超高压超临界流体微型撞击流发生器的机理及性能研究

Grain refining technique has been widely used to high and new technology industry, However research of liquid particles refining technology has still many deficiencies.Researches using ultra-high pressure impinging technology to liquid particles refinement have achieved good effects. However, when loading pressure further rises, the liquid viscosity increasing, the rate of diffusion reducing, make the impact shattered energy decreasing, it can't improve crushing level. In order to effectively solve the technical bottleneck, this project introduces the concept of supercritical CO2 on base of ultra-high pressure impinging technology. Because of the double characteristics of liquid-gas phases, the supercritical CO2 fluid can be applied to ultra-high pressure field and impinging generator of super-small aperture pipe can be used to get more focused energy,strengthens shattered refining effect. First,this project will research thermodynamics characteristic of supercritical CO2 in ultra-high pressure state, Second,research the quantitative relationship between several forces that micron channel play a part in the refinement of crushing under the super-high pressure and establish crushing impact flow model, develop ultra-high pressure supercritical fluid micron impinging stream generator and evaluate its performance on base of it. The project has important significance in order to effectively expand application impact crushing technology under ultra-high pressure applied in engineering .

颗粒细化技术已经被广泛运用到高新技术产业中，然而液态颗粒细化技术的研究仍然存在很多不足。已有研究利用超高压撞击流技术进行液态颗粒细化，并取得较好效果。但研究发现，当加载压力进一步升高时，液体的粘度增大，扩散率降低，使得撞击粉碎的能量减少，无法提高粉碎的级别。为了有效解决这一技术上的瓶颈，本项目试图在现有超高压撞击流技术的基础上，引入超临界CO2的概念。由于超临界CO2流体兼有气液两相的双重特点，因此可以应用于超高压领域以及具有超小孔径管道的撞击流发生器中，强化了流体被粉碎细化的效果。本项目将首先对超临界CO2在超高压状态下热力学特性进行研究，其次研究超高压下微米级别通道对液态物料起粉碎细化作用的几种作用力之间的量化关系并建立撞击流粉碎模型，并在此基础上研制超高压超临界CO2撞击流微米级发生器并对其进行性能评价。本项目对有效拓展超高压撞击流粉碎技术在工程上的应用具有及其重要的意义。

国内外对采用超高压撞击流进行颗粒细化的技术很重视，本研究在此技术的基础上，引入超临界CO2，并进行了深入的研究。研究了超临界CO2在超高压状态下热力学特性，由于超临界CO2流体兼有气液两相的双重特点，因此可以应用于超高压领域以及具有超小孔径管道的撞击流发生器中，强化细化粉碎效果，并取得了一些成果。推导了宏观圆形管内和微尺寸圆管内的速度边界层厚度方程，结合比表面积的计算分析了微尺寸通道中流体的质量传递和动量传递特性，从各个方面得出微尺寸管道对颗粒细化的作用。在理论论证的基础上，研制了不同结构的超高压超临界CO2撞击流微米级发生器并对其进行性能评价，取得了良好的效果。