate-frame oil filter, the vacuum oil filter, the first basket filter, the oil pump, the oil cooler, the duplex filter, and the second basket filter through the above pipelines, and the slope of the connected pipelines is 3‰;

[0019] The pipeline flushing includes the following steps:

[0020] Step 1: Close the first cut-off valve and open the second cut-off valve to enable the oil storage tank to enter the oil tank through the second cut-off valve, the vacuum oil filter, and the circulating oil inlet;

[0021] Step 2: After the oil injection is completed, conduct an oil circulation process. Close the second cut-off valve and open the first cut-off valve; start the oil pump so that the lubricating oil in the oil tank passes through the first basket filter, the oil pump, the duplex filter, each temporary hose, and the corresponding first temporary filter, the electro-hydraulic conversion device, the main air valve of the centrifuge unit, and the emergency trip device of the centrifuge unit, as well as the corresponding second temporary filter; finally, it flows back into the oil tank through the second basket filter installed on the return oil pipeline.

[0022] Step 3: During the oil circulation process in Step 2 above, start the plate-frame oil filter and the vacuum oil filter so that the lubricating oil in the oil tank is filtered by the plate-frame oil filter and the vacuum oil filter and then re-enters the oil tank.

[0023] Step 4: While starting the plate-frame oil filter and the vacuum oil filter in Step 3 above, let the air or nitrogen in the air storage tank or nitrogen storage tank enter the oil tank through the gas distributor to form a disturbance to the bottom of the oil tank.

[0024] Step 5: During the oil circulation process in Step 2 above, adopt an alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 1 - 3 hours.

[0025] When hot oil operation is required, start the electric heater and the vacuum oil filter to heat the lubricating oil on the premise of filtration. The temperature of the heated lubricating oil is: 35 - 75 °C.

[0026] When cold oil operation is required, start the oil cooler to cool the lubricating oil. The temperature of the cooled lubricating oil is: 15 - 30 °C.

[0027] Step 6: During the operation of Step 2, Step 3, Step 4, and Step 5 in the above pipeline flushing, start the smoke exhaust fan so that the inside of the oil tank is in a slightly negative pressure state with a pressure of: -5 Kpa.

[0028] Step 7: During the operation of Step 2, Step 3, Step 4, and Step 5 in the above pipeline flushing, the filter meshes used for the first basket filter and the second basket filter are 150 meshes; the filter meshes of the first temporary filter, the second temporary filter, and the duplex filter are 100 meshes, and the plate-frame oil filter and the vacuum oil filter are 40 microns and 3 microns respectively; check the filter meshes of the first basket filter, the second basket filter, the first temporary filter mesh, the second temporary filter mesh, and the duplex filter every 2 hours, and clean the impurities with degreased white cloth.

[0029] Step 8: Detect the quality of the lubricating oil. When the detected impurities in the oil quality are < 80 microns, the pipeline flushing is completed. Close the oil pump, the plate-frame oil filter, the vacuum oil filter, and the smoke exhaust fan.

[0030] The system flushing includes the following steps:

[0031] Step 1: Remove the detachable blind plate, temporary hose and first temporary filter used during the pipeline flushing. Install orifice plates on the oil circuits at the inlet ends of the first bearing housing, the second bearing housing of the centrifuge, the third bearing housing of the centrifuge, and the fourth bearing housing of the centrifuge. Install check valves on the oil circuits at the outlet ends of the first bearing housing, the second bearing housing of the centrifuge, the third bearing housing of the centrifuge, and the fourth bearing housing of the centrifuge.

[0032] Replace the second temporary filters at the front end of the oil inlet of the electro-hydraulic conversion device, the front and rear ends of the main air valve of the centrifuge unit, and the front and rear ends of the emergency trip device of the centrifuge unit with third temporary filters; the filter screen of the third temporary filter is 200 mesh.

[0033] Step 2: Start the oil pump so that the lubricating oil in the oil tank passes through the first basket filter, the oil pump, the duplex filter, the first bearing housing of the centrifuge, the second bearing housing of the centrifuge, the third bearing housing of the centrifuge, the fourth bearing housing of the centrifuge, the electro-hydraulic conversion device, the main air valve of the centrifuge unit, the emergency trip device of the centrifuge unit, and the corresponding third temporary filters; finally, it flows back into the oil tank through the second basket filter installed on the return oil pipeline.

[0034] Step 3: During the oil circulation process in Step 2 above, start the plate and frame oil filter and the vacuum oil filter so that the lubricating oil in the oil tank is filtered by the plate and frame oil filter and the vacuum oil filter and then re-enters the oil tank.

[0035] Step 4: While starting the plate and frame oil filter and the vacuum oil filter in Step 3 above, let the air or nitrogen from the air storage tank or nitrogen storage tank enter the oil tank through the gas distributor to form a disturbance at the bottom of the oil tank.

[0036] Step 5: During the oil circulation process in Step 2 above, adopt an alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 1 - 3 hours.

[0037] When hot oil operation is required, start the electric heater and the vacuum oil filter to heat the lubricating oil on the premise of filtration. The temperature of the heated lubricating oil is: 35 - 75 °C.

[0038] When cold oil operation is required, start the oil cooler to cool the lubricating oil. The temperature of the cooled lubricating oil is: 15 - 30 °C.

[0039] Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, start the smoke exhaust fan so that the internal pressure of the oil tank is in a slightly negative pressure state of -5 Kpa.

[0040] Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used for the first basket filter and the second basket filter are 150 meshes; the filter meshes of the third temporary filter and the duplex oil filter are 200 meshes, and those of the plate-frame oil filter and the vacuum oil filter are 40 microns and 3 microns respectively; the filter meshes of the first basket filter, the second basket filter, the first temporary filter mesh, the second temporary filter mesh, and the duplex oil filter are inspected every 2 hours, and the impurities are cleaned with degreased white cloth;

[0041] Step 8: Detect the grease of the lubricating oil. When the detected impurities in the oil quality are < 80 microns, the system flushing is completed, and the oil pump, the plate-frame oil filter, the vacuum oil filter, and the exhaust fan are turned off.

[0042] A centrifugal unit oil circulation system and a circulation flushing method made according to the above scheme can cause the lubricating oil to be disturbed in the oil tank by setting a gas distributor, avoiding the precipitation of impurities, and cooperating with a filtering device to filter the oil to achieve the purpose of self-cleaning; further, the present invention realizes the disturbance inside the oil tank by defining the structure of the body distributor, the angle of the air outlet holes, and the diameter of the air outlet holes, can avoid the precipitation of impurities, and cooperate with the plate-frame oil filter and the vacuum oil filter to realize the filtration of the lubricating oil; the disturbance in the above process is a regular disturbance of the lubricating oil at the lower layer of the oil tank, which can avoid the precipitation of impurities, and at the same time can reduce the influence on the temperature of the lubricating oil, and avoid the problems of sealing and oxidation caused by large-scale irregular disturbance of the lubricating oil; further, the present invention is based on the above self-cleaning oil tank unit, and cooperates with the basket filters, temporary filters, orifice plates, check valves, duplex oil filters, etc. in the whole system to remove impurities from the grease as a whole, and in the process of impurity removal, through the form of alternating hot and cold oil circulation, the advantages of shortening the oil circulation time, not needing to replace new lubricating oil, enabling the unit to enter the commissioning work in advance, shortening the project construction period, and ensuring the safe and stable operation of the unit are realized. Description of the Drawings

[0043] Figure 1 It is a schematic structural diagram when the pipeline of the present invention is flushed.

[0044] Figure 2 It is a schematic structural diagram when the system of the present invention is flushed.

[0045] Figure 3 It is a schematic structural diagram of the gas distributor of the present invention.

[0046] Figure 4 It is a schematic diagram of the positional structural relationship of the air outlet holes of the present invention. Detailed Embodiments

[0047] For a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described with reference to the accompanying drawings. The same reference numerals in each figure represent the same components. To make the drawings concise, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product as a whole.

[0048] As Figures 1-4 shown, the present invention relates to an oil circulation system and a circulation flushing method for a centrifugal unit. Among them, the system includes a centrifugal unit body 1, and the centrifugal unit body 1 is connected to a self-cleaning fuel tank unit through an oil circulation pipeline unit; the self-cleaning fuel tank unit includes a fuel tank 2, a gas distributor 3 connected to a gas pipeline is provided at the inner bottom of the fuel tank 2, a circulating oil outlet 4 is provided on the side of the fuel tank 2, and the circulating oil outlet 4 is connected to a circulating oil inlet 5 at the top of the fuel tank 2 through a filtering device. By providing the gas distributor 3 at the inner bottom of the fuel tank 2, the present invention can directly introduce gas into the lower inner part of the fuel tank 2, thereby disturbing the lubricating oil. During the disturbing process, impurities fluctuate with the lubricating oil to avoid precipitation, and enter the filtering device for filtration, so as to achieve the purpose of removing impurities in the fuel tank from the lubricating oil.

[0049] Furthermore, the gas distributor 3 is connected to an air storage tank or a nitrogen storage tank 6 through a gas pipeline; the gas distributor 3 includes a central air inlet pipe 7 and a plurality of annular pipes 8 arranged outside the central air inlet pipe 7, and connecting pipes 9 are respectively provided between the central air inlet pipe 7 and the adjacent annular pipe 8 and between two adjacent annular pipes 8; a plurality of groups of air outlet parts are evenly distributed on the annular pipe 8, and each group of air outlet parts includes three air outlets 10, one of the air outlets 10 is arranged at the top of the annular pipe 8, and the other two air outlets 10 are arranged on both sides of the top air outlet 10, and the included angle between the two side air outlets 10 and the top air outlet 10 is 60°, and the diameter of the air outlet is 3 mm. Through the above settings, the present invention can realize the upward or obliquely upward spraying of gas, and the above spraying method can make the lubricating oil generate regular disturbance, and this regular disturbance mainly occurs in the lower layer of the lubricating oil, avoiding affecting the temperature of the lubricating oil during the actual process, and avoiding problems such as sealing and oxidation deterioration of the lubricating oil caused by large-scale irregular disturbance of the lubricating oil.

