Testing and thermodynamic analysis of low-grade heat power generation system using organic Rankine cycle

Low grade heat power generation system using Organic Rankine Cycle (ORC) was introduced in this work. This system behaved better in thermodynamic efficiency than stream-Rankine cycle. Numerical thermodynamic model of Organic Rankine Cycle system was given in this work. Water, R142b, R123, R245fa and some other organic fluids were used as working fluid. The results will show that thermodynamic properties of working fluid and working conditions of the system can affect thermal efficiency greatly. The computation result will also show that system behavior in superheat is quite different for different working fluid. That is, when using water as working fluid, the efficiency will increase when the superheat increases; but when it is R123 or some other organic working fluids, the result may be just the opposite. The reason will be given in the paper. Experimental data of ORC using R142b is also showed.