A small power generator test system with low-temperature waste heat was built using R123 as working fluid and a scroll expander as a power recovery machine on the basis of the theory of organic Rankine cycle. The influence of the rotating speed of the scroll expander on the system performance was analyzed at the same inlet temperature and mass flow rate of heat source

and the two different mass flow rates of working fluid. The results show that the suction pressure and the suction temperature of the scroll expander decreased but the discharge pressure and the discharge temperature increased with the increase in the rotating speed. The power generated and the total efficiency decreased while the volumetric efficiency of the scroll expander increased with the increase in the rotating speed. Under the two test conditions

the maximum power generated was 0.66 kW and 0.62 kW

respectively; both the maximum total efficiencies were 2.1%; the range of volumetric efficiency was 38.5%-56.5% and 39.7%-60.0%

respectively.