Thermodynamic Cycles
Simple Rankine, air-standard Brayton and single-stage vapour-compression cycles, solved state by state with component energy balances and first-law residuals. Impossible inputs are reported, not hidden.
All work and heat magnitudes are per kilogram of working fluid and reported positive; the column header states direction (input or output). Net work = turbine output − compressor/pump input. Thermal efficiency = net work / heat input. Refrigeration COP = evaporator heat / compressor work; heating COP = condenser heat / compressor work — these are distinct quantities and both are shown.
- Rankine: real-fluid properties, saturated liquid at pump inlet. Variants: single reheat; one open feedwater heater with saturated-liquid heater exit. Closed heaters, multiple bleeds and multi-stage reheat are not implemented.
- Brayton: air-standard ideal gas. Either constant cp and γ (user values) or variable cp using exact ideal-gas h(T), s°(T) of the CoolProp Air model (still ideal gas, not real-fluid). Optional recuperator by effectiveness (0 % = none). No intercooling, reheat or pressure losses.
- Refrigeration: single stage, isenthalpic throttle, refrigerant from the fluid list (R410A as pseudo-pure). No pressure drops or heat-exchanger sizing.
- Exergy (optional): physical exergy only, dead state = same working fluid and model at T0, P0. Heat is exchanged with isothermal reservoirs at the stated temperatures; component exergy destruction T0·Sgen, heat-exergy transfer Q(1 − T0/Tb) and a closing exergy balance are reported. Reservoir temperatures that violate the second law are flagged as FAIL, not adjusted.
Engine: CoolProp 8.0.0 (pinned) — I. H. Bell, J. Wronski, S. Quoilin, V. Lemort, "Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp", Ind. Eng. Chem. Res. 53(6), 2498–2508 (2014), doi:10.1021/ie4033999. Distributed under the MIT licence. Water: IAPWS-95 (HEOS) and IAPWS-IF97 (industrial formulation) as implemented in CoolProp. Remaining limitations are listed above.