(PPE)

POWER PLANT ENGINEERING

QUESTION BANK FOR CLASS TEST – 1

QUESTION FOR 2 MARKS.

1) STATE THE TYPES OF POWER PLANT.

 Hydroelectric power plant.
 Nuclear power plant.
 Thermal power plant.
 Diesel power plant.
 Gas turbine power plant.
 Solar power plant.
 Tidal power plant.
 Geothermal power plant.
 Biomass power plant.

2) Classify Fuel handling system in Steam Power plants.

 Belt conveyors.
 Screw conveyors.
 Vee bucket elevator and conveyor.
 Pivoted bucket conveyor.
 Grab bucket conveyor.
 Fight conveyors.
 Skip hoists.
 Mass flow conveyor.
 Chutes.

3) State the two types of FBC boiler.

 1) Atmospheric fluidized Bed Combustion (AFBC).
a) Bubbling fluidized bed combustors.
b) Circulating fluidized bed combustors.
2) Circulating fluidized Bed Combustion (CFBC).
3) Pressurized Fluidized Bed Combustion (PFBC).

4) Name any four components of diesel power plants.

 Engine.
 Air intake system.
 Exhaust system.
 Fuel system.
 Cooling system.
 Lubrication system.
 Engine starting system.
 Governing system.

5) Name any two high pressure boilers.

 Lamount boiler.
 Benson boiler.
 Velox boiler.
 Loeffler boiler.
 Babcock & wilcox boiler.

6) State any four drawbacks of Thermal Power Plant.

1) Maintenance and operating cost is high.
2) The cost of plant increases with increase in temperature and pressure.
3) Long time required for erection and putting into action.
4) A large quantity of water is required.
5) Great difficulty experienced in coal handling.
6) The plant efficiency decreases rapidly below about 75% load.
7) Presence of troubles due to smoke and heat in the plant.

7) Define power plant.

 An industrial facility that generates electricity from primary energy like
(coal, oil, natural gas, water wind solar etc.)

8) Give any four advantages of Diesel Power Plant.

 Design and installation are very simple
 Can respond to varying loads without any difficulty
 The standby losses are less
 Occupy less space
 Can be started and put on load quickly
 Require less quantity of water for cooling purposes
 Overall capital cost is lesser than that for steam plants.

9) Mention the steps involved in coal handling.

QUESTION FOR 4 MARKS.

 1) Compare Lamont and Benson Boiler.

LA-MONT BOILER BENSON BOILER

1) Storage and separating drum 1) It is Drumless boiler.
required.
2) The cost of boiler is low. 2) Cost of boiler is high.
3) Formation of bubble occurs. 3) No bubbles are formed.
4) Danger of overheating due to salt 4) No danger of overheating.
deposition.
5) More space required. 5) Compact less space required.
6) Pressure – 120 BAR 7) Pressure – 250 BAR
Temperature – 5000 C Temperature – 6500 C
Capacity – 45 to 50 TON Capacity – 1,35,000 Kg/Hr

2) Discuss in brief, the maintenance of Diesel Power Plant.

 Maintain log sheets, which include correct record of instrument readings
and condition of operation at regular intervals.
 Check periodically the various temperatures, pressures, electric load etc
 Proper maintenance includes cleaning of fuel or oil from dirt and other
impurities by means of filters.
 Replace the choked power elements of a filter by a new cloth or fiber
element
 Check the temperatures of flow of coolant, lubricating oil and exhaust
gases at regular intervals.
 Do not run diesel engine plant, when the plant is operating at below half
load condition.
 Ensure that, the radiator is filled with sufficient coolant or cold water.
 Occasionally, all the fuel should be drained and the fuel tank cleaned
thoroughly.
 The temperature and flow of coolant, lubricating oil and exhaust gases
should be checked at regular interval.
 The fuel oil must be cleaned from dirt and other impurities by means of
filters.
 3) Draw typical layout of diesel engine power plant showing all
system.

4) Draw a layout of ‘Hydro-Electric Power Plant’.

 5) Explain construction & working of Benson Boiler.

