JPH10253276A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set simply the required performance of respective core units, in a heat exchanger, integrating two sets of heat exchanging core units, such as a core unit for radiator of a vehicle and a core unit for condenser, and employing integrally formed common corrugate fins. SOLUTION: In a heat exchanger, a ratio (Nc/Lc) of the width Lc of fins in the air flow direction of corrugate fins 22 in a core unit 2 for a condenser to the number of sheets Nc of a louver 220 and a ratio (Nr/Lr) of the width Lr of fins in the air flow direction of corrugate fins 32 in a core unit 3 for a radiator to the number of sheets Nr of a louver 320 are set so that the ratio of the core unit, smaller in the required heat radiation amount between the first core unit 2 and the second core unit 3, becomes small and the radio of the core unit, larger in the necessary radiation amount, becomes big. According to this method, in the core unit, smaller in the necessary radiation amount, the number of sheets of louver with respect to the width of fin becomes smaller and the heat transfer rate is reduced, however, pressure loss is reduced due to the reduction of the number of sheets of louver whereby the flow rate of air is increased. As a result, in the core unit, bigger in the necessary radiation amount, the radiation amount can be increased by the increase of flow of the air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger having a plurality of heat exchange cores for exchanging heat of different kinds of fluids and using fins integrally formed in the plurality of heat exchange cores. Is suitable for use in a heat exchanger in which a condenser core of an automotive air conditioner and a radiator core for cooling an engine are integrated.

[0002]

2. Description of the Related Art Conventionally, a heat exchanger integrating a plurality of heat exchange cores for exchanging heat of different types of fluids is disclosed in, for example,
In this prior art, a corrugated fin on the first core portion side and a corrugated fin on the second core portion side are integrally formed, and the corrugated fins are first and second core portions. Part is connected to the flat tube.

In corrugated fins, the first
A plurality of slits for preventing heat conduction are provided at an intermediate portion between the core portion and the second core portion.
Of the first core portion and the second core portion, heat is transferred from a high-temperature side heat exchange core portion (for example, a radiator core portion) to a low-temperature side heat exchange core portion (for example, a condenser core portion) via a corrugated fin. The conduction is prevented from occurring.

[0004]

The heat exchange performance (radiation amount) of the first core portion (condenser core portion) and the second core portion (radiator core portion) is the same even in the same vehicle. In other words, even if the heat exchanger physique is the same), it differs depending on the type of engine, vehicle size, and the like. Therefore, when configuring a single heat exchanger for each application,
The required performance is set by changing the fin pitch of the corrugated fins according to the type of engine and the vehicle size.

However, in a heat exchanger using a common fin integrally formed in a plurality of core portions, the fin pitch cannot be set independently in both core portions. The technique of pitch change cannot be adopted. JP-A-3-17779
In the prior arts such as Japanese Patent Laid-Open Publication No. H10-214, when a common fin integrally formed in a plurality of core portions is used, there is no disclosure at all about how to set required performance for each core portion.

In view of the above, the present invention provides a heat exchanger having a plurality of cores for exchanging heat of different fluids and using a common fin integrally formed with the plurality of cores. It is an object of the present invention to provide a heat exchanger that can easily set required performance for each unit.

[0007]

Under the condition of the same heat exchanger physique, the two major factors in determining the heat transfer performance (radiation amount) of the heat exchanger are the heat transfer coefficient and the ventilation resistance. Focusing on the fact that these two major elements change depending on the shape of the louver cut and raised obliquely on the fin,
In the present invention, the above object is achieved by changing the form of the louver in the integrally formed common fin between the first core portion side and the second core portion side.

That is, according to the first aspect of the present invention, the first
Core portion (2) the ratio of the number of external fluid flow direction of the fin width of the corrugated fin (22) (L _C) and louver (220) (N _c) in the (N _c / L _C), the second core portion external fluid flow direction of the fin width of the corrugated fin (32) in (3) (L _r) and the ratio of the number (N _r) of the louver _{(320) (N r / L} r), the first, second It is characterized in that, of the core portions (2, 3), the core portion having a smaller required heat radiation amount is set to be small, and the core portion having a large required heat radiation amount is set to be large.

According to this, in the core portion having a smaller required heat radiation amount, the number of louvers with respect to the fin width becomes small, and the heat transfer coefficient decreases. However, the pressure loss decreases due to the decrease in the number of louvers. The flow rate of the external fluid increases by the amount. As a result, the performance (radiation amount) can be increased by increasing the flow rate of the external fluid in the core portion having the larger required heat radiation amount.

In other words, in a heat exchanger using a common corrugated fin integrally formed on the first core portion side and the second core portion side, the necessity for each core portion is obtained without employing a technique of changing the fin pitch. Performance can be easily set. In particular, according to the present invention, the number of louvers of corrugated fins in the core portion having a smaller required heat radiation amount is set to the number of louvers of corrugated fins in the core portion having a larger required heat radiation amount. Preferably, it is reduced by 30% or more.

According to this, the reduction in pressure loss can be sufficiently increased by reducing the number of louvers by 30% or more in the core portion having the smaller required heat radiation. Further, in the present invention, it is preferable that the louver pitch is larger in the core part having the smaller required heat radiation than in the core part having the larger required heat radiation.

According to this, in the core portion having a smaller required heat radiation amount, even if the number of louvers is reduced, the louvers can be formed over a relatively wide range of the fin surface of the corrugated fin. It is possible to effectively suppress a decrease in the heat transfer coefficient in the core portion having a smaller heat radiation amount. According to the present invention, a turning louver (223, 323) for turning the flow direction of the external fluid is provided at an intermediate portion of the louver (220, 320), and the turning louver (223, 323) is provided. Before and after, a first louver group (221, 321) and a second louver group (222, 322) whose inclination angles are reversed are formed, and the first and second core portions (2, 322) are formed.
In 3), a flat turning surface (223) is provided on the turning louver of the corrugated fin in the core portion having the smaller required heat release amount.
a, 323a) and the louvers (220,
320), a flat fluid inlet (224, 3) on the fluid inlet side.
24), and in the core portion having a smaller required heat radiation amount,
It is preferable that the length (L _T ) of the flat turning surface (223a, 323a) is larger than the length (L _i ) of the fluid introduction part (224, 324).

