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.

本文介绍了住宅燃气炉模型中流场的实验研究，重点是测量初级热交换器周围的详细流场。改进的煤气炉模型在空气循环系统中进行了测试，该系统旨在产生良好控制的条件，以便获得的实验数据可进一步用于验证设计输出。除了使用压力计和热线风速计监测流动压力和速度外，粒子图像测速仪还应用于通过将雾颗粒播种到循环气流中来表征等温条件下住宅燃气炉的主热交换器周围的流场。分别为无阻尼箱）、正常运行条件（打开阻尼箱）和过滤器严重堵塞的情况（高度受限的阻尼箱）。使用粒子图像测速仪 (PIV) 测量不同操作条件下燃气炉中主换热器周围的二维流场。在理想和正常条件下，流场是对称的，而在主换热器上部上方观察到分离，在侧板尖端下游观察到涡流脱落。在高度受限的条件下，流场与炉右侧的逆流变得不对称。这种情况对数值工具预测正确的平均流动结构提出了严峻的挑战。