Тест по Separators, ALCAP Fuel Oil System (CES v5.0)

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Правильні відповіді:
1

Biodiesel is being proposed as an alternative fuel for use in marine diesel engines. Which one of the options best describes biodiesel that can be used in an unmodified diesel engine?

Правильну відповідь:

A blend of petroleum based diesel fuel and less than 20 % bio fuel.; A blend of petroleum based fuel and water.

Ваша відповідь:

A blend of petroleum based diesel fuel and less than 20 % bio fuel.
2

Blended fuel is the term applied to those fuels which are normally produced by mixing which two of the following categories of fuel?

Ваша відповідь правильна:

Marine residual fuels.; Marine distillate fuel.
3

Combustion of fuel oil can be considered to be an energy conversion process. Which of the following options best describes the conversion?

Ваша відповідь правильна:

Chemical to heat energy.
4

Dual fuel diesel engines which use gas and fuel oil are used on some ships. Select the option which best describes one of the methods of operation of the fuel systems for these engines:

Ваша відповідь правильна:

Low pressure gas is used as the main fuel with fuel oil used to ignite it.
5

Dual fuel systems have been developed to allow diesel engines to operate on gas fuel on some ships. How is the gas admitted to the cylinder in these systems? Select all the options that apply:

Ваша відповідь правильна:

Admitted through the air inlet.; Admitted directly to the cylinder through a separate injection valve to the fuel oil.
6

From the options given select all of those which make up the fire triangle:

Ваша відповідь правильна:

Heat.; Fuel.; Oxygen.
7

Fuel oil viscosity control is considered necessary for diesel engines operating on heavy fuel oil. Which one of the following best describes the principle of operation of a Viscotherm unit?

Ваша відповідь правильна:

Measurement of differential pressure in a capillary tube.
8

Fuels are sometimes blended onboard the ship prior to use. Which one of the following best describes why this process carried out?

Ваша відповідь правильна:

To control the fuel viscosity at the engine inlet.
9

How is the fuel normally ignited during the start-up of a ship’s boiler?

Ваша відповідь правильна:

Using a spark igniter.
10

In fuel combustion what is meant by the term “stoichiometric mixture”?

Ваша відповідь правильна:

A fuel air mixture, which has the ideal minimum amount of air required for complete combustion of the fuel.
11

Many boiler burner units include an air register. What is the purpose of an air register?

Ваша відповідь правильна:

It controls the quantity of combustion air entering the furnace.
12

Many diesel engine high pressure fuel pumps have plungers with helical profiles cut into them. How do these helical profile type plungers control the timing and quantity of fuel delivered to the cylinder?

Ваша відповідь правильна:

The leading edge controls the start of injection and the trailing edge controls the end of injection.
13

Most boiler burner units feature a swirl plate and a diffuser. What is the purpose of these two components?

Ваша відповідь правильна:

To control the combustion air movement and promote mixing with the fuel.
14

On large diesel engines it is common practice to use individual high pressure pumps positioned at each cylinder unit. Which one of the following gives the reason for doing this?

Ваша відповідь правильна:

To keep the high pressure fuel pipes as short as possible.
15

Select the correct option from those given to complete the statement. The fuel standard commonly used for the specification of marine fuels is:

Ваша відповідь правильна:

ISO 8217.
16

Some boiler burner units have steam passing through them during operation. What is the main purpose of using steam in a boiler burner unit?

Ваша відповідь правильна:

To improve fuel atomisation.
17

Some boiler use rotary cup burners instead of jet nozzle types. Which one of the following options best describes how rotary cup burners differ from jet nozzle types?

Правильну відповідь:

Rotary cup burners operate on much lower fuel pressures than simple jet nozzle types.

Ваша відповідь:

Rotary cup burners normally use steam atomisation.
18

Some diesel engine fuel injectors are designed to re-circulate the fuel when not actually injecting it. Why is recirculation desirable? Select all of the options which are correct:

Правильну відповідь:

It allows the engine to be stopped on heavy fuel oil.; It helps to remove residual heat from the injection.; It means that separate fuel valve cooling is not required.

Ваша відповідь:

It helps to remove residual heat from the injection.; It helps to maintain correct fuel viscosity.
19

Some diesel engine manufacturers have introduced the use of fuel and water emulsion as part of their exhaust emission control measures. How do these emulsions help to reduce air pollutants in exhaust gas emissions?

Ваша відповідь правильна:

They lower the maximum cylinder temperature and reduce NOx levels.
20

Some diesel engines feature a twin injection system designed to improve fuel injection performance. Select the option, which best describes this feature:

Ваша відповідь правильна:

A constant amount of fuel is injected by the first injector at all loads, while the amount through the second one varies.
21

Some diesel engines have fuel injection systems, which incorporate pilot injection. What is the main purpose of using pilot injection?

Ваша відповідь правильна:

To reduce ignition delay.
22

Some diesel engines operate on a fuel mixture, which is blended onboard. Which one of the following is a means to control the makeup of the blended fuel?