[0050] Further, there are two circulating oil outlets 4, one of which is arranged at the bottom side of the fuel tank, and the other is arranged at the middle and lower part of the side of the fuel tank; the circulating oil outlet 4 at the bottom side of the fuel tank is connected to the circulating oil inlet 5 through a plate-frame oil filter 11; the circulating oil outlet 4 at the middle and lower part of the side of the fuel tank is connected to the circulating oil inlet 5 through a vacuum oil filter 12. The present invention uses a plate-frame oil filter 11 and a vacuum oil filter 12 to filter impurities in the lubricating oil in the fuel tank 2 at the same time. The filtration accuracy of the vacuum oil filter 12 is higher than that of the plate-frame oil filter 11, which can not only effectively filter the oil but also ensure the normal operation of the filtering device; the gas distributor 3 provided in the present invention is mainly considered to avoid impurity precipitation without affecting the normal use of the lubricating oil, and the filtering device can filter the oil on the premise that impurities do not precipitate. Since the filtration accuracy of the vacuum oil filter 12 is relatively high and can deeply filter the oil, but there is also a problem of easy blockage at the same time. The present invention realizes the preliminary filtration of the oil through the plate-frame oil filter 11 to reduce the risk of blockage of the vacuum oil filter 12, and can also supplement the vacuum oil filter 12, that is, when the vacuum oil filter 12 fails, the filtering device can still operate normally.

[0051] Further, an oil inlet tee is provided between the circulating oil outlet 4 at the middle and lower part of the side of the fuel tank and the vacuum oil filter 12. The third end of the oil inlet tee is connected to an oil storage tank 29. A first cut-off valve 30 is provided between the circulating oil outlet 4 at the middle and lower part of the side of the fuel tank and the oil inlet tee, and a second cut-off valve 31 is provided between the third end of the oil inlet tee and the oil storage tank 29. Through the above settings, the vacuum oil filter 12 can filter the oil and supplement new lubricating oil.

[0052] Further, an electric heater 32 is provided inside the fuel tank 2, and an exhaust air blower 33 is provided on one side of the top of the fuel tank 2. By setting the electric heater 32, the hot and cold oil can be circulated alternately during oil circulation. By setting the exhaust air blower 33, the flue gas of the heated oil and the gas entering the gas distributor can be discharged in time, which can not only keep the oil circulation in the system smoother but also reduce the risk of oxidation of the lubricating oil, so as to improve the service life of the oil.

[0053] Further, the oil circulation pipeline unit includes a first basket filter 13 connected to the oil outlet of the oil tank 2. The first basket filter 13 is successively connected to an oil pump 14, an oil cooler 15, a duplex filter 16 and a three-way joint. The second ends of the three-way joint are respectively connected to a first bearing housing 17 of the centrifuge, a second bearing housing 18 of the centrifuge, a third bearing housing 19 of the centrifuge and a fourth bearing housing 20 of the centrifuge. The first bearing housing 17 of the centrifuge, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge and the fourth bearing housing 20 of the centrifuge are respectively connected to an oil return pipeline; the third end of the three-way joint is connected to a four-way joint. The second end of the four-way joint is connected to the oil inlet of an electro-hydraulic conversion device 21. The third end of the four-way joint is connected to the oil return pipeline through a main air valve 22 of the centrifuge unit. The third end of the four-way joint is connected to the oil return pipeline through a critical speed trip 23 of the centrifuge unit; a second basket filter 24 is provided on the oil return pipeline, and the end of the oil return pipeline is connected to the oil return port of the oil tank 2.

[0054] Further, pipeline flushing units or system flushing units are provided at the oil circuits at both ends of the first bearing housing 17, the oil circuits at both ends of the second bearing housing 18 of the centrifuge, the oil circuits at both ends of the third bearing housing 19 of the centrifuge, the oil circuits at both ends of the fourth bearing housing 20 of the centrifuge, the front end of the oil inlet of the electro-hydraulic conversion device 21, the front end and the rear end of the main air valve 22 of the centrifuge unit, and the front end and the rear end of the critical speed trip 23 of the centrifuge unit.

[0055] Further, the pipeline flushing unit includes removable blind plates 25 respectively provided on the oil circuits at both ends of the first bearing housing 17, the oil circuits at both ends of the second bearing housing 18 of the centrifuge, the oil circuits at both ends of the third bearing housing 19 of the centrifuge, and the oil circuits at both ends of the fourth bearing housing 20 of the centrifuge. A temporary hose 26 is provided between the outer sides of the removable blind plates 25 that can be opened on the same centrifuge bearing housing. First temporary filters 27 are respectively provided at the inlet end and the outlet end of the temporary hose 26; second temporary filters 28 are respectively provided at the front end of the oil inlet of the electro-hydraulic conversion device 21, the front end and the rear end of the main air valve 22 of the centrifuge unit, and the front end and the rear end of the critical speed trip 23 of the centrifuge unit.

[0056] Further, the system flushing unit includes orifice plates 34 respectively provided on the oil circuits at the inlet ends of the first bearing housing 17, the oil circuits at the inlet ends of the second bearing housing 18 of the centrifuge, the oil circuits at the inlet ends of the third bearing housing 19 of the centrifuge, and the oil circuits at the inlet ends of the fourth bearing housing 20 of the centrifuge. Check valves 35 are respectively provided on the oil circuits at the outlet ends of the first bearing housing 17, the oil circuits at the outlet ends of the second bearing housing 18 of the centrifuge, the oil circuits at the outlet ends of the third bearing housing 19 of the centrifuge, and the oil circuits at the outlet ends of the fourth bearing housing 20 of the centrifuge; third temporary filters 36 are respectively provided at the front end of the oil inlet of the electro-hydraulic conversion device 21, the front end and the rear end of the main air valve 22 of the centrifuge unit, and the front end and the rear end of the critical speed trip 23 of the centrifuge unit.

[0057] The present invention also provides a circulating flushing method for the oil circulation system of a centrifugal unit. The circulating flushing method includes preliminary preparation, pipeline flushing, and system flushing;

[0058] The preliminary preparation includes the following steps:

[0059] Step 1: Select stainless steel pipes for the pipelines, perform in-pipe polishing treatment on the pipelines. The pipeline construction is carried out in a dust-free closed environment, and the construction is carried out in the form of mechanical cutting, argon arc welding backing, and segmented prefabrication. After the pipeline construction, scrub the inside of the pipeline, and after scrubbing, blow it clean with clean compressed air, clean it with chemical acid, dry it after cleaning, and protect the seals at both ends after drying to ensure the cleanliness inside the pipeline;

[0060] Step 2: Remove the filter elements of the first basket filter 13, the second basket filter 24, the first temporary filter 27, the second temporary filter 28, the third temporary filter 36, the plate-frame oil filter 11, the vacuum oil filter 12, the orifice plate 34, the check valve 35, and the duplex filter 16 in the system, and check whether there are foreign objects inside; and clean them with kerosene, dry them with compressed air after cleaning, and reinstall them;

[0061] Step 3: Assemble the system, connect the centrifugal unit body 1, the oil tank 2, the plate-frame oil filter 11, the vacuum oil filter 12, the first basket filter 13, the oil pump 14, the oil cooler 15, the duplex filter 16, and the second basket filter 24 through the above pipelines. The slope of the connected pipeline is 3‰;

[0062] The pipeline flushing includes the following steps:

[0063] Step 1: Close the first cut-off valve 30 and open the second cut-off valve 31, so that the oil storage tank 29 enters the oil tank 2 through the second cut-off valve 31, the vacuum oil filter 12, and the circulating oil inlet 5;

[0064] Step 2: After the oil injection is completed, carry out the oil circulation process. Close the second cut-off valve 31 and open the first cut-off valve 30; start the oil pump 14, so that the lubricating oil in the oil tank 2 passes through the first basket filter 13, the oil pump 14, the duplex filter 16, each temporary hose 26, and the corresponding first temporary filter 27, the electro-hydraulic conversion device 21, the main air valve 22 of the centrifugal unit, and the overspeed trip 23 of the centrifugal unit, and the corresponding second temporary filter 28; finally, it flows back into the oil tank 2 through the second basket filter 24 provided on the return oil pipeline;

[0065] Step 3: During the oil circulation process in Step 2 above, start the plate-frame oil filter 11 and the vacuum oil filter 12, so that the lubricating oil in the oil tank 2 is filtered by the plate-frame oil filter 11 and the vacuum oil filter 12 and then re-enters the oil tank 2;

[0066] Step 4: While starting the plate-frame oil filter 11 and the vacuum oil filter 12 in the above Step 3, let the air or nitrogen in the air storage tank or nitrogen storage tank 6 enter the oil tank 2 through the gas distributor 3 to disturb the bottom of the oil tank 2;

[0067] Step 5: During the oil circulation process in the above Step 2, adopt the alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 1 - 3 hours;

[0068] When hot oil operation is required, start the electric heater 32 and the vacuum oil filter 12 to heat the lubricating oil on the premise of filtration, and the temperature of the heated lubricating oil is: 35 - 75 °C;

[0069] When cold oil operation is required, start the oil cooler 15 to cool the lubricating oil, and the temperature of the cooled lubricating oil is: 15 - 30 °C;

[0070] Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, start the smoke exhaust fan 33 to make the inside of the oil tank 2 in a slightly negative pressure state with a pressure of: -5 Kpa;

