Boiler Quiz

MSAT

PAGE

WSATUtility Boiler Quiz

EnVision Systems Inc.EnVision Systems Inc.

Version 1.1, March 20012 Shunpike Road, Suite 30Madison, NJ 07940, USATable of Contents

Page1.Chapter 1: Overview

2

2.Chapter 2: Boiler Components

4

3.Chapter 3: Boiler Performance

9

4.Chapter 4: Boiler Control System

12

5.Chapter 5: Boiler Trips and Interlocks

16

6.Chapter 6: Basic Operations

18

7.Chapter 7: Normal Operation

21

8.Chapter 8: Emergency Operations

22

9.Chapter 9: Other Operating Conditions

25

Chapter 01: OverviewSub-Chapter 01: Introduction

1. The gas formed by burning of fuel is called:

a) Fuel gas

b) Flue gas

c) Synthesis gas

d) Natural gas

2. The fuel used in a boiler is non-combustible.

a) True

b) False

Sub-Chapter 02: Applications of Boiler

3. In process plants, steam is available as:

a) High pressure steam

b) Medium pressure steam

c) Low pressure steam

d) All the above

4. A boiler specifically designed to generate electric power and simultaneously provide steam to the plant is known as a Co-Generation Boiler.

a) True

b) False

Sub-Chapter 03: Types of Boiler

5. In some boilers, water is converted to steam as it flows from the inlet to the outlet of the heating tubes. This type of boiler is known as:

a) A fire-tube boiler

b) A once-through boiler

c) A drum-type boiler

d) None of the above

6. In some boilers, the flue gas flows through the boiler tubes, which are submerged in the water. The steam is generated by transferring heat from hot flue gas in the tubes to the water on the shell side. This type of boiler is known as:





7. In some boilers, water circulates within the boiler between two drums. This type of boiler is known as:





8. A fire-tube boiler is mainly used as:

a) A small to medium size industrial boiler

b) A power plant boiler

c) A large size industrial boiler


9. The most commonly used boilers in oil refineries and petrochemical plants are:

a) Fire-tube boilers

b) Once-through boilers

c) Drum-type boilers


10. In a Forced-Draft system, the air and the flue gas flows are achieved by:

a) Fans or blowers

b) Turbines

c) Pumps

d) Compressors

11. In a __________, a fan or a blower is located downstream of the boiler to maintain flue-gas flow.

a) Forced-draft boiler

b) Induced-draft boiler

c) Balanced-draft boiler

d) Natural-draft boiler

12. In a __________, fans or blowers are located both upstream and downstream of the boiler to maintain flue gas flow to the stack.





13. In a __________, a fan or a blower is located upstream of the boiler to maintain flue gas flow.





14. In a Natural-Draft boiler, no fan or a blower is used. The air and the flue gas are maintained by a phenomenon called:

