Heating tube, dry heater and water heater

Abstract

Disclosed are a heating tube (1), a dry heater and a water heater. The heating tube (1) includes a tube body (11) and a heating element (12). The tube body (11) has a first end and a second end respectively provided at both axial ends, and the heating element (12) is provided at the tube body (11). 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) extend in the axial direction of the tube body (11) to the second end. The two heating sections (121) are respectively provided with terminals (122) at the second end, and two terminals (122) extend out of the second end.

Description

TECHNICAL FIELD

[0001] The present invention relates to the technical field of water heaters, and in particular to a heating tube, a dry heater and a water heater.BACKGROUND

[0002] Dry heaters are used in storage-type electric water heaters. Dry heaters generally have a heating tube and a heater sleeve. The heater sleeve is fixed inside the inner tank, and the heating tube is provided in the heater sleeve. When the heating tube is working, the heating tube is energized to convert electrical energy into thermal energy, and the heat is exchanged with the water in the inner tank through the heater sleeve, thereby heating the water in the inner tank.

[0003] The heating tube of the existing dry heater needs to be folded in half, hydraulically formed and other processes during the processing. Since a heating wire is inserted through the heating tube and the heating tube is filled with magnesium oxide powder, during the folding and hydraulic forming process, external force squeezes the pipe material of the heating tube and the magnesium oxide powder in the heating tube, which will affect the heating tube. The resistance wire causes mechanical damage, which can easily cause premature damage to the resistance wire during use.SUMMARY

[0004] The main purpose of the present invention is to propose a heating tube, a dry heater and a water heater, aiming to simplify processing and reduce the risk of wire breakage.

[0005] In order to achieve the above purpose, the heating tube proposed in the present invention includes a tube body and a heating element.

[0006] In an embodiment of the present invention, the tube body has a first end and a second end, and the first end is axially opposite to the second end.

[0007] Optionally, the heating element may be provided at the tube body, the heating element may be bent inside the tube body to form two heating sections arranged side by side, and the two heating sections may extend in an axial direction of the tube body to the second end.

[0008] Optionally, the two heating sections may be respectively provided with terminals at respective second end, and two terminals may extend out of the second end.

[0009] Optionally, the heating element may be a resistance wire.

[0010] Optionally, an inner peripheral wall of the tube body may be provided with a positioning boss for positioning a bent section of the heating element. The positioning boss may be provided at a position of the tube body adjacent to the first end.

[0011] Optionally, the heating tube may further include a seal cover provided at an opening of the first end, the seal cover may be fixedly connected to the tube body to block the opening of the first end, and the heating element may be spaced apart from the seal cover.

[0012] Optionally, the seal cover may be provided inside the tube body, and an end surface of the seal cover away from the heating element may be flush with an end surface of the first end of the tube body.

[0013] Optionally, the seal cover may be fixed to the tube body by welding.

[0014] Optionally, the heating tube may further include an insulation plug provided at the second end of the tube body and blocking the opening, the insulation plug. The seal cover and the tube body may be enclosed to form a seal cavity, the heating element may be provided in the seal cavity, and the two terminals may be inserted through the insulation plug.

[0015] Optionally, the two terminals may be arranged at an angle. Preferably, a distance between the two terminals gradually may increase in a direction away from the tube body.

[0016] Optionally, the terminal may include: a lead-out rod with one end connected to the heating section, and the other end extending out of the second end of the tube body; an insulation wrapper connected to the second end and wrapped around an outside of the lead-out rod; and a connection sheet with one end providing in the insulation wrapper and electrically connected to the lead-out rod, and the other end extending out of the insulation wrapper for external connection.

[0017] Optionally, the tube body may be filled with an insulation and heat conductive material, and the insulation and heat conductive material may isolate the two heating sections and isolate the heating element from a wall of the tube body.

[0018] Optionally, the tube body may be an insulation and heat conductive member.

[0019] Optionally, the heating tube may further include a first flange sleeved outside the tube body, and the first flange may be installed at a position of the tube body adjacent to the second end.

[0020] In order to achieve the above purpose, the present invention also provides a dry heater, including: a heater sleeve with one end closed and the other end open; an installation base connected to an open end of the heater sleeve and open at a position corresponding to the heater sleeve; and the heating tube as described above, the heating tube is provided in the heater sleeve, and a terminal of the heating tube is provided outside the heater sleeve.

[0021] In order to achieve the above purpose, the present invention also provides a water heater, including the dry heater as described above and an inner tank, a closed end of a heater sleeve extends into the inner tank, and an installation base is fixed to an aperture of the inner tank.

[0022] In the heating tube of the technical solution of the present invention, the heating element is bent in the tube body to form two heating sections. The two heating sections are respectively provided with terminals at the second end of the tube body, and the two terminals extend out of the second end of the tube body for electrical connection with the power supply outside the tube body, to realize the normal heating function of the heating element in the tube body. In this embodiment, both terminals are extended from the same end of the tube body, thereby eliminating the need to fold the tube body in half using hydraulic pressure, simplifying the processing technology, and reducing mechanical damage to the tube body and the heating element. At the same time, it is convenient to control the outer diameter of the tube body, with high processing precision, which greatly reduces the gap between the heating tube and the inner wall of the heater sleeve, ensuring that the heat of the heating tube is transferred to the sleeve in a timely manner and exchanges heat with water, and ensuring the life of the heating tube.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly describe the embodiments of the present invention or the technical solutions in the related art, accompanying drawings needed to be used in the description of the embodiments or the related art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts. FIG. 1 is a schematic structural view of a heating tube according to an embodiment of the present invention. FIG. 2 is a partial enlarged view at portion A in FIG. 1. FIG. 3 is a partial enlarged view at portion B in FIG. 1. FIG. 4 is a side view of the heating tube of the embodiment of FIG. 1. FIG. 5 is a schematic structural view of a dry heater according to an embodiment of the present invention. FIG. 6 is a schematic structural view of a water heater according to an embodiment of the present invention. Description of reference signs

[0024] reference signnamereference signname1heating tube14insulation plug11tube body15insulation and heat conductive material111positioning boss16first flange12heating element2heater sleeve121heating section3installation base122terminal4inner tank1221lead-out rod41aperture1222insulation wrapper51water inlet pipe1223connection sheet52water outlet pipe13seal cover

[0025] The realization of the purpose, functional features and advantages of the present invention will be further described in conjunction with the embodiments, with reference to the accompanying drawings.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present invention.

[0027] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship, movement conditions, etc. between the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0028] At the same time, the meaning of "and / or" in the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution that A and B satisfy at the same time.

