The opening of an exhaust valve on a modem, large, low-speed, main propulsion diesel engine may be actuated by （）.

[单选题]Exhaust valve grooving and corrosion is caused by certain components of residual fuel oilThese components are sodium, sulfur, and （）.A . vanadiumB . carbonC . copperD . ash

[单选题]Leaky exhaust valve will result in which of the following?（）(1) high exhaust temperature;(2) low compression pressure;(3) low firing pressure.A . (1) and (2)B . (1) onlyC . (2) onlyD . (1),(2) and (3)

[单选题]The needle valve in a fuel valve will （） when the fuel pressure action on the needle valve tapered face exerts a force lower than that of the spring compression.A . be jammedB . be openedC . be seatedD . be broke

[单选题]The rising of the exhaust temperature in manifold pipe may NOT result from （）.A . too great a loadingB . fouled turbochargerC . bad combustionD . excessive air

[单选题]The needle valve in the injector （） at a pre-set pressure which ensures that the fuel will atomize once it enters the cylinder.A . will liftB . will be liftedC . will closeD . will be closed

[单选题]B．y comparing the exhaust gas temperature of each cylinder, the operator can determine if the load is balanced throughout the engine The device most commonly used is aA．tachometerB．pyrometerC．dynamometerD．calorimeter

[单选题]E．xhaust gas pyrometers are useful forA．detecting faulty combustion in individual cylindersB．adjusting fuel racks to maintain equal loading between cylindersC．adjusting the load limit setting of the governor at idle conditionsD．calculating engine hor

[单选题]Scavenging is （） of exhaust gases by blowing in fresh air.A . the suctionB . the compressionC . the removalD . the deliver

[单选题]（） is the removal of exhaust gases by blowing in fresh air.A . Gas exchangeB . ChargingC . ScavengingD . Supercharging

4.单选题（1分）The bicuspid valve is also known as the ___ valve.A. mitralB. aorticC.