4th Class Power Engineering Part B Ch91- Ch96 Questions & Answers.

CH.91

Computer "soft keying" is:

A )  done only with lap top units

B )  done to make the computer quicker and easier to use

C )  a method of pressing a key twice before a result is obtained

D )  the same as using a mouse or joystick

E )  a system used to tint graphics

Computer "Run Time Totals" are commonly used:

A )  in graphic displays

B )  for inventory control

C )  for logic supervisory systems

D )  for maintenance management

E )  with a MODEM

When personal computers are linked together and information flows between them, it is called:

A )  telecommunicating

B )  networking

C )  teleconferencing

D )  linking

E )  hardware sharing

As superintendent of a small steam plant, you are buying a computer. Which of the following would you choose?

A )  the minicomputer

B )  the mainframe computer

C )  the microcomputer

D )  a stationary unit

E )  a lap top unit

Computer information can be stored on a:1. hard copy2. floppy disk3. hard disk4. CPU

A )  1, 2

B )  2, 3, 4

C )  1, 2, 3

D )  2, 3

E )  3, 4

The main function of a mainframe computer system is to:

A )  evaluate systems by comparison

B )  rapidly process large amounts of data

C )  perform only a specific dedicated task

D )  produce "hypothetical" solutions to problems

E )  act as a networking switch

The common standard control modes for a plant control system are:

A )  integral and derivative

B )  proportional and reset

C )  proportional, reset, and integral

D )  reset, integral, and rate

E )  derivative, proportional, and integral

Transmitters, which transmit digital codes directly to a computer, are known as

A )  digital transmitters

B )  smart transmitters

C )  analog transmitters

D )  pneumatic transmitters

E )  AND-OR devices

A typical use of a mainframe computer system in a process would be:

A )  the operation of a modulating control valve

B )  acting as a host computer

C )  producing hard copies of a plant system

D )  producing graphics of a plant system

E )  storing information onto a floppy disk

Inputs for logic and supervisory computer functions are mainly:

A )  by switch contacts

B )  actions of an operator using the keyboard

C )  stored on a disk which is required for operation

D )  controlled by relays

E )  non-decision making

CH.92

The combustion chamber of a serpentine tube watertube boiler is:

A )  equipped with gas power burners

B )  located above the tube

C )  surrounded by the tube

D )  located below the tube

E )  enclosed by a non-insulated metal casing

An advantage of a packaged low pressure tubular or watertube boiler is

A )  its ability to meet load changes due to its heat reserve

B )  its less critical water treatment requirement

C )  its lower initial cost

D )  easier waterside maintenance

E )  safety due to the low volume of water it contains

An initial problem with the tubular boiler being used as a steam unit was:

A )  metals which would not stand up to the temperatures involved

B )  dissolved impurities forming scale on the tube

C )  metals not standing up to the pressures involved

D )  inadequate capacities

E )  inability to maintain pressure

A packaged tubular steam boiler often has a steel sheathing in front of the waterwall tubes due to:

A )  the high radiant energy from the flame

B )  overheating of the tubing due to poor circulation

C )  the erosive action of the flame

D )  the high corrosion action of the combustion process

E )  the formation of superheated steam in the tubing

In order to keep salt concentrations within safe limits the packaged tubular steam boiler utilises:

A )  an automatic blowdown

B )  a desalinator

C )  a water softener after the condensate receiver

D )  a mixing chamber before the heating coil

E )  a liquid flow control device

The use of bent tube boiler designs allows the furnace wall to be lined with tubes, thereby exposing more of the heating surface to:

A )  convection heat

B )  conducted heat

C )  radiant heat

D )  residual heat

E )  latent heat

A reason for preferring copper tubing in a tubular boiler is:

A )  faster heat transfer rate

B )  because of its good ductility

C )  its ability to withstand high temperature

D )  scale does not adhere to it

E )  its lower cost than steel

A disadvantage of the watertube or tubular boiler is:

A )  its long warm-up period

B )  water treatment monitoring

C )  its thermal stresses

D )  the foundation requirements due to mass

E )  it's high maintenance cost

The copper tube tubular boiler:

A )  can be gas or oil fired

B )  has a one part heating surface

C )  has the furnace in the upper section

D )  is highly susceptible to corrosion

E )  is capable of very large capacities

A membrane waterwall:

