The EC-BEST technology is proposed for the next generation of 700 ℃ advanced ultra supercritical power generation technology.Whether it has economic benefits when applying the EC-BEST technology to the current 600 ℃ ultra supercritical 1 000 MW units has been controversial all the time.On the basis of the calculation method for thermal dynamic system and basic principle of steam dynamic cycle

the changes of structure

steam water distribution parameter and efficiency of major energy conversion process in the thermal dynamic cycle of the thermal dynamic system in an ultra supercritical 1 000 MW unit applying the BEST technology were studied in detail.The results show that

by applying the BEST technology

the fraction of the reheat steam reduces obviously

and the benefit of the reheat cycle decreases.The efficiency and output power of each cylinder all changes

and the overall efficiency of the turbine increases to a certain degree.The BEST steam turbine efficiency is the key factor influencing the system's economy.The economy of the BEST scheme will be superior to the conventional scheme only if the turbine efficiency of the thermal system applying the BEST was 5.5 percent higher than that of the conventional thermal system

at that time the EC-BEST technology has application value.