Heating pipe, dry heater and water heater

Abstract

The utility model discloses a heating pipe, a dry type heater and a water heater, and relates to the technical field of water heaters. The heating pipe comprises a pipe body and a heating piece, and the pipe body is provided with a first end and a second end which are arranged at the two axial ends respectively. The heating piece is arranged in the pipe body; the heating piece is bent in the pipe body to form two heating sections arranged side by side, and the two heating sections extend to the second end in the axial direction of the pipe body. The second ends of the two heating sections are respectively provided with a wiring end, and the two wiring ends extend out of the second ends. According to the technical scheme, folding oil pressure operation does not need to be carried out on the pipe body, the processing technology of the heating pipe is simplified, and the wire breaking risk is reduced.

Description

Technical Field

[0001] This utility model relates to the field of water heater technology, and in particular to a heating element, a dry heater, and a water heater. Background Technology

[0002] Dry-type heaters are used as heating elements in storage-type electric water heaters. A typical dry-type heater consists of a heating element and a heater sleeve. The heater sleeve is fixed inside the inner tank, and the heating element is placed inside the heater sleeve. When the heating element is working, it is energized, converting electrical energy into heat energy. This heat is then exchanged with the water in the inner tank through the heater sleeve, thus heating the water in the tank.

[0003] The heating tubes of existing dry heaters require folding and hydraulic forming processes during manufacturing. Since the heating tube contains a heating wire and is filled with magnesium oxide powder, the external force exerted during folding and hydraulic forming can mechanically damage the heating tube material and the magnesium oxide powder inside, easily causing premature damage to the heating wire during use. Utility Model Content

[0004] The main purpose of this invention is to provide a heating element, a dry heater, and a water heater, which aims to simplify processing and reduce the risk of wire breakage.

[0005] To achieve the above objectives, the heating tube proposed in this utility model includes:

[0006] The tube body has a first end and a second end located at opposite axial ends; and

[0007] A heating element is disposed inside the tube; the heating element is bent inside the tube to form two heating sections arranged side by side, and the two heating sections extend along the axial direction of the tube to the second end;

[0008] Each of the two heating sections is provided with a wiring terminal at the second end, and both wiring terminals extend out of the second end.

[0009] In one embodiment of this application, the heating element is a resistance wire;

[0010] And / or, the inner peripheral wall of the tube body is provided with a positioning boss for positioning the bent section of the heating element; the positioning boss is located on the tube body near the first end.

[0011] In one embodiment of this application, the heating tube further includes a sealing cap disposed at the opening of the first end, the sealing cap being fixedly connected to the tube body to seal the opening of the first end; the heating element is spaced apart from the sealing cap.

[0012] In one embodiment of this application, the sealing cap is housed inside the tube body; the end face of the sealing cap facing away from the heating element is flush with the end face of the first end of the tube body.

[0013] And / or, the sealing cap is welded and fixed to the tube body.

[0014] In one embodiment of this application, the heating tube further includes an insulating plug disposed at the second end of the tube body and sealing the tube opening. The insulating plug, the sealing cap, and the tube body enclose a sealed cavity, the heating element is located inside the sealed cavity, and the two terminals pass through the insulating plug.

[0015] In one embodiment of this application, the two terminals are arranged at an angle, and the distance between the two terminals gradually increases in the direction away from the tube body.

[0016] In one embodiment of this application, the terminal includes:

[0017] The lead-out rod has one end connected to the corresponding heating section and the other end extending out of the second end of the tube body;

[0018] An insulating wrapping element, connected to the second end and wrapped around the outside of the lead-out rod; and

[0019] The connecting piece has one end located inside the insulating package and electrically connected to the corresponding lead-out rod, and the other end extends out of the insulating package for external connection.

[0020] In one embodiment of this application, the tube is filled with an insulating and thermally conductive material, which isolates the two heating sections and isolates the heating element from the tube wall.

