JP2005308311A - Fin tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fin tube for an air-cooling condenser, of high performance capable of avoiding a problem on depletion of ground water in inland urban areas, and economically constructing power equipment even in inland areas not having much cooling water. <P>SOLUTION: This fin tube comprises a flat tube 1, and a number of fins 11A-11G having approximately uniform rectangular outer shape, and respectively constituted by being bent at a right angle at its long side end parts 11b, 11b opposite to each other, having a plurality of openings 13 between the long side end parts from its front face to a rear face, having louvers respectively projecting from one end part in the short side direction of the openings in a state of being inclined by a specific angle with respect to a virtual segment in parallel with the short side, joining one side 11b of the bent long side end parts with an outer flat part, and joining the other side 11a of the bent long side end parts with the others to successively form air flow channels 14 respectively having a rectangular cross-sectional shape. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fin tube used for an air-cooled condenser.

  As a fin tube used in a recent air-cooled condenser, as shown in a perspective view with a part thereof broken in FIG. 8, an outer flat portion 22 of a flat-shaped tube 21 that condenses this through steam is used. A fin tube 20 in which an aluminum strip is formed in a meandering shape and one end of the formed portion is brazed to the outer flat portion 22 is employed. FIG. 9 is an enlarged cross-sectional view showing a state in which one end of a meandering fin 23 formed by forming an aluminum strip is brazed to the outer flat portion 22.

  The fins 23 shown in FIGS. 8 and 9 are formed, for example, by forming an aluminum base strip having a thickness of about 0.3 mm and a width of about 200 mm into a bellows shape having a height of about 19 mm, and the pitch of each mountain is 2 to 2. It joins to the outer flat part 22 of the tube 21 by brazing so that it may be set to about 3 mm. Therefore, the fin tube 20 as a whole is manufactured such that the longitudinal direction thereof coincides with the meandering direction of the fin 23 and the width of the fin 23 is equal to the width of the outer flat portion 22 of the tube 21 (for example, , See Patent Document 1).

In the fin tube 20 configured as described above, cooling air generated by a fan separately provided outside is guided, and this cooling air is passed between the fins 23 in a meandering direction in a direction perpendicular to the meandering direction of the fins 23. Allow to pass and cool.
Japanese Patent Laid-Open No. 9-280752

  As described above, an air-cooled condenser using the fin tube 20 generally requires a huge installation area. In areas with high land prices such as urban areas, it is clarified how the heat transfer performance changes depending on the fin shape of the fin tube 20 despite the strong desire to reduce groundwater and reduce the installation area. In other words, there is a lack of information for providing a more compact air-cooled condenser, which makes it difficult to effectively reduce construction costs and operating costs.

  The present invention has been made to solve the above problems, and its purpose is to avoid the problem of groundwater depletion in inland urban areas and to economically construct power facilities even in inland areas where cooling water is scarce. An object of the present invention is to provide a fin tube for a high-performance air-cooled condenser.

  When the influence of various parameters on the heat transfer characteristics of the fin tube as described above was investigated, the following points became clear. That is, fin height, fin pitch, fin length, and fin thickness can be considered as the main shape parameters regarding the heat transfer performance of the fin tube. The analysis was performed under a plurality of conditions in which these parameters were combined in various ways, and the influence of each parameter on the performance and the pressure loss of the flowing air was evaluated from the analysis results. FIG. 10 is an example of the result, and is a diagram showing the relationship between the fin height and the heat transfer performance.

  As is apparent from the characteristic line P in FIG. 10, the heat transfer performance increases as the fin height increases. However, since the pitch of the fin tubes is also increased, there is a possibility that the overall shape of the air-cooled capacitor is increased. On the other hand, although illustration is omitted, it has become clear that the longer the fin length, the lower the performance. This is considered to be because even if the length of the fin is increased, the air temperature is increased on the downstream side of the air, and the rate of contribution to the increase of the exchange heat amount is decreased.

  The present invention takes into account the height and length of these fins, and the condition of air passing through a narrow space is that the dimensionless Reynolds number Re represented by the kinematic viscosity coefficient, flow velocity, and representative dimensions of air is 2300 or less. In this case, the flow condition becomes laminar, and the flow condition becomes turbulent as it exceeds 2300. Among these, in the flow condition called laminar flow, the fluid particles do not exchange in the direction perpendicular to the wall surface, and the heat transfer coefficient is In contrast, the heat transfer coefficient is increased in the flow state called turbulent flow because the replacement of fluid particles in the direction perpendicular to the wall surface is promoted.

  Therefore, in the invention according to claim 1, the flat tube and the outer shape are substantially the same rectangle, the opposing long side ends are bent at a substantially right angle, and between these long side ends, from the surface thereof A plurality of openings penetrating the back surface are formed, and a louver that protrudes from one short side end of the opening and is inclined by a predetermined angle with respect to a virtual line segment parallel to the short side is formed and bent. One of the long side end portions is joined to the outer flat portion of the tube, and the other of the folded long side end portions is joined to the other to form an air flow path having a rectangular cross section in order. It is a fin tube provided with many fins.

