Lubricating oil supply system

Abstract

The utility model relates to the technical field of steam turbine oil systems, in particular to a lubricating oil supply system which comprises an oil tank, a main oil pump, an alternating-current auxiliary oil pump and a steam turbine. One end of the three-way valve is communicated with an energy accumulator set, the other end of the three-way valve is communicated with a cooler, the cooler is communicated with a filter, and lubricating oil in the oil tank is output by the main oil pump or the alternating-current auxiliary oil pump, sequentially passes through the three-way valve, the cooler and the filter and then is supplied to all bearings of the steam turbine. The lubricating oil of each bearing returns to the oil tank through the oil return pipeline, and the energy accumulator group is additionally arranged at the outlet of the main oil pump, so that the energy accumulator group can balance the pressure in the pipeline.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbine oil systems, in particular to a lubricating oil supply system. Background Art

[0002] When steam turbines are operating, they often require an oil supply system to regulate and cool them, while also providing lubrication. This system not only dissipates the frictional heat generated by the friction pair but also removes and flushes out impurities as the oil flows and circulates, achieving excellent lubrication, reducing friction, minimizing wear, reducing the consumption of wearing parts, lowering power consumption, and extending the life of the equipment.

[0003] The steam turbine lubricating oil system is a crucial component of a power plant's steam turbine and primarily consists of a main oil pump and an AC auxiliary oil pump. During turbine operation, the main oil pump in the system supplies lubricating oil to the bearings. When the main oil pump's pressure is insufficient to meet system requirements, the AC auxiliary oil pump is required to supply lubricating oil to the bearings to ensure sufficient lubricating oil is provided. However, conventional main oil pumps often have internal gear machining errors, resulting in substandard gear meshing and slippage. This leads to unstable lubricating oil pressure and fluctuations in the lubricating oil pressure at the main oil pump outlet. Excessive pressure can cause pipeline vibrations, potentially leading to cracks in pipeline welds. Low pressure can trigger the AC oil pump, which can cause the unit to trip if the oil pressure is severely low. Utility Model Content

[0004] The purpose of the utility model is to provide a lubricating oil supply system to solve the problem in the prior art that errors may occur in the machining of the internal gears of the main oil pump, resulting in unqualified gear meshing and slipping, causing unstable lubricating oil pressure and fluctuations in the lubricating oil pressure at the main oil pump outlet.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A lubricating oil supply system includes an oil tank, a main oil pump, an AC auxiliary oil pump and a steam turbine. The main oil pump is installed at the front end of the main shaft of the steam turbine so that the main shaft of the steam turbine drives the main oil pump to operate. The outlet ends of the main oil pump and the AC auxiliary oil pump are connected in parallel with each other. One end of the parallel connection is connected to a three-way valve. One end of the three-way valve is connected to an accumulator group, and the other end is connected to a cooler. The cooler is connected to a filter. The lubricating oil in the oil tank is output by the main oil pump or the AC auxiliary oil pump, and is supplied to each bearing of the steam turbine after passing through the three-way valve, the cooler and the filter in sequence. The lubricating oil of each bearing returns to the oil tank through the return oil pipeline.

[0007] A further technical solution is that the accumulator group includes three 100L bladder accumulators, and the three bladder accumulators are all connected in parallel with one end of the three-way valve.

[0008] A further technical solution is that the cooler is a cooling tube type cooler, in which a cooling tube for conveying lubricating oil is provided inside the cooler, and a number of heat dissipation fins are provided on the outer surface of the cooling tube along its length direction. Both ends of the cooling tube are sealed and pass through the cooler, and are respectively connected to the three-way valve and the filter. Both ends of the cooler are respectively provided with a water inlet and a water outlet connected to its interior, and the horizontal position of the water inlet is lower than that of the water outlet.

[0009] A further technical solution is that the bottom of the return oil pipeline is connected to a sedimentation pipe, on which a stop valve and a discharge valve are installed from top to bottom, and a filter is provided on the side of the sedimentation pipe close to the oil tank inside the return oil pipeline.

[0010] A further technical solution is that the filter screen is arranged at an angle, with the inclined bottom surface of the filter screen facing the sedimentation pipe.