[0071] Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used for the first basket filter 13 and the second basket filter 24 are 150 meshes; the filter meshes of the first temporary filter 27, the second temporary filter 28, and the duplex filter 16 are 100 meshes, and the plate-frame oil filter 11 and the vacuum oil filter 12 are 40 microns and 3 microns respectively; check the filter meshes of the first basket filter 13, the second basket filter 24, the first temporary filter mesh 27, the second temporary filter mesh 28, and the duplex filter 16 every 2 hours, and clean the impurities with degreased white cloth;

[0072] Step 8: Detect the grease of the lubricating oil. When the impurities detected in the oil quality are < 80 microns, the pipeline flushing ends, and the oil pump 14, the plate-frame oil filter 11, the vacuum oil filter 12, and the smoke exhaust fan 33 are turned off;

[0073] The system flushing includes the following steps:

[0074] Step 1: Remove the detachable blind plate 25, the temporary hose 26, and the first temporary filter 27 used during the pipeline flushing. Install orifice plates 34 on the oil circuits at the inlet ends of the first bearing housing 17, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, and the fourth bearing housing 20 of the centrifuge, and install check valves 35 on the oil circuits at the outlet ends of the first bearing housing 17, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, and the fourth bearing housing 20 of the centrifuge;

[0075] Replace the second temporary filter 28 at the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the emergency governor 23 of the centrifuge unit with a third temporary filter 36; the filter screen of the third temporary filter 36 is 200 mesh;

[0076] Step 2: Turn on the oil pump 14 so that the lubricating oil in the oil tank 2 passes through the first basket filter 13, the oil pump 14, the duplex filter 16, the first bearing housing 17 of the centrifuge, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, the fourth bearing housing 20 of the centrifuge, the electro-hydraulic conversion device 21, the main air valve 22 of the centrifuge unit, and the emergency governor 23 of the centrifuge unit, and the corresponding third temporary filter 36; finally, it flows back into the oil tank 2 through the second basket filter 24 provided on the return oil pipeline;

[0077] Step 3: During the oil circulation process in Step 2 above, turn on the plate and frame filter press 11 and the vacuum oil filter 12 so that the lubricating oil in the oil tank 2 is filtered by the plate and frame filter press 11 and the vacuum oil filter 12 and then re-enters the oil tank 2;

[0078] Step 4: While turning on the plate and frame filter press 11 and the vacuum oil filter 12 in Step 3 above, let the air or nitrogen in the air storage tank or nitrogen storage tank 6 enter the oil tank 2 through the gas distributor 3 to form a disturbance at the bottom of the oil tank 2;

[0079] Step 5: During the oil circulation process in Step 2 above, adopt an alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 1 - 3 hours;

[0080] When hot oil operation is required, turn on the electric heater 32 and the vacuum oil filter 12 to heat the lubricating oil on the premise of filtration, and the temperature of the heated lubricating oil is: 35 - 75 °C;

[0081] When cold oil operation is required, turn on the oil cooler 15 to cool the lubricating oil, and the temperature of the cooled lubricating oil is: 15 - 30 °C;

[0082] Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, turn on the exhaust fan 33 so that the internal pressure of the oil tank 2 is in a slightly negative pressure state of -5 Kpa;

[0083] Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used in the first basket filter 13 and the second basket filter 24 are 150 meshes; the filter meshes of the third temporary filter 28 and the duplex oil filter 16 are 200 meshes, and the plate - frame oil filter 11 and the vacuum oil filter 12 are 40 microns and 3 microns respectively; Check the filter meshes of the first basket filter 13, the second basket filter 24, the first temporary filter mesh 27, the second temporary filter mesh 28, and the duplex oil filter 16 every 2 hours, and clean the impurities with degreased white cloth;

[0084] Step 8: Detect the grease of the lubricating oil. When the detected impurities in the oil quality are < 80 microns, the system flushing ends, and the oil pump 14, the plate - frame oil filter 11, the vacuum oil filter 12, and the smoke exhaust fan 33 are turned off.

[0085] The circulating flushing method in the present invention includes preliminary preparation, pipeline flushing, and system flushing. Among them, the preliminary preparation is mainly used to avoid the problem that it is difficult to clean up a large amount of impurities generated during the assembly and use of equipment, pipelines, and filtering devices in the subsequent process. Pipeline flushing is mainly to remove impurities in the pipeline first during the trial operation period. In the flushing process of the present invention, a form of self - cleaning filtration in the fuel tank and filtration based on the alternating operation of hot and cold oil in the system is used, realizing a way of combining segmented filtration and overall filtration. Specifically, larger impurities are filtered out in segments, so that the impurities entering the fuel tank are in a smaller quantity and particle size state. At this time, the effective filtration of this part of impurities is achieved through the cooperation of the self - cleaning fuel tank unit; Further, when flushing the system, relevant filters are replaced to improve the filtration accuracy of the segmented filter, which not only prepares for the normal operation in the later stage but also can effectively reduce the filtration load of the self - cleaning fuel tank unit; The above - mentioned methods cooperate with each other to reduce the original oil circulation time from 3 months to 1 month now, and on the basis of timely filtering and removing impurities of the grease, shorten the contact time between the grease and the impurities, thereby extending the service life of the lubricating oil, laying a foundation for shortening the project construction period and ensuring the safe and stable operation of the unit.

[0086] In order to explain the present invention in more detail, the present invention will be further described in combination with embodiments. The specific embodiments are as follows:

[0087] Embodiment 1

[0088] A centrifugal unit oil circulation system, including the centrifugal unit body 1, the centrifugal unit body 1 is connected to a self-cleaning oil tank unit through an oil circulation pipeline unit; the self-cleaning oil tank unit includes an oil tank 2, a gas distributor 3 connected to a gas pipeline is provided at the inner bottom of the oil tank 2, a circulating oil outlet 4 is provided on the side of the oil tank 2, and the circulating oil outlet 4 is connected to a circulating oil inlet 5 at the top of the oil tank 2 through a filtering device. The gas distributor 3 is connected to an air storage tank or a nitrogen storage tank 6 through a gas pipeline; the gas distributor 3 includes a central air inlet pipe 7 and a plurality of annular pipes 8 arranged outside the central air inlet pipe 7, and connecting pipes 9 are respectively provided between the central air inlet pipe 7 and the adjacent annular pipe 8 and between two adjacent annular pipes 8; a plurality of groups of air outlet parts are evenly distributed on the annular pipe 8, and each group of air outlet parts includes three air outlets 10, one of the air outlets 10 is arranged at the top of the annular pipe 8, and the other two air outlets 10 are arranged on both sides of the top air outlet 10, and the included angle between the two side air outlets 10 and the top air outlet 10 is 60°, and the diameter of the air outlet is 3 mm. There are two circulating oil outlets 4, one is arranged at the bottom side of the oil tank, and the other is arranged in the middle and lower part of the side of the oil tank; the circulating oil outlet 4 at the bottom side of the oil tank is connected to the circulating oil inlet 5 through a plate-frame oil filter 11; the circulating oil outlet 4 in the middle and lower part of the side of the oil tank is connected to the circulating oil inlet 5 through a vacuum oil filter 12. An oil inlet tee is provided between the circulating oil outlet 4 in the middle and lower part of the side of the oil tank and the vacuum oil filter 12, a third end of the oil inlet tee is connected to an oil storage tank 29, a first cut-off valve 30 is provided between the circulating oil outlet 4 in the middle and lower part of the side of the oil tank and the oil inlet tee, and a second cut-off 31 is provided between the third end of the oil inlet tee and the oil storage tank 29. An electric heater 32 is provided inside the oil tank 2, and an exhaust air fan 33 is provided on one side at the top of the oil tank 2. The oil circulation pipeline unit includes a first basket filter 13 connected to the oil outlet of the oil tank 2, the first basket filter 13 is sequentially connected to an oil pump 14, an oil cooler 15, a duplex oil filter 16 and a tee, a second end of the tee is respectively connected to a first bearing box 17 of the centrifuge, a second bearing box 18 of the centrifuge, a third bearing box 19 of the centrifuge and a fourth bearing box 20 of the centrifuge, and the first bearing box 17 of the centrifuge, the second bearing box 18 of the centrifuge, the third bearing box 19 of the centrifuge and the fourth bearing box 20 of the centrifuge are respectively connected to an oil return pipeline; a third end of the tee is connected to a four-way, a second end of the four-way is connected to an oil inlet of an electro-hydraulic conversion device 21, a third end of the four-way is connected to an oil return pipeline through a main air valve 22 of the centrifugal unit, and a third end of the four-way is connected to an oil return pipeline through a critical speed trip 23 of the centrifugal unit; a second basket filter 24 is provided on the oil return pipeline, and the end of the oil return pipeline is connected to an oil return port of the oil tank 2.The oil circuits at both ends of the first bearing housing 17, the oil circuits at both ends of the second bearing housing 18 of the centrifuge, the oil circuits at both ends of the third bearing housing 19 of the centrifuge, the oil circuits at both ends of the fourth bearing housing 20 of the centrifuge, the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the emergency overspeed trip 23 of the centrifuge unit are provided with a pipeline flushing unit or a system flushing unit. The pipeline flushing unit includes that detachable blind plates 25 are respectively arranged on the oil circuits at both ends of the first bearing housing 17, the oil circuits at both ends of the second bearing housing 18 of the centrifuge, the oil circuits at both ends of the third bearing housing 19 of the centrifuge, and the oil circuits at both ends of the fourth bearing housing 20 of the centrifuge. A temporary hose 26 is arranged between the outsides of the detachable blind plates 25 that can be opened on the same centrifuge bearing housing. The inlet end and the outlet end of the temporary hose 26 are respectively provided with a first temporary filter 27; the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the emergency overspeed trip 23 of the centrifuge unit are respectively provided with a second temporary filter 28. The system flushing unit includes that orifice plates 34 are respectively arranged on the oil circuits at the inlet ends of the first bearing housing 17, the oil circuits at the inlet ends of the second bearing housing 18 of the centrifuge, the oil circuits at the inlet ends of the third bearing housing 19 of the centrifuge, and the oil circuits at the inlet ends of the fourth bearing housing 20 of the centrifuge. Check valves 35 are respectively arranged on the oil circuits at the outlet ends of the first bearing housing 17, the oil circuits at the outlet ends of the second bearing housing 18 of the centrifuge, the oil circuits at the outlet ends of the third bearing housing 19 of the centrifuge, and the oil circuits at the outlet ends of the fourth bearing housing 20 of the centrifuge; the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the emergency overspeed trip 23 of the centrifuge unit are respectively provided with a third temporary filter 36.

