JP2715265B2 - Cross-flow heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross-flow heat exchanger used for a radiator of an automobile.

[0002]

2. Description of the Related Art A so-called cross-flow heat exchanger in which the flow direction of air is orthogonal to the flow direction of a cooling liquid has a structure as shown in FIG. More specifically, reference numeral 1 denotes a fin tube type cross-flow heat exchanger, in which a plurality of flat tubes 3 for a coolant passage are inserted and fixed in a horizontal state between fins 2 and 2 arranged in parallel at regular intervals in a vertical direction. An upper tank 5 and a lower tank 6 are attached to the upper and lower open ends of the flat tube 3 via flat end plates 4 respectively.

[0003] This type of cross-flow heat exchanger 1 includes:
As shown in FIG. 6, when viewed from the flow direction of the air A, a plurality of the flat tubes 3 arranged in a row are connected to upper and lower or left and right tanks. As shown in FIG. 7, a partition wall 7 is provided in the tank 5 so that the coolant flows in opposite directions to each other.

[0006] In the one-pass type cross-flow heat exchanger 1 shown in FIG. 6, the cooling liquid W injected from the water suction port 5 a of the upper tank 5 flows down the flat tube 3 to the lower tank 5. When the air is circulated so as to be discharged from the drain port 6a of the cooling water 6, the air flows between the fin 2 and the flat tube 3 in a horizontal direction as indicated by an arrow, that is, in a direction orthogonal to the flowing direction of the cooling liquid W. A is used to cool the cooling liquid W flowing down the flat tube 3 by passing the A. The 1-pass type cross-flow heat exchanger 1 is compared with the 2-pass type heat exchanger shown in FIG. And its performance is known to be inferior.

That is, as shown in FIG. 7, when the cross-flow heat exchanger 1 is viewed from the side, the two-pass type heat exchanger has a plurality of flat tubes 3A in the flow direction of the air A. , 3B are erected on top of each other, and the inside of the upper tank 5 is divided into two right and left by a partition wall 7. One of the divided upper tank chambers 5A has a water inlet 7a, and the other has a water inlet 7a. A drain port 8a is provided in each of the upper tank chambers 5B. The upper ends of the flat tubes 3A and 3B are respectively opened in the divided upper tank chambers 5A and 5B.

Therefore, the coolant W injected from the water inlet 7a of the upper tank chamber 5A is supplied to the flat tube 3A.
After flowing down into the lower tank 6 and flowing into the lower tank 6, the liquid flows upward from the lower tank chamber 6 into the other flat tube 3B, flows into the other upper tank chamber 5B, and is circulated so as to be discharged from the drain port 8a. That is, the flow direction of the coolant flowing through one flat tube 3A and the flow direction of the coolant flowing through the other flat tube 3B are opposite to each other.

[0007] In the two-pass type cross-flow heat exchanger 1 shown in FIG.
There are two types, a pattern shown in FIG. 8 and a pattern shown in FIG. First, the two shown in FIG. 8 are two sets of path groups P each including a plurality of flat tubes 3A and 3B.
1 and P2, and the coolant W injected from the water inlet 7a branches off into each tube 3A of one of the path groups P1 and flows down, merges at the lower end thereof, and the temperature of the coolant W is mixed. At the lower end of each tube 3B of the other path group P2, it branches and rises, merges at its upper end, and is discharged from the drain 8a.

In the pattern shown in FIG. 9, the coolant W injected from the water inlet 7a branches off into each tube 3A of one path group P1, flows down, and then does not merge with the other path group. Each of the tubes 3B of P2 rises individually from the lower end thereof, merges at the upper end thereof, and is discharged from the drain 8a. In short, the conventional two-pass type heat exchanger is
The cooling liquids W flowing through the tubes 3A, 3B of the set of path groups P1, P2 have opposite flows.

[0009]

The two-pass type cross-flow heat exchanger 1 having the structure as shown in FIG.
Compared to the one-pass type, the heat passage unit (NT
When U) is 1, the temperature efficiency is improved by about 3%, and when NTU is 2 or more, the temperature efficiency is improved by about 5%. However, even in this case, the improvement in the temperature efficiency by about 5% has leveled off.