[0011] A further technical solution is to provide a fuel filling port on the top side of the fuel tank which is connected to the interior of the fuel tank.

[0012] A further technical solution is to open an observation hole on the side of the oil tank, and high-temperature explosion-proof glass is sealed and embedded in the observation hole.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: by adding an accumulator group at the outlet of the main oil pump, the accumulator group can balance the pressure in the pipeline. When the pressure at the outlet of the main oil pump is too high, and the instantaneous flow at the outlet of the main oil pump is higher than the average flow, at this time, part of the oil at the outlet of the main oil pump whose instantaneous flow is higher than the average flow is absorbed by the accumulator group, thereby reducing the pressure of the lubricating oil, avoiding pipeline vibration caused by excessive pressure, and causing cracks in the pipeline welds. When the pressure at the outlet of the main oil pump is too low, and the instantaneous flow at the outlet of the main oil pump is lower than the average flow, at this time, part of the oil at the outlet of the main oil pump whose instantaneous flow is lower than the average flow is supplemented by the accumulator group, so that the instantaneous flow in the pipeline is the same as the average flow, thereby avoiding the AC oil pump being started due to low pressure, and causing the machine to trip when the low oil pressure is serious. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a top view of a lubricating oil supply system of the utility model.

[0015] Figure 2 This is a cross-sectional connection diagram of the cooler, cooling pipe and heat dissipation fins of the utility model.

[0016] Figure 3 This is a cross-sectional connection diagram of the return pipe and sedimentation pipe of the utility model.

[0017] Icons: 1-Oil tank, 2-Main oil pump, 3-AC auxiliary oil pump, 4-Steam turbine, 5-Three-way valve, 6-Bladder accumulator, 7-Cooler, 8-Filter, 9-Oil return pipe, 10-Cooling pipe, 11-Radiating fins, 12-Water inlet, 13-Water outlet, 14-Sedimentation pipe, 15-Stop valve, 16-Discharge valve, 17-Filter, 18-Refueling port. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Example 1:

[0020] See also Figure 1 The utility model shows a lubricating oil supply system, including an oil tank 1, a main oil pump 2, an AC auxiliary oil pump 3 and a steam turbine 4. The main oil pump 2 is installed at the front end of the main shaft of the steam turbine 4 so that the main shaft of the steam turbine 4 drives the main oil pump 2 to operate. The main oil pump 2 is installed at the front end of the main shaft of the steam turbine 4 so that the main shaft of the steam turbine 4 drives the main oil pump 2 to operate as in the prior art, and no further description is given here. The outlet ends of the main oil pump 2 and the AC auxiliary oil pump 3 are connected in parallel with each other, and one end of the parallel connection is connected to a three-way valve 5. One end of the three-way valve 5 is connected to an accumulator group, and the other end is connected to a cooler 7. The cooler 7 is connected to the filter 8, and the main oil pump 2, the AC auxiliary oil pump 3, the three-way valve 5, the cooler 7, the filter 8 and the steam turbine 4 are connected to each other through stainless steel pipe fittings. The lubricating oil in the oil tank 1 is output by the main oil pump 2 or the AC auxiliary oil pump 3, and is supplied to the various bearings of the steam turbine 4 through the three-way valve 5, the cooler 7 and the filter 8 in turn. The lubricating oil of each bearing is returned to the oil tank 1 through the return oil pipe 9. The accumulator group includes three 100L bladder accumulators 6, and the three bladder accumulators 6 are all connected in parallel with one end of the three-way valve 5.

