Variable temperature flushing process becomes possible by adjacent heating system

and the flushing mode of utility boilers can be changed. Taking the practical application of a 660 MW ultra-supercritical unit as an example

this paper analyzes the operation mode and technical essentials of variable temperature flushing by adjacent heating system. The temperature rise rate of flushing water

the maximum temperature limit of flushing water and the key points of boiler hydrodynamic safety are given. A method of simplifying the heating system by means of canceling the drainage system is also presented. Through analysis of the practical application of the example unit

the temperature boundary between cold flushing and hot flushing is eliminated by variable temperature flushing with the adjacent heating system. The flexible start-up of the boiler is realized

which is beneficial to reducing the thermal stress of the boiler start-up and improving the ignition characteristics of the boiler.