[0010]

SUMMARY OF THE INVENTION According to the present invention, from the viewpoint of improving the temperature efficiency of a cross-flow heat exchanger, it is possible to improve the temperature efficiency by improving the flow of a coolant in a two-pass type. The purpose of the present invention is to provide a counter-current type that is close to the temperature efficiency of a heat exchanger that allows the flow direction of air to flow in the opposite direction to the flow direction of the coolant, the gist of which is: In a cross-flow heat exchanger that cools a coolant by flowing air from a direction orthogonal to a coolant passage tube, the coolant passage tubes are arranged in two front and rear rows in a horizontal direction with respect to a flow direction of the air. Then, the inside of the upper and lower tanks provided above and below the front and rear two rows of tubes are partitioned back and forth by partition walls to form front and rear tank chambers, respectively. Upper and lower tanks The rear tank chamber and the upper and lower ends of the front tube are connected to the front tank chambers of the upper and lower tanks, respectively, and the lower rear tank chamber of the lower tank and the upper front tank chamber of the upper tank are also connected. The cooling liquid that has entered the lower rear tank chamber via the rear row tube from the upper rear tank chamber of the upper tank is introduced into the upper front tank chamber, and the upper front tank chamber is connected to the upper front tank chamber. A cross-flow through the front tube to the lower front tank chamber.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the embodiments shown in FIGS. 1 to 4. In the drawings, reference numeral 1 denotes a fin tube type cross-flow heat exchanger, which is arranged at regular intervals in the vertical direction. A plurality of flat tubes 3 for the coolant passages are inserted and fixed in the parallel fins 2 in the horizontal direction. That is, when the tubes 3 are viewed from the side surface (the flow direction of the air A) of the cross-flow heat exchanger 1, a plurality of tubes 3A and 3B are arranged in two front and rear rows in the row direction. Upper and lower end plates 4 and 4 of upper and lower end plates 4 and 4 are fixed to upper and lower end plates 4 and 4 of the rear row tube 3A and the front row tube 3B, respectively. And lower tank 6
They communicate with each other. .

The interior of the upper tank 5 and the interior of the lower tank 6 are divided into two parts by partition walls 7 and 8 respectively.
A and the upper front side of the tank chamber 5B, respectively, the upper end of the rear row side tube 3A and the front row side tube 3B are opened separately, respectively. The lower ends of the rear row tubes 3A and the front row tubes 3B are respectively opened in the tank chamber 6A on the side and the tank chamber 6B on the lower front side, respectively.

The divided upper rear tank chamber 5A and upper front tank chamber 5B of the upper tank 5 are divided.
Are provided with water inlets 9a and 11a, respectively.
The divided lower rear tank chamber 6A and lower front tank chamber 6B have drain ports 10a and 12a, respectively.
The drain port 10a provided in the lower rear tank chamber 6A is directly connected to the water intake port 11a provided in the upper front tank chamber 5B. Therefore, the rear tube 3A and the front tube 3B are connected in series at their lower ends and upper ends.

Therefore, the coolant W injected from the water suction port 9a of the tank chamber 5A on the upper rear side of the upper tank 5 flows down in the tube 3A on the rear row side and the tank chamber 6A on the lower rear side of the lower tank 6 Flows into. Then, it flows into the tank chamber 5B on the upper front side of the upper tank 5 from the drain port 10a of the tank chamber 6A on the part rear side from the water suction port 11a, flows down the tube 3B on the front row side, and flows into the lower front side. And flows into the tank chamber 6B of the above (drainage) and drains from the drain port 12a (cocurrent).

In the course of the flow of the cooling liquid W through the above-mentioned path, the air A is passed from the horizontal direction between the fins 2 and the tubes 3 as shown by arrows in FIG. 3A and front row tube 3
The cooling liquid W flowing down in each of the tubes B is cooled. When the tube 3A in the rear row, in which the cooling liquid having a high temperature flows down, is seen, the temperature of the high-temperature side fluid flowing down the tube 3A and The difference from the temperature of the air flowing between the tubes 3A becomes substantially uniform.