a) Forced convection

b) Induced convection

c) Balanced convection

d) Natural convection

Chapter 02: Boiler ComponentsSub-Chapter 01: Introduction

1. In the deaerator of a boiler, trapped air present in water is removed.

a) True

b) False

2. The combustion of fuel oil or fuel gas in a boiler takes place in the:

a) Burners

b) Superheater

c) Air preheater

d) Economizer

Sub-Chapter 02: Deaerator and Feedwater System

3. The deaerated water is heated and sent to the:

a) Steam drum

b) Mud drum

c) Burner

d) Steam header

4. The dissolved oxygen and carbon dioxide in boiler feedwater can cause corrosion in boiler parts.

a) True

b) False

5. In a deaerator, the air and the dissolved gases are stripped with:

a) Fuel gas

b) Steam

c) Air

d) Flue gas

6. The water entering the steam drum is called:

a) Saturated water

b) Condensed water

c) Raw water

d) Feedwater

Sub-Chapter 03: Water Circulation and Heating System

7. The steam is separated from the steam-water mixture in the mud drum.

a) True

b) False

8. In the steam drum, the steam is in equilibrium with water and is called:

a) Saturated steam

b) Superheated steam

c) Unsaturated steam

d) Subcooled steam

9. The feedwater which enters the boiler may contain small amounts of:

a) Organic compounds

b) Inorganic compounds

c) Air

d) All the above

10. The process by which the accumulated solids in the steam drum and the mud drum are removed is called:

a) Deaeration

b) Blowdown

c) Water Softening

d) Corrosion removal

11. The water from the steam drum flows to the mud drum through:

a) Downcomer

b) Blowdown line

c) Risers

d) Economizer

12. The water is boiled by heat generated by combustion of fuel and as a result, a steam-water mixture is generated in the:

