JPH03279763A - Multiple heat exchanger - Google Patents

Abstract

PURPOSE:To increase the amount of heat exchange by providing fins between adjacent tubes, installing heat exchangers in parallel under an adjacent condition in front and rear where both ends of each tube are connected with a pair of hollow headers, and connecting a refrigerant circuit of each heat exchanger. CONSTITUTION:A multiple heat exchanger H comprises a front side heat exchanger A on the windward side in the air circulating direction W and a rear side heat exchanger B on the leeward side. The front side heat exchanger A is provided with a plurality of tubes 1, corrugated fins 2 provided between adjacent tubes 1, and headers 3 and 4 on both sides. On the other hand, the rear side heat exchanger B has a structure similar to that of the front side heat exchanger A. The header to header span dimension LA is set to be longer than the header to header span dimension LB for the front side heat exchanger A. The headers 3, 23, 4 and 24 are installed in parallel so that they may not pile up. A refrigerant circuit is connected with both the front side heat exchanger A and the rear side heat exchanger B in series.

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.
Due to the installation space, there are often dimensional restrictions on the length and width of the heat exchanger, ie, 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, if the tube width is set wide, the outer diameter of the header also increases accordingly, 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.

Therefore, in order to eliminate the above-mentioned drawbacks in the previous application, the applicant of the present application developed multi-flow type heat exchangers (A) (B).
) was proposed, which was constructed by arranging them one behind the other in the air flow direction to form a single duplex heat exchanger (
(See Figure 11).

However, when the headers are arranged side by side in this way, the headers are arranged so that they overlap one another in the air flow direction, resulting in the problem that the overall thickness of the heat exchanger becomes thick and bulky. . In particular, if the mounting side is formed in a gentle arc shape, such as the front grille of a vehicle, a dead space will be created between the mounting side and the front grille.

An object of the present invention is to provide a heat exchanger that can solve the above-mentioned problems and further increase the amount of heat exchanged.

Means for Solving the Problems In order to achieve the above objects, the present invention provides a multi-flow type heat exchanger in which header-to-header dimensions of different sizes are arranged side by side adjacently in the air flow direction. The idea is to configure it into a dual heat exchanger.

That is, the present invention provides at least one tube in which a plurality of tubes are arranged in parallel, fins are arranged between these adjacent tubes, and both ends of each tube are connected to a pair of hollow headers, and the dimensions between the headers are different. It has two heat exchangers, these heat exchangers are arranged side by side, front and back, adjacent to each other in the air flow direction, and the refrigerant circuits of each heat exchanger are connected in series or in parallel. It is something to do.

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.

Since the heat exchangers with different header-to-header dimensions are arranged side by side adjacently in the air flow direction, the thickness of the heat exchanger as a whole can be reduced without overlapping the headers.

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 multiple type heat exchanger, and this multiple type heat exchanger (H) has front and rear heat exchangers arranged in two stages in parallel in the flow direction (W) of heat exchange air. Exchanger (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)
It is constructed from a flat extruded section made of aluminum. This tube (1) may be of a porous type such as a so-called harmonica tube, or an electric resistance welded tube may be used instead of an extruded shape.
In either case, it is preferable to use one having a reinforcing partition wall or a reinforcing partition bar that connects both the upper and lower inner wall surfaces in order to sufficiently withstand internal pressure. The corrugated fin (2) has approximately the same width as the tube (1) and is joined to the tube by brazing. The corrugated fin (2) is also made of aluminum, preferably with louvers cut and raised. Header (3) (
4) is formed from an aluminum pipe with 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. Also left header (3)
Lid pieces (6) (6) are attached to the upper and lower ends of the
Lid pieces (7) (7) are also attached to the upper and lower ends of the right header (4). Note that side plates (8) (8) are arranged on the outside of the outermost corrugated fin (2).