[0029] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying its relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions in the various embodiments can be combined with each other, but it must be based on what a person of ordinary skill in the art can implement. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions does not exist, nor is it within the scope of the present invention.

[0030] The heating tube of the existing dry heater needs to be integrally folded in half, hydraulic forming and other processes during the processing process. It is processed from a long straight round tube into a long straight oval tube body after being folded in half. Since a heating wire is inserted through the heating tube and the heating tube is filled with magnesium oxide powder, during the hydraulic forming process, external force squeezes the tube and the magnesium oxide powder in the heating tube, causing mechanical damage to the resistance wire in the heating tube. It is easy to cause the resistance wire to be damaged in advance during use. The existing technology has the problem that the heating tube has complicated processing technology and the resistance wire is easy to break.

[0031] Based on this, the present invention proposes a heating tube, which aims to eliminate the need to bend the electric heating tube as a whole, simplify the processing technology, and reduce the risk of wire breakage. The structure of the heating tube will be described below by way of embodiment.

[0032] In the embodiment of the present invention, as shown in FIG. 1 to FIG. 4, the heating tube 1 includes a tube body 11 and a heating element 12.

[0033] The tube body 11 has a first end and a second end, and the first end is axially opposite to the second end. The heating element 12 is provided at the tube body 11, and is bent inside the tube body 11 to form two heating sections 121 arranged side by side. The two heating sections 121 extend in an axial direction of the tube body 11 to the second end, and are respectively provided with terminals 122 at respective second end. Two terminals 122 extend out of the second end.

[0034] In this embodiment, the tube body 11 plays the role of installing the heating element 12 and conducting the heat of the heating element 12 away. It can be understood that the insulation between the tube body 11 and the heating element 12 prevents leakage problems caused by electrical conduction between the heating element 12 and the tube body 11. At the same time, the tube body 11 can quickly conduct the heat inside to the outside. In an embodiment, the tube body 11 can be a metal tube or a non-metal tube with good thermal conductivity. The tube body 11 itself can be made of insulating material or non-insulating material. When the tube body 11 is made of non-insulating material, the tube body 11 can be isolated and insulated from the heating element 12 by filling the inside of the tube body 11 with insulating material. In an embodiment, the cross-sectional shape of the tube body 11 can be circular, semicircular, square, triangular or other special shapes. In practical applications, the tube body 11 can be configured as a circular tube for easy molding.

[0035] The heating element 12 is bent inside the tube body 11 to form two heating sections 121 arranged side by side, so that the two heating sections 121 are electrically connected inside the tube body 11, and the two heating sections 121 are respectively provided with terminals 122 at the second end. The two terminals 122 are respectively a positive terminal 122 and a negative terminal 122, which are used to extend out of the second end of the tube body 11 and electrically connected to the external power supply structure, to realize the energization and heating of the two heating sections 121. It can be seen from this that the terminals 122 of the two heating sections 121 extend from the same end of the tube body 11, and there is no need to fold the tube body 11 in half or hydraulic pressure, which simplifies the process and reduces mechanical damage to the tube body 11 and the resistance wire.

[0036] In an embodiment, the heating element 12 can be a resistance wire structure with high heating efficiency.

[0037] The specific structure of the terminal 122 can be determined according to the actual situation, for example, it can be a lead-out rod 1221, 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 body 11 is electrically connected to the external power supply, and its specific structure is not limited here.

[0038] In practical applications, the inside of the tube body 11 is filled with magnesium oxide powder with good thermal conductivity. The compactness of the magnesium oxide powder is related to the thermal conductivity. In the related technology, in order to realize the folding and extrusion of the heating tube 1 as a whole, the magnesium oxide powder filled inside needs to be in a loose state, and the heat transfer efficiency of loose magnesium oxide powder is poor, which causes the internal heating wire to overheat and cause dry burning. In this embodiment, there is no need to bend the heating tube 1 as a whole, and there is no need to reduce the compactness of the magnesium oxide powder. This can ensure the compactness of the magnesium oxide powder and improve the thermal conductivity efficiency, thereby preventing the heating wire from dry burning and overheating, and reducing the occurrence of malfunctions.

[0039] It should be noted that the heating element 12 is bent in the tube body 11 to form two heating sections 121, so there is no need to provide additional electrical connectors to connect the two heating sections 121. Compared with the solution in the related art that the two heating sections 121 are extended to the outside of the tube body 11 through two electrical connectors for electrical connection, the heating tube 1 of this embodiment only needs to undergo a normal sealing process, and there is no need to additionally consider the insulation problem of the conductor being exposed or extending outside the tube body 11. In addition, there is no additional issues regarding the connection of the external insulation structure and the temperature resistance of the material, that is, the heating tube 1 of this embodiment has a simpler process and higher production efficiency.

[0040] In summary, in the heating tube 1 of the technical solution of the present invention, the heating element 12 is bent in the tube body 11 to form two heating sections 121. The two heating sections 121 are respectively provided with terminals 122 at the second end of the tube body 11. The two terminals 122 extend out of the second end for electrical connection with the power source outside the tube body 11, thereby realizing the normal heating function of the heating element 12 in the tube body 11. In this embodiment, two terminals 122 are extended from the same end of the tube body 11, thereby eliminating the need to fold the tube body 11 in half using hydraulic pressure, simplifying the processing technology, and reducing the mechanical damage to the tube body 11 and the heating element 12. At the same time, it is convenient to control the outer diameter of the tube body 11, and the processing precision is high, 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 sleeve in time and is exchanged with water to ensure the life of the heating tube 1.

[0041] In an embodiment of the present invention, as shown in FIG. 1 and FIG. 2, an inner peripheral 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 provided at a position of the tube body 11 adjacent to the first end.

[0042] It can be understood that the positioning boss 111 is provided on the inner peripheral 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, to facilitate filling the tube body 11 with insulation and heat conductive material 15 (such as magnesium oxide powder, etc.). At the same time, it can ensure the separation between the heating element 12 and the tube body 11, and prevent the heating element 12 from contacting tube body 11 and cause short circuit and other faults.

[0043] In practical applications, taking the insulation and heat conductive material 15 as magnesium oxide powder as an example, the magnesium oxide powder can be used to first make a fixed plate with two through holes, then the heating element 12 can be bent and pass through the two through holes in sequence to form two heating sections 121, and the positioning and installation of the heating element 12 and the tube body 11 is realized through the fixed cooperation between the fixed plate and the positioning boss 111 in the tube body 11. Then, the magnesium oxide powder is added into the tube body 11. When the tube is shrunk (reduced in the diameter so that the solidity of the magnesium oxide powder in the tube meets the requirements) after the powder addition is completed, the fixed plate made of magnesium oxide powder is crushed at the same time. Thus, the installation of the heating element 12 in the bent state and the tube body 11 is achieved.

