JP2002048488A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger to enable reduction of a content amount of a header as a sufficient pressure strength is ensured and enable ensuring of lightness not accompanied by an increase in weight. SOLUTION: The tube connection side of a hollow header 2 is formed in a flat wall part 10 and the tube non-connection side thereof in an arcuate wall part 11, the two sides being smoothly interconnected through a curve-form connection wall part 12. Parameters, such as a radius of curvature Ra of the outer surface of the flat wall part 10, a radius of curvature Rb of the outer surface of the connection wall part 12, and a radius of curvature r of the outer surface of the arcuate wall part 11, are set to a particular range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat exchanger used as a condenser for a car cooler, a room air conditioner, and the like.

[0002]

2. Description of the Related Art In recent years, for example, as a condenser for a car cooler, a so-called multi-flow type heat exchanger has been widely used.

In such a condenser, since the pressure of the refrigerant flowing inside the condenser is high, a cross section as shown in FIG. 4A is used as a header (100) in order to improve the pressure resistance of the condenser. Circular ones are used. Alternatively, a pair of header halves (10
2) A split type in which (103) is integrated is often used.

[0004]

By the way, since the header is a portion which does not contribute to heat exchange and is a portion which becomes a so-called dead space, it is necessary to make the header as small as possible in terms of heat exchange efficiency. Is desired.

[0005] However, the former header (100) having a circular cross section is excellent in terms of pressure resistance, but the diameter of the header must be large enough to insert the end of the tube (101). As a result, the maximum width of the header in the longitudinal direction of the tube (101) is increased, which causes a problem that the internal capacity of the header (100) is increased, that is, a dead space portion that does not contribute to heat exchange is increased.

On the other hand, in the latter split type, the cross section is substantially elliptical, and although the internal capacity of the header can be reduced and the dead space can be reduced to some extent, it is necessary to secure sufficient pressure resistance. In addition, it is necessary to increase the thickness of the header half (102) on the connection side of the tube (101), so that the weight of the header increases, and there is a problem that the weight cannot be reduced.

The present invention has been made in view of such technical background, and it is possible to reduce the internal capacity of a header while securing sufficient pressure resistance, and to reduce the weight without increasing the weight. It is an object of the present invention to provide a heat exchanger that can ensure the heat exchange.

[0008]

In order to achieve the above object, the present inventor has conducted intensive studies and found that the tube connection side of the hollow header is a flat wall and the tube non-connection side is an arc wall. And these are smoothly connected by a curved connecting wall, and parameters such as the radius of curvature of the outer surface of the flat wall, the radius of curvature of the outer surface of the connecting wall, and the radius of curvature of the outer surface of the arcuate wall are used. By setting to a specific range, it has been found that the desired heat exchanger can be obtained, and the present invention has been completed.

That is, a heat exchanger according to the present invention is a heat exchanger in which a plurality of tubes for heat exchange are connected to a hollow header in a communicating state. In the meantime, the peripheral wall on the tube non-connection side is formed in an arc-shaped wall, and the arc-shaped wall and the flat-shaped wall are smoothly formed by the curved connecting wall. The present invention is characterized in that it is configured so as to be connected, and is configured to satisfy all of the following conditions A to E.

Condition A: r = 5 to 15 mm Condition B: Ra ≧ 6 r Condition C: Rb ≧ 4 mm Condition D: h = 4 to 6 mm Condition E: T = 0.1 r to 0.2 r (Ra: flat wall portion) Rb: radius of curvature of the outer surface of the connecting wall, r: radius of curvature of the outer surface of the arc-shaped wall,
h: perpendicular length from the center of the arc of the arc-shaped wall to the outer surface of the flat wall, T: thickness of the peripheral wall of the header).

Since the configuration is such that all of the above conditions A to E are satisfied, the internal capacity of the header can be reduced while securing sufficient pressure resistance as the header. Further, it is not necessary to increase the thickness of the header peripheral side wall in order to secure the pressure resistance, so that the weight of the header is not increased, so that the lightness is also ensured. Further, since the peripheral length of the header is reduced due to the presence of the flat wall portion, the weight of the header is reduced correspondingly, which contributes to further weight reduction.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat exchanger (1) according to one embodiment of the present invention will be described with reference to the drawings. The heat exchanger shown in FIG. 3 is an aluminum condenser used in a car cooler or a room air conditioner, and (1) is a plurality of flat tubes for heat exchange;
(2) (2) is a hollow header, (3) ... are fins. The fin (3) is a corrugated fin made of an aluminum brazing sheet. (4) (4) is a partition member, (5) is a refrigerant inlet pipe, and (6) is a refrigerant outlet pipe.

A plurality of flat tubes (1) are arranged in parallel at a predetermined interval from each other, and a pair of hollow headers (2) (2) are in internal communication with both ends of these tubes (1), respectively. And the fins (3) are arranged between the tubes (1).
Tube (1) excluding hollow header (2) and (2)
The portion constituted by the fins (3) is a core portion effective for heat exchange.

