Compound heat exhanger having cooling fins introducing different heat exhanging performances within heat exchanging core portion

Information

  • Patent Grant
  • 6561264
  • Patent Number
    6,561,264
  • Date Filed
    Thursday, March 15, 2001
    23 years ago
  • Date Issued
    Tuesday, May 13, 2003
    21 years ago
Abstract
A condenser core portion carries out a heat exchange between refrigerant and air. The condenser core portion includes a plurality of condenser tubes through which the refrigerant flows and condenser fins disposed between each pair of adjacent condenser tubes. A radiator core portion is disposed in series with the condenser core portion in an external fluid flow direction with a predetermined clearance therebetween, to carry out a heat exchange between engine coolant and the air. The radiator core portion includes a plurality of radiator tubes through which the engine coolant flows and radiator fins disposed between each pair of adjacent radiator tubes. A connecting portion integrates each of condenser fins and radiator fins. The condenser fins disposed at an upper area of the condenser core portion introduce cooling performances more than the condenser fins disposed at a lower area thereof.
Description




CROSS REFERENCE TO RELATED APPLICATION




This application is based on and incorporates herein by reference Japanese Patent Application Nos. 2000-79350 filed on Mar. 16, 2000, and 2001-67002 filed on Mar. 9, 2001.




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to a compound heat exchanger including a plurality of heat exchangers suitable for use in an automotive cooling module in which a condenser is integrated with a radiator.




2. Description of Related Art




JP-A-10-253276 discloses a compound heat exchanger in which a condenser is integrated with a radiator. In the conventional compound heat exchanger, fin of a condenser core portion and fin of a radiator core portion are integrally formed, and a louver arrangement of the condenser fin is different from a louver arrangement of the radiator fin for adjusting heat exchanging performances of the radiator and the condenser.




Here, the louver arrangement includes etching angle, louver etching length, width dimension, the number of louvers, and the like.




However, in the conventional compound heat exchanger, heat exchanging performance does not vary within the condenser or within the radiator. Thus, when required heat exchanging performances are different between at one area and another area within the condenser or within the radiator, the conventional compound heat exchanger cannot satisfy such a request.




SUMMARY OF THE INVENTION




An object of the present invention is to provide a compound heat exchanger easily attaining required heat exchanging performance between at one area and another area within a heat-exchanging core.




According to the present invention, a first core portion to carries out a heat exchange between a first fluid and an external fluid. The first core portion includes a plurality of first tubes through which the first fluid flows and first cooling fins disposed between each pair of adjacent first tubes. A second core portion is disposed in series with the first core portion in an external fluid flow direction with a predetermined clearance therebetween, to carry out a heat exchange between a second fluid and the external fluid. The second core portion includes a plurality of second tubes through which the second fluid flows and second cooling fins disposed between each pair of adjacent second tubes. A connecting portion integrates each of first cooling fins and second cooling fins. At least one of the first cooling fins and the second cooling fins introduce different cooling performances between at one area and another area within at least one of the first core portion and the second core portion. Thus, the compound heat exchanger easily attains the required heat exchanging performance being different between at one area and another area within at least one of the first core portion and the second core portion.











BRIEF DESCRIPTION OF THE DRAWINGS




Additional objects and advantages of the present invention will be more readily apparent from the following detailed description of preferred embodiments thereof when taken together with the accompanying drawings in which:





FIG. 1

is a perspective view showing a compound heat exchanger viewing from a radiator side (first embodiment);





FIG. 2

is a perspective view showing the compound heat exchanger viewing from a condenser side (first embodiment);





FIG. 3A

is a cross-sectional view showing an upper area of a heat exchanging core portion with respect to line III—III in

FIG. 1

(first embodiment);





FIG. 3B

is a cross-sectional view showing a lower area of the heat exchanging core portion with respect to line III—III in

FIG. 1

(first embodiment);





FIG. 4

is a perspective view showing an integrated fin (first embodiment);





FIG. 5A

is a schematic view showing a roller forming apparatus (first embodiment);





FIG. 5B

is an enlarged view of V-portion in

FIG. 5A

(first embodiment);





FIG. 6

is a graph showing heat exchanging performances of the condenser and the radiator in accordance with a ratio of integrated fins


300




a


to integrated fins


300




b


(first embodiment);





FIG. 7

is a perspective view showing a compound heat exchanger (second embodiment);





FIG. 8

is a cross-sectional view showing a heat exchanging core portion (second embodiment), and





FIG. 9

is a cross-sectional view showing a heat exchanging core portion (second embodiment).