A )  is usually not gas-tight

B )  consists of a metal sheeting in front of the tubes

C )  has metal connecting the tubes

D )  has firebrick in front of the tubes

E )  is applicable to an externally fired boiler 

CH.93

The ratio of heat released to heat transferred to boiler water is known as:

A )  combustion efficiency

B )  heating surface efficiency

C )  boiler efficiency

D )  section ratio

E )  enthalpy transfer ratio

Boiler water legs:

A )  increase the heating surface

B )  surround the furnace entirely

C )  make water treatment less critical

D )  support the boiler on concrete piers

E )  make waterside maintenance easier

Low pressure boilers are made of:1. steel2. stainless steel3. aluminium 4. cast iron

A )  1, 2

B )  2, 4

C )  1, 4

D )  2, 3

E )  1, 2, 3

Sectional cast-iron boiler sections are connected with:

A )  push nipples

B )  modules

C )  victaulic couplings

D )  unions

E )  threaded fittings

The steam and water spaces of a cast iron sectional boiler are held together by:

A )  cast iron pipes

B )  push nipples

C )  steel studs

D )  tie rods

E )  push studs

Cast-iron boiler capacity:

A )  is very large compared to steel boilers

B )  can be increased by simply adding sections

C )  cannot be increased once assembly is completed

D )  is not a function of section numbers

E )  can be increased by increasing section size

Modular cast-iron boiler water flow is:

A )  continuous through all modules

B )  connected in series

C )  intermittent, occurring only while the unit is firing

D )  always vertically upwards

E )  done without the use of headers or manifolds

A cast-iron boiler disadvantage is:

A )  it is subject to corrosion

B )  its difficult assembly

C )  its extremely high cost

D )  its high ductility

E )  its pressure limitations

The steam and water spaces of a cast iron sectional boiler are connected by:

A )  tie rods

B )  tie nipples

C )  hydraulic jacks

D )  steel studs

E )  push nipples

A cast-iron boiler advantage is:

A )  its high factor of brittleness

B )  light weight resulting in lesser foundation requirements

C )  its ability to withstand high pressure

D )  the choice of assembly location

E )  their large capacity

 CH.94

The forerunner of the modern packaged firetube boiler was the:

A )  horizontal return tubular boiler

B )  locomotive boiler

C )  firebox boiler

D )  Sterling boiler

E )  Scotch Marine boiler

One of the earliest firetube boilers was the:

A )  locomotive boiler

B )  firebox boiler

C )  HRT boiler

D )  Haycock boiler

E )  marine boiler

When the hot combustion gases travel through boiler tubes which are surrounded by the boiler water, the boiler is called a:

A )  watertube boiler

B )  tubular boiler

C )  packaged boiler

D )  coil type boiler

E )  firetube boiler

A firetube boiler commonly used for hot water heating systems in residences and small apartments is the:

A )  Scotch firetube packaged unit

B )  HRT unit

C )  steel plate vertical unit

D )  firebox unit

E )  tubular unit

Regarding fire tube boilers HRT stands for:

A )  hot refractory type

B )  high recovery tubes

C )  hard reversing tubes

D )  horizontal return tubular

E )  horizontally reversed transmission

Packaged firetube boilers:

A )  are not very rugged relative to portability

B )  have very specific design pressures to meet customer needs

C )  require relatively small building volumes

D )  require special foundations or footings

E )  have maintenance access difficulties

When a packaged firetube boiler is used as a hot water unit:

A )  it can be constructed of thinner material for a given pressure

B )  an atmospheric burner must be used

C )  it will not require an expansion tank

D )  forced circulation is required

E )  the water column and gage glass must be raised slightly

The advantages of a packaged boiler are:1. lower freight costs because of less handling 2. lower initial cost because they are mass produced 3. quality control is easier to implement 4. the boilers can be factory tested before being sent to the customer 5. it requires little time to put the unit into operation at the plant site

A )  1, 3

B )  2, 5

C )  2, 3, 4

D )  1, 2, 3, 4, 5

E )  2, 3, 4, 5

Smaller firetube boilers are low cost and:

