CAJ | 학술논문

微通道沸腾不稳定性降低设备运行性能及传热特性。设计入口集成种子汽泡发生器的三角形硅基微通道热沉。搭建同步光学可视化测量实验台。研究加热膜长度、质量流量及种子汽泡触发频率对微通道内沸腾不稳定性及传热影响。结果表明：加热膜长度和质量流量作为控制沸腾不稳定性的关键参数，加热膜长度越长或质量流量越低，沸腾起始点和临界热流密度越早发生。单相液体区域，热流密度增大，压降略微降低，温度线性升高。汽液两相区域，热流密度增大，压降迅速增大，温度呈指数式上升。触发种子汽泡作为一种主动式控制技术，沸腾不稳定性得到抑制或消除，换热得到显著增强，是一种值得推广的技术。
미통도비등불은정성강저설비운행성능급전열특성。설계입구집성충자기포발생기적삼각형규기미통도열침。탑건동보광학가시화측량실험태。연구가열막장도、질량류량급충자기포촉발빈솔대미통도내비등불은정성급전열영향。결과표명：가열막장도화질량류량작위공제비등불은정성적관건삼수，가열막장도월장혹질량류량월저，비등기시점화림계열류밀도월조발생。단상액체구역，열류밀도증대，압강략미강저，온도선성승고。기액량상구역，열류밀도증대，압강신속증대，온도정지수식상승。촉발충자기포작위일충주동식공제기술，비등불은정성득도억제혹소제，환열득도현저증강，시일충치득추엄적기술。
Flow boiling instabilities in microchannel can reduce the performance of equipment operation and disturb the heat transfer characteristic. The parallel triangle silicon microchannel heat sink was integrated with seed bubble generators in the microchannel upstream. The simultaneous optical visualization measurement experimental systems were set up. The flow boiling instability and heat transfer under different heater lengthes, mass fluxes and seed bubble frequencies were examined. The results show that, the heater length, heat and mass flux were identified as the key parameters to the boiling instability process. Longer heater length or lower flow rate induces earlier appearance of boiling incipience and critical heat flux. With heat flux increasing, the pressure drop decreases slightly and the temperature increases linearly in the single liquid phase region. However, the pressure drop increases sharply and the temperature increases exponentially in the vapor-liquid two phase flow region. Using triggering the generation of seed bubbles as the active controlling technic, the self-sustained boiling instability can be effectively controlled or fundamentally eliminated. Moreover, the heat transfer could be enhanced markedly. The seed bubble triggered technology is worth to be promoted.