[0044] In an embodiment, the positioning boss 111 can be an annular boss, or can be a protrusion structure spaced around the circumference of the tube body 11, or the like.

[0045] Furthermore, the positioning boss 111 is provided at the position of the tube body 11 adjacent to the first end, so that the heating section 121 has a sufficient extension length within the tube body 11 to increase the heating area.

[0046] In an embodiment of the present invention, as shown in FIG. 1 and FIG. 2, the tube body 11 is filled with the insulation and heat conductive material 15. The insulation and heat conductive material 15 isolates the two heating sections 121 and isolates the heating element 12 from the wall of the tube body 11.

[0047] The insulation and heat conductive material 15 can conduct the heat of the heating section 121 to the wall of the tube body 11, which is conducive to transferring the heat of the heating section 121. Furthermore, the insulation and heat conductive material 15 can isolate the two heating sections 121 to prevent potential safety hazards caused by the two heating sections 121 contacting each other. At the same time, the insulation and heat conductive material 15 can isolate the heating element 12 and the inner wall of the tube body 11 to prevent the heating element 12 from contacting the inner wall of the tube body 11 and causing electric leakage. Generally, the insulation and heat conductive material 15 is magnesium oxide powder. The magnesium oxide powder has good insulation properties and thermal conductivity, can effectively isolate the current inside the heating tube 1, and transfer the heat of the resistance wire to the tube body 11 in time, which plays the role of insulation and heat conduction. Powdered magnesium oxide powder can form a stable support structure in the heating tube 1, so that the heating section 121 of the heating tube 1 is well fixed and supported. This helps to maintain the relative position between the two heating sections 121 and prevent accidental damage to the heating section 121 due to vibration or displacement.

[0048] It can be understood that compared with the heating tube 1 of the related art, the heating tube 1 in the embodiment of the present invention simplifies the processing process and does not require folding, hydraulic molding and other processes. The design of the straight tube facilitates the addition of magnesium oxide powder, so that the filling density of the internal magnesium oxide powder is high, and the heat of the resistance wire can be conducted outward in time, reducing the impact of high temperature environment on the resistance wire and ensuring the life of the resistance wire.

[0049] In an embodiment of the present invention, as shown in FIG. 1 and FIG. 2, the heating tube 1 also includes a seal cover 13 provided at an opening of the first end. The seal cover 13 is fixedly connected to the tube body 11 to block the opening of the first end. The heating element 12 and the seal cover 13 are spaced apart.

[0050] It can be understood that in actual application, the tube body 11 is filled with insulation and heat conductive material 15 (such as magnesium oxide powder, etc.), and the seal cover 13 in this embodiment plays a role in sealing the opening of the first end of the tube body 11, to prevent the insulation and heat conductive material 15 (such as magnesium oxide powder, etc.) inside the tube body 11 from leaking.

[0051] It can be understood that the seal cover 13 can be completely provided inside the tube body 11, or can be partially provided inside the tube body 11 and partially outside the tube body 11, as long as it can seal the opening of the tube body 11. As an example, taking into account factors such as the difficulty and cost of the processing technology, the seal cover 13 is provided inside the tube body 11 in this embodiment. During processing, the seal cover 13 can be made of metal material such as stainless steel, and can be fixed to the tube body 11 by welding. In some other embodiments, the seal cover 13 can be made of hot-melt material such as glass. After the heating element 12 and the insulation and heat conductive material 15 are provided in the tube body 11, the hot-melt material is filled into the first end, and the seal cover 13 is molded through high-temperature hot melting.

[0052] Furthermore, an end surface of the seal cover 13 away from the heating element 12 is flush with the end surface of the first end of the tube body 11. In this way, the end surface of the first end of the heating tube 1 is flush, which makes it easier to control the length and size of the heating tube 1. When the heating tube 1 is used in the heater sleeve 2, the gap between the first end of the heating tube 1 and the inner wall of the heater sleeve 2 is easier to control, thereby improving the size matching accuracy of the heating tube 1 and the heater sleeve 2.

[0053] In an embodiment of the present invention, as shown in FIG. 1 and FIG. 3, the heating tube 1 also includes an insulation plug 14 provided at the second end of the tube body 11 and blocking the opening. The insulation plug 14, the seal cover 13 and the tube body 11 are enclosed to form a seal cavity, and the heating element 12 is provided in the seal cavity. The two terminals 122 are inserted through the insulation plug 14.

[0054] In this embodiment, the insulation plug 14 serves to seal the opening of the second end of the tube body 11 to prevent the insulation and heat conductive material 15 (such as magnesium oxide powder, etc.) from getting wet and prevent the insulation and heat conductive material 15 inside the tube body 11 from leaking. At the same time, the insulation plug 14 also plays a role of supporting and fixing the two terminals 122. Specifically, the insulation plug 14 is provided with two positioning holes spaced apart, and the two terminals 122 respectively pass through the two positioning holes located at the second end.

[0055] It can be understood that the insulation plug 14 can be completely provided inside the tube body 11, or can be partially provided inside the tube body 11 and partially provided outside the tube body 11, as long as the opening of the tube body 11 can be blocked. As an example, considering factors such as the difficulty of the processing process and cost, in this embodiment, the insulation plug 14 is provided inside the tube body 11. During processing, the insulation plug 14 can be made of hot-melt material such as glass. After the heating element 12 and the insulation and heat conductive material 15 are provided in the tube body 11, the second end is filled with hot melt material, and then the insulation plug 14 is molded by high-temperature hot melting. At the same time, the two terminals 122 is fixed through the insulation plug 14.

[0056] Furthermore, the end surface of the insulation plug 14 away from the first end is flush with the end surface of the second end of the tube body 11.

[0057] It can be understood that in practical applications, in order to ensure the electrical safety of the two terminals 122 of the heating tube 1, an insulation wrapper 1222 can be provided at the portion extending from the tube body 11. In this embodiment, the end surface of the insulation plug 14 away from the first end is flush with the end surface of the second end of the tube body 11, so that the insulation wrapper 1222 can be connected to the insulation plug 14 and the tube body 11 at the same time, and the insulation effect at the second end of the heating tube 1 can be further improved.

[0058] Further, as shown in FIG. 1, FIG. 3 and FIG. 4, in order to ensure the safety of wiring, it is necessary to increase the creepage distance between the two terminals 122 as much as possible to prevent short circuit. During application, the distance between the two terminals 122 can gradually increase in the direction away from the tube body 11. In an embodiment, the two terminals 122 generally form a "V"-shaped structure.