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS




First Embodiment




As shown in

FIGS. 1 and 2

, a heat exchanger


700


includes a condenser


100


and a radiator


200


. The condenser


100


cools a refrigerant (first fluid) circulating in a vehicle refrigerating cycle, and the radiator


200


cools an engine coolant (second fluid). In the heat exchanger


700


, the condenser


100


and the radiator


200


are integrated with each other.





FIG. 1

is a perspective view showing the heat exchanger


700


viewing from the radiator


200


side (downstream side of air flow), and

FIG. 2

is a perspective view showing the heat exchanger


700


viewing from the condenser


100


side (upstream side of air flow).




As shown in

FIG. 2

, the condenser


100


includes a condenser core portion (first core portion)


110


. In the condenser core portion


110


, condenser tubes


111


and corrugate fins


112


are provided. The condenser tube


111


is made of aluminum and formed in a flat. The condenser tube


111


has a refrigerant passage therein. The fin


112


is formed in a wave, and brazed to the condenser tube


111


.




As shown in

FIG. 1

, the radiator


200


includes a radiator core portion (second core portion)


210


. In the radiator core portion


210


, radiator tubes


211


and corrugate fins


212


are provided. The radiator tube


211


is made of aluminum and formed in a flat. The radiator tube


111


has an engine coolant passage therein. The fin


212


is formed in a wave, and brazed to the radiator tube


211


. The condenser tube


111


and the radiator tube


211


are arranged perpendicularly to the air flow, and arranged in parallel with each other.




In both core portions


110


,


210


, as shown in

FIG. 3

, a predetermined gap δ is provided between the condenser tube


111


and the radiator tube


211


for preventing the heat of the radiator core portion


210


from being transmitted to the condenser core portion


110


.




The fins


112


and


212


are integrally roller-formed, and as shown in

FIG. 4

, include a plurality of peaks


112




a


,


212




a


, a plurality of valleys


112




b


,


212




b


, and a plurality of flat portions


112




c


,


212




c


. The flat portions


112




c


,


212




c


are formed between the peaks


112




a


,


212




a


and valleys


112




c


,


212




c


adjacent thereto.




Hereinafter, the fins


112


,


212


integrally formed and extending over both core portions


110


,


210


is referred as an integrated fin


300


, and both core portions


110


,


210


integrated by the integrated fin


300


is referred as an heat exchanging portion


330


.




As shown in

FIG. 3

, the flat portions


112




c


,


212




c


, include louvers


112




d


,


212




d


, respectively, to disorder the air-flow passing through the fins


112


,


212


for preventing thermal boundary layer from increasing. The louvers


112




d


,


212




d


are formed by etching a part of flat portions


112




c


,


212




c


. Further, as shown in

FIG. 4

, connecting portions


310


are partially provided between the flat portions


112




c


and


212




c


for partially connecting the condenser fin


112


to the radiator fin


212


while keeping the condenser fin


112


apart from the radiator fin


212


by a predetermined gap W.




Here, the predetermined gap W is at least larger than plate thickness of both fins


112


,


212


. A slit


320


is provided by keeping the condenser fin


112


apart from the radiator fin


212


, and the slit


320


suppresses the heat transmission from the radiator core portion


210


to the condenser core portion


110


.




In the integrated fin


300


, arrangements and design of the louvers


112




d


and


212




d


are different between at an upper area and a lower area of one-dotted chain line III—III in FIG.


1


. For example, as shown in

FIG. 3A

, at the upper area of the line III—III, the arrangements and design of the louvers


112




d


are the same as of the louvers


212




d


. That is, etching angle, etching length, width dimension, and the number of louvers


112




d


are the same as of the louvers


212




d


. At the lower area of the line III—III, as shown in

FIG. 3B

, the number of louvers


112




d


is smaller than that of louvers


212




d


, and remaining arrangements and design thereof are the same as of the louvers


212




d.






As shown in

FIGS. 1 and 2

, a side plate


400


is provided at the bottom of both core portions


110


,


210


for supporting both core portions


110


,


210


. The side plate


400


includes a bracket


410


for attaching the heat exchanger


500


to a vehicle.




A first radiator tank


220


is disposed at one end of the radiator core portion


210


. The first radiator tank


220


distributes the engine coolant into each radiator tube


211


. A second radiator tank


230


is disposed at the other end of the radiator core portion


210


. The second radiator tank


230


receives the engine coolant having been heat-exchanged with the air.




