Generator sealing pad detection system

Abstract

The utility model provides a generator sealing pad detection system, comprising an excitation end integrated controller, a steam end integrated controller and hydrogen detection probes, the interface end of the excitation end integrated controller and the interface end of the steam end integrated controller are respectively provided with a plurality of hydrogen detection probes, the plurality of hydrogen detection probes are circumferentially arranged in gaps between end covers at two ends of the generator and the main shaft of the engine respectively. Hydrogen leakage at the gap in the circumferential direction of the sealing pad can be detected, each hydrogen detection probe is connected with the controller, the controller can display the hydrogen leakage condition, feed back the hydrogen leakage position and give an alarm, and the hydrogen leakage phenomenon can be found in time. Therefore, the problems of the sealing tile are judged according to the on-site detection condition, the overhaul period is scientifically set, the sealing tile needs to be repaired completely, unnecessary overhaul is not carried out, and equipment damage is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbine detection, in particular to a generator sealing shoe detection system. Background Art

[0002] The oil required for the generator sealing pads is the lubricating oil for the turbine bearings. People usually call it sealing oil according to its purpose. The sealing oil system is dedicated to supplying oil to the generator sealing pads, and the oil pressure is higher than the hydrogen pressure in the generator by a certain amount to prevent the hydrogen in the generator from leaking out along the gap between the shaft and the sealing pads. At the same time, it is also necessary to prevent the oil pressure from being too high, which may cause a large amount of oil to enter the generator. Therefore, the sealing oil system is equipped with an oil-hydrogen differential pressure valve at the outlet of the sealing oil pump to automatically adjust the oil-hydrogen differential pressure to meet the requirement of 0.055±0.02MPa. Figure 1 This is a schematic diagram of the shaft end sealing shoe structure of an existing power plant generator.

[0003] When the generator sealing tile fails, hydrogen may leak out from the generator end cover through the sealing tile. In this case, there is a great risk of hydrogen explosion. The power plant generally arranges personnel to conduct a comprehensive hydrogen test every 2 hours. When personnel approach the generator to measure hydrogen leakage, they put themselves in great danger, and even a short-term accumulation of hydrogen leakage will cause an explosion. On the other hand, there may also be a problem of increased return oil volume of the sealing oil. Since there is no special detection system, the sealing tile failure is generally disassembled during the unit overhaul to check the sealing tile failure, especially when there is a minor failure in the sealing tile, it cannot be judged by parameters such as oil pressure. Since the maintenance of the generator sealing tile requires the unit to be shut down and turned, it can only be started at least 15 days after the shutdown. When it is uncertain whether the sealing tile has a fault and whether it is necessary to perform maintenance, it is difficult to schedule the maintenance period in advance. If the sealing tile is not repaired when it is faulty, there will be a great safety hazard. Maintenance when the sealing tile is not faulty will cause a waste of personnel and time, and also affect the capacity compensation cost of the unit, resulting in economic losses. Summary of the invention

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A generator sealing shoe detection system is provided, comprising an excitation end centralized controller, a steam end centralized controller and a hydrogen detection probe, wherein a plurality of hydrogen detection probes are respectively arranged at the interface end of the excitation end centralized controller and the interface end of the steam end centralized controller, wherein the plurality of hydrogen detection probes are respectively arranged circumferentially at the gaps between the end covers at both ends of the generator and the main shaft of the engine.

[0006] Preferably, it also includes an air-side oil return end and a hydrogen-side oil return end, wherein the air-side oil return end is connected to the air precipitation tank through a pipeline, and an oil return meter is arranged on the pipeline; the hydrogen-side oil return end is connected to the sealing oil expansion tank through a pipeline, and an oil return meter is also arranged on the pipeline.

[0007] Preferably, hydrogen exhaust fans are provided at both ends of the generator, wherein the hydrogen exhaust fan on one side is started by the excitation end centralized controller, and the hydrogen exhaust fan on the other side is started by the steam end centralized controller.

[0008] Preferably, the air intake of the hydrogen exhaust fan can be led to both ends of the generator through a soft pipe.