[0089] The present invention also provides a circulating flushing method for the oil circulation system of a centrifuge unit. The circulating flushing method includes preliminary preparation, pipeline flushing, and system flushing;

[0090] The preliminary preparation includes the following steps:

[0091] Step 1: Stainless steel pipes are selected for the pipelines. The inner surfaces of the pipes are polished. The pipeline construction is carried out in a dust-free closed environment. Mechanical cutting, argon arc welding for backing, and segmented prefabrication are adopted for construction. After the pipeline construction, the inside of the pipeline is scrubbed. After scrubbing, it is blown clean by clean compressed air, chemically acid-cleaned, dried after cleaning, and the seals at both ends are protected after drying to ensure the cleanliness inside the pipeline;

[0092] Step 2: Remove the filter elements of the first basket filter 13, the second basket filter 24, the first temporary filter 27, the second temporary filter 28, the third temporary filter 36, the plate and frame oil filter 11, the vacuum oil filter 12, the orifice plate 34, the check valve 35 and the duplex oil filter 16 in the system, check the inside for foreign objects; clean them with kerosene, dry them with compressed air after cleaning and reinstall them;

[0093] Step 3: Assemble the system, connect the centrifuge unit body 1, the oil tank 2, the plate and frame oil filter 11, the vacuum oil filter 12, the first basket filter 13, the oil pump 14, the oil cooler 15, the duplex oil filter 16, the second basket filter 24 through the above pipelines, and the slope of the connected pipelines is 3‰;

[0094] The pipeline flushing includes the following steps:

[0095] Step 1: Close the first cut-off valve 30, open the second cut-off valve 31, and make the oil storage tank 29 enter the oil tank 2 through the second cut-off valve 31, the vacuum oil filter 12 and the circulating oil inlet 5;

[0096] Step 2: After the oil injection is completed, carry out the oil circulation process, close the second cut-off valve 31, and open the first cut-off valve 30; start the oil pump 14, and make the lubricating oil in the oil tank 2 pass through the first basket filter 13, the oil pump 14, the duplex oil filter 16, each temporary hose 26 and the corresponding first temporary filter 27, the electro-hydraulic conversion device 21, the main air valve 22 of the centrifuge unit and the overspeed governor 23 of the centrifuge unit and the corresponding second temporary filter 28; finally, it flows back into the oil tank 2 through the second basket filter 24 arranged on the return oil pipeline;

[0097] Step 3: During the oil circulation process in Step 2 above, start the plate and frame oil filter 11 and the vacuum oil filter 12, and make the lubricating oil in the oil tank 2 pass through the plate and frame oil filter 11 and the vacuum oil filter 12 for filtration and then re-enter the oil tank 2;

[0098] Step 4: While starting the plate and frame oil filter 11 and the vacuum oil filter 12 in Step 3 above, make the air or nitrogen in the air storage tank or nitrogen storage tank 6 enter the oil tank 2 through the gas distributor 3 to form a disturbance to the bottom of the oil tank 2;

[0099] Step 5: During the oil circulation process in Step 2 above, adopt the alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 1 hour;

[0100] When hot oil operation is required, start the electric heater 32 and the vacuum oil filter 12 to heat the lubricating oil on the premise of filtration, and the temperature of the heated lubricating oil is: 35°C;

[0101] When cold oil operation is required, the oil cooler 15 is turned on to cool the lubricating oil. The temperature of the cooled lubricating oil is: 15°C;

[0102] Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the exhaust fan 33 is turned on to make the inside of the oil tank 2 in a slightly negative pressure state with a pressure of: -5 Kpa;

[0103] Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used for the first basket filter 13 and the second basket filter 24 are 150 meshes; the filter meshes of the first temporary filter 27, the second temporary filter 28, and the duplex oil filter 16 are 100 meshes, and the plate - type oil filter 11 and the vacuum oil filter 12 are 40 microns and 3 microns respectively; The filter meshes of the first basket filter 13, the second basket filter 24, the first temporary filter mesh 27, the second temporary filter mesh 28, and the duplex oil filter 16 are checked every 2 hours, and the impurities are cleaned with degreased white cloth;

[0104] Step 8: Detect the grease of the lubricating oil. When the impurity in the oil quality detection is 75 microns, the pipeline flushing ends, and the oil pump 14, the plate - type oil filter 11, the vacuum oil filter 12, and the exhaust fan 33 are turned off;

[0105] The system flushing includes the following steps:

[0106] Step 1: Remove the detachable blind plate 25, the temporary hose 26, and the first temporary filter 27 used during the pipeline flushing. Install orifice plates 34 on the oil circuits at the inlet ends of the first bearing housing 17, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, and the fourth bearing housing 20 of the centrifuge, and install check valves 35 on the oil circuits at the outlet ends of the first bearing housing 17, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, and the fourth bearing housing 20 of the centrifuge;

[0107] Replace the second temporary filter 28 at the front end of the oil inlet of the electro - hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the overspeed governor 23 of the centrifuge unit with a third temporary filter 36; The filter mesh of the third temporary filter 36 is 200 meshes;

[0108] Step 2: Turn on the oil pump 14 so that the lubricating oil in the fuel tank 2 passes through the first basket filter 13, the oil pump 14, the duplex filter 16, the first centrifuge bearing housing 17, the second centrifuge bearing housing 18, the third centrifuge bearing housing 19, the fourth centrifuge bearing housing 20, the electro-hydraulic conversion device 21, the main air valve 22 of the centrifuge unit, and the emergency trip device 23 of the centrifuge unit, as well as the corresponding third temporary filter 36; finally, it flows back into the fuel tank 2 through the second basket filter 24 provided on the return oil pipeline;

[0109] Step 3: During the oil circulation process in Step 2 above, turn on the plate-frame filter press 11 and the vacuum oil filter 12 so that the lubricating oil in the fuel tank 2 is filtered by the plate-frame filter press 11 and the vacuum oil filter 12 and then re-enters the fuel tank 2;

[0110] Step 4: While turning on the plate-frame filter press 11 and the vacuum oil filter 12 in Step 3 above, let the air or nitrogen in the air storage tank or nitrogen storage tank 6 enter the fuel tank 2 through the gas distributor 3 to form a disturbance at the bottom of the fuel tank 2;

[0111] Step 5: During the oil circulation process in Step 2 above, adopt an alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 3 hours;

[0112] When hot oil operation is required, turn on the electric heater 32 and the vacuum oil filter 12 to heat the lubricating oil on the premise of filtration, and the temperature of the heated lubricating oil is: 75°C;

[0113] When cold oil operation is required, turn on the oil cooler 15 to cool the lubricating oil, and the temperature of the cooled lubricating oil is: 30°C;

[0114] Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, turn on the exhaust fan 33 so that the internal pressure of the fuel tank 2 is in a slightly negative pressure state of -5Kpa;

[0115] Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used for the first basket filter 13 and the second basket filter 24 are 150 meshes; the filter meshes of the third temporary filter 28 and the duplex filter 16 are 200 meshes, and the plate-frame filter press 11 and the vacuum oil filter 12 are 40 microns and 3 microns respectively; check the filter meshes of the first basket filter 13, the second basket filter 24, the first temporary filter mesh 27, the second temporary filter mesh 28, and the duplex filter 16 every 2 hours, and clean the impurities with degreased white cloth;

[0116] Step 8: Detect the grease of the lubricating oil. When the detected impurity in the oil quality is 75 microns, the system flushing ends, and turn off the oil pump 14, the plate-frame filter press 11, the vacuum oil filter 12, and the exhaust fan 33.

