The application of supercritical fluids as an alternative heat transfer medium in thermal processes is becoming increasingly important, whereby the understanding of their pressure drop characteristics is essential for the process and component design. With a total of 96 experiments, this publication shows a systematic analysis of the pressure drop of CO2 flow at supercritical pressures in a heated smooth pipe with an inner diameter of 4 mm, at a pressure of 7.75 MPa, mass fluxes up to 2000 kg/m2s and heat fluxes up to 235 kW/m2. The hydrostatic pressure drop accounts for between 4 % and 24 % of the total pressure drop and the pressure drop due to flow acceleration for between 12 % and 30 %, with the frictional pressure drop accounting for the largest percentage. It was found that the Filonenko correlation can predict the pipe friction pressure drop in the investigated parameter range with a mean absolute deviation of 7 %.

中文翻译：

---

不同取向加热的 4 mm 光滑管中 CO2 流动在超临界压力下压降的实验研究


超临界流体作为热过程中的替代传热介质的应用变得越来越重要，因此了解其压降特性对于工艺和组件设计至关重要。本出版物总共进行了 96 次实验，系统分析了内径为 4 mm、压力为 7.75 MPa、质量通量高达 2000 kg/m2s 和热通量高达 235 kW/m2 的加热光滑管中 CO2 流动在超临界压力下的压降。静水压降占总压降的 4 % 至 24 %，流动加速引起的压降占 12 % 至 30 %，其中摩擦压降所占比例最大。发现 Filonenko 相关性可以预测所研究参数范围内的管道摩擦压降，平均绝对偏差为 7 %。