气液两相流动及沸腾传热流体模化分析

Fluid-to-fluid modeling method for gas-liquid two-phase flow and boiling heat transfer

基于制冷剂类物质热物性表与水和水蒸气热力性质图表,计算并比较了R12、R22、R123、R134a在相同气液密度比条件下模化水热力过程的能力;应用相似原理与量纲理论分析了流体模化方法在研究气液两相流动特性、高温高压传热过程、临界热流密度现象以及近临界和超临界传热方面的优势与方法。结果表明:制冷剂类物质具有良好的热力性质,其中R134a在相同气液密度比条件下的压力值仅约为水的1/5,而且其臭氧消耗潜能值为0,是环境友好的理想模化流体。提出并探讨了从本质上革新准则数以及基于模型探索新的模化条件和发展新的准则关系式的流体模化技术发展思路。

The capability of refrigerants R12,R22,R123 and R134a for modeling the two-phase flow and heat transfer processes of water was calculated and analyzed according to the thermodynamic property data of refrigerants and water.Fluid-to-fluid modeling method was introduced to model the flow characteristics of gas-liquid two-phase flow,heat transfer under high pressure and temperature,Critical Heat Flux（CHF）,and Supercritical Heat Transfer（SCHT）.It was found that the alternative refrigerant R134a is one of the best modeling fluids due to its excellent environmental and thermodynamic properties.The pressures of R134a are only 20% of those of water under the same liquid-gas density ratios and its Ozone Depleting Potential（ODP） is zero.As the principle of choosing criterion numbers for modeling methods,those having significant influence on the flow and heat transfer phenomenon or consisting of only the fluid physical property parameters should be selected,but those including parameters that can not be measured should be discarded.Suggestions are proposed for improving the fluid-to-fluid modeling method,which includes reforming criterion numbers and originating new modeling conditions and criterion relationships.