KR20090125345A - Heat exchanger for vehicle - Google Patents

Abstract

PURPOSE: A heat exchanger for vehicle is provided to improve heat radiation performance by setting a ratio of an internal heat exchange area and an external heat exchange area to a predetermined value. CONSTITUTION: A heat exchanger for vehicle comprises a plurality of tubes(111), a core, and a main tank. The plural tubes are arranged in parallel to an air flow direction. A heat exchange medium flows within the tube. The core includes a pin(112) interposed between the neighboring tubes. The main tank is located in top and bottom of the core, and connected to the tube. In one side of the main tank, an outlet pipe and an inlet pipe in which the heat exchange medium flows in and out are formed.

Description

Heat exchanger for vehicle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle heat exchanger, and more particularly, to a vehicle heat exchanger in which a heat exchange rate of a heat exchanger is improved by fitting a ratio between an internal heat exchange area and an external heat exchange area of a core of a heat exchanger.

Typically, the heat exchanger is a device having a flow path through which a heat exchange medium such as cooling water or a refrigerant can flow, so that the medium can exchange heat with the outside air while the medium flows through the flow path. The vehicle is typically equipped with a radiator for cooling the engine, a heater core, and a heat exchanger such as an evaporator for air conditioning in the vehicle compartment. Heat exchangers have been developed in various ways depending on the type of refrigerant used as the heat exchange medium and the internal pressure generated inside the heat exchanger.

1 is a schematic perspective view showing an example of a typical vehicle heat exchanger.

Referring to the drawings, the vehicle heat exchanger 11 is formed by stacking a plate 12 having an uneven portion of a predetermined shape, and the heat dissipation fins 14 are disposed therebetween. The plate 12 may form a concave-convex surface having a predetermined shape in an aluminum plate material which is generally flat, so that a flow path of a heat exchange medium may be formed therein when the pair of plates are brazed in a state in which they face each other. .

Fluid passages 15 formed by deforming the plate are formed at the top and bottom of the plate 12. The inflow pipe 16 which can connect the supply pipe of a heat exchange medium, and the outflow pipe 17 which can connect the outflow pipe with respect to the said fluid passage 15 are arrange | positioned.

The heat exchanger 11 formed as described above includes air between the plates 12 until the heat exchange medium supplied through the inlet pipe 16 circulates the flow path between the plates 12 and flows out through the outlet pipe 17. The heat exchange is performed, and the heat radiating fins 14 serve to assist the heat exchange action.

The heat exchanger 11 shown in FIG. 1 has a core width of W, a core height of h, and a thickness of t. Air flows in the direction indicated by A at this time.

Since the heat exchange of the vehicle heat exchanger is performed in the order of air → heat exchanger → heat exchange medium (refrigerant), the heat exchange amount between the air and the heat exchanger and the heat exchange amount between the heat exchanger and the heat exchange medium (refrigerant). Is the same.

The heat exchange amount of the air and the heat exchange medium and the heat exchanger, that is, the heat exchange amount of the heat exchanger is referred to as a heat radiation amount of the heat exchanger.

The heat radiation amount Q of the heat exchanger is calculated as shown in [Equation 1].

[Equation 1]

Q = U _Refrigerant A _Refrigerant ΔT _Refrigerant = U _Air A _Air ΔT _Air

(Q: heat radiation amount, U _refrigerant : total heat transfer coefficient of _refrigerant , A _refrigerant : heat exchange area of refrigerant side, ΔT _refrigerant : temperature difference between inlet and outlet of refrigerant, U _air: total heat transfer coefficient of _air , A _air : heat exchange area of _air , ΔT _air: Air outlet temperature difference)

As can be seen from the above equation, since the heat dissipation amount of the heat exchanger is proportional to the heat exchange area A _refrigerant and A _air , it is preferable to increase the A _refrigerant and A _air to increase the heat dissipation amount of the heat exchanger.

However, the vehicle heat exchanger is limited in the mounting space, and as shown in FIG. 2, the internal heat exchange area A _{in which} is the refrigerant side heat exchange area A _refrigerant and the external heat exchange area A which is the _air side heat exchange area A _air . _out ) is inversely proportional in structure, and there is a limit to uniformly increasing the internal heat exchange area (A _in ) and the external heat exchange area (A _out ) _in order to improve heat dissipation performance.

Accordingly, when the heat exchanger is designed in consideration of only a space in which the vehicle is mounted, a heat exchange efficiency of the heat exchanger is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to improve a relationship between an internal heat exchange area and an external heat exchange area, and to provide a vehicle heat exchanger having high heat dissipation performance.

The present invention for achieving the above object is arranged in parallel in the air flow direction, the core including a plurality of tubes through which a heat exchange medium flows, and a pin interposed between the neighboring tube; Located above and below the core, the tube communicates with the tube, and includes a main tank having an inflow pipe and an outflow pipe through which a heat exchange medium flows in and out, and the core 113 is determined by Equation 2 below. A ratio A _out / A _{in of the} heat exchange area A _in and the external heat exchange area A _out of the core 113 is provided between 1.70 and 2.23.

