JPH0441278B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention utilizes an electric field to discharge condensate in a condensing heat exchanger having heat transfer tubes installed in the vertical direction, thereby improving the heat transfer. The present invention relates to a device for promoting.

(Prior Art) A condensing heat exchanger performs heat exchange by discharging the latent heat of steam to a heat receiving part and condensing it. The condensing heat exchanger to which the present invention is applied is of a type that is provided with heat transfer tubes vertically arranged as a heat receiving section through which a cooling water medium passes.

In condensing heat exchangers, condensed liquid adheres to the outer circumferential surface of the heat transfer tube to form a liquid film, and this liquid film inhibits the condensation of new vapor, causing a deterioration in heat exchange efficiency.

Therefore, conventionally, the condensate on the outer surface of the heat exchanger tube is removed using an electric field as shown in Figure 3.
Devices have been proposed to enhance heat transfer.

This conventional device uses the heat exchanger tube 1 as one electrode,
The spiral wire electrode 2 and the cylindrical surface electrode 3 are used as the other electrode, and a high voltage is applied between the heat exchanger tube 1, the wire electrode 2, and the surface electrode 3 to form an electric field. Due to this electric field, the condensate 4 is drawn from the heat exchanger tube 1 to the wire electrode 2, as shown in FIG.
The wire electrode 2 leads to the drained liquid 5, and the drained liquid 5
is discharged along the On the other hand, in the heat exchanger tube 1 facing the surface electrode 3, the condensate 4 is turned into droplets by the electric field. This promotes condensation of steam in the exposed portion 6 of the heat exchanger tube 1.

In this conventional device, most of the condensate 4 adhering to the heat exchanger tube 1 is drawn and removed by the wire electrode 2, and the remaining condensate 4 is turned into droplets at a location facing the surface electrode 3.

(Problems to be Solved by the Invention) However, in the above-mentioned known heat transfer accelerator, the wire electrode 2 and the surface electrode 3 are provided separately, and their functions are independent. That is, the function of the line electrode 2 was to attract condensate and discharge it, and the function of the surface electrode 3 was only to cause a thin condensate film to form droplets to promote condensation.

The present invention is an improvement of the above-mentioned conventional electric heating accelerator using an electric field.

That is, an object of the present invention is to provide an electrode structure for a heat transfer accelerator that simultaneously performs the liquid attracting function of a conventional spiral wire electrode and the droplet forming function of a surface electrode.

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

That is, the present invention provides a heat exchanger tube in a condensing heat exchanger from which latent heat of vapor of a heat medium is released, and a heat exchanger tube that is formed so as to surround the heat exchanger tube in a spiral manner, and an inner surface is formed on the outer surface of the heat exchanger tube. opposing plate-shaped spiral surface electrodes; a support that supports the spiral surface electrodes while maintaining a predetermined distance from the heat exchanger tube;
A rod-shaped drainage liquid is provided parallel to the heat exchanger tube at a position further away from the support toward the outside of the heat exchanger tube, and the lower end of the spiral surface electrode is gently connected to the drainage liquid. , the spiral surface electrode is one electrode, the heat exchanger tube is the other electrode, and a high voltage is applied between the spiral surface electrode and the heat exchanger tube.

(effect) The invention works as follows.

The condensed liquid forms droplets on the surface of the heat exchanger tube facing above the spiral surface electrode. These droplets gather and grow as they flow downward, are attracted to the spiral surface electrode, and fall while swirling along the lower end of the spiral surface electrode, reaching a position further away from the support of the heat exchanger tube. It reaches the drainage liquid provided, flows down along the drainage liquid, and is discharged. In this case, since the drained liquid is located away from the heat transfer tube, the centrifugal force that causes it to fall while rotating is greater than the force that holds the condensate between the heat transfer tube and the spiral surface electrode due to the electric field. The condensed liquid is easily moved to the draining liquid side, and the condensed liquid is reliably discharged.

(Example) An example of the present invention will be described below based on FIGS. 1 and 2.

Referring to FIG. 1, inside the condensing heat exchanger,
A plurality of heat exchanger tubes 1 are provided vertically. Cooling water is flowing through the heat exchanger tube 1, and the latent heat of the heat medium vapor is released to the heat exchanger tube 1 and condensed.
Heat exchange takes place.

However, a liquid film of the condensed liquid 4 is formed on the outer surface of the heat exchanger tube 1, and in the past, this liquid film has inhibited further condensation, posing a problem in terms of heat exchange efficiency.

In order to continuously remove the condensate 4 from the heat transfer tube 1, the present invention installs a helical surface electrode 12 as follows.

