KR20040089722A - Heat exchanger - Google Patents

Abstract

The present invention relates to a heat exchanger (1) of a motor vehicle, in which a first fluid (FL1) can flow therethrough and is provided in parallel with each other and parallel to each other, and flow direction of the second fluid (FL2) A cooling tube 3 extending across the adjacent S2 and having a flat tube 2 having a space formed therein so as to form a flow path for the second fluid FL2, and extending between adjacent flat tubes. Include. Also included in the flow of the second fluid (FL2) in series and includes multiple corrugated pins 3 curved laterally with respect to each other, the corrugated pin is provided as a cooling fin.

Description

Heat exchanger {HEAT EXCHANGER}

The heat exchanger of the invention comprises a heat exchanger of DE 198 13 989 A1. The heat exchanger may take the form of a condenser in an air conditioning system in a motorcycle. The heat exchanger may also take the form of a radiator provided to cool the lubricating oil of the lubrication circuit in the motor vehicle. The heat exchanger includes a plurality of flat tubes arranged side by side and parallel to each other and the cross section of the singer tube is rectangular. Flowing in the tube is the first fluid, a lubricant in the case of radiators or a gaseous coolant condensed in the case of an air conditioning system condenser. The flat tube is connected to a manifold or collection pipe and is in contact with a flow of a second fluid, such as ambient air, to produce heat transfer between the fluids. A flow path in the second fluid is formed between each flat tube.

Cooling fins are provided and secured between the flat tubes to improve heat transfer between the fluids. In the heat exchanger included in DE 198 13 989 A1 the surface of the cooling area is provided opposite to the flow direction of the second fluid. This means has a fluid resistance that affects the second fluid. Designing a cooling fin to shut off the fluid aims to reduce the flow rate of the second fluid. This also increases the time that the second fluid flows through the heat exchanger. This time is the time for the second fluid to absorb heat from the first fluid or heat transfer. On the other hand, however, the low flow rate of the second fluid limits the amount of heat transfer between the first and second fluids, which is related to the efficiency of the heat exchanger.

Heat exchangers with cooling fins are also disclosed in US Pat. No. 4,676,304. In such a heat exchanger the cooling fins are parallel to the flow direction of the second fluid (in this case air). Despite the shape of the partition heat sink provided in each of the cooling fans, it is impossible to prevent the second fluid flowing through the heat exchanger from the flow between adjacent cooling fins without releasing energy to the fins or absorbing energy from the fins. This problem is particularly important when the heat exchanger has a small area in the flow direction of the second fluid. In this case the high mass flow of the second fluid does not necessarily result in a high heat transfer coefficient. A relatively small portion of the temperature difference available between the first and second fluids is used.

The present invention relates to a heat exchanger and to an automobile heat exchanger having the features set forth in claim 1.

1a and 1b respectively show a heat exchanger having two consecutive curved corrugated fins as cooling fins between two adjacent flat tubes,

2a and 2b respectively show a heat exchanger having three consecutive curved corrugated fins as cooling fins between two adjacent flat tubes,

3 shows two corrugated pins formed from one strip,

4 shows three corrugated pins formed from one strip,

FIG. 5A shows a cross section of an uncurved corrugated pin with two GILLED panels;

Figure 5b shows a cross section of an uncurved corrugated pin with two guild panels;

Figure 5c shows a cross section of a corrugated pin from one strip having two rows,

Figure 5d shows a cross section of a corrugated pin from one strip with three rows,

5e shows a cross section of a corrugated pin from one strip having four rows;

5f shows a cross section of a corrugated pin from one strip having five rows;

Figure 5g shows a cross section of a corrugated pin from one strip having five rows,

Figure 5h shows a cross section of a corrugated pin from one strip having five rows,

5i shows a cross section of a corrugated pin from one strip having three rows;

Figure 5j shows a cross section of a corrugated pin from one strip with three rows,

FIG. 6 shows a snapshot of air flow simulated through a corrugated pin with no curves,

7 shows a snapshot of the simulated air flow through a curved corrugation pin,

FIG. 8 shows plotting multiple flows of air through a heatsink as a ratio of multiple flows of total air to tube length at low air flow rates,

FIG. 9 shows plotting multiple flows of air through a heat sink as a ratio of multiple flows of total air to tube length at high air flow rates.

1 ... heat exchanger 2 ... flat tube

2a ... bulkhead 3 ... corrugated fin, cooling fin

4a, b ... pin part 5 ... outer peripheral surface

6 ... End 7 ... Gill

8 ... strip 10a-j ... crimp

11-44 ... Gilled panel

b ... width FL1 ... first fluid

FL2 ... second fluid S1 ... fluid flow direction

S2 ... direction of fluid flow T ... depth

It is an object of the present invention to specify heat exchangers in automobiles with flat tubes and cooling fins designed to promote flow at the same time and to ensure high heat transfer coefficients.

