JPH02233996A - Heat transfer pipe - Google Patents

Abstract

PURPOSE:To reduce the production cost without reducing the heat transfer efficiency by forming an uneven layer aside to a specified direction over the inner surface of a pipe. CONSTITUTION:A porous galvanized layer (uneven layer) 3 having recessed parts 2 with relatively constricted openings is formed over the inner surface of a pipe, and the thickness of the layer is increased toward one side in the circumferential direction. The heat transfer pipes of this constitution are used as evaporation and condensation pipes in heat exchangers, for example, in such a manner that a heat carrier L flows along the opposite side of the galvanized layer 3 formed aside. In this case, they can be used without a reduction in the heat exchange efficiency. In addition, when the pipes are used for a heat exchanger in which heat-exchange takes place between fluid 'L out' flowing outside the pipes perpendicularly to the axes of the pipes and fluid 'L in' flowing inside the pipes, the pipes are arranged so that the galvanized layer 3 sides face the upstream side of the fluid 'L out'. In this case, the reduction in the heat exchange efficiency can be controlled to a very little value.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to, for example, evaporation tubes and condensation tubes of heat exchangers for air conditioning;
The present invention also relates to a heat exchanger tube used in a heat pipe having a wick, and particularly to a heat exchanger tube that is inexpensive to manufacture and has excellent heat transfer characteristics.

[Prior Art] This type of heat transfer tube includes, for example, one in which spiral grooves are formed on the inner surface of the tube body by a rolling method, and one in which granular or linear metal is brazed on the inner surface of a regular body. A material that is attached by a method is used.

The spiral grooves, granular or linear metal, etc. are formed almost uniformly in the circumferential direction on the inner circumferential surface of the tube, thereby improving heat transfer efficiency.

[Problems to be Solved by the Invention] However, in the conventional heat transfer tube described above, when used as an evaporation tube or a condensation tube in a heat exchanger, for example, the liquid heat medium is absorbed into the inner circumferential surface of the tube. It may flow without touching only a part. In this case, the helical grooves, granular or linear metal, etc. in the portions that are not in contact with the liquid heat medium do not contribute to the heat transfer efficiency, and the helical grooves in those portions do not contribute to the heat transfer efficiency. It's wasted. Therefore, in the above case, the spiral grooves etc. are formed in vain.
There is a problem with high costs.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat exchanger tube that can reduce manufacturing costs without reducing heat transfer efficiency. In order to achieve the above-mentioned object, the present invention has the following features:
In a heat exchanger tube on which a concavo-convex layer is formed, the concave-convex layer is formed so as to be biased in a predetermined direction on the inner circumferential surface.

[Function] In the present invention, it is used, for example, in an evaporation tube or a condensation tube of a heat exchanger, so that the liquid heat medium flows through a portion of the uneven layer opposite to the unevenly formed portion. . Thereby, it can be used without causing a decrease in heat exchange efficiency.

In addition, it is used in a heat exchanger that exchanges heat between the outer fluid that flows across the axis of the tube and the fluid that flows inside the tube. It is used by placing it on the windward side. In this case, it can be used with almost no reduction in heat exchange efficiency. In this case, the fluid resistance of the inner fluid is reduced in the portion where the uneven layer is less, and the thermal efficiency is improved accordingly.

Furthermore, it is used in a heat exchanger that radiates heat in a specific direction, such as in floor heating, with the side on which the uneven layer is unevenly formed facing the radial direction. Since radiation of heat in directions that do not require radiant heat can be suppressed, heat can be radiated more efficiently in directions where it is needed. Furthermore, in this case as well, the fluid resistance is reduced in the portions where the uneven layer is less, and the thermal efficiency is improved accordingly.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. However, in this example, a porous plating layer (for example, see Japanese Patent Application No. 60-252358) is formed on the inner surface of the tube to form an uneven layer on the inner surface of the tube.

In Figures 1 and 2, 1 is a tube body, and on the inner peripheral surface of this tube body 1 there is a porous plating layer (uneven layer) 3 having a recess 2 with a relatively narrow opening. It is formed. The height of the porous plating layer 3 is biased towards one side in the circumferential direction.

Such a plating layer 3 is formed by a plating apparatus shown in FIG.

The plating device has a vibe support mechanism (
(not shown) and a wire support mechanism (not shown) for inserting and supporting an insoluble anode wire 4 made of Ti-P L or the like into the tube 1 while applying tension along the axis of the tube 1. )
, a storage tank 5 for storing copper sulfate plating solution, a pipe 6 communicating the storage tank 5 with both ends of the pipe l, a chemical pump 7 installed in the pipe 6, and a connection between the pipe l and the anode wire 4. It consists of an energizing device (not shown) that passes a plating current between them, and basic copper carbonate is added to compensate for the decrease in copper ions caused by the plating process in this storage tank 5, thereby increasing the copper ion concentration of the plating solution. It is configured so that it is kept constant and supplied to the tube body l. The anode wire 4 can be finely adjusted in the radial direction from the axial center position of the tube by the wire support mechanism.

A plating layer 3 is formed inside the pipe body 1 using the plating apparatus configured as described above.
To form the tube, first, a hydrophobic substance such as silicone oil diluted with a volatile solvent such as ethanol is applied to the inner surface of the tube body 1 made of copper or the like, and then the solvent is evaporated. Forms a hydrophobic thin film. Then, a porous layer 3 is electrodeposited on the inner surface of the tube 1 using a plating device. During electrodeposition, a pulsed current such as an intermittent current, a normal pulsed current, or a PR current is applied between the tubular body 1 and the insoluble anode wire 4 as appropriate.

