Flame failure in an automatically fired auxiliary boiler can from a/an （）

单项选择题Cold weather starting of a diesel engine may be made easier by（）

A.decreasing the compression ratio
B.using a special fuel having a high ignition temperature
C.increasing the starting air supply
D.heating the jacket water

单项选择题Diesel engine air start system check valves are opened by （）

A.an air start cam
B.cylinder compression pressure
C.starting air pressure
D.valve springs

单项选择题The cetane rating of diesel fuel is an indication of the （）

A.ignition quality of the fuel
B.calorific value of the fuel
C.flash point of the fuel
D.rate of fuel consumption

单项选择题The condensers located in various stages of a flash evaporator are cooled by（）

A.distillate
B.seawater
C.brine
D.air

单项选择题Which of the diesel engine components listed increase air density and helps to improve engine operating efficiency?（）

A.Impeller
B.Compressor
C.After-cooler
D.Exhaust differ