气-固循环流化床螺旋板式换热器的传热性能与压降

Thermal performance and pressure drop in a gas-solid circulating fluidized bed spiral plate heat exchanger

设计并搭建了气-固循环流化床螺旋板式换热装置,研究了空气流量(80~125 m^(3)·h^(-1))、颗粒加入量(0.5%~2.0%)和颗粒类型等操作参数对以恒温水作为热流体、空气作为冷流体、3种固体颗粒作为固相工作介质的循环流化床螺旋板式换热器传热性能和压降的影响。实验的结果显示,添加颗粒可以明显改善螺旋板式换热器的传热性能,但同时也会增大压降。在实验考察的操作参数范围内,强化传热效果最佳时的传热增强因子可以达到29.28%,此时系统内添加的颗粒为聚甲醛颗粒,空气流量为125 m^(3)·h^(-1),颗粒加入量为2.0%,但相应的压降比率也达到了20.86%。绘制了传热增强因子和压降比率的三维图以及综合影响雷达图,可指导工业应用。

In this study,the fluidized bed heat transfer and fouling prevention technology is applied to the gas-phase heat transfer process in spiral plate heat exchanger,and a gas-solid circulating fluidized bed spiral plate heat exchanger is designed and built.The effects of operating parameters such as air flow rate(80—125 m^(3)·h^(-1)),particle addition(0.5%—2.0%)and particle type on the heat transfer performance and pressure drop of circulating fluidized bed spiral plate heat exchanger using constant temperature water as hot fluid,air as cold fluid and three kinds of solid particles as solid working medium are studied.The experimental results show that the addition of particles can obviously improve the heat transfer performance of the spiral plate heat exchanger,but also increase the pressure drop.Within the range of operating parameters investigated in the experiment,the heat transfer enhancement factor of the best heat transfer enhancement effect can reach 29.28%.At this time,the particles added in the system are polyformaldehyde particles,the air flow rate is 125 m^(3)·h^(-1),and the amount of added particles is 2.0%,but the corresponding pressure drop ratio also reaches 20.86%.The three-dimensional diagrams of heat transfer enhancement factor and pressure drop ratio and the comprehensive influence radar diagrams are drawn which can guide the industrial applications.