Abstract: According to the design idea of large capacity unit system, there is an inseparable interlock between the boiler, the steam turbine and the generatortransformer set; in most cases, any one of the three main equipments tripping should cause the others to trip. In some thermal power plants, in order to effectively avoid the losses in both economy and credit caused by the unit nonplanned outage, the reformation for boiler shutdown without turbine outage had been carried out. When the boiler shutdown accident occurred, which counts about 60% of the unit nonplanned outage, the turbinegenerator set will no longer be broken from the power grid; by the human intervention, adding some operation technical measures, the turbinegenerator set could operate continuously to ensure that the unit can recover to normal operation quickly.

Key words: reformation for boiler shutdown without turbine outage, boiler combustion, heat stress of steam turbine