JPH0765872B2 - EHD condensing heat exchanger - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrohydrodynamics (Erec).
tro Hydro Dynamics, hereafter EHD
Is used to discharge the condensate that is condensed and adhered to the pipe, and more specifically, the EH that is designed to discharge the condensed liquid that is condensed and adhered to the horizontal pipe.
D Condensation heat exchanger.

[0002]

2. Description of the Related Art In a condensation heat exchanger, it is important to discharge the condensate condensed and adhered to the pipe as soon as possible because the existence of a liquid film of the condensed liquid condensed and adhered to the pipe hinders the condensation of new vapor. Is. Heretofore, various condensate drawing devices have been proposed in which the condensate is forcibly discharged by utilizing the EHD effect.

Referring to FIG. 7, a spiral electrode 2 is wound around a vertically placed tube 1 and a supporting rod 3 for supporting the spiral electrode 2 is provided in the vertical direction. On the outer peripheral side of the support rod 3, a drainage drain 4 to which the lower end of the spiral electrode is connected is provided in the vertical direction. The reason why the drainage rod 4 is located on the outer peripheral side of the support rod 3 is to increase the diameter of the spiral electrode 2 so as to promote the discharging and flowing down of the condensed liquid attracted to the spiral electrode 2. Further, a large number of spacers 5 are provided to maintain the space between the spiral electrode 2 and the tube 1.

The action is that when a high voltage (6000 V or more) is applied between the tube 1 and the spiral electrode 2, the condensate condensed and adhered to the tube 1 is attracted to the spiral electrode 2 by the EHD effect, While swirling the 2 flow down, the drainage rod 4
It is discharged and flowed through.

In addition to the above-mentioned condensate attracting device using the spiral electrode, an EHD condensing heat exchanger utilizing the phenomenon of condensate dripping by the surface electrode is also known. Referring to FIG. 8, the surface electrode 12 is installed facing the pipe 11 through which the cooling water flows,
A high voltage is applied between the tube 11 and the surface electrode 12. Then, the film of the condensate condensed and adhered to the tube 11 is partially made into drops, and is divided into a thick part of the liquid film (dropped part) and a thin part of the liquid film. Condensation is further generated on the dripping portion, or the dripping portion flows down in the direction of gravity and gradually grows, and the spiral electrode 1 installed below the plane electrode 12
The condensate is attracted to 3 and discharged.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The condensing heat exchanger has a complicated structure because the tubes are vertically installed, and therefore a spiral electrode for discharging the condensate must be installed, and a large number of spacers must be provided.
The installation work became difficult and the device was expensive. Further, if the pipe is placed vertically, the length in the vertical direction is inevitably required, and a large space is required in the vertical direction. Furthermore, since the radius near the lower end of the conventional spiral electrode is gradually increased to promote the flow down of the condensate, the space around the tube is increased, and that much space is required. There is also a drawback that the entire device becomes large.

[0007]

The features of the present invention are as follows. That is, a horizontal pipe that constitutes one electrode and at the same time allows cooling water to flow, and a tubular EHD electrode that constitutes the other electrode and has a large number of slits through which the pipe penetrates. It is formed below the inner peripheral surface of the EHD electrode in the direction of gravity, and is composed of a gutter portion not provided with the slit, and a spacer is provided at a position excluding the gutter portion between the EHD electrode and the pipe, and the pipe and the EHD An EHD condensing heat exchanger characterized in that a high voltage is applied between the electrodes.

[0008]

[Operation] Vapor enters through the slit, contacts the tube, and condenses. The condensate becomes droplets due to the EHD effect received from the EHD electrode. Then, it flows down in the direction of gravity and is attracted or dropped to the gutter. The condensate that has flowed down the trough drops from the end of the trough and is discharged.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view showing an embodiment of the present invention.
2 is a sectional view taken along line AA of FIG. In the following embodiments, only one pipe portion will be illustrated and described,
The present invention relates to a condensing heat exchanger composed of horizontal tubes to which a large number of tubes are attached.

