Silicon nitride heating element and heating device

Abstract

The present application relates to a silicon nitride heating element and a heating device, wherein the silicon nitride heating element comprises a sandwich structure; the sandwich structure comprises a first heating part and a second heating part, wherein the first heating part and the second heating part have a common silicon nitride intermediate layer, and the silicon nitride heating element leads out a lead structure for separate control at the first heating part and the second heating part, respectively. The above silicon nitride heating element adopts a sandwich design in a pioneering way. On the one hand, the volume of the structure is reduced by sharing a silicon nitride intermediate layer, which saves materials relatively; on the other hand, the two heating parts are used to realize separate and precise control of the partitions, so that the separate temperature control effect of the dual temperature zones can be achieved; on the other hand, through an array distribution setting or a volume enlargement and reduction setting, it can be applied to multiple different fields, including electronic cigarettes, water heaters, electric kettles, instant faucets, etc. It can also be applied to the fields of heating for daily life or car heating, enriching the application line of the product.

Description

Technical Field

[0001] The present application relates to the field of electric heating elements, and in particular to silicon nitride heating elements and heating devices. Background Art

[0002] Silicon nitride has the properties of high strength, low density, and high temperature resistance. It is a superhard material that has lubricity, wear resistance, and oxidation resistance at high temperatures. It can also resist thermal shocks and will not break even if it is heated to over 1000°C in air, cooled rapidly, and then heated rapidly.

[0003] Silicon nitride heating elements are also called silicon nitride ceramic heating elements. They have strong insulation, high electric heat conversion efficiency, acid resistance, alkali resistance, corrosion resistance, and no scaling. They are widely used in aviation, aerospace, weapons, communications, machinery, medical equipment, metallurgy, chemical industry, petroleum, automobiles, internal combustion engines, and household appliances.

[0004] The Chinese patent with publication number CN105936595A discloses a silicon nitride heating element and its preparation method. The silicon nitride heating element is composed of a heat source and a heating body. The heat source is a tungsten wire. The heating body is made of silicon nitride (Si3N4), aluminum oxide (Al2O3), yttrium trioxide (Y2O3), and aluminum nitride (AlN) as raw materials, and is prepared by a preparation method of preparation grinding, molding, and high-temperature sintering. Based on the total weight of the raw materials, the weight proportions of the components in the raw materials are: silicon nitride (Si3N4) 80-95, aluminum oxide (Al2O3) 0.1-5, yttrium trioxide (Y2O3), 2-8 aluminum nitride (AlN) 3-5. The silicon nitride heating element produced by this method has high reliability and safety, increased fracture toughness, and increased bending strength.

[0005] A Chinese patent with publication number CN114679801A discloses an all-ceramic heating element, including an outer heating layer, an inner insulating layer and an inner heating layer, which are the inner heating layer, the inner insulating layer and the outer heating layer from the inside to the outside. The outer heating layer is electrically connected to the inner heating layer. The weight ratio of the ceramic materials of the outer resistance layer and the inner resistance layer is: silicon nitride: silicon carbide: aluminum oxide: yttrium oxide: lanthanum oxide: molybdenum disilicide = (500-700): (100-300): (40-80): (50-90): (0-30): (500-800). The ratio values ​​of the outer resistance layer and the inner resistance layer are different. It integrates heat generation and temperature sensing, is not affected by the external environment, is reliable in heating or ignition, and has a reliable life.

[0006] The applicant has not found any relevant product that combines the advantages of both. Summary of the invention

[0007] Based on this, it is necessary to provide a silicon nitride heating element and a heating device.

[0008] A silicon nitride heating element, comprising a sandwich structure;

[0009] The sandwich structure includes a first heating part and a second heating part, wherein the first heating part and the second heating part have a common silicon nitride intermediate layer, and the silicon nitride heating element has lead structures for separate control respectively led out from the first heating part and the second heating part.

