碳氢燃料变压力过程中传热研究

Heat Transfer of Hydrocarbon Fuel During Transient Pressure

关键词:  碳氢燃料  压力  传热  动态特性

Key words:  Hydrocarbon fuel  Pressure  Heat transfer  Dynamic characteristics

摘要:

碳氢燃料广泛应用于再生冷却技术中，为了研究其在不同压力下和压力变化过程中的传热规律，使用内径1mm圆管进行了变压力过程实验。试验参数:冷态流量1g/s，流体出口温度500℃，压力1～4MPa。在不同压力稳态的传热试验中发现了两种类型的传热恶化:亚临界下的膜态沸腾和超临界时的入口层流化。研究了变压力时的传热特性，重点分析了不同换热区域的外壁温动态变化，发现了变压力过程中的壁温非单调特性，在超临界压力下动态变化时的传热弱于稳态的传热。实验中还研究了三种不同升压速率对换热的影响，结果显示压力变化速率对传热影响不大。

Abstract:

Hydrocarbon fuel is widely used in the regenerative cooling technology. To investigate heat transfer characteristics of the fuel at different pressure and during transient pressure，a mini circular tube with 1mm inner diameter was employed to conduct pressure changing experiments. Mass flow rate was 1g/s，outlet fluid temperature was 500℃，and pressure was changed from 1 to 4MPa. Firstly，heat transfer under different steady states was studied. Results show that two kinds of heat transfer deterioration appear: film boiling happens at subcritical pressure and inlet flow laminarization occurs at supercritical pressure. Then the dynamic changes of outside wall temperature in different heat transfer regions during transient pressure was analyzed. Results indicate that wall temperature does not change monotonically and heat transfer is worse than that under steady states at supercritical pressure. Pressure transients at three different rates were also carried out，there are neglectable effects on the variations of outside wall temperature.