Graphene PTC heating devices and vehicles

Abstract

This invention provides a graphene PTC heating device and a vehicle, relating to the field of heating device technology. The graphene PTC heating device includes: a mounting base connected to a mounting foundation; a heating shell connected to the mounting base, the heating shell having a heat dissipation cavity; and a heating body connected to the mounting base, the heating body being disposed within the heat dissipation cavity. The heating body has a multi-layer structure, including at least one composite heating layer and at least one thermally conductive and temperature-equalizing layer, one side of the composite heating layer being bonded to the thermally conductive and temperature-equalizing layer; wherein the composite heating layer includes multiple graphene PTC ceramic sheets. This solution at least solves the problems of low heating efficiency, poor temperature control, and high energy consumption in existing technologies for new energy vehicles.

Description

Technical Field

[0001] This invention relates to the field of heating device technology, and more specifically, to a graphene PTC heating device and a vehicle. Background Technology

[0002] New energy vehicles use power batteries as their power source, eliminating the engine of traditional fuel vehicles. This means they cannot utilize engine waste heat for cabin heating, and the charging and discharging performance of power batteries degrades significantly in low-temperature environments. Therefore, dedicated heating devices are needed to achieve cabin heating and battery preheating. Currently, the mainstream new energy vehicle uses traditional ceramic PTC heating devices, but these have several technical drawbacks: First, they have low heating efficiency and slow heating speed; it takes 5-8 minutes to reach the set temperature from startup at room temperature, affecting the user experience. Second, they have poor heating uniformity; traditional PTC ceramic plates provide point-like heating, easily leading to localized overheating and uneven overall temperature. Third, they have low temperature control precision, mostly using on / off control, with temperature fluctuations reaching ±5℃, affecting comfort and causing energy waste. Fourth, they have high energy consumption; the heating efficiency ratio of traditional PTC heating devices is relatively low, increasing the power consumption of the power battery and shortening the driving range of new energy vehicles.

[0003] Graphene, as a novel two-dimensional carbon material, possesses extremely high thermal conductivity and excellent electrical conductivity. Combining graphene with PTC ceramics can effectively improve the heating efficiency and heating rate of PTC elements. Although there is some research on graphene PTC heating elements in the existing technology, most of them are laboratory samples, and integrated heating devices suitable for new energy vehicles have not yet been developed. Furthermore, engineering problems such as precise temperature control, modular installation, and airflow heat dissipation matching of graphene PTC elements have not been solved.

[0004] There is currently no effective solution to the aforementioned technical problems. Summary of the Invention

[0005] The main objective of this invention is to provide a graphene PTC heating device and vehicle to solve the problems of low heating efficiency, poor temperature control, and high energy consumption in existing new energy vehicles.

[0006] To achieve the above objectives, according to one aspect of the present invention, a graphene PTC heating device is provided, comprising: a mounting base connected to a mounting foundation; a heating shell connected to the mounting base, the heating shell having a heat dissipation cavity; and a heating body connected to the mounting base, the heating body being disposed within the heat dissipation cavity, the heating body having a multi-layer structure, the multi-layer structure including at least one composite heating layer and at least one thermally conductive and temperature-equalizing layer, one side of the composite heating layer being bonded to the thermally conductive and temperature-equalizing layer; wherein the composite heating layer includes a plurality of graphene PTC ceramic sheets.

[0007] Furthermore, the graphene PTC ceramic sheet is made by sequentially dry pressing graphene powder, barium titanate-based ceramic powder, and rare earth dopants, followed by high-temperature sintering, with multiple graphene PTC ceramic sheets covering at least part of the surface of the composite heating layer.

[0008] Furthermore, adjacent graphene PTC ceramic sheets are connected in series via a conductive connecting material, and / or adjacent graphene PTC ceramic sheets are connected in parallel via a conductive connecting material, wherein the conductive connecting material is one or more of conductive paste, conductive adhesive, and metal wire.

[0009] Furthermore, the thermally conductive heat spreader includes a metal substrate and a thermally conductive filler, wherein the thermally conductive filler is at least one of graphene, carbon nanotubes, and graphite sheets, and the metal substrate is at least one of aluminum and aluminum alloys.

[0010] Furthermore, the multi-layer structure of the heating body also includes a mounting base layer, one side of which is bonded to the heat-conducting and temperature-equalizing layer, and the other side of which is bonded to the mounting base; an insulating protective layer, which is disposed on the outer peripheral surface of the composite heating layer and the heat-conducting and temperature-equalizing layer, and is bonded to at least a portion of the outer peripheral surface of the composite heating layer and the heat-conducting and temperature-equalizing layer; wherein, the insulating protective layer is a high-temperature resistant insulating film, and the thickness of the insulating protective layer is 0.1mm~0.3mm.

