CAJ | 학술논문

建立微尺度通道流动沸腾换热试验台，采用高速摄像仪对水平微尺度单管（内径0．8mm）内低沸点制冷工质（R32／R134a（25％／75％））气液两相流动特性进行可视化观察研究分析，获得了流型照片。在各种质量流量和进口干度下对工质在微尺度管内的两相流流动特性进行了试验，观察到了各种工况下流型的转化特点，对流型的影响因素进行分析。试验工况为：质量流量G=760～10360kg／（m2．s1，进口干度x=0．01～0．77。实验结果表明：在较高的质量流量工况下，工质在微尺度单通道内的流型比较单一，主要呈气状流／雾状间隔流动。在进口质量干度较低的情况下，也会出现比较明显的环状流，但液膜总处于波动状态，有不稳定现象。无论什么工况，均没有出现像常规通道内的分层流动现象。·
건립미척도통도류동비등환열시험태，채용고속섭상의대수평미척도단관（내경0．8mm）내저비점제랭공질（R32／R134a（25％／75％））기액량상류동특성진행가시화관찰연구분석，획득료류형조편。재각충질량류량화진구간도하대공질재미척도관내적량상류류동특성진행료시험，관찰도료각충공황하류형적전화특점，대류형적영향인소진행분석。시험공황위：질량류량G=760～10360kg／（m2．s1，진구간도x=0．01～0．77。실험결과표명：재교고적질량류량공황하，공질재미척도단통도내적류형비교단일，주요정기상류／무상간격류동。재진구질량간도교저적정황하，야회출현비교명현적배상류，단액막총처우파동상태，유불은정현상。무론십요공황，균몰유출현상상규통도내적분층류동현상。·
The test rig on heat transfer for flow boiling in a single microchannel with a diameter of 0.8 ram, was designed and the flow characteristics of gas-liquid two-phase of refrigerant （R32/R134a （25%/75%）） with low boiling point in a single microchannel was observed by using a high-speed photographic instrument. The photos of flow patterns were got. Experiments were performed to observe the conversion characteristics of flow pattern in various working conditions, and the influence factors on flow patterns were analyzed. The working conditions of the present study are： mass flux G=760-10360 kg/（m2.s） and quality x=0.01-0.77. The results show that under the high mass flux condition, the flow patterns of working fluid flowing in microchannel are singular and the bubbly flow or fog flow are dominant. For the condition of low inlet quality of refrigerant, annular flow appear clearly, but the liquid film is unstable. The stratified flow existing in conventional tubes has not been appeared in any conditions in the horizontal single microchannel.