On-Line Parameter Identification Algorithm for Distributed Parameter Plug Flow Systems

This paper presents a sequential parameter identification algorithm for estimating the time delays and time constants of distributed parameter plug flow processes which use fluid as a heat transport medium such as heat exchangers. The dynamics of these processes can be modeled by first order hyperbolic partial differential equations. The parameter identification problem is put into the general framework of a nonlinear identification problem which is solved by a Nonlinear Recursive Least Square (NRLS) algorithm. The NRLS algorithm is applied to estimate the thermal time constants and transit times of solar collectors using fluid as heat transport medium. Different implementations of the parameter identification algorithm are presented including the estimation of the parameters of different models of the collector namely the first order One Temperature Plug Flow (OTPF) and the second order Two Temperature Plug Flow (TTPF) models.