JPS62123292A - Fluted heat transfer pipe for condenser - Google Patents

Abstract

PURPOSE:To prevent worsening of the heat transmission coefficient of a lower fin or a pipe, by a method wherein partitions are located at intervals of a proper distance in the recessed parts of the outer surface of a heat transfer pipe, and a spiral core having an outer side slightly smaller than the inner size of the transfer pipe is inserted in the inner surface of the transfer pipe. CONSTITUTION:Partitions 103 are situated at intervals of a proper distance so that a groove in the outer surface of a flute 102, protruded from the inner side of the pipe 1, is closed thereby, and are secured at right angles with the axial direction of the pipe 1 or at an oblique angle. A core 2 has a spiral flite 201 having an outer size enoughly smaller than the inner size of the fluted pipe, and is inserted into the heat transfer pipe 1 so that cooling water or cooling liquid is forced to make meanly well contact with the inner surface of the flute. The flute needs a size being large enough to allow prevention of gathering of liquid drop between the grooves of the flute, and has the inner and outer surface area of the flute being 1.6 times or about 2 times as wide as that of the surface area of a round pipe having the same outer size as that of the flute. Condensed liquid drops are adhered to the outer surface of the flute 102, they gradually further gather to produce a flow, the flow is intercepted by the partitions 103 to produce a liquid flow, which is separated from the flute 102, and dropform condensation is started again at a portion right below the partition 103. The length of a passage for a cooling medium is reduced to 1/3, a single pass simplifies structure, the number of pipes is reduced, and heat transmission coefficient is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a shell-and-tube heat exchanger, particularly a heat exchanger tube for a condenser.

[Conventional technology and its problems]

Conventional multi-tube condensers use simple cylindrical tubes or improved versions thereof, such as low-height fin tubes with fine pitches in a direction perpendicular to the axis of the tubes.

This fin tube is constructed as a horizontal type, but the condensed liquid from above drips into the tube at the bottom, filling the space between the fins with liquid, so heat transfer is performed through this liquid. As a result, the fins are not very effective.

In addition, a vertical ammonia condenser has good performance despite its simple structure, but since the outer surface of the lower part of the tube is still covered with condensate, no heat flow takes place in the bare upper part. I curse.

[Means for solving problems]

The present invention has been made for the purpose of providing a heat exchanger tube for a condenser that can solve the problems of the prior art as described above.The present invention has a straight tube section at both ends. In a heat exchanger tube formed by forming a plurality of uneven folds projecting inwardly between straight pipe parts, partition plates are provided at appropriate intervals in the concave portions of the folds on the outer surface, and the outer periphery of the partition plates is It is characterized by being approximately equal to or smaller than the outer circumference of the straight pipe portion.

[For production]

That is, the main purpose of the present invention is to configure the heat transfer tubes as described above and arrange them vertically to configure a condenser, so that cooling water or cooling liquid is provided on the inner surface of the tube. Similarly, when the outer surface is brought into contact with the gas to be condensed, the condensed liquid flowing down the grooves on the outer surface will collide with the partition plate and be blown off to the outer periphery, and the condensed liquid will still adhere to the lower part of the partition plate. This is to avoid deterioration of the heat transfer coefficient in the lower part of the lower fin or tube as in the prior art.

Note that the partition plate is formed into a ring by welding or brazing, which has a remarkable effect on reinforcing the strength of the folds, especially the strength against internal pressure.

〔Example〕 Next, an example of implementation of the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a heat exchanger tube as an example of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and the cross section in FIG.
Corresponds to position 1.

1 is a heat exchanger tube according to an example of the present invention, 101 is a straight pipe portion at both ends, and 102 is a plurality of folds protruding inside the tube 1. In this embodiment, the number of folds is 6. And so. 103
are partition plates provided at appropriate intervals so as to close the grooves on the outer surface of the folds 102, and are fixed by brazing or welding at right angles to the axial direction of the tube 1, but they may be sloped appropriately. However, if the pipe is tilted, the upward direction of the pipe l will be determined unilaterally, so care must be taken when installing it.

