Numerical investigation of heat transfer and erosion characteristics for H-type finned oval tube with longitudinal vortex generators and dimples

To improve heat transfer performance and reduce erosion of economizers in coal-fired power plants, firstly the heat transfer and erosion characteristics is numerically studied for the single H-type finned oval tube with enhanced heat transfer structures including bleeding dimples, longitudinal vortex generators (LVGs), and compound dimple-LVG. The simulation results show that the oval tube with compound LVG-dimple achieves the highest overall heat transfer performance while the oval tube with LVG works most efficiently in the anti-wear performance. Then based on the H-type finned oval tube, the LVG structure on the first row of tubes together with hemisphere protrusions design, while the compound LVG-dimple on the rest tubes are also simulated. The optimized H-type finned oval tube bank heat exchanger is demonstrated of high performance on both heat transfer and anti-wear.