非均匀加热波纹管内高温三元氟盐的传热研究

Study of Heat Transfer Characteristics of High Temperature Ternary Fluoride with inhomogeneous Heating in Corrugated Tube

为了分析波纹管对高温熔盐传热工质的强化传热效果,选用三元氟盐高温熔盐为研究对象,对比分析了三元氟盐在光管和波纹管内的对流传热性能,并研究了熔盐速度、非均匀热流密度对其传热性能的影响。数值模拟结果表明,波纹管比光管具有更好的对流传热性能。另外,模拟分析了当量直径相同、波深波距比不同的五种波纹管中三元氟盐的传热性能,结果表明波纹管的波深波距比和雷诺数都对传热性能有着显著的影响。在一定范围内三元氟盐在波纹管内的对流换热系数随着雷诺数的增大而增大,当波深/波距比高于0.2时,对流换热系数开始减小,可以得到当波纹管的波深/波距比值在0.2左右时波纹管的对流换热系数可以达到一个相对较优的值。

To study the effect of corrugated tube to the property of melting fluids in heat transfer with high temperature, ternary fluoride was selected as the object, its heat transfer performances in smooth tube and in corrugated tube were analyzed and compared, also the effects of salt melting rate and inhomogeneous heat density to the heat transfer performance were studied. It was shown from the results of simulation that convection heat transfer in corrugated tube is better in smooth tube. In addition, in five corrugated tubes with the same equivalent diameter but different corrugation distances, the heat transfer performance of ternary fluoride was simulated, and it was that both the ratio of corrugation depth to its distance and Reno number has remarkable influence in heat transfer. To some extent, the convection heat transfer factor of ternary fluoride will increase with the upward of Reno number. But when the ratio of the depth of corrugation to its distance is greater than 0.2, the convection heat transfer factor starts reduction. Thus it can be concluded that the convection heat transfer factor of corrugated tube will reach the relative optimum value when the ratio of the depth of corrugation to its distance is around 0.2.