The first radiator tank


220


includes an inlet port


221


at the upper area thereof. The engine coolant flowing out of the engine is introduced into the first radiator tank


220


through the inlet port


221


. The second radiator tank


230


includes an outlet port


231


at the lower area thereof. The engine coolant flows out of the second radiator tank


230


through the outlet port


231


, and flows to the engine.




A joint pipe


222


,


232


is brazed to each radiator tank


220


,


230


for connecting outside pipes (not illustrated) to each radiator tank


220


,


230


.




A first condenser tank


120


is disposed at one end of the condenser core portion


110


. The first condenser tank


120


distributes the refrigerant into each condenser tube


111


. A second condenser tank


130


is disposed at the other end of the condenser core portion


110


. The second condenser tank


130


receives the refrigerant having heat-exchanged with the air.




The first condenser tank includes an inlet port


121


at the upper area thereof. The refrigerant discharged from a compressor (not illustrated) is introduced into the first condenser tank


120


through the inlet port


121


. The second condenser tank


130


includes an outlet port


131


at the lower area thereof. The refrigerant having heat-exchanged with the air flows into an expansion valve (not illustrated) through the outlet port


131


.




A joint pipe


122


,


132


is brazed to each condenser tank


120


,


130


for connecting outside pipes (not illustrated) to each condenser tank


120


,


130


.




Next, a method for manufacturing the integrated fin


300


will be explained.





FIG. 5

is a schematic view showing a roller-forming apparatus. As shown in

FIG. 5

, fin material


1




a


is rolled around a material roll


1


. A tension apparatus


2


gives a predetermined tension force to the fin material


1




a


fed from the material roll


1


. The tension apparatus


2


includes a weight tensioner


2




a


, and a roller tensioner


2




d


having a roller


2




b


and a spring


2




c


. The weight tensioner


2




a


gives a predetermined tension force to the fin material


1




a


due to gravity force. The roller


2




b


rotates along the proceeding of the fin material


1




a


. The spring


2




c


gives a predetermined tension force to the fin material


1




a


through the roller


2




b.






Since the tension apparatus


2


gives a predetermined tension force to the fin material


1




a


, fin height h of the corrugate fin bending-formed by a fin forming apparatus


3


is constantly attained. Here, the fin height h is defined by a height difference between the peak


112




a


,


212




a


and the valley


112




b


,


212




b


adjacent thereto.




The fin forming apparatus


3


bends the fin material


1




a


to form a plurality of rectangular peaks


112




a


,


212




a


and rectangular valleys


112




b


,


212




b


. Hereinafter, the peak


112




a


,


212




a


and the valley


112




b


,


212




b


are referred as a bent potion


1




b


. Further, the fin forming apparatus


3


forms louvers


112




d


,


212




d


on the flat portions


112




c


,


212




c.






The fin forming apparatus


3


includes a pair of gear-like forming rollers


3




a


having a cutter (not illustrated) on the tooth flank thereof. The cutter forms the louvers


112




d


,


212




d


. When the fin material


1




a


passes through the forming rollers


3




a


, the teeth of the forming roller


3




a


bends the fin material


1




a


to form the bent portion


1




b


, and the cutter forms the louvers


112




d


,


212




d


simultaneously.




A cutting apparatus


4


cuts the fin material


1




a


including the bent portions


1




b


and the louvers


112




d


,


212




d


. The fin material


1




a


is cut every predetermined length such that each corrugate fin has a predetermined number of bent portions


1




b


. A feeder


5


feeds the predetermined length fin material


1




a


toward a straightening apparatus


6


.




The feeder


5


includes a pair of gear-like feeding rollers


5




a


having a standard pitch being substantially the same as a distance between the adjacent bent potions


1




b.






When a fin pitch (distance between adjacent bent portions


1




b


) of the corrugate fin is designed small, pressure angle of the forming roller


3




a


is designed large, and when the fin pitch is designed large, the pressure angle is designed small. Here, a module difference between the forming roller


3




a


and the feeding roller


5




a


is within 10%, the corrugate fin is formed without changing the feeding roller


5




a.






The straightening apparatus


6


presses the bent portion


1




b


from a direction perpendicular to a ridge direction of the bent portion


1




b


to remove concaves and convexes from the bent portion


1




b


. The straightening apparatus


6


includes a pair of straightening rollers


6




a


,


6




b


catching the fin material


1




a


therebetween. The straightening rollers


6




a


,


6




b


rotates in accordance with the proceeding of the fin material


1




a


. The straightening rollers


6




a


,


6




b


are arranged in such a manner that a line extending through the rotation centers of the straightening rollers


6




a


,


6




b


is perpendicular to the proceeding direction of the fin material


1




a.






