Organic Rankine Cycle — marine diesel exhaust waste-heat recovery

A closed R245fa Rankine loop recovers waste heat from a heavy marine diesel engine's exhaust: a two-stream boiler vaporizes the working fluid against the hot exhaust gas, a real isentropic-efficiency turbine expands it to shaft power, an ambient-cooled condenser returns it to saturated liquid, and a pump restores boiler pressure. The exhaust-gas composition is a representative combustion-product mix (N2/CO2/O2/H2O), not a specific engine's measured flue analysis. Honesty note: the boiler's cold-outlet temperature is a fixed spec (not an approach-temperature/pinch rating against the real exhaust flow), so this demonstrates cycle convergence and net power, not a bounded heat-recovery-area design.