Jacking oil system of subcritical intermediate reheating condensation type steam turbine

Abstract

The utility model relates to the technical field of steam turbine maintenance, and discloses a subcritical intermediate reheating condensation type steam turbine jacking oil system which comprises a unit main oil tank and a jacking oil system which are connected with each other, and further comprises an oil filter and a bypass valve, the oil filter comprises an oil inlet end and an oil outlet end, the oil inlet end of the oil filter is connected with the unit main oil tank, and the oil outlet end of the oil filter is connected with the jacking oil system. The oil outlet end of the oil filter is connected with the jacking oil system; the bypass valve comprises an inlet end and an outlet end, the inlet end of the bypass valve is connected with the oil outlet end of the oil filter, and the outlet end and the inlet end of the bypass valve are connected with the unit main oil tank. When a lubricating oil system is in a shutdown maintenance state, the jacking oil system has a starting condition, and the maintenance safety is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbine maintenance, in particular to a subcritical intermediate reheat condensing steam turbine top shaft oil system. Background Art

[0002] Subcritical intermediate reheat condensing steam turbine refers to an intermediate reheat condensing steam turbine with subcritical steam. Subcritical refers to steam parameters, specifically a pressure boiler with a rated gauge pressure of 14-22.2MPa at the outlet of the superheater. Intermediate reheat refers to the main steam coming out of the boiler superheater, which is sent to the reheater for reheating to increase the temperature after working in the high and medium pressure cylinders of the steam turbine, and then sent to the low pressure cylinder of the steam turbine to continue to expand and work. Among them, the turbine top shaft oil system is an important part of the subcritical intermediate reheat condensing steam turbine. Its main function is that under the operating condition, the lubricating oil system extracts the turbine lubricating oil through the oil pump, and uses the turbine lubricating oil as the oil source to provide a certain value of top shaft oil pressure from the top shaft oil pump to the turbine and generator bearings, so as to lift the turbine rotor to a certain height, so that the lubricating oil can be smoothly passed into the matching area between the turbine rotor shaft neck and the bearing, avoiding friction overheating in the matching part, even the burning of the bearing or serious wear of the shaft neck.

[0003] During the overhaul of the steam turbine generator set, the lubricating oil system cannot be put into operation before the bearing work is completed or the lubricating oil system work is completed, that is, the top shaft oil system has no oil source and cannot start working. As a result, in the actual overhaul work, it is necessary to add a large amount of thrust to the rotor of the steam turbine generator set (rotor weight is up to 125T) to achieve the purpose of moving the rotor. In the process of pushing and transferring, it is easy to cause damage to the bearing or rotor, and it is also difficult to achieve the requirements for adjusting the thrust clearance of the steam turbine and the axial displacement positioning accuracy, which brings certain operational difficulties to the overhaul of the steam turbine. Utility Model Content

[0004] The utility model aims to provide a subcritical intermediate reheat condensing steam turbine top shaft oil system, so that when the lubricating oil system is shut down for maintenance, the top shaft oil system has a starting condition, thereby improving the safety of maintenance.

[0005] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a subcritical intermediate reheat condensing steam turbine top shaft oil system, including a main oil tank and a top shaft oil system of the unit connected to each other, and also including an oil filter and a bypass valve, the oil filter including an oil inlet end and an oil outlet end, and the oil inlet end of the oil filter is connected to the main oil tank of the unit, and the oil outlet end of the oil filter is connected to the top shaft oil system; the bypass valve includes an inlet end and an outlet end, and the inlet end of the bypass valve is connected to the oil outlet end of the oil filter, and the outlet end of the bypass valve is connected to the main oil tank of the unit.

[0006] The beneficial effects of this scheme are: 1. The added oil filter pipeline realizes the connection between the main oil tank of the unit and the top shaft oil system in the subcritical intermediate reheat condensing steam turbine, and utilizes the oil in the original main oil tank of the unit of the steam turbine as the oil source required by the top shaft oil system, thereby solving the problem that the top shaft oil system has no oil source and cannot be started during the maintenance of the existing steam turbine, resulting in damage to equipment during the maintenance process and low operational safety.

[0007] 2. By adjusting the opening of the bypass valve, the oil supply level of the additional oil filter pipeline can be controlled to further ensure the normal operation of the equipment.

