Membrane heater with inner fins
By introducing an inner fin structure into the membrane heater, the problems of insufficient flow and low heat exchange efficiency caused by unreasonable flow channel design are solved, and the effect of efficient and rapid heating and reducing leakage risk is achieved.
Patent Information
- Application Number
- CN202422502942.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-16
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2034-10-16
AI Technical Summary
The design of the internal flow path of the membrane heater shell of the prior art is unreasonable, resulting in insufficient flow of the heating medium, low heat exchange efficiency, and high cost, high weight, and easy leakage.
The film heater design is adopted with inner fins, including a three-part runner fin structure, the fin section is zigzag or triangular or wavy, and the dislocation is distributed, the fin material is aluminum alloy, the pipe joint is connected through the medium inlet and medium outlet, and the fin is welded to the shell, increasing the heat exchange area and media disturbance.
The fluidity and heat exchange efficiency of the heating medium in the shell are improved, the cost and leakage risks are reduced, and rapid heating and efficient heat exchange are achieved.
Smart Images
Figure CN223228829U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a film heater with inner fins, belonging to the technical field. Background Art
[0002] In the field of electric vehicles, electric heating is commonly used to heat the cabin and battery pack. Due to the advantages of small size and light weight, film heaters can better match the overall vehicle layout and are therefore widely used in electric vehicles. The film heater includes a shell and a heating film fixed to the shell. The heating film is formed by sintering insulating media, heating resistors and other materials onto a metal substrate at high temperature. A heating medium (usually water) is introduced into the shell and heated by the heating film. The internal flow channel design of the membrane heater shell in the existing technology is unreasonable, and the flow of the heating medium is insufficient, resulting in low heat exchange efficiency. In addition, there are disadvantages such as high cost, high weight, and easy leakage. Utility Model Content
[0003] The purpose of the utility model is to provide a film heater with internal fins to solve the technical problems of unreasonable design of the internal flow channel of the film heater shell in the prior art, insufficient flow of the heating medium, and low heat exchange efficiency.
[0004] The utility model adopts the following technical solution: a film heater with internal fins, comprising a shell and a heating film fixed on the shell, the shell being provided with a medium inlet and a medium outlet, a partition being provided in the shell, the partition dividing the space in the shell into two left and right areas, one end of the partition being fixedly and sealedly connected to the front side wall of the shell, and a gap being provided between the rear end of the partition and the rear side wall of the shell, the medium inlet and the medium outlet being respectively arranged at positions on both sides of the partition on the front side wall of the shell, a flow channel fin being provided in the shell, the flow channel fin comprising three parts, the first part of the flow channel fin being located on the left side of the partition, the second part of the flow channel fin being located on the right side of the partition, and the third part of the flow channel fin being located between the rear end of the partition and the rear side wall of the shell, the first part of the flow channel fin and the second part of the flow channel fin both having flow channels extending forward and backward, the third part of the flow channel fin having a flow channel extending left and right, and the two ends of the flow channel of the third part of the flow channel fin being respectively connected to the flow channels of the first part of the flow channel fin and the second part of the flow channel fin.
[0005] The cross section of the flow channel fin is a sawtooth, triangular or wavy structure. The bottom of the flow channel fin is welded to the bottom surface of the shell, and there is a gap between the top of the flow channel fin and the top of the shell.
[0006] A water-permeable hole is provided at the highest point of the flow channel fin.
[0007] The first part of the flow channel fins and the second part of the flow channel fins each include more than two flow channel fins arranged in front and behind, and the flow channel fins arranged in front and behind are staggered; the third part of the flow channel fins includes more than two flow channel fins arranged in the left and right, and the flow channel fins arranged in the left and right are staggered.
[0008] A cavity is defined between the front end of the first portion of the flow channel fins and the front side wall of the shell; and a cavity is defined between the front end of the second portion of the flow channel fins and the front side wall of the shell.
[0009] The flow channel fins are made of aluminum alloy, and the surface of the flow channel fins is provided with aluminum alloy solder.
[0010] The shell is a rectangular, square, circular or elliptical structure, the bottom surface and side walls of the shell are integrally connected, and a cover plate is welded on the top of the shell.
[0011] The surface of the cover plate is provided with aluminum alloy solder.
[0012] The shell is a metal shell.
[0013] Pipe joints are respectively connected to the medium inlet and the medium outlet outside the shell.
[0014] The beneficial effects of the present invention are as follows: when the film heater with internal fins of the present invention is used, the heating medium liquid enters the interior of the shell through the medium inlet (the medium inlet and the medium outlet can be reversed), and the heat generated by the heating film provided on the outer side of the bottom of the shell is transferred to the flow channel fins through the shell. The flow channel fins quickly heat the medium liquid inside the shell, and finally discharge the liquid from the shell through the medium outlet. The flow channel fins adopt a fin-type structure with flow channels. The heating medium passes through the first part of the flow channel fins, the third part of the flow channel fins, and the second part of the flow channel fins in the shell in sequence. The heating medium is in full contact with the flow channel fins in the shell, and the heating medium flows fully in the shell, resulting in a large heat exchange area, a faster heating speed, and thus a higher heating efficiency.
