A generator seal oil tank vacuum maintenance system

Abstract

The present application relates to power generation equipment technical field, particularly to a kind of generator sealing oil tank vacuum maintaining system, including sealing oil tank, power generation boiler, first pipe body and induced draft fan, sealing oil tank is equipped with sealing cavity, the lower part of sealing cavity is equipped with sealing oil, the first end of first pipe body is communicated with the upper portion of sealing cavity, the second end of first pipe body and the smoke outlet of power generation boiler are all communicated with the air inlet of induced draft fan, provide negative pressure to generator sealing oil tank by induced draft fan, induced draft fan is high parameter, high stability large auxiliary machine equipment, stable operating performance and high efficiency, and, when generator set operates, power generation boiler must operate, induced draft fan also operates, so induced draft fan can and generator sealing oil system synchronous work, without vacuum pump set to maintain the negative pressure state of sealing oil tank, avoid the damage of vacuum pump set caused by long-term operation.

Description

Technical Field

[0001] This invention relates to the field of power generation equipment technology, and in particular to a vacuum maintenance system for a generator sealing oil tank. Background Technology

[0002] During rotor rotation, the stator and rotor windings of a generator generate a large amount of heat due to the rapid cutting of magnetic lines of force. This heat needs to be dissipated promptly to prevent the generator temperature from exceeding limits and causing equipment damage. Typically, water or gas is used to remove this heat. However, water, due to its inherent properties, can only be used for cooling the fixed stator windings, limiting its application space. Since generators have a large overall space and the generator rotor rotates at high speed during operation, gas cooling is generally used for the rotor and core of large generators. Because hydrogen is a good conductor and has characteristics such as low density, non-oxidization, and non-combustibility, it has become the primary cooling medium used in generators.

[0003] Except for the dynamic and static joints between the rotor bearings and the housing, the rest of the generator is a sealed whole. In order to cool the generator's core, coils, and rotor windings, hydrogen must be injected into the generator and kept at an absolute purity of over 95%, and a certain pressure must be maintained. The generator rotor is a rotating device, and at both ends of the rotor, the dynamic and static joints between the rotor and the generator housing must be sealed to prevent hydrogen leakage and potential safety accidents.

[0004] Because sealing oil has a certain viscosity, it can establish a good oil film between the rotor and bearings. This oil film can prevent gas leakage and has lubrication and cooling functions, effectively protecting the generator rotor. Therefore, oil seals are used at both ends of the generator rotor, forming a generator sealing oil system. This system includes oil sealing rings at both ends of the generator rotor, an oil inlet pipe, an oil return pipe, an oil pump, a sealing oil tank, and a vacuum pump unit. The sealing oil tank is used to store and receive return oil, buffer the oil flow from the sealing oil pump, and handle sludge discharge. To ensure the smooth return of the generator sealing oil to the sealing oil tank, a certain negative pressure needs to be maintained inside the tank. Currently, this is often achieved by continuously running a vacuum pump unit; however, the vacuum pump unit is prone to damage from long-term operation, leading to insufficient negative pressure inside the sealing oil tank, which can severely damage the generator and even cause it to shut down. Summary of the Invention

[0005] The technical problem to be solved by this invention is that the vacuum pump set of the sealed oil tank is prone to damage during long-term operation, resulting in insufficient negative pressure in the sealed oil tank, which may lead to generator shutdown in severe cases.

[0006] To solve the above-mentioned technical problems, the purpose of this invention is to provide a generator sealing oil tank vacuum maintenance system, including a sealing oil tank, a power generation boiler, a first pipe body and an induced draft fan. The sealing oil tank is provided with a sealing cavity, and the lower part of the sealing cavity is provided with sealing oil. The first end of the first pipe body is connected to the upper part of the sealing cavity, and the second end of the first pipe body and the flue gas outlet of the power generation boiler are both connected to the air inlet of the induced draft fan.

[0007] As a preferred embodiment, the first pipe body is equipped with a pressure regulating valve.

[0008] As a preferred embodiment, the first pipe body is provided with a one-way valve, which is located between the pressure regulating valve and the sealing oil tank, and the opening direction of the one-way valve is towards the second end of the first pipe body.

[0009] As a preferred embodiment, the first pipe body includes a vertically extending section and a horizontally extending section that are interconnected, and the bottom wall of the horizontally extending end is connected to an oil drain pipe.

