单项选择题When the heat load begins to increase, the needle valve of an expansion valve will()

A.move in an opening direction
B.move in a closing direction
C.either open or close
D.not move at all


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1.单项选择题One of the main purposes of refractories in a boiler furnace is to()

A.help preheat the air for the furnaces
B.help preheat the feedwater
C.protect economizer from excessive heat
D.prevent excessive furnace heat losses

2.单项选择题What is the first thing you would check on taking over a watch?()

A.the bilges
B.the periscope
C.the water level
D.the oil pressure

3.单项选择题Soot blowers should be used in proper sequence so that()

A.excess stresses will not be set up in the boiler
B.the decks will not be covered with soot
C.the soot will be swept toward the uptakes
D.there will not be a loss of steam pressure

4.单项选择题The valve that prevents water from backing out of the boiler into the feed line is the().

A.bottom-blow valve
B.skin valve
C.feed-check valve
D.feed-stop valve

5.单项选择题The mechanical exhaust valve operation system is replaced by()in an electronic controlled ME engine.

A.a system with a Hydraulic Power Supply (HPS) unit
B.a system with roller guides for exhaust valves
C.a system with an electronically controlled Alpha Lubricator
D.a system directly powered by electric motor

6.单项选择题()is not a feature of the electronic controlled engines.

A.Lower fuel consumption
B.Better balanced cylinder power
C.A shorter overhaul period
D.Less smoke emission

9.单项选择题The main purpose of changing main engine to electronic controlled is not to()

A.control fuel injection time more precisely
B.control fuel injection rate more precisely
C.meet the environmental requirements
D.meet high engine speed requirements

10.单项选择题To meet the market requirements, a marine diesel engine should not be of()

A.big size
B.fuel economy
C.low speed
D.high power