基于响应面法的上游泵送机械密封优化

为了找出更有效的优化方法,在考虑空化模型的基础上,以螺旋槽的几何参数(槽深h、螺旋角α、槽径宽径比β以及槽区宽度比γ)为设计变量,以泄漏量为优化目标,采用均匀试验设计法设计了50组机械密封端面槽型几何参数值,并利用CFD方法计算目标函数值,从而建立端面槽型几何参数和泄漏量的回归模型.运用Matlab软件绘制等值云图,利用响应面法分析端面槽型几何参数槽深、螺旋角、槽径宽径比以及槽区宽度比之间的交互作用对泄漏量的影响,并对机械密封微间隙内流场进行数值模拟验证,从而得到端面参数的最佳组合.研究表明:采用响应面法对上游泵送机械密封进行优化可行;螺旋槽的槽深h、螺旋角α、槽径宽径比β、槽区宽度比γ分别在6~12 μm,16°~20°,0.35~0.55和0.45~0.6取值时,能够获得更好的密封性能.

Study on optimization of upstream pumping mechanical seal based on response surface method

To achieve a more effective optimization method for upstream pumping mechanical seals, based on cavitation model, the spiral groove geometrical parameters, such as groove depth h, spiral angle α, groove diameter ratio β and groove width ratio γ are considered as the design variables and the leakage through the seal is used as the objective function. Then, 50 mechanical seals are designed by means of uniform experimental design method, and the values of objective function are calculated by CFD to establish regression models of the objective function with respect to these variables. The response surface method is used to analyze the interaction of between the design variables and their effects on the leakage by making use of the leakage contours generated in MATLAB. Consequently, the optimal ranges of the design variables are determined. The fluid dynamics in three seals with design variables in the optimal ranges is simulated to decide the optimal combination of the design variables. It is confirmed that it is feasible to use the response surface method in upstream pumping mechanical seal optimization. When the groove depth h, spiral angle α, groove diameter ratio β and groove width ratio γ are in range of 6-12 μm, 16°-20°, 0.35-0.55 and 0.45-0.6, respectively, the mechanical seal performance is even better.