Low liquid level anti-oil running sealing oil efficient treatment device and method

Abstract

The application provides a low liquid level oil leakage prevention sealing oil efficient treatment device and method, wherein the oil-gas separation tank body is connected in series between the sealing oil tank of the hydrogen-cooled generator set and the air side sealing oil alternating oil pump, the oil inlet assembly sends the sealing oil mist to be purified into the tank after atomization, the vacuum air extraction assembly maintains high vacuum in the tank, the oil discharge assembly sends the purified sealing oil back to the main oil circuit, the liquid level regulation and control assembly detects the oil level and transmits a signal to the electric control unit, the electric control unit cooperatively regulates and controls each assembly, the oil level in the tank is controlled in the interval of 1 / 8-1 / 4 of the total height of the tank body, and the gas phase defoaming buffer space of not less than 750mm is reserved above the liquid surface. The application solves the problems of foam overflow and oil leakage under high vacuum condition, improves the purification efficiency of the sealing oil, guarantees the safe operation of the unit, and is suitable for various industrial lubricating oil vacuum deaeration and water removal treatment scenes.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil treatment technology for hydrogen-cooled generators, and in particular to a high-efficiency treatment device and method for low-level oil leakage prevention sealing oil, used in the sealing oil system of hydrogen-cooled generators. Background Technology

[0002] Medium and large steam turbine generator sets mostly adopt a composite cooling method of water cooling for stator windings and hydrogen cooling for stator core and rotor windings. Hydrogen is used as the cooling medium for stator core and rotor windings. Relying on the high thermal conductivity and excellent cooling effect of hydrogen, the heat dissipation problem of core components can be solved when the unit is running under high load. In the aforementioned combined cooling methods, the rapid degradation of hydrogen purity inside the hydrogen-cooled generator is a prominent issue. According to power industry standards, hydrogen purity must be consistently above 98%. Below this standard, it can lead to a sharp drop in cooling efficiency, localized overheating of the unit, insulation aging, the formation of an explosive mixture of hydrogen and air, reduced power generation efficiency, and increased plant power consumption. While power plants typically maintain purity through periodic hydrogen replacement, frequent operations increase the costs of hydrogen procurement and maintenance of hydrogen production equipment. They can also cause pressure fluctuations in the hydrogen system, disrupting the pressure differential and oil level in the sealing oil system, and increasing the probability of leaks in the sealing tiles and hydrogen.

[0003] Research has shown that the core reason for the decrease in hydrogen purity is the diffusion of impurity gases carried during the sealing oil circulation process. The sealing oil originates from the main unit's lubricating oil and, during circulation, carries water vapor, air, and small-molecule impurities generated by the high-temperature decomposition of the lubricating oil. These impurities diffuse with the hydrogen at the sealing tiles, diluting its purity. Therefore, the industry commonly installs vacuum oil filters at the inlet of the AC oil pump (air side) of the sealing oil system to pre-treat the sealing oil by degassing and dehydrating it, reducing the dissolved gas content in the oil from the source, thus balancing the safety and economy of unit operation.

[0004] Existing vacuum oil filters have several shortcomings, making it difficult to meet the requirements for deep purification of sealing oil: First, it is difficult to balance vacuum level and foam control. Under medium to high liquid levels, low vacuum purification is insufficient, while high vacuum easily leads to oil leakage and damages the vacuum pump. Second, external air and moisture are prone to backflow. Slightly opening the vacuum breaker valve to suppress foam creates an ineffective cycle of alternating air extraction and replenishment, contaminating the sealing oil. Third, the liquid level detection accuracy is low, contact sensors are easily interfered with, the control logic is simplistic, and adjustment is lagging under varying operating conditions. Fourth, existing foam suppression technology is ineffective. In summary, existing devices suffer from limited vacuum levels and frequent oil leakage, requiring urgent optimization and improvement. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a high-efficiency sealing oil treatment device and method for preventing oil leakage at low liquid levels. Through a vacuum oil-gas separation structure with ultra-low liquid level operation and precise liquid level detection and control, it achieves deep degassing and dehydration of the sealing oil, stable liquid level control, prevention of oil leakage, and blocking of backflow of external air and water vapor. This solves the problems of foam overflow and oil leakage in the oil-gas separator and unstable liquid level control under high vacuum conditions, effectively improves the purification efficiency of sealing oil, ensures the safe and stable operation of hydrogen-cooled generator sets, and is suitable for various industrial lubricating oil treatment scenarios that require vacuum degassing and dehydration.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-efficiency sealing oil treatment device for preventing oil leakage at low liquid levels, comprising an oil-gas separation tank, an oil inlet assembly, a vacuum pumping assembly, an oil discharge assembly, a liquid level control assembly, and an electrical control unit. The oil-gas separation tank is connected in series on the oil supply pipeline between the sealing oil tank of a hydrogen-cooled generator set and the air-side sealing oil AC pump. The oil inlet assembly atomizes the sealing oil to be purified and delivers it to the oil-gas separation tank. The vacuum pumping assembly maintains a high vacuum environment within the oil-gas separation tank and treats the mixed gas released from the tank. The oil discharge assembly delivers the purified sealing oil from the tank back to the main oil circuit. The liquid level control assembly detects the oil level in the tank in real time and transmits the detection signal to the electrical control unit. The electrical control unit coordinates the operation of each assembly based on the received detection signal to keep the oil level in the tank constantly controlled within a preset ultra-low liquid level range. This preset ultra-low liquid level range is 1 / 8 to 1 / 4 of the total height of the oil-gas separation tank, with a gas phase defoaming buffer space of not less than 750 mm reserved above the liquid surface.

[0007] Furthermore, the oil inlet assembly includes an oil inlet pipe and an atomizing spray head; one end of the oil inlet pipe is connected to the main oil circuit at the front end of the air-side sealing oil AC oil pump, and the other end passes through the upper part of the side wall of the oil-gas separator and extends to the top of the tank; the atomizing spray head is located at the end of the oil inlet pipe inside the tank.

[0008] Furthermore, it also includes an inlet valve, a coarse filter, an inlet solenoid valve, an inlet temperature sensor, and a float valve connected in series along the oil flow direction on the oil inlet pipe. The float valve is placed inside the oil-gas separator tank and is used to cut off the oil inlet pipe when the oil level exceeds the preset ultra-low liquid level range or an abnormality occurs.

[0009] Furthermore, the atomizing spray head is installed on the top of the oil-gas separator tank and has a swirling atomizing structure. At least 8 sets of swirling spray holes are evenly arranged circumferentially at the inner end of the oil inlet pipe, and the diameter of the swirling spray holes is 1.5mm.

[0010] Furthermore, the atomizing spray head disperses the sealing oil into micron-sized oil mist particles of 5~10μm through the swirling spray holes and delivers them to the oil-gas separator tank.

[0011] Furthermore, an air extraction port is provided at the top of the oil-gas separator. The vacuum extraction assembly is connected to the interior of the oil-gas separator through this air extraction port. Along the direction of mixed gas flow, the air extraction port is connected in series with a vacuum pump outlet valve, an oil-water condenser, a vacuum solenoid valve, and a vacuum pump via a sealed pipeline. The bottom of the oil-water condenser is connected to a vacuum buffer tank via a branch pipeline. A vacuum separation isolation valve is connected in series on the branch pipeline. A drain valve is provided at the bottom of the vacuum buffer tank for collecting condensate.

