JPH1123180A - Heat transfer accelerator for heat transfer tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat transfer accelerator of a heat transfer tube for effectively preventing bypassing of fluid by easily and effectively preventing a gap generated between an inner wall of the tube and a twisted plate. SOLUTION: In the heat transfer accelerator 3 for generating a swirl in fluid flowing in the heat transfer tube 1 by spirally inserting it into the tube 1 of a heat exchanger, a strip plate 2 extended in a lengthwise direction of the tube 1 is twisted to form a spirally twisted plate 2. And, U-shaped sectional springs 4 are integrally provided with both edges of the plate 2 to suppress a gap to the tube 1 by bringing into contact with an inner wall surface side of the tube 1 while urging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat exchanger provided in a petrochemical plant, a storage plant, and the like.
In particular, the present invention relates to a heat transfer enhancer inserted into the heat transfer tube.

[0002]

2. Description of the Related Art As shown in FIG.
Ethylene evaporator and LP provided in storage plants, etc.
A helical torsion plate 2 is accommodated in a heat transfer tube 1 such as a G evaporator. By generating a swirl in a fluid flowing in the heat transfer tube 1, heat transfer of the fluid is promoted. ing.

That is, when a low-boiling fluid such as ethylene or LPG is allowed to flow into the heat transfer tube 1 as it is, the low-boiling fluid causes film boiling, and the low-boiling fluid flows to the interface between the inner wall surface of the heat transfer tube 1 and the low-boiling fluid. Vapor may flow in a layered manner, and the heat transfer coefficient to the liquid side may be significantly reduced. Therefore, the torsion plate 2 is accommodated in the heat transfer tube 1 and a fluid is spirally generated to generate a centrifugal force, thereby suppressing the occurrence of film boiling and preventing a decrease in the heat transfer coefficient due to the film boiling. I have to.

[0004]

Since the torsion plate 2 has a substantially straight cross section as shown in FIG.
If the gap between the heat transfer tube 1 and the torsion plate 2 accommodated therein is too large (for example, 0.5 mm or more), the gap between the edge of the torsion plate 2 and the inner wall of the heat transfer tube 1 as shown in FIG. A large gap (gap) G is generated, and the fluid bypasses the gap G. As a result, good swirl is not generated, and the performance may be greatly reduced.

Therefore, in order to eliminate such a gap as much as possible, the inner diameter d of the heat transfer tube 1 is accurately measured each time, and then the outer diameter (width) of the torsion plate 2 is determined, and several kinds of these are manufactured. It is necessary to select the one with the minimum gap above and construct it.

[0006] Therefore, producing a single heat transfer tube with a twisted plate results in wasting a great deal of cost and time.

The present invention has been devised in order to effectively solve such a problem, and an object of the present invention is to eliminate easily and reliably a gap generated between an inner wall of a heat transfer tube and a torsion plate. Accordingly, the present invention provides a novel heat transfer promoting body for a heat transfer tube that can surely prevent a bypass flow.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a heat exchanger which is spirally inserted into a heat transfer tube of a heat exchanger to generate a swirl in a fluid flowing through the heat transfer tube. In the body, a helical torsion plate is formed by twisting the strip extending in the length direction of the heat transfer tube, and is closely attached to both edges of the torsion plate while urging the inner wall surface side of the heat transfer tube. Thus, a spring body having a U-shaped cross section is integrally provided to suppress the cap with the heat transfer tube.

Accordingly, the torsion plate generates a swirl in the fluid flowing in the heat transfer tube, and the spring bodies provided on both sides of the torsion plate are brought into close contact with the inner wall surface of the heat transfer tube due to a springback effect. Thus, the gap between the inner wall of the heat transfer tube and both edges of the torsion plate is eliminated, and the bypass flow of the fluid can be effectively prevented. Further, the width of the heat transfer tube promoting body can be freely changed by the spring back effect of the spring body, so that the tolerance between both can be effectively allowed. The same effect can be obtained even if the torsion plate itself is formed in an S-shaped cross section.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a heat transfer enhancer 3 according to the present invention. As shown in the figure, the heat transfer promoting body 3 is helically inserted into the heat transfer tube 1, and divides a fluid flowing inside the heat transfer tube 1 into two parts in the longitudinal direction of the heat transfer tube 1. It is made to flow while swirling in a shape.