[0021] And / or, the tube body is an insulating and heat-conducting component.

[0022] In one embodiment of this application, the heating tube further includes a first flange sleeved on the outside of the tube body, the first flange being installed on the tube body near the second end.

[0023] To achieve the above objectives, this application also provides a dry-type heater, comprising:

[0024] The heater sleeve has one closed end and the other open end;

[0025] Mounting base, connected to the open end of the heater sleeve, and open corresponding to the position of the heater sleeve; and

[0026] The heating tube described above is located inside the heater sleeve, and the wiring terminal of the heating tube is located outside the heater sleeve.

[0027] To achieve the above objectives, this application also provides a water heater, including the aforementioned dry heater and inner tank, wherein the closed end of the heater sleeve extends into the inner tank, and the mounting base is fixed to the inlet of the inner tank.

[0028] In the heating tube of this utility model, the heating element is bent inside the tube to form two heating sections. Each heating section has a terminal at its second end, extending outwards for electrical connection to an external power source, thus enabling the heating element to heat the tube normally. This embodiment simplifies the manufacturing process by having both terminals extend from the same end of the tube, eliminating the need for hydraulic bending of the tube. This reduces mechanical damage to the tube and heating element. Furthermore, it facilitates control of the tube's outer diameter, ensuring high processing precision and significantly reducing the gap between the heating tube and the inner wall of the heater sleeve. This guarantees timely heat transfer from the heating tube to the sleeve and heat exchange with water, extending the lifespan of the heating tube. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of an embodiment of the heating tube provided by this utility model;

[0031] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0032] Figure 3 for Figure 1 A magnified view of a section at point B in the middle;

[0033] Figure 4 for Figure 1 Side view of the heating element in the embodiment;

[0034] Figure 5 This is a schematic diagram of the structure of an embodiment of the dry heater of this utility model;

[0035] Figure 6 A schematic diagram of the structure of an embodiment of the water heater provided by this utility model.

[0036] Explanation of icon numbers:

[0037]

[0038]

[0039] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0041] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0042] Meanwhile, the meaning of "and / or" or "and / or" appearing throughout the text is that it includes three options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0043] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0044] Existing dry-type heaters require processes such as folding and hydraulic forming during manufacturing to transform a long, straight, round tube into a folded, long, straight, elliptical tube. Because the heating tube contains a heating wire and is filled with magnesium oxide powder, the external force during hydraulic forming causes mechanical damage to the heating wire, compressing both the tube and the magnesium oxide powder. This can lead to premature failure of the heating wire during use. Existing technology suffers from complex manufacturing processes and a high risk of wire breakage.

[0045] Based on this, the present invention proposes a heating tube that eliminates the need for overall bending of the electric heating tube, simplifying the processing technology and reducing the risk of wire breakage. The structure of the heating tube is described below by way of embodiments.

[0046] In the embodiments of this utility model, such as Figures 1 to 4 As shown, the heating tube 1 includes a tube body 11 and a heating element 12.

[0047] The tube body 11 has a first end and a second end respectively located at both ends of the axial direction; the heating element 12 is disposed inside the tube body 11, and the heating element 12 is bent inside the tube body 11 to form two heating sections 121 arranged side by side, the two heating sections 121 extending along the axial direction of the tube body 11 to the second end; the two heating sections 121 are respectively provided with wiring terminals 122 at the second end, and both wiring terminals 122 extend out of the second end.

[0048] In this embodiment, the tube 11 serves to mount the heating element 12 and conduct heat from the heating element 12. It is understood that the tube 11 and the heating element 12 are insulated to prevent electrical leakage between them, while the tube 11 can quickly conduct heat from its interior to the outside. Optionally, the tube 11 can be a metal tube or a non-metal tube with good thermal conductivity. The tube 11 itself can be an insulating material or a non-insulating material. When it is a non-insulating material, insulation between it and the heating element 12 can be achieved by filling the inside of the tube 11 with insulating material. Optionally, the cross-sectional shape of the tube 11 can be circular, semi-circular, square, triangular, or other irregular shapes. In practical applications, the tube 11 can be a circular tube that is easy to form.