a) Downcomers

b) Blowdown line

c) Water wall

d) Economizer

13. The blowdown operation from the mud drum is usually an intermittent operation.

a) True

b) False

14. The water is circulated between the steam drum and the mud drum usually by:

a) Forced circulation

b) Natural circulation

c) Balanced circulation

d) All the above

15. The purpose of a mud drum is to:

a) Collect sludge and other impurities deposited as solids

b) Condense steam

c) Mix water with steam


Sub-Chapter 04: Superheater and Heat Recovery System

16. When the saturated steam is heated further, it becomes:

a) Superheated steam

b) Subcooled steam

c) Condensed steam


17. The cooling of saturated steam results in:

a) Formation of superheated steam

b) Formation of water droplets

c) None of the above

18. The steam from the steam drum passes through:

a) Mud drum

b) Steam header

c) Economizer

d) Superheaters

19. In the primary superheater, the saturated steam is primarily heated by:

a) Convective heat transfer from the flue gas

b) Radiative heat transfer from the flue gas

c) Water-steam mixture

d) Water injected to the primary superheater

20. In the desuperheater, a small quantity of water is injected to reduce the __________ of the steam.

a) Pressure

b) Temperature

c) Flow rate

d) Density

21. The steam from the desuperheater enters the secondary superheater where it is heated primarily by:

a) Convective heat transfer from the flue gas

b) Radiative heat transfer from the flue gas

c) Circulating water

d) Water injected to the secondary superheater

22. Usually the economizer heats the feedwater with:

a) Flue gas

b) Air

c) Steam leaving the steam drum

d) Steam leaving the superheater

23. The use of economizer decreases the fuel requirement and increases the efficiency of the boiler unit.

a) True

b) False

Sub-Chapter 05: Combustion System

24. The air flow to the burners can be adjusted by:

a) Dampers in air circuit

b) Dampers in flue gas circuit

c) Burner air-registers

d) Air blower vane position

e) All the above

25. The fuel oil has to be __________ prior to mixing with air for combustion.

a) Mixed with fuel gas

b) Vaporized

c) Converted to a fine mist

d) Cooled

26. For a better combustion, the fuel oil is converted to a fine mist using steam injection. This process is known as:

a) Splitting

b) Atomization

c) Evaporation

d) Oxidation

27. The burner which provides ignition to the main burner is known as the:

a) Pilot burner

b) Oil burner

c) Gas burner

d) Combination oil and gas burner

Sub-Chapter 06: Draft System

28. The pressure difference between the heating section in a boiler and the atmosphere is known as draft.

a) True

b) False

29. The air entering the burners is heated in the air heater normally with:

a) Flue gas leaving the boiler

b) Fuel gas

c) Electric heaters

d) Hot oil

30. The type of air heater commonly used is:

a) A shell and tube type

b) A kettle type

c) A regenerative type


Sub-Chapter 07: Steam Distribution System

31. The steam generated in a boiler is distributed to various steam users in the plant through:

a) Steam headers

b) Deaerator

c) Blowdown valve

d) Vent valve

32. A part of the source for medium pressure steam in MP-Steam header is high pressure steam in HP-Steam header.

a) True

b) False

Chapter 03: Boiler PerformanceSub-Chapter 01: Introduction

1. Shutdown of the boiler unit may result in shutdown of most process units in the plant.

a) True

b) False

2. The fuels used in the boiler unit are:

a) Combustible

b) Cold

c) Hot

d) Inert

Sub-Chapter 02: Burner Characteristics

3. The flame of the burners can always be sustained as long as air and fuel are present.

a) True

b) False

4. A flame out in a burner can happen even when air and fuel are provided to the burner.

a) True

b) False

5. For a fuel gas burner, the stable operating range is determined by:

a) The fuel gas pressure at the burner inlet

b) The fuel oil pressure at the burner inlet

c) The atomizing steam pressure at the burner inlet


6. For a fuel oil burner, the stable operating range is determined by:

a) The fuel oil pressure at the burner inlet

b) The atomizing steam pressure at the burner inlet

c) The fuel gas pressure at the burner inlet

d) Both fuel oil and atomizing steam pressure at the burner inlet

7. When an additional burner is fired during startup, the flames at the burners already in service may go out unless sufficient fuel pressure is maintained at the burner inlet.

a) True

b) False

Sub-Chapter 03: Combustion Air

8. Inadequate combustion air leads to:

a) Complete combustion of fuel in the burner

b) Partial combustion of fuel in the burner

c) Lower fuel flow to the burner

d) Increase in the steam pressure

9. The carbon in a hydrocarbon fuel mixes with oxygen to form carbon monoxide, which further burns with oxygen to form carbon dioxide. Which of the following reactions generate heat?

a) Formation of carbon monoxide only

b) Formation of carbon dioxide only

c) Formation of both carbon monoxide and carbon dioxide


10. During partial combustion due to insufficient air, the partially unburned fuel escapes with the flue gas.

a) True

b) False

11. When the air supplied to the burner is significantly higher than the required air for the combustion, it leads to:

a) Partial combustion

b) Increased loss of energy to atmosphere

c) Loss of flue gas


12. The minimum amount of air required for complete combustion is known as:

a) Inadequate air

b) Theoretical air

c) Excess air

d) Minimum air

13. A certain amount of excess air is required for complete combustion because the theoretical air may not be sufficient due to:

a) Improper mixing of air and fuel

b) Perfect mixing of air and fuel

c) Lower calorific value of fuel

d) Higher calorific value of fuel

14. The excess air is the difference between the amount of air supplied and the:

a) Theoretical air

b) Total amount of flue gas produced

c) Carbon monoxide produced

d) Air used for burning fuel

15. To ensure complete combustion, excess air is required. Thus, it is a good practice to supply as much air as possible for efficient boiler operation.

a) True

b) False

16. Let's assume that the theoretical air flow rate is 25 units ( KNM3/hr or MMSCF/Hr ), while the actual supplied air flow rate is 30 units ( KNM3/Hr or MMSCF/Hr ), respectively. What is the excess air in %?