[Equation 2]

Internal heat exchange area (A _in ) = Number of tubes x 4 x Tube flow area x Core height (H _core ) / Hydraulic diameter of the _tube (Dh _tube )

External heat exchange area (A _out ) = Fin height (H _fin ) × Fin width (W _fin ) × Core height (H _core ) × Number of _fins / Fin pitch (P _fin )

Wherein the hydraulic diameter of the tube (Dh _tube ) = 4 × flow area / receiving length, the flow path area means the cross-sectional area of the flow path of the tube, the receiving length means the circumferential length of the flow path.

Preferably, the inner heat exchange area A _in is 1.35 cm 2 to 1.6 cm 2, and the outer heat exchange area A _out is 2.6 cm 2 to 3.0 cm 2.

In addition, the tube 111 is 31 to 34, the pin 112 is 32 to 35, the pin height is 5.6mm, the pin width is 35mm, the core (Hcore) is 1.4mm to 3.0 mm, the hydraulic diameter (Dh _tube ) is 0.97mm to 1.63mm, the height of the fin (Hfin) is preferably 5.6mm to 7.0mm, FPDM is 64 to 84.

According to the present invention as described above, by setting the ratio of the internal heat exchange area and the external heat exchange area to 1.70 to 2.23, there is an advantage to provide a vehicle heat exchanger having a high heat dissipation performance while having a limited mounting space.

In addition, by providing the optimum ratio of the internal heat exchange area and the external heat exchange area and the specifications of the tube and fin for the heat dissipation performance, it is possible to facilitate the design of heat exchanger with improved heat dissipation performance.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various equivalents that may be substituted for them at the time of the present application It should be understood that there may be water and variations.

Figure 3 is a perspective view of a vehicle heat exchanger according to an embodiment of the present invention, Figure 4 is a partial cutaway perspective view showing the tube and fin of the vehicle heat exchanger shown in Figure 3, Figure 5 is a tube of the vehicle heat exchanger shown in Figure 3 6 is a graph relating to heat dissipation performance of the vehicle heat exchanger illustrated in FIG. 3.

As shown in Figure 3 and 4, the vehicle heat exchanger according to an embodiment of the present invention, the core 111 consisting of a tube 111 and the fin 112, and the main tank 114.

31 to 34 of the tubes 111 are arranged in parallel in the air flow direction, the refrigerant flows inside the tube.

A fin 112 is formed between the tube and the neighboring tube. In the present embodiment, the fins 112 are louver fins, and 32 to 35 fins are formed.

The height (H _tube ) of the _tube is 1.4mm to 3.0mm, the fin height (H _fin ) is 5.6mm, the fin width (W _fin ) is 35mm, the fin pitch (P _fin ) is 0.74mm The width W _core of the tube and the pin is 273 mm to 280 mm, and the height H _{core of the core} is 233 mm.

The main tank 114 is positioned to communicate with the upper and lower sides of the tube, one side is formed with an outlet pipe 117 and the inlet pipe 118.

The refrigerant flows into the main tank 114 through the inlet pipe 118, circulates through a heat exchanger, exchanges heat with the heat exchanger, and then flows out through the outlet pipe 117.

Meanwhile, the air introduced into the core 113 passes through the core 113 and exchanges heat with the tube 111 and the fin 112.

In this case, the heat exchange area of the heat exchanger becomes the internal heat exchange area A _in of the refrigerant side heat exchange area and the external heat exchange area A _out of the air side heat exchange area, respectively, and the heat dissipation performance of the heat exchanger is determined according to these areas. .

Looking at the relationship between the internal heat exchange area and the external heat exchange area and the heat dissipation of the heat exchanger according to an embodiment of the present invention.

First, the internal heat exchange area A _in and the external heat exchange area A _out of the heat exchanger of this embodiment are calculated as shown in Equation 2.

[Equation 2]

Internal Heat Exchange Area (A _in ) = Number of Tubes x 4 × Tube Flow Area × Core Height (H _core ) / Hydraulic Diameter of Tube (Dh _tube )

An external heat transfer area (A _out) = fin height (H _fin) × pinpok (W _fin) × core height (H _core) × number of pins / fin pitch (P _fin) of

Where the hydraulic diameter (Dh _tube ) of the _tube is calculated as follows.

Hydraulic _tube diameter (Dh _tube ) = 4 × Euro area / reception length

Here, the flow path area means the cross-sectional area of the flow path 120 of the tube as seen in the cross-sectional view of the tube shown in FIG. 5, and the receiving length is equal to the circumferential length of the flow path 120 shown in FIG. 5.

On the other hand, since the heat radiation amount of the heat exchanger is calculated by the Equation 1, the heat dissipation performance of the heat exchanger depends on the internal heat transfer area (A _in) and the external heat transfer area (A _out). However, since the internal heat exchange area A _in and the external heat exchange area A _out are in inverse relationship, and the air and the refrigerant have different heat transfer coefficients, an area ratio of the internal heat exchange area and the external heat exchange area (A _out /). The proper heat dissipation performance can be achieved by properly determining A _in ).

