Self-sealing electric heater

Abstract

The present application relates to molten salt energy storage electric heater technical field, specifically to a kind of self-sealing electric heater, including shell, electric heating tube, clamping portion and connecting piece;Connecting piece is fixed on shell, electric heating tube is threaded through connecting piece and extends into shell, clamping portion is sleeved on the outside of electric heating tube and at least part of connecting piece, clamping portion clamps connecting piece, so that connecting piece extrudes electric heating tube;Connecting piece includes cavity, cavity is communicated with the inner cavity of shell by communicating port, communicating port is used for the medium in shell to flow into cavity, so that connecting piece is expanded and extrudes electric heating tube.The present application is configured by connecting piece on the shell of electric heater, electric heating tube is clamped by clamping portion and connecting piece, wherein connecting piece has cavity communicating with the inner cavity of shell, after medium in shell enters cavity, connecting piece can be expanded to extrude electric heating tube threaded therein, so as to realize self-sealing between connecting piece and electric heating tube.

Description

Technical Field

[0001] This invention relates to the field of molten salt energy storage electric heater technology, and specifically to a self-sealing electric heater. Background Technology

[0002] Sealing is crucial for electric heaters, directly affecting the normal operation, lifespan, and production efficiency of the equipment. Among these aspects, the sealing between the heating element and the housing is a key focus.

[0003] If only the sealing effect is considered, welding sealing is a common and effective sealing method, but there are still some shortcomings in practical applications, mainly including: (1) Once the welding seal is completed, it is usually impossible to disassemble. If it is necessary to repair or replace components such as heating tubes, it may be necessary to replace the entire welded component, which increases the maintenance cost and time; (2) A heat-affected zone will be generated during the welding process, which may lead to changes in material properties, such as hardening, cracking or deformation, affecting the quality and life of the seal; (3) Welding seal usually requires the seal to have good weldability with the substrate. For some non-weldable materials or composite materials, welding seal may not be suitable; (4) The welding quality is affected by a variety of factors such as welding process, operator skills, and welding equipment, such as (5) Improper operation may lead to welding defects and affect the sealing effect; (6) For some complex structures, such as the curved part of the pipe or the small diameter pipe, welding may not be able to achieve a complete seal and there is a risk of leakage; (7) Welding may require professional welding equipment and skills, especially for high precision or special materials, the cost will be relatively high; (8) Harmful gases and fumes may be generated during the welding process, which may pose a potential hazard to the environment and the health of operators; (9) The welding process may take a long time, and welding may not be the best choice for occasions that require quick replacement or repair; (10) Once the welding seal has a problem, maintenance and repair may be difficult, especially in places that are hard to access or have limited space.

[0004] To overcome the shortcomings of welded seals, other sealing methods or combinations of multiple sealing technologies are needed to improve sealing effectiveness and reliability. Existing technologies describe some electric heaters with detachable heating elements. A threaded seat is welded to the side of the heater housing near the junction box. The heating element passes through the threaded seat and the heater housing, and a pressure nut is screwed onto the threaded seat to achieve a sealed connection. Specifically, a gasket and a sealing plate are provided between the end of the pressure nut and the threaded seat to seal the gap between the heating element and the threaded seat from the end, preventing the medium inside the heater housing from leaking out through this gap.

[0005] The aforementioned patented detachable heating element electric heater, while replacing the direct welding installation method of the heating element and enabling its detachability, suffers from inferior sealing compared to welding. Specifically, the connector is welded to the heater housing near the junction box, allowing the heating element to pass through for easy assembly and disassembly. However, this structure creates a gap between the connector and the heating element, making it prone to leakage of the medium inside the heater housing. The only solution is to use a sealing element added to the outside of the connector for sealing, resulting in poor overall sealing. It can only passively block any overflowing medium, leaving a significant risk of medium leakage from the heater housing. Summary of the Invention

[0006] To address the shortcomings of existing electric heaters, this invention provides a self-sealing electric heater. It uses a connector on the housing of the electric heater to clamp the electric heating tube with a clamping part and the connector. The connector has a cavity that communicates with the inner cavity of the housing. When the medium inside the housing enters the cavity, it can cause the connector to expand and squeeze the electric heating tube inserted therein, thereby achieving self-sealing between the connector and the electric heating tube.