According to this, flat turning surfaces (223a, 3
By having a longer length of 23a) (L _T), the flow rate of such air is recovered by a flat deflection surface, at a faster rate in the second louver group located downstream of the flat turning surface, fluid flows Therefore, the heat transfer coefficient in the second louver group can be improved to a value close to that of the first louver group. As a result, it is possible to effectively suppress a decrease in the heat transfer coefficient in the core portion having a smaller required heat release amount.

Next, according to the fifth aspect of the present invention, the fin width of the corrugated fin in the direction of the external fluid flow is the smaller one of the first and second core portions (2, 3). Is smaller than the length of the flat tube in the cross-section longitudinal direction, and the ratio of the length of the flat tube in the cross-section longitudinal direction to the number of louvers in the core portion having the smaller required heat radiation is determined by the larger core having the required heat radiation. The ratio is smaller than the ratio of the length of the flat tube in the section longitudinal direction and the number of louvers at the portion.

According to this, in the core portion having the smaller required heat radiation amount, the fin width and the number of louvers with respect to the length in the cross-section longitudinal direction of the flat tube are both small, and the fin heat radiation area is reduced. Since the pressure loss decreases due to the decrease in the number of louvers and the number of louvers, the flow rate of the external fluid increases by the decrease in the pressure loss. As a result, the performance (radiation amount) can be increased by increasing the flow rate of the external fluid in the core portion having the larger required heat radiation amount.

According to the present invention, the fin width of the corrugated fin in the direction of external fluid flow in the core portion having the smaller required heat radiation amount is reduced to 80% or less of the length in the cross-section longitudinal direction of the flat tube. Is preferred. According to this, the fin width in the core portion having the smaller required heat radiation amount is reduced to 80% or less with respect to the length in the cross-section longitudinal direction of the flat tube, so that the reduction amount of the pressure loss can be sufficiently increased.

Next, in the invention according to claim 7, of the first and second core portions (2, 3), the cut length of the louver in the smaller core portion of the required heat radiation amount is determined by the larger the required heat radiation amount. It is characterized in that it is smaller than the cut length of the louver in the core portion. According to this, the heat transfer coefficient is reduced by reducing the cut length of the louver in the core portion having a smaller required heat release amount, but the pressure loss is reduced by the decrease in the cut length of the louver. Only, the flow rate of the external fluid increases. As a result, the performance (radiation amount) can be increased by increasing the flow rate of the external fluid in the core portion having the larger required heat radiation amount.

Further, according to the present invention, the cut length of the louver in the core portion having the smaller required heat radiation is 50% or more than the cut length of the louver in the core portion having the larger required heat radiation. It is preferable to make it smaller. According to this, by reducing the cut length of the louver in the core portion having the smaller required heat radiation amount by 50% or more, the reduction amount of the pressure loss can be sufficiently increased.

Next, according to the ninth aspect of the present invention, the inclination angle of the louver in the core portion of the first and second core portions (2, 3) having the smaller required heat radiation amount is determined by increasing the inclination angle of the louver. It is characterized in that the inclination angle of the louver in the core portion is smaller than that of the louver. According to this, in the core portion having a smaller required heat radiation amount, the heat transfer coefficient decreases by decreasing the inclination angle of the louver, but the pressure loss decreases due to the decrease in the inclination angle of the louver. Only, the flow rate of the external fluid increases. As a result, the performance (heat dissipation) of the core with the larger required heat dissipation is increased by increasing the flow rate of the external fluid.
Can be increased.

Further, according to the present invention, the inclination angle of the louver in the core portion having the smaller required heat radiation is 20% less than the inclination angle of the louver in the core portion having the larger required heat radiation. It is preferable to make it smaller. According to this, the reduction amount of the pressure loss can be sufficiently increased by reducing the inclination angle of the louver in the core portion having the smaller required heat radiation amount by 20% or more.

According to the present invention, there is provided a heat exchanger mounted on a vehicle according to claim 11, wherein the first core is a condenser (1) for condensing refrigerant of a refrigeration cycle, and the second core is Is used as a radiator (20) for cooling the engine cooling water, and the condenser (1) can be suitably applied to a heat exchanger disposed upstream of the radiator (20) in the air flow.

The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiments described later.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIGS. 1 to 5 show a first embodiment of the present invention. In this embodiment, a condenser core portion (first core portion) 2 and an engine in a refrigeration cycle of an automotive air conditioner are shown. An example in which the present invention is applied to a heat exchanger 1 in which a cooling radiator core portion (second core portion) 3 is integrated is shown.

Usually, the temperature of the refrigerant flowing through the condenser core 2 (about 50 ° C.) is lower than the temperature of the engine cooling water flowing through the radiator core 3 (about 90 ° C.). The vessel 1 has a condenser core portion 2 arranged in series upstream of an air flow (external fluid) from a radiator core portion 3 and is mounted at the forefront of an engine room (not shown).

First, the overall configuration of the heat exchanger according to the present embodiment will be described. The condenser core 2 and the radiator core 3 are flattened, as described later, in order to cut off heat conduction therebetween. A predetermined gap 46 between the tubes 21 and 31
Are set in series in the air flow direction. The condenser core part 2 includes a flat tube 21 and a flat tube 2.
1 and a corrugated fin 22 disposed between them.

The flat tubes 21 are formed of aluminum to have a flat cross section and are formed in a shape having a large number of refrigerant passage holes, and are arranged in parallel in a direction orthogonal to the longitudinal direction of the cross section. In addition, the corrugated fin 22
As shown in FIG. 4, is formed of aluminum in a corrugated shape (wave shape) having a large number of bent portions 22a. And the corrugated fin 22 is a flat tube 21.
Is joined by brazing to the outer wall surface in the cross-section longitudinal direction.

The radiator core 3 also has the same structure as the condenser core 2, and the flat tubes 31 arranged in parallel on the downstream side of the flat tubes 21 on the condenser side.
And the corrugated fins 32 arranged between the flat tubes 31. However, the flat tube 31 on the radiator side has a shape that forms one water passage hole as a whole.

And, these flat tubes 21 and 31
And the corrugated fins 22 and 23 are alternately laminated,
Each is brazed. The corrugated fins 22 and 32 have louvers 22 for promoting heat exchange.
0 and 320 are cut and raised obliquely. Here, the two corrugated fins 22 and 32 are integrally formed via the coupling portion 45, and are formed by molding an aluminum thin material with a forming roller having a gear-shaped cutter, and having louvers 220 and 320. It is formed in a predetermined shape. A slit 47 for heat insulation is formed on both sides of the joint 45, and the width of the joint 45 is sufficiently smaller than the fin height (dimension between the flat tubes 21 and between the flat tubes 31). Thus, heat conduction from the high-temperature radiator core 3 to the low-temperature condenser core 2 can be suppressed.

