Dealing with this problem, the paper presents the concept of a mean temperature differece correction factor, which, applied to the heat absorption deviation coefficient, considers the effect of changes of the mean temperature difference on heat absorption deviation.

On the basis of numerical simulation of furnace processes in a 350MW boiler and some experimental data, this paper analyzed the distribution pattern of heat absorption deviation of superheaters and reheaters along furnace width in the furnace exit of tangentially fired boilers.

The thermal deviation in reheater was experimental studied in 300MW unit of Zhanjiang Power Station.

Based on explaining the thermal deviation and its harms,this paper analyzes the reasons of generating the thermal deviation of the superheater and reheater of W flame boiler,and probes into the measures for reducing the thermal deviation.

Overheating appeared in the tubes of the outlet section outside the furnace and outlet vertical section of the reheater duo to thermal deviations,accompanied by tube explosion.

Analysis of heat deviation of high temperature heated delivery surface in power station boiler

According to the analysis for the overheating of hightemperature superheater in a 1025t/h utility boiler through the heat deviation theory, the discord between heat load distribution on gas side and flow distribution on stean side across the furnace width is the main reason for causing overheating.

The paper makes an important on the heat deviation calculation based on the Soviet standard of thermal calculation, the national standard of the boiler hydrodynamics calculation (JB/Z201 83) and the scientific research results on the flow deviation along the box axis and the radiant heat deviation in the same board.

With the reference of numerical simulation method and the premise of reserving the virtue of tangential firing, it advances that the burner jet is disposed in-whirl and de-whirl time and again to obtain and maintain the state of slender whirl which will make the boiler stable, and accordingly resolves the problem of heat difference.

Boilers with four corner tangentially firing combustors are widely used in large fossil fuel firing power plants, but excessive temperature deviations, effected by stray flue flow, often cause overheating and tube bursting of high temperature convection heating surfaces, which would seriously impair the sets safety and efficiency.