Chapter 8, Problem 8.19CU

What was the formula for exergy destruction for heat addition?

Thermodynamics Fill in the Blanks: 1) In a spark-ignition engine, a mixture of fuel and air is ignited by a(n) _____________ 2) In a cold air-standard analysis, the specific heats are assumed ___________ at their ambient temperature values. 3) Ericsson and Stirling cycles operating between thermal reservoirs at TH and Tc have thermal efficiencies equal to that of a _____________ cycle operating between the same thermal reservoirs.

An industrial process discharges 5,700 m³/min of gaseous products at 200°C, 100 kPa. The figure below shows a proposed system for utilizing the combustion products and its steady state conditions. Heat transfer from the outer surface of the steam generator (heat exchanger) and turbine can be ignored, as can the changes in kinetic and potential energies of the streams. There is no pressure drop through the heat exchanger. The combustion product can be modeled as air as an ideal gas. Determine: a) The turbine inlet temperature, T4; b) the power developed by the turbine; and c) the rates of entropy generation in the heat exchanger and turbine, each in kW/K. Combustion products in P1 = 100 kPa 1 T1 = 480 K (AV), = 5700 m³/min Turbine 4 Power out P4 = 300 kPa %3D Combustion products out P2 = 100 kPa T2 = 400 K Steam generator 3 Water in P3 = 300 kPa T3 = 40°C m3 = 120 kg/min Water out Ps = 5 kPa X5 = 97% %3D %3D wwww wwww