JP2008261611A - Outdoor unit for air conditioner, and bending device and method for fin and tube type heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein sufficient heat exchange performance cannot be obtained due to the increase of ventilation resistance as an inside fin clearance is short compared with a center part in a bent part of a fin and tube type heat exchanger of approximately L-shape, U-shape or other shape. <P>SOLUTION: This outdoor unit for an air conditioner comprises the fin and tube type heat exchanger 2 held in a casing 1 and having linear parts 2s and bent parts 2c, and a fan 5 allowing air current to flow to the heat exchanger. In this case, the fin pitch P<SB>2</SB>of the bent part is enlarged to satisfy an expression 1: P<SB>2</SB>=k×P<SB>1</SB>when the fin pitch of the linear part of the heat exchanger is set to P<SB>1</SB>and the fin pitch of the bent part is set to P<SB>2</SB>, wherein a coefficient k satisfies 1.05≤k≤1.15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an outdoor unit of an air conditioner, a bending apparatus for a fin-and-tube heat exchanger that can be preferably used in the outdoor unit, and a bending method.

  As a conventional outdoor unit of an air conditioner, in order to uniformize the wind speed distribution due to the positional relationship between the propeller fan and the fin-and-tube heat exchanger, the fin pitch of the part where the wind speed is fast is made dense and the part where the wind speed is slow Sparse fin pitch (see, for example, Patent Document 1), plate fin tube heat exchanger is divided into a plurality of upper and lower parts, and the fin pitch and fin notch shape are changed, or the fin shape is trapezoidal By making the triangle, the air pressure loss when passing through the heat exchanger is changed, and the wind flow between the heat exchanger and the fan is changed, and the front wind speed of the plate fin tube heat exchanger is made uniform (See, for example, Patent Document 2).

JP-A-7-198167 (first page, FIG. 1) Japanese Patent Laid-Open No. 11-118199 (first page, FIG. 3)

  Recently, in an air conditioner or the like, a plate-like fin-and-tube heat exchanger is, for example, an L shape or U shape in order to achieve both reduction in size and cost and improvement in heat exchange efficiency. A heat exchanger bent in a U-shape or the like is used. Among them, in the conventional heat exchangers such as Patent Documents 1 and 2, since the fin pitch inside the bent portion of the heat exchanger is smaller than the fin pitch of the straight portion, the pressure loss at the bent portion is large. As a result, there was a problem that sufficient heat exchange performance at the bent portion could not be obtained.

  The present invention was made to solve the above-described problems of the prior art, and is an outdoor unit of an air conditioner that has improved heat exchange performance at a bent portion of a fin-and-tube heat exchanger, An object of the present invention is to provide a bending apparatus and a bending method for a fin-and-tube heat exchanger that can be preferably mounted on the outdoor unit or the like.

An outdoor unit of an air conditioner according to the present invention includes a fin-and-tube heat exchanger having a straight portion and a bent portion, which is housed in a housing, and a fan for allowing an air flow to flow through the heat exchanger. In the outdoor unit of the air conditioner provided, when the fin pitch of the straight part of the heat exchanger is P ₁ and the fin pitch of the bent part is P ₂ , the above (Formula 1) is satisfied. The fin pitch P2 of the bent portion is widened.
P ₂ = k × P ₁ (Formula 1)
However, the coefficient k is 1.05 ≦ k ≦ 1.15.
Further, a bending apparatus for a fin-and-tube heat exchanger according to the present invention includes a gantry holding a fin-and-tube heat exchanger, and a rotator provided to be rotatable with respect to the gantry. A clamp for gripping a predetermined portion on one end side, a drive device for rotating the clamp, and the other end portion of the heat exchanger held on the gantry in the axial direction of the heat exchanger according to the rotation operation of the clamp And a pusher for moving to the clamp side.
Also, the bending method of the fin-and-tube heat exchanger according to the present invention is a method of bending a fin-and-tube heat exchanger in which the fin pitch of the bent portion is larger than the fin pitch of the straight portion. After clamping the straight part on one side with respect to the bent part, the clamp is rotated and at the same time, the straight part on the other side is pushed in the direction of the bent part without bending the inner bending die. is there.