[0011] Furthermore, the graphene PTC heating device also includes: a heat insulation layer, one side of which is connected to the mounting base; and a heat dissipation component, which includes multiple heat sinks, one end of which is connected to the other side of the heat insulation layer, and the other end of which is connected to the mounting base.

[0012] Furthermore, the graphene PTC heating device also includes a temperature control module, which comprises: a temperature sensor connected to the thermally conductive heat exchanger layer, with the sensor's detection end bonded to the surface of the heat exchanger layer; a microcontroller, with its signal input terminal electrically connected to the temperature sensor's output terminal; and a voltage regulation drive circuit electrically connected to the microcontroller's output terminal and to the composite heating layer, used to adjust the voltage of the composite heating layer.

[0013] Furthermore, the graphene PTC heating device also includes a power supply module, which includes: a high-voltage terminal, which is electrically connected to an external power source; a protection circuit, one end of which is connected to the high-voltage terminal and the other end of which is connected to a voltage regulating drive circuit, the protection circuit being used to control the power supply to the voltage regulating drive circuit; and a voltage converter, which is located between the protection circuit and the high-voltage terminal, the voltage converter being used to convert the high-voltage electricity on the high-voltage terminal into the low-voltage electricity required by the voltage regulating drive circuit.

[0014] Furthermore, the heating housing is provided with an air inlet and an air outlet. The air inlet is located at one end of the heating housing, and the air outlet is located at the other end of the heating housing. The air inlet is connected to a cold air source. The graphene PTC heating device also includes a fan, which is located at the air outlet and is electrically connected to a single-chip microcomputer. The fan is used to exhaust the warm air in the heat dissipation cavity.

[0015] According to another aspect of the present invention, a vehicle is provided having a graphene PTC heating device, wherein the graphene PTC heating device is the aforementioned graphene PTC heating device.

[0016] Applying the technical solution of this invention, the mounting base serves as a rigid connection interface between the device and the mounting foundation, ensuring stable installation of the overall structure and providing mechanical support for heat conduction. The heating shell 2 encloses a sealed heat dissipation cavity, which guides orderly airflow, improves heat exchange efficiency, and prevents external interference and disordered heat loss through structural isolation, enhancing the controllability of the thermal field. The heating body is located within the heat dissipation cavity and is configured as a multi-layer structure. The composite heating layer consists of multiple graphene PTC ceramic sheet arrays, which utilize graphene to enhance thermal conductivity and PTC self-limiting temperature characteristics, achieving rapid start-up and temperature self-stabilization, and avoiding local overheating. The heat-conducting and temperature-equalizing layer is bonded to the composite heating layer, efficiently converting heat generation into uniform surface heat release, significantly reducing surface temperature differences, and improving heating comfort and energy efficiency. This configuration abandons the traditional single-piece stacking mode, achieving a dual improvement in heating performance and engineering adaptability through functional layering, spatial constraints, and heat flow guidance. It solves the problems of slow heating, uneven temperature distribution, high energy consumption, and poor adaptability of traditional PTC heaters. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of the structure of a first embodiment of the graphene PTC heating device according to the present invention is shown;

[0019] Figure 2 A schematic diagram of a second embodiment of the graphene PTC heating device according to the present invention is shown;

[0020] Figure 3 A schematic diagram of a third embodiment of the graphene PTC heating device according to the present invention is shown;

[0021] Figure 4 A schematic diagram of an embodiment of the composite heating layer according to the present invention is shown.

[0022] The above figures include the following reference numerals:

[0023] 1. Install the base;

[0024] 2. Heating housing; 200. Heat dissipation cavity; 21. Air inlet;

[0025] 3. Heating element; 31. Composite heating layer; 310. Graphene PTC ceramic sheet; 32. Thermally conductive and temperature-equalizing layer; 33. Mounting base layer; 34. Insulating protective layer;

[0026] 4. Thermal insulation layer;

[0027] 5. Heat sink; 50. Heat sink fins;

[0028] 6. Temperature control module; 61. Temperature sensor; 62. Microcontroller; 63. Voltage regulation drive circuit;

[0029] 7. Power supply module; 71. Protection circuit; 72. Voltage converter;

[0030] 8. Fan. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0035] Combination Figures 1 to 4 As shown, according to a specific embodiment of this application, a graphene PTC heating device is provided.

[0036] Specifically, such as Figure 1 , Figure 2 As shown, the graphene PTC heating device includes a mounting base 1, a heating shell 2, and a heating body 3. The mounting base 1 is connected to the mounting base; the heating shell 2 is connected to the mounting base 1 and has a heat dissipation cavity 200; the heating body 3 is connected to the mounting base 1 and is disposed within the heat dissipation cavity 200. The heating body 3 has a multi-layer structure, which includes at least one composite heating layer 31 and at least one thermally conductive and temperature-equalizing layer 32. One side of the composite heating layer 31 is bonded to the thermally conductive and temperature-equalizing layer 32. The composite heating layer 31 includes multiple graphene PTC ceramic sheets 310.

