Power Station Equipment - Exam Solution
1.a) What is the effect of steam temp. from boiler to the cycle efficiency for "S.S.R., S.H.R., and S.F.R."?
- Increasing steam temperature increases the thermal efficiency of the Rankine cycle.
- In S.S.R. (Simple Steam Rankine), efficiency is limited by saturated steam.
- In S.H.R. (Superheated Rankine), superheating increases average heat addition temperature higher efficiency.
- In S.F.R. (Supercritical/Feedwater Regeneration), high-pressure and regenerative heating further improve efficiency.
1.b) What factors should be taken into consideration while selecting the type and site for steam power plant?
- Fuel availability and cost
- Water supply
- Land availability and cost
- Proximity to load centers (reduce transmission losses)
- Environmental regulations and constraints
- Transportation access
- Cooling water source
- Topography and soil condition
- Expansion potential
- Seismic/weather risks
1.c) Define the boiler efficiency and explain the heat losses in the boiler?
Boiler Efficiency = (Heat Output in Steam / Heat Input from Fuel) 100%
Heat Losses in Boiler:
1. Dry flue gas loss
2. Incomplete combustion
3. Unburnt fuel in ash
4. Radiation and convection losses
5. Moisture in fuel and air
1.d) What is the short technical specification for the 'Boiler - Pump - Diesel generator'?
Boiler:
Power Station Equipment - Exam Solution
- Type: Water tube / Fire tube
- Pressure: 60 bar
- Steam Temp: 450C
- Capacity: 100 TPH
Pump:
- Type: Centrifugal
- Flow rate: 100 m/h
- Head: 60 m
- Power: 15 kW
Diesel Generator:
- Type: 4-stroke, water-cooled
- Rating: 1000 kVA
- Voltage: 400V, Frequency: 50 Hz
1.e) State the advantages of Reheat cycle over Rankine cycle?
Advantages of Reheat Cycle:
1. Increased thermal efficiency
2. Reduces moisture content in turbine exhaust
3. Higher work output (two-stage expansion)
4. Improved turbine performance and longevity
