01․ Pumped storage plant is a
A base load power plant is a power station that usually provides a continuous supply of electricity throughout the year with some minimum power generation requirement. Base load power plants will only be turned off during periodic maintenance, upgrading, overhaul or service. Base load power plant has the character of slow demand respond, a mechanism to match generation with the load it supplies.
Some examples of base load plants are
1. Thermal plants
2. Hydro plants
3. Nuclear plants
4. Tidal power plants
A peaking power plant is a power station that only runs during high demands of electricity throughout the day during peak hours. Because of that, the price of electricity it generates is generally higher than the electricity generated by base load power plant, which operates continuously throughout the year.
Some examples are
1. Pumped storage plant
2. Diesel plants
3. Hydro plants ( when water availability is less)
4. Gas fired power plants
02․ Advantages of pumped storage plants is/are
Advantages of pumped storage plants:
1. Most economical as a peak load supply plant
2. Used as load frequency control
3. If it is combined with thermal plant of an area load factor is increased
4. Pollution free
5. Easily adaptable for remote operation
6. Operating time is minimum
03․ Which of the following materials is/are used as moderators?
Moderator is used to moderate the speed of neutron. Materials of moderator must have low molecular weight.
In case of enriched uranium plants ordinary water is used as a moderator. In other plants heavy water, graphite, beryllium are used as moderators.
04․ In nuclear power plants which material is/are used as coolant?
In a nuclear plant heat is produced due to nuclear fission change reaction and heat is absorbed by the coolant which is used to convert water into steam in the heat exchanger. This steam is used for producing electrical power output.
The materials of coolant are water, heavy water, liquid sodium, sodium potassium etc.
05․ One million cubic meters of water is stored in a reservoir feeding a water turbine. The density of water is 993 kg/m³. If the centre of mass of water is 50 meters above the turbine and losses are negligible, the energy produced by that volume of water is
Power generation P = 9.81×10-3×ηQWH kW
Where,
η = Plant efficiency = 1
Q = Discharge of water = 1×106/3600 m³/s = 277.78 m³/s
W = Density of water = 993 kg/m³
H = Mean head of water = 50 m
Power generation P = 135.3 MW
Energy E = P × t = 135.3 MWhr
06․ A coal fired steam power station working at a plant factor of 80% has one 500 MW generating unit. If the heat content of coal is 2 kWh/kg, the overall plant efficiency is 40% and a train load of coal is 2000 metric tons, then the number of trains required daily for the plant is
Maximum power Pmax = 500 MW
Load factor = 0.8
Average power Pavg = 0.8×500 = 400 MW
One day energy = 400×10³×24 kWhr = 9600×10³ kWhr
Efficiency η = 0.4
Energy generated by coal = 2 kWhr/kg
Therefore, actual energy generated by coal = 2×0.4 = 0.8 kWhr/kg
One train coal = 2000×10³ kg
One train coal can generate energy = 2000×10³×0.8 kWhr
07․ Which of the following plants is/are base load plants
Some examples of base load plants are
1. Thermal plants
2. Hydro plants
3. Nuclear plants
4. Tidal power plants
5. Run off river plants
Some examples of peak load plants are
1. Pumped storage plant
2. Diesel plants
3. Hydro plants ( when water availability is less)
4. Gas fired power plants
08․ Which of the following statements is/are true?
Moderator:
Moderator is used to moderate the speed of neutron. Materials of moderator must have low molecular weight.
In case of enriched uranium plants ordinary water is used as a moderator. In other plants heavy water, graphite, beryllium are used as moderators
09․ A thermal generating station has an installed capacity of 15 MW and supplies a daily load of 10 MW for 12 hours and 5 MW for remaining 12 hours. The plant capacity factor for the station is
Plant capacity factor (Pcf) is defined as the ratio of average power to the plant capacity.
Pcf = Average power/ Plant capacity
Pcf = Energy produced by the plant/ (Energy that can be able to produce as per plant capacity during total hours)
10․ A thermal generating station has an installed capacity of 15 MW and supplies a daily load of 10 MW for 12 hours and 5 MW for remaining 12 hours. If the load factor is 0.8. Find the reserve capacity of the station?
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