Then, the water in the plating solution is electrolyzed and oxygen sludge is generated from the anode wire 4. A part of this oxygen sludge adheres to the hydrophobic thin film coated on the inner surface of the tube body 1, which is the cathode, and the air bubbles are generated. A porous plating layer 3 is formed by enveloping the deposited metal. Then, by shifting the anode wire 4 by a minute amount in the radial direction from the axis of the tube body 1, a plating layer 3 with a high uneven height is formed on the inner peripheral surface in the direction in which the anode wire 4 is shifted. Ru.

The heat transfer tube configured as described above is used, for example, as an evaporation tube or a condensation tube of a heat exchanger, as shown in FIG. Use the part on the opposite side so that it flows. In this case,
It can be used without reducing heat exchange efficiency.

Furthermore, as shown in FIG. The layer 3 is used by placing the unevenly formed side on the windward side of the outer fluid Lout. In this case, the decrease in heat exchange efficiency can be minimized. At this time, the resistance of the fluid Lin is reduced in the portions where the plating layer 3 is small, so that the thermal efficiency is improved accordingly.

Furthermore, as shown in FIG. 6, the plating layer 3
Use the side with the unevenly formed side facing the radial direction. In this case, radiation of the heat Q to the side that does not require heating can be suppressed, and thereby the heat Q can be radiated more effectively to the side that requires heating. Also in this case, since the resistance of the fluid Lin is reduced in the portion where the plating layer 3 is small, the thermal efficiency is improved accordingly.

Further, in the above plating apparatus, the anode wire 4 is connected to the tube body.
Rather than adjusting the axis so that it coincides with the axis of the tube body 1, the J. You can easily adjust -1: J, 7+. For this reason, it is easier to form the plating layer 3 by biasing it toward the inner circumference of the tubular body l than by forming it uniformly on the inner circumference.

Therefore, according to the heat exchanger tube configured as above,
This has the extremely effective effect of reducing manufacturing costs without reducing heat transfer efficiency.

In the above embodiments, the uneven layer 3 is made of a groove-like layer formed by rolling, a granular or linear layer. It may also be made of brazed metal. Also, when forming grooves, it is easier to manufacture the grooves by allowing deviations than by forming them uniformly on the inner circumferential surface, so that manufacturing costs can be reduced. In addition, when brazing granular or linear metal, it is possible to reduce the amount of metal brazing in a specific direction, which saves the effort of brazing, which also reduces manufacturing costs. be able to.

Furthermore, in the above embodiment, the plating layer 3 was formed so as to be biased by making the anode wire 4 eccentric from its axis.
As shown in FIG. 7, the tube body 1 may have an elliptical cross section so that more plating layers 3 are formed in a portion close to the anode wire 4. In this case, by arranging the portion of the plating layer 3 parallel to the flow direction of the outer fluid L out, The thickness of the t-crystalline boundary layer can be made to match the extremely thin part of the boundary layer, thereby making it possible to greatly improve the heat exchange efficiency.

Furthermore, the uneven layer may be biased so that the difference in height between the uneven surfaces becomes larger on the inner circumferential surface side in a predetermined direction, or may be biased so that the intervals between the uneven surfaces become closer.

[Effects of the Invention] As explained above, according to the present invention, for example, when used in an evaporation tube or a condensation tube of a heat exchanger, a liquid heat medium is formed on the side opposite to the part formed by the bias of the uneven layer. By touching the parts and using it so that it flows, it can be used without reducing the heat exchange efficiency. In addition, it is used in a heat exchanger that exchanges heat between the outer a-body that flows across the axis of the tube and the fluid that flows inside the tube, so that the side where the uneven layer is unevenly formed is placed outside. By placing it on the upwind side of the fluid, it is possible to use it with minimal decrease in heat exchange efficiency. At this time, the fluid resistance of the fluid passing through the inner surface of the layer is reduced in the portion where the uneven layer is small, and the thermal efficiency is improved accordingly. Furthermore, when used in a heat exchanger that radiates heat in a specific direction, such as in floor heating, by using the side on which the uneven layer is unevenly formed facing the radiating direction, the side that does not require radiant heat can be used. This allows heat to be radiated more effectively to the side where it is needed. In this case as well, the fluid resistance of the inner fluid is reduced in areas with less uneven layers, so the thermal efficiency is improved accordingly. Furthermore, it is easier to manufacture the concave and convex layer formed on the inner circumferential surface of the tubular body if it is formed unevenly by 6' than if it is formed uniformly on the inner circumferential surface.

Therefore, an extremely effective effect is achieved in that the manufacturing cost can be reduced without reducing the heat transfer efficiency.

[Brief explanation of the drawing]

1 to 6 are diagrams showing an embodiment of the present invention, in which FIG. 1 is a sectional view of a heat exchanger tube, FIG. 2 is a sectional view of a main part of the heat exchanger tube, and FIG. 3 is a plating device. 4 is a cross-sectional view showing how to use the heat transfer tube, FIG. 5 is a cross-sectional view showing another method of using the heat transfer tube, and FIG. 6 is a cross-sectional view showing another method of using the heat transfer tube. FIG. 7 is a cross-sectional view showing another heat exchanger tube. ■...Tubular body, 3...Porous plating layer.

Claims (1)

[Claims] In a heat exchanger tube in which an uneven layer is formed on the inner peripheral surface of the tube,
The heat exchanger tube is characterized in that the uneven layer is formed biased in a predetermined direction on the inner circumferential surface.