Investigation on the fractional nature of a refrigeration evaporator. (October 2020)

• Record Type: Journal Article
• Authors: Casagrande, Daniele; Cortella, Giovanni; Krajewski, Wiesław; Miani, Stefano; Viaro, Umberto
• Is Part Of: Applied thermal engineering. Volume 179(2020)
• Publication Date: 2020-10
• Subjects: Refrigeration -- Evaporator -- Frequency response -- Physical model -- Identification -- Data fitting -- Fractional systems -- Experimental data; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2020.115626
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Experimental frequency response of a commercial evaporator Data do not fit with classical transfer function models Simplified modeling of heat transfer by coupled PDEs Simple fractional order model fits experimental data Abstract: The frequency response of an evaporator for commercial refrigeration is investigated to develop a control-oriented model which balances simplicity with accuracy. The dynamics of such devices is highly nonlinear; the response curve was experimentally identified around an operating point by recording the output of the system for several sinusoidal input signals. Among the possible linear approximating models, the collected data turn out to be best fitted with a fractional order transfer function. The proposed identification and process model allow for online tuning at different operating points for an efficient control design.