科研之友
微信
新浪微博
Facebook
分享链接
摘要
In order to study the effects of electric and ultrasound fields on bubble characteristics and heat transfer performance of flow boiling in microchannels, heat transfer experiments of refrigerant R141b under different fields were studied. Quantitative research on bubble characteristics was carried out through topological analysis of high-speed photography, where the first Betti number ￡i indicates the number of bubbles and the zeroth Betti number ￡o indicates the number of confined bubbles. The results show that 400, 600, 800 V electric fields increase 四 by 23.3%, 36.3%, 43.1% and decrease 夕o by 13.6%, 19.6%, 23.2%, respectively, which indicates that electric fields significantly increase the number of bubbles and decrease the number of confined bubbles. The heat transfer enhancement ratio reaches its peak at 1.56 under 800V electric field. Moreover, ultrasound fields (23, 40 kHz in frequency and 12.5, 50 W in power) increase by the range of 22.7% to 55.6% and decrease So by the range of 12.8% to 25.8%, respectively, which indicates that ultrasound field also increases the number of bubbles and decrease the number of confined bubbles. The enhancement ratio reaches its peak at 1.79 under 23 kHz, 50 W ultrasound field. Furthermore, the improvement of bubble characteristics and heat transfer performance were more obvious when two types of fields were collaboratively applied. ? 2023 Zhejiang University.
- 单位