The object of the invention can be achieved by a heat exchanger having the features of claim 1. Here, the heat exchanger is a heat exchanger having a flat tube through which the first fluid can flow and which is in external contact with the second fluid. The flat tubes are provided in parallel with each other and are opposite to the second fluid flow direction. A flow path for the second fluid is formed in the flat tube, and a cooling fin is provided, and the cooling fin extends between adjacent flat tubes. The cooling fins take the form of pleat fins and the multiple pleat fins are provided in series in the second fluid flow direction and are laterally curved with respect to each other, and are bent in the flow direction of the first fluid. Continuously bending the corrugated fins means that a very high portion of the second fluid stream flowing through the heat exchanger is used during heat transfer. In the case of corrugated pins with a GILL, the greater overall mass flow of the second fluid is dependent on the area of the side of the fin provided on the downstream side during the second fluid flow than when there is no curvature between the corrugated pins. Can flow through the road provided. This can give rise to increased heat transfer coefficients. In addition this affects the thermal confinement layer which can be formed in the tube wall. Thus, heat transfer from the tube wall to the second fluid or vice versa can be increased.

The design of the flow extension for the corrugated pin can be achieved in that the surface of the pin is parallel to the second fluid flow direction and means that the surface of the corrugated pin is normally curved to the right with the second fluid flow direction. Despite the design of the flow extension for the corrugation pins, the curvature of the sides of the corrugation pins arranged in series ensures a small portion between the second fluid flow between the unused flat tubes. This means that there is no significant heat transfer than there is no curvature. This advantage makes the larger space b between the two pins more apparent. Two or three similarly shaped corrugated pins are preferably curved continuously with respect to each other. In order to ensure a high heat transfer coefficient, each of the corrugated fins is provided directly adjacent to each other. This means that there is no space in the second fluid stream. This provides a large heat exchanger surface. This narrower arrangement of corrugated pins is also provided to reduce the scratch resistance.

According to a more preferred embodiment the corrugation pin has a GILL to guide the second fluid. Inflated flow in the so-called GILL has a high temperature gradient in the region of the corrugated fins and ensures better heat transfer between the second fluid and the corrugated fins.

All the GILLs of the fin part included between the two flat tubes are curved in the direction of the flow direction of the same second fluid. The constant curvature of the GILL in the fin part has the advantage that the flow is directed in the downstream direction of the fin part.

The GILL of the continuously curved pin portion is preferably curved in the opposite direction. This is because a longer flow path can be defined for the second fluid flow through the heat exchanger. Two adjacent GILLED panels can be bent in the same direction, which is upstream or downstream of two adjacent GILLED panels curved in opposite directions relative to two adjacent GILLED panels. There may be advantages with respect to the GILL of the provided GILLED panel.

The same range of fluid cross section through the second fluid flow is preferably obtained in that the successive curved fin ends are parallel to each other. In this case the curved pin end is preferably perpendicular to the flat tube. If the pin surface deviates from being parallel (up to 6 ° upwards), the pin surface may be judged to be parallel from the technical idea of the present invention. This has little effect on the thermodynamic effects of curved fins. The appearance of the fins according to the invention is especially used in automotive heat exchangers such as radiators, heating elements, condensers and evaporators.

Multiple continuous corrugated pins are preferably formed from a common strip and have the advantage of production technology. The corrugated pin including the GILL may be manufactured by rolling from a metal strip. In addition, an odd number of corrugated pins, such as three or five corrugated pins rolled from one strip in a production process, would have the advantage of production technology.

In a preferred advantage of the present invention, when the angle of the GILL is from 20 ° to 30 °, the depth LP of the GILL is effective in the range of 0.7 mm to 3 mm. This is because the deflection of the second fluid to produce a longer flow path for the adjacent channel, the second fluid in one channel. In such a system the pin height is in the range of 4 mm to 12 mm. The mill density in this system is in the range of 40 fins / dm to 85 fins / dm and coincides with a fin interval or a fin space of 1.18 mm to 2.5 mm.

Preferred embodiments of the present invention will be described in more detail with reference to the following drawings.

Hereinafter, the most preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. . Other objects, features, and operational advantages, including the object, operation, and effect of the present invention will become more apparent from the description of the preferred embodiment. Like parts in the drawings are designated by like reference numerals.

