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Example • • • • Expansion and compression are isentropic. Find Thermal efficiency For a net power output of 330MW, find the steam flow rate through the first turbine stage (kg/hr) Cogeneration • Utilization factor * U = (net work + process heat)/(total heat input) Combined cycle • th = (powergas + powervapor)/(total heat input) Industrial Processes Energy forms • Electricity • Direct-fired • Steam Steam system • • • • High heat capacity Ease of transport Low cost vs alternatives Non-toxic Steam system usage 2006: percent of energy used from steam • Petroleum refining: 28% • Chemical manufacture: 47% • Forest products: 76% Paper manufacture Fiber board Plywood Generation • • • • • Boiler Fuel supply Combustion air system Feed water supply system Exhaust gas system Distribution • Pressure & flow regulation • Thermal insulation • Traps End Use • Heat exchangers – transfer energy • Turbines – convert thermal energy to mechanical energy Recovery • Condensate S.D. Warren • Condensers: power & recovery boilers • Dryers: product water removal and moisture control • Evaporators: increase solids of black liquor for fuel • Steam ejector: vacuum for condenser & low pressure steam recovery • Steam injector: process chemical heating U.S. Department of Energy • Improving Steam System Performance • Combined Heat and Power: A Clean Energy Solution