Pressure regulation method of lubricating oil system of equipment

Abstract

The present invention relates to a method for regulating the pressure of a lubricating oil system of a device, comprising the following steps: before starting the device, closing the first pressure regulating valve; starting the first driving pump so that the pressure of the main line is within a preset range and has a first pressure value, and the outlet pressure of the second pressure regulating valve is the first pressure value; gradually opening the first pressure regulating valve so that the discharge amount of the second pressure regulating valve gradually decreases until the pressure of the main line is within a preset range and has a second pressure value, and the second pressure value is less than the first pressure value. First, fully closing the first pressure regulating valve and then adjusting the second pressure regulating valve avoids interference with the setting of the second pressure regulating valve. Adjusting the pressure of the first pressure regulating valve to a level lower than the pressure of the second pressure regulating valve will not affect the set pressure of the second pressure regulating valve, thus solving the problem of inaccurate dual-valve outlet pressure setting in the original regulation method, reducing the range of lubricating oil pressure fluctuations when the first driving pump stops, and avoiding the pressure deviation causing the first driving pump to start again and trip.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power, and more particularly to a method for regulating the pressure of a lubricating oil system of equipment. Background Art

[0002] The lubricating oil system of nuclear power internal circulation water pump 1 (see attached Figure 1 ), the pressure for the lubricating oil circulation flow is provided by an electric oil pump 511 and an onboard oil pump 521. A pressure regulating valve (541, 551) is configured at each pump outlet to adjust the lubricating oil system pressure (referring to the pressure at the system outlet). The startup logic of the lubricating oil system is as follows: first start the electric oil pump 511 for pre-lubrication. When the system pressure reaches above 1.6 bar, after a delay of 10 minutes, the circulating water pump is started. The start of circulating water pump 1 drives the onboard oil pump 521 to automatically operate. After 5 minutes, when the system pressure reaches at least 1.8 bar, the electric oil pump 511 is shut down. For equipment protection, if the system pressure drops below 1.3 bar, the electric oil pump 511 will be restarted. If the pressure continues to drop to 1 bar, the circulating water pump 1 will be directly shut down.

[0003] The original pressure adjustment method is:

[0004] During the start-up process of the electric oil pump 511, adjust the outlet pressure control valve of the electric oil pump 511 so that the system pressure meets the start-up conditions. If the adjustment cannot meet the requirements, adjust the outlet pressure regulating valve of the onboard oil pump 521 so that the system pressure meets the conditions. After stopping the electric oil pump 511, adjust the outlet pressure regulating valve of the onboard oil pump 521 according to the pressure situation. If it cannot be adjusted to a normal operating pressure of above 2.1 bar, restart the electric oil pump 511 and adjust the outlet pressure regulating valve of the electric oil pump 511.

[0005] The above has the following problems:

[0006] 1) Since the oil circuit pressure is controlled by two valves, the original adjustment process cannot accurately determine the opening value of the two valves, that is, it is impossible to determine the pressure value at the outlet of the two valves.

[0007] 2) The pilot-operated pressure control valves included with the equipment have a slow spool response. This means that when electric oil pump 511 stops operating, the oil system pressure will fluctuate slightly. This fluctuation is affected by the pressure settings of the dual valves. If the fluctuation is too large, causing the system pressure to drop to 1.3 bar, electric oil pump 511 will restart instantly. If the pressure drops below 1.0 bar, water pump 1 will stop operating. To accurately determine the outlet pressure of the two pressure regulating valves during regulation and prevent pressure deviations from causing electric oil pump 511 to restart and trip, a new regulation method must be developed. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method for regulating the pressure of the lubricating oil system of an equipment in view of the above-mentioned defects of the prior art.

[0009] The technical solution adopted by the present invention to solve its technical problem is: constructing a method for regulating the pressure of a lubricating oil system of an equipment, the lubricating oil system comprising a first oil supply pipeline and a second oil supply pipeline arranged in parallel, and a main pipeline connected to first ends of the first oil supply pipeline and the second oil supply pipeline, the other ends of the first oil supply pipeline and the second oil supply pipeline being connected to the lubricating oil chamber of the equipment, and the main pipeline being connected to the area to be lubricated of the equipment; a first driving pump is provided on the first oil supply pipeline, a first pressure regulating pipeline is provided between the downstream of the first driving pump and the lubricating oil chamber, a first pressure regulating valve is provided on the first pressure regulating pipeline, a second driving pump is provided on the second oil supply pipeline, a second pressure regulating pipeline is provided between the downstream of the second driving pump and the lubricating oil chamber, a second pressure regulating valve is provided on the second pressure regulating pipeline, and a flow pressure gauge is provided on the main pipeline; the regulating method comprises:

[0010] Before starting the equipment, closing the first pressure regulating valve;

[0011] Turning on the first driving pump so that the pressure of the main line is within a preset range and has a first pressure value, and the outlet pressure of the second pressure regulating valve is the first pressure value;

[0012] The first pressure regulating valve is gradually opened, so that the discharge amount of the second pressure regulating valve is gradually reduced, until the pressure of the main line is within a preset range and has a second pressure value, which is less than the first pressure value.

