鼓泡式烟气脱硫原理性试验台气体流动冷模试验

Cold Model Tests of Gas-liquid Flows in a Wet Bubbling Flue-gas Desulfurization Test Rig

描述了鼓泡式烟气脱硫原理性试验台气体流动冷模试验及结果。试验发现 ,对管外喷射 ,三种试验管型中底端封口的喷射管鼓泡层高度和压力降的变化都非常稳定 ;对管内喷射 ,随喷射速度和喷射管插入深度的变化 ,喷射器压力降波动很大 ,很不稳定。因而建议工程应用时采用管外喷射。采用PIV仪器对底端封口喷射管管外喷射的速度场进行测定 ,试验发现 ,在气液充分混合区域内 ,气泡的运动轨迹非常复杂 ,形成大量的涡团 ,气液剧烈扰动 ;在速度超过 16m/s ,涡团主要存在管壁附近 ,中间气体形成腾涌 ,对气液接触非常不利。

Cold model tests and test results are described of gas-liquid flows in a wet bubbling flue-gas desulfurization test rig. Through the tests it is found that with regard to tube-outside jets the variation of injection pipe bubbling layer height and pressure drop at a bottom seal in three kinds of test tubes is very stable. As for tube-inside jets the injector pressure drop fluctuates dramatically with the change of injection speed and insertion depth of the jet pipe, thus being regarded as very unstable. In view of the above it is recommended to employ tube-outside jets for engineering applications. Measurements were taken of the jet velocity field of jet pipe tube-outside injection at a bottom seal with the use of a PIV (particle imaging velocimetry) instrument. It was discovered that in a gas-liquid fully mixed zone the motion trajectory of the gas bubbles are very complicated with a large quantity of vortex groups being formed accompanied by an intensive perturbation of gas-liquid. When the speed is in excess of 16 m/s, the vortex groups mainly appear in the neighborhood of tube walls and the intermediate gas-liquid assumes the form of surge waves, which is very unfavorable for gas-liquid contact.