[0012] Furthermore, a vacuum gauge, a vacuum pressure sensor, a vacuum breaking solenoid valve, a vacuum breaking manual valve, and a vacuum filter are also installed at the air extraction port on the top of the oil-gas separation tank, and all of them are connected to the air extraction port; the vacuum pressure sensor transmits the vacuum level signal inside the tank to the electronic control unit, and the electronic control unit controls the vacuum pump and the vacuum solenoid valve based on the vacuum level signal.

[0013] Furthermore, the oil discharge assembly includes an oil discharge pipe, one end of which is connected to the bottom of the oil-gas separator tank, and the other end is connected to the main oil circuit at the front end of the air-side sealing oil AC oil pump. Along the oil flow direction, the oil discharge pipe is connected in series with a frequency conversion oil discharge pump, a recirculation valve, an oil discharge temperature sensor, an oil discharge flow sensor, an oil discharge temperature gauge, an oil discharge pressure gauge, a valve before the fine filter, a fine filter, a fine filter differential pressure alarm, an oil discharge valve, and a check valve.

[0014] Furthermore, the variable frequency oil pump is electrically connected to the electronic control unit. The electronic control unit dynamically adjusts the operating frequency of the variable frequency oil pump based on the liquid level signal and the oil discharge flow signal. The fine filter is used to filter out tiny impurities in the purified sealing oil. The fine filter differential pressure alarm is used to monitor the filtration status of the fine filter and promptly report any blockage faults.

[0015] Furthermore, the liquid level control component includes an upper limit microwave liquid level sensor and a lower limit microwave liquid level sensor, both of which are installed on the side wall of the oil-gas separator tank via a fixed bracket. They use a non-contact detection method to collect the oil level signal inside the tank and transmit it to the electronic control unit. The upper limit microwave liquid level sensor corresponds to the upper limit position of the preset ultra-low liquid level range and is installed at the lower 1 / 4 position of the side wall of the tank. The lower limit microwave liquid level sensor corresponds to the lower limit position of the preset ultra-low liquid level range and is installed at the lower 1 / 8 position of the side wall of the tank.

[0016] Furthermore, the electronic control unit adopts a PLC programmable controller with a built-in multivariable coupled adaptive control algorithm. Its signal input terminal is electrically connected to the vacuum pumping component, liquid level control component, oil inlet component, and oil outlet component to receive signals transmitted by the detection elements of each component. The signal output terminal of the electronic control unit is electrically connected to the oil inlet component, oil outlet component, and vacuum pumping component to output control commands and coordinate the operation of the oil-gas separation tank, oil inlet component, vacuum pumping component, oil outlet component, and liquid level control component to achieve constant oil level control in the tank.

[0017] This invention also provides a method for efficient treatment of low-level oil leakage prevention sealing oil, applied to the aforementioned device for efficient treatment of low-level oil leakage prevention sealing oil, comprising the following steps: The sealing oil to be purified in the sealing oil tank of the hydrogen-cooled generator set is transported by the oil inlet assembly and enters the oil-gas separator. The oil inlet assembly atomizes the sealing oil to be purified into micron-sized oil mist particles. The oil inlet assembly collects the oil inlet temperature signal and transmits it to the electronic control unit. The vacuum pumping unit is activated to extract the mixed gas inside the oil-gas separator tank, creating a high-vacuum environment. Impurities in the atomized oil mist particles are rapidly released under the high vacuum and form a mixed gas. After being processed by the vacuum pumping unit, the liquid oil-water mixture is collected, and the remaining dry mixed gas is discharged. At the same time, the vacuum pumping unit collects the vacuum level signal inside the tank, and the liquid level control unit collects the oil level signal inside the tank, both of which are transmitted to the electronic control unit. Based on the received oil level signal, vacuum signal, and oil inlet temperature signal, the electronic control unit dynamically adjusts the operating status of the oil discharge component and the oil inlet component to maintain the oil level in the tank within the preset ultra-low level range; at the same time, the electronic control unit adjusts the operating status of the vacuum pumping component according to the vacuum signal. The purified sealing oil gathers at the bottom of the oil-gas separator tank. After being extracted and processed by the oil draining component, it is transported to the main oil circuit between the air-side sealing oil AC oil pump to complete the closed-loop circulation of the sealing oil. The oil draining component collects oil draining related signals and transmits them to the electronic control unit.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: This invention provides a high-efficiency sealing oil treatment device for preventing oil leakage at low liquid levels. The oil-gas separation tank is connected in series between the sealing oil tank and the air-side sealing oil AC pump. The oil level in the tank is controlled in the range of 1 / 8 to 1 / 4 of the total height. A gas phase defoaming buffer space of not less than 750 mm is reserved above the liquid surface to reduce foam generation at the source. Even under the extreme vacuum condition of -101 kPa, oil leakage can be completely eliminated, achieving the dual goals of high vacuum oil-gas separation and preventing oil leakage.

[0019] Furthermore, the oil inlet assembly atomizes the sealing oil through the atomizing spray head on the top of the tank. Combined with components such as the imported valve and coarse filter, it can disperse the oil into 5~10μm micron-sized oil mist particles, which greatly increases the oil-gas contact area and improves the efficiency of impurity gas extraction. The float valve can also cut off the oil inlet pipeline when the oil level is abnormal, providing mechanical protection.

[0020] Furthermore, the vacuum pumping assembly of this invention connects the components in series along the direction of the mixed gas flow. The condensation buffer structure effectively collects the oil-water mixture, preventing oil from entering the vacuum pump and causing equipment damage. Closing the vacuum breaker valve completely blocks backflow of external air and water vapor, avoiding contamination of the sealing oil and maintaining a stable high vacuum environment inside the tank. The liquid level control uses a non-contact microwave sensor, which has strong resistance to foam and oil mist interference, high detection accuracy, and is precisely installed within the corresponding liquid level range, providing reliable data for oil level control. The electrical control unit uses a PLC programmable controller with a built-in multivariable coupled adaptive control algorithm to achieve coordinated control of all components, solving the problems of liquid level detection distortion and control lag.

[0021] Furthermore, the processing technology provided by this invention, relying on the aforementioned device, achieves closed-loop purification of sealing oil, with fully automated operation requiring no manual intervention. The entire device can be directly connected to existing oil circuits, making installation convenient, maintenance simple, and adaptable to various operating conditions. It can also be extended to the purification of various industrial lubricating oils. Long-term operation can significantly improve the purification efficiency of sealing oil, reduce the cost of hydrogen replenishment for the unit and the equipment failure rate, extend the service life of the equipment, and improve the safety and stability of hydrogen-cooled generator sets, demonstrating broad prospects for widespread application. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a high-efficiency sealing oil treatment device for preventing oil leakage at low liquid levels.

