NF型搪瓷蓄热元件的传热与流动特性实验

Experimental research on heat transfer and flow characteristics of an NF-type enamel heat storage element

回转式空气预热器(空预器)的传热与流动特性和所用蓄热元件的类型密切相关。搭建了回转式空预器蓄热元件传热与流动特性实验台,并通过周期性的风门切换,使得冷、热风交替冲刷蓄热元件,模拟回转式空预器的非稳态换热过程。通过实验研究NF型搪瓷蓄热元件不同雷诺数下的努塞尔数、压降以及阻力系数的变化规律,得出其传热和流动特性的拟合公式。

The heat transfer and flow characteristics of rotary air preheater is closely related to the type of the heat storage element,in which the NF-type enamel heat storage elements can be used in the cold end of rotary air preheater.However,the heat transfer and flow characteristics requires further study.The experi-mental system was built up for studying the heat transfer and flow characteristics of the heat storage ele-ment.By switching the damper periodically,the cold and hot air scours the storage element alternately,thus the unsteady heat transfer process of rotary air preheater is simulated.Through experimental study on change rules of the NF-type enamel heat storage elements＇Nusselt number,pressure drop and drag coeffi-cient with different Reynolds numbers,the NF-type enamel heat storage elements＇fitting formulas of heat transfer characteristics and flow characteristics were obtained.