CN103857974B - Fin-tube heat exchanger and its manufacture method - Google Patents

Abstract

The present invention provides a finned tube heat exchanger, which has: a plurality of fins (1) forming a gas flow path; and a heat conduction tube (21) passing through the plurality of fins and circulating fluid for heat exchange with gas , the fins have: a first inclined portion (6), which is inclined relative to the flow direction of the gas so that at least one peak portion (3) is formed; tube peripheral portions (5), which are respectively formed at The first position and the second position pass through the periphery of the heat transfer tube of the fin; and the second inclined part (7), which connects the surrounding part of the tube and the first inclined part to each other, and connects the respective first positions in the first position and the second position The groove portion (8) of the second inclined portion is formed on the surface of the first inclined portion, whereby the condensed water flows along the groove portion and is smoothly guided downward in the direction of gravity, thereby improving drainage performance.

Description

Finned tube heat exchanger and its manufacturing method

technical field

The present invention relates to a finned tube heat exchanger for exchanging heat with gas and its manufacturing method.

Background technique

Conventionally, such a finned tube heat exchanger is composed of a plurality of fins arranged at predetermined intervals and a heat transfer tube passing through the plurality of fins. Air (gas) flows between the fins to exchange heat with the fluid in the heat pipe.

Here, in the case of using a finned tube heat exchanger as an evaporator, when the surface temperature of the fin is lower than the dew point of the air for heat exchange, moisture in the air condenses and water droplets (condensed water) adhere to the fin surface. When condensed water adheres to the surface of the fins in this way, moisture bridging (crosslinking) occurs between adjacent fins, and the air flow path between the fins is blocked by the condensed water, resulting in an increase in ventilation resistance.

As a result, in equipment such as an air conditioner and a water heater using such a finned tube heat exchanger, there are problems of increased power consumption and decreased energy efficiency. Therefore, it is preferable to quickly remove condensed water from the fin surface.

Therefore, by forming a hydrophilic coating layer on the surface of the fins and reducing the contact angle with respect to the water adhering to the surface of the fins, the drainage performance is improved and the air flow path between the fins caused by the generated condensed water is prevented. of clogging (for example, see reference 1).

In addition, there is also a device for improving hydrophilicity by irradiating a hydrophilic coating layer on the surface of a fin with plasma to form fine unevenness (for example, refer to Document 2).

In addition, there is also a device that improves drainage of condensed water by forming drain grooves on fins (for example, refer to Document 3). FIG. 10 shows the structure of the finned tube heat exchanger of the document 3. As shown in FIG. As shown in FIG. 10 , a drain groove 116 is provided on the fin 131 , and the drain groove 116 extends obliquely downward along the surface of the fin 131 from the stagnant area of drain water (condensed water 113 ) under the heat pipe 121 . By providing the drain groove 116 , the condensed water 113 stagnant in the drain stagnation area below the heat transfer pipe 121 is quickly drained.

prior art literature

non-patent literature

Document 1: Hideko Hirasawa "Surface Treatment Technology of Pre-coated Aluminum Fin Material", Surface Technology, Vol.57 (2006), No.2, p.127

patent documents

Document 2: (Japanese) Unexamined Patent Publication No. 2010-175131

Document 3: (Japan) Publication No. 64-22186

Contents of the invention

The problem to be solved by the invention

However, the technique described in Document 1 has a problem of insufficient drainage of condensed water, particularly when cross-linking of condensed water occurs between fins stacked at predetermined intervals.

In addition, in the technique described in Document 2, when fine unevenness is formed on the surface of the fin, an expensive processing process such as plasma irradiation is required, and there is a problem that the production cost is very high.

In addition, the technology described in Document 3 is a technology in which discharge grooves are provided on flat fins. As shown in FIGS. 2 and 5 of Document 3, it is difficult to avoid crosslinking between adjacent fins and cannot sufficiently The problem of smoothly guiding condensed water to the bottom of the fins.

The present invention was developed in view of the above circumstances, and an object of the present invention is to provide a finned tube heat exchanger and a manufacturing method thereof that improve drainage performance of condensed water adhering to the fin surface through an inexpensive process and that are excellent in energy efficiency.

