Power station and substation Interview Question - Day 1

[Q:-01] What is called generation ?

Ans :

To generate electrical energy, is called generation.

[Q:-02] What are the sources of energy for electric power generation ?

Ans :

      The sources of energy can be divided into two categories—

(i) Non conventional primary sources, like geothermal energy, solar energy, ocean tides and waves, winds etc.

(ii) Conventional secondary sources, namely, fossil fuels like coal, oil and natural gas, hydraulic energy and nuclear energy.

[Q:-03] Which types of sources are commonly used ?

Ans :

Secondary sources.

[Q:-04] What are the types of power stations ?

Ans :

(i) Thermal power station.

(ii) Hydro electric power station.

(iii) Diesel power station.

(iv) Nuclear power station.

(v) Gas turbine plants.

(vi) Magneto hydro-dynamic power station.

[Q:-05] What is called prime mover ?

Ans :

      The equipment which drives the electric generator or gives mechanical power to the generator, is called prime mover.

[Q:-06] What fuel is used in diesel engine prime mover ?

Ans :

Diesel oil.

[Q:-07] What type of engines are used in diesel engine prime movers ?

Ans :

      Internal combustion engines are used in diesel engine prime mover.

[Q:-08] What is the usual speed range of diesel engine ?

Ans :

500 to 1000 r.p.m.

[Q:-09] What are the uses of diesel power stations ?

Ans :

      Diesel power stations are mainly used as

(a) Standby plants,

(b) Peak load plants,

(c) Emergency plants,

(d) Mobile plants & small supply units.

[Q:-10] For what localities a diesel station is suitable ?

Ans :

      Where water supply is limited and oil is cheaper than coal.

[Q:-11] What is the principal characteristics of diesel engine ?

Ans :

(i) It can be started and put to service quickly,

(ii) It has no stand by loss,

(iii) It requires no large quantity of water for cooling.

[Q:-12] What is the name of the power station in which Steam is used for driving the turbine ?

Ans :

Thermal power station.

[Q:-13] What prime mover is used in thermal power station

Ans :

Steam turbine.

[Q:-14] What type of fuel is used in thermal power station ?

Ans :

      The main fuel used in thermal power station is coal which contains carbon, volatile matter, sulphur, ash & moisture.

[Q:-15] What are the different elements of thermal power station ?

Ans :

(i) Coal handling plant.

(ii) Boiler house plant.

(iii) Turbine house plant.

(iv) Electrical plant.

(v) Condensing plant.

(vi) Water treatment plant.

(vii) Ash handling system.

(viii) Station auxiliary drive.

[Q:-16] What are the factors to be considered for selecting the site of a thermal power station ?

Ans :

(i) The site should be away from densely populated area to keep it free from pollution and should have good transport facilities.

(ii) It should be near any coal available area and where abundant supply of cooling water is available.

(iii) It should be on ample quantity of free land to make convenient disposal of ashes.

[Q:-17] What are the merits & demerits of thermal power station ?

Ans :

(a) Merits:—

(i) The station can be located close to the load centre.

(ii) Higher economic size of unit may be used.

(iii) Production cost is low due to cheaper fuel.

(b) Demerits:—

(i) Land requirements is high.

(ii) Fuel and ash handling is difficult.

(iii) Maintenance is complicated.

(iv) It pollutes the atmosphere by fumes etc.

(v) Start up time is longer.

[Q:-18] What is the overall efficiency of thermal power station ?

Ans :

About 20% to 25%.

[Q:-19] What is the main reason for low overall efficiency of a thermal plant ?

Ans :

Inefficient method of coal burning.

[Q:-20] What type of coal is used in boilers and what calorific value is obtained ?

Ans :

      Bituminous coal having calorific value of 6000 to 8000 K. Cal/Kg is used in boilers.

[Q:-21] Where does the heat loss take place In a thermal power plant ?

Ans :

      The heat loss takes place in the dry flue gases, moisture in gas, the process of radiation, evaporation and leakage, in unburnt fuel & ash, in the condenser, due to friction and windage.

      The major heat loss about 40 to 45% takes place in the condenser.

[Q:-22] Which power plant is economical of (i) steam power plant & (ii) diesel power plant ?

Ans :

Steam power plant.

[Q:-23] What is called hydro electric power station ?

Ans:

      The power station, in which the kinetic energy of water is converted into electrical energy, is called hydro-electric power station.

[Q:-24] What is the source of generation In hydro-electric power station ?

Ans :

Water.

[Q:-25] What are the different sections of a hydro-electric power station ?

Ans :

      The different sections of a hydro-electric power station are dams, spillways, gates, penstock & hydro-electric generators.