[0021] In this embodiment, the main shaft of the steam turbine 4 drives the main oil pump 2 to operate. The main oil pump 2 drives the lubricating oil in the oil tank 1 to pass through the accumulator group, the cooler 7, and the filter 8 to supply lubricating oil to each bearing of the steam turbine 4 for lubrication. The lubricating oil of each bearing is returned to the oil tank 1 through the return oil pipe 9. When the main oil pump 2 fails and stops working, the AC auxiliary oil pump 3 supplies oil to ensure that the lubrication work does not stop. The accumulator group is connected through the three-way valve 5. The accumulator group includes three 100L bladder accumulators 6. The bladder accumulator 6 is provided with a bladder for storing lubricating oil and is filled with nitrogen for balancing pressure. At the same time, the bladder accumulator 6 will automatically store a part of the pressurized lubricating oil in the bladder when it is not working. The bladder accumulator 6 is a prior art and its working principle will not be repeated here. When in use, when the gear inside the main oil pump 2 fails, the bladder accumulator 6 will automatically store a part of the pressurized lubricating oil in the bladder. The bladder accumulator 6 is a prior art and its working principle will not be repeated here. When slippage occurs, the accumulator group can balance the pressure in the pipeline. When the pressure at the outlet of the main oil pump 2 is too high, the instantaneous flow at the outlet of the main oil pump 2 will be higher than the average flow. At this time, part of the lubricating oil whose instantaneous flow at the outlet of the main oil pump 2 is higher than the average flow is absorbed by the accumulator group and absorbed into the bladder inside the bladder-type accumulator 6, thereby reducing the pressure of the lubricating oil and avoiding pipeline vibration caused by excessive pressure, which causes cracks in the pipeline welds. When the pressure at the outlet of the main oil pump 2 is too low, the instantaneous flow at the outlet of the main oil pump 2 will be lower than the average flow. At this time, part of the oil whose instantaneous flow at the outlet of the main oil pump 2 is lower than the average flow is replenished by the accumulator group, and the lubricating oil in the air bag inside the bladder-type accumulator 6 flows out, making the instantaneous flow in the pipeline the same as the average flow, thereby avoiding starting the AC oil pump due to low pressure, which causes the machine to trip when the low oil pressure is serious.

[0022] Example 2:

[0023] Based on the above examples, please refer to Figure 2 As shown, the cooler 7 is a cooling pipe 10 type cooler 7, and a cooling pipe 10 for conveying lubricating oil is provided inside the cooler 7. A plurality of heat dissipation fins 11 are arranged around the outer surface of the cooling pipe 10 along its length direction. Both ends of the cooling pipe 10 are sealed and pass through the cooler 7, and are respectively connected to the three-way valve 5 and the filter 8. The two ends of the cooler 7 are respectively provided with a water inlet 12 and a water outlet 13 connected to its interior. The horizontal position of the water inlet 12 is lower than the horizontal position of the water outlet 13. By providing the water inlet 12 and the water outlet 13, it is convenient to connect the inlet and outlet cooling water pipelines, thereby facilitating the cooling of the lubricating oil inside the cooling pipe 10. By providing the heat dissipation fins 11 on the outer surface of the cooling pipe 10, the contact area between the cooling pipe 10 and the cooling water in the cooler 7 can be increased, thereby making it easier to cool the lubricating oil flowing through the cooling pipe 10. By setting the horizontal position of the water inlet lower than the horizontal position of the water outlet 13, it can be ensured that the cooler 7 can be fully filled with cooling water for cooling.

[0024] Example 3:

[0025] Based on the above examples, please refer to Figure 3 As shown, the bottom of the return oil pipeline 9 is connected to a sedimentation pipe 14, and a check valve 15 and a discharge valve 16 are installed on the sedimentation pipe 14 from top to bottom in sequence. There is a certain pipeline distance between the check valve 15 and the discharge valve 16 for precipitating impurities. A filter screen 17 is provided on the side of the sedimentation pipe 14 close to the oil tank 1 inside the return oil pipeline 9. When in use, the check valve 15 is opened and the discharge valve 16 is closed. After the lubricating oil lubricates the bearings in the turbine 4 and the impurities in the bearings are taken away and rinsed clean with the flow and circulation of the lubricating oil, the impurities in the lubricating oil can be filtered out by setting the filter screen 17 to prevent the impurities from directly returning to the oil tank 1 with the lubricating oil. After the filter screen 17 filters the impurities, the impurities are precipitated in the sedimentation pipe 14 and are cleaned regularly. When cleaning, the check valve 15 is closed first, and then the discharge valve 16 is opened to allow the impurities to be discharged through the sedimentation pipe 14. At this time, since the check valve 15 is in a closed state, the lubricating oil in the return oil pipeline 9 will not flow out, so it can be cleaned without stopping the machine, thereby improving practicality.