a) 30 %

b) 15 %

c) 20 %

d) 25 %

Sub-Chapter 04: Damper and Air Registers

17. In a forced-draft boiler, the air-registers are used only for fine adjustment of air flow through each burner.

a) True

b) False

18. In a forced-draft boiler, the total air flow rate is controlled primarily by:

a) Solenoid valve

b) Air-registers

c) Theoretical air

d) Vanes of the forced-draft fan

19. The effect of mixing of air and fuel in the burner can be observed from the:

a) Air flow rate

b) Fuel flow rate

c) Flame color of the burner

d) Atomizing steam flow rate to the burner

Sub-Chapter 05: Fuel Characteristics

20. The fuel oil viscosity does not have any effect on the burner flame condition in the boiler.

a) True

b) False

21. In the boiler, __________ is affected if the fuel oil and the atomizing steam pressures at the burner vary.

a) Burner air flow

b) Fuel gas flow

c) Fuel oil temperature

d) Fuel oil atomization

Chapter 04: Boiler Control SystemSub-Chapter 01: Introduction

1. Control schemes in the boiler ensure that the steam generation is continuous.

a) True

b) False

2. Which of the following are the objectives of the boiler control systems?

a) Safe working environment

b) Maximum efficiency

c) Perform normal operations safely

d) All the above

Sub-Chapter 02: Three-Element Feedwater Control

3. When the steam consumption is suddenly increased, the level in the steam drum:

a) Rises momentarily

b) Falls momentarily

c) Does not change

d) Drops to zero

4. Any change in boiler steam consumption initially causes a change in the:

a) Flue gas temperature

b) Steam temperature

c) Steam drum level

5. With a sudden drop in steam pressure, the steam bubbles in the water wall and the steam drum:

a) Swell momentarily

b) Shrink momentarily

c) Do not get affected

6. When the steam consumption is reduced suddenly, the pressure in the steam drum:

a) Rises

b) Drops

c) Does not change

d) Drops to zero

7. In a conventional two-element steam drum level control:

a) The feedwater flow controller is cascaded to the steam temperature controller

b) The steam drum level controller is cascaded to the feedwater flow controller

c) The steam pressure controller is cascaded to the feedwater flow controller

d) The steam pressure controller is cascaded to the steam drum level controller

8. In a conventional two-element steam drum level control, during a sudden increase in the steam consumption rate, the feed-water flow to the steam drum:

a) Increases initially and then decreases

b) Decreases initially and then increases

c) Continues to decrease


9. In a three-element steam drum level control system, the steam consumption rate is added to the output of the level controller as a:

a) Feed forward signal

b) Feed back signal

10. In a three-element steam drum level control strategy, the effect of shrink and swell of water is:

a) Minimized

b) Maximized

c) Not affected at all

Sub-Chapter 03: Steam Temperature Control

11. The main steam temperature is controlled by spraying feedwater in a:

a) Secondary superheater

b) Primary superheater

c) De-superheater

d) Steam drum

12. In the boiler, the air flow signal is provided as a __________ signal to the main steam temperature controller.

a) Feed forward

b) Feed back

c) Cascade

d) Automatic

Sub-Chapter 04: Steam Pressure Control

13. When the steam demand is increased, the steam pressure:

a) Increases

b) Decreases

c) Does not change

14. The main steam pressure is controlled by the steam pressure controller which adjusts primarily the:

a) Combustion air flow

b) Fuel flow

c) Feedwater flow

d) Steam injection

15. When the steam consumption is increased, the steam pressure controller:

a) Increases the feedwater flow

b) Decreases the combustion air flow

c) Increases the fuel flow

d) Decreases the fuel flow

16. In some steam pressure control strategies, in order to speed up the response of the steam pressure controller for steam consumption changes, the value of __________ is added to the output of the steam pressure controller as a compensation signal.

a) The main steam flow rate

b) The air flow rate

c) The feedwater flow rate


17. The Boiler Master Signal determines the:

a) Fuel and air demand

b) Main steam pressure

c) Main steam temperature

d) Feedwater demand

18. The MP-Steam header pressure controller controls the MP-Header pressure by adjusting the letdown steam flow from the:

a) MP-Steam header

b) HP-Steam header

c) LP-Steam header

d) Steam drum

Sub-Chapter 05: Fuel Control

19. When both the fuel oil and the fuel gas are used simultaneously, the Boiler Master Signal is always split equally and sent to the fuel oil flow and the fuel gas flow controllers as set points.

a) True

b) False

20. The calorific value of all fuel gases and fuel oils is the same.

a) True

b) False

Sub-Chapter 06: Total Calorie/BTU Control

21. The use of the total calorie controller ensures a better control of steam pressure when the __________ changes.

a) Steam demand

b) Fuel pressure

c) Feedwater flow

d) Fuel composition

22. The total calorie control scheme takes into account the changes in calorific value of the fuel.

a) True

b) False

Sub-Chapter 07: Combustion Air Control

23. When the fuel flow demand (Boiler Master Signal) increases, the required air flow must:

a) Decrease

b) Stay the same

c) Increase

24. The total air flow is controlled by the air flow controller, which adjusts the:

a) Air-register openings of all burners

b) Steam flow

c) Fuel flow

d) Vanes of FD fan

Sub-Chapter 08: Oxygen Control

25. In the oxygen control scheme, the output of the oxygen controller is added to the __________ which becomes the process value ( PV ) for the air flow controller.

