【正文】 ntake filters B. Piston blowby C. A defective aftercooler后冷卻機 D. Faulty exhaust valves Jimei University 0857 If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe_____. A. high steam pressure in the boiler B. abnormally high feed water temperature C. abnormally high boiler water temperature D. steam demand exceeding feed pump capacity Jimei University 0858 Lubrication for the main reduction gears used with diesel engines is usually supplied by_____. A. oil from the main engine sump B. an independent lube oil system C. the stem bearing head tank D. the stem bearing sump tank Jimei University 0859 When there is a flame failure in an automatically fired auxiliary boiler, the_____. A. air supply is shut off B. fuel supply is shut off C. water supply is shut off D. safety valve lifts Jimei University 0860 Excessive vibration of an automatically fired auxiliary boiler can be caused by_____. A. air or water in the furnace B. bustion pulses C. fuel oil pump failure D. flame failure Jimei University 0861 Cooling the intake air supplied to a diesel engine will_____. A. reduce mean effective pressure B. decrease average pression pressure C. decrease air charge density D. increase power output Jimei University 0862 The water in an auxiliary boiler should be tested for chloride content to determine _____. A. total dissolved solids B. salt contamination C. water hardness D. chlorine contamination Jimei University 0863 The concentration of total dissolved solids in the water of an auxiliary boiler can increase as a result of_____. A. seawater contamination B. frequent surface blows C. dissolved oxygen deaeration (除氣 ) D. frequent bottom blows Jimei University 0864 The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speed. In maintaining this relationship, the camshaft drive causes the camshaft to rotate at_____. A. onehalf crankshaft speed in a twostroke cycle diesel engine B. crankshaft speed in a twostroke cycle diesel engine C. two times crankshaft speed in a twostroke cycle diesel engine D. onefourth times crankshaft speed in a fourstroke cycle diesel engine Jimei University 0865 A threeway thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water_____. A. around the engine B. around the cooler C. to the expansion tank D. overboard Jimei University *0866 Bottom blow valves are installed on auxiliary watertube boilers to_____. A. remove suspended and precipitated沉淀的 solids from the boiler water B. pletely drain the boiler in an emergency situation C. prevent hardened scale deposits in the water drum D. remove floating impurities from the oily water surface Jimei University 0867 Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are_____. A. operated manually once an hour B. operated until the engine has started C. placed into operation only at maximum load D. adjustable to meet lubrication requirements Jimei University 0868 In a closed diesel engine freshwater cooling system, the amount of coolant flowing through the heat exchanger is controlled by the_____. A. suction pressure regulator B. thermostatic bypass valve (恒溫閥 ) C. sea water temperature D. water level in the expansion tank Jimei University 0869 The opening of an exhaust valve on a modem, large, lowspeed, main propulsion diesel engine may be actuated by_____. A. direct action of cam shaft B. pressed air pressure C. hydraulic push rods D. direct action of the main piston moving down Jimei University 0870 The speed of the camshaft in a twostroke/cycle diesel engine, running at 950 RPM, is _____. A. 475 RPM B. 950 RPM C. 1900 RPM D. 2400 RPM 0871 Cylinder lubrication oil for low speed main propulsion diesel engines is admitted to each cylinder during_____. A. the power stroke B. the pression stroke C. low load operation only D. periods of standby Jimei University 0872 Temperature control valves installed in the jacket cooling water system of a diesel engine modulates the rate of water flow through the_____. A. cooling water pump B. nozzle cooling passages C. cylinder jackets D. heat exchanger Jimei University 0873 A restricted air intake to a diesel engine may result in the engine_____. A. failing to reach rated speed B. knocking under maximum load C. hunting or surging under light load D. overspeeding and running away Jimei University 0874 In a fourstroke/cycle diesel engine, the camshaft rotates at_____. A. twice the crankshaft speed B. half the crankshaft speed C. the same speed as that of the crankshaft D. a speed independent of that of the crankshaft Jimei University 0875 For diesel engine piston cooling, lubricating oil can be supplied to the pistons by a/an _____. A. oil spray B. oil bath C. oil control rings D. drilled passage through the camshaft Jimei University 0876 The jacket wat