WO2014000666A1

WO2014000666A1 - Ptc electric heating assembly, electric heating device and electric vehicle

Info

Publication number: WO2014000666A1
Application number: PCT/CN2013/078193
Authority: WO
Inventors: Qing Gong; Xinping Lin; Maolin REN; Xiaofang Li; Mengxiang WU; Shumin Wang; Tianyou DENG; Hongmei QIU
Original assignee: Shenzhen Byd Auto R&D Company Limited; Byd Company Limited
Priority date: 2012-06-27
Filing date: 2013-06-27
Publication date: 2014-01-03

Abstract

A PTC electric heating assembly, an electric heating device and an electric vehicle are provided. The PTC electric heating assembly (2) comprises a first electrode assembly including a first fixed electrode; a second electrode assembly including a second fixed electrode; a PTC heating module (20) disposed between the first electrode assembly and the second electrode assembly; and an insulating layer (23) disposed on an outer surface of each of the first electrode assembly and the second electrode assembly; wherein an inner surface of at least one of the first fixed electrode and the second fixed electrode facing to the PTC heating module (20) is a vertical surface, an outer surface of the at least one of the first fixed electrode and the second fixed electrode facing to the insulating layer (23) is an inclined surface.

Description

PTC ELECTRIC HEATING ASSEMBLY, ELECTRIC HEATING DEVICE AND

ELECTRIC VEHICLE

FIELD

The present disclosure relates to a PTC electric heating assembly, an electric heating device having the PTC electric heating assembly and an electric vehicle having the electric heating device.

BACKGROUND ART

Air-conditioning and heating system of a conventional fuel vehicle generally uses the waste heat of flue gas or circulating cooling water of the engine as a heating source. However, for a hybrid electric vehicle or a pure electric vehicle, there is no sufficient waste heat for heating of the interior of the vehicle. Furthermore, under a condition of extremely low temperature, the heat source is also used to defrost and defog. Thus, an auxiliary electric heating device is needed.

Therefore, an electric heating device using a PTC (Positive Temperature Coefficient) heating assembly is proposed. The electric heating device has a casing and at least one PTC heating assembly disposed inside the casing. However, the conventional electric heating device has a lower thermal efficiency and structure of the conventional electric heating device is complicated structure which is difficult to fix.

SUMMARY

Embodiments of the present disclosure seek to solve at least one of the problems existing in the prior art to at least some extent.

According to embodiments of a first broad aspect of the present disclosure, there is provided a PTC electric heating assembly comprising a first electrode assembly including a first fixed electrode; a second electrode assembly including a second fixed electrode; a PTC heating module disposed between the first electrode assembly and the second electrode assembly; and an insulating layer disposed on an outer surface of each of the first electrode assembly and the second electrode assembly; wherein an inner surface of at least one of the first fixed electrode and the second fixed electrode facing to the PTC heating module is a vertical surface, an outer surface of the at least one of the first fixed electrode and the second fixed electrode facing to the insulating layer is an inclined surface inclined inwardly from top to bottom.

According to embodiments of a second broad aspect of the present disclosure, there is provided an electric heating device, comprising a casing defining a plurality of thermal conductive grooves of which at least one side surface is inclined and a medium circulating cavity hermetically isolated from the thermal conductive grooves, the medium circulating cavity defining a medium inlet and a medium outlet; and a plurality of PTC electric heating assemblies mounted into the thermal conductive grooves respectively, each PTC electric heating assembly is according to the first aspect of the present disclosure.

According to embodiments of a third broad aspect of the present disclosure, there is provided an electric vehicle, employing an air conditioning system, the air conditioning system includes the electric heating device according to the second aspect of the present disclosure.

With the PTC electric heating assembly and the electric heating device according to embodiments of the present disclosure, at least one side surface of the thermal conductive grooves is inclined, the PTC electric heating assemblies is mounted into the thermal conductive grooves. Therefore the PTC electric heating assemblies may be stably positioned in the thermal conductive grooves without other fixed part. The heat generated by the PTC electric heating assembly could be transmitted to the medium in the medium circulating cavity directly via the thermal conductive grooves, the thermal losses may be reduced, and therefore, the heating effect of the electric heating device may be efficient increased. Thus the electric heating device may be better for heating of the interior of the vehicle, defrosting, defogging and heating other component.

BRIEF DESCRIPTION OF EACH FIGURE OF THE DRAWING

Fig.l is a perspective view of an electric heating device according to an embodiment of the present disclosure;

Fig.2 is a partially exploded view of the electric heating device according to an embodiment of the present disclosure;

Fig.3 is an exploded view of the electric heating device according to an embodiment of the present disclosure;

Fig.4 is a sectional view of a casing and a PTC electric heating assembly according to an embodiment of the present disclosure;

Fig.5 is a sectional view of the PTC electric heating assembly in Fig.4;

Fig.6 is a partial sectional view of the PTC electric heating assembly mounted into a thermal conductive groove of the casing in Fig.5;

Fig.7 is an exploded view of a PTC electric heating assembly in Fig.5;

Fig.8 is a schematic view of a PTC heating module in Fig.5;

Fig.9 is a schematic view of an insulation fixing frame of the PTC heating module in Fig. 8; Fig.10 is a schematic view of a casing of the electric heating device according to an embodiment of the present disclosure;

Fig. 11 is an exploded view of a thermal conductive trough and a shell body according to an embodiment of the present disclosure;

Fig.12 is an exploded view of the casing of the electric heating device according to an embodiment of the present disclosure; and

Fig.13 is a top view of the casing of the electric heating device according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present disclosure.

In the specification, Unless specified or limited otherwise, relative terms such as "central", "longitudinal", "lateral", "front", "rear", "right", "left", "inner", "outer", "lower", "upper", "horizontal", "vertical", "above", "below", "up", "top", "bottom" as well as derivative thereof (e.g., "horizontally", "downwardly", "upwardly", etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the present disclosure be constructed or operated in a particular orientation.

In addition, terms such as "first" and "second" are used herein for purposes of description and are not intended to indicate or imply relative importance or significance. Thus, characteristics defined by the terms "first" and "second" may indicatively or impliedly comprise one or plurality of the characteristics. In the description of the present disclosure, term "plurality of means two or more than two, unless there is another certain definition.

Unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

As shown in Fig.l to Fig.3, an electric heating device according to an embodiment of the present disclosure comprises: a casing 1, a plurality of PTC electric heating assemblies 2 mounted in the casing 1 and a circuit control module 3 mounted above the casing 1.

The casing 1 comprises: a heating chamber 11 configured to accommodate the PTC electric heating assemblies 2, a medium circulating cavity 12 configured for containing the medium and allowing the medium circulating therein, a medium inlet 13 communicated with the medium circulating cavity 12 and configured for feeding the medium into the medium circulating cavity 12 and a medium outlet 14 configured for discharging the medium out of the medium circulating cavity 12. The heating chamber 11 comprises a plurality of thermal conductive grooves 160, the PTC electric heating assemblies 2 are mounted into the thermal conductive grooves 160. The medium circulating cavity 12 is hermetically isolated from the thermal conductive grooves 160. The circuit control module 3 is mounted above the casing 1 and connected to the PTC electric heating assemblies 2. The circuit control module 3 comprises an electronic component (for example. IGBT module) configured to control the electric heating device.

In some embodiments of the present disclosure, the electric heating device further comprises an upper cover 5 defining a control cavity; the circuit control module 3 is disposed in the control cavity. The circuit control module 3 comprises a control panel configured for mounting the electronic component (for example: IGBT module). The electronic component is the key part of the circuit control module 3, of which lower temperature safer. In embodiments of the present disclosure, the circuit control module 3 may be any common circuit control module in the art, the control panel, the electronic component and the circuit control part may be performed by the technologies in the art.

In some embodiments of the present disclosure, the electric heating device further comprises a heat-insulation module 4 disposed on the casing 1 and located between the PTC electric heating assemblies 2 and the circuit control module 3. The heat-insulation module 4 comprises a thermal conductive rubber plate 41, a heat-insulation foam plate 43 disposed above the thermal conductive rubber plate 41, and a heat- insulation rubber plate 42 disposed between the thermal conductive rubber plate 41 and the heat- insulation foam plate 43.