a) Measured fuel gas flow rate

b) Measured fuel oil flow rate

c) Measured air flow rate

d) Measured steam flow rate

26. The air flow controller manipulates the air flow based on oxygen content of flue gas in the radiation section of the boiler.

a) True

b) False

Sub-Chapter 09: Cross Limit Control

27. A Cross Limit control ensures that when the fuel demand is increased, the air flow increases __________ the fuel flow is increased.

a) After

b) Before

c) And simultaneously

28. A Cross Limit control ensures that when the fuel demand is decreased, the air flow decreases __________ the fuel flow is decreased.

a) After

b) Before

c) And simultaneously

Chapter 05: Boiler Trips and InterlocksSub-Chapter 01: Introduction

1. The interlocks present in the boiler ensure plant operation at design conditions always.

a) True

b) False

2. The interlock trip button in the boiler __________, when activated.

a) Closes the fuel valves

b) Starts combustion

c) Increases heat recovery in flue gas heat recovery section

d) All the above

Sub-Chapter 02: Trip Logic

3. The fuel emergency shutdown valve or trip valve can be manually opened any time.

a) True

b) False

4. When an interlock trip in a boiler unit is activated:

a) The fuel flows to the burners are stopped

b) The air flow to the burners are stopped

c) Feedwater flow is stopped

d) Steam draw is stopped

5. After a boiler trip, the fuel line is closed by the trip logic automatically. The air flow to the unit must continue to:

a) Heat the boiler unit

b) Purge and cool the boiler unit

c) Cut the burner flame

d) Maintain steam pressure

6. A boiler unit trips when:

a) Only the steam drum level is low

b) Only the air flow rate is low

c) Only the fuel pressure is low

d) All the above

7. If the steam drum becomes empty while all the burners are firing:

a) The tubes in the boiler unit are cooled

b) The tubes in the boiler unit may melt due to high temperature

c) Blowdown flow increases


8. The accumulation of unburned fuel in the boiler leads to:

a) Increased efficiency of the boiler

b) Explosion hazard of the boiler unit

c) Increase in the steam pressure

d) Increase in the feedwater flow

9. The low fuel pressure is one of the causes of the boiler trip. The reason is that:

a) Flame may extinguish and as a result unburned fuel will accumulate in the boiler

b) Fuel supply will be completely stopped

c) Due to the control strategy, air supply will be completely stopped


10. A low air flow rate is one of the causes of the boiler trip. The reason is that:

a) Due to the control strategy, the fuel flow will be completely stopped

b) Main steam flow to the HP-Header will be stopped

c) Incomplete combustion may occur and as a result unburned fuel will accumulate in the boiler


Sub-Chapter 03: Purge Logic

11. Only after the purging operation has been completed, the fuel trip valves or emergency shutdown valves can be manually opened.

a) True

b) False

12. If there is presence of unburned fuel in the boiler unit, the boiler unit should be purged:

a) Before air is introduced to the boiler unit

b) Before ignition of burners

c) After ignition of burners

d) Before feedwater is introduced to the boiler unit

13. A purging operation is performed when the air flow to the boiler unit is very low.

a) True

b) False

14. The purging must be performed before the startup of the boiler because:

a) Steam and water are still present in the boiler

b) Unburned fuel may be present in the boiler

c) The boiler unit is still too hot

d) Steam pressure is still too high

Chapter 06: Basic OperationsSub-Chapter 01: Pre Startup

1. Before the boiler unit is started up, all controllers should be in __________ mode.

a) Manual

b) Automatic

c) Cascade

2. Prior to starting a boiler unit, the drain and the vent valves should be:

a) Opened

b) Closed

3. During the startup, when fuel oil is used, it is advisable to start the circulation of fuel oil at the normal temperature and pressure conditions.