[0007] The technical solution provided by this invention is as follows: a self-sealing electric heater, comprising a housing, an electric heating tube, a clamping part, and a connector; the connector is fixed to the housing, the electric heating tube passes through the connector and extends into the housing, the clamping part is sleeved on the outside of the electric heating tube and at least a portion of the connector, the clamping part clamps the connector so that the connector squeezes the electric heating tube; the connector includes a cavity, the cavity is connected to the inner cavity of the housing through a communication port, the communication port is used for the medium inside the housing to flow into the cavity, so that the connector expands due to heat and squeezes the electric heating tube.

[0008] Optionally, the connector is formed by a connecting bottom shell, a central shell wall, a first shell portion, and a second shell portion; the connecting bottom shell, the first shell portion, and a portion of the central shell wall form a first portion of the connector; the second shell portion and a portion of the central shell wall form a second portion of the connector; the connecting bottom shell is fixedly connected to the housing, the second shell portion is used to connect with the locking portion, and the inner cavities of the first and second portions communicate to form the cavity; the inner cavity volume of the first portion is greater than the inner cavity volume of the second portion.

[0009] Optionally, the first shell portion is an obliquely arranged transition shell wall, and the two sides of the transition shell wall are fixedly connected to the connecting bottom shell and the second shell portion respectively, so that the shape of the first portion smoothly converges from the side closer to the shell to the other side.

[0010] Optionally, the second section is provided with a plurality of reinforcing ribs, and flow channels are provided on the reinforcing ribs and / or between the reinforcing ribs.

[0011] Optionally, the reinforcing rib plate located at the end of the second portion is provided with a concave arc surface.

[0012] Optionally, the second shell portion includes a top shell wall and a side shell wall that are orthogonal to each other. The top shell wall is fixedly connected to the central shell wall, and the side shell wall is fixedly connected to the first shell portion. The locking portion is provided with a first contact wall and a second contact wall that are orthogonal to each other. The first contact wall is used to abut against the top shell wall, and the second contact wall is used to abut against the side shell wall.

[0013] Optionally, the connector is provided with a blocking member on the side facing the housing that is in close contact with the electric heating tube. The blocking member is provided with a flow guiding surface, which is used to guide the medium inside the housing to the communication port.

[0014] Optionally, the clamping part includes a first clamping member, a second clamping member, and a fastener; the first clamping member and the second clamping member form a clamp-like structure to be sleeved on the outside of the electric heating tube and at least part of the connecting member, and the first clamping member and the second clamping member are fastened together by the fastener.

[0015] Optionally, a Tesla valve channel is provided in the clamping part; at least a portion of the Tesla valve channel is circumferentially disposed around the electric heating tube and communicates with the gap between the clamping part and the electric heating tube; at least a portion of the Tesla valve channel is circumferentially disposed around the connector and communicates with the gap between the clamping part and the connector.

[0016] Optionally, the material of the connection portion between the connector and the housing is the same as the material of the housing; the coefficient of thermal expansion of the material of the remaining portion of the connector is greater than the coefficient of thermal expansion of the material of the housing.

[0017] Compared with existing technologies, the technical solution provided by this invention has the following advantages: Addressing the shortcomings of existing electric heaters, this invention configures a connector on the heater's housing. The electric heating element is clamped between the connector and a clamping part. The connector has a cavity communicating with the inner cavity of the housing. When the medium inside the housing enters the cavity, the connector expands and compresses the electric heating element inserted within it, thus achieving a self-sealing between the connector and the electric heating element. This actively cuts off the medium overflow channel, completing the first seal. This structural design also reduces the difficulty of achieving further sealing on the outside of the connector, improves the overall sealing effect, and reduces the risk of medium overflow, thereby solving the sealing problem of electric heaters with detachable heating elements. Attached Figure Description

[0018] Figure 1 This is one of the partial structural schematic diagrams of the self-sealing electric heater proposed in the embodiments of the present invention.

[0019] Figure 2 This is a second partial structural schematic diagram of the self-sealing electric heater proposed in an embodiment of the present invention.

[0020] Figure 3 This is the third partial structural schematic diagram of the self-sealing electric heater proposed in the embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the clamping part proposed in an embodiment of the present invention. Detailed Implementation

[0022] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0023] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. The terms "first," "second," etc., used in this invention are for the convenience of describing the technical solutions of the invention and have no specific limiting effect; they are all general terms and do not constitute a limitation on the technical solutions of the invention. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict, all of which are within the scope of protection claimed by this invention.