With the heat-insulation module 4 located between the PTC electric heating assemblies 2 and the circuit control module 3, an internal environmental temperature of the electric heating device may be reduced dramatically, and the working environmental temperature may be about 60 °C which is lower than the normal working temperature (about 80 °C) of the electronic component, therefore the circuit control module 3 may be protected effectively.

The mainly improvement of the present disclosure will be described in details below.

1. PTC electric heating assembly

According to the present disclosure, one mainly improvement of the PTC electric heating assembly may be that the PTC electric heating assembly has a different structure from conventional PTC electric heating assembly, the PTC electric heating assembly according to the present disclosure may be stably positioned in the thermal conductive grooves 160 without other pressure elements.

As shown in Fig.4 to Fig.9, a PTC electric heating assembly 2 according to an embodiment of the present disclosure comprises: a first electrode assembly, a second electrode assembly, a PTC heating module 20 disposed between the first electrode assembly and the second electrode assembly, and an insulating layer 23 disposed on an outer surface of each of the first electrode assembly and the second electrode assembly.

The PTC heating module 20 includes at least one PTC heating elements 27. Each of the first electrode assembly and the second electrode assembly includes a contact electrode 21 contacted to the PTC heating module 20 and a fixed electrode 22 disposed between the contact electrode 21 and the insulating layer 23. An inner surface of the fixed electrode 22 of at least one of the first electrode assembly and the second electrode assembly facing to the PTC heating module 20 is a vertical surface, an outer surface of the fixed electrode 22 of at least one of the first electrode assembly and the second electrode assembly facing to the insulating layer 23 is an inclined surface inclined inwardly from top to bottom.

In some embodiments of the present disclosure, the inner surface of the fixed electrode 22 of both the first electrode assembly and the second electrode assembly facing to the PTC heating module 20 is the vertical surface, an outer surface of the fixed electrode 22 of both the first electrode assembly and the second electrode assembly facing to the insulating layer 23 is the inclined surface inclined inwardly from top to bottom.

In the present disclosure, the PTC electric heating assembly 2 may not adopt any pressure element, instead, the inner surface of the fixed electrode 22 of at least one of the first electrode assembly and the second electrode assembly facing to the PTC heating module 20 is the vertical surface, an outer surface of the fixed electrode 22 of at least one of the first electrode assembly and the second electrode assembly facing to the insulating layer 23 is the inclined surface inclined inwardly from top to bottom, therefore the fixed electrode 22 may be work as a pressure element, thus the space can be saved, the mass can be reduced, and also the fixed electrode 22 can be served as a fixed element.

Especially, the heat generated by the PTC electric heating assembly 2 can be transmitted to the medium in the medium circulating cavity directly via the thermal conductive grooves 160 without through an extra pressure element, thus the thermal losses may be reduced.

In some embodiments of the present disclosure, two side surfaces of the thermal conductive grooves 160 are inclined, correspondingly, the fixed electrodes 22 of the first electrode assembly and the second electrode assembly are inclined inwardly so as to adapt to the inclined side surface of the thermal conductive grooves 160. Therefore the PTC electric heating assembly 2 may be embedded in the thermal conductive grooves 160 conveniently, and a desire contact between the PTC electric heating assemblies 2 and the thermal conductive grooves 160 may be formed by a press force applied to the PTC electric heating assembly 2 by the side surface of the thermal conductive grooves 160 during mounting of the PTC electric heating assembly 2.

In addition, the PTC electric heating assembly 2 is embedded in the thermal conductive grooves 160 is deeper, the press force applied to the PTC electric heating assembly 2 is larger, and it is more difficult to take out the PTC electric heating assembly.

The PTC electric heating assemblies 2 are embedded in the thermal conductive grooves 160 respectively, so that the heat generated by the PTC electric heating assemblies 2 may be conducted to the walls of thermal conductive grooves 160. In this case, the walls of thermal conductive grooves 160 not only isolate the medium from the PTC electric heating assemblies 2, but also conduct the heat. The walls of thermal conductive grooves 160 may be made of a metal having a good conducting performance, such as aluminum or aluminum alloy.

In embodiments of the present disclosure, at least one side surface of the thermal conductive grooves 160 is inclined inwardly in the up and down direction, it is of benefit for demolding and manufacturing the PTC electric heating assemblies 2 to form a favorable contact between the PTC electric heating assemblies 2 and the thermal conductive grooves 160.

A person skilled in the art will appreciate that one side surface of each of the thermal conductive grooves 160 may be the vertical surface, and the other side surface thereof may be an inclined surface inclined inwardly from top to bottom. Alternatively, both side surfaces of each of the thermal conductive grooves 160 may be the inclined surface inclined inwardly from top to bottom.

As shown in Fig.5 to Fig.7, specifically, the fixed electrode 22 may be served as a pressure element when connected to a power, the fixed electrode 22 is inclined inwardly so as to adapt to the inclined side surface of the thermal conductive grooves 160.

Therefore the PTC electric heating assembly 2 may be embedded in the thermal conductive grooves 160 conveniently, and a desire contact between the PTC electric heating assemblies 2 and the thermal conductive grooves 160 may be formed by a press force applied to the PTC electric heating assembly 2 by the side surface of the thermal conductive grooves 160 during mounting of the PTC electric heating assembly 2. The fixed electrode 22 is made of conductive material; preferably, the fixed electrode 22 is made of metal having a large hardness, such as Al, Au, stainless steel or aluminum alloy.

The fixed electrode 22 comprises a terminal 221 extended from an upper end of the fixed electrode 22 and configured for coupling to a power supply. The terminal 221 can be fixed on the fixed electrode 22 by a welding or riveting. The terminal 221 is configured to electrically connect to the circuit control module 3. In order to ensure the proper contact between the PTC heating module 20 and the fixed electrode 22, the area of the side surface of the fixed electrode 22 is larger than or equal to that of the PTC heating module 20.

In some embodiments of the present disclosure, the area of the side surface of the fixed electrode 22 is larger than that of the PTC heating module 20, so that the fixed electrode 22 extend upwardly and/or downwardly beyond the PTC heating module 20 so as to form extending portions. A heat conducting sealing glue is filled between the extending portions of the two fixed electrodes so as to insulate the two fixed electrodes 22 and avoid a short circuit therebetween; the heat conducting sealing glue is made of organosilicone sealant, polyurethane sealant or epoxy resin sealant.

In addition, as shown in Fig.5 to Fig.7, it is known that an electric conductivity between the PTC heating elements of the PTC electric heating assembly 2 and electrode plate (fixed electrode) as well as the value of the contact resistance has a great influence on the voltage resistance performance of the PTC heating module 20, especially on the safety and the reliability of the PTC heating module 20 under a long time and a high voltage operation condition.

In the related art, the PTC heating elements of the PTC electric heating assembly 2 and electrode plate of the conventional electric heating assembly are contacted directly and rigidly, so that an interfacial gap is formed therebetween. There may be manufacturing tolerance when manufacturing PTC heating elements, therefore, when the PTC heating elements have a different thickness, an incomplete contact will occur between some of the PTC heating elements and electrode when arranging plurality of PTC heating elements on a electrode plate.

Under the high voltage condition, this contacting manner can easily cause the PTC heating elements broken down due to the arc discharge, thus resulting in the short circuit. Therefore, in embodiments of the present disclosure, a contact electrode 21 is disposed between the PTC heating module 20 and the fixed electrode 22.

The contact electrode 21 is made of electrically and thermally conductive material which is compressible elastically deformable, therefore an elastic compression deformation of the contact electrode 21 may occur so as to make up the thickness tolerance of the PTC heating elements to make sure that the contact between the PTC heating elements and the two electrode assemblies is favorable.

The contact electrode 21 is made of electrically and thermally conductive material which is compressible elastically deformable, such as electric conducting polymer (for example, electric conducting polymer, stannum, stannum alloy, copper, copper alloy or electric conducting graphite), metal and alloy (for example, stannum, stannum alloy, copper, copper alloy or electric conducting graphite.

