JPH0384395A - Duplex heat exchanger - Google Patents

Abstract

PURPOSE:To increase the exchanged heat amount by a method wherein a plurality of heat exchangers in which a plurality of tubes are installed in parallel and fins are arranged between the adjacent tubes and the both ends of the respective tubes are interconnected to a pair of hollow headers are installed in parallel at the front and rear of the air flow direction. CONSTITUTION:A duplex heat exchanger H consists of the front heat exchanger A at the windward and the rear heat exchanger B at the leeward which are arranged in two parallel stages of the front and rear in the flow direction W of the air for heat exchangers. The front heat exchanger A is equipped with a plurality of tubes 1 arranged in the upper and lower directions in horizontal condition, corrugated fins 2 between adjacent tubes 1 and 1, and the right and left headers 3, 4 and the rear heat exchanger B is almost similarly constituted as the exchanger A but the length of tubes 21, however, is set to be longer than that of tubes of the exchanger A. Refrigerant is let to flow from the rear heat exchanger B to the front heat exchanger A and during the refrigerant flows through respective tubes of the exchangers A, B, heat is exchanged between the refrigerant and the air flowing in the direction indicated by the arrow W.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to heat exchangers used in condensers, evaporators, oil coolers, etc. for car coolers, and particularly to multiple heat exchangers composed of a plurality of heat exchangers. Regarding.

BACKGROUND OF THE INVENTION As a heat exchanger used for the above-mentioned applications, a heat exchanger called a multi-flow type has been attracting a lot of attention. This heat exchanger has a plurality of flat tubes arranged in parallel, corrugated fins are arranged between adjacent tubes, and both ends of each tube are It has a configuration in which it is communicatively connected to a pair of hollow headers. In such a multi-flow type heat exchanger, while the refrigerant flows through a refrigerant circuit made up of a group of tubes, it exchanges heat with the air flowing between the tubes. It is recognized that it has superior performance compared to conventional general-purpose serpentine heat exchangers in terms of heat exchange efficiency.

Problems to be Solved by the Invention By the way, in the above-mentioned multi-flow type heat exchanger, it may be necessary to increase the amount of heat exchanged.
In general, due to the installation space, there are often dimensional restrictions on the vertical and horizontal dimensions of the heat exchanger, that is, increases in tube length and number of tubes. For this reason, the width of the tube, in other words, the depth of the heat exchanger is increased to cope with the increase in the amount of heat exchanged.

However, as the width of the tube increases, the outer diameter of the header also increases, which reduces the effective length of the tube that contributes to heat exchange, making it impossible to obtain the desired increase in heat exchange. There was a drawback.

The present invention was made to eliminate such drawbacks, and an object of the present invention is to provide a heat exchanger that can increase the amount of heat exchanged.

Means for Solving the Problems In order to achieve the above object, the present invention uses a plurality of multi-flow type heat exchangers, and arranges them one behind the other in the air flow direction to form one multiple heat exchanger. It is intended to be configured.

That is, in this invention, a plurality of heat exchangers are provided in which a plurality of tubes are arranged in parallel, fins are arranged between adjacent tubes, and both ends of each tube are connected to a pair of hollow holes to communicate with a ladder. The heat exchangers are arranged in parallel in the flow direction, and the refrigerant circuits of each heat exchanger are connected in series or in parallel.

Since heat exchange is performed with the circulating air in each heat exchanger arranged in parallel before and after the action, the total amount of heat exchanged increases.

Embodiments [First Embodiment] FIGS. 1 to 9 show an embodiment in which the present invention is applied to an aluminum condenser for a car cooler. In these figures, (H) is a duplex heat exchanger, and this duplex heat exchanger (H) is a front heat exchanger on the windward side that is installed in two stages, front and rear, in parallel in the flow direction (W) of heat exchange air. Vessel (A)
and a rear heat exchanger (B) on the leeward side.