According to the outdoor unit of the air conditioner of the present invention, the fin pitch of the straight portion of the fin-and-tube heat exchanger is made dense, and the fin pitch of the bent portion is made sparse, so that the heat exchange performance of the bent portion is improved. There is an unprecedented remarkable effect such as improvement.
Further, according to the fin and tube type heat exchanger bending apparatus of the present invention, the other end of the heat exchanger held by the gantry is moved in the axial direction of the heat exchanger according to the pivoting operation of the clamp. By providing the pusher to be moved to the clamp side, the inner bending die is not required, and the fin buckling of the bending portion of the obtained fin-and-tube heat exchanger can be eliminated.
Further, according to the method of bending a fin-and-tube heat exchanger according to the present invention, the buckling of the bent portion of the obtained fin-and-tube heat exchanger is generated without using the inner bending die. Can be bent without

Embodiment 1 FIG.
1 to 4 schematically illustrate the main parts of an outdoor unit of an air conditioner according to Embodiment 1 of the present invention. FIG. 1 is a top view, FIG. 2 is a front view, and FIG. 1 is a detailed view around the bent portion of the fin-and-tube heat exchanger shown in FIG. 1, and FIG. 4 is a detailed view of the fin-and-tube heat exchanger shown in FIG. 1 before bending. In the drawings, the same reference numerals denote the same or corresponding parts. In the figure, the outdoor unit of the air conditioner is a container that is arranged along the outer periphery of the casing 1 composed of a bottom plate 1a and four pillars 1b and the three-way outer periphery of the bottom plate 1a in the casing 1. A fin-and-tube heat exchanger 2 curved in a letter shape, a machine room 3 for storing a refrigerant circuit such as a compressor provided inside the U-shape of the heat exchanger 2, and an upper front side of the machine room 3 And a propeller fan 5 installed upward on the top of the housing 1.

The fin-and-tube heat exchanger 2 is composed of fins (straight fins) 21 and tubes 22, and in a state before bending, the fin pitch of the bent portion 2 c with respect to the fin pitch P ₁ of the straight portion 2 s. P ₂ is set to expand as the following equation (1).
P ₂ = k × P ₁ (Formula 1)
However, the coefficient k is 1.05 ≦ k ≦ 1.15.
In the above configuration, the bending process is performed in the bending process of the fin-and-tube heat exchanger 2, but the elongation rate of the tube 22 at this time is 2% or less, and the influence on the fin pitch is ignored. possible for the central bending radius R, and the width of the fin 21 is C, fin pitch P ₂ of the bent portion 2c is as follows (equation 2).

  As a commonly used fin dimension, the width C of the fin 21 is 16 mm ≦ C ≦ 20 mm, and the central bending radius R is 70 mm ≦ R ≦ 150 mm. The fin pitch is set to be substantially equal to the fin pitch in the straight portion 2s.

  Next, the operation of the first embodiment configured as described above will be described. The fan 5 sucks air in the direction of arrow A through the fin-and-tube heat exchanger 2 disposed on both sides and the back of the housing 1 and discharges it upward as shown by arrow B. When passing through the fin-and-tube heat exchanger 2, the pitch of the fins 21 in the bent portion 2c is expanded so as to be sparser than the straight portion 2s, and the pitch inside the bent portion 2c is equal to the pitch of the straight portion 2s. Equally, since the outside of the bent portion 2c is wider than the pitch of the straight portion 2s, the pressure loss of the bent portion 2c after bending is made equal to the pressure loss of the straight portion 2s. Good ventilation and heat exchange are ensured.

