Pressure protection device for offshore wind power generation transformer

Abstract

The invention relates to the technical field of transformer parts, and discloses a pressure protection device for an offshore wind power generation transformer, and the device comprises a transformer protector which is provided with an emergency explosion venting mechanism, and the emergency explosion venting mechanism is used for achieving rapid pressure relief and inhibiting temperature rising when the pressure of transformer cooling oil abnormally rises; the emergency explosion venting mechanism comprises a pressure relief box, the liquid inlet end of the pressure relief box is communicated with an upper-layer oil area of a transformer cooling oil tank through a liquid pumping assembly, the liquid pumping assembly is configured to synchronously pump oil with the temperature exceeding a specified numerical value in multiple directions, the initial state of the pressure relief box maintains an ultra-negative pressure environment, and an electric control valve is arranged at a connecting port; the gas outlet end of the low-temperature inert gas tank extends to the upper-layer oil area of the transformer cooling oil tank, an electric control valve is arranged at a connecting port, and ultrahigh-pressure inert gas is stored in the low-temperature inert gas tank in an initial state; oil with the temperature exceeding the specified numerical temperature is synchronously extracted in multiple directions through the ultra-negative pressure environment maintained by the pressure relief box in combination with the liquid extraction assembly.

Description

Technical Field

[0001] This invention relates to the field of transformer parts, and more specifically, to a pressure protection device for offshore wind power transformers. Background Technology

[0002] Offshore wind power, as a clean energy source, has developed rapidly worldwide. However, offshore wind power transformers face severe safety challenges due to their unique operating environment and high-load operation. During operation, the cooling oil inside the transformer can experience temperature increases due to load changes, rising ambient temperatures, or internal faults, leading to oil volume expansion and a sharp rise in internal pressure.

[0003] Traditional pressure relief valves or explosion-proof diaphragms only activate after the pressure reaches a set value, resulting in a relatively slow pressure relief process. For sudden, rapidly rising internal pressures, they may not be able to relieve pressure effectively and in a timely manner, leading to continued pressure increases and raising the risk of explosion. Therefore, we propose a pressure protection device for offshore wind power transformers. Summary of the Invention

[0004] This invention provides a pressure protection device for offshore wind power transformers, which solves the technical problem that the pressure relief process in related technologies is relatively slow, and may not be able to relieve pressure in a timely and effective manner when there is a sudden and rapid increase in internal pressure, resulting in the pressure continuing to rise and increasing the risk of explosion.

[0005] This invention provides a pressure protection device for offshore wind power transformers, comprising: a transformer protector, wherein an emergency pressure relief mechanism is installed on the transformer protector to quickly relieve pressure and suppress temperature rise when the transformer cooling oil pressure rises abnormally.

[0006] Emergency explosion relief organizations include:

[0007] The pressure relief box has its inlet end connected to the upper oil zone of the transformer cooling oil tank through a liquid extraction component. The liquid extraction component is configured to simultaneously extract oil exceeding a specified temperature from multiple directions. The pressure relief box initially maintains an ultra-negative pressure environment, and an electrically controlled valve is provided at the connection port.

[0008] The cryogenic inert gas tank extends its outlet to the upper oil zone of the transformer cooling oil tank. An electrically controlled valve is installed at the connection port. The cryogenic inert gas tank initially stores ultra-high pressure inert gas, which is used to inject gas into the upper oil layer where the temperature exceeds a specified value to achieve dual-effect cooling.

[0009] The data detection module includes multiple sets of sensors distributed in the upper oil zone, which are used to collect oil temperature, pressure and gas concentration data in real time, and to control the working status of the electronic control valve through the control system.

[0010] The liquid inlets of the liquid extraction assembly are located at different positions in the upper oil zone of the cooling oil tank to ensure the uniformity of oil extraction above the specified temperature. The outlets of the cryogenic inert gas tanks are located at different positions in the upper oil zone of the cooling oil tank to enhance the mixing efficiency of the gas with the oil above the specified temperature. The sensors are encapsulated with a corrosion-resistant coating to adapt to the high salt spray environment at sea.

