ME 18b Thermodynamics

Introduction to Rankine Cycle Processes

Mike Pauken

From Wikipedia• The Rankine cycle is a thermodynamic cycle which converts

heat into work. The heat is supplied externally to a closed loop, which usually uses water as the working fluid.

• This cycle generates about 80% of all electric power used throughout the world, including virtually all solar thermal, biomass, coal and nuclear power plants.

• It is named after William Rankine, a Scottish engineer and physicist.

• Rankine developed a complete theory of the steam engine and indeed of all heat engines. His manuals of engineering science and practice were used for many decades after their publication in the 1850s and 1860s. He published several hundred papers and notes on science and engineering topics, from 1840 onwards.

Simplified coal-fired power plant 1. Cooling tower 11. High pressure steam turbine 20. Fan 2. Cooling water pump 12. Deaerator 21. Reheater 3. Three-phase transmission line 13. Feedwater heater 22. Combustion air intake 4. Step-up transformer 14. Coal conveyor 23. Economiser 5. Electrical generator 15. Coal hopper 24. Air preheater 6. Low pressure steam turbines 16. Coal pulverizer 25. Electrostatic precipitator 7. Boiler feedwater pump 17. Steam drum 26. Fan 8. Surface condenser 18. Bottom ash hopper 27. Flue gas scrubber 9. Intermediate press. steam turbine 19. Superheater 28. Flue gas stack 10. Steam control valve

http://en.citizendium.org/wiki/Conventional_coal-fired_power_plant

Two Babcock & Wilcox 420 MW variable pressure, supercritical (spiral wound universal pressure, SWUP™) units with boiler terminal conditions of 248 bar, 596°C.http://www.babcock.com/library/brochures-steam.html#E3185

Typical B&W spiral wound universal pressure boiler.

Steam Turbine Power PlantLignite-fired (brown coal) power plant: this high-output plant began its operation in summer 2000. Its large steam turbine-generator has an output of 906 MW. Designed for supercritical steam conditions of 258 bar at 541 °C it is the first to be equipped with a six-flow low-pressure section.http://www.powergeneration.siemens.com/products-solutions-services/power-plant-soln/

Coal Fired Steam TurbineSiemens is planning the world’s most efficient coal-fired power plant that is expected to operate at a steam temperature of 700°C with an efficiency over 50%. The facility is being designed to produce 40% less CO2 than the current international. Plans call for the plant to go into service in 2014.

Steam TurbineSteam turbine (123 MW) for the first commercial solar thermal power plant in the U.S. using a power tower. Steam is generated from water heated by thousands of mirrors. The power plant will begin operations in late 2011, supplying power to 35,000 households. The facility in California’s Mojave Desert is being built by BrightSource Energy.

Gas TurbineThe SGT5-8000H gas turbine. Capacity: 340 megawatts (MW). The world’s most powerful gas turbine. Output equals that of 13 jumbo jet engines . This unit will be expanded to become a combined cycle power plant with an output of 530 megawatts (MW) with an efficiency greater than 60%. Compared to an average coal-fired power plant with the same output, this power plant emits approx. 2.8 million tons less CO2 per year (as much as one million automobiles emit).