In other words, an electrically and thermally conductive material which is compressible elastically deformable can be used for preparing the contact electrode 21.

Comparing with the conventional direct contact between the rigid PTC heating elements 21 and the electrode plates 23, it may reduce the contact resistance and not affect the heat conduction at the interface by disposing the contact electrode 21 between the PTC heating module 20 and the fixed electrode 22.

Thus, the heat generated by the PTC heating elements can be conducted to the fixed electrode 22 fully, and the PTC heating elements can be used safely for a long time under the high voltage condition. A person skilled in the art will appreciate that the electrode assembly which comprises a contact electrode is suited to high voltage condition. When the voltage is lower than 400 Volts, the electrode assembly could comprise a fixed electrode without a contact electrode.

As shown in Fig.5 to Fig.7, the PTC electric heating assembly further comprises an insulating layer 23 disposed on the outer surface of each of the fixed electrode 22, the insulating layer 23 has a U-shape section so as to cover the outer surface and the bottom surface of the fixed electrode 22, thus the fixed electrode 22 are insulated from the thermal conductive grooves 160.

The insulating layer 23 is an electrical-insulation and thermal conductive film and made of a material with an electrical insulatibity and a high thermal conductivity, so as to reduce the heat loss. For example, the insulating layer 23 may be made of an organic silicon rubber, a butadiene- acrylonitrile rubber or a ceramic insulating material.

A person skilled in the art will appreciate that the electrode plate should be insulated from the thermal conductive grooves 160.

In some embodiment of the present disclosure, an insulating layer 23 is disposed between the fixed electrode and the thermal conductive grooves 160.

However, when the PTC electric heating assemblies is inserted into the thermal conductive grooves 160, a shear force is applied to the insulating layer 23, which may bring damage to the insulating layer 23. Therefore, in one embodiment of the present disclosure, the PTC electric heating assemblies 2 further comprises a slid film 24 covered on an outer surface of the insulating layer 23. The slid film 24 may be made of materials which have high strength and a smooth surface, such as organic polymer film or metal film.

In some embodiment, the slid film includes polyimide film or copper foil film. With the slid film 24 covered on the outer surface of the insulating layer 23, the insulating layer 23 may be protected effectively from being destroyed.

As well known, As the PTC electric heating assembly 2 includes a plurality of the PTC heating elements, the plurality of the PTC heating elements are difficultly fixed due to different thicknesses or improper arranging positions of the PTC heating elements. Furthermore, because the PTC heating element is very sensitive to the temperature and the heating effects of the plurality of the PTC heating elements are not identical, the plurality of the PTC heating elements may contact each other during heating, thus causing that the plurality of the PTC heating elements can not give full play to their heating performance.

In addition, when used in the electric vehicle, the PTC heating element subjects to a high voltage, so that a distance between the two electrode plates is increased in order to avoid arc discharge occurred between the two electrode plates, thus the requirement of the distance between the two electrode plates is strict. However, increasing the distance between the two electrode plates may increase the volume and the occupied space of the PTC heating element.

Therefore, another mainly improvement of the present disclosure may be that the PTC heating module 20 comprises an insulation fixing frame 26 and a plurality of PTC heating elements 27. The insulation fixing frame 26 has a plurality of fixing units 260, and the plurality of PTC heating elements 27 is fixed in the plurality of fixing units 260. The insulation fixing frame 26 is used to fix the plurality of the PTC heating elements 27 therein and isolate the adjacent PTC heating elements 27 from each other.

Thus, the PTC heating elements 27 can be fixed stably, the interference with each other during operation can be reduced, and the PTC heating elements 27 can give full play to the heating performance thereof.

As shown in Fig.7 to Fig.9, specifically, the PTC heating module 20 is the heating element of the PTC electric heating assembly 2. The PTC heating module 20 includes at least two PTC heating elements 27.

In some embodiments, the PTC heating module 20 includes six PTC heating elements 27. The PTC heating elements 27 may be any common PTC heating elements used in the art, in some embodiments of the present disclosure, the PTC heating elements 27 is ceramic PTC heating pieces, and conductive electrodes (not shown) are disposed on opposite side surfaces of the ceramic PTC heating pieces by spraying or printing, and the conductive electrodes may be silver electrodes.

In the present disclosure, the number of the PTC heating elements 27 is not limited and adjustable according to the heating requirements.

In some embodiment of the present disclosure, the PTC electric heating assembly 2 further comprises an insulation fixing frame 26. The heating module 20 comprises the insulation fixing frame 26 and the PTC heating elements 27 disposed in the insulation fixing frame 26, and the heating module 20 is disposed between the first electrode assembly and the second electrode assembly, therefore the PTC heating elements 27 can be fixed properly.

As shown in Fig.7 to Fig.9, in some embodiments, the insulating fixing frame 26 comprises a plurality of first isolating bars 261 and a plurality of second insolating bars 262. The first isolating bars 261 are parallel to and spaced apart from one another, and the second insolating bars 262 are parallel to and spaced apart from one another. Each of the second insolating bars 262 is perpendicular to and intersected with the plurality of the first insolating bars 261 so as to form a plurality of fixing units 260.

As shown in Fig.9, in one embodiment of the present disclosure, the insulating fixing frame

26 comprises two first insolating bars 261 and three second insolating bars 262. The two first isolating bars 261 are parallel to and spaced from each other by a first predetermined interval, and the three second insolating bars 262 are parallel to and spaced from one another by a second predetermined interval.

Each of the first insolating bars 261 is perpendicular to and intersected with the second insolating bars 262 so as to form six fixing units 260, thus providing six mounting positions for six PTC heating elements 27. A person skilled in the art will appreciate that the number of the fixing units 260 can be determined by the number of the PTC heating elements 27, then the number of the first isolating bars 261 and the second insolating bars 262 are further determined. A person skilled in the art will appreciate that the insulation fixing frame 26 is not limited to the structure and configuration shown in Fig. 9.

In some embodiment of the present disclosure, the two first insolating bars 261 are disposed along a width direction of the PTC heating elements 27, and a distance between the two first insolating bars 261 is equal to a length of the PTC heating elements 27 (a size of the PTC heating element 27 in a length direction thereof), so that the PTC heating element 27 is positioned in the length direction efficiently.

The three second insolating bars 262 are disposed along the length direction C of the PTC heating elements 27, and a distance between the two second insolating bars 262 is equal to a width of the PTC heating elements 27 (a size of the PTC heating element 27 in the width direction thereof), so that the PTC heating element 27 is positioned in the width direction efficiently.

Furthermore, as shown in Fig. 9, in the length direction, the adjacent PTC heating elements 27 are spaced apart from each other by the first insolating bars 261, and in the width direction, the adjacent PTC heating elements 27 are spaced apart from each other by the second insolating bars 262. The adjacent PTC heating elements 27 are spaced apart from each other by the first isolating bars 261 and/or the second insolating bars 262, thus reducing the mutual influence of the PTC heating elements 27 during the operation, so that the PTC heating elements 27 can be improved in heating power thereof and give full play to the heating performance thereof.

As shown in Fig.5 to Fig.8, in some embodiments of the present disclosure, the insulation fixing frame 26 is disposed between the two fixed electrode 22 and may be adhered to the two fixed electrode 22 by an adhesive, so that a thickness of the insulation fixing frame 26 is substantially equal to that of the PTC heating elements 27, so that the insulation fixing frame 26 is fixed between the fixed electrode 22 reliably, thus fixing the PTC heating elements 27 therein reliably, without affecting proper contacts between the PCT heating elements 27 and the contact electrode 21 (or fixed electrode 22).

Thus, the PTC heating elements 27 are isolated and positioned in the length direction and the width direction by the insulation fixing frame 26, and are clamped and held between the two contact electrodes 21 in the thickness direction, so that the PTC heating elements 27 can be efficiently positioned. Conventionally, a person skilled in the art will appreciate that, when the PTC electric heating assembly 2 is used under a high voltage condition, in order to avoid the arc discharge occurred between the first electrode assembly and the second electrode assembly and meet the safe standard, the requirements for the distance between the first electrode assembly and the second electrode assembly are strict. Consequently, the volume of the PTC electric heating assembly 2 is increased.

