Using supercritical carbon dioxide(S-CO_2) power cycle to recover waste heat from gas turbine exhaust can improve system performance

increase system flexibility and reduce system volume. In this paper

by employing the genetic algorithm

four S-CO_2 power cycle configurations are proposed and optimized to recover the exhaust waste heat of gas turbine Taurus 60. The results show that

the configuration 4 with two-stage heater(high temperature heater and low temperature heater) has the highest net power output(2.30 MW)

which can increase the system thermal efficiency by 17.78 percentage points and is suitable for gas turbine exhaust waste heat recovery. To solve the problem of large energy loss of the S-CO_2 power cycle cold source

a transcritical CO_2(T-CO_2) power cycle with liquid natural gas(LNG) as the cold source is further employed to recycle the waste heat of S-CO_2 power cycle

which can further increase the net output by 1.23 MW

and the system thermal efficiency by 6.86 percentage points. The pinch point analysis for the pre-cooler shows that

the minimum heat exchange temperature difference occurs at the hot end of the pre-cooler

which means no pinch effect has occurred and the system meets the design requirements.