[0026] See also Figure 3 As shown, the filter screen 17 is arranged at an angle, and the inclined bottom surface of the filter screen 17 faces the sedimentation tube 14, so that impurities are not easily adhered to the filter screen 17 due to their own gravity. At the same time, the inclined bottom surface of the filter screen 17 faces the sedimentation tube 14, so that impurities fall directly into the sedimentation tube 14 when precipitated. Since the lubricating oil has a certain flow rate in the return oil pipe 9, if impurities adhere to the inclined filter screen 17, they are more likely to be washed off by the lubricating oil with a certain flow rate, thereby making it difficult for impurities to adhere to the filter screen 17.

[0027] See also Figure 1 As shown, a refueling port 18 communicating with the interior of the oil tank 1 is provided on the top side thereof. The provision of the refueling port 18 facilitates replenishment of lubricating oil into the oil tank 1 .

[0028] An observation hole is provided on the side of the fuel tank 1 , and a high-temperature explosion-proof glass is sealed and embedded in the observation hole (not shown in the figure). The high-temperature explosion-proof glass allows for direct observation of the interior of the fuel tank 1 .

[0029] Although the present invention has been described herein with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and implementations may be devised by those skilled in the art that fall within the scope and spirit of the principles disclosed herein. More specifically, within the scope of the present disclosure, the drawings, and the claims, various variations and modifications may be made to the components and / or layout of the subject combination arrangement. In addition to variations and modifications to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A lubricating oil supply system comprising an oil tank (1), a main oil pump (2), an AC auxiliary oil pump (3) and a steam turbine (4), characterized in that: The main oil pump (2) is installed at the front end of the main shaft of the steam turbine (4) so ​​that the main shaft of the steam turbine (4) drives the main oil pump (2) to operate. The outlet ends of the main oil pump (2) and the AC auxiliary oil pump (3) are connected in parallel with each other, and one end of the parallel connection is connected with a three-way valve (5). One end of the three-way valve (5) is connected with an accumulator group, and the other end is connected with a cooler (7). The cooler (7) is connected with a filter (8). The lubricating oil in the oil tank (1) is output by the main oil pump (2) or the AC auxiliary oil pump (3), and is sequentially supplied to each bearing of the steam turbine (4) after passing through the three-way valve (5), the cooler (7), and the filter (8). The lubricating oil of each bearing is returned to the oil tank (1) through the return oil pipeline (9).

2. A lubricating oil supply system according to claim 1, characterized in that: The accumulator group includes three 100L bladder accumulators (6), and the three bladder accumulators (6) are all connected in parallel with one end of the three-way valve (5).

3. The lubricating oil supply system according to claim 1, characterized in that: The cooler (7) is a cooling tube (10) type cooler (7), wherein a cooling tube (10) for conveying lubricating oil is provided inside the cooler (7), and a plurality of heat dissipation fins (11) are provided on the outer surface of the cooling tube (10) along its length direction. Both ends of the cooling tube (10) are sealed and pass through the cooler (7), and are respectively connected to the three-way valve (5) and the filter (8). Both ends of the cooler (7) are respectively provided with a water inlet (12) and a water outlet (13) connected to the interior thereof, and the horizontal position of the water inlet (12) is lower than the horizontal position of the water outlet (13).

4. The lubricating oil supply system according to claim 1, characterized in that: The bottom of the oil return pipe (9) is connected to a sedimentation pipe (14), and a stop valve (15) and a discharge valve (16) are installed on the sedimentation pipe (14) in sequence from top to bottom. A filter screen (17) is provided inside the oil return pipe (9) on the side of the sedimentation pipe (14) close to the oil tank (1).

5. The lubricating oil supply system according to claim 4, characterized in that: The filter screen (17) is arranged in an inclined manner, and the lower portion of the inclined bottom surface of the filter screen (17) faces the sedimentation pipe (14).

6. The lubricating oil supply system according to claim 1, characterized in that: A refueling port (18) communicating with the interior of the oil tank (1) is provided on the top side of the oil tank (1).

7. The lubricating oil supply system according to claim 1, characterized in that: An observation hole is provided on the side of the oil tank (1), and a high-temperature explosion-proof glass is sealed and embedded in the observation hole.

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