Estimation of heat transfer parameters in a trickle-bed reactor using differential evolution and orthogonal collocation

A new non-sequential technique is proposed for the estimation of effective heat transfer parameters using radial temperature profile measurements in a gas-liquid co-current downflow through packed bed reactors (often referred to as trickle bed reactors). Orthogonal collocation method combined with a new optimization technique, differential evolution DE is employed for estimation. DE is an exceptionally simple, Fast and robust, population based search algorithm that is able to locate near-optimal solutions to difficult problems. The results obtained from this new technique are compared with that of radial temperature profile (RTP) method. Results indicate that orthogonal collocation augmented with DE offer a powerful alternative to other methods reported in the literature. The proposed technique takes less computational time to converge when compared to the existing techniques without compromising with the accuracy of the parameter estimates. This new technique takes on an average 10s on a 90 MHz Pentium processor as compared to 30s by the RTP method. This new technique also assures of convergence from any starting point and requires less number of function evaluations. (C) 1999 Elsevier Science Ltd. All rights reserved.