Technical solutions for solving problems

In order to solve the above-mentioned conventional problems, the present invention provides a finned tube heat exchanger characterized in that it has: a plurality of fins arranged in parallel to form gas flow paths therebetween; A heat transfer pipe having a plurality of fins and passing a fluid for heat exchange with the gas inside, the fins having: a first inclined portion inclined with respect to the flow direction of the gas so as to form at least one peak; the circumference of the pipe parts, which are respectively formed at the circumference of the heat transfer tube penetrating the fin at first and second positions separated from each other in the direction of gravity; A manner in which an inclined portion is connected to each other is inclined relative to the gas flow direction, and a groove portion connecting the second inclined portion at the first position and the second inclined portion at the second position is formed in the first inclined portion s surface.

Invention effect

According to the present invention, it is possible to provide a finned tube heat exchanger excellent in energy efficiency in which drainage performance of condensed water adhering to the surface of the fins is improved by an inexpensive process.

Description of drawings

Fig. 1 is a perspective view of a finned tube heat exchanger according to Embodiment 1 of the present invention.

2A is a plan view of corrugated fins of the finned tube heat exchanger according to Embodiment 1. FIG.

Fig. 2B is an AA sectional view of the corrugated fin of Fig. 2A.

Fig. 2C is a BB sectional view of the corrugated fin in Fig. 2A.

3 is a cross-sectional view showing a fin material structure of the fin-tube heat exchanger according to Embodiment 1. FIG.

FIG. 4 is an explanatory view of a state in which condensed water stagnates in the corrugated fins of the finned tube heat exchanger according to the comparative example of the first embodiment.

Fig. 5 is an explanatory diagram of the condensed water drainage function of the corrugated fins of the finned tube heat exchanger according to the first embodiment.

6 is a cross-sectional view showing a detailed shape of a groove portion of the fin-tube heat exchanger according to Embodiment 1. FIG.

7 is a cross-sectional view showing another detailed shape of the groove portion of the fin-tube heat exchanger according to Embodiment 1. FIG.

Fig. 8 is a plan view of corrugated fins of a finned tube heat exchanger according to Embodiment 2 of the present invention.

9A is a plan view of corrugated fins of the finned tube heat exchanger according to Embodiment 3. FIG.

Fig. 9B is an AA sectional view of the corrugated fin of Fig. 9A.

Fig. 9C is a BB sectional view of the corrugated fin in Fig. 9A.

Fig. 10 is a plan view of a fin of a conventional finned tube heat exchanger.

Detailed ways

The first invention provides a finned tube heat exchanger comprising: a plurality of fins arranged in parallel to form a gas flow path therebetween; A heat pipe for heat exchange fluid, the above-mentioned fins have: a first inclined portion, which is inclined with respect to the direction of gas flow so as to form at least one peak portion; The position and the second position pass through the periphery of the heat transfer tube of the above-mentioned fin; and the second inclined part, which is inclined with respect to the flow direction of the gas in such a manner as to connect the above-mentioned tube peripheral part and the above-mentioned first inclined part to each other, connects the above-mentioned first inclined part. The first inclined portion and the groove portion of the second inclined portion at the second position are formed on the surface of the first inclined portion.

Thereby, condensed water can be efficiently guided downward in the direction of gravity from the second inclined portion (or from the pipe peripheral portion via the second inclined portion) which is the main stagnation area of the condensed water through the groove portion. That is, the condensed water stagnant at the second slope at the first position can be efficiently guided to the second slope at the second position below the first position in the direction of gravity through the groove. Thereby, the drainage performance of condensed water adhering to the fin surface can be improved, crosslinking between adjacent fins and the like can be suppressed, and a fin-tube heat exchanger excellent in energy efficiency can be provided. In addition, such a groove portion can be formed by a relatively simple process, and an increase in manufacturing cost accompanying the formation of the groove portion can be suppressed.

A second invention is the finned tube heat exchanger according to the first invention, wherein the opening width of the groove is 2 mm or less.

Accordingly, since a capillary effect is generated between the groove portion and the condensed water, the condensed water can be drained more efficiently.

