Deck 1: Boiler Efficiency and Classification

Question 1

Rankine cycle efficiency of a good Steam

A)15 to 20%
B)35 to 45%
C)70 to 80%
D)90 to 95%

Answer 1

35 to 45%

Question 2

A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature of 350°C and the Condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle?

A)7.7
B)17.7
C)27.7
D)37.7

Answer 2

27.7

Question 3

On what basis are fire and water tube boilers are classified?

A)depending the combustion products formed
B)depending the state of fuel
C)depending on the steam formation rate
D)depending tubular heating surface

Answer 3

depending tubular heating surface

Question 4

Cornish boiler is an example of which type of boiler?

A)fire tube boiler
B)water tube boiler
C)vertical tube boiler
D)externally fired boiler

Question 5

Stirling boiler is an example of which type of boiler?

A)inclined tube boilers
B)mobile boiler
C)fire tube boiler
D)water tube boiler

Question 6

Which of these is a stationary boiler?

A)locomotive boiler
B)marine boiler
C)mobile boiler
D)babcock-wilcox boiler

Question 7

Which of these is a mobile boiler?

A)lancashire boiler
B)stirling boiler
C)locomotive boiler
D)cochran boiler

Question 8

Are boilers defined on the basis of heat source.

Question 9

What is the steam pressure limit of natural circulation boilers?

A)650bar
B)180bar
C)400bar
D)550bar

Question 10

Which of the given boilers operate above critical pressure?

A)natural circulation boilers
B)forced circulation boilers
C)once-through boilers
D)water tube boilers

Question 11

Which type of boilers are called drum-less boilers?

A)natural circulation boilers
B)fire tube boilers
C)positive forced circulation boiler
D)forced circulation boiler

Question 12

Chances of sediments depositing inside the water tubes in the shell is less due to?

A)low working pressure
B)natural circulation of water
C)partial circulation of water
D)high working pressure

Question 13

Out of the given option choose the advantage that supports fire tube boilers?

A)water circulation is cyclic
B)used as a mobile boiler
C)water circulation is limited inside boiler shell
D)bursting of flue tube does not cause any explosion

Question 14

Apart from feedheating, what should a plant have to obtain a gain in thermal efficiency?

A)lubrication
B)differential heating
C)reheating cycles
D)regenerative cycles

Question 15

Which of the following needs to be incorporated to prevent the low pressure turbine exhaust wetness from being excessive?

A)double regeneration
B)double carnotization
C)double reheat
D)double cooling

Question 16

What is the critical point of steam generation in a "once through" boiler?

A)221.5 bar
B)221.4 bar
C)221.3 bar
D)221.2 bar

Question 17

In a typical layout of a 215MW reheat power plant, the feed in the boiler is at?

A)280 degree centigrade
B)230 degree centigrade
C)238 degree centigrade
D)250 degree centigrade

Question 18

The input to the low pressure feedwater heater is from?

A)drain heater
B)drain cooler
C)drain pipe
D)none of the mentioned

Question 19

The best capable alternative source which can meet the future energy demand is

A)thermal power plant
B)nuclear power plant
C)hydroelectric power plant
D)geothermal power plant