A Low-order hybrid dynamic model for evaporators
A low-order hybrid model, which can present the transient behaviors of evaporators, is proposed in this paper. The model is derived from the fundamental conversation of energy and mass of the working fluid flowing though the evaporator, while its geometrical dimensions, thermodynamic coefficients that can be considered as constants and some variables that keep small variety during the operation (such as cross sectional areas of tube, mean void fraction, the density of the working fluid in the superheated section, etc.), are lumped into unknown parameters. The linear least squares method is employed to estimate these unknown parameters using measured experimental data collected from the experimental testing facility. The model is just two orders, but can accurately capture the transient behaviors of evaporators. Validation results confirm a good agreement between simulation results and experimental data. The developed models will be suitable for the dynamic behavior analysis and the advanced controller design.