[0049] The heating element 12 is bent inside the tube body 11 to form two parallel heating sections 121, thus the two heating sections 121 are electrically connected inside the tube body 11. Each heating section 121 has a terminal 122 at its second end, which is the positive terminal 122 and the negative terminal 122, respectively. These terminals extend beyond the second end of the tube body 11 and connect to an external power supply structure, enabling the two heating sections 121 to generate heat. Therefore, the terminals 122 of both heating sections 121 extend from the same end of the tube body 11, eliminating the need for hydraulic bending of the tube body 11, simplifying the process, and reducing mechanical damage to the tube body 11 and the resistance wire.

[0050] Optionally, the heating element 12 can be a resistance wire structure with high heating efficiency.

[0051] The specific structure of terminal 122 can be determined according to the actual situation. For example, it can be a lead-out rod 1221 structure, a wire structure, a conductive sheet structure, or other terminal structures, as long as it can ensure that the heating section 121 inside the tube 11 is electrically connected to the external power supply. Its specific structure is not limited here.

[0052] In practical applications, the tube body 11 is filled with magnesium oxide powder with good thermal conductivity. The compactness of the magnesium oxide powder is related to its thermal conductivity. In related technologies, in order to achieve the overall folding and compression of the heating tube 1, the magnesium oxide powder inside needs to be in a relatively loose state. However, the heat transfer efficiency of the loosely compacted magnesium oxide powder is poor, which can lead to overheating of the internal heating wire and dry burning and wire breakage. In this embodiment, it is not necessary to bend the heating tube 1 as a whole, so there is no need to reduce the compactness of the magnesium oxide powder. This ensures the compactness of the magnesium oxide powder, improves the thermal conductivity, and thus prevents the heating wire from dry burning and overheating, reducing the occurrence of failures.

[0053] It should be noted that by bending the heating element 12 inside the tube body 11 to form two heating sections 121, there is no need to set up additional electrical connectors to connect the two heating sections 121. Compared with the related technology, which connects the two heating sections 121 to the outside of the tube body 11 through two electrical connectors, the heating tube 1 in this embodiment only needs to undergo a normal sealing process. There is no need to consider the insulation problem of exposed conductors or conductors extending to the outside of the tube body 11. Therefore, there are no additional problems such as the connection of the external insulation structure and the temperature resistance of the material. In other words, the process of the heating tube 1 in this embodiment is simpler and the production efficiency is higher.

[0054] In summary, in the heating tube 1 of this utility model, the heating element 12 is bent inside the tube body 11 to form two heating sections 121. Each of the two heating sections 121 has a terminal 122 at the second end of the tube body 11, and both terminals 122 extend out of the second end for electrical connection to a power source outside the tube body 11, thereby enabling the heating element 12 to perform normal heating within the tube body 11. This embodiment simplifies the manufacturing process by having both terminals 122 extend from the same end of the tube body 11, eliminating the need for hydraulic bending of the tube body 11, thus reducing mechanical damage to the tube body 11 and the heating element 12. Simultaneously, it facilitates control of the outer diameter of the tube body 11, achieving high processing precision and significantly reducing the gap between the heating tube 1 and the inner wall of the heater sleeve 2. This ensures that the heat from the heating tube 1 is promptly transferred to the sleeve and exchanges heat with the water, guaranteeing the lifespan of the heating tube 1.

[0055] In one embodiment of this application, as Figure 1 and Figure 2 The inner circumferential wall of the tube body 11 is provided with a positioning boss 111 for positioning the bent section of the heating element 12; the positioning boss 111 is located near the first end of the tube body 11.