[0023] In the attached diagram: 01. Generator set sealing oil tank (dual flow ring is empty side); 02. Generator set AC oil pump (dual flow ring is empty side); 03. Normally open isolation valve; 1. Oil inlet pipe; 2. Inlet valve; 3. Coarse filter; 4. Oil inlet solenoid valve; 5. Inlet temperature sensor; 6. Float valve; 7. Atomizing spray head; 8. Upper limit microwave level sensor; 9. Lower limit microwave level sensor; 10. Vacuum break solenoid valve; 11. Vacuum break manual valve; 12. Vacuum filter; 13. Vacuum gauge; 14. Vacuum pressure sensor; 1 5. Vacuum pump outlet valve; 16. Oil-water condenser; 17. Vacuum solenoid valve; 18. Vacuum pump; 19. Vacuum separation isolation valve; 20. Vacuum buffer tank; 21. Drain valve; 22. Oil-gas separator; 23. Variable frequency oil discharge pump; 24. Recirculation valve; 25. Oil discharge temperature sensor; 26. Oil discharge flow sensor; 27. Oil discharge temperature gauge; 28. Oil discharge pressure gauge; 29. ​​Valve before fine filter; 30. Differential pressure alarm for fine filter; 31. Oil discharge valve; 32. Check valve; 33. Oil discharge pipeline; 34. Fine filter. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0025] This invention provides a high-efficiency treatment device for low-level oil leakage prevention sealing oil, including an oil-gas separation tank 22 connected in series on the oil supply pipeline between the generator set sealing oil tank 01 and the air-side sealing oil AC pump 02; an oil inlet port is opened in the upper middle part of the side wall of the oil-gas separation tank 22, and the end of the oil inlet pipe 1 of the oil inlet assembly passes through the port and extends to the top of the tank, with the end connected to an atomizing spray head 7. The sealing oil to be purified is atomized into micron-sized oil mist particles through the oil inlet pipe 1 and the atomizing spray head 7 and enters the tank, completing the process. The sealing oil is input and pre-treated; an air extraction port is set at the top of the oil-gas separation tank 22, and the vacuum extraction component is connected to the tank through the air extraction port. The mixed gas precipitated from the sealing oil in the tank is extracted and discharged by the vacuum pump 18 through the air extraction port, so as to maintain the high vacuum environment in the tank and treat the mixed gas; an oil discharge port is set at the bottom of the oil-gas separation tank 22, and the input end of the oil discharge component is sealed to the oil discharge port. The purified sealing oil in the tank is extracted by the variable frequency oil discharge pump 23 and transported back to the main oil circuit to complete the purified output of the sealing oil; The liquid level control component is installed at the corresponding height position on the side wall of the tank to detect the oil level in the tank in real time; the detection elements and actuators of each component are electrically connected to the electronic control unit through shielded wires, and the electronic control unit realizes the coordinated control of the operating status of each component.

[0026] The device of this invention connects to the existing oil supply pipeline through a normally open isolation valve 03 installed on the oil supply pipeline between the generator set sealing oil tank 01 and the air-side sealing oil AC pump 02. This eliminates the need to modify the original oil circuit and enables deep degassing, dehydration, and impurity filtration of the sealing oil. It solves the problems of difficulty in balancing vacuum and foam control and easy backflow of external impurities in existing devices, ensuring the safe and stable operation of the hydrogen-cooled generator set. At the same time, it can be adapted to vacuum purification scenarios for various industrial lubricating oils.

[0027] 1) Oil inlet assembly The oil inlet assembly includes an oil inlet pipe 1. The end of the oil inlet pipe 1 passes through the oil inlet interface in the upper middle part of the side wall of the oil-gas separator tank 22 and extends to the top of the tank. Multiple atomizing spray heads 7 are provided on the oil inlet pipe 1 extending to the top of the tank. The sealing oil to be purified is transported through the oil inlet pipe 1 and atomized into micron-sized oil mist particles by the atomizing spray heads 7 before entering the tank.

[0028] Furthermore, the oil inlet pipe 1 is made of oil-resistant, high-pressure seamless steel pipe. One end is connected to the main oil circuit at the front end of the air-side sealing oil AC oil pump 02 via a flange, and the other end extends through the oil inlet interface of the tank to the top of the tank. The atomizing spray head 7 is threadedly connected to the oil inlet pipe 1 extending to the top of the tank. The interface is sealed with a sealing gasket to prevent vacuum leakage.

[0029] Furthermore, the atomizing spray head 7 adopts a swirling atomization structure, with 8 sets of 1.5mm diameter swirling spray holes evenly arranged circumferentially on the oil inlet pipe 1 extending to the top of the tank. This can disperse the oil flow into 5~10μm micron-sized oil mist particles, increase the specific surface area of ​​the oil, accelerate the release of gas in the oil, and improve the oil-gas and oil-water separation efficiency.

[0030] Furthermore, along the oil flow direction, the oil inlet pipe 1 is also sequentially equipped with an inlet valve 2, a coarse filter 3, an inlet solenoid valve 4, an inlet temperature sensor 5, and a float valve 6. Specifically: The inlet valve 2 is a manual shut-off valve, connected in series with the oil inlet pipe 1, used to cut off the oil circuit during equipment maintenance.

[0031] The coarse filter 3 adopts a detachable filter element structure with a filtration accuracy of 25μm. It is connected in series with the oil inlet pipe 1 to intercept large particles of sludge, metal impurities and colloids in the sealing oil, so as to avoid polluting the tank environment and clogging the spray nozzles of the atomizing spray head 7, and to ensure the atomization effect and the service life of the components.

[0032] The oil inlet solenoid valve 4 is an electrically controlled normally open solenoid valve, which is electrically connected to the electrical control unit. It controls the opening and closing and the degree of opening according to parameters such as the liquid level and vacuum in the tank, so as to realize the dynamic adjustment of the oil inlet volume. It works with the oil discharge assembly to complete the closed-loop constant control of the liquid level in the tank.

[0033] The imported temperature sensor 5 uses a high-precision platinum resistance detection element and is installed in the oil inlet pipe 1. It collects the oil inlet temperature in real time and transmits it to the electronic control unit as an auxiliary parameter for the multivariable coupled adaptive control algorithm, which facilitates the optimization of the control strategy and adapts to different oil temperature conditions.

[0034] The float valve 6 is a mechanical liquid level protection device, which is installed on the oil inlet pipe 1 inside the oil-gas separator tank 22 and is located close to the tank. The float of the float valve 6 is placed in the oil in the tank. When the liquid level rises abnormally to the upper limit due to the failure of the electronic control unit, the oil inlet pipe is automatically closed through the lever mechanism, forming a mechanical double protection to prevent oil leakage.

[0035] 2) Vacuum pumping assembly The vacuum pumping assembly includes a vacuum pump outlet valve 15, an oil-water condenser 16, a vacuum solenoid valve 17, and a vacuum pump 18 arranged sequentially along the gas flow direction. The vacuum pumping assembly is connected to the oil-gas separation tank 22 through an air extraction port located at the top of the tank. The mixed gas separated from the sealing oil inside the tank enters the vacuum pumping assembly through the air extraction port and is finally extracted and discharged by the vacuum pump 18, thereby maintaining a high vacuum environment inside the tank and treating the mixed gas.

[0036] Furthermore, the drain port at the bottom of the oil-water condenser 16 is connected to the inlet of the vacuum buffer tank 20 through a branch pipeline. The vacuum separation isolation valve 19 is connected in series on this branch pipeline, and the drain valve 21 is installed at the bottom of the vacuum buffer tank 20 to discharge the condensate. This branch pipeline is arranged to collect the oil-water mixture generated by the oil-water condenser 16.

[0037] Furthermore, the vacuum pumping assembly also includes a vacuum gauge 13, a vacuum pressure sensor 14, a vacuum rupture solenoid valve 10, a vacuum rupture manual valve 11, and a vacuum filter 12. All of these components are centrally located at the extraction port at the top of the oil-gas separator 22 to achieve vacuum monitoring, vacuum depressurization, and impurity filtration within the tank, as detailed below: 1. The vacuum gauge 13 and vacuum pressure sensor 14 work together to realize the vacuum monitoring function. The vacuum gauge 13 is used by on-site maintenance personnel to intuitively view the real-time vacuum level inside the tank, which is convenient for on-site inspection. The vacuum pressure sensor 14 is responsible for accurately collecting the vacuum level signal and transmitting it to the electronic control unit. It serves as the core basis for the electronic control unit to regulate the operating status of the vacuum pump 18 and the vacuum solenoid valve 17, thereby realizing closed-loop control of the vacuum level.

