DCS中凝结水密度的一种简化计算方法

One Simplified Method for DCS Feedwater Density Calculation

DCS中凝结水流量计算中,通常需要进行凝结水密度的修正。由于水物理特性的复杂性,密度与温度及压力均直接相关。采用国际汽水性质IFC公式计算,由于其复杂性DCS中并不采用;采用查表方法需要输入大量数据,不便于DCS中采用。介绍了一种基于基准工况水密度,并对实际运行压力、温度分别进行修正的凝结水密度计算方法,并对其误差进行了计算。结果表明,计算精度及误差可以满足现场应用要求。

Condensate water density correction is usually made in the DCS condensate water flow calculation.Density is both related to medium temperature and pressure due to the complexity of the water physical characteristics.Both the IFC equation calculation method and the table data looking-up method are not suitable for application in DCS.A new condensate water density calculation method was introduced,which considered the density of the baseline operation condition,and corrected actual operation pressure and temperature separately.Tolerance was analyzed for this calculation method,and it’s proved that the calculation accuracy and tolerance can meet the site application requirement.