A double-flow ring seal oil pressure stabilizing system for a conventional hydrogen-cooled generator

Abstract

This utility model discloses a conventional hydrogen-cooled generator dual-flow-ring sealing oil pressure stabilization system, including a gas turbine generator and a hydrogen-side oil tank. The gas turbine generator has an excitation end and a steam end at its two ends, and sealing tiles are installed at the connection points between the excitation end and the steam end and the gas turbine generator. An accumulator and a check valve are installed on the air-side sealing oil header. Through the cooperation of the accumulator and the check valve, the pressure self-holding time during a brief pressure loss of the air-side sealing oil system is extended to more than 3 seconds. When the pressure of the air-side sealing oil header suddenly rises, the accumulator can relieve the pressure and avoid excessive oil-hydrogen pressure difference. When the original operating pump is shut down, the header flow rate is instantly halved and the pressure drops, the accumulator automatically releases the stored sealing oil to maintain the header pressure stability until the oil-hydrogen pressure difference regulating valve completes the adjustment, ensuring that the oil-hydrogen pressure difference is basically maintained at about 84 kPa. This avoids unit tripping caused by excessive pressure fluctuations, ensures the long-term stable and safe operation of the generator set, and significantly improves the economic benefits of the power plant.

Description

Technical Field

[0001] This utility model belongs to the technical field of hydrogen-cooled generators, specifically relating to a pressure stabilization system for dual-flow-ring sealing oil in a conventional hydrogen-cooled generator. Background Technology

[0002] A conventional hydrogen-cooled generator's dual-flow-ring sealing oil system consists of two independent yet interconnected oil circuits: one on the air side and one on the hydrogen side. Both air-side and hydrogen-side sealing oils simultaneously supply oil to the dual-flow-ring sealing pads at both ends of the generator. Return oil from the generator bearings is pressurized by the air-side sealing oil pump and then passes through the air-side sealing oil cooler and filter to the air-side oil rings of the dual-flow-ring sealing pads at both ends of the generator. The air-side sealing oil pressure is controlled by the differential pressure valve. When the hydrogen pressure inside the generator changes or the air-side sealing oil pressure fluctuates, the differential pressure valve adjusts the air-side sealing oil discharge rate to maintain the air-side sealing oil pressure approximately 84 kPa higher than the hydrogen pressure inside the generator. The return oil from the air-side sealing oil is discharged to the return oil system of the generator support bearings. After being pressurized by the hydrogen-side sealing oil pump, the hydrogen-side sealing oil passes through the hydrogen-side sealing oil cooler and filter screen, and is then divided into two paths, which pass through the balance valves at both ends of the generator to the hydrogen-side oil rings of the sealing tiles at both ends of the generator. The function of the balance valves at both ends of the generator is to track the pressure in the empty-side oil rings in the sealing tiles at both ends and adjust the pressure difference between the hydrogen-side oil rings and the empty-side oil rings in the sealing tiles at both ends to be no greater than ±490Pa. The hydrogen-side sealing oil returns to the sealing oil tank. The oil level in the sealing oil tank is controlled by replenishing oil at the outlet of the empty-side sealing oil pump or discharging oil at the inlet of the empty-side sealing oil pump. The control of the air-side sealing oil pressure of the dual-flow ring sealing oil in a conventional hydrogen-cooled generator is as follows: Figure 1 As shown, the control mainly relies on the oil discharge of the oil-hydrogen differential pressure regulating valve. This valve is a purely mechanical differential pressure valve with no thermal factors. The sealing oil signal pressure of the oil-hydrogen differential pressure regulating valve is taken from the pressure on the air-side sealing oil header connected to the outlet end of the valve via a signal oil pipe. The hydrogen signal pressure is taken from the generator's defoaming chamber via a signal oil pipe. The oil-hydrogen differential pressure regulating valve automatically adjusts the oil discharge of the air-side sealing oil pipeline based on the introduced air-side sealing oil pressure and hydrogen pressure signals, ensuring that the air-side sealing oil pressure is always approximately 84 kPa higher than the hydrogen pressure. Because this oil-hydrogen differential pressure regulating valve is purely mechanical, fluctuations in the air-side sealing oil pressure, especially during the periodic rotation of the standby oil pump, result in significant lag and overshoot characteristics in valve adjustment, and may even lead to mechanical jamming. This can result in excessively low sealing oil pressure, causing generator tripping and hydrogen leakage, among other serious accidents. Utility Model Content