[0037] Applying the technical solution of this embodiment, the mounting base 1 serves as a rigid connection interface between the device and the mounting foundation, ensuring stable installation of the overall structure and providing mechanical support for heat conduction. The heating shell 2 encloses and forms a sealed heat dissipation cavity 200, which can guide the orderly flow of airflow, improve heat exchange efficiency, and prevent external interference and disordered heat loss through structural isolation, thereby enhancing the controllability of the thermal field. The heating body 3 is located within the heat dissipation cavity 200 and is configured as a multi-layer structure. The composite heating layer 31 is composed of an array of multiple graphene PTC ceramic sheets 310, which can utilize graphene to improve thermal conductivity and PTC self-limiting temperature characteristics to achieve rapid start-up and temperature self-stabilization, avoiding local overheating. The thermally conductive and temperature-equalizing layer 32 is attached to the composite heating layer 31, which can efficiently convert heat generation into uniform surface heat release, significantly reducing surface temperature difference and improving heating comfort and energy efficiency. This configuration abandons the traditional single-piece stacking mode and achieves a dual improvement in heating performance and engineering adaptability through functional layering, spatial constraints, and heat flow guidance. This solves the problems of slow heating, uneven temperature distribution, high energy consumption, and poor adaptability of traditional PTC heaters.

[0038] It should be noted that the installation base can be the vehicle battery, or other spaces or structural components that require heat, such as the passenger compartment.

[0039] Specifically, the graphene PTC ceramic sheet 310 is made by sequentially dry pressing graphene powder, barium titanate-based ceramic powder, and rare earth dopants, followed by high-temperature sintering. Multiple graphene PTC ceramic sheets cover at least a portion of the surface of the composite heating layer. The introduction of graphene powder improves the thermal and electrical conductivity of the ceramic matrix, increasing the heating rate and enabling rapid response. Barium titanate-based ceramic, as the main material of the PTC, provides a stable positive temperature coefficient, ensuring automatic temperature limiting and avoiding overheating risks. Rare earth dopants optimize grain growth and phase transition behavior, improving Curie temperature consistency and long-term cycling reliability. Simultaneously, multiple graphene PTC ceramic sheets covering at least a portion of the composite heating layer constitute a distributed array of heating units, achieving flexible coverage and adjustable power density of the heating area, and enhancing system fault tolerance through localized independent operation. This modular, high-density distribution matches the planar heat transfer requirements of the thermally conductive and temperature-equalizing layer, solving the shortcomings of traditional PTC point heating and large temperature differences.

[0040] In one embodiment of this application, such as Figure 4 As shown, adjacent graphene PTC ceramic sheets 310 can be connected in series via conductive connecting material, or in parallel via conductive connecting material, or some graphene PTC ceramic sheets 310 can be connected in series while others are connected in parallel. This allows for the construction of a flexible and controllable electrothermal network, balancing power regulation, electrical safety, and system redundancy. Series connection increases the overall impedance, making it suitable for high-voltage platforms, reducing operating current, and minimizing line loss and overheating risks. Parallel connection ensures that other units can continue to operate normally in the event of a partial failure, preventing a complete power outage and significantly improving reliability. The multi-mode connection structure enables the heating device to adapt to different voltage platforms and power requirements, achieving modular expansion while reducing the risk of systemic failure due to partial faults.

[0041] Preferably, the conductive connecting material is one or more of conductive paste, conductive adhesive, and metal wire. The selection of conductive paste, conductive adhesive, or metal wire as the conductive connecting material satisfies different process and performance requirements: conductive paste and conductive adhesive can achieve low-temperature curing and flexible bonding, adapting to the microstructure surface of ceramic sheets to form a stable, low-resistance path; metal wire carries high current, is suitable for main circuit connections, and improves power density.

[0042] Furthermore, the thermally conductive and temperature-equalizing layer 32 includes a metal substrate and a thermally conductive filler. The thermally conductive filler is at least one of graphene, carbon nanotubes, and graphite sheets, and the metal substrate is at least one of aluminum and aluminum alloys. The metal substrate is made of aluminum or aluminum alloys, which have the advantages of high thermal conductivity, good mechanical strength, and low cost, serving as a structural framework to support the entire heating layer. The thermally conductive filler is made of one or more of graphene, carbon nanotubes, or graphite sheets, which utilizes high thermal conductivity to significantly improve the lateral heat conduction rate and temperature uniformity, enabling heat to diffuse in-plane in a very short time and transforming a point heat source into a uniform surface heat source.

