It is always to be a problem that the high-pressure regulating valve opening is too small

which leads to too large throttling loss when the ultra-supercritical throttle governing steam turbine is operated by the sliding pressure operation curve provided by the manufacturer. Thus

it is not conducive to the economic operation of the unit. To solve this problem

by taking an ultra-supercritical 1 000 MW throttle governing steam turbine as the example

this paper introduces the optimization test method of sliding pressure operation for the throttle governing steam turbine. Through the heat rate comparison test at various typical loads and combining with the actual flow characteristics of the unit's high pressure regulating valve

the sliding pressure operation curve which takes account into both the unit's economical performance and response requirement is obtained. Moreover

on the basis of the actual operation back pressure

this paper proposes the correction method for back pressure corresponding to different seasons

and the practical application method for the sliding pressure operation curve with modified back pressure is also given. The results show that

this method can improve the actual economy of the throttle governing steam turbine

which has a certain value of practical application.