A novel mass transfer effectiveness model incorporating water activity for moisture evaporation rate prediction from fabric clothes

Household clothes dryers (HCDs) are popular in modern society and account for a large portion of domestic energy consumption. Moisture evaporation from fabric is an essential phenomenon that must be considered in HCD control to improve energy efficiency and reduce drying time. This study aims to develop a novel mass transfer effectiveness model to predict the moisture evaporation rate (MER) by considering the thermophysical phenomena occurring during the drying process of fabrics. An experimental apparatus was constructed to measure the filling degree (FD) of fabrics in the dryer drum, leading to the development of a model predicting FD with a mean absolute percentage error (MAPE) of 10%. The FD correlation can be used to estimate the volume change of the fabric during the drying process. Simultaneously, experiments using a commercially available HCD were conducted to measure the moisture evaporation rate and associated parameters. Throughout the drying process, distinct changes in mass transfer effectiveness and water activity were identified. Subsequently, two empirical correlations for mass transfer effectiveness corresponding to each distinct drying regime were developed. These two correlations were integrated into a comprehensive model that aligns well with MER data from real-world HCDs, achieving a MAPE of approximately 11%.