Construction
 Air preheater in which air is preheated for economical combustion
 Economizer in which sensible heat is used to preheat feed water.
 Radiant Evaporator - In which radiant heat is supplied to water by
combustion for steam formation.
 Convective Evaporator - where the major quantity of water is
evaporated from water Steam mix.
 Superheater tubes in which steam is superheated and supplied to the
steam turbine.
Working
 In the LaMont boiler, the main difficulty experienced is the formation
and attachment of bubbles.
 The attached bubbles to the tube surfaces reduce the heat flow.
 At critical pressure (225 atm.) danger of bubble formation can be easily
eliminated.
 This boiler does not use any drum.
 The feed water after circulating through the economiser tubes flows
through the radiant parallel tube section evaporator.
 In this majority of water is converted into steam. The steam water
mixture produced then moves to the convective evaporator where this
mixture is converted into steam.
 The steam is now passed through the convection superheater where
saturated steam is superheated. Such boilers have a working pressure of
225 bar.
 At normal Load Operating pressure – 210 bar Evaporating capacity –
13500 Kg/hr.

6) Explain ‘World and National scenario of demand and supply

of energy’ in brief.

The primary reserves of various major countries are given below:

1. Coal:
● United states of America (USA) has the largest share of the global
energy reserves. The reserve of coal at USA is almost 25.4%
● Russia had 15.9% reserve of coal
● China had 11.6% reserve of coal
● India had 8.6% reserve of coal.
2. Oil:
● The oil reserves are measured in barrel. One barrel of oil is
approximately equal to 160 litres
● Saudi Arabia has the largest share of the oil rese with almost 23% 3.
Gas:
● The Russian Federation has the largest share of the gas reserve with
almost 27%.
● The Russian Federation has gas reserves equivalent to 365.2 million
tonnes of oil.
● World oil and gas reserves are estimated to last for just 45 years and
65 years respectively.

Energy Scenario in India

 In world ranking, India is the 11"' greatest energy producer accounting
for about 2% of total world production.
 At the same time, India is ranking world's 6th greatest energy consumer,
accounting for 3% of total energy consumption annually in the world.
 Therefore, India is the net energy importer due to large imbalance
between production and consumption
7) Classify ‘Hydroelectric Power Plant’.

1) According to the availability of head

 High head power plants
 Medium head power plants
 Low head power plants
2) According to the nature of load
 Base load plants
 Peak load plants
3) According to quantity of water available
 Run-off river power plants without pondage.
 Run-off river power plants with pondage
 Reservoir power plants.
 Pump storage plants
 Mini and micro Hydel plants

8) State the advantages and disadvantages of Steam Power Plant

with respect to Gas Power Plant.
Advantages:
 They can respond to rapidly changing loads without difficulty.
 A portion of the steam generated can be used as a process steam in
different industries.
 Can be located very conveniently near the load centre.
 As these plants can be set up near the industry transmission costs are
reduced.
 Steam engines and turbines can work under 25 per cent of overload
continuously.
 Fuel used is cheaper.
 Less space is required in comparison with that for hydroelectric plants.
 Cheaper in production cost in comparison with that of diesel power
stations.
 Cheaper in initial cost in comparison with that of diesel power stations.
Disadvantages:
 Maintenance and operating costs are high.
 The cost of plant increases with increase in temperature and pressure.
 Long time required for erection and putting into action.
 A large quantity of water is required.
 Great difficulty experienced in coal handling.
 The plant efficiency decreases rapidly below about 75 per cent load.
 Presence of troubles due to smoke and heat in the plant.

9) Explain with neat sketch construction and working of Lamont

boiler.

• In a La-Mont boiler the major difficulty

experienced is the deposition of salt.
• The deposition reduces the he
generating capacity.
• It is prevented by preventing the flow
of water into the boiler tubes.
• It consists of an evaporator drum
which any convenient point outside the
furnace
• The feed water pump draws feed water and through economizer & then to
evaporator
• The economizer gives sensible heat to water flue gases.
• The steam circulating pump extracts steam from the evaporator drum and
forces it to pass through the radiant and convective surfa placed in the path of
the hot flue
• From the superheater tube, a big portion (about 3/4) of the superheated
steam is trapped off for external use while the remainder (1/4) passes on to
the evaporator drum.
• Where it gives its superheat to the water contained in this drum that
generates an amount of steam used in turbine.