[0010] The oil drain pipe is located between the pressure regulating valve and the second end of the first pipe body.

[0011] As a preferred embodiment, the first end of the first pipe body is provided with a first shut-off valve, and the second end of the first pipe body is provided with a second shut-off valve.

[0012] As a preferred embodiment, the flue gas outlet of the power generation boiler is connected to a flue gas pipeline, and the second end of the first pipe body is connected to the middle of the flue gas pipeline.

[0013] The system includes two induced draft fans arranged in parallel. The air inlets of both induced draft fans are connected to induced draft pipes. The end of each induced draft pipe furthest from the corresponding induced draft fan is connected to the smoke exhaust pipe. Each induced draft pipe is equipped with a third shut-off valve.

[0014] As a preferred embodiment, the upper part of the sealed cavity is connected to a vacuum breaking door.

[0015] As a preferred embodiment, the generator sealing oil tank vacuum maintenance system includes a second pipe body, which is arranged in parallel with the first pipe body. The first end of the second pipe body is connected to the upper part of the sealing cavity, and the second end of the second pipe body is connected to a vacuum pump group. A fourth shut-off valve is provided on the second pipe body.

[0016] As a preferred embodiment, the vacuum pump assembly includes a first Roots pump, a second Roots pump, and a water ring vacuum pump arranged in series.

[0017] As a preferred embodiment, the exhaust end of the water ring vacuum pump is connected to an exhaust pipe and a drain pipe.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] The generator sealing oil tank vacuum maintenance system of the present invention includes a sealing oil tank, a power generation boiler, a first pipe body, and an induced draft fan. The sealing oil tank has a sealing cavity, and the lower part of the sealing cavity is filled with sealing oil. The first end of the first pipe body is connected to the upper part of the sealing cavity, and the second end of the first pipe body and the flue gas outlet of the power generation boiler are both connected to the air inlet of the induced draft fan. The induced draft fan provides negative pressure to the generator sealing oil tank. The induced draft fan is a large auxiliary machine with high parameters and high stability. It has stable operation performance and high efficiency. Moreover, when the generator set is running, the power generation boiler must run, and the induced draft fan also runs. Therefore, the induced draft fan can work synchronously with the generator sealing oil system, and the negative pressure state of the sealing oil tank can be maintained without the need for a vacuum pump set, avoiding the damage to the vacuum pump set caused by long-term operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the generator sealing oil tank vacuum maintenance system of the present invention;

[0021] In the diagram, 1. Sealed oil tank; 2. Power generation boiler; 3. First pipe body; 31. Pressure regulating valve; 32. Check valve; 33. Oil drain pipe; 34. First shut-off valve; 35. Second shut-off valve; 4. Exhaust fan; 5. Smoke exhaust pipe; 51. First smoke exhaust pipe; 52. Second smoke exhaust pipe; 53. Fifth shut-off valve; 6. Exhaust duct; 61. Third shut-off valve; 7. Vacuum breaker gate; 8. Second pipe body; 81. Fourth shut-off valve; 9. Vacuum pump set; 91. First Roots pump; 92. Second Roots pump; 93. Water ring vacuum pump; 931. Exhaust pipe; 932. Sewage pipe; 10. Chimney. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0023] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "top," "bottom," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be understood that the terms "first," "second," etc., are used in this invention to describe various information, but this information should not be limited to these terms; these terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this invention, "first" information can also be referred to as "second" information, and similarly, "second" information can also be referred to as "first" information.

[0024] like Figure 1 As shown, a preferred embodiment of the generator sealing oil tank vacuum maintenance system of the present invention includes a sealing oil tank 1, a generator boiler 2, a first pipe body 3, and an induced draft fan 4. The sealing oil tank 1 has a sealing cavity, and sealing oil is provided in the lower part of the sealing cavity. The first end of the first pipe body 3 is connected to the upper part of the sealing cavity, and the second end of the first pipe body 3 and the flue gas outlet of the generator boiler 2 are both connected to the air inlet of the induced draft fan 4. The induced draft fan 4 provides negative pressure to the generator sealing oil tank 1. The induced draft fan 4 is a large auxiliary machine with high parameters and high stability, exhibiting stable operation and high efficiency. Moreover, when the generator set is running, the generator boiler 2 will inevitably run, and the induced draft fan 4 will also run. Therefore, the induced draft fan 4 can work synchronously with the generator sealing oil system, maintaining the negative pressure state of the sealing oil tank 1 without the need for a vacuum pump set, thus avoiding damage to the vacuum pump set caused by long-term operation. Furthermore, this application reduces energy consumption compared to the need for an additional vacuum pump set operating for extended periods.