In the present disclosure, the insulation fixing frame 26 is made of a material having a high temperature resistance and a high voltage resistance, so that a high voltage resistance between the first electrode assembly and the second electrode assembly is improved, a possibility of the arc discharge occurred between the first electrode assembly and the second electrode assembly is reduced and the PTC heating elements 27 are prevented from being broken down.

In some examples, advantageously, the insulation fixing frame 26 having the high voltage resistance and high temperature resistance is made of an organic polymer, such as organic silicon or polyimide, with a thermal conductivity between 0.02W/(m^»K) and 5.0W/(m^»K). The insulation fixing frame 26 may be manufactured by a process of injection molding. With the insulation fixing frame 26, an insulating performance between the first electrode assembly and the second electrode assembly is efficiently increased, so that the PTC electric heating assembly 2 can be adapted to a high voltage condition, and the safety and adaptability thereof are improved.

According to the present disclosure, an electric heating device is provided. The electric heating device comprises a casing 1 defining a plurality of thermal conductive grooves 160 and a medium circulating cavity 12 hermetically isolated from the thermal conductive grooves 160, and a plurality of PTC electric heating assemblies 2. The medium circulating cavity 12 comprises a medium inlet 13 and a medium outlet 14. The PTC electric heating assemblies 2 may be the PTC electric heating assemblies 2 described with reference to the above embodiments.

In some embodiments of the present disclosure, two side surfaces of the thermal conductive grooves 160 are inclined so that the PTC electric heating assemblies 2 can be mounted into the thermal conductive grooves 160 properly. As described above, the PTC electric heating assemblies 2 are embedded in the thermal conductive grooves 160 respectively, so that the heat generated by the PTC electric heating assemblies 2 may be conducted to the walls of thermal conductive grooves 160. In this case, the walls of thermal conductive grooves 160 not only isolate the medium from the PTC electric heating assemblies 2, but also conduct the heat. The walls of thermal conductive grooves 160 may be made of a metal having a good conducting performance, such as aluminum or aluminum alloy.

During manufacturing and assembling the PTC electric heating assemblies 2, firstly the insulation fixing frame 26 is disposed onto the contact electrode 24 of the first electrode assembly, then the PCT heating elements 27 are disposed into the fixing units 260 of the insulation fixing frame 22 respectively. Next, the second electrode assembly is disposed on the other side of the insulation fixing frame 26. The heat conducting sealing glue is filled between edges the two electrode assemblies. Then the insulating layer 23 is disposed on the outer surfaces and the bottom surfaces of the two fixed electrode 22, finally, a slid film 24 is covered on the outer surfaces of the insulating layer 23 so as to form the PTC electric heating assemblies 2.

The assembled PTC electric heating assemblies 2 are embedded into the thermal conductive grooves 160 respectively. In practice, the medium is fed into the medium circulating cavity 12 through the medium inlet 13 of the casing 1, then the PTC electric heating assemblies 2 are energized, the PTC heating elements 21 start heating. The heat is conducted to the medium via the electrode plates, insulating layer 23 and the walls of the thermal conductive grooves 160. The medium flows out of the medium circulating cavity 12 through the medium outlet 14 of the casing 1 for heating, defrosting, defogging the interior of a vehicle and preheating battery of the vehicle.

As mentioned above, the inner surface of the first fixed electrode facing to the PTC heating module is the vertical surface; the outer surface of the fixed electrode facing to the insulating layer is the inclined surface inclined inwardly from top to bottom. And also, two side surfaces of the thermal conductive grooves are inclined. The PTC electric heating assemblies are mounted into the thermal conductive grooves.

Therefore the PTC electric heating assemblies may be stably positioned in the thermal conductive grooves without other fixed part (pressure element). The heat generated by the PTC electric heating assembly can be transmitted to the medium in the medium circulating cavity directly via the thermal conductive grooves, the thermal losses may be reduced, the mounting space of the PTC electric heating assemblies can be saved, and the mass can be reduced. Therefore, the heating effect of the electric heating device may be efficient increased. Thus the electric heating device may be better for supplying heating, defrosting, defogging and heating other component.

In addition, the electrode assembly of the PTC electric heating assembly of the electric heating device further comprises a contact electrode disposed between the fixed electrode and the PCT heating elements, comparing with the conventional direct contact between the rigid PTC heating elements and the fixed electrode, the contact resistance may be reduced and the heat conduction at the interface may not be affected. Thus, the heat generated by the PTC heating elements can be conducted to the fixed electrode fully, and the PTC heating elements can be used safely for a long time under the high voltage condition.

Moreover, the PTC electric heating assembly according to the present disclosure further comprises the slid film covered on the outer surface of the insulating layer, thus the insulating layer may be protected well.

The fixing units are formed in the electric heating assembly by the insulation fixing frame, and the PTC heating elements are fixed in the fixing units in one to one correspondence relationship so as to ensure the stability of the PTC heating elements. Furthermore, the PTC heating elements are also isolated from one another by means of the insulation fixing frame, so that the interference among the PTC heating elements can be reduced during operation, give full play to the heating performance thereof, and improve the heating power and the heating effect thereof.

Correspondingly, the heating power and the heating efficiency of the electric heating device are improved efficiently, and the heating device can provide heat for heating, defrosting, defogging and heating other component of the electric vehicle.

The insulation fixing frame is made of the material having a high temperature resistance and a high voltage resistance, and the high voltage resistance between the two electric heating assemblies is improved, thus reducing the arc discharge between the two electric heating assemblies and preventing the PTC heating elements from being broken down due to the arc discharge. Thus, the PTC electric heating assemblies are suitable for the high voltage condition and have an excellent safety, and the PTC heating module can be used safely in the high voltage system (the electric vehicle) for long time.

2. Casing of the electric heating device

A person skilled in the art will appreciate that even though the PTC electric heating assembly of the present disclosure is different from the conventional PTC electric heating assembly, structure of the casing of the electric heating device may be similar to any common casing used in the art.

In order to further improve the thermal efficiency of the electric heating device, another mainly improvement of the present disclosure may be that the structure of the casing of the present disclosure is different from a traditional casing. A length of the medium passing path is increased in the casing of the present disclosure.

As shown in Fig. l to Fig.4, Fig.10 to Fig.13, the casing 1 comprises: a shell body 15; and a thermal conductive trough 16 mounted onto the shell body 15. In some embodiments of the present disclosure, the shell body 15 is a hollow rectangular parallelepiped and made of an insulating material. A top of the shell body 15 is opened. For example, the shell body 15 is manufactured by a process of injection molding with plastics having thermo stability, and configured to form the medium circulating cavity 12 for accommodating cooling liquid. The shell body 15 comprises a bottom plate 150 and four side plates so as to form a receiving chamber 155. The four side plates, such as a first side plate 151, a second side plate 152, a third side plate 153 and a fourth side plate 154, are extended upwardly from four edges of the bottom plate 150 along a substantially vertical direction. The first side plate 151 and the second side plate 152 are disposed oppositely along a length direction of the shell body 15, and the third side plate 153 and the fourth side plate 154 are disposed oppositely along a width direction of the shell body 15.

The shell body 15 comprises a medium inlet 13 for feeding the medium into the casing and a medium outlet 14 for discharging the medium out of the casing. In order to increase flowing time and flowing distance of the medium, a distance between positions of the medium inlet 13 and the medium outlet 14 is as far as possible, for example, as shown in Fig.12, the medium inlet 13 and the medium 14 may be formed in two ends of the second side plate 152. A person skilled in the art will appreciate that the medium inlet 13 and the medium 14 may be also formed in two ends of the first side plate 151, or formed in the third side plate 153 and the four side plate 154 respectively (as shown in Fig.4).

The thermal conductive trough 16 is mounted above the shell body 15; the thermal conductive trough 16 is made of heat conducting material (for example, metal). For example, the thermal conductive trough 16 is manufactured by a process of die-cast molding with aluminum alloy to form the thermal conductive grooves 160 for accommodating the PTC electric heating assemblies 2.

