AN APPLICATION OF EXTENDED KALMAN FILTERING TO HEAT-EXCHANGER MODELS

This paper shows how an extended Kalman filter can be applied to the p arameter estimation in continuous time heat exchanger models. The mode l is based on lumping of the heat exchanger. It is on state space form where the temperature in each section is a model state. By letting th e model parameters be functions of the massflows and the temperatures one obtains a model that is capable of accurately describing the dynam ics of the heat exchanger for all relevant working conditions. Since t he parameters are functions of temperature, the model is nonlinear in the states and an extended Kalman filter is applied to the state estim ation. Empirical relations of the heat transfer coefficients are incor porated in the model parameters in order to cope with the mass flow an d temperature dependence. Some of the parameters in the empirical rela tions are also estimated, thereby adjusting the formulas to the specif ic heat exchanger.