Numerical analysis of transient coupled heat and moisture transfer in textile drying with porous relative impact jet

Abstract

• Textile jet drying model with thermo-hydro bidirectional coupling is established. • Multiphase flow components are used to describe heat and mass transfer process. • Enhancement of heat and mass transfer by impinging jet. • The influence of working condition parameters is discussed. Convective drying of textiles is a multi-physical problem coupled with fluid flow, heat, and mass transfer, and is directly affected by the form of air supply. In this study, a coupled heat and mass transfer model for convective drying of textiles was established by focusing on the effects of a porous relative impinging jet on the coupled heat and mass transfer of textiles under different influencing factors. The results show that temperature and wind velocity, as the two most important influencing parameters, change the variation of steam concentration and convective heat transfer coefficient, respectively, thus affecting the drying process. Reducing the relative humidity of the air in the oven can accelerate the drying process. The accuracy of the proposed model was validated against the experimental results, and the error was within 10%. The optimal operating conditions ( v = 10 m/s, T = 180 ℃, RH = 10%) were determined via numerical simulation. The air supply mode of the orifice impinging jet accelerated the drying rate and simultaneously improved the uniformity of the change in textile moisture. The model enhances the understanding of the impinging jet drying mechanism for textiles and provides theoretical guidance for fabric drying equipment such as heat-setting machines.