Between the partition wall 22 of one manifold 21 and the partition wall 24 of the other manifold 23, a pipe 25 through which cooling water flows is installed horizontally. A tubular EHD electrode 26 is provided on the outer periphery of the tube 25, and the tube 25 is provided with the EHD electrode 2
6 is provided so as to penetrate. The EHD electrode 26 is formed by forming a thin conductive metal plate into a cylindrical shape, and a large number of slits 27 are formed on the peripheral surface thereof. Tube 25 and E
A notched ring-shaped spacer 28 for maintaining a space is provided between the HD electrode 26 and the HD electrode 26. Spacer 2
The installation positions of 8 need only be provided at both end positions of the EHD electrode 26, but the installation positions at the intermediate position and other positions are not excluded. A lower part of the inner peripheral surface of the EHD electrode 26 in the direction of gravity is a trough 29 in which the slit 27 is not formed, and the condensate flows down along the trough 29. . The spacer 28 is installed so that the position of the notch is located in the trough 29. The tube 25 and the EHD electrode 26 may be installed horizontally, but the effect of discharging the condensate is higher if the tube 25 and the EHD electrode 26 are installed slightly inclined (up to about 15 °) with respect to the horizontal direction. Tube 25 and EH
A high voltage is applied to the D electrode 26.

The operation of the present invention configured as described above will be described below. The cooling water in the manifold 21 is pipe 2
It flows through 5 and is discharged to the other manifold 23. The condensed vapor enters through the slit 27 formed in the EHD electrode 26 and comes into contact with the pipe 25, and is deprived of heat by the cooling water and condensed. Condensate is tube 2 which is two electrodes
5 is formed by the EHD effect generated between the EHD electrode 26 and the EHD electrode 26. Then, when the size of the droplet becomes large, it flows down in the direction of gravity and falls to the trough 29, or is attracted by the EHD effect. The condensate collected in the gutter 29 is the gutter 29.
And then falls from its end and is discharged.

The structure described above is one embodiment of the present invention, and the present invention is not limited to the above embodiments. For example, a structure in which a separate groove body is installed as a trough portion inside the EHD electrode may be used. Further, a structure in which a plurality of spacers divided and separated as a spacer are installed in a ring shape may be used. Further, the shape of the slit is not limited to the rectangular shape, and an appropriate shape such as a square shape, a circular shape or an elliptical shape is adopted.

3 and 4 are views showing another embodiment of the EHD electrode of the present invention. In this example, a cylindrical EH
A trough-shaped groove 29a is integrally formed in the lower portion of the D electrode 26a, and the condensate is discharged through the groove 27a.

FIG. 5 is a front view showing still another embodiment of the present invention. In this embodiment, a cylindrical EHD electrode 26b is provided with a slit 27b formed of a circular hole on the upper surface thereof. The shape of the slit 27b is not limited to the circular hole according to this embodiment, and may be another shape as described above. When attracting the condensed liquid by the EHD electrode, it is necessary to maximize the area of the EHD electrode. For this purpose, it is desirable to have a structure in which a slit is formed at a position effective for infiltration of medium vapor and escape of non-condensable gas (air, water vapor, etc.) and no slit is formed at other positions. Since the non-condensable gas has a lighter specific gravity than the vapor of the condensing medium, if the upper part of the EHD electrode is closed, it will accumulate in the space above the EHD electrode. However, according to the embodiment shown in FIG.
The medium vapor becomes able to enter the inside through the slit 27b on the upper surface of the EHD electrode 26b, and the EHD electrode 26
Since the non-condensable gas accumulated inside a can escape through the slits 27b on the upper surface, the area where the EHD electrode 26b is reduced can be suppressed as much as possible, and vapor can effectively enter and escape. .