By the way, 23 and 33 are the core parts 2 for the condenser.
And side plates forming a reinforcing member for the radiator core portion 3, as shown in FIG.
Are arranged at both upper and lower ends. As shown in FIG. 1, the side plates 23 and 33 have a substantially U-shaped cross section and are integrally formed from a single aluminum plate. The side plate 23 and the side plate 3 are provided at both ends of the side plates 23 and 33 in the longitudinal direction.
3 are provided.

The connecting portion 4 is provided with a Z
Bent portion 41 and Z-shaped bent portion 4 of side plate 33
2 are integrally joined at a thin portion 43 at the tip end. The width of the connecting portion 4 is set to be sufficiently smaller than the length of the side plate 23 or 33 in the longitudinal direction, thereby suppressing heat conduction between the side plates 23 and 33.
Further, the thin end portion 43 of the connecting portion 4 has a cutout shape in which the plate thickness of the connecting portion 4 is reduced.

As shown in FIG. 2, the cooling water is distributed to the flat tubes 31 on one (left side) of the left and right side surfaces of the radiator core 3 where the side plate 33 is not disposed. A first header tank 34 is provided, and the flat tubes 31 are brazed to the first header tank 34 with one end thereof open. The front shape of the first header tank 34 is substantially triangular, and a cooling water inlet pipe 35 is brazed to a wide portion on the upper side of the substantially triangular shape.

On the other (right side) of the left and right side surfaces of the radiator core portion 3, a second header tank 36 for collecting the cooling water having undergone heat exchange is disposed. Each of the flat tubes 31 is brazed with its other end open. The second header tank 36 has the same shape as the first header tank 34. An outlet pipe 37 for discharging the cooling water is brazed to the bottom side of the second header tank 36.

In FIGS. 2 and 3, reference numeral 24 denotes a first header tank for distributing the refrigerant to each flat tube 21 of the condenser core 2. The main body of the first header tank 24 is formed in a cylindrical shape. Each flat tube 21 is brazed with one end thereof open. The main body of the first header tank 24 is disposed with a predetermined gap from the second header tank 36 of the radiator core 3. Reference numeral 26 denotes a refrigerant inlet joint for connecting a refrigerant pipe (not shown), and the inlet joint 26 is brazed to the main body of the first header tank 24 so as to communicate with the inside of the main body. .

Further, on the opposite side of the first header tank 24 of the condenser core 2, a second header tank 25 for collecting the refrigerant that has completed heat exchange is provided with the first header tank 34 of the radiator core 3. They are arranged with a predetermined gap. The main body of the second header tank 25 is formed in a cylindrical shape, and a refrigerant outlet joint 27 for connecting a refrigerant pipe (not shown) is brazed to the main body.

Next, a specific embodiment of the corrugated fins 22 and 32, which form a main part of the present invention, will be described in detail with reference to FIG.
In this example, the fin width L of both corrugated fins 22 and 32 is
_C, L _r is are the same as the cross-sectional longitudinal dimension of the flat tubes 21 and 31 (the tube width). Here, the fin widths L _C and L _r refer to the dimensions of the flat tubes 21 and 31 along the cross-section longitudinal direction (the air flow direction).

The corrugated fin 2 on the side of the condenser core 2
The second louver 220 includes a first louver group 221 and a second louver group 222, and a turning louver 223 located between the two louver groups 221 and 222 to turn the air flow direction. The louver inclination angles of the first louver group 221 and the second louver group 222 are opposite.

Similarly, the first louver group 321 and the second louver group 321 are connected to the corrugated fins 32 on the radiator core 3 side.
A louver 320 including a louver group 322 and a turning louver 323 is provided. However, in the first embodiment, the heat transfer performance (radiation amount) on the radiator core 3 side.
In order to increase the louvers, specific forms of both louvers 220 and 320 are set as follows. That is, in the louver 220 of the condenser-side corrugated fin 22, the number of louvers in the first and second louver groups 221 and 222 is set to three, whereas in the louver 320 of the radiator-side corrugated fin 32, the first and second louvers 320 are arranged. Second louver group 321, 32
The number of louvers in 2 is five by five.

Here, the number of louvers is the number of louver pieces cut and raised on both front and back surfaces of each louver group in each louver group, and is formed by cutting and raising only one side of the fin surface like the turning louver 323. The part is not included in the number. While the total louver number N _c = 6 in the condenser side corrugated fins 22, a total of louver number N _r = 10 of the radiator-side corrugated fins 32.

Therefore, in the first embodiment, the ratio of N _c to L _C (N _c /
And L _C), the magnitude relation between the ratio (N _r / L _r) of N _r and L _r in the radiator-side corrugated fins 32 is as follows. _{That, (N c / L C)} <(N r / L r)
Holds. Meanwhile, in the condenser-side corrugated fins 22, the number of louvers that can be originally installed (= 10) with respect to the fin width L _C is intentionally reduced to six, so that the flat surfaces formed before and after the louver 220 are formed. The area of the air introduction parts (fluid introduction parts) 224 and 225 consisting of the louvers 220 increases.

Accordingly, the ratio of the total length (L ₁ + L ₂ ) of the air introduction portions 224 and 225 in the condenser side corrugated fin 22 in the air flow direction and the length L ₃ of the formation region of the louver 220 in the air flow direction [ (L ₁ + L ₂ ) / L ₃ ] and the air inlet 3 in the radiator-side corrugated fin 32.
Total length of air flow direction of 24, 325 (L ₄ + L ₅ )
The relationship between the ratio [(L ₄ + L ₅ ) / L ₆ ] and the length L ₆ of the louver 320 in the air flow direction is as follows.

That is, [(L ₁ + L ₂ ) / L ₃ ]>
The relationship [(L ₄ + L ₅ ) / L ₆ ] holds. Next, the operation of the above configuration will be described. Now, when a cooling fan (not shown) arranged on the air downstream side of the radiator core unit 3 is operated, the cooling air passes through the condenser core unit 2 as shown in FIGS. It passes through the radiator core 3.