A plurality of rod-shaped supports 11 are provided around the heat exchanger tube 1 in parallel to the axial direction of the heat exchanger tube 1 . A plurality of spiral surface electrodes 12 wound spirally around the heat exchanger tube 1 are fixed to the support 11 . The support body 11 holds the spiral surface electrode 12 at a predetermined distance from the surface of the heat exchanger tube 1 . Here, the inclination angle θ of the spiral is 30° to 45°
is desirable. The inner surface 13 of the spiral surface electrode 12 faces the outer surface of the heat exchanger tube 1 with a predetermined distance therebetween. In order to form condensate on the outer surface of the heat transfer tube 1 into droplets as described later, it is preferable to set the distance H between the spiral surface electrode 12 and the heating tube 1 to about 0.5 to 5 mm. The width S of the spiral surface electrode 12 can be freely selected, but it is preferably about 3 mm to 100 mm.

In the present invention, the spiral surface electrode 12 is used as one electrode, the heat exchanger tube 1 itself is used as the other electrode, and a high voltage is applied between the spiral surface electrode 12 and the heat exchanger tube 1.

Spacing members 14 are passed through various parts of the support 11, and the spacing members 14 come into contact with the heat exchanger tubes 1, thereby maintaining the distance H between the spiral surface electrodes 12 and the heat exchanger tubes 1.

A rod-shaped waste liquid 5 is provided on the outside of the support 11 of the spiral surface electrode 12 in parallel to the axial direction of the heat exchanger tube 1 . This drained liquid 5 has a spiral surface electrode 1
The lower ends 15 of 2 are smoothly connected.

The present embodiment configured as described above operates as follows.

A high voltage is applied between the spiral surface electrode 12 and the heat exchanger tube 1 to form an electric field. Then, the condensate 4 adhering to the outer surface of the heat transfer tube 1 located above the surface facing the spiral surface electrode 12 becomes droplets as shown in FIG. 2. As the droplets flow downward, they gather and become larger, and are attracted to the spiral surface electrode 12 at a position near the lower end of the spiral surface electrode 12, and are drawn to the spiral surface of the spiral surface electrode 12. It flows down along the draining liquid 5 and is discharged downward. In this case, since the drained liquid 5 is located away from the heat transfer tube 1, the flowing condensate is forced to flow downward along the spiral rather than by the force that holds the flowing condensate between the heat transfer tube 1 and the spiral surface electrode 12 by the electric field. The centrifugal force caused by this becomes larger, and the movement of the condensed liquid to the drained liquid 5 side becomes easier, and the condensed liquid is reliably discharged.

By removing the condensed liquid 4 from the heat exchanger tube 1 in this manner, new condensation is promoted and the heat exchange efficiency of the heat exchanger is improved.

(Effects of the Invention) According to the present invention, it is possible to simultaneously convert the liquid film into droplets and discharge the condensate using a single helical surface electrode. At the same time as removing the attached condensate, new condensation is promoted by forming droplets, so the heat exchange efficiency of the condensing heat exchanger can be improved.

In addition, since the lower end of the spiral surface electrode is connected to the drain liquid located at a location away from the heat exchanger tube, the force that holds the condensate between the heat exchanger tube and the spiral surface electrode due to the electric field is stronger. The centrifugal force of the condensate flowing down while spirally turning becomes greater, so that the condensate can be easily moved to the drainage liquid, and the condensate can be reliably discharged.

Furthermore, since the electrode is planar, it is less likely to deform and has fewer failures.

[Brief explanation of drawings]

FIG. 1 is a front view of a heat transfer accelerator according to an embodiment of the present invention. FIG. 2 is a sectional view of essential parts showing the operation of the device shown in FIG. 1. FIG. 3 is a front view of a conventional electric field-based heat transfer accelerator. 4 and 5 are sectional views of essential parts showing the operation of the apparatus of FIG. 3. 1... Heat exchanger tube, 4... Condensate, 12... Surface electrode.

Claims (1)

[Claims] 1 A heat exchanger tube in a condensing heat exchanger from which latent heat of vapor of a heat medium is released, and a plate-shaped plate formed to spirally surround the heat exchanger tube and whose inner surface faces the outer surface of the heat exchanger tube. a spiral surface electrode, a support that supports the spiral surface electrode while maintaining a predetermined distance from the heat transfer tube, and a support that supports the spiral surface electrode at a position farther outward from the heat transfer tube than the support. A rod-shaped waste liquid provided parallel to the heat tube is provided, the lower end of the spiral surface electrode is gently connected to the waste liquid, and the spiral surface electrode is connected to one electrode, and the heat transfer tube is connected to one electrode. A device for promoting heat transfer using an electric field in a condensing heat exchanger, characterized in that the other electrode is used as the other electrode, and a high voltage is applied between the spiral surface electrode and the heat transfer tube.