[0025] The first pipe body 3 is equipped with a pressure regulating valve 31. Specifically, a negative pressure higher than -1 kPa in the sealing cavity ensures that the generator sealing oil flows smoothly back to the sealing oil tank. The negative pressure at the air inlet of the induced draft fan 4 can reach -6 kPa. The pressure regulating valve 31 is used to adjust the negative pressure at the first end of the first pipe body 1 to -1 kPa, which not only maintains the stability of the negative pressure in the sealing cavity but also reduces the impact of connecting the sealing cavity to the air inlet of the induced draft fan 4 on the boiler induced draft pressure. Specifically, the pressure regulating valve 31 is a needle valve.

[0026] Furthermore, a one-way valve 32 is provided on the first pipe body 3. The one-way valve 32 is located between the pressure regulating valve 31 and the sealing oil tank 1, and the opening direction of the one-way valve 32 is towards the second end of the first pipe body 3. The one-way valve 32 can prevent the flue gas discharged from the flue gas outlet of the power generation boiler 2 from entering the sealing cavity, thus ensuring the purity of the sealing oil in the sealing cavity.

[0027] Furthermore, the first pipe body 3 includes a vertically extending section and a horizontally extending section that are interconnected. The bottom wall of the horizontally extending end is connected to an oil drain pipe 33. The mixed gas extracted from the sealing cavity includes air and oil mist mixed in the air. The oil sludge is formed by sealing oil. After the mixed gas passes through the pressure regulating valve 31, the negative pressure increases. After the negative pressure increases, the oil mist will precipitate from the mixed gas. The precipitated oil sludge sinks to the bottom wall of the horizontally extending end. The oil drain pipe is set between the pressure regulating valve 31 and the second end of the first pipe body 3, thereby discharging the oil sludge that falls on the bottom wall of the horizontally extending section from the first pipe body 3.

[0028] The first pipe body 3 has a first shut-off valve 34 at its first end and a second shut-off valve 35 at its second end. The first shut-off valve 34 and the second shut-off valve 35 are provided to facilitate the isolation of flue gas from the power generation boiler when the sealed oil tank or the first pipe body is being maintained.

[0029] In this embodiment, the flue gas outlet of the power generation boiler 2 is connected to a flue gas pipeline 5, and the second end of the first pipe body 3 is connected to the middle of the flue gas pipeline 5. Two induced draft fans 4 are provided, arranged in parallel. The air inlets of both induced draft fans 4 are connected to induced draft pipes 6, and the end of each induced draft pipe 6 furthest from the corresponding induced draft fan 6 is connected to the flue gas pipeline 5. Each induced draft pipe 6 is equipped with a third shut-off valve 61. The two induced draft fans 4, operating in parallel, provide redundant safety conditions, ensuring that even if a single induced draft fan trips, the system will not shut down. This guarantees the negative pressure condition at the inlet of the induced draft fans 4, ensuring the safe and stable operation of the induced draft system and the generator sealing oil system. Specifically, the flue gas pipeline includes a first flue gas pipe 51 and a second flue gas pipe 52 arranged in parallel. The ends of the first flue gas pipe 51 and the second flue gas pipe 52 are connected or isolated by a fifth shut-off valve 53. The second end of the first pipe body 3 is connected to the middle of the first flue gas pipe 51 or the middle of the second flue gas pipe 52.

[0030] To facilitate maintenance of the sealed oil tank, a vacuum rupture door 7 is connected to the upper part of the sealed cavity.

[0031] In this embodiment, the generator sealing oil tank vacuum maintenance system includes a second pipe body 8, which is connected in parallel with the first pipe body 3. The first end of the second pipe body 8 is connected to the upper part of the sealing cavity, and the second end of the second pipe body 8 is connected to a vacuum pump group 9. A fourth shut-off valve 81 is provided on the second pipe body 8. Specifically, there are two fourth shut-off valves 81, which are arranged in series. During normal operation, the fourth shut-off valves 81 are closed, while the first and second shut-off valves are open. The vacuum pump group 9 serves as a backup, increasing the safety redundancy of the generator sealing oil system and improving its safety and stability.

