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.

A Continuous Commissioning Analysis and its Application to a New Installed Solar Driven DEC System Coupled with Heat Pump

“…For this specific sub-system, the choice of the reference model is a strong issue, as information on manufacturer's data sheets are not sufficient to get reliable models. A mathematical model has been developed [5], along with a fast computational method [6], and calibrated on a desiccant wheel similar to the one used in our plant. Regression coefficients are derived from this model to get simple algebraic equations, presented in [3], in the range of temperature and humidity of interest for the application.…”