Тестовые задания для курсантов 4 курса обучающихся по специальности 26.02.05 ЭКСПЛУАТАЦИЯ СУДОВЫХ ЭНЕРГЕТИЧЕСКИХ УСТАНОВОК
1. What is the difference between the superheated, cooled and saturated steam?
1. Humidity rate.
2. Enthalpy at the same pressure.
Pressure at the same enthalpy.
2. Name the main feature of the heatdynamic equilibrium in boiler operation.
1. Constant fuel consumption per hour.
2. Constant parameters of generated steam.
Constant feed water consumption.
Constant number of turbine revolutions.
3. Name the main feature of the material equilibrium in boiler operation.
Constant fuel consumption per hour.
Constant steam consumption per hour.
3.Constant feed water consumption per hour.
'4. Constant water level in the boiler.
4. On which heating surface of the boiler does heat transfer take place at the highest gas temperature?
1. In the superheater.
'2. On steam generating surface.
In the economizer.
In the airheater.
On which heating surface of the boiler does heat transfer take place at the highest metal temperature?
On steam generating surface.
In the economizer,
In the airheater.
'4. In the superheater.
6 In what places of the boiler do we see damaging effect of the vanadium in the fuel oil?
1, In superheaters at high metal temperature
In airheaters at low metal temperature.
At presence of water due to tube leakages.
At presence of water from atmosphere when boiler does not operated
7. For what purpose should you know the specific gravity of fuel ?
1. To determine the grade of fuel oil.
2. To recalculate the tank volumes into weight units.
To determine the temperature of heating for pumping.
To determine the T° of heating before atomization.
8. What feature determines the grade of fuel oil?
1. . Heating value.
2.. Sulphur content.
4, Ash content.
9. What is the function of separators in the system?
To remove sulphur.
To remove mechanical impurities.
'3. Те remove water and mechanical impurities.
4. To decrease heavy fuel oil viscosity.
10. For what purpose is the fuel atomized before the furnace?
1. For increasing active surface.
2. For complete, thorough mixture with air.
3. For increasing fuel heating.
11. For what purpose is the fuel heated before the burner?
1. To increase kinetic energy of fuel particles.
2. To decrease viscosity and increase atomization dispersity.
To increase temperature determining rate of combustion.
To remove extra humidity from fuel oil.
12. For what purpose the air supplied to the furnace is given a whirling motion.
1. For proper direction of air flow along the furnace axis.
2. For cleaning from dust and moisture by centrifugal forces.
3. For increase of oxygen supply rate and better mixture.
13. For what purpose is the air supplied to the furnace heated?
1.. For removal humidity from air.
2. For increase of T° and rate of combustion.
For increase of fuel energy.
For increase of specific volume and air rate.
14. What is the function of the diffuser?
1. To supply limited quantity of air to the flame.
To control the air supply to the furnace.
To change the direction of air flow in the furnace.
To control the length of flame in the furnace.
15. On what factors does dispersity of fuel atomization depend?
On air rate.
On pressure and temperature.
4. On cone angle of atomization.
16. What forces perform work on fuel atomization in mechanical burners?
Resistance of air.
l7. What insures atomization of fuel in rotary cup atomizers?
1. Pressure of primary air.
2. Forces, appearing due to cup rotation.
3. Forces, appearing due to spray rotation.
18. How is the change in air supply made?
1- By turning vanes.
2. By controlling damper on the register.
3. By controlling damper on air line before the boiler.
4. By changing fan number of revolutions.
19. Up to what T° can we heat the fuel in hermetic tanks ?
1. 15°C lower than fuel ignition point.
2. 15°C lower than fuel boiling point at atm. pressure.
3- 15°C lower than fuel flash point.
20. What should be shut down first, when taking boiler off fhe steam line, or fuel pump?
1. First fan, then pump.
2. First pump, then fan.
3. Both devices at once.
21. Which of the furnace walls is called screened ?
1. Protected from the flame by firebricks.
2. On which there is no heat transfer to water.
3. On which radiant heating surface is located.
4. On which convection heating surface is located.
22. Is it good to increase boiler radiant surface?
1. There is no necessity, as boiler efficiency decreases.
2. It is necessary, as this surface transfers more heat than the convection one.
It is necessary, as water cooling protects firebrick and metal.
There is no necessity, as gas temperature decreases.
23. How does water walls cooling effect reliability of boiler operation?
1. Negatively, due to the high temperature of tube metal.
2. Positively, due to the absence of firebrick walls.
Negatively, due to the decrease of furnace volume and increase T0 of combustion.
Positively, due to the absence of corrosive products of incomplete combustion.
24. What is the advantage of furnace water walls cooling?
Simple automatic control of combustion.
High steam parametrs.
3. Decrease in boiler size, weight and cost.
25. What boiler do we call double-flow?
1. With double gas flow.
With two turns of gas flow,
With two superheaters.
26. Name the main difference between our boilers, single-flow foreign
1. Vertical superheater and two water drums
The only one side screen
Completely water-cooled furnace
Steam air heater.
27. What boiler is called single-flow?
1. With one flow of gases
Without turns of gas flow
With two water drums.
28 What construction is mostly often used in modern boilers?
29. In what cases coil-type superheaters are used ?
1. To get high temperature of steam.
2. To make cleaning of boiler heating surface easier.
3. To enlarge heating surface in small sizes.
30. What changes in parts of boiler heating surface cause steam parameters increase?
1. Increase in screened surfaces.
2. Decrease in economizer surface.
3. Increase in economizer surface.
4. Decrease in airheater surface.
31. Name the main disadvantage of vertical superheater in boiler KVG.
1. Increase of number of boiler drums.
2. Bad access for repair and cleaning.
3. Impossibility of steam temperature increase.
32. Name the least reliable part of a modern boiler.
1. Screened tubes.
3. Water economizer.
4. Steam-water drum.
1. Name the main tendency in modernization of marine water-tube boilers?
1. Increase of economy.
2. Increase of reliability.
Decrease of weight and size.
