JP2007192474A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat exchanging efficiency near a bent portion of a tube, in a longitudinally-turned type heat exchanger. <P>SOLUTION: In this heat exchanger, an arranging order in the tube width direction, of refrigerants R flowing in refrigerant passages 12 is same between the refrigerant passages 12 at a windward side of cooling wind W and the refrigerant passages 12 at a leeward side at the bent part 7 formed on an intermediate part of the tube 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat exchanger that includes a heat exchange region that is substantially U-shaped in a plan view, and that allows a refrigerant to flow through the heat exchange region in a front-rear turn manner.

Conventionally, as a method for improving the performance of a heat exchanger, a method in which a refrigerant is used as a counter flow is known. In condensers and radiators used for automotive air conditioners and engine cooling, the core part is arranged at the front and back with respect to the cooling air inflow direction, and the refrigerant is turned from one core to the other core part to face each other. The front and back turn method is known. As a conventional example of such a front-rear turn type heat exchanger, a twisted bent portion is provided at an intermediate portion of each tube, and a U-shaped bent portion is formed at this portion, whereby a refrigerant is connected with one communicating tube. Is known to be turned back and forth (see Patent Document 1).
JP-A-8-145580

  However, as in the above Japanese Patent Laid-Open No. 8-145580, in a heat exchanger of a type in which the refrigerant is turned back and forth by bending the communicating tube into a U shape, the refrigerant temperature in the vicinity of the bent portion of the tube has a temperature of the heat exchanger. There is a problem that the heat exchange efficiency is lowered because the temperature becomes lower at the center in the thickness direction and the temperature difference from the cooling air becomes smaller.

  An object of the present invention is to improve heat exchange efficiency in the vicinity of a bent portion of a tube in a front-rear turn type heat exchanger.

  In order to solve the above-described problems, a heat exchanger according to the present invention is configured such that a tube having a plurality of refrigerant passages and cooling fins are alternately stacked, and a bent portion formed in an intermediate portion is substantially U-shaped in plan view. And a pair of header tanks connected to both ends of the core body respectively, and cooling air flowing perpendicularly to the refrigerant passage of the core body in plan view, and refrigerant flowing through the refrigerant passage A heat exchanger for exchanging heat between the refrigerant passages in the tube width direction of the refrigerant flowing through the refrigerant passages, the same order for the refrigerant passages on the upstream side of the cooling air and the refrigerant passages on the leeward side It is characterized by being in order.

  According to the above configuration, since the refrigerant temperature of the refrigerant passing through the refrigerant passage on the air downstream side of the core body can be increased, the temperature difference with the cooling air is increased, and the heat exchange efficiency can be improved. .

  Hereinafter, embodiments of a heat exchanger according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a heat exchanger according to the present embodiment. As shown in FIG. 1, the heat exchanger 1 according to the present embodiment includes a core body 2 formed so as to be substantially U-shaped in plan view, and inlet headers connected to both ends of the core body 2. A tank 3 and an outlet header tank 4 are provided.

  The core body 2 includes a first core portion 5 and a second core portion 6 in which tubes 10 each having a plurality of refrigerant passages and cooling fins 11 are alternately stacked, and a bent portion 7 formed at an intermediate portion thereof. It consists of and.

  As shown in FIG. 2, the tube 10 of the core body 2 is a flat tube having a multi-hole tube structure, in which a bent portion 7 is formed at an intermediate portion thereof and straight portions 8 and 9 are formed on both sides. Of these, the bent portion 7 is bent so that the tube ends are located on the same plane and the straight portions 8 and 9 are arranged in parallel, and the tube 10 is substantially U-shaped in plan view. The bent portion 7 is a refrigerant passage of the straight portion 9 in which the arrangement order in the tube width direction of the refrigerant R flowing through the plurality of refrigerant passages 12 formed inside the straight portions 8 and 9 is the upwind side of the cooling air W. 12 and the refrigerant passage 12 of the straight portion 8 on the leeward side are twisted as a whole in the same order. As the tube 10, for example, a metal member such as aluminum that can be easily bent can be used.

  By inserting the cooling fins 11 into the straight portions 8 and 9 of the tube 10 configured as described above and laminating them in the height direction, the first core portion 5 and the second core portion 6 serving as a heat exchange region are provided. The core body 2 can be manufactured. In this embodiment, the windward side of the cooling air W is the second core part 6, and the leeward side is the first core part 5.

  As shown in FIG. 1, the inlet header tank 3 is connected to a refrigerant inlet pipe 13, and distributes the refrigerant R flowing in from the inlet pipe 13 to each tube 10 of the first core portion 5 that communicates therewith. . The outlet header tank 4 is connected to the outlet pipe 14, and discharges the refrigerant R that has passed through the tubes 10 of the second core portion 6 that is in communication from the outlet pipe 14 to the outside. That is, the refrigerant R passes through the first core portion 5 from the inlet header tank 3, turns back at the bent portion 7, passes through the second core portion 6, and is further discharged from the outlet header tank 4 to the outside. While the refrigerant R passes through the first core portion 5 and the second core portion 6, the temperature of the refrigerant R is lowered by exchanging heat with the cooling air W.