As shown in Fig. 11, the thermal conductive trough 16 has a corrugated vertical section and comprises a corrugated top plate 161, each of the thermal conductive grooves 160 is defined by two side isolating plates 162, a front plate 166, a real plate 168 and a bottom plate 167.

An upper portion of each of the side isolating plates 162, the front plate 166 and the rear plate 168 is connected to the top plate 161, and a lower portion of each of the side isolating plates 162, the front plate 166 and the rear plate 168 is connected to the bottom plate 167. And adjacent side isolating plates 162 are spaced apart from each other. The thermal conductive grooves 160 are configured for mounting the PTC electric heating assemblies 2.

As mentioned above, at least one side surface of the thermal conductive grooves 160 is inclined. In some embodiments, both two side surfaces of the thermal conductive grooves 160 are inclined. The PTC electric heating assemblies 2 are adapted to the thermal conductive grooves 160 and mounted therein. Thus, the thermal conductive grooves 160 isolate the medium from the PTC electric heating assemblies 2 and conduct the heat. The thermal conductive grooves 160 may be made of a material having an excellent conducting performance, such as metal. In some embodiments, the thermal conductive grooves 160 may be made of aluminum or aluminum alloy. In one embodiment, an open end of the thermal conductive grooves 160 is connected to the top plate 161, and the thermal conductive grooves 160 extends into an receiving chamber 155 of the shell body 15. As shown in Fig.4, the thermal conductive grooves 160 are formed by two side isolating plates 162, the front plate 166, the real plate 168 and the bottom plate 167, and the plurality of thermal conductive grooves 160 form the heating chamber 11.

Advantageously, the top plate 161, the side plates 162, the front plate 166, a real plate 168 and the bottom plate 167 are made of a material having an excellent conducting performance and formed integrally into one piece, thus the thermal conductive grooves 160 formed may have a stable structure and an excellent conducting performance.

A person skilled in the art will appreciate that the receiving chamber 155 of the shell body 15 is divided into a heating chamber 11 for accommodating the PTC electric heating assemblies 2 and a medium circulating cavity 12 for accommodating the medium by the side plates 162.

As shown in Fig.4, in some embodiment of the present disclosure, the medium circulating cavity 12 includes a plurality of circulating grooves 120 disposed between the side isolating plate 162 and the shell body 15 and located under the top plate 161. The outermost circulating groove 120 is formed between the outermost thermal conductive groove 160 and the shell body 15, the remaining circulating grooves 120 are formed between the adjacent thermal conductive grooves 160.

The thermal conductive grooves 160 are sealed relative to the circulating grooves 120, so as to prevent the medium from damaging the PTC electric heating assemblies 2.

In some embodiment of the present disclosure, in order to ensure the plurality of medium circulating cavity 120 is communicated to each other, furthermore, in order to form a longer passing path of the medium, the communicating channel 17 is formed by the walls of the thermal conductive grooves 160 and the first side plate 151 or the second side plate 152 of the shell body 15 (As shown in Fig.13, a person skilled in the art will appreciate that Fig.13 only shows the position of the communicating channel 17, the communicating channel 17 is located inside the casing).

The thermal conductive grooves 160 are communicated via the communicating channel 17, and the medium circulating cavity 120 defines a curved path. Thus, the medium is fed into the medium circulating cavity 120 via the medium inlet 13 and then passes through the medium circulating cavity 120 along the curved path, so that the length of the medium passing path is increased, the heat absorbing time is increased and the heating absorbing efficiency is improved. Moreover, the medium flows around the thermal conductive grooves 160 so as to improve the heating absorbing efficiency.

In some embodiments of the present disclosure, the plurality of thermal conductive grooves 160 are divided into a plurality of first thermal conductive grooves 1601 and a plurality of second thermal conductive grooves 1602, and the first thermal conductive grooves 1601 and the second thermal conductive grooves 1602 are arranged alternately.

The first thermal conductive grooves 1601 is connected to the first side plate 151, and the communicating channel 17 is formed between the first thermal conductive grooves 1601 and the second side plate 152. The second thermal conductive grooves 1601 is connected to the second side plate 152, and the communicating channel 17 is formed between the second thermal conductive grooves 1601 and the first side plate 151.

The circulating grooves 120 are communicated to each other by the communicating channel

17 so as to define an S-shaped medium circulating cavity 12. The medium is fed into the medium circulating cavity 12 via the medium inlet 13, and then passes through the S-shaped medium circulating cavity 12 along a circumferential and curved path, finally discharged from the medium outlet 14. The flow path in the S-shaped medium circulating cavity 12 is the longest flow path between the inlet 13 and the outlet 14. Thus, the passing path between the medium inlet 13 and the medium outlet 14 is increased, so that the heat absorbing time is increased and the heating absorbing efficiency is improved.

Furthermore, the medium flows around the thermal conductive grooves 160 so as to efficiently absorb the heat generated by the PTC electric heating assemblies 2 embedded into the thermal conductive grooves 160, and a heat efficiency of the electric heating device is improved.

In this embodiment, the number of the thermal conductive grooves 160 is nine, the number of the first thermal conductive grooves 1601 is five, and the number of second thermal conductive grooves 1602 is four. A person skilled in the art will appreciate that the number of the thermal conductive grooves 160, the first thermal conductive grooves 1601 and second thermal conductive grooves 1602 is adjustable according to requirements.

In one embodiment of the present disclosure, the plurality of thermal conductive grooves

160 are arranged parallel to one another along a length direction of the thermal conductive trough 16.

A communicating channel 17 is formed by the plates of the thermal conductive grooves 160 and the first side plate or the second side plate, thus the length of the thermal conductive grooves 160 can be shorter than the thermal conductive trough 16. Therefore more thermal conductive grooves 160 can be arranged for accommodating the PTC electric heating assemblies 2.

When the medium passes through the medium circulating cavity 12, the medium may flow through two sides of the thermal conductive grooves 160 or three sides (two side surfaces and a bottom surface) of the thermal conductive grooves 160. By arranging more thermal conductive grooves 160, the heat collected by the medium can be increased, thus the heat efficiency of the electric heating device can be enhanced.

A person skilled in the art will appreciate that the plurality of thermal conductive grooves

160 may also be arranged parallel to on another along a width direction of the thermal conductive trough 16; correspondingly, the first side wall and the second side wall are two side walls that arranged along a width direction of the shell body. Also, the casing of the present disclosure may be any casing which can form a medium circulating cavity with a longer flow path (For example, curved path).

Correspondingly, the structure of the plurality of thermal conductive grooves 160 which are arranged parallel to one another along a length direction of the thermal conductive trough 16 is reasonable and suitable for mounting the PTC electric heating assemblies.

As shown in Fig.ll, the thermal conductive trough 16 comprises an annular plate 163 extended upwardly from the thermal conductive trough 16. The annular plate 163 is disposed on the top of the shell body 15. The shell body 15 comprises a connecting element 156 formed on an upper end of the shell body 15.

Accordingly, a mounting element 164 is disposed on the annular plate 163; the mounting element 164 is disposed in the connecting element 156. The thermal conductive trough 16 is mounted on the shell body 15 via a screw through a hole in the mounting element 164 and the connecting element 156. In one embodiment of the present disclosure, a sealing ring 61 is disposed between the thermal conductive trough 16 and the shell body 15.

The sealing ring 61 may be made of a plastic injection element which has an excellent performance under both high temperature and low temperature to make sure that the shell body 15 is sealed from the thermal conductive trough 16 to prevent the medium in the shell body 15 from leaking.

In addition, as shown in Figs.10 and 13, in some embodiments of the present disclosure, the shell body 15 comprises a fixed element 158 disposed on an outside wall of the shell body 15. The fixed element 158 comprises a mounting hole. The electric heating device of the present disclosure may be mounted into a vehicle via a screw through the mounting hole of the fixed element 158. Besides, the shell body 15 further comprises a strengthening rib 1571 configured for reinforcing the shell body 15 and improving strength of the shell body 15 to make sure that the shell body 15 can not deform during the operation of the electric heating device is o.

