Page 197 - Entrophy Analysis in Thermal Engineering Systems

Index 195

H
Expansion, of ideal gas, 48–50, 48f
Extent of reaction, 158, 190–191 Heat addition process, 93–94
Heat engine, 17, 67–68, 77–78
Heat exchange process, 18, 41
F Heat flow, 46
Fahrenheit scale, 35 Heat Recovery Steam Generator (HRSG),
Feed water pump, 119
119–121, 121t
First law of thermodynamics, 3–4 Heat transfer, 46, 48–49, 52–53
Fixed heat input, 102 Higher heating value (HHV), 106–107,
Flow exergy, 171–172 175–176
Flue gas, 103, 116–119, 121–126, 145 High-temperature fuel cell, 131–132
Fuel cell High-temperature reservoir, 30–31, 39
applications, 131–132 History, of thermodynamics, 13
hybrid cycle, 142–147 Hot combustion gas, 116
maximum conversion efficiency, 134, Hot flue gas, 115, 119
136–137, 137–138f Hybrid cycle, 142–147
hydrogen-air, 135 net power generation, 144–145
methane, 135–136 optimum pressure ratio, 146–147
misconceptions, 139–142
performance comparison, 146, 147t
net cell reaction, 131
schematic of, 142f
open circuit voltage, 137–138, 138t specific entropy generation, 145,
total entropy generation, 133
145–146f
Fuel compressor, 112 thermal efficiency, 144–145
Fuel-to-power conversion efficiency, 132 Hydrocarbon fuel, 103–104
Fuel utilization factor, 142, 144 Hydrogen fuel cell
maximum conversion efficiency, 135,
G 137f
system boundary, 132–133, 133f
Gas power cycles
vs. Carnot engine, 141–142
thermal efficiency, 64, 64t
Gas turbine cycle, 103, 131–132, 142
combined cycle, 115 I
enthalpy and entropy flows, 111–112 Ideal Brayton cycle, 100–101.
irreversible open Brayton cycle, 110 See also Brayton Cycle
maximum thermal efficiency, 114 Ideal gas equation, 19, 35
minimum SEG, 114–115 Ideal gas law, 20, 26
pressure ratio, 114 Irreversibility, 7
regenerative, 115 Irreversible engines, 67–68
specific entropy generation (SEG), closed cycles
Atkinson cycle, 85–86, 86t,93–97
113–114, 189–190, 190t
thermal energy, 115 Brayton cycle, 85–91, 86t
Diesel cycle, 85–86, 86t,97–99
thermodynamic model of, 110–111, 111f
turbine inlet temperature, 114–115 fixed heat input, 102
Gay-Lussac law, 16 Otto cycle, 85–86, 86t,91–93
Geothermal power plant, 126–127 open cycles
Gibbs criterion, 150–152, 157–158, combined cycle, 119–126
162–163 combustion-driven power generation
Gibbs function, 134 systems, 103