Experimental Study And Simulation Of The Organic Rankine Cycle

Organic Ranline Cycle(ORC)is one of the potential techologies in recovering the energy from low and medium temperature heat source.It’s more and more important to study it.An ORC experimental platform was established to research the performance of single-screw expander.The model of expander and exchanger of ORC was established with MATLAB.And the ORC integrated machine was designed.A software was finished for the thermodynamic analysis of ORC.An ORC experimental work bench driven by the conductive oil was established with R123 as working fluid.The effect of temperature of heat source and superheating at expander inlet to expander performance was investigated with the ORC platform.The maximum output power were 3.42 k W and 3.15 k W respectively when the temperature of heat source were 140°C and 130°C,and the maximum operating efficiency were 0.72 and 0.79.At the same torque,the output power and operating efficiency at 130°C were larger than those at 140°C in most cases.With the decrease of superheating at expander inlet,the output power and operating efficiency increase firstly and then decrease.There existed optimal superheating that the output power and efficiency reach the maximum.A universal semi-empirical model of scroll expander and single-screw expander based on experiment was developed in this paper.Seven parameters in this model were identified.The supply pressure,discharge temperature and shaft power were used to validate the model.The errors between the predictions by the model and the measurements were within ±5%,±5°C and ±8% respectively for the scroll expander,and +10%,±5°C and ±10% for the single-screw expander.The outside pressure ratio,inside pressure ratio and external isentropic efficiency were defined according to the model.Compared with the outside pressure ratio,the inside pressure ratio established the relationship between the performance and construction of expander.The leakage is the leading factor that low the efficiency.The decrease of leakage can improve the external isentropic efficiency and shaft power effectively.An ORC machine with rated power of 5k W was developed.The single-screw expander was used to output shaft power and the working fluid was R245 fa.Based on the experiments,a software was builded to analyse the system of ORC.