Pneumatic pushing device for counter weight of butterfly valve of hydropower station

Abstract

The utility model relates to the technical field of hydropower stations, in particular to a hydropower station butterfly valve heavy punch pneumatic pushing device which comprises a pushing air cylinder and a pushing electromagnetic valve. The pushing air cylinder is installed on a concrete wall at the downstream position of the butterfly valve through the pushing support, and a telescopic rod of the pushing air cylinder and the top of the butterfly valve heavy hammer are located on the same plane. The pushing air cylinder is controlled by a pushing electromagnetic valve, a control relay of the pushing electromagnetic valve and the butterfly valve PLC control system respectively use two groups of contacts of the same valve closing relay to achieve synchronism of actions, and an air source of the pushing electromagnetic valve is provided by a maintenance low-pressure air storage tank. After the butterfly valve heavy hammer is pushed to move for a certain distance, the butterfly valve heavy hammer can complete active closing action under the action of self gravity; a power station site is provided with a matched air source, the air source does not need to be provided independently, an original water inlet butterfly valve PLC controls a thrust device electromagnetic valve to achieve action and resetting of an air cylinder, the problem that the water inlet butterfly valve is jammed when being automatically closed is temporarily solved through a single device, and the automatic valve closing reliability of the butterfly valve is practically improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydropower stations, in particular to a hydropower station butterfly valve weight pneumatic driving device. Background Art

[0002] The hydropower station's inlet butterfly valve is installed at the front end of the power plant's penstock, shutting off water flow during pipe blasting and power station unit maintenance. Closing the inlet valve during extended turbine shutdowns can reduce leakage from the water guide mechanism or top cover, preventing cavitation and abrasion. The inlet butterfly valve is hydraulically opened through the startup process linkage or remote on-site opening. Remote or on-site control uses a heavy hammer to drop the main valve plate to close the inlet butterfly valve. Most importantly, in the event of a fault in the turbine generator's water guide mechanism or a turbine accident, the protective linkage closes the inlet butterfly valve, achieving an emergency shutdown and preventing the turbine accident from escalating.

[0003] When a butterfly valve exhibits a refusal to close defect, the following suspicions arise based on the equipment structure: 1. A blockage in the hydraulic components or piping during the automatic pressure relief of the hydraulic circuit during closing causes pressure buildup, preventing the weight from moving; 2. The weight is opened too vertically after the butterfly valve is fully opened, resulting in insufficient torque during closing, preventing the weight from moving and failing to close the valve. To address these two issues, the butterfly valve is inspected separately at this stage: first, the hydraulic circuit and components are cleaned and oil filtered. Secondly, the full opening angle of the butterfly valve is adjusted after calculation. Without affecting the normal operation of the butterfly valve, the full opening angle is reduced from 90 degrees to 88 degrees, increasing the closing torque. However, after implementing these two measures and operating for a period of time, the problem persists. Furthermore, a counterweight is added below the original weight. This method also increases the weight torque to achieve automatic closing of the butterfly valve. After calculating the strength of the hydraulic system and crank, a counterweight of 554 kg is added to the weight alone, for a total weight increase of 1,108 kg. After this, the butterfly valve closes normally. However, the butterfly valve may occasionally fail to close automatically during closing. If the butterfly valve cannot be closed, the on-site production personnel will use a force rod to pry the hammer or apply impact force to the butterfly valve hammer to close the butterfly valve.

[0004] According to the butterfly valve structure and fault phenomenon, the main reason for the above problems is that there are sleeve devices on the upper and lower valve shafts of the main valve disc. The main function of this device is to reduce friction when the valve shaft rotates, fix the valve shaft position, withstand sliding friction, and reduce noise. After a certain period of operation, the butterfly valve shaft and the sleeve are subjected to uneven force, resulting in serious wear of the sleeve. After the valve shaft is displaced, it cannot move within the effective prescribed range in the sleeve. There is a slight displacement of the valve shaft and valve disc as a whole. The original design of the valve disc weight torque and opening angle have changed. At the same time, the wear of the sleeve on the valve shaft has reversed the sliding friction that it originally borne, generating friction resistance, which makes the valve body unable to close automatically. Utility Model Content

[0005] The purpose of the present invention is to provide a hydropower station butterfly valve hammer pneumatic driving device to solve the defects and shortcomings of the prior art.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical solutions: it includes a pushing cylinder and a pushing solenoid valve; the pushing cylinder is installed on the concrete wall downstream of the butterfly valve using a pushing bracket, and the telescopic rod of the pushing cylinder and the top of the butterfly valve hammer are located on the same plane; the pushing cylinder is connected to a pushing solenoid valve, the pushing solenoid valve is electrically connected to the PLC control end, and the pushing solenoid valve is connected to the maintenance gas tank.

[0007] Furthermore, the pushing bracket 1 is a triangular bracket and is made of I-beam.

[0008] Furthermore, the telescopic rod stroke of the pushing cylinder 2 is 10 cm.

