KR20030019684A - Heat exchanger - Google Patents

Abstract

PURPOSE: A heat exchanger is provided to improve performance by optimizing depth, diameter, horizontal pitch and vertical pitch of a dimple formed on an inside of a tube. CONSTITUTION: A plurality of dimples(130) are formed on an inside of a plate(111) so that depth(Dp) of the dimples is larger than 0 and smaller than or equal to 0.3*H where H is height of a channel in a tube(110). Diameter of the dimple is smaller than or equal to 2.5mm. Horizontal pitch between the dimples is 3-9mm. Vertical pitch between the dimples is 5-16mm. The dimples formed on insides of a pair of the plates facing each other are arranged to cross each other so as not to be joined to each other.

Description

Heat exchanger

The present invention relates to a heat exchanger, and more particularly to a heat exchanger having a dimple formed in the tube to promote turbulence of the heat exchange medium.

In general, a heat exchanger is a device for exchanging heat by directly or indirectly contacting two fluids having different temperatures. The heat exchanger includes a passage portion through which a heat exchange medium can flow, so that the heat exchange medium and the outside air flow through the passage portion. It is a device designed to perform heat exchange. Heat exchangers are also indispensable in automotive air conditioning systems.

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. Typical heat exchangers include fin tube type, serpentine type and drone cup type. (drawn cup type), parallel flow type (parallel flow type).

1 is a perspective view showing an example of a conventional drone cup type heat exchanger.

Referring to the drawings, the conventional drone cup type heat exchanger 10 has cups 17, 18, 20, and 21 formed at upper and lower ends thereof, respectively, The edges are coupled to each other to form a passage through which a heat exchange medium flows and a tube 11 provided with tanks 19 and 22 at both ends thereof, and a plurality of tubes 11 are stacked. A corrugated heat dissipation fin 16 is interposed between the stacked tubes 11, and end plates 25 and 26 are coupled to the outermost portion. The tanks 19 and 22 are provided with an inlet 14 for supplying heat exchange medium to the upper end tank 19 and an outlet 15 for discharging through the lower end tank 22.

The performance of heat exchangers is known to be proportional to heat transfer rate and heat exchange area. However, heat exchangers used in automobile air conditioners require volume reduction and weight reduction, and it is not easy to satisfy the above requirements.

In order to solve the problem, a heat exchanger having a plurality of dimples formed on the inner surface of the tube to promote turbulence of the heat exchange medium is known. The dimples have a great influence on the performance of the heat exchanger according to their size or arrangement, and their performance may be deteriorated rather than the heat exchanger without dimples if their design dimensions are inadvertently set. In other words, if the size of the dimple is small and the arrangement is not dense, the flow resistance of the heat exchange medium is small, but the turbulence effect is reduced, and the heat contact area with the heat dissipation fin can be reduced, thereby reducing the heat exchange efficiency. If the arrangement is dense, the flow resistance of the refrigerant may be so large that the passage flow rate of the heat exchange medium decreases and the heat transfer amount may decrease.

The present invention has been made to solve the above problems, the technical problem to be achieved by the present invention is to provide a heat exchanger with improved performance by optimizing the depth, diameter, horizontal pitch and vertical pitch of the dimple formed on the inner surface of the tube will be.

Another object of the present invention is to provide a laminated heat exchanger which can reduce the number of production processes by integrally forming the flow path and the tank of the heat exchange medium.

1 is a perspective view showing a conventional heat exchanger.

Figure 2 is a perspective view showing a partial cutaway one embodiment of the heat exchanger of the present invention.

3a and 3b are front views showing the first and second plates forming a tube in the heat exchanger of FIG.

4 to 7 are graphs showing the relationship between the depth of the dimple, the diameter of the dimple, the horizontal pitch or the vertical pitch between the dimples, and the amount of heat dissipation and pressure drop of the heat exchanger of the present invention.

8 is a perspective view showing the flow of the heat exchange medium in the heat exchanger of FIG.

Figure 9a is a front view showing a plate of a heat exchanger having two tanks in the upper end of another embodiment of the present invention, Figure 9b is a perspective view showing the flow of the heat exchange medium in the heat exchanger.

FIG. 10A is a front view showing a plate of a heat exchanger having two tanks each at an upper end and a lower end thereof according to another embodiment of the present invention, and FIG. 10B is a perspective view showing the flow of a heat exchange medium in the heat exchanger.

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

10,100 ... heat exchanger 11,110 ... tube

12, 13, 111, 112 ... Plate 14, 124 ... Inlet

15,125 ... Outlet port 16,115 ...

