Thick film heater adopting indirect heat dissipation technology

Abstract

The invention belongs to the technical field of heating devices, and discloses a thick film heater adopting an indirect heat dissipation technology, which comprises a main shell and a film heating plate, the film heating plate is connected with a radiator, the radiator is connected with heat dissipation fins, the inner side of a heating cavity is connected with a sealing element, and the main shell is connected with a water inlet pipe and a water outlet pipe. A heat dissipation water channel is defined by the heat dissipation device, the heat dissipation fins and the water closing plate, the main shell is connected with a PCBA circuit control board, and the main shell is connected with a low-voltage connector and a high-voltage connector. According to the technical scheme, due to the arrangement of the radiator and other structures, the situation that the radiating fins are directly welded to the heating plate to cause deformation of the heating plate to affect the heating effect or insulation faults is avoided, the radiator and the radiating fins are integrally die-cast, the heat exchange area is greatly increased, the heat exchange coefficient is increased, the heater cannot be locally overheated, and the service life of the heater is prolonged. The tolerance robustness of bubbles existing in a whole vehicle cooling liquid system is enhanced, and the use stability of the heater is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of heating devices, and in particular to a thick film heater adopting an indirect heat dissipation technology. Background Art

[0002] A thick film heater uses a thick film heating plate as a heating element, converts high-voltage electrical energy into heat energy, provides a heat source for new energy vehicles, and is used for heating a passenger compartment or / and a battery pack. The core thick film heating plate element uses a high-temperature resistant and high-thermal conductivity material (such as stainless steel, alumina ceramic, silicon nitride or aluminum alloy) as a substrate, and ceramic materials (such as Al2O3 / SiO2, etc.), conductive heating paste (such as Ag / Pd, etc.) and ceramic materials (such as Al2O3 / SiO2, etc.) are printed on the substrate in layers by a screen printing process, and a plate-shaped element with power resistance characteristics is formed through a high-temperature sintering process. For traditional thick film heaters, since the stainless steel substrate of the thick film heating plate is in plane contact with the heat exchange medium, its heat exchange area is small, the heat transfer coefficient is low, the available power density of the thick film heating plate is low, and the temperature of the thick film heating plate is high, which places extremely high requirements on the operating conditions of the heater and the vehicle assembly method. Especially under conditions such as abnormal coolant flow or air bubbles in the coolant, the heater is prone to local overheating, resulting in the failure of the thick film heating plate.

[0003] In order to eliminate the operating limit conditions of the thick film heater and improve the reliability of the product, a group of metal heat exchange fins are generally welded on the plane of the stainless steel substrate of the thick film heating plate on the market to increase the heat exchange area. This welding scheme generally adopts a brazing process, and the high temperature during the welding process will cause deformation of the thick film heating plate, resulting in direct fracture or invisible local fracture of the heating layer and isolation layer of the thick film heating plate under the deformation stress, posing a great hidden danger of insulation failure. Secondly, it is difficult to inspect the welding quality at the welding point. The virtual welding or cold welding at the welding point will cause uneven heat exchange of the thick film heating plate, resulting in local overheating failure and causing the thick film heating plate to overheat and fail. Summary of the Invention

[0004] The present invention aims to provide a thick film heater adopting an indirect heat dissipation technology to solve the problems raised in the above background art.

[0005] To achieve the above object, the present invention provides the following technical solutions: A thick-film heater adopting an indirect heat dissipation technology, comprising a main housing and a film heating plate. The film heating plate is connected with a radiator, the radiator is connected with heat dissipation fins, a water-sealing plate divides the main housing into a heating chamber (15) and a control chamber. A sealing element is connected to the inner side of the heating chamber. The film heating plate and the radiator are connected with the sealing element. The main housing is connected with an upper housing. The sealing element and the main housing enclose a cooling water tank. The main housing is connected with a water inlet pipe and a water outlet pipe. The water inlet pipe and the water outlet pipe are respectively communicated with the cooling water tank. The heat dissipation fins are located inside the cooling water tank. The heat dissipation fins and the water-sealing plate enclose a heat dissipation channel. A PCBA circuit control board is connected to the inner side of the control chamber. The film heating plate is electrically connected with the PCBA circuit control board. The main housing is connected with a low-voltage connector and a high-voltage connector. The low-voltage connector and the high-voltage connector are respectively electrically connected with the PCBA circuit control board. The main housing is connected with a lower housing.

