Experimental Characterization of Flow Field Around Heat Exchanger Cells in a Residential Gas Furnace
Conference Year
2018
Keywords
gas furnace, PIV, flow dynamics
Abstract
DOE recently proposed to significantly increase the minimum furnace efficiency standards. This stringent requirement presents a major challenge to manufacturers for designing the next-generation product, which heavily relies on CFD-based design tool. In this study, Particle Image Velocimetry (PIV) is applied to measure the flow field around heat exchanger cells in a general model of a residential gas furnace to provide benchmark validation of CFD validations and to inspire new designs that must abide by the new regulations. The gas furnace, combined with inlet and outlet duct and a large exhaust chamber, can simulate a set of realistic operational conditions with seeded particles circulated inside. It is discovered that strong circulation exists around the top of the cells due to flow separation. Vortex shedding from two curved end plates is also observed. The result also shows that, by changing the inlet settings, the flow field between cells may transit from symmetric to asymmetric. The detailed flow structures will help optimize the deployment of key components that was practiced before in a trial and error approach.