[0013] In some embodiments, the first drive pump is an electric oil pump, and the second drive pump is an onboard oil pump that runs with the device.

[0014] In some embodiments, the first pressure value is 0.3 bar-0.5 bar greater than the second pressure value.

[0015] In some embodiments, the first pressure value is 2.3 bar-2.5 bar.

[0016] In some embodiments, the preset pressure range of the main line is above 1.8 bar.

[0017] In some embodiments, a check valve is provided on each of the first oil supply pipeline and the second oil supply pipeline.

[0018] In some embodiments, a first feedback loop is provided between the first pressure regulating valve and the main line to feed back the pressure value of the main line to the first pressure regulating valve;

[0019] A second feedback loop is provided between the second pressure regulating valve and the main line to feed back the pressure value of the main line to the second pressure regulating valve.

[0020] In some embodiments, pre-lubrication is completed after the first driving pump continues to operate for a preset time, and the preset time is at least 10 minutes.

[0021] In some embodiments, a cooling device and a filtering device are provided on the main line.

[0022] In some embodiments, a pressure relief pipeline for pressure relief is provided on the main pipeline, and a safety valve is provided on the pressure relief pipeline.

[0023] The lubricating oil system pressure regulation method of the equipment implemented in the present invention has the following beneficial effects: by improving the time sequence and setting method of setting the pressure of the first pressure regulating valve and the second pressure regulating valve of the lubricating oil system, the first pressure regulating valve is fully opened first, and then the second pressure regulating valve is adjusted, which can avoid interference with the setting of the second pressure regulating valve, and then the pressure of the first pressure regulating valve is lowered to be lower than the pressure of the second pressure regulating valve, which will not affect the set pressure of the second pressure regulating valve, thereby solving the problem of inaccurate pressure setting of the double valves in the original regulation method. According to the new pressure control valve constant setting method, the lubricating oil pressure fluctuation range at the moment the first drive pump stops can be reduced, thereby avoiding the pressure deviation causing the first drive pump to start again and the pump to trip. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0025] Figure 1 It is a structural diagram of a lubricating oil system configured for a nuclear power internal circulation water pump in the background art;

[0026] Figure 2 is a schematic structural diagram of the equipment and lubricating oil system in an embodiment of the present invention;

[0027] Figure 3 It is a flow chart of the method for regulating the pressure of the lubricating oil system of the equipment of the present invention. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0029] like Figure 2As shown, a circulating water pump 1 for a nuclear power plant in a preferred embodiment of the present invention includes a drive shaft 11 and pump blades 12 mounted on the drive shaft 11. The output shaft of the drive motor 2 is connected to the drive shaft 11 via a reduction gearbox 3, allowing the drive motor 2 to rotate the drive shaft 11 and the pump blades 12 to pump water. Lubricating oil is injected between the drive shaft 11 and the support base 4 supporting the drive shaft 11, as well as into the reduction gearbox 3 for circulation lubrication. The injected lubricating oil flows into the lubricating oil chamber A of the oil tank and is driven by the lubricating oil system 5 to be injected back into the support base 4 and the lubrication area B of the reduction gearbox 3 to lubricate the gears, bearings, etc.

[0030] Furthermore, the lubricating oil system 5 includes a first oil supply pipeline 51 and a second oil supply pipeline 52 arranged in parallel, and an inlet end of a main pipeline 53 connected to the first ends (outlet ends) of the first oil supply pipeline 51 and the second oil supply pipeline 52. The other ends of the first oil supply pipeline 51 and the second oil supply pipeline 52 are connected to the lubricating oil chamber A of the circulating water pump 1. A first driving pump 511 is provided on the first oil supply pipeline 51, and a first pressure regulating pipeline 54 is provided between the downstream of the first driving pump 511 and the lubricating oil chamber A. A first pressure regulating pipeline 54 is provided on the first pressure regulating pipeline 54. A first pressure regulating valve 541 is provided on the first pressure regulating pipeline 54. A second driving pump 521 is provided on the second oil supply pipeline 52. The outlet end of the main pipeline 53 is connected to the to-be-lubricated area B of the circulating water pump 1. A second pressure regulating pipeline 55 is provided between the downstream of the second driving pump 521 and the lubricating oil chamber A. A second pressure regulating valve 551 is provided on the second pressure regulating pipeline 55.