A brake apparatus


7


includes brake faces


7




a


,


7




b


. The brake faces


7




a


,


7




b


contact the plurality of bent portions


1




b


to generate friction force against the proceeding of the fin material


1




a


. The brake apparatus


7


is disposed at the proceeding forward side of the fin material


1




a


more than straightening apparatus


6


. The brake apparatus


7


presses to gather the fin material


1




a


such that the bent portions


1




b


contact each other, by feeding force of the feeding apparatus


5


and friction force generated at the brake faces


7




a


,


7




b.






A brake shoe


7




c


having the brake face


7




a


is rotatably supported at one end thereof, and a spring


7




d


is provided at the other end of the brake shoe


7




c


. The friction force generated at the brake faces


7




a


,


7




b


is adjusted by adjusting the deflection amount of the spring


7




d


. The brake shoe


7




c


and a plate


7




e


including the brake face


7




b


are made of die steel having good wear resistance.




An operation of the corrugate fin forming apparatus will be explained.




The fin material


1




a


is drawn from the material roll


1


(drawing process). The tension apparatus


2


gives the predetermined tension force to the fin material


1




a


in the proceeding direction of the fin material


1




a


(tensioning process). The fin forming apparatus


3


forms the bent portions


1




b


and the louvers of the fin material


1




a


(fin forming process). The cutting apparatus


4


cuts the fin material


1




a


every predetermined length.




Next, the feeding apparatus


5


feeds the predetermined length fin material


1




a


toward the straightening apparatus


6


(feeding process), and the straightening apparatus


6


presses the bent portions


1




b


to remove the concaves and convexes from the bent portions


1




b


(straightening process). After that, the brake apparatus


7


presses to gather the fin material


1




a


so that the adjacent bent portions


1




b


contact each other (gathering process).




After the gathering process, the fin material


1




a


expands, due to the resilient force thereof, to have a predetermined fin pitch, and after an inspection, the corrugate fin forming is completed.





FIG. 6

is a graph showing heat exchanging performances of the condenser core portion


110


and the radiator core portion


210


in accordance with a ratio of the integrated fin


300


shown in

FIG. 3A

(hereinafter, referred as integrated fin


300




a


) to the integrated fin


300


shown in

FIG. 3B

(hereinafter, referred as integrated fin


300




b


). A linier line L


1


extending through point A and point 0 denotes the heat exchanging performances when the integrated fin


300




a


is used for the entire heat exchanging portion


330


.




While the ratio of the integrated fin


300




b


relative to the integrated fin


300




a


increases, linier line denoting the heat exchanging performances of the condenser core portion


110


and the radiator core portion


210


slides from L


1


to L


3


through L


2


. The linier line L


3


denotes the heat exchanging performances when the integrated fin


300




b


is used for the entire heat exchanging portion


330


.




As described above, according to the present embodiment, since the integrated fin


300




a


,


300




b


introducing different heat exchanging performances are appropriately arranged, required heat exchanging performance is easily attained with low cost.




Second Embodiment




In the second embodiment, a compound heat exchanger


700


is used for a hybrid car. The hybrid car includes an engine and an electric motor, and switches them to attain a driving source. The engine is mainly used to generate electric power for the motor, and the motor is mainly used for driving the hybrid car.




In the hybrid car, in addition to the engine, an electronic part such as an inverter controlling the motor has to be also cooled. For cooling the engine, the radiator has to be designed such that engine coolant temperature is less than 100-110° C. For cooling the electronic part, the radiator has to be designed such that electric part coolant is less than 60-70° C. which is lower than the engine coolant temperature.




In a vehicle having an automotive air conditioner, since the maximum refrigerant temperature is 80-90° C. which is lower than the engine coolant, the condenser for cooling the high-pressure refrigerant is disposed at air upstream side more than the radiator.




In the second embodiment, as shown in

FIG. 7

, a second radiator


500


for cooling the electric part is provided in addition to a first radiator


200


for cooling the engine coolant. The second radiator


500


has the same structure as the first radiator


200


, and is integrated with the first radiator


200


by tanks.