[0043] In this embodiment, the metal substrate has a microchannel structure with heat diffusion function, and the thermally conductive filler constructs a three-dimensional nano-thermal conductive network inside the metal substrate, which can quickly and uniformly conduct the heat generated by the graphene PTC ceramic sheet 310 to the entire surface of the heating body, thereby achieving uniform surface heating.

[0044] Furthermore, such as Figure 2 As shown, the multi-layer structure of the heating body 3 also includes a mounting base 33 and an insulating protective layer 34. One side of the mounting base 33 is bonded to the thermally conductive and temperature-equalizing layer 32, and the other side of the mounting base 33 is connected to the mounting base 1. The insulating protective layer 34 is disposed on the outer peripheral surface of the composite heating layer 31 and the thermally conductive and temperature-equalizing layer 32, and the insulating protective layer 34 is bonded to at least a portion of the outer peripheral surface of the composite heating layer 31 and the thermally conductive and temperature-equalizing layer 32. The insulating protective layer 34 is a high-temperature resistant insulating film with a thickness of 0.1mm to 0.3mm. The mounting base 33 is bonded to the thermally conductive and temperature-equalizing layer 32 and connected to the mounting base 1, undertaking the dual functions of structural support and heat conduction. It can work with the thermally conductive and temperature-equalizing layer 32 to efficiently transfer heat to the heat dissipation cavity 200, while ensuring that the device is firmly installed on the vehicle structure to avoid vibration and loosening. The insulating protective layer 34 covers the outer periphery of the composite heating layer 31 and the thermally conductive and temperature-equalizing layer 32, with a thickness limited to 0.1–0.3 mm. This satisfies electrical insulation requirements without increasing thermal resistance, preventing safety risks caused by leakage or short circuits under high-voltage conditions. The insulating protective layer 34 is made of a high-temperature resistant insulating film, which maintains stable performance over a wide temperature range and withstands long-term thermal cycling and environmental aging, ensuring long-term reliable operation of the device in harsh vehicle environments. This design clearly defines functional layers, avoiding the contradiction between insulation and heat dissipation in traditional integrated structures, and significantly improving system safety and durability.

[0045] In one embodiment of this application, the insulating protective layer 34 may be made of polyetherimide (PEI) or polyether ether ketone (PEEK) film, which has better temperature resistance; the mounting base layer 33 may be made of magnesium alloy to reduce weight, or a ceramic coating may be sprayed on the substrate surface to enhance insulation.

[0046] Furthermore, the graphene PTC heating device also includes a heat insulation layer 4 and a heat dissipation component 5. One side of the heat insulation layer 4 is connected to the mounting base 33; the heat dissipation component 5 includes multiple heat sinks 50, one end of which is connected to the other side of the heat insulation layer 4, and the other end of which is connected to the mounting base 1. The heat insulation layer 4 is attached to the side of the mounting base 33 facing away from the heating side, which can effectively block unnecessary heat loss to the mounting base 1 and the vehicle structure, and direct more heat energy to the target heating area (such as the cabin or battery pack), thereby improving the heating efficiency ratio and reducing the power battery energy consumption. The heat dissipation component 5 is composed of multiple heat sinks 50, one end of which is connected to the heat insulation layer 4, and the other end extends to the mounting base 1, forming a heat conduction channel, which quickly conducts the locally accumulated residual heat to the air area outside the mounting base, preventing material aging or temperature control instability caused by heat accumulation. This arrangement can achieve spatial separation of heat insulation and heat dissipation, improve the effective heat utilization rate, and ensure the thermal stability of the device during long-term operation.

[0047] Furthermore, such as Figure 1 , Figure 3 As shown, the graphene PTC heating device also includes a temperature control module 6, which includes a temperature sensor 61, a microcontroller 62, and a voltage regulation drive circuit 63. The temperature sensor 61 is connected to the thermally conductive heat exchange layer 32, and the detection end of the temperature sensor 61 is attached to the surface of the thermally conductive heat exchange layer 32. The signal input end of the microcontroller 62 is electrically connected to the output end of the temperature sensor 61. The voltage regulation drive circuit 63 is electrically connected to the output end of the microcontroller 62 and is also electrically connected to the composite heating layer 31. The voltage regulation drive circuit 63 is used to adjust the voltage of the composite heating layer 31. Temperature sensor 61 is attached to the surface of the heat-conducting and temperature-equalizing layer 32 to sense the average temperature of the heat distribution in real time, ensuring that the feedback signal accurately reflects the overall heating status and avoiding control deviations caused by localized temperature measurement. After receiving the temperature signal, the microcontroller 62 dynamically calculates the required output power based on the preset target temperature and drives the voltage regulating drive circuit 63 to apply a continuously adjustable voltage to the composite heating layer 31, replacing the traditional on / off control, controlling temperature fluctuations, and improving heating comfort and energy efficiency. The voltage regulating drive circuit 63 can directly control the heating power of the graphene PTC ceramic sheet 310 by adjusting the input voltage, achieving active regulation based on the PTC's self-limiting temperature, balancing energy efficiency and response speed. This configuration allows the device to utilize the inherent safety of PTC materials while overcoming its temperature lag limitation through electronic control, achieving intelligent constant temperature.