[0038] II. The vacuum rupture solenoid valve 10 and the vacuum rupture manual valve 11 jointly undertake the vacuum pressure relief function. Both valves are shut-off structures and remain closed during normal operation. They are only opened when the equipment is shut down or under maintenance to quickly release the vacuum in the tank and ensure the safety of maintenance operations. The vacuum rupture solenoid valve 10 can be remotely controlled by the electronic control unit, while the vacuum rupture manual valve 11 serves as a backup, achieving dual protection of electronic control and manual operation.

[0039] Third, the vacuum filter 12 achieves the impurity filtration function. It is installed on the outside of the vacuum break solenoid valve 10 and the vacuum break manual valve 11. The filtration accuracy is up to 5μm. It can effectively filter dust, particles and other impurities in the outside atmosphere, prevent impurities from entering the tank through the air extraction port and contaminating the sealing oil, and at the same time avoid impurities from entering the subsequent vacuum extraction circuit and damaging related components.

[0040] Furthermore, the preferred structures of each component of the vacuum pumping assembly are as follows: Vacuum pump 18 is a rotary vane vacuum pump with a rated ultimate vacuum of -101 kPa and a rated pumping speed of 2 L / s, providing high vacuum power inside the tank. Its start-up, shutdown and operating power are adjusted by the electronic control unit according to the vacuum signal to ensure stable vacuum.

[0041] The oil-water condenser 16 adopts a shell-and-tube condensation structure and is installed between the air inlet of the vacuum pump 18 and the air extraction port of the tank. Cooling water is introduced into the shell. After the oil-gas mixture enters, the oil mist and water vapor liquefy upon cooling to form an oil-water mixture, which flows into the vacuum buffer tank 20 for storage, thus preventing oil mist from entering the vacuum pump 18 and causing damage, and extending its service life.

[0042] The vacuum solenoid valve 17 is an electrically controlled normally closed solenoid valve, connected in series between the oil-water condenser 16 and the vacuum pump 18, and electrically connected to the electronic control unit. It controls the opening and closing according to the vacuum level signal to realize the on / off control of the pumping circuit and prevent the outside air from flowing back in after the vacuum pump 18 stops.

[0043] The vacuum buffer tank 20, as a branch component of the oil-water condenser 16, is connected to the drain port at the bottom of the oil-water condenser 16 via a pipeline. It is used to store the oil-water mixture formed by liquefaction within the oil-water condenser 16, serving as a buffer, storage, and gas-liquid separator. A vacuum separation isolation valve 19 is installed on the branch connected to the oil-water condenser 16. When draining accumulated liquid, the valve is first closed to cut off the connection between the branch and the main extraction circuit. Then, the drain valve 21 at the bottom of the vacuum buffer tank 20 is opened to drain the accumulated liquid, preventing backflow of the accumulated liquid into the oil-water condenser 16 and the main extraction circuit, and ensuring that the normal flow of the main gas flow is not affected.

[0044] The vacuum pressure sensor 14 is a high-precision diffused silicon pressure sensor with a detection accuracy of 0.1 kPa. It is installed at the vent of the tank and collects the vacuum signal in real time and transmits it to the electronic control unit as a core control parameter to dynamically adjust the vacuum pump 18 and the vacuum solenoid valve 17 to maintain a stable vacuum.

[0045] Both the vacuum breaker solenoid valve 10 and the vacuum breaker manual valve 11 are shut-off valves installed at the tank's air extraction port. During normal operation, both valves are completely closed, preventing backflow of external air, water vapor, and dust, and eliminating the decrease in oil-gas separation efficiency caused by alternating air extraction and replenishment. The vacuum filter 12 (filtration accuracy 5μm) is installed on the outside of the valve and filters external impurities during pressure relief, protecting the sealing oil inside the tank.

[0046] The vacuum pump outlet valve 15 is a manual shut-off valve, installed at the outlet end of the vacuum pump 18. It is opened during operation to ensure gas discharge, and closed when the pump is stopped or under maintenance to prevent backflow of outside air and impurities from entering the vacuum pump 18.

[0047] 3) Oil drain assembly The oil discharge assembly includes core components such as a variable frequency oil discharge pump 23, an oil discharge pipe 33, and a fine filter 34. Its input end is sealed to the oil discharge port at the bottom of the oil-gas separation tank 22 via a flange. The purified sealing oil in the tank is drawn out by the variable frequency oil discharge pump 23, flows through the oil discharge pipe 33 through each auxiliary component, and is then transported back to the main oil circuit at the front end of the air-side sealing oil AC oil pump 02 to complete the purified output of the sealing oil.

[0048] Furthermore, the auxiliary components include, in sequence along the oil flow direction, a recirculation valve 24, an oil discharge temperature sensor 25, an oil discharge flow sensor 26, an oil discharge temperature gauge 27, an oil discharge pressure gauge 28, a valve before the fine filter 29, a fine filter 34, a fine filter differential pressure alarm 30, an oil discharge valve 31, and a check valve 32.

[0049] Furthermore, the oil drain pipe 33 is made of oil-resistant, high-pressure seamless steel pipe. One end is connected to the output end of the variable frequency oil drain pump 23, and the other end extends to the main oil circuit at the front end of the air-side sealing oil AC oil pump 02. A one-way valve 32 is installed at the end to prevent backflow of high-pressure sealing oil in the main oil circuit and ensure the stability of the oil drain passage.

[0050] Furthermore, the preferred structures of each component of the oil drainage assembly are as follows: The variable frequency oil pump 23 is a variable frequency controlled centrifugal pump. Its input end is sealed to the oil discharge port of the tank through a flange, and its output end is connected to the oil discharge pipe 33. The rated flow rate is 6m³ / h. 3 / h, rated head 30m, frequency conversion range 0~50Hz. Its operating frequency is adjusted by the electronic control unit according to the liquid level and oil discharge flow signals, and works with the oil inlet solenoid valve 4 to achieve closed-loop control of ultra-low liquid level in the tank, avoiding liquid level fluctuations caused by frequent start and stop of traditional fixed frequency oil pumps, and reducing energy consumption.

[0051] The recirculation valve 24 is a manually adjustable valve, installed at the output end of the variable frequency oil pump 23 and the recirculation branch at the top of the tank, used to assist in adjusting the liquid level. During the initial start-up of the equipment or when the liquid level fluctuates slightly, opening this valve allows some purified oil to flow back, quickly adjusting the liquid level to the set range and improving control flexibility.

[0052] Oil discharge flow sensor 26 adopts an electromagnetic flow sensor with a detection range of 0~10m. 3 / h, detection accuracy ±0.5%, installed on the main return oil pipeline, collects the oil discharge flow signal in real time and transmits it to the electronic control unit as the core control parameter, used to dynamically adjust the frequency of the variable frequency oil discharge pump 23 to achieve the balance of inlet and outlet oil flow.

[0053] The oil discharge temperature sensor 25 uses a high-precision platinum resistance element, with a detection range of 0~100℃ and an accuracy of ±0.5℃. It collects the oil discharge temperature signal and transmits it to the electronic control unit. The oil drain temperature gauge 27 is a pointer-type temperature gauge used to visually display the oil drain temperature on-site, facilitating operation and maintenance monitoring.

