Heating plate for flow heater

Abstract

Disclosed is a heating plate for a flow heater, comprising a substrate (1) made of metal, a heating resistor arranged on one side of the substrate (1), and a fin (5) arranged on the other side of the substrate (1), where the fin (5) is brazed to the substrate (1), made of a corrugated metal sheet, and provided with a series of cuts (6) on the ridges of the corrugated metal sheet. According to the utility model, the ridges are extruded, so that the opposite surfaces on the inner sides of the ridges are in contact with each other.

Description

Technical Field

[0001] The utility model relates to a heating plate for a flow heater. A heating plate for a flow heater is disclosed in US2022 / 0082297A1. Background Art

[0002] The heating plate disclosed in US2022 / 0082297A1 includes a substrate provided as a plate made of steel, and fins brazed to the substrate. The fins are made of a corrugated metal plate, and a series of cuts are provided on the ridges of the corrugated metal plate. On one side of the substrate are the fins, and on the other side of the substrate is a heating resistor provided as a resistive rail on a dielectric layer. The liquid to be heated flows above the grooves of the corrugated metal plate and below the ridges.

[0003] Such a heating plate is used in a flow heater in a vehicle for heating a liquid. The development goals of flow heaters for vehicles have always been compact design, low manufacturing cost, and high efficiency, so that they can operate at high power to heat a large amount of liquid in a short time. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a more efficient heating plate for a flow heater.

[0005] This purpose is achieved by the heating plate for a flow heater provided by the utility model. The heating plate includes: a substrate made of metal, a heating resistor provided on one side of the substrate, and fins provided on the other side of the substrate; wherein, the fins are brazed to the substrate, made of a corrugated metal plate, and a series of cuts are provided on the ridges of the corrugated metal plate. The feature is that: the ridges of the corrugated metal plate are extruded, so that the fins are arranged at a distance greater than the thickness of the fins, and this thickness is measured at the middle position between the proximal end and the distal end of the fins.

[0006] In the heating plate according to the utility model, the fins are made of a corrugated metal plate, and the ridges of the corrugated metal plate are extruded, so that the fins (5) are arranged at a distance greater than the thickness of the fins (5), for example, this distance is at least 1.4 times the thickness, and the thickness is measured at the middle position between the proximal end and the distal end of the fins.

[0007] By using the extruded fins, the contact area between the corrugated metal plate and the substrate is increased. The inventor found that in the area of the metal substrate in contact with the corrugated metal plate, heat is transferred out of the substrate more effectively than in the area directly in contact with the liquid to be heated. Therefore, compared with the heating plate known in US2022 / 0082297A1, using the extruded fins can transfer heat out of the substrate more effectively.

[0008] In an improvement of the present utility model, between the bottom of the ridge connected to the base of the heating plate and the top of the ridge facing away from the base, the opposite surfaces inside the ridge are in contact with each other. In other words, the opposite surfaces of the inner metal plates of the fins are in contact with each other. The base is made of steel. Therefore, the contact area between the corrugated metal plate and the base can be further increased.

[0009] The opposite surfaces inside the ridge can be in contact with each other or in contact through a connecting layer, for example, a brazing layer.

[0010] In another improvement of the present utility model, the narrow fins are formed by extruding the ridges. For example, the thickness of the ridges can be three times or less than the thickness of the metal plate from which they are made.

[0011] In the heating plate according to the present utility model, the incisions on the ridges of the corrugated metal plate greatly increase the flexibility of the fins. During the brazing process of connecting the fins to the base, the thermal expansion difference between the fins and the metal base will generate strain, resulting in the bending of the base. The incisions on the ridges make the fins more flexible, thus reducing the unacceptable bending risk during the brazing process.

[0012] When the ridges on the metal plate are extruded to form fins, cracks may form at the distal bends of the fins, that is, the bends connecting the two sides of the fins. These cracks extend along the bends. Since the cracks do not affect the function of the fins, these cracks are acceptable. Compressing the corrugations of the metal plate forms cracks, which in turn stabilizes the extruded fins.

[0013] In an improvement of the present utility model, the opposite surfaces inside the ridge are connected by the combination of substances, such as brazing or welding. In other words, the opposite surfaces of the inner metal plates of the fins can be connected by brazing. Therefore, the inner surfaces of the fins are fixed to each other, which is beneficial for handling the fins and reducing the stress on the base.

[0014] The thickness of the fins is approximately twice the thickness of the metal plate from which the fins are made. If there is a brazing layer inside the fins, then the thickness of the fins may be slightly greater than twice the thickness of the metal plate from which the fins are made, but even in this case, the thickness of the fins is less than three times the thickness of the metal plate from which the fins are made.

[0015] More details and advantages of the present utility model will be described through exemplary embodiments in conjunction with the accompanying drawings. Brief Description of the Drawings

[0016] Figure 1 An embodiment of the heating plate is shown;

[0017] Figure 2 The heating plate and the fins brazed thereto are shown; and

[0018] Figure 3 is a cross-sectional view of the heating plate and the fins. Detailed implementation mode

[0019] Figure 1 The shown heating plate includes a substrate 1 made of metal (such as steel), an insulating layer 2 covering the substrate 1, and a heating layer including a resistance rail 3. The resistance rail 3 is disposed on the insulating layer 2 and is thus electrically isolated from the substrate 1. The resistance rails 3 are arranged side by side, for example, as parallel strips. The resistance rails 3 can be electrically connected in series through a connecting portion 4. The connecting portion is made of metal and has a resistance lower than the resistance value of the resistance rail 3. The substrate 1 is made of steel. A dielectric layer 2 is disposed between the resistance rail 3 and the substrate 1. During operation, the resistance rail 3, acting as a heating resistor, provides heat, while the connecting portion 4 generates only negligible heat.

