Steam engines combined cycling

The wave of the future in power generation is the combined cycle, in which gas turbines are combined with steam turbines, with the hot exhaust from the gas turbine used to generate steam. The combined cycle is a cascade of heat engines operating over temperatures from 1200-1300°C to about 30°C. This broad temperature range renders the combined cycle efficient. 

J. N. Chapman and N. R. Johanson, "Design Considerations for a Class of 600 MWe MHD Steam Combined Cycle Plants," 28th Intersociety Energy Conversion Engineering Conference, Adanta, Ga., Aug. 1993. 

Lozza, G. and Chiesa, P. Natural gas decarbonization to reduce C02 emission from combined cycles Part II Steam-methane reforming. Journal of Engineering for Gas Turbines and Power, Transactions ofASME, 2002, 124, 89. 

As we have just seen, the flow of energy as heat does not indicate whether or not a process will occur spontaneously. So we must also consider another thermodynamic state function, called entropy. Historically, entropy was first introduced in considering the efficiency of steam engines. Figure 10.2 illustrates the Carnot cycle, which uses a combination of adiabatic processes (in which no heat is exchanged) and isothermal, or constant temperature, processes. The Carnot cycle demonstrated that a previously unknown state function existed because the sum of q/T (heat divided by temperature) around the closed path is zero. This new state... 

Similarly to turbocharged internal combustion engines and to large-scale steam turbines within combined cycle power plants, MCFCs also can be integrated with turbines. 

Sanjay, Y., Singh, O., Prasad BN, 2007, Energy and exergy analysis of steam cooled reheat gas- steam combined cycle. Applied Thermal Engineering 27 2779-2790. 

Electricity Generation Options Internal combustion engines Combustion turbines and microturbines Combined cycle plants Steam boilers and steam turbines Fuel cells... 

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