盐穴储气库建腔期边界区域流场的模化实验研究

Experimental Study Using Modeling Theory on Flow Field at Boundary Region of Salt-cavern Gas Storage

为了解盐穴储气库建腔阶段中心管、外管循环流体所产生的对流扩散运动对盐腔壁区域流场速度的影响,运用相似模化原理建立了相似模型,采用粒子图像测速系统(PIV)和Fluent数值模拟软件,对不同条件下建腔阶段的边界附近流场进行测试与数值模拟。结果表明,正循环下,底部边界受到的流体对流扩散的影响要大于侧壁边界,在本模型中对距离盐腔侧壁边界0.2m区域内流场速度影响非常小;反循环下,随外管的提升,对流扩散的主要影响区域发生变化,并且边界区域流体速度也随对流扩散的主要影响区域而变化;在反循环下,缩短外管长度和增大流量都会使得边界区域流体速度增大,但两者主要影响的边界区域范围有所不同。数值模拟和实验得出的结论吻合度较高。本实验结果对提高盐穴储气库建腔效率有一定的参考价值。

In order to reveal the impact of convection diffusion in the circulating fluid between the central and intermediate tube on the flow velocity on salt cavity wall region during establishment of salt-cavern gas storage,analogous model was established by applying the similarity simulation principle,and flow field near the boundary was tested and numericaly simulated by using the particle image velocimetry system(PIV)and the numerical simulation software of Fluent under the different conditions of building cavity.The results show that the impact on the bottom boundary flow field was stronger than that for two lateral boundaries under the positive cycle,the velocity of flow field was little influenced at 0.2maway from wall boundary of salt cavity in this model.With the intermediate pipe ascension,the main in fluencing scope of convection diffusion was changed under the reverse cycle,and flow field velocity of boundary region was changed with the main scope of convection diffusion.Under the reverse cycle,decreasing intermediate tube length and increasing flow could increase flow velocity of boundary region,but the main influences on the scopes of boudary region were different.Several advices improving the efficiency of building cavern in the engineering practice were put forward on the basis of experimental results.The numerical simulation results were in good agreement with the result of PIV test.