By analyzing the factors affecting the economical performance of 1 000 MW class ultra-supercritical double-reheat units

combing with the case study on economical performance difference between the single-reheat units and double-reheat units

the actual performance of the double-reheat units was evaluated according to the performance acceptance test results of sample units. The results show that

as a result of series of optimizations to the regenerative system design

pipe pressure drop reduction

flue gas heat recovery

boiler efficiency enhancement and auxiliary power ratio reduction(besides the advantages of thermal cycle and parameters)

the in-service1 000 MW class ultra-supercritical double-reheat units' design coal consumption rate is 5.7% lower than that of the same scale single-reheat units. The application of double-reheat cycle

steam parameters improvement and regenerative system optimization greatly reduces the unit's heat rate

which is the major reason for overall performance improvement of the double-reheat units. The overall economical performance of domestic in-service 1 000 MW class double-reheat units meets the design requirement

and has achieved the best level of coal-fired units at present.