[0010] The above-mentioned silicon nitride heating element has innovatively adopted a sandwich design. On the one hand, the volume of the structure is reduced by sharing the silicon nitride middle layer, which saves materials relatively. On the other hand, the two heating parts are used to achieve separate and precise control of the partitions, so as to achieve separate temperature control effects in dual temperature zones. On the other hand, through array distribution settings or volume enlargement and reduction settings, it can be applied to multiple different fields, including electronic cigarettes, water heaters, electric kettles, instant faucets, etc., and can also be used in fields such as domestic heating or car heating, enriching the product application line.

[0011] Furthermore, in one of the embodiments, the lead structure is arranged to avoid the silicon nitride intermediate layer.

[0012] Furthermore, in one embodiment, the lead structure includes a ground lead and the first heating portion and the second heating portion share the ground lead.

[0013] Furthermore, in one of the embodiments, the silicon nitride heating element also includes a protective film layer covering at least a portion of the outside of the sandwich structure.

[0014] In one embodiment, the first heating part and the second heating part are both a heating wire covered with silicon nitride structure or a heating film covered with silicon nitride structure; or, one of the first heating part and the second heating part is a heating wire covered with silicon nitride structure, and the other is a heating film covered with silicon nitride structure.

[0015] In one embodiment, the first heating portion and the second heating portion are both silicon nitride composite molybdenum disilicide structures.

[0016] In one embodiment, the first heating part is a silicon nitride structure coated on the outside of a heating wire or a silicon nitride structure coated on the outside of a heating film, and the second heating part is a silicon nitride composite molybdenum disilicide structure.

[0017] In one embodiment, the sandwich structure has different ends, one end of which is the first heat-generating portion, and the other end of which is the second heat-generating portion.

[0018] In one embodiment, the sandwich structure has flat ends, one side of which is the first heat-generating portion, and the other side of which is the second heat-generating portion.

[0019] In one embodiment, the first heating portion and the second heating portion respectively lead out the lead structures in the same direction.

[0020] In one embodiment, the remaining positions of the first heat generating portion and the second heat generating portion except the lead structure and the silicon nitride intermediate layer are used to contact the liquid heat conducting medium.

[0021] In one embodiment, the silicon nitride heating element has a cylindrical or stud-shaped structure as a whole.

[0022] In one embodiment, the remaining positions of the first heating part and the second heating part except the lead structure and the silicon nitride intermediate layer are used to contact the liquid heat-conducting medium; and the silicon nitride heating element as a whole has a cylindrical or stud-shaped structure.

[0023] In one of the embodiments, the silicon nitride heating element has a through groove in the middle thereof, the through groove only passes through one of the first heating part and the second heating part, and the through groove avoids the silicon nitride intermediate layer.

[0024] In one of the embodiments, a heating device includes any one of the silicon nitride heating elements and a power supply module electrically connected to the silicon nitride heating element. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a schematic structural diagram of an embodiment of the silicon nitride heating element described in this application.

[0027] Figure 2 for Figure 1 Another identification schematic diagram of the illustrated embodiment.

[0028] Figure 3 for Figure 1 Another identification schematic diagram of the illustrated embodiment.

[0029] Figure 4 for Figure 3 Another schematic diagram of the embodiment shown.

[0030] Figure 5 This is a schematic structural diagram of another embodiment of the silicon nitride heating element described in the present application.

[0031] Figure 6 This is a schematic structural diagram of another embodiment of the silicon nitride heating element described in the present application.

[0032] Figure 7 for Figure 6 Another identification schematic diagram of the illustrated embodiment.

[0033] Figure 8 for Figure 6 Another identification schematic diagram of the illustrated embodiment.

[0034] Fig. 9 for Figure 8 Another schematic diagram of the embodiment shown.

[0035] Fig.10 This is a schematic structural diagram of another embodiment of the silicon nitride heating element described in the present application.

[0036] Fig.11 This is a schematic structural diagram of another embodiment of the silicon nitride heating element described in the present application.

