Steam and Gas Turbines Multiple Choice Questions on “Cooling of Gas Turbine Blades”.
1. Cooling is classified into ________
a) air cooling
b) liquid cooling
c) air & liquid cooling
d) none of the mentioned
Answer: c
Clarification: Cooling is of two types. They are
Air cooling
Liquid cooling.
2. Liquid cooling method has _______
a) high specific heat capacity
b) low specific heat capacity
c) low evaporative cooling
d) none of the mentioned
Answer: a
Clarification: Liquid cooling method has a high specific heat capacity.
3. In liquid cooling leakages are _________
a) increases
b) reduced
c) equal in both air and liquid cooling
d) none of the mentioned
Answer: b
Clarification: In liquid cooling leakages are reduced.
4. Quality of air required for air cooling is ______
a) 1-3 %
b) 2-5 %
c) above 5 %
d) none of the mentioned
Answer: a
Clarification: 1-3% air quality is required for air cooling.
5. By liquid cooling blade temperature can be reduced by ________
a) 300 – 400%
b) 200 – 300%
c) 100 – 500%
d) none of the mentioned
Answer: b
Clarification: Liquid cooling decreases blade temperature by 200-300%.
6. For air cooling,cooling air comes from _________
a) compressor
b) atmosphere
c) condenser
d) none of the mentioned
Answer: a
Clarification: In air cooling, cooling air comes from compressor.
7. In impingement cooling ___________
a) cooling is done by fins
b) by making air with high velocity to hit the blades
c) holes in the blades
d) none of the mentioned
Answer: b
Clarification: In impingement cooling method cooling is done my making air with high velocity to hit the blades.
8. In impingement cooling majority of cooling is done by ________
a) convection
b) conduction
c) radiation
d) none of the mentioned
Answer: a
Clarification: In impingement cooling majority of cooling is done by convection.
9. Impingement cooling is used for lesser loads of heating.
a) True
b) False
Answer: b
Clarification: Impingement cooling is done when lesser loads of cooling is done.
10. In cooling effusion blade surface is made of _______
a) porous material having small orifice
b) fins
c) with larger surface area
d) none of the mentioned
Answer: a
Clarification: In cooling effusion blade surface is made of porous material with small loads so that cooling is more efficiently done.