[0117] Example 2

[0118] A centrifugal unit oil circulation system includes a centrifugal unit main body 1, and the centrifugal unit main body 1 is connected to a self-cleaning oil tank unit through an oil circulation pipeline unit; the self-cleaning oil tank unit includes an oil tank 2, a gas distributor 3 connected to a gas pipeline is arranged at the inner bottom of the oil tank 2, a circulating oil outlet 4 is arranged on the side of the oil tank 2, and the circulating oil outlet 4 is connected to a circulating oil inlet 5 at the top of the oil tank 2 through a filtering device. The gas distributor 3 is connected to an air storage tank or a nitrogen storage tank 6 through a gas pipeline; the gas distributor 3 includes a central air inlet pipe 7 and a plurality of annular pipes 8 arranged outside the central air inlet pipe 7, and connecting pipes 9 are respectively arranged between the central air inlet pipe 7 and an adjacent annular pipe 8 and between two adjacent annular pipes 8; a plurality of groups of air outlet parts are evenly distributed on the annular pipe 8, each group of air outlet parts includes three air outlets 10, one of the air outlets 10 is arranged at the top of the annular pipe 8, the other two air outlets 10 are arranged on both sides of the air outlet 10 at the top, and the included angle between the air outlets 10 on both sides and the air outlet 10 at the top is 60°, and the diameter of the air outlet is 3 mm. There are two circulating oil outlets 4, one of which is arranged at the bottom side of the oil tank, and the other is arranged at the middle and lower part of the side of the oil tank; the circulating oil outlet 4 at the bottom side of the oil tank is connected to the circulating oil inlet 5 through a plate-frame oil filter 11; the circulating oil outlet 4 at the middle and lower part of the side of the oil tank is connected to the circulating oil inlet 5 through a vacuum oil filter 12. An oil inlet tee is arranged between the circulating oil outlet 4 at the middle and lower part of the side of the oil tank and the vacuum oil filter 12, a third end of the oil inlet tee is connected to an oil storage tank 29, a first cut-off valve 30 is arranged between the circulating oil outlet 4 at the middle and lower part of the side of the oil tank and the oil inlet tee, and a second cut-off valve 31 is arranged between the third end of the oil inlet tee and the oil storage tank 29. An electric heater 32 is arranged inside the oil tank 2, and an exhaust fan 33 is arranged on one side at the top of the oil tank 2. The oil circulation pipeline unit includes a first basket filter 13 connected to the oil outlet of the oil tank 2, the first basket filter 13 is successively connected to an oil pump 14, an oil cooler 15, a duplex filter 16 and a tee, a second end of the tee is respectively connected to a first bearing box 17 of the centrifuge, a second bearing box 18 of the centrifuge, a third bearing box 19 of the centrifuge and a fourth bearing box 20 of the centrifuge, and the first bearing box 17 of the centrifuge, the second bearing box 18 of the centrifuge, the third bearing box 19 of the centrifuge and the fourth bearing box 20 of the centrifuge are respectively connected to a return oil pipeline; a third end of the tee is connected to a four-way, a second end of the four-way is connected to an oil inlet of an electro-hydraulic conversion device 21, a third end of the four-way is connected to the return oil pipeline through a main air valve 22 of the centrifugal unit, and a third end of the four-way is connected to the return oil pipeline through a centrifugal unit emergency trip device 23; a second basket filter 24 is arranged on the return oil pipeline, and the end of the return oil pipeline is connected to a return oil port of the oil tank 2.The oil circuits at both ends of the first bearing housing 17, the oil circuits at both ends of the second bearing housing 18 of the centrifuge, the oil circuits at both ends of the third bearing housing 19 of the centrifuge, the oil circuits at both ends of the fourth bearing housing 20 of the centrifuge, the front end of the oil inlet of the electro-hydraulic conversion device 21, the front end and the rear end of the main air valve 22 of the centrifuge unit, and the front end and the rear end of the emergency governor 23 of the centrifuge unit are provided with a pipeline flushing unit or a system flushing unit. The pipeline flushing unit includes that detachable blind plates 25 are respectively arranged on the oil circuits at both ends of the first bearing housing 17, the oil circuits at both ends of the second bearing housing 18 of the centrifuge, the oil circuits at both ends of the third bearing housing 19 of the centrifuge, and the oil circuits at both ends of the fourth bearing housing 20 of the centrifuge. A temporary hose 26 is arranged between the outsides of the detachable blind plates 25 that can be opened on the same centrifuge bearing housing. A first temporary filter 27 is respectively arranged at the inlet end and the outlet end of the temporary hose 26; a second temporary filter 28 is respectively arranged at the front end of the oil inlet of the electro-hydraulic conversion device 21, the front end and the rear end of the main air valve 22 of the centrifuge unit, and the front end and the rear end of the emergency governor 23 of the centrifuge unit. The system flushing unit includes that orifice plates 34 are respectively arranged on the oil circuits at the inlet ends of the first bearing housing 17, the oil circuits at the inlet ends of the second bearing housing 18 of the centrifuge, the oil circuits at the inlet ends of the third bearing housing 19 of the centrifuge, and the oil circuits at the inlet ends of the fourth bearing housing 20 of the centrifuge. Check valves 35 are respectively arranged on the oil circuits at the outlet ends of the first bearing housing 17, the oil circuits at the outlet ends of the second bearing housing 18 of the centrifuge, the oil circuits at the outlet ends of the third bearing housing 19 of the centrifuge, and the oil circuits at the outlet ends of the fourth bearing housing 20 of the centrifuge; a third temporary filter 36 is respectively arranged at the front end of the oil inlet of the electro-hydraulic conversion device 21, the front end and the rear end of the main air valve 22 of the centrifuge unit, and the front end and the rear end of the emergency governor 23 of the centrifuge unit.

[0119] The present invention also provides a circulating flushing method for the oil circulation system of a centrifuge unit. The circulating flushing method includes preliminary preparation, pipeline flushing, and system flushing;

[0120] The preliminary preparation includes the following steps:

[0121] Step 1: Stainless steel pipes are selected for the pipelines. The inner surfaces of the pipes are polished. The pipeline construction is carried out in a dust-free closed environment, and the construction is carried out in the form of mechanical cutting, argon arc welding for backing, and segmented prefabrication. After the pipeline construction, the inside of the pipeline is scrubbed, and after scrubbing, it is blown clean by clean compressed air, chemically acid-cleaned, dried after cleaning, and the seals at both ends are protected after drying to ensure the cleanliness inside the pipeline;

[0122] Step 2: Remove the filter elements of the first basket filter 13, the second basket filter 24, the first temporary filter 27, the second temporary filter 28, the third temporary filter 36, the plate-frame oil filter 11, the vacuum oil filter 12, the orifice plate 34, the check valve 35 and the duplex filter 16 in the system, check the inside for foreign objects; clean them with kerosene, dry them with compressed air after cleaning and reinstall them;

[0123] Step 3: Assemble the system, connect the centrifuge unit body 1, the oil tank 2, the plate-frame oil filter 11, the vacuum oil filter 12, the first basket filter 13, the oil pump 14, the oil cooler 15, the duplex filter 16, and the second basket filter 24 through the above pipelines, and the slope of the connected pipeline is 3‰;

[0124] The pipeline flushing includes the following steps:

[0125] Step 1: Close the first shut-off valve 30 and open the second shut-off valve 31, so that the oil storage tank 29 enters the oil tank 2 through the second shut-off valve 31, the vacuum oil filter 12 and the circulating oil inlet 5;

[0126] Step 2: After the oil injection is completed, carry out the oil circulation process. Close the second shut-off valve 31 and open the first shut-off valve 30; start the oil pump 14, so that the lubricating oil in the oil tank 2 passes through the first basket filter 13, the oil pump 14, the duplex filter 16, each temporary hose 26 and the corresponding first temporary filter 27, the electro-hydraulic converter 21, the main air valve 22 of the centrifuge unit and the overspeed governor 23 of the centrifuge unit and the corresponding second temporary filter 28; finally, it flows back into the oil tank 2 through the second basket filter 24 provided on the return oil pipeline;

[0127] Step 3: During the oil circulation process in Step 2 above, start the plate-frame oil filter 11 and the vacuum oil filter 12, so that the lubricating oil in the oil tank 2 is filtered by the plate-frame oil filter 11 and the vacuum oil filter 12 and then re-enters the oil tank 2;

[0128] Step 4: While starting the plate-frame oil filter 11 and the vacuum oil filter 12 in Step 3 above, let the air or nitrogen in the air storage tank or nitrogen storage tank 6 enter the oil tank 2 through the gas distributor 3 to form a disturbance to the bottom of the oil tank 2;

[0129] Step 5: During the oil circulation process in Step 2 above, adopt the way of alternating operation of hot oil and cold oil, and the time of each alternating operation is 2 hours;

[0130] When hot oil operation is required, start the electric heater 32 and the vacuum oil filter 12 to heat the lubricating oil on the premise of filtering, and the temperature of the heated lubricating oil is: 55°C;

[0131] When cold oil operation is required, turn on the oil cooler 15 to cool the lubricating oil. The temperature of the cooled lubricating oil is: 22 °C;

[0132] Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, turn on the exhaust fan 33 to make the inside of the oil tank 2 in a slightly negative pressure state with a pressure of: -5 Kpa;

[0133] Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used for the first basket filter 13 and the second basket filter 24 are 150 meshes; the filter meshes of the first temporary filter 27, the second temporary filter 28, and the duplex filter 16 are 100 meshes, and the plate frame type oil filter 11 and the vacuum oil filter 12 are 40 microns and 3 microns respectively; check the filter meshes of the first basket filter 13, the second basket filter 24, the first temporary filter mesh 27, the second temporary filter mesh 28, and the duplex filter 16 every 2 hours, and clean the impurities with degreased white cloth;

[0134] Step 8: Detect the grease of the lubricating oil. When the impurity detected in the oil quality is 70 microns, the pipeline flushing ends, and turn off the oil pump 14, the plate frame type oil filter 11, the vacuum oil filter 12, and the exhaust fan 33;

[0135] The system flushing includes the following steps:

[0136] Step 1: Remove the detachable blind plate 25, the temporary hose 26, and the first temporary filter 27 used during the pipeline flushing. Install orifice plates 34 on the oil circuits at the inlet ends of the first bearing housing 17, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, and the fourth bearing housing 20 of the centrifuge, and install check valves 35 on the oil circuits at the outlet ends of the first bearing housing 17, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, and the fourth bearing housing 20 of the centrifuge;

[0137] Replace the second temporary filter 28 at the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the emergency trip device 23 of the centrifuge unit with a third temporary filter 36; the filter mesh of the third temporary filter 36 is 200 meshes;

[0138] Step 2: Turn on the oil pump 14 so that the lubricating oil in the oil tank 2 passes through the first basket filter 13, the oil pump 14, the duplex filter 16, the first centrifuge bearing housing 17, the second centrifuge bearing housing 18, the third centrifuge bearing housing 19, the fourth centrifuge bearing housing 20, the electro-hydraulic converter 21, the main air valve 22 of the centrifuge unit, the emergency governor 23 of the centrifuge unit, and the corresponding third temporary filter 36; finally, it flows back into the oil tank 2 through the second basket filter 24 provided on the oil return pipeline.

