單項選擇題Moisture in the refrigerant may （）.

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


您可能感興趣的試卷

你可能感興趣的試題

1.單項選擇題Why will a two stage flash type distilling plant tend to operate more efficiently when operating in cold seawater?（）

A.The colder seawater passing through the condenser tube bundles of the various stages increases evaporator vacuum
B.The amount of heated feed water discharged from the feed water heater after cndenser is increased
C.Fewer non-condensable gases are created by the flow of colder seawater
D.More seawater is allowed to pass through the flint stage overflow weir

2.單項選擇題Moisture is removed from a refrigeration system by（）.

A.bleeding refrigerant from the condenser
B.opening a drain petcock on the oil separator
C.condensing the water in the heat exchanger
D.using a dehydrator cartridge

3.單項選擇題A centrifugal pump vibrates excessively during operationUpon disassembling the pump it is found that the impeller is out of balanceWithout an available spare, you should （）.

A.drill holes through the heavy side of the impeller until it balances
B.weld counterweights to the light side of the impeller
C.remove metal from the heavy side by machining in a lathe
D.acid wash and serape the heavy side until it balances

4.單項選擇題An axial piston, variable stroke pump is used in a vessels hydraulic steering gearUnder pressure, oil continually leaks out from between the valve plate/cylinder barrel and will（）.

A.cause loss of hydraulic oil from the system
B.result in extreme damage to the pump
C.cause damage to the pump ff not continually drained from the pump casing
D.result in the system high side pressure to substantially drop off

5.單項選擇題In a flash type evaporator, all saltwater headers are vented through individual vent cocks to the（）.

A.saltwater heater shell
B.second-stage condenser
C.atmosphere
D.second-stage flash chamber