Increase of safety.
2. What is called circulation in the boiler?
1. Movement of gas flow.
2. Movement of water and steam-water mixture.
3. Movement of steam bubbles,
3. What causes natural circulation?
1. Difference of specific weights of water and steam-water mixture.
Difference of specific weights of cold and hot water.
Head produced by the feed pump.
4. How is the forced circulation accomplished?
1. By operation of feed pump.
2. By operation of a special circulating pump.
3. By operation of non-cooled downcomers.
5. What steam is produced in auxiliary boilers?
1. Only the saturated steam.
'2. Steam of low pressures and temperatures.
3. Steam for ship's heating.
6. Name the principal difference between the auxiliary boiler and the main one
1. Low steam parameters and efficiency.
Auxiliary boilers have no automatic combustion control.
Auxiliary boilers have no superheaters.
Auxiliary boilers are heated by exhaust steam.
7. What superheaters are installed in marine boilers?
1. Radiant superheaters
2. Convection superheaters.
3. Radiant-convection superheaters.
8. Name the main sequences of temperature increase of superheated steam, compared to the designed temperature.
1, Decrease of boiler efficiency and increase of fuel consumption.
2. Overheating of superheater tubes and turbine blades.
3. Decrease of boiler steam generating capacity and turbine efficiency.
9.Up to what temperature is the water heated in the economizer?
1.. Up to the temperature of saturation (boiling).
2. At 35 — 40°C lower than the temperature of saturation.
3. Up to the temperature of flue gases.
10. Why is the feed valve made of double type?
1. One of the valves, non-return, takes the boiler off the line when the latter is damaged.
Two non-return valves are fitted to let the water pass only in one direction.
One valve is connected with automatic feed, the other is manually operated.
11. On which marine boilers double safety valves are installed ?
1. At pressures over 8 ata.
At pressures over 12 ata.
At steam generating capacity over 1/hour.
On all marine boilers.
12. How are the dimensions of valves calculated ?
1- By steam or water consumption per hour and pressure.
2. By recommended steam or water rate and pressure.
3. In dependence on valve and consumption per hour.
13. How many water gauges should be fitted on the boiler?
1. On auxiliary boilers — one, on main boilers — two. '
2. On all boilers not less than two.
On small boilers — one, on large boilers — two.
With pressure up to 20 ata — one, higher — two.
14. What work does the force of draft perform?
1. . Supply of air necessary for fuet combustion.
2. Movement of air in the air lines and gases in gas passages.
3. Overcoming the resistance of airheater and burning equipment.
15. What are the main tensions of boiler parts when in operation?
1. Mechanical from steam pressure and thermal from high] temperatures.
Mechanical from steam pressure and ship's virbation.
Mechanical from shocks of load when safety valves are blown off.
16. What factors determine the use of special grades of steel in boilers?
1. Temperature of metal higher than 450°C.
Pressure over 45 ata.
Great sulfur content in fuel oil.
17. Name the main factor determining the choice of boiler tubes material.
3. The highest temperature.
18. On what does the thickness of drum walls depend?
1. On working temperature of walls.
2. On steam pressure and diameter of the drum.
3. On length and diameter of the drum.
19. Why are steam-water drums usually made of sheets of different thickness?
1. Weakened part, due to the orifices for the tubes, is made thicker. I
In the lower part the drum has higher temperature.
In the upper part of the drum there is higher pressure.
20. Why is the failure in circulation dangerous for the boiler?
In the part of the tube filled with steam heat transfer from the wall decreases.
In the part of the tube filled with steam pressure rapidly increases.
In place of circulation failure scale is formed on the walls.
21. Where is the rate of circulation determined in the cycle?
1. At the entrance to the downcomers.
2. At the entrance to the risers.
3. At the exit from the downcomers.
22. What is called economizer part of boiler tubes?
1. Tubes of boiler water economizer.
2. Parts of the tubes where steam-water mixture is not formed.
3. Those downcomers in which water is heated.
23. What is the approximate wall temperature of a water heating tube?
Intermediate temperature of gas flow.
Intermediate temperature of gases and steam.
3. Temperature of saturated steam. (+ 50 — 100").
24. Why are salt deposits so dangerous for modern boilers?
1. Decrease in heat transfer of the walls and extra fuel consumption.
2. Overheating of metal and damage of tube metal.
3. Damaging effect of salts on boiler metal.
25. On what does the solubility of oxygen and other gases in water depend?
1. Increases with temperature increase, pressure decrease and vice versa.
2. Increases with temperature decrease, pressure increase and vice versa.
3. Increases with general salt content decrease and decreases with its increase.
26. What is more important for the boiler water regime: hardness, salt content
1. Chloride content.
2. General salt content.
3. General hardness.
27. What do we call water «hardness»?
1. All mineral impurities content.
'2. Calcium and magnesium salts content.
3, Sulphate content in water.
28. What salts are included into a separate group of «hard» ones?
1. Those which form scale.
Not removed by evaporation.
Not removed by chemical treatment.
