Steam Turbine Interview Questions and Answers on “Heat and Steam Rate”.
1. Heat rate defines how much energy is to be expanded for obtaining a unit of useful work.
a) True
b) False
Answer: a
Clarification: Heat rate means the amount of energy that must be expanded for obtaining an unit of useful work.
2. What is heat rate in turbine?
a) Heat required for unit of power generated in specific conditions and specific fuel burning
b) Amount of heat required to expand turbine blades
c) Amount of heat required to increase pressure of steam
d) None of the mentioned
Answer: a
Clarification: Heat rate in turbines is defined as heat required to generate unit power in turbine at specific fuel being burned at specific conditions.
3. For calculating heat rate in steam turbines enthalpy is calculated.
a) False
b) True
Answer: b
Clarification: Heat rate can be calculated by using enthalpy method.
4. Steam turbine governing can be defined as __________
a) increasing the steam speed
b) adjusting the governors for particular speeds
c) controlling the flow rate of steam
d) none of the mentioned
Answer: c
Clarification: Governors are used to control the fuel needed to the load and they are no way related to the steam turbine governing. Steam turbine governing is controlling the flow rate of steam.
5. Why is steam turbine governing used?
a) To increase the steam speed
b) To maintain steam speed constant
c) To decrease the steam speed
d) None of the mentioned
Answer: b
Clarification: Flow rate if steam is controlled to maintain the constant speed.
6. In nozzle governing the flow rate is controlled by ____________
a) opening and closing the valves at nozzle
b) adding more number of nozzles
c) increasing nozzle efficiency
d) none of the mentioned
Answer: a
Clarification: Opening and closing of valves at nozzle is called nozzle governing.
7. During overload of turbines __________ are used.
a) throttle governing
b) nozzle valves
c) bypass governing
d) none of the mentioned
Answer: c
Clarification: During overload conditions fresh steam is added into later stages called as bypass governing.
8. When is emergency governing used?
a) Speed of shaft increased above 110%
b) When turbine is shut down due to overload
c) When Low steam is entering
d) None of the mentioned
Answer: a
Clarification: When speed of shaft is increased to 110% then emergency governing is used to control the speed.
9. When balancing of the turbine is disturbed ___________ is used.
a) Potter governor
b) Centrifugal governor
c) Emergency governor
d) None of the mentioned
Answer: c
Clarification: Emergency governor is also used when balancing of the turbine is disturbed.
10. When lubrication is failed _____________ is used.
a) Centrifugal governor
b) Emergency governor
c) Potter governor
d) None of the mentioned
Answer: b
Clarification: Emergency governor is used in all emergency situations like when the lubrication system is failed, when speed is increased when balancing is disturbed etc.
Steam Turbines for Interviews,