To solve the large water wall temperature deviation problem occurred on ultra supercritical 1 000 MW unit boiler of Pingdingshan Power Plant

a mathematical model for the 1 000 MW unit boiler was established according to the boiler structure and the heat load distribution features in the furnace. By comparing the calculated results and the measured data

the boiler heat load distribution was deduced

and the reasons for the excessive deviation of the boiler water wall temperature were analyzed. The results show that

the uneven heat load and uneven flow distribution in the furnace mainly leads to the large temperature deviation. In addition

the structure of the boiler has a certain influence on sensitivity of the wall temperature deviation. The calculation results and the measured data can be in good agreement at high load. But there is a big difference between the calculated steam temperature and the measured data. However

when the heat load distribution in the furnace is modified time after time

it indicates that the calculation results agree with the field data well. It suggests to adjust the uniform distribution of pulverized-coal and air in the same layer swirl burner during the operation. The ratio of coal to water should be controlled under variable load or disturbance conditions. Moreover

in boiler design

the flow cross ratio of the front wall and the back wall in the upper furnace can be adjusted

so that the flow can beevenly distriibuted.