Abstract:

A measuring system using compressed air as the working fluid was built in order to verify the flow resistance uniformity of the helical tubes of the experimental assembly for the high temperature gas-cooled reactor (HTGR) steam generator. The influence of the compressibility of compressed air on the measurement accuracy was carefully discussed. Two data reduction methods with linear average and integration were proposed, and the accuracies of the two methods were compared. Acceleration pressure drop should also be considered during data reduction, and its influence was analyzed under different working conditions. The accuracy and repeatability of the measuring system were first verified using a smooth straight tube and corresponding correlation. Then the flow resistances of the 9 helical tubes of the 5th layer of the experimental assembly were measured. The results show that the maximum relative deviation of friction factor among the 9 helical tubes is 5%. The main cause of the deviation comes from the deviation of the tube inside diameters. The flow transition Reynolds number of helical tubes is different from that of straight tubes. The flow transition Reynolds number of the 5th layer helical tubes of the experimental assembly is about 6000.

Key words: high temperature gas-cooled reactor, steam generator, helical tube, friction factor

摘要：

为验证高温气冷堆蒸汽发生器实验本体螺旋管流动阻力的一致性，搭建了以压缩空气为工质的阻力测量系统。详细探讨了空气可压缩性对阻力测量准确性的影响。提出了线性平均法和积分法两种数据处理方法，且数据处理过程中需要考虑动压修正。对比分析了两种数据处理方法的准确性，分析了不同工况下动压修正对测量结果的影响。用光滑直管经验公式验证了测量系统及数据处理方法的准确性及重复性。然后对蒸汽发生器实验本体第5层共9根螺旋管的阻力进行了测量，结果表明9根螺旋管间阻力系数相对偏差最大为5%。经过对不同影响因素进行分析，结果认为主要影响因素为管内径偏差。螺旋管内层流向湍流的转捩雷诺数与直管不同，高温气冷堆蒸汽发生器实验本体第5层螺旋管的层流向湍流的转捩雷诺数约为6 000。

关键词: 高温气冷堆, 蒸汽发生器, 螺旋管, 阻力系数