Method for controlling size of boiling liquid bubbles

Abstract

The invention relates to a method for controlling size of boiling liquid bubbles. The method specifically includes that (1) when a magnetic field generating device generates a gradient magnetic field of which a gradient direction and a gravity direction are the same, a magnetic force is exerted on boiling liquid, the direction of the magnetic force and the gravity direction are the same, at the moment, bubble desorption size is reduced due to combined action of a resultant force, bubbles are rapidly subjected to desorption from a heating surface, and the boiling heat transmission efficiency is increased; the bubble desorption size is smaller and the boiling heat transmission efficiency is higher with the increasing of gradient of the gradient magnetic field; (2) when the magnetic field generating device generates a gradient magnetic field of which the gradient direction and the gravity direction are opposite, a magnetic force is exerted on the boiling liquid, the direction of the magnetic force and the gravity direction are opposite, at the moment, bubble desorption size is increased due to combined action of the resultant force, desorption of the bubbles from the heating surface slows down, and the boiling heat transmission efficiency is reduced; the bubble desorption size is larger and the boiling heat transmission efficiency is lower with the increasing of gradient of the gradient magnetic field. According to the method for controlling size of the boiling liquid bubbles, wide scientific and applicable values can be achieved in terms of fields of heat exchangers, cooling loops and energy conversion.

Description

technical field [0001] The invention relates to a method for controlling the bubble size of liquid boiling. Background technique [0002] Boiling generally refers to a violent heat transfer phenomenon that occurs at the solid-liquid interface and is accompanied by a large number of bubbles. It is a complex phenomenon in which fluid mechanics, heat transfer, mass transfer, and interface phenomena are intertwined. This process occurs when the temperature of the heating surface exceeds the saturation temperature of the liquid at system pressure. The boiling of a liquid is a convective heat transfer accompanied by a phase change process. When the superheated wall liquid changes from a liquid phase to a gas phase, it absorbs a large amount of latent heat of phase change, so the heat transfer coefficient of boiling heat transfer is much higher than that of single-phase heat transfer. This means that the boiling heat transfer process can remove a large amount of heat from a superh...

AI Technical Summary

Problems solved by technology

The desorption size of the bubbles is affected by the combined effects of buoyancy and surface tension, so far there is no good way to control the size of the desorption bubbles

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