为了研究超临界CO2螺旋槽管内的流动换热特性，本文首先在入口温度323.15 K、入口压力8.0 MPa、入口雷诺数35 000、总热量4 200 W的条件下对不同结构参数的螺旋槽管进行了数值计算，分析了各参数对换热系数及流动过程的影响，并根据换热评价因子，得到了最优螺旋槽管结构(管槽半径r1为6.5 mm，管槽圆角r2半径为2.0 mm，管槽槽深e1为5.5 mm，套管间距e2为1.0 mm，螺旋角w为0.70 rad)。在此基础上，实验研究了不同压力、不同入口雷诺数对换热系数的影响，得出其影响机理。分析换热系数的影响因素，并结合数值计算和实验数据，建立了超临界CO2螺旋槽管内冷却换热关联式，并对实验数据进行了预测计算。结果表明，预测值与实验值的平均绝对值偏差为11.65%，最大绝对值偏差不超过25%，证明了其具有较好的准确性。

To study the heat transfer and flow characteristics of supercritical CO2 in the spirally fluted tubes,the numerical calculation of the spirally fluted tubes with different geometric parameters at inlet temperature of 323.15 K,operating pressure of 8.0 MPa,inlet Reynolds number of 35 000 and total heat of 4 200 W was presented,the effects of various parameters on heat transfer coefficient and flow process were analyzed in this paper,and the optimal structure of spirally fluted tubes was obtained according to the heat transfer evaluation factors(the radius of the groove r1of 6.5 mm,the radius of the fillet r2 of 2.0 mm,the depth of the groove e1 of 5.5 mm,the space between the main tube and the outer sleeve e2 of 1.0 mm,and the helix angle w of 0.70 rad).On this basis,the effects of different pressures and inlet Reynolds numbers on the heat transfer coefficient were studied experimentally,and its impact mechanism was obtained.Thecorrelation of the cooling heat transfer of supercritical CO2 in the spirally fluted tubes was established,which was used to predict on the test data,by analyzing the influence factors of heat transfer coefficient and combining with numerical calculation and experimental data.The results show that the average absolute value deviation between the predicted value and experimental value is 11.65%,and the maximum absolute value deviation is not more than 25%,which proves the accuracy of the method.

TK124

超临界CO2；螺旋槽管；冷却换热；结构优化；关联式