单项选择题
A.precipitate silica from solution B.reduce corrosion in the heating coil C.prevent clogging and erosion in the coil D.maintain zero water hardness
Diesel engine waste heat boiler construction is usually...
单项选择题Diesel engine waste heat boiler construction is usually of the fire-tube or（）
A.cyclone furnace boiler type B.dry back boiler type C.water-tube type D.critical circulation boiler type
Auxiliary boilers are divided into several classificati...
单项选择题Auxiliary boilers are divided into several classifications, one of which is（）
A.fire-tube controlled circulation B.fire-tube supercritical circulation C.water-tube natural circulation D.water-tube express circulation
Which of the lists forms of heat transfer, if any, is i...
单项选择题Which of the lists forms of heat transfer, if any, is illustrated by the flow of combustion gases through a boiler?（）
A.Natural convection only B.Forced convection only C.Both natural convection and forced convection D.None