[0011] Furthermore, a first lifting plate is provided at the top layer inside the pressure relief box, and a first piston ring is fixedly provided on the outer ring of the first lifting plate. The first lifting plate is slidably connected to the pressure relief box through the first piston ring, and the size of the first piston ring matches the internal size of the pressure relief box.

[0012] Furthermore, a first sealing film is fixedly installed on the upper wall of the first lifting plate. The outer ring of the first sealing film is fixed to the inner wall of the top layer inside the pressure relief box. The negative pressure space of the pressure relief box is the space below the first lifting plate. In the negative pressure state of the pressure relief box, the first lifting plate is at the bottom of the pressure relief box, and the first sealing film is stretched, always applying a pulling force to the first lifting plate.

[0013] Furthermore, a pressure-drawing pipe is fixedly connected to the top of the pressure relief box, and a pressure-drawing pump is connected to the end of the pressure-drawing pipe away from the pressure relief box. The pressure-drawing pump is controlled by the system. The more dangerous the change in oil pressure in the transformer is detected by the data detection module, the greater the air pressure drawn by the pressure-drawing pump from the space above the first lifting plate, and the faster the amount of cooling oil drawn into the pressure relief box.

[0014] Furthermore, the electrically controlled valve at the connection port of the pressure relief box is the first electrically controlled valve. The bottom of the first electrically controlled valve is connected to the oil extraction main pipe. An oil extraction inner pipe is fixedly installed inside the oil extraction main pipe. The oil extraction main pipe extends to the upper layer of the transformer oil tank. A large amount of oil exceeding the specified temperature flows into the pressure relief box through the oil extraction inner pipe.

[0015] Furthermore, the pumping assembly includes multiple pressure relief pumping channels in the main pumping pipe, and the multiple pressure relief pumping channels extend to different locations on the upper layer of the transformer tank. The lower wall of the pressure relief pumping channel has an array of oil inlet holes. The gap between the inner wall of the main pumping pipe and the outer wall of the inner pumping pipe is a sub-pumping chamber. The sub-pumping chamber is connected to the pressure relief pumping channels. During pumping, the inner pumping pipe and the pressure relief pumping channels do not affect each other.

[0016] Furthermore, a second lifting plate is provided inside the cryogenic inert gas tank, and a second piston ring is fixedly provided on the outer ring of the second lifting plate. The second lifting plate is slidably connected to the cryogenic inert gas tank through the second piston ring.

[0017] Furthermore, a second sealing film is fixedly installed on the lower wall of the second lifting plate, and the outer ring of the second sealing film is fixedly connected to the lower inner wall of the cryogenic inert gas tank. Below the second lifting plate is an ultra-high pressure space. Under ultra-high pressure, the second lifting plate is pushed to the top of the cryogenic inert gas tank, and the second sealing film always applies a pulling force to the second lifting plate.

[0018] Furthermore, a pressure supply pipe is fixedly connected to the top of the cryogenic inert gas tank. The end of the pressure supply pipe away from the cryogenic inert gas tank is connected to a pressure supply pump. The pressure supply pump is controlled by the system. The data detection module monitors that the more dangerous the change in oil pressure in the transformer, the faster the pressure is pushed into the space above the second lifting plate.

[0019] Furthermore, the electrically controlled valve at the connection port of the cryogenic inert gas tank is a second electrically controlled valve. The outlet end of the second electrically controlled valve is connected to a gas supply pipe, which extends to the upper space of the transformer oil tank. The other end of the gas supply pipe is provided with a diversion channel, which runs horizontally through the entire upper layer of the transformer oil tank. On both sides of the diversion channel, there are upper oil layer partition plates, and the interior of the upper oil layer partition plates is hollow. There are air jet holes on the upper oil layer partition plates. The inert gas in the cryogenic inert gas tank is ejected from the air jet holes. Sensors are all arrayed on the upper oil layer partition plates to detect changes in cooling oil in multiple directions.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention achieves rapid response and efficient pressure relief of the transformer's internal pressure by maintaining an ultra-negative pressure environment through a pressure relief tank, combined with the multi-directional synchronous extraction of oil exceeding a specified temperature by the liquid pumping component. At the same time, the low-temperature inert gas tank can actively inject ultra-high pressure inert gas into the oil exceeding the specified temperature, which not only achieves rapid cooling through vaporization heat absorption, but also dilutes the flammable gases in the oil through inert gas, suppressing the risk of fire. This achieves dual protection of pressure relief and cooling, fundamentally solving the problem that traditional pressure relief devices cannot suppress temperature rise.