[0006] Preferably, the sealing element is connected with a sealing ring.

[0007] Preferably, the film heating plate is connected with a thermal conductive adhesive, and the thermal conductive adhesive is connected with the radiator.

[0008] Preferably, the thickness of the radiator is 3 mm.

[0009] Preferably, the thickness of the thermal conductive adhesive is 0.3 mm, and the thermal conductivity of the thermal conductive adhesive is 4 w / m℃.

[0010] Preferably, the main housing is provided with an upper sealing groove and a lower sealing groove. The upper housing is matched with the upper sealing groove, and the lower housing is matched with the lower sealing groove.

[0011] Preferably, the film heating plate is provided with positioning holes, the radiator is connected with positioning posts, and the positioning posts are matched with the positioning holes.

[0012] Preferably, there are several groups of the heat dissipation channels, and the heat dissipation channels are arranged in an S shape.

[0013] The beneficial effects of this technical solution compared with the prior art: (1) This technical solution is provided with a radiator. By increasing the heat exchange capacity of the radiator, heat dissipation fins and the like can be arranged on the radiator, avoiding the situation that the heat dissipation fins are directly welded on the heating plate, which may cause deformation of the heat dissipation plate and affect the heating effect. At the same time, the heat dissipation channel of this application is enclosed by the heat dissipation fins, the radiator and the main housing, greatly increasing the contact area between the cold medium, the heat dissipation fins and the radiator, improving the heat transfer coefficient, preventing the heater from overheating locally, enhancing the tolerance robustness to bubbles in the vehicle coolant system, and greatly improving the use stability of the heater.

[0014] (2) In this technical solution, a thermal conductive adhesive is provided between the membrane heating plate and the radiator, which greatly improves the contact effect between the radiator and the membrane heater, reduces the contact thermal resistance, makes the heat transfer more uniform and stable, and limits the thickness and thermal conductivity of the thermal conductive adhesive to ensure the thermal conductivity efficiency while reducing the usage cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is an exploded view of Embodiment 1 of the present invention; Figure 2 is a top view structural diagram of the main housing provided in Embodiment 1 of the present invention; Figure 3 is a bottom view of the main housing provided in Embodiment 1 of the present invention; Figure 4 is a bottom view of the radiator provided in Embodiment 1 of the present invention; Figure 5 is a top view structural schematic diagram of the radiator provided in Embodiment 1 of the present invention; Figure 6 is a top view structural view of the membrane heater provided in Embodiment 1 of the present invention; Figure 7 is a structural schematic diagram of Embodiment 1 of the present invention; Figure 8 is a view of the longitudinal section of Embodiment 1 of the present invention; Figure 9 is a side cross-sectional view of Embodiment 2 of the present invention; Figure 10 is an exploded view of Embodiment 2 of the present invention; Figure 11 is a structural schematic diagram of Embodiment 2 of the present invention; Reference numerals: upper housing 1, radiator 2, thermal conductive adhesive 3, lower housing 4, membrane heating plate 5, main housing 6, sealing element 7, low-voltage connector 9, high-voltage connector 10, PCBA circuit control board 11, sealing ring 12, heat dissipation fins 13, heating cavity 15, control cavity 16, cooling water tank 17, heat dissipation water channel 18, positioning column 19, positioning hole 20, upper sealing groove 21, lower sealing groove 22, water inlet pipe 23, water outlet pipe 24, bolt hole 25, water blocking sealing plate 26, buffer transition area 27. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The present invention will be further described in detail below with reference to the drawings and embodiments: Embodiment