29. Choose the reactions of chemical corrosion.
1. Fe + O2 = FeO2.
2. 3Fe + 4H2O = Fe3O,
3. 4Fe + 3O2 = 2Fe2O3
30. Where does the direct reaction of iron with steam take place in the boiler
1. In tubes with steam water mixture.
2. In steam separators.
3. In superheater tubes.
31. On what principal are ship's deaerators based?
1. On removal of oxygen with the decrease of pressure of medium above the water.
2. On removal of oxygen from water by means of chemical agents.
3. On decrease of solubility of oxygen with water heating.
1. Where can we use magnetic water treatment?
1. In boilers fed by fresh water taken from ashore.
2. In low-pressure boilers with large water volumes for which sludgel not dangerous.
3. Only in waste-heat boilers which operate with low heat rates.
2. For what purpose is the boiler blow off used?
1. To control boiler water salt content.
2. To control boiler water level.
3. To decrease humidity of saturated stead.
3. For what purpose is the boiler blow down used?
1. To decrease salt content and remove sludge.
To control boiler water level.
To remove scale formed on the metal.
To change boiler water periodically.
4. When is it necessary to blow the boiler down ?
At every watch.
Not more often than once per day.
3. When the boiler water is not of a good quality.
5. What is saturated steam?
1. Steam contacting with water from which it has been formed.
2, Steam containing particles of moisture.
3. Steam not containing particles of moisture.
6. On what is the operation of steam separators based ?
On difference of steam and water rate.
On division of water sprays with shocks.
On difference of steam and water density.
7. What is the principle of operation of a cyclone separator?
1. Cyclone separator lets the steam pass and detains water.
2, The water is thrown by the centrifugal force against the wall and flows down.
3. Drops of water do not swirl in the cyclone and flow down.
8. At what temperature can we perform the boiler hydraulic test?
At saturation temperature.
At temperature of 30°C,
3. At temperature not less, than 5°C.
4. At temperature of outside air.
9. By means of what device can we raise the boiler pressure during the hydraulic test?
1. By a special hand-operated pump.
By a special electric pump.
By the boiler feed pump.
By raising steam on 1 — 2 burners.
10. Name the main principles of marine boiler maintenance.
1. Reliability at all ratings and economy.
Safety of operation at all ratings.
Economy and high steam generating capacity.
11. Name the principal causes of failure in boiler operation.
1. Low grades of fuel and water.
2. Unsatisfactory technology of boiler manufacture.
3. Breaking the «Rules of technical maintenance».
4. Formation of scale on heating surfaces.
12. Name the elements, the failure of which demand the boiler to be taken off the line.
1. Water heating tubes, superheater and furnace setting.
Economizer and airheaters.
Boiler accessories and protective devices.
13. Name the elements, the failure of which decreases the economy of boiler operation considerably.
1. Superheaters and economizers.
2. Economizers and airheaters.
3. Automatic combustion and protection.
14. Name the principal means to maintain the boiler plant in good order. * 1. Systematic inspection and repairs.
2. Provision with spare parts.
Normal fuel consumption.
High grade of fuel.
15. What equipment should be open when filling the boiler up with water?
1. Safety valves and blow off valve.
'2. Air vent valve, pressure gauge and water gauge valves.
3. Stop valves and blow off valve.
16. Tell the recommended time for raising steam in marine water-tube boilers.
1. Not less than 3 hours.
Not less than 40 minutes.
Not less than an hour.
17. What should be checked when raising steam in the boiler after the pressure of 1 kg/cm2 has been reached?
1. Proper state of safety valves.
2I. Operation of gauge glasses.
3. Readings of pressure gauges and thermometers.
18. When is the boiler considered to be on the line?
1. From the moment since the first burner is ignited.
2. From the moment when the steam is raised higher than atm.
3. From the moment when the working steam pressure has been reached.
19. By what factors can the boiler operation at low loads be characterized?
1. By greater reliability and safety.
2. By decrease in efficiency and contamination of the heating surface.
3. By lower parameters of generated steam.
20. What is called forcing a boiler?
Operation with higher than designed steam parameters.
Operation with higher than normal fuel consumption.
3. Operation with higher than normal steam generating capacity.
21. What should be done, when it is impossible to shut down the boiler in which leakage has appeared?
1. To increase feeding.
To decrease fuel supply.
To decrease steam consumption.
22. What is called "water loss" in the boiler?
1. Lowering of water level down to the heating surface.
Loss of all water contained in the boiler.
Failure of boiler feeding system.
4. Drop of water level down to its lowest point.
23. What should be done when tubes are damaged?
1. To take the boiler off the line at once.
To decrease rate of combustion and draft.
To stop boiler feeding and blow the safety valves off.
24. Where is the danger of boiler «overfeeding» ?
1. In damage of steam lines and superheater from hydraulic shock.
In decrease of steam temperature and the efficiency of the propulsion turbine.
In improper circulation in the boiler and metal overheating.
15. What factors determine the economic efficiency of boiler operation?
Boiler steam generating capacity.
3. Reliability in operation.
4. Long life.
16.-What may happen when steam is too rapidly raised?
1. Loss of water.
2. Damage of brickwork setting.
3. Overheating of metal.
17. What parts of boiler heating surface are mostly subjected to the low-temperature corrosion?
1. Air heater and economizer (heating surface ends).
Outside walls of convection gas passages.
18. What parts of the boiler are subjected to high-temperature corrosion?
I. Screen tubes and superheater.
Furnace firebrick setting.
Burners and air controlling vanes.
19. By means of what steam is sootblowing process performed?
When the boiler is in operation
2. By the saturated steam of working pressure.
3. By the saturated steam of low pressure.
20. When is the boiler soot blowing done?
l. When the boiler is in operation
2. When the boiler is out of service.
3. At reduced loads.
21. How should the boiler be prepared for shutting-down?
1. By stopping the boiler feeding.
2. By blowing down, sootblowing and using manual control
3. By shutting off burners, gradually one after the other.
MARINE DIESEL ENGINES
1. In what do the high-speed and slow-speed diesel engines differ?
1. In medium speed of the piston movement,
In max. allowable number of revolutions.
In power output per cylinder.
In nominal number of revolutions.
