DSG吸热管内插入扭带的汽水动力学数值模拟

Numerical simulation for steam and water dynamics in absorber tubes with twisted-tape insert of DSG system

文章使用欧拉多相流模型对插入扭带后的DSG吸热管的汽水动力学特性进行数值模拟。该数值模型充分考虑了DSG吸热管表面上非均匀热流密度的影响。基于此,文章分析了当吸热管内两相区插入扭带后,管内的汽水两相分布情况、壁面温度以及壁面温度梯度等。研究结果表明:y=4扭带扰乱了吸热管内的分层流型,这使得吸热管内蒸汽分布更为均匀;插入y=4扭带使得DSG吸热管管壁周向温度与温度梯度相对减小,吸热管周向壁面的最大温差减少33.3%;插入y=4扭带使得吸热管周向角度θ=120°处的壁面径向温差减少35.9%,径向最大温度梯度减少74.1%,壁面温度分布更加均匀。

Numerical simulations were conducted to investigate the steam and water dynamics in absorber tubes with twisted-tape insert of DSG system in the Eulerian multiphase flow model. The numerical model took the effect of non-uniform heat flux on the surface of DSG absorber tube into account, analyzed the distribution of steam and water, wall temperature and gradient of wall temperaturein absorber tubes with the twisted-tape inserted. The results show that： the distribution ofthe steam and water is relatively uniform, disrupting the stratified flow patterninabsorber tubeswith twisted-tape insert. Both the circumferential wall temperature and gradient of wall temperature all decreases, and the circumferential wall temperature decreased 12.8%. The radial wall temperature and radial gradient of wall temperature decreased 14.4% and 30.9%, respectively, at thecircumferential angle=120 °, the distribution ofthe wall temperaturebemore uniforminabsorber tubeswith twisted-tape insert of DSG system.