Heating tube and cooking equipment

Abstract

The utility model provides a heating tube and cooking equipment, the heating tube is used for the cooking equipment, and the heating tube comprises a sleeve; the heating piece is arranged in the sleeve; and the thermal radiation coating is arranged on the outer side wall of the sleeve, and the radiance of the thermal radiation coating is larger than that of the sleeve. According to the scheme, the heat radiation coating with the good radiation rate is arranged on the outer wall of the metal sleeve, the heating efficiency of the heating pipe is improved, and the problem that the external radiation efficiency of an existing metal heating pipe is low is solved.

Description

Technical Field

[0001] The present application relates to the field of household appliances, and more particularly, to a heating tube and a cooking device. Background Art

[0002] For cooking devices such as ovens, they generally use heating tubes for heating. However, for existing heating tubes, their heating efficiency is relatively low and the heating speed is relatively slow.

[0003] Therefore, how to provide a heating tube with high heating efficiency and fast heating speed has become an urgent problem to be solved at present. Summary of the Utility Model

[0004] The present application aims to at least solve the technical problem in the prior art or related art that the existing heating tube has relatively low heating efficiency and relatively slow heating speed.

[0005] To this end, in the first aspect of the present application, a heating tube is proposed.

[0006] In the second aspect of the present application, a cooking device is proposed.

[0007] To achieve the above object, the present application provides a heating tube for a cooking device, including: a sleeve; a heating element disposed inside the sleeve; and a thermal radiation coating disposed on the outer sidewall of the sleeve, wherein the emissivity of the thermal radiation coating is greater than that of the sleeve.

[0008] In this technical solution, the heating tube can be specifically used for cooking devices such as ovens and microwave ovens. The heating tube includes a sleeve and a heating element. Among them, the heating element is used to generate heat, and the heat generated by the heating element can be transferred to the sleeve, and then the sleeve radiates the heat outward. In the present application, the heating tube can be a thermal radiation tube or a heat transfer tube. The thermal radiation tube mainly realizes the heating of an object through thermal radiation, that is, non-contact heating, while the heat transfer tube mainly heats an object through contact heat conduction. A thermal radiation coating is provided on the outer wall of the sleeve. Since the emissivity of the thermal radiation coating is greater than that of the sleeve, the ability of the sleeve to radiate heat outward can be enhanced through the thermal radiation coating, thereby improving the rate at which the heating tube heats other objects, and thus the heating efficiency of the heating tube can be efficiently improved. In particular, when the heating tube is used for non-oven applications and realizes thermal radiation heating, its emissivity of heat is significantly enhanced, which can significantly improve the heating efficiency of the heating tube and increase the heating rate of the heating tube.

[0009] In addition, the heating tube in the above embodiment provided by the present application may further have the following additional technical features:

[0010] Among them, thermal radiation refers to the heat transfer method in which heat is transferred through electromagnetic wave radiation. The rate of thermal radiation depends on the temperature of the object, surface characteristics, and radiation wavelength. Thermal radiation follows the Stefan-Boltzmann law:

[0011] Q = εσA(T1 4 - T2 4 );

[0012] Among them, ε is the emissivity or emittance. Q is the heat dissipated by the object through radiation, ε is the emissivity or emittance of the radiating object, A is the surface area of the radiating object, σ is the Boltzmann constant, T1 is the temperature of the radiating object, and T2 is the temperature of the surrounding environment. It can be seen from the Stefan-Boltzmann law that the higher the emissivity, the greater the radiated heat.

[0013] Optionally, a filler is provided between the sleeve and the heating element. Through the filler, heat transfer between the sleeve and the heating element can be carried out and insulation isolation between the sleeve and the heating element can be achieved. At the same time, the filler can also be used to fix the spatial position of the heating element in the sleeve and ensure uniform heating of the sleeve.

[0014] Optionally, the filler is a filling medium, such as a solid powder medium, liquid, air, or a combination thereof.

[0015] Optionally, the filler can also be a part with a certain structure and shape. For example, the filler is a hollow cylindrical structure arranged between the sleeve and the heating element.

[0016] Among them, the emissivity of the thermal radiation coating is greater than or equal to 0.9.

[0017] In this technical solution, when preparing the thermal radiation coating, a material with a relatively high emissivity can be selected. For example, cerium oxide, zirconia, carbon nanotube heat dissipation coatings can be used to ensure the emissivity of the thermal radiation coating. Among them, for general metals, their emissivity for heat is only about 0.5. It can be seen that setting the emissivity of the thermal radiation coating to be greater than or equal to 0.9 can ensure that the thermal radiation coating has a high emissivity, significantly enhancing the thermal radiation heating effect of the heating tube.

[0018] In any of the above embodiments, optionally, the thickness of the thermal radiation coating is greater than or equal to 50 μm and less than or equal to 150 μm.