[0031] The first pressure regulating valve 541 and the second pressure regulating valve 551 are pilot-operated pressure feedback pressure regulating valves. Figure 2 As shown, the lubricating oil system 5 also includes a first feedback loop 542 connected between the main line 53 and the first pressure regulating valve 541, so as to automatically control the opening and closing of the first pressure regulating valve 541 by means of the pressure value of the main line 53; a second feedback loop 552 is provided between the second pressure regulating valve 551 and the main line 53, so as to automatically control the opening and closing of the second pressure regulating valve 551 by means of the pressure value of the main line 53.

[0032] It should be noted that, for the first pressure regulating valve 541 and the second pressure regulating valve 551, the valve pressure setting value of the valve reflects the opening degree. The larger the valve pressure setting value, the smaller the valve opening degree, the smaller the flow through the first pressure regulating valve 541 and the second pressure regulating valve 551, and the smaller the outlet pressure of the first pressure regulating valve 541 and the second pressure regulating valve 551.

[0033] like Figure 2 As shown, a flow pressure gauge is provided on the main line 53 for monitoring the flow and pressure of the main line 53 .

[0034] Combine Figure 3As shown, in order to avoid the pressure deviation causing the first driving pump 511 to restart and trip the pump, the pressure of the first pressure regulating valve 541 and the second pressure regulating valve 551 need to be set in advance.

[0035] Lubricating oil system pressure regulation methods include:

[0036] Before the circulating water pump 1 is started, the second driving pump 521 is turned off, and the first driving pump 511 is started alone. The valve pressure setting value of the first pressure regulating valve 541 is increased until the first pressure regulating valve 541 is fully closed, so that the outlet pressure of the first oil supply pipeline 51 reaches the maximum value;

[0037] Adjust the second pressure regulating valve 551 while observing the system oil pressure using a flow pressure gauge so that the oil pressure in the system main line 53 remains within a preset range and has a first pressure value. At this time, the second pressure regulating valve 551 has a first valve pressure setting value, the outlet pressure of the second pressure regulating valve 551 is the first pressure value, and the second pressure regulating valve 551 has a first opening value, completing the setting of the second pressure regulating valve 551.

[0038] Adjust the outlet pressure of the first pressure regulating valve 541, that is, slowly reduce the valve pressure setting value of the first pressure regulating valve 541 until the oil pressure in the main line 53 remains within the preset range and has a second pressure value, which is less than the first pressure value.

[0039] As the first pressure regulating valve 541 is adjusted and opened, some lubricating oil flows back through it into the lubricating oil chamber A of the oil tank. The oil pressure in the main line 53 slowly decreases for a period of time, and the opening of the second pressure regulating valve 551 gradually decreases, causing the amount of oil discharged from the outlet of the second pressure regulating valve 551 to gradually decrease. At this time, the opening of the first pressure regulating valve 541 gradually increases, causing the oil pressure in the main line 53 to remain relatively stable and not decrease further. When the oil pressure in the main line 53 drops to the second pressure value and no longer decreases significantly, adjustment of the first pressure regulating valve 541 is stopped. At this point, the second pressure regulating valve 551 approaches a fully closed state (in practice, fully closed or nearly fully closed). The first pressure regulating valve 541 has the second set pressure value, its outlet pressure is close to the second pressure value, and it has the second opening value, indicating that the first pressure regulating valve 541 is operating in a stable state.

[0040] Subsequently, the electric oil pump and circulating water pump can be started according to the normal starting logic without adjusting the oil system pressure again.

[0041] The normal startup logic can be:

[0042] After the first drive pump 511 continues to operate for a preset time, pre-lubrication is completed. Preferably, the preset time is at least 10 minutes, such as 15 minutes, 20 minutes, or 25 minutes. Then, the circulating water pump 1 is started and the first drive pump 511 is deactivated. At the same time, when the circulating water pump 1 is started, it automatically drives the second drive pump 521 to operate, and the system pressure remains within the preset range, and the circulating water pump 1 enters a stable operating state.