Also, the shell body 15 further comprises an inner strengthening rib 1572 configured for improving strength of the shell body 15, increasing a water resistance and increasing the contact time of the cooling liquid and the thermal conductive trough 16, therefore the heat transferred by the thermal conductive trough 16 can be taken away sufficiently. The shell body 15 further comprises a vent 159 communicated with the medium circulating cavity 12 and configured to make sure that a water vapor in the shell body 15 can be discharged timely during a long time operation of the electric heating device so as to protect the casing.

As shown in Fig.12, in one embodiment of the present disclosure, the plurality of thermal conductive grooves 160 comprises a strengthening rib 165 formed on the outside thereof. The strengthening rib 165 is configured for improving strength of the thermal conductive trough 16, increasing a water resistance and increasing the contact time of the cooling liquid and the thermal conductive trough 16, therefore the heat transferred by the thermal conductive trough 16 can be taken away sufficiently.

The plurality of thermal conductive grooves 160 is extended into the receiving chamber 155 of the shell body 15. With the inner strengthening rib 1572 and the strengthening rib 165, the plurality of thermal conductive grooves 160 can be fixed in the shell body 15 properly.

In the present disclosure, the size of the PTC electric heating assemblies 2 is corresponded to the size of each thermal conductive groove 160, and each thermal conductive groove 160 accommodates one PTC electric heating assemblies 2. A person skilled in the art will appreciate that when the plurality of thermal conductive grooves 160 is arranged parallel to on another along a width direction of the casing, the length of the thermal conductive grooves 160 is longer, therefore there are at least two PTC electric heating assemblies 2 housed in the thermal conductive grooves 160.

In some embodiments of the present disclosure, the thermal conductive grooves 160 extend into the receiving chamber 155 of the shell body 15. The shell body 15 further comprises a block 157. Two adjacent blocks 157 may form an mounting portion for fastening the thermal conductive grooves 160. The plurality of thermal conductive grooves 160 of the thermal conductive trough 16 are fixed into the mounting portion to make the connection between the thermal conductive trough 16 and the shell body 15 stably.

In addition, in some embodiments of the present disclosure, the plurality of thermal conductive grooves 160 may also comprise a block disposed on a bottom surface thereof and at least on side surface thereof. The block of the thermal conductive groove 160 has a width smaller than that of the thermal conductive groove 160. Correspondingly, the shell body 15 may comprise a slot formed on four side plates of the shell body 15 and an inner side of the bottom plate 150.

The block is mounted in the slot so that the thermal conductive trough 16 is fixed in the receiving chamber 155. The block of the thermal conductive grooves 160 is connected to the slot on the bottom plate 150 and the slot on the first side plate 151 or the second side plate 152 respectively. Specifically, block of the first thermal conductive groove 1601 is connected to the slot on the bottom plate 150 and the first side plate 151.

There is no clearance between the connection position of the block and the slot, the communicating channel is formed between the first thermal conductive groove 1601 and the second side plate 152. Similarly, the communicating channel 17 is formed between the second thermal conductive groove 1602 and the first side plate 151. The plurality of circulating grooves is communicated with each other via the communicating channel 17.

Thus the medium flows through the communicating channel 17 between the thermal conductive grooves 160 and the first side plate 151 or the second side plate 152. The medium flows through two sides or three sides (involve partial bottom surface) of the thermal conductive grooves 160 and around the thermal conductive grooves 160 to increase the flow path. Therefore, the medium may absorb the heat generated by the PTC electric heating assemblies 2 effectively.

The assembling and usage of the PTC electric device according to embodiments of the present disclosure will be described below.

Firstly, the PTC electric heating assemblies 2 is embedded into the thermal conductive grooves 160 by a clamp, then the thermal conductive trough 16 is mounted to the shell body 15, a sealing ring 61 is disposed between the shell body 15 and the thermal conductive trough 16. Then the thermal conductive trough 16 is mounted onto the shell body 15 via a screw through the hole in the mounting element 164 and the connecting element 156. Then the thermal conductive grooves 160 are embedded into the receiving chamber 155 of the shell body 15 to form the medium circulating cavity 12.

The medium is fed into the medium circulating cavity 12 through the medium inlet 13 of the shell body 15, when the PTC electric heating assemblies 2 are energized, the PTC heating elements 27 start heating, and the heat is conducted to the medium via the contact electrode 21, the fixed electrode 22, the insulating layer 23, the slid film and the thermal conductive grooves 160. The medium flows out of the medium circulating cavity 12 through the medium outlet 14 of the thermal conductive trough 16 so as to carry the heat for heating, defrosting and defogging the interior of the vehicle.

As mentioned above, the casing of the electric heating device according to the present disclosure comprises a shell body, and a thermal conductive trough disposed on the top of the shell body. The heating chamber comprises a plurality of thermal conductive grooves formed by the side isolating plate; the medium circulating cavity comprises plurality of thermal medium circulating grooves.

The communicating channel is formed by the plurality of thermal conductive grooves and the first side plate or the second side plate. The medium circulating cavity has a curved path (for example, S-shaped medium circulating cavity) formed by the communicated communicating channel. The medium passes through the medium circulating cavity along a curved path, so that the passing path of the medium and the time for absorbing heat are increased. Moreover, the medium flows around the walls of thermal conductive grooves so as to increase the contact area and improve the heating absorbing efficiency, and the heat efficiency of the electric heating device is further improved.

3. heat- insulation module

As shown in Figs.2 and 3, in some embodiments of the present disclosure, the electric heating device further comprises a heat-insulation module 4 disposed on the casing 1 and disposed between the PTC electric heating assemblies 2 and the circuit control module 3, the heat- insulation module 4 comprises a thermal conductive rubber plate 41, heat- insulation foam plate 43 disposed above the thermal conductive rubber plate 41, and a heat- insulation rubber plate

42 disposed between the thermal conductive rubber plate 41 and the heat-insulation foam plate 43.

The thermal conductive rubber plate 41 is configured to conduct the heat transferred upwardly back to the PTC electric heating assemblies 2, then the heat can be taken away by the cooling liquid. The heat-insulation foam plate 43 is configured to prevent the heat generated by the PTC electric heating assemblies 2 from transmitting upwardly. The heat- insulation rubber plate 42 is configured for bonding the thermal conductive rubber plate 41 and the heat- insulation foam plate 43. The heat- insulation rubber plate 42 can fasten the heat-insulation foam plate 4 effectively and prevent the heat transferred from the thermal conductive rubber plate 41 from transmitting upwardly.

With the heat-insulation module 4 according to the present disclosure, an internal environment temperature of the electric heating device may be reduced dramatically, and the working environment temperature may be about 60 °C which is lower than the normal working temperature (about 80 °C) of the electronic component, therefore the circuit control module 3 may be protected effectively.

As shown in Figs.2 and 3, in some embodiment of the present disclosure, the heat-insulation module 4 has a three layer structure and a thickness of about 9 millimeters to about 11 millimeters.

The first layer may be the thermal conductive rubber plate 41, and the thermal conductive rubber plate 41 has a thickness of about 1.5 millimeters to about 2.5 millimeters. The thermal conductive rubber plate 41 may be made of heat-conducting glue which has a thermal conductivity larger than 1.5 W/(m* K) and a heat-resistance temperature higher than 280 °C . The heat-conducting glue has a thermal conductivity of about 1.5W/(m* K) to about 3.0W/(m* K) and a heat-resistance temperature of about 280 °C to about 300 °C . For example, the thermal conductive rubber plate 41 may be made of high temperature silicon rubber or epoxy resin.