[0032] Specifically, the vacuum pump assembly 9 includes a first Roots pump 91, a second Roots pump 92, and a water ring vacuum pump 93 arranged in series. The series arrangement of the first Roots pump 91 and the second Roots pump 92 can ensure the stability of the vacuum within the sealed cavity.

[0033] In this embodiment, the exhaust end of the water ring vacuum pump 93 is connected to an exhaust pipe 931 and a drain pipe 932.

[0034] In summary, the present invention provides a generator sealing oil tank vacuum maintenance system, comprising a sealing oil tank 1, a generator boiler 2, a first pipe body 3, and an induced draft fan 4. The sealing oil tank 1 has a sealing cavity, the lower part of which is filled with sealing oil. The first end of the first pipe body 3 is connected to the upper part of the sealing cavity, and the second end of the first pipe body 3 and the exhaust port of the generator boiler 2 are both connected to the air inlet of the induced draft fan 4. The induced draft fan 4 provides negative pressure to the generator sealing oil tank 1. The induced draft fan 4 is a large-scale auxiliary machine with high parameters and high stability, exhibiting stable operation and high efficiency. Furthermore, when the generator set is running, the generator boiler 2 will inevitably run, and the induced draft fan 4 will also run. Therefore, the induced draft fan 4 can work synchronously with the generator sealing oil system, maintaining the negative pressure state of the sealing oil tank 1 without the need for a vacuum pump set, thus avoiding damage to the vacuum pump set caused by long-term operation.

[0035] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A vacuum maintenance system for a generator sealing oil tank, characterized in that, It includes a sealed oil tank (1), a power generation boiler (2), a first pipe body (3) and an induced draft fan (4). The sealed oil tank (1) is provided with a sealing cavity, and the lower part of the sealing cavity is provided with sealing oil. The first end of the first pipe body (3) is connected to the upper part of the sealing cavity, and the second end of the first pipe body (3) and the flue gas outlet of the power generation boiler (2) are both connected to the air inlet of the induced draft fan (4). The first pipe body (3) is provided with a pressure regulating valve (31). The first pipe body (3) includes a vertical extension section and a horizontal extension section that are interconnected. The bottom wall of the horizontal extension section is connected to an oil drain pipe (33). The oil drain pipe (33) is disposed between the pressure regulating valve (31) and the second end of the first pipe body (3); The generator sealing oil tank vacuum maintenance system includes a second pipe body (8), which is arranged in parallel with the first pipe body (3). The first end of the second pipe body (8) is connected to the upper part of the sealing cavity, and the second end of the second pipe body (8) is connected to a vacuum pump group (9). A fourth shut-off valve (81) is provided on the second pipe body (8). The vacuum pump assembly (9) includes a first Roots pump (91), a second Roots pump (92), and a water ring vacuum pump (93) arranged in series. The exhaust end of the water ring vacuum pump (93) is connected to an exhaust pipe (931) and a sewage pipe (932).

2. The generator sealing oil tank vacuum maintenance system according to claim 1, characterized in that, The first pipe body (3) is provided with a one-way valve (32), which is located between the pressure regulating valve (31) and the sealing oil tank (1). The opening direction of the one-way valve (32) is towards the second end of the first pipe body (3).

3. The generator sealing oil tank vacuum maintenance system according to claim 1, characterized in that, The first end of the first pipe body (3) is provided with a first shut-off valve (34), and the second end of the first pipe body (3) is provided with a second shut-off valve (35).

4. The generator sealing oil tank vacuum maintenance system according to claim 1, characterized in that, The flue gas outlet of the power generation boiler (2) is connected to a flue gas pipeline (5), and the second end of the first pipe body (3) is connected to the middle of the flue gas pipeline (5). There are two exhaust fans (4), which are arranged in parallel. The air inlets of the two exhaust fans (4) are connected to exhaust pipes (6). The end of each exhaust pipe (6) away from the corresponding exhaust fan (4) is connected to the smoke exhaust pipe (5). Each exhaust pipe (6) is equipped with a third shut-off valve (61).

5. The generator sealing oil tank vacuum maintenance system according to claim 1, characterized in that, The upper part of the sealed cavity is connected to a vacuum breaking door (7).

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