轮机英语多媒体课件2.ppt

1615 Why will a two stage flash type distilling plant tend to operate more efficiently when operating in cold seawater? 1615．当海水温度较低时，两级闪发式造水机的效率较高，因为闪发式的真空度提高了 A. The colder seawater passing through the condnser tube bundles of the various stages increases evaporator vacuum. B. The amount of heated feed water discharged from the feed water heater after condenser is increased. C. Fewer non-condensable gases are created by the flow of colder seawater. D. More seawater is allowed to pass through the first stage overflow weir. 1616 Moisture in the refrigerant may ____ 1616、制冷系统中的水分会在膨胀阀座结冰，并会减少制冷剂的流量。 A. freeze on the expansion valve seat and reduce the flow of liquid refrigerant B. emulsify the oil in the condenser C. freeze in the king valve D. clog the oil trap 1617 The tendency of a flammable liquid to vaporize is indicated by its ____ 1617．可燃液体的蒸发趋势可以用闪点来表示 A. ignition temperature B. flash point C. flammable range D. convection index 1615 A 1616 A 1617 B 1618 When the propeller blades are integral with the hub, the propeller is called a ____ 1618．当螺旋桨的桨口子与桨毂是整体式时，这种螺旋桨称为整体式螺旋桨。 A. built up propeller B. solid propeller C. controllable pitch propeller D. suction back propeller 1619 Moisture in a refrigeration system can cause ____ 1619．制冷系统中的水分会造成膨胀阀结冰，系统管系腐蚀并使温度调节不正常。 A. freezing the expansion valve closed B. corrosion of system piping C. improper temperature regulation D. all of the above 1620 Which of the problems listed could be indicated if a sight glass in the refrigerant liquid line is full of bubbles? 1620．如果制冷剂液态管路中的示液镜充满气泡，可能表明制冷剂不足。 A. Proper refrigerant charge. B. Faulty expansion valve. C. Insufficient refrigerant. D. Solenoid valve stuck open. 1621 Which of the following statements describes the functions of a reser