  According to a second aspect of the present invention, in the fin tube according to the first aspect, a plurality of openings and louvers are formed in the long side direction, and one or a plurality of rows are formed.

  The invention according to claim 3 is the fin tube according to claim 1 or 2, wherein the inclination angle of the louver is about 45 degrees.

  In the invention according to claim 4, the flat tube and the outer shape are substantially the same rectangle, the opposing long side end portions are bent at a substantially right angle, and the long side end portions are respectively in the long side direction. An offset louver is formed in which a plurality of openings penetrating from the front surface to the back surface are formed, and one of the folded long side ends is joined to the outer flat portion of the tube, and the other of the folded long side ends is The fin tube includes a plurality of fins that are joined to each other and that sequentially form air passages each having a rectangular cross-sectional shape.

  According to a fifth aspect of the present invention, in the fin tube according to any one of the first to fourth aspects of the present invention, the fins used are ones in which opposite long side end portions are bent in the same direction, or mutually. The one bent in the opposite direction is used.

  The invention according to claim 6 is the fin tube according to any one of claims 1 to 5, wherein adjacent fins having openings formed at different positions are used.

  According to the present invention, there is provided a fin tube for a high-performance air-cooled condenser capable of avoiding the problem of groundwater depletion in inland urban areas and economically constructing power equipment even in inland areas where cooling water is scarce. be able to.

  Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the drawings. FIG. 1 is a perspective view showing a schematic configuration of a first embodiment of a fin tube according to the present invention with a part thereof broken. In the figure, a tube 1 is a flat shape that condenses this through steam. A large number of fins 11A having substantially the same outer shape and rectangular shapes are joined to the outer flat portion 2 of the tube 1 by, for example, brazing. In the fin 11A, the opposite long side end portions are bent at substantially right angles in the same direction, and intermediate portions of these long side end portions are cut and raised at a plurality of locations, and the louver 12 and the opening 13 are cut and raised portions. And one of the end portions is joined to the outer flat portion 2 of the tube 1 and the other end portion is joined to the other to form the air flow paths 14 each having a rectangular cross section in order. ing. And the fin tube 10 is comprised by the tube 1 and many fin 11A. In addition, although the fin 11A similar to the above is joined also to the other outer flat part 2 of the tube 1, it is abbreviate | omitting for the simplification of drawing.

  FIG. 2 is a perspective view showing a detailed configuration of the fin 11A. Here, the fin 11A has a rectangular outer shape, and the long side end portions are bent in the same direction to form bent portions 11a and 11b. Of these bent portions 11a and 11b, one bent portion 11b is brazed to the outer flat portion 2 of the tube 1, and the tip of the other bent portion 11a is brazed to the base end of the bent portion 11a of the other fin. The The louvers 12 and the openings 13 are formed at three positions at substantially equal intervals in the fin longitudinal direction, that is, the X direction, in the center of the fin height direction, that is, the Y direction. The louvers 12 are formed so as to have an inclination of 45 degrees with respect to an imaginary line segment parallel to the short side.

  Incidentally, when the fin height A is about 22 mm, the width B of the bent portions 11a and 11b is about 2 mm, and when the louver 12 is formed about 6 mm away from the bent portions 11a and 11b, the louver pitch C in the X direction is the louver. The height of the louver 12 itself is about 1 to 2 mm, which is 1 to 2 times the length of 12.

  A plurality of fins 11A shown in FIG. 2 are brazed to the outer flat portion 2 of the tube 1 in a state of being packed in the longitudinal direction of the tube 1 with the width of the bent portion 11b, and the bent portions 11a are adjacent to each other. By brazing each other, a large number of air flow paths 14 having a rectangular cross-sectional shape are formed as shown in FIG. In this case, it is important that all the louvers 12 are inclined in the same direction.

  With the above configuration, for example, when cooling air is introduced in the direction indicated by the arrow W in FIG. 2, this cooling air is deflected by the louver 12 toward the bent portion 11 b side part of which is joined to the tube 1. The other part flows out to the adjacent air flow path 14 through the opening 13, and the remaining part passes between the louver 12 and the bent portion 11a. The air flow condition is turbulent and passes through the air flow path 14. Further, the air flowing in the vicinity of the bent portion 11b increases in speed, and further, a part of the increased air flows out of the air in the adjacent air flow path 14 through the opening 13 as the atmospheric pressure decreases. The action to enter is performed.