[0037] Figure numerals: first heating part 100 , second heating part 200 , through groove 300 , silicon nitride intermediate layer 400 , lead structure 500 , sandwich structure 600 , first lead structure 510 , second lead structure 520 , first lead portion 511 , second lead portion 512 , third lead portion 521 , fourth lead portion 522 . DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0039] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0040] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0041] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0042] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0043] The present application discloses a silicon nitride heating element and a heating device, which include some or all of the structures of the following embodiments; that is, the silicon nitride heating element and the heating device include some or all of the following technical features. In one embodiment of the present application, a silicon nitride heating element includes a sandwich structure; the sandwich structure includes a first heating part and a second heating part, wherein the first heating part and the second heating part have a common silicon nitride intermediate layer, and the silicon nitride heating element leads out a lead structure for separate control at the first heating part and the second heating part, respectively. The above silicon nitride heating element adopts a sandwich design in a pioneering way. On the one hand, the volume of the structure is reduced by sharing the silicon nitride intermediate layer, which saves materials relatively; on the other hand, the two heating parts are used to realize separate precise control of the partitions, and the separate temperature control effect of the dual temperature zones can be realized; on the other hand, through the array distribution setting or the volume enlargement and reduction setting, it can be applied to multiple different fields, including electronic cigarettes, water heaters, electric kettles, instant faucets, etc., and can also be applied to the fields of heating for daily life or car heating, enriching the application line of the product.

[0044] In one embodiment, a silicon nitride heating element such as Figure 1As shown, it includes a sandwich structure 600 and a lead structure 500; the sandwich structure 600 includes a first heating portion 100 and a second heating portion 200, combined with Figure 2 , wherein the first heating part 100 and the second heating part 200 have a common silicon nitride intermediate layer 400, and the silicon nitride heating element is respectively led out to a lead structure 500 for separate control at the first heating part 100 and the second heating part 200. In this embodiment, the lead structure 500 includes a first lead structure 510 and a second lead structure 520, wherein the silicon nitride heating element is led out to a first lead structure 510 for separate control of the first heating part 100 at the first heating part 100, and the silicon nitride heating element is led out to a second lead structure 520 for separate control of the second heating part 200 at the second heating part 200; the first lead structure 510 includes a first lead part 511 and a second lead part 512, and the second lead structure 520 includes a third lead part 521 and a fourth lead part 522. In this embodiment, the first heating part 100 and the second heating part 200 respectively lead out the lead structure 500 in the same direction. In other embodiments, the first heating part 100 and the second heating part 200 may also be provided with the lead structures 500 in different directions. The position and direction of the lead structures 500 may be set according to the actual product and its actual needs, but the specific needs must be determined before the design is finalized.

[0045] In one embodiment, the silicon nitride heating element has a cylindrical or stud-shaped structure. Figure 3As shown, the silicon nitride heating element or its sandwich structure 600 is cylindrical, that is, the silicon nitride heating element or its sandwich structure 600 has a cylindrical or stud-shaped structure as a whole. The cylindrical or stud-shaped structure will have the problem of internal heat conduction, so the design of the through groove described in its embodiment can be adopted to facilitate heat transfer. Further, in one of the embodiments, the silicon nitride heating element has a long strip structure as a whole, one end of which is the first heating part 100, the other end is the second heating part 200, and the middle position is the silicon nitride intermediate layer 400. In one of the embodiments, the sandwich structure 600 has different ends, one end of which is the first heating part 100, and the other end is the second heating part 200. In one of the embodiments, the sandwich structure 600 has flat ends, one side of which is the first heating part 100, and the other side is the second heating part 200. The rest of the embodiments are similar and will not be described in detail. Further, in one embodiment, the silicon nitride intermediate layer 400 has at least two parts of intermediates that are physically separated, such as two intermediates that are arranged opposite to each other or at least three intermediates that are arranged in a ring shape, etc.; each of the intermediates is arranged adjacent to the external environment, and two adjacent intermediates are separated by air, the first heating part 100 or the second heating part 200, and each of the intermediates is adjacent to the first heating part 100 or the second heating part 200, that is, a plurality of relatively independent sandwich structures are formed. Such a design is conducive to providing multi-stage heating effect, meeting the heating requirements of two or more high-heat positions and multiple low-heat positions for specific products, and there is also a relatively good heat dissipation environment between the at least two parts of the intermediates formed by the silicon nitride intermediate layer 400, which can output high and low temperatures in multiple regions and accurately control the temperature, and can also meet the needs of controlling the temperature in multiple regions separately, which is particularly suitable for application on micro products with strict temperature control requirements.

