Modelling of a desiccant rotor by using the collocation method

Abstract

Purpose

This article aims to develop a fast numerical method for solving the one-dimensional heat and mass transfer problem within a desiccant rotor.

Design/methodology/approach

The collocation method is used for discretizing the axial dimension and reducing the number of dependent variables. The resulting system of equation is then solved through backward differentiation formulas.

Findings

The numerical results obtained here focus on verifying the accuracy and the computation time of the proposed method with respect to the finite difference method. The proposed numerical solution method resulted faster than, and as much accurate as, the finite difference method, over a large range of operating conditions that are of interest in desiccant cooling applications.

Research limitations/implications

For heat and mass transfer analysis, constant average transfer coefficients are used. The results are calculated for NTU between 2 and 15 and for Le number between 0.5 and 2.

Practical implications

The results can be used in designing desiccant heat exchangers and desiccant cooling systems including complex rotor arrangements.

Originality/value

Different from other simplified solution techniques, the proposed method relies on few parameters that retain physical meaning and applies also to complex rotor configurations.

Citation

Aprile, M. and Motta, M. (2014), "Modelling of a desiccant rotor by using the collocation method", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 24 No. 1, pp. 201-220. https://doi.org/10.1108/HFF-02-2012-0035