PHEP 12 Flashcards
How do head develop at most hydroelectric plants?
Head Fluctuates based on inflows and demand
What does intake design have an effect on?
Velocity, head and volume
Partially clogged trash rack has what effects?
Decrease in effective head
Wood Stale Pipe should not be in what penstocks?
Penstocks w/ heads above 500 ft
Open Conduit system implies
Presence of a free surface
Best cross section of a canal hydraulically
Has minimum wetted perimeter
Least effective high Line circuit
Has most effect on available head
Why are steel pipe commonly used in penstock construction?
Can be Riveted
Can be Welded
Better able to withstand static and dynamic changes
Degree of flexibility in design criteria by all above
Advantage of pressure tunnel in a power conduit system
Permits use of full available head
Positive water hammer can be dealt with using
Relief valve
Pressure Regulator
Surge Tank
When is negative water hammer is created
Sudden demand increase
What would cause water level in differential surge tank to rise?
Load rejection
Pumped storage hydroelectric plant is capable of
Improving load factors on grid
Provide power system reserve capacity
Improved peak operation
Best hydraulic rectangular cross section
Width is twice depth
Penstock Flow velocity
6-20 ft/sec