[0059] Specifically, the terminal 122 includes a lead-out rod 1221, an insulation wrapper 1222 and a connection sheet 1223. One end of the lead-out rod 1221 is connected to the corresponding heating section 121, and the other end of the lead-out rod 1221 extends out of the second end of the tube body 11. The insulation wrapper 1222 is connected to the second end and wrapped around the outside of the lead-out rod 1221. One end of the connection sheet 1223 is provided in the insulation wrapper 1222 and is electrically connected to the corresponding lead-out rod 1221, and the other end of the connection sheet 1223 extends out of the insulation wrapper 1222 for external connection.

[0060] It can be understood that the lead-out rod 1221 can be a conductive rod, a wire, a 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. It can be understood that the lead-out rod 1221 has a connecting end, and the cross-sectional area of the lead-out rod 1221 gradually decreases from the middle of the lead-out rod 1221 to the connecting end, so that the connecting end forms a tapered shape, which is advantageous for the spiral resistance wire to be sleeved on the connection end, thereby 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.

[0061] In order to prevent short circuits, the insulation wrapper 1222 is provided on each lead-out rod 1221, and the connection sheet 1223 is provided in the insulation wrapper 1222 to electrically connect with the lead-out rod 1221. The connection sheet 1223 is used to smoothly connect to an external power source. In an embodiment, the insulation wrapper 1222 can be a heat-shrinkable sleeve structure. In an embodiment, the connection sheet 1223 is a metal connection sheet. In order to ensure the creepage distance between the two terminals 122, the connection sheet 1223 can be a metal connection sheet with an angle of 135 ° .

[0062] In an embodiment of the present invention, as shown in FIG. 1, FIG. 3 and FIG. 4, the heating tube 1 also includes a first flange 16 sleeved on the outside of the tube body 11. The first flange 16 is installed at the position of the tube body 11 adjacent to the second end.

[0063] In this embodiment, by providing the first flange 16 outside the tube body 11, when the heating tube 1 is used in a dry heater, and the heating tube 1 is inserted into the heater sleeve 2, the first flange 16 can be driven to be assembled to the fixed column of the heater installation base. At this time, only the first flange 16 and the fixed column need to be limited and fixed to install the heating tube 1 without further installation of additional support pieces, thereby reducing installation steps and simplifying installation operations.

[0064] It can be understood that the fixing method of the first flange 16 and the tube body 11 can be determined according to the actual situation, for example, it can be interference fixing, welding fixation, snap-in fixation, etc.

[0065] The present invention also proposes a dry heater, as shown in FIG. 5, the dry heater includes a heater sleeve 2, an installation base and a heating tube 1. The specific structure of the heating tube 1 refers to the above embodiment. Since this dry heater adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated. One end of the heater sleeve 2 is closed and the other end of the heater sleeve 2 is open. The installation 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 provided in the heater sleeve 2. The terminal 122 of the heating tube 1 is provided outside the heater sleeve 2.

[0066] In actual application, the closed end of the heater sleeve 2 extends into the inner tank 4 of the water heater, and the installation base is installed at the aperture 41 of the inner tank 4, so that the heater sleeve 2 can be fixed inside the inner tank 4. The heating tube 1 is installed in the heater sleeve 2, and the water in the inner tank 4 is heated through the heater sleeve 2. If the dry heater fails, there is no need to disassemble the installation base or drain the water in the inner tank 4, and the heating tube 1 is directly removed from the heater sleeve 2. The disassembly and installation are very simple.

[0067] In this embodiment, the tube body 11 of the heating tube 1 does not need to be folded in half using oil pressure and other processes, so the tube body 11 can be processed with higher precision. The outer diameter of the heating tube 1 can be processed by a multi-roller tube shrinking machine and can be controlled within the range of ± 0.1mm, which greatly reduces the gap between the heating tube 1 and the inner wall of the heater sleeve 2 and can ensure that the heat of the heating tube 1 is transferred to the heater sleeve 2 in time and conducts heat exchange with the water, ensuring that the life of the heating tube 1.

[0068] The present invention also proposes a water heater, as shown in FIG. 6, the water heater includes an inner tank 4 and a dry heater. The specific structure of the dry heater refers to the above embodiments. Since this water heater adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated again. The closed end of the heater sleeve 2 extends into the inner tank 4, and the installation base is fixed to the aperture 41 of the inner tank 4.

[0069] The inner pot 4 has a water inlet pipe 51 and a water outlet pipe 52. The water inlet pipe 51 is used to feed cold water into the inner tank 4, and the water outlet pipe 52 is used to discharge hot water from the inner tank 4. The inner tank 4 is provided with the aperture 41. By fixing the installation base 3 to the aperture 41, the heater sleeve 2 is fixed inside the inner tank 4. The heating tube 1 is installed in the heater sleeve 2, and the water in the inner tank 4 is heated through the heater sleeve 2. When the heating tube 1 fails, there is no need to disassemble the installation base 3 or drain the water in the inner tank 4. The heating tube 1 can be directly removed. The disassembly and installation are very simple.

Examples

Embodiment Construction

[0026]The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present invention.

[0027]It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship, movement conditions, etc. between the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0028]At the same time, the meaning of "and / or" in the text includes three parallel solutions. Taking "A and / or B" as an exampl...

TECHNICAL FIELD

[0001] The present invention relates to the technical field of water heaters, and in particular to a heating tube, a dry heater and a water heater.BACKGROUND

[0002] Dry heaters are used in storage-type electric water heaters. Dry heaters generally have a heating tube and a heater sleeve. The heater sleeve is fixed inside the inner tank, and the heating tube is provided in the heater sleeve. When the heating tube is working, the heating tube is energized to convert electrical energy into thermal energy, and the heat is exchanged with the water in the inner tank through the heater sleeve, thereby heating the water in the inner tank.

[0003] The heating tube of the existing dry heater needs to be folded in half, hydraulically formed and other processes during the processing. Since a heating wire is inserted through the heating tube and the heating tube is filled with magnesium oxide powder, during the folding and hydraulic forming process, external force squeezes the pipe material of the heating tube and the magnesium oxide powder in the heating tube, which will affect the heating tube. The resistance wire causes mechanical damage, which can easily cause premature damage to the resistance wire during use.SUMMARY

[0004] The main purpose of the present invention is to propose a heating tube, a dry heater and a water heater, aiming to simplify processing and reduce the risk of wire breakage.

[0005] In order to achieve the above purpose, the heating tube proposed in the present invention includes a tube body and a heating element.

[0006] In an embodiment of the present invention, the tube body has a first end and a second end, and the first end is axially opposite to the second end.

