轮机英语 lesson 10.ppt

1、LESSON 10,PREPARATION FOR STAND-BY,When instructions have been received that the main engine is to be prepared for running the following procedure for any make of marine diesel engine should be followed:,1. Check that the fuel, lubricating oil and cooling water are at working level and drain any wat

2、er or sludge from all lubricating oil and fuel tanks.,The purified fuel tanks to be raised to the required temperature. Switch on the power to various auxiliaries and to the control console.,2. Check that all valves in the various systems are operational and check the jacket water and lubricating pu

3、mps. Any leaks to be rectified(改正) immediately.,3. Start up jacket water pumps and check pressures. Bring into operation the heating system of the cooling water.,The temperature of the cooling water returns from the jackets, liners and pistons should be raised gradually to 60(140).,The warming throu

4、gh period should extend over a period of approximately four hours.,4. Check through the crankcase, etc, for any tools, obstructions(障碍物) or waste material and remove them and make sure that everything is correct(in good order).,5. Start up lubricating oil pumps and check that at working pressure, oi

5、l flows uniformly(均匀地) from all the bearings and then close up the crankcase.,On engines having oil cooled pistons the lubricating oil pre-heater must be put into operation,and the rate of heating so arranged that the temperature of the piston cooling oil returns are 32 to 35 over a period of at lea

6、st two hours.,6. Start up injector cooling pumps, check pressure. Bring into operation the heating system for the fuel injector cooling water tank to raise the temperature of the water to 60 over a period of about two hours.,If the engine is to be started on high viscosity fuel the temperature of th

7、e water should be raised to 77 to 82.,7. If hoppers or sight glasses are fitted check that there is an adequate flow of coolant through each piston, cylinder head, cylinder jacket, turbocharger casing and injector.,8. Check that any vents in the systems are clear to allow the free flow of air from t

8、he cylinder cooling passages and turbochargers.,The charge air coolers should also be vented. Unvented spaces encourage the formation of steam, corrosion, erosion(侵蚀) and local overheating.,9. Start up fuel priming pumps, check pressure. The system should be cleared of air by means of the various ai

9、r vent cocks or valves.,With the fuel oil at about the working pressure, check for leakage.,If the engine can be started and maneuvered on high viscosity fuel, the temperature of the fuel reaching the injectors should be raised to such a point that the viscosity is less than the required value, i.e,

10、 27 centistoke(厘沲).,10. Check that the level of oil in the turbocharger is correct. 11. Ensure that starting and control air valves are shut off and engage the turning gear.,12. Start the turning gear, and with some one hand-operating(manual) the cylinder lubricators at regular intervals, and with t

11、he indicator cocks open, and with the control gear in the stop position, give the engine at least one complete turn.,Whilst the engine is turning check to see that no water is leaking into crankcase, scavenge air belt, or from the indicator cocks. Having found all correct, take out the turning gear.

12、,13. Pump up the starting air reservoirs to their maximum pressure and drain the air reservoirs and air system.,14. The scavenge drain should be cracked open, the drains from diaphragm(横隔板) glands should be slightly open.,15. All hand oil- and grease- lubricated bearing must be checked to see that t

13、heir lubrication is correct, the control linkage is well lubricated and easily operated.,16. Check the engine room telegraph(车钟) for proper functioning and at the same time check the telephones to the bridge and Chief Engineers office.,17. Check the reversing and control gear, running direction safe

14、ty interlocks, auto-shut-down devices, alarm devices for correct functioning.,18. Open shut-off valve(截止阀) for starting air tank, close the drain valve on the starting air manifold.,19.Check and if necessary, adjust oil, water and fuel pressure and temperatures.,20.Switch the controls on the auxilia

15、ry blowers to the automatic position and start the fuel booster(增压) pump.,21. Inform bridge that engine room would like to turn engine over slowly on air. On engine with bridge control the control selector must be turned to the desired position.,22. Start the engine on air briefly on both direction

16、and then close all indicator cocks.,23. Finally, before stand-by is rung on the engine telegraph, it is usually to give the main diesel engine a brief trial on power ahead and astern.,READING MATERIAL,A. ARRIVAL IN PORT,If the engine is to be manoeuvred on diesel oil the change-over from heavy oil s

17、hould be made about one hour before engine movements are expected.,An additional generator engine should be started to provide a spinning(自转, 绕转, 空转) power reserve during the arrival period, and the starting air system should be drained.,If permissible, a test reversal of the engine should be carrie

18、d out prior to arrival in restricted waterway(狭窄水域).,After finish with engine is given, ensure that the telegraph is at stop, the fuel control or speed adjusting lever is at zero and the starting air lever is in the neutral position.,Shut the starting air valve and starting air tanks, close the auto

19、matic starting air valve, if fitted, isolate control air to engine.,Open drain cocks on the starting air manifold and ensure that there is no pressure anywhere in the starting air line.,The fuel booster pump and steam to fuel heater, together with fuel pipe heater tracer lines should be shut off as

20、soon as the finished with engines order is acknowledged.,Engage the turning gear and lock the lever, open the indicator cocks. By-pass the jacket water and lubricating oil coolers and continue circulating the coolant.,The cooling water temperature should be gradually reduced over a period of 8 hours

21、 to allow the engine to cool down to an even temperature equal to the inlet temperature of the cooling water.,This should also be the procedure when lubricating oil is used for piston cooling.,Crankcase lubricating oil pumps should be kept running for about half an hour and oil then pumped up to the

22、 gravity tank(重力油柜) for treatment.,The main engine should be turned through three or four complete turns at first and through one turn at intervals during cooling.,The cylinder lubricators should be operated by hand during the turning.,Open all drain cocks of the scavenge air receiver, diaphragm gla