1a, 1b, and 2a, 2b are part of a heat exchanger 1 provided parallel to each other and with a fret tube 2 through which the first fluid FL1 flows in the fluid flow direction S1. The flat tube (2) is fixed to the partition (2a) and connected to the manifold or dust collection pipe. The fluid FL1 is a lubricant such as a condensing coolant in the heat exchanger 1.

Two (Fig. 1A, 1B) or three (Fig. 2A, 2B) corrugated fins 3 are provided as cooling fins in two adjacent flat tubes 2, respectively. An embodiment with multiple corrugation pins 3 is implemented. The corrugated pin 3 is bent in a square wave shape from the sheet and the pin portion 4a is adjacent to the flat tube 2 intersecting with the pin portion 4b connecting two adjacent flat tubes 2. The fin portion 4a adjacent to the flat tube 2 is connected to the flat tube by a heat conduction method by metallurgy (BRAZING). The fin part 4b connected with the adjacent flat tube 2 forms a flow path for the air perpendicular to the flat tube 2 and flowing through the heat exchanger in the second fluid FL2, for example the fluid flow direction S2. The second fluid FL2 flows parallel to the surface of the corrugated fin 3, which means that the second fluid FL2 flows into the heat exchanger 1 inclined at the end 6 of the corrugated fin 3. Thus, the second fluid FL2 can flow through the heat exchanger at a high flow rate and at a high speed.

The road GILL 7 extends transversely with the flow direction S2 of the second fluid FL2 and transversely with the flow direction S1 of the first fluid FL1 and is formed outside the fin portion 4b as shown in FIGS. 3 and 4. do. The way 7 in the fin part 4b produces on the one hand a particularly desirable heat transfer between the second fluid FL2 and the fin part 4b and on the other hand the fin part obliquely provided behind the flow direction S2 ( Guide to 4b). This method induces a large amount of flow of the second fluid FL2 flowing through the heat exchanger 1 and effectively makes the temperature difference between the first fluid FL1.

Two corrugated fins 3 provided in series between two flat tubes 2 are provided to be curved with respect to each other by dividing the width b between two adjacent fin portions 4b in half. As shown in Figs. 2 and 4, in the case where three corrugated pins are provided in series, the curvature of b / 3 can be more preferably selected and different curvature values can be obtained.

Two or three adjacent corrugated fins 3 extend beyond the depth T of the heat exchanger 1 and are produced by rolling from one sheet 8. In this rolling the sheet 8 is cut in a curved area between the two (Fig. 1a, 1b and 3) or three (Fig. 2a, 2b and 4) corrugated pins 3 respectively and the road 7 is It is cut by the curved pin 3. One (Figures 1A, 1B, 3, 5C) or two (Figures 2A, 2B, 4, 5D) higher order of the curved or corrugated pins 3 (Figures 5E, 5F, 5G) The curvature of) can be produced selectively and the separate corrugated pin 3 with the curvature between 0.1 mm and b / 2 has the distance between two adjacent tubes 2.

The pin portion 4a of the corrugated fin 3 adjacent to the flat tube 2 does not have a length GILL. The laminar flow of the second fluid FL2 in this region can be more easily formed in the fin part 4b provided with the road GILL 7 and connected to the adjacent flat tube 2. Laminar flows over longer distances can lead to the formation of a limiting layer with a temperature gradient descending in the flat tube 2. This effect is achieved by the fact that the flow of the second fluid FL2 formed between two adjacent pin portions 4b of the corrugated pin is shorter by the continuous corrugated pin 3 in the flow direction S2 (Ta) (FIGS. 1A and 1B). 3, FIG. 5C) or T / 4 (FIGS. 2A and 2B, 4, 5D) is limited to meaningless amounts in that it can be further interrupted, causing increased temperature gradients and increased heat transfer. In this way high efficiency heat transfer is obtained between the same second fluid FL2 and the first fluid FL1 in a heat exchanger having a low depth T of 12 to 20 mm.

Figure 5 shows a cross section of each corrugated pin 10a, b ... j having a multi-guilled panel. In a conventional cooling fin having a heat dissipation hole of a partition wall at each fin, the fin between two tubes in the main flow direction of the second fluid is used alone without bending (see FIGS. 5A and 5B). The above-described cooling fins having at least two so-called guild respective panels 11, 12 and 13, 14 are separated from one another by a mesh of various designs. In this case, the bulkhead heat sinks of adjacent GILLED panels are generally aligned in opposite directions.