[0024] Combined with appendix Figure 1-4This embodiment proposes a self-sealing electric heater, including a housing 1, an electric heating tube 2, a clamping part 3, and a connector 4. The connector 4 is fixed to the housing 1, the electric heating tube 2 passes through the connector 4 and extends into the housing 1, and the clamping part 3 is sleeved on the outside of the electric heating tube 2 and at least a portion of the connector 4, clamping the connector 4 to compress the electric heating tube 2. The connector 4 includes a cavity, which communicates with the inner cavity of the housing 1 through a connecting port 40. The connecting port 40 allows a medium from inside the housing 1 to flow into the cavity, causing the connector 4 to expand upon heating and compress the electric heating tube 2.

[0025] This embodiment aims to provide a self-sealing electric heater, which relies on the self-expansion of the connector 4 to achieve efficient sealing between the electric heating tube 2, the clamping part 3 and the connector 4, while ensuring the ease of disassembly and assembly of the electric heating tube 2, so as to facilitate maintenance.

[0026] In this embodiment, the connector 4 has a cavity communicating with the inner cavity of the self-sealing electric heater. When heated, the medium inside the shell 1 of the self-sealing electric heater can enter the cavity, causing the connector 4 to expand due to heat and compress the electric heating tube 2 inserted therein. This achieves self-sealing of the axial gap between the connector 4 and the electric heating tube 2, thereby actively cutting off the medium overflow channel and completing the first seal. This structural form also reduces the difficulty of achieving further sealing on the outside of the connector 4, improves the overall sealing effect, reduces the risk of medium overflow, and thus solves the sealing problem of the detachable electric heater with electric heating tube 2.

[0027] For the self-sealing electric heater of this embodiment, the main bodies of the housing 1, the clamping part 3, and the connecting part 4 are generally made of metal, such as steel. The connecting part 4 is initially fixed to the housing 1 by welding or other methods, and has a connecting port 40 that connects the cavity of the connecting part 4 to the inner cavity of the housing 1. During assembly of the self-sealing electric heater, the electric heating tube 2 is first inserted into the connecting part 4 and extends into the housing 1. Then, the clamping part 3 clamps the connecting part 4 to secure the electric heating tube 2. When disassembly is required, the clamping part 3 is released, and the electric heating tube 2 can be pulled out.

[0028] Combined with appendix Figure 4 In one embodiment, the clamping part 3 includes a first clamping member 30, a second clamping member 31, and a fastener 32. The first clamping member 30 and the second clamping member 31 form a clamp-like structure to be sleeved on the outside of the electric heating tube 2 and at least part of the connecting member 4. The first clamping member 30 and the second clamping member 31 are fastened together by the fastener 32. In use, the first clamping member 30 and the second clamping member 31 can be fastened together by the fastener 32, which is composed of nuts and bolts, thereby pressing the connecting member 4 to clamp the electric heating tube 2. This further achieves a compression seal between the connecting member 4 and the electric heating tube 2, and between the connecting member 4 and the clamping part 3.

[0029] Based on the foregoing structural description, the self-sealing electric heater of this embodiment, taking the housing 1, clamping part 3, and connecting part 4 all made of steel as an example, achieves its self-sealing principle as follows: When the self-sealing electric heater is working, the heated fluid medium enters the housing 1 and then enters the cavity of the connecting part 4 through the connecting port 40. Since the connecting part 4 is made of metal, it will generate axial expansion stress after being heated, which will make the contact between the connecting part 4, the electric heating tube 2, and the clamping part 3 tighter, thus enhancing the mechanical sealing effect. It can be understood that during assembly, the clamping part 3 has already clamped or pressed the connecting part 4. In this embodiment, the connecting part 4 can utilize the characteristics of metal (or other materials) to deform under heat, achieving a secondary pressing purpose and strengthening the sealing effect.

[0030] Here, the tight contact between connector 4 and electric heating element 2 is considered the first seal, which is strengthened by the thermal expansion of connector 4. Based on this, a second seal can be provided by improving the locking part 3. (See attached diagram.) Figure 1 Based on the aforementioned embodiment, a Tesla valve channel 33 may be provided within the clamping part 3. At least a portion of the Tesla valve channel 33 is circumferentially disposed around the electric heating tube 2 and communicates with the gap between the clamping part 3 and the electric heating tube 2; at least a portion of the Tesla valve channel 33 is circumferentially disposed around the connector 4 and communicates with the gap between the clamping part 3 and the connector 4. The flow path direction of the Tesla valve channel 33 is opposite to the normal operating path direction of a conventional Tesla valve, i.e., it is configured in a path direction that obstructs fluid flow.