2.What is the difference between the four-cycle engine and the two-cycle diesel engine?
1. Number of piston strokes per cycle.
Number of cycles per one revolution of the shaft.
Number of revolutions per cycle.
3. Name the advantage (among the given below) of a trunk piston engine over the crosshead one.
1. Lesser wear of the liner,
2, Lesser pressure on the bearings.
3. Simplier construction.
4. Greater economy.
4. In which type of diesel engines uniflow-scavenging is used?
In Russian diesel.
In MAN diesel engine,
3. In Sulzer diesel engine.
4. In Burmeister & Wain.
5. What type of diesel engines uses cross-scavenging?
MAN diesel engines.
6. What position of the piston is taken as the initial one?
I. At the beginning of the working stroke.
2. At the top dead centre (TDC).
At the bottom dead centre (BDC).
At the point of fuel injection.
7. Name the disadvantage of a two-cycle diesel engine over the four-cycle one.
1. Greater pressure of gases.
2. Worse cylinder scavenging.
More complex construction.
Greater wear of the liner.
8. What type of scavenging is used in the diesel of the Brjansk plant?
1. Cross scavenging.
2. Loop scavenging.
3. Uniflow scavenging.
9. For what purpose is the bedplate of a diesel used ?
1. To take the efforts of gas pressure and inertia forces.
To prevent the diesel movement during operation.
To fasten the upper parts of a diesel.
To take the inertia forces of rotating masses.
10. What is the function of a cylinder jacket?
1. To make the liner dismantling easier.
2. To make the inspection of the liner outside easier.
3. To cool the cylinder liner.
4. To reduce the weight and thickness of a liner.
11. By means of what are the liner outlets from the cylinder jackets packed?
1. By rubber rings.
By fitted surfaces.
By alumunium packings.
12. On what factors does the number of piston rings' depend?
1. On pressure and diameter of the cylinder.
On height of the piston head.
On cross section of the packing rings.
13. For what purpose have the crosshead diesel engines skirts?
1. For covering exhaust and scavenging ports.
For decreasing cylinder liner wear.
For transference of efforts on the liner.
For preventing the passage of gases into the crankcase.
14. What part of the mentioned below is the most important for a diesel engine?
15. On what parts of a diesel are crankshafts placed?
1. On the framework.
2. On the main bearings.
3. On the bedplate.
16. What is the principal difference between the working cycle of a four-stroke engine and two-stroke type?
1. There is no suction stroke.
Motion of air in the engine cylinder.
Pressure of combustion in the cylinder.
17. Which unit among the given below is necessary for a two-stroke engine?
4. Scavenging pump.
18. What is mechanical efficiency of an engine?
1. The ratio between the brake horsepower and indicated one.
Summary value of all the friction losses.
The ratio between the indicated power and brake horsepower.
Summary losses into the surrounding medium.
19. What factor among the mentioned below determines the value of injection timing?
1. Diesel engine revolutions.
Diesel engine output.
Pressure of combustion.
20. Which type of the diesel engine has no scavenging ports?'
1. Two-stroke engine.
2. Four-stroke diesel.
21. Which of the mechanisms of a fuel system produces the pressure sufficient to supply fuel to the cylinder?
1. Fuel transfer pump.
2. Fuel pump.
3. Fuel injection valve.
22. What method of fuel supply control is better for the diesel with variable speed ?
With the change at the end of fuel supply.
With the change at the beginning of fuel supply.
3. With the change at the beginning and end of fuel supply.
23. Name the disadvantage of fuel pumps with combined type of fuel supply control.
1. Complex system of control.
Low pressure of atomization at low speeds.
Dynamic indicators of the working cycle become worse.
24. What type of fuel pump is installed on diesel engines В & W?
1. With valve distribution.
2. With plunger distribution.
3. With accumulator type.
25. For what purpose is a diesel fuel injection valve used?
1. For atomization and equal distribution of fuel drops in the combustion chamber.
2. For rapid stop of fuel supply at the proper moment.
3. For the fuel supply into the combustion chamber at the proper moment.
26. Name the main advantage of closed fuel valves of marine diesel engines.
Absence of nozzle orifices coking.
2. Greater speed of fuel supply
3. Good atomization at low loads.
27. What store of diesel oil should be kept on the ship besides the double bottom tanks?
1. Sufficient for 24 hours' full speed.
In dependence on engine power.
In dependence on the time for voyage.
Sufficient for 2 days medium speed.
28. What are the advantages of the diesel operation on heavy fuel?
1. Increase of reliability in operation.
2.. Increase of engine efficiency.
3. Reduction of maintenance costs.
29. What is the purpose of diesel fuel oil separation?
1. For decrease of viscosity before the supply to the engine.
2. For separation of water and mechanical impurities.
3. For separation of water from diesel fuel oil.
30. Why should the fuel oil be heated before separation?
1. To increase the speed of separation.
2. To increase separator efficiency.
3. To decrease fuel viscosity.
4. To prevent coke formation in the separator.
31. Why is the lubrication system of a diesel called circulating?
1. Lub. oil in the system circulates in a closed cycle.
Lubrication is accomplished under pressure.
Oil supply is accomplished by centrifugal pumps.
Lub. system has a circulating tank.
32. By means of what is the pressure in the oil line kept constant?
By the control of oil temperature.
By changing the pump capacity.
By means of a reduction valve.
33. What is the main advantage of a circulating system of lubrication?
Supply of cooled, filted oil to all the parts.
2. Convenience of checking and control of oil supply to the engine.
3. Lubrication by cooled oil under pressure and heat dispose.
4. Supply of oil to the most important parts of a diesel under pressure,
34. Why is there a separate lubrication system for cylinders?
1. To use special grades and exact dosing of oil.
To increase oil delivery pressure to the cylinder.