[0007] Optionally, the heating element may be provided at the tube body, the heating element may be bent inside the tube body to form two heating sections arranged side by side, and the two heating sections may extend in an axial direction of the tube body to the second end.

[0008] Optionally, the two heating sections may be respectively provided with terminals at respective second end, and two terminals may extend out of the second end.

[0009] Optionally, the heating element may be a resistance wire.

[0010] Optionally, an inner peripheral wall of the tube body may be provided with a positioning boss for positioning a bent section of the heating element. The positioning boss may be provided at a position of the tube body adjacent to the first end.

[0011] Optionally, the heating tube may further include a seal cover provided at an opening of the first end, the seal cover may be fixedly connected to the tube body to block the opening of the first end, and the heating element may be spaced apart from the seal cover.

[0012] Optionally, the seal cover may be provided inside the tube body, and an end surface of the seal cover away from the heating element may be flush with an end surface of the first end of the tube body.

[0013] Optionally, the seal cover may be fixed to the tube body by welding.

[0014] Optionally, the heating tube may further include an insulation plug provided at the second end of the tube body and blocking the opening, the insulation plug. The seal cover and the tube body may be enclosed to form a seal cavity, the heating element may be provided in the seal cavity, and the two terminals may be inserted through the insulation plug.

[0015] Optionally, the two terminals may be arranged at an angle. Preferably, a distance between the two terminals gradually may increase in a direction away from the tube body.

[0016] Optionally, the terminal may include: a lead-out rod with one end connected to the heating section, and the other end extending out of the second end of the tube body; an insulation wrapper connected to the second end and wrapped around an outside of the lead-out rod; and a connection sheet with one end providing in the insulation wrapper and electrically connected to the lead-out rod, and the other end extending out of the insulation wrapper for external connection.

[0017] Optionally, the tube body may be filled with an insulation and heat conductive material, and the insulation and heat conductive material may isolate the two heating sections and isolate the heating element from a wall of the tube body.

[0018] Optionally, the tube body may be an insulation and heat conductive member.

[0019] Optionally, the heating tube may further include a first flange sleeved outside the tube body, and the first flange may be installed at a position of the tube body adjacent to the second end.

[0020] In order to achieve the above purpose, the present invention also provides a dry heater, including: a heater sleeve with one end closed and the other end open; an installation base connected to an open end of the heater sleeve and open at a position corresponding to the heater sleeve; and the heating tube as described above, the heating tube is provided in the heater sleeve, and a terminal of the heating tube is provided outside the heater sleeve.

[0021] In order to achieve the above purpose, the present invention also provides a water heater, including the dry heater as described above and an inner tank, a closed end of a heater sleeve extends into the inner tank, and an installation base is fixed to an aperture of the inner tank.

[0022] In the heating tube of the technical solution of the present invention, the heating element is bent in the tube body to form two heating sections. The two heating sections are respectively provided with terminals at the second end of the tube body, and the two terminals extend out of the second end of the tube body for electrical connection with the power supply outside the tube body, to realize the normal heating function of the heating element in the tube body. In this embodiment, both terminals are extended from the same end of the tube body, thereby eliminating the need to fold the tube body in half using hydraulic pressure, simplifying the processing technology, and reducing mechanical damage to the tube body and the heating element. At the same time, it is convenient to control the outer diameter of the tube body, with high processing precision, which greatly reduces the gap between the heating tube and the inner wall of the heater sleeve, ensuring that the heat of the heating tube is transferred to the sleeve in a timely manner and exchanges heat with water, and ensuring the life of the heating tube.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly describe the embodiments of the present invention or the technical solutions in the related art, accompanying drawings needed to be used in the description of the embodiments or the related art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts. FIG. 1 is a schematic structural view of a heating tube according to an embodiment of the present invention. FIG. 2 is a partial enlarged view at portion A in FIG. 1. FIG. 3 is a partial enlarged view at portion B in FIG. 1. FIG. 4 is a side view of the heating tube of the embodiment of FIG. 1. FIG. 5 is a schematic structural view of a dry heater according to an embodiment of the present invention. FIG. 6 is a schematic structural view of a water heater according to an embodiment of the present invention. Description of reference signs

[0024] reference signnamereference signname1heating tube14insulation plug11tube body15insulation and heat conductive material111positioning boss16first flange12heating element2heater sleeve121heating section3installation base122terminal4inner tank1221lead-out rod41aperture1222insulation wrapper51water inlet pipe1223connection sheet52water outlet pipe13seal cover

[0025] The realization of the purpose, functional features and advantages of the present invention will be further described in conjunction with the embodiments, with reference to the accompanying drawings.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present invention.

[0027] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship, movement conditions, etc. between the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0028] At the same time, the meaning of "and / or" in the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution that A and B satisfy at the same time.

[0029] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying its relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions in the various embodiments can be combined with each other, but it must be based on what a person of ordinary skill in the art can implement. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions does not exist, nor is it within the scope of the present invention.

[0030] The heating tube of the existing dry heater needs to be integrally folded in half, hydraulic forming and other processes during the processing process. It is processed from a long straight round tube into a long straight oval tube body after being folded in half. Since a heating wire is inserted through the heating tube and the heating tube is filled with magnesium oxide powder, during the hydraulic forming process, external force squeezes the tube and the magnesium oxide powder in the heating tube, causing mechanical damage to the resistance wire in the heating tube. It is easy to cause the resistance wire to be damaged in advance during use. The existing technology has the problem that the heating tube has complicated processing technology and the resistance wire is easy to break.

[0031] Based on this, the present invention proposes a heating tube, which aims to eliminate the need to bend the electric heating tube as a whole, simplify the processing technology, and reduce the risk of wire breakage. The structure of the heating tube will be described below by way of embodiment.

[0032] In the embodiment of the present invention, as shown in FIG. 1 to FIG. 4, the heating tube 1 includes a tube body 11 and a heating element 12.

[0033] The tube body 11 has a first end and a second end, and the first end is axially opposite to the second end. The heating element 12 is provided at the tube body 11, and is bent inside the tube body 11 to form two heating sections 121 arranged side by side. The two heating sections 121 extend in an axial direction of the tube body 11 to the second end, and are respectively provided with terminals 122 at respective second end. Two terminals 122 extend out of the second end.

[0034] In this embodiment, the tube body 11 plays the role of installing the heating element 12 and conducting the heat of the heating element 12 away. It can be understood that the insulation between the tube body 11 and the heating element 12 prevents leakage problems caused by electrical conduction between the heating element 12 and the tube body 11. At the same time, the tube body 11 can quickly conduct the heat inside to the outside. In an embodiment, the tube body 11 can be a metal tube or a non-metal tube with good thermal conductivity. The tube body 11 itself can be made of insulating material or non-insulating material. When the tube body 11 is made of non-insulating material, the tube body 11 can be isolated and insulated from the heating element 12 by filling the inside of the tube body 11 with insulating material. In an embodiment, the cross-sectional shape of the tube body 11 can be circular, semicircular, square, triangular or other special shapes. In practical applications, the tube body 11 can be configured as a circular tube for easy molding.