[0031] Therefore, the Tesla valve channel 33 provides a secondary seal. Based on the principle of the Tesla valve, the Tesla valve channel 33 can be understood as a special type of one-way valve, impeding the flow of internal fluid in the opposite direction. In this embodiment, the Tesla valve channel 33 surrounding the electric heating tube 2 counteracts radial leakage, while the Tesla valve channel 33 surrounding the connector 4 counteracts axial leakage. In short, the secondary seal reduces leakage, decreases the leakage per unit time, and improves the safety factor. Furthermore, the combined design of the first and second seals enhances the overall sealing strength of the self-sealing electric heater, avoiding the risk of failure associated with traditional packing seals. In a further embodiment, multiple Tesla valve channels 33 can be connected in series to further strengthen the effect of the secondary seal.

[0032] In this embodiment, the connector 4 is the core component for achieving self-sealing. In this embodiment, the connector 4 is further formed by a connecting bottom shell 41, a central shell wall 42, a first shell portion 43, and a second shell portion 44. The connecting bottom shell 41, the first shell portion 43, and part of the central shell wall 42 together form the first portion of the connector 4; the second shell portion 44 and part of the central shell wall 42 together form the second portion of the connector 4. The connecting bottom shell 41 is fixedly connected to the housing 1, and the second shell portion 44 is used to connect with the locking portion 3. The inner cavities of the first and second portions communicate to form a cavity; and the inner cavity volume of the first portion is greater than the inner cavity volume of the second portion.

[0033] In this embodiment, the connector 4 is divided into two parts: a first part and a second part. The connector 4 is connected to the housing 1 via a connecting base 41, and a communication port 40 is provided on the connecting base 41 to allow for the flow of the medium. In this embodiment, the inner volume of the first part is larger than that of the second part. The larger volume of the first part means a stronger capacity to hold the medium, allowing for the acquisition of more heat and thus increasing the overall expansion of the connector 4. Generally, because the first part has a larger volume, the area of ​​the connecting base 41 is also larger, and the communication port 40 on it can also be made larger to allow the medium to enter the interior of the connector 4 more easily.

[0034] Generally, as shown in the appendix Figure 1 As shown, the first segment has a cylindrical shape, meaning the first shell 43 has a partially cylindrical structure. This shape results in right-angled cross-sections for the first and second segments. In a preferred embodiment, the first shell 43 is an obliquely arranged transition shell wall, with both sides of the transition shell wall fixedly connected to the connecting bottom shell 41 and the second shell 44, respectively, so that the shape of the first segment smoothly converges from the side closest to the shell 1 to the other side. (See attached diagram) Figure 2 As shown, the structure of the transition shell wall is similar to the sidewall of a cone or frustum, or it can be in the form of a concave or convex surface.

[0035] These arrangements of the transition shell wall allow the first section to smoothly converge from the side closest to shell 1 to the other side. The purpose is to guide the medium to the second section, allowing it to quickly enter the dead zone at the far end of the second section and preventing the far end of the second section from becoming a cold end with insufficient heating. And with the attached... Figure 1 Compared to the right-angled structure shown, the inclined transition shell wall can generate both radial and axial elongation components when heated, resulting in a better compression effect.

[0036] In this embodiment, the second section is used to contact the clamping part 3 for clamping. It needs to be made thinner and lighter to ensure its structural strength and resistance to deformation. Furthermore, in a further improvement, several reinforcing ribs 5 can be provided within the second section. By adding reinforcing ribs 5, the deformation resistance of the second section can be improved, allowing it to adapt to the greater clamping force applied by the locking part, thereby improving the locking and sealing effect. In addition, flow channels 50 (as shown in the attached diagram) need to be provided on the reinforcing ribs 5. Figure 2 (As shown) to avoid obstructing the flow of the medium. Alternatively, the reinforcing ribs 5 can be arranged in a staggered manner, and the gaps between the staggered reinforcing ribs 5 can naturally form flow channels 50 to ensure the free flow of the medium.

[0037] And, as attached Figure 1 In the preferred embodiment shown, the second shell portion 44 includes a top shell wall 441 and a side shell wall 442 that are orthogonal to each other. The top shell wall 441 is fixedly connected to the central shell wall 42, and the side shell wall 442 is fixedly connected to the first shell portion 43. The locking portion 3 is provided with a first contact wall 301 and a second contact wall 302 that are orthogonal to each other. The first contact wall 301 abuts against the top shell wall 441, and the second contact wall 302 abuts against the side shell wall 442. Thus, a right-angled contact surface exists between the connector 4 and the locking portion 3, which further enhances the effect of preventing media leakage.