[0019] In this technical solution, the thickness of the thermal radiation coating can be set as needed, but generally it cannot be set too thick, otherwise it is easy to fall off and be damaged, nor can it be set too thin, as this cannot effectively improve the radiation rate of the heating tube. Therefore, taking all factors into consideration, the thickness of the thermal radiation coating can be set to be less than or equal to 150 μm, but preferably greater than or equal to 50 μm.

[0020] In any of the above technical solutions, the filling medium is a solid powder medium, and the solid powder medium has heat conduction and insulation properties.

[0021] In this technical solution, the filling medium is a solid powder. For example, magnesium oxide powder. At the same time, a solid powder with heat conduction and insulation properties can be selected and filled into the heating tube. In this way, the filling medium can not only conduct heat transfer, but also achieve insulation between the sleeve and the heating element. When the heating element is a component that generates heat when powered on, the current on the heating element can be prevented from being conducted to the sleeve by the filling medium, thereby ensuring the insulation of the sleeve and avoiding electric leakage of the sleeve.

[0022] In other technical solutions, if the insulation of the filling medium is not considered, other forms of media can also be used, such as liquids or gases.

[0023] Optionally, the solid powder can be selected as low-temperature, medium-temperature, or high-temperature powder according to the heating temperature.

[0024] Exemplarily, the solid powder is magnesium oxide powder. Magnesium oxide powder has high heat resistance and excellent insulation properties, and can not only play an insulating role between the heating element and the sleeve, but also play a heat transfer role between the heating element and the sleeve.

[0025] In any of the above technical solutions, optionally, the sleeve includes a metal sleeve. Selecting a metal sleeve can ensure the heat conduction performance, strength, and high-temperature resistance of the sleeve. In other technical solutions, a sleeve made of ceramics or other materials can also be selected.

[0026] Optionally, the metal sleeve includes at least one of the following or a combination thereof: a stainless steel sleeve, a red copper sleeve, and a carbon steel sleeve. The materials of these sleeves are relatively inexpensive, so the cost of the metal sleeve can be reduced.

[0027] In any of the above technical solutions, optionally, the heating element is a resistance wire, that is, a component that generates heat when powered on. The form of resistance wire heating is relatively common, with low cost and good heating effect. Of course, in other embodiments, the heating element can also be an electromagnetic heating element, a microwave heating element, an infrared heating element, etc.

[0028] In any of the above technical solutions, optionally, considering that the heating efficiency and high-temperature resistance of the alloy wire are better, the resistance wire can be set as an electrothermal alloy wire.

[0029] In any of the above technical solutions, optionally, the resistance wire includes iron-chromium-aluminum and / or nickel-chromium alloy wire. The above materials have high resistance, good plasticity, low cost, and are relatively easy to produce. They can save more costs while ensuring the quality and working efficiency of the heating tube.

[0030] In any of the above technical solutions, the heating wire is spirally arranged along the axial direction of the sleeve. The spiral arrangement of the heating wire can make the length of the heating wire longer, thereby increasing the heating area of the heating wire and improving the heating efficiency. Of course, the heating wire can also be in a serpentine structure with back-and-forth bends.

[0031] In any of the above technical solutions, the heating tube further includes: two terminal posts respectively arranged at both ends of the sleeve, and one end of each terminal post is electrically connected to the heating element; two sealing members respectively arranged at both ends of the sleeve and closing both ends of the sleeve.

[0032] In this technical solution, the terminal posts are used to connect the heating tube to an external power source. In this way, the heating tube can be powered on more conveniently. Among them, the sealing members are used to close both ends of the sleeve to prevent the substances inside the sleeve from flowing out. For example, when a solid powder medium is filled between the sleeve and the heating element, the sleeve can be closed through the sealing members so that the solid powder medium can be filled inside the sleeve.

[0033] Among them, the sealing member is a silica gel member formed by secondary solidification. When installing the heating tube, the heating element can be first installed inside the sleeve, and then the filling member or filling medium is set between the sleeve and the heating element. Then, the terminal posts at both ends of the sleeve can be fixed, and silica gel members can be formed by solidification at both ends of the sleeve to achieve the sealing of both ends of the sleeve. This sealing method has a simple structure, low cost, and better sealing effect.

[0034] Optionally, at least part of the terminal post is located outside the sleeve, and a pressing head is installed on the part of the terminal post located outside the sleeve to press the sealing member to prevent the sealing member from falling off. For example, a thread can be provided on the part of the terminal post located outside the sleeve, and then the pressing head is sleeved on the terminal post, and the pressing head is pressed by a nut adapted to the thread on the terminal post. At the same time, in order to ensure strength, a gasket can also be provided between the pressing head and the nut.

[0035] Exemplarily, the pressing head can be a ceramic head.

[0036] The technical solution of the second aspect of the present application provides a cooking device, including the heating tube provided by the technical solution of the first aspect.

[0037] According to the cooking device provided by the present application, since it includes the heating tube provided by the technical solution of the first aspect, therefore, this cooking device also has all the beneficial effects of the heating tube provided by any technical solution of the first aspect, which will not be elaborated here.

