Analysis of Heat Addition in Rankine Cycle P

Analysis of Heat Addition in Rankine Cycle P M V Subbarao Professor Mechanical Engineering Department Right Placement of Natural source of Energy into A Working Fluid (Pure Substance)

Cost to Benefit Ratio Analysis of Rankine Cycle

Rankine’s Clues to Generate High Economy and Eco-friendly Steam Generation……

Economics of Flow Steam generation

Quasistatic Steam Generation Process Theory of flowing Steam Generation

Creation of High Temperature @Constant Pressure Steam Generation Process

Selection of Steam Generation Pressure in A Rankine Cycle T C v, m 3/kg

Entropy: A Measure of State of Matter So (J/K • mol) H 2 O(liq) 69. 95 H 2 O(gas) 188. 8 For a given substance S (gaseous state) > S (liquid state) > S (solid state)

Entropy and Order of Molecules of Matter S˚(Br 2 liq) < S˚(Br 2 gas) S˚(H 2 O solid) < S˚(H 2 O liquid)

Entropy, S : Molecular Complexity Increase in molecular complexity generally leads to increase in S.

Entropy and Temperature S increases slightly with T S increases a large amount with phase changes

Entropy Change during a Reversible Process • From the definition of the entropy, it is known that Q=Td. S during a reversible process. • The total heat transfer during this process is given by Qreversible = Td. S • Therefore, it is useful to consider the T-S diagram for a reversible process involving heat transfer T • On a T-S diagram, the area under the process curve represents the heat transfer for a reversible process • A reversible adiabatic process S

Process : h-s Diagram : Mollier Diagram • Enthalpy-entropy diagram, h-s diagram: it is valuable in analyzing steady-flow devices such as turbines, compressors, etc. • Dh: Ability of Steam to perform work (Expenditure) • Ds: change of entropy from the second law (wastage) Dh h Ds s

Enthalpy Vs Entropy Diagram

Constant Pressure Steam Generation Process Theory of flowing Steam Generation Quasi-static supply of this heat to flowing water/steam Constant Pressure Steam Generation: A clue to creation of high temperature with same amount of burnt fuel

Steam Generation : Expenditure vs Wastage h mfuel Vapour r u o ap V + d i u q i L Liquid s

Steam Generation @ High Pressure h x=s

Analysis of Steam Generation at Various Pressures Specific Pressure Enthalpy Entropy Temp MPa k. J/kg/K C 1 1 3500 7. 79 509. 9 2 5 3500 7. 06 528. 4 3 10 3500 6. 755 549. 6 4 15 3500 6. 582 569 5 20 3500 6. 461 586. 7 6 25 3500 6. 37 602. 9 7 30 3500 6. 297 617. 7 8 35 3500 6. 235 631. 3

Fuel Savings during Steam Generation Temp C 575 575 575 Pressure MPa 5 10 12. 5 15 17. 5 20 22. 5 25 30 35 Specific Enthalpy k. J/kg 3608 3563 3540 3516 3492 3467 3441 3415 3362 3307 Specific Entropy k. J/kg/K 7. 191 6. 831 6. 707 6. 601 6. 507 6. 422 6. 344 6. 271 6. 138 6. 015