[0020] Figure 1 The drying surface of the heating plate is shown. During operation, the drying surface does not contact the liquid to be heated. As Figure 2 and Figure 3 shown, fins 5 are provided on the other side of the heating plate. The fins 5 are brazed to the substrate 1 of the heating plate and are made of a corrugated metal sheet, for example, an aluminum-based alloy. The fins 5 are provided with a series of cuts 6 on the ridges of the corrugated metal sheet. These cuts 6 can improve the flexibility of the metal sheet and reduce the thermal strain that may occur on the substrate during the brazing process.

[0021] Refer to Figure 3 , the ridges of the metal sheet forming the fins 5 are extruded such that the fins 5 are arranged at a distance greater than the thickness of the fins 5, which is measured at the middle position between the proximal end and the distal end of the fins.

[0022] In the shown embodiment, in the region between the bottom of the ridge adjacent to the substrate 1 and the top of the ridge facing away from the substrate 1, the opposite surfaces inside the ridge are in contact. In other words, the opposite surfaces of the metal sheet inside the fins 5 are in contact with each other. In the shown embodiment, the opposite surfaces inside the ridge are connected through a brazing layer 8, that is, in contact through the brazing layer 8. Alternatively, the opposite surfaces of the metal sheet inside the fins 5 can be connected by brazing. Therefore, the thickness of the fins 5 is twice the thickness of the metal sheet forming the fins 5 plus the thickness of the brazing layer 8. Generally, the thickness of the fins 5 is less than three times the thickness of the metal sheet folded to form the fins 5. For example, the thickness of the metal sheet forming the fins 5 can be between 0.3 mm and 0.6 mm, and the thickness of the brazing layer 8 can be between 0.2 mm and 0.4 mm.

[0023] Refer to Figure 2 and Figure 3 , if the opposite surfaces inside the ridge are not welded to each other, that is, in contact through a brazing layer, the opposite surfaces inside the ridge can simply be in contact with each other.

[0024] As Figure 2As shown, the cut 6 can extend from the top or distal end of the fin 5 close to the base 1. Ideally, the cut 6 terminates at a certain distance from the base 1, which corresponds to the thickness of the corrugated metal sheet, i.e., half of the thickness of the fin 5. However, good results may have been obtained if the cut 6 terminates at a distance from the base 1 that does not exceed the thickness of the fin 5. The width of the cut 6 can be greater than half of the thickness of the fin 5 but less than twice the thickness of the fin 5.

[0025] The fins 5 are arranged such that the distance d between them is greater than the thickness of the fin 5. For example, the distance d is greater than 1.8 times the thickness of the fin 5 but less than 5 times the thickness of the fin 5. For example, the width of the cut 6 can be greater than the thickness of the fin 5 but less than 10 times the thickness of the fin 5.

[0026] List of reference numerals

[0027] 1 Base;

[0028] 2 Insulating layer;

[0029] 3 Resistance rail;

[0030] 4 Connecting part;

[0031] 5 Fin;

[0032] 6 Cut;

[0033] 8 Brazing layer;

[0034] d Distance between fins.

Claims

1. A heating plate for a flow heater, comprising: a substrate (1) made of metal, A heating resistor is arranged on one side of the substrate (1) and a fin (5) is arranged on the other side of the substrate (1), The fins (5) are brazed to a substrate (1) and are made of a corrugated metal sheet with a series of cutouts (6) on the ridges of the corrugated metal sheet. Features: The ridges are extruded so that the fins (5) are arranged at a distance greater than the thickness of the fin (5), said thickness being measured at a position midway between the proximal and distal ends of the fin (5).

2. The heating plate according to claim 1, wherein The opposing surfaces of the metal plates inside the fins (5) are in contact with each other.

3. A heating plate according to any one of the preceding claims, wherein: The opposite surfaces of the inner metal plates of the fins (5) are connected by brazing.

4. A heating plate according to any one of the preceding claims, wherein The heating resistor comprises a resistive track (3), and wherein a dielectric layer (2) is arranged between the resistive track (3) and the substrate (1).

5. A heating plate according to any one of the preceding claims, wherein The substrate (1) is made of steel.

6. A heating plate according to any one of the preceding claims, wherein The fins (5) are made of aluminum-based alloy.

7. A heating plate according to any one of the preceding claims, wherein The opposing surfaces of the inside of the ridges are in contact in the region between the bottom of the ridge connected to the base (1) of the heating plate and the top of the ridge facing away from the base (1).

8. A heating plate according to any one of the preceding claims, wherein The fins (5) are arranged at a distance greater than 1.8 times the thickness of the fin (5) but less than 5 times the thickness of the fin (5).

9. A heating plate according to any one of the preceding claims, wherein: The width of the cutout (6) is greater than half the thickness of the fin (5).

10. The heating plate according to claim 9, wherein The width of the cutout (6) is greater than the thickness of the fin (5) but less than 10 times the thickness of the fin (5).

11. A heating plate according to any one of the preceding claims, wherein The thickness of the fin (5) is less than 3 times the thickness of the metal plate making the fin (5).

12. A heating plate according to any one of the preceding claims, wherein: The crack extends along the bend at the distal end of the fin (5).

13. A heating plate according to any one of the preceding claims, wherein: The fins (5) are arranged at a distance of at least 1.4 times the thickness of the fin (5), the thickness being measured at a midpoint between the proximal end and the distal end of the fin (5).

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