To reduce oil consumption at low speeds.
To change oil consumption with variable speeds.
35. Name the type of pumps used in the lubricating system of a marine diesel.
3. Gear or screw type.
4. Centrifugal pump.
36. Which filter ensures highly effective cleaning of oil from metalic impurities?
1. The filter with cotton element.
2. Metalic strainer.
3. Magnetic filter
37. What is the main disadvantage of the sea water cooling system of a diesel ?
1. Heat losses when cooled with cold water.
2. Corrosion of cooled parts.
3. Formation of scale in cylinder jackets.
38. What parts of a diesel (among the given below) are first cooled by water?
1. What is the period of the starting process of a slow-speed engine?
1. One or three revolutions of the crankshaft.
Five or ten revolutions of the crankshaft.
Five or ten working strokes of every piston,
2 After what number of revolutions on the air are slow-speed diesels transferred to the fuel?
1. At 50 - 70 r.p.m.
2. At 10 - 20 r.p.m.
3. At 20-30 r.p.m.
3. What part of the given below is more quickly heated during warming operation?
1. Cylinder liner.
2. Cylinder head.
3. Piston head.
4. Main bearings.
4. How does the scale on the liner surfaces and heads of the working cylinders effect the time of diesel warming?
1. Decreases the time of warming.
2. Does not effect the time of warming.
3. Increases the time of warming.
5. What value of the given horsepower is of greater importance?
1. Indicated horsepower Ni.
Nominal horsepower — Nnom
6.. What factors determine the starting qualities of a diesel?
Temperature of fuel and air heating.
Number of working cylinders.
3. Temperature of air in the cylinder at the end of the compression.
4. Pressure of starting air.
7. What is the function of air distributors in the starting air system?
1. To supply starting air to the cylinders.
2. To open and close air starting valves.
To stop the supply of air to the cylinder.
To supply air to the starting valves.
8. Where is the air distributing device generally located in the diesel?
Next to the diesel control panel.
On the heads of the working cylinders.
3. Next to the main starting valve.
4. In the area of the cylinder heads.
9. What is the function of the main (manoeuvring) starting valve of a diesel?
1. To connect or disconnect the starting air line with air containers (bottles).
To supply air to the diesel air distributor.
To shut off the air supply at reversing,
To suppiy air to the starting valves.
10. By what means is the reversing operation on the "Russian diesel" accomplished?
1. By axial movement of the camshaft.
2. By turning the camshaft on the angle of reverse.
3. By using symmetrical cams.
11 By what factors does gas turbocharging differ from the mechanical one?
1. By the pressure of supercharging. '
2. By the drive of the charger.
3. By the temperature of the supplied air.
12. What unit is necessary in different systems of a diesel engine supercharging?
4. Air cooler.
13. Which part of the given below refers to the reciprocating (crank -connecting rod —piston) mechanism?
Exhaust valves drivers.
14. What is the function of a connecting rod?
To connect the piston rod with the crankshaft.
To transfer the torque moment to the crankshaft.
3. To transfer the efforts from pressure on the piston to the crankshaft.
15. To what part of a diesel is the high-pressure oil pump attached?
1. To the piston rod
2. To the crosshead with the sliding shoes.
3. To the connecting rod.
16. In what points of lubricating system is it necessary to check up oil pressure periodically?
Before each bearing and after it.
Before oil coolers and after them.
3. Before the diesel engine, reduction gear, before and after filters.
17. In what points of lubricating system is it necessary to check up oil temperature periodically?
1. Before the diesel engine, reduction gear, before and after the oil filters.
1. Before the diesel engine, reduction gear, before and after the oil coolers,
3. Before each bearing and after it.
18. What should be periodically checked in the cooling system of burners?
Pressure at the inlet and outlet of cooling water (fuel).
Pressure and T° at the outlet of cooling water (fuel).
3. Temperature at the inlet and outlet of cooling water (fuel).
4. Reliability of water (fuel) circulation.
20. In what points of fuel system is it necessary to check up fuel pressure?
1. After fuel transfer pump.
After fuel pumps.
Before the fuel pumps and after them.
At the suction of fuel transfer pump.
21. In what points of diesei fuel system fuel temperature (viscosity) should be checked up?
Before the fuel transfer pump.
In gravity tanks.
3. Before the fuel pumps.
22. What is it necessary to check up in the starting air system periodically?
1. Temperature of air in air bottles.
2. Pressure of air in air bottles.
3. Lack of oil in the starting system.
23. What parameters of scavenging air should be periodically checked up?
1. Temperature on stages after coolers.
2. Pressure and temperature on stages before and after coolers.
3. Pressure on stages of coolers.
24. In what points is the temperature of exhaust gases periodically checked up?
1. After cylinders, before the turbochargers and after them.
Before the exhaust of gases to the waste-heat boiler.
On the exhaust of gases from the waste-heat boiler.
25. What does the periodic check up of diesei operation depend on?
1. On number of revolutions per minute (r.p.m.).
2. On the degree of automation, signal systems and protection.
On the power output and mean indicated pressure (m.i.p.)
On the orders of the chief engineer.
26. How should the main engine be put into operation regime after starting or manoeuvring?
1. Immediately after starting or finishing the manoeuvre.
2. Gradually in accordance with the time in the Regulations.
3. During an hour when using light oil.
27. To what should be paid special attention when putting the engine into.
1. To temperature of gases, cooling and lubrication.
To temperature of supercharged air after turbocharger.
To temperatures of all diesel engine bearings.
To equal loads on all the cylinders.
28. What is it necessary to do to avoid diesel engine overloading?
1. To maintain nominal values of Pc and Pz
To maintain nominal number of revolutions.
To maintain nominal pressure of supercharging.
