Carnot Cycle for Scientific Design of Watt Engine P M V Subbarao Professor Mechanical Engineering Department Model for A Scientific Design of PGS
Carnot’s Model for Power Generation System Expansion work
Carnot’s Identification of Thermodynamic Cycle for Watts Engine Burn Coal (to add Heat slowly) Ability to perform The Work (Move piston slowly) Wastage or Ecological Nuisance
Carnot’s Model for Power Cycle 1 – 2 : Compressor : Isentropic Compression : s2 = s1 2 – 3 : Boiler: Isothermal Heating : T3 = T2 3 – 4 : Turbines : Isentropic Expansion : s4 = s3 4 – 1 : Condenser: Isothermal Cooling : T1 = T4
Air Standard Carnot Cycle 1 2 3 4 Practice on your own……
First Law for A Control Volume Conservation of mass: Conservation of momentum: Conservation of energy:
Compressor : Isentropic Process SSSF: Conservation of mass First Law : No heat transfer during compression.
2 – 3 : (Fire Tube) Boiler for Isothermal Steam Generation QCV 3 2 No work transfer in boiler
Identification of Carnot’s High Temperature for Isothermal Steam Generation, T3 = T2 = Thigh For reversible constant Pressure & Temperature Process
Expansion : Adiabatic Process : No wastage 3 4 T Avoid heat transfer during expansion. Ideally zero….
4 – 1 : Condenser : Isothermal Cooling : T1 = T4 QCV 4 1 No work transfer in condenser
Analysis of Cycle First law for a cycle: For reversible adiabatic expansion and pumping: Rate of Heat addition
Cost to Benefit Ratio Analysis of James Watt Engine using Carnot’s Model for Cycle Work done per unit volume of the engine: Mean Effective Pressure
Engineering of Carnot Cycle Isotherms
Use of Carnot Model for Optimization of Power Plant Minimize the capital & running costs. Compact and efficient.
Selection of A Perspective for Description of Scientific PGS René Descartes Academic, Philosopher, Mathematician, Scientist (1596–1650) Discourse on; The Method of Rightly Conducting the Reason and Seeking Truth in the Sciences. Published in 1637.
Geometrical Route to Define A Naturally Feasible Cycle for A PGS x
Lame’s Curve n=0 n=0.5 0 < n < 0.5
Natural Power Generation Cycle V
Natural Power Generation Cycle Tmax T Tmin Smin Smax S
Natural Power Generation Cycle Tmax T Tmin Smin S Smax
Computation of Cyclic Energy Interactions Net work out put : Heat Input :
Cost to Benefit Analysis of Natural Cycle Efficiency