Comp 7

Question 1

137. In determining the efficiency of a gas turbine, there are 1 factors for the calculation of input or the rate at which energy is supplied. One is the fuel’s flow rate. What is the other one?
     A. The fuel’s viscosity at 15degC.
     B. The duel’s octane index.
     C. The fuel’s HC index.
     D. The fuel’s heating value.

Answer 1

D. The fuel’s heating value

Question 2

138. In combustion technology, what is the quantity of air, and no more, which is theoritically needed to burn completely a unit quantity of fuel?
     A. Stoichiometric
     B. Sub-stoichiometric
     C. Primary air
     D. Secondary air

Answer 2

A. Stoichiometric

Question 3

139. The blades of air compressor in a gas turbine plant are designed so that the highest efficiency is achieved near the soeeda normal for the rotor. However, at reudced power, the flow conditions will be poor, and efficiency will be lower tjan the designed point. What is done to prevent the reduction in efficiency?
     A. Compressor is provided with diaphragm nozzle.
     B. Compressor is provided with increased number of blades.
     C. Compressor is provided with adjustable blades.
     D. Compressor is provided with suction nozzle.

Answer 3

C. Compressor is provided with adjustable blades.

Question 4

140. In a property designed boiler, which of the end points should be reached first?
     A. Circulation
     B. Evaporation
     C. Combustion
     D. Compressor

Answer 4

C. Combustion

Question 5

141. A boiler high efficiency is obtained when heat losses due to radiation are low. How can radiation losses be contained?
     A. By proper maintence and care of the combustion equipment
     B. By keeping the temperature and quantity of the exhaust gases as low as possible.
     C. By keeping all insulation in good order.
     D. By operating with minimum of excess air for combustion.

Answer 5

C. By keeping all insulation in good order.

Question 6

142. Atmospheric pressure is the pressure due to thw weight of the atmosphere. What is the atmospheric pressure value at sea level?
     A. 101.325 kPa
     B. 0.76 mmHg
     C. 1.0 kPa
     D. 1 psi

Answer 6

A. 101.325 kPa

Question 7

143. What is termed as steam boiler’s rated output or the maximum evaporation rate that can be sustained for 24hrs?
     A. Nominal continuous rating.
     B. Combustion efficiency.
     C. Evaporation ratio.
     D. Maximum continuous rating.

Answer 7

D. Maximum continuous rating.

Question 8

144. For tha marine gas turbine to work properly, what air anf fuel ratio must be applied to ignite and produce high pressure gas?
     A. 100:1 by weight
     B. 60:1 by weight
     C. 60:1 by volume
     D. 30:1 by weight

Answer 8

B. 60:1 by weight

Question 9

145. Why is it necessary to use the vacuum pump after a major overhaul of a refrigeration system?
     A. To check the condition of the various seals in the system.
     B. To create a vacuum to helpspeed up refrigerant recharging of tje sytem.
     C. To remove any lubricating oilform the system pipework.
     D. To remove any air and water from the system in order to prevent problems during operation.

Answer 9

D. To remove any air and water from the system in order to prevent problems during operation.

Question 10

146. The term “3-element control” applied to medium and high pressure boilers refer to the number of process variables (PVs) that are measured to effect control of the boiler feedwater control valve. Two of these measured PVs are the liquid level in the boiler drum and flow of feed water to the boiler drum. What is the 3rd PV element applied?
     A. Steam pressure in the boiler drum
     B. Flow of steam leaving the boiler drum
     C. Temperature of steam in the boiler drum
     D. Windbox-Furnace differential pressure

Answer 10

B. Flow of steam leaving the boiler drum

Question 11

147. Overheating of the generating tubes will occur when the boiler reaches its end point of:
     A. Decreasing the amount of valve overlapse
     B. Combustion
     C. Circulation
     D. Moitire carry over

Answer 11

C. Circulation

Question 12

148. A boiler high efficiency is obtained when heat losses are low. What is considered the biggest single heat loss in a boiler?
     A. The products of combustion exhausted to atmosphere
     B. The damaged insulation materials of combustion chamber
     C. The latent heat of moisture formed during combustion from hydrogen in fuel
     D. Improper maintenance and care of combustion equipment

Answer 12

A. The products of combustion exhausted to atmosphere