As described above, according to the first embodiment, with respect to the fin pitch P ₁ of the straight portion 2s of the heat exchanger 2, the fin pitch P ₂ in the bent portion 2c, so as to satisfy the above equation (1) As a result, the heat exchange performance at the bent portion 2c can be increased. In addition, when the pressure loss which generate | occur | produces in the part which the bending part 2c is obstruct | occluded by the pillar 1b is large, it can eliminate by making the value of k larger than 1.15 as needed. Furthermore, by widening the fin pitch P ₂ of the bent portion 2c, it is possible to reduce the overall number of fins used, effects such as can be achieved cost reduction can be obtained.
In the following description of the embodiments, portions common to those in FIGS. 1 to 4 will be described with reference to FIGS. 1 to 4 and the reference numerals as appropriate.

Embodiment 2. FIG.
FIG. 5 is a front view showing fins of a fin-and-tube heat exchanger, which is a main part of an outdoor unit of an air conditioner according to Embodiment 2 of the present invention. In the figure, a large number of louvers 21a are cut and raised in the fin 21A. In the second embodiment, the fin pitch of the fin-and-tube heat exchanger 2 is the same in the straight portion 2s and the bent portion 2c as in the first embodiment, and the straight portion 2s has the fin pitch as shown in FIG. A louver-shaped fin 21A formed by cutting and raising a large number of louvers 21a is used, and a straight fin 21 similar to that of the first embodiment having a flat surface is used for the bent portion 2c.

  According to the second embodiment, with the above configuration, the louver-shaped fin 21A used for the straight portion 2s has a larger pressure loss than the straight-type fin 21 used for the bent portion 2c. Therefore, the pressure loss of the bent portion 2c can be made equal to the pressure loss of the straight portion 2s, and the heat exchange performance at the bent portion 2c can be increased. In addition, since the louver-shaped fin 21A is used for the straight portion 2s, the heat exchange performance in the straight portion 2s can be further increased, so that the performance of the entire apparatus can be further increased. Further, since the straight fin 21 used in the bent portion 2c has a higher buckling strength than the louver-shaped fin 21A, there is an advantage that a yield due to the buckling of the fin hardly occurs during bending.

Embodiment 3 FIG.
6A and 6B show fins of a fin-and-tube heat exchanger that is a main part of an outdoor unit of an air conditioner according to Embodiment 3 of the present invention. FIG. 6A is a front view, and FIG. 6B is a side view. It is. In the figure, the fin 21B has a step D formed by bending both end portions in the width direction into a cross-sectional crank shape. The third embodiment is the same as the first embodiment in that the fin pitch is the same between the straight portion and the bent portion, and a step D is formed on the straight portion 2s of the fin-and-tube heat exchanger as shown in FIG. A fin 21B provided with a straight surface and a flat fin 21 having a flat surface similar to that of the first embodiment is used for the bent portion 2c. Other configurations are the same as those of the first embodiment.

  In the third embodiment configured as described above, the fin 21B provided with the step D used for the straight portion 2s has a larger pressure loss than the straight fin 21 used for the bent portion 2c. The pressure loss of the bent portion 2c and the pressure loss of the straight portion 2s can be made equal, and the heat exchange performance at the bent portion 2c can be increased. Moreover, by using the fin 21B provided with the step D, the fin surface area at the straight portion 2s is increased, and the heat exchange performance can be further enhanced.

Embodiment 4 FIG.
FIG. 7 is a front view schematically showing a bending apparatus and a bending method for a fin-and-tube heat exchanger according to Embodiment 4 of the present invention, in which (a) is before bending and (b) is Shown after bending. In the figure, a bending apparatus for a fin-and-tube heat exchanger includes, for example, a gantry 6 holding a linear fin-and-tube heat exchanger 20 similar to that shown in FIG. A clamp 7 which is provided so as to be rotatable in the direction of arrow E and grips a predetermined portion on one end side (right side in the figure) of the heat exchanger 20, a drive device 8 which rotates the clamp 7 in the direction of arrow E, and The pusher 9 is configured to move the other end (left side of the drawing) of the heat exchanger 20 held on the gantry 6 in the direction of the arrow F in the axial direction of the heat exchanger 20 in accordance with the rotation of the clamp 7. ing. In addition, in FIG. 7, the fin of the heat exchanger 20 is abbreviate | omitting illustration and has shown typically in the form integrated with the tube.

