Study On Strength Analysis Of High Parameter Boiler Header

With the rapid development of power industry,high-capacity,high-parameter,low-emission power stations are emerging,and the pressure and temperature parameters are getting up,and supercritical or ultra supercritical unit has become the main direction of development.The safety,reliability and longevity of pressure parts are becoming the focus of power plant investors and equipment manufacturers.In this paper,the strength of the boiler header system has been analyzed systematically.The plastic limit pressure method was put forward to check header strength.The stress distribution of single radial and non-radial opening,longitudinal and diagonal ligaments have been analyzed,and the Decock formula is well matched with the FEA results.The results from FEA are less than the longitudinal ligament efficiency from formula,and The results from FEA are greater than double diagonal ligament efficiency from formula.The stress distributions of cap and thermo-extrusion tee were studied by FEA and it is found that the stress distribution is related to the transition radius R of the shoulder region of thermo-extrusion tee.The thermal stress of the header was analyzed and found there is no stress concentration in the tee.A better method of how to calculate creep-fatigue life damage was proposed and a life assessment of the superheater header has been made with this method.The research of this paper provides theoretical guidance for safe operation of power station boiler header.