Stationary and dynamic simulation of multipass shell and tube heat exchangers with the dispersion model for both fluids

The dispersion model is applied to the description of the effects of shell and tubeside flow maldistribution. By means of this model, an efficient and versatile method of predicting transient response of multipass shell and tube heat exchangers is developed. The method allows for effect of maldistribution on transient process, influence of heat capacities of fluids and solid components, arbitrary inlet temperature variations and step disturbances of flow rates. General forms of initial conditions and two different flow arrangements are considered. A general form of the solution for steady-state and dynamic simulation is derived. Temperature profiles are determined with numerical inversion of the Laplace transform. Some examples are calculated and the effect of maldistribution is discussed.