19,22,119,123 ... Tank 130 ... Dimple

In order to achieve the above technical problem, a pair of plates are joined to each other, and a tube forming a flow path of a single-phase heat exchange medium and a tank are alternately stacked and provided with a tank for distributing or collecting on the plate. The heat exchanger, in which a single-phase heat exchange medium flows and heats or cools, has a plurality of dimples formed on an inner surface of the plate, and the depth of the dimple is Dp and the height of the flow path inside the tube is H. <Dp ≤ 0.3H.

Preferably, the dimple has a diameter of 2.5 mm or less.

The horizontal pitch between the dimples is preferably 3 to 9 mm.

The vertical pitch between the dimples is preferably 5 to 16 mm.

It is preferable that the dimples formed on the inner surfaces of the pair of plates facing each other are arranged so as not to be shifted from each other.

The plate is provided with a cup for forming a tank at the top and / or bottom one by one, the tank may be formed detachably from the tube.

The plate may be provided with a plurality of cups for forming a tank on at least one of the upper and lower sides thereof, and a central partition wall for guiding the single-phase heat exchange medium may be formed at a central portion thereof.

Hereinafter, the heat exchanger of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a perspective view showing a partial cutaway an embodiment of the heat exchanger of the present invention, an enlarged cutaway surface. Referring to the drawings, the heat exchanger 100 has the same components as the conventional heat exchanger 10 shown in FIG. 1, but the inlet of the heat exchange medium is cut away and omitted from the figure. A plurality of dimples 130 are provided on the inner surfaces of the plates 111 and 112 constituting the tube 110 to promote turbulence of the heat exchange medium.

Referring to the operation of the heat exchanger 100, the single-phase heat exchange medium is introduced into the upper end tank 119 through an inlet (not shown), and descends along the stacked tube 110. Heat dissipation or heat absorption is promoted by the dimple 130 formed on the flow path of the heat exchange medium to the outside of the tube 110, and is blown by a blower (not shown) to radiate heat ( 115) Heat exchange takes place with the external fluid passing between them. The heat exchange medium after the heat exchange process is collected in the lower tank 123 and discharged through the outlet 125.

3A and 3B are front views illustrating the first and second plates 111 and 112 constituting the tube 110 in the heat exchanger 100 of FIG. 2. Referring to the drawings, the first and second plates 111 and 112 have edges 111a and 112a joined to each other to form a tube, and cups 117, 118, 121 and 122 that form a tank are formed at upper and lower ends thereof. A plurality of dimples 130 are formed in a constant array on the inner surfaces of the plates 111 and 112. Based on any horizontal line formed by the arrangement of dimples 130, the corresponding dimples of neighboring lines are arranged at an angle inclined rather than perpendicular to the horizontal line. The arrangement of the dimples 130 in the horizontal line of the second plate 112 corresponding to the arbitrary horizontal line (reference line) of the first plate 111 is arranged to deviate from the dimples of the reference line. In other words, when the plates 111 and 112 of FIGS. 3A and 3B overlap each other, it means that the dimples of the second plate 112 are positioned between the dimples of the first plate 111. Accordingly, the tube 110 having the plates 111 and 112 overlapped has a flow path having a zigzag cross section as shown in FIG. 2. According to the present invention, as a characteristic of the dimple 130 for determining the specific shape of the flow path, the diameter of the dimple (D), the depth of the dimple (Dp), the horizontal pitch (Wp) between the dimples and the vertical pitch (Lp) between the dimples Is presented. Unexplained reference numerals 117 and 118 denote cups forming the upper tank 119, 121 and 122 denote cups forming the lower tank 123, H denotes the height of the flow path inside the tube, and 126 and 127 denote end plates. . The shape of the dimple may be molded into a circle, a rectangle, and the like, and will be described here as a circular dimple.

4 to 7 show the depth Dp of the dimple, the diameter D of the dimple, the horizontal pitch Wp or the vertical pitch Lp between the dimples, the heat radiation amount Q and the pressure drop amount of the heat exchanger according to the present invention. It is a graph showing the relationship with dPw). 4 is a ratio of the dimple depth Dp to the flow height H inside the tube as the dimple ratio, and the graph shown at the top shows the heat dissipation amount Q of the heat exchanger, and the graph shown at the bottom shows the heat exchanger. Represents the pressure drop amount dPw. As the dimple diameter D and the vertical pitch Lp are kept constant and the dimple depth Dp is increased, both the heat dissipation amount Q and the pressure drop dPw increase. In addition, as the horizontal pitch Wp is increased, the heat dissipation amount Q and the pressure drop amount dPw decrease as shown by one arrow in the figure. Although not shown, the horizontal pitch Wp and the vertical pitch Lp are kept constant and the dimple diameter D is increased or the horizontal pitch Wp and dimple diameter D are kept constant and the vertical pitch ( In the case of increasing Lp), a trend similar to the above appears.