[0017] As Figures 1 - 7The thick film heater using indirect heat dissipation technology shown in the figure includes a main shell 6 and a film heating plate 5, the radiator 2 is 3 mm thick, the film heating plate 5 is connected to the radiator 2 on the lower side, the film heating plate 5 is connected to the thermal conductive adhesive 3, the thermal conductive adhesive 3 is connected to the radiator 2, that is, the thermal conductive adhesive 3 is located between the film heating plate 5 and the radiator 2, the thickness of the thermal conductive adhesive 3 is 0.3 mm, the thermal conductivity of the thermal conductive adhesive 3 is 4 w / m ° C, the lower side of the radiator 2 is connected to the heat dissipation fins 13, the heat dissipation fins 13 are provided with a plurality of groups, the heat dissipation fins 13 are S-shaped heat dissipation ribs arranged in an interlaced manner, the main shell 6 is connected to a closed water The sealing plate 26 divides the main housing 6 into a heating chamber 15 and a control chamber 16 through the closed water sealing plate 26. In this embodiment, the closed water sealing plate 26 is integrally molded with the main housing 6. After the main housing 6 and the closed water sealing plate 26 are integrally connected, the overall cross-section is a side I-shaped. The upper side of the main housing 6 is the heating chamber 15, that is, the upper side wall of the closed water sealing plate 26 and the main housing 6 form the heating chamber 15, and the lower side is the control chamber 16, that is, the lower side plate of the closed water sealing plate 26 and the main housing 6 form the control chamber 16. The heating chamber 15 and the control chamber 16 are connected by a through hole set in the middle of the closed water sealing plate 26. The inner side of the heating chamber 15 is connected to The sealing element 7, that is, the sealing element 7 is connected to the closed water sealing plate 26. In this embodiment, there are two groups of sealing elements 7. The sealing element 7 located on the inner side is located outside the through hole, thereby preventing the medium in the cooling water tank 17 from entering the control chamber 16 along the through hole. The sealing element 7 is provided with a plurality of bolt holes 25. The membrane heating plate 5 and the radiator 2 are detachably connected by bolts and the bolt holes 25 on the sealing element 7. The sealing element 7 is connected with a sealing ring 12, and the sealing ring 12 is located between the radiator 2 and the sealing element 7. The main housing 6 is connected with the upper housing 1, and the membrane heating plate 5 and the radiator 2 are respectively provided with a plurality of mounting holes, and the sealing element 7 is provided with a plurality of bolt holes 25. When installing, the film heating plate 5 and the radiator 2 are first bonded together by the thermal conductive adhesive 3, and then the corresponding bolts are inserted into the mounting holes of the film heating plate 5 and the radiator 2 in sequence, and the sealing ring 12 is inserted into the sealing element 7, and the film heating plate 5 and the radiator 2 are buckled above the sealing element 7, so that the bolts are aligned with the corresponding bolt holes 25. At this time, the lower side wall of the radiator 2 is in conflict with the sealing ring 12, and then the bolts are screwed to insert the bolts into the bolt holes 25, and the connection between the film heating plate 5 and the radiator 2 and the main housing 6 is completed; The sealing element 7 and the main housing 6 enclose a cooling water tank 17. The main housing 6 is connected with a water inlet pipe 23 and a water outlet pipe 24. The water inlet pipe 23 and the water outlet pipe 24 are respectively communicated with the cooling water tank 17. A buffer transition zone 27 is provided at the connection of the water inlet pipe 23 and the water outlet pipe 24 with the cooling water tank 17. The buffer transition zone 27 is a groove formed by a cuboid, which is convenient for buffering the cold medium entering the cooling water tank 17. The heat dissipation fins 13 are located inside the cooling water tank 17. The heat dissipation fins 13, the radiator 2 and the water sealing plate 26 enclose a heat dissipation water channel 18. There are several groups of heat dissipation fins 13. Therefore, there are also several groups of heat dissipation water channels 18. In actual setting, due to the existence of several groups of heat dissipation water channels 18, the side wall of the sealing element 7 can also be used as the side wall of the heat dissipation water channel 18. For example, the outermost heat dissipation water channel 18 is formed by the heat dissipation fins 13, the water sealing plate 26, the radiator 2 and the side wall of the sealing element 7. The heat dissipation water channel 18 is arranged in an S shape; When the membrane heating plate 5 and the radiator 2 are connected to the main housing 6 according to the above operations, the radiator 2 seals the upper side of the cooling water tank 17, making the cooling water tank 17 a relatively sealed space. Therefore, when installing the membrane heating plate 5 and the radiator 2, turn the bolt. The bolt gradually inserts into the threaded hole while pressing the membrane heating plate 5 and then pressing the radiator 2, so that the radiator 2 squeezes the sealing ring 12, and further makes the radiator 2 in close contact with the sealing element 7. Through the sealing ring 12, it also prevents the cold medium from flowing out of the gap between the radiator 2 and the sealing element 7, making the cooling water tank 17 a relatively stable sealed space; After the heat dissipation fins 13 are inserted into the cooling water tank 17, they contact the bottom side wall of the cooling water tank 17, that is, contact the water sealing plate 26, and further make the heat dissipation fins, the radiator 2 and the water sealing plate 26 enclose a heat dissipation water channel 18, so that the cold medium can enter the cooling water tank 17 along the water inlet pipe 23, then flow along the corresponding heat dissipation water channel 18, complete the heat exchange with the radiator 2 and the heat dissipation fins 13, complete the heat exchange of the radiator 2 to the membrane heating plate 5, and then flow out through the water outlet pipe 24.

