Chem. Eng. Thermodynamics (TKK-2137)

1. 14/15 Semester 3 Chem. Eng. Thermodynamics(TKK-2137) Instructor: Rama Oktavian Email: rama.oktavian86@gmail.com • Office Hr.: M.13-15, Tu. 13-15, W. 13-15, Th. 13-15, F. 09-11

2. Outlines 1. Heat engine (Power from heat) 2. Steam power plant 3. Carnot cycle power plant 4. Rankine cycle power plant

3. TH QH W HE QC TC Heat engine HE = heat engine TH = high temp. reservoir TC = cold temp. reservoir

4. TH QH W HE QC TC Heat engine Thermal efficiency: Net work output h = ----------------------- Heat absorbed For 100% efficiency, QC= 0 (impossible)

5. Heat engine Production power from heat: The potential energy of tides - possible source of power hydroelectric power is generated by conversion of the potential energy of water into work Combustion of fuel – the most important power source: - power plant : steam power plant, coal power plant, NG power plant Internal combustion engine: -Otto and Diesel engine

6. Steam power plant Produces steam in boiler

7. Steam power plant Carnot cycle for steam power plant: idealized cycle would be represented on t-s diagram 1 2 is the vaporization process 2 3 is a reversible, adiabatic expansion of saturated vapor into the two-phase region 3 4 is a partial condensation process 4 1 takes the cycle back to its origin

8. Ideal Rankine cycle • simplest real power plant cycle is Rankine cycle • pump, 4 - 1 • boiler, 1 - 2 • turbine, 2 – 3 • condenser, 3 - 4

9. Rankine cycle • allowing for inefficiencies in turbine and pump

10. Rankine cycle • Ex. 8.1

11. Rankine cycle increase η – increase boiler pressure • increase in pressure has QH entering at higher t • trade-off occurs due to change in Δs Cengel, Y. A., Introduction to Thermodynamics and Heat Transfer, McGraw-Hill,1997

12. Rankine cycle increase η – lower condenser pressure THIS RESULTS IN MORE AVAILABLE WORK Cengel, Y. A., Introduction to Thermodynamics and Heat Transfer, McGraw-Hill,1997

13. Rankine cycle increase η – SUPERHEATING STEAM • superheating steam gives a higher TH for QH addition. • also avoids condensing in the turbine. Cengel, Y. A., Introduction to Thermodynamics and Heat Transfer, McGraw-Hill,1997

14. Rankine cycle increase η – INTERMEDIATE REHEAT CYCLE • MULTIPLE REHEAT STAGES ARE POSSIBLE • REDUCES CONDENSATION AT THE TURBINE DISCHARGE Cengel, Y. A., Introduction to Thermodynamics and Heat Transfer, McGraw-Hill,1997

15. Rankine cycle Regenerative Rankine Cycle

16. Rankine cycle Regenerative Rankine Cycle this method can increase the boiler feed water temperature but it lowers steam flow to the turbine

17. Thank You !