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.

Taking introduced 300 MW generate sets for example,the effect on generating sets produced by super-heater and re-heater de-superheating spray is analyzed by utilizing the thermo-economy system state equations.

Taking the system of boiler pollution discharged and de-superheating spray as the research object,the article that bases on the structure and principium of the energy efficiency distribution matrix derives the models of quantitative analysis and calculation for the system of boiler pollution discharged and de-superheating spray.

Structural design of new type spray desuperheater;

This paper introduced the characters and operation status of the spray desuperheaters of 1 025 t/h boiler.

Because of temperature stress,the spray tube of secondary superheater spray attemperator of 300 MW subcritical boiler may generate crack,the generation of crack can be prevented by change the material nature and wall thickness,and decrease the temperature stress.