[0048] Furthermore, the graphene PTC heating device also includes a power supply module 7, which includes a high-voltage terminal, a protection circuit 71, and a voltage converter 72. The high-voltage terminal is electrically connected to an external power source. One end of the protection circuit 71 is connected to the high-voltage terminal, and the other end is connected to the voltage regulating drive circuit 63. The protection circuit 71 is used to control the power supply to the voltage regulating drive circuit 63. The voltage converter 72 is located between the protection circuit 71 and the high-voltage terminal. The voltage converter 72 is used to convert the high-voltage electricity on the high-voltage terminal into the low-voltage electricity required by the voltage regulating drive circuit 63. The high-voltage terminal is directly connected to the high-voltage DC bus of the power battery (e.g., 380V) to ensure high-power input. The voltage converter 72 steps down the high-voltage electricity to a low-voltage range (e.g., 12–48V) that the voltage regulating drive circuit 63 can withstand, which not only ensures the safety of the control circuit but also improves the energy conversion efficiency and avoids the energy waste caused by traditional resistor voltage reduction. The protection circuit 71 is connected in series between the high-voltage input and the voltage regulating drive, integrating overvoltage, overcurrent, and overtemperature protection mechanisms. When an abnormal operating condition is detected, it immediately cuts off the power supply to prevent thermal runaway or electrical damage caused by abnormal PTC temperature rise, short circuit, or battery fluctuations, significantly improving system safety. This configuration allows the device to seamlessly adapt to new energy vehicle models with different voltage platforms, improving the practicality of the heating device. Simultaneously, the protection circuit 71 is linked with the voltage regulating drive circuit 63, enabling the temperature control system to have proactive fault response capabilities, achieving an integrated safety closed loop of sensing, protection, and shutdown.

[0049] In one embodiment of this application, the voltage converter 72 may employ a DC-DC isolated module to improve the electrical isolation level, or use an LLC resonant topology to improve efficiency; the protection circuit 71 may integrate a smart fuse or a solid-state relay for faster response and longer lifespan.

[0050] Furthermore, such as Figure 1 , Figure 3As shown, the heating housing 2 has an air inlet 21 and an air outlet. The air inlet 21 is located at one end of the heating housing 2, and the air outlet is located at the other end. The air inlet 21 is connected to a cold air source. The graphene PTC heating device also includes a fan 8, which is located at the air outlet and is electrically connected to the microcontroller 62. The fan 8 is used to exhaust the warm air from the heat dissipation cavity 200. The air inlet 21 and the air outlet on the heating housing 2 form a through-type air duct structure. Together with the fan 8 located at the air outlet, an active thermal convection system can be constructed to achieve efficient and uniform heat transfer. Cold air is introduced into the heat dissipation cavity 200 through the air inlet 21, flows over the surface of the heating body 3 and is rapidly heated. Then, it is forcibly extracted by the fan 8 and directed to the target area (such as the cabin or battery pack), significantly improving the hot air output rate and distribution uniformity, overcoming the shortcomings of slow response and insufficient air volume in traditional natural convection heating. The fan 8 is electrically connected to the microcontroller 62, enabling intelligent linkage between airflow and heating capacity. When heating demand increases, the microcontroller 62 synchronously increases the fan 8 speed to enhance heat dissipation efficiency and prevent localized overheating. When the temperature stabilizes, the fan 8 operates at a reduced speed to decrease energy consumption and noise, achieving coordinated optimization of temperature and airflow control. This setup improves heating efficiency and, through airflow guidance, avoids localized discomfort caused by concentrated hot air blowing, enhancing passenger comfort.

[0051] According to another specific embodiment of this application, a vehicle is also provided, the vehicle having a graphene PTC heating device, the graphene PTC heating device being the graphene PTC heating device in the above embodiment.

[0052] This application also provides a preferred embodiment of a graphene PTC heating device. This embodiment takes a graphene PTC heating device for cabin heating in new energy passenger vehicles as an example. The rated heating power is 2000W and the working voltage is 380V, which is compatible with the high-voltage battery system of new energy passenger vehicles.

[0053] Specifically, the graphene PTC heating device includes a heating body 3, a temperature control module 6, a power supply module 7, and a heat dissipation duct structure (i.e., heating shell 2). The temperature control module 6 and the power supply module 7 are electrically connected to the heating body 3, and the heat dissipation duct structure covers the outside of the heating body 3. The heating body 3 is the core heating component of the device, with graphene PTC ceramic sheet 310 as the core, to achieve efficient surface heating. The temperature control module 6 realizes real-time detection and precise control of the heating temperature. The power supply module 7 is adapted to the high-voltage battery system of new energy vehicles, providing a stable working voltage for the device and having multiple protection functions. The heat dissipation duct structure realizes the rapid and uniform dissipation of heat from the heating body 3, and is adapted to the duct layout of new energy vehicle cabin heating or battery preheating.