[0139] Step 3: During the oil circulation process in Step 2 above, turn on the plate and frame filter press 11 and the vacuum oil filter 12 so that the lubricating oil in the oil tank 2 passes through the plate and frame filter press 11 and the vacuum oil filter 12 for filtration and then re-enters the oil tank 2.

[0140] Step 4: While turning on the plate and frame filter press 11 and the vacuum oil filter 12 in Step 3 above, let the air or nitrogen in the air storage tank or nitrogen storage tank 6 pass through the gas distributor 3 into the oil tank 2 to form a disturbance at the bottom of the oil tank 2.

[0141] Step 5: During the oil circulation process in Step 2 above, adopt an alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 2 hours.

[0142] When hot oil operation is required, turn on the electric heater 32 and the vacuum oil filter 12 to heat the lubricating oil on the premise of filtration. The temperature of the heated lubricating oil is: 55°C.

[0143] When cold oil operation is required, turn on the oil cooler 15 to cool the lubricating oil. The temperature of the cooled lubricating oil is: 23°C.

[0144] Step 6: During the operation of Step 2, Step 3, Step 4, and Step 5 in the above pipeline flushing, turn on the exhaust fan 33 to make the internal pressure of the oil tank 2 in a slightly negative pressure state of -5 Kpa.

[0145] Step 7: During the operation of Step 2, Step 3, Step 4, and Step 5 in the above pipeline flushing, the filter meshes used for the first basket filter 13 and the second basket filter 24 are 150 meshes; the filter meshes of the third temporary filter 28 and the duplex filter 16 are 200 meshes, and the plate and frame filter press 11 and the vacuum oil filter 12 are 40 microns and 3 microns respectively; check the filter meshes of the first basket filter 13, the second basket filter 24, the first temporary filter mesh 27, the second temporary filter mesh 28, and the duplex filter 16 every 2 hours, and clean the impurities with degreased white cloth.

[0146] Step 8: Detect the quality of the lubricating oil. When the impurity in the oil quality detection is 70 microns, the system flushing is completed, and turn off the oil pump 14, the plate and frame filter press 11, the vacuum oil filter 12, and the exhaust fan 33.

[0147] Example 3

[0148] A centrifugal unit oil circulation system includes a centrifugal unit body 1. The centrifugal unit body 1 is connected to a self-cleaning oil tank unit through an oil circulation pipeline unit. The self-cleaning oil tank unit includes an oil tank 2. A gas distributor 3 connected to a gas pipeline is provided at the inner bottom of the oil tank 2. A circulating oil outlet 4 is provided on the side of the oil tank 2. The circulating oil outlet 4 is connected to a circulating oil inlet 5 at the top of the oil tank 2 through a filtering device. The gas distributor 3 is connected to an air storage tank or a nitrogen storage tank 6 through a gas pipeline. The gas distributor 3 includes a central air inlet pipe 7 and a plurality of annular pipes 8 arranged outside the central air inlet pipe 7. Connecting pipes 9 are respectively provided between the central air inlet pipe 7 and the adjacent annular pipe 8 and between two adjacent annular pipes 8. A plurality of groups of air outlet parts are evenly distributed on the annular pipe 8. Each group of air outlet parts includes three air outlets 10. One of the air outlets 10 is arranged at the top of the annular pipe 8, and the other two air outlets 10 are arranged on both sides of the top air outlet 10. The included angle between the two side air outlets 10 and the top air outlet 10 is 60°, and the diameter of the air outlet is 3 mm. There are two circulating oil outlets 4. One is arranged at the bottom side of the oil tank, and the other is arranged in the middle and lower part of the side of the oil tank. The circulating oil outlet 4 at the bottom side of the oil tank is connected to the circulating oil inlet 5 through a plate frame oil filter 11. The circulating oil outlet 4 in the middle and lower part of the side of the oil tank is connected to the circulating oil inlet 5 through a vacuum oil filter 12. An oil inlet tee is provided between the circulating oil outlet 4 in the middle and lower part of the side of the oil tank and the vacuum oil filter 12. The third end of the oil inlet tee is connected to an oil storage tank 29. A first cut-off valve 30 is provided between the circulating oil outlet 4 in the middle and lower part of the side of the oil tank and the oil inlet tee. A second cut-off valve 31 is provided between the third end of the oil inlet tee and the oil storage tank 29. An electric heater 32 is provided inside the oil tank 2. A smoke exhaust fan 33 is provided on one side at the top of the oil tank 2. The oil circulation pipeline unit includes a first basket filter 13 connected to the oil outlet of the oil tank 2. The first basket filter 13 is successively connected to an oil pump 14, an oil cooler 15, a double filter 16 and a tee. The second end of the tee is respectively connected to a first bearing box 17 of the centrifuge, a second bearing box 18 of the centrifuge, a third bearing box 19 of the centrifuge and a fourth bearing box 20 of the centrifuge. The first bearing box 17 of the centrifuge, the second bearing box 18 of the centrifuge, the third bearing box 19 of the centrifuge and the fourth bearing box 20 of the centrifuge are respectively connected to an oil return pipeline. The third end of the tee is connected to a four-way. The second end of the four-way is connected to the oil inlet of an electro-hydraulic conversion device 21. The third end of the four-way is connected to the oil return pipeline through the main air valve 22 of the centrifugal unit. The third end of the four-way is connected to the oil return pipeline through the emergency trip device 23 of the centrifugal unit. A second basket filter 24 is provided on the oil return pipeline. The end of the oil return pipeline is connected to the oil return port of the oil tank 2.The oil circuits at both ends of the first bearing housing 17, the oil circuits at both ends of the second bearing housing 18 of the centrifuge, the oil circuits at both ends of the third bearing housing 19 of the centrifuge, the oil circuits at both ends of the fourth bearing housing 20 of the centrifuge, the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the emergency trip device 23 of the centrifuge unit are provided with a pipeline flushing unit or a system flushing unit. The pipeline flushing unit includes detachable blind plates 25 respectively arranged on the oil circuits at both ends of the first bearing housing 17, the oil circuits at both ends of the second bearing housing 18 of the centrifuge, the oil circuits at both ends of the third bearing housing 19 of the centrifuge, and the oil circuits at both ends of the fourth bearing housing 20 of the centrifuge. A temporary hose 26 is arranged between the outer sides of the detachable blind plates 25 that can be opened on the same centrifuge bearing housing. The inlet end and the outlet end of the temporary hose 26 are respectively provided with a first temporary filter 27; the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the emergency trip device 23 of the centrifuge unit are respectively provided with a second temporary filter 28. The system flushing unit includes orifice plates 34 respectively arranged on the oil circuits at the inlet ends of the first bearing housing 17, the oil circuits at the inlet ends of the second bearing housing 18 of the centrifuge, the oil circuits at the inlet ends of the third bearing housing 19 of the centrifuge, and the oil circuits at the inlet ends of the fourth bearing housing 20 of the centrifuge. Check valves 35 are respectively arranged on the oil circuits at the outlet ends of the first bearing housing 17, the oil circuits at the outlet ends of the second bearing housing 18 of the centrifuge, the oil circuits at the outlet ends of the third bearing housing 19 of the centrifuge, and the oil circuits at the outlet ends of the fourth bearing housing 20 of the centrifuge; the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the emergency trip device 23 of the centrifuge unit are respectively provided with a third temporary filter 36.

[0149] The present invention also provides a circulation flushing method for an oil circulation system of a centrifuge unit. The circulation flushing method includes preliminary preparation, pipeline flushing, and system flushing;

[0150] The preliminary preparation includes the following steps:

[0151] Step 1: Select stainless steel pipes for the pipelines, perform in-pipe polishing treatment on the pipelines. The pipeline construction is carried out in a dust-free enclosed environment, and the construction is carried out in the form of mechanical cutting, argon arc welding for backing, and segmented prefabrication. After the pipeline construction, the inside of the pipeline is scrubbed, and after scrubbing, it is blown clean with clean compressed air, chemically acid-cleaned, dried after cleaning, and the seals at both ends are protected after drying to ensure the cleanliness inside the pipeline;

[0152] Step 2: Remove the filter elements of the first basket filter 13, the second basket filter 24, the first temporary filter 27, the second temporary filter 28, the third temporary filter 36, the plate-frame oil filter 11, the vacuum oil filter 12, the orifice plate 34, the check valve 35 and the duplex filter 16 in the system, check the inside for foreign objects; clean them with kerosene, dry them with compressed air after cleaning and reinstall them;

[0153] Step 3: Assemble the system, connect the centrifuge unit body 1, the oil tank 2, the plate-frame oil filter 11, the vacuum oil filter 12, the first basket filter 13, the oil pump 14, the oil cooler 15, the duplex filter 16, and the second basket filter 24 through the above pipelines, and the slope of the connected pipeline is 3‰;

[0154] The pipeline flushing includes the following steps:

[0155] Step 1: Close the first shut-off valve 30 and open the second shut-off valve 31, so that the oil storage tank 29 enters the oil tank 2 through the second shut-off valve 31, the vacuum oil filter 12 and the circulating oil inlet 5;

[0156] Step 2: After the oil injection is completed, carry out the oil circulation process, close the second shut-off valve 31 and open the first shut-off valve 30; start the oil pump 14, so that the lubricating oil in the oil tank 2 passes through the first basket filter 13, the oil pump 14, the duplex filter 16, each temporary hose 26 and the corresponding first temporary filter 27, the electro-hydraulic conversion device 21, the main air valve 22 of the centrifuge unit and the overspeed trip 23 of the centrifuge unit and the corresponding second temporary filter 28; finally, it flows back into the oil tank 2 through the second basket filter 24 arranged on the return oil pipeline;