This method of forming the folds 102 may be performed by directly forming the pipe,
The intermediate fitting may be formed from a plate, and the caps at both ends may be formed from tubes by brazing or pressing and then brazed or welded.

FIG. 3 shows a core body 2 which is inserted into the interior of the heat exchanger tube 1 to bring the flow of cooling water or coolant into even and good contact with the inner surfaces of the folds 102. This core body 2 has a structure of a spiral strip 201 having an outer diameter sufficiently smaller than the inner diameter of the tube, and is intended to bring the flow inside the tube into contact with the inner surface of the tube as evenly as possible. If there is no core body 2 like this,
The result is that the cooling medium flows preferentially through the central cavity of the tube 1 and does not effectively contact the inner surface of the folds 102.

In addition, 3 indicates a tube plate, and 4 indicates a part where the tube is penetrated by expansion.

Therefore, since the material of the core body 2 has no relation to heat transfer,
It is not limited to metal, it may be plastic, and it should be as cheap as possible, and the structure may be simply a long sheet metal twisted, and the method of fixing this core body 2 is to press the appropriate places with a press. There are methods etc.

FIG. 4 shows that condensed droplets 5 adhere to the outer surface of the folds 102, gradually gather to form a flow 6, are dammed up by the partition plate 103, become a liquid flow 7, and leave the folds 102, leaving the partition plate 103.
This shows a state in which droplet condensation begins again just below. The spacing between the partition plates 103 is appropriately selected depending on the properties of the liquid to be condensed and other design conditions.

The size of the pleats 102 must be large enough to prevent droplets from accumulating between the grooves. In the case of a shape like the cross section shown in Fig. 2, if the outer diameter of the tube is 25 mm, six pleats should be formed on the outside. If the width of the groove is set to 4 mm, the inner and outer surface area of the fold is 1 of the surface area of a circular tube with the same outer diameter.
．． You can get around 6 times as much.

Next, an example of a condenser using the heat exchanger tube of the present invention will be shown.

FIG. 6 shows a four-pass type condenser B using a conventional heat transfer tube, and FIG. In the fabricated one-pass condenser A, the number of heat exchanger tubes in the former condenser B is 50.
In contrast, the number of heat exchanger tubes 1 in the latter condenser A using the heat exchanger tubes 1 of the present invention was only 28.

However, since condenser B is a 4-pass type, the MJ structure had to be complicated and large, but since condenser A uses the heat exchanger tube 1 of the present invention, it can be of a 1-pass type, so the structure can be reduced. is extremely simple and compact.

〔Effect of the invention〕

The present invention is as described above, and if a condenser is constructed using the heat exchanger tube of the present invention, significant advantages arise in terms of both cost and performance. In other words, while the heat transfer area increases by about 1.6 times compared to conventional circular heat transfer tubes, the number of coolant passages increases to about 173, so the number of coolant passages is different from the conventional one. There is no need to fold the tubes back and forth, and only a single pass is required, which simplifies the structure.Also, since the number of tubes decreases in inverse proportion to the multiplication factor of the heat transfer area, the condenser itself becomes smaller. Furthermore, the heat transfer coefficient is 2
The synergistic effect will be enormous, nearly doubling.

