Flow heater

Abstract

The utility model discloses a flow type heater, which comprises a shell (6), a flow channel extending from an inlet (11) to an outlet (12) is arranged in the shell (6), and liquid to be heated flows in the flow channel; a box (8) arranged inside the housing (6); and a heating resistor (16) arranged inside the cartridge (8). According to the utility model, the heating resistor (16) is a lead embedded in an insulating material.

Description

Technical Field

[0001] The utility model relates to a flow heater for heating a liquid. Background Art

[0002] In US8731386B2, a flow heater is disclosed, which includes a housing, a cartridge and a heating resistor. A flow passage extending from an inlet to an outlet is provided in the housing for the liquid to be heated to flow therein, the cartridge is arranged inside the housing, and the heating resistor is arranged inside the cartridge.

[0003] When designing a flow heater for heating a liquid, a constant goal is to provide a compact and cost-effective flow heater. An object of the utility model is to provide a more compact, more robust and cost-effective flow heater. Summary of the Utility Model

[0004] In the flow heater according to the utility model, the heating resistor is a wire embedded in an insulating material in the cartridge, the cartridge is arranged in the housing, in which a flow passage for the liquid to be heated extends from an inlet to an outlet. In this way, the cartridge with the heating resistor can be cost-effectively manufactured as a separate component and then arranged in the housing of the flow heater. In addition, the wire embedded in the insulating material can withstand high operating temperatures, so that the liquid can be quickly heated in the compact flow heater. The wire used as the heating resistor can be made of a nickel-based alloy, such as nichrome alloy. The insulator inside the cartridge in which the wire is embedded can be ceramic powder, such as magnesium oxide.

[0005] In an advantageous improvement of the utility model, the cartridge can be provided with fins arranged inside the flow passage. Therefore, heat can be more effectively transferred to the liquid in the flow passage, and the heating device can be made more compact and more durable. The fins can be brazed or welded to the outer surface of the cartridge, for example. The fins can significantly reduce the surface temperature of the cartridge, thereby improving the heat transfer efficiency.

[0006] In another advantageous improvement of the utility model, the cartridge is arranged in the flow passage such that the flow passage branches into a first part and a second part flowing along opposite sides of the cartridge. The first part is arranged between a first housing wall and a first surface of the cartridge, and the second part is arranged between a second housing wall and a second surface of the cartridge, wherein the second surface of the cartridge is opposite to the first surface of the cartridge. In this way, the heat transfer from the cartridge to the liquid can be improved. Then fins can be provided on both sides of the cartridge.

[0007] In another advantageous improvement of the utility model, fins are arranged on the first surface and the second surface of the cartridge.

[0008] In another advantageous refinement of the present utility model, the housing is strip-shaped or plate-shaped. For example, the housing can be a flat cube or oval. Such a housing has two opposite wide sides (or main sides), which are connected by narrow, smaller sides. The heat sink can be arranged on the wide sides. Such a housing can be produced cost-effectively by folding a metal sheet into a flat tube. The edges of the sheets that are brought together by folding can be connected by welding. Then, the ends of such a housing can be closed with separate closing elements.

[0009] In another advantageous refinement of the present utility model, the housing is strip-shaped or plate-shaped. That is to say, the thickness of the housing is less than the width and length of the housing, for example not exceeding one fifth of the width of the housing and not exceeding one fifth of the length of the housing. Such a housing has two opposite wide sides (or main sides), which are connected by narrow, smaller sides. The inlet and outlet can be arranged on the narrow sides, preferably on the same narrow side.

[0010] In another advantageous refinement of the present utility model, it further includes a circuit board arranged on the flat side of the housing, and wire terminals are connected to the circuit board.

[0011] In a flow heater having a strip-shaped or plate-shaped housing, the flow channel can have a first end and a second end. The first end is adjacent to the inlet and is arranged between the first narrow side of the housing and the housing, and the second end is adjacent to the outlet and is arranged between the second narrow side of the housing and the housing. The first narrow side of the housing is opposite to the second narrow side. In such an embodiment, the ends have widths that increase respectively towards the inlet and the outlet. Therefore, the flow of the liquid to be heated through the housing can be optimized, and heat transfer is improved. The housing can be further optimized to have a more uniform coolant distribution and an increased coolant speed, thereby reducing the surface temperature of the housing and increasing the durability of the heating device. Description of the Drawings

[0012] With reference to the accompanying drawings, more details and advantages of the present utility model are explained below in connection with illustrative embodiments of the present utility model. In the different drawings, the same and corresponding parts have the same reference numerals.

