In view of large quantity of desuperheater spray problem of boiler,this paper proposed a method to reduce the quantity of desuperheater spray of boiler through the transformation low temperature heating surface.

This paper analyzed the weld crack cause of the micro spray water desuperheater tube joint of 1 025 t/h boiler A reheater,it considers that the crack is not caused by metal material and welding quality,but by incorrect assembly gap and low strength of spray water device,and effective improving measure was adopted,and obtained good results.

In view of the feature and requirements of steam temperature control system of supercritical generation units, based on the analysis of temperature regulating theory, this paper discussed key points in design of the fuel water ratio(F/W) regulation and spray desuperheating control.

Based on the thermal balance matrix equation for thermodynamic system and different sources of spray desuperheating water, mathematical models for the influence of spray desuperheating on thermal economy under conditions of constant power output were derived.

It is found out that the main causes are excessive attempering water,air leakage of the boiler system and scaling of heating surface.

In view of the main steam temperature control difficulty caused by type-choosing error of attempering water control valve for 410 t/h boiler in Guohua Shenmu Power Generating Co.

The question of insufficiency of self-produced condensate,for superheater attemperation during operation,of a high pressure cogeneration set is being mentioned,pointing out the damage that may be caused to the boiler by frequent use of emergency attempering water.