[0157] Step 3: During the oil circulation process in Step 2 above, start the plate-frame oil filter 11 and the vacuum oil filter 12, so that the lubricating oil in the oil tank 2 is filtered by the plate-frame oil filter 11 and the vacuum oil filter 12 and then re-enters the oil tank 2;

[0158] Step 4: While starting the plate-frame oil filter 11 and the vacuum oil filter 12 in Step 3 above, let the air or nitrogen in the air storage tank or nitrogen storage tank 6 enter the oil tank 2 through the gas distributor 3 to form a disturbance to the bottom of the oil tank 2;

[0159] Step 5: During the oil circulation process in Step 2 above, adopt the alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 1.5 hours;

[0160] When hot oil operation is required, start the electric heater 32 and the vacuum oil filter 12 to heat the lubricating oil on the premise of filtration, and the temperature of the heated lubricating oil is: 60°C;

[0161] When cold oil operation is required, the oil cooler 15 is turned on to cool the lubricating oil, and the temperature of the cooled lubricating oil is: 25°C;

[0162] Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the exhaust fan 33 is turned on to make the inside of the oil tank 2 in a slightly negative pressure state with a pressure of: -5 Kpa;

[0163] Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used for the first basket filter 13 and the second basket filter 24 are 150 meshes; the filter meshes of the first temporary filter 27, the second temporary filter 28, and the duplex filter 16 are 100 meshes, and the plate-frame filter press 11 and the vacuum oil filter 12 are 40 microns and 3 microns respectively; the filter meshes of the first basket filter 13, the second basket filter 24, the first temporary filter mesh 27, the second temporary filter mesh 28, and the duplex filter 16 are checked every 2 hours, and the impurities are cleaned with degreased white cloth;

[0164] Step 8: Detect the grease of the lubricating oil. When the impurity detected in the oil quality is 70 microns, the pipeline flushing ends, and the oil pump 14, the plate-frame filter press 11, the vacuum oil filter 12, and the exhaust fan 33 are turned off;

[0165] The system flushing includes the following steps:

[0166] Step 1: Remove the detachable blind plate 25, the temporary hose 26, and the first temporary filter 27 used during the pipeline flushing. Install orifice plates 34 on the oil circuits at the inlet ends of the first bearing housing 17, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, and the fourth bearing housing 20 of the centrifuge, and install check valves 35 on the oil circuits at the outlet ends of the first bearing housing 17, the second bearing housing 18 of the centrifuge, the third bearing housing 19 of the centrifuge, and the fourth bearing housing 20 of the centrifuge;

[0167] Replace the second temporary filter 28 at the front end of the oil inlet of the electro-hydraulic conversion device 21, the front and rear ends of the main air valve 22 of the centrifuge unit, and the front and rear ends of the overspeed trip 23 of the centrifuge unit with a third temporary filter 36; the filter mesh of the third temporary filter 36 is 200 meshes;

[0168] Step 2: Turn on the oil pump 14 so that the lubricating oil in the oil tank 2 passes through the first basket filter 13, the oil pump 14, the duplex filter 16, the first bearing box 17 of the centrifuge, the second bearing box 18 of the centrifuge, the third bearing box 19 of the centrifuge, the fourth bearing box 20 of the centrifuge, the electro-hydraulic conversion device 21, the main air valve 22 of the centrifuge unit, the emergency trip device 23 of the centrifuge unit, and the corresponding third temporary filter 36; finally, it flows back into the oil tank 2 through the second basket filter 24 provided on the oil return pipeline.

[0169] Step 3: During the oil circulation process in Step 2 above, turn on the plate and frame filter press 11 and the vacuum oil filter 12 so that the lubricating oil in the oil tank 2 is filtered by the plate and frame filter press 11 and the vacuum oil filter 12 and then re-enters the oil tank 2.

[0170] Step 4: While turning on the plate and frame filter press 11 and the vacuum oil filter 12 in Step 3 above, let the air or nitrogen in the air storage tank or nitrogen storage tank 6 enter the oil tank 2 through the gas distributor 3 to form a disturbance at the bottom of the oil tank 2.

[0171] Step 5: During the oil circulation process in Step 2 above, adopt an alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 2 hours.

[0172] When hot oil operation is required, turn on the electric heater 32 and the vacuum oil filter 12 to heat the lubricating oil on the premise of filtration. The temperature of the heated lubricating oil is: 45°C.

[0173] When cold oil operation is required, turn on the oil cooler 15 to cool the lubricating oil. The temperature of the cooled lubricating oil is: 28°C.

[0174] Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, turn on the exhaust fan 33 to make the internal pressure of the oil tank 2 in a slightly negative pressure state of -5 Kpa.

[0175] Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used for the first basket filter 13 and the second basket filter 24 are 150 meshes; the filter meshes of the third temporary filter 28 and the duplex filter 16 are 200 meshes, and the plate and frame filter press 11 and the vacuum oil filter 12 are 40 microns and 3 microns respectively; check the filter meshes of the first basket filter 13, the second basket filter 24, the first temporary filter mesh 27, the second temporary filter mesh 28, and the duplex filter 16 every 2 hours, and clean the impurities with degreased white cloth.

[0176] Step 8: Detect the quality of the lubricating oil. When the impurity in the oil quality detection is 65 microns, the system flushing is completed, and turn off the oil pump 14, the plate and frame filter press 11, the vacuum oil filter 12, and the exhaust fan 33.

[0177] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, terms such as "connection", "connected" and the like should be understood in a broad sense. For example, it may be a fixed connection, an integral connection, or a detachable connection; it may also be the communication inside two elements; it may be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The above examples are only specific descriptions of the feasible implementation manners of the present invention, and they are not intended to limit the protection scope of the present invention. All equivalent implementation manners, changes and modifications made without departing from the technical spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An oil circulation system for a centrifugal unit, comprising a centrifugal unit body (1), characterized in that: The centrifuge unit body (1) is connected to a self-cleaning oil tank unit through an oil circulation pipeline unit; The self-cleaning oil tank unit includes an oil tank (2). A gas distributor (3) connected to a gas pipeline is provided at the inner bottom of the oil tank (2). A circulating oil outlet (4) is provided on the side of the oil tank (2). The circulating oil outlet (4) is connected to a circulating oil inlet (5) at the top of the oil tank (2) through a filtering device; The gas distributor (3) is connected to an air storage tank or a nitrogen storage tank (6) through a gas pipeline; The gas distributor (3) includes a central air inlet pipe (7) and a plurality of annular pipes (8) arranged outside the central air inlet pipe (7). Connecting pipes (9) are respectively provided between the central air inlet pipe (7) and the adjacent annular pipe (8) and between two adjacent annular pipes (8); There are two circulating oil outlets (4). One is arranged at the bottom side of the oil tank, and the other is arranged in the middle and lower part of the side of the oil tank; The circulating oil outlet (4) at the bottom side of the oil tank is connected to the circulating oil inlet (5) through a plate and frame oil filter (11); The circulating oil outlet (4) in the middle and lower part of the side of the oil tank is connected to the circulating oil inlet (5) through a vacuum oil filter (12).

2. The oil circulation system of a centrifugal unit according to claim 1, wherein: A number of groups of air outlet parts are evenly distributed on the annular pipe (8). Each group of air outlet parts includes three air outlets (10). One air outlet (10) is arranged at the top of the annular pipe (8). The other two air outlets (10) are arranged on both sides of the air outlet (10) at the top. The included angle between the air outlets (10) on both sides and the air outlet (10) at the top is 60°. The diameter of the air outlet is 3 mm.

3. The oil circulation system of a centrifugal unit according to claim 1, characterized in that: An oil inlet tee is provided between the circulating oil outlet (4) in the middle and lower part of the side of the oil tank and the vacuum oil filter (12). The third end of the oil inlet tee is connected to an oil storage tank (29). A first cut-off valve (30) is provided between the circulating oil outlet (4) in the middle and lower part of the side of the oil tank and the oil inlet tee. A second cut-off valve (31) is provided between the third end of the oil inlet tee and the oil storage tank (29).

4. A centrifugal unit oil circulation system according to any one of claims 1-3, characterized in that: An electric heater (32) is provided inside the oil tank (2). A smoke exhaust fan (33) is provided on one side at the top of the oil tank (2).

5. The oil circulation system of a centrifugal unit according to claim 1, characterized in that: The oil circulation pipeline unit includes a first basket filter (13) connected to the oil outlet of the oil tank (2). The first basket filter (13) is successively connected to an oil pump (14), an oil cooler (15), a duplex oil filter (16) and a tee. The second end of the tee is respectively connected to a first bearing box (17) of the centrifuge, a second bearing box (18) of the centrifuge, a third bearing box (19) of the centrifuge and a fourth bearing box (20) of the centrifuge. The first bearing box (17) of the centrifuge, the second bearing box (18) of the centrifuge, the third bearing box (19) of the centrifuge and the fourth bearing box (20) of the centrifuge are respectively connected to an oil return pipeline; The third end of the tee is connected to a four-way. The second end of the four-way is connected to the oil inlet of an electro-hydraulic conversion device (21). The third end of the four-way is connected to the oil return pipeline through the main air valve (22) of the centrifuge unit. The third end of the four-way is connected to the oil return pipeline through the emergency trip device (23) of the centrifuge unit; A second basket filter (24) is provided on the oil return pipeline, and the end of the oil return pipeline is connected to the oil return port of the oil tank (2).

6. The oil circulation system of a centrifugal unit according to claim 5, characterized in that: Pipeline flushing units or system flushing units are provided at the oil circuits at both ends of the first bearing housing (17), the oil circuits at both ends of the second bearing housing (18) of the centrifuge, the oil circuits at both ends of the third bearing housing (19) of the centrifuge, the oil circuits at both ends of the fourth bearing housing (20) of the centrifuge, the front end of the oil inlet of the electro-hydraulic conversion device (21), the front end and the rear end of the main air valve (22) of the centrifuge unit, and the front end and the rear end of the emergency trip device (23) of the centrifuge unit.

