A simplified thermal CFD approach to fins and tube heat exchanger: Application to maldistributed airflow on an open display cabinet. (September 2015)

• Record Type: Journal Article
• Authors: Rossetti, A.; Minetto, S.; Marinetti, S.
• Is Part Of: International journal of refrigeration. Volume 57(2015:Sep.)
• Page Start: 208
• Page End: 215
• Publication Date: 2015-09
• Subjects: Air distribution -- Heat exchanger -- Simulation -- Display cabinet -- Computational fluid dynamics -- Heat transfer; Distribution d'air -- Echangeur thermique -- Simulation -- Meuble de vente -- Dynamique numérique des fluides -- Transfert de chaleur; Refrigeration and refrigerating machinery -- Periodicals; 621.56
• DOI: 10.1016/j.ijrefrig.2015.05.014
• Languages: English
• ISSNs: 0140-7007

Abstract

Abstract: Airflow maldistribution in heat exchangers and air channels is a common problem in HVAC&R systems. Furthermore, in the refrigeration field, temperature and velocity maldistribution downstream the evaporator can reach the discharge air grille, negatively influencing the heat removal from the exposed goods. In the present paper, the effect of the flow maldistribution in the air channel of an open refrigerated display cabinet is studied by means of computational fluid dynamics simulations. An equivalent thermal approach is presented: in combination with the equivalent resistance approach, it allows a drastic reduction of computational effort. This thermal CFD model allows to evaluate the 3D effects of the maldistribution in terms of temperature, heat transfer coefficients, and cooling power in the full channel model. Discussion of the results is reported. Highlights: Air maldistribution affects heat exchanger performance. A 3D numerical model is necessary to describe air maldistribution effects. A simplified 3D CFD approach is proposed, aimed at reducing the model grid size. The simplified approach is based on an equivalent resistance and thermal approach. An open display cabinet air channel affected by maldistribution is used as test case.