On the other hand, in the condenser core 2, the refrigerant gas discharged from the compressor of the refrigeration cycle (not shown) flows into the first header tank 24 from the refrigerant inlet joint 26, and the refrigerant flows therefrom. 2 and 3 flows from the right side to the left side in FIGS. 2 and 3, and during this time, heat is radiated into the cooling air via the corrugated fins 22 and condensed. The condensed liquid refrigerant is collected in the second header tank 25 and is passed through the refrigerant outlet joint 27 to the condenser core 2.
Out of

In the radiator core 3, high-temperature cooling water from an engine (not shown) is supplied to the inlet pipe 35.
The cooling water flows from the left side to the right side in FIGS. 2 and 3 through the flat tube 31, from which the cooling water flows through the corrugated fins 32 into the cooling air, thereby cooling the cooling water. The water is cooled. The cooling water after the cooling gathers in the second header tank 36, flows out of the outlet pipe 37 to the outside, and returns to the engine.

Incidentally, the heat exchange performance (radiation amount) in the condenser core 2 and the radiator core 3 described above.
Is determined by two major factors, heat transfer coefficient and ventilation resistance, under the condition of the same heat exchanger size. These two major elements change depending on the form of the louvers 220 and 320. That is, the heat transfer coefficient decreases due to the decrease in the number of louvers 220 and 320, but the pressure loss (ventilation resistance) also decreases.

In this embodiment, paying attention to the above points, the number of louvers _Nc in the condenser-side corrugated fins 22 is reduced from 10 that can be originally formed to six, whereas the radiator-side corrugated fins 32 are reduced in the radiator-side corrugated fins 32. are remains of 10 sheets of the original can be molded louvers number N _r. As a result, in the condenser core 2, the heat transfer coefficient is reduced due to the decrease in the number of louvers _Nc , and the heat exchange performance is reduced. On the other hand, in the radiator core 3, the air flow increases due to a decrease in pressure loss due to a decrease in the number of louvers _{Nc in} the condenser core 2, and the heat exchange performance is improved.

(Second Embodiment) FIG. 6 shows a second embodiment. Contrary to the first embodiment, the number of louvers in the radiator core portion 3 is reduced from 10 which can be originally formed to 6 sheets. It was done. Therefore, in the second embodiment,
The relationship of (N _c / L _c )> (N _r / L _r ) is satisfied, whereby the heat radiation amount of the radiator core 3 decreases, and instead, the condenser core 2 increases the air flow by The amount of heat radiation can be increased.

FIG. 7 shows the relationship between the reduction rate of the number of louvers and the performance ratio of each of the cores 2 and 3 under the condition that the wind speed of the air blown to the cores is constant. Here, the louver number reduction rate is a predetermined fin width L _C , L _r
In the first embodiment of FIG. 5, the condenser-side corrugated fins 22 have a ratio of 10 to 6 which can be originally formed.
Since the number of louvers is reduced, the louver number reduction rate is 40%. Similarly, in the second embodiment in FIG. 6, the louver number reduction rate in the radiator-side corrugated fin 32 is 40%.

As can be understood from the graph of FIG. 7, for example, when the louver number reduction rate is set to 50% in either the condenser core 2 or the radiator core 3, the core having a reduced number of louvers is set. Then the amount of heat radiation is about 10
% And the pressure drop is reduced by about 30%. About 30 of this pressure loss
As a result, the amount of heat radiation can be increased by about 5% in the other core part.

From the study results of FIG. 7, it is necessary to set the louver number reduction rate to 30% or more in order to secure the reduction rate of the pressure loss at least about 20%. (Third Embodiment) FIG. 8 shows a third embodiment, which is a modification of the first embodiment. In the corrugated fin 32 of the radiator core 3, an end on the air flow upstream side (for the condenser) at opposite ends) to the core section 2, to form a protruding portion 326 that protrudes from the end portion of the flat tube 31 into the air flow upstream side, the louver number N _r of the radiator-side corrugated fins 32 than the first embodiment Is increasing.

Specifically, in the example of FIG.
Number of louvers N of rugate fins 32 _r12
You. Thus, in the third embodiment, the condenser core 2
The difference in the amount of heat radiation between the radiator and the radiator core 3
Wear. (Fourth Embodiment) FIG. 9 shows a fourth embodiment.
This is another modified example of the embodiment, and the number of louvers N_cOriginally
Condenser side cols reduced from 10 moldable to 6 moldable
In the gate fin 22, the number of louvers N_cDecrease
Along with the louver pitch L of the condenser-side louver 220_pcTo
Louver pitch L of radiator side louver 320_prMore than
That's a big deal. Here, the louver pitch L_pc, L_prWhen
Is the spacing between each louver piece, and this spacing is
It matches the length of the piece in the air flow direction.

As described above, as the louver number _Nc decreases, the louver pitch L _pc of the condenser-side louver 220 is enlarged, so that the region (L ₁₎ of the air introduction portions 224 and 225 in the condenser-side corrugated fin 22 is increased. + L ₂ ) in FIG.
Can be reduced as compared with the first embodiment. When the formation region (L ₃ ) of the louver 220 is concentrated at the center of the fin surface as in the first embodiment, the oblique air flow along the inclination angle of the louver 220 is biased toward the center of the fin width L _C , The degree of decrease in the heat transfer coefficient may increase. In such a case, as in the fourth embodiment, with the decrease of the louver number N _c, by enlarging the louver pitch L _pc condenser side louvers 220, the range of oblique air flow for fin width L _C By expanding, the degree of decrease in the heat transfer coefficient can be reduced.

(Fifth Embodiment) FIG. 10 shows a fifth embodiment.
As shown in FIG.
In width L_CIn the longitudinal dimension of the cross section of the flat tube 21
A certain tube width L_tcIt is shorter. On the other hand,
In the side corrugated fin 32, the fin width L_r= Chu
Width L _trIt has become. Also, in the example of FIG.
Side tube width L_tc= Radiator side tube width L_trBecome
ing.

Accordingly, the ratio (N _c / L _tc ) between the number of louvers N _c (six in the example of FIG. 10) of the condenser-side corrugated fins 22 and the condenser-side tube width L _tc , and the radiator-side corrugated fin 22 (in the example of FIG. 10, 10 sheets) louver number N _r of the fins 32 the ratio between the radiator-side tube width L _tr (N
_r / _Ltr ) is as follows.