  Next, the operation of the configuration of the present embodiment will be described with reference to FIG. FIG. 3A is an explanatory diagram showing the relationship between the refrigerant temperature and the air temperature in the vicinity of the bent portion 7 of the tube 10. FIG. 3B is an explanatory view showing the relationship between the refrigerant temperature and the air temperature in the conventional tube, and shows a portion corresponding to the twisted bent portion of the above-mentioned Japanese Patent Application Laid-Open No. 8-145580. (Some shapes are omitted).

  As shown in FIG. 3B, in the conventional example, the arrangement order of the refrigerant R in the tube width direction is different between the refrigerant passage on the windward side of the cooling air W and the refrigerant passage on the leeward side. The arrangement order of the passages e to a is the arrangement order of a to e on the leeward side. On the other hand, as shown in FIG. 3A, in this embodiment, the arrangement order of the refrigerant R in the tube width direction is the same for the refrigerant passage on the upstream side of the cooling air W and the refrigerant passage on the leeward side, The arrangement order of the refrigerant passages a to e on the leeward side is also the order of a to e on the leeward side.

  3A and 3B, when the cooling air W flows through the tubes arranged at the front and rear, the cooling air W exchanges heat with the refrigerant, so that the air temperature is increased from the windward side. It gradually rises toward the leeward. In the conventional example, as shown in FIG. 3 (b), the refrigerant temperature of the refrigerant passing through the central portion in the thickness direction of the heat exchanger, that is, the inner refrigerant passage a is lowered, Since the refrigerant passing through the refrigerant passage a has a small temperature difference from the cooling air W, the heat exchange efficiency is lowered (the same applies to the refrigerants in the refrigerant passages b to d). On the other hand, in the configuration of the present embodiment, as shown in FIG. 3A, the refrigerant temperature of the refrigerant passing through the refrigerant passage e on the inner side of the windward side can be increased. A temperature difference becomes large and heat exchange efficiency can be improved (the same applies to the refrigerant passages b to d).

Next, another configuration example of the tube will be described with reference to FIG. 4A is a perspective view showing another configuration example of the tube, FIG. 4B is a side view when viewed from the arrow I of FIG. 4A, and FIG. 5 is a cross-sectional view when the core portion is configured. Is shown. In each figure, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  In the tube 10 shown in FIG. 2, both tube ends are located on the same plane. However, in the tube 10A of this example, the tube ends are moved up and down by one stage as shown in FIGS. 4 (a) and 4 (b). It is set at a position shifted in the direction. In the case of such a tube configuration, the bending angle of the bent portion 7 becomes gentler than in the example of FIG. 2, so that the flow of the refrigerant becomes smooth and the bending process becomes easy. Further, when the tube portion 10A of this example is laminated to constitute the core portion, as shown in FIG. 5, the straight portion (8 or 9) is not arranged in parallel at the uppermost portion and the lowermost portion. 11 becomes difficult to hold. However, by arranging the dummy tubes (indicated by a two-dot chain line in the figure) above and below, the cooling fins 11 can be reliably held in the tube width direction even at the uppermost part and the lowermost part.

The schematic block diagram of the heat exchanger concerning embodiment. The perspective view of a tube. (A) is explanatory drawing which shows the relationship between the refrigerant | coolant temperature and air temperature in the bending part vicinity of a tube. (B) is explanatory drawing which shows the relationship between the refrigerant | coolant temperature and air temperature in the tube of a prior art example. (A) is a perspective view which shows the other structural example of a tube. (B) is a side view when (a) is viewed from an arrow I. Sectional drawing at the time of comprising a core part using the tube of Fig.4 (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heat exchanger 2 ... Core main body 3 ... Inlet header tank 4 ... Outlet header tank 5 ... 1st core part 6 ... 2nd core part 7 ... Bending part 8 ... Straight part (leeward side)
9 ... Straight section (windward side)
DESCRIPTION OF SYMBOLS 10, 10A ... Tube 11 ... Cooling fin 12 ... Refrigerant passage 13 ... Inlet pipe 14 ... Outlet pipe

Claims (1)

Tubes (10) having a plurality of refrigerant passages (12) and cooling fins (11) are alternately stacked, and formed into a substantially U shape in plan view by a bent portion (7) formed in an intermediate portion. A core main body (2) and a pair of header tanks (3, 4) communicating with both ends of the core main body are provided, and flows perpendicularly to the refrigerant passage (12) of the core main body (2) in plan view. A heat exchanger for exchanging heat between the cooling air and the refrigerant flowing through the refrigerant passage (12),
The arrangement order of the refrigerant flowing through the refrigerant passage (12) in the tube width direction is the same as the arrangement of the refrigerant passage (12) on the upstream side of the cooling air and the refrigerant passage (12) on the leeward side. A heat exchanger characterized by that.