[0018] Inside the control cavity 16, a PCBA circuit control board 11 is connected. The PCBA circuit control board 11 is detachably connected to the lower side wall of the water shut-off plate 26 by bolts. The membrane heating plate 5 is electrically connected to the PCBA circuit control board 11. The electrical connection structure of the membrane heating plate 5 can pass through the through-hole and be electrically connected to the PCBA circuit control board 11. The main housing 6 is detachably connected with a low-voltage connector 9 and a high-voltage connector 10 by bolts. The low-voltage connector 9 and the high-voltage connector 10 are respectively electrically connected to the PCBA circuit control board 11. The main housing 6 is connected with a lower housing 4. The overall sealing of the heater is completed through the lower housing 4 and the upper housing 1. The main housing 6 is provided with an upper sealing groove 21 and a lower sealing groove 22. The upper housing 1 cooperates with the upper sealing groove 21. During installation, the upper housing 1 can be inserted into the upper sealing groove 21. The lower housing 4 cooperates with the lower sealing groove 22. During installation, the lower housing 4 can be inserted into the lower sealing groove 22, thereby improving the connection stability between the upper housing 1 and the lower housing 4 and the main housing 6. After the upper housing 1 is installed in the sealing groove 21, sealant is applied at points in the sealing groove 21 to achieve sealing. After the lower housing 2 is installed in the sealing groove 22, sealant is applied at points in the sealing groove 22 to achieve sealing. The membrane heating plate 5 is provided with a positioning hole 20. The radiator 2 is connected with a positioning post 19. The positioning post 19 cooperates with the positioning hole 20. The positioning post 19 can be inserted into the positioning hole 20. When connecting the radiator 2 and the membrane heating plate 5, the positioning group can be inserted into the positioning hole 20 to play a positioning role, enabling the membrane heating plate 5 and the radiator 2 to be smoothly spliced.

[0019] Embodiment 2 The difference between Embodiment 2 and Embodiment 1 lies in the connection methods of the radiator and the water shut-off plate to the main housing. In this embodiment, the radiator and the main housing are integrally formed during manufacturing. The water shut-off plate is detachably connected to the main housing by bolts. When installing the water shut-off plate, by screwing the bolts, the water shut-off plate can be connected to the main housing while the sealing element moves upward and tightly abuts against the radiator, thereby ensuring the sealing of the heat dissipation water channel. In this embodiment, the through-hole through which the control cavity communicates with the heating cavity is provided between the sealing element and the main housing, that is, the through-hole is located outside the cooling water tank. Therefore, at this time, only one set of sealing elements needs to be provided. A relatively closed cooling water tank can still be formed by one set of sealing elements, the radiator, and the water shut-off plate.