[0046] Further, in each embodiment, the first heating part 100 and the second heating part 200 are both structural parts using silicon nitride as raw material, that is, the main component of the first heating part 100 and the second heating part 200 is silicon nitride. In one embodiment, the silicon nitride of the first heating part 100 and the second heating part 200 accounts for more than 60% to 70% by mass. Other components include rare earth elements, the third main group (III A) such as aluminum, the fourth main group (IV A) such as silicon, transition elements and their compounds, etc.; they can also include the constituent elements of the heating wire and the heating film and their compounds. As mentioned above, in addition to silicon nitride, the component materials of the first heating part 100 and the second heating part 200 can also include aluminum oxide, yttrium oxide, aluminum nitride and molybdenum disilicide.

[0047] In one of the embodiments, the first heating part 100 and the second heating part 200 are both electric heating wires covered with silicon nitride structures or electric heating films covered with silicon nitride structures; in one of the first heating part 100 and the second heating part 200, one is an electric heating wire covered with silicon nitride structure, and the other is an electric heating film covered with silicon nitride structure. Further, in one of the embodiments, the first heating part 100 and the second heating part 200 are both electric heating wires covered with silicon nitride structures or electric heating films covered with silicon nitride structures, and the density ratio or power density of the electric heating wires or electric heating films is set differently, that is, the number of electric heating wires or electric heating films distributed inside is different, so that the heating values ​​of the first heating part 100 and the second heating part 200 are set differently. In addition, different heating wire or heating film structures, as well as different input voltages or input currents, can be used to achieve different heating values. Such a design, on the one hand, is conducive to achieving separate temperature control effects in dual temperature zones through separate and precise control of the zones, and on the other hand, is conducive to forming heat output in different positions through different heating value designs, which is especially suitable for use in some moxibustion therapy devices and heating devices in different positions.

[0048] In one embodiment, the first heating part 100 and the second heating part 200 are both silicon nitride composite molybdenum disilicide structures. In one embodiment, the first heating part 100 is a silicon nitride structure coated with an electric heating wire or a silicon nitride structure coated with an electric heating film, and the second heating part 200 is a silicon nitride composite molybdenum disilicide structure. Such a design, on the one hand, combines the advantages of the two silicon nitride heating elements, and on the other hand, further utilizes the advantage of the small thermal expansion coefficient of the silicon nitride heating element, avoiding structural deformation or poor connection problems caused by thermal expansion and contraction of different structures during long-term use.

[0049] Furthermore, in one embodiment, the silicon nitride intermediate layer 400 is adjacent to the heating structure of the first heating part 100 and the second heating part 200, and the heating structure is generally an electrothermal structure, such as the aforementioned electric heating wire or electric heating film. Furthermore, in one embodiment, the silicon nitride heating element is also provided with a heat-conducting strip extending in the silicon nitride intermediate layer 400, and the heat-conducting strip is used to transfer heat by conduction to conduct the internal heat of the silicon nitride intermediate layer 400. Furthermore, in one of the embodiments, the heat conductive strip extends outside the sandwich structure 600 to form an external heat conductor, and the profile of the external heat conductor is at least partially similar to the profile of the sandwich structure 600. Such a design, on the one hand, is conducive to extracting the internal heat of the silicon nitride intermediate layer 400; on the other hand, it is conducive to cooperating with products or related embodiments with a liquid heat conductive medium, which greatly improves the internal heat extraction of the silicon nitride intermediate layer 400 and has a relatively better heating effect; on the other hand, it forms protection for the silicon nitride intermediate layer 400 to prevent the silicon nitride heating element from being damaged due to too slow heat transfer due to heat accumulation. It can be understood that Figures 1 to 10 The embodiments are for reference only. The structures may be different in actual applications, but the principles are the same. The heating structure is arranged close to the silicon nitride intermediate layer 400, or one layer of the heating structure is arranged close to the silicon nitride intermediate layer 400, so as to make full use of the common advantages of the silicon nitride intermediate layer 400 to achieve the effect of saving materials and reducing volume. Since silicon nitride heating elements have the advantages of durability and high temperature resistance, in the aging test, although the silicon nitride intermediate layer 400 is repeatedly used, especially when the first heating part 100 and the second heating part 200 are working at the same time, the silicon nitride intermediate layer 400 is the position with the highest heat output, but it still passed the aging test and can work normally without unexpected safety problems. In particular, the embodiment with the thermal conductive strip has a relatively better heating effect.