A )  have simple rugged construction

B )  require very critical water treatment

C )  are not very suitable for ON-OFF operation

D )  do not cause much damage on waterside rupture

E )  reach operating pressures very quickly from cold start

A steel plate vertical firetube unit is divided into two sections and the upper part is often called the:

A )  reversing section

B )  furnace

C )  expansion tank

D )  flue gas collector section

E )  heat exchanger 

CH.95

The minimum distance from furnace to oil storage tank is:

A )  7 m

B )  5.2 m

C )  2.1 m

D )  4.7 m

E )  9.8 m

When using mechanical fuel oil atomization:

A )  70 kPa steam pressure is required at the burner

B )  35 to 40 kPa oil pressure is required

C )  high pump pressure is required

D )  steam pressure is required to keep the bypass open

E )  dry saturated steam or superheated steam should be used

Before atomization can occur, heavy oils are heated to approximately:

A )  203 °C

B )  95 °C

C )  115 °C

D )  75 °C

E )  150 °C

A fuel filter consists of:

A )  a cartridge

B )  wool felt

C )  three main parts

D )  a Y-strainer

E )  a canister

Oil flow rate to a modulating burner is regulated by:

A )  a return line modulating valve

B )  a PRV on the burner line

C )  pump speed

D )  pump capacity

E )  firing rate

The reducing of oil into very small particles is termed:

A )  fluidization

B )  fractionation

C )  turbulence

D )  atomization

E )  distillation

A time delay oil valve:

A )  opens when the pump starts

B )  opens once ignition is verified

C )  opens on flame failure

D )  is located on the return line

E )  is upstream of the pressure regulating valve

Maximum static pressure in a fuel oil line is approximately:

A )  10 kPa

B )  15 kPa

C )  80 kPa

D )  35 kPa

E )  70 kPa

Burner light oil supply pressure range is approximately:

A )  50 to 100 kPa

B )  150 to 250 kPa

C )  300 to 550 kPa

D )  550 to 700 kPa

E )  700 to 850 kPa

The capacity of a constant capacity mechanical atomizer is a function of:

A )  orifice size

B )  pump speed

C )  pump size

D )  supply pressure

E )  oil viscosity

CH.96

Atmospheric burners are used for:

A )  gas stoves, hot water heaters, heating furnaces, and many heating boilers

B )  ring type burners

C )  coal firing

D )  lowering the relative humidity in the combustion air

E )  warming the incoming combustion air

Large capacity burners:

A )  require high flow on ignition

B )  are very safe relative to puff-back

C )  require only a small pilot flame

D )  should have minimum flow on ignition

E )  are too hazardous and not recommended

A very popular packaged boiler gas burner is the:

A )  ring burner

B )  non-articulated burner

C )  post mix atmospheric burner

D )  mechanical atomizing burner

E )  cluster nozzle burner

The main function of a gas burner is:

A )  atomization of the fuel

B )  a source of ignition

C )  provision of O2 - fuel contact

D )  regulation of the fuel flow

E )  airflow control

The main function of a gas burner is:

A )  to regulate the gas flow into the furnace

B )  to shoot the gas into the furnace

C )  to provide intimate mixing of gas with combustion air

D )  to regulate the amount of excess air

E )  to consume the combustion air

The amount of pre-mix air to an atmospheric burner should be:

A )  10 to 12%

B )  5 to 8%

C )  20 to 30%

D )  30 to 40%

E )  40 to 50%

An intermittent pilot:

A )  lights the main flame then extinguishes

B )  must be manually ignited

C )  lights the main flame and remains on with it

D )  remains on when the main flame extinguishes

E )  lights a pilot flame then extinguishes

When a gas fired burner is burning fuel properly:

A )  it will have a blue flame with short yellow tips

B )  the furnace will pulsate

C )  there will be no turbulence

D )  it will have a long bright yellow flame

E )  the induced draft fan can be shut off

A solenoid type fuel valve:

A )  is held closed by fuel pressure

B )  always opens rapidly

C )  is held closed by electrical current

D )  closes slowly

E )  does not have positive shut-off

A hydramotor valve:

A )  opens and closes quickly

B )  helps to prevent puff-backs

C )  uses air as its working medium

D )  should not be the last fuel valve to open

E )  closes slowly