The third invention is the finned tube heat exchanger according to the first or second invention, wherein in the fins, the ridges of the peaks formed by the first slope are arranged along the direction of gravity, and the grooves are arranged in the direction of gravity. direction extension.

Thereby, the condensed water which has entered into the groove part can be efficiently drained downward in the direction of gravity.

A fourth invention is the finned tube heat exchanger according to any one of the first to third inventions, wherein the fin has a base material and a coating layer formed on the surface of the base material, and the layers constituting the coating layer are Part of it is a hydrophilic coating.

As a result, the condensed water stagnant at the tube periphery or the second inclined portion spreads (spreads) flatly along the fin surface due to the hydrophilic coating, further suppressing the occurrence of crosslinking, and making it easier to guide the condensed water to the groove. water.

The fifth invention provides the method for manufacturing the finned tube heat exchanger according to the fourth invention, comprising forming the first inclined portion, the second inclined portion, and the second slope simultaneously by using the base material after forming the hydrophilic coating on the base material. The fins are formed by forming the inclined portion and the groove portion.

Accordingly, since the first and second inclined portions and the groove portions of the fins are formed at the same time, it is possible to provide a finned tube heat exchanger with reduced manufacturing costs and excellent energy efficiency without increasing the manufacturing process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(implementation mode 1)

FIG. 1 shows a perspective view of a finned tube heat exchanger according to Embodiment 1 of the present invention. As shown in FIG. 1 , the finned tube heat exchanger 100 according to Embodiment 1 has a plurality of fins 1 arranged in parallel at predetermined intervals in order to form a flow path of air A (gas), and a fin penetrating through these fins 1 . Heat pipe 21. The finned tube heat exchanger 100 exchanges heat between the medium B flowing inside the heat transfer tube 21 and the air A flowing along the surface of the fin 1 .

As the medium B, for example, a refrigerant such as carbon dioxide or hydrofluorocarbon can be used. The heat transfer pipe 21 may be connected into one, or may be divided into a plurality.

2A, 2B, and 2C show the detailed structure of the fin 1 according to the first embodiment. As shown in FIG. 2A , the fin 1 is formed so that at least one peak 3 appears with respect to the flow direction S of the air. Specifically, the fin 1 has two crests 3 with respect to the air flow direction S, and is formed as a corrugated fin having a substantially M-shaped cross-sectional shape as shown in the cross-sectional view of FIG. 2B .

In addition, as shown in FIG. 2B and FIG. 2C , the fin 1 has a tube peripheral portion 5 formed around the heat transfer tube 21 passing through the fin 1 , and a first peak portion 3 that is inclined with respect to the flow direction S of the air to form a peak portion 3 . The inclined portion 6 and the second inclined portion 7 connecting the pipe peripheral portion 5 and the first inclined portion 6 to each other.

As shown in FIG. 2B , two peaks 3 and valleys 4 disposed between the peaks 3 are formed by alternately connecting first inclined portions 6 having different inclination angles with respect to the air flow direction S. In the fin 1 according to Embodiment 1, the ridges of the peaks 3 and the valleys 4 are formed along the direction of gravity, respectively.

The tube peripheral portion 5 is an annular portion disposed so as to surround the periphery of the heat transfer tube 21 at the penetration position where the heat transfer tube 21 penetrates into the fin 1 . As shown in FIG. 2C , in Embodiment 1, the tube peripheral portion 5 is formed as a flat surface that is a plane along the air flow direction. In addition, as shown in FIG. 2A , the heat transfer tubes 21 penetrate the fin 1 at a plurality of positions separated along the gravity direction, and the tube peripheral portions 5 are provided at the respective penetration positions.

The second inclined portion 7 is a portion disposed around the pipe peripheral portion 5 . As shown in FIG. 2C , the pipe peripheral portion 5 which is a flat surface and the first inclined portion 6 which is an inclined surface are connected by a second inclined portion 7 which is an inclined surface. Therefore, as shown in FIG. 2C , a concave region surrounded by the inclined surface of the second inclined portion 7 is formed around the penetration position of the heat transfer pipe 21 . This concave area becomes an area where condensed water tends to stagnate.

