高雷诺数下电蓄热锅炉内螺纹管换热计算与分析

Analysis of Heat Transfer Coeffcient of Internal Threaded Tube in Electric Heat Storage Boiler Under High Reynolds Number

以某高校电蓄热锅炉为研究对象,对内螺纹管管内的流动换热情况进行研究分析。在确定内螺纹管的参数的前提下,以空气作为换热介质,选取相应换热经验公式进行计算,并将计算结果与数值模拟结果进行对比分析。结果表明,在4×10^(4)≤Re≤1.6×10^(5)且T=673 K的工况下,由经验公式计算所得的对流换热系数a与模拟结果均有一定误差;采用重庆大学经验计算公式所得的部分数值在工程允许误差范围(±30%)之内,可以获得较为理想的结果。

Taking an electric boiler heat reservoir in a university as an engineering background,the flow heat transfer in the internal threaded pipe of the boiler is studied and analyzed.For the given parameters of the internal threaded pipe,the relevant empirical formula is chosen to carry out the heat transfer calculations with high temperature air as the fluid medium and convective heat transfer coefficient in compared with simulation results of ANSYS FLUENT software.The results showed that the convective heat transfer coefficients a obtained from the empirical formula and simulation under the condition of 4×10^(4)≤Re≤16×10^(5),T=673 K both have a certain errors.But some of the values obtained by using the empirical formula of Chongqing University are within the engineering allowable error range(±30%),thus a relatively ideal result can be obtained.