[0015] Preferably, the cross section of the flow channel fin is a sawtooth, triangular or wavy structure, and there are flow channels for the medium to pass through on the upper and lower sides of the flow channel fin, thereby further improving the heat exchange area and heating efficiency.
[0016] Preferably, a water-permeable hole is provided at the highest point of the flow channel fin, so that the heating medium can flow up and down the flow channel fin, which is beneficial to improving the disturbance of the heating medium and thus improving the heating efficiency.
[0017] Preferably, the flow channel fins are distributed in a staggered manner to increase the disturbance of the medium, so that the medium forms turbulent flow in the shell, further improving the heating efficiency.
[0018] Preferably, a metal shell is helpful in improving heating efficiency.
[0019] Preferably, the pipe joints at the medium inlet and the medium outlet are conducive to quickly connecting the water inlet pipe and the water outlet pipe. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is an external view of a film heater with internal fins according to an embodiment of the present invention;
[0021] Figure 2 yes Figure 1 Schematic diagram of partial section;
[0022] Figure 3 yes Figure 1 Schematic diagram of a membrane heater with internal fins without the cover;
[0023] Figure 4 yes Figure 3 sectional view of
[0024] Figure 5 yes Figure 3 Cross-section of the mid-channel fin;
[0025] Figure 6 yes Figure 3 A schematic diagram of the shell in FIG.
[0026] Figure 7 yes Figure 6 Plan view of
[0027] Figure 8 yes Figure 1 Schematic diagram of the middle cover;
[0028] Figure 9 This is a schematic diagram of a flow channel fin of a film heater with inner fins according to another embodiment of the present invention.
[0029] In the figure: 1-shell, 1.1-medium inlet, 1.2-medium outlet, 1.3-pipe joint, 2-partition plate, 3-flow channel fin, 4-water permeable hole, 5-cover plate. DETAILED DESCRIPTION
[0030] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0031] like Figures 1 to 8As shown, a film heater with internal fins according to an embodiment of the present invention comprises a shell 1 and a heating film fixed to the shell 1 (not shown in the drawings), a medium inlet 1.1 and a medium outlet 1.2 are provided on the shell 1, a partition 2 is provided inside the shell 1, the partition 2 divides the space inside the shell 1 into two left and right areas, one end of the partition 2 is fixedly and sealedly connected to the front side wall of the shell 1, and a gap is formed between the rear end of the partition 2 and the rear side wall of the shell, the medium inlet 1.1 and the medium outlet 1.2 are respectively provided on the front side wall of the shell 1 at the partition. At the positions on both sides of the plate 2, flow fins 3 are provided in the shell 1, and the flow fins 3 include three parts. The first part of the flow fins is located on the left side of the partition 2, the second part of the flow fins is located on the right side of the partition 2, and the third part of the flow fins is located between the rear end of the partition 2 and the rear side wall of the shell. The first part of the flow fins and the second part of the flow fins both have flow channels extending forward and backward, and the third part of the flow fins has a flow channel extending left and right. The two ends of the flow channel of the third part of the flow fins are respectively connected to the flow channels of the first part of the flow fins and the second part of the flow fins.
[0032] The cross section of the flow channel fin 3 is a sawtooth, triangular or wavy structure. In this embodiment, the flow channel fin 3 adopts a sawtooth cross section. The bottom of the flow channel fin 3 is welded to the bottom surface of the shell 1, and there is a gap between the top of the flow channel fin 3 and the top of the shell 1. A water permeable hole 4 is opened at the highest point of the flow channel fin 3. Figure 3 As shown, a cavity is formed between the front end of the first portion of the flow channel fins and the front side wall of the housing; a cavity is formed between the front end of the second portion of the flow channel fins and the front side wall of the housing. The flow channel fin 3 is made of aluminum alloy, and the surface of the flow channel fin 3 is provided with aluminum alloy solder.
[0033] The housing 1 has a rectangular, square, circular, or oval structure. In this embodiment, the housing 1 is rectangular. The housing 1 is metal, with the bottom and side walls integrally connected. A cover plate 5 is welded to the top of the housing 1. The surface of the cover plate 5 is coated with aluminum alloy solder. Pipe joints 1.3 are connected to the outside of the housing 1 at the medium inlet 1.1 and the medium outlet 1.2, respectively.
[0034] In the present invention, the shell of the heater flow channel is a metal shell, such as cast aluminum, cast iron, titanium alloy, aluminum profile, etc. Taking aluminum alloy ADC12 or profile G77 as an example, a heating film is fixedly attached to the outer side of the bottom surface of the shell, and the fin flow channel is welded inside the shell by brazing. The material of the fin flow channel is 4343 (10%) / 3003 / 4343 (10%) or 4045 (10%) / 3003 / 4045 (10%) aluminum alloy. The shape of the fin flow channel is wavy or zigzag. Such a shape has a large heat dissipation area, which is conducive to quickly dissipating heat. The heat generated by the heating film is transferred to the internal fins through the flow channel shell, which can fully utilize its heat and achieve rapid heating.