The front heat exchanger (A) includes a plurality of tubes (1) arranged vertically in a horizontal state, and adjacent tubes (1) (
1) It has a corrugated fin (2) interposed therebetween and left and right headers (3) and (4). Tube (1)
is constructed from a flat extruded section made of aluminum lamb material. This tube (1) may be of a porous type, so-called a harmonica tube. Moreover, an electric resistance welded tube may be used instead of the extruded shape. The corrugated fin (2) has approximately the same width as the tube (1) and is joined to the tube by brazing. The corrugated fins (2) are also made of aluminum, preferably with louvers cut and raised. The headers (3) and (4) are formed with an aluminum vibrator having a circular cross section. Tube insertion holes (5) are bored in each header at intervals along the length direction, and both ends of each tube (1) are inserted into the chain holes and are firmly joined and connected by brazing. There is. Additionally, lid pieces (6) (6) are attached to the upper and lower ends of the left header (3), and lid pieces (7) (6) are attached to the upper and lower ends of the right header (4).
7) is attached. Note that side plates (8) (8) are arranged on the outside of the outermost corrugated fin (2).

On the other hand, in the rear heat exchanger (B), (21) is a tube, (22) is a corrugated fin, (23) and (24) are left and right headers, (25) is a tube insertion hole, (2B)
(2B) (27) (27) is a lid piece, (28
) (28) is a side plate, and the front heat exchanger (A
) has almost the same configuration as the front heat exchanger (A
), the length of the tube (21) and therefore the lateral length of the heat exchanger is set longer than that of the heat exchanger.

The refrigerant circuits of the front heat exchanger (A) and rear heat exchanger (B) are connected in series. That is, a refrigerant inlet pipe (40) is connected to the upper part of the left header (28) of the rear heat exchanger (B), while a refrigerant outlet is connected to the upper part of the left header (3) of the front heat exchanger (A). A tube (50) is connected. The left header <28> (3) of the rear heat exchanger (B) and the front heat exchanger (A) are connected to each other through a connecting pipe (60). In addition, Figures 2 to 4
Reference numerals (71) and (72) shown in the figure are brackets for mounting the heat exchanger to the vehicle body. By the way, the rear heat exchanger (B
) is provided with a partition plate (29) approximately in the center of the left header (23) to partition the header into two upper and lower chambers. On the other hand, the left header (
3) has a total of two partition plates (9) (9), one each at the upper and lower positions of the central part, and the inside of the header (3) is 3
The right header (4) is also provided with a partition plate (10) approximately in the center, and the inside of the header is partitioned into two rooms. Such partition plate (29) (9) (1
0), the refrigerant flowing into the ladder (23) from the refrigerant inlet pipe (40) to the left of the rear heat exchanger (B) is
As shown in the figure, the tube group of the rear heat exchanger (B) is
After meandering around and flowing to the bottom of the left header (23),
The connecting pipe (60) leads to the lower part of the left header (3) of the front heat exchanger (A), and from there the front heat exchanger (A)
Go up while meandering through the group of tubes 3 times and reach the left header (3
) and flows out of the vessel from the refrigerant outlet pipe (50). While the refrigerant flows through each tube of the front and rear heat exchangers (A) and (B), heat exchange is performed with the air flowing in the direction shown by the arrow (W). In this way, the refrigerant is allowed to flow from the rear heat exchanger (B) to the front heat exchanger (A) by first passing it through the leeward heat exchanger and then passing it through the upwind heat exchanger. This is to increase the temperature difference with the air and increase heat exchange efficiency. Also,
The reason why the number of meanderings in the front heat exchanger (A) is made greater than the number of meanderings in the rear heat exchanger (B) is that this allows the passage cross-sectional area of the front heat exchanger (A) to be reduced, thereby reducing the volume change of the refrigerant. This is to create a condenser with a passage cross-sectional area that changes according to the conditions.

That is, the refrigerant that has flowed into the rear heat exchanger (B) is still in a gasified state with a large volume, but as heat is exchanged, it is gradually cooled and liquefied, and its volume decreases. Therefore, a large cross-sectional area of the refrigerant passage in the rear heat exchanger where the refrigerant is in a gasified state is ensured to ensure sufficient heat exchange, and a cross-sectional area of the passage in the front heat exchanger (A) is secured as the refrigerant volume decreases. This is intended to improve the heat exchange efficiency of the entire heat exchanger and to suppress pressure loss as much as possible.