In particular, it is considered to be extremely preferable as a condenser for a heat pump used under conditions with a small heat drop.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view of a heat exchanger tube according to an example of the present invention, Figure 2 is a cross-sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a view of the heat exchanger tube shown in Figure 1 with the core inserted. The partial cross-sectional view of FIG. 4 is a diagram showing a state in which droplet condensation begins after condensed droplets adhere to the outer surface of the folds of the heat exchanger tube shown in FIG. 1. 1... Heat exchanger tube, 101... Straight pipe part of heat exchanger tube, 10
2... Pleat, 103... Partition plate, 2... Core body, 20
DESCRIPTION OF SYMBOLS 1... Spiral strip, 3... Tube sheet, 4... Biting part by tube expansion, 5... Condensed droplet, 6... Flow of condensed droplet, 7
・・・Liquid flow No. 111 No. 231 Figure 5 Figure 6 Procedural amendment (January 30, 1985 Director General of the Japan Patent Office Michibe Uga 1, Indication of the case 1985 Patent Application No. 241257 2) , Title of the invention: Puckered heat exchanger tube for condenser 3, Relationship to the case of the person making the amendment Patent applicant No. IO, 1-13 Tsukiji, Chuo-ku, Tokyo - Koshuha Kogyo Co., Ltd. Representative Atsushi Hirayama 4, Agent Postal code: 105 Omura Building 5, 2-5-6 Shinbashi, Minato-ku, Tokyo Date of amendment: January 8, 1985 (Despatch date: January 28, 1986) ``Brief description of drawings'' in the specification ” Column 7, contents of the amendment The description starting from line 10 on page 7 of the specification is amended as follows. Note 4: Brief description of the drawings FIG. 1 is a longitudinal cross-sectional view of a heat exchanger tube as an example of the present invention. Fig. 2 is a sectional view taken along line nn in Fig. 1, and Fig. 3 is a partial sectional view of the heat exchanger tube shown in Fig. 1 with the core inserted. Fig. 4 is a sectional view of the heat transfer tube shown in Fig. 1. FIG.
The figure is a vertical cross-sectional view of a one-pass type condenser using the heat exchanger tube of the present invention, FIG. 6 is a vertical cross-sectional view of a four-pass type condenser using a conventional heat exchanger tube, and FIGS. The condensers are designed to have the same heat exchange rate. 1... Heat exchanger tube, 101... Straight pipe part of heat exchanger tube, 102
... Folds, 103 ... Partition plate, 2 ... Core body, 201
...Spiral strip, 3...Tube plate 4...Encroachment part due to tube expansion, 5...Condensed droplet, 6...Flow of condensed droplet, 7...
・Liquid flow procedure amendment (oral) December 24, 1985 Commissioner of the Patent Office Kuro 1) Akio Yu 1, Indication of the case 1985 Patent Application No. 241257 2, Name of the invention Pleated heat exchanger tube for condenser 3. Relationship with the case of the person making the amendment Patent applicant Address: 1-13-10 Tsukiji, Chuo-ku, Tokyo Name: Dai-ichi Koshuha Kogyo Co., Ltd. Representative: Atsushi Hirayama 4, Agent postal code: 105 Address: Minato-ku, Tokyo Omura Building 5, 2-5-6 Shinbashi, subject of amendment 6, contents of amendment (1) "Straight pipe section" on page 4, line 1 of the specification. Correct the circular tube part. (2) Similarly, "upper" in the 7th line of the 4th page is corrected vertically. (3) Similarly, in the 6th line of the 5th page, amend J to ``It may be a thing.'' (4) Similarly, after the ``ru.'' in the 1st line of the 6th page, further add the number of folds. If you set it to 8, it will be around twice as much. join. (5) Similarly, next to “The insulation area is” on page 6, line 18,
For example, join.

Claims (1)

[Scope of Claims] 1. In a heat exchanger tube having straight pipe portions at both ends and having a plurality of folds of concavities and convexities protruding inwardly between the straight pipe portions, the concave portions of the folds on the outer surface may be formed as appropriate. A pleated heat exchanger tube for a condenser, characterized in that partition plates are provided at intervals, and the outer periphery of the partition plates is approximately equal to or smaller than the outer periphery of the straight pipe portion of the heat transfer tube. 2. The heat exchanger tube according to claim 1, wherein a spiral core having an outer diameter slightly smaller than the inner diameter is inserted into the inner surface and fixed as appropriate.