On the basis of simplified algorithm for principle thermodynamic system of large scale power units

a mathematical model evaluating the effect of enhancing the reheat temperature(to higher than the new steam temperature)on unit's thermal economy was established

combining with the changes of steam parameters under variable working conditions.Taking a domestic N600-16.67/537/537type subcritical unit as an example

the unit's thermal economy and the reliability of metal materials was analyzed

when the reheat temperature was increased to 570℃.The results show that:due to the 12Cr1MoV steel this unit applied

increasing the reheat temperature to 570℃is feasible;the reheat temperature shows an linear relationship with each thermal economic index of the unit

for example

when the reheat temperature is increased from 537℃to 567℃

the total heat efficiency will grow by 0.66%and the coal consumption rate will drop by 4.6g/(kW·h)

indicating the energy saving effect is dramatic.