  Thus, according to the first embodiment shown in FIGS. 1 and 2, by providing the fin 11A with the louver 12 and the opening 13, the flow state of the cooling air becomes turbulent, and the vertical direction of the wall surface Since the exchange of fluid particles is promoted and the heat transfer coefficient is increased, high performance of the fin tube for the air-cooled condenser is realized.

  FIG. 3 is a perspective view showing only the shape of the fin, omitting the joined state with the tube 1 as a second embodiment of the fin tube according to the present invention. In the figure, the same elements as those in FIG. The fin 11B shown here is different from the fin 11A shown in FIG. 2 only in that one bent portion 11a and the other bent portion 11c at the end of the long side are bent in opposite directions. 2 are all the same. The fins 11B shown in FIG. 3 are brazed to the outer flat portion 2 of the tube 1 in a state of being packed in the longitudinal direction of the tube 1 with the width of the bent portion 11c, and the bent portions 11a are adjacent to each other. By brazing each other, a large number of air flow paths 14 having a rectangular cross-sectional shape are sequentially formed as shown in FIG. In this case, it is important that all the louvers 12 are inclined in the same direction.

  Thus, the high performance of the fin tube for the air-cooled condenser is also realized by the second embodiment in which the fins 11B are shown in FIG.

FIG. 4 is a perspective view showing only the shape of the fin, omitting the joined state with the tube 1 as a third embodiment of the fin tube according to the present invention. In the figure, the same elements as those in FIG. The fin 11C shown here has two rows of louvers and openings formed in the height direction of the fins, that is, the Y direction, and 1 at the same time that the plate is cut and raised in the longitudinal direction of the fins, that is, the X direction. The louvers 12 ₁₁ , 12 ₁₂ , 12 ₁₃ in the row and the louvers 12 ₂₁ , 12 ₂₂ , 12 _{23 in} the second row are formed. In this case, the inclination angle is formed to align on the same extension line from each other the same as the first louvers 12 ₁₁ and louvers 12 ₂₁ viewed in the X direction. Similarly, the second louver 12 ₁₂ and louver 12 ₂₂ as viewed in the X direction, and the third louver 12 ₁₃ and louver 12 ₂₃ have the same inclination angle and are formed on the same extension line. .

  As described above, by forming the louver 12 and the opening 13 shown in FIG. 2 in a divided manner, there is an advantage that the flow state of the cooling air tends to be turbulent.

FIG. 5 is a perspective view showing only the shape of the fin, omitting the joined state with the tube 1 as a fourth embodiment of the fin tube according to the present invention. In the figure, the same elements as those in FIG. The fin 11D shown here has two rows of louvers and openings formed in the height direction of the fins, that is, the Y direction, and one row at the same time as the plate is cut and raised in the longitudinal direction of the fins, that is, the X direction. The eye louvers 12 ₁₁ , 12 ₁₂ , and 12 ₁₃ and the second row of louvers 12 ₂₁ , 12 ₂₂ , and 12 ₂₃ are formed. In this case, the first louvers 12 ₁₁ and louvers 12 ₂₁ viewed in the X direction is formed by aligning a passage end of the cooling air at the same distance. Similarly, the second louver 12 ₁₂ and louver 12 ₂₂ as viewed in the X direction, and the third louver 12 ₁₃ and louver 12 ₂₃ are also formed at the same distance from the circulation end of the cooling air.

  As a result, the air flow situation is slightly different from that shown in FIG. 4, but the advantage that it is easy to create a turbulent state is obtained.

  FIG. 6 is a side view showing a fifth embodiment of the fin tube according to the present invention, in which the joined state with the tube 1 is omitted, the shapes of a pair of adjacent fins are overlapped, and a part thereof is broken. It is. In this embodiment, a fin 11E in which two rows of louvers 12 and openings 13 are formed at different positions in the fin longitudinal direction and a fin 11F in which two rows of louvers 12 'and openings 13' are formed are connected to the tube 1. It is shown alternately arranged in the longitudinal direction. In this case, the louver 12 and the opening 13 and the louver 12 'and the opening 13' are formed at positions shifted by just a half pitch in the fin longitudinal direction.

  By comprising in this way, the flow condition of cooling air can be made more turbulent.

  FIG. 7 is a perspective view showing only the shape of the fin, omitting the joined state with the tube 1 as a sixth embodiment of the fin tube according to the present invention. In the fin 11G shown here, opposite long side end portions are bent at substantially right angles in the same direction to form bent portions 11a and 11b. Then, three offset louvers 15 different from those in the above embodiments are formed in the air flow direction at the intermediate portion between these bent portions 11a and 11b. The offset louver 15 is formed by cutting a part of the fins in parallel and press-molding the fins so as to be raised in a trapezoidal shape, and has openings 16 arranged side by side in the air flow direction.