[0056] Understandably, a positioning boss 111 is provided on the inner circumferential wall of the tube body 11. The positioning boss 111 can position the bent section of the heating element 12 during the manufacturing process of the heating tube 1, so as to facilitate the filling of the tube body 11 with insulating and heat-conducting material 15 (such as magnesium oxide powder, etc.), and at the same time ensure the separation between the heating element 12 and the tube body 11, and prevent short circuits and other faults caused by the contact between the heating element 12 and the tube body 11.

[0057] In practical applications, taking magnesium oxide powder as an example of insulating and heat-conducting material 15, a fixing plate with two through holes can be made using magnesium oxide powder. Then, the heating element 12 is bent and passed through the two through holes to form two heating sections 121. The fixing plate and the positioning boss 111 inside the tube body 11 are used to limit the positioning and installation of the heating element 12 and the tube body 11. Then, magnesium oxide powder is added into the tube body 11. After the powder is added, the tube is shrunken (the diameter is reduced so that the density of the magnesium oxide powder inside the tube meets the requirements), and at the same time, the fixing plate made of magnesium oxide powder is crushed. Thus, the installation of the bent heating element 12 and the tube body 11 is realized.

[0058] Optionally, the positioning boss 111 can be an annular boss, or it can be a protrusion structure spaced around the periphery of the tube body 11.

[0059] Furthermore, the positioning boss 111 is located near the first end of the tube body 11 so that the heating section 121 has sufficient extension length within the tube body 11 to increase the heating area.

[0060] In one embodiment of this application, as Figure 1 and Figure 2 The tube body 11 is filled with an insulating and heat-conducting material 15, which isolates the two heating sections 121 and the heating element 12 from the tube wall of the tube body 11.

[0061] The insulating thermal conductive material 15 can conduct the heat from the heating section 121 to the tube wall of the tube body 11, which is beneficial for the heat transfer of the heating section 121. Furthermore, the insulating thermal conductive material 15 can isolate the two heating sections 121, preventing them from contacting each other and causing safety hazards. Simultaneously, the insulating thermal conductive material 15 can isolate the heating element 12 from the inner wall of the tube body 11, preventing the heating element 12 from contacting the inner wall of the tube body 11 and causing leakage risks. Generally, the insulating thermal conductive material 15 is magnesium oxide powder. Magnesium oxide powder has good insulation and thermal conductivity, effectively isolating the current inside the heating tube 1 and transferring the heat from the resistance wire to the tube body 11 in a timely manner, thus playing a role in insulation and heat conduction. The powdered magnesium oxide powder can form a stable support structure inside the heating tube 1, ensuring good fixation and support for the heating section 121. This helps maintain the relative position between the two heating sections 121, preventing accidental damage to the heating section 121 caused by vibration or displacement.

[0062] Understandably, compared with the heating tube 1 of the prior art, the heating tube 1 of this utility model embodiment simplifies the processing flow, eliminating the need for processes such as folding and hydraulic forming. The straight cylindrical design facilitates the addition of magnesium oxide powder, resulting in a high density of magnesium oxide powder filling inside. This allows the heat of the resistance wire to be conducted outward in a timely manner, reducing the impact of high-temperature environment on the resistance wire and ensuring the lifespan of the resistance wire.

[0063] In one embodiment of this application, as Figure 1 and Figure 2 The heating tube 1 also includes a sealing cap 13 located at the opening of the first end of the tube. The sealing cap 13 is fixedly connected to the tube body 11 to seal the opening of the first end of the tube. The heating element 12 is spaced apart from the sealing cap 13.

[0064] Understandably, in practical applications, the tube body 11 is filled with an insulating and heat-conducting material 15 (such as magnesium oxide powder). In this embodiment, the sealing cap 13 serves to seal the opening at the first end of the tube body 11, preventing the insulating and heat-conducting material 15 (such as magnesium oxide powder) inside the tube body 11 from leaking.