[0022] The data detection module uses multiple sensors to collect key data such as oil temperature, pressure, and gas concentration in real time. It also controls the working status of the electronically controlled valves through linkage with the control system. This intelligent control method enables the device to accurately perform pressure relief and cooling operations based on the actual situation inside the transformer, avoiding excessive or insufficient intervention and improving the precision and effectiveness of protection. Attached Figure Description

[0023] Figure 1 This is a schematic diagram showing the location and structure of the transformer protector on the transformer according to the present invention;

[0024] Figure 2 This is a schematic diagram of the transformer protector structure of the present invention;

[0025] Figure 3 This is a schematic diagram of the low-temperature inert gas tank structure of the present invention;

[0026] Figure 4 This is the invention Figure 3 Enlarged view of point A in the middle;

[0027] Figure 5 This is a schematic diagram of the pressure relief box structure of the present invention;

[0028] Figure 6 This is a schematic diagram of the negative pressure state structure of the first lifting plate of the present invention;

[0029] Figure 7 This is a schematic diagram of the normal pressing structure of the first lifting plate of the present invention;

[0030] Figure 8 This is a schematic diagram of the high-pressure structure of the second lifting plate of the present invention.

[0031] In the diagram: 11. Transformer protector; 12. Pressure supply pump; 13. Pressure extraction pump; 2. Emergency explosion relief mechanism; 21. Pressure relief box; 22. Pressure relief oil extraction channel; 23. First electrically controlled valve; 24. Pressure extraction pipe; 25. Oil extraction main pipe; 26. First lifting plate; 27. First sealing film; 28. First piston ring; 29. ​​Oil extraction inner pipe; 201. Diversion chamber; 31. Low-temperature inert gas tank; 32. Diversion channel; 33. Upper oil layer partition plate; 34. Second electrically controlled valve; 35. Gas supply pipe; 36. Pressure supply pipe; 37. Jet nozzle; 38. Sensor; 39. Second lifting plate; 301. Second piston ring; 302. Second sealing film; 4. Mechanical pressure relief valve. Detailed Implementation

[0032] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0033] like Figure 1 - Figure 8 As shown, a pressure protection device for offshore wind power transformers includes: a transformer protector 11, and an emergency pressure relief mechanism 2 installed on the transformer protector 11, which is used to quickly relieve pressure and suppress temperature rise when the transformer cooling oil pressure rises abnormally.

[0034] Emergency explosion relief mechanism 2 includes:

[0035] The pressure relief box 21 has its inlet end connected to the upper oil area of ​​the transformer cooling oil tank through the liquid pumping assembly. The liquid pumping assembly is configured to simultaneously pump oil exceeding the specified temperature from multiple directions. The pressure relief box 21 initially maintains an ultra-negative pressure environment, and an electric control valve is provided at the connection port.

[0036] The low-temperature inert gas tank 31 has its outlet end extended to the upper oil area of ​​the transformer cooling oil tank. An electric control valve is provided at the connection port. The low-temperature inert gas tank 31 initially stores ultra-high pressure inert gas, which is used to inject gas into the upper oil where the temperature exceeds a specified value to achieve dual-effect cooling.

[0037] The data detection module includes multiple sets of sensors 38 distributed in the upper oil zone, which are used to collect oil temperature, pressure and gas concentration data in real time, and to control the working status of the electronic control valve through the control system.

[0038] The inlet of the liquid extraction component is located at different positions in the upper oil zone of the cooling oil tank to ensure the uniformity of oil extraction above the specified temperature. The outlet of the cryogenic inert gas tank 31 is located at different positions in the upper oil zone of the cooling oil tank to enhance the mixing efficiency of gas and oil above the specified temperature. The sensor 38 is encapsulated with a corrosion-resistant coating to adapt to the high salt spray environment at sea.

[0039] The pressure relief box 21 has a first lifting plate 26 at the top internal position. The outer ring of the first lifting plate 26 is fixedly provided with a first piston ring 28. The first lifting plate 26 is slidably connected to the pressure relief box 21 through the first piston ring 28. The size of the first piston ring 28 matches the internal size of the pressure relief box 21.

