Consider the following statements regarding the nozzle governing of steam turbines:
1. Working nozzles receive steam at full pressure
2. High efficiency is maintained at all loads
3. Stage efficiency suffers due to partial admission
4. In practice each nozzle of the first stage is governed individually
Of these statements
Option (A)
1, 2 and 3 are correct
Option (B)
1 and 2 are correct
1, 3 and 4 are correct
1, 2 and 4 are correct
Correct Option:
Question Solution:
Nozzle control governing is more efficient method of governing compared with throttle governing specially at part loads. The principal of nozzle control governing is that according to the load on the turbine the steam supply is varied by means of nozzle. The nozzle are made up in sets each set being controlled by a separate value. The sets need not consists of equal number of nozzle, but are arranged to give the required degree of control