[0054] The heating element 3 includes a composite heating layer 31 of graphene PTC ceramic sheets 310, a thermally conductive and heat-equalizing layer 32, an insulating protective layer 34, and a metal mounting base 33. The composite heating layer 31 is attached to the upper surface of the thermally conductive and heat-equalizing layer 32. The insulating protective layer 34 covers the periphery of the composite heating layer 31 and the thermally conductive and heat-equalizing layer 32. The metal mounting base 33 is fixed to the lower surface of the thermally conductive and heat-equalizing layer 32. The composite heating layer 31 consists of several arrayed graphene PTC ceramic sheets 310. Adjacent graphene PTC ceramic sheets 310 are connected in series / parallel via conductive silver paste. The number and connection method of the graphene PTC ceramic sheets can be flexibly adjusted according to the heating power requirements, achieving a modular design.

[0055] The graphene PTC ceramic sheet 310 is made of graphene powder, barium titanate-based ceramic powder, and lanthanide rare earth dopants through dry pressing and high-temperature sintering at 1200℃. The Curie temperature is 100℃, the room temperature resistivity is 50Ω·cm, and the heating rate can reach 8℃ / s. The thermally conductive heat spreader layer 32 is an aluminum microchannel heat spreader plate filled with graphene / aluminum composite thermally conductive material with a thermal conductivity of 250W / (m·K). The insulating protective layer 34 is a 0.2mm thick high-temperature resistant polyimide film with a temperature resistance range of -40℃ to 200℃. The metal mounting base layer 33 is made of 6061 aluminum alloy, with 15 evenly arranged heat sinks 50 on the lower surface. The base layer has 4 mounting holes to fit the housing of the cabin heater of new energy passenger vehicles.

[0056] The temperature control module 6 includes a microcontroller 62, a temperature sensor 61, a voltage regulating drive circuit 63, and an alarm unit. The detection end of the temperature sensor 61 is attached to the surface of the heat-conducting and heat-equalizing layer 32 to detect the heating temperature of the heating body 3 in real time. The output end is electrically connected to the signal input end of the microcontroller 62 to transmit the temperature signal to the microcontroller 62. The control output end of the microcontroller 62 is electrically connected to the voltage regulating drive circuit 63, which is electrically connected to the composite heating layer 31. Based on the received temperature signal, the microcontroller 62 adjusts the voltage input to the composite heating layer 31 through the voltage regulating drive circuit 63 to achieve continuous and precise temperature control, replacing the traditional on / off control and improving temperature control accuracy. The alarm unit is electrically connected to the signal output end of the microcontroller 62. When the heating device experiences over-temperature, over-current, or other faults, the microcontroller 62 triggers the alarm unit to provide fault warning.

[0057] In the temperature control module, the microcontroller is an STM32F103 series microcontroller; the voltage regulation drive circuit 63 uses a MOSFET voltage regulation circuit, which can achieve continuous voltage regulation from 0 to 380V; the alarm unit includes a buzzer and a red fault indicator light, both integrated into the passenger vehicle's center console control panel. When the device temperature exceeds 110℃ or overcurrent or overvoltage occurs, the microcontroller triggers the buzzer to sound continuously, and the fault indicator light stays on, making it easy for the driver to detect device malfunctions in a timely manner. The temperature sensor 61 is an NTC thermistor, with at least three sensors, evenly arranged along the length of the thermally conductive and temperature-equalizing layer 32, enabling multi-point temperature detection on the surface of the heating body 3, avoiding local overheating, and improving the accuracy of temperature detection, with a detection precision of ±0.5℃.

[0058] The power supply module 7 includes a high-voltage terminal, a voltage converter 72, and a protection circuit 71. The high-voltage terminal is electrically connected to the high-voltage battery pack of the new energy vehicle, introducing high-voltage DC power to the device. The voltage converter 72 is used to convert the high-voltage DC power into a working voltage that is compatible with the composite heating layer 31. It can adapt to different working voltages such as 24V / 48V / 380V to meet the electrical system requirements of different new energy vehicles. The protection circuit 71 includes an overvoltage protection unit, an overcurrent protection unit, and an overtemperature protection unit, all of which are linked to the voltage regulation drive circuit 63. When overvoltage, overcurrent, or overtemperature occurs, the protection circuit 71 immediately cuts off the power supply to the voltage regulation drive circuit 63, achieving dual protection for the heating body 3 and the power supply module 7, and improving the safety of the device.