As shown in

FIG. 7

, the second radiator


500


includes a second radiator core portion


510


where the electric part coolant is heat-exchanged with the air. The second radiator core portion


510


has a plurality of second radiator tubes


511


through which the electric part coolant flows, and a plurality of second radiator fins


512


provided between the adjacent second radiator tubes


511


. A second radiator inlet tank


520


is disposed at one end of the second radiator tubes


511


, and a second radiator outlet tank


530


is disposed at the other end of the second radiator tubes


511


. The second radiator inlet tank


520


distributes the electric part coolant into each second radiator tube


511


, and the second radiator outlet tank


530


receives the electric part coolant from each second radiator tube


511


.




The first radiator inlet tank


220


and the second radiator inlet tank


520


are integrated within a cylindrical inlet tank having rectangular shape in cross section. Similarly, the first radiator outlet tank


230


and the second radiator outlet tank


530


are integrated within a cylindrical outlet tank having rectangular shape in cross section. Inside the inlet tank, a partition plate


521


partitions the second radiator inlet tank


520


from the first radiator inlet tank


220


. Similarly, inside the outlet tank, a partition plate


531


partitions the second radiator outlet tank


530


from the first radiator outlet tank


230


.




In this way, the first radiator core


210


and the second radiator core


510


are disposed in parallel with the air flow direction, and the condenser core


110


is disposed at the air upstream side of both radiator cores


210


,


510


in series therewith.




The integrated fin


300


, as shown in

FIG. 8

, is connected to the outer surface of the tubes


111


,


211


, and


511


for promoting the heat exchanging performance, and extends over the tubes


111


and


211


, and the tubes


111


and


511


. According to an example shown in

FIG. 8

, the number of the louvers


212




d


and


512




d


are different between in the first radiator


200


and the second radiator


500


. That is, the integrated fin


300




a


is used for the first radiator


200


, and the integrated fin


300




b


is used for the second radiator


500


.




Here, alternatively, as shown in

FIG. 9

, the number of louvers may be different within the condenser core


110


.




Modifications




According to the above-described embodiments, the number of louvers is different within the heat exchanging portion


330


. Alternatively, etching angle of the louver, etching length of the louver, fin pitch P of the louver may be different between at one area and another area within the heat exchanging core portion


330


.




According to the above-described embodiments, the roller forming apparatus produces the integrated fin


300


. Alternatively, a pressing apparatus or the like may produce the integrated fin.




According to the above-described embodiments, the compound heat exchanger is used for the cooling module including the condenser and the radiator. Alternatively, the double heat exchanger may be used for other heat exchangers.




According to the above-described embodiments, arrangements of louvers are different between at the upper area and the lower area with respect to the line III—III in FIG.


1


. Alternatively, arrangements of the louvers may be different between at right area and left area in

FIG. 1

, or the louvers


300




a


and


300




b


may be alternately arranged.



