转炉复吹用等截面有摩擦绝热管流属性研究

Airflow properties of constant cross section heat insulation pipe with friction for combined blowing converter

为了优化氧气转炉复吹技术,有必要了解等截面管有摩擦绝热流的空气动力学性质。采用钢管束测量气流的关键参数(压力P、流量Q和推力F等),结合理论分析,得到表征沿管道流动方向和管道出口的有摩擦绝热管流的性质的数据(马赫数M、速度V、温度T、密度ρ、弗鲁德准数Fr、熵增ΔS、喷吹效率η和边界层厚度δ等)。测量的主要参数和所用钢管可满足转炉透气砖的设计。研究底吹气流与熔池作用和制定复吹工艺制度,为发展复吹技术提供了必要的基础数据。本实验是国内首次系统、全面地对透气砖用等截面管有摩擦绝热流进行研究,所采用的管束方法可以简化实验设备和减少测试数据的系统误差。同时提出了根据钢管尺寸和等截面绝热流的喷吹效率来计算边界层厚度的公式。

In order to optimize combined blowing technology of oxygen converter, it is necessary to understand the aerodynamic properties of the isothermal tube with frictional adiabatic flow. The key parameters of the gas flow(pressure P, flow Q and thrust F, etc.) are measured by using steel pipe bundles. Combined with theoretical analysis, a series of datum(Mach number M, velocity V, temperature T, density ρ, Froude′s number Fr, entropy increase ΔS, blowing efficiency η, boundary layer thickness δ, etc.) can be obtained to characterize the properties of frictional adiabatic tube flow along the direction of pipe flow and pipe exit. The main measured parameters and the used steel pipes can meet the requirements of the design of converter permeable element. The study on interaction between the bottom blowing air flow and the molten pool, and the formulation of the combined blowing process provide necessary basic data for the development of combined blowing technology. This experiment is the first domestic research to systematically and comprehensively study the frictional adiabatic flow of pipes with cross-sections for air-permeable bricks. The used tube bundle method can simplify the experimental equipment and reduce the systematic error of the test data. A formula for calculating the thickness of the boundary layer is proposed based on the size of the steel pipe and the injection efficiency of the adiabatic flow of constant cross section.