Organic flash cycle(OFC) with ejector can effectively match for medium-low temperature heat source and avoid throttling loss of medium-low pressure throttle valve in conventional OFC. In order to explore exergy loss situation of the OFC with ejector

an exergy analysis model of the OFC with ejector driven by 100～200℃ geothermal water was established. R601

R600 a

R123

R1234 ze and R1234 yf were selected as working fluids. The variations of exergy loss

internal exergy efficiency

external exergy efficiency and exergy loss distribution of each component of the system in heat absorption process with geothermal water inlet temperature were analyzed. The results show that

the system using fluid with higher critical temperature has the higher internal exergy efficiency. Moreover

there is a characteristic temperature

when the geothermal water inlet temperature equals the characteristic temperature

the exergy loss of the system in heat absorption process reaches the minimum

and the internal and external exergy efficiency of the system reaches the maximum. In addition

the condenser's exergy loss distribution reaches 23%～28.7%

indicating the condenser is the component with the largest exergy loss distribution in the system. Therefore

reducing the condenser's exergy loss is an important way to improve the system performance.