[0050] Further, in one embodiment, if Figure 4 As shown, the lead structure 500 is arranged to avoid the silicon nitride intermediate layer 400. Further, in one embodiment, the lead structure 500 contains a ground lead and the first heating part 100 and the second heating part 200 share the ground lead or the ground lead of the first heating part 100 and the ground lead of the second heating part 200 are at least partially overlapped. In one embodiment, as Figure 5 As shown, the second lead portion 512 and the third lead portion 521 are both ground leads, and the second lead portion 512 and the third lead portion 521 are partially overlapped. Such a design is conducive to further reducing the product volume and simplifying the connection structure.

[0051] In one of the embodiments, the silicon nitride heating element has a through groove in the middle thereof, and the through groove only passes through one of the first heating part and the second heating part. In one of the embodiments, the silicon nitride heating element has a through groove in the middle thereof, and the through groove only passes through one of the first heating part and the second heating part, and the through groove avoids the silicon nitride intermediate layer. The rest of the embodiments are similar and will not be described in detail. In one of the embodiments, Figure 6 As shown, the silicon nitride heating element has a through groove 300 in the middle thereof, the through groove 300 only passes through one of the first heating part 100 and the second heating part 200, and the through groove 300 avoids the silicon nitride intermediate layer 400. In one embodiment, as Figure 6 As shown, the silicon nitride heating element has a through slot 300 in the middle of the sandwich structure 600 that penetrates the sandwich structure 600 itself. Figure 7 , the through groove 300 only passes through the second heating part 200, and the through groove 300 avoids the silicon nitride intermediate layer 400, so as to achieve heat transfer of the second heating part 200. This structural design is more suitable for columnar products, and can also be applied to long strip products. Furthermore, in one of the embodiments, the silicon nitride heating element can be provided with a plurality of the through grooves 300, but one of the through grooves 300 only passes through the first heating part 100 or only passes through the second heating part 200. It was found in the test that if one of the through grooves 300 passes through the first heating part 100 and the second heating part 200 at the same time, it will affect the uniform arrangement of heating components such as heating wires or heating films, which may cause uneven heating, thereby affecting the design life of the product and the safety of use.

[0052] Combination Figure 8 Similarly, in this embodiment, the lead structure 500 is arranged to avoid the silicon nitride intermediate layer 400. In one embodiment, combined with Fig. 9 The silicon nitride heating element or its sandwich structure 600 has a cylindrical structure as a whole, and the first heating part 100 and the second heating part 200 are respectively led out of the lead structure 500 in the same direction, that is, the first lead part 511, the second lead part 512, the third lead part 521 and the fourth lead part 522 are led out in the same direction.

[0053] Further, in one embodiment, if Fig.10As shown, the sandwich structure 600 is staggered, wherein the ends of the first heating part 100 and the second heating part 200 are arranged differently, that is, the first heating part 100 and the second heating part 200 have non-flat ends. In this embodiment, both ends of the second heating part 200 protrude from the first heating part 100 to achieve additional heat transfer parts. Such a design allows the silicon nitride heating element to have more applicable product options, and due to the pioneering use of a sandwich design, on the one hand, the volume of the structure is reduced by sharing the silicon nitride intermediate layer 400, which saves materials relatively; on the other hand, the two heating parts are used to achieve separate and precise control of the partitions, and the separate temperature control effect of the dual temperature zones can be achieved. When the two heating parts work at the same time, it can provide a faster heating effect; on the other hand, through the array distribution setting or the volume enlargement and reduction setting, it can be applied to multiple different fields, enriching the application line of the product.