[0038] Based on the above-mentioned improved structure, the operating conditions of the self-sealing electric heater are as follows: In the initial stage (start-up stage) of the self-sealing electric heater, the medium enters the shell 1 of the self-sealing electric heater, and the liquid level of the medium in the shell 1 gradually rises, gradually submerging the electric heating tube 2 and the connecting port 40 on the connector 4. At this time, the medium begins to flow into the cavity of the connector 4.

[0039] After the start-up phase ends and the system enters the stable operation phase, the cavity of connector 4 is always filled with medium and is in a relatively stable state. At this time, the medium in the cavity exchanges with the medium in the shell 1 through density changes. Specifically, after the hot medium enters the cavity of connector 4 and transfers heat to connector 4, the medium cools down, causing its density to increase (i.e., higher than the density of the hot medium in shell 1). This results in a tendency to be squeezed towards the low-density medium. Thus, the medium can naturally release heat in the cavity of connector 4 and flow back into shell 1, exchanging the hot medium in shell 1 into connector 4. This process continuously renews the hot medium in the cavity of connector 4, continuously obtains heat, continuously maintains the self-sealing effect of connector 4, and avoids the risk of the medium in connector 4 solidifying and blocking.

[0040] In practice, during the initial stage of operation of the self-sealing electric heater, as the medium begins to flow into the cavity, it may cause a certain impact on the connector 4. The vibration caused by this impact may loosen the connector 4 and weaken the sealing effect between the connector 4 and the other components.

[0041] Therefore, based on the embodiment of providing reinforcing ribs in the second section, a concave arc surface 51 can be provided on the reinforcing rib plate 5 located at the end of the second section. (See attached...) Figure 2 As shown, the concave arc surface 51 faces the direction of the shell 1, that is, the direction of the fluid medium inflow. The reinforcing rib 5 with the concave arc surface 51 can not only gently guide the impacted fluid medium in the reverse direction along the circumference, reducing turbulence to reduce vibration, but also improve the support capacity.

[0042] In addition, a blocking member 6, which is in close contact with the electric heating tube 2, can be provided on the side of the connector 4 facing the housing 1. The blocking member 6 is provided with a flow guiding surface 60, which is used to guide the medium inside the housing 1 to the communication port 40. (See attached image) Figure 3 As shown, the guide surface 60 is a concave arc-shaped guide surface. In other embodiments, the guide surface 60 may also be an inclined surface, etc.

[0043] Therefore, by setting a blocking member 6 that is close to the electric heating tube 2 on the side of the connector 4 near the housing 1, the medium that originally flowed towards the gap between the electric heating tube 2 and the connector 4 is obliquely guided towards the connecting port 40. This reduces the probability of the medium entering the gap and guides the medium towards the connecting port 40, improving the efficiency of the medium entering the cavity. Moreover, it makes the medium fluid at the connecting port 40 more concentrated, increases the flow rate, thereby increasing the replacement rate of the medium fluid in the cavity, improving the heating effect on the connector 4, and enhancing the expansion self-sealing effect.

[0044] Furthermore, the setting of the blocking member 6 can also form a vortex stagnation zone, which can guide the fluid to the interior of the connecting member 4 under the action of vortex motion.

[0045] In this embodiment, the connector 4 is initially fixed to the housing 1. Generally, taking the connector 4 and the housing 1 as examples where both are made of steel, the connection part between the connector 4 and the housing 1, such as the aforementioned connecting bottom shell 41, can be made of the main body steel. That is, the material of the connection part between the connector 4 and the housing 1 is the same as the material of the housing 1, so that the connection part between the connector 4 and the housing 1 will not expand after receiving heat from the heat medium, and thus will not shrink the communication opening 40.

[0046] The remaining parts of the connector 4 can be made of different types of steel. That is, the remaining parts of the connector 4 can be made of a different material than the shell 1. The coefficient of thermal expansion of the material should be greater than that of the shell 1 to achieve thermal expansion and thus ensure the self-sealing effect.