  Next, the operation of the bending apparatus configured as described above and the bending method will be described. A linear fin-and-tube heat exchanger 20 installed on the gantry 6 is fixed by a clamp 7, and the clamp 7 is rotated in the direction of arrow E by the driving device 8, and at the same time, interlocked with the rotation operation. Then, by pushing the pusher 9 installed at the rear portion of the heat exchanger 20 in the direction of the bending portion G indicated by the arrow F, the fin and bent in a substantially L shape as shown in FIG. A tube-type heat exchanger is obtained.

Next, an example in which the fin and tube type heat exchanger is configured in three rows in the ventilation direction using the fin and tube type heat exchanger bending apparatus and bending method shown in FIG. explain. Table 1 fin width C of about 17.67Mm, the bent portion of the pipe (tube) fin pitch _{P 2} of about 1.6mm at the center, the bending radius R of the first column (inside) of about 69.00Mm, When the bending radius R of the second row (center) is about 86.67 mm and the bending radius R of the third row (outside) is about 104.33 mm, the inner fin pitch P _2a and the outer fin pitch P _2b of each row Design values are shown.

The fin-and-tube heat exchanger having a three-row configuration bent into a substantially L shape using the fin-and-tube heat exchanger bending apparatus shown in FIG. 7 with respect to the design values in Table 1 above. (Not shown) The average value (Avr.) Of the measured values at 30 locations in total for each of the inner fin pitch P _2a and the outer fin pitch P _2b of the bent portion of each row, and the fin pitch P at the center of the tube Table 2 shows a value (1.6 / Avr.) Obtained by dividing ₂ (= about 1.6 mm) by an average value (Avr.). As is apparent from Table 2, the fin-and-tube heat exchanger obtained by the bending apparatus and the bending method of the present invention is processed into a fin pitch substantially equal to the designed value, and fins are used for all samples. The occurrence of buckling was not observed. Further, in this example, the spreading rate (1.6 / Avr., Equivalent to the count k) of the fin pitch P ₂ (= about 1.6 mm) at the center of the tube when the inner fin pitch P _2a is 1 is 1.129 to 1.086, which is in the range of 1.05 ≦ k ≦ 1.15.

  As described above, according to the bending apparatus and the bending method of the fourth embodiment, a cylindrical inner bending die (not shown) is not used at the center of bending as in the conventional bending apparatus. The heat exchanger 20 can be bent. Further, according to such a bending method, it is not necessary to bring the heat exchanger 20 into contact with the inner bending mold, and therefore, for example, the fin pitch of the heat exchanger 2 similar to that shown in FIG. Even if the buckling strength of the fin formed sparsely in the bent portion 2c (scheduled bent portion) is reduced, the bending processing is performed without causing the fin buckling in the bending processing portion G. Can do. In the above embodiment, the linear fin-and-tube heat exchanger 20 is used. However, the heat exchanger 20 is not limited to this. For example, an L-shaped bent portion is further bent to be U-shaped. Even when it is formed into a shape, it can be applied.

Embodiment 5. FIG.
FIG. 8 is a top view schematically showing main parts of a fin-and-tube heat exchanger according to Embodiment 5 of the present invention. In the figure, the fin-and-tube heat exchanger 2 is placed together with a normal fin 21 at a place where a buckling of the fin can occur or a place where the buckling of the fin is likely to occur during a bending process, such as a bent part or a clamp part during bending. The fins 21C having a large thickness or high buckling strength are mixed at a predetermined ratio. Since other configurations are the same as those of the first embodiment, description thereof is omitted.
In the fifth embodiment configured as described above, since the fin 21C having a high buckling strength is responsible for the load applied to the fins 21 and 21C in the bending process by the bending apparatus, the yield due to the buckling of the fins is reduced. The effect that it can be obtained.