[0059] When the device experiences faults such as overheating (exceeding 110℃), overvoltage, or overcurrent, the protection circuit 71 immediately cuts off the power supply. At the same time, the microcontroller 62 triggers the alarm unit, the buzzer sounds continuously, and the fault indicator light stays on, thus providing a fault warning. When a single graphene PTC ceramic sheet 310 fails, the remaining ceramic sheets can work normally, ensuring the device's basic heating function and improving its reliability.

[0060] In the power supply module 7, the high-voltage terminal adopts a high-voltage connector specifically for new energy vehicles, and the voltage converter 72 is a DC-DC converter that converts the 380V DC power of the high-voltage battery pack of the new energy passenger vehicle into the working voltage of the composite heating layer 31.

[0061] The heat dissipation duct structure includes an air inlet shroud and an air outlet shroud. The air inlet shroud is located at the air inlet 21 on the heating housing 2, and the air outlet shroud is located at the air outlet on the heating housing 2. A 50W centrifugal fan is also installed inside the air outlet shroud. The centrifugal fan is electrically connected to a microcontroller 62. The microcontroller 62 can adjust the speed of the centrifugal fan (500~2000r / min) according to the heating temperature to achieve matching between air volume and heating capacity, thereby improving heat dissipation efficiency. The air inlet shroud introduces cold air, which is heated by passing over the surface of the heating body 3 and then flows to the air outlet shroud. The guide ribs are made of ABS engineering plastic, and there are 8 of them. They are evenly distributed between the heating body and the air outlet shroud to achieve uniform delivery of hot air and avoid local discomfort caused by concentrated hot air blowing.

[0062] The heating device also includes a heat insulation layer 4, which is disposed between the lower surface of the metal mounting base 33 and the heat sink 50. It is an aerogel heat insulation material with a thickness of 0.5~1mm and a thermal conductivity of ≤0.02W / (m·K). It can effectively reduce the heat loss of the heating body 3 to the mounting base, improve the heat utilization efficiency, reduce energy consumption, and improve the heating energy efficiency ratio of the device by 15%~20%.

[0063] Tests showed that the heating device in this embodiment takes only 2 minutes to reach the set temperature (25°C) from startup, with a heating speed that is more than 60% faster than traditional PTC heating devices; the heating efficiency ratio is improved by 18%, and energy consumption is reduced by 18%; the heating uniformity is good, with the surface temperature fluctuation of the heating body ≤ ±1°C; it can start heating normally in a low temperature environment of -20°C, and can also preheat the power battery, improving the low-temperature charging and discharging performance of the power battery.

[0064] As can be seen from the above description, the graphene PTC heating device in the above embodiments has the following beneficial effects:

[0065] 1) The graphene PTC heating device uses graphene PTC ceramic sheet 310 as the core heating element. The addition of graphene significantly improves the heating efficiency and heating speed of the PTC element. The heating rate is ≥5℃ / s, which is more than 50% faster than the traditional PTC heating device. The time from start-up to reaching the set temperature is greatly shortened, improving the user experience.

[0066] 2) The graphene PTC heating device is equipped with an aluminum microchannel heat spreader and a heat-conducting heat spreader layer 32, which is filled with heat-conducting graphene composite material. This can quickly and evenly conduct heat to the entire surface of the heating body, achieving uniform surface heating. This solves the technical problems of point heating, local overheating, and uneven temperature in traditional PTC heating devices. The surface temperature fluctuation of the heating body is ≤±1℃.

[0067] 3) The temperature control module 6 of the graphene PTC heating device adopts multi-point temperature detection and single-chip microcomputer 62 voltage regulation drive to achieve continuous and precise control of heating temperature. The temperature control accuracy can reach ±1℃, which replaces the traditional on-off control, which not only improves heating comfort, but also avoids energy waste caused by frequent on-off.

[0068] 4) The graphene PTC heating device is equipped with an aerogel heat insulation layer 4, which can effectively reduce the heat loss of the heating body 3, improve the heating energy efficiency ratio by 15%~20%, reduce energy consumption by 15%~20%, reduce the power consumption of the power battery, and extend the driving range of new energy vehicles.

[0069] 5) The graphene PTC heating device has multiple protection functions such as overvoltage, overcurrent and overtemperature, and each graphene PTC ceramic sheet 310 is an independent heating unit. When some units fail, the remaining units can work normally, avoiding the failure of the whole device and improving the safety and reliability of the device.

[0070] 6) The graphene PTC heating device has a compact structure and standardized mounting holes on the metal mounting base 33. It can directly replace the existing traditional PTC heating device without making major modifications to the original installation structure of new energy vehicles. It has strong installation adaptability and can be widely used in cabin heating and battery preheating scenarios of new energy passenger vehicles and commercial vehicles, and has good engineering application scenarios.

