单选题The interior of some diesel engine saltwater heat exchangers are protected from corrosion by the use of（）Aaluminum platesBlead cathodesCcopper baffle platesDsacrificial zincs
单选题
The interior of some diesel engine saltwater heat exchangers are protected from corrosion by the use of（）
A
aluminum plates
B
lead cathodes
C
copper baffle plates
D
sacrificial zincs
参考解析
解析：
暂无解析
相关考题：
From the last paragraph we can learn that __A. some pipes have to be re-arranged in winterB. the system can do more than warming up the buildingC. the exchangers will pick up heat from the street surfaceD. less heat may be collected in winter than in summer
In an auxiliary diesel engine bypass type lubricating oil system, the main lube oil pump forces_______ .A.all of the oil used by the engine through a filterB.some of the oil used by the engine through a filterC.some of the oil used by the engine through a centrifugeD.all of the oil used by the engine through a centrifuge
Which of the following conditions could contribute to the cracking of a diesel engine cylinder head?A.Leaking seal ringB.Insufficient heat transfer from the exhaust valvesC.Blocked cooling water passages to the headD.Excessive scavenging air provided to the engine
Which of the following factors tends to increase scale formation on the saltwater side of a heat exchanger used in a diesel engine cooling water system?A.Baffle plates that have been bent during prior removalB.Leaks m the cooler tube nestC.Operating the engine while maintaining a high sea water outlet temperatureD.A punctured sea water strainer supplying cooling water to the heat exchanger
Immediately after any diesel engine is started, the engineer should check the ______.A.crankcase pressureB.lube oil pressureC.saltwater pressureD.exhaust temperature
A bypass line provided around a waste heat auxiliary boiler in a diesel engine exhaust system, may be used to avoid boiler ______.A.corrosion at low engine loadsB.erosion at high engine loadsC.overload at high engine loadsD.scaling at all exhaust temperatures
单选题As a heat engine,（） energy is the source of power by which the diesel engine can be operated.AelectricBheatCmechanicalDexhaust
单选题In a diesel engine, offers the heat energy directly（）； works as working medium and changes the heat energy to mechanical energy（）Athe burning of the fuel； medium shaftBfuel spray； fresh airCfuel； fuel sprayDthe burning of the fuel； the burned gas mixture
单选题Which of the following factors tends to increase scale formation on the saltwater side of a heat exchanger used in a diesel engine cooling water system?（）ABaffle plates that have been bent during prior removalBLeaks in the cooler tube nestCOperating the engine while maintaining a high sea water outlet temperatureDA punctured sea water strainer supplying cooling water to the heat exchanger
单选题The diesel engine exhaust gas bypass, as fitted with some waste heat boilers, is installed to （）Aprevent engine back pressure at heavy loadsBincrease total engine efficiency at low loadsCprevent boiler corrosion at low engine loadsDimprove engine fuel consumption at any load
单选题Which of the following conditions could contribute to the cracking of a diesel engine cylinder head?（）ALeaking seal ringBInsufficient heat transfer from the exhaust valvesCBlock cooling water passages to the headDExcessive scavenging air provided to the engine
单选题If the jacket water temperature in an auxiliary diesel engine cooling system is lower than normal, the probable cause is （）Aair binding of the engine cooling systemBa cracked water cooled exhaust manifoldCblockage in the heat exchangerDfaulty operation of the thermostat
单选题Incomplete combustion in a running diesel engine can cause piston rings to become stuck as a result of （）Aresidual carbon depositsBlube oil viscosity breakdownCuneven heat expansion of the ringsDuneven heat expansion of the piston
单选题Increasing the compression ratio of a diesel engine while maintaining the designed rate of fuel flow will result in （）Aincreased horsepowerBreduced efficiencyCincreased heat lossDlower cylinder pressures
单选题In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.Afluctuates with the engine speed to some extent, independent of the engine speedBkeeps constant at all engine speed, dependent on the engine speed to some extentCkeeps constant at all engine speed, independent of the engine speedDis decided by the engine speed, constant at all engine speed
单选题In a diesel engine cooling system, the high temperature alarm contact maker will be activated on excessively high water discharge temperature from the （）Araw water pump dischargeBexpansion tank outletCcooling water heat exchangerDoutlet engine jacket water outlet
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In motor ship, （） is often used to recover some of the heat carried in the exhaust gases from the main engine.Aan diesel oil heaterBa waste heat boilerCa fresh water generatorDall the above
单选题Trunk-type diesel engine pistons are most effectively cooled by heat（）Aconducted through the engine blockBconducted to water cooled cylinder wallsCconducted through the piston crownDloss to escaping exhaust gases
单选题What preventative maintenance should be done frequently to diesel engine starting air receivers?（）ADrain the accumulated moistureBTest the relief valvesCWatch the temperature to prevent fluctuations in pressureDClean the interior to remove oil and foreign matter
单选题Heat for igniting the fuel oil in the cylinder of a diesel engine is generated by the （）Aelectronic ignition systemBcompression of air by the pistonCfriction in the fuel injectorDfuel oil bearing system
单选题The essential part of the diesel engine, whose function is to convert the heat energy into the mechanical power, is the （）.AcrankshaftBpistonCconnecting rodDbearing
单选题The purpose of compressing the air within the cylinder of a diesel engine is to （）Aproduce the heat for ignitionBdecrease injection lagCincrease ignition delayDaid in exhausting burnt gases
单选题Which of the general advantages listed does the electrical pyrometer have over the mechanical pyrometer?（）AWhen heated, it will move proportional to the amount the metal has lengthened or expandedBThe pointer associated with the pyrometer scale can be made to also measure engine RPMCIt can be utilized in exhaust manifolds and heat exchangers interchangeablyDIt can indicate temperature at a distant point from the source heat
单选题The function of diesel engine piston compression rings is to （）.Aprevent piston side thrustBprevent engine friction lossesCtransmit heat from the piston to the cylinder linerDremove oil from the cylinder combustion space
单选题Sacrificial zinc anodes are used on the saltwater side of diesel engine heat exchangers to（）.Areduce electrolytic action on heat exchanger metalsBkeep heat transfer surfaces shiny and cleanCprevent rapid accumulation of marine growthDprovide a protective coating on heat exchanger surfaces
单选题A faulty thermostatic bypass valve, in a diesel engine cooling system, can result in （）Aexcessive time required for warming-upBexcessive freshwater corrosionCscale formation on the saltwater sideDsaltwater mixing with the freshwater