a) True

b) False

4. During the startup, when fuel gas is used, the fuel gas lines should be sufficiently heated. If the fuel gas lines are not heated:

a) The water vapor present in the fuel gas may condense, disturbing the fuel gas flow

b) The temperature of fuel gas will become too low

c) The fuel gas calorific value will decrease


Sub-Chapter 02: Startup

5. The steam is used in the deaerator to:

a) Eliminate the inorganic compounds contained in the water

b) Increase the pressure of the deaerator

c) Strip off air trapped in the water


6. The firing of burners can be initiated any time after the steam drum is filled with sufficient water.

a) True

b) False

7. Before the purging operation, the air-registers of all burners should be:

a) Fully opened

b) Fully closed

c) Any opening

8. The purging operation can be commenced when:

a) Steam drum level is normal

b) Air flow is sufficient

c) Steam drum level is normal and air flow is sufficient


9. After the purging operation has been completed, the trip valves for the fuel line can be opened manually.

a) True

b) False

10. The fuel to the burners should be introduced:

a) Only after the pilot flame is established

b) Before the pilot flame is established

c) At any pilot flame condition

d) After the pilot flame is extinguished

11. When the fuel pressure at the burner inlet becomes lower than a certain value, a flame out can occur.

a) True

b) False

12. In a boiler unit with multiple burners, after one burner has started firing:

a) All the other burners should be ignited simultaneously

b) The other burners should be ignited one by one

13. The flame in a burner can be stabilized by adjusting the air-register.

a) True

b) False

14. A high __________ content in flue gas is desired during startup.

a) Carbon monoxide

b) Oxygen

c) Hydrocarbons

d) Carbon dioxide

15. Before igniting the oil burners, the atomizing steam lines should be drained to prevent accumulation of __________ in the firebox.

a) Unburned fuel

b) Water

c) Air

d) Hydrocarbons

16. During the initial stage of startup operation, it is recommended to place the fuel and the air flow controllers in automatic mode:

a) Immediately after the air and fuel are introduced

b) After the pilot gas is introduced

c) After the burner flames are stabilized

d) After the burners are ignited

17. The main steam pressure controller can be placed in automatic mode only after:

a) The steam pressure is stabilized

b) The steam temperature is stabilized

c) Both fuel and air flows are stabilized

d) The burner flames are stabilized

18. The fuel and air flow controllers are placed in cascade mode with the steam pressure controller in automatic mode, after:

