Dynamic response of the crossflow heat exchanger with finite wall capacitance

Abstract

This paper shows how the transient response of a cross-flow heat exchanger with finite wall capacitance may be calculated by analytical method. Making usual idealizations for the analysis of dynamic behavior of the heat exchanger, the model is based on three local energy balance equations which are solved by using the Laplace transform method for step change of the primary fluid inlet temperature. The solutions are found in the case of constant initial conditions and expressed in the explicit analytical form used to find temperature distributions of both fluids and the wall as well as the mean mixed fluid temperatures at the exit. Presented solutions are valid in cases where fluid velocities are different or equal and finite or infinite, respectively. The solutions can be very suitable for mathematical modeling systems containing such types of heat exchangers. © 1991 Springer-Verlag.