[0013] Figure 1 A top view of a flow heater including a peripheral housing is shown;

[0014] Figure 2 Shows Figure 1 The bottom view of the flow heater of;

[0015] Figure 3 Shows without a lid Figure 1 The top view of the flow heater of;

[0016] Figure 4shows the flow heater without a circuit board Figure 3 in a top view;

[0017] Figure 5 shows the flow heater without a peripheral housing and a circuit board Figure 1 ;

[0018] Figure 6 shows the exploded view of Figure 5 without a baffle;

[0019] Figure 7 schematically shows the details of the flow heater; and

[0020] Figure 8 schematically shows the production stage of the cartridge for the flow heater. Detailed Description

[0021] Figure 1 and Figure 2 show a top view and a bottom view of the flow heater respectively, which includes a peripheral housing 1 having an inlet joint 2, an outlet joint 3 and an electrical connector 4. For example, the peripheral housing 1 can be a two-piece housing including a cover portion 1a and a bottom portion 1b. For example, the flow heater can be adapted to heat a liquid in an automobile.

[0022] Figure 3 shows a top view of such a flow heater without the cover portion. In this view, the circuit board 5 is visible and the electrical connector 4 is connected to the circuit board 5. In Figure 4 , the circuit board is removed so that the housing 6 is visible, and the inlet joint 2 and the outlet joint 3 are connected to the housing 6, and the liquid to be heated flows through the housing 6. In Figure 5 , the housing 6 through which the liquid to be heated flows is schematically shown in a translucent manner. Figure 6 shows Figure 5 the exploded view of the housing 6 shown in

[0023] Inside the housing 6 is a cartridge 8 in which a heating resistor in the form of a wire is arranged. The wire can be made of a nickel-based alloy, such as nichrome alloy. The wire can be wound around a molded insulator and embedded in a ceramic powder such as magnesium oxide. Such insulator powder can fill the space between the heating wire and the cartridge. In Figure 6 the cartridge shown, two or more wires can be arranged as a heating resistor. The terminals 9 of these wires extend from the cartridge 8 and are connected to Figure 3 the circuit board 5 shown in

[0024] The housing 8 is plate-shaped or bar-shaped and can, for example, be a flat cube or oval. It has two opposite wide sides (or main sides), which are connected by narrow, smaller sides. In Figure 6 the view in

[0025] the housing 8 is shown facing one of the two wide sides (or main sides). Both wide sides can be provided with heat sinks 10, which can be soldered or brazed to the housing 8. The housing 6 can also be plate-shaped and thus also has two opposite wide sides (or main sides), which are connected by narrow, smaller sides.

[0026] The housing 6 has an inlet 11 connected to the inlet joint 2 respectively and an outlet 12 connected to the outlet joint 3. The flow channel for the liquid to be heated extends from the inlet 11 to the outlet 12 within the housing 6. In the illustrated embodiment, both the inlet 11 and the outlet 12 are arranged on the same narrow front side of the housing 8, but the inlet and / or the outlet can also be arranged at different positions. Figure 5 In the perspective view shown, a part of the liquid to be heated flows behind the housing 8 between the housing 8 and the rear wall of the housing 6, while another part flows in front of the housing 8 between Figure 5 the front wall of the housing shown and the housing 8.

[0027] As Figure 5 shown, the end portions of the flow channels on the left and right sides of the housing 6 gradually narrow in the direction away from the inlet 11 or the outlet 12 respectively. Therefore, the distance from the narrow side of the housing 8 to the adjacent inner surface of the housing 6 decreases respectively as the distance from the inlet 11 or the outlet 12 increases. Starting from the inlet 11, as more and more liquid flows into the gap, which is located between the heat sink-supported wide side of the housing 8 and the adjacent housing wall, the amount of the liquid to be heated in the left end portion of the housing 8 decreases as the distance from the inlet 11 increases. Correspondingly, in the right end portion of the housing 8, the closer to the outlet 12, the more liquid there is. Therefore, the narrowing end portions improve the flow of the liquid through the housing 6.

