Abstract:In main-pipeline back-pressure thermal power plant,multi-boilers and multi-steam turbines are in parallel operation.Any turbine trip or the main auxiliary machine trip of any boiler has an impact on the whole thermal system and improper control may directly jeopardize the operation safety of the unit and affect the safety of heat users.Based on a thermal power unit project of 3×480 t/h ultra high temperature and high pressure coal fired boilers and 2×50 MW bleeding back-pressure steam turbines,the RB control technology of decreasing load rapidly and maintaining steam supply for the heating network are applied when the turbine trip or the main auxiliaries trip,so that the unit can be smoothly reduced to the safe operation mode in a short time,avoiding the artificial operation risk and the loss of users of the heating network.