[0035] The heating element 12 is bent inside the tube body 11 to form two heating sections 121 arranged side by side, so that the two heating sections 121 are electrically connected inside the tube body 11, and the two heating sections 121 are respectively provided with terminals 122 at the second end. The two terminals 122 are respectively a positive terminal 122 and a negative terminal 122, which are used to extend out of the second end of the tube body 11 and electrically connected to the external power supply structure, to realize the energization and heating of the two heating sections 121. It can be seen from this that the terminals 122 of the two heating sections 121 extend from the same end of the tube body 11, and there is no need to fold the tube body 11 in half or hydraulic pressure, which simplifies the process and reduces mechanical damage to the tube body 11 and the resistance wire.

[0036] In an embodiment, the heating element 12 can be a resistance wire structure with high heating efficiency.

[0037] The specific structure of the terminal 122 can be determined according to the actual situation, for example, it can be a lead-out rod 1221, 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 body 11 is electrically connected to the external power supply, and its specific structure is not limited here.

[0038] In practical applications, the inside of the tube body 11 is filled with magnesium oxide powder with good thermal conductivity. The compactness of the magnesium oxide powder is related to the thermal conductivity. In the related technology, in order to realize the folding and extrusion of the heating tube 1 as a whole, the magnesium oxide powder filled inside needs to be in a loose state, and the heat transfer efficiency of loose magnesium oxide powder is poor, which causes the internal heating wire to overheat and cause dry burning. In this embodiment, there is no need to bend the heating tube 1 as a whole, and there is no need to reduce the compactness of the magnesium oxide powder. This can ensure the compactness of the magnesium oxide powder and improve the thermal conductivity efficiency, thereby preventing the heating wire from dry burning and overheating, and reducing the occurrence of malfunctions.

[0039] It should be noted that the heating element 12 is bent in the tube body 11 to form two heating sections 121, so there is no need to provide additional electrical connectors to connect the two heating sections 121. Compared with the solution in the related art that the two heating sections 121 are extended to the outside of the tube body 11 through two electrical connectors for electrical connection, the heating tube 1 of this embodiment only needs to undergo a normal sealing process, and there is no need to additionally consider the insulation problem of the conductor being exposed or extending outside the tube body 11. In addition, there is no additional issues regarding the connection of the external insulation structure and the temperature resistance of the material, that is, the heating tube 1 of this embodiment has a simpler process and higher production efficiency.

[0040] In summary, in the heating tube 1 of the technical solution of the present invention, the heating element 12 is bent in the tube body 11 to form two heating sections 121. The two heating sections 121 are respectively provided with terminals 122 at the second end of the tube body 11. The two terminals 122 extend out of the second end for electrical connection with the power source outside the tube body 11, thereby realizing the normal heating function of the heating element 12 in the tube body 11. In this embodiment, two terminals 122 are extended from the same end of the tube body 11, thereby eliminating the need to fold the tube body 11 in half using hydraulic pressure, simplifying the processing technology, and reducing the mechanical damage to the tube body 11 and the heating element 12. At the same time, it is convenient to control the outer diameter of the tube body 11, and the processing precision is high, 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 sleeve in time and is exchanged with water to ensure the life of the heating tube 1.

[0041] In an embodiment of the present invention, as shown in FIG. 1 and FIG. 2, an inner peripheral 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 provided at a position of the tube body 11 adjacent to the first end.

[0042] It can be understood that the positioning boss 111 is provided on the inner peripheral 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, to facilitate filling the tube body 11 with insulation and heat conductive material 15 (such as magnesium oxide powder, etc.). At the same time, it can ensure the separation between the heating element 12 and the tube body 11, and prevent the heating element 12 from contacting tube body 11 and cause short circuit and other faults.

[0043] In practical applications, taking the insulation and heat conductive material 15 as magnesium oxide powder as an example, the magnesium oxide powder can be used to first make a fixed plate with two through holes, then the heating element 12 can be bent and pass through the two through holes in sequence to form two heating sections 121, and the positioning and installation of the heating element 12 and the tube body 11 is realized through the fixed cooperation between the fixed plate and the positioning boss 111 in the tube body 11. Then, the magnesium oxide powder is added into the tube body 11. When the tube is shrunk (reduced in the diameter so that the solidity of the magnesium oxide powder in the tube meets the requirements) after the powder addition is completed, the fixed plate made of magnesium oxide powder is crushed at the same time. Thus, the installation of the heating element 12 in the bent state and the tube body 11 is achieved.

[0044] In an embodiment, the positioning boss 111 can be an annular boss, or can be a protrusion structure spaced around the circumference of the tube body 11, or the like.

[0045] Furthermore, the positioning boss 111 is provided at the position of the tube body 11 adjacent to the first end, so that the heating section 121 has a sufficient extension length within the tube body 11 to increase the heating area.

[0046] In an embodiment of the present invention, as shown in FIG. 1 and FIG. 2, the tube body 11 is filled with the insulation and heat conductive material 15. The insulation and heat conductive material 15 isolates the two heating sections 121 and isolates the heating element 12 from the wall of the tube body 11.

[0047] The insulation and heat conductive material 15 can conduct the heat of the heating section 121 to the wall of the tube body 11, which is conducive to transferring the heat of the heating section 121. Furthermore, the insulation and heat conductive material 15 can isolate the two heating sections 121 to prevent potential safety hazards caused by the two heating sections 121 contacting each other. At the same time, the insulation and heat conductive material 15 can isolate the heating element 12 and the inner wall of the tube body 11 to prevent the heating element 12 from contacting the inner wall of the tube body 11 and causing electric leakage. Generally, the insulation and heat conductive material 15 is magnesium oxide powder. The magnesium oxide powder has good insulation properties and thermal conductivity, can effectively isolate the current inside the heating tube 1, and transfer the heat of the resistance wire to the tube body 11 in time, which plays the role of insulation and heat conduction. Powdered magnesium oxide powder can form a stable support structure in the heating tube 1, so that the heating section 121 of the heating tube 1 is well fixed and supported. This helps to maintain the relative position between the two heating sections 121 and prevent accidental damage to the heating section 121 due to vibration or displacement.