[0065] Understandably, the sealing cap 13 can be completely housed inside the tube body 11, or it can be partially located inside and partially outside the tube body 11, as long as it can seal the opening of the tube body 11. As an example, considering factors such as the ease of processing and cost, in this embodiment, the sealing cap 13 is housed inside the tube body 11. During processing, the sealing cap 13 can be made of a metal material such as stainless steel and fixed to the tube body 11 by welding. Alternatively, in some other embodiments, the sealing cap 13 can be made of a thermoplastic material such as glass. After the heating element 12 and the insulating heat-conducting material 15 are placed inside the tube body 11, the thermoplastic material is filled into the first end, and then the sealing cap 13 structure is formed by high-temperature thermoforming.

[0066] Furthermore, the end face of the sealing cap 13 facing away from the heating element 12 is flush with the end face of the first end of the tube body 11. This arrangement makes the end face of the first end of the heating tube 1 flush, which makes it easier to control the length of the heating tube 1. When the heating tube 1 is used in the heater sleeve 2, the gap between the end face of the first end of the heating tube 1 and the inner wall of the heater sleeve 2 is easier to control, thus improving the dimensional matching accuracy between the heating tube 1 and the heater sleeve 2.

[0067] In one embodiment of this application, as Figure 1 and Figure 3 The heating tube 1 also includes an insulating plug 14 located at the second end of the tube body 11 and sealing the tube opening. The insulating plug 14, the sealing cap 13, and the tube body 11 form a sealed cavity. The heating element 12 is located inside the sealed cavity, and the two terminals 122 pass through the insulating plug 14.

[0068] In this embodiment, the insulating plug 14 seals the opening at the second end of the tube body 11, preventing the insulating heat-conducting material 15 (e.g., magnesium oxide powder) from getting damp and preventing leakage of the insulating heat-conducting material 15 inside the tube body 11. Simultaneously, the insulating plug 14 also supports and fixes the two terminals 122. Specifically, the insulating plug 14 has two spaced-apart positioning holes, through which the two terminals 122 respectively pass.

[0069] Understandably, the insulating plug 14 can be completely housed inside the tube body 11, or it can be partially located inside and partially outside the tube body 11, as long as it can seal the opening of the tube body 11. As an example, considering factors such as the ease of processing and cost, in this embodiment, the insulating plug 14 is housed inside the tube body 11. During processing, the insulating plug 14 can be made of a hot-melt material such as glass. After the heating element 12 and the insulating heat-conducting material 15 are placed in the tube body 11, the hot-melt material is filled into the second end, and then the insulating plug 14 structure is formed by high-temperature hot melting. At the same time, the insulating plug 14 fixes the two terminals 122.

[0070] Furthermore, the end face of the insulating plug 14 facing away from the first end is flush with the end face of the second end of the tube body 11.

[0071] Understandably, in practical applications, in order to ensure the electrical safety of the two terminals 122 of the heating tube 1, an insulating wrapping 1222 can be provided at the part extending out of the tube body 11. In this embodiment, by making the end face of the insulating plug 14 away from the first end flush with the end face of the second end of the tube body 11, the insulating wrapping 1222 can be connected to both the insulating plug 14 and the tube body 11 at the same time, thus further improving the insulation effect at the second end of the heating tube 1.

[0072] Furthermore, such as Figure 1 , Figure 3 as well as Figure 4 To ensure wiring safety, the creepage distance between the two terminals 122 should be maximized to prevent short circuits. In application, the distance between the two terminals 122 can be gradually increased in the direction away from the tube body 11. Optionally, the two terminals 122 can roughly form a "V" shape.

[0073] Specifically, terminal 122 includes lead-out rod 1221, insulating wrapping 1222, and connecting piece 1223. One end of lead-out rod 1221 is connected to the corresponding heating section 121, and the other end extends out of the second end of tube body 11. Insulating wrapping 1222 is connected to the second end and wraps around the outside of lead-out rod 1221. One end of connecting piece 1223 is located inside insulating wrapping 1222 and electrically connected to the corresponding lead-out rod 1221, and the other end extends out of insulating wrapping 1222 for external connection.