[0047] For example, in one embodiment, the housing 1 is made of carbon steel, and the part of the connector 4 that connects to the housing 1, such as the aforementioned connecting bottom shell 41, is also made of carbon steel, while the rest of the connector 4 is made of 347H stainless steel. This difference in material selection allows the connector 4 as a whole (except for the part connecting the connector 4 to the housing 1) to expand more easily due to heat, thus enhancing the self-sealing effect. The part connecting the connector 4 to the housing 1 can expand synchronously, preventing cracking and ensuring the stability of the connection between the connector 4 and the housing 1.

[0048] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A self-sealing electric heater, characterized in that, It includes a housing (1), an electric heating element (2), a clamping part (3), and a connector (4); The connector (4) is fixed to the housing (1), the electric heating tube (2) passes through the connector (4) and extends into the housing (1), the clamping part (3) is sleeved on the outside of the electric heating tube (2) and at least part of the connector (4), and the clamping part (3) clamps the connector (4) so ​​that the connector (4) squeezes the electric heating tube (2); The connector (4) includes a cavity, which is connected to the inner cavity of the housing (1) through a communication port (40). The communication port (40) is used to allow the medium inside the housing (1) to flow into the cavity, so that the connector (4) expands under heat and squeezes the electric heating tube (2).

2. The self-sealing electric heater according to claim 1, characterized in that, The connector (4) is formed by connecting the bottom shell (41), the central shell wall (42), the first shell part (43), and the second shell part (44); The connecting bottom shell (41), the first shell portion (43), and part of the central shell wall (42) together form the first part of the connector (4); the second shell portion (44) and part of the central shell wall (42) together form the second part of the connector (4); The connecting bottom shell (41) is fixedly connected to the shell (1), the second shell part (44) is used to connect with the clamping part (3), and the inner cavities of the first part and the second part are connected to form the cavity; the inner cavity volume of the first part is greater than the inner cavity volume of the second part.

3. A self-sealing electric heater according to claim 2, characterized in that, The first shell portion (43) is an obliquely arranged transition shell wall. The two sides of the transition shell wall are fixedly connected to the connecting bottom shell (41) and the second shell portion (44) respectively, so that the shape of the first portion smoothly converges from the side closer to the shell (1) to the other side.

4. A self-sealing electric heater according to claim 2, characterized in that, The second section is provided with a plurality of reinforcing ribs (5), and flow channels (50) are provided on the reinforcing ribs (5) and / or between the reinforcing ribs (5).

5. A self-sealing electric heater according to claim 4, characterized in that, A concave arc surface (51) is provided on the reinforcing rib plate (5) located at the end of the second section.

6. A self-sealing electric heater according to claim 2, characterized in that, The second shell portion (44) includes a top shell wall (441) and a side shell wall (442) that are orthogonal to each other. The top shell wall (441) is fixedly connected to the central shell wall (42), and the side shell wall (442) is fixedly connected to the first shell portion (43). The locking part (3) is provided with a first contact wall (301) and a second contact wall (302) that are orthogonal to each other. The first contact wall (301) is used to abut against the top shell wall (441), and the second contact wall (302) is used to abut against the side shell wall (442).

7. A self-sealing electric heater according to claim 1, characterized in that, The connector (4) is provided with a blocking member (6) that is in close contact with the electric heating tube (2) on the side facing the housing (1). The blocking member (6) is provided with a flow guiding surface (60) for guiding the medium inside the housing (1) to the communication port (40).

8. A self-sealing electric heater according to claim 1, characterized in that, The clamping part (3) includes a first clamping member (30), a second clamping member (31), and a fastener (32); the first clamping member (30) and the second clamping member (31) form a clamp-like structure to be sleeved on the outside of the electric heating tube (2) and at least part of the connector (4), and the first clamping member (30) and the second clamping member (31) are fastened together by the fastener (32).

9. A self-sealing electric heater according to claim 1, characterized in that, The clamping part (3) is provided with a Tesla valve channel (33); At least a portion of the Tesla valve channel (33) is arranged circumferentially around the electric heating tube (2) and communicates with the gap between the clamping part (3) and the electric heating tube (2); At least a portion of the Tesla valve passage (33) is circumferentially disposed around the connector (4) and communicates with the gap between the locking part (3) and the connector (4).

10. A self-sealing electric heater according to claim 1 or 2, characterized in that, The material of the connection part of the connector (4) to the housing (1) is the same as the material of the housing (1); the coefficient of thermal expansion of the material of the remaining part of the connector (4) is greater than the coefficient of thermal expansion of the material of the housing (1).

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