a) The burner flames are stabilized

b) The steam temperature is stabilized

c) Both fuel and air flow are stabilized

d) The steam pressure is stabilized

Sub-Chapter 03: Shutdown

19. When the steam withdrawal rate is decreased, the fuel and the feedwater flows are:

a) Increased proportionally

b) Decreased proportionally

c) Maintained constant

20. During a normal shutdown, all burners should be extinguished simultaneously.

a) True

b) False

21. The pilot gas should be shut off immediately after all burners are turned off. This way, the fuel can be saved.

a) True

b) False

22. After the oil burner is shut off, steam should be blown into the extinguished burner to:

a) Keep the burner warm

b) Eliminate the condensed steam

c) Expel the remaining oil


Sub-Chapter 04: Post Shutdown

23. After the boiler unit has been shutdown, the air-registers should be kept fully:

a) Opened

b) Closed

24. If the boiler is to be started soon after the shutdown, the steam drum should be drained.

a) True

b) False

Chapter 07: Normal OperationSub-Chapter 01: Introduction

1. Boiler load refers to the steam requirement by the downstream units.

a) True

b) False

2. The change in the boiler load affects:

a) Fuel flow rate

b) Air flow rate

c) Feedwater flow rate

d) All the above

Sub-Chapter 02: Effect of Load Change on Pressure

3. When the HP-Steam load increases, the fuel flow rate and the air flow rate __________ due to the control scheme.

a) Decrease

b) Increase

c) Do not change

4. When the HP-Steam load increases, the steam pressure increases.

a) True

b) False

Sub-Chapter 03: Effect of Load Change on Level

5. When the HP-Steam load increases, the steam drum level:

a) Continues to increase

b) Stays the same

c) Increases initially and then continues to decrease


6. When the LP-Steam load is decreased, the entire boiler unit is upset and the control strategy eventually brings it back to the desired condition by:

a) Decreasing fuel flow

b) Decreasing air flow

c) Decreasing feedwater flow

d) All the above

7. In most steam drums, the rate of change of steam drum level is faster due to its geometry when the steam drum level is:

a) High

b) Low

Chapter 08: Emergency OperationsSub-Chapter 01: Introduction

1. Most modern boilers have __________ for purpose of safety.

a) Advanced control system

b) Trip and interlock system

c) Purge logic

d) All the above

2. __________ causes hazardous situations in a boiler unit.

a) A high air flow rate

b) A low hydrocarbon percentage in flue gas

c) A low temperature in boiler

d) An incomplete combustion of fuel in burner

Sub-Chapter 02: Low Steam Drum Level

3. An overheating of tubes causes thermal stresses to the tube metal, increasing the possibility of tube rupture in future.

a) True

b) False

4. A low steam drum level can occur due to many factors. Let's assume that the following conditions are observed.

Observation 1: Feedwater pump discharge pressure is normal.

Observation 2: Feedwater flow rate is decreased.

Observation 3: Feedwater control valve is working properly.

Which of the following is the cause for low steam drum level in this case?

a) Leakage of the feedwater in the heating tube

b) Feedwater pump is tripped

c) Level transmitter drifts high


5. A low steam drum level can occur due to many factors. Let's assume that the following conditions are observed.

Observation 1: Feedwater pump discharge pressure is normal.

Observation 2: Feedwater flow rate is increased.

Observation 3: Feedwater control valve is working properly.

Which of the following is the cause for low steam drum level in this case?

a) Leakage of the feedwater in the heating tube

b) Feedwater pump is tripped

c) Level transmitter drifts high


6. When the feedwater pump fails, it leads to:

a) Unburned fuel in the firebox

b) Increased feedwater flow to the steam drum

c) Low drum level trip

d) Low fuel oil pressure trip

7. When a transmitter drift is detected, the immediate corrective action is to place the controller, which uses the drifted signal as PV, in manual mode.

a) True

b) False

8. When the steam drum level transmitter drifts high, the actual steam drum level __________ due to the action of the steam drum level controller.

a) Rises

b) Falls

c) Does not get affected

d) Fluctuates rapidly

9. When a control valve closes fully due to some malfunction, the corrective action is to:

a) Place the associated controller into manual mode and operate it manually

b) Change the set point of the associated controller

c) Operate the associated bypass valve


10. When the feedwater pump fails:

a) The boiler unit should be shutdown immediately

b) The backup pump should be started immediately

c) Purging operation must be performed

d) All the above

11. A feedwater pump failure can be detected by sudden __________ in the feedwater pump discharge pressure.

a) Rise

b) Drop

c) Fluctuations

12. The recovery action for a low steam drum level must always be gradual. This is because a sudden increase in the feedwater flow can cause thermal stresses to the heating tubes.

a) True

b) False

Sub-Chapter 03: Rupture of Heating Tubes

13. The rupture of the heating tubes results in:

a) Sudden increase in the feedwater flow

b) Drop in flue gas temperature

c) Rise in flue gas temperature

d) Both a) and b)

e) Both a) and c)

