Calculation for buffer intensity of drum-boiler water by phosphate treatment

The buffer intensity(buffer index) of boiler water is an important criterion for evaluating the interference of boiler water with strong acid or alkaline chemicals.Power plant boilers with big capacity and high temperature steam conditions are more and more being used,the dosage of chemicals to the boiler water is controlled more and more strictly,which needs to precisely calculate intensity buffer of boiler water precisely in different working conditions.A formulation according to charge balance equation and material balance equation was put forward,and the relation ship between the buffer intensity and pH value of the boiler water was investigated.Then the buffer capacity of the respective water treatment is calculated,and the buffer ablity of boiler water is discussed.The results show that the buffer intensities and capacities of different boiler water increase with the increase of the concentration of alkaline substance at pH 9～10 and the effect of ammonia upon the buffer ability of boiler water is more efficient than that of NaOH when equilibrium phosphate treatment(EPT)was adoptd.