水合物浆体在直管中的流动换热特性研究

FLOW AND HEAT TRANSFER CHARACTERISTICS OF CLATHRATE HYDRATE SLURRY IN STRAIGHT TUBES

本文实验研究了体积分数为5.0%～20.0%的四丁基溴化铵（TBAB）水合物浆体在内径为6 mm和14 mm的圆直铜管中的流动和换热特性。通过测量浆体的流量和压降得到浆体的流动曲线,采用幂律模型描述浆体的流动特性,得到浆体的本构方程。实验测得的摩擦系数结果与经验、半经验关联式有较好的吻合。在等热流密度加热条件下,测量出加热功率、流速、管壁和流体进出口温度。利用能量守恒计算得出流体的沿程温度变化,由此计算出流体的局部换热系数,并分析了各种因素对换热系数的影响。对浆体局部Nusselt数进行拟合,得到了浆体管内对流换热的经验关联式。

The flow and heat transfer characteristics of tetrabutylammonium bromide（TBAB） clathrate hydrate slurry with 5.0%～20.0%volume fraction in 6 mm and 14 mm straight copper tubes were investigated.Flow curves of clathrate hydrate slurry were obtained by measuring the flow rate and pressure drop.Power law equation was applied to the slurry and the corresponding constructive equation was obtained.The measured flow friction factor was well fitted by the empirical and semi-empirical equations.Heating power,flow rate,temperature of outer tube wall and temperature of fluid were measured under constant heat flux.Slurry temperature along the flow direction was calculated based on energy balance equation,in turn the local heat transfer coefficient was obtained. Effects of influential factors on the heat transfer between the tube and the slurry were analyzed. Empirical correlations for predicting the heat transfer behavior of clathrate hydrate slurry in straight tube was developed based on the experimental data.