[0074] Understandably, the lead-out rod 1221 can be a conductive rod, wire, conductive sheet, or other conductive structure. The lead-out rod 1221 and the heating section 121 can be connected by welding, winding, or other electrical connection methods. Understandably, the lead-out rod 1221 has a connecting end, and from the middle of the lead-out rod 1221 to the connecting end, the cross-sectional area of ​​the lead-out rod 1221 gradually decreases, so that the connecting end forms a cone shape. This facilitates the spiral resistance wire being sleeved on the connecting end, increasing the contact area between the lead-out rod 1221 and the resistance wire, and ensuring the electrical connection between the lead-out rod 1221 and the resistance wire.

[0075] To prevent short circuits, an insulating wrapping 1222 is provided on each lead-out rod 1221. A connecting piece 1223 is provided within the insulating wrapping 1222 and electrically connected to the lead-out rod 1221. The connecting piece 1223 facilitates smooth wiring to an external power source. Optionally, the insulating wrapping 1222 can be a heat-shrink tubing structure. Optionally, the connecting piece 1223 is a metal contact piece. To ensure creepage distance between the two terminals 122, the connecting piece 1223 can be a metal contact piece with a 135° included angle.

[0076] In one embodiment of this application, as Figure 1 , Figure 3 as well as Figure 4 The heating tube 1 also includes a first flange 16 sleeved on the outside of the tube body 11, and the first flange 16 is installed on the tube body 11 near the second end.

[0077] In this embodiment, by setting a first flange 16 on the outside of the tube body 11, when the heating tube 1 is applied to the dry heater, when the heating tube 1 is inserted into the heater sleeve 2, the first flange 16 can be driven to be assembled onto the fixing post of the heater mounting base. At this time, it is only necessary to limit and fix the first flange 16 to the fixing post to realize the installation of the heating tube 1, without the need to install additional support plates, thereby reducing installation steps and simplifying installation operations.

[0078] Understandably, the method of fixing the first flange 16 to the pipe body 11 can be determined according to the actual situation, such as interference fit, welding, or snap-fit, etc.

[0079] This utility model also proposes a dry heater, such as Figure 5The dry heater includes a heater sleeve 2, a mounting base, and a heating tube 1. The specific structure of the heating tube 1 is as described in the above embodiments. Since this dry heater adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here. One end of the heater sleeve 2 is closed, and the other end is open; the mounting base is connected to the open end of the heater sleeve 2 and is open corresponding to the position of the heater sleeve 2; the heating tube 1 is located inside the heater sleeve 2, and the wiring terminal 122 of the heating tube 1 is located outside the heater sleeve 2.

[0080] In practical applications, the closed end of the heater sleeve 2 extends into the inner tank 4 of the water heater, and the mounting bracket is installed at the tank opening 41 of the inner tank 4, allowing the heater sleeve 2 to be fixed inside the inner tank 4. The heating element 1 is installed inside the heater sleeve 2, heating the water in the inner tank 4 through the heater sleeve 2. If the dry heater malfunctions, it is not necessary to remove the mounting bracket or drain the water from the inner tank 4; simply remove the heating element 1 directly from the heater sleeve 2. Disassembly and installation are very simple.

[0081] In this embodiment, the tube body 11 of the heating tube 1 does not require processes such as folding and hydraulic pressing, so the processing precision of the tube body 11 is higher. The outer diameter of the heating tube 1 can be controlled within ±0.1mm by processing it with a multi-roller tube shrinking machine, which greatly reduces the gap between the heating tube 1 and the inner wall of the heater sleeve 2, ensuring that the heat of the heating tube 1 is transferred to the heater sleeve 2 in a timely manner and exchanges heat with the water, thus ensuring the life of the heating tube 1.

