冷却塔管式配水系统配水计算新方法

New Calculation Method of Piped Water Distribution in Cooling Tower

冷却塔配水系统的配水计算是一项不可或缺的设计计算工作,目前常用的计算方法是基于经典伯努利方程和连续性方程的一维水力计算方法,该方法需要求解大型联列方程组,故其计算工作量很大。提出了一种将单根配水管等效简化为一个水阻元件的新方法,并通过理论推导,建立了该水阻元件的等效阻力系数计算公式等相关数学模型,利用该模型,整个配水系统即可简化为仅由配水干管和若干水阻元件组成的简单水力系统,其各配水管优化计算即成为各水阻元件的优化计算,从而将系统整体优化与各配水管局部优化成功解耦。工程算例验证表明,该新方法与目前常用方法的计算结果非常吻合,能满足工程设计要求,且其模型简单、编程方便、计算工作量大幅减小,可以在今后的工程设计中推广应用。

The calculation of water distribution in the cooling tower is an indispensable procedure for its design. However,the current one-dimensional hydraulic calculation method based on the Bernoulli equation and the continuity equation needs to solve large-scale set of equations,which consumes a large quantity of work. In view of this,a new method simplifying a water distribution pipe as a water resistance unit was proposed,and the mathematic model for the calculation of the equivalent resistance coefficient of the water resistance unit was built. By applying the model,the water distribution system could be simplified as a simple hydraulic system which consists of a main pipe and several water resistance units. This turned the optimal calculation of the pipe into the optimal calculation of the water resistance unit so as to successfully decouple the global system optimization with the pipe local optimization. The validation of the proposed method in an engineering example showed that the calculation result of the proposed method was consistent to that of the current method,which could satisfy the design requirement. In addition,as the model is simple and convenient to program,which can significantly reduce workload,it is worth being applied in the future projects.