[0038] In the above technical solution, optionally, the cooking device includes at least one of the following: an oven, a microwave oven, and a rice cooker. Any cooking device that can be heated by a heating tube falls within the scope of the cooking device in this application.

[0039] In this technical solution, the cooking device includes the above heating tube. Through the high-efficiency heating of the heating tube, compared with other cooking devices, when the cooking device is heated to the same heat, it consumes less electric energy and better completes the heating work.

[0040] The additional aspects and advantages of the present utility model will become apparent in the following description section, or be learned through the practice of the present utility model. Brief Description of the Drawings

[0041] The above and / or additional aspects and advantages of this application will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, where:

[0042] Figure 1 A schematic structural diagram of a heating tube in the related art is shown.

[0043] Among them, Figure 1 The corresponding relationship between the reference numerals and the part names in is as follows:

[0044] 100' Metal heating tube, 1' Sleeve, 2' Heating element, 3' Filling medium, 5' Terminal, 6' Sealing member.

[0045] Figure 2 A schematic structural diagram one of the heating tube of an embodiment of this application is shown;

[0046] Figure 3 A schematic structural diagram two of the heating tube of an embodiment of this application is shown;

[0047] Figure 4 A schematic structural diagram one of the cooking device of an embodiment of this application is shown;

[0048] Figure 5 A schematic structural diagram two of the cooking device of an embodiment of this application is shown.

[0049] Among them, Figures 2 to 5 The corresponding relationship between the reference numerals and the part names in is as follows:

[0050] 100 Heating tube, 1 Sleeve, 2 Heating element, 3 Filling medium, 4 Thermal radiation coating, 5 Terminal, 6 Sealing member, 7 Compression head, 8 Nut, 200 Cooking device, 210 Cabinet, 220 Door body. Detailed Description of the Embodiments

[0051] In order to more clearly understand the above-mentioned objects, features, and advantages of the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.

[0052] In the following description, many specific details are set forth in order to fully understand the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0053] The following will refer to Figures 2 to 5 to describe a heating tube 100 and a cooking device 200 according to some embodiments of the present application.

[0054] As Figure 2 shown, the present application provides a heating tube 100 for a cooking device 200, including a sleeve 1, a heating element 2, and a thermal radiation coating 4. Among them, the heating element 2 is disposed inside the sleeve 1. The thermal radiation coating 4 is disposed on the outer sidewall of the sleeve 1, and the emissivity of the thermal radiation coating 4 is greater than that of the sleeve 1.

[0055] In this embodiment, the heating tube 100 can be specifically used for cooking devices 200 such as ovens and microwave ovens. The heating tube 100 includes a sleeve 1 and a heating element 2. Among them, the heating element 2 is used to generate heat, and the heat generated by the heating element 2 can be transferred to the sleeve 1, and then the sleeve 1 radiates the heat outward. In the present application, the heating tube 100 can be a thermal radiation tube or a heat transfer tube. The thermal radiation tube mainly realizes the heating of an object through thermal radiation, that is, non-contact heating, while the heat transfer tube mainly heats an object through contact heat conduction. The outer wall of the sleeve 1 is provided with a thermal radiation coating 4. Since the emissivity of the thermal radiation coating 4 is greater than that of the sleeve 1, the ability of the sleeve 1 to radiate heat outward can be enhanced through the thermal radiation coating 4, thereby improving the heating rate of the heating tube 100 for heating other objects, and thus the heating efficiency of the heating tube 100 can be efficiently improved. In particular, when the heating tube 100 is used for non-oven and other thermal radiation heating, its emissivity is significantly enhanced, so that the heating efficiency of the heating tube 100 can be significantly improved, and the heating rate of the heating tube 100 can be increased.

[0056] Among them, thermal radiation refers to the heat transfer method in which heat is transferred through electromagnetic wave radiation. The rate of thermal radiation depends on the temperature, surface characteristics, and radiation wavelength of the object. Thermal radiation follows the Stefan-Boltzmann law:

[0057] Q = εσA(T1 4 -T2 4 )

[0058] Among them, Q is the heat radiated by the object, ε is the emissivity or radiation rate of the radiating object, A is the surface area of the radiating object, σ is the Boltzmann constant, T1 is the temperature of the radiating object, and T2 is the temperature of the surrounding environment. It can be seen from the Stefan-Boltzmann law that the higher the radiation rate, the greater the radiated heat.

[0059] Optionally, as Figure 2 shown, a filler is provided between the sleeve 1 and the heating element 2. Heat transfer between the sleeve 1 and the heating element 2 can be carried out through the filler, and insulation isolation between the sleeve 1 and the heating element 2 can be achieved. At the same time, the filler can also be used to fix the spatial position of the heating element 2 in the sleeve 1 and ensure uniform heating of the sleeve 1.

[0060] Optionally, the filler is a filling medium 3, such as a solid powder medium, liquid, air, or a combination thereof.

[0061] Optