【正文】 r cooler accumulator Jimei University 0819 Scavenging in a fourstroke/cycle diesel engine occurs during the_____. A. last part of the exhaust stroke, and the first part of the intake stroke B. last part of the intake stroke only C. early part of the injection stroke only D. early part of the power stroke 0820 The color of the exhaust from a diesel engine should be_____. A. clear B. hazy light brown C. hazy light blue D. hazy light grey Jimei University 0821 In a large, slowspeed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running? A. Bed plate B. Column C. Entablature D. Tie rod Jimei University 0822 The lube oil cooler is located after the lube oil filter in order for_____. A. the filter to operate more efficiently B. the lube oil cooler to be bypassed C. positive lube oil pump suction to be assured D. galvanic action in the cooler to be minimized 電位差引起的腐蝕 * 過(guò)濾前冷卻液體流動(dòng)性差 ， 過(guò)濾效果就差 Jimei University 0823 The highest pressure in any closed diesel engine freshwater cooling system is at the _____. A. jacket water outlet B. expansion tank inlet C. heat exchanger inlet D. cooling water pump outlet Jimei University 0824 Concerning diesel propelled vessels, the astern power is to provide for continuous operation astern_____. A. equal to that available for ahead operation B. at 70 percent of the ahead rpm at rated speed C. while underway and under all normal conditions D. at 70 percent of the ahead rpm of average continuos sea speed Jimei University 0825 In a twostroke/cycle diesel engine, the process of scavenging begins as the_____. A. piston nears and passes TDC B. latter part of the down stroke C. piston passes BDC D. early part of the down stroke *開(kāi)始掃氣是在活塞下行時(shí)掃氣口一打開(kāi)就掃氣 Jimei University 0826 If the fire goes out熄火 in an automatically fired auxiliary boiler and the burner continues to supply fuel, there is a potential danger of_____. A. overpressure and dry firing B. a severe furnace explosion C. spalling( 散裂 ) damage to the brickwork (耐火磚 ) D. heat damage to the atomizer Jimei University 0827 Improper maintenance of an automatic auxiliary boiler oil burner could result in _____. A. fuel pump failure B. fan motor failure C. increased feedwater consumption D. decreased boiler efficiency Jimei University 0828 The bearings used to support the crankshaft are generally called_____. A. line shaft bearings B. connecting rod beatings C. main bearings D. support bearings Jimei University 0829 With respect to the flow of lubricating oil through a diesel engine, the lube oil coolers are located after filters in order to_____. A. allow filtration of less viscous oil B. decrease the pressure drop across the filter C. improve overall filtration(過(guò)濾 ) D. all of the above Jimei University 0830 In any diesel engine closed freshwater cooling system, the lowest pressure exists at the _____. A. jacket water outlet B. cooling water pump outlet C. heat exchanger outlet D. expansion tank atmospheric vent Jimei University 0831 Maintaining the lowest possible scavenging air temperature at all times is not remended due to the possibility of the_____. A. air charge density being too high B. piston crown surfaces being too cold C. formation of excessive quantities of condensate D. pression pressure being greatly reduced Jimei University 0832 After a normal, or safety shutdown, automatic bustion control systems for an auxiliary boiler are designed to prevent the immediate refiring of a burner in order for the_____. A. furnace to be repurged(再次掃氣 ) B. electric charge to buildup in the igniter C. fuel pump to restart D. drum level to stabilize Jimei University *0833 Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the _____. A. main bearings B. connecting rod bearings C. piston pin bushings D. All of the above Jimei University 0834 The outlet from an expansion tank of a closed freshwater cooling system should be piped to the_____. A. cylinder head water outlet header B. cylinder jacket inlet main C. heat exchanger inlet connection D. jacket water pump suction line 0835 The intake valves in a diesel engine are reseated by_____. A. cam followers B. push rods C. bustion gases D. valve springs Jimei University 0836 The main function of tie rods in the construction of large, low speed diesel engines is to _____. A. stiffen the bedplate in way of the main bearings to increase the engine39。s longitudinal strength B. accept most of the tensile (拉力 )loading that results from the firing forces developed during operation C. mount the engine frame securely to the hull to prevent shaft coupling misalignment D. connect the crosshead solidly to the piston rod Jimei University 0837 On most modern diesel engines, the main and connecting rod bearings receive their lubricating oil by_____. A. banjo feed B. splash feed C. gravity feed D. pressure feed 0838 The expansion tank in a die