Here, the passage cross-sectional area of the front heat exchanger (A) is set to 30 to 60% of the passage cross-sectional area of the rear heat exchanger (B). When this is less than 30%, the passage cross-sectional area of the front heat exchanger (A) corresponding to the supercooling section becomes too small, resulting in a large refrigerant pressure loss, and the rear heat exchanger (A) corresponding to the condensing section becomes too small. If the cross-sectional area of the passage B) becomes too large, the flow rate of the refrigerant decreases, and there is a risk that efficient heat exchange will not be performed. Also, when it exceeds 60%,
The passage cross-sectional area of the rear heat exchanger (B) corresponding to the condensing section becomes too small, and the pressure loss of the refrigerant becomes large.
The heat transfer area becomes insufficient and the heat exchange efficiency decreases.

Therefore, in order to perform efficient heat exchange and reduce pressure loss, the passage cross-sectional area of the front heat exchanger (A) is set to 30 to 60% of the passage cross-sectional area of the rear heat exchanger (B). It is preferable to set it to 35 to 50%.

Further, other preferable design conditions for the front and rear heat exchangers (A) and (B) will be explained as follows.

The tube (1) (21) has a width (Wt > in the range of 6 to 20 m, a height (Ht) in the range of 1.5 to 7 m,
It is preferable to set the height (Hp) of the refrigerant passage in the tube to 1.0 m or more, respectively, and the height (If) of the corrugated fins (2) (22), that is, the height (Hp) of the adjacent tubes (1) (1) ( 21) Set the interval of (21) to 6~
In the range of 16#, the fin pitch (Fp) is 1.6 to 4.
It is preferable to set each in a range of 0 mm. below,
The reasons for each will be explained.

If the tube width (W t ) is less than 6 tubes, the width of the corrugated fins (2) (22) interposed between the adjacent tubes (1) (1) or (21) (21) will also be small, and the heat exchange Performance deteriorates. 20m on the contrary
Fins (2) (22)
The width of the condenser also increases, leading to an increase in pressure loss due to an increase in the flow resistance of the circulating air, and an increase in the weight of the condenser. Therefore, preferably 6 to 1
It is best to set it to 6mm, and the most suitable range is 10 to 14m.
It is m.

If the tube height (Ht) exceeds 7 mm, the pressure loss of the circulating air will increase, and conversely, if it is less than 1.5 seconds, the refrigerant passage height (Hp) in the tube should be adjusted in relation to the tube wall thickness. It becomes difficult to secure 1.0 mm or more.

Preferably, it is 1°5 to 5 mm. The most preferred range is 2°5 to 4rIun.

Refrigerant passage height in tubes (1) (21) (Hp)
If this is less than 1.0 mm, the pressure loss of the refrigerant will increase, resulting in a decrease in heat exchange efficiency.

Preferably it is 1.5 to 2.0 mm.

On the other hand, if the fin height (Hf) is less than 6 mm, the pressure loss of the circulating air increases, and conversely, if it is 16 rrrm or more, the total number of fins decreases, the fin efficiency decreases, and the heat exchange performance deteriorates. Preferably it is 8 to 16 mm. The most preferred range is 8-12 mm.

1 If the fin pitch (Fp) is less than 1.6 mm, air pressure loss increases, and conversely, if it exceeds 4 mm, heat exchange performance deteriorates. Preferably 1.6-3.2m
It is better to set it to m. The most preferred range is 2.0-3. ．． 2
It is mm.

In this way, the tube (1
) (21) and corrugated fins (2) and (22), by setting the tube width, tube height, refrigerant passage height in the tube, fin height, and fin pitch to the most appropriate ranges as above. Therefore, it is possible to provide a condenser that can be operated in an optimal state with high efficiency in which the pressure loss of the refrigerant and circulating air and heat exchange performance are more harmonized without causing an increase in weight.

[Second Embodiment] FIGS. 10 and 11 show a second embodiment of the present invention. This embodiment is applied to a condenser like the first embodiment, and also has a front heat exchanger (A) and a rear heat exchanger (A).
B) are connected in series, and the front heat exchanger and rear heat exchanger 2 are designed to be the same size, but the configuration of each heat exchanger's header, tubes, corrugated fins, etc. Since this is the same as in the first embodiment, the same components are given the same reference numerals and the explanation thereof will be omitted.

