Fundamentals of Power Plant Engineering

Power Plant Engineering Fundamentals

• Working Cycles: Key cycles include Rankine, Brayton, Otto, Diesel, and Carnot. Otto, Diesel, and Dual cycles are primarily used for internal combustion engines. Rankine and Brayton cycles are used in power generation.

• Thermodynamic Processes:

  • Reversible Process: Fluid and surroundings can be restored to the original state.
  • Irreversible Process: Cannot be restored to original state, relates to practical scenarios.
  • Isothermal Process: No temperature change during the process.
  • Adiabatic Process: No heat transfer in/out during the process.
  • Isentropic Process: Reversible and adiabatic at constant entropy.
  • Isobaric Process: Constant pressure process.
  • Polytropic Process: Transitioned between two states with a specific relation.
  • Throttling Process: Free expansion process without work done.

• Power Cycles: Continuous conversion of heat into work. Evaluation occurs through a series of ideally continuous and reversible events.

• Energy Definition: Energy is the capacity for doing work, generating heat, or emitting light.

• Heat Sources for Rankine Cycle: Common sources include coal, natural gas, solar, and nuclear fission. Rankine cycle is effective in steam-operated heat engines for power generation.

• Brayton Cycle: Used in gas turbines; includes processes like isentropic compression and constant pressure heat addition.

• Hydroelectric Power: Harnesses kinetic energy from flowing water; critical in renewable energy generation. Key factors in hydropower generation include flow rate and head, where flow rate signifies the quantity of water and head denotes the height from which water falls.

• Hydroelectric System Components: Must consider reservoir, dam, turbines, generators, and transmission systems. Different types include impoundment systems (dams) and run-of-the-river systems.

• Advantages of Hydropower: Low operational costs, quick load variations, and reliability. It is pollution-free during operation but entails high initial capital costs and significant designs.

• Environmental Impact: High-head plants can disrupt ecosystems; thus, minimizing their impact through technological advancements is essential.

• Classification by Capacity: Power plants can be classified into small (<5 MW), medium (5-100 MW), and high-capacity plants (1000+ MW).

• Global Energy Sources Distribution: Major sources include coal (27%), natural gas (21%), crude oil (39%), nuclear (6%), and hydroelectric power (6%). 87% is derived from fossil fuels.

• Renewable Energy in Hydropower: Utilizes the continuous water cycle ensuring long-term sustainability. Advanced technologies aim to develop low-head and low-impact systems for energy generation.