[0040] A first sealing film 27 is fixedly installed on the upper wall of the first lifting plate 26. The outer ring of the first sealing film 27 is fixed to the inner wall of the top layer of the pressure relief box 21. The negative pressure space of the pressure relief box 21 is the space below the first lifting plate 26. When the pressure relief box 21 is in a negative pressure state, the first lifting plate 26 is at the bottom of the pressure relief box 21, and the first sealing film 27 is stretched, always applying a pulling force to the first lifting plate 26.

[0041] The top of the pressure relief box 21 is fixedly connected to a pressure extraction pipe 24. The end of the pressure extraction pipe 24 away from the pressure relief box 21 is connected to a pressure extraction pump 13. The pressure extraction pump 13 is controlled by the system. The more dangerous the change in oil pressure in the transformer is detected by the data detection module, the greater the air pressure drawn by the pressure extraction pump 13 from the space above the first lifting plate 26, and the faster the amount of cooling oil is drawn into the pressure relief box 21.

[0042] The electrically controlled valve at the connection port of the pressure relief box 21 is the first electrically controlled valve 23. The bottom of the first electrically controlled valve 23 is connected to the oil extraction main pipe 25. An oil extraction inner pipe 29 is fixedly installed inside the oil extraction main pipe 25. The oil extraction main pipe 25 extends to the upper layer of the transformer oil tank. A large amount of oil exceeding the specified temperature flows into the pressure relief box 21 through the oil extraction inner pipe 29.

[0043] The pumping assembly includes multiple pressure relief pumping channels 22 of the main pumping pipe 25, and the multiple pressure relief pumping channels 22 extend to different positions on the upper layer of the transformer tank. The lower wall of the pressure relief pumping channel 22 has an array of oil inlet holes. The gap between the inner wall of the main pumping pipe 25 and the outer wall of the inner pumping pipe 29 is a sub-pumping chamber 201. The sub-pumping chamber 201 is connected to the pressure relief pumping channels 22. During pumping, the inner pumping pipe 29 and the pressure relief pumping channels 22 do not affect each other.

[0044] The cryogenic inert gas tank 31 is provided with a second lifting plate 39 inside. A second piston ring 301 is fixedly provided on the outer ring of the second lifting plate 39. The second lifting plate 39 is slidably connected to the cryogenic inert gas tank 31 through the second piston ring 301.

[0045] The lower wall of the second lifting plate 39 is fixedly provided with a second sealing film 302, and the outer ring of the second sealing film 302 is fixedly connected to the lower inner wall of the cryogenic inert gas tank 31. The space below the second lifting plate 39 is an ultra-high pressure space. Under ultra-high pressure, the second lifting plate 39 is pushed to the top of the cryogenic inert gas tank 31, and the second sealing film 302 always applies a pulling force to the second lifting plate 39.

[0046] A pressure supply pipe 36 is fixedly connected to the top of the cryogenic inert gas tank 31. The end of the pressure supply pipe 36 away from the cryogenic inert gas tank 31 is connected to a pressure supply pump 12. The pressure supply pump 12 is controlled by the system. The data detection module monitors that the more dangerous the change in oil pressure in the transformer, the faster the pressure is pushed into the space above the second lifting plate 39.

[0047] The electrically controlled valve at the connection port of the cryogenic inert gas tank 31 is a second electrically controlled valve 34. The outlet end of the second electrically controlled valve 34 is connected to an air supply pipe 35, which extends to the upper space of the transformer oil tank. The other end of the air supply pipe 35 is provided with a diversion channel 32, which runs horizontally through the entire upper layer of the transformer oil tank. On both sides of the diversion channel 32, there are upper oil layer partition plates 33, and the interior of the upper oil layer partition plates 33 is hollow. Air jet holes 37 are arrayed on the upper oil layer partition plates 33. The inert gas in the cryogenic inert gas tank 31 is ejected from the air jet holes 37. Sensors 38 are arrayed on the upper oil layer partition plates 33 to detect changes in cooling oil in multiple directions.

[0048] Phase 1: High-speed suction of oil exceeding the specified temperature using ultra-negative pressure, achieving rapid pressure relief and initial cooling.