Ваша відповідь правильна:

Preset viscosity and temperature with varying ratio of blend components.
23

Some diesel engines operate with pilot injection as a feature of the fuel injection system. How is pilot injection usually achieved?

Ваша відповідь правильна:

By having two injection periods with a single injector.
24

Some high pressure pumps used in diesel engine fuel injection systems control the timing and quantity with a valve arrangement rather than a helix cut into the plunger. How is control of the pumps usually achieved using valves?

Правильну відповідь:

Suction valve to control start of injection and spill valve to control the end.

Ваша відповідь:

Spill valve to control start of injection and suction valve to control the end.
25

Some machines use fuel directly to provide the energy required for operation. Which of the following machines would you include in this group?

Ваша відповідь правильна:

Diesel engine.
26

The complete combustion of carbon should produce which of the given options?

Ваша відповідь правильна:

Carbon dioxide and heat.
27

The peak pressure allowed in a diesel engine cylinder is limited to a maximum value during the engine design stage. What determines this limit?

Ваша відповідь правильна:

The strength of the combustion chamber components.
28

The term jerk pump is often used when describing the type of high pressure fuel pump used in diesel engine fuel injection systems. Which one of the following options best defines this type of pump?

Правильну відповідь:

A cam actuated pump, which has a rapid movement.

Ваша відповідь:

A positive displacement pump.
29

The term “atomisation” is often used in relation to diesel engine fuel injection. Which of the following options best defines the term “atomisation”?

Правильну відповідь:

The breakup of a liquid fuel stream into fine droplets.

Ваша відповідь:

The formation of a combustible fuel air mixture.
30

The vessel you are sailing on, which has one settling tank and one service tank in the fuel system, is due operate in a SECA. When would you need to start to change over to low sulphur fuel if you are currently operating on normal heavy fuel?

Ваша відповідь правильна:

At the time before entry into the SECA stated in the ship’s fuel changeover procedure.
31

Under MARPOL Annex VI legislation which one of the following best describes the difference between operating an engine inside a SECA compared to one outside a SECA?

Ваша відповідь правильна:

Fuel with a lower sulphur content must normally be used in a SECA.
32

Variable injection timing (VIT) is sometimes used in the control of a diesel engine fuel injection system. How is a high pressure fuel pump using valve control arranged to provide VIT?

Ваша відповідь правильна:

The governor output is used to control both suction and spill valve.
33

Water/fuel emulsions are used in some diesel engines as a means of reducing the level of NOx emissions. What is a possible side effect of using these emulsions?

Ваша відповідь правильна:

Emulsions will give some secondary atomisation of heavy fuel improving combustion efficiency.
34

What are the products from the complete combustion of hydrogen?

Ваша відповідь правильна:

Water vapor and heat.
35

What is meant by the term common rail system when applied to a diesel engine fuel injection system?

Ваша відповідь правильна:

A system in which the high pressure pumps deliver into a manifold supplying all of the fuel injectors.
36

What is meant by the term direct injection in relation to diesel engine fuel injection systems?

Ваша відповідь правильна:

A system in which fuel is injected into the combustion chamber.
37

What is the most common method used to allow the position of fuel cams to be individually adjusted on the camshaft?

Ваша відповідь правильна:

The majority of fuel cams are mounted on hydraulic sleeve couplings.
38

What is the normal source of ignition in most diesel engines?

Ваша відповідь правильна:

Heat from the compressed air charge in the cylinder.
39

When diesel engines are operated on heavy fuel oil, the fuel is heated up to achieve the correct injection viscosity. How is the fuel system prevented from gassing up when operating this way?

Ваша відповідь правильна:

By maintaining a high enough pressure in the low pressure system to prevent vapor formation.
40

When would an oil fired inert gas generator normally be fitted onboard an oil tanker?

Правильну відповідь:

When the vessel has no steam boiler.

Ваша відповідь:

When the vessel has diesel propulsion and an auxiliary steam plant.
41

Which marine legislation has led to the introduction of low sulphur fuels in the shipping industry?

Ваша відповідь правильна:

MARPOL (Annex VI).
42

Which of the following are commonly used as fuels onboard commercial ships? Select all the correct options:

Ваша відповідь правильна:

Marine diesel oil.; Boil off gas from LNG cargoes.; Marine residual fuel.
43

Which of the following components in a diesel engine high pressure fuel injection system contribute to the control of the quantity and timing of the fuel delivery to the engine? Select all applicable options:

Правильну відповідь:

High pressure fuel pump.; Fuel pump cam.; Fuel injector.; Engine governor.

Ваша відповідь:

High pressure fuel pump.; Fuel pump cam.; Fuel injector.
44

Which of the following fuel components will release the most energy, measured in MJ/kg, during the combustion of marine residual fuel?

Ваша відповідь правильна:

Hydrogen.
45

Which of the following machines would be described as an internal combustion engine?

Ваша відповідь правильна:

A diesel engine.
46

Which of the following options best describes the term “self ignition temperature”?

