Analytical solution of coupled heat-moisture-VOCs transfer process in liquid desiccant dehumidifier for indoor VOCs removal

Abstract

Indoor volatile organic compounds (VOCs) have a serious impact on human health. Liquid dehumidification shows a potential to remove VOCs during dehumidification process. To improve its VOCs removal performance, it's important to analyze mass transfer behaviors of VOCs at design stage. However, previous research methods mainly focused on experimental or numerical simulation, by neglecting the analytical solution. In fact, the analytical solution shows many advantages in terms of time, cost, and intuition etc. Therefore, in this study, an analytical solution is proposed to characterize heat-moisture-VOCs transfer performance in liquid dehumidifier. The proposed analytical solution is derived based on the existing theoretical model. Moreover, a piecewise function method is proposed to address the nonlinear and complex relationship between Henry's law constant and temperature in the VOCs transfer model. Thus, the analytical solution is set as a piecewise function considering both accuracy and gas-liquid flow rate ratio. Using the proposed analytical solution, the influences of some key operating parameters on VOCs removal performances are demonstrated. The results indicate that the analytical solutions are basically consistent with the numerical solutions and it can effectively predict the trend of VOCs removal performance with key parameters change. Comprehensive analysis of the mass transfer behavior of VOCs in liquid dehumidifier is effective with the analytical solution. This work provides a theoretical support for indoor VOCs removal with liquid dehumidifier.