Project introduction:

In view of the problems that traditional economizer usually adopts a round tube flat fin arrangement, which leads to large pressure drop loss and serious ash accumulation in the heat exchanger, in order to reduce the flow resistance of the heat exchanger and reduce the heat loss caused by ash accumulation, an elliptical tube H-shaped fin heat exchanger was developed.

Outcome advantages:

This heat exchanger combines multiple technologies for flow resistance reduction, heat transfer enhancement and ash accumulation reduction. First, by installing triangular winglets on the surface of the heat exchanger, the heat exchange effect on the surface of the fin is increased; at the same time, the cooperative arrangement of multiple winglets is adopted, and a larger angle of attack and size are used in areas with relatively low flow velocity at both ends of the fin to enhance the disturbance effect; in the middle of the fin, in turbulent areas with high flow velocity, a smaller angle of attack and winglet size are used, thereby reducing the heat transfer thermal resistance of the viscous bottom layer. Secondly, the heat exchanger adopts an elliptical heat exchange tube arrangement, which can "inhibit flow separation, reduce backflow behind the tube, and reduce shape resistance." Thirdly, the comprehensive arrangement of elliptical tubes and winglets can "increase the disturbance in the vortex attachment area in front of the tube, introduce high-speed fluid into the tube, and reduce the distribution of lower flow velocity areas on the tube wall", thereby reducing particulate matter deposition and making the heat exchanger It can operate efficiently in dusty flue gas environments for long periods of time. Research shows that under the same geometric parameters, when the inlet wind speed is 5m/s, the pressure drop in the elliptical tube is 20% of that of the circular tube. Compared with the flat fins of the circular tube, the dust particle deposition rate decreases by more than 50%.

Application Scenarios and Fields:

The heat exchanger is suitable for flue gas waste heat recovery processes in various industrial processes such as industrial boilers and power station boilers. While improving the heat recovery efficiency of equipment, it can reduce the thermal pollution of low-temperature waste heat to the environment and increase additional environmental and economic benefits., has good application prospects.

The project was carried out under the support of the National Key Basic Research and Development Plan (973 Plan) project (2013 CB228304) and the National Natural Science Foundation of China NSFC-Guangdong Joint Fund Key Project (No. U0934005).