That is, tubes 3A in the rear row through which the high-temperature fluid flows down and tubes 3B in the front row through which the lower-temperature fluid flows lower are respectively denoted by A and B and C and D respectively.
More specifically, with reference to the explanatory diagram shown in FIG. 10A divided into two cores, the cores C and D in the front row are cooled by air T1 having the same temperature. Next, when the air T1 passes between the cores C and D, the cores A and B in the rear row are cooled by the heated airs T2 and T3, respectively. A is higher in temperature than core B (A> B).

Since the temperature of the core C in the front row is higher than that of the core D, the temperature of the air T2 passing through the core C is higher than the temperature of the air T3 passing through the core D (T2> T3). Therefore, the high-temperature core A is cooled by the high-temperature air T2, and the low-temperature core B is cooled by the low-temperature air T3. As a result, as shown in an explanatory diagram of FIG.
Each temperature of the cores A and B and air T2 and T
The difference h from the temperature of No. 3 becomes substantially uniform between the side of the water inlet 9a and the side of the drain port 10a, and the temperature efficiency is improved accordingly.

On the other hand, in the conventional structure shown in FIG. 7, as shown in FIG. 11A, the high-temperature air T2 passing through the core C (higher temperature than the air T3 passing through the core D) is applied to the core. Since the core B having a lower temperature than the core A and the cold air T3 having passed through the core D cool the core A having a higher temperature than the core B, the core A having a higher temperature is cooled by the air T3 having a lower temperature and the core having a lower temperature. B is cooled by the high-temperature air T2. Therefore, as shown in FIG.
Each temperature of the cores A and B and the air T3 and T
The difference H from the temperature 2 is large on the water suction port 7a side and small on the lower tank chamber 6 side, and the temperature efficiency deteriorates accordingly.

Here, the flow of the coolant W in the cross-flow heat exchanger 1 according to the present invention, which is formed into two passes in parallel when connected in series, is shown by the patterns of FIGS. First, the cooling water mixing type shown in FIG.
A and 3B are composed of two sets of path groups P1 and P2, and the coolant W injected into the upper rear tank chamber 5A from the water suction port 9a is supplied to each tube 3 of the rear path group P1.
A, branches down and flows down, merges in the tank room 6A on the lower rear side of the lower end, and then the water intake port 11a of the path group P2 in the front row
From above into the upper front tank chamber 5B, from which it branches off into each tube 3B of the path group P2, flows down, joins in the lower front tank chamber 6B at the lower end, and its drain port 12a.
Drained from

The pattern shown in FIG. 3 is a cooling water non-mixing type, and the cooling liquid W injected into the tank room 5A on the upper rear side from the water suction port 9a of the path group P1 in the rear row is used for each pattern of the path group P1. After branching off to the tube 3A and flowing down, it enters the upper front tank chamber 5B of the path group P2 in the front row without merging in the lower rear tank chamber 6A. Then, it flows down to each tube 3B of the path group P2 separately from here, merges in the tank room 6B at the lower front side of the lower end thereof, and is drained from the drain port 12a. In short, each of the tubes 3A, 3B of the two path groups P1 and P2 connected in series.
One system of the cooling liquid W flows in the same direction (downward in parallel).

In the above embodiment, the rear tube 3A and the front tube 3B in the flow direction of the air A are used.
Is connected to the lower one of the tank chambers 6 on the rear side.
Although the drain port 10a of A is directly connected to the water inlet port 11a of the tank chamber 5B on the upper front side on the other side, in the embodiment of FIG.
Inside the cross-flow heat exchanger 1, the tank chamber 6 </ b> A on one lower rear side and the tank chamber 5 </ b> B on the other upper front side are directly connected by an oblique tube 11.

Therefore, the tank chamber 5A on one upper rear side
The coolant W that has flowed down through the tube 3A on the rear row side from the tank chamber 6A on the lower rear side of the tube 3A
After flowing up into the other upper front tank chamber 5B, the other front tube 3
B flows down into the tank chamber 6B on the lower front side. The other points are the same as in the above embodiment.

