Power Plant Engineering Multiple Choice Questions on “Regeneration – 1”.
1. What is the basic principle of regeneration?
a) Steam after coming out of condenser is circulated to boiler
b) Steam after coming out of condenser is circulated to turbine
c) Steam after coming out of turbine is circulated to boiler
d) Two stage turbine is used
Answer: b
Clarification: In regeneration steam from condenser is circulated through turbine to increase steam temperature before it enters boiler.
2. Ideal regenerative rankine cycle _______
a) Increases efficiency
b) Increases work output
c) Increases the heat supplied
d) Does not effect efficiency
Answer: a
Clarification: Feedwater is preheated so as to decrease the fuel consumption which increases efficiency.
3. Mean temperature of heat addition is _______ due to Regeneration.
a) Decreases
b) Not effected
c) Increases
d) Varied exponentially
Answer: c
Clarification: Since less heat is required in the boiler so mean temperature of heat addition increases.
4. Name the coolants commonly used for fast breeder reactors?
a) Liquid metal (Na (or) Na K)
b) Helium (He)
c) Carbon dioxide
d) All of the mentioned
Answer: d
Clarification: Liquid metals are commonly used, in some plants He and CO2 are also used.
5. Why trash rack is used?
a) To prevent the entry of debris
b) To prevent steam overflow
c) It is used as an insulter
d) Prevents back flow
Answer: a
Clarification: The trash rack is used to prevent the entry of debris, which might damage the turbine runners and chock up the nozzle of impulse turbine.
6. What is the use of surge tank?
a) To store condensate
b) To prevent surging
c) To provide better regulation of water pressure in the system
d) To prevent chocking
Answer: c
Clarification: The surge tank controls the water when the load on the turbine decreases and supplies water when the load on the turbine increases.
7. What is the function of Fore bay?
a) Temporary water storage
b) Steam passage
c) Water flow in penstock
d) Condensate storage
Answer: a
Clarification: It is temporary water storage when the load on the plant is reduced and provides water for initial increment on increasing load.
8. What is the use of draft tube?
a) To regain kinetic energy
b) To regain potential energy
c) Passage for water
d) Stores energy
Answer: a
Clarification: The draft tube is used to regain the kinetic energy of water coming out of reaction turbine. It enables the reaction turbine to be placed over tailrace level.
9. Is regenerative cycle alone useful?
a) yes
b) no
c) may be
d) depends on other factors
Answer: a
Clarification: Feedwater is preheated so as to decrease fuel consumption which increases efficiency.
10. What is the function of surge tank?
a) Regulation of water pressure
b) Regulation of steam pressure
c) Storage
d) Regulation of lubricants
Answer: a
Clarification: The surge tank controls the water when the load on the turbine decreases and supplies water when the load on the turbine increases