[0003] The purpose of this invention is to provide a pressure stabilization system for dual-flow ring sealing oil in a conventional hydrogen-cooled generator, in order to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system, comprising: A gas turbine generator, wherein the gas turbine generator has an excitation end and a steam end at its two ends, and the connection between the excitation end and the steam end and the gas turbine generator is provided with a sealing tile; The hydrogen-side oil tank is located on one side of the gas turbine generator and is connected to the sealing tiles at the excitation end and the steam end via an oil supply pipe. Two sets of air-side AC oil pumps are provided on one side of the hydrogen-side oil tank, and the oil outlet of the air-side AC oil pumps is connected to the hydrogen-side oil tank via the air-side sealing oil header. An accumulator and a check valve are provided on the air-side sealing oil header. Sealing oil is released through the accumulator to maintain the pressure stability in the air-side sealing oil header.

[0005] Preferably, the inlet of the air-side AC oil pump is connected to the air-side oil tank via a connecting pipe, and the connecting pipe is equipped with an oil-hydrogen differential pressure regulating valve.

[0006] Preferably, the empty-side sealing oil header is also equipped with a digital pressure switch and a digital pressure transmitter.

[0007] Preferably, one end of the hydrogen-side oil tank is connected to the inlet of two sets of hydrogen-side AC oil pumps via a straight pipe, and the outlet of the hydrogen-side AC oil pumps is connected to the sealing tile at the excitation end via a branch pipe.

[0008] Preferably, both the air-side sealing oil header and the straight pipe are equipped with a shut-off valve, a level gauge, and a heat exchanger.

[0009] Preferably, the connecting pipe is equipped with a vacuum oil purification device, and the bottom of the air-side oil tank is connected to the air-side sealing oil main pipe through a shunt pipe, and the shunt pipe is equipped with an air-side DC oil pump.

[0010] Preferably, the empty side oil tank is equipped with an exhaust fan.

[0011] Preferably, one side of the empty side oil tank is connected to an oil drain tank via a pipe.

[0012] Compared with the prior art, the beneficial effects of this utility model are: (1) By cooperating with the accumulator and the check valve, the pressure self-holding time of the air-side sealing oil system during a brief pressure loss is extended to more than 3 seconds. During the periodic rotation of the standby oil pump, when two air-side AC oil pumps are running at the same time and the pressure of the air-side sealing oil main pipe suddenly rises, the accumulator can relieve the pressure and avoid excessive oil-hydrogen pressure difference. When the original running pump is shut down, the main pipe flow rate is instantly halved and the pressure drops, the accumulator automatically releases the stored sealing oil to maintain the main pipe pressure stable until the oil-hydrogen pressure difference regulating valve completes the regulation, ensuring that the oil-hydrogen pressure difference is basically maintained at about 84 kPa, avoiding unit tripping due to excessive pressure fluctuation, ensuring the long-term stable and safe operation of the generator unit, and significantly improving the economic benefits of the power plant.

