Chapter 10 hydraulic Turbines Flashcards
Which of the following would not be used with a peloton wheel?
Wicket gates
Pelton wheels:
May use two or more jets per Wheel to obtain increased power
Power available at the nozzles varies
Directly with the head and quantity of water
Water hammer:
Can damage the penstock, if not, kept within reasonable limits
The purpose of an auxiliary needle is to
Providing means for reducing flow to an impulse wheel, rapidly, while reducing the flow slowly through the penstock
To deliver the same amount of power, a smaller diameter runner is required for a reaction turbine than for an impulse wheel, because
The entire circumference of the runner of the reaction turbine is being acted on by the water stream
Which of the following would not be found on a reaction turbine
Stripper
For most reaction turbines greatest efficiency is obtained when the wicket gates are
80 to 90% open
A draft tube:
Increases the effective head of the turbine
Readings from a pressure gauge on the crown plate of your reaction Turbine give a good indication of the
Seal ring effectiveness
A Kaplan turbine;
Propeller blades, adjust automatically to maintain best efficiency for gate position and variations in head
Net head most nearly means:
Gross or static head less the frictional losses in feet
Which of the below factors would not generally contribute to cavitation change?
Little or no variation in effective head
How much head would be required to develop 10,000 hp from a turbine operating at 80% efficiency from a stream with the flow of 100 ft.³ per second
1100 feet
What is the best speed of rotation in RPM for a peloton wheel 54 inches in diameter on which the net head is 625 feet?
360 rpm