To maintain nominal temperatures of cooling water.
28. Is the normal diesel operation allowed with temperature of exhaust gases higher than nominal?
1. It is allowed not more than 110%.
2. It is forbidden in all cases.
3. It is allowed at low loads.
29. On what number of revolutions is the diesel operation forbidden?
1. On number of revolutions exceeding nominal.
2. On critical number or with considerable vibration.
3. On number of revolutions causing noise and bearing heating,
30. Is the operation of a diesel engine with shut off cylinders allowed?
1. Only in emergency cases.
Only with one power cylinder shut off.
Not allowed in any cases.
31. How often should the diesei engine points of friction and running parts be checked up during the watch ?
1. Every hour.
Two times per watch.
Every half an hour.
Every 15 minutes.
32. How often should the cylinder oil from under piston spaces be analysed?
1. Once per watch.
Once per 24 hours.
Every 100 hours of engine operation.
After change of loading.
33 What should be done when the temperature of main and crankpin bearings exceeds 65°C?
1. To decrease engine or cylinder loading and increase oil supply.
To decrease lub. oil T" before the engine bearings.
To stop the engine and determine the cause of bearing overheating.
To increase oil cooling in the cooler.
34. What should be done with the diesel engine if noise, rumbling and vibration appear?
1. To increase lubrication of running parts.
2. To reduce number of revolutions or stop the engine.
3. To increase the pressure of cooling water.
35. How should the control over lubricating system of the diesel. and turbocompressor be accomplished?
1. By maintaining and control of the lub. oil pressure and T°.
By controlling constant quantity of supplied lubrication.
By periodic check of lub. oil at the outlet of bearings.
36. How is the regulation of lub. oil temperature accomplished?
By changing the pressure of oil in the systems.
By controlling the operation of the main oil distributors.
3. By changing the quantity of water passing through the oil cooler.
37. What should be done if the oil pressure drops and the T° increases exceedingly in the circulating system of a diesel?
1. To increase number of revolutions of the oil circulating pump.
2. To increase the quantity of water passing through the oil cooler.
3. To use lubrication of a stand-by pump and decrease the load.
4. To inform the chief engineer immediately.
38. How often should the lubrication of turbochargers be checked up?
1. Once per hour.
Once per watch.
Every 15 minutes.
In dependence on the oil T°C.
1. What does the control of turbocharger lubrication include?
Provision of continuous supply of oil to the oil collector.
Control of oil T° before the oil collector.
3. Control of the level in oil collectors, the T° and colour of oil.
2. Is the insufficient supply or excess oil supply to the cylinders allowed?
1. It is allowed on the permission of the chief engineer.
2. It is not allowed in any cases.
3. Only excess oil supply is allowed.
3. How should the systematic control over the lubricators operation on
cylinders be accomplished?
1. By watching gauge glasses.
2. By watching levels in the lubricators.
3. By watching colour of exhaust gases.
4. What should the pressure in the lub. system of a diesel engine be to prevent the oil quality becoming worse ?
1. The pressure should be lower than that of water.
2. The pressure should be higher than that of water.
3. The pressure should approximately be equal that of water.
5. What should be done at the increase of circulating oil pressure drop on the filter?
To increase the circulating oil pressure before the filter.
To increase the circulating oil temperature before the filter.
3. To switch off the operation of the lub. system to the reserve filter.
6. What should be done when the circulating oil pressure drop at the filter rapidly decreases ?
1. To decrease the pressure before the filter.
2. To change the filter element.
3. To increase the pressure before the filter.
7. Up to what temperature should the circulating oil be heated before it is supplied to the separator?
1. Not lower than 40°C.
2. Not higher than 40"C.
3. Not higher than 80°C.
8. What are the limits allowing the change in T° of cooling water (oil) after piston at constant load of diesel engine (cylinder) ?
1. Not more than 2°C.
Not more than 3DC.
Not more than 10DC.
Not allowed at all.
9. What should be done at the sudden pressure drop or great increase of
temperature of cooling water?
1. To pass to engine cooling by a reserve pump.
2. To decrease the engine load and pass to a reserve pump.
3. To decrease the engine load and increase the quantity of cooling water.
10. What should the T° of sea water be before the aircoolers?
1. Not less than 10°C.
2. Not more than 20°C.
3. Not less than 20°C.
11. What does the rapid drop of fresh water level in the expansion tank of cylinder cooling indicate?
1. The leakage in the system.
The decrease of T° of cooling water.
The improper operation of the pump.
12. For what purpose should you watch the water surface in the expansion tank of a diesel cooling system?
1. For appearance of oil.
For appearance of sludge.
For appearance of rust.
For checking the water level.
13. How is it recommended to consume fuel in heavy weather?
1. From two tanks by turn
Not more than 2/3 of tank volume.
Not more than 3/4 of tank volume.
14. For what purpose is there an upper valve on some of the gravity tanks?
I. For the case of contamination of the lower valve.
2. For diesel operation in stormy weather.
For removal of water in gravity tank.
For removal of air in the tank.
15. What should you do when there is a rapid decrease of pressure drop at the fuel filters?
1. To decrease the TD of water before filter.
2. To change (replace) the filter element.
To increase the fuel pressure before filter.
4. To pump through the filter
16. What indicates the contamination of fuel nozzles of a diesel operating without fuel heating?
Weak pulsation of fuel in nozzle tubes.
Temperature drop of exhaust gases.
3. Overheating of tubes and increase of fuel pulsation.
17. How to prepare fuel before transference of a diesel to a high-viscosity fuel?
1. To increase the T" of high-viscosity fuel in the tank up to 70°C.
2. To increase the T° of high-viscosity fuel in the tank up to 70°C and that of diesel fuel up to 60°C.
3. To remove water and sludge from the tank of high-viscosity fuel.
18. When can you transfer the diesel to a high-viscosity fuel?
After heating fuel up to the proper viscosity.