[0020] The specific implementation process is as follows: During use, first complete the overall installation of the heater. The film heating plate is powered on and controlled by the PCBA circuit control board 11 to generate heat. The electric power generated by the film heating plate 5 is transmitted to the radiator 2 through the thermal conductive adhesive 3. The radiator 2 then transfers the heat to the heat dissipation fins 13. The cold medium enters the cooling water tank 17 from the water inlet pipe 23 and then flows along the heat dissipation water channel 18. When the cold medium flows along the heat dissipation water channel 18, it contacts the lower side wall of the radiator 2 and the heat dissipation fins 13 for heat exchange to complete the absorption of the heat of the radiator 2. With the flow of the cold medium, the uniform heat dissipation of the radiator 2 and the film heating plate 5 is completed. The cold medium that absorbs heat is discharged from the heater through the water outlet pipe 24.

[0021] The above are only embodiments of the present invention. Specific technical solutions and / or common knowledge such as characteristics well known in the art are not described in detail herein. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. A thick film heater using indirect heat dissipation technology, characterized in that: It includes a main housing (6) and a film heating plate (5). The film heating plate (5) is connected to a radiator (2), and the radiator (2) is connected to heat dissipation fins (13). There are several groups of the heat dissipation fins (13). The main housing (6) is connected to a water shut-off plate (26). The main housing (6) includes a heating chamber (15) and a control chamber (16). The water shut-off plate (26) divides the main housing (6) into the heating chamber (15) and the control chamber (16). A sealing element (7) is connected to the inner side of the heating chamber (15). The film heating plate (5) and the radiator (2) are connected to the sealing element (7). The main housing (6) is connected to an upper housing (1). The sealing element (7) and the main housing (6) enclose a cooling water tank (17). The main housing (6) is connected to a water inlet pipe (23) and a water outlet pipe (24). The water inlet pipe (23) and the water outlet pipe (24) are respectively communicated with the cooling water tank (17). The heat dissipation fins (13) are located inside the cooling water tank (17). The radiator (2), the heat dissipation fins (13) and the water shut-off plate (26) enclose a heat dissipation water channel (18). A PCBA circuit control board (11) is connected to the inner side of the control chamber (16). The film heating plate (5) is electrically connected to the PCBA circuit control board (11). The main housing (6) is connected to a low-voltage connector (8) and a high-voltage connector (10). The low-voltage connector (9) and the high-voltage connector (10) are respectively electrically connected to the PCBA circuit control board (11). The main housing (6) is connected to a lower housing (4).

2. The thick film heater using an indirect heat dissipation technology as described in claim 1, wherein: The heat dissipation fins (13) and the radiator (2) are made of aluminum alloy, and the heat dissipation fins (13) and the radiator (2) are integrally die-cast.

3. The thick film heater adopting an indirect heat dissipation technology according to claim 1, characterized in that: The sealing element (7) is connected with a sealing ring (12).

4. The thick film heater adopting the indirect heat dissipation technology according to claim 1, characterized in that: The film heating plate (5) is connected with a thermal conductive adhesive (3), and the thermal conductive adhesive (3) is connected to the radiator (2).

5. The thick film heater adopting an indirect heat dissipation technology as described in claim 1, wherein: The thickness of the radiator (2) is 2mm - 3.5mm.

6. The thick film heater adopting the indirect heat dissipation technology as described in claim 5, wherein: The thickness of the thermal conductive adhesive (3) is 0.2mm - 0.4mm; the thermal conductivity of the thermal conductive adhesive (3) is 3 - 5w / m℃.

7. The thick film heater adopting an indirect heat dissipation technology as claimed in claim 1, wherein: The main housing (6) is provided with an upper sealing groove (21) and a lower sealing groove (22). The upper housing (1) is matched with the upper sealing groove (21), and the lower housing (4) is matched with the lower sealing groove (22).

8. The thick film heater adopting an indirect heat dissipation technology as described in claim 1, characterized in that: The film heating plate (5) is provided with a positioning hole (20), and the radiator (2) is connected with a positioning post (19). The positioning post (19) is matched with the positioning hole (20).

9. The thick film heater adopting an indirect heat dissipation technology as described in claim 1, characterized in that: There are several groups of the heat dissipation water channels (18), and the heat dissipation water channels (18) are arranged in an S shape.

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