[0054] The oil discharge pressure gauge 28 is a pointer-type pressure gauge with a range of 0~1.6MPa. It is installed on the main return oil pipeline to display the oil discharge pressure on site. This allows maintenance personnel to judge the operating status of components such as the variable frequency oil discharge pump 23 and the fine filter 34 based on pressure changes and to troubleshoot faults in a timely manner.

[0055] The valve 29 before the fine filter is a manual shut-off valve, used to cut off the oil circuit of the fine filter 34 during maintenance, facilitating component replacement and repair; the fine filter 34 has a detachable filter element structure with a filtration accuracy of 5μm, used for secondary interception of fine colloids and impurities, improving the cleanliness of the sealing oil and extending the service life of the sealing oil system components.

[0056] The differential pressure alarm 30 for fine filter uses a differential pressure alarm device, which is connected in parallel with the fine filter 34 to monitor the differential pressure before and after the fine filter 34 in real time. When the differential pressure exceeds 0.15MPa, it will issue an audible and visual alarm to remind the filter element to be replaced, so as to ensure the filtration effect and the smooth flow of the oil discharge system and avoid damage to the variable frequency oil discharge pump 23.

[0057] The oil drain valve 31 is a manual shut-off valve, installed on the main return oil pipeline at the rear end of the fine filter 34. It is used to cut off the oil circuit during maintenance, and can also adjust the oil drain flow rate according to the operating requirements to assist in controlling the liquid level.

[0058] The one-way valve 32 is a swing-type one-way valve, installed at the end of the oil drain pipe 33 near the main oil circuit to prevent the high-pressure sealing oil in the main oil circuit from flowing back and damaging the vacuum environment inside the tank, while also preventing impurities in the main oil circuit from flowing back and contaminating the purified oil.

[0059] The oil drain pipe 33 is made of oil-resistant, high-pressure seamless steel pipe, which is used to transport the purified oil back to the main oil circuit at the front end of the air-side sealing oil AC oil pump 02. The interface is sealed with a gasket to prevent leakage and realize the closed-loop circulation of sealing oil.

[0060] 4) Liquid level control component The liquid level control component includes an upper limit microwave liquid level sensor 8 and a lower limit microwave liquid level sensor 9. This component is installed at the corresponding height position on the side wall of the oil-gas separator 22. It collects the oil level data in the tank in real time through non-contact detection and transmits the signal to the electronic control unit, providing a reliable basis for closed-loop control of the liquid level in the tank.

[0061] Furthermore, both the upper limit microwave level sensor 8 and the lower limit microwave level sensor 9 are mounted on the side wall of the tank with fixed brackets, with the probes facing the oil inside the tank and not in contact with the inner wall of the tank. The sensors are electrically connected to the electronic control unit through shielded wires to ensure the stability of the detection signal transmission and avoid signal interference.

[0062] Preferably, the upper limit microwave liquid level sensor 8 adopts non-contact microwave detection technology, with a detection blind zone of ≤10mm and an accuracy of ±1mm. It is installed on the lower 1 / 4 position (about 300mm) of the side wall of the tank to detect whether the oil level exceeds the set upper limit. When the oil level exceeds the limit, it sends a signal to the electronic control unit to trigger the potential adjustment command, control the oil inlet solenoid valve 4 to close, and increase the frequency of the variable frequency oil discharge pump 23 to speed up the oil discharge.

[0063] Preferably, the lower limit microwave liquid level sensor 9 has the same parameters as the upper limit sensor and is installed on the lower 1 / 8 position of the side wall of the tank. It is used to detect whether the oil level is lower than the set lower limit. When the oil level is low, it sends a signal to the electronic control unit to trigger the oil replenishment adjustment command, control the oil inlet solenoid valve 4 to open and the frequency of the variable frequency oil pump 23 to decrease, thereby reducing the oil discharge speed.

[0064] Both sets of sensor signal output terminals are electrically connected to the electronic control unit through shielded wires to transmit oil level signals in real time, providing accurate data for the multivariable coupled adaptive control algorithm, realizing closed-loop control of oil level in the tank without hysteresis or fluctuation, with a liquid level control accuracy of up to 200mm±10mm.

[0065] 5) Oil-gas separator tank The oil-gas separator tank 22 is a horizontal pressure-bearing stainless steel tank with a total height of 1200mm. It is made of oil-resistant and corrosion-resistant 304 stainless steel, which meets the pressure and corrosion resistance requirements of vacuum conditions. The tank is welded using a seamless welding process to ensure the airtightness and pressure bearing capacity of the tank, and is suitable for extreme vacuum operation conditions of -101kPa.

[0066] Furthermore, the oil-gas separator 22 adopts an ultra-low liquid level constant operation mode, setting the constant liquid level threshold inside the tank to 1 / 8 to 1 / 4 of the total tank height. During normal operation, the liquid level is stable at around 1 / 8. This setting can significantly reduce the contact area between the oil and the vacuum phase space, reducing foam generation at the source. A gas phase defoaming buffer space of no less than 750mm is reserved above the liquid surface. Even under the extreme vacuum condition of -101kPa, foam cannot fill the gas phase space, completely eliminating oil leakage. At the same time, the amount of sealing oil stored in the tank is small under ultra-low liquid level, which can achieve extreme high vacuum oil-gas separation while ensuring the oil leakage prevention effect, improving degassing and water removal efficiency, and solving the pain point of difficulty in balancing vacuum degree and foam control in existing technologies.

[0067] 6) Electronic control unit The electrical control unit adopts a PLC programmable controller with a built-in multivariable coupled adaptive control algorithm. The detection and execution elements of each component are electrically connected to the electrical control unit through shielded wires to realize the coordinated control of the operating status of each component and ensure the stable and efficient operation of the device.

[0068] Furthermore, the signal input terminal of the electronic control unit is electrically connected to detection elements such as vacuum pressure sensor 14, upper limit microwave liquid level sensor 8, lower limit microwave liquid level sensor 9, inlet temperature sensor 5, oil discharge flow sensor 26, and oil discharge temperature sensor 25, for real-time acquisition of core operating parameters such as tank vacuum, oil level, inlet oil temperature, and oil discharge flow; the output terminal is electrically connected to actuators such as inlet solenoid valve 4, variable frequency oil discharge pump 23, vacuum pump 18, vacuum solenoid valve 17, and vacuum breaking solenoid valve 10, for outputting control commands to adjust the operating status of each component.

[0069] Furthermore, the electrical control unit also integrates functions such as operating parameter display, fault alarm, data storage, and remote communication. Key operating parameters are displayed intuitively on the field display screen. In case of a fault, it issues an audible and visual alarm and stores relevant information. At the same time, it can interface with the power plant's DCS system to support remote monitoring and control and meet the needs of intelligent operation and maintenance.

[0070] Furthermore, the core control logic of the electronic control unit is based on a multivariable coupled adaptive control algorithm. It synchronously collects four core parameters: tank vacuum, real-time oil level, oil discharge flow rate, and oil inlet temperature. It dynamically adjusts the frequency of the variable frequency oil discharge pump 23, the opening degree of the oil inlet solenoid valve 4, the operating status of the vacuum pump 18, and the opening degree of the vacuum solenoid valve 17 to achieve stable control of ultra-low liquid level and vacuum. The specific control logic is as follows: 1. When the upper limit microwave liquid level sensor 8 detects that the oil level is higher than 1 / 4 of the tank height, the electronic control unit closes the oil inlet solenoid valve 4, increases the frequency of the variable frequency oil discharge pump 23, and speeds up the oil discharge until the oil level drops back to the 1 / 8~1 / 4 range.

