Experimental study on the comparative performance of R1233zd(E) and R123 for organic rankine cycle for engine waste heat recovery

The organic Rankine cycle (ORC) is an effective way for engine waste heat recover (WHR). The selection of the working fluid is crucial. In recent years, low GWP and ODP working fluid have been invented. For R123, which is commonly used in engine ORC-WHR system, the alternative working fluid is R1233zd(E). In order to explore the performance of R123 and R1233zd(E) when applied to ORC-WHR system, this study conducted experimental studies of R123 and R1233zd(E) under a wide range of engine working conditions. The experiments were carried out under seven sets of engine working conditions with gradually increasing loads. Variable operating parameter experiments were carried out for R123 and R1233zd(E) at each engine load. The selected operating parameters include expander speed and superheat degree. The experimental results show that R123 has higher output power and thermal efficiency compared to R1233zd(E) at all engine conditions.The maximum output power and thermal efficiency of R123 are 1.55 kw and 5.81% respectively.The maximum output power and thermal efficiency of R1233zd(E) are 1.43 kw and 5.29% respectively. Taking the net output power as the evaluation index, the optimal expander speed of R123 is higher than that of R1233zd(E) under the same engine working condition, and the superheat degree has little effect on the net output power.