The top view which shows typically the principal part of the outdoor unit of the air conditioner by Embodiment 1 of this invention. The front view of the outdoor unit shown by FIG. FIG. 2 is a detailed view around a bent portion of the fin-and-tube heat exchanger shown in FIG. 1. The detailed view before the bending process of the fin and tube type heat exchanger shown in FIG. The front view which shows the fin of the fin and tube type heat exchanger which is the principal part of the outdoor unit of the air conditioner by Embodiment 2 of this invention. The fin of the fin and tube type heat exchanger which is the principal part of the outdoor unit of the air conditioner by Embodiment 3 of this invention is shown, (a) is a front view, (b) is a side view. It is a front view which shows typically the bending apparatus of the fin and tube type heat exchanger by Embodiment 4 of this invention, and the bending method, (a) is before a bending process, (b) is after a bending process. Indicates. The top view which shows typically the principal part of the fin and tube type heat exchanger by Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Case, 1a Bottom plate, 1b Pillar, 2, 20 Heat exchanger, 2s Straight part, 2c Bending part, 21, 21A, 21B, 21C Fin, 21a Louver, 22 Tube, 3 Machine room, 4 Control box, 5 Fan , 6 frame, 7 clamp, 8 drive, 9 pusher, C step, G bending part.

Claims (6)

In an outdoor unit of an air conditioner including a fin-and-tube heat exchanger having a straight portion and a bent portion, and a fan for allowing an air flow to flow through the heat exchanger, housed in the housing, the heat When the fin pitch of the straight portion of the exchanger is P ₁ and the fin pitch of the bent portion is P ₂ , the fin pitch P ₂ of the bent portion is set to the fin of the straight portion so as to satisfy the following (Formula 1). outdoor unit of an air conditioner, characterized in that spread than the pitch P _1.
P ₂ = k × P ₁ (Formula 1)
However, the coefficient k is 1.05 ≦ k ≦ 1.15.   In an outdoor unit of an air conditioner including a fin-and-tube heat exchanger having a straight portion and a bent portion, and a fan for allowing an air flow to flow through the heat exchanger, housed in the housing, the heat An outdoor unit of an air conditioner, wherein a louver fin having a plurality of louvers cut and raised is used for a straight portion of an exchanger, and a straight fin having a flat surface is used for the bent portion.   In an outdoor unit of an air conditioner including a fin-and-tube heat exchanger having a straight portion and a bent portion, and a fan for allowing an air flow to flow through the heat exchanger, housed in the housing, the heat An outdoor unit of an air conditioner, wherein fins having a step are used in a straight portion of an exchanger, and straight fins having a flat surface are used in the bent portion.   A gantry that holds a fin-and-tube heat exchanger, a clamp that is rotatably provided to the gantry and that grips a predetermined portion on one end of the heat exchanger, and a drive device that rotates the clamp. A fin-and-tube comprising a pusher that moves the other end of the heat exchanger held by the gantry to the clamp side in the axial direction of the heat exchanger in accordance with the rotation of the clamp. Bending device for mold heat exchanger.   In a method of bending a fin-and-tube heat exchanger in which the fin pitch of the bent portion is larger than the fin pitch of the straight portion, after clamping the straight portion on one side with respect to the bent portion, the clamp is rotated. At the same time, the bending method for the fin-and-tube heat exchanger is characterized by bending the other side straight portion in the direction of the bending portion without using the inner bending die.   Fin-and-tube heat exchange, characterized by mixing thick fins or fins with high buckling strength at locations where fin buckling is likely to occur during bending of fin-and-tube heat exchangers Bending method of vessel.

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