Alter reduction of number of revolutions up to 70 — 75% from nominal.
3. After reduction of number of revolutions up to 80 — 85% from nominal.
19. How can you get the normal number of revolutions after passing to a high-viscosity fuel?
1. Not less than an hour of operation on a high-viscosity fuel.
2. Immediately after the fuel is heated up to the proper viscosity.
3. Gradually, at the time when fuel is heated up to the proper viscosity.
20. What should be done before the diesel is transferred from a high-viscosity oil to the diesel one?
1, To bring up the speed to normal.
2. To decrease the number of revolutions up to 80 — 85% from nominal.
3. To decrease the number of revolutions up to 70% from nominal.
21. What does periodic control over the tubes of starting air, connected with starting valves include?
1. Control of absence of air leakage.
2. Hand control of tubes temperature.
Control of absence of oil in tubes.
Control of absence of dangerous vibration.
22. Why is a special check over the T" of supercharging, air after aircoolers necessary?
To avoid excessive cooling of a cylinder liner.
To avoid excessive drop of compression temperature.
3. To avoid the appearance of moisture and metal corrosion.
4. To avoid decrease of cylinder output.
23. What is the maximum T" of supercharging air?
1. Not higher than 30°C,
2. Not lower than 23°C.
3. At 3 — 4°C lower than "dew point".
24. What temperature of the supercharging air should be maintained?
1. Low, not lower than25°C and 3 — 4°C higher than "dew point".
Not higher than 30°C and 3 - 4°C higher than "dew point".
Not lower than 25"C and 3 — 4°C lower than "dew point".
25. When is it forbidden to cool the scavenging air?
During the operation on high-viscosity fuel.
When the sea water T° is lower than 5DC.
3. When starting the engine and manoeuvring.
4. When running in the Arctic.
26. What rating is recommended for the diesel before manoeuvring.
Rating of 50% of nominal load not less than 15 minutes.
Rating of 50% of nominal number of revolutions.
3. Rating of 50% of nominal load not less than 30 minutes.
27. What should be done before manoeuvring and shutting-down the diesel running on a high-viscosity fuel ?
1. To run on diesel oil not less than 30 minutes.
Gradually to decrease the T° of the fuel heating.
Gradually to increase the T" of fuel on 5 — 10°C.
28. What should the temperature of water be when pumped through the cVHnders and pistons during the preparation for starting?
4. Not less than 70°C.
29. What should the T of water be for colling the burners during the preparation for starting?
4. Not higher than 60°C,
30. When is it necessary to pump through the burners, tubes and pumps of the fuel system?
1. When the grade of fuel is changed.
2. When the diesel was out of operation for 6 hours.
3. When the diesel was out of operation more than 12 hours.
4. Before every starting of a diesel.
31. When is it necessary to pump through the burners, tubes and pumps of the fuel system?
Before every starting of a diesel.
After any repair work.
After repairing the unit of fuel system.
32. What should the T° of a high-viscosity fuel be in gravity tanks?
1. Not less than 55 - 60°C.
2. Not lower than 90°C.
3. Within the 60 -85°C.
4. Not lower than 40 - 45°C.
33. What should be done first before supplying starting air to the diesel engine?
1. To check whether there is air in the containers (bottles).
2. To blow off the water and oil from the containers.
3. To check whether the starting system is in order.
34. What should be the T of starting air supplied to the diesel?
1. Not higher than 40°C.
2. Not higher than 60°C.
Not lower than 40°C.
Not lower than 60°C.
35. What should you make sure in before connecting the turning gear with the diesel engine?
1. That the control level is in "stop position".
That current is supplied to the turning gear.
That the turning gear is in proper order.
36. What should be done before the turning gear is connected?
To shut off the fuel system.
To put the cooling system into operation.
3. To close the valves on the starting air bottles.
4. To get the permission of the chief engineer.
37. What is the cooling rate of the aircooler at continuous operation of the diesel at low loads?
1. With lower temperature of cooling water.
2. With higher temperature of cooling water.
3. With lower supply of water.
4. With passing to a periodic cooling.
38. How should the number of revolutions of a diesel be changed in stormy weather when there is no all-rating governor?
To reduce on 10% from nominal.
To reduce on 5% from nominal.
3. To reduce up to the number appointed by the chief engineer.
4. Up to the stop of the safe operation of the governor.
39. What operations (among given below) are carried out before manoeuvring?
Consumption of water to the aircooler is reduced.
Fire pumps are prepared for operation.
3. Secondary consumers of energy are shut off.
4. Lubrication of starting valves is carried out.
40. What operations (among mentioned below) are carried out before manoeuvring?
1. Reserve diesel generator is prepared for starting.
2. Fire pumps are prepared for starting.
3. Heating of oil and fuel is increased.
41. In what case is the scavenging of compressed air bottles and pipes obligatory?
1. When the engine operates with overloading.
2, When the pressure-gauges on the bottles are out of order.
3. After the signal about coming manoeuvres.
4. When the pressure in the bottles drops.
42. What processes should be avoided (among the given below) at manoeuvring?
1. Decrease of starting air pressure.
2. Decrease of water and oil consumption.
3. Decrease of water (oil) temperature.
4. Decrease of exhaust temperature.
43. How to decrease the vibration of a diesel generator, working with the cylinder shut off?
To reduce number of diesel engine revolutions.
To increase oil supply.
3. To reduce diesel engine load. 4. To change the load on cylinders.
44. What should you do with the lubrication of a shut off cylinder?
1. To decrease oil supply.
To increase oil supply.
Not to change oil supply.