[0008] 3. Directly use the lubricating oil filter in the original steam turbine unit to provide the oil source. The oil pressure and oil quality can meet the use requirements. It is convenient to directly install the pipe on site without additional oil quality testing and processing, and the transformation cost is low.

[0009] 4. The transformation of the turbine jacking oil system can be completed with relatively low cost and simple results, meeting the on-site maintenance needs of various steam turbines, solving the problem of being unable to put the jacking oil system into operation during the maintenance of steam turbine power generation units or turbine bearings, and improving the safety and efficiency of equipment maintenance.

[0010] Preferably, a first filtering device is provided between the main oil tank of the unit and the top shaft oil system, the first filtering device comprises a filter screen, and the oil outlet end of the oil filter is connected to the filter screen of the first filtering device.

[0011] Preferably, the jacking oil system comprises a jacking oil pump, and the outlet of the jacking oil pump is connected to the second filtering device.

[0012] Preferably, the main oil tank of the unit further includes a plurality of oil injectors and a plurality of oil coolers, the plurality of oil injectors and the plurality of oil coolers are connected to each other, and the plurality of oil coolers are all connected to the first filtering device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the system in the embodiment of the utility model. DETAILED DESCRIPTION

[0014] The following is further described in detail through specific implementation methods:

[0015] The reference numerals in the drawings of the specification include: main oil tank 1 of the unit, DC emergency oil pump 11, AC lubricating oil pump 12, oil injector 13, oil cooler 14, first filter device 2, top shaft oil pump 3, second filter device 4, oil filter 5, bypass valve 6.

[0016] Example

[0017] The embodiment is basically as shown in the attached Figure 1As shown, a subcritical intermediate reheat condensing steam turbine top shaft oil system includes a unit main oil tank 1, a top shaft oil system and an oil filter 5. The oil filter 5 includes an oil inlet end and an oil outlet end, and the top shaft oil system includes a top shaft oil pump 3. The oil inlet end of the oil filter 5 is connected to the unit main oil tank 1 by setting a pipeline, and the oil outlet end of the oil filter 5 is connected to the top shaft oil pump 3 by setting a pipeline.

[0018] At the same time, it also includes a bypass valve 6. The end of the pipeline connected to the oil outlet of the oil filter 5 near the top shaft oil pump 3 is connected to the inlet end of the bypass valve 6 through a three-way valve, and the outlet end of the bypass valve 6 is connected to the main oil tank 1 of the unit. When the oil in the main oil tank 1 of the unit enters the top shaft oil system for use by the top shaft oil pump 3 after being filtered and impurities removed by the oil filter 5, the excess oil output from the oil outlet of the oil filter 5 will return to the main oil tank through the bypass valve 6, so that during use, according to the outlet pressure and flow changes of the top shaft oil pump 3, the opening of the bypass valve 6 can be adjusted to achieve the control of the oil supply level of the pipeline of the additional oil filter 5. Since the pipeline of the oil filter 5 added to this system is a temporary connection system, after the pipeline connection and installation, it is necessary to adjust the inlet flow and pressure of the top shaft oil pump 3 to match the parameters of the top shaft oil pump 3, that is, by adjusting the opening of the bypass valve 6 to control the oil flow and pressure entering the top shaft oil pump 3, and start the maintenance operation after the oil flow in the pipeline of the oil filter 5 is adjusted and stabilized, thereby ensuring the normal operation of the equipment.

[0019] The main oil tank 1 of the unit mainly includes a DC emergency oil pump 11, an AC lubricating oil pump 12 and a plurality of oil injectors 13. In this embodiment, two oil injectors 13 are provided. When the steam turbine is operating normally, the main oil pump provided by the steam turbine rotor provides oil to the top shaft oil pump 3. When the unit is under maintenance or the steam turbine rotor is not operating normally in other situations, the AC lubricating oil pump 12 provides oil to the top shaft oil pump 3; when an accident occurs, the factory power is lost, or the main oil pump and the AC lubricating oil pump 12 fail and cannot be put into use normally, the DC lubricating oil pump provides oil to the top shaft oil pump 3. When connecting the oil filter 5, it is directly connected through the main oil tank pipeline of the unit, and the oil in the bypass valve 6 can also be selected to connect the main oil tank pipeline of the unit. The specific connection scheme can be selected according to the on-site construction environment.

