Characterization of the flow field around the primary heat exchanger of a residential gas furnace via particle image velocimetry. (16th March 2022)

• Record Type: Journal Article
• Authors: Wu, Puyuan; Shang, Weixiao; Chen, Jun; Sardar, Asad; Mielke, Ross; Russell, David
• Is Part Of: Science and technology for the built environment. Volume 28:Number 3(2022)
• Page Start: 338
• Page End: 349
• Publication Date: 2022-03-16
• Subjects: Heating -- Periodicals; Ventilation -- Periodicals; Air conditioning -- Periodicals; Refrigeration and refrigerating machinery -- Periodicals; Indoor air quality -- Periodicals; Indoor air quality; Air conditioning; Heating; Refrigeration and refrigerating machinery; Ventilation; Periodicals; 697
• DOI: 10.1080/23744731.2021.1994285
• Languages: English
• ISSNs: 2374-474X

Abstract

Abstract : This paper presents an experimental study of the flow field in a residential gas furnace model, with a focus on the measurement of the detailed flow field around the primary heating exchangers. A modified gas furnace model was tested in an air circulation system, which was designed to generate well-controlled conditions so that the obtained experimental data can be further used to validate design outputs. In addition to monitoring the flow pressures and velocities using manometers and hot-wire anemometer, Particle Image Velocimetry was applied to characterize the flow field around the primary heat exchangers of a residential gas furnace at isothermal condition by seeding fog particles into the circulated air flow. Three cases with different operating conditions are generated by controlling the differential pressure of the inlet and the outlet of the furnace, simulating the ideal design condition ( no damper case ), normal operation condition ( open damper case ), and the condition with severe filter blockage ( highly restricted damper case ), respectively. The 2D flow field around the primary heat exchangers in the gas furnace at different operating conditions is measured with Particle Image Velocimetry (PIV). Under ideal and normal conditions, the flow field is symmetric, while separation is observed above the upper portion of the primary heat exchangers, and vortex shedding is observed downstream of the tip of the side baffles. In the highly restricted condition, the flow field becomes asymmetric with the reverse flow at the furnace's right side. This case presents a severe challenge for the numerical tools to predict the correct mean flow structures.