JPS61225590A - Heat transferring rate regulator utilizing electric field on high-performance boiling surface - Google Patents

Abstract

PURPOSE:To promote and to regulate the heat transfer rate on a high-performance boiling surface,and to make the design of a boiling surface easy and simple, by molding a number of ruggedness on the surface, by providing a mesh electrode which promotes boiling in the face of a high-performance boiling surface, and by applying high voltage across the boiling surface and the mesh electrode. CONSTITUTION:A mesh electrode 12 consisting of conductive fine wire 11 is provided in the face of a high-performance boiling surface 1 having a slight gap between them. Being the boiling surface 1 as an electrode on one side, high voltage is applied across the surface 1 and the electrode 12. In the part A under the fine wire 11 of an electrode 12 on the boiling surface 1, bubbles 4 are forcibly taken away from the surface 1 by an electric field, and foaming is promoted as shown by foamed bubbles 5 in the figure. While in the part B except the under part A, fluid drips down spontaneously as shown by arrow signs M. The heat transferring rate on the boiling surface 1 can be arbitrarily regulated, since the boiling surface 1 can artificially be divided by the electrode 12 into the part A for foamed bubbles 5 and the part M along which fluid will spontaneously drip down. The heat transferring rate also can be controlled by changing the promoting rate of foaming by making the applying voltage variable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for adjusting the amount of heat transfer of a high-performance boiling surface using an electric field.

(Prior art) As shown in FIG. 5, the high-performance boiling surface 1 is made by forming a large number of irregularities 2 on the surface by mechanically processing the metal surface or creating a surface layer of sintered metal. Tunnel 3 in some cases
It is formed.

On the high performance boiling surface 1, depending on the condition of the surface irregularities 2, the distinction between the foaming point 5 where bubbles 4 are generated and the part where the liquid naturally flows down to the high performance boiling surface 1 as shown by arrow M is constant. However, it is known that there are design difficulties.

(Problems to be Solved by the Invention) When manufacturing a heat exchanger, it is difficult to predict the number of foaming points 5 of the high performance boiling surface 1 in advance. Therefore, the number of foaming points 5 of the high-performance boiling surface 1 and the related amount of heat transfer varied from product to product.

The purpose of the present invention is to promote the amount of heat transfer on the high-performance boiling surface by making it possible to artificially set the portion of the high-performance boiling surface that becomes the foaming point and the portion where the liquid flows down to the high-performance boiling surface. Another object of the present invention is to provide a device for simplifying and facilitating adjustment ridge design.

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows.

A mesh electrode is installed facing a high-performance boiling surface that forms many irregularities on the surface to promote boiling, and the high-performance boiling surface is used as one electrode, and the mesh electrode is used as the other electrode. It is configured to apply a high voltage between the mesh electrode and the mesh electrode.

(effect) The invention works as follows.

A high voltage is applied between the mesh electrode and the high performance boiling surface. Then, where an electric field is applied, an electrostatic pressure expressed by Maxwell stress is applied, so
The static pressure there is lower than that without an electric field, and because the pressure is lower, the bubbles are forced to leave the high-performance boiling surface.

In other words, the area below the thin wire of the mesh electrode is the foaming point where the electric field forces the bubbles to separate and promotes foaming, and the other area is where the liquid flows down, causing the effect on the high-performance boiling surface to be artificial. It will be classified according to

(Example) Next, an example of the present invention will be described based on PIS1 diagram to ttS2 diagram.

As shown in the ptSi diagram and Fig. 2, the high performance boiling surface 1
A mesh electrode 12, which is formed from thin electrical conductor wires 11 in a mesh shape, is placed opposite to the electrode 12 with a slight distance therebetween.

The high-performance boiling surface 1 is used as one electrode, the mesh electrode 12 is used as the other electrode, and a high voltage is applied between the high-performance boiling surface 1 and the mesh electrode 12.

Electrostatic pressure equivalent to Maxwell stress is acting between the electrodes, and this force only makes the bubble 4 vertically long.
With respect to the movement of the bubbles 4 in the direction of the mesh electrode 12, the pressure becomes lower by the amount of electrostatic pressure, so the bubbles 4 are forcibly separated from the high-performance boiling surface 1.

In this way, the mesh electrode 12 of the high-performance boiling surface 1 is thin! In the lower part A of 11, the electric field forces the bubbles 4 to separate and promotes foaming, resulting in a foaming point 5. On the other hand, a portion B of the high-performance boiling surface 1 other than the lower portion A of the mesh electrode 12 is a portion where the liquid naturally flows down as shown by arrow M.

Since the mesh electrode 12 allows the surface of the high-performance boiling surface 1 to be artificially set at the foaming point 5 and the region where the liquid naturally flows down, the amount of heat transfer on the high-performance boiling surface 1 can be adjusted to the desired value. Furthermore, heat transfer can be further promoted.

Furthermore, when the voltage applied between the mesh electrode 12 and the high-performance boiling surface 1 is high, the effect of forcibly separating the bubbles 4 and promoting foaming is greater than when the voltage is low. Utilizing this fact, it is also possible to vary the level of voltage to change the degree of foaming promotion and adjust the amount of heat transfer.

Furthermore, in the present invention, since foaming is promoted by an electric field, it is clear that the amount of heat transfer is also promoted compared to when no electric field is applied.

Next, another embodiment of the present invention will be described based on FIGS. 3 and 4.

As shown in FIG. 3 and #S4, the mesh electrode 12 of this embodiment has one narrow space ν between the thin wires 11 to form wide and narrow regions in the mesh.

When a high voltage is applied between the mesh electrode 12 and the high-performance boiling surface 1, liquid is forced to rise as a jet convection from between the narrow lines 11 in the narrow portion C of the mesh as shown by the arrow N in FIG. 4.

As in the previous embodiment, the liquid flows down naturally in the portion B of the mesh electrode 12 other than the portion below the thin wire 11, and the air bubbles 4 below the thin wire 11 are forcibly removed by the electric field.

In this embodiment, the high-performance boiling surface 1 can be artificially set at the foaming point 5 and the part where the liquid flows down, and also has the effect of promoting heat transfer by the jet convection caused by the electric field.

(Effect of the invention) The present invention has the following effects.

By artificially setting the high-performance boiling surface at the foaming point and the region where the liquid naturally flows down, the heat transfer amount of the high-performance boiling surface can be set to an arbitrary value.

Furthermore, the electric field forcibly removes the bubbles and promotes foaming, so the amount of heat transfer increases compared to when no electric field is applied.

[Brief explanation of drawings]

FIG. 1 is a sectional view according to an embodiment of the present invention, and FIG.
FIG. 3 is a sectional view of another embodiment of the present invention; FIG. 4 is a plan view of the embodiment of FIG. 3; FIG. 5 is a high-performance boiling FIG. 1: High performance boiling surface 2 2 unevenness 12: Mesh electrode Figure 1 Figure 2 Fl! J Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A mesh electrode (12) is installed facing a high-performance boiling surface (1) that forms a large number of irregularities (2) on the surface to promote boiling, and the high-performance boiling surface (1) is used as one electrode, and The mesh electrode (12) is the other electrode, and the high-performance boiling surface (
1) A heat transfer amount adjusting device using an electric field of a high-performance boiling surface, which is characterized by applying a high voltage between the mesh electrode (12) and the mesh electrode (12).