[0049] Oil exceeding the specified temperature is above 85°C.

[0050] Triggering and Activation: Sensor 38 detects an abnormal oil pressure signal. Assuming the normal oil pressure is atmospheric pressure (approximately 101.3 kPa), when the oil pressure rises to 150 kPa (warning value), the control system first issues a warning; if the pressure continues to climb to 200 kPa (danger value), the system determines it to be in an emergency.

[0051] Establishing strong suction power: The control system immediately starts the suction pump 13, which rapidly pumps out the air above the first lifting plate 26 inside the pressure relief tank 21 through the suction pipe 24. According to the ideal gas law (PV=nRT), when the temperature (T) and the gas quantity (n) are constant, the volume (V) is forcibly expanded by the suction pump, resulting in a sharp drop in pressure (P). The suction pump 13 adjusts its power according to the pressure hazard level; the higher the hazard level, the faster the pumping rate, ultimately creating a significant negative pressure environment below the first lifting plate 26 inside the pressure relief tank 21 (e.g., -95 kPa, i.e., the relative pressure is much lower than the pressure inside the transformer tank).

[0052] The system uniformly and rapidly extracts oil exceeding a specified temperature: Simultaneously, the control system opens the first electrically controlled valve 23. Driven by a huge pressure difference (ΔP = transformer oil pressure - negative pressure of pressure relief tank 21 ≈ 200 kPa - (-95 kPa) = 295 kPa), the oil exceeding the specified temperature in the upper layer of the tank is rapidly drawn in. The design of the pumping assembly ensures uniformity and high efficiency in extraction.

[0053] Oil exceeding the specified temperature is directly pumped into the pressure relief tank 21 through the centrally located oil extraction pipe 29.

[0054] Meanwhile, some oil enters the distribution chamber 201 through multiple pressure relief oil extraction channels 22 located at different positions on the upper layer of the oil tank, and then flows into the main oil extraction pipe 25. This design avoids the problem that a single oil extraction port may fail due to poor oil flow or excessively high local oil temperature, and realizes multi-directional synchronous extraction of oil in the upper layer that exceeds the specified temperature value.

[0055] Pressure relief and primary cooling effects: A large amount of oil exceeding the specified temperature is instantly transferred to the pressure relief tank 21, directly and rapidly reducing the oil volume and pressure in the transformer body, fundamentally curbing the root cause of pressure rise. Simultaneously, the oil exceeding the specified temperature is also removed, carrying away a significant amount of heat. The system dynamically adjusts the oil extraction rate by controlling the negative pressure value of the pressure relief tank 21, achieving intelligent pressure relief.

[0056] Second stage: Injection of ultra-high pressure inert gas to achieve secondary cooling and explosion suppression:

[0057] Synchronous triggering: At the same time as or shortly after starting the oil extraction process (based on intelligent decision-making based on temperature and gas concentration data fed back by sensor 38), the control system opens the second electronically controlled valve 34.

[0058] Release of inert gas: High-pressure (e.g., 10 MPa) inert gas is stored below the second lifting plate 39 inside the cryogenic inert gas tank 31. When the second electrically controlled valve 34 is opened, the high-pressure gas instantly enters the distribution channel 32 through the gas supply pipe 35 and is evenly distributed to each upper oil layer partition plate 33. Finally, it is sprayed into the upper oil layer above the specified temperature in the form of fine bubbles through the array of jet holes 37.

[0059] Dual cooling and explosion suppression mechanism:

[0060] Physical cooling: As the inert gas bubble rises in the oil, it undergoes forced convection heat transfer with the oil, which is at a temperature exceeding a specified value, absorbing heat from the oil and achieving direct cooling. The heat transfer (Q_gas) can be estimated using the convection heat transfer formula Q_gas = h * A * ΔT, where h is the convection heat transfer coefficient, A is the total surface area of ​​the bubble, and ΔT is the gas-liquid temperature difference. The array design of the jet holes 37 significantly increases the total bubble surface area A, improving heat transfer efficiency.

[0061] Inerting of the gas phase space: Inert gas is released into the upper gas phase space of the fuel tank, which rapidly dilutes and reduces the concentration of oxygen and combustible gas below the explosion limit (for example, reducing the oxygen concentration to below 8%), effectively suppressing the risk of combustion and explosion that may be caused by electric arc or hot spots.

