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
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 loads
B.erosion at high engine loads
C.overload at high engine loads
D.scaling at all exhaust temperatures
相关考题：
A water jacket is placed around the exhaust manifolds of propulsion diesel enginesto( ).A.reduce heat radiation to the engine roomB.aid in preventing turbocharger overheatingC.condense and drain moisture from exhaust gasesD.dampen exhaust gas pulsations in the manifold
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
The maximum pressure developed by a waste heat boiler is determined by the main engine exhaust ______.A.gas compositionB.gas temperatureC.pressureD.timing
单选题Before shutting off the fuel supply to stop a medium or high–speed diesel engine, why is it necessary to allow the engine to idle for a few minutes?（）ATo prevent internal damage form local overheatingBTo ensure the fuel nozzles are flushed cleanCTo clear the smoke stackDTo let the waste heat boiler reduce its rate of steam generation
单选题A water jacket is placed around the exhaust manifolds of propulsion diesel engines to（）Areduce heat radiation to the engine roomBaid in preventing turbocharger overheatingCcondense and drain moisture from exhaust gasesDdampen exhaust gas pulsations in the manifold
单选题White smoke issuing from the exhaust of an auxiliary diesel engine valve opening （）Athe engine is overloadedBthe engine is coldCthere is too much lube oil in the cylindersDthe turbocharger is fouled
单选题An exhaust gas bypass is installed on a waste heat boiler in order to （）.Abypass exhaust gas at high loads to prevent excessive back pressureBbypass a portion of the exhaust gas at peak loads for better efficiencyCrecycle exhaust gas to the turbochargerDminimize moisture condensation in the boiler gas passages at low loads
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An auxiliary diesel engine may fail to start due to（）Alow exhaust back pressureBhigh lube oil temperatureCinsufficient cranking speedDexcessive fuel atomization
单选题High exhaust temperature and black smoke exhausting from an auxiliary diesel engine can be caused by （）.Aengine overloadBlow combustion temperatureCplugged fuel nozzle holesDexcessive compression pressure
单选题Trunk type diesel engine pistons are effectively cooled when heat is（）Aradiated through the engine blockBtransferred to water cooled cylinder wallsCconducted through the piston crownDtransferred to escaping exhaust gases
单选题Diesel engine waste heat boiler construction is usually of the fire-tube or（）Acyclone furnace boiler typeBdry back boiler typeCwater-tube typeDcritical circulation boiler type
单选题The maximum pressure developed by a waste heat boiler is determined by the main engine exhaust （）.Agas compositionBgas temperatureCpressureDtiming
单选题Exhaust pipes for separate diesel engines can be combined only when （）Aspace limitations prevent separately run pipesBthe engines are small auxiliary unitsCthey are arranged to prevent gas backflow to each engineDa waste heat boiler is installed
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If an auxiliary diesel engine frequently stalls, the trouble may be caused by （）Alow exhaust back pressureBair in the fuel systemCgasket blow-by or leakageDincorrect assembly of idler springs
单选题If the turbocharger failed on an auxiliary diesel engine, which of the following conditions would probably occur?（）AFull power cannot be developedBThe exhaust will contain black smokeCComplete combustion will be impossibleDAll of 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When a diesel engine compression pressure is checked, the indicator is connected to the （）Acylinder exhaust portsBinjection lineCcylinder indicator cockDbanjo oiler line
单选题The PRIMARY function of a waste heat boiler is to （）.Areduce engine exhaust noiseBreduce engine back pressureCrecover heat which otherwise would be lostDincrease turbocharger efficiency
单选题If you observe smoke coming from the turbocharger of an auxiliary diesel engine, you should（）Acheck the air filter for obstructionBcheck for an exhaust leakCcheck the exhaust temperatureDsecure the engine
单选题An electrically driven automatically operating auxiliary blower is provided for slow speed and （） of a low speed diesel engine.Amanoeuvring operationsBbad combustionCcoolingDmooring trial
单选题A waste heat boiler is installed on some diesel propelled vessels to （）.Aprovide steam for emergency propulsionBprovide steam for the turbo-generatorCheat the waste water tanksDsteam for warming engines
单选题A SECONDARY function of a waste heat boiler is to （）.Areduce engine exhaust noiseBreduce engine back pressureCincrease engine cycle efficiencyDincrease turbocharger efficiency