[0043] It is understood that the first and second pressure values ​​are not stable values ​​but may fluctuate within an acceptable range. For example, during adjustment, if the fluctuation range of the first and second pressure values ​​does not exceed 0.2 bar after a predetermined stabilization time (e.g., several seconds), the desired first and second pressure values ​​can be considered to have been achieved.

[0044] Likewise, the difference between the first pressure value and the second pressure value is outside the aforementioned fluctuation range.

[0045] Specifically, the second pressure value is 0.3 bar-0.5 bar less than the first pressure value.

[0046] The lubricating oil system pressure regulation method provided in the embodiment of the present application improves the time sequence and setting method of setting the pressures of the first pressure regulating valve 541 and the second pressure regulating valve 551 of the lubricating oil system 5. First, the first pressure regulating valve 541 is fully closed, and then the second pressure regulating valve 551 is adjusted. This can prevent the pressure at the outlet of the first pressure regulating valve 541 from interfering with the opening value setting of the second pressure regulating valve 551. Then, by slowly opening the first pressure regulating valve 541 until the second pressure regulating valve 551 tends to close automatically, the system oil pressure is reduced and maintained within a preset range, ensuring that the second valve pressure setting value of the first pressure regulating valve 541 remains lower than the first valve pressure setting value of the second pressure regulating valve 551, solving the problem in the original method that the outlet pressure setting values ​​of the two valves cannot be accurately known. According to the new lubricating oil system pressure regulation method of the present application, the fluctuation range of the lubricating oil pressure at the moment when the first driving pump 511 stops can be reduced, avoiding the pressure deviation causing the first driving pump 511 to start again and trip the pump.

[0047] In this embodiment, the first driving pump 511 is an electric oil pump driven by a motor. The second driving pump 521 is an onboard oil pump that is started when the circulating water pump 1 is started.

[0048] The system's onboard oil pump is the same model and speed as the electric oil pump (within a certain tolerance range). Furthermore, this pressure regulation method for the lubricating oil system 5 is applicable not only to the lubricating oil system 5 of the nuclear power circulating water pump 1, but also to similar dual-valve, dual-oil pump systems on other equipment.

[0049] The preset range of the system oil pressure is above 1.8 bar, optionally, it can also be above 2.08 bar, further, it can be above 2.3 bar.

[0050] Typically, the first pressure value is 0.3 bar to 0.5 bar greater than the second pressure value, leaving a certain safety margin. The first pressure value is the oil injection pressure of the onboard oil pump. Specifically, in this embodiment, the first pressure value is 2.3 bar to 2.5 bar, and the second pressure value is 2.0 bar.

[0051] The following is the lubricating oil pressure data during the startup process of different pump groups after adopting this adjustment method:

[0052]

[0053] The lubricating oil system pressure regulation method provided in the embodiment of the present application can set the pressure of the lubricating oil system 5 before the circulating water pump 1 is started. The circulating water pump 1 does not have any problems of restarting the electric oil pump and tripping the pump due to inaccurate pressure setting of the first pressure regulating valve 541 and the second pressure regulating valve 551, which greatly ensures the stable and safe startup and operation of major equipment and saves construction time and labor costs.

[0054] In some embodiments, a check valve 56 is provided on each of the first oil supply pipeline 51 and the second oil supply pipeline 52 to prevent the lubricating oil from flowing back.

[0055] Preferably, a cooling device 531 and a filtering device 532 are provided on the main line 53, so that the liquid flowing out of the lubricating oil chamber A can be cooled and filtered of impurities before flowing to the area to be lubricated B, so that the area to be lubricated B can be lubricated with clean lubricating oil of suitable temperature.

[0056] The main line 53 is provided with a pressure relief line 533 for pressure relief. The pressure relief line 533 is provided with a safety valve 534, which can relieve pressure when the pressure on the main line 53 is too high. Preferably, the pressure relief line 533 is connected to the lubricating oil chamber A, which can output again for lubrication.

[0057] The main innovations of the pressure regulation method of the lubricating oil system 5 of the circulating water pump 1 are:

[0058] 1. Change the previous pressure setting time point of the pressure regulating valve, and change the original online adjustment after starting the pump to setting the first driving pump 511 before starting the pump;

[0059] 2. More accurate pressure regulating valve settings. The original adjustment method for the dual-valve control oil system cannot accurately determine the valve pressure setting value of each pressure control valve. By initially raising the valve pressure setting value of the low-pressure valve, the first pressure regulating valve 541, to the closed position, the first pressure regulating valve 541 is effectively isolated from the system, and the second pressure regulating valve 551 is set independently. The first pressure regulating valve 541 is then lowered, making the valve pressure setting values ​​of the first and second pressure regulating valves 541 and 551 more accurate.