23、nds, scavenge spaces and exhaust gas systems.,Shut down the lubricating oil pump and open up the crankcase for running gear inspection, but it should not be opened until 15 minutes after the engine is shut down,the staff should also be engaged in thoroughly cleaning the engine externally which of co

24、urse is easier to do when the engine is still warm.,If in port for only a few days, keep the cooling water circulating at near normal temperature by using either a heating system or the heat of the cooling system from the auxiliary engines.,At regular intervals the engine should be turned over by tu

25、rning gear with the indicator cocks open,and the lubricating oil pumps in operation, and the cylinder lubricators worked by hand to minimize corrosive action on the liners.,In high humidity climates the engine should be turned over twice a day.,All fastenings (nuts, bolts, etc.) to be tested for tig

26、htness, notes taken of all leaking glands, and excessive lubricating oil leakage from bearings and connections, and any damage to be corrected before the engine is next used.,Any adjustments needed to improve efficiency noted during the previous voyage to be carried out.,Spare parts and the stores t

27、o be checked, including consumption of all lubricating and fuel oils and other consumable. Replacements are, if necessary, to be requisitioned.,If the engine is to remain idle for several weeks it must be given an extra cleaning and all bright parts suitably protected against corrosion.,The cylinder

28、 liners and pistons should be thoroughly oiled. This could be achieved by turning the engine with the turning gear and operating the cylinder lubricators by hand.,Should the auxiliary engines and boilers be put out of action and there is a danger of frost then the water cooling system should be thor

29、oughly drained.,Chemically clean charge air coolers if necessary. Turbocharger air filter to be inspected and if necessary washed in a bath of paraffin(煤油) and then thoroughly dried before reassembly.,B.MAINTENANCE AND OVERHAULING(大修,彻底检修),Satisfactory and proper operation of the engine depends not

30、only on correct manoeuvring but also on how well it is kept in order.,Regular maintenance of the engine helps a lot in preventing early wear of parts and in ensuring a long service as well as the working efficiency of the engine.,With various types of engines, of course, the maintenance and overhaul

31、, is different. Instruction books are to be referred to whenever necessary.,The individual parts of the engine should be inspected and thoroughly cleaned at regular intervals.,The periods for such overhaul work depend largely on the quality of the lubricating oil and fuel used, on the load of the en

32、gine and on the efficiency of the operator in locating troubles and remedying them in time.,During overhaul the safety rules have to be observed as required in order to prevent the danger of accidents.,Special precaution is necessary when the engine is running with the lagging removed.,During overha

33、uls, with the engine shut down, safety measures should be taken to avoid undesirable turning of the crankshaft.,All pipes should be pressure relieved before the repair work is started. Read the pressure gauges and/or check the pipe by carefully loosening the screw plugs(插头，插销) or connections.,If som

34、e parts of the running gear are dismantled, before using the turning gear, make sure that no loose parts are jammed(上紧，卡住) in the crankcase where it is easy for them to cause damage.,During dismantling work, lubrication lines and orifices(孔, 口) must be sealed off.,The main bearings and the connectin

35、g-rod bearings should be checked at regular intervals.,In some cases the bearing clearance may increase to approximately twice its original size.,Defective bearing shells should be turned out of the housings and renewed.,The piston, as a rule(通常), should be lifted out after a period of operation and

36、 cleaned with the piston rings renewed if necessary.,If the piston rod stuffing box is carefully handled and thoroughly greased, it requires overhaul only when the piston is removed.,In such a case, the gap clearance(天地间隙) of the sealing rings and fire rings(顶环) must be reset to original value and t

37、he worn-out parts replaced.,The withdrawing of the cylinder liners, in general(as a rule), depends on their wear. This may amount to approximately 1/120 of the diameter in some engines.,When carrying out overhaul, thoroughly check to see that all bolts are properly re-tightened.,The bolts for the pi

38、ston rods, connecting rods and all other important bolts must be given a proper pre-stress.,After overhaul, the inner spaces have to be checked to see whether all impurities, tools, etc. have been removed.,Any parts which have been filed(锉，刮) or, scraped(刮，磨) must be thoroughly cleaned. Make sure th

39、at all safety devices have been re-fitted.,Check renewed and /or re-fitted parts for exact setting and clearance.,Before starting the engine after overhaul work the crankshaft should be turned by means of a turning gear to see that all parts move freely.,C. CYLINDER EXAMINATION THROUGH SCAVENGE PORT

40、S,In port the scavenging air boxes should be cleaned of sludge after every 2,000 running hours(500 to 1,000 hours for a new engine), liner ports cleaned, and components inspected.,Jacket and piston coolants should be circulated at this time so that possible leakage may be discovered. Similar action

41、may also be necessary to see if piston ring leakage or scavenge fires are experienced.,With the piston on bottom dead centre a power lamp may be introduced through the scavenge ports to sight the liner wall surface, which should be clean and mirror surface bright with a well-oiled appearance.,Inadeq

42、uate lubrication may be indicated by deterioration of the liner surface and piston ring faces,with a striped(有斑的，有条纹的) appearance due to micro-seizure(微咬) of liner/piston ring mating surfaces and by a sharp burr(毛刺) on the edges of piston rings.,Dark areas or black dry zones on the upper part of the

43、 wall may indicate combustion gas blow-by between wall and piston rings.,The surface of the rings may be examined by turning the engine to bring the rings in line with(与成直线) the scavenge ports. *The outer surface of the rings, the underside and the mating floor of the piston grooves should be worn b

44、right; the rings must move freely in the grooves, should show oil at the edges(excepting the top ring), be intact(完好的，完整的), and not unduly(过度的，不适当的) worn.,The surface of the rings may be examined by turning the engine to bring the rings in line with the scavenge ports.,The outer surface of the rings, the underside and the mating floor of the piston grooves