[0013] (2) By adding a digital pressure switch and a digital pressure transmitter to the air-side sealing oil header, the most realistic oil-hydrogen pressure difference at the sealing tile under actual conditions can be reflected and participate in generator protection, whereas in the original system, such as Figure 1 As shown, due to the problem with the sampling pipeline, the calculated oil-hydrogen pressure difference cannot accurately reflect the oil-hydrogen pressure difference at the sealing tile, which can easily lead to protection malfunctions and generator tripping. The improved system, through more accurate sampling by digital pressure switches and digital pressure transmitters, avoids unnecessary risks to generator operation caused by protection malfunctions, and further ensures the safe and stable operation of the generator. Attached Figure Description

[0014] Figure 1 This is a process flow diagram of the existing technology; Figure 2 This is a process flow diagram of the present invention; Figure 3 This is a flowchart of the present invention.

[0015] In the diagram: 1. Gas turbine generator; 2. Exciter end; 3. Steam end; 4. Sealing tile; 5. Hydrogen-side oil tank; 6. Oil supply pipe; 7. Air-side AC oil pump; 8. Air-side sealing oil header; 9. Accumulator; 10. Check valve; 11. Connecting pipe; 12. Air-side oil tank; 13. Oil-hydrogen differential pressure regulating valve; 14. Digital pressure switch; 15. Digital pressure transmitter; 16. Straight pipe; 17. Hydrogen-side AC oil pump; 18. Branch pipe; 19. Shut-off valve; 20. Level gauge; 21. Heat exchanger; 22. Vacuum oil purification device; 23. Diverter pipe; 24. Air-side DC oil pump; 25. Exhaust fan; 26. Oil drain tank. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped with", "sleeved with", "connected", etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0018] This utility model provides, for example Figure 2-3 The conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system shown includes: A gas turbine generator 1, wherein the two ends of the gas turbine generator 1 are respectively provided with an excitation end 2 and a steam end 3, and the connection between the excitation end 2 and the steam end 3 and the gas turbine generator 1 is provided with a sealing tile 4; The hydrogen-side oil tank 5 is located on one side of the gas turbine generator 1 and is connected to the sealing tiles 4 at the excitation end 2 and the steam end 3 via an oil supply pipe 6. Two sets of air-side AC oil pumps 7 are provided on one side of the hydrogen-side oil tank 5, and the oil outlet of the air-side AC oil pumps 7 is connected to the hydrogen-side oil tank 5 via an air-side sealing oil header 8. An accumulator 9 and a check valve 10 are provided on the air-side sealing oil header 8. Sealing oil is released through the accumulator 9 to maintain the pressure stability in the air-side sealing oil header 8.

[0019] The inlet of the air-side AC oil pump 7 is connected to the air-side oil tank 12 via a connecting pipe 11, and the connecting pipe 11 is equipped with an oil-hydrogen differential pressure regulating valve 13.

[0020] The empty-side sealing oil header 8 is also equipped with a digital pressure switch 14 and a digital pressure transmitter 15. The digital pressure switch 14 and the digital pressure transmitter 15 can monitor the pressure inside the empty-side sealing oil header 8 in real time, thereby reflecting the most realistic oil-hydrogen pressure difference at the sealing tile 4 under actual conditions.

[0021] One end of the hydrogen-side oil tank 5 is connected to the inlet of two sets of hydrogen-side AC oil pumps 17 via a straight pipe 16, and the outlet of the hydrogen-side AC oil pump 17 is connected to the sealing tile 4 at the excitation end 2 via a branch pipe 18.

[0022] Both the empty-side sealing oil header 8 and the straight pipe 16 are equipped with a shut-off valve 19, a level gauge 20, and a heat exchanger 21. The shut-off valve 19 on both the empty-side sealing oil header 8 and the straight pipe 16 can control the opening and closing of the oil circuit. The level gauge 20 is used to monitor the oil level in the pipeline, while the heat exchanger 21 regulates the temperature of the sealing oil to ensure that the sealing oil works within a suitable temperature range, avoiding the impact of excessively high or low oil temperature on the performance of the sealing oil and the stable operation of the system.

