Enhancement of convective drying of a moist porous material with impinging slot jet by implementation of micro-encapsulated phase change material: A numerical feasibility study. (1st August 2022)

• Record Type: Journal Article
• Authors: Karami, Amirhossein; Kowsary, Farshad; Hanafizadeh, Pedram; Nejad, Alireza Mahdavi
• Is Part Of: International journal of heat and mass transfer. Volume 191(2022)
• Publication Date: 2022-08-01
• Subjects: Convective drying -- Impinging slot jet -- Moist porous media -- Micro-encapsulated phase change material -- Transient heat and mass transfer; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2022.122828
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: The idea of jet impingement convective drying utilizing micro-encapsulated PCM is introduced for the first time in the literature. MEPCM particles dispersed in moisture content of porous material and is exposed to a compressible air jet. PCM commences its role as a heat sink then becomes a heat source for the rest of drying process. 70.2% improvement in heat transfer enhancement corresponding to 50% PCM volume fraction. Abstract: The concept of convective drying of a moist porous material in the presence of micro-encapsulated phase change material is introduced in this study and then its favorable impact on drying efficiency is numerically investigated. In this regard, encapsulated PCM particles are dispersed inside the void part of porous medium while the moist sample is exposed to a compressible impinging slot jet. The transient evaporation process from a moist porous material exposed to a compressible air jet while PCM particles dispersing in water content of a porous sample is mathematically modeled and solved afterwards employing Finite Element Methods. A mathematical optimization technique is performed on the melting temperature of PCM to select a PCM appropriate to the thermal drying process. The numerical experiment in this work indicates that PCM facilitates the moisture removal process and dramatically reduces the water content in a typical convective drying. Investigating the transport mechanism, results show that PCM acts as a heat sink at the early stages of drying and then alternates to a heat source, releasing previously stored energy and internally heating the moist sample. According to the results, a 70.2% improvement in heat transfer enhancement is reported corresponding to 50% PCM volume fraction. The effects of PCM volume fraction, exit Reynolds number, and jet outlet temperature on PCM-equipped convective drying is considered. Graphical abstract: Image, graphical abstract .