蒸汽管道孔口泄放流量工程计算方法探究

Research on Engineering Calculation Method for Flow of Steam Pipes Discharge Orifice

常用的蒸汽管道孔口泄放流量计算方法是借助喷管流量计算公式,公式中的进口蒸汽比体积需借助蒸汽热力性质表换算,且低过热度时绝热指数采用经验值,得到的计算值与实际有偏差,此外,传统计算式的形式较为繁琐,这些因素在一定程度上影响了其在工程中的使用。为满足工程需求,完善蒸汽管道孔口泄放流量的工程计算方法,推导出一个适用于蒸汽状态、压力参数多变,便于工程设计分析的更为简便、准确的孔口泄放流量工程计算式,式中涉及的蒸汽状态参数易于测试,采用的温度修正因子则提高了公式在低过热度下使用的准确性。同时,结合工程实例,分析此计算式的使用情况,并认为,完善后的蒸汽管道孔口泄放流量计算式将在蒸汽管道孔口泄放问题中有更为广泛的应用。

Common method of flow calculation for orifice of steam pipe is the use of the flux formula of tapered nozzle, the volume per kilometer of inlet-steam can be got by thermodynamic properties of steam, and there will be mistake between calculated and actual values, when using experiential adiabatic index at low superheat temperature, in addition, the traditional flux formula is complex, to some extent, these factors affect their use in engineering. To meet the project requirements and improve the flow of steam pipes discharge orifice engineering calculation method, the paper deduces a flux formula that is suitable for variable state and pressure of steam, and simpler and more accurate. The vapor state parameters involved in the formula are easier to test, and the temperature correction factor used in the new formula improves the accuracy. Meanwhile, the use of the formula combined with engineering example is analyzed in this paper, and it will be widely used in the steam orifice discharge problems.