12-26-2025, 11:45 PM
I'm a mechanical engineer working on a prototype for a small-scale waste heat recovery system, and I'm stuck on the thermodynamic analysis. I'm trying to model the Rankine cycle efficiency for a low-temperature heat source, around 150°C, using an organic working fluid. My calculations keep giving me an unrealistically high theoretical efficiency, and I suspect my assumptions about isentropic pump and turbine efficiencies are way off for this scale. Has anyone else designed a similar small ORC system and can share realistic component efficiency values or point out common modeling pitfalls for these low-grade heat applications?