[0009] Furthermore, the pushing solenoid valve 3 is a two-position four-way solenoid valve.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a pneumatic driving device for the butterfly valve hammer of a hydropower station, which acts on the butterfly valve hammer at the initial stage of butterfly valve closing, pushes the butterfly valve hammer to move a certain distance, and then the butterfly valve hammer can complete the active closing action under the action of its own gravity; there is a matching air source on site at the power station, and there is no need to provide a separate air source. The original water inlet butterfly valve PLC controls the solenoid valve of the thrust device to realize the action and return of the cylinder. A single device not only temporarily solves the problem of the automatic closing of the water inlet butterfly valve being stuck, and effectively improves the reliability of the automatic closing of the butterfly valve, but also does not affect the operation of the turbine. In the event of a unit accident, it can also effectively ensure the safe operation of the turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural diagram of the present utility model.

[0012] Description of reference numerals:

[0013] Push the bracket 1, push the cylinder 2, push the solenoid valve 3, and push the butterfly valve hammer 4. DETAILED DESCRIPTION

[0014] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. The preferred embodiments in the description are only used as examples. All other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present invention.

[0015] like Figure 1As shown, this specific embodiment adopts the following technical scheme: it includes a pushing cylinder 2 and a pushing solenoid valve 3; the pushing cylinder 2 is installed on the concrete wall at the downstream position of the butterfly valve by using a pushing bracket 1 in the form of a tripod (the pushing bracket 1 is made of I-beam), and the telescopic rod of the pushing cylinder 2 and the top of the butterfly valve weight 4 are located on the same plane, and the telescopic rod stroke of the pushing cylinder is 10 cm; the pushing cylinder 2 is connected to the pushing solenoid valve 3, which is a two-position four-way solenoid valve, the pushing solenoid valve 3 is electrically connected to the PLC control end, and the pushing solenoid valve 3 is connected to the maintenance gas tank; the pushing cylinder 2 is controlled by the pushing solenoid valve 3, and the control relay of the pushing solenoid valve 3 and the butterfly valve PLC control system respectively use two sets of contacts of the same valve closing relay to achieve synchronization of action, and the gas source of the pushing solenoid valve 3 is provided by the maintenance low-pressure gas tank.

[0016] When the utility model is in use, after the butterfly valve receives the valve closing signal output by the PLC, the valve closing relay of the butterfly valve hydraulic station simultaneously actuates the valve closing solenoid valve and the push solenoid valve 3, the main valve opens the hydraulic circuit to release the pressure, and after the lock of the butterfly valve hammer 4 is pulled out, the push cylinder 2 is actuated to push the butterfly valve hammer 4 to close the butterfly valve. After the PLC obtains the main valve full-close signal, the push solenoid valve 3 is pushed to return. At this time, the push solenoid valve 3 is reversed to push the cylinder 2, so that the piston of the push cylinder 2 returns to its original position. After the recovery, it does not affect the full opening of the butterfly valve and prepares for the next valve closing.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a pneumatic driving device for the butterfly valve hammer of a hydropower station, which acts on the butterfly valve hammer at the initial stage of butterfly valve closing, pushes the butterfly valve hammer to move a certain distance, and then the butterfly valve hammer can complete the active closing action under the action of its own gravity; there is a matching air source on site at the power station, and there is no need to provide a separate air source. The original water inlet butterfly valve PLC controls the solenoid valve of the thrust device to realize the action and return of the cylinder. A single device not only temporarily solves the problem of the automatic closing of the water inlet butterfly valve being stuck, and effectively improves the reliability of the automatic closing of the butterfly valve, but also does not affect the operation of the turbine. In the event of a unit accident, it can also effectively ensure the safe operation of the turbine.

[0018] For those skilled in the art, they can modify the technical solutions described in the aforementioned embodiments and make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hydropower station butterfly valve hammer pneumatic driving device, characterized by: The invention comprises a pushing cylinder (2) and a pushing electromagnetic valve (3); the pushing cylinder (2) is installed on a concrete wall at a downstream position of a butterfly valve by means of a pushing bracket (1), and the telescopic rod of the pushing cylinder (2) and the top of the butterfly valve weight (4) are located on the same plane; the pushing cylinder (2) is connected to the pushing electromagnetic valve (3), the pushing electromagnetic valve (3) is electrically connected to a PLC control terminal, and the pushing electromagnetic valve (3) is connected to a maintenance gas storage tank.

2. A hydropower station butterfly valve weight pneumatic driving device according to claim 1, characterized in that: The pushing bracket (1) is a triangular bracket.

3. The hydropower station butterfly valve weight pneumatic driving device according to claim 2, characterized in that: The telescopic rod stroke of the pushing cylinder (2) is 10 cm.

4. A hydropower station butterfly valve weight pneumatic driving device according to claim 3, characterized in that: The pushing solenoid valve (3) is a two-position four-way solenoid valve.

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