In this embodiment, the front and rear heat exchangers (A) and (B) are connected for communication using connection blocks. That is, a male block (80) is joined to the lower end of the left header (3) of the front heat exchanger (A) by welding or the like. A fitting protrusion (81) is provided on the inner surface of the male block (80), and a refrigerant flow hole (82) communicating with the left header (3) is formed in the fitting protrusion (81). There is. On the other hand, a female block (90) is joined to the lower end of the left header (23) of the rear heat exchanger (B), and a header (23) is attached to the inner surface of the female block (90).
) A fitting hole (91) is formed which communicates with the hole. Then, the fitting protrusion (81) of the male block (80) is fitted into the fitting hole (91) of the female block (90), and the inner surfaces of the male and female blocks (80) (90)3 are brought into close contact with each other. , male block (80)
The male and female blocks (90) (80) are connected by a bolt (100) inserted through the through hole (83) of the female block (90) and screwed into the screw hole (92) of the female block (90), thereby connecting the front and rear heat exchangers ( The refrigerant circuits A) and (B) are connected in series. Further, an artificial block (110) having a fitting hole is joined to the upper end of the rear heat exchanger CB), and an inlet pipe connecting block (110) having a fitting protrusion (121) is joined to this.
An inlet pipe (130) is connected via the inlet pipe (20). Note that the inlet block (110) and the inlet pipe connection block (120) are connected by bolts (140). On the other hand, an outlet block (150) having a fitting hole (151) is joined to the upper end of the left header (3) of the front heat exchanger (A), and an outlet block (150) having a fitting protrusion (161) is joined to the upper end of the left header (3) of the front heat exchanger (A). Connect the outlet pipe (
170) are connected in communication. Note that the outlet block (150) and the outlet pipe connection block (160) are also connected by bolts (180).

By using the block connection as described above, it is possible to manufacture the front and rear heat exchangers (A) and (B) separately, conduct refrigerant leakage tests independently, and then connect them at the final stage. Since this can be easily carried out, work efficiency and productivity can be improved.

[Third Embodiment] FIGS. 12 and 13 show a third embodiment of the present invention. This embodiment is also applied to a condenser, but differs from the first and second embodiments in that front and rear heat exchangers of the same shape and size are connected in parallel. That is, the bifurcated refrigerant inlet pipe (190) is connected to the upper part of each left header (3) (23) of the front and rear heat exchangers (A) and (B), while the left header (3) (23) A bifurcated refrigerant outlet pipe (200) is connected to the lower end of the refrigerant outlet pipe (200). In addition, the left header (3) of the front heat exchanger (A) has a
partition plates (9) are provided. On the other hand, in the rear heat exchanger (B), the leftward 5 rudder (23) is provided with partition plates (29) (29) at two locations, at the upper and lower sides of the center, and the right header (24).
Although not shown, one partition plate is provided approximately in the center of ). By installing such a partition plate, the refrigerant flowing from the refrigerant artificial pipe (190) into the front and rear heat exchangers (A) and (B) is separated once in the front heat exchanger (A), as shown in FIG. In the rear heat exchanger, the refrigerant meanderes three times to reach the lower part of each left header (3) (23), and flows out of the refrigerant outlet pipe (200). In this way, when the front and rear heat exchangers are connected in parallel, the rear heat exchanger (
The reason for increasing the number of meandering steps in B) is as follows. That is,
Because the rear heat exchanger (B) is located on the leeward side, the heat transfer coefficient is lower than that of the front heat exchanger (A), so the number of meandering increases to increase the flow length, thereby improving heat exchange. This is to increase the heat exchange rate and maintain a balance with the heat exchange rate of the front heat exchanger (A).

[Fourth Embodiment] FIGS. 14 and 15 show a fourth embodiment of the present invention. In this example, the front heat exchanger (A)
The corrugated fins of the rear heat exchanger (B) and the rear heat exchanger (B) are shared by one wide corrugated fin (210) arranged in a manner that it spans the heat exchanger. With this configuration, the cores of the front and rear heat exchangers (A) and (B) are connected, and the heat exchange efficiency can be improved. Furthermore, the connection strength of the heat exchangers can be improved, and only one heat exchanger needs to be fixed when attached to a vehicle body, so the number of parts to be attached can be reduced and productivity can be improved.