In the fin 1 according to Embodiment 1, a plurality of concave grooves 8 for draining the condensed water accumulated in the second slope 7 are formed. Specifically, the concave groove portion 8 is formed so as to extend in the gravitational direction on the surface of the pair of first inclined portions 6 forming the valley portion 4 . Each groove portion 8 is formed along the peak portion 3 and the valley portion 4 , and is formed in the vicinity of the valley portion 4 .

In addition, as shown in FIG. 2A , in the fin 1 , the first position P1 and the second position P2 that are separated from each other in the direction of gravity are respectively disposed in the concave region around the heat transfer pipe 21 of the fin 1 (the second inclination part 7) are connected to each other by a plurality of groove parts 8. That is, each groove portion 8 extends in the gravitational direction to connect concave regions surrounded by the gravitational adjacent second inclined portions 7 to each other. In addition, it is preferable that at least a part of the concave cross section of the groove portion 8 is opened on the second slope portion 7 side at the connection portion with the second slope portion 7 .

As for the material of the surface of the fin 1, it is preferable to use a metal whose contact angle with water is 30 degrees or less. In addition, when the metal is exposed to air or moisture, an oxide film or a corrosion product is formed, so a substrate having a hydrophilic coating formed by surface treatment as a substrate constituting the fin 1 can also be used.

In this case, as the fin material, as shown in FIG. 3 , a material in which the coating layer 10 is formed on the surface of the base material 9 is used. The coating layer 10 is a layer in which a corrosion-resistant coating 10a is superimposed, and a hydrophilic coating 10b and a lubricating coating 10c are superimposed thereon. As for the base material 9, a steel material, a copper material, or an aluminum material can be applied.

The corrosion-resistant coating 10 a is formed by phosphoric acid chromate treatment, and the hydrophilic coating 10 b can use inorganic (water glass-based, boehmite-based), organic resin-based, and organic-inorganic composite-based coatings. In Embodiment 1, as the hydrophilic coating 10b, a coating formed of a composite coating of silica/resin, which is an organic-inorganic composite, is used by chemical conversion treatment.

In addition, the lubricating coating 10 c is used to improve the lubricity when the fin material is press-worked into the fin 1 , and when a water-soluble coating is used, it tends to disappear due to condensed water generated on the fin 1 . Therefore, the hydrophilicity of the hydrophilic coating 10b is not lowered by the lubricating coating 10c formed on the upper layer.

In this way, if at least one layer of the coating layer 10 composed of a plurality of layers is constituted by the hydrophilic coating 10b, condensed water spreads flatly along the surface of the fin. Therefore, generation of cross-linking between adjacent fins 1 and the like can be suppressed, and condensed water can be easily guided to the groove portion 8 as will be described later.

Next, with regard to the fin-tube heat exchanger 100 of the first embodiment having such a structure, the operation and effect of discharging the condensed water adhering to the fins 1 will be described.

Here, FIG. 4 shows a plan view of the fin 1 in which the groove portion 8 is not formed in the fin-tube heat exchanger as a comparative example of the first embodiment. In addition, the structure other than the groove part 8 is attached|subjected with the same reference number as each component of the fin 1 of this Embodiment 1, and the description is abbreviate|omitted.

As shown in FIG. 4 , in the finned tube heat exchanger of the comparative example in which the groove portion 8 is not formed, the condensed water 13 generated in the fin 1 , especially around the heat transfer tube 21 gradually flows along the surface of the fin 1 . flow downward in the direction of gravity. The condensed water 13 gradually stagnates in the pipe peripheral portion 5 and the second slope portion 7 without passing over the peak portion 3 at the boundary portion with the first slope portion 6 .

When the condensed water 13 is further generated, the amount of retained condensed water increases, crosslinking occurs between adjacent fins 1 , and the space between the fins 1 is blocked. As a result, the ventilation resistance increases, and the heat transfer area of the fins for heat exchange with air decreases, resulting in a decrease in energy efficiency.