[0048] It can be understood that compared with the heating tube 1 of the related art, the heating tube 1 in the embodiment of the present invention simplifies the processing process and does not require folding, hydraulic molding and other processes. The design of the straight tube facilitates the addition of magnesium oxide powder, so that the filling density of the internal magnesium oxide powder is high, and the heat of the resistance wire can be conducted outward in time, reducing the impact of high temperature environment on the resistance wire and ensuring the life of the resistance wire.

[0049] In an embodiment of the present invention, as shown in FIG. 1 and FIG. 2, the heating tube 1 also includes a seal cover 13 provided at an opening of the first end. The seal cover 13 is fixedly connected to the tube body 11 to block the opening of the first end. The heating element 12 and the seal cover 13 are spaced apart.

[0050] It can be understood that in actual application, the tube body 11 is filled with insulation and heat conductive material 15 (such as magnesium oxide powder, etc.), and the seal cover 13 in this embodiment plays a role in sealing the opening of the first end of the tube body 11, to prevent the insulation and heat conductive material 15 (such as magnesium oxide powder, etc.) inside the tube body 11 from leaking.

[0051] It can be understood that the seal cover 13 can be completely provided inside the tube body 11, or can be partially provided inside the tube body 11 and partially outside the tube body 11, as long as it can seal the opening of the tube body 11. As an example, taking into account factors such as the difficulty and cost of the processing technology, the seal cover 13 is provided inside the tube body 11 in this embodiment. During processing, the seal cover 13 can be made of metal material such as stainless steel, and can be fixed to the tube body 11 by welding. In some other embodiments, the seal cover 13 can be made of hot-melt material such as glass. After the heating element 12 and the insulation and heat conductive material 15 are provided in the tube body 11, the hot-melt material is filled into the first end, and the seal cover 13 is molded through high-temperature hot melting.

[0052] Furthermore, an end surface of the seal cover 13 away from the heating element 12 is flush with the end surface of the first end of the tube body 11. In this way, the end surface of the first end of the heating tube 1 is flush, which makes it easier to control the length and size of the heating tube 1. When the heating tube 1 is used in the heater sleeve 2, the gap between the first end of the heating tube 1 and the inner wall of the heater sleeve 2 is easier to control, thereby improving the size matching accuracy of the heating tube 1 and the heater sleeve 2.

[0053] In an embodiment of the present invention, as shown in FIG. 1 and FIG. 3, the heating tube 1 also includes an insulation plug 14 provided at the second end of the tube body 11 and blocking the opening. The insulation plug 14, the seal cover 13 and the tube body 11 are enclosed to form a seal cavity, and the heating element 12 is provided in the seal cavity. The two terminals 122 are inserted through the insulation plug 14.

[0054] In this embodiment, the insulation plug 14 serves to seal the opening of the second end of the tube body 11 to prevent the insulation and heat conductive material 15 (such as magnesium oxide powder, etc.) from getting wet and prevent the insulation and heat conductive material 15 inside the tube body 11 from leaking. At the same time, the insulation plug 14 also plays a role of supporting and fixing the two terminals 122. Specifically, the insulation plug 14 is provided with two positioning holes spaced apart, and the two terminals 122 respectively pass through the two positioning holes located at the second end.

[0055] It can be understood that the insulation plug 14 can be completely provided inside the tube body 11, or can be partially provided inside the tube body 11 and partially provided outside the tube body 11, as long as the opening of the tube body 11 can be blocked. As an example, considering factors such as the difficulty of the processing process and cost, in this embodiment, the insulation plug 14 is provided inside the tube body 11. During processing, the insulation plug 14 can be made of hot-melt material such as glass. After the heating element 12 and the insulation and heat conductive material 15 are provided in the tube body 11, the second end is filled with hot melt material, and then the insulation plug 14 is molded by high-temperature hot melting. At the same time, the two terminals 122 is fixed through the insulation plug 14.

[0056] Furthermore, the end surface of the insulation plug 14 away from the first end is flush with the end surface of the second end of the tube body 11.

[0057] It can be understood that in practical applications, in order to ensure the electrical safety of the two terminals 122 of the heating tube 1, an insulation wrapper 1222 can be provided at the portion extending from the tube body 11. In this embodiment, the end surface of the insulation plug 14 away from the first end is flush with the end surface of the second end of the tube body 11, so that the insulation wrapper 1222 can be connected to the insulation plug 14 and the tube body 11 at the same time, and the insulation effect at the second end of the heating tube 1 can be further improved.

[0058] Further, as shown in FIG. 1, FIG. 3 and FIG. 4, in order to ensure the safety of wiring, it is necessary to increase the creepage distance between the two terminals 122 as much as possible to prevent short circuit. During application, the distance between the two terminals 122 can gradually increase in the direction away from the tube body 11. In an embodiment, the two terminals 122 generally form a "V"-shaped structure.

[0059] Specifically, the terminal 122 includes a lead-out rod 1221, an insulation wrapper 1222 and a connection sheet 1223. One end of the lead-out rod 1221 is connected to the corresponding heating section 121, and the other end of the lead-out rod 1221 extends out of the second end of the tube body 11. The insulation wrapper 1222 is connected to the second end and wrapped around the outside of the lead-out rod 1221. One end of the connection sheet 1223 is provided in the insulation wrapper 1222 and is electrically connected to the corresponding lead-out rod 1221, and the other end of the connection sheet 1223 extends out of the insulation wrapper 1222 for external connection.

[0060] It can be understood that the lead-out rod 1221 can be a conductive rod, a wire, a 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. It can be understood that the lead-out rod 1221 has a connecting end, and the cross-sectional area of the lead-out rod 1221 gradually decreases from the middle of the lead-out rod 1221 to the connecting end, so that the connecting end forms a tapered shape, which is advantageous for the spiral resistance wire to be sleeved on the connection end, thereby 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.

[0061] In order to prevent short circuits, the insulation wrapper 1222 is provided on each lead-out rod 1221, and the connection sheet 1223 is provided in the insulation wrapper 1222 to electrically connect with the lead-out rod 1221. The connection sheet 1223 is used to smoothly connect to an external power source. In an embodiment, the insulation wrapper 1222 can be a heat-shrinkable sleeve structure. In an embodiment, the connection sheet 1223 is a metal connection sheet. In order to ensure the creepage distance between the two terminals 122, the connection sheet 1223 can be a metal connection sheet with an angle of 135 ° .

[0062] In an embodiment of the present invention, as shown in FIG. 1, FIG. 3 and FIG. 4, the heating tube 1 also includes a first flange 16 sleeved on the outside of the tube body 11. The first flange 16 is installed at the position of the tube body 11 adjacent to the second end.

