Turbine main Valve-3

Release time:

2024-08-02

Type of main valve

This is a device that provides reliable backup protection for small and medium-sized water turbine generator units, and it is also an accessory equipment that provides safety guarantee for small and medium-sized hydropower stations to achieve the goal of "unattended". Compared with the conventional electric manual butterfly valve, it has the following characteristics:

1) the heavy hammer valve is equipped with a hydraulic linkage bypass valve. When the oil pump motor is started, the bypass valve will open for water filling (the allowable water time can be adjusted according to the actual situation). After the two sides are flat pressed, the circuit switches automatically, the oil cylinder starts to work, the hammer is lifted to store energy, and the valve is opened. After reaching the fully open position, the hook is locked, the oil pump stops automatically, and the bypass valve closes automatically. The conventional electric manual butterfly valve can start the bypass valve manually.

2) the fully open position of the heavy hammer valve is mechanically located by the heavy hammer hook to avoid the deviation of the fully open position of the electric manual butterfly valve due to the inaccurate travel switch.

3) the fully closed position is guaranteed by the mechanical limit of the heavy hammer, which avoids the over closing of the conventional butterfly valve caused by the refusal of the travel switch, and avoids the damage of the rubber seal ring or the fracture of the fan-shaped turbine.

4) the double eccentric flat valve structure of the heavy hammer valve has small water loss and reasonable opening and closing moment configuration. The seal is composed of a whole ring of dovetail shaped rubber ring fixed by clamp pressure and a copper ring fixed on the valve body, which has reliable performance and better sealing effect than the rubber ring with two round end faces of electric and manual butterfly valves.

5) when the system loses power, the operation of emergency shutdown is simple. It only needs to operate the supporting rod gently, release the gravity energy in time with the heavy hammer, close the valve and cut off the water quickly, avoiding the manual and electric butterfly valves closing by hand for nearly 10 minutes.

(6) the heavy hammer valve has the adjustable fast and slow closing characteristics, which effectively controls the excessive pressure rise of water hammer, which is incomparable with conventional electric and manual butterfly valves. There are three ways of butterfly valve operation: manual, electric and hydraulic. The valve diameter of small and medium-sized water turbine generator set in rural area is small, which is usually operated manually. Many small and medium-sized water turbine generator sets have large diameter butterfly valves, which are difficult to operate manually. Many large units have large flow and large valve diameter, and generally adopt hydraulic operation mode.

(2) the structure of butterfly valve, which is mainly composed of cylindrical valve body, butterfly plate, bearing, sealing device, locking device and accessory parts.

1) valve body. The valve body is the main part of the butterfly valve, which is cylindrical in shape. Water flows through it. Therefore, it should bear the pressure of water, support all parts of the butterfly valve, and bear the operating torque. Therefore, it should have sufficient strength and rigidity, generally made of steel plate welding or cast steel. The valve body with a nominal diameter of less than 1200mm is usually integrally cast and made of WCB; the valve body with a nominal diameter of more than 1200mm is usually made of steel plate rolled into a round barrel and then welded. The steel plate material is Q345 and the shaft sleeve is zg20simn.