Chapter 8

  1. A single element feedwater system compensates for variations in:
    a. Level and pressure
    b. Shrinkage and swell
    c. Level only
    d. Pressure only
    e. flow only
    Level only
  2. With On – Off boiler feed water control, water is supplied _____________ to the boiler, either by fully opening or fully closing a valve in the feedwater line.
    a. partially
    b. intermittently
    c. fully
    d. steadily
    intermittently
  3. In ______ control, a change in drum level causes a proportional change in output from the transmitter to reposition the feedwater control valve to correct the drum level setpoint.
    a. proportional
    b. reset
    c. feedback
    d. water
    feedback
  4. A rapid increase in boiler load causes an immediate increase in steam flow from the boiler, which creates a sudden _____ in the boiler steam drum pressure.
    a. drop
    b. increase
    c. change
    d. temperature
    drop
  5. A sudden increase in load, a decrease in drum pressure, and an immediate increase in heat release, is called ______.
    a. rate
    b. swell
    c. shrinkage
    d. condensing
    swell
  6. The two-element feedwater control system, is similar to the single element type, only with a ______ flow transmitter added.
    a. fuel
    b. feedwater
    c. air
    d. steam
    steam
  7. A two-element control system may be called a _________ system as it anticipates what will happen to the drum level with a change in load and acts accordingly to avoid large level fluctuations.
    a. reverse feed
    b. feed-forward
    c. good
    d. smart
    feed-forward
  8. Shrinkage may be the result of:
    1. A reduction in boiler output
    2. An increase in firing rate
    3. A decrease in firing rate
    4. An increase in steam drum pressure
    a. 1, 3, 4
    b. 1, 2, 3
    c. 2, 3, 4
    d. 1, 2, 4
    e. 1,2,3,4
    1,3,4
  9. Three-element feedwater control compensates for:
    1. Level variation
    2. Steam flow variation
    3. Feedwater flow variation
    4. Shrinkage and swell
    a. 2, 3, 4
    b. 1, 3, 4
    c. 1, 2, 4
    d. 1, 2, 3, 4
    e. 1, 2, 3
    1,2,3,4
  10. The three-element feedwater control system overcomes the effects of swell and shrinkage and also responds to _________ flow.
    a. fuel
    b. steam
    c. feedwater
    d. blowdown
    feedwater
  11. An oxygen analyzer can also be provided to indicate the excess oxygen in the flue gas, assisting the operator to control the excess air and increasing boiler _______.
    a. load
    b. firing
    c. temperature
    d. efficiency
    efficiency
  12. A pressure modulating control (pressuretrol):
    a. Maintains a constant firing rate
    b. Will vary fuel and air supply according to steam pressure
    c. Cannot be adjusted
    d. Can vary fuel and air supply separately
    e. Starts and stops the burner at predetermined settings
    Will vary fuel and air supply according to steam pressure
  13. Direct combustion control measures and responds to:
    a. Air flow and steam pressure
    b. Air flow and fuel flow
    c. Steam pressure only
    d. Steam pressure and fuel flow
    e. Steam pressure and steam flow
    Steam pressure only
  14. By measuring and comparing the steam and the ________, it is possible to obtain efficient combustion in a boiler by maintaining a proper steam to airflow ratio.
    a. feedwater
    b. fuel
    c. airflow
    d. drum level
    airflow
  15. The furnace pressure controller will adjust the boiler ______ dampers to keep the pressure constant at all boiler loads.
    a. Outlet????
    b. inlet
    c. air
    d. burner
    e. Induced draft
    Induced draft
  16. In a fuel flow – airflow combustion control system, the fuel flow signal makes the final adjustment to the ________.
    a. feedwater
    b. fuel
    c. airflow
    d. drum level
    airflow
  17. When increasing the firing rate manually it is best to:
    a. Increase air flow before fuel flow
    b. Increase fuel flow before air flow
    c. Increase air and fuel together
    d. It really doesn't matter
    e. Decrease fuel flow before increasing air flow
    Increase air flow before fuel flow
  18. Before making adjustments or altering the fuel-air ratio of a combustion control system, we would:
    a. Measure fuel flow
    b. Analyze flue gas
    c. Increase air flow
    d. Decrease firing rate
    e. Measure steam flow
    Analyze flue gas
  19. When master controller output goes directly to a fuel valve and a modulating relay we have:
    a. Multi-element control
    b. Air flow-fuel flow control
    c. Fuel flow-air flow control
    d. Steam flow-air flow control
    e. Positioning Control
    Fuel flow-air flow control
  20. n a airflow-fuel flow combustion control, airflow signal becomes the set point of the ____ controller.