[0062] Pressure buffer: The injection of gas also provides a gentle pressure compensation, preventing excessive negative pressure from forming in the oil tank due to excessively rapid oil extraction.

[0063] Intelligent control throughout the entire process:

[0064] Throughout the process, multiple sets of corrosion-resistant sensors 38 distributed on the upper oil layer partition plate 33 continuously feed back oil temperature, pressure, and gas concentration data to the control system.

[0065] Based on this real-time data, the control system dynamically adjusts the power of the pumping pump 13 (thereby controlling the negative pressure of the pressure relief tank 21 and the oil extraction rate), the opening degree of the first solenoid valve 23 and the second solenoid valve 34, and the rhythm of gas release, forming a closed-loop intelligent protection response until all parameters are restored to a safe range.

[0066] Fast pressure relief and significant explosion-proof effect: By pre-establishing an ultra-negative pressure environment in the pressure relief box 21, the cooling oil can be rapidly extracted in milliseconds by relying on the huge pressure difference when a fault occurs. This far exceeds the response speed of traditional mechanical pressure relief valves and can eliminate the threat before the internal pressure of the transformer exceeds the mechanical strength limit, thus preventing the box from bursting.

[0067] Dual active cooling to prevent thermal runaway chain reaction: This device not only cools the oil by removing it from temperatures exceeding a specified value, but also innovatively introduces an ultra-high pressure, low-temperature inert gas tank 31 to inject inert gas into the oil. This achieves the dual effects of "liquid-phase heat transfer cooling" and "gas-phase mass transfer explosion suppression," rapidly reducing the temperature at the fault point and inertizing any potentially flammable gases, fundamentally blocking the catastrophic chain reaction path of "overheating – gas generation – pressure increase – electric arc – explosion."

[0068] Intelligent linkage, precise and reliable protection: Based on a multi-sensor 38 data detection module and control system, fully automatic intelligent protection is achieved from "sensing" to "decision-making" and then to "multi-actuator linkage". The system can respond in stages according to the severity of the fault (such as pressure rise rate, absolute temperature value), accurately control the oil extraction volume and gas release volume, avoid over-reaction or insufficient protection, and greatly improve the reliability and intelligence level of protection.

[0069] To further enhance the safety redundancy of the pressure protection device, a mechanical pressure relief valve 4 can be added to the side wall of the pressure relief box 21. The mechanical pressure relief valve 4 is preferably a special pressure relief valve with a high sealing level and suitable for high salt spray environment at sea, such as the pressure relief valve structure known in the art for offshore wind power transformers.

[0070] The mechanical pressure relief valve 4 is fixedly installed on the upper side wall of the pressure relief box 21 via flange or welding. Its opening pressure is reasonably set, higher than the maximum working pressure of the pressure relief box 21 during normal pressure relief, but lower than the structural pressure bearing limit of the pressure relief box 21 itself. When the internal pressure of the pressure relief box 21 abnormally rises and exceeds the set threshold due to failure of the pressure pump 13, failure of the solenoid valve, or other abnormal conditions, the mechanical pressure relief valve 4 will automatically open, quickly releasing the overpressure gas and oil in the box, thereby preventing the pressure relief box 21 from being damaged by overpressure and achieving the final protection of the pressure relief box 21 body.

[0071] The outlet of the mechanical pressure relief valve 4 can be connected to a safety discharge line to guide the released medium to a safe area. Furthermore, the valve body can be made of corrosion-resistant materials, and all interfaces are equipped with sealing rings or waterproof glands to withstand the harsh environments of high humidity and high salt spray at sea, ensuring long-term reliable operation.

[0072] The newly added mechanical pressure relief valve 4 serves as the last physical protection barrier of the pressure relief system. Combined with the aforementioned active protection mechanism based on negative pressure suction and inert gas injection, it forms a multi-layered, hierarchical, and complementary safety protection system, which greatly improves the overall reliability and safety of the offshore wind power transformer pressure protection system.