That is, (N _c / L _tc ) <(N _r /
_Ltr ) holds. In FIG. 10, L _F
Is the overall fin width of both corrugated fins 22, 32, and L is the dimension between both ends of both flat tubes 21, 31 in the air flow direction, that is, the overall width of the heat exchanger. According to the fifth embodiment of FIG. 10, the condenser core 2
In comparison with the radiator core 3, the tube width _Ltc
For fin width L _C is small with respect to, but decrease the amount of heat generated by the heat radiating area decreases in the condenser side occurs, instead, a decrease in fin width L _C, fins radiating area of the condenser side and louver number N _c Both decrease from the radiator side. As a result, the pressure loss (ventilation resistance) in the condenser core portion 2 is reduced, and the air flow is increased, so that the performance (radiation amount) of the radiator core portion 3 can be increased.

[0055] (Sixth Embodiment) FIG. 11 shows a sixth embodiment, contrary to the above fifth embodiment, the cross-sectional longitudinal direction of the flat tubes 31 a fin width L _r in the radiator core portion 3 It is shorter than the dimension of the tube width _Ltr . On the other hand, in the condenser core portion 2, it has become fin width L _c = tube width L _tc. In the example of FIG. 11, the condenser-side tube width L _tc = the radiator-side tube width L _tr .

Accordingly, the ratio (N _c / L _tc ) between the number of louvers N _c (10 in the example of FIG. 10) of the condenser-side corrugated fins 22 and the condenser-side tube width L _tc , and the radiator-side corrugated fin 22 (in the example of FIG. 10, six) louver number N _r of the fins 32 the ratio between the radiator-side tube width L _tr (N
_r / _Ltr ) is as follows.

That is, (N _c / L _tc )> (N _r /
_Ltr ) holds. According to the sixth embodiment, the performance (radiation amount) of the radiator core unit 3 is reduced, but instead, the pressure loss (ventilation resistance) in the radiator core unit 3 is reduced, and the air volume is increased. In addition, the performance (radiation amount) of the condenser core 2 can be increased.

FIG. 12 shows the result of the study by the present inventor. In the fifth and sixth embodiments, the tube widths L _tc , L _tc , L
The ratio of the fin widths L _C and L _{r to tr} (L _C / L _tc , L _r
/ L _tr ) and the performance ratio of the condenser core portion 2 and the radiator core portion 3, and the characteristic shown is the relationship under the condition that the wind speed of the air blown to the core portion is constant. Is shown.

As understood from the graph of FIG. 12, the fin widths L _C and L _r are set to, for example, eight of the tube widths L _tc and L _tr .
When the fin width is reduced to 0%, the amount of heat radiation is reduced by about 10% in the core portion in which the fin width is reduced, but the pressure loss can be reduced by about 20%. As a result, the amount of heat radiation can be increased by about 3% in the core portion where the fin width is not reduced. From the study of FIG. 12, it can be seen that in order to reduce the pressure loss by about 20% or more, the fin widths L _C and L
It is necessary to reduce _r to 80% or less of the tube widths _Ltc and _Ltr .

(Seventh Embodiment) FIG. 13 shows a seventh embodiment. As in the first and second embodiments, the number of louvers _Nc of the condenser-side corrugated fins 22 or the radiator-side corrugated fins is different from that of the first and second embodiments. 32 reduces the louver number N _r of, in the case of reducing the pressure loss, louver number N
_{This is} for suppressing a decrease in heat transfer coefficient in the corrugated fin 22 or 32 in which _c or _Nr is decreased.

[0061] Figure 14 is a comparative example with respect to the seventh embodiment, a core section 2 (3) having a louver number N _c or N Colgate _r person with reduced fin 22 (32). The comparative example of FIG. 14 is obtained by simply reducing the number of louvers N _c (N _r ) from the comparative example of FIG.
The present inventor experimentally examined the relationship between the number of louvers N _c (N _r ) in the corrugated fins 22 (32) and the performance ratio of the core portion 2 (3) for the comparative example of FIG. 320), the number of louvers N _c
It was found that when (N _r ) was simply reduced from both the front and rear sides of the air flow, both the pressure loss and the heat transfer coefficient were proportionally reduced as shown in FIG.

Therefore, the present inventor has determined that the louvers 220 (32
0), the first louver inclination angle is in the opposite direction.
Louver group 221 (321) and second louver group 222
Paying attention to the presence of the turning louver 223 (323) located between the turning louver 223 (323) and the flat turning surface 223a (323) of the turning louver 223 (323).
a) The relationship between the length _LT (see FIG. 13) and the performance ratio of the core part 2 (3) was examined.

FIG. 17 shows the flat turning surface 223a (323).
a) The relationship between the length _LT and the performance ratio of the core part 2 (3) is shown under the condition that the wind speed of the air blown to the core part is constant. Flat deflection surface length L _T of the horizontal axis of FIG. 17 is a multiple with respect to the louver pitch L _p. As understood from the graph of FIG. 17, it can be seen that the heat transfer coefficient and pressure loss of the fin are both increased as the flat turning surface length L _T becomes large.

[0064] Here, increase of the heat transfer coefficient and pressure loss of the fin louver pitch L since three times around the _p tends to be saturated, the flat deflection surface length L _T 3 of louver pitch L _p
It is preferable to set it to twice or more. As described above, by increasing the length L _T of the flat turning surface, because of the following reasons of heat transfer coefficient of the fin increases.

[0065] That is, according to the analysis result of the air flow in the corrugated fin 22 performed by the present inventors (32), by an increase of the length L _T of the flat turning surface, located on the downstream of the turning louver 223 (323) Second louver group 22
It is considered that the flow velocity of the air passing through the second louver group 222 (322) is restored, and the air passes through the second louver group 222 (322) at a high speed.

FIG. 13 shows the flat turning surface 223a (323a) of the turning louver 223 (323) based on the above concept.
Of the length L _T increased to a size of more than 3 times the louver pitch L _p, a louver shape example of the seventh embodiment. In the louver shape example of FIG. 13, and set the length L _T of the flat turning surface approximately 5.5 times the louver pitch L _p. FIG.
(A) shows the portion in the air flow direction of the fin cross-sectional shape of the comparative example shown in FIG. 14B on the horizontal axis, and FIG. 18B shows the seventh embodiment shown in FIG. 13B on the horizontal axis. The portion in the air flow direction of the fin cross section is taken.