[0028] Figure 7The detail of the cross-section of a flow-through heater without an outer housing is schematically shown. The circuit board 5 carries the transistor switch 13, which converts the heating power supplied to the heating resistor inside the cartridge 8. The transistor switch 13 is arranged between the circuit board 5 and the housing 6, i.e., on the side of the circuit board 5 facing the housing 6. The transistor switch 13 is thermally connected to the cartridge 8. Thus, the waste heat of the transistor switch 13 is transferred to the housing 6 and the liquid flowing through the housing 6. The heat sink 10 is arranged between the cartridge 8 and the housing 6, and the insulating powder 14 fills the space around the heating resistor 16 inside the cartridge 8.

[0029] The cartridge 8 can be made of a metal strip by folding the metal strip into a flat tube and connecting the edges of the metal strip together by folding. For example, the edges of the metal strip can be connected by welding. Figure 8 Schematically shows how the cartridge 8 is made of a metal strip. The metal strip 15 is folded into a flat tube or plate. The edges of the contacting metal strips are then connected, for example by welding. Then one or more wires are arranged inside the cartridge 8 and embedded in the insulating material. The cartridge 8 can be formed, for example, by rolling and cut to the appropriate size. After one or more wires and the insulating material have been arranged inside the cartridge 8, both ends of the cartridge 8 can be closed by covers as closing elements.

[0030] List of reference numerals:

[0031] 1 Outer housing;

[0032] 1 a Cover part;

[0033] 1 b Bottom;

[0034] 2 Inlet connection;

[0035] 3 Outlet connection;

[0036] 4 Electrical connector;

[0037] 5 Circuit board;

[0038] 6 Housing;

[0039] 8 Cartridge;

[0040] 9 Terminal;

[0041] 10 Heat sink;

[0042] 11 Inlet;

[0043] 12 Outlet;

[0044] 13 Transistor switch;

[0045] 14 Insulating powder;

[0046] 15 Metal strip;

[0047] 16 Heating resistor.

Claims

1. Flow heater, including A shell (6), wherein the shell (6) has a flow channel extending from an inlet (11) to an outlet (12) for the liquid to be heated to flow therein; a box body (8) arranged inside the housing (6); and a heating resistor (16) arranged inside the box body (8); It is characterized in that The heating resistor (16) is a wire embedded in an insulating material.

2. The flow heater according to claim 1, wherein: The box body (8) is provided with a heat sink (10) arranged in the flow channel.

3. The flow heater according to claim 2, wherein: The heat sink (10) is brazed or welded to the box body (8).

4. A flow heater according to any one of the preceding claims, wherein: The flow channel branches into a first part and a second part, the first part is arranged between a first shell wall and a first surface of the box body (8), and the second part is arranged between a second shell wall and a second surface of the box body (8), wherein the second surface of the box body (8) is opposite to the first surface of the box body (8).

5. The flow heater according to claim 4, wherein: The heat sink (10) is arranged on the first surface of the box body (8) and the second surface of the box body (8).

6. The flow heater according to claim 1, wherein: The box body (8) is in a plate shape or a strip shape.

7. The flow heater according to claim 6, wherein: The box body (8) is made of a metal strip consisting of a metal sheet (15) which is folded into a plate or a flat tube.

8. The flow heater according to claim 1, wherein: The shell (6) is plate-shaped or strip-shaped, and has opposite wide sides and narrow sides connecting the wide sides, wherein the flow channel has a first end and a second end, the first end is adjacent to the inlet (11) and is arranged between the first narrow side of the shell and the box body (8), and the second end is adjacent to the outlet (12) and is arranged between the second narrow side of the shell and the box body (8), wherein the first narrow side of the shell (6) is opposite to the second narrow side of the shell (6).

9. The flow heater according to claim 8, wherein: The end portions have widths that increase toward the inlet and the outlet, respectively.

10. The flow heater according to claim 8 or 9, wherein: The inlet and the outlet are arranged on the same side of the housing, and a width measured from the first narrow side to the second narrow side increases toward the inlet (11) and the outlet (12).

11. The flow heater according to claim 1, wherein: The flow heater comprises a circuit board (5) to which lead terminals (9) are connected, the circuit board being arranged on a flat side of the box body (8).

12. The flow heater according to claim 11, wherein: A transistor switch (13) is arranged on the circuit board (5), wherein the transistor switch (13) is arranged on a side of the circuit board (5) facing the box body (8) and is thermally connected to the box body (8).

13. The flow heater according to claim 11 or 12, wherein: The flow heater comprises an outer shell (1), in which the box body (8) and the circuit board (5) are arranged.

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