Further, the inside of the hollow headers (2) and (2) is partitioned at predetermined positions in the longitudinal direction by partition members (4) and (4), and the lengths of the headers (2) and (2) are correspondingly changed. At a predetermined position in the direction, the refrigerant inlet pipe (5) and the refrigerant outlet pipe (6) are connected in communication with each other, and the refrigerant inlet pipe (5)
Refrigerant flows from the tubes (1)... In a meandering manner and leaves the refrigerant outlet pipe (6).

The flat tubes (1) are, as shown in FIG. 3 (c), a harmonica tube formed in an elliptical cross section and having upper and lower flat walls connected by connecting walls. It depends on the shape. In addition, a tube made of an electric resistance welded pipe may be used.

The hollow header (2) comprises a tubular header pipe (2a) and lids (2b) (2b) for sealing the ends of the pipe (2a) in a sealed state. The header pipe (2a) is a brazing pipe formed by bending an aluminum brazing sheet in which a brazing material layer is clad on one or both sides of a core material in a state in which both side edges are abutted. These headers (2) (2)
On the peripheral side wall opposite to the side where the side edge abutting portion (9) is located, tube insertion holes (7) are provided at predetermined intervals along the length direction thereof, and the tube insertion holes (7) are provided. Are inserted and connected to both ends of each tube (1). As the header pipe (2a), for example, an electric resistance welded pipe, an extruded pipe, or the like may be used in addition to the above-described brazed pipe.

A flat wall portion (1) in which the peripheral side wall of the hollow header (2) on the tube connection side swells outward.
0), while the peripheral side wall on the tube non-connection side is formed in an arc-shaped wall portion (11), and the arc-shaped wall portion (11) and the flat wall portion (10) are curved connecting walls. It is configured to be smoothly connected by the portion (12). The arc-shaped wall portion (11) is formed so as to form a substantially semicircular arc in the circumferential direction of the header (2).

The cross-sectional shape of the hollow header (2) having the characteristic shape as described above is configured so as to further satisfy all of the following conditions A to E.

Condition A: r = 5 to 15 mm Condition B: Ra ≧ 6 r Condition C: Rb ≧ 4 mm Condition D: h = 4 to 6 mm Condition E: T = 0.1 r to 0.2 r (Ra: flat wall portion) Rb: radius of curvature of the outer surface of the connecting wall, r: radius of curvature of the outer surface of the arc-shaped wall,
h: length of the perpendicular from the center of the arc (K) of the arc-shaped wall to the outer surface of the flat wall, T: thickness of the peripheral wall of the header.

The adoption of the flat wall portion (10) makes it possible to reduce the internal capacity of the header (2). In addition, the header (2) is configured to satisfy all of the above conditions A to E. Therefore, it is possible to reduce the internal capacity of the hollow header (2) while securing sufficient pressure resistance. Further, since it is not necessary to increase the thickness (T) of the header peripheral side wall in order to ensure the pressure resistance, the weight of the header (2) is not increased, and the weight is also secured. Further, the perimeter of the header (2) is reduced due to the presence of the flat wall portion (10), and accordingly, the weight of the header (2) is reduced, and the weight is further reduced.

The radius of curvature (R) of the outer surface of the flat wall (10)
a) is the radius of curvature (r) of the outer surface of the arc-shaped wall portion (11), which is 6;
If it is less than twice, sufficient pressure resistance cannot be secured.
The radius of curvature (Rb) of the outer surface of the connecting wall portion (12) is 4
If it is less than mm, sufficient pressure resistance cannot be secured. The perpendicular length (h) from the arc center (K) of the arc-shaped wall portion (11) to the outer surface of the flat wall portion (10) is 4 mm.
If it is less than this, it becomes difficult to assemble the tube (1).
It becomes difficult to satisfy the condition B. On the other hand, if it exceeds 6 mm, the internal capacity cannot be sufficiently reduced. Furthermore,
If the thickness (T) of the header peripheral side wall is less than 0.12 times the radius of curvature (r) of the outer surface of the arc-shaped wall portion (11), sufficient pressure resistance cannot be ensured, and if it exceeds 0.15 times, the header ( It is difficult to secure the lightness of 2). When the radius of curvature (r) of the outer surface of the arc-shaped wall portion (11) deviates from the above-described limited range, a substantially semi-arc shape having an appropriate size is formed as the arc-shaped wall portion (11) of the header (2). It will be difficult.

Thus, in the condenser having the above structure, the high-pressure gaseous refrigerant is received through the refrigerant inlet pipe (5), and while flowing through the internal passage, the air and heat flowing in the condenser in the front-rear direction are exchanged with the heat. After the exchange, the refrigerant is condensed and liquefied and exits from the refrigerant outlet pipe (6). As described above, the hollow header (2) is formed by the flat wall (10), the arc-shaped wall (11) and Since the header (2) is constituted by the curved connecting wall portion (12) that smoothly connects them and satisfies all of the above conditions A to E, the header (2) sufficiently withstands the pressure of the high-pressure gas refrigerant. The use of the flat wall (10) can reduce the internal capacity of the header (2), and can reduce the size of the dead space that does not contribute to heat exchange. Good and bad .