[0071] 2. When the lower limit microwave liquid level sensor 9 detects that the oil level is lower than 1 / 8 of the tank height, the electronic control unit opens the oil inlet solenoid valve 4, reduces the frequency of the variable frequency oil discharge pump 23, and reduces the oil discharge speed until the oil level rises back to the set range.

[0072] 3. During normal high vacuum operation, the electronic control unit controls the vacuum breaking solenoid valve 10 and the vacuum breaking manual valve 11 to be completely closed, preventing the backflow of outside air and water vapor; during shutdown and maintenance, the vacuum breaking solenoid valve 10 is controlled to open to achieve rapid pressure relief.

[0073] In addition, the electrical control unit is equipped with functions such as display of operating parameters, fault alarm, data storage, and remote communication. It can display key operating parameters on the field display screen, issue audible and visual alarms and store relevant information when a fault occurs, and can also interface with the power plant's DCS system to support remote monitoring and control, meeting the needs of intelligent operation and maintenance.

[0074] The working process of the low-level oil leakage prevention and high-efficiency sealing oil treatment device of the present invention is as follows: 1. Sealing oil input and atomization stage: The sealing oil to be purified is introduced from the main oil line at the inlet of the air-side sealing oil AC pump 02. It then passes through the inlet valve 2 and coarse filter 3 sequentially via the inlet pipe 1. After the coarse filter 3 intercepts large particles of impurities, the sealing oil flows through the inlet solenoid valve 4 and the inlet temperature sensor 5, and then through the float valve 6 into the oil-gas separator tank 22. The sealing oil is then dispersed into micron-sized oil mist particles by the swirling atomizing spray head 7 at the top of the tank, significantly increasing the specific surface area of ​​the oil. The inlet temperature sensor 5 collects the inlet oil temperature in real time and transmits the temperature signal to the electronic control unit as a control parameter.

[0075] 2. Vacuum Oil-Gas Separation Stage: After vacuum pump 18 starts, it continuously extracts the mixed gas in oil-gas separator 22 through the vacuum pumping circuit, creating an extreme high vacuum environment of approximately -101 kPa inside the tank. Under the action of high vacuum, the dissolved air, water vapor, and lubricating oil cracking impurities inside the atomized oil mist particles are rapidly released and separated from the oil mist to form a mixed gas. The mixed gas enters the oil-water condenser 16 through the exhaust port at the top of the tank. The oil mist and water vapor liquefy upon cooling, forming a liquid oil-water mixture, which flows into the vacuum buffer tank 20 for storage. The remaining dry mixed gas is discharged to the outside through vacuum pump 18. During this process, the vacuum pressure sensor 14 collects the vacuum level inside the tank in real time, and the microwave level sensors (upper limit microwave level sensor 8 and lower limit microwave level sensor 9) collect the oil level inside the tank in real time. All detection signals are transmitted synchronously to the electronic control unit. The electronic control unit dynamically adjusts the frequency of the variable frequency oil pump 23 and the opening of the oil inlet solenoid valve 4 through a multivariable coupling adaptive control algorithm to maintain the oil level inside the tank at a constant ultra-low range of about 1 / 8 of the tank height. At the same time, the vacuum breaking solenoid valve 10 and the vacuum breaking manual valve 11 are kept completely closed to prevent backflow of external air and water vapor.

[0076] 3. Purified Oil Discharge Stage: After degassing and dehydration purification, the sealing oil gathers at the bottom of the oil-gas separator 22. It is then drawn by the variable frequency oil discharge pump 23 and flows sequentially through the oil discharge pipe 33, passing through the recirculation valve 24, oil discharge flow sensor 26, oil discharge temperature sensor 25, oil discharge pressure gauge 28, the valve 29 before the fine filter, and the fine filter 34. The fine filter 34 performs secondary filtration of the sealing oil, intercepting fine impurities. The purified sealing oil then passes through the oil discharge valve 31 and the check valve 32, ultimately being returned to the main oil circuit at the front end of the air-side sealing oil AC oil pump 02, achieving closed-loop circulation of the sealing oil. The oil discharge flow sensor 26 and the oil discharge temperature sensor 25 collect the oil discharge flow and temperature signals in real time and transmit them to the electronic control unit for optimizing the control strategy. The fine filter differential pressure alarm 30 monitors the pressure difference before and after the fine filter 34 in real time, promptly reminding maintenance personnel to replace the filter element.

[0077] Through the above three-stage cyclic operation, water vapor, air and various impurities in the sealing oil are continuously removed. The purified sealing oil re-enters the sealing oil system for circulation, reducing the diffusion of gas in the sealing oil to the generator hydrogen side from the source, and maintaining the generator hydrogen purity in compliance with standards in the long term.

[0078] To further illustrate the technical solution of the present invention, the device will be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0079] Example 1 The low-level oil leakage prevention and high-efficiency sealing oil treatment device provided in this embodiment is installed on the oil supply pipeline between the sealing oil tank 01 of the hydrogen-cooled generator set and the air-side sealing oil AC pump 02. A normally open isolation valve 03 is installed in the middle of the oil supply pipeline to achieve convenient connection with the original oil circuit. The overall structure of the device is as follows: Figure 1 As shown.

[0080] In this embodiment, the specific parameters of each core component of the device are adapted to the operating requirements of a 600MW hydrogen-cooled generator set, as follows: 1. Oil-gas separator tank 22: A horizontal stainless steel pressure tank with a total height of 1200mm, a tank diameter of 800mm, and an effective volume of 0.6m³. 3 The tank is set with a constant ultra-low liquid level range of 150mm~300mm (corresponding to 1 / 8~1 / 4 of the tank height), and the height of the gas phase space above the liquid surface is ≥750mm, with sufficient defoaming buffer space reserved to adapt to extreme vacuum operation conditions.

[0081] 2. Oil Inlet Assembly: The coarse filter 3 has a filtration accuracy of 25μm, which can effectively intercept large particulate impurities; the oil inlet solenoid valve 4 is a DN50 electrically controlled normally open solenoid valve, which is sensitive and precise in adjustment; the imported temperature sensor 5 has a detection range of 0~100℃ and an accuracy of ±0.5℃, which can collect the oil inlet temperature in real time; the atomizing spray head 7 has 8 sets of 1.5mm diameter swirling spray holes, which can disperse the sealing oil into micron-level oil mist particles of 5~10μm, improving the oil-gas separation efficiency.

[0082] 3. Vacuum Pumping Components: Vacuum pump 18 is a rotary vane vacuum pump with a rated ultimate vacuum of -101 kPa and a rated pumping speed of 2 L / s, providing stable high vacuum power inside the tank; oil-water condenser 16 is a shell-and-tube structure with a cooling area of ​​5 m² and a cooling water inlet temperature ≤30℃, which can efficiently condense oil mist and water vapor in the mixed gas; vacuum pressure sensor 14 has a detection range of 0~-101 kPa and an accuracy of 0.1 kPa, accurately acquiring vacuum signals; vacuum breaking solenoid valve 10 is a pulse-type small-diameter solenoid valve with a single gas replenishment time ≤5 s, used only for shutdown pressure relief; vacuum filter 12 has a filtration accuracy of 5 μm, which can filter external atmospheric impurities; vacuum buffer tank 20 serves as a branch component of oil-water condenser 16, connected to the drain port at the bottom of the condenser, with a vacuum separation isolation valve 19 on the branch and a drain valve 21 at the bottom of the buffer tank, used to collect condensate without affecting the main airflow.