Preferred two, three or more similar types of corrugated pins according to the present invention are continuously curved with respect to each other, which means that corrugated pins with partition heat dissipation holes can be curved in multiple planes. A number of corrugated fins provided in series at the same time may be selected as a function of the depth of the heat exchanger and / or of the depth of the corrugated fins. For example, 2, 3 or more rows have a total depth of 12 mm to 18 mm, 2, 3, 4 or more rows have a full depth of 18 mm or more, and 2, 3, 4, 5 or more rows have 30 mm More than 2, 3, 4, 5, 6 or more rows have a total depth of at least 36 mm, 2, 3, 4, 5, 6, 7 or more rows have a total depth of at least 42 mm, 2, 3, 4, 5, 6, 7, 8 or more rows have a total depth of at least 48 mm, 2, 3, 4, 5, 6, 7, 8, 9 or more rows have a total depth of at least 54 mm, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more rows have a total depth of at least 60 mm, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or more rows have 66 mm It can be used as the overall depth of the above.

FIG. 5C shows a cross section of a corrugated pin as an embodiment with two rows of 15 and 16, FIG. 5D shows a cross section of a corrugated pin as an embodiment with three rows of 17, 18 and 196, FIG. 5E shows a cross section of a corrugated pin as an embodiment having four rows of 20, 21, 22 and 23, and FIG. 5F is an embodiment having five rows of 24, 25, 26, 27, and 28. FIG. Figure 5g shows a cross section of a corrugated pin, Figure 5g shows an example with five rows of 29, 30, 31, 32 and 33 showing a cross section of a corrugated pin, Figure 5h shows 34, 35, 36, 37 and An example of five rows of 38 shows a cross section of a corrugated pin.

As in the embodiment shown in Figs. 5D, 5E and 5G, two or more curved rows ROW may be distributed in total two planar curvatures with respect to each other. However, the rows ROW may be distributed in three or more different planes with intervals between two planes, each identical or different, as in the embodiment of FIGS. 5F and 5H.

In addition, the area 41 or 44 between the two GILLED planes 39 and 40 and the planes 42 and 43 provided in one plane may include the GILLED panel 39 and 30 and Can be curved with respect to panels 42 and 43 (see FIGS. 5I and 5J). This development also affects the thermal limit layer of the tube wall or improves the flow through the heat sink.

The number of paths per row ROW is between two and thirty roads GILL and depends, for example, on the number of rows and depths of the heat exchanger. During the production process, it is desirable that the number of GILLs per GILL panel is not equal in odd rows, i.e. 1, 3, 5, 7, 9 or 11. If you have even rows, multiple GILLs per GILL panel may be the same, although not effective.

6 to 9, a simulation of air flow through a heat exchanger having three different corrugated fin shapes will be described.

The simulation is performed under the following conditions; Tube temperature 60 °; Air inlet temperature = 45 ° C .; Air density = 1.097 kg / m ³ ; Air inlet velocity vL = 1 and 3 m / s, pin height = 8 mm, pin depth = 16 mm. The simulation takes into account one corrugated pin in the row, which consists of rows of ROW with GILLED panels separated from each other by a loop-shaped net according to the prior art, which is not curved. Also contemplated are one corrugated pin with two rows and one corrugated pin with three rows. Also in the air-side pressure drop, the simulation determines the volume of flow through each heat sink and the output radiated to the cooling air from the tube.

FIG. 6 shows a heat exchanger 51 having corrugated fins 52 and 53 under the above-described limit conditions in the region between two GILLED panels 54 and 55 and panels 56 and 57, respectively. The air inlet velocity V _LUFT at s shows the air flow range. The nets 58 and 59 between each two guild panels are loop-shaped in this case. The arrow 60 shown indicates the particle flow path of air and flows through the last heat sink 61 in front of the mesh 59 and before flowing through the heat sinks 62 and 63 in the adjacent guild panel 57. Flow deflection occurs. A higher number of air particles can be seen in shape that they flow through the second heat dissipation hole 62 in the guild panel 57, which is through the third heat dissipation hole 63 and the speed range is Start again to approximate the velocity pattern in the previous guild panel 56.

FIG. 7 shows a heat exchanger with corrugated fins 72 and 73 under the above-described limit conditions in the region of the bends 74 and 75 between two GILLED panels 76 and 77 and panels 78 and 79, respectively. (71) shows the air flow range at the air inlet velocity V _LUFT of 3 m / s. The arrow 80 shown indicates the particle flow path of air in front of the bend 75 and first flows through the last heat dissipation hole 81 in front of the bend and secondly through the bend opening 75. After flowing through the curved opening 75, the air particles cause flow deflection and the air particles flow through the curved openings, preferentially through the first and second heat radiating holes 82, 83 in the adjacent guild panel 79. Flow. After the flow deflection occurs, the air particles flowing through the last heat dissipation hole 81 before the bending flow preferentially through the third heat dissipation hole 84 of the following guild panel 79.