[0009] The beneficial effect of the utility model is that the utility model is provided with a plurality of hydrogen detection probes at both ends of the generator, and the hydrogen detection probes are arranged in a circumferential row around the outer end cover of the sealing tile, which can detect hydrogen leakage in the circumferential gap of the sealing tile, and each hydrogen detection probe is connected to the controller, which can display the hydrogen leakage situation, feedback the hydrogen leakage position, and alarm, so that the hydrogen leakage phenomenon can be discovered in time. Then, the problems existing in the sealing tile can be judged through the on-site detection situation, and the maintenance period can be scientifically scheduled. All necessary maintenance should be carried out, and unnecessary maintenance should not be carried out to avoid equipment damage. The hydrogen leakage of the generator can be discovered in time, and the accumulation of hydrogen can be avoided, thereby avoiding the occurrence of casualties caused by hydrogen explosion of the generator and personnel measurement. The safety of the unit is enhanced, the reliability of the equipment is improved, and the economic benefits for the enterprise are increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 It is a schematic diagram of the existing generator sealing shoe structure;

[0012] Figure 2 It is a generator sealing shoe detection system in the embodiment of the utility model;

[0013] In the figure: 1-excitation end centralized controller, 2-steam end centralized controller, 3-hydrogen detection probe, 4-hydrogen exhaust fan, 5-sealing oil expansion tank, 6-air precipitation tank, 7-return oil meter, 8-generator, a-air side oil inlet end, a1-air side oil return end, b-hydrogen side oil inlet end, b1-hydrogen side oil return end, c-sealing bush floating oil air side supply end, d-double-flow double-ring sealing bearing bush, e-labyrinth sealing ring, f-sealing bush shaft seat, g-engine main bearing, h-engine main shaft, k-end cover. DETAILED DESCRIPTION

[0014] The above scheme is further described below in conjunction with specific examples. It should be understood that these examples are used to illustrate the utility model rather than to limit the scope of the utility model. The implementation conditions used in the examples can be further adjusted according to the conditions of the specific manufacturer, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0015] In a specific embodiment, a generator sealing shoe detection system is provided, comprising an excitation end centralized controller 1, a steam end centralized controller 2 and a hydrogen detection probe 3, wherein a plurality of hydrogen detection probes 3 are respectively arranged at the interface end of the excitation end centralized controller 1 and the interface end of the steam end centralized controller 2, wherein the plurality of hydrogen detection probes 3 are respectively arranged circumferentially at the gap between the end cover k at both ends of the generator 8 and the engine main shaft h.

[0016] Specifically, since the existing generator sealing shoes are sealed with sealing oil, the engine main shaft and the sealing shoes are in a sliding connection, and hydrogen is used to cool the inside of the generator. In order to avoid leakage of hydrogen in the generator, the sealing oil is also used to pressurize the sealing shoe structure to improve the sealing performance, and this pressurized sealing performance needs to be maintained. Therefore, the sealing shoe structure is provided with an oil inlet and an oil outlet to maintain the oil pressure balance. The oil enters from the air side oil inlet end a and the hydrogen side oil inlet end b respectively, passes through the gap h between the sealing shoe and the engine main shaft, and is finally recovered from the air side oil discharge end a1 and the hydrogen side oil discharge end b1. The air side oil return end a1 is connected to the air precipitation box 6 through a pipeline, and the hydrogen side oil return end b1 is connected to the sealing oil expansion tank 5 through a pipeline to recover the hydraulic oil.