[0083] 4. Oil discharge assembly: Variable frequency oil discharge pump 23 with a rated flow rate of 6m³ / h 3 / h, rated head 30m, frequency conversion range 0~50Hz, enabling precise flow regulation; oil discharge flow sensor 26 detection range 0~10m 3 / h, accuracy ±0.5%; oil discharge temperature sensor 25, detection range 0~100℃, accuracy ±0.5℃, can collect oil discharge parameters in real time; fine filter 34, filtration accuracy 5μm, can realize secondary purification of sealing oil; fine filter differential pressure alarm 30, alarm threshold 0.15MPa, can promptly remind you to replace the filter element.

[0084] 5. Liquid level control component: The upper and lower limit microwave liquid level sensors have a detection range of 0~500mm, a detection blind zone of ≤10mm, an accuracy of ±1mm, and an operating temperature range of -20~80℃. They can be adapted to the high temperature and oil mist environment inside the tank to achieve accurate oil level detection.

[0085] 6. Electrical Control Unit: It adopts a PLC programmable controller with a built-in multivariable coupled adaptive control program. It has functions such as display of operating parameters, fault alarm, data storage, and remote communication. It can be seamlessly connected with the power plant's DCS system to realize remote monitoring and control of the device.

[0086] The specific steps for operating and debugging the device in this embodiment are as follows: 1. Preparations before startup: Conduct a comprehensive inspection of the secure connections of all pipelines and the opening and closing status of valves (inlet valve 2, drain valve 31, vacuum pump outlet valve 15, and vacuum solenoid valve 17 are open; vacuum breaker solenoid valve 10, vacuum breaker manual valve 11, and recirculation valve 24 are closed); verify the operating status of each detection element and actuator and the power supply stability of the electrical control unit; turn on the sealing oil system to allow the sealing oil to be purified to slowly flow into the inlet pipe 1, expelling air from the pipeline and preparing for the startup of the unit.

[0087] 2. Start-up and Liquid Level Regulation: The electronic control unit is started, and the ultra-low liquid level threshold in the tank is set to 200mm (1 / 8 of the tank height). Simultaneously, the variable frequency oil discharge pump 23 and vacuum pump 18 are started. After vacuum pump 18 starts, air is extracted from the tank through the vacuum pumping circuit, and the vacuum level in the tank gradually increases. At the same time, the oil inlet solenoid valve 4 opens, and the purified sealing oil enters the tank after being atomized by the atomizing spray head 7, causing the oil level to rise slowly. When the lower limit microwave liquid level sensor 9 detects that the oil level has reached 150mm, the electronic control unit adjusts the operating frequency of the variable frequency oil discharge pump 23 to 25Hz to control the oil discharge flow rate. When the oil level rises to 200mm, the oil discharge pump frequency remains unchanged, achieving dynamic balance between the inlet and outlet oil flow rates, ensuring that the oil level remains stable within the range of 200mm ± 10mm.

[0088] 3. Vacuum Regulation: Vacuum pump 18 continuously pumps air, gradually increasing the vacuum level inside the tank. Vacuum pressure sensor 14 collects the vacuum level signal in real time and transmits it to the electronic control unit. When the vacuum level inside the tank reaches -101 kPa, the electronic control unit adjusts the operating power of vacuum pump 18 to maintain the vacuum level stable at around -101 kPa. If the vacuum level fluctuates slightly, it is quickly corrected by adjusting the opening of vacuum solenoid valve 17. During operation, vacuum rupture solenoid valve 10 and vacuum rupture manual valve 11 remain closed to prevent backflow of outside air and moisture.

[0089] 4. Sealing Oil Purification and Circulation: After atomization and vacuum oil-gas separation, the purified sealing oil accumulates at the bottom of the oil-gas separation tank 22. It is then drawn by the variable frequency oil discharge pump 23, filtered twice by the fine filter 34, and finally returned to the main oil circuit at the front end of the air-side sealing oil AC oil pump 02, achieving closed-loop circulation of the sealing oil. The oil discharge flow sensor 26 and oil discharge temperature sensor 25 collect oil discharge parameters in real time and transmit them to the electronic control unit. The electronic control unit dynamically optimizes the control strategy based on parameter changes to ensure stable purification effect.

[0090] After applying the device from Example 1 to a 600MW hydrogen-cooled generator unit in a power plant, a six-month on-site operation verification was conducted. The unit maintained normal load operation, the sealing oil temperature remained stable at around 50℃, the device operated stably, and all performance indicators met the design requirements. The specific verification results are as follows: 1. Liquid level control effect: The oil level in the tank is always kept constant in the ultra-low liquid level range of 200mm±10mm without large fluctuations, and the liquid level control accuracy meets the design standards; the microwave liquid level sensor does not show detection distortion or false alarm, and is completely unaffected by foam and oil mist in the tank, with excellent detection stability.

[0091] 2. Vacuum operation performance: The vacuum level inside the tank is stably maintained at around -101kPa, far exceeding the limit vacuum of -82kPa in the existing technology, and the vacuum fluctuation range is ≤±0.5kPa, with good operational stability; the vacuum breaking solenoid valve 10 and the vacuum breaking manual valve 11 are closed throughout the process, and there is no backflow of external air or water vapor, and the cleanliness of the sealing oil inside the tank remains excellent.

[0092] 3. Foam and oil spill control effect: Only a small amount of foam is generated inside the tank, and the highest height of the foam does not exceed 300mm, which is far below the height of the gas phase space in the tank. There is no risk of rapid foam rise and overflow; there is no foam and oil is extracted from the exhaust end of the vacuum pump 18, which completely eliminates the oil spill failure and greatly reduces the amount of sealing oil loss.

[0093] 4. Sealing oil purification effect: The degassing and water removal efficiency of the sealing oil is improved by more than 85%. After purification, the water content of the sealing oil is ≤50ppm and the gas content is ≤0.1%, which is far better than the industry standard requirements. The purity of the generator hydrogen is consistently above 98.5%, and can reach up to 99.2%, which fully meets the operating specifications of the power industry.

[0094] 5. Economic and safety benefits: The average daily hydrogen replenishment frequency of the unit has been reduced from once every 3 days to once a month, and the amount of hydrogen replenishment has been reduced by 95%, saving approximately RMB 200,000 in hydrogen procurement costs annually. During the operation of the unit, no problems such as oil leakage, vacuum pump failure, or leakage of the sealing oil system occurred. The generator did not experience any abnormalities such as local overheating or insulation aging. The number of unplanned shutdowns for maintenance was 0, which greatly improved the economic efficiency and safety of the unit's operation.

Claims

1. A high-efficiency sealing oil treatment device for preventing oil leakage at low liquid levels, characterized in that, The system includes an oil-gas separator tank (22), an oil inlet assembly, a vacuum pumping assembly, an oil outlet assembly, a liquid level control assembly, and an electrical control unit. The oil-gas separator tank (22) is connected in series to the oil supply pipeline between the sealing oil tank (01) of the hydrogen-cooled generator set and the air-side sealing oil AC pump (02). The oil inlet assembly atomizes the sealing oil to be purified and delivers it to the oil-gas separator tank (22). The vacuum pumping assembly maintains a high vacuum environment in the oil-gas separator tank (22) and processes the mixed gas released from the tank. The oil outlet assembly delivers the purified sealing oil in the tank back to the main oil circuit. The liquid level control assembly detects the oil level in the tank in real time and transmits the detection signal to the electrical control unit. The electrical control unit coordinates the operation of each component based on the received detection signal to keep the oil level in the tank constant within a preset ultra-low liquid level range. This preset ultra-low liquid level range is 1 / 8 to 1 / 4 of the total height of the oil-gas separator tank (22). A gas phase defoaming buffer space of not less than 750 mm is reserved above the liquid surface.

