By riser two-phase flow model and thermodynamic model

exergy analysis for the thermosyphon-based trilateral cycle(TTLC) proposed in the previous work by the authors is carried out to investigate the exergy performance of the system and the relevant influencing factors. The results show that

the system exergy efficiency varies in the range of 15%～30% with the increasing inlet temperature of heat source

which always helps to enhance the exergy efficiency. As the inlet temperature of cooling source decreases

the exergy efficiency changes from 23%to 27% with an optimum value. An optimization opportunity exists for the temperature difference of heater at the hot side

for example

a setting value of 4 ℃ seems to be a better choice. The riser exergy loss rate is a key factor to determine the system efficiency

especially under the condition where the temperature difference of the cycle is relatively larger. Decreasing temperature pinch point of the heater helps to decrease the internal and external exergy loss rates of the heater

but will lead to more exergy destructions in other processes. However

it exerts positive effects on system efficiency on the whole.