In this embodiment, the ratio (A _out / A _in ) of the internal heat exchange area (A _in ) of the core 13 of the heat exchanger and the external heat exchange area (A _out ) of the core to achieve the maximum heat dissipation performance is 1.70. To 2.23.

[Table 1] is a table showing the change in heat dissipation according to the ratio of the internal heat exchange area and the external heat exchange area according to the experimental example of the present invention, Figure 6 shows the change in the heat dissipation according to the ratio of the internal heat exchange area and the external heat exchange area. One graph.

TABLE 1

No Internal heat exchange area External heat exchange area Outside / inside Heat dissipation [Cm2] [Cm2] One 1.49 2.83 1.90 4643 2 1.37 2.91 2.12 4642 3 1.26 2.67 2.12 4639 4 1.37 2.91 2.12 4659

In this example, the height of the _tube (H _tube ) is 1.4mm to 3.0mm, the hydraulic diameter (Dh _tube ) is 0.97 to 1.63mm, the height of the _fin (H _fin ) is 5.6mm to 7.0mm, FPDM (Fins Per Deci Meter) is 64 to 84. Here, FPDM means the number of peaks or valleys of a pin falling within 10 cm, as shown in FIG. 4.

As shown in Table 1 and Figure 6, the number of tubes of the heat exchanger of the present experimental example is 31 to 34, the flow path area is 21.9 to 23.7 mm2, the hydraulic diameter (Dh _tube ) is 1.26 to 1.49, Fin _fin width (W _fin ) is 35mm, fin pitch (P _fin ) is 0.74mm, the number of fins is 32 to 35, the internal heat exchange area is 1.35cm 2 to 1.6cm 2, the external heat exchange area is 2.6cm 2 To 3.0 cm 2.

When the internal heat exchange area and the external heat exchange area ratio of the heat exchanger of the present experiment example is approximately 2.0, the maximum heat dissipation performance (Max) is represented. When the internal heat exchange area and the external heat exchange area ratio are 1.70 to 2.23 (section R), the maximum heat dissipation amount (Max) The heat dissipation amount of 99.5% (0.995Max) or more) can be obtained.

That is, according to the present invention, the area ratio of the internal heat exchange area and the external heat exchange area of the heat exchanger is set to 1.70 to 2.23, so that the heat exchanger whose heat dissipation amount satisfies 99.5% of the maximum heat dissipation amount can be stably provided.

As mentioned above, although this invention was demonstrated by the limited embodiment and drawing, this invention is not limited by this, The person of ordinary skill in the art to which this invention belongs, Of course, various modifications and variations are possible within the scope of equivalent claims.

1 is a perspective view showing an example of a typical vehicle heat exchanger,

2 is a graph illustrating a relationship between an internal heat exchange area and an external heat exchange area of a general vehicle heat exchanger;

3 is a perspective view of a vehicle heat exchanger according to an embodiment of the present invention;

4 is a partial cutaway perspective view of the tube and fin of the vehicle heat exchanger shown in FIG.

5 is a cross-sectional view of the tube of the vehicle heat exchanger shown in FIG.

6 is a graph related to heat dissipation performance of the vehicle heat exchanger illustrated in FIG. 3.

<Brief description of symbols for the main parts of the drawings>

111: tube 112: pin

113: core 114: main tank

117: outflow pipe 118: inflow pipe

Claims (3)

A core 113 arranged in parallel in the air flow direction, the core 113 including a plurality of tubes 111 through which a heat exchange medium flows, and fins 112 interposed between the neighboring tubes 111; Located above and below the core 113, and in communication with the tube 111, the vehicle heat exchanger including a main tank 114, the outlet pipe 117 and the inlet pipe 118 through which the heat exchange medium flows in and out; In the phase, The ratio A _out / A _in of the internal heat exchange area A _{in of} the core 113 and the external heat exchange area A _out of the core 113 determined by Equation 2 below is 1.70 to 2.23. Vehicle heat exchanger, characterized in that. Internal heat exchange area (A _in ) = Number of tubes x 4 x Tube flow area area ㅧ Core height (H _core ) / Hydraulic diameter of _tube (Dh _tube ) External heat exchange area (A _out ) = Fin height (H _fin ) × Fin width (W _fin ) × Core height (H _core ) × Number of _fins / Fin pitch (P _fin ) Wherein the hydraulic diameter of the tube (Dh _tube ) = 4 × flow path area / receiving length, the flow path area means the flow path cross-sectional area of the tube, the receiving length means the circumferential length of the flow path. The method of claim 1, The internal heat exchange area A _in is 1.35 cm 2 to 1.6 cm 2, and the external heat exchange area A _out is 2.6 cm 2 to 3.0 cm 2. The method of claim 1, The tube 111 is 31 to 34, the pin 112 is 32 to 35, the pin height is 5.6mm, the pin width is 35mm, the core (Hcore) is 1.4mm to 3.0mm , Hydraulic diameter (Dh _tube ) is 0.97mm to 1.63mm, fin height (Hfin) is 5.6mm to 7.0mm, FPDM is 64 to 84, characterized in that the vehicle heat exchanger.

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