The minimum temperature required to ignite gas or vapor without a spark or flame being present is called ______．A.Flash pointB.Fire pointC.Autoignition temperatureD.Lower explosive limit
The minimum temperature required to ignite gas or vapor without a spark or flame being present is called ______．
A.Flash point
B.Fire point
C.Autoignition temperature
D.Lower explosive limit
相关考题：
Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?A.compression must be low for effective spark ignitionB.compression must be low for required horsepower and torque generationC.compression must be low to prevent pre-ignitionD.compression must be low to have effective pre-ignition
A dry-type spark arrestor removes sparks from a diesel engine exhaust by ____.A.increasing the linear velocity of the exhaust gasesB.changing directions of exhaust gas flowC.decreasing the temperature of the exhaust gasesD.accelerating the exhaust gas through a reduced size orifice
In the event of the cylinder starting valve leakage ______would pass into the air pipes and ignite the oil deposited.A.cooling waterB.vapor from the boilerC.starting airD.hot gases
A large metallic device，mounted directly in the piping (usually located at the dock near the point where the vapor hose is attached)，designed to prevent the passage of a rapidly moving flame through the piping is called a ______.A.flame arrestorB.flame screenC.detonation arrestorD.detonation blocker
The blowers of an inert gas generation system aboard a tanker，will be automatically secured if ______．A.Normal water supply at the water seal is lostB.The temperature of the inert gas being delivered to the cargo tanks is more than 150℉C.The cooling water supply to the scrubbers is lostD.All of the above
What best describes for how long a gas-free test is good ________．A.For as long as is indicated on the gas-free certificateB.For the instant that it is madeC.Until valves in line with the tank or compartment are reopenedD.Until changes in temperature or pressure affect the vapor content in the space
A flame screen ______.A.permits the passage of vapor but not of flameB.prevents the passage of flammable vaporC.prevents inert gas from leaving a tankD.permits vapors to exit but not enter a tank
Each ship having an inert gas system must have a portable instruments to measure concentrations of hydrocarbon vapor in inert atmospheres and also to measure ______.A.nitrogenB.oxygenC.carbon dioxideD.water vapor
单选题The purpose of a temperature sensing device installed in the stack of a small automatically fired auxiliary steam boiler is to secure the oil burner（）Ain the event of a flame failureBin the event of a stack fireCwhen the water level reach the crown sheetDwhen the feed pump discharge pressure drops to a preset minimum
单选题The vapor pressure of a substance（）.Adecreases as temperature increasesBincreases with the temperatureCis not affected by temperatureDmay increase or decrease as the temperature rises
单选题A flame screen（）.Apermits the passage of vapor but not of flameBprevents the passage of flammable vaporsCprevents inert gas from leaving a tankDpermits vapors to exit but not enter a tank
单选题The (auto)ignition temperature is that temperature atwhich（）.Ano spark or flame is required to ignite gas or vaporBa fuel begins to give off explosive vaporsCa fuel if ignited will continue to burnDa 1% mixture of the fuel with air will explode
单选题In a compression refrigeration plant the refrigerant flows from the expansion valve and through the （） where it absorbs heat from the space being cooled and becomes a gas or vapor.AcompressorBcondenserCthrottle valveDevaporator
单选题CFC refrigerants exposed to high temperature or direct flame, will decompose and may produce（）Amethyl chlorideBammoniaChydrofluoric acidDozone
问答题The difference between a liquid and a gas is obvious (1)____ the conditions of temperature and pressure commonly found at the surface of the Earth. A liquid can be kept in an open container and fills it to the level of a free surface. A gas forms no free surface but tends to diffuse throughout the space available; it must (2)____ be kept in a closed container, as in the (3)____ of a planet’s atmosphere. The distinction was a prominent feature of early theories (4)____(describe) the phases of matter. In the nineteenth century, for example, one theory maintained that a liquid could be “dissolved” in a vapor without losing its identity, and another theory held that the two phases are made up of different kinds of molecules (分子). The theories now prevailing (5) t____ a quite different approach by emphasizing what liquids and gases have in common. They are both forms of matter (6)____ have no permanent structure, and they both flow easily. They are fluids.The (7)____(fundament) similarity of liquids and gases becomes clearly apparent when the temperature and pressure are raised somewhat. Suppose a closed container partially filled with a liquid is heated. The liquid expands, or in other (8)____, becomes less dense; some of it evaporates. In contrast, the vapor above the liquid surface becomes dense as the evaporated molecules are added to it. The combination of temperature and pressure (9)____ which the densities become equal is called the critical point. Above the critical point the liquid and the gas can no longer be (10)____(distinguish); there is a single, undifferentiated fluid phase of uniform density.
单选题The temperature at which water vapor in the atmosphere begins to condense is called the （）.Adew point temperatureBcondensation temperatureCpsychometric temperatureDabsolute humidity temperature
单选题The temperature at which the air is saturated with water vapor and below which condensation of water vapor will occur is referred to as the（）.Aprecipitation pointBvapor pointCdew pointDabsolute humidity
单选题A dry-type spark arrestor removes sparks from a diesel engine exhaust by（）Aincreasing the linear velocity of the exhaust gasesBchanging directions of exhaust gas flowCdecreasing the temperature of the exhaust gasesDaccelerating the exhaust gas through a reduced size orifice
单选题In the refrigeration compressor the temperature of the vapor is （） by compression.AraisedBrisenCreducedDmaintained constant
单选题Diesel fuel vapors （）.Acan not be ignited by a spark unless the vapor is in a confined spaceBare nontoxic in all concentrationsCcan not be ignited by a spark unless they are at their auto-ignition temperatureDare heavier than air
单选题Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?（）Acompression must be low for effective spark ignitionBcompression must be low for required horsepower and torque generationCcompression must be low to prevent pre-ignitionDcompression must be low to have effective pre-ignition
单选题The heat required to change a substance from a liquid to a gas without experiencing a temperature change is defined as the latent heat of （）.AfusionBvaporizationCsublimationDcondensation
单选题Before entering a tank，always check the vapor content（）a combustible gas indicator.AwithBbyCofDfor
单选题Each ship having an inert gas system must have a portable instruments to measure concentrations of hydrocarbon vapor in inert atmospheres and also to measure（）.AnitrogenBoxygenCcarbon dioxideDwater vapor
单选题The blowers of an inert gas generation system aboard a tanker，will be automatically secured if（）.Anormal water supply at the water seal is lostBthe temperature of the inert gas being delivered to the cargo tanks is more than 150°FCthe cooling water supply to the scrubbers is lostDall of the above
单选题To find the cause of a gasoline engine’s failure to start，you should（）.ABreak the joint in the fuel line at the engine and let the gas run in the bilgesBDisconnect the wires at the spark plugs and make the spark jump the gapCPrime the engine with ether through spark plug openingsDVentilate the space，then check the battery，spark plugs，carburetor，and fuel line
单选题The lowest temperature at which a liquid gives off enough vapor to ignite in the presence of an ignition source is called its （）.Aboiling pointBflash pointCviscosity pointDtoxic point