The third layer may be the heat- insulation foam plate 43, and the heat- insulation foam plate 43 has a thickness of about 5 millimeters to about 7 millimeters. The heat-insulation foam plate

43 may be made of insulation foam with poor heat-conducting performance, such as an insulation foam having a thermal conductivity smaller than 0.15 W/(m* K) and a heat-resistance temperature lower than 200 °C , preferably, the insulation foam has a thermal conductivity of about 0.05W/(m* K) to about 0.15W/(m* K) and a heat-resistance temperature of about 200 °C to about 300 °C . In some embodiment of the present disclosure, the insulation foam may be made of closed foam material, such as polyurethane foam material or silicon rubber foam material. The second layer is disposed between the first and the third layer. The second layer is the heat-insulation rubber plate 42 which has a thickness of about 1.5 millimeters to about 2.5 millimeters. The heat- insulation rubber plate 42 is made of colloidal material which has a poor heat-conducting performance and an excellent elasticity. Preferably, the colloidal material has a thermal conductivity smaller than 0.15 W/(m* K) and a heat-resistance temperature lower than 200 °C . More preferably, the heat- insulation rubber plate 42 has a thermal conductivity of about 0.05W/(m*K) to about 0.15W/(m*K) and a heat-resistance temperature of about 200 °C to about 300 ^°C .

For example, the heat-insulation rubber plate 42 may be made of silica gel. The heat- insulation rubber plate 42 is configure for bonding the thermal conductive rubber plate 41 and the heat- insulation foam plate 43 to fasten the heat-insulation foam plate 43. Besides, the heat-insulation rubber plate 42 can prevent the heat transferred from the thermal conductive rubber plate 41 from transmitting upwardly to the circuit control module 3.

Moreover, the heat-insulation rubber plate 42 may show a cushioning effect when the vehicle is running in a bumpy road. The heat- insulation rubber plate 42 has an excellent elasticity and a large amount of elastic deformation which may reduce the damage possibility of the PTC electric heating assemblies and the heat- insulation foam plate 43.

The assembling and usage of the heat-insulation module according to embodiments of the present disclosure will be described below.

The heat-insulation rubber plate 42 is bonded between the thermal conductive rubber plate

41 and the heat-insulation foam plate 43 to form the heat-insulation module 4. Then the plurality of PTC electric heating assemblies 2 is embedded into the thermal conductive grooves 160 by a clamp, and the heat-insulation module 4 is mounted on the top of the casing 1. Next the circuit control module 3 is mounted on the heat-insulation module 4.

The thermal conductive rubber plate 41 is close to the PTC electric heating assemblies 2 and the heat- insulation foam plate 43 is close to the circuit control module 3. Finally the upper cover 5 is disposed on the top of the circuit control module 3 and fixed on the casing 1 to finish the assembling of the electric heating device and the circuit control module 3.

The medium is fed into the medium circulating cavity 12 through the medium inlet 13 of the shell body 15, when the PTC electric heating assemblies 2 are energized, the PTC electric heating assemblies 2 start heating, and the heat is conducted along the upward, downward, right and left direction.

The heat conducted along the downward, right and left direction can be taken away by the medium (cool liquid) flowing through the casing. While the heat conducted along the upward direction can be prevented from transmitting to the circuit control module 3 upwardly due to the heat-insulation module 4, moreover, the heat can be transmitted back to the PTC electric heating assemblies 2 via the thermal conductive rubber plate 41 and then be taken away by the medium (cool liquid) in the medium circulating cavity 12 of the casing 1.

Therefore, the electronic component on the circuit control module 3 may be protected effectively, the service life of the electric heating device can be increased, and the electric heating device may have a stable performance. In addition, the medium may absorb more heat so as to reduce heat losses and improve the heat efficiency of the electric heating device.

As mentioned above, the electric heating device according to the present disclosure comprises a heat-insulation module which comprises a thermal conductive rubber plate, a heat-insulation foam plate disposed above the thermal conductive rubber plate, and a heat-insulation rubber plate disposed between the thermal conductive rubber plate and the heat-insulation foam plate.

The heat conducted upward form the PTC electric heating assembly may be transmitted back to the PTC electric heating assembly via the thermal conductive rubber plate and then be taken away by the medium. The heat-insulation foam plate may prevent the heat generated by the PTC electric heating assembly from transmitting upwardly. The heat-insulation rubber plate is configured for bonding the thermal conductive rubber plate and the heat-insulation foam plate to fasten the heat-insulation foam plate effectively and prevent the heat transferred from the thermal conductive rubber plate from transmitting upwardly.

With the heat-insulation module according to the present disclosure, an internal environment temperature of the electric heating device may be reduced dramatically, and the working environment temperature may be about 60 °C which is lower than the normal working temperature (about 80 °C) of the electronic component, therefore the circuit control module 3 may be protected effectively. Thus the electric heating device may have a long service life and a stable performance.

4. Other components

As shown in Figs.2 and 3, the electric heating device further comprises a circuit control module 3. The circuit control module 3 comprises a control panel and an electronic component disposed on the control panel. The electronic component (For example, IGBT module) may be any common electronic component used in the art which has ability of resistant high voltage. The electronic component is the key part of the circuit control module 3, of which lower temperature safer. The electronic component is electrically connected to the plurality of PTC electric heating assemblies (the terminal of the fixed electrode), and configured to regulate the number of the PTC electric heating assembly, therefore the electric heating device may output different power to meet the requirements of different working condition of the vehicle.

As shown in Fig.l to Fig.3, the electric heating device further comprises an upper cover 5 connected to the shell body 15. The upper cover 5 comprises a control cavity; the circuit control module 3 is disposed in the control cavity.

The upper cover 5 is configured to make sure that the circuit control module 3 is used in a sealing environment to prevent water from entering and destroying the circuit control module 3.

In some embodiment of the present disclosure, a seal ring 62 is disposed between the upper cover 5 and the shell body 15. The seal ring 62 may be made of a plastic injection element which has an excellent performance both under high temperature and low temperature to make sure that the upper cover 5 is sealed from the shell body 15 to prevent water and dust from entering the control cavity and destroying the circuit control module 3.

In some embodiments of the present disclosure, the control cavity comprises a convex plate 31 and a supporting plate. The convex plate 31 and the supporting plate are connected to the control panel of the circuit control module 3. The convex plate 31 is configured to fasten the

IGBT module disposed on the control panel and prevent the control panel from vibrating during vehicle running, and to transmit the heat generated by the IGBT module to the thermal conductive trough 16 timely.

The supporting plate is located between the control panel and the heat-insulation module and configured to support the support parts of the control panel to prevent the electronic component on the control panel from loosing or dropping off during vehicle running.

As shown in Fig.2 and 3, the electric heating device further comprises a relay 7 mounted on the shell body 15 and electrically connected to the circuit control module 3. The relay 7 is a safety protection device, when the circuit control module 3 is out of control, the relay 7 may cut off the current in the circuit to avoid explosion.

A person skilled in the art will appreciate that the circuit control module and the relay may be any common circuit control module and relay used in the art, the control panel of the circuit control module, the electronic component and the control parts may be performed by the technologies in the art. Besides, the upper cover 5, the convex plate and the supporting plate may be any common structural component used in the art, thus the detail description will be omitted here.

An electric vehicle according to embodiments of the present disclosure comprises an air conditioning system including the electric heating device described with reference to the above embodiments and a heating exchanger or radiator coupled to the electric heating device. The medium (for example, cooling liquid) is heated during passing through the electric heating device and then flows into the heating exchanger or radiator, such that the heat is exchanged and released to be used for heating, defrosting, defogging, preheating the battery or realizing other functions.

The heating exchanger, radiator and other components of the air conditioning system may be any common heating exchanger, radiator and component used in the art, thus the details description will be omitted.

Reference throughout this specification to "an embodiment," "some embodiments," "one embodiment", "another example," "an example," "a specific examples," or "some examples," means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the phrases such as "in some embodiments," "in one embodiment", "in an embodiment", "in another example, "in an example," "in a specific examples," or "in some examples," in various places throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that the above embodiments can not be construed to limit the present disclosure, and changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the present disclosure.

