Cooling of engines is achieved by circulating a cooling liquid around internal ______within the engine.A.airB.passagesC.pipesD.means
Cooling of engines is achieved by circulating a cooling liquid around internal ______within the engine.
A.air
B.passages
C.pipes
D.means
相关考题：
The space between cylinder liner and jacket is called _____.A.the cooling waterB.the circulating waterC.the coolerD.the cooling water space
The cooling liquid used for the cylinder may be referred to as _____.A.jacket waterB.make-up waterC.boiler waterD.flushing water
Diesel engines are started by supplying into the cylinders in the appropriate sequence for the required direction.A.cooling waterB.compressing airC.compressed airD.cylinder oil
The temperature of the refrigerant in the evaporator coil depends mostly upon the ___.A.refrigerant pressure in the evaporatorB.cooling water temperature to the condenserC.heat load in the refrigerator compartmentD.solenoid valve in the liquid line
第一组Older loop scavenged engines may have a single injector mounted centrally in the cylinder head. Because the exhaust valve is in the center of the cylinder head on modern uniflow scavenged engines the fuel valves (2 or 3) are arranged around the periphery of the head. The pressure at which the injector operates can be adjusted by adjusting the loading on the spring. The pressures at which the injectors operate vary depending on the engine, but can be as high as 540 bar. Some injectors have internal cooling passages in them extending into the nozzle through which cooling water is circulated. This is to prevent overheating and burning of the nozzle tip. Injectors on modern engines do not have internal cooling passages. They are cooled by a combination of the intensive bore cooling in the cylinder head being close to the valve pockets and by the fuel which is re-circulated through the injector when the follower is on the base of the cam or when the engine is stopped. As well as cooling the injector, re-circulating the fuel when the engine is stopped keeps the fuel at the correct viscosity for injection by preventing it from cooling down. Fuel injectors must be kept in good condition to maintain optimum efficiency, and to prevent conditions arising which could lead to damage within the cylinder. Injectors should be changed in line with manufacturers recommendations, overhauled and tested. Springs can weaken with repeated operation leading to the injector opening at a lower pressure than designed. The needle valve and seat can wear which together with worn nozzle holes will lead to incorrect atomization and dribbling.Modern uniflow scavenged engines have______.A.a single injector mounted in the center of the cylinder headB.several injectors mounted around the external boundary of the cylinder headC.a single injector mounted at the external boundary of the cylinder headD.several injectors mounted in the center of the cylinder head
Cooling water is circulated through______in some injectors.A.the nozzleB.the nozzle tipC.the internal passagesD.the fuel re-circulated
Diesel engines are started by supplying_____into the cylinders in the appropriate sequence for the required direction.A.cooling waterB.compressing airC.compressed airD.cylinder oil
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?A.A shortage of liquid refrigerant.B.Excessive frost on the evaporator.C.Excessive condenser cooling water.D.Insufficient condenser cooling water flow.
Sub-cooling is a method of reducing the temperature of the liquid refrigerant below its ______.A.freezing pointB.floc point(浊点)C.condensing temperatureD.compression temperature
Modern desktop computer systems require the following to properly dissipate heat（）A、Temperature Control PanelB、Thermal CompoundC、Liquid Cooling SystemsD、Processor Heat SinkE、Case Fan
Which of the following accurately describes the meaning of redundant cooling？（）A、The source of cooling to a RAID systemB、The cooling system in a redundant power supplyC、A cooling system that can be installed in case of failureD、A second cooling system in case of a failure
Which of the following is the MOST critical component related to removing heat from the CPU?（）A、Vented caseB、Number of fansC、Thermal pasteD、Liquid cooling
Which of the following would BEST provide cooling to a processor?（）A、Case fanB、HeatsinkC、Liquid cooling systemD、CPU fan
单选题Auxiliary diesel engines can be automatically shut down as a result of （）Alow lube oil temperatureBlow lube oil pressureChigh exhaust temperatureDhigh cooling water pressure
单选题Cooling of engine is achieved by circulation a cooling liquid around internal passages within the （）.AboilerBheaterCengineDcooler
单选题In order to control thermal stresses, some types of modern engines use pistons with（）Aheavy wall and intensive coolingBheavy wall and no coolingCthin wall and no coolingDthin wall and intensive cooling
单选题The cooling of the piston is carried out by circulating （） across the underside of the crown and inside the ring belt or through specially shaped passages.Asea waterBscavenging airClubricating oilDfuel oil
单选题Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）AA shortage of liquid refrigerantBExcessive frost on the evaporatorCExcessive condenser cooling waterDInsufficient condenser cooling water flow
单选题The cooling liquid used for the cylinder may be referred to as （）.Ajacket waterBmake-up waterCboiler waterDflushing water
单选题Which of the following accurately describes the meaning of redundant cooling？（）AThe source of cooling to a RAID systemBThe cooling system in a redundant power supplyCA cooling system that can be installed in case of failureDA second cooling system in case of a failure
单选题The space between cylinder liner and jacket is called （）.Athe circulating tankBthe scavenge boxCthe cooling water spaceDthe cooler
单选题Cylinder liners from older lower powered engines had a uniform wall thickness and the cooling was achieved by circulating cooling water through a space formed between （）.Acrown and skirtBliner and jacketCring and grooveDjacket and block
单选题Which of the following statements is correct concerning diesel engine cooling water systems?（）AEach engine must have its own engine driven cooling water pump capable of providing cooling for all ranges of operationBpropulsion engines with bores exceeding 200 mm are to be fitted with a means to display the cooling water temperature of each cylinderCAt least two independent sea suctions are to be provided for supplying water to the engine jackets or to the heat exchangersDSuitable strain are to be fitted between the circulating pumps and heat exchangers when sea water is used for direct cooling
单选题If the water level dropped rapidly in the expansion tank of a closed diesel engine cooling water system, you should suspect a （）.Aloss of suction in the circulating pumpBleak in the primary cooling systemCbroken raw water pump shaftDburned or cracked piston in one cylinder
单选题（）diesel engines generally have two systems of lubrication:（）a total loss system feeding and a circulating system lubricating the running gear and cooling the pistons.ALarge crosshead type；crossheadsBHigh speed；the cylindersCLarge crosshead type；the cylindersDFour-stroke；pistons and cylinders
单选题Which of the following statements is correct for the design and installation of diesel engine cooling water systems?（）AAn alarm device with audible and visible signals is required for all cooling water systemsBPropulsion engines with bores over 200 mm are to be fitted with cooling water jacketsCEach totally enclosed cooling system shall be provided with a suitable head tankDDrain cocks are to be provided at the lowest points of all cylinder water jackets
单选题Some diesel engines are fitted with a thermometer in the cooling water outlet from each cylinderIf the cooling water temperature from all cylinders begins to rise above normal, you should suspect （）Aincrease blow-by in all cylindersBincomplete combustion in all cylinderCoverloading in all cylindersDinsufficient fuel delivery to all cylinders