[0020] The oil injector 13 ensures that the oil output from the main oil tank 1 of the steam turbine unit is always at an appropriate level to ensure the smooth operation of the steam turbine generator set and prevent unnecessary failures. The right end of the oil injector 13 is connected to a plurality of oil coolers 14 through a pipeline, and two oil coolers 14 are also provided in this embodiment; since the oil supply between the main oil tank 1 of the unit and the top shaft oil system is a circulating supply, and the oil will take away the heat generated by friction when it enters the bearings of the steam turbine and the generator for lubrication, and the oil temperature will rise, the oil cooler 14 is mainly used to reduce the temperature of the circulating oil to ensure the viscosity and lubrication effect of the oil.

[0021] A first filter device 2 is also connected between the oil cooler 14 and the top shaft oil pump 3 through a pipeline, and the first filter device 2 filters and removes impurities from the oil that is about to enter the top shaft oil pump 3. A filter screen is provided at the inlet of the first filter device 2, and the oil outlet end of the oil filter 5 is connected to the front end of the filter screen through a pipeline, thereby further ensuring the quality of the oil provided to the top shaft oil pump 3 by the additional oil filter 5 of this system, and ensuring the safe operation of the system. At the same time, the right end of the top shaft oil pump 3 is also connected to a second filter device 4, and the second filter device 4 once again removes impurities and purifies the oil output from the top shaft oil pump 3 to ensure the safety of oil circulation and equipment operation.

[0022] As an important power generation equipment, the subcritical intermediate reheat condensing steam turbine has a complex structure and heavy weight, so it has certain maintenance difficulties. Based on the actual problems existing in the maintenance of existing steam turbines, this scheme innovatively proposes to add an oil filter 5 pipeline to directly use the lubricating oil in the main oil tank 1 of the original steam turbine unit as the oil source for the top shaft oil pump 3, thereby solving the current maintenance problems that the top shaft oil pump 3 cannot work due to the lack of oil source, resulting in laborious maintenance and equipment structure damage. In addition, the lubricating oil filter 5 in the original steam turbine unit is directly used to provide the oil source, and the oil pressure and oil quality can meet the use requirements, which is convenient for direct installation and connection on site, without additional oil quality detection and processing, etc., and the transformation cost is low. When connecting the oil filter 5, a bypass is matched, and the flow and pressure of the main oil circuit entering the top shaft oil system can be controlled by adjusting the bypass valve 6 to ensure the safety of system operation, so that the pipeline connection and improvement content of the entire system are extremely small, and the steam turbine generator set can be improved under various environmental conditions, with high versatility. Finally, the oil outlet of the oil filter 5 is connected to the filter screen at the front end of the first filter device 2 at the inlet of the original top shaft oil system to further ensure the quality of the input oil and ensure the safety of the equipment operation.

[0023] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the technical solution of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A subcritical intermediate reheat condensing steam turbine top shaft oil system, comprising a main oil tank and a top shaft oil system of the unit connected to each other, characterized in that: It also includes an oil filter and a bypass valve. The oil filter includes an oil inlet end and an oil outlet end, and the oil inlet end of the oil filter is connected to the main oil tank of the unit, and the oil outlet end of the oil filter is connected to the top shaft oil system; the bypass valve includes an inlet end and an outlet end, and the inlet end of the bypass valve is connected to the oil outlet end of the oil filter, and the inlet and outlet ends of the bypass valve are connected to the main oil tank of the unit.

2. A subcritical intermediate reheat condensing steam turbine top shaft oil system according to claim 1, characterized in that: A first filter device is provided between the main oil tank of the unit and the top shaft oil system. The first filter device comprises a filter screen, and the oil outlet end of the oil filter is connected to the filter screen of the first filter device.

3. A subcritical intermediate reheat condensing steam turbine top shaft oil system according to claim 2, characterized in that: The jacking oil system comprises a jacking oil pump, and the outlet of the jacking oil pump is connected to a second filtering device.

4. A subcritical intermediate reheat condensing steam turbine top shaft oil system according to claim 3, characterized in that: The main oil tank of the unit also includes a plurality of oil injectors and a plurality of oil coolers. The plurality of oil injectors and the plurality of oil coolers are connected to each other, and the plurality of oil coolers are all connected to the first filtering device.

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