(SEM VII) THEORY EXAMINATION 2024-25 POWER PLANT ENGINEERING

SECTION A

(2 × 10 = 20 marks | Short Answers)

a) Energy

Energy is the capacity to do work. It exists in different forms such as thermal, mechanical, electrical, chemical, and nuclear energy.

b) Conventional and non-conventional energy resources

Conventional: Coal, oil, natural gas, nuclear, hydro

Non-conventional: Solar, wind, biomass, tidal, geothermal
Non-conventional sources are renewable and eco-friendly.

c) Governing in steam power plants

Governing controls the speed and power output of the turbine by regulating steam flow.
Methods:                                                       Throttle governing

Nozzle control governing                               Bypass governing

Combination governing

d) Diesel power plant – advantages & disadvantages

Advantages:                                                  Quick start

Low installation cost                                       Suitable for small power

Disadvantages:                                             High fuel cost

Limited capacity                                             More maintenance

e) Nuclear reactor

A nuclear reactor is a device where controlled nuclear fission takes place to produce heat for power generation.

f) Function of superheater

A superheater increases the temperature of saturated steam, improving efficiency and reducing turbine blade erosion.

g) Principle of wind energy conversion

Wind energy is converted into mechanical energy using a turbine, which is then converted into electrical energy using a generator.

h) Advantages of MHD power generation

High efficiency                                                No moving parts

Less pollution                                                  Faster response

i) Particulate emission & gaseous pollutants

Particulate emission consists of solid or liquid particles released into the atmosphere.
Gaseous pollutants concentration is expressed in ppm or mg/m³.

j) Generator

A generator converts mechanical energy into electrical energy based on electromagnetic induction.

SECTION B

(Attempt any 3 | 10 marks each)

a) Why electrical energy is most convenient

Electrical energy is easy to generate, transmit, control, and convert into other forms with high efficiency and minimal losses.

b) Hydroelectric power plant

It converts potential energy of water into electrical energy using turbines and generators.
Applications:                                               Base load supply

Irrigation support                                          Flood control

c) Radioactive decay, half-life, moderating power

Radioactive decay: Spontaneous disintegration of unstable nuclei

Half-life: Time required for half the nuclei to decay

Moderating power: Ability of a material to slow down neutrons

Moderating ratio: Effectiveness of a moderator considering absorption

d) Geothermal power plant

It uses heat from earth’s interior to generate steam for power production.
Steam rotates the turbine connected to a generator. It is renewable and reliable.

e) Cooling of transformers

Air cooling                                                     Oil natural cooling

Forced oil and air cooling                             Water cooling
Cooling prevents overheating and insulation failure.

SECTION C

Q3 (Attempt any one)

a) Types of power plants & future energy trends

Types:                                                           Thermal

Hydroelectric                                                Nuclear

Gas turbine                                                   Solar and wind

Future trends focus on renewable energy, hybrid systems, energy storage, and reduced carbon emissions.

b) Layout of modern thermal power plant

Main components:                                        Boiler

Turbine                                                         Condenser

Cooling tower                                              Generator

Feedwater system

Coal is burned to produce steam, which drives the turbine and generator.

Q4 (Attempt any one)

a) Reheating, intercooling & regeneration in gas turbines

Reheating: Increases turbine output            Intercooling: Reduces compressor work

Regeneration: Uses exhaust heat to improve efficiency
These processes improve overall plant performance.

b) Combined steam and gas turbine power plant

Exhaust heat from gas turbine is used to produce steam for steam turbine, improving overall efficiency and reducing fuel consumption.

Q5 (Attempt any one)

a) Nuclear reactor & moderator

Main components:                                        Fuel rods

Moderator                                                     Control rods

Coolant                                                          Shielding

Moderator function: Slows down fast neutrons.
Light materials like graphite or heavy water are used because they absorb fewer neutrons.

b) Solar thermal energy

It uses solar radiation to produce heat, which generates steam for power.
Advantages: Renewable, clean
Disadvantages: High initial cost, weather dependent
Applications: Power plants, water heating

Q6 (Attempt any one)

a) Wind electric generating system

Components:                                                 Rotor blades

Gearbox                                                         Generator

Tower                                                             Controller

It converts wind energy into electrical energy.

b) Spring tides and neap tides

Spring tides: High tidal range during full/new moon

Neap tides: Low tidal range during quarter moon

Tidal power schemes include single basin and double basin systems.

Q7 (Attempt any one)

a) Generator construction & cooling

Main parts:                                                     Stator

Rotor                                                              Shaft

Cooling system

Cooling is required to remove heat losses and prevent insulation damage.

b) Power plant pollutants & health effects

Pollutants:                                                      SO₂, NOₓ, CO₂

Fly ash                                                            Particulates

Effects:                                                            Respiratory problems

Eye irritation                                                   Global warming

DONE: ALL SEM VII SUBJECTS – SECTION-WISE

You now have:                                                HVAC Systems

Mathematical Modeling of Manufacturing Processes

Machine Learning                                          Maintenance Engineering & Management

Power Plant Engineering