JPH0440639B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is installed in a condensing heat exchanger that performs heat exchange by discharging the latent heat of heat medium vapor into a heat transfer tube, The present invention relates to a device for promoting heat transfer in the condensing heat exchanger, in which a force is applied and condensate is discharged by this force.

(Prior Art) A known electric field-based heat transfer promoting device will be described with reference to FIGS. 2, 3, and 4.

First, the outline of the condensing heat exchanger will be explained with reference to FIG.

1 is a condensing heat exchanger. A plurality of heat exchanger tubes 3 are provided vertically within the casing 2.

Cooling water is introduced from a cooling water inlet 4 at the bottom of the casing 2 and rises inside the heat exchanger tubes 3. On the other hand, steam of a heat medium such as fluorocarbon is introduced into the casing 2 from the steam inlet.

The steam of the heat medium emits latent heat and condenses and adheres to the surface of the heat transfer tube 3 through which the cooling water flows. The cooling water whose temperature has increased by receiving heat while moving up the heat exchanger tube 3 is led out from the cooling water outlet 6 . The condensed liquid of the heat medium is transferred to the heat transfer tube 3.
The condensate is then lowered by gravity and is discharged from the condensate outlet 7 at the bottom of the casing 2.

However, a liquid film of the condensate flowing downward was formed on the surface of the heat exchanger tube 3, and this liquid film inhibited the condensation of new vapor. In other words, the thinner the liquid film of the condensate adhering to the surface of the heat exchanger tube 3 is, the more desirable it is for new vapor to condense and adhere. Therefore, the heat transfer promoting device described below is a device that draws and removes the condensed liquid from the heat exchanger tubes 3 using the action force of an electric field, thins the liquid film on the surface of the heat exchanger tubes 3, and promotes condensation.

Referring to FIG. 3, a wire electrode 9 is spirally wound in a single layer around a heat exchanger tube 3 made of a conductor such as a metal at a distance from the surface 8 of the heat exchanger tube 3, and extends in the vertical direction. It is supported and provided by a support body 10. The terminal end 11 of the wire electrode 9 is connected to a waste liquid 12 extending longitudinally away from the heat exchanger tube 3 .

When the heat exchanger tube 3 is used as one electrode and the wire electrode 9 is used as the other electrode, and a high voltage is applied between the two, the condensate flows from the surface 8 of the heat exchanger tube 3 to the wire electrode 9 as shown in FIG. being pulled towards someone. The condensate flows down along the helical line electrode 9, and the centrifugal force of the flowing condensate overcomes the force due to the electric field and is connected to the drain liquid 12, causing it to flow downward along the drain liquid 12. The condensate is then discharged to the outside of the casing 2 from the condensate discharge port 7.

(Problems to be Solved by the Invention) In the above-described conventional heat transfer promoting device for a condensing heat exchanger, single wire electrodes 9 were installed in multiple stages.

In order to drain as much condensate as possible,
It is more effective to wind the spiral wire electrode 9 as tightly as possible. Therefore, the spiral wire electrode 9 shown in the figure
An experiment was conducted in which the tubes were wound in multiple stages around the heat exchanger tube 3, with the other configurations unchanged.

However, with the double spiral wire electrode 9, most of the condensate is drawn out by the upper wire electrode 9.
A small amount of condensate is drawn out to the lower wire electrode 9. Therefore, the centrifugal force of the condensate flowing down the wire electrode 9 due to gravity does not exceed the force exerted by the electric field, and remains attached to the wire electrode 9 due to the force exerted by the electric field. That is, the condensed liquid does not transfer from the wire electrode 9 to the drained liquid 12.

The present invention is an improvement on the above-mentioned known electric field-based heat transfer accelerator.

An object of the present invention is to provide a heat transfer promoting device using an electric field, which allows a larger amount of condensate to be drawn out than before and has a high heat transfer promoting effect.

(Means for Solving the Problems) The present invention is characterized by a heat exchanger tube that is installed vertically in a condensing heat exchanger and releases the latent heat of vapor of a heat medium, and a spiral coil around the heat exchanger tube. A wire electrode provided in a shape and simultaneously provided in multiple stages, and a drain liquid to which the terminal end of the wire electrode is connected, the wire electrode being one electrode and the heat exchanger tube being the other electrode, and both A heat transfer promoting device using an electric field, in which a high voltage is applied to draw the condensed liquid of the heat medium on the surface of the heat transfer tube to a wire electrode, and the liquid is discharged from the waste liquid, thereby thinning the liquid film on the surface of the heat transfer tube. In this case, the wire electrode is spirally wound in an upper and lower layer, and the end of the lower wire electrode in the upper double helix electrode is the starting end of the upper wire electrode in the lower double helix electrode. The terminal end of the upper wire electrode in the upper double helix electrode is connected to the draining liquid.

(Example) An example of the present invention will be described below with reference to FIG.

3 is a heat transfer tube installed vertically within the condensing heat exchanger. Cooling water flows through the heat exchanger tube 3, and vapor of a heat medium such as fluorocarbon releases latent heat to the heat exchanger tube 3, and condenses and adheres to the surface of the tube. On the other hand, the cooling water receives heat and rises in temperature.

However, a liquid film of the condensate flowing downward is formed on the surface of the heat transfer tube 3, and this liquid film obstructs the condensation of new vapor. Therefore, the heat transfer promoting device of the present invention for removing the condensate on the surface 8 of the heat transfer tube 3 using an electric field is provided as follows.

