Energy Flexibility Flashcards
(51 cards)
What is the equation for velocity?
v = SQRT(2 g h)
What are the values for low, medium and high head?
below 10 m
10 - 100 m
above 100 m
What are the three types of turbine used in hydro power?
Francis
Propellers
Impulse Turbine
What speeds does the francis run at?
low speeds
What heads are best for francis turbines?
low head
What is the maximum efficiency of a francis turbine?
95 %
What head is best for propellers?
Low head
What is special about a Kaplan turbine?
The blade angles can be altered
What head is best for impulse turbines?
High head (>250m)
When is maximum energy extracted in an impulse turbine?
Cups at half speed of water
What causes tides?
Moon gravitational pull
How many tides are there?
Twice upstream and twice ebb (downstream)
What is the minimum tidal range>
5 m
What is the energy equation for tidal power?
E = 0.5 rho A R^2 g
What is flood pumping?
pump extra head into basin at high tide
input work is less than can be recovered from additional head
What causes waves?
Wind shear
What is the power equation for wave power?
P = rho g^2 h^2 T / (32 pi) [W/m]
What is Darcy’s Law?
v = K_w H/L
What is K_w?
Hydraulic conductivity
What is the heat conduction equation?
q = K delta T / z
What are the indirect geothermal plant types?
Dry steam
Single flash - pressure reduction
organic rankine - secondary fluid
double flash
What are the components of a heat pump?
condenser
evaporator
compressor
expansion valve
What are the benefits of bio fuels?
Carbon neutral
high energy density
wate product use
What are the downsides of bio fuels?
Not actually carbon neutral
combustion creates emissions
competition for land use
low solar conversion efficiency