14. When there is a rupture in the heating tubes:

a) The leaked water vaporizes due to intense heat in the boiler

b) The feedwater flow decreases suddenly

c) The leaked water is sent through blowdown line


Sub-Chapter 04: Flame Out of All Burners

15. A flame out of burners can occur when the air flow is:

a) Too little

b) Too high

c) Either too high or too little

16. After a flame out has occurred in a burner, the fuel flow to that particular burner:

a) Stops

b) Is decreased automatically

c) Continues to flow into the burner

d) Fluctuates rapidly

Chapter 09: Other Operating ConsiderationsSub-Chapter 01: Introduction

1. The key operating conditions in the boiler unit should be monitored continuously.

a) True

b) False

2. The conditions that have to be monitored in a boiler unit are:

a) Combustion conditions

b) Soot deposits

c) Both a) and b)

Sub-Chapter 02: Combustion Conditions

3. The combustion condition of a burner can be monitored by observing:

a) The color of the flame

b) The shape of the flame

c) The position of the flame

d) All the above

4. The color of the flame is independent of the type of fuel used for combustion.

a) True

b) False

5. A blue flame in a fuel gas burner indicates:

a) Incomplete combustion due to shortage of air

b) Poor combustion due to excess secondary air

c) Proper combustion

d) Poor combustion due to excess primary air

6. A long flame indicates:

a) Complete combustion

b) Incomplete combustion due to low primary air

c) Excess secondary air

d) Excess primary air

7. When poor combustion is caused due to excess primary air:

a) The flame color is bluish white

b) The flame color is light orange

c) The flame color is red

d) The flame lifts off the base

8. When an incomplete combustion of fuel oil is caused due to the shortage of air flow or improper atomization, the flame color becomes:

a) Orange

b) Red

c) Dark red

d) Light orange

9. The flame condition can be changed by adjusting:

a) The primary or secondary air-register openings

b) The steam flow to the burner

c) The total air flow rate

d) All the above

Sub-Chapter 03: Water Leakage

10. At steady state, the feedwater flow rate should be:

a) Sum of steam rate and blowdown rate

b) Difference between steam rate and blowdown rate

c) Sum of steam rate and attemperator water rate

d) Difference between steam rate and attemperator water rate

11. A leakage in the boiler can be detected by __________ steam generation rate for a particular feedwater flow rate.

a) Increased

b) Decreased

12. When there is feedwater leakage at the upstream of flow and pressure measurement devices in the feedwater circuit:

a) The flow and pressure increase

b) The flow and pressure decrease

c) The flow increases but the pressure decreases

d) The flow decreases but the pressure increases

13. When there is feedwater leakage at the downstream of flow and pressure measurement devices in the feedwater circuit:

a) The flow and pressure increase

b) The flow and pressure decrease

c) The flow increases but the pressure decreases

d) The flow decreases but the pressure increases

Sub-Chapter 04: Soot Deposits

14. The presence of soot deposits in a boiler:

a) Enhances the heat transfer through the heating tubes

b) Reduces the heat transfer through the heating tubes

c) Decreases the flue gas temperature


15. When large amount of soot deposits are formed in the boiler, the boiler efficiency:

a) Decreases

b) Increases

c) Is unaffected

16. The soot accumulation can be __________ by maintaining proper combustion condition at the burner.

a) Minimized

b) Maximized

17. The soot deposits in a boiler can be removed by:

a) A soot blower

b) A blowdown valve

c) A drain valve

d) A vent valve

18. The soot blowers use __________ to remove soot deposits.

a) Steam

b) Compressed air

c) Either a) or b)

d) Feedwater

Sub-Chapter 05: Measurement Errors

19. Transmitter drift will not affect the measurement of process values.

a) True

b) False

20. When a measurement error is detected in a transmitter, the controller associated with the transmitter should be operated in:

a) Automatic mode

b) Cascade mode

c) Manual mode

Copyright 2001 EnVision Systems Inc.PAGE 26Copyright 2001 EnVision Systems Inc.

_953714608.doc

Documents

Boiler Quiz