[0073] Pressure relief valve structure and working principle:

[0074] The mechanical pressure relief valve 4 mainly consists of core components such as a valve body, a sealing diaphragm (or valve disc), a pressure regulating spring, a sealing assembly, and a signal indicator rod. Its working principle is based on a preset mechanical force balance.

[0075] Normal sealing state: When the pressure relief box 21 is in a standby over-negative pressure state, the internal pressure of the mechanical pressure relief valve 4 is lower than its preset opening pressure (the set value is precisely calculated, higher than the highest working pressure that the pressure relief box 21 may reach at the maximum design oil pumping rate, but far lower than the structural safety pressure bearing limit of the pressure relief box 21 itself). At this time, the clamping force applied by the pressure regulating spring is greater than the force of the medium inside the box on the sealing diaphragm, and the diaphragm is tightly pressed against the valve seat sealing surface (usually a top rubber ring and a side rubber ring made of elastic materials such as oil-resistant rubber are used to achieve double sealing). The valve is in a tightly closed state, ensuring the sealing integrity of the pressure relief box 21, maintaining its negative pressure environment or preventing outside air from entering.

[0076] Overpressure opening and venting status:

[0077] When the internal pressure of the pressure relief tank 21 rises abnormally and exceeds the set opening pressure of the relief valve, the force of the medium acting on the sealing diaphragm will overcome the preload of the pressure regulating spring. The diaphragm is lifted, disengaged from the valve seat sealing surface, and opens rapidly. The overpressurized gas or gas-liquid mixture inside the pressure relief tank 21 is then rapidly discharged through the flow channel formed by the valve opening into the safety discharge pipeline connected to the valve outlet, ultimately leading to a safe area. This process is a purely mechanical response, independent of any electrical or control system, and is rapid and reliable.

[0078] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of the present embodiments, all of which are within the protection scope of the present embodiments.

Claims

1. A pressure protection device for offshore wind power transformers, characterized in that, include: Transformer protector (11), wherein an emergency pressure relief mechanism (2) is installed on the transformer protector (11) to quickly relieve pressure and suppress temperature rise when the transformer cooling oil pressure rises abnormally; The emergency explosion relief mechanism (2) includes: The pressure relief box (21) has its inlet end connected to the upper oil area of ​​the transformer cooling oil tank through the liquid pumping assembly. The liquid pumping assembly is configured to simultaneously pump oil exceeding the specified temperature from multiple directions. The pressure relief box (21) initially maintains an ultra-negative pressure environment, and an electric control valve is provided at the connection port. The low-temperature inert gas tank (31) has its outlet end extended to the upper oil area of ​​the transformer cooling oil tank. An electric control valve is provided at the connection port. The low-temperature inert gas tank (31) initially stores ultra-high pressure inert gas, which is used to inject gas into the upper oil that exceeds the specified temperature to achieve dual-effect cooling. The data detection module includes multiple sets of sensors (38) distributed in the upper oil zone, which are used to collect oil temperature, pressure and gas concentration data in real time, and control the working status of the electronic control valve through the control system. The inlet of the liquid extraction component is located at different positions in the upper oil zone of the cooling oil tank to ensure the uniformity of oil extraction at temperatures exceeding a specified value. The outlet of the low-temperature inert gas tank (31) is distributed at different positions in the upper oil zone of the cooling oil tank to enhance the mixing efficiency of gas and oil at temperatures exceeding a specified value. The sensor (38) is encapsulated with a corrosion-resistant coating to adapt to the high salt spray environment at sea.

2. A pressure protection device for offshore wind power transformers according to claim 1, characterized in that, The pressure relief box (21) is provided with a first lifting plate (26) at the top internal position. A first piston ring (28) is fixedly provided on the outer ring of the first lifting plate (26). The first lifting plate (26) is slidably connected to the pressure relief box (21) through the first piston ring (28). The size of the first piston ring (28) matches the internal size of the pressure relief box (21).

3. A pressure protection device for offshore wind power transformers according to claim 2, characterized in that, A first sealing film (27) is fixedly provided on the upper wall of the first lifting plate (26). The outer ring of the first sealing film (27) is fixed on the inner wall of the top layer of the pressure relief box (21). The negative pressure space of the pressure relief box (21) is the space below the first lifting plate (26). When the pressure relief box (21) is in a negative pressure state, the first lifting plate (26) is at the bottom of the pressure relief box (21), and the first sealing film (27) is stretched, always applying a pulling force to the first lifting plate (26).