The heat exchanger tube 3 is made of a conductor such as metal, and around the heat exchanger tube 3 there are two
Heavily spirally wound wire electrodes 9a, 9b are supported by a support 10 extending in the longitudinal direction. The wire electrodes 9a, 9b are provided in multiple sets in multiple stages from the upper end to the lower end of the heat exchanger tube 3. In FIG. 1, two sets of wire electrodes, upper stage X and lower stage Y, are shown to simplify the explanation.
The invention is not limited to this example. Moreover, the cross-sectional shape of the heat exchanger tube 3 is not limited to a circle.

The heat exchanger tube 3 is used as one electrode, and the wire electrodes 9a,
A high voltage is applied between them with 9b as the other electrode, and the condensate on the surface 8 of the heat exchanger tube 3 is transferred to the wire electrodes 9a, 9.
It is pulled out to the b side. In the present invention, the wire electrode 9
The reason why a and 9b are wound twice is to draw out a larger amount of condensate than a single wire electrode.

In order to prevent the heat exchanger tube 3 and the wire electrodes 9a and 9b from coming into contact and shooting, the heat exchanger tube 3 and the wire electrodes 9a and 9b are
A spacer made of an insulating material may be provided to maintain the distance a, 9b.

The drawn condensate is transferred to spiral wire electrodes 9a, 9.
It flows downward along b, but in this example,
The spiral slope of the wire electrodes 9a, 9b is formed at a steeper angle as it goes downward, increasing the acceleration of the condensate and increasing the centrifugal force.

A terminal end 11a of the upper wire electrode 9a is connected to a drained liquid 12 extending vertically away from the heat exchanger tube 3.

However, since the lower line electrode 9b draws out less amount of condensate than the upper line electrode 9a, the centrifugal force when flowing down the line electrode 9b is not large enough to reach the drained liquid 12, and the line It moves while adhering to both the electrode 9b and the surface 8 of the heat exchanger tube 3 (see FIG. 4), stops midway, and moves away toward the drained liquid 12 and does not flow. Therefore, the terminal end of the lower line electrode 9b in the upper stage The drain liquid 12 is configured to be connected to the drain liquid 12 via the drain liquid 12 . Since the upper line electrode 9a draws out a large amount of condensate as described above, the centrifugal force acting on the condensate is large, and the condensate can reach the drained liquid 12. Note that the present invention is not limited to the above embodiment, and the lower wire electrode 9a by the upper stage
The terminal end 11b of the lower wire electrode 9a in the lower Y
It may also be configured to communicate with the starting end of.

This embodiment operates as follows.

The heat exchanger tube 3 is used as one electrode, and the wire electrodes 9a,
9b is used as the other electrode, and a high voltage is applied between them. Then, since the heat exchanger tube 3 is planar and the wire electrode is linear, an unequal electric field is formed between them, and the heat exchanger tube 3
A force in the direction of the wire electrodes 9a, 9b acts on the molecules of the condensate on the surface 8, and the condensate is drawn out toward the wire electrodes 9a, 9b.

Since the wire electrodes 9a and 9b are wound twice,
The amount of condensate drawn out is larger than that of a single wire electrode. It is transmitted on the wire electrode 9a by centrifugal force, is connected to the drained liquid 12, and is caused to flow down the drained liquid 12 by gravity and is discharged downward. Further, the condensate drawn out to the lower line electrode 9b in the upper stage flows down and is discharged downward.

As the spiral slope of the wire electrodes 9a, 9b becomes steeper as it goes downward, the centrifugal force acting on the condensate increases, so that the wire electrode 9a can reliably communicate with the drained liquid 12, and It never stands still.

(Effects of the Invention) As already mentioned, in the case where a double helix wire electrode is simply installed, the amount of condensate adhering to the lower wire electrode of the double helix wire electrode is small; Since the centrifugal force acting on the liquid becomes smaller than the force exerted by the electric field, the condensate is not discharged. However, in the present invention, the terminal end of the lower line electrode in the upper stage is connected to the starting end of the lower line electrode. , even if the amount of condensate attached to the lower wire electrode is small,
The condensate can be applied to the starting end of the lower wire electrode and discharged at the lower stage.

Therefore, it becomes possible to draw out a large amount of condensate from the surface of the heat exchanger tube, and the heat transfer promoting effect of the condensing heat exchanger can be further improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of one embodiment of the present invention.
FIG. 2 is a sectional view of a condensing heat exchanger equipped with a conventional heat transfer accelerator. FIG. 3 is an enlarged view of the main part of FIG. 2. FIG. 4 is a partially enlarged view of FIG. 3. 1: Condensing heat exchanger, 3: Heat exchanger tube, 8: Surface, 9
a:, 9b: wire electrode, 10: support, 12: draining liquid.

Claims (1)

[Scope of Claims] 1. A heat exchanger tube that is installed vertically in a condensing heat exchanger and releases the latent heat of vapor of a heat medium, and a heat exchanger tube that is installed in a spiral shape around the heat exchanger tube and is also provided in multiple stages. It is equipped with a wire electrode and a drain liquid connected to the terminal end of the wire electrode, the wire electrode is used as one electrode, the heat exchanger tube is used as the other electrode, and a high voltage is applied between the two to drain the heat exchanger tube. In a heat transfer promoting device using an electric field, the condensed liquid of the heat medium on the surface is drawn out to a wire electrode and discharged from the waste liquid, thereby thinning the liquid film on the surface of the heat transfer tube. The terminal end of the lower wire electrode in the upper double helix electrode is connected to the starting end of the upper wire electrode in the lower double helix electrode, and the A heat transfer promoting device using an electric field, characterized in that the terminal end of the upper wire electrode is connected to a draining liquid.