The performance of the heat exchanger will be improved primarily if the heat dissipation amount (Q) is large, but if the pressure drop (dPw) is too high, there is a problem that the heat transfer amount decreases due to the small flow rate of the heat exchange medium due to the fluid resistance in the operation of the actual heat exchanger. have. That is, the design area of the dimple depth Dp should be determined in the region where the heat radiation Q is high and the pressure drop dPw is low. Therefore, the dimple depth Dp is 0.3 times the internal flow height as defined by the two arrows. 0.3H) or less.

Referring to Figure 5, the horizontal axis represents the dimple diameter (D), the graph shown at the top represents the heat radiation amount (Q), the graph shown at the bottom represents the pressure drop (dPw). As the horizontal pitch Wp and the vertical pitch Lp are kept constant and the dimple diameter D is increased, the heat dissipation amount Q decreases after increasing, and the pressure drop dPw gradually increases. . In addition, as the dimple depth Dp increases, the heat dissipation amount Q and the pressure drop amount dPw increase as shown by one arrow in the figure. Although not shown, when the dimple depth Dp and the vertical pitch Lp are kept constant and the horizontal pitch Wp is increased or the dimple depth Dp and the horizontal pitch Wp are kept constant and the vertical pitch ( In the case of increasing Lp), a trend similar to the above appears. As described above with reference to FIG. 4, the design area of the dimple diameter D should be determined in a region in which the heat dissipation amount Q is high and the pressure drop amount dPw is low, and the heat dissipation amount Q is substantially constant. It is preferable to set it to 2.5 mm or less to maintain the level.

Referring to FIG. 6, the horizontal axis represents the horizontal pitch Wp, the graph shown at the top represents the heat radiation amount Q, and the graph at the bottom represents the pressure drop dPw. As the dimple diameter (D) and the vertical pitch (Lp) are kept constant and the horizontal pitch (Wp) is increased, the heat dissipation amount (Q) decreases after increasing, and the pressure drop (dPw) also decreases after increasing. have. In addition, as the Dp increases, the heat dissipation door Q and the pressure drop amount dPw increase as shown by one arrow in the figure. Although not shown, when the horizontal pitch Wp and the dimple diameter D are kept constant and the vertical pitch Lp is increased, or the horizontal pitch Wp and the vertical pitch Lp are kept constant and the dimple diameter is not shown. In the case of increasing (D), a similar trend as described above appears. When applying the criterion as described above in FIG. 4, the design area of the horizontal pitch Wp is less than 3 mm, which is an area where the pressure drop dPw increases, and is preferably set to 3 mm to 9 mm.

7, the horizontal axis represents the vertical pitch (Lp), the graph shown at the top represents the heat radiation amount (Q), the graph shown at the bottom represents the pressure drop (dPw). As the dimple depth (Dp) and the horizontal pitch (Wp) are kept constant and the vertical pitch (Lp) is increased, the heat radiation amount (Q) decreases after increasing, and the pressure drop (dPw) decreases after increasing. have. In addition, as the dimple diameter D increases, the heat radiation amount Q and the pressure drop amount dPw increase as shown by one arrow in the figure. Although not shown, when the dimple diameter (D) and the dimple depth (Dp) are kept constant and the horizontal pitch (Wp) is increased or the dimple diameter (D) and the horizontal pitch (Wp) are kept constant and the dimple depth ( In the case of increasing Dp), a trend similar to the above appears. When applying the criterion as described above in FIG. 4, the design area of the vertical pitch Lp is preferably set to 5 to 16 mm having a relatively low pressure drop dPw while maintaining a high level of heat radiation Q. FIG.

The above-described design areas of the diameter (D), dimple depth (Dp), horizontal pitch (Wp) and vertical pitch (Lp) of the dimples have been described based on the stacked heat exchanger according to the drawings, but the present invention is not limited thereto. It can be applied to all kinds of heat exchangers formed.

