Thermal Performance Analysis of Ice Thermal Storage Device Based on Micro Heat Pipe Arrays: Role of Bubble-Driven Flow

In this paper, bubble-driven flow mechanism is applied to an ice thermal storage device based on micro heat pipe arrays. A visual experimental system is established to investigate the effect of bubble-driven flow on the performance of proposed device. The temperature distribution of water/ice, charging/discharging time, charging/discharging power, real-time phase change behaviors and phase change rate without bubble injection and at different bubble flow rates are compared. Based on without bubble injection, the temperature uniformity are significantly promoted by 57.14% and 56.07% in the sensible heat charging/discharging stage, while the improvement of the latent heat charging/discharging stage is not obvious. In addition, the negative effect of bubble-driven flow in the latent heat charging stage is greater than the positive effect in the sensible heat charging stage, thereby the charging time increases by 19.46%, and the charging power decreases by 17.91%. However, bubble-driven flow is positive for the entire discharging process, especially for the latent heat discharging stage, bubbles boost the decomposition of ice layer, the discharging time decreases by 20%, and the discharging power raises by 31.07%. Therefore, the operation strategy of turning on bubble driven-flow during the discharging process and turning it off during the charging process is recommended.