In order to estimate the parameters of selective catalytic reduction(SCR)denitration thermodynamics system in power plants

concerning the fact that the relevant data contains colored noises

this paper introduces an on-line estimation method based on standard recursive least squares with instrumental variable for the estimation of both time delay and other parameters.Combining with the variable regression estimation method

the parameters and time delay can be obtained by minimizing the loss function in a two-step estimation algorithm.Moreover

estimation is conducted with both standard and instrumental variable recursive least square for the SCR system in a 350 MW unit.The simulation results show that the introduced estimation algorithm improves the results' convergency and accuracy

indicating this method is appropriate for estimating the parameters of the model of second-order inertia transfer function plus a time delay.