  In this case, a part of the cooling air flows out from the upstream opening 16 to the adjacent air flow path 14, or the cooling air of the adjacent air flow path 14 flows from the downstream opening 16. As in the above embodiments, the flow state of the cooling air becomes turbulent, the replacement of fluid particles in the direction perpendicular to the wall surface is promoted, and the heat transfer coefficient increases, so the performance of the fin tube for the air-cooled condenser is improved. Is realized.

  Incidentally, the lifting length A of the offset louver 15 in the fin height direction is 12.5 mm, the distance between the bent portions 11a and 11b is 5 mm, the width B in the fin longitudinal direction is 5 mm, and the distance between adjacent offset louvers 15 is 25 mm. Good results have been obtained by creating

  In addition, three offset louvers 15 are formed not only in the cooling air flow direction as shown in FIG. 7, but also in a plurality of rows in the fin height direction, or as described with reference to FIG. The same effect as described above can be obtained by forming two types so as to be shifted by half a pitch from each other and alternately joining to the outer flat portion 2 of the tube 1.

  Further, the fin 11G shown in FIG. 7 has the long side end portions bent in the same direction, but even if these long side end portions are bent in opposite directions, the fins for the air-cooled condenser are the same as described above. High performance of the tube is realized.

  Thus, according to each of the above-described embodiments, the high performance of the fin tube for the air-cooled condenser is realized, thereby avoiding the problem of depletion of groundwater in inland urban areas, and also in the inland area where cooling water is scarce. Equipment can be built economically.

  As described above, the amount of inflow is increased by improving the heat transfer performance of the fin. When the amount of inflow steam increases, the flow velocity increases and the pressure loss also increases. Since this increase in pressure loss reduces the effect of increasing heat transfer performance, if the cross-sectional area of the tube 1 is made larger than the improvement in heat transfer performance, there will be no increase in flow velocity. Can be suppressed.

The perspective view which fractured | ruptured and showed the schematic structure of 1st Embodiment of the fin tube which concerns on this invention. The perspective view which shows the detailed structure of the fin which comprises the fin tube shown in FIG. The perspective view which abbreviate | omitted the joining state with the tube as 2nd Embodiment of the fin tube which concerns on this invention, and showed only the shape of the fin. The perspective view which abbreviate | omitted the joining state with the tube as 3rd Embodiment of the fin tube which concerns on this invention, and showed only the shape of the fin. The perspective view which abbreviate | omitted the joining state with the tube as 4th Embodiment of the fin tube which concerns on this invention, and showed only the shape of the fin. The side view which abbreviate | omitted and showed the shape of a pair of fin which adjoins mutually as a 5th embodiment of the fin tube which concerns on this invention, abbreviate | omitted the joining state with a tube. The perspective view which abbreviate | omitted the joining state with the tube as 6th Embodiment of the fin tube which concerns on this invention, and showed only the shape of the fin. The perspective view which fractured | ruptured and crimped a part of conventional fin tube used for an air-cooled condenser. The expanded sectional view which showed the state which brazed the end of the fin which comprises the fin tube shown in FIG. 8 to the outer flat part of the tube. The diagram which showed the relationship between the height of a fin and heat transfer performance among the main shape parameters regarding the heat transfer performance of a fin tube.

Explanation of symbols

1, 21 Tube 2, 22 Outer flat portion 10, 20 Fin tube 11A to 11G, 23 Fin 11a, 11b, 11c Bending portion 12 Louver 13, 12 _{11 to} 12 ₂₃ Opening 14 Air flow path 15 Offset louver 16 Opening

Claims (6)

A flat tube,
The outer shapes are substantially the same rectangle, the opposing long side ends are bent at a substantially right angle, and a plurality of openings penetrating from the front surface to the back surface are formed between these long side ends, One louver projecting from one end in the short side direction and inclined by a predetermined angle with respect to an imaginary line segment parallel to the short side is formed, and one of the bent long side ends is an outer flat portion of the tube A plurality of fins that are joined to each other, and the other of the bent long-side end portions are joined to each other to form air passages each having a rectangular cross-sectional shape, and
Fin tube with.   The fin tube according to claim 1, wherein a plurality of the openings and louvers are formed in the long side direction and are formed in one or a plurality of rows.   The fin tube according to claim 1 or 2, wherein an inclination angle of the louver is about 45 degrees. A flat tube,
An offset louver in which the outer shapes are substantially the same rectangle, the opposing long side ends are bent at a substantially right angle, and a plurality of openings penetrating from the front surface to the back surface are arranged in the long side direction between the long side ends. One of the bent long side end portions is joined to the outer flat portion of the tube, and the other of the bent long side end portions is joined to the other to form a rectangular cross section. A number of fins that sequentially form the air flow path,
Fin tube with.   The fin according to any one of claims 1 to 4, wherein the fins used are those in which opposite long side ends are bent in the same direction, or those in which the fins are bent in opposite directions. tube.   The fin tube according to claim 1, wherein the adjacent fins have the openings formed at different positions.

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