Next, the drainage action of the condensed water in the fin 1 of the first embodiment will be described using FIG. 5 . 5 , (a), (b), (c), and (d) are sequentially arranged sequentially from the left. First, as shown in FIG. 5( a ), at the first position P1 , when the condensed water 13 starts to stagnate in the second inclined portion 7 , the stagnant condensed water is guided to the second inclined portion 7 as shown in FIG. 5( b ). In the groove part 8 connected to the lower part of the part 7 in the direction of gravity, the condensed water is guided by the groove part 8 to the second inclined part 7 at the second position P2 adjacent to the lower part in the direction of gravity. Condensed water 13 is guided from the tube peripheral part 5 and the second inclined part 7 above the gravity direction (first position P1) to the tube circumference below the gravity direction (second position P2) by the guide action of the condensed water generated by the groove part 8. Section 5 and the second inclined section 7 are conveyed (Fig. 5(c)). By repeating the guide action of the condensed water generated in the groove portion 8 , the condensed water 13 is further conveyed downward ( FIG. 5( d )).

In this way, the condensed water 13 accumulated in the tube peripheral portion 5 and the second inclined portion 7 can be quickly discharged by the guiding function of the condensed water generated by the groove portion 8 , so that the drainage performance of the fin 1 can be remarkably improved.

Furthermore, in Embodiment 1, the grooves 8 are formed so as to connect the second inclined portions 7 adjacent in the direction of gravity to each other. When the second inclined portion 7 at the lower position in the direction of gravity is in contact with each other, the condensed water remaining on the second inclined portion 7 can be guided downward in the direction of gravity.

In addition, in the first embodiment, two grooves 8 are formed parallel to the ridgeline of the peak 3 formed by the first slope 6 , but there may be one groove 8 or three or more grooves. In addition, in the first embodiment, the grooves 8 are formed avoiding the ridgelines of the peaks 3 or valleys 4 formed by the first slope 6, but the peaks 3 or valleys 4 may be further formed on these ridgelines. Concave to form a groove.

In addition, as shown in FIG. 6 , the opening width L of the groove portion 8 is preferably 2 mm or less in order to utilize the capillary phenomenon, and preferably 0.5 mm or less in order to further enhance the effect of the capillary phenomenon. By adopting such an opening width dimension, it is possible to significantly improve the guiding effect of the condensed water 13 generated in the groove portion 8 .

In addition, the shape of the groove portion 8 shown in FIG. 6 is configured so that the side surface 8a is inclined in consideration of the reduction of the ventilation resistance of the air passing between the fins 1. However, as shown in FIG. 7, the side surface 8a may also be vertical. It may be formed in a pointed shape (V-shape) such that opposing side surfaces 8 a meet at bottom 8 b.

In the fin 1 of the first embodiment having such a structure, the first inclined portion 6 , the second inclined portion 7 , and the groove portion 8 can be simultaneously formed by pressing the base material on which the film layer is formed. Therefore, it is possible to manufacture an inexpensive fin-tube heat exchanger with excellent drainage without adding a new process.

(Embodiment 2)

Fig. 8 is a plan view of the fins of the finned tube heat exchanger according to Embodiment 2 of the present invention. In addition, in this second embodiment, the same components as those in the above-mentioned first embodiment are given the same reference numerals, and their detailed descriptions are omitted.

The second embodiment differs from the first embodiment described above in that grooves 8 are provided near the crests 3 of the fins 1 .

As shown in FIG. 8 , the groove portion 8 is formed to connect adjacent second inclined portions 7 in the gravity direction along the crest portion 3 of the fin 1 .

In such a structure, each lower end in the direction of gravity of the second inclined portion 7 is connected to each upper end of the groove portion 8, so that the condensed water 13 stagnant on the second inclined portion 7 can be smoothly guided downward.

(Embodiment 3)

9A is a plan view of corrugated fins of a finned tube heat exchanger according to Embodiment 3 of the present invention, and FIGS. 9B and 9C are cross-sectional views. In addition, in this Embodiment 3, the same reference numerals are assigned to the same components as in the above-mentioned Embodiment 1, and detailed description thereof will be omitted.

The difference between this third embodiment and the above-mentioned first embodiment is that, as shown in FIG. 9B and FIG. 9C , the fins 15 are formed as corrugated fins having a substantially inverted V-shaped cross-sectional shape (that is, only one peak 3).

In addition, as shown in FIG. 9A , the groove portion 8 is formed to connect the adjacent second slope portions 7 in the direction of gravity along the crest portion 3 of the fin 15 .