On the other hand, in both rear heat exchangers (B), (21) is a tube, (22) is a corrugated fin, (23) and (24) are left and right headers, (25) is a tube insertion hole, (2G)
(2B) (27) (27) is a lid piece, (28
) (28) is site play 1, and both front heat exchangers (
It has almost the same configuration as A), but the dimension between headers (LA) is the same as the dimension between headers (LD) of both front heat exchangers (A).
).

After this, both front heat exchangers (A) are placed in the center of the front side of both heat exchangers (B), and a header (3) is installed in the air flow direction.
(23), (4), and (24) are arranged side by side so that they do not overlap and are adjacent to each other.

The refrigerant circuits of the front heat exchanger (A) and the rear heat exchanger (B) are connected in series. That is, the refrigerant inlet pipe (40) is connected to the upper part of the left header (23) of the rear heat exchanger (B), while the refrigerant is connected to the lower part of the left header (3) of the front heat exchanger (A). An outlet pipe (50) is connected. Then, the rear heat exchanger (B) and the front heat exchanger (
A) left header (23) (3) is connected to the connecting pipe (
60). Note that (71) and (72) shown in FIGS. 2 to 4 are brackets for attaching the heat exchanger to the vehicle body. By the way, the rear heat exchanger (B)
The left header (23) has a partition plate (
29) is provided to partition the header into two upper and lower chambers. On the other hand, the left header (3) of the front heat exchanger (A)
) is equipped with two partition plates (9) (9), one each on the upper and lower sides of the center, dividing the inside of the header (3) into three rooms, while the right header (4) A partition plate (10) is provided almost at the center of the header, and the inside of the header is partitioned into two chambers.

By installing the partition plates (29), (9), and (10), the refrigerant flowing from the refrigerant inlet pipe (40) into the left header (23) of the rear heat exchanger (B) is as shown in FIG. , after meandering once through the tube groups of both rear heat exchangers (B) and flowing to the lower part of the left header (23), the connection pipe (60
) to reach the upper part of the left header (3) of both front heat exchangers (A), and from there it descends while meandering three times through the tube group of both front heat exchangers (A) and reaches the left header (3). The refrigerant reaches the lower part of the refrigerant and flows out of 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 rear heat exchanger (B
) to the front heat exchanger (A).
By first circulating the air to the leeward heat exchanger and then to the windward heat exchanger, the temperature difference between each heat exchanger and the air flowing therein can be increased, increasing heat exchange efficiency. be.

In addition, the passage cross-sectional area of each meandering passage group of the front heat exchanger (A) and the rear heat exchanger (B) is set to gradually become smaller from the population side to the outlet side. . This passage cross-sectional area is set using the partition plate (9) (10).
Tube (2) determined by the partition position of (29)
(21) The number of tubes constituting each passage group from the inlet side to the outlet side is 1.
They are set to 3, 10, 8, 6, 5, and 4, respectively. The reason why the passage cross-sectional area is gradually reduced in this way is to create a condenser in which the passage cross-sectional area changes in response to changes in the volume of the refrigerant. That is, the rear heat exchanger (B)
Immediately after the refrigerant flows into the refrigerant, it is still in a gasified state with a large volume, but as it passes through each refrigerant passage, heat is exchanged and the refrigerant is gradually cooled and liquefied, and its volume gradually decreases.

Therefore, a large cross-sectional area of the refrigerant passage on the refrigerant inlet side where the refrigerant is in a gasified state is ensured to ensure sufficient heat exchange, and the cross-sectional area of each passage is gradually reduced as the refrigerant volume decreases. This aims to improve the overall heat exchange efficiency and also suppress pressure loss as much as possible.

Also, the fin pitch 0 (PpA) of the rear heat exchanger (B) is the fin pitch (PpA) of the front heat exchanger (A).
pB). The reason why the fin pitch (ppA) (FpB) was changed before and after in this way is to improve heat exchange efficiency without increasing pressure loss.