    a. feedwater
    b. fuel
    c. airflow
    d. drum level
    fuel
  21. The attemperator is used to control the temperature of feedwater from the economizer
    a. True
    b. False
    false
  22. To maintain turbine __________ and avoid fluctuations in the turbine metal temperatures, it is necessary to hold the superheated steam temperature and the reheated steam temperature, at a constant value.
    a. life
    b. integrity
    c. efficiency
    d. operation
    efficiency
  23. There are two types of attemperators used:
    a. surface type
    b. spray type
    c. direct contact type
    d. cross flow type
    e. A, D
    f. A, C
    a,c
  24. The direct contact attemperator, which is also referred to as the ______ type desuperheater, introduces feedwater into the superheated steam, through a spray nozzle.
    a. shell
    b. spray
    c. drum
    d. condenser
    spray
  25. The ______ ,used in the spray desuperheater, must be of the highest quality since any solids carried over will cause deposits in superheater tubes and on turbine blades.
    a. steam
    b. metal
    c. water
    d. internals
    water
  26. The Gas Recirculation method is used to maintain the desired steam temperature at ________ loads.
    a. high
    b. partial
    c. over
    d. no
    partial
  27. Gas bypass method involves the separation of the convection section of the boiler into two, or more, _________ gas passes.
    a. reverse
    b. crossing
    c. parallel
    d. counter
    parallel
  28. At high loads when the steam temperature tends to go above the desired value, the tilting burners are tilted ___________.
    a. downwards
    b. upwards
    c. tangents
    d. sideways
    downwards
  29. At low loads when the steam temperature drops, the tilting burners are tilted _________.
    a. downwards
    b. upwards
    c. tangents
    d. sideways
    upwards
  30. Programming controls:
    a. Function during operation
    b. Function during start up and shut down
    c. Function during start up
    d. Function during shut down
    e. Function during emergency situations
    Function during start up and shut down
  31. On a semi-automatic boiler the programming controls are activated by:
    a. Pressure
    b. The operator
    c. Temperature
    d. Water level
    e. Temperature and pressure
    The operator
  32. Purging a furnace means:
    a. Ensuring the furnace is pressurized with air
    b. Ensuring air is flowing through the furnace
    c. Ensuring fuel is entering the furnace
    d. Causing air to flow for no more than five seconds
    e. Ensuring the air flow to the furnace has stopped
    Ensuring air is flowing through the furnace
  33. Pilot gas valve and ignition transformer should be energized:
    a. Before pre purge
    b. During post purge
    c. After pre purge
    d. On program start
    e. after the pilot burner is lit
    After pre purge
  34. Limit switches of a programmed circuit tend to be:
    a. In parallel
    b. Normally closed
    c. In series
    d. Activated by the programmer
    e. supervise the pilot flame
    In series
  35. When we manually close the start switch we:
    a. Close the fan circuit
    b. Energize the programmer
    c. Close the timer circuit
    d. Initiate the purge dampers
    e. energize the spark igniter
    Close the timer circuit
  36. At the end of the pre-purge the timer:
    a. Opens the fuel valve
    b. Opens the pilot valve
    c. Goes through an ignition trial
    d. Energizes the ignition transformer
    e. shuts off the igniter and the pilot
    Energizes the ignition transformer
  37. When steam pressure reaches cut-out value:
    a. The timer stops
    b. The master relay becomes energized
    c. The coil of the burner valve is de-energized
    d. The timer causes the fuel valve to close
    e. the flame scanner becomes de-energized
    The coil of the burner valve is de-energized
Author
PowerPrep
ID
317628
Card Set
Chapter 8
Description
chapter 8
Updated