The Study On The Mechanism Of Enhancement Of Supercooled Water Crystallization By Power Ultrasound

Ice storage power as a peak load shifting technology in today’s society, it has an important practical significance in reasonable allocation and use of energy and ease the electricity supply-demand balance. Ice making process can be divided into two major categories of static and dynamic. Dynamic ice can greatly reduce energy consumption, and the system out of the ice slurry storage density and good heat transfer performance. It is today’s most has the development prospects of ice making technology. The formation of initial nucleation is random in Water too cold crystallization process. Ultrasonic wave can form ahead of supercooled water is greater than the critical size of the nuclei, lift the supercooled state and decrease the crystallization degree of supercooling. Therefore studied the mechanism of action of ultrasound cold crystallization dynamics, and explore more efficient methods of ice, ice slurry preparation to achieve a breakthrough technology, it has an important scientific significance and value in improving the efficiency of dynamic ice storage system, the stability and energy efficiency.This article introduces the basic theory of ultrasonic and mechanism of action. Summarized the research progress of ultrasonic influence nucleation and growth of ice crystals. Establishing bubble floatation motion equation and analysis the bubble floatation process of all kinds of mechanical impact factor on its movement and focusing on the bubble size when plus ultrasonic role change rule and the effect of ultrasound on bubble floating movement. Based on population balance crystallization theory, simulate the supercooled water dynamic crystallization process. Analyzed the wall temperature and flow rate on the crystal size and the influence of grain number density. On the building under the action of ultrasonic supercooled water dynamic crystallization microscopic test bench, has observed under the action of ultrasonic cavitation bubble is generated and the micro process of the movement. The particle size are mainly distributed in the range of50-100microns. The existence of the bubble induced the heterogeneous nucleation of supercooled water under the ultrasonic action. The ultrasonic has a significant impact on the crystallization of supercooling water degree. Through the experimental analysis of the presence of ultrasonic action, different cooling rate and the different samples supercooled water dynamic crystallization process. Obtained the cooling curve of water and the images of ice nucleation growth process. The experimental results show that ultrasonic not only can improve the crystallization degree of supercooling of water and can effectively refine the grain size.