[0063] In this embodiment, by providing the first flange 16 outside the tube body 11, when the heating tube 1 is used in a dry heater, and the heating tube 1 is inserted into the heater sleeve 2, the first flange 16 can be driven to be assembled to the fixed column of the heater installation base. At this time, only the first flange 16 and the fixed column need to be limited and fixed to install the heating tube 1 without further installation of additional support pieces, thereby reducing installation steps and simplifying installation operations.

[0064] It can be understood that the fixing method of the first flange 16 and the tube body 11 can be determined according to the actual situation, for example, it can be interference fixing, welding fixation, snap-in fixation, etc.

[0065] The present invention also proposes a dry heater, as shown in FIG. 5, the dry heater includes a heater sleeve 2, an installation base and a heating tube 1. The specific structure of the heating tube 1 refers to the above embodiment. Since this dry heater adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated. One end of the heater sleeve 2 is closed and the other end of the heater sleeve 2 is open. The installation 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 provided in the heater sleeve 2. The terminal 122 of the heating tube 1 is provided outside the heater sleeve 2.

[0066] In actual application, the closed end of the heater sleeve 2 extends into the inner tank 4 of the water heater, and the installation base is installed at the aperture 41 of the inner tank 4, so that the heater sleeve 2 can be fixed inside the inner tank 4. The heating tube 1 is installed in the heater sleeve 2, and the water in the inner tank 4 is heated through the heater sleeve 2. If the dry heater fails, there is no need to disassemble the installation base or drain the water in the inner tank 4, and the heating tube 1 is directly removed from the heater sleeve 2. The disassembly and installation are very simple.

[0067] In this embodiment, the tube body 11 of the heating tube 1 does not need to be folded in half using oil pressure and other processes, so the tube body 11 can be processed with higher precision. The outer diameter of the heating tube 1 can be processed by a multi-roller tube shrinking machine and can be controlled within the range of ± 0.1mm, which greatly reduces the gap between the heating tube 1 and the inner wall of the heater sleeve 2 and can ensure that the heat of the heating tube 1 is transferred to the heater sleeve 2 in time and conducts heat exchange with the water, ensuring that the life of the heating tube 1.

[0068] The present invention also proposes a water heater, as shown in FIG. 6, the water heater includes an inner tank 4 and a dry heater. The specific structure of the dry heater refers to the above embodiments. Since this water heater adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated again. The closed end of the heater sleeve 2 extends into the inner tank 4, and the installation base is fixed to the aperture 41 of the inner tank 4.

[0069] The inner pot 4 has a water inlet pipe 51 and a water outlet pipe 52. The water inlet pipe 51 is used to feed cold water into the inner tank 4, and the water outlet pipe 52 is used to discharge hot water from the inner tank 4. The inner tank 4 is provided with the aperture 41. By fixing the installation base 3 to the aperture 41, the heater sleeve 2 is fixed inside the inner tank 4. The heating tube 1 is installed in the heater sleeve 2, and the water in the inner tank 4 is heated through the heater sleeve 2. When the heating tube 1 fails, there is no need to disassemble the installation base 3 or drain the water in the inner tank 4. The heating tube 1 can be directly removed. The disassembly and installation are very simple.

Examples

Embodiment Construction

[0026]The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present invention.

[0027]It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship, movement conditions, etc. between the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0028]At the same time, the meaning of "and / or" in the text includes three parallel solutions. Taking "A and / or B" as an exampl...

Claims

1. A heating tube (1) comprising: a tube body (11) having a first end and a second end, the first end axially opposite to the second end; and a heating element (12) provided at the tube body (11), wherein 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 in an axial direction of the tube body (11) to the second end, wherein the two heating sections (121) are respectively provided with terminals (122) at the second end, and the two terminals (122) extend out of the second end.

2. The heating tube (1) according to claim 1, wherein the heating element (12) is a resistance wire, and / or an inner peripheral wall of the tube body (11) is provided with a positioning boss (111) for positioning a bent section of the heating element (12), the positioning boss (111) being provided at a position of the tube body (11) adjacent to the first end.

3. The heating tube (1) according to claim 1 or 2, further comprising a seal cover (13) provided at an opening of the first end, wherein the seal cover (13) is fixedly connected to the tube body (11) to block the opening of the first end, and the heating element (12) is spaced apart from the seal cover (13).

4. The heating tube (1) according to claim 3, wherein the seal cover (13) is provided inside the tube body (11), wherein an end surface of the seal cover (13) away from the heating element (12) is flush with an end surface of the first end of the tube body (11), and / or wherein the seal cover (13) is fixed to the tube body (11) by welding.

5. The heating tube (1) according to claim 3 or 4, further comprising an insulation plug (14) provided at the second end of the tube body (11) and blocking the opening, wherein the insulation plug (14), the seal cover (13) and the tube body (11) are enclosed to form a seal cavity, the heating element (12) is provided in the seal cavity, and the two terminals (122) are inserted through the insulation plug (14).

6. The heating tube (1) according to any one of claims 1 to 5, wherein the two terminals (122) are arranged at an angle, and a distance between the two terminals (122) gradually increases in a direction away from the tube body (11).

7. The heating tube (1) according to any one of claims 1 to 6, wherein the terminal (122) comprises: a lead-out rod (1221) with one end connected to the heating section (121), and the other end extending out of the second end of the tube body (11); an insulation wrapper (1222) connected to the second end and wrapped around an outside of the lead-out rod (1221); and a connection sheet (1223) with one end providing in the insulation wrapper (1222) and electrically connected to the lead-out rod (1221), and the other end extending out of the insulation wrapper (1222) for external connection.

8. The heating tube (1) according to any one of claims 1 to 7, wherein the tube body (11) is filled with an insulation and heat conductive material (15), and the insulation and heat conductive material (15) isolates the two heating sections (121) and isolate the heating element (12) from a wall of the tube body (11), and / or wherein the tube body (11) is an insulation and heat conductive member.

9. The heating tube (1) according to any one of claims 1 to 8, further comprising a first flange (16) sleeved outside the tube body (11), wherein the first flange (16) is installed at a position of the tube body (11) adjacent to the second end.

10. A dry heater comprising: a heater sleeve (2) with one end closed and the other end open; an installation base (3) connected to an open end of the heater sleeve (2) and open at a position corresponding to the heater sleeve (2); and the heating tube (1) according to any one of claims 1 to 9, wherein the heating tube (1) is provided in the heater sleeve (2), and a terminal (122) of the heating tube (1) is provided outside the heater sleeve (2).

11. A water heater comprising: the dry heater according to claim 10 and an inner tank (4), wherein a closed end of a heater sleeve (2) extends into the inner tank (4), and an installation base (3) is fixed to an aperture (41) of the inner tank (4).

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