锅炉管组集箱静压分布的离散模型

A Discrete Model for the Pressure Distribution in Boiler Manifolds

集箱中的静压分布是计算诸如过热器和再热器锅炉管组流量分配的关键。由于集箱中的流动情况十分复杂，在目前的计算方法中，采用连续模型来简化静压分布。一种方法是用一条简单的抛物线静压分布曲线；另一种方法是假定一条连续的长槽来代替集箱上离散的支管。该文通过理论分析和实验结果的比较，指出这些连续模型存在的问题，并通过沿集箱长度有支管和无支管的实际情况列出的动量方程得出离散模型下的静压分布。离散模型的计算结果和实验数据吻合很好。

The knowledge concerning the static pressure distribution in headers is the most crucial for the proper calculaiton of flow distribution in boiler manifolds of such components as superheaters and reheaters. Since the flow conditions in headers are rather complex, the simplified continuous static pressure distribution models are employed in current calculations. One model assumes a simple parabolic static pressure distribution and another supposes a continuous long slot to replace the discrete branch tables on the header. With the help of theoretical analysis and test results, this paper points out the inadequacy of continuous models and gives the momentum equation for the actual cases where there are and also where there are no branch tubes distributed along the header's length and herewith the static pressure distribution calculated with the discrete model. Calculation results with discrete model agree quite well with test data.