In the comparative example, the turning louvers 223 (3
23) is V-shaped and does not have a flat turning surface, so the second louver 223 (323) is located downstream of the turning louver 223 (323).
Of the air passing through the louver group 222 (322) does not recover, and remains low. As a result, FIG.
As shown in FIG. 7, the heat transfer coefficient of the second louver group 222 (322) located downstream of the turning louver 223 (323) is considerably lower than that of the first louver group 221 (321).

[0068] In contrast, according to the louver shape of the seventh embodiment, since the flat turning surface 223a (323a) has a sufficient length L _T set at approximately 5.5 times the louver pitch L _p, this Since the flow velocity recovers while the air flows along the flat surface of the flat turning surface 223a (323a), and the air passes through the second louver group 222 (322) at a high speed, the air flow is reduced as shown in FIG. As shown, turning louver 2
23 (323), second louver group 222 located downstream of
The heat transfer coefficient at (322) is the first louver group 221 (32
It is improved to a level close to that of 1).

Therefore, the louver shape of the seventh embodiment is changed to the condenser-side corrugated fin 22 in which the number of louvers Nc is reduced in the first embodiment of FIG. 5, or the number of louvers N in the second embodiment of FIG. By applying _r to the reduced radiator-side corrugated fin 32,
Strive to decrease the pressure loss, louvers number Nc, a decrease in heat transfer coefficient due to the decrease in N _r can be suppressed.

According to the study of the present inventor, the flat turning surface 223 of the corrugated fin with the reduced number of louvers was found.
a length L _T of the (323a) are louvers 220 (320)
The flat air introduction portions 224 (32) formed before and after
4) Of 225 (325), air inlet 2 on the inlet side
In comparison with the length L _i of the air inlet section 24 (324), it may be effective to make the length larger than the length L _{i of the} air introduction portion to recover the flow velocity of the air passing through the second louver group 222 (322). Do you get it.

(Eighth Embodiment) FIG. 19 shows an eighth embodiment in which the two major factors, heat transfer coefficient and ventilation resistance, which determine the heat exchange performance (radiation amount) at each core portion are louvers 22.
Paying attention to the fact that the cut lengths 0 and 320 (cut lengths in the direction perpendicular to the air flow direction) Ec and Er change, the condenser-side louvers 220 and the radiator-side louvers 320 are changed.
Thus, the cut lengths Ec and Er are changed.

That is, when the cut lengths Ec and Er of the louvers 220 and 320 are reduced, the heat transfer coefficient is reduced.
On the other hand, ventilation resistance (pressure loss) also decreases. Therefore, the eighth
In the embodiment, the cut length Ec of the condenser-side louver 220 is changed to the cut length Er of the radiator-side louver 320 in order to improve the performance of the radiator core unit 3 by focusing on the above points.
Shorter.

As a result, in the condenser core 2, the heat transfer coefficient is reduced due to the decrease in the louver cut length Ec, and the performance is reduced. However, the pressure loss is reduced due to the decrease in the louver cut length Ec on the condenser side. However, the ventilation resistance of the heat exchanger as a whole decreases and the air volume increases, so that the performance of the radiator core 3 can be improved. As a specific design example, when the fin height Hf (= interval between the flat tubes) of the corrugated fins 22 and 32 is 8 mm, the cut length Er of the radiator-side louver 320 is 7 mm (the original cut length with respect to the fin height Hf). The cut length Ec of the condenser-side louver 220 is 5 mm.

(Ninth Embodiment) FIG. 20 shows a ninth embodiment. Contrary to the eighth embodiment, the condenser core 2
In order to improve the performance, the cut length Er of the radiator-side louver 320 is shorter than the cut-out length Ec of the condenser-side louver. All other points are the same as in the eighth embodiment.

(Tenth Embodiment) FIG. 21 shows a tenth embodiment, which is a modification of the eighth embodiment, in which the projection 326 described in FIG. The container side corrugated fin 22 is also provided with a protruding portion 327 opposed to the protruding portion 326, and the second louver group 2 in the condenser side louver 220 is provided.
The louver number of the louver 22 and the louver number of the first louver group 322 in the radiator-side louver 320 are both increased.

In the corrugated fins 22 and 32 having such a louver structure, the condenser-side louvers 22
The cut length Ec of 0 is shorter than the cut length Er of the radiator-side louver 320. Other points are the same as in the eighth embodiment. FIG. 22 shows the relationship between the louver cut length and the performance according to the eighth to tenth embodiments under the condition that the wind speed of the airflow to the core portion is constant. The louver cut length ratio on the horizontal axis is the fin height. The louver cut length relative to Hf (for example, the cut length Er of the radiator-side louver 320 in the eighth embodiment of FIG. 18) and the fin peak height H
The louver break length intentionally shortened with respect to f (for example,
In the eighth embodiment shown in FIG. 18, the ratio is a ratio to the louver cut length Ec) on the condenser side.

That is, the louver cut length ratio is the ratio of intentionally shortened louver cut length / original louver cut length. As can be understood from FIG. 22, when the length of the louver cut on one side, which is intentionally shortened, is reduced to, for example, half, the amount of heat radiation in the core portion where the louver cut length is reduced by half is reduced by about 10%.
Pressure loss is reduced by about 30%. By reducing the pressure loss by about 30%, the performance (amount of heat radiation) of the core on the other side having the original louver cut length can be improved by about 5%.

(Eleventh Embodiment) FIG. 23 shows an eleventh embodiment in which two major factors, heat transfer coefficient and ventilation resistance, which determine the heat exchange performance (radiation amount) in each core portion are louvers 220. , by paying attention to changing the inclination angle theta _c, theta _r of 320, at the condenser side louver 220 and the radiator-side louver 320 has changed its inclination angle theta _c, a theta _r.

That is, when the inclination angles θ _c and θ _r of the louvers 220 and 320 are reduced, the wind speed of the air passing between the louver pieces of the louvers 220 and 320 is reduced, and the heat transfer coefficient is reduced. On the other hand, ventilation resistance (pressure loss) also decreases. Therefore, in the eleventh embodiment, focusing on the above point, in order to improve the performance of the radiator core portion 3, the inclination angle θ _c of the condenser-side louver 220 is changed to the inclination angle of the radiator-side louver 320 (high heat transfer coefficient). It is intentionally reduced from the original tilt angle) theta _r to obtain.

