更多"In a （） boiler the hot gases from t"的相关试题:
[单项选择]The furnace of an oil fired boiler should be （） before the operating burner is lit.
A. filled with water
B. purged
C. cleared of air
D. None of the above is true
[单项选择]Too much air in the furnace of an oil-fired boiler would be indicated by （）.
A. yellowish flame
B. golden yellow flame
C. white flame
D. brilliant white flame
[单项选择]You are the network consultant from pass4sure.com. One of your customer has six sites, three of which process a large amount of traffic among them. He plans to grow the number of sites in the future. Which is the most appropriate design topology?（）
A. full mesh
B. peer-to-peer
C. partial mesh
D. hub and spoke
[单项选择]Exhaust gases are generally removed from the cylinders of a two-stroke/cycle diesel engine by（）
A. natural aspiration
B. masked intake valves
C. air cells
D. scavenging air
[单项选择]Additional heat extraction from the exhaust gases can be effected by adding an （） section to the unit in plants.
A. air cooler
B. economizer
C. injector
D. air blower
[单项选择]The rate of heat transfer from a hot region to a cold region is affected most by the （）.
A. size of the heat sink
B. temperature difference between the regions
C. size of the heat source
D. total heat of the system
[单项选择]Hot gas defrosting uses the hot gas from （） to defrost the evaporator.
A. starting air bottles
B. diesel engines
C. boilers
D. refrigeration compressors
[单项选择]A pumproom is suspected of accumulating gases after a ventilation machinery breakdown. Where should the combustible gas indicator case be placed when testing the pumproom atmosphere for combustible gases? （）
A. In the lower level of the pumproom
B. In the middle level of the pumproom
C. In the upper level of the pumproom
D. On the deck outside the pumproom
[单项选择]Which of the following gases represents the greatest threat to personnel safety in an engine room where the exhaust is leaking from a diesel engine?（）
A. Carbon dioxide
B. Carbon monoxide
C. Carbon trioxide
D. Hydrogen sulfide
[单项选择]The two most common gases used in pneumatic system are （）
A. compressed air and nitrogen
B. helium and nitrogen
C. oxygen and hydrogen
D. oxygen and acetylene
[单项选择]The process to remove exhaust gases by blowing in fresh air is called （）.
A. charging
B. supercharging
C. starting
D. scavenging
[单项选择]Forcing the exhaust gases form the cylinder of an operating diesel engine with the aid of a blower is known as （）
A. scavenging
B. forced draft
C. turbo-charging
D. aspiration
[单项选择]Combustion gases formed in the cylinder of a diesel engine are prevented from blowing past the piston by （）
A. cylinder valves
B. compression rings
C. piston skirts
D. oil rings
[单项选择]The atmosphere（）certain gases mixed together in definite proportions.
A. composes of
B. is made up
C. consists of
D. makesup of
[单项选择]The exhaust gases in a supercharged two-stroke/cycle diesel engine are expelled from the cylinder by （）
A. pumping action of the piston
B. pressure of the fuel charge
C. vacuum developed in the manifold
D. pressure of the fresh air charge
[单项选择]Scavenging is （） of exhaust gases by blowing in fresh air.
A. the suction
B. the compression
C. the removal
D. the deliver
