ZHANG Renping, ZHOU Zuxiang, HUANG Ju, XIN Jiajun, WANG Qi, YUE Wentao
(School of Materials Science and Engineering, Jingdezhen ceramic institute, Jingdezhen 333403, Jiangxi, China)
Abstract: As an important technical measure for energy saving and carbon reduction in ceramic enterprises, the recovery of flue gas from the heat exchanger is inseparable. In order to improve the flow heat transfer performance of AlN ceramic heat exchanger, the thermal resistance ratio was analyzed. The effects of fin spacing, fin thickness, tube spacing and eddy current generator on flow heat transfer performance of the heat exchanger were simulated and studied by establishing the flow heat transfer model of the finned tube AlN ceramic heat exchanger. The heat transfer thermal resistance of air outside the tube of AlN heat exchanger is the main thermal resistance, accounting for more than 85%. When the fin spacing, tube transverse spacing, and tube longitudinal spacing are increased, Nu increases and the pressure drop decreases, which has a great influence on Nu value and pressure drop. When the fin thickness increases, the Nu decreases and the pressure drop increases, but the fin thickness has little effect on the Nu value and pressure drop. In the simulated structural parameters, the comprehensive performance of AlN ceramic heat exchanger is highest, when the fin spacing is 5 mm, the fin thickness is 1.2 mm, the transverse spacing of the tube is 12 mm, and the longitudinal spacing of the tube is 16 mm. Under the same calculation conditions, the total heat transfer coefficient of the finned tube AlN ceramic heat exchanger is increased by 378.24–466.41% compared with the plain tube AlN ceramic heat exchanger, while the total heat transfer coefficient of the eddy current generator finned tube AlN ceramic heat exchanger is increased by 32.78–88.76% compared with the finned tube AlN ceramic heat exchanger.
Key words: finned tube AlN ceramic heat exchanger; vortex generator; heat transfer performance; pressure drop performance; Nussel number; thermal resistance