That is, the louver inclination angle θ _c on the condenser side <
It is the louver inclination angle θ _r of the radiator side. As a result, in the condenser core 2, the heat transfer coefficient is reduced due to the decrease in the louver inclination angle θ _c and the performance is reduced, but instead, the pressure loss is decreased due to the decrease in the louver inclination angle θ _c on the condenser side. Since the ventilation resistance of the heat exchanger as a whole decreases and the air volume increases, the performance of the radiator core 3 can be improved.

As a specific design example, the louver inclination angle θ _c = 18 ° on the condenser side and the louver inclination angle θ on the radiator side
_r = 25 °. (Twelfth Embodiment) FIG. 24 shows a twelfth embodiment. Contrary to the eleventh embodiment, in order to improve the performance of the condenser core 2, the inclination angle θ _r of the radiator-side louver 320 is changed. It is intentionally reduced than the inclination angle theta _c of the condenser-side louver 220.

That is, the louver inclination angle θ _c of the condenser side>
It is the louver inclination angle θ _r of the radiator side. All other points are the same as in the eleventh embodiment. (Thirteenth Embodiment) FIG. 25 shows a thirteenth embodiment, which is different from the eleventh embodiment of FIG.
The projections 326 and 327 in the embodiment are provided on both corrugated fins 22 and 32.

That is, a projection 326 is provided on the radiator-side corrugated fin 32, and a projection 327 facing the projection 326 is also provided on the condenser-side corrugated fin 22, so that the second louver group in the condenser-side louver 220 is provided. The number of louvers 222 and the number of louvers in the first louver group 322 in the radiator-side louvers 320 are both increased.

In the corrugated fins 22 and 32 having such a louver structure, the relationship is set such that the louver inclination angle θ _c on the condenser side <the louver inclination angle θ _r on the radiator side. FIG. 26 shows the eleventh of FIGS.
13 shows the relationship between the lowering of the louver inclination angle and the performance of the core according to the thirteenth embodiment under the condition that the wind speed of the airflow to the core is constant. The louver inclination angle reduction rate on the horizontal axis is
This is the ratio between the original louver inclination angle for obtaining a high heat transfer coefficient and the louver inclination angle intentionally reduced from the original louver inclination angle.

That is, the louver inclination angle reduction rate is (intentionally reduced louver inclination angle / original louver inclination angle).
× 100. As can be understood from FIG. 26, the reduction rate of the louver inclination angle on one side intentionally shortened is, for example, 20%.
In this case, the amount of heat radiation is reduced by about 10% in the core portion where the louver inclination angle is reduced, but the pressure loss is reduced by about 25%. By reducing the pressure loss by about 25%, the performance (heat dissipation) of the core on the other side having the original louver inclination angle by about 4%
Can be improved.

(Other Embodiments) In each of the above embodiments, the present invention is applied to a heat exchanger in which the condenser core 2 of the automotive air conditioner and the radiator core 3 for cooling the engine are integrated. Although the description has been given of the case where the present invention is applied, the present invention is applicable to a heat exchanger for any use as long as it is a heat exchanger integrating two heat exchange cores for heat exchange of two kinds of fluids. It can be implemented similarly.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing an integrated heat exchanger structure of a condenser core portion and a radiator core portion to which the present invention is applied.

FIG. 2 is a front view of the heat exchanger shown in FIG.

FIG. 3 is a top view as viewed in the direction of arrow C in FIG. 2;

FIG. 4 is a perspective view of a single corrugated fin shown in FIG. 1;

FIG. 5A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to the first embodiment of the present invention, and FIG. 5B is a sectional view taken along line AA of FIG.

6A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a second embodiment of the present invention, and FIG. 6B is a sectional view taken along line AA of FIG.

FIG. 7 is a graph showing a relationship between a louver number reduction rate of corrugated fins and performance.

8A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a third embodiment of the present invention, and FIG. 8B is a sectional view taken along the line AA of FIG.

FIG. 9A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a fourth embodiment of the present invention, and FIG. 9B is a sectional view taken along line AA of FIG. 9A.

FIG. 10A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a fifth embodiment of the present invention, and FIG. 10B is a sectional view taken along line AA of FIG.

FIG. 11A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a sixth embodiment of the present invention, and FIG. 11B is a cross-sectional view taken along the line AA of FIG.

FIG. 12 is a graph showing the relationship between fin width and performance of a corrugated fin.

13A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a seventh embodiment of the present invention, and FIG. 13B is a sectional view taken along line AA of FIG.

14A is a partial front view showing an assembled state of a corrugated fin and a flat tube in a comparative example of the seventh embodiment, and FIG. 14B is a sectional view taken along line AA of FIG.

FIG. 15A is a partial front view showing an assembled state of a corrugated fin and a flat tube in another comparative example of the seventh embodiment, and FIG. 15B is a sectional view taken along the line AA of FIG.

FIG. 16 is a graph showing the relationship between the number of louvers of corrugated fins and performance.

FIG. 17 is a graph showing the relationship between the flat turning surface length of the louver portion of the corrugated fin and the performance.

FIG. 18 is a graph showing changes in the heat transfer coefficient of each part along the air flow direction of the corrugated fin.

19A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to an eighth embodiment of the present invention, and FIG. 19B is a sectional view taken along line AA of FIG.

20A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a ninth embodiment of the present invention, and FIG. 20B is a sectional view taken along line AA of FIG.

21A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a tenth embodiment of the present invention, and FIG. 21B is a sectional view taken along line AA of FIG.

FIG. 22 is a graph showing the relationship between the louver break length ratio of corrugated fins and performance.

23A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to an eleventh embodiment of the present invention, and FIG. 23B is a sectional view taken along the line AA of FIG.

FIG. 24A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a twelfth embodiment of the present invention, and FIG. 24B is a sectional view taken along line AA of FIG.

25A is a partial front view showing an assembled state of a corrugated fin and a flat tube according to a thirteenth embodiment of the present invention, and FIG. 25B is a sectional view taken along line AA of FIG.

FIG. 26 is a graph showing a relationship between a louver inclination angle reduction rate of corrugated fins and performance.

[Explanation of symbols]

2 ... condenser core part, 3 ... radiator core part, 21,
31 ... flat tube, 22, 32 ... corrugated fin,
220, 320: louvers, 221, 321: first louver group, 222, 322: second louver group, 223, 32
3 ... turning louvers, 223a, 323a ... flat turning surfaces.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F28F 9/26 F28F 9/26 (72) Inventor Yasutori Yamanaka 1-1-1, Showa-cho, Kariya-shi, Aichi Pref.

