Research Of Ultrasonic’s Influence On Water Freezing And Ice Unloading

During the freezing of the solution,ultrasonic has the advantages of reducing the subcooling degree of the initial nucleation and promoting the secondary nucleation.However,there are few research on ultrasonic effect on water freezing rate.In the process of ice-making and ice storage,accelerated freezing rate has important practical significance and economic value.Especially in the ice storage industry,accelerated freezing rate can make full use of the period of electricity troughs;In view of the disadvantages of the current ice machine in the process of ice-making and ice unloading,it is argued a technique of ultrasonic to ice unloading,and explored the feasibility of using ultrasonic ice unloading.Ultrasonic ice unloading has the advantages of improving the hygienic quality of ice and reducing the secondary energy consumption.Around the two aspects of ultrasonic’s influence on water freezing and ice unloading,the following works have been done in this paper:(1)The thermodynamics conditions of the formation of ice nucleation and ice crystal growth were discussed;The growth rate of ice layer and the mechanism of ultrasonic action on water freezing were summarized and analyzed.(2)In this paper,ultrasonic is applied in the process of water freezing,and the effect of different power ultrasonic is compared.The results show that ultrasonic can accelerate the freezing rate of water.Under 45W(40kHz)conditions,accelerated the freezing effect is best,the water completed freezing time ahead of 16 min.(3)Based on the theoretical analysis,by using finite element analysis software ANSYS,coupling filed calculation was done on iced plate.Got the ice plate stress nephogram and stress value of each nodes,compared with the maximum adhesion stress of ice in the ice plate 0.85 MPa,ultrasonic ice unloading is theoretically feasible.(4)On the basis of the simulation calculation,the experiment study on ultrasonic ice unloading was carried out.When application of ultrasonic was about 165 s,the ice in the other parts was removed from the ice trays besides some ices in the corner of plate,which verified the feasibility of ultrasonic ice unloading.However,the experiment produced some water in the process of ice unloading.The production of water is not conducive to the storage of ice and some ice structures are destroyed,so the ultrasonic application of ice unloading need to further explore.