[0071] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0072] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0073] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A graphene PTC heating device, characterized in that, include: Mounting base (1), which is connected to the mounting foundation; Heating housing (2), the heating housing (2) is connected to the mounting base (1), and the heating housing (2) has a heat dissipation cavity (200). Heating body (3), the heating body (3) is connected to the mounting base (1), the heating body (3) is disposed in the heat dissipation cavity (200), the heating body (3) is a multi-layer structure, the multi-layer structure includes at least one composite heating layer (31) and at least one thermally conductive and temperature-equalizing layer (32), one side of the composite heating layer (31) is attached to the thermally conductive and temperature-equalizing layer (32); The composite heating layer (31) includes multiple graphene PTC ceramic sheets (310).

2. The graphene PTC heating device according to claim 1, characterized in that, The graphene PTC ceramic sheet (310) is made by sequentially pressing graphene powder, barium titanate-based ceramic powder, and rare earth dopants into shape and sintering at high temperature. Multiple graphene PTC ceramic sheets (310) cover at least part of the surface of the composite heating layer (31).

3. The graphene PTC heating device according to claim 2, characterized in that, The adjacent graphene PTC ceramic sheets (310) are connected in series by a conductive connecting material, and / or the adjacent graphene PTC ceramic sheets (310) are connected in parallel by the conductive connecting material, wherein the conductive connecting material is one or more of conductive paste, conductive adhesive, and metal wire.

4. The graphene PTC heating device according to claim 1, characterized in that, The thermally conductive and temperature-equalizing layer (32) includes a metal substrate and a thermally conductive filler, wherein the thermally conductive filler is at least one of graphene, carbon nanotubes, and graphite sheets, and the metal substrate is at least one of aluminum and aluminum alloys.

5. The graphene PTC heating device according to any one of claims 1-4, characterized in that, The multi-layer structure of the heating body (3) further includes: The mounting base (33) has one side attached to the heat-conducting and temperature-equalizing layer (32) and the other side attached to the mounting base (1). An insulating protective layer (34) is disposed on the outer peripheral surface of the composite heating layer (31) and the thermally conductive and temperature-equalizing layer (32), and the insulating protective layer (34) is bonded to at least a portion of the outer peripheral surface of the composite heating layer (31) and the thermally conductive and temperature-equalizing layer (32). The insulating protective layer (34) is a high-temperature resistant insulating film, and the thickness of the insulating protective layer (34) is 0.1mm~0.3mm.

6. The graphene PTC heating device according to claim 5, characterized in that, The graphene PTC heating device also includes: A heat insulation layer (4) is provided, one side of which is connected to the mounting base layer (33); Heat sink (5), the heat sink (5) includes a plurality of heat sinks (50), one end of the plurality of heat sinks (50) is connected to the other side of the heat insulation layer (4), and the other end of the plurality of heat sinks (50) is connected to the mounting base (1).

7. The graphene PTC heating device according to claim 6, characterized in that, The graphene PTC heating device further includes a temperature control module (6), which includes: Temperature sensor (61), the temperature sensor (61) is connected to the thermally conductive heat-dissipating layer (32), and the detection end of the temperature sensor (61) is attached to the surface of the thermally conductive heat-dissipating layer (32). A microcontroller (62) is provided, wherein the signal input terminal of the microcontroller (62) is electrically connected to the output terminal of the temperature sensor (61); A voltage regulating drive circuit (63) is electrically connected to the output terminal of the microcontroller (62) and electrically connected to the composite heating layer (31). The voltage regulating drive circuit (63) is used to regulate the voltage of the composite heating layer (31).

8. The graphene PTC heating device according to claim 7, characterized in that, The graphene PTC heating device further includes a power supply module (7), which includes: A high-voltage terminal is electrically connected to an external power source. Protection circuit (71), one end of which is connected to the high voltage terminal, and the other end of which is connected to the voltage regulating drive circuit (63). The protection circuit (71) is used to control and protect the power supply of the voltage regulating drive circuit (63). A voltage converter (72) is disposed between the protection circuit (71) and the high voltage terminal. The voltage converter (72) is used to convert the high voltage on the high voltage terminal into the low voltage required by the voltage regulating drive circuit (63).

9. The graphene PTC heating device according to claim 8, characterized in that, The heating housing (2) is provided with an air inlet (21) and an air outlet. The air inlet (21) is located at one end of the heating housing (2), and the air outlet is located at the other end of the heating housing (2). The air inlet (21) is connected to a cold air source. The graphene PTC heating device also includes a fan (8). The fan (8) is located at the air outlet. The fan (8) is electrically connected to the microcontroller (62). The fan (8) is used to exhaust the warm air in the heat dissipation cavity (200).

10. A vehicle, characterized in that, The vehicle has a graphene PTC heating device, which is the graphene PTC heating device according to any one of claims 1-9.

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