2. The low-level oil leakage prevention and high-efficiency treatment device for sealing oil according to claim 1, characterized in that, The oil inlet assembly includes an oil inlet pipe (1) and an atomizing spray head (7); one end of the oil inlet pipe (1) is connected to the main oil circuit at the front end of the air-side sealing oil AC oil pump (02), and the other end passes through the upper middle part of the side wall of the oil-gas separator tank (22) and extends to the top of the tank. The atomizing spray head (7) is set at the end of the oil inlet pipe (1) inside the tank. The atomizing spray head (7) is installed at the top of the oil-gas separator tank (22) and has a swirling atomizing structure. At least 8 sets of swirling spray holes are uniformly arranged circumferentially at the end of the oil inlet pipe (1). The diameter of the swirling spray holes is 1.5 mm. The atomizing spray head (7) disperses the sealing oil into micron-sized oil mist particles of 5~10 μm through the swirling spray holes.

3. The low-level oil leakage prevention and high-efficiency treatment device for sealing oil according to claim 2, characterized in that, It also includes an inlet valve (2), a coarse filter (3), an inlet solenoid valve (4), an inlet temperature sensor (5), and a float valve (6) connected in series along the oil flow direction on the oil inlet pipe (1). The float valve (6) is placed inside the oil-gas separator tank (22) and is used to cut off the oil inlet pipe when the oil level exceeds the preset ultra-low liquid level range or an abnormality occurs.

4. The low-level oil leakage prevention and high-efficiency treatment device for sealing oil according to claim 1, characterized in that, The top of the oil-gas separator (22) has an air extraction port. The vacuum pumping assembly is connected to the inside of the oil-gas separator (22) through the air extraction port. Along the direction of mixed gas flow, the air extraction port is connected in series with the vacuum pump outlet valve (15), oil-water condenser (16), vacuum solenoid valve (17), and vacuum pump (18) through a sealed pipeline. The bottom of the oil-water condenser (16) is connected to the vacuum buffer tank (20) through a branch pipeline. A vacuum separation isolation valve (19) is connected in series on the branch pipeline. A drain valve (21) is provided at the bottom of the vacuum buffer tank (20) for collecting condensate.

5. The low-level oil leakage prevention and high-efficiency treatment device for sealing oil according to claim 4, characterized in that, The top of the oil-gas separator tank (22) is equipped with a vacuum gauge (13), a vacuum pressure sensor (14), a vacuum breaking solenoid valve (10), a vacuum breaking manual valve (11), and a vacuum filter (12), all of which are connected to the exhaust port. The vacuum pressure sensor (14) transmits the vacuum level signal inside the tank to the electronic control unit, which controls the vacuum pump (18) and the vacuum solenoid valve (17) based on the vacuum level signal.

6. The low-level oil leakage prevention and high-efficiency treatment device for sealing oil according to claim 1, characterized in that, The oil discharge assembly includes an oil discharge pipe (33), one end of which is connected to the bottom of the oil-gas separator tank (22), and the other end is connected to the main oil circuit at the front end of the air-side sealing oil AC oil pump (02). Along the oil flow direction, the oil discharge pipe (33) is connected in series with a frequency conversion oil discharge pump (23), a recirculation valve (24), an oil discharge temperature sensor (25), an oil discharge flow sensor (26), an oil discharge temperature gauge (27), an oil discharge pressure gauge (28), a valve before the fine filter (29), a fine filter (34), a fine filter differential pressure alarm (30), an oil discharge valve (31), and a check valve (32).

7. The low-level oil leakage prevention and high-efficiency treatment device for sealing oil according to claim 6, characterized in that, The variable frequency oil pump (24) is electrically connected to the electronic control unit. The electronic control unit dynamically adjusts the operating frequency of the variable frequency oil pump (24) based on the liquid level signal and the oil discharge flow signal. The fine filter (34) is used to filter out tiny impurities in the purified sealing oil. The fine filter differential pressure alarm (30) is used to monitor the filtration status of the fine filter (34) and promptly report any blockage faults.

8. The low-level oil leakage prevention and high-efficiency treatment device for sealing oil according to claim 1, characterized in that, The liquid level control component includes an upper limit microwave liquid level sensor (8) and a lower limit microwave liquid level sensor (9), both of which are installed on the side wall of the oil-gas separator (22) by a fixed bracket. The oil level signal in the tank is collected by a non-contact detection method and transmitted to the electronic control unit. The upper limit microwave liquid level sensor (8) corresponds to the upper limit position of the preset ultra-low liquid level range and is installed at the lower 1 / 4 position of the side wall of the tank. The lower limit microwave liquid level sensor (9) corresponds to the lower limit position of the preset ultra-low liquid level range and is installed at the lower 1 / 8 position of the side wall of the tank.

9. The low-level oil leakage prevention and high-efficiency treatment device for sealing oil according to claim 1, characterized in that, The electrical control unit adopts a PLC programmable controller with a built-in multivariable coupling adaptive control algorithm. Its signal input terminal is electrically connected to the vacuum pumping component, liquid level control component, oil inlet component, and oil outlet component to receive signals transmitted by the detection elements of each component. The signal output terminal of the electrical control unit is electrically connected to the oil inlet component, oil outlet component, and vacuum pumping component to output control commands and coordinate the operation of the oil-gas separation tank (22), oil inlet component, vacuum pumping component, oil outlet component, and liquid level control component to achieve constant oil level control in the tank.

10. A method for efficiently treating sealing oil at low liquid levels to prevent oil leakage, characterized in that, The low-level oil leakage prevention and high-efficiency treatment device for sealing oil, as described in any one of claims 1 to 9, comprises the following steps: The sealing oil to be purified in the sealing oil tank (01) of the hydrogen-cooled generator set is transported by the oil inlet assembly and enters the oil-gas separator (22). The sealing oil to be purified is atomized into micron-sized oil mist particles by the oil inlet assembly. The oil inlet assembly collects the oil inlet temperature signal and transmits it to the electronic control unit. The vacuum pumping assembly is activated to extract the mixed gas in the oil-gas separator tank (22), creating a high vacuum environment inside the tank. The impurities in the atomized oil mist particles are rapidly released under the high vacuum and form a mixed gas. After the mixed gas is processed by the vacuum pumping assembly, the liquid oil-water mixture is collected, and the remaining dry mixed gas is discharged. At the same time, the vacuum pumping assembly collects the vacuum degree signal inside the tank, and the liquid level control assembly collects the oil level signal inside the tank, both of which are transmitted to the electronic control unit. Based on the received oil level signal, vacuum signal, and oil inlet temperature signal, the electronic control unit dynamically adjusts the operating status of the oil discharge component and the oil inlet component to maintain the oil level in the tank within the preset ultra-low level range; at the same time, the electronic control unit adjusts the operating status of the vacuum pumping component according to the vacuum signal. The purified sealing oil gathers at the bottom of the oil-gas separator (22), and after being extracted and processed by the oil draining assembly, it is transported to the main oil circuit between the air-side sealing oil AC oil pump (02) to complete the closed-loop circulation of the sealing oil; the oil draining assembly collects oil draining related signals and transmits them to the electrical control unit.

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