8 and 9 show fluid FL2 for three different corrugated pin fluid shapes at air flow rates of V _Luft = 1 m / s (Fig. 8) and V _Luft = 3 m / s (Fig. 9) under the above-mentioned limitations. A graph of the ratio of the number of flows m _Kieme through each guild heat sink halved the total flow of air 1 / 2m _ges , inversely proportional to the depth of each heat exchanger and the tube depth It is. 100 percent flow through the opening in the curve is not shown.

As shown in Fig. 8, the 100% air flow in a corrugated pin shape with two or three rows is always 9% excessive, whereas in the case of corrugated pins in plane / column, two of the adjacent roots of the network region are shown. The air flow in the heat sink drops to at least about 4% and less than 8%. In the case of corrugated fins consisting of one plane, the air flow is about 12% to 10% in the heat sinks provided before the network area, and in the case of two planar / heated corrugated fins, the last heat sink is provided before bending. The airflow through is increased from 12% to 13%. This occurs after the airflow and the curvature in the new direction of the first heat sink are exposed to a partial air flow of about 10%. In the case of three rows of corrugated pins, the air flow through the last heat sink before the curve increases by about 13%. This occurs after the airflow and the curvature in the new direction of the first heat sink are exposed to a partial air flow of about 10% -11%.

As shown in Fig. 9, the 100% air flow in a corrugated pin shape with two or three rows (ROW) is always 12% excessive, whereas in the case of corrugated pins in planes / columns, two of the adjacent roots of the network region are shown. Air flow in the heat sink drops to at least about 4.5% and less than 11%. In the case of corrugated fins consisting of one plane, the air flow is about 16.5% to 15% in the heat sinks provided before the network area, and in the case of two planar / heated corrugated fins, the last heat sink provided before bending The airflow through is increased from 16.5% to 18%. This occurs after the airflow and the curvature in the new direction of the first heat sink are exposed to a partial air flow of about 14%. In the case of three rows of corrugated pins, the flow of air through the last heat sink before the curve increases by about 18-19%. This occurs after the airflow and the curvature in the new direction of the first heat sink are exposed to a partial air flow of about 14%.

For reference, the embodiments disclosed herein are only presented by selecting the most preferred embodiment in order to help those skilled in the art from the various possible examples, the technical spirit of the present invention is not necessarily limited or limited only by this embodiment Rather, various changes, additions, and changes are possible within the scope without departing from the spirit of the present invention, as well as other equivalent embodiments.

Claims (11)

The first fluid FL1 may flow therethrough, and may be provided to be in contact with the outside of the second fluid FL2 and be parallel to each other, and may cross the flow direction S2 of the second fluid FL2, and In a heat exchanger of a vehicle having a flat tube (2) spaced to form a flow path, and including a cooling fin provided in the flow path and extending between adjacent flat tubes, And a plurality of corrugated fins (3) provided in series in the flow of the second fluid (FL2) and curved laterally with respect to each other, wherein the corrugated fins are provided as cooling fins. The method of claim 1, Heat exchanger, characterized in that the surface of the corrugated fins (3) is provided in parallel in the fluid flow direction of the second fluid. The method according to claim 1 or 2, The multi-pleat curved fins (3) is characterized in that provided in a similar shape to each other. The method according to any one of claims 1 to 3, Wherein said at least one corrugated fin (3) has a GILL with respect to the second fluid direction. The method of claim 4, wherein Heat exchanger, characterized in that all the lengths (7) of the fin portion (4b) defined by the two flat tubes (2) are curved in the same direction as the flow direction of the second fluid (FL2). The method of claim 5, Heat exchanger, characterized in that the road (7) of the two consecutive curved fin portion (4b) is curved in the same direction. The method of claim 5, The heat (7) of the two consecutive curved fin portions (4b) is curved in opposite directions to each other. The method according to any one of claims 1 to 7, Heat exchanger, characterized in that two consecutive curved fin portions (4b) are parallel to each other. The method of claim 8, The heat exchanger, characterized in that the fin portion (4b) is provided perpendicular to the trat tube (2). The method according to any one of claims 1 to 9, The heat exchanger characterized in that the corrugated fins (3) extend equally or are provided at similar distances in the flow direction of the second fluid. The method according to any one of claims 1 to 10, Heat exchanger, characterized in that the multiple corrugated fins (3) provided in series are formed from a common strip (8).