Study on Steam Temperature Control Strategy in Primary Fan RB Process of1000 MW Ultra Supercritical Unit

In order to decrease the fluctuation of steam temperature during primary fan RUBACK (RB) process of 1000MW ultra supercritical unit, the influence factors, the excess air coefficient and the ratio of fuel and feed water were studied and analyzed in detail. The control relationship of fuel, feed water and air input during normal operation was discussed and the effective temperature control strategy about these variables during RB process was proposed. Variation results of main steam temperature, reheat steam temperature, unit load and main steam pressure were given. The application results of improving control strategy in Chaozhou power plant show that the proposed strategy is effective for steam temperature and pressure control and is valuable to RB experiments in similar power plant units.