饱和地热蒸汽管道长距离水力计算研究

Research on Hydraulic Calculation of Saturated Geothermal Steam in Long Distance Pipeline

地热电厂的设计需考虑饱和地热蒸汽管道的水力计算,这和常规热电厂中过热蒸汽管道的设计有较大区别。从管道散热损失和压力损失入手,对饱和地热蒸汽在管道内流动状态进行定量分析。研究发现,200~250℃是饱和蒸汽的最佳输送温度,此时蒸汽在管道内压降最小,临界比容比最大,安全传输距离最远。研究还指出应选择合适的管径和流速以避免大量疏水的析出,同时又将压降控制在合理范围内。通过对比,基于本研究的水力计算结果与专业计算软件的计算结果以及地热电厂实测数据接近,可在缺少相应计算软件情况下进行饱和蒸汽管道定量分析,并满足工程设计的要求。

The design of geothermal power plant needs to consider the hydraulic calculation of saturated geothermal steam pipeline,which is different from the design of superheated steam pipeline in conventional thermal power plant.In this paper,the flow state of saturated geothermal steam in the pipeline is quantitatively analyzed from the perspective of heat dissipation loss and pressure drop.It is found that 200~250℃is the best temperature for saturated steam flow.It is also pointed out that appropriate pipe diameter and flow rate should be chosen to avoid large amount of hydrophobic precipitation while the pressure drop should be controlled within a reasonable range.By comparison,the results of hydraulic calculation based on this study are close to those of professional calculation software and measured data from geothermal power plant,which can be used for quantitative analysis of saturated steam pipeline in the absence of corresponding calculation software,and meet the requirements of engineering design.