Claims
  • 1. A heat exchanger comprising:a first core portion to carry out a heat exchange between a first fluid and an external fluid, said first core portion including a plurality of first tubes through which the first fluid flows and first cooling fins disposed between said each pair of adjacent first tubes; and a second core portion disposed in series with said first core portion in an external fluid flow direction with a predetermined clearance therebetween, to carry out a heat exchange between a second fluid and the external fluid, said second core portion including a plurality of second tubes through which the second fluid flows and second cooling fins disposed between said each pair of adjacent second tubes, wherein each of said first cooling fins and said second cooling fins is integrated by a connecting portion, and one of said first cooling fins and said second cooling fins introduce different cooling performances between a first area and a second area within a respective one of said first core portion and said second core portion.
  • 2. A heat exchanger according to claim 1, whereinsaid first cooling fins and said second cooling fins include a plurality of louvers, respectively, and arrangements of said louvers within said one of said first cooling fins and said second cooling fins are different between said first area and said second area of said respective one of said first core portion and said second core portion.
  • 3. A heat exchanger according to claim 2, wherein the number of said louvers within said one of said first cooling fins and said second cooling fins are different between said first area and said second area of said respective one of said first core portion and said second core portion.
  • 4. A heat exchanger according to claim 1, wherein said first and second cooling fins are formed by a roller forming apparatus for continuously forming a plate material into a predetermined shape while rotating.
  • 5. A compound heat exchanger including a refrigerant condenser and an engine coolant radiator, comprising:a condenser core portion to carry out a heat exchange between a refrigerant and air, said condenser core portion including a plurality of condenser tubes through which the refrigerant flows and condenser fins disposed between said each pair of adjacent condenser tubes; and a radiator core portion disposed in series with said condenser core portion in an air flow direction with a predetermined clearance therebetween, to carry out a heat exchange between an engine coolant and the air, said radiator core portion including a plurality of radiator tubes through which the engine coolant flows and radiator fins disposed between said each pair of adjacent radiator tubes; wherein each of said condenser fins and said radiator fins are integrated by a connecting portion, and one of said condenser fins and said radiator fins introduce different cooling performances between a first area and a second area within a respective one of said condenser core portion and said radiator core portion.
  • 6. A compound heat exchanger according to claim 5, whereinsaid condenser fins and said radiator fins include a plurality of louvers, respectively, and arrangements of said louvers within said one of said condenser fins and said radiator fins are different between said first area and said second area said respective one of said condenser core portion and said radiator core portion.
  • 7. A compound heat exchanger according to claim 6, wherein the number of said louvers within said one of said condenser fins and said radiator fins are different between said first area and said second area of said respective one of said condenser core portion and said radiator core portion.
  • 8. A compound heat exchanger according to claim 5, whereinsaid radiator core portion includes a first radiator core portion and a second radiator core portion, said first radiator core portion includes a plurality of first radiator tubes through which the engine coolant flows and first radiator fins disposed between said each pair of adjacent first radiator tubes; said second radiator core portion includes a plurality of second radiator tubes through which an electronic part coolant flows and second radiator fins disposed between said each pair of adjacent second radiator tubes, and said first radiator fins and said second radiator fins introduce cooling performances different from each other.
  • 9. A compound heat exchanger according to claim 8, wherein said first radiator fins introduce cooling performance is more than said second radiator fins.
  • 10. A heat exchanger comprising:a heat exchanging core portion including: a first core portion to carry out a heat exchange between a first fluid and an external fluid, said first core portion including a plurality of first tubes through which the first fluid flows and first cooling fins disposed between said each pair of adjacent first tubes; a second core portion disposed in series with said first core portion in an external fluid flow direction with a predetermined clearance therebetween, to carry out a heat exchange between a second fluid and the external fluid, said second core portion including a plurality of second tubes through which the second fluid flows and second cooling fins disposed between said each pair of adjacent second tubes; and a third core portion disposed in series with said first core portion in the external fluid flow direction with a predetermined clearance therebetween, and disposed in parallel with said second core portion in the external fluid flow direction to carry out a heat exchange between a third fluid and the external fluid, said third core portion including a plurality of third tubes through which the third fluid flows and third cooling fins disposed between said each pair of adjacent third tubes, wherein each of some first cooling fins and said second cooling fins is integrated by a connecting portion, each of remaining first cooling fins and said third cooling fins is integrated by a connecting portion, and said first cooling fins, said second cooling fins and said third cooling fins introduce different cooling performances between one area and another area within said heat exchanging core portion.
  • 11. A heat exchanger according to claim 10, wherein said second cooling fins and said third cooling fins introduce different cooling performances from each other.
  • 12. A heat exchanger according to claim 10, wherein said first cooling fins introduce different cooling performances between at one area and another area within said first core portion.
  • 13. A heat exchanger comprising:a core portion to carry out heat exchange between an internal fluid and an external fluid, said core portion including a first plurality of tubes through which the first fluid flows and a first plurality of cooling fins disposed between said each pair of adjacent first tubes, wherein said first cooling fins are arranged to achieve a first cooling performance; and a second plurality of tubes through which the first fluid flows and a second plurality of cooling fins disposed between each pair of adjacent second tubes, wherein said second plurality of cooling fins are arranged to achieve a second cooling performance, wherein said second cooling performance is different from said first cooling performance.
Priority Claims (1)
Number Date Country Kind
2000-079350 Mar 2000 JP
US Referenced Citations (12)
Number Name Date Kind
4063431 Dankowski Dec 1977 A
5033540 Tategami et al. Jul 1991 A
5046554 Iwasaki et al. Sep 1991 A
5176200 Shinmura Jan 1993 A
5366005 Kadle Nov 1994 A
5566748 Christensen Oct 1996 A
5992514 Sugimoto et al. Nov 1999 A
6170565 Nishishita Jan 2001 B1
6173766 Nakamura et al. Jan 2001 B1
6209628 Sugimoto et al. Apr 2001 B1
6305465 Uchikawa et al. Oct 2001 B1
6357518 Sugimoto et al. Mar 2002 B1
Foreign Referenced Citations (1)
Number Date Country
0 866 298 Sep 1998 EP