Claims

What is claimed is: 1. A PTC electric heating assembly, comprising:

a first electrode assembly including a first fixed electrode;

a second electrode assembly including a second fixed electrode;

a PTC heating module disposed between the first electrode assembly and the second electrode assembly; and

an insulating layer disposed on an outer surface of each of the first electrode assembly and the second electrode assembly;

wherein an inner side surface of at least one of the first and the second fixed electrodes facing to the PTC heating module is a vertical surface, and an outer surface of the at least one of the first and the second fixed electrodes facing to the insulating layer is an inclined surface inclined inwardly from top to bottom.

2. The PTC electric heating assembly of claim 1, wherein the inner surfaces of both the first and the second fixed electrodes facing to the PTC heating module are the vertical surfaces, and the outer surfaces of both the first and the second fixed electrodes facing to the insulating layer are the inclined surfaces.

3. The PTC electric heating assembly of claim 1, wherein the first electrode assembly includes a first contact electrode contacted with the PTC heating module, and the first fixed electrode is disposed between the first contact electrode and the insulating layer,

wherein the second electrode assembly includes a second contact electrode contacted with the PTC heating module, , and the second fixed electrode is disposed between the second contact electrode and the insulating layer.

4. The PTC electric heating assembly of claim 3, wherein each of the contact electrodes is made of an electrically and thermally conductive material which is compressible elastically deformable.

5. The PTC electric heating assembly of claim 1 or 4, wherein the first and the second contact electrodes are made of electric conductive polymer, stannum, stannum alloy, copper, copper alloy or electrical conductive graphite,

wherein the first and the second fixed electrode are made of Al, Au or stainless steel.

6. The PTC electric heating assembly of claim 1, wherein the insulating layer is configured as an electric-insulation and thermal conductive film, and the insulating layer disposed on an outer surface and a bottom surface of each of the first and the second electrode assemblies.

7. The PTC electric heating assembly of claim 6, wherein the insulating layer is made of organic silicon rubber or butadiene-acrylonitrile rubber.

8. The PTC electric heating assembly of claim 1, further comprising a slid film covering an outer surface of the insulating layer.

9. The PTC electric heating assembly of claim 8, wherein the slid film is configured as a polyimide film or a copper foil film.

10. The PTC electric heating assembly of claim 1, wherein an area of the inner and the outer surfaces of each of the first and second fixed electrodes is larger than that of a side surface of the heating module so that an extending portion is formed and extended beyond the PTC heating module,

wherein a thermal conductive sealing glue is filled between the extending portions of the first and second fixed electrodes, and the thermal conductive sealing glue is made of organosilicone sealant, polyurethane sealant or epoxy resin sealant.

11. The PTC electric heating assembly of claim 1, wherein the PTC heating module comprises: an insulation fixing frame defining a plurality of fixing units,

a plurality of PTC heating elements disposed in the fixing units respectively.

12. The PTC electric heating assembly of claim 11, wherein the insulation fixing frame is made of an organic polymer having a thermal conductivity between 0.02W/(m^»K) and

5.0W/(m-K),

wherein the insulation fixing frame comprises:

a plurality of first isolating bars parallel to and spaced apart from one another,

a plurality of second insolating bars parallel to and spaced apart from one another, each of the plurality of second insolating bars being perpendicular to and intersected with the plurality of first insolating bars so as to form the plurality of fixing units.

13. The PTC electric heating assembly of claim 12, wherein adjacent PTC heating elements are spaced apart from each other by the first insolating bars or the second insolating bars.

14. The PTC electric heating assembly of claim 12, wherein the plurality of first insolating bars are parallel to a width direction of the PTC heating elements so that an interval between the adjacent first insolating bars is equal to a length of the PTC heating element,

wherein the plurality of second insolating bars are parallel to a length direction of the PTC heating elements so that an interval between the adjacent second insolating bars is equal to a width of the PTC heating element, a thickness of the first insolating bars and/or the second insolating bars is equal to that of the PTC heating elements.

15. An electric heating device, comprising:

a casing defining a plurality of thermal conductive grooves and a medium circulating cavity hermetically isolated from the thermal conductive grooves, at least one side surface of the thermal conductive groove is inclined, and the medium circulating cavity defining a medium inlet and a medium outlet; and

a plurality of PTC electric heating assemblies mounted into the thermal conductive grooves respectively, each PTC electric heating assembly is according to any one of claims 1-14.

16. The electric heating device of claim 15, wherein both side surfaces of each of thermal conductive grooves are inclined so as to be adapted to that of each of the first and the second electrode assemblies respectively.

17. The electric heating device of claim 15, wherein the casing comprises:

a shell body; and

a thermal conductive trough disposed on a top of the shell body and extended into the shell body,

wherein the thermal conductive grooves are defined by the thermal conductive trough, the medium circulating cavity is defined between the thermal conductive trough and the shell body, and the medium inlet and the medium outlet are formed in the shell body.

18. The electric heating device of claim 17, wherein the thermal conductive trough has a corrugated vertical section and comprises a corrugated top plate, each of the thermal conductive grooves is defined by two side isolating plates, a front plate, a real plate and a bottom plate,

wherein an upper portion of each of the side isolating plates, the front plate and the rear plate is connected to the top plate, and a lower portion of each of the side isolating plates, the front plate and the rear plate is connected to the bottom plate,

wherein adjacent side isolating plates are spaced apart from each other,

wherein the medium circulating cavity includes a plurality of circulating grooves defined between the side isolating plate and the shell body,

wherein the shell body comprises a first side wall and a second side wall, a communicating channel is defined between the thermal conductive trough and the first side wall or the second side wall, and the thermal conductive grooves are communicated via the communicating channel.

19. The electric heating device of claim 18, wherein the plurality of thermal conductive grooves are divided into a plurality of first thermal conductive grooves and a plurality of second thermal conductive grooves,

wherein the first thermal conductive grooves and the second thermal conductive grooves are arranged alternately, the first thermal conductive grooves are extended to the first side wall, the second thermal conductive grooves are extended to the second side wall, the communicating channel is formed between the first thermal conductive grooves and the first side wall as well as between the second thermal conductive grooves and the second side wall.

20. The electric heating device of any one of claims 15-19, further comprising a circuit control module mounted above the casing and electrically connected to the PTC electric heating assemblies,

wherein the circuit control module comprises a control panel and an electronic component which is disposed on the control panel and configured to control the electric heating device, each of the first and second fixed electrode comprises a terminal extended form an upper ends thereof and electrically connected to the electronic component.

21. The electric heating device of claim 20, further comprising a heat-insulation module disposed on the casing and between the PTC electric heating assemblies and the circuit control module,

wherein the heat-insulation module comprises a thermal conductive rubber plate, a heat-insulation foam plate disposed above the thermal conductive rubber plate, and a heat-insulation rubber plate disposed between the thermal conductive rubber plate and the heat-insulation foam plate.

22. The electric heating device of claim 21, wherein the heat- insulation module has a thickness of about 9 millimeters to about 11 millimeters,

wherein the thermal conductive rubber plate has a thickness of about 1.5 millimeters to about 2.5 millimeters, a thermal conductivity of about 1.5W/(m* K) to about 3.0W/(m* K) and a heat-resistance temperature of about 280 °C to about 300 °C ,

wherein the heat-insulation foam plate has a thickness of about 5 millimeters to about 7 millimeters, a thermal conductivity of about 0.05W/(m* K) to about 0.15W/(m* K) and a heat-resistance temperature of about 200 °C to about 300 °C ,

wherein the heat- insulation rubber plate has a thickness of about 1.5 millimeters to about 2.5 millimeters, a thermal conductivity of about 0.05W/(m* K) to about 0.15W/(m* K) and a heat-resistance temperature of about 200 °C to about 300 °C .

23. The electric heating device of claim 22, wherein the thermal conductive rubber plate is made of silicon rubber or epoxy resin, the heat-insulation foam plate is made of polyurethane foam material or silicon rubber foam material, and the heat-insulation rubber plate is made of silica gel.

24. The electric heating device of claim 20, further comprising:

an upper cover connected to the casing and defining a control cavity for receiving the circuit control module therein,

a relay mounted on the casing and electrically connected to the circuit control module, and a seal ring disposed between the upper cover and the casing.

25. An electric vehicle comprising an air conditioning system employing an electric heating device according to any one of claims 15-24.