As a result of the calculation, when the NTU is 1, the flow of the coolant W, that is, the conventional coolant shown in FIG. There is little difference in temperature efficiency between liquids flowing in the same direction as each other.
%, Whereas in the latter case it was 6% or more, and the temperature efficiency was improved.

The difference between the mixing and non-mixing of the cooling liquid between the two passes is small in the conventional one, but in the present invention, the non-mixing is 1 to 1.5% more than the mixing in the mixing. The degree of thermal efficiency has improved. In particular, in the case of the non-mixture of the present invention, the effect of improving the temperature efficiency was large, and when NTU was 5, the temperature efficiency was 7.8%, which was remarkable.

[0025]

As described above, the cross-flow heat exchanger according to the present invention is a cross-flow heat exchanger that cools a coolant by flowing air from a direction orthogonal to a tube for a coolant passage. The tubes for the coolant passages are arranged in two rows in the front and rear direction in the horizontal direction, and the insides of the upper and lower tanks provided above and below the two rows of tubes are partitioned forward and backward by partition walls. The front and rear tank chambers are respectively formed, and the upper and lower ends of the rear row tubes are connected to the rear tank chambers of the upper and lower tanks.
At the same time as being connected to the front tank chamber of the lower tank, respectively, the lower rear tank chamber of the lower tank and the upper front tank chamber of the upper tank are directly connected to each other. A structure in which the cooling liquid that has entered the lower rear tank chamber via the rear row tube is introduced into the upper front tank chamber, and flows from the upper front tank chamber to the lower front tank chamber via the front tube. Therefore, there is an effect that the temperature efficiency is remarkably improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a cross-flow heat exchanger according to the present invention.

FIG. 2 is a pattern showing an example of a flow of a coolant W in a cross-flow heat exchanger.

FIG. 3 is a pattern showing another example of how the coolant W flows.

FIG. 4 is a side sectional view showing another embodiment of the cross-flow heat exchanger.

FIG. 5 is a perspective view in which a part of a general-purpose cross-flow heat exchanger is cut away.

FIG. 6 is a side sectional view showing one embodiment of a conventional cross-flow heat exchanger.

FIG. 7 is a side sectional view showing another embodiment of the conventional cross-flow heat exchanger.

FIG. 8 is a pattern showing an example of a flow of a coolant W in a conventional cross-flow heat exchanger.

FIG. 9 is a pattern showing another example of how the coolant W flows.

FIG. 10 is an operation explanatory view of the cross-flow heat exchanger according to the present invention.

FIG. 11 is a diagram illustrating the operation of a conventional cross-flow heat exchanger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fin-tube type cross-flow heat exchanger 2 Fin 3 Flat tube 3A Back row tube 3B Front row tube 4 End plate 5 Upper tank 5A Upper rear tank chamber 5B Upper front tank chamber 6 Lower tank 6A Lower rear side Tank room 6B Lower front side tank room 7 Partition wall 8 Partition wall 9a Water intake port 10a Drain port 11a Water intake port 12a Drain port W Coolant A Air

Claims (1)

(57) [Claims] In a cross-flow heat exchanger for cooling a coolant by flowing air from a direction orthogonal to a tube for a coolant passage, the tube for a coolant passage is moved back and forth in a row direction with respect to a flow direction of the air. When arranged in two rows, the front and rear 2
The upper and lower tanks provided above and below the row of tubes are partitioned back and forth by partition walls to form front and rear tank chambers, respectively, and the upper and lower ends of the rear row tubes are rear tanks of the upper and lower tanks. The upper and lower ends of the upper and lower tanks are connected to the upper and lower tanks, respectively, and the lower rear tank chamber of the lower tank is directly connected to the upper front tank chamber of the upper tank. The cooling liquid that has entered the lower rear tank chamber through the rear tube from the upper rear tank chamber of the upper tank is introduced into the upper front tank chamber, and from the upper front tank chamber, A cross-flow heat exchanger, wherein the heat is passed through the lower tube to the lower front tank chamber.