[0023]

Next, specific embodiments of the present invention will be described.

<Example 1> In the hollow header, the peripheral side wall on the tube connection side is formed as a flat wall portion bulging outward, while the peripheral side wall on the tube non-connection side is formed in an arc wall portion. A wall header and the flat wall portion are smoothly connected by a curved connecting wall portion, and a hollow header in which the above conditions are set to the following values is manufactured. A vessel was manufactured.

Condition A: r = 10 mm Condition B: Ra = 60 mm Condition C: Rb = 4 mm Condition D: h = 5 mm Condition E: T = 1.3 mm The stress generated in the conventional header having a circular cross section of 100% is reduced.
Then, the generated stress in this header was 163%, and the generated stress was suppressed to be small, and it was confirmed that a sufficient pressure-resistant strength could be secured.

The internal volume of the header can be reduced by about 25% as compared with the conventional header having a circular cross section. Further, the peripheral length of the header is also reduced by about 10% as compared with the conventional header having a circular cross section, the weight of the header is reduced by about 10%, and the weight of the header can be reduced. Was something.

<Example 2> A configuration similar to that of Example 1 was adopted except that the respective conditions were set to the following values.

Condition A: r = 7.94 mm Condition B: Ra = 50 mm Condition C: Rb = 4 mm Condition D: h = 4 mm Condition E: T = 1.1 mm The stress generated in a conventional header having a circular cross-section is calculated as follows: 100%
Then, the generated stress in this header was 146%, the generated stress was small, and it was confirmed that sufficient pressure resistance could be ensured. The data of Example 2 is omitted in Table 1.

[0029]

[Table 1]

Comparative Example 1 Condition A was fixed at r = 10 mm, condition D was fixed at h = 5 mm, condition E was fixed at T = 1.3 mm, and condition B (Ra = 20, 30, 40, 50, 50) was fixed. 6
0 mm) and condition C (Rb = 2, 3, 4 mm) were set to respective values, and evaluation was performed in the same manner as described above. Table 1 shows the results. All the generated stresses were large, and it was difficult to secure sufficient pressure resistance.

[0031]

According to the heat exchanger of the present invention, the peripheral side wall on the tube connection side of the hollow header is formed as a flat wall portion bulging outward, while the peripheral side wall on the tube non-connection side is formed as an arc-shaped wall portion. The arc-shaped wall portion and the flat-shaped wall portion are smoothly connected by a curved connecting wall portion, and the use of the flat-shaped wall portion can reduce the internal capacity of the header. However, since the configuration is such that all of the above conditions A to E are satisfied, the internal capacity of the hollow header can be reduced while securing sufficient pressure resistance. Therefore, since the size of the dead space that does not contribute to heat exchange can be reduced, the heat exchanger can have excellent heat exchange efficiency.

Further, since it is not necessary to increase the thickness of the peripheral side wall of the header in order to secure the pressure resistance, the weight of the header is not increased and sufficient lightness is secured. Furthermore,
Since the peripheral length of the header is also reduced by the presence of the flat wall portion, the weight of the header is correspondingly reduced, thereby further reducing the weight.

In addition, since the peripheral side wall on the tube connection side of the header is formed in the flat wall portion, the brazing length between the header and the tube is short, and it is possible to reduce the occurrence of brazing defects. At the same time, the assemblability of the tube is improved.

[Brief description of the drawings]

1A and 1B are views showing a header, wherein FIG. 1A is a side view of a tube connection side, and FIG. 1B is a cross-sectional view taken along line XX in FIG.

FIGS. 2A and 2B are views showing a header in a state where a tube is connected, wherein FIG. 2A is an enlarged front view of a main part, FIG. 2B is a sectional view taken along line YY in FIG. 2A, and FIG. It is a side view.

FIG. 3 is a view showing a heat exchanger, (a) is a front view,
(B) is a right side view.

FIG. 4 is a diagram showing a cross section of a header in a conventional heat exchanger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tube 2 ... Hollow header 10 ... Flat wall part 11 ... Arc-shaped wall part 12 ... Curved surface connection wall part

Claims (1)

[Claims] 1. A heat exchanger in which a plurality of heat exchange tubes are connected to a hollow header in a communicating state, wherein the hollow header is formed in a flat wall portion whose peripheral side wall on the tube connection side expands outward. On the other hand, the peripheral side wall on the tube non-connection side is formed in an arc-shaped wall portion, and the arc-shaped wall portion and the flat wall portion are smoothly connected by a curved connecting wall portion. A heat exchanger configured to satisfy all of the conditions A to E. Condition A: r = 5 to 15 mm Condition B: Ra ≧ 6r Condition C: Rb ≧ 4 mm Condition D: h = 4 to 6 mm Condition E: T = 0.1r to 0.2r (Ra: outer surface of the flat wall portion) Radius of curvature, Rb: radius of curvature of the outer surface of the connecting wall, r: radius of curvature of the outer surface of the arc-shaped wall,
h: perpendicular length from the center of the arc of the arc-shaped wall to the outer surface of the flat wall, T: thickness of the peripheral wall of the header)