FIG. 6 is a sectional view showing still another embodiment of the present invention. That is, in this embodiment, the opening area of the slit 27c formed in the EHD electrode 26c is gradually reduced from the upper side to the lower side. Also in this embodiment, the shape of the slit 27c is arbitrarily selected. The effect of pulling the condensed liquid from the tube to the EHD electrode is
It is caused by the non-uniform electric field created between the tube and the EHD electrode. According to the structure of this embodiment, the magnitude of the unequal electric field generated between the tube and the EHD electrode 26c is weaker in the upper portion and becomes larger in the lower portion, and the gradient of the unequal electric field causes the condensed liquid to fall to the lower portion. It will have the effect of being pushed.

[0016]

The effects of the present invention having the above-described structure are as follows. In the EHD condensing heat exchanger of the present invention, since the tubes are placed horizontally, it is not necessary to install a spiral electrode, its supporting rod, other draining rods or the like for discharging the condensate, and further, spacers are provided at both ends. Since only one piece is provided, the structure is simple and there is no difficulty in mounting work, and the cost of the entire apparatus is low. Further, the length in the vertical direction is inevitably reduced as compared with the case where the pipe is placed vertically, and the degree of freedom in the installation layout in the vertical direction is increased. Further, since there is no portion where the radius is enlarged unlike the conventional spiral electrode, the space around the tube may be small, and the entire device can be downsized accordingly. Since the condensate dropletization phenomenon due to the EHD effect is mainly used, and the condensate attracting phenomenon is secondary, the rate of use in the state where the condensate film is thin becomes large, and the condensate attracting phenomenon is mainly used. The heat exchange rate is improved as compared with the conventional EHD condensing heat exchanger used.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention. Figure 2
FIG. 2 is a sectional view taken along line AA of FIG. FIG. 3 is a front view showing another embodiment of the present invention. FIG. 4 is a sectional view taken along line BB of FIG. FIG. 5 is a front view showing still another embodiment of the present invention. FIG. 6 is a front view showing another embodiment of the present invention. FIG. 7 is a front view for explaining a condensing heat exchanger utilizing a conventionally known condensate drawing phenomenon due to the EHD effect. FIG. 8 is a cross-sectional view for explaining a condensing heat exchanger using a conventionally known condensate liquefying phenomenon due to the EHD effect.

[Explanation of symbols]

21: Manifold 22: Partition 23: Manifold 2
4: Partition wall 25: Tubes 26, 26a, 26b ,: EHD electrodes 27, 27a, 27b, 27c: Slit 28:
Spacers 29, 29a: gutter

Claims (4)

[Claims] 1. A cylindrical EHD electrode having one electrode and a horizontal pipe through which cooling water flows, and a plurality of slits through which the pipe is formed and at the same time constituting the other electrode. And a gutter part formed below the inner peripheral surface of the EHD electrode in the direction of gravity and not provided with the slit, and applying a high voltage between the tube and the EHD electrode. EHD condensing heat exchanger. 2. A cylindrical EHD electrode having one side electrode and a horizontal pipe through which cooling water flows, and another electrode at the same time having a plurality of slits penetrating the pipe. And a gutter portion formed below the inner peripheral surface of the EHD electrode in the direction of gravity and not provided with the slit, wherein the slit is formed only on the upper surface of the EHD electrode, and the tube and the EHD electrode are provided. An EHD condensing heat exchanger characterized in that a high voltage is applied between the two. 3. A cylindrical EHD electrode having one side electrode and a horizontal pipe through which cooling water flows, and another electrode and at the same time a large number of slits through which the pipe penetrates. And a gutter portion which is formed below the inner peripheral surface of the EHD electrode in the direction of gravity and in which the slit is not provided, and the opening area of the slit is formed to be gradually smaller from the upper portion of the EHD electrode toward the lower portion. Becomes
An EHD condensing heat exchanger, characterized in that a high voltage is applied between the tube and the EHD electrode. 4. The EHD condensing heat exchange according to claim 1, wherein a spacer is provided between the EHD electrode and the tube at a position excluding the trough portion. vessel.