In order to improve the net output power and efficiency of organic Rankine cycles

the dual fluid organic Rankine cycle system was proposed.An organic fluid R245 fa for high temperature cycle and three low temperature cycle fluids

R134 a

R152aand R236 fa

were selected to combine together.The REFPROP and MATLAB software were employed to calculate and compare thermodynamic performance of the system in the above three combinations.The results show that

the thermodynamic performance of the system using R245 fa as the high temperature cycle fluid and R152 aas the low temperature cycle fluid is better than the other two combinations

the maximum net output power

thermal efficiency and exergy efficiency of this system reaches 35 kW

7.67% and 62.53%

and the high temperature evaporation temperature is 417 K.The variation of the system net output power is larger than that of the heat efficiency and exergy efficiency.The net output power increases with the evaporation temperature in low temperature system.The overheat degree affects the system thermodynamic performance little

indicating there's no need to increase the overheat degree to optimize the system.