[单选题]The temperature is an indication of the amount of the fuel burnt in the cylinder concerned and, in general, temperatures of all cylinders should be______with each other.
[单选题]The diesel engine consumes considerably less fuel than the steam engine for equal output; ____ enables a motor-ship to load more cargo.
[问答题]Hand control of excitation is difficult so use is made of an automatic voltage regulator (AVR) . The AVR consists basically of a circuit fed from the alternator output voltage which detects small changes in voltage and feed a signal to an amplifier which changes the excitation to correct the voltage. Stabilizing features are also incorporated in the circuits to avoid ‘hunting’ (constant voltage fluctuations) or overcorrecting. The statically excited alternator has a static excitation system instead of a d.c. exciter. This type of alternator will more accept the sudden loading by direct online starting of large squirrel cage motors. The static excitation system uses transformers and rectifiers to provide series and shunt components for the alternator field, that is, it is compounded. Brushes and sliprings are used to transfer the current to the field coils which are mounted on the rotor. The terminal voltage from the alternator thus gives the no-load voltage and the load current provides the extra excitation to give a steady voltage under any load condition. The compensation necessary for speed variation requires that a voltage regulator be also built into the system. The brushless high speed alternator was also developed to eliminate d.c. exciters with their associated commutators and brushgear. The alternator and exciter rotors are on a common shaft, which also carries the rectifiers. The exciter output is fed to the rectifiers and then through conductors in the hollow shaft to the alternator field coils. An automatic voltage regulator is used with this type of alternator.
[单选题]Cooling of engine is achieved by circulation a cooling liquid around internal passages within the _____.
[问答题]Watch requirements (a) Every member of the watch shall be familiar with his assigned watchkeeping duties. In addition, every member shall have with respect to that ship; (i) knowledge of the use of appropriate internal communication systems; (ii) knowledge of escape routes from machinery spaces; (iii) knowledge of engine room alarm systems and the ability to distinguish between the various alarms with special reference to the CO2 alarm; (iv) knowledge of the positions and use of the fire-fighting equipment in the machinery spaces. (b)The composition of an underway watch shall, at all times, be adequate to ensure the safe operation of all machinery affecting the operation of the ship, in either automated or manual mode and be appropriate to the prevailing circumstances and conditions. To achieve this, the following, inter alia, shall be taken into account: (i) Adequate supervision, at all times of machinery affecting the safe operation of the ship; (ii) condition and reliability of any remotely operated propulsion and steering equipment, their controls , control location and the procedures involved in placing them in a manual mode of operation in the event of break-down or emergency; (iii) location and operation of fixed fire detection, fire extinction or fire containment devices and apparatus; (iv)use and operational condition of auxiliary, standby and emergency equipment affecting the safe navigation, mooring or docking operations of the ship; (v) steps and procedures necessary to maintain the condition of machinery installations in order to ensure their efficient operation during all modes of ship operation; (vi)any other demands on the watch which may arise as a result of special operating circumstance, (c)At an unsheltered anchorage the chief engineer officer shall consult with the master whether or not to maintain an underway watch. Fitness for duty The watch system shall be such that the efficiency of the watch is not impaired by fatigue. Duties shall be so organized by the chief engineer officer that first watch at the commencement of a voyage and the subsequent relieving watches are sufficiently rested and otherwise fit for duty. Protection of the marine environment All engineer officers and engine room ratings shall be aware of the serious effects of operational or accidental pollution of the marine environment and shall take all possible precautions to prevent such pollution, particularly within the framework of relevant international and port regulations. (The following questions are based on the passage above)
[问答题]The main starting valve (automatic valve) is operated by a pneumatic actuator, and similar actuator controls are fitted for slow turning and to the distributor or timing valves. The main starting valve can be locked shut and this must be done before the engine turning gear is engaged. When this valve is open, air passes through a non-return valve and flame arrester to the main manifold supplying pressure to the cylinder valves, one of which is fitted to each cylinder of the engine. The cylinder air start valves are normally held closed by a compression spring together with cylinder pressure acting over the valve lid. Air from the manifold enters these valves where it forms a pressure balance between the underside of the valve lid and a balance piston of equal area on the valve spindle. Consequently this does not cause the valve to open. Cylinder valves are opened when operating air, transmitted from the distributor, applies pressure to the larger operating piston on the valve spindle. As the valve is forced open, starting air from the manifold enters the cylinder, applying pressure on the piston and causing the engine to rotate in the corresponding direction. To close the cylinder valves the connection from the distributor is opened to atmosphere, allowing the spring to close the valve and return the operating piston.