4. A pressure protection device for offshore wind power transformers according to claim 3, characterized in that, The top of the pressure relief box (21) is fixedly connected to a pressure extraction pipe (24). The end of the pressure extraction pipe (24) away from the pressure relief box (21) is connected to a pressure extraction pump (13). The pressure extraction pump (13) is controlled by the system. The more dangerous the change in oil pressure in the transformer is detected by the data detection module, the greater the air pressure drawn by the pressure extraction pump (13) from the space above the first lifting plate (26), and the faster the amount of cooling oil drawn into the pressure relief box (21).

5. A pressure protection device for offshore wind power transformers according to claim 1, characterized in that, The electrically controlled valve at the connection port of the pressure relief box (21) is the first electrically controlled valve (23). The bottom of the first electrically controlled valve (23) is connected to the oil extraction main pipe (25). An oil extraction inner pipe (29) is fixedly installed inside the oil extraction main pipe (25). The oil extraction main pipe (25) extends to the upper layer of the transformer oil tank. A large amount of oil exceeding the specified temperature flows into the pressure relief box (21) through the oil extraction inner pipe (29).

6. A pressure protection device for offshore wind power transformers according to claim 5, characterized in that, The pumping assembly includes multiple pressure relief pumping channels (22) of the main pumping pipe (25), and the multiple pressure relief pumping channels (22) extend to different positions on the upper layer of the transformer tank. The lower wall of the pressure relief pumping channel (22) has an array of oil inlet holes. The gap between the inner wall of the main pumping pipe (25) and the outer wall of the inner pumping pipe (29) is a sub-pumping chamber (201). The sub-pumping chamber (201) is connected to the pressure relief pumping channel (22). During pumping, the inner pumping pipe (29) and the pressure relief pumping channel (22) do not affect each other.

7. A pressure protection device for offshore wind power transformers according to claim 1, characterized in that, The cryogenic inert gas tank (31) is provided with a second lifting plate (39) inside. A second piston ring (301) is fixedly provided on the outer ring of the second lifting plate (39). The second lifting plate (39) is slidably connected to the cryogenic inert gas tank (31) through the second piston ring (301).

8. A pressure protection device for offshore wind power transformers according to claim 7, characterized in that, The lower wall of the second lifting plate (39) is fixedly provided with a second sealing film (302), and the outer ring of the second sealing film (302) is fixedly connected to the lower inner wall of the cryogenic inert gas tank (31). The space below the second lifting plate (39) is an ultra-high pressure space. Under ultra-high pressure, the second lifting plate (39) is pushed to the top of the cryogenic inert gas tank (31), and the second sealing film (302) always applies a pulling force to the second lifting plate (39).

9. A pressure protection device for offshore wind power transformers according to claim 8, characterized in that, The top of the cryogenic inert gas tank (31) is fixedly connected to a pressure supply pipe (36). The end of the pressure supply pipe (36) away from the cryogenic inert gas tank (31) is connected to a pressure supply pump (12). The pressure supply pump (12) is controlled by the system. The data detection module detects that the more dangerous the change in oil pressure in the transformer, the faster the pressure is pushed into the space above the second lifting plate (39).

10. A pressure protection device for offshore wind power transformers according to claim 9, characterized in that, The electrically controlled valve at the connection port of the cryogenic inert gas tank (31) is a second electrically controlled valve (34). The outlet end of the second electrically controlled valve (34) is connected to a gas supply pipe (35). The gas supply pipe (35) extends to the upper space of the transformer oil tank. The other end of the gas supply pipe (35) is provided with a diversion channel (32). The diversion channel (32) runs horizontally through the entire upper layer of the transformer oil tank. On both sides of the diversion channel (32) are arranged upper oil layer partition plates (33). The interior of the upper oil layer partition plate (33) is hollow. Air jet holes (37) are arranged on the upper oil layer partition plate (33). The inert gas in the cryogenic inert gas tank (31) is ejected from the air jet holes (37). The sensors (38) are all arranged on the upper oil layer partition plate (33) to detect the change data of cooling oil in multiple directions.

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