A 330MW condensing unit was taken as the example to analyze the performance change of regenerative system after the cogeneration retrofit.The pinch theory was employed to carry out network optimization on heat transfer in this regeneration system.The results showed that

if conducting the regeneration system transformation simultaneously during the heat supply retrofit

and setting up the external superheated steam cooler

the system efficiency and generation capacity under rated inlet steam amount condition can be enhanced by 0.31%and 3MW

respectively.During the practical transformation

the reliability and investment cost should be considered

and the external superheated steam cooler is not necessary for all extraction steam with high superheating ratio.The steam extracted before and after the reheater

which has high superheat ratio and can enhance the system efficiency effectively

should be considered as a priority.