[0060] 3. The pressure setting of the second pressure regulating valve 551 at the outlet pressure control valve of the second drive pump 521 is 0.3-0.5 bar higher than the setting of the first pressure regulating valve 541 at the outlet pressure control valve of the first drive pump 511. During dual oil pump operation, the opening of the first pressure regulating valve 541 of the first drive pump 511 is increased, while the opening of the second pressure regulating valve 551 of the second drive pump 521 is decreased. This reduces the stroke required for the pressure regulating valve of the second drive pump 521 to operate when the first drive pump 511 stops operating. This effectively speeds up the response time of the lubricating oil system 5 and reduces the pressure fluctuation of the lubricating oil system 5 at that moment. This also ensures a safety margin between the lower limit of the lubricating oil pressure and the required value, preventing the lubricating oil pressure from being too high, which could cause system leaks.

[0061] It can be understood that the above technical features can be used in any combination without limitation.

[0062] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for regulating the pressure of a lubricating oil system of an equipment, wherein the lubricating oil system (5) comprises a first oil supply pipeline (51) and a second oil supply pipeline (52) arranged in parallel, and a main pipeline (53) connected to the first ends of the first oil supply pipeline (51) and the second oil supply pipeline (52), the other ends of the first oil supply pipeline (51) and the second oil supply pipeline (52) being connected to the lubricating oil chamber (A) of the equipment, and the main pipeline (53) being connected to the lubricating area (B) of the equipment; a first driving pump ( 511), a first pressure regulating pipeline (54) is provided between the downstream of the first driving pump (511) and the lubricating oil chamber (A), a first pressure regulating valve (541) is provided on the first pressure regulating pipeline (54), a second driving pump (521) is provided on the second oil supply pipeline (52), a second pressure regulating pipeline (55) is provided between the downstream of the second driving pump (521) and the lubricating oil chamber (A), a second pressure regulating valve (551) is provided on the second pressure regulating pipeline (55), and a flow pressure gauge is provided on the main pipeline (53); characterized in that, The adjustment method comprises: Before starting the device, closing the first pressure regulating valve (541); Turning on the first driving pump (511) so that the pressure of the main line (53) is within a preset range and has a first pressure value, and the outlet pressure of the second pressure regulating valve (551) is the first pressure value; gradually opening the first pressure regulating valve (541) so that the discharge amount of the second pressure regulating valve (551) gradually decreases until the pressure of the main line (53) is within a preset range and has a second pressure value, which is less than the first pressure value; A first feedback loop (542) is provided between the first pressure regulating valve (541) and the main line (53) to feed back the pressure value of the main line (53) to the first pressure regulating valve (541); A second feedback loop (552) is provided between the second pressure regulating valve (551) and the main line (53) to feed back the pressure value of the main line (53) to the second pressure regulating valve (551).

2. The method for regulating the lubricating oil system pressure of the equipment according to claim 1, characterized in that: The first driving pump (511) is an electric oil pump, and the second driving pump (521) is an onboard oil pump, which operates along with the device.

3. The method for regulating the lubricating oil system pressure of the equipment according to claim 1, characterized in that: The first pressure value is 0.3 bar-0.5 bar greater than the second pressure value.

4. The method for regulating the lubricating oil system pressure of the equipment according to claim 3, characterized in that: The first pressure value is 2.3 bar-2.5 bar.

5. The method for regulating the lubricating oil system pressure of the equipment according to claim 1, characterized in that: The preset pressure range of the main line (53) is above 1.8 bar.

6. The method for regulating the lubricating oil system pressure of the equipment according to any one of claims 1 to 5, characterized in that: The first oil supply pipeline (51) and the second oil supply pipeline (52) are respectively provided with a check valve (56).

7. The method for regulating the lubricating oil system pressure of the equipment according to any one of claims 1 to 5, characterized in that: After the first driving pump (511) continues to operate for a preset time, pre-lubrication is completed, and the preset time is at least 10 minutes.

8. The method for regulating the lubricating oil system pressure of the equipment according to any one of claims 1 to 5, characterized in that: The main pipe (53) is provided with a cooling device (531) and a filtering device (532).

9. The method for regulating the lubricating oil system pressure of the equipment according to any one of claims 1 to 5, characterized in that: A pressure relief pipeline (533) for pressure relief is provided on the main pipeline (53), and a safety valve (534) is provided on the pressure relief pipeline (533).

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