Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
14/15 Semester 3 Chem. Eng. Thermodynamics (TKK-2137) Instructor: Rama Oktavian Email: [email protected] Office Hr.: M.13-15, Tu. 13-15, W. 13-15, Th. 13-15, F. 09-11 Outlines 1. Heat engine (Power from heat) 2. Steam power plant 3. Carnot cycle power plant 4. Rankine cycle power plant Heat engine TH QH W HE QC TC HE = heat engine TH = high temp. reservoir TC = cold temp. reservoir Heat engine W QH QC TH QH HE QC TC h 1 QC QH W Thermal efficiency: Net work output h = ----------------------Heat absorbed h W QH QH QC QH For 100% efficiency, QC = 0 (impossible) 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 Steam power plant Produces steam in boiler 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 Ideal Rankine cycle simplest real power plant cycle is Rankine cycle pump, 4 - 1 boiler, 1 - 2 turbine, 2 – 3 condenser, 3-4 Rankine cycle allowing for inefficiencies in turbine and pump Rankine cycle Ex. 8.1 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 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 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 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 Rankine cycle Regenerative Rankine Cycle Rankine cycle Regenerative Rankine Cycle this method can increase the boiler feed water temperature but it lowers steam flow to the turbine