Generally, the V-shaped corrugated fin tends to have a larger surface area than the M-shaped corrugated fin, and tends to improve heat exchange performance.

On the other hand, compared with the M-shaped corrugated fin, the V-shaped corrugated fin has the problem that the stagnation area of the condensed water 13 becomes larger due to the larger area of the flat tube peripheral portion 5 and the second inclined portion 7 , and the condensed water 13 is easy to stay.

Therefore, like the third embodiment, by providing the groove portion 8, the condensed water 13 can be smoothly guided downward in the direction of gravity. Therefore, a V-shaped corrugated fin having high heat exchange performance and excellent drainage performance can be realized.

In the above description, the case where the groove portion 8 extends in the gravitational direction has been described as an example, but the groove portion only needs to continuously have a direction component downward in the gravitational direction, for example, it may be inclined or curved relative to the gravitational direction. Happening.

In the above description, the case where the drainability of the condensed water adhering to the fin surface can be improved by providing grooves on the fin surface has been described, but in addition to the condensed water, the drainability of liquid adhering to the fin surface can also be improved .

In addition, in the above description, the case of exchanging heat with the air passing through the finned tube heat exchanger has been described as an example, but it is also possible that a gas other than air passes through the finned tube heat exchanger and is exchanged with the air. A case where heat is exchanged between gases.

In addition, by appropriately combining any of the various embodiments described above, respective effects can be achieved.

Preferred embodiments of the present invention have been fully described with reference to the accompanying drawings, but it is a matter of course for those skilled in the art that various modifications and corrections can be made. Such changes and corrections should be understood to be included in the scope of protection of the present invention as long as they do not depart from the scope of the present invention of the appended claims.

Industrial availability

As described above, the finned tube heat exchanger of the present invention can improve drainage by the grooves provided on the surface of the fins, so it can be applied to heat exchangers used in air conditioners, water heaters, heaters, and the like.

Symbol Description

1, 15 fins (corrugated fins)

3 peaks

4 Tanibe

5 around the tube

6 first slope

7 Second inclined part

8 slots

9 Substrate

10 coating layer

10a Corrosion Resistant Coating

10b Hydrophilic coating

10c Lubricious coating

13 Condensate

21 heat pipe

100 Fin Tube Heat Exchanger

P1 first position

P2 second position

S Air flow direction

L Opening width dimension of the opening

Claims (5)

1. a kind of fin-tube heat exchanger, it is characterised in that have：

For the multiple fins for forming gas flow path among each other and being arranged in parallel；With

Penetrate the multiple fin and circulation internally carry out the heat conducting pipe of the fluid of heat exchange with the gas,

The fin has：

Two the first inclined planes, it is inclined such that at least one valley of formation, and by described relative to the flow direction of gas The crest line connection of valley；

Pipe periphery, it is respectively formed in penetrates the fin in the separated first position of gravity direction and the second place Around the heat conducting pipe；

Second inclined plane, it is so that the pipe periphery and described two first inclined planes are mutually connected relative to gas Flow direction tilt,

Connect second inclined plane of the first position and second inclined plane of the second place groove portion avoid it is described The crest line of valley and it is arranged on first inclined plane along the crest line, the groove portion is in first inclined plane and described the The Border Open of two inclined planes.

2. fin-tube heat exchanger as claimed in claim 1, it is characterised in that：

The A/F size of the groove portion is below 2mm.

3. fin-tube heat exchanger as claimed in claim 1, it is characterised in that：

In the fin, the crest line of the valley formed by first inclined plane configures along gravity direction, the groove portion Extend in gravity direction.

4. such as fin-tube heat exchanger according to any one of claims 1 to 3, it is characterised in that：

The fin has base material and is formed at the coating layer on the surface of the base material, forms a part for the layer of the coating layer For hydrophilic coating film.

A kind of 5. manufacture method of fin-tube heat exchanger, it is characterised in that：

It is the manufacture method of the fin-tube heat exchanger described in manufacturing claims 4, forms the hydrophily on the substrate After overlay film, shape first inclined plane, second inclined plane, the groove portion simultaneously using the base material and shape the wing Piece.