[Fifth Embodiment] FIGS. 16 and 17 show a fifth embodiment of the present invention. This embodiment shows the case where it is applied to an evaporator for a car cooler. By applying it to an evaporator as in this embodiment, it is possible to reduce refrigerant pressure loss.

In this embodiment, both the front and rear heat exchangers (A) and (B) are arranged in parallel in the left-right direction with the tubes (1) (21) vertically arranged, and the headers 7 (3) (4) (23) (24 ) are arranged horizontally one above the other. and each top header (3
A bifurcated refrigerant inlet pipe (220) is connected to the left end of ) (23), and a bifurcated refrigerant outlet pipe (230) is connected to the right end of each lower header (4) (24). The refrigerant circuits of exchangers (A) and (B) are connected in parallel. Therefore, the refrigerant flowing into the upper headers (3) (23) of the front and rear heat exchangers (A) and (B) from the refrigerant inlet pipe (220') flows downward through each tube (1) (21) and flows downward through the lower header (23) of the front and rear heat exchangers (A) and (B). 4) (24) and flows out from the outlet pipe (230). Furthermore, in this embodiment, as shown in FIG. 17, the fin pitch (F
p') is set larger than the fin pitch (Fp) of the corrugated fins (2) of the front heat exchanger (A). By doing this, the pressure loss of the circulating air can be reduced, and it is also possible to prevent so-called water splash, where condensed water accumulates between the fins of the rear heat exchanger and is blown toward the passenger compartment by the circulating air. . Note that partition plates may be provided in the upper and lower headers to allow the refrigerant to meander.

Effects of the Invention As described above, the present invention provides a heat exchanger in which a plurality of tubes are arranged in parallel, fins are arranged between adjacent tubes, and both ends of each tube are communicatively connected to a pair of hollow headers. A plurality of heat exchangers are arranged in parallel in the air flow direction, and the refrigerant circuits of each heat exchanger are connected in series or in parallel. Therefore, since heat exchange is performed in each heat exchanger, it is possible to increase the amount of heat exchanged. Moreover, by combining multiple heat exchangers, it is possible to expand the flexibility of changing the partition position and number of partitions in the hezugu according to the refrigerant distribution form, resulting in high heat exchange efficiency and low pressure loss. In order to obtain the best design and use, you can choose the best heat exchanger and heat exchanger with excellent performance.

[Brief explanation of drawings]

9 Figures 1 to 9 show a first embodiment of the present invention, where Figure 1 is a perspective view showing the front and rear heat exchangers separated, and Figure 2 is a perspective view showing the front and rear heat exchangers separated.
The figure is a front view of the entire duplex heat exchanger, Figure 3 is a plan view, Figure 4 is a side view, and Figure 5 shows the header, tubes, and corrugated fins of the front or rear heat exchanger separated. 6 is a sectional view taken along the VI-Vl line in FIG. 2, FIG. 7 is an enlarged sectional view of the front or rear heat exchanger seen from the same direction as FIG. 6, and FIG. 8 is a corrugated fin. FIG. 9 is a refrigerant circuit diagram, FIG. 1O and FIG. 11 show a second embodiment of the present invention, and FIG. 10 shows the front and rear heat exchangers separated. Perspective view of main parts,
Figure i1 is a side view after connection, Figures 12 and 13 show a third embodiment of the invention, Figure 12 is an overall perspective view, Figure 13 is a refrigerant circuit diagram, and Figure 14. and Fig. 15 show a fourth embodiment of the present invention, Fig. 14 is a plan sectional view, Fig. 15 is a sectional view taken along the line XV-XV in Fig. 14, and Fig.
6 and 17 show a fifth embodiment of the present invention, FIG. 16 is an overall perspective view, and FIG. 17 is a sectional perspective view of the main part thereof. (H)...Double heat exchanger, (A)...Front heat exchanger, (B)...Rear heat exchanger, (1) (21)...
・Tube, (2) (22)... Corrugated fin, (3) (3) (23) (24)...
Header or more 1

Claims (1)

[Claims] A plurality of heat exchangers in which a plurality of tubes are arranged in parallel, fins are arranged between adjacent tubes, and both ends of each tube are communicatively connected to a pair of hollow headers,
A compound heat exchanger characterized in that the heat exchangers are arranged in parallel in the air flow direction, and the refrigerant circuits of each heat exchanger are connected in series or in parallel.