[问答题]High sulphur content increases the risk for corrosion and wear, particularly at low loads, and may contribute to high- temperature deposit formation. The lubricating oil specification must be matched to this. High vanadium content causes hot corrosion on exhaust valves particularly in combination with high sodium content. The corrosion increases with increased temperatures (increased engine output). High Conradson carbon may cause deposit formation in combustion chamber and exhaust system, particularly at low engine output. High content of asphaltenes may contribute to deposit formation in combustion chamber and exhaust systems ( at low loads). Asphaltenes may under certain circumstances, precipitate from the fuel and block filters and/or cause deposits in the fuel system. Precipitating asphaltenes may also cause excessive centrifuge sludge. Heavy fuels may contain up to 1% water at delivery. Water may also originate from the installation bunker tanks. To avoid difficulties in the engine fuel injection system water must be removed. Although low ignition quality produces long ignition delay, advancing the ignition timing makes things only worse; fuel is injected at a lower compression temperature and this will produce even longer ignition delay. Aluminum + Silicon. Fuels may contain highly abrasive particles composed of aluminum and silicon oxides known as "catalytic fines" from certain refining processes. If not removed by efficient fuel treatment, wear down of high pressure fuel pumps, nozzles and cylinder liners in a few hours may expected.
[单选题]The main propulsion diesel continues running after you try to shut down. You should now attempt to ____.
[单选题]In a common sea water cooling system, from the sea suction one of a pair of sea water circulating pumps provides sea water which circulates the lubricating oil cooler, the jacket water cooler and the piston water cooler before _____.
[单选题]When the normal compression ratio of a diesel engine is not very high, misfiring at light loads may be caused by ________.
[单选题]An increased pressure differential between the inlet and outlet of a strainer usually indicates the strainer is _______.
[单选题]To shut down a diesel engine after it exceeds the set maximum speed, which type of device listed should be used?
[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_____.
[单选题]目前，船舶柴油机推进装置的发展趋势是______． Ⅰ．大型低速机向少缸数、大缸径发展；Ⅱ. 大型低速机向多缸数、大缸径发展；Ⅲ．大型低速机向少缸数、小缸径发展；Ⅳ．控制技术向电子化、智能化发展；Ⅴ．双燃料柴油机用于散货船的前景可观；Ⅵ．滚装客船首选大功率中速机。
[单选题]Which of the following statements describes the_____relationship between viscosity and specific gravity?
[单选题]Your vessel is entering a tropical area and high humidity is expected. To avoid condensation in the main engine’s air cooler, it is recommended to____.
[单选题]Air in the fuel lines to the fuel injection nozzles of a diesel engine will cause the engine to ______.
[单选题]The transmission system transmitting power from the engine to the propeller is composed of shafts, bearings, and______.
[单选题]Since the burning or combustion takes place within the engine itself, the engine is known as _____.
[单选题]The presence of scale and dirt on the saltwater side of a lube oil cooler is usually indicated by______.
[单选题]Use the following equation to calculate the cylinder oil feed rate at specified MCR: Q = BS×Pe×24×10-3 (kg/24 h), Q = Feed rate at specified MCR BS = Basic Setting, see Item 4.3 Pe = Effective engine power at specified MCR Engine Type Pe (bhp) at Specified MCR Basic Setting (g/bhph) at Specified MCR 6L60MC 15600 1.0 6S80MC 29700 1.2 The cylinder oil feed rate at specified MCR of 6L60MC is ____.