To study the performance of solar organic Rankine cycle (ORC) system

a low temperature solar ORC system is proposed and constructed. The system employs R245fa as the working fluid in the power cycle and WD350 heat transfer oil as the heat transfer fluid in the solar collector. The experimental installation consists of a trough solar collector

a screw expander

a working fluid pump

a heat regenerator

a water cooled condenser

and a vapour generator. When the solar beam radiation is about 400 W·m-2 in the experiment

the thermal oil temperature at the outlet of solar heat collector can reach up to 140℃. The collecting efficiency of the collector is 60% at the outlet oil temperature of 110℃. When the working mode of system changes from basic ORC to regenerative cycle

the calculated efficiency of the system is improved from 9.3% to 10.8%

and the experimental value is improved from 1.57% to 1.67%. The measured exergy efficiency of the system is about 10%. The value under regenerative cycle mode is higher than that under the basic ORC mode. The cycle performance at different working fluid flow rates was also studied. The measured maximum average power output was obtained at 386.27 W and working fluid flow rate of 6.88 kg·min-1. With the increase of working fluid flow rate

both expander inlet pressure and work output increase at fixed heat source temperature. With the increase of heat source temperature

the expander inlet temperature and pressure

and the power output increase at fixed flow rate.