8 is a perspective view illustrating a flow of a heat exchange medium in the heat exchanger of FIG. 2. The heat exchanger illustrated as described above is a one-tank heat exchanger 100 provided with one tank 119 and 123 at an upper end and a lower end, respectively. The heat exchange medium in the heat exchanger 100 enters the upper end tank 119 through the inlet 124 as shown by the arrow, descends along the stacked tubes 110, and passes through the lower end tank 123 to discharge the outlet 125. To be discharged. The flow of the heat exchange medium is only a representative example of the one-tank heat exchanger, and various modified flows are possible according to the positions of the inlet, the outlet, and the baffle (not shown).

Figure 9a is a front view showing a plate of a two-tank heat exchanger having two tanks in the upper end of another embodiment of the present invention, Figure 9b is a perspective view showing the flow of the heat exchange medium in the heat exchanger. Referring to the drawings, the plate 211 includes cups 221 and 231 for forming the first and second tanks 220 and 230 at the upper end, and a partition wall 213 for allowing the heat exchange medium to flow along the U-shaped flow path in the tube 210. And a dimple 214 on the inner surface of the plate 211. In the heat exchanger 200, the heat exchange medium enters the first tank 220 through the inlet 201 as shown by the arrow in FIG. 9B, and descends and rises in a U shape along the stacked tubes 210. Passed through the tank 230 is discharged to the outlet 202. It will be appreciated that the flow of the heat exchange medium is only a representative example of the upper two-tank heat exchanger, and various modified flows are possible depending on the positions of the inlet, the outlet, and the baffle (not shown).

Figure 10a is a front view showing a plate of a two-tank heat exchanger having two tanks at the top and bottom of another embodiment of the present invention, Figure 10b is a perspective view showing the flow of the heat exchange medium in the heat exchanger. Referring to the drawings, the plate 311 includes cups 321 and 331 for forming two tanks 320 and 330 at the upper end, cups 341 and 351 for forming two tanks 340 and 350 at the lower end, and a flow path through which the heat exchange medium rises. And a partition wall 313 for separating the flow path that descends and the dimple 314 on an inner surface of the plate 311. In the heat exchanger 300, the heat exchange medium enters the upper end first tank 320 through the inlet 201 as shown by the arrow in FIG. 10B, and descends along one side flow path of the stacked tube 310 to lower the first end. Flows into the tank 340. Since the lower end first and second tanks 340 and 350 are separated from each other but communicate with each other at the right end, the heat exchange medium flows into the lower end second tank 350, and ascends to the outlet through the upper end second tank 330. 302). It will be appreciated that the flow of the heat exchange medium is only a representative example of the upper and lower end two-tank heat exchangers, and various modified flows are possible depending on the positions of the inlet, the outlet, and the baffle (not shown).

As described above, the heat exchanger of the present invention has the following effects.

First, it is possible to easily provide a heat exchanger having improved performance by defining a desirable design area of depth, diameter, horizontal pitch and vertical pitch of dimples formed on the inner surface of the tube.

Second, by joining a pair of plates to form a heat exchange medium flow path and a tank integrally and by stacking the heat exchanger to reduce the number of production processes it is possible to improve productivity.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Could be. Therefore, the true technical protection scope of the present invention should be defined only by the technical spirit of the appended claims.

Claims (8)

A single-phase heat exchange medium is formed by joining a pair of plates and having a tube for alternately stacking a tube forming a flow path of the single-phase heat exchange medium, and a tank for distributing or collecting on the plate. In the heat exchanger, A plurality of dimples are formed on the inner surface of the plate, When the depth of the dimple is Dp and the height of the flow path inside the tube is H, Dp satisfies the inequality 0 <Dp ≤ 0.3H. The method of claim 1, The dimple has a diameter of 2.5mm or less heat exchanger. The method of claim 1, Heat exchanger, characterized in that the horizontal pitch between the dimple is 3 to 9mm. The method of claim 1, Heat exchanger, characterized in that the vertical pitch between the dimple is 5 to 16mm. The method of claim 1, Heat exchanger, characterized in that the dimples formed on the inner surface of the pair of plates facing each other are arranged so as not to be mutually shifted. The method according to claim 1, wherein The plate is provided with a cup for forming a tank on the top and / or bottom one by one heat exchanger. The method of claim 6, And the tank is detachable from the tube. The method according to any one of claims 6 to 9, The plate is provided with a plurality of cups for forming a tank on at least one side of the upper and lower, heat exchanger, characterized in that the central portion is formed in the longitudinal partition wall for guiding the single-phase heat exchange medium.