Claims (11)

[Claims] 1. Heat exchange between a first fluid and an external fluid is performed.
A first core portion (2), and a second core portion for performing heat exchange between the second fluid and the external fluid.
(3), wherein the core portions (2, 3) are located in the flow direction of the external fluid.
The first core part (2) is arranged in parallel with a constant gap (46) therebetween, and the first fluid is arranged in parallel.
Numerous flat tubes (21) flowing through the flat tubes
(21) Corrugated fins located between each other
(22), wherein the second core portion (3) is arranged in parallel and the second fluid is
A number of flat tubes (31) flowing through the flat tubes
(31) Corrugated fins located between each other
(32), and the two corrugated fins (22, 32) are connected to each other by a connecting portion (4).
5) and are integrally formed through the corrugated fins (22, 32).
And a corrugated filter in the first core portion (2).
Of the fin (22) in the external fluid flow direction (L)_C) And before
The number of louvers (220) (N_c) And the ratio (N _c/
L_C), And a corrugated fin (3) in the second core portion (3).
2) Fin width (L) in the external fluid flow direction_r) And the roux
Number of buses (320) (N_r) And the ratio (N_r/ L_r) Of the first and second core portions (2, 3).
The smaller core is smaller, and the larger
Heat exchange characterized by setting the core to be large
Exchanger. 2. The method according to claim 1, wherein the number of louvers of the corrugated fins in the core part having the smaller required heat radiation is reduced by 30% or more with respect to the number of louvers of the corrugated fins in the core part having the larger required heat radiation. The heat exchanger according to claim 1, wherein: 3. The heat-generating device according to claim 1, wherein the louver pitch of the core portion having the smaller required heat radiation amount is larger than that of the core portion having the larger required heat radiation amount. Exchanger. 4. A turning louver (223, 323) for turning the flow direction of the external fluid is formed at an intermediate portion of the louver (220, 320), and the turning louver (223, 323) is inclined before and after the turning louver (223, 323). Forming a first louver group (221, 321) and a second louver group (222, 322) whose angles are reversed; In the core part having the smaller heat radiation amount, the turning louver (22)
3, 323) and flat fluid introduction portions (224, 324) on the fluid inlet side of the louvers (220, 320) to reduce the required heat radiation. The length (L _T ) of the flat turning surface (223a, 323a) in the one core portion is larger than the length (L _i ) of the fluid introduction portion (224, 324). 4. The heat exchanger according to any one of items 3 to 3. 5. A first core part for exchanging heat between a first fluid and an external fluid, and a second core part for exchanging heat between a second fluid and an external fluid. The two core portions (2, 3) are arranged in series in a flow direction of the external fluid via a predetermined gap (46), and the first core portions (2) are arranged in parallel and the first fluid And the corrugated fins (22) disposed between the flat tubes (21), and the second core portions (3) are arranged in parallel with each other. It is composed of a number of flat tubes (31) through which two fluids flow, and corrugated fins (32) arranged between the flat tubes (31). (4
5). The two corrugated fins (22, 32) are provided with louvers (220, 320), respectively. Further, the first and second core portions (2, 3) are provided. In the core portion having the smaller required heat radiation, the fin width of the corrugated fin in the external fluid flow direction is shorter than the length of the flat tube in the cross-section longitudinal direction. The ratio between the length of the cross-section longitudinal direction of the flat tube and the number of the louvers in the portion is calculated from the ratio of the length of the cross-section longitudinal direction of the flat tube in the core portion having the larger required heat release amount and the number of the louvers. A heat exchanger characterized by being reduced in size. 6. The fin width of the corrugated fin in the direction of the external fluid flow in the core portion having the smaller required heat radiation amount is 80% of the length in the cross-section longitudinal direction of the flat tube.
6. The heat exchanger according to claim 5, wherein the heat exchanger is reduced as follows. 7. A first core part (2) for exchanging heat between a first fluid and an external fluid, and a second core part (3) for exchanging heat between a second fluid and an external fluid. The two core portions (2, 3) are arranged in series in a flow direction of the external fluid via a predetermined gap (46), and the first core portions (2) are arranged in parallel and the first fluid And the corrugated fins (22) disposed between the flat tubes (21), and the second core portions (3) are arranged in parallel with each other. It is composed of a number of flat tubes (31) through which two fluids flow, and corrugated fins (32) arranged between the flat tubes (31). (4
5). The two corrugated fins (22, 32) are provided with louvers (220, 320), respectively. Further, the first and second core portions (2, 3) are provided. ), Wherein the cut length of the louver in the core portion having the smaller required heat radiation is smaller than the cut length of the louver in the core portion having the larger required heat release. 8. The cut length of the louver in the core part having the smaller required heat radiation is 50% smaller than the cut length of the louver in the core part having the larger required heat radiation.
The heat exchanger according to claim 7, wherein the heat exchanger is made smaller. 9. A first core part (2) for exchanging heat between a first fluid and an external fluid, and a second core part (3) for exchanging heat between a second fluid and an external fluid. The two core portions (2, 3) are arranged in series in a flow direction of the external fluid via a predetermined gap (46), and the first core portions (2) are arranged in parallel and the first fluid And the corrugated fins (22) disposed between the flat tubes (21), and the second core portions (3) are arranged in parallel with each other. It is composed of a number of flat tubes (31) through which two fluids flow, and corrugated fins (32) arranged between the flat tubes (31). (4
5). The two corrugated fins (22, 32) are provided with louvers (220, 320), respectively. Further, the first and second core portions (2, 3) are provided. ), Wherein the inclination angle of the louver in the core part having the smaller required heat radiation is smaller than the inclination angle of the louver in the core part having the larger required heat radiation. 10. An inclination angle of the louver in the core portion having the smaller required heat radiation amount is smaller than that of the louver in the core portion having the larger required heat radiation amount by 20% or more. The heat exchanger according to claim 9. 11. A heat exchanger mounted on a vehicle, comprising:
The first core part is a condenser core part (2) for condensing refrigerant of a refrigeration cycle, the second core part is a radiator core part (3) for cooling engine cooling water,
The said external fluid is outside air, The said core part (2) for condensers is arrange | positioned more upstream of the air flow than the core part (3) for radiators, The Claim 1 characterized by the above-mentioned. A heat exchanger according to one.