The heat transfer promoting body 3 has a U-shaped cross section in opposite directions on both edges of the twisted plate 2 formed by spirally twisting a strip made of a corrosion-resistant metal thin plate such as stainless steel. The fluid flowing in the heat transfer tube 1 is divided into two in the longitudinal direction of the heat transfer tube 1 by the torsion plate 2, and the torsion plate 2 is Is supported in the center.
The spring bodies 4 are urged so as to spread outward in the width direction of the torsion plate 2. Therefore, the outer diameter of the heat transfer promoting body 3 before being inserted into the heat transfer tube 1 is larger than the inner diameter d of the heat transfer tube 1 by + α as shown in FIG. For example, when the inner diameter of the heat transfer tube 1 is 20 mm, the outer diameter before insertion is increased by about +0.5 to 1.0 mm.

Then, as described above, such a heat transfer promoting body 3 is, for example, 3 to 5D (outer diameter of the heat transfer tube) / 180.
When spirally inserted into the heat transfer tube 1 at a pitch of ゜, the torsion plate 2 is supported at the center of the heat transfer tube 1 by the springback effect of the spring bodies 4 and 4, and the inside of the heat transfer tube 1 is equally divided into two. At the same time, the spring bodies 4 and 4 come into close contact with the inner wall of the heat transfer tube 1, thereby eliminating the gap between both edges of the heat transfer promoting body 3 and the inner wall of the heat transfer tube 1 as shown in FIG. Is effectively prevented.

Therefore, since good swirling flows are formed on both surfaces of the heat transfer promoting body 3, respectively, a centrifugal force is effectively applied to the fluid, and film boiling is suppressed and good heat exchange is achieved. . Further, by providing the spring bodies 4 and 4 on both edges of the torsion plate 2, the width of the heat transfer promoting body 3 can be freely changed to some extent. On the other hand, there is no need to prepare a plurality of twisted plates 2,
Significant costs and time required for fabrication can be saved.

The spring members 4 and 4 are formed separately from the torsion plate 2 and then joined to both edges of the torsion plate 2 by welding or the like. A large torsion plate may be prepared, and both edges of the torsion plate may be formed by bending by hot working. Alternatively, the torsion plate 2 may be formed to have an S-shaped cross section so that the torsion plate 2 itself has a spring pack function. Further, the spring members 4 and 4 may be formed so that the bending directions thereof are the same.

[0016]

In summary, according to the present invention, since the gap between the heat transfer promoting body and the inner wall of the heat transfer tube is easily and reliably eliminated, the bypass flow of the fluid is effectively prevented, and good heat exchange is achieved. In addition to being able to perform, the size of the torsion plate in the width direction can be freely changed, so there is no need to prepare a plurality of torsion plates for one heat transfer tube as in the conventional case, which is a great deal of Excellent effects such as saving of cost and time can be exhibited.

[Brief description of the drawings]

FIG. 1 is a side view showing one embodiment of a heat transfer enhancer according to the present invention.

FIG. 2A is a sectional view taken along line XX in FIG. FIG. 2B is a sectional view taken along line YY in FIG.

FIG. 3 is a sectional view showing a relationship between a heat transfer tube diameter and a heat transfer promoting body diameter.

FIG. 4 is a partially enlarged view showing a portion A in FIG. 2 (B).

FIG. 5 is a side view showing a conventional twisted plate.

FIG. 6A is a sectional view taken along line XX in FIG. (B) is a sectional view taken along the line YY in FIG. 5.

FIG. 7 is a partially enlarged view showing a portion A in FIG. 6 (B).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat transfer tube 2 Twisted plate 3 Heat transfer promoting body 4 Spring part G gap

Claims (2)

[Claims] 1. A heat-transfer accelerating body which is spirally inserted into a heat-transfer tube of a heat exchanger and generates a swirl in a fluid flowing through the heat-transfer tube, a strip extending in the longitudinal direction of the heat-transfer tube. A twisted helical torsion plate is formed, and both sides of the torsion plate are pressed against the inner wall surface side of the heat transfer tube while being in contact with the heat transfer tube to suppress a cap with the heat transfer tube. A heat transfer enhancer for a heat transfer tube, wherein the heat transfer tube is integrally provided with a spring portion. 2. A heat-transfer accelerating body which is spirally inserted into a heat-transfer tube of a heat exchanger so as to spirally flow a fluid flowing through the heat-transfer tube, a strip extending in the longitudinal direction of the heat-transfer tube. The twisted helical twisted plate was formed, and the torsion plate was formed in an S-shaped cross-section and inserted into the heat transfer tube so that both edges thereof were brought into close contact with the heat transfer tube inner wall side, respectively. A heat transfer enhancer for heat transfer tubes.