Improving flow performance in a heat pump tumble dryer using MRV-based structural modifications

(Improving flow performance in a heat pump tumble dryer using MRV-based structural modifications)

The Multiscale Heat & Fluid Flow Lab (MFL) applies MRV-based techniques to characterize three-dimensional flow and turbulence structures in a heat pump tumble dryer, with the goal of reducing flow-induced noise and enhancing energy efficiency. Scaled-down models of the machine room and rear duct were fabricated using stereolithography 3D printing, and the 3D mean velocity and turbulent kinetic energy (TKE) fields were measured. Results from the reference model showed highly non-uniform flow distribution, high TKE regions, and a high backflow ratio at the perforated plate, which may have contributed to lint accumulation. The structural modifications resulted in a reduction of over 50% in high-TKE regions within the machine room, along with improved flow uniformity and a noticeable decrease in secondary flow intensity. In the rear duct, high-TKE regions were reduced by more than 80%, and the backflow ratio at the perforated plate decreased by over 54%, which is considered a key factor contributing to the suppression of lint accumulation in the rear duct region. These findings offer valuable insights into the complex flow behavior of heat pump tumble dryers, and demonstrate the potential of MRV as a powerful tool for investigating, understanding, and optimizing the flow performance of household appliances.  This research is being conducted in collaboration with the Vibration Noise Project at the H&A R&D Center of LG Electronics.