[0054] Further, in one embodiment, the silicon nitride heating element is Fig.11 As shown, it also includes a sandwich structure and a lead structure; the sandwich structure includes a first heating part 100 and a second heating part 200, wherein the first heating part 100 and the second heating part 200 have a common silicon nitride intermediate layer 400, and the silicon nitride heating element is respectively led out from the first heating part 100 and the second heating part 200 for independent control of the lead structure, the lead structure includes a first lead structure and a second lead structure, wherein the silicon nitride heating element is led out from the first heating part 100 for independent control of the first heating part 100, and the silicon nitride heating element is led out from the second heating part 200 for independent control of the second heating part 200; the first lead structure includes a first lead part 511 and a second lead part 512, and the second lead structure includes a third lead part 521 and a fourth lead part 522. In this embodiment, the first lead portion 511, the second lead portion 512, the third lead portion 521 and the fourth lead portion 522 are all flat connectors. In other embodiments, the first lead portion 511, the second lead portion 512, the third lead portion 521 and the fourth lead portion 522 may also adopt other structural designs, as long as the conductor can be led out from the sandwich structure to connect to the power supply. Such a design, as mentioned above, reduces the volume of the structure by sharing the silicon nitride intermediate layer 400, which relatively saves materials, and realizes precise control of the partitions through the two heating parts, which can achieve the independent temperature control effect of the dual temperature zones. Combined with the extended design, more temperature ranges can be achieved, and when the two heating parts work at the same time, it can provide a faster heating effect.

[0055] Furthermore, in one of the embodiments, the silicon nitride heating element further includes a protective film layer covering at least a portion of the sandwich structure 600; further, in one of the embodiments, the protective film layer is an insulating thermal conductive film. In other embodiments, the silicon nitride heating element can also be made into a film to form a silicon nitride heating film. As mentioned above, the silicon nitride heating element of the present application can be applied to multiple different fields through an array distribution arrangement or a volume enlargement and reduction arrangement, enriching the application line of the product.

[0056] In order to enhance the efficiency of heat transfer, in one embodiment, the remaining positions of the first heating part 100 and the second heating part 200 except the lead structure 500 and the silicon nitride intermediate layer 400 are used to contact the liquid heat-conducting medium, that is, the sandwich structure 600 is used to contact the liquid heat-conducting medium. That is, the remaining positions of the silicon nitride heating element that are in contact with the outside, except for the lead structure 500, are in contact with the liquid heat-conducting medium. Further, in one embodiment, at least one guide groove is provided in the sandwich structure 600, and the guide groove is used to guide the liquid heat-conducting medium into the sandwich structure 600 to contact the first heating part 100 and / or the second heating part 200. Further, in one embodiment, at least one guide groove is provided in the silicon nitride intermediate layer 400. Alternatively, in one embodiment, the through groove 300 is used as the guide groove. This is to utilize the effect of transferring heat by convection. Under certain restrictions, convection has a more effective effect than conduction and radiation in medium and low temperature heat transfer. However, it should be noted that the embodiment with the guide groove has a negative impact on the overall compressive strength of the silicon nitride heating element, and is suitable for related heating products that are not subjected to large pressure and are used with liquid heat-conducting media. Even so, the thermal shock resistance test method and system with publication number CN110411884A was used to test the thermal shock resistance of the trial product. The embodiment with the through groove 300 or other guide grooves has also achieved the qualified quality requirements of the target product.