Ваша відповідь правильна:

The minimum temperature at which a combustible mixture of fuel vapor and air will ignite without an external ignition source.
47

Which one of the following best describes the purpose of the spring in a fuel injection valve?

Ваша відповідь правильна:

To give positive seating of the valve to prevent back flow of gas from the cylinder into the fuel system.
48

Which one of the following best describes why a low pressure alarm is often fitted in the low pressure part of a diesel engine heavy fuel oil system?

Ваша відповідь правильна:

To minimize the risk of engine fuel starvation.
49

Which one of the following best explains why high pressure fuel pipes fitted to many diesel engines are often double skinned?

Ваша відповідь правильна:

So that any leakage is contained.
50

Which one of the following boiler operating parameters would normally give automatic shut-down of the boiler in event of alarm condition?

Ваша відповідь правильна:

Flame failure.
51

Which one of the following elements of diesel engine exhaust emissions are considered as atmospheric pollutants?

Ваша відповідь правильна:

Carbon dioxide.
52

Which one of the following features would you expect to find with an inline multi cylinder fuel pump block arrangement?

Ваша відповідь правильна:

A single rack to control all of the fuel pumps simultaneously.
53

Which one of the following gases would you normally associate with the combustion of hydrocarbon fuel containing sulphur in a diesel engine?

Ваша відповідь правильна:

Sulphur dioxide, SO2.
54

Which one of the following options best describes a “stoichiometric mixture”?

Ваша відповідь правильна:

A mixture of fuel and air containing the exact theoretical amount of air for complete combustion of the fuel.
55

Which one of the following options best describes how combustion in a boiler furnace is different to that in a diesel engine cylinder?

Ваша відповідь правильна:

Boiler combustion is a continuous process.
56

Which one of the following options best describes the gas used as a source of fuel on some LNG carriers?

Ваша відповідь правильна:

It is a low pressure gas, having evaporated from the cargo tanks.
57

Which one of the following options best describes when you would normally expect to find a thermal oil heating unit fitted onboard a ship?

Ваша відповідь правильна:

When the ship operators on heavy fuel, but has no steam boiler.
58

Which one of the following options best describes why incinerators need a fuel oil system?

Правильну відповідь:

To establish a flame prior to burning waste oil.

Ваша відповідь:

To allow the incinerator to be operated when there is no waste oil, sludge or waste material.
59

Which one of the following options best describes why recirculation type fuel injectors are sometimes fitted to diesel engines?

Правильну відповідь:

A separate fuel valve cooling system is not required.

Ваша відповідь:

They allow the engine to be run on heavy fuel oil.
60

Which one of the following options is a requirement of a diesel engine fuel injection pump?

Ваша відповідь правильна:

Ensure the correct quantity of fuel injected.
61

Which one of the following options is an acceptable method of checking the timing of diesel engine high pressure fuel pumps?

Правильну відповідь:

Spill cut off method.

Ваша відповідь:

Matching witness marks on pump casing and camshaft cover.
62

Which one of the following options is considered to be a product of incomplete combustion of fuel in a diesel engine cylinder?

Ваша відповідь правильна:

Carbon monoxide.
63

Which one of the following options is the best definition of the “flash point” of a fuel?

Ваша відповідь правильна:

The temperature, at which a fuel gives off vapors which can be ignited by an external ignition source.
64

Which one of the following problems is likely to occur if the correct procedure for changing over from heavy fuel to distillate fuel prior to stopping a diesel engine is not followed?

Ваша відповідь правильна:

Gassing up due to distillate fuel component overheating.
65

Which one of the following problems is most often associated with blended marine fuels?

Ваша відповідь правильна:

Instability.
66

Which one of the following statements is true?

Ваша відповідь правильна:

Marine diesel oil is a mixture of distillate and a small amount of residual or heavy fuel.
67

Which parameters of a diesel engine fuel system are normally covered by alarm monitoring? Select all of the correct options:

Ваша відповідь правильна:

Fuel temperature.; Fuel pressure.; Fuel viscosity.
68

Which part of a diesel engine fuel cam profile is normally used to control the rate of fuel delivery?

Правильну відповідь:

The controlled speed section.

Ваша відповідь:

The acceleration and deceleration sections.
69

Why is the exhaust from an oil fired boiler a suitable source of inert gas to use to inert cargo tanks on an oil tanker?

Ваша відповідь правильна:

The boiler exhaust normally contains less than 5 % oxygen.
70

Why is variable injection timing (VIT) incorporated in some diesel engine fuel systems?

Ваша відповідь правильна:

To increase thermal efficiency and reduce specific fuel consumption.
71

“Turbulence” is the term used to describe the movement of the charge air in a diesel engine cylinder. Which one of the following options best describes a feature which helps in generating turbulence?

Правильну відповідь:

The geometry of air inlet ports and valves.; The length of the charge air receiver.

Ваша відповідь:

The geometry of air inlet ports and valves.
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