网友您好, 请在下方输入框内输入要搜索的题目:

题目内容 (请给出正确答案)
单选题
Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to()
A

facilitate bi-directional operation

B

provide the greatest pump efficiency

C

prevent pump clogging from marine growth

D

prevent cavitation at the pump outlet


参考答案

参考解析
解析: 暂无解析
更多 “单选题Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to()A facilitate bi-directional operationB provide the greatest pump efficiencyC prevent pump clogging from marine growthD prevent cavitation at the pump outlet” 相关考题
考题 The cooling water of the diesel engine should be treated with chemical, because it contains .A.alkaliB.acidityC.salinityD.impurity

考题 High diesel engine cooling water temperatures can be caused by ______.A.air in the cooling systemB.an overhauled water pumpC.correct amount of coolantD.no air in the cooling system

考题 单选题If a diesel engine were running at 20% overload with a smoky exhaust, you should()A stop the engine immediately to prevent damageB increase lube oil pressureC slow the engine allowing it to gradually coolD decrease the cooling water it temperature to the water jacket

考题 单选题The device allowing for the change in volume of the cooling water in a propulsion diesel engine closed cooling system is the ().A fresh water expansion tankB sea water expansion tankC thermostatic expansion valveD jacket water cooler accumulator

考题 单选题One of the purposes for water cooling the exhaust manifold in marine diesel engine is to ()A reduce lube oil temperatureB raise exhaust temperature reduceC excessive heating of engine roomD reduce load on cooling water pump

考题 单选题The purpose of treating the cooling water of the diesel engine is to() Ⅰ. resist the scale formation in the cooling chamber Ⅱ.lubricate the engine part Ⅲ.increase thermal capacity Ⅳ.resist corrosionA Ⅰ+ⅡB Ⅱ+ⅢC Ⅲ+ⅣD Ⅰ+Ⅳ

考题 单选题If the cooling water temperature and the lube oil temperature in a diesel engine are too high, the cause can be ()A a dirty lube oil strainerB internal water leaksC an oil suction line restrictionD excessive wears of the cooling water pump

考题 单选题Why the cooling water of the diesel engine should be treated? Because the()A Cooling water is alkalescenceB cooling water is acidityC cooling water has salinityD cooling water has impurity

考题 单选题If the jacket water temperature in an auxiliary diesel engine cooling system is lower than normal, the probable cause is ()A air binding of the engine cooling systemB a cracked water cooled exhaust manifoldC blockage in the heat exchangerD faulty operation of the thermostat

考题 单选题In order to reverse the rotation of a two-stroke/cycle loop scavenged, direct reversing, propulsion diesel engine, the cam positions must be changed for the ().A starting air and fuel pumpsB piston cooling pumpsC exhaust valvesD all of the above

考题 单选题High diesel engine cooling water temperatures can be caused by ().A air in the cooling systemB an overhauled water pumpC correct amount of coolantD no air in the cooling system

考题 单选题In a closed cooling system for a turbocharged, four-stroke/cycle diesel engine, fluctuating water pressure can be caused by ()A improper venting of the cooling systemB carrying the expansion tank water level too highC a totally clogged impeller in the cooling water pumpD an incorrectly set cooling system temperature control

考题 单选题Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to()A facilitate bi-directional operationB provide the greatest pump efficiencyC prevent pump clogging from marine growthD prevent cavitation at the pump outlet

考题 单选题The expansion tank for a diesel engine closed cooling system is designed to maintain a constant head on the system and ().A reduce water temperatureB reduce water turbulenceC provide an air cushionD allow for an increase in water volume as the engine warms up

考题 单选题Corrosion inhibitors and/or soluble oils are added to diesel engine cooling systems to ()A maintain low pH in the cooling waterB reduce the cooling water temperatureC increase cooling water hardnessD form a protective film on metal surfaces

考题 单选题During maneuvering operations for a direct reversing large, low-speed, main propulsion diesel engine, which of the following actions is used to stop the shaft from turning prior to reversing the engine rotation?()A Flywheel inertiaB Admission of starting airC The way of the vesselD securing of fuel to the cylinders

考题 单选题The cooling water of the diesel engine should be treated, because it has()A alkale scenceB acidityC salinityD impurity

考题 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 ()A raw water pump dischargeB expansion tank outletC cooling water heat exchangerD outlet engine jacket water outlet

考题 单选题Which of the following statements is correct concerning diesel engine cooling water systems?()A Each engine must have its own engine driven cooling water pump capable of providing cooling for all ranges of operationB propulsion engines with bores exceeding 200 mm are to be fitted with a means to display the cooling water temperature of each cylinderC At least two independent sea suctions are to be provided for supplying water to the engine jackets or to the heat exchangersD Suitable strain are to be fitted between the circulating pumps and heat exchangers when sea water is used for direct cooling

考题 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 ().A loss of suction in the circulating pumpB leak in the primary cooling systemC broken raw water pump shaftD burned or cracked piston in one cylinder

考题 单选题Which of the following problems can cause fluctuating pressures in the closed cooling system of a main propulsion diesel engine?()A Defective temperature controls in the systemB Cavitation in the cooling water pumpC Opened vent in the cooling systemD Restricted water passages in the engine

考题 单选题Temperature control valves installed in the jacket cooling water system of a diesel engine modulates the rate of water flow through the ().A cooling water pumpB nozzle cooling passagesC cylinder jacketsD heat exchanger

考题 单选题In a diesel engine cooling water system, a pH of 60 indicates a/an ().A slightly acidic conditionB slightly alkaline conditionC overtreatment of waterD neutral condition of water

考题 单选题About the jacket water, that of the auxiliary engines usually() is circulated by pumps, and the main engine usually ()A an engine-driven;as wellB an engine-driven;has an independent pumpC an independent;as wellD an independent;has an engine-driven pump

考题 单选题Fuel oil transfer systems used onboard diesel propelled vessels are required to have ().A two fuel oil transfer pumps provided where one is to be independent of the main engineB two fuel oil transfer pumps, with a combined capacity exceeding the maximum consumption of the main engineC engine driven transfer pumps and only used in constant speed applicationsD the capacity of the engine driven pump exceed the consumption rate of the engine to which it is attached

考题 单选题Which of the following conditions will develop if the flow of ‘raw’ cooling water to diesel engine is obstructed?()A Air will enter the cooling systemB Carbon will plug the water cooled exhaust manifoldsC The jacket water temperature will riseD The lube oil viscosity will increase

考题 单选题In the process of the stand-by, warm-up the engine usually through give preheat of which parts of the diesel engine?()A cooling water of the cooling systemB fuel of the FO systemC LO of the LO systemD cooling water of the cooling system and LO of the LO system

考题 单选题High diesel engine cooling water temperatures can be caused by ().A a worn water pumpB not enough coolantC air in the cooling systemD all of the above