[0023] The connecting pipe 11 is equipped with a vacuum oil purification device 22. The sealing oil is used in the hydrogen-cooled generator dual-flow ring sealing oil system for a long time, and inevitably it will mix with contaminants such as water, gas and mechanical impurities. The vacuum oil purification device 22 uses the vacuum environment to reduce the surface pressure of the sealing oil, so that the water and gas in it will evaporate quickly and be discharged through the air extraction device in the vacuum oil purification device 22. At the same time, the filtration system in the device will intercept mechanical impurities and separate them from the sealing oil. After purification, the water content and gas content of the sealing oil are greatly reduced, the impurity content is significantly reduced, and the oil quality is significantly improved. The bottom of the empty side oil tank 12 is connected to the empty side sealing oil main pipe 8 through the diversion pipe 23, and the diversion pipe 23 is equipped with an empty side DC oil pump 24.

[0024] The empty side oil tank 12 is equipped with a range hood 25, which can be used to exhaust the oil vapor in the oil tank and maintain the pressure inside the oil tank.

[0025] One side of the empty-side oil tank 12 is connected to an oil drain tank 26 via a pipe. The oil drain tank 26 is used to receive excess oil discharged from the empty-side oil tank 12.

[0026] In this conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system, sealing tiles 4 are installed at the connection points between the excitation end 2 and the steam end 3 at both ends of the gas turbine generator 1 and the generator. These are key components to prevent hydrogen leakage. The hydrogen-side oil tank 5 is connected to the sealing tiles 4 at the excitation end 2 and the steam end 3 via an oil supply pipe 6, providing the basic conditions for the circulation of air-side and hydrogen-side sealing oil. In the air-side oil circuit, the air-side AC oil pump 7 draws oil from the air-side oil tank 12. The oil-hydrogen differential pressure regulating valve 13 on the oil inlet connecting pipe 11 is used to initially regulate the amount of oil entering the oil pump. After the oil pump pressurizes the oil, it is delivered to the air-side oil ring of the sealing tile 4 through the air-side sealing oil header 8. The accumulator 9 installed on the air-side sealing oil header 8 (selected according to the pressure of the working oil circuit and the rated flow rate of a single air-side AC oil pump 7 during operation) is one of the core components for maintaining pressure stability. When the pressure in the air-side sealing oil circuit fluctuates, such as when the standby oil pump is rotated periodically, the oil-hydrogen differential pressure valve has a lag due to its purely mechanical structure during the start-up and shutdown of the oil pump. Taking the startup of two sets of air-side sealing oil pumps as an example, the oil volume in the air-side sealing oil header 8 doubles, and the oil pressure in the air-side sealing oil header 8 rises. However, the oil-hydrogen differential pressure regulating valve 13 is slow to adjust and cannot act in time. The newly added accumulator 9 then plays its role, storing a corresponding capacity of sealing oil to buffer the oil pressure fluctuations in the air-side sealing oil header 8 and prevent a sudden and significant increase in oil pressure. When the air-side sealing oil pumps are shut down, the oil-hydrogen differential pressure regulating valve 13 is also slow to adjust, and the air-side sealing oil header 8 briefly loses pressure. The accumulator 9 releases a corresponding capacity of sealing oil to maintain the oil-hydrogen differential pressure at a stable level of about 84 kPa. This process can last up to 3 seconds, which is longer than the time required for adjusting the valve position of the oil-hydrogen differential pressure regulating valve 13. This ensures that during the period of lag in the adjustment of the oil-hydrogen differential pressure regulating valve 13, the oil-hydrogen differential pressure is continuously maintained within the range that meets the technical requirements for generator operation safety. This effectively avoids safety hazards such as generator hydrogen leakage or protection tripping due to excessively low oil-hydrogen differential pressure, and ensures the continuous, safe, and stable operation of the unit.

