According to the characteristics of circulating fluidized bed(CFB)boilers,optimization on selective non-catalytic reduction(SNCR)denitrification system applying urea as the reducing agent was conducted.Numerical simulation results indicate that,spraying the injecting reducing agent from the upper side of the separator inlet to the inner side can result in higher reducing agent's efficiency;decreasing the urea solution concentration from 50%to 10%,the SNCR system can be operated without heat tracing system;t...