更多"Hot gas defrosting uses the hot gas"的相关试题:
[单项选择]Hot gas bypass is one of the methods used to （）
A. relieve excessive compressor head pressure
B. produce flash gas at the expansion valve
C. reduce flooding of the receiver at low load
D. defrost the evaporator coils
[单项选择]The hot expanding gas rotates the blades of the exhaust turbine, thus giving out large part of its power, which drives （）.
A. the oil separator
B. the fresh water generator
C. the compressor
D. fire pump
[单项选择]For use as protection from gas leaking from a refrigeration unit，each ship must be equipped with a（）.
A. portable ventilation system
B. flame safety lamp
C. self-contained breathing apparatus
D. gas mask
[单项选择]Gas turbines differ from steam turbines in that （）.
A. steam rather than gas is used to turn a shaft
B. vapor rather than gas is used to turn a shaft
C. the former uses gas to turn a shaft
D. the latter uses gas to turn a shaft
[单项选择]Air or noncondensable gas is removed from a refrigeration system by a （）
A. separating chamber
B. system of baffles
C. purge valve
D. vacuum reducing valve
[单项选择]The rate of heat transfer from a hot region to a cold region is affected most by the （）.
A. size of the heat sink
B. temperature difference between the regions
C. size of the heat source
D. total heat of the system
[单项选择]Which method is used to supply inert gas from a flue gas system to the cargo tanks?（）
A. Exhaust gas pressure from the stack
B. High capacity fan
C. Inert gas compressor
D. Natural aspiration
[单项选择]In a （） boiler the hot gases from the furnace pass through the tubes while the water is on the outside.
A. water-tube
B. fire-tube
C. exhaust gas
D. None of the above is true
[单项选择]Each inert gas system gas main must have an automatic shut down valve at the outlet of the gas production plant. This valve must close automatically upon（）.
A. cargo pump failure
B. blower failure
C. deck seal low water level
D. low inert gas temperature
[单项选择]Gas masks（）.
A. should be worn while fighting a fire
B. can be used in atmospheres deficient in oxygen
C. filter contaminants from air that is to be breathed
D. may be substituted for a self-contained breathing apparatus
[单项选择]A marine chemist issues gas free certificates and is certified by the（）.
A. Mine Safety Appliance Association
B. American Chemical Society
C. Marine Chemists Association
D. National Fire Protection Association
[单项选择]A combustible gas indicator meter is calibrated to read the percentage of（）.
A. vapor to oxygen
B. the flammable limit concentration
C. the autoignition concentration
D. the lower explosive limit concentration
[单项选择]Combustible gas indicators operate by drawing an air sample into the instrument（）.
A. over an electrically heated platinum filament
B. where it is mixed with nitrogen
C. where it is ignited by a sparking device
D. where its specific gravity is measured
[单项选择]Fires in escaping flammable gas are quickly brought under control by（）
A. stopping the flow of gas
B. reducing the chemical chain reaction
C. increasing the oxygen supply
D. cooling below the autoignition point
[单项选择]The primary hazard of liquefied petroleum gas and liquefied natural gas is（）.
A. pressure
B. toxicity
C. temperature
D. flammability
[单项选择]Name one major advantage of transporting gas under refrigeration.（）
A. It increases its volume
B. It reduces its volume
C. It has less product per volume
D. None of the above
[单项选择]某学生在学习“gas—煤气”这一单词时加入中介词，将其加工成“gas—该死—煤气”。该学生所使用的策略是（）
A. 精细加工策略
B. 组织策略
C. 复述策略
D. 计划监控策略