[0027] The check valve 10 on the air-side sealing oil header 8 prevents oil backflow and ensures normal oil flow. The digital pressure switch 14 and digital pressure transmitter 15 monitor the pressure inside the air-side sealing oil header 8 in real time, convert the pressure signal into an electrical signal, and feed it back to the control system so that the staff can keep track of the pressure and make adjustments in a timely manner. The vacuum oil purification device 22 on the connecting pipe 11 purifies the oil entering the air-side AC oil pump 7, removes impurities and moisture from the oil, and improves the oil quality. The shunt pipe 23 at the bottom of the air-side oil tank 12 is connected to the air-side sealing oil header 8. When the system needs it, the air-side DC oil pump 24 can transport the oil in the air-side oil tank 12 to the air-side sealing oil header 8 to replenish the oil volume. In the hydrogen-side oil circuit, one end of the hydrogen-side oil tank 5 is connected to the inlet of two sets of hydrogen-side AC oil pumps 17 through a straight pipe 16. After the hydrogen-side AC oil pump 17 pressurizes the oil, it is delivered to the hydrogen-side oil ring of the sealing tile 4 at the excitation end 2 through the branch pipe 18. The balance valves at both ends of the generator track the pressure in the empty-side oil ring of the sealing tile 4 at both ends, and adjust the pressure difference between the hydrogen-side oil ring and the empty-side oil ring in the sealing tile 4 at both ends to be no greater than ±490Pa, so as to ensure the pressure balance of the hydrogen-side and empty-side sealing oil and prevent hydrogen leakage. Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A conventional hydrogen-cooled generator dual-flow-ring sealing oil pressure stabilization system, characterized in that, include: Gas turbine generator (1), the two ends of the gas turbine generator (1) are respectively provided with excitation end (2) and steam end (3), and the connection between the excitation end (2) and steam end (3) and the gas turbine generator (1) is provided with sealing tile (4). The hydrogen-side oil tank (5) is located on one side of the gas turbine generator (1) and is connected to the sealing tiles (4) at the excitation end (2) and the steam end (3) via the oil supply pipe (6). Two sets of air-side AC oil pumps (7) are provided on one side of the hydrogen-side oil tank (5) and the oil outlet of the air-side AC oil pump (7) is connected to the hydrogen-side oil tank (5) via the air-side sealing oil header (8). An accumulator (9) and a check valve (10) are provided on the air-side sealing oil header (8). The sealing oil is released through the accumulator (9) to maintain the pressure stability in the air-side sealing oil header (8).

2. The conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system according to claim 1, characterized in that: The inlet of the air-side AC oil pump (7) is connected to the air-side oil tank (12) through a connecting pipe (11), and the connecting pipe (11) is equipped with an oil-hydrogen differential pressure regulating valve (13).

3. The conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system according to claim 1, characterized in that: The empty-side sealing oil header (8) is also equipped with a digital pressure switch (14) and a digital pressure transmitter (15).

4. The conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system according to claim 1, characterized in that: One end of the hydrogen-side oil tank (5) is connected to the inlet of two sets of hydrogen-side AC oil pumps (17) through a straight pipe (16), and the outlet of the hydrogen-side AC oil pump (17) is connected to the sealing tile (4) at the excitation end (2) through a branch pipe (18).

5. The conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system according to claim 1, characterized in that: Both the empty-side sealing oil header (8) and the straight pipe (16) are equipped with a shut-off valve (19), a level gauge (20), and a heat exchanger (21).

6. The conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system according to claim 2, characterized in that: The connecting pipe (11) is equipped with a vacuum oil purification device (22), and the bottom of the air-side oil tank (12) is connected to the air-side sealing oil main pipe (8) through the diversion pipe (23), and the diversion pipe (23) is equipped with an air-side DC oil pump (24).

7. The conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system according to claim 2, characterized in that: The empty side oil tank (12) is equipped with an exhaust fan (25).

8. The conventional hydrogen-cooled generator dual-flow ring sealing oil pressure stabilization system according to claim 2, characterized in that: The empty side oil tank (12) is connected to an oil drain tank (26) via a pipe on one side.

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