[0017] Since hydrogen is colorless, odorless, flammable and explosive, when there is a problem with the sealing tile and the sealing oil system, hydrogen will leak from the gap. Once accumulated, it is easy to cause danger. Therefore, in this example, several hydrogen detection probes 3 are respectively set at the interface end of the excitation end centralized controller 1 and the interface end of the steam end centralized controller 2. The hydrogen detection probe 3 in this example is consistent with the existing hydrogen leak detector probe, and the controller is a conventional control converter that converts the hydrogen leakage signal into a digital signal. During installation, several hydrogen detection probes 3 are arranged circumferentially in the gap between the end cover k at both ends of the generator 8 and the engine main shaft h. The hydrogen detection probe 3 is arranged circumferentially around the outer end cover of the sealing tile, and can detect hydrogen leakage in the circumferential direction of the sealing tile. When hydrogen leaks in the generator, the hydrogen detection probe 3 will detect it and transmit the signal to the corresponding controller. At this time, the controller can display the hydrogen leakage situation, feedback the hydrogen leakage position, and alarm, so that the hydrogen leakage phenomenon can be discovered in time. Then, the problems of the sealing tiles can be judged through on-site inspection, and the maintenance period can be scientifically scheduled. All necessary maintenance should be carried out, and unnecessary maintenance should not be carried out to avoid equipment damage. Hydrogen leakage of the generator can be discovered in time to avoid the accumulation of hydrogen, thereby avoiding the occurrence of hydrogen explosion of the generator and casualties caused by personnel measurement. The safety of the unit is enhanced, the reliability of the equipment is improved, and the economic benefits for the enterprise are increased.

[0018] In addition, since the hydrogen leakage phenomenon will also be reflected by the return oil flow to a certain extent, in order to further improve the detection reliability and backup requirements, the air side return oil end a1 is connected to the air precipitation box 6 through a pipeline, and an oil return meter 7 is set on the pipeline. In this example, the oil return meter 7 preferably adopts an ultrasonic flow meter; the hydrogen side return oil end b1 is connected to the sealing oil expansion tank 5 through a pipeline, and an oil return meter 7 is also set on the pipeline. Therefore, the flow change can be used to judge whether the sealing tile gap is normal and whether there are abnormal conditions such as jamming.

[0019] In addition, in order to better realize the timely and rapid discharge of hydrogen in the machine room and avoid accidents, hydrogen exhaust fans 4 are respectively provided at both ends of the generator 8, wherein the hydrogen exhaust fan 4 on one side is controlled and started by the centralized controller 1 at the excitation end, and the hydrogen exhaust fan 4 on the other side is controlled and started by the centralized controller 2 at the steam end. Once the hydrogen concentration in the machine room exceeds the set threshold, the controller controls the hydrogen exhaust fan 4 to start and discharge the leaked hydrogen in the machine room to the outside. On this basis, a soft pipe is added to the air intake of the hydrogen exhaust fan 4, which can be led to the hydrogen leakage-prone places at both ends of the generator 8 through the soft pipe, and the hydrogen leakage detection value of the controller 2 is set to a minimum. Once the hydrogen is leaked, the hydrogen exhaust fan 4 immediately absorbs and discharges the hydrogen, thereby avoiding the diffusion of hydrogen and improving the installation performance.

[0020] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the technical concept of the invention through the above description. The technical scope of the invention is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A generator sealing shoe detection system, characterized in that: The invention comprises an excitation end centralized controller (1), a steam end centralized controller (2) and a hydrogen detection probe (3), wherein a plurality of hydrogen detection probes (3) are respectively arranged at an interface end of the excitation end centralized controller (1) and an interface end of the steam end centralized controller (2), wherein the plurality of hydrogen detection probes (3) are respectively arranged in a circular arrangement at the gaps between the end covers (k) at both ends of the generator (8) and the engine main shaft (h).

2. A generator sealing shoe detection system as claimed in claim 1, characterized in that: It also includes an air-side oil return end (a1) and a hydrogen-side oil return end (b1), wherein the air-side oil return end (a1) is connected to an air precipitation tank (6) via a pipeline, and an oil return meter (7) is provided on the pipeline; and the hydrogen-side oil return end (b1) is connected to a sealing oil expansion tank (5) via a pipeline, and an oil return meter (7) is also provided on the pipeline.

3. A generator sealing shoe detection system as claimed in claim 1, characterized in that: Hydrogen exhaust fans (4) are respectively arranged at both ends of the generator (8), wherein the hydrogen exhaust fan (4) on one side is controlled to start by the excitation end centralized controller (1), and the hydrogen exhaust fan (4) on the other side is controlled to start by the steam end centralized controller (2).

4. A generator sealing shoe detection system as claimed in claim 3, characterized in that: The air intake of the hydrogen exhaust fan (4) can be led to the two ends of the generator (8) through a soft pipe.

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