[0035] The welding process for the fins to the flow channel housing, and the flow channel fins to the cover plate, is as follows: a brazing flux is sprayed onto the fins with the composite layer, the flow channel fins are placed in the housing, wherein the flow channel housing is a cast aluminum or extruded part without a solder composite layer, the cover plate is pressed and fastened to the upper opening of the housing, and the flow channel fins and the housing, and the flow channel fins and the cover plate are connected using fasteners or clamps. The connected housing assembly is placed in a brazing furnace (or vacuum brazing furnace), and after passing a protective atmosphere, the furnace temperature is raised to 570-700°C, maintained for 5-30 minutes, and then cooled. After welding is completed, the brazing furnace is removed. The brazing furnace is protected by a pure nitrogen atmosphere, or a nitrogen-hydrogen atmosphere. The dew point of the brazing furnace is -50°C, and the oxygen concentration is controlled at or below 100 ppm to minimize the formation of an oxide film during the brazing process. The brazing flux concentration is set at 20%, which effectively destroys the oxide film on the surface of the fin solder composite layer, facilitates solder flow, and ensures weld quality. The brazing flux concentration is 5% to 30%. This concentration effectively destroys the oxide film on the surface of the solder composite layer, allowing the solder to flow. The brazing furnace dew point is -70°C to -40°C, and the oxygen concentration in the brazing furnace is 100 ppm or less. This oxygen concentration limit reduces the oxide film on the solder composite layer during welding between the fins, the flow channel housing, and the cover plate, ensuring weld quality and a stable weld between the fins, the housing, and the cover plate, preventing them from easily falling off. This improves the overall sealing of the housing and prevents leakage.
[0036] The heating medium liquid enters the shell through the medium inlet (the medium inlet and medium outlet can be swapped), and a heating film is provided on the outside of the bottom of the shell. The heat generated by the heating film is transferred to the flow channel fins through the shell. The flow channel fins quickly heat the medium liquid inside the shell, and finally it is discharged from the shell through the medium outlet.
[0037] In other embodiments of the present invention, the flow channel fins can also be used as follows Figure 9 In the staggered structure shown, the first part of the flow fins and the second part of the flow fins each include more than two flow fins arranged front and back, and the flow fins arranged front and back are staggered; the third part of the flow fins includes more than two flow fins arranged left and right, and the flow fins arranged left and right are staggered.
[0038] The above embodiments and descriptions are only for explaining the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, which shall fall within the scope of the present invention to be protected.
Claims
1. A film heater with internal fins, comprising a housing and a heating film fixed to the housing, wherein the housing is provided with a medium inlet and a medium outlet, characterized in that: A partition is provided in the shell, which divides the space in the shell into two left and right areas. One end of the partition is fixedly and sealedly connected to the front side wall of the shell, and there is a gap between the rear end of the partition and the rear side wall of the shell. The medium inlet and the medium outlet are respectively arranged on the front side wall of the shell at positions on both sides of the partition. A flow channel fin is provided in the shell, and the flow channel fin includes three parts. The first part of the flow channel fin is located on the left side of the partition, the second part of the flow channel fin is located on the right side of the partition, and the third part of the flow channel fin is located between the rear end of the partition and the rear side wall of the shell. The first part of the flow channel fin and the second part of the flow channel fin both have a flow channel extending front and back, and the third part of the flow channel fin has a flow channel extending left and right. The two ends of the flow channel of the third part of the flow channel fin are respectively connected to the flow channels of the first part of the flow channel fin and the second part of the flow channel fin.
2. The film heater with inner fins according to claim 1, characterized in that: The cross section of the flow channel fin is a sawtooth, triangular or wavy structure. The bottom of the flow channel fin is welded to the bottom surface of the shell, and there is a gap between the top of the flow channel fin and the top of the shell.
3. The film heater with inner fins according to claim 2, characterized in that: A water-permeable hole is provided at the highest point of the flow channel fin.
4. The film heater with inner fins according to claim 2, characterized in that: The first part of the flow channel fins and the second part of the flow channel fins each include more than two flow channel fins arranged in front and behind, and the flow channel fins arranged in front and behind are staggered; the third part of the flow channel fins includes more than two flow channel fins arranged in the left and right, and the flow channel fins arranged in the left and right are staggered.
5. The film heater with internal fins according to claim 1, characterized in that: A cavity is defined between the front end of the first portion of the flow channel fins and the front side wall of the shell; and a cavity is defined between the front end of the second portion of the flow channel fins and the front side wall of the shell.
6. The film heater with internal fins according to claim 1, characterized in that: The flow channel fins are made of aluminum alloy, and the surface of the flow channel fins is provided with aluminum alloy solder.
7. The film heater with internal fins according to claim 1, characterized in that: The shell is a rectangular, square, circular or elliptical structure, the bottom surface and side walls of the shell are integrally connected, and a cover plate is welded on the top of the shell.
8. The film heater with internal fins according to claim 7, characterized in that: The surface of the cover plate is provided with aluminum alloy solder.
9. The film heater with internal fins according to claim 1, characterized in that: The shell is a metal shell.
10. The film heater with internal fins according to claim 1, characterized in that: Pipe joints are respectively connected to the medium inlet and the medium outlet outside the shell.