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# and a height (Ht) of 1.5 to 7 mIn.
The height (Hp) of the refrigerant passage in the tube is 1.0 #l.
#I or above is preferable, and the height (Hf) of the corrugated fins (2) (22), that is, the interval between adjacent tubes (1) (1) (21) (21), is set in the range of 6 to 16IIun. , the fin pitch (F
p) is preferably set in the range of 1.6-4.0 mm. Each reason will be explained below.

If the tube width (wB) is less than 6 mm, the width of the corrugated fins (2) (22) interposed between the adjacent tubes (1) (1) or (21) (21) 1 will also be small, resulting in poor heat exchange performance. Deteriorates.On the contrary, 2
If the width exceeds 0#, the fin (2) (2
The width of 2) 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, it is preferably 6 to 16 #I #I, and the most suitable range is 10 to 14 mm.

If the tube height (Ht) exceeds 7 mm, the pressure loss of the circulating air will increase; 5#
If it is less than lIl+, it becomes difficult to ensure the refrigerant passage height (Hp) in the tube to be 1.0 mm or more in relation to the tube wall thickness. Preferably, it is 1°5 to 5#lll+. The most preferred range is 2°5-4m.

Refrigerant passage height in tubes (1) (21) (Hp)
Well, this is 1. , Os, the pressure loss of the refrigerant increases, resulting in a decrease in heat exchange efficiency.

Preferably it is 1.5 to 2.0 #.

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

Moreover, when the fin pitch (PpA) (FpI3) is less than 1.6111111, the air pressure loss increases, and conversely, when it exceeds 4.0 m, the heat exchange performance deteriorates.

The length is preferably 1.6 to 3.2 m.

The most preferred range is 2.0-3.2 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.

In the above embodiment, three heat exchangers were arranged in two stages, front and rear, but the present invention is not limited to this, and as shown in FIG. It can also be applied to heat exchangers (A) and (C) with small header-to-header dimensions arranged side by side, or even more arranged side by side.

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. The heat exchangers are arranged adjacently in front and back 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 header as appropriate depending on the refrigerant distribution form, resulting in high heat exchange efficiency and low pressure loss. The optimum design and use can be selected to obtain a heat exchanger with excellent performance.

Moreover, the dimensions between the headers of the front heat exchangers and the headers of the rear heat exchangers are set differently, and since these heat exchangers are arranged side by side in the front and rear in the air flow direction, multiple Although it is a multiple heat exchanger with heat exchangers arranged in front and back, the headers do not overlap front to back, making it possible to reduce the thickness of the entire heat exchanger, making it more compact. , it is possible to design an optimal shape taking into consideration the shape of the mounting side, and it is possible to eliminate dead space between the mounting side and the mounting state.

[Brief explanation of drawings]

1 to 10 show embodiments of the present invention, in which FIG. 1 is a perspective view showing the front and rear heat exchangers separated, FIG. 2 is a front view of the entire duplex heat exchanger, and FIG. Figure 4 is a side view, Figure 5 is a perspective view showing the header, tubes, and corrugated fins of both the front and rear heat exchangers separated, and Figure 6 is the same as Figure 2. -■ line sectional view, Figure 57 is an enlarged sectional view of both the front and rear heat exchangers seen from the same direction as Figure 6, Figure 8 is an enlarged front view showing the corrugated fins and tubes, and Figure 9 is A refrigerant circuit diagram, FIG. 10 is a schematic plan view showing another embodiment. FIG. 11 is a schematic plan view of a conventional dual heat exchanger. (H)...Double heat exchanger, (A)...Both front heat exchanger, (B)...Both rear heat exchanger, (1) (21)...
・Tube, (2) (22)...Fin, (
3) (3) (23) (24)...Header
(LA) (LB)... Dimension between headers. Above 6

Claims (1)

[Claims] A plurality of tubes are arranged in parallel, fins are arranged between these adjacent tubes, and both ends of each tube are connected to a pair of hollow headers, the headers having different dimensions. It is characterized by having at least two heat exchangers, these heat exchangers being arranged side by side in a front and rear adjacent state in the air flow direction, and the refrigerant circuits of each heat exchanger being connected in series or parallel. A double heat exchanger with