Numerical simulation analysis and experimental study on tobacco leaf curing process in detachable curing barn

To solve problems such as low utilization rate of fixed curing barn, high transportation costs for fresh tobacco leaves, and resources waste caused by tobacco cultivation areas relocation in hilly and mountainous regions, a detachable curing barn was designed．Based on an analysis of heat and mass transfer mechanism during tobacco curing process, a numerical simulation model of tobacco curing process was constructed using porous media theory．By analyzing velocity and temperature distribution patterns of hot air flow within tobacco-loading room and combining with experimental research methods, effects of different hot air inlet velocities and tobacco-loading amount on uniformity of flow field inside curing barn were analyzed．Results have shown that relative errors between simulated and measured values for flow field velocity and temperature were small across different tobacco leaf curing curing stages．Numerical simulation model of tobacco leaf curing process in detachable curing barn accurately reflected internal flow field distribution characteristics in curing barn．Under of same tobacco-loading account conditions, increasing hot air inlet velocity has reduced flow field uniformity in tobacco-loading room．At same hot air inlet velocity, increasing tobacco-loading amount has helped improve flow field uniformity in tobacco-loading room．Therefore, it was determined that at hot air inlet velocities of 4.5 m/s（yellowing period and color fixing period）and 5.7 m/s（ stem-drying period）, with a tobacco-loading amount of 6 t, internal flow field uniformity in curing barn was optimal．A theoretical basis has been established for optimized design of detachable curing barn and baking process improvement, which has significant implications for effectively leveraging benefits of curing infrastructure in hilly tobacco cultivation regions．