To switch on oil supply periodically.
45. Which of the systems is functioning after the piston of the crosshead diese engine has been dismantled?
Cooling system of the cylinder.
Lubricating system of the cylinder.
3. Lubricating system of the main bearings.
46. How is the mean indicated pressure Pi determined?
1. By the readings of the pimeter.
2. By indicating the power cylinder.
By number of revolutions.
By the torque moment.
47. What parameters of the diesel working process are checked up during operation?
1. Coefficient of excess air, number of revolutions and Pz.
2. Number of revolutions, Pz, P..
Cooling water temperature, scavenging air pressure.
Volumetric efficiency, number of revolutions, exhaust gas temperature.
48. Which parameters of the diesel working process are checked up during operation?
1. Volumetric efficiency, exhaust gas T°, cooling water To.
2. Number of revolutions, coefficient of excess air, torque moment.
3. Exhaust gas T°, specific fuel oil consumption, scavenging air pressure.
4. Fuel oil pressure, coefficient of remaining gases, cooling water temperature.
49. Name the main reasons causing troubles in diesel operation.
Operation with overload due to the damage of the propeller.
Too great a number of reverses and forcings.
Not proper quality of fuel and lubricating oil.
4. Bad maintenance and repair and drawbacks of the diesel itself.
50. By what means should the fuel supplied to the diesel be cleaned?
1. By filters or separators.
2. In settling tanks for light fuel.
3. By all the means of cleaning.
51 Name the methods of water treatment on ships for enclosed cooling system.
1. Distillation, boiling and chemical treatment.
Treatment of water in (ion) filters.
Filtration of water through carbon and stuff filters.
52 What should be watched during the diesel operation when one or several turbochargers are out of action?
1- There should be no smoky combustion in cylinders.
2. There should be neither fire nor exceeding the T° of exhaust gases.
53 What is taken into consideration first when the period of diesel technical tenance is determined?
1. Peculiarities of a diesel construction.
2. Real technical conditions.
3. The area of ship's voyages,
4. Stock of spare parts.
54. What should be carried out first when preparing diesel for operation?
1. To check the fuel in gravity tanks.
2. To make the exterior inspection.
To open the indication valves.
To check the storage of air in the bottles.
55. How can the time of preparation of a diesel for running be shortened? (quick starting).
By shortening the time on all operations.
By omitting the checking of the control system.
3, By omitting the diesel engine complete turning of the shaft.
4. By omitting the warming operation.
56. What should be done first after starting the oil pumps?
To make sure there is no leakage of oil.
To make sure the oil is supplied to lub. points.
3. To discharge air from the system through the air valves.
57. What condition should be observed when oil pressure in the system is brought up to the working one?
1. To increase the oil pressure gradually.
2. To turn the diesel engine and reduction gear by means of a turning gear.
To keep the oil temperature constant,
Not to cool the oil in the oil cooler.
58. What is the purpose of using tie-rods (anchor ties) in marine diesel engines?
To improve the engine rigidity.
To fasten cylinder blocks to the bedplate.
3. To relieve cylinders and bedplate of a diesel from tensile stresses.
4. To decrease the engine vibration.
59. Which of the given below parts of a diesel refers to the reciprocating mechanism?
1. Reversing arrangement.
2- Exhaust valve drive.
60. What is the function of a diesel connecting-rod ?
1. To connect the piston rod with the crankshaft.
2. To transfer the torque moment to the crankshaft.
3. To transfer pressure stresses on the piston to the crankshaft.
61. To what part of the reciprocating mechanism is the autonomous high-pressure oil pump attached ?
1. To the piston rod.
2. To the crosshead with sliding shoes.
3. To the crank.
4. To the connecting rod.
62. By what factors is the quality of fuel atomization in a diesel cylinder characterized?
By quantity of fuel atomized.
By quickness of fuel evaporation in the cylinder,
3. By the diameter (size) of the drop and by the even atomization.
4. By the equal distribution of fuel in the air.
63. What is the main cause of the noisy diesel operation ?
1. Insufficient lubrication of rubbing parts.
2. Air supply to the diesel engine and discharge of exhaust gases.
3. Great speed of pressure increase on the angle of crankshaft turn.
4. Operation of rotary compressors of supercharging.
64. Name the main advantage of the contour (without valves) systems of scavenging.
1. High quality of mixture formation.
2. Simplicity of diesel engine construction.
3. Good quality of cylinder cleaning.
65. What is the principle of fresh water temperature regulation in the diesel doling system?
1. According to the water T° after the engine.
2. According to the power of the main engine.
3. According to the water T° before the engine.
4. According to the sea water temperature.
66. What is the function of a fuel supply pump in modern fuel systems?
1. To ensure continuous fuel supply to the pump.
To take fuel from double-bottom tanks.
To produce pressure before the fuel pump.
67. Name the main part among the given below of a diesel fuel injection valve (burner}.
1. Spring-loaded needle.
Needle valve seat.
Needle of the burner.
Multihole (perforated) atomizer.
68. What is the pressure of the fuel injection in a slow-speed marine diesel engine?
1. 400 - 800 kg/cm2.
40- 50 kg/'cm2.
69. How much time is it necessary to form a proper fuel/air mixture in a slow-speed diesel?
2. 0,03-0,06 sec.
70. On what pressure is the safety valve of the diesel operating cylinder set?
1. On the pressure exceeding that of the ignition on 25%.
On the pressure exceeding that of the mean effective on 50%.
On the pressure exceeding that of the mean indicative 10 fold.
On the pressure exceeding that of the mean indicative 5 fold.
- Просмотры: 288
- Просмотры: 139
- Просмотры: 106
- Просмотры: 167
- Просмотры: 147
- Просмотры: 348
- Просмотры: 214