[0082] This utility model also proposes a water heater, such as Figure 6 The water heater includes an inner tank 4 and a dry heater. The specific structure of the dry heater is as described in the above embodiments. Since this water heater adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments. It will not be described in detail here. The closed end of the heater sleeve 2 extends into the inner tank 4, and the mounting base is fixed to the tank opening 41 of the inner tank 4.

[0083] The inner tank 4 has an inlet pipe 51 and an outlet pipe 52. The inlet pipe 51 is used to introduce cold water into the inner tank 4, and the outlet pipe 52 is used to expel hot water from the inner tank 4. The inner tank 4 has a tank opening 41. By fixing the mounting base to the tank opening 41, the heater sleeve 2 is fixed inside the inner tank 4. The heating tube 1 is installed inside the heater sleeve 2, and heats the water in the inner tank 4 through the heater sleeve 2. When the heating tube 1 malfunctions, it is not necessary to remove the mounting base or drain the water from the inner tank 4; the heating tube 1 can be directly removed, making disassembly and installation very simple.

[0084] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A heating tube, characterized by, The heating tube comprises: a tube body having a first end and a second end arranged at two axial ends respectively; and a heating element arranged in the tube body; the heating element is bent in the interior of the tube body to form two heating segments arranged side by side, and the two heating segments extend to the second end along the axial direction of the tube body; the two heating segments are respectively provided with terminal ends at the second end, and the two terminal ends extend out of the second end; an inner circumferential wall of the tube body is provided with a positioning boss for positioning the bent segment of the heating element.

2. The heating tube of claim 1 wherein, The heating element is a resistance wire; and / or, the positioning boss is arranged at a position of the tube body close to the first end.

3. The heating tube according to claim 1 or 2, wherein The heating tube further comprises a sealing cover arranged at the tube opening of the first end, the sealing cover is fixedly connected with the tube body to block the tube opening of the first end; the heating element is arranged in a spaced manner with the sealing cover.

4. The heating tube of claim 3 wherein, The sealing cover is accommodated in the interior of the tube body; an end face of the sealing cover away from the heating element is flush with an end face of the first end of the tube body; and / or, the sealing cover is welded and fixed with the tube body.

5. The heating tube of claim 3 wherein, The heating tube further comprises an insulating plug arranged at the second end of the tube body and blocking the tube opening; the insulating plug, the sealing cover and the tube body enclose a sealed cavity, the heating element is located in the sealed cavity, and the two terminal ends are arranged through the insulating plug.

6. The heating tube according to claim 1 or 2, wherein The two terminal ends are arranged at an included angle, and the distance between the two terminal ends is gradually increased in a direction away from the tube body.

7. The heating tube of claim 6 wherein, The terminal end comprises: an outgoing rod having one end connected with the corresponding heating segment and the other end extending out of the second end of the tube body; an insulating wrapping member connected with the second end and wrapped outside the outgoing rod; and a connecting sheet having one end electrically connected with the corresponding outgoing rod in the insulating wrapping member and the other end extending out of the insulating wrapping member for external connection.

8. The heating tube according to claim 1 or 2, wherein The tube body is filled with insulating and heat-conducting material, which separates the two heating segments and separates the heating element from the tube wall of the tube body; and / or, the tube body is an insulating and heat-conducting member.

9. The heating tube according to claim 1 or 2, wherein The heating tube further comprises a first flange sleeved outside the tube body, and the first flange is arranged at a position of the tube body close to the second end.

10. A dry heater characterized by, The heating tube comprises: a heater sleeve having a closed end and an open end; a mounting seat connected with the open end of the heater sleeve and corresponding to the position of the heater sleeve; and the heating tube as claimed in any one of claims 1 to 9 is arranged in the heater sleeve, and the terminal end of the heating tube is arranged outside the heater sleeve.

11. A water heater, characterized by The dry-type heater and the liner as claimed in claim 10, the closed end of the heater sleeve extends into the liner, and the mounting seat is fixed to the liner opening.

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