Francis Turbine generator Unit Switching Function in HPP
Author: source: date: 2019-07-05 18:09:36
The Francis turbine generator unit for HPP medium water head heights typically has two common shutdown and opening and closing functions.
1, Turbine with counter weight
2, Hydraulic operation shutdown function
Francis Turbogenerator Unit Switching Function:
A. Turbine with counter weight
This turbine is equipped with counter weight device for opening and closing .Usually,the start-up is realized by the governor controlling the servomotor to operate the water water distributor. when the unit shut down, the potential energy of counter weight directly operate the water guiding mechanism without oil pressure to close.
Advantages: When the governor loses oil pressure , it can be emergency shutdown to avoid damage.
Disadvantages: There is pressure in the opening cavity of servomotor , the weight of the counterweight can not alose closed effectively, it needs to be combined with pressure release valve to sut down. This control system is relatively complicated, or the weight of the counter weight is too heavy.
B， Hydraulic operation shutdown function
The startup and shutdown of the unit is by the oil pressure from the governor to opearate the servomotor.
Advantages: Both the startup and shutdown is operated by oil pressure. It is safe and reliable.the diameter of servomotor is smaler without counterweighter. Now the pressure oil source of the governor is a nitrogen-filled bladder storage tank,so the pressure oil source is safe and reliable.
Disadvantages: In extreme cases, after the pressure oil source loses pressure, it cannot be shut down normally and has to close the electric valve. However, the current pressure oil source technology is advanced and reliable, and the probability of pressure loss is very small.
The above two functions can be purchased according to the characteristics of your HPP. Forster will be happy to provide the best solution for your site.