[0057] In one embodiment, a heating device includes the silicon nitride heating element described in any embodiment and a power supply module electrically connected to the silicon nitride heating element. In each embodiment, the power supply module supplies power to the silicon nitride heating element through the lead structure to achieve the heating function. The power supply module can be a simple battery or battery pack according to actual needs, or it can be an electric power device with a control function, and it can also have a transformer and other power conversion equipment. In one embodiment, a heating device includes a silicon nitride heating element and a power supply module electrically connected to the silicon nitride heating element, and the silicon nitride heating element includes a sandwich structure; the sandwich structure includes a first heating part and a second heating part, wherein the first heating part and the second heating part have a common silicon nitride intermediate layer, and the silicon nitride heating element leads out lead structures for separate control at the first heating part and the second heating part, respectively. The remaining embodiments are similar and will not be described in detail. With such a design, the heating device reduces the volume of the silicon nitride heating element structure through the shared silicon nitride intermediate layer structure of the silicon nitride heating element, relatively saves materials, and realizes separate and precise control of the two heating parts of the silicon nitride heating element, which can achieve separate temperature control effects in two temperature zones. As mentioned above, the heating device includes electronic cigarettes, water heaters, electric kettles, instant faucets, etc., and may also include heating equipment for daily life or automobile heating equipment, etc.

[0058] It should be noted that other embodiments of the present application also include silicon nitride heating elements and heating devices having the silicon nitride heating elements that can be implemented by combining the technical features in the above embodiments. According to the adjustment of structure, volume and connection mode, the silicon nitride heating element can be applied to electronic cigarettes, water heaters, electric kettles, instant faucets, etc., and can also be applied to the fields of heating for daily life or automobile heating.

[0059] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A silicon nitride heating element, characterized in that: including a sandwich structure; The sandwich structure comprises a first heating part and a second heating part, wherein the first heating part and the second heating part have a common silicon nitride intermediate layer, and the silicon nitride heating element leads out lead structures for separate control from the first heating part and the second heating part respectively; The lead structure includes a ground lead and the first heating part and the second heating part share the ground lead; The silicon nitride intermediate layer has at least two physically separated intermediate bodies, each of which is arranged adjacent to the external environment, and two adjacent intermediate bodies are separated by air, the first heating part or the second heating part, and each of which is adjacent to the first heating part or the second heating part.

2. The silicon nitride heating element according to claim 1, characterized in that: The first heating part and the second heating part are both electric heating wires covered with silicon nitride or electric heating films covered with silicon nitride; or, one of the first heating part and the second heating part is an electric heating wire covered with silicon nitride, and the other is an electric heating film covered with silicon nitride; The density ratio or power density of the electric heating wire or electric heating film in the first heating part and the second heating part is set differently, so that the heat generation of the first heating part and the second heating part is set differently.

3. The silicon nitride heating element according to claim 1, characterized in that: The first heating portion and the second heating portion are both silicon nitride composite molybdenum disilicide structures.

4. The silicon nitride heating element according to claim 1, characterized in that: The first heating part is a silicon nitride structure coated on the outside of the electric heating wire or a silicon nitride structure coated on the outside of the electric heating film, and the second heating part is a silicon nitride composite molybdenum disilicide structure.

5. The silicon nitride heating element according to claim 1, characterized in that: The sandwich structure has different ends, one end of which is the first heat generating portion, and the other end of which is the second heat generating portion.

6. The silicon nitride heating element according to claim 1, characterized in that: The sandwich structure has flat ends, one side of which is the first heat-generating portion, and the other side of which is the second heat-generating portion.

7. The silicon nitride heating element according to claim 1, characterized in that: The first heat generating portion and the second heat generating portion are respectively led out of the lead structure in the same direction.

8. The silicon nitride heating element according to claim 1, characterized in that: The remaining positions of the first heating part and the second heating part except the lead structure and the silicon nitride intermediate layer are used to contact the liquid heat-conducting medium; and / or, the silicon nitride heating element has a cylindrical or stud-shaped structure as a whole.

9. The silicon nitride heating element according to any one of claims 1 to 8, characterized in that: The silicon nitride heating element has a through groove in the middle thereof, the through groove only passes through one of the first heating part and the second heating part, and the through groove avoids the silicon nitride intermediate layer.

10. A heating device, characterized in that: It comprises the silicon nitride heating element as described in any one of claims 1 to 9 and a power supply module electrically connected to the silicon nitride heating element.

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