1450kw Francis Turbina Generator For Hydro Power Station Water Head 70m

rief introduction of turbine structure and main component

1.Water inlet part

Water inlet part consists of valve. The valve is used to close the unit in static water when need stop, it is also used to close the unit and cut the water flow in dynamic water when the unit is in emergency and turbine distributor break down.

2.Spiral case

Spiral case is welding part, equipped with fixed guide vane in it. Spiral case shall make the water become number of swirl of water flow and guide water to flow regularly into guide vane apparatus and runner along circumference. It is equipped with an air relieve valve on the top of spiral case to exhaust air when filling water initially.

3.Turbine distributor

It consists of guide vane, guide vane lever, shaft sleeve, front cover, back cover, etc. It can form or change number of swirls of water flow to adjust turbine discharge according to variation of load. It is also used to normal and emergency shut down. The guide vane shaft sleeve has O ring for sealing. The control ring is welded by steel plate as a whole. Circular guiding rail and wiring plate with lubricating performance are located on the bottom surface of the control ring. The control ring has enough strength and rigidity, won’t occur excessive bending due to unbalance stress of servomotor. Counterweight is located on counterweight support. In case the servomotor is in fault, counterweight will close the guide vane by action of gravity.

4.Runner

Runner is the heart of turbine to change the water energy to mechanical energy. It is casted and welded as a whole, crown, band and blade is made of stainless steel ZG06Cr13Ni4Mo which has perfect performance of anti-cavitation, anti- corrosion and weldable. The runner is subject to static balance testing after machining. Holes on runner crown can reduce the pressure applied on runner by the water.

5.Draft tube assembly

Draft tube assembly consists of draft tube elbow and draft tube cone, guide the water flow into lower stream, make use of the potential energy of water flow at suction height, recycle major kinetic energy of the flow at runner outlet by its diffusion. All connecting flange shall be sealed, immersed depth of draft tube shall not be less than 30cm to prevent air into draft tube.

6.Pressure gauge and vacuum gauge

Pressure gauge is located on spiral case for observing the pressure in spiral case.

Vacuum gauge is located on draft tube elbow for observing the degree of vacuum. Valves shall be equipped on pressure gauge and vacuum gauge piping for close and open the piping.