7. The oil circulation system of a centrifugal unit according to claim 6, characterized in that: The pipeline flushing unit includes detachable blind plates (25) provided respectively on the oil circuits at both ends of the first bearing housing (17), the oil circuits at both ends of the second bearing housing (18) of the centrifuge, the oil circuits at both ends of the third bearing housing (19) of the centrifuge, and the oil circuits at both ends of the fourth bearing housing (20) of the centrifuge. A temporary hose (26) is provided between the outer sides of the detachable blind plates (25) that can be opened on the same centrifuge bearing housing. First temporary filters (27) are provided respectively at the inlet end and the outlet end of the temporary hose (26). Second temporary filters (28) are provided respectively at the front end of the oil inlet of the electro-hydraulic conversion device (21), the front end and the rear end of the main air valve (22) of the centrifuge unit, and the front end and the rear end of the emergency trip device (23) of the centrifuge unit.

8. The oil circulation system of a centrifugal unit according to claim 6, wherein: The system flushing unit includes orifice plates (34) provided respectively on the oil circuits at the inlet ends of the first bearing housing (17), the second bearing housing (18) of the centrifuge, the third bearing housing (19) of the centrifuge, and the fourth bearing housing (20) of the centrifuge. Check valves (35) are provided respectively on the oil circuits at the outlet ends of the first bearing housing (17), the second bearing housing (18) of the centrifuge, the third bearing housing (19) of the centrifuge, and the fourth bearing housing (20) of the centrifuge. Third temporary filters (36) are provided respectively at the front end of the oil inlet of the electro-hydraulic conversion device (21), the front end and the rear end of the main air valve (22) of the centrifuge unit, and the front end and the rear end of the emergency trip device (23) of the centrifuge unit.

9. A circulating flushing method using the oil circulation system of the centrifugal unit as described in claim 8, characterized in that: The described circulating flushing method includes preliminary preparation, pipeline flushing and system flushing. The preliminary preparation includes the following steps: Step 1: Stainless steel pipes are selected for the pipeline. The inner surface of the pipes is polished. The pipeline construction is carried out in a dust-free closed environment. Mechanical cutting, argon arc welding backing and segmented prefabrication are adopted for construction. After the pipeline construction, the inside of the pipeline is scrubbed, and after scrubbing, it is blown clean by clean compressed air, chemically acid-cleaned, dried after cleaning, and the seals at both ends are protected after drying to ensure the cleanliness inside the pipeline. Step 2: Remove the filter elements of the first basket filter (13), the second basket filter (24), the first temporary filter (27), the second temporary filter (28), the third temporary filter (36), the plate and frame oil filter (11), the vacuum oil filter (12), the orifice plate (34), the check valve (35) and the duplex filter (16) in the system, check the inside for foreign objects; clean them with kerosene, dry them with compressed air after cleaning and reinstall them; Step 3: Assemble the system, connect the centrifuge unit body (1), the oil tank (2), the plate and frame oil filter (11), the vacuum oil filter (12), the first basket filter (13), the oil pump (14), the oil cooler (15), the duplex filter (16), the second basket filter (24) through the above pipelines, and the slope of the connected pipelines is 3‰; The pipeline flushing includes the following steps: Step 1: Close the first shut-off valve (30), open the second shut-off valve (31), and let the oil storage tank (29) enter the oil tank (2) through the second shut-off valve (31), the vacuum oil filter (12) and the circulating oil inlet (5); Step 2: After the oil injection is completed, carry out the oil circulation process. Close the second shut-off valve (31) and open the first shut-off valve (30); start the oil pump (14), so that the lubricating oil in the oil tank (2) passes through the first basket filter (13), the oil pump (14), the duplex filter (16), each temporary hose (26) and the corresponding first temporary filter (27), the electro-hydraulic conversion device (21), the main air valve (22) of the centrifuge unit and the overspeed governor (23) of the centrifuge unit and the corresponding second temporary filter (28); finally, it flows back into the oil tank (2) through the second basket filter (24) arranged on the return oil pipeline; Step 3: During the oil circulation process in Step 2 above, start the plate and frame oil filter (11) and the vacuum oil filter (12), so that the lubricating oil in the oil tank (2) is filtered by the plate and frame oil filter (11) and the vacuum oil filter (12) and then re-enters the oil tank (2); Step 4: While starting the plate and frame oil filter (11) and the vacuum oil filter (12) in Step 3 above, let the air or nitrogen in the air storage tank or nitrogen storage tank (6) enter the oil tank (2) through the gas distributor (3) to form a disturbance to the bottom of the oil tank (2); Step 5: During the oil circulation process in Step 2 above, adopt the alternating operation mode of hot oil and cold oil, and the time of each alternating operation is 1 - 3 hours; When hot oil operation is required, start the electric heater (32) and the vacuum oil filter (12) to heat the lubricating oil on the premise of filtration, and the temperature of the heated lubricating oil is: 35 - 75°C; When cold oil operation is required, start the oil cooler (15) to cool the lubricating oil, and the temperature of the cooled lubricating oil is: 15 - 30°C; Step 6: During the operation of Step 2, Step 3, Step 4 and Step 5 in the above pipeline flushing, start the exhaust fan (33) to make the inside of the oil tank (2) in a slightly negative pressure state with a pressure of: -5Kpa; Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter screens used for the first basket filter (13) and the second basket filter (24) are 150 mesh; the filter screens for the first temporary filter (27), the second temporary filter (28), and the duplex oil filter (16) are 100 mesh, and the plate-frame oil filter (11) and the vacuum oil filter (12) are 40 microns and 3 microns respectively; Check the filter screens of the first basket filter (13), the second basket filter (24), the first temporary filter screen (27), the second temporary filter screen (28), and the duplex oil filter (16) every 2 hours, and clean the impurities with degreased white cloth; Step 8: Detect the grease of the lubricating oil. When the detected impurities in the oil quality are <80 microns, the pipeline flushing ends, and the oil pump (14), the plate-frame oil filter (11), the vacuum oil filter (12), and the smoke exhaust fan (33) are turned off; The system flushing includes the following steps: Step 1: Remove the detachable blind plate (25), the temporary hose (26), and the first temporary filter (27) used during the pipeline flushing. Install orifice plates (34) on the oil circuits at the inlet ends of the first bearing housing (17), the second bearing housing (18) of the centrifuge, the third bearing housing (19) of the centrifuge, and the fourth bearing housing (20) of the centrifuge, and install check valves (35) on the oil circuits at the outlet ends of the first bearing housing (17), the second bearing housing (18) of the centrifuge, the third bearing housing (19) of the centrifuge, and the fourth bearing housing (20) of the centrifuge; Replace the second temporary filter (28) at the front end of the oil inlet of the electro-hydraulic conversion device (21), the front and rear ends of the main air valve (22) of the centrifuge unit, and the front and rear ends of the overspeed governor (23) of the centrifuge unit with a third temporary filter (36); The filter screen of the third temporary filter (36) is 200 mesh; Step 2: Start the oil pump (14) so that the lubricating oil in the oil tank (2) passes through the first basket filter (13), the oil pump (14), the duplex oil filter (16), the first bearing housing (17) of the centrifuge, the second bearing housing (18) of the centrifuge, the third bearing housing (19) of the centrifuge, the fourth bearing housing (20) of the centrifuge, the electro-hydraulic conversion device (21), the main air valve (22) of the centrifuge unit, and the overspeed governor (23) of the centrifuge unit, and the corresponding third temporary filter (36); Finally, it flows back into the oil tank (2) through the second basket filter (24) provided on the return oil pipeline; Step 3: During the oil circulation process of the above Step 2, start the plate-frame oil filter (11) and the vacuum oil filter (12) so that the lubricating oil in the oil tank (2) is filtered by the plate-frame oil filter (11) and the vacuum oil filter (12) and then re-enters the oil tank (2); Step 4: While starting the plate-frame oil filter (11) and the vacuum oil filter (12) in the above Step 3, let the air or nitrogen in the air storage tank or nitrogen storage tank (6) enter the oil tank (2) through the gas distributor (3) to form a disturbance at the bottom of the oil tank (2); Step 5: During the oil circulation process in the above Step 2, adopt the alternating operation mode of hot oil and cold oil, and the time for each alternating operation is 1 - 3 hours; When hot oil operation is required, start the electric heater (32) and the vacuum oil filter (12) to heat the lubricating oil on the premise of filtration, and the temperature of the heated lubricating oil is: 35 - 75 °C; When cold oil operation is required, start the oil cooler (15) to cool the lubricating oil, and the temperature of the cooled lubricating oil is: 15 - 30 °C; Step 6: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, start the exhaust fan (33) to make the internal pressure of the oil tank (2) in a slightly negative pressure state of -5 Kpa; Step 7: During the operation of Steps 2, 3, 4, and 5 in the above pipeline flushing, the filter meshes used for the first basket filter (13) and the second basket filter (24) are 150 meshes; the filter meshes of the third temporary filter (28) and the duplex oil filter (16) are 200 meshes, and the plate-frame oil filter (11) and the vacuum oil filter (12) are 40 microns and 3 microns respectively; Check the filter meshes of the first basket filter (13), the second basket filter (24), the first temporary filter mesh (27), the second temporary filter mesh (28), and the duplex oil filter (16) every 2 hours, and clean the impurities with degreased white cloth; Step 8: Detect the grease of the lubricating oil. When the detected impurities in the oil quality are < 80 microns, the system flushing ends, and the oil pump (14), the plate-frame oil filter (11), the vacuum oil filter (12), and the exhaust fan (33) are turned off.

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