Advancing sustainable laundry practices utilizing waste heat from commercial laundry facilities

To enhance efficiency and reduce operational costs in mechanical drying for energy equipment, this study introduces a novel sustainable laundering approach using an innovative waste heat recovery (WHR) method in commercial laundry facilities utilizing gas dryers and boilers as waste heat sources. The proposed WHR system serves as a pre-dehumidification stage, where laundry undergoes centrifugation, initial drying in the WHR chamber, and final drying with a gas dryer. Building on established foundational data and models for heat and moisture transfer from previous research, this study rigorously evaluates the performance of the proposed system. The evaluation integrates three mathematical models to simulate the WHR laundry drying system: heat exchange, laundry drying, and mass movement. The laundry drying model utilizes the thermodynamic energy of moisture for water transfer. Various simulations are conducted, adjusting the laundry's forward speed and interval. The effectiveness of the system is assessed using three indicators: quantity of laundry processed, latent heat load, and degree of laundry dryness. The simulations reveal that the system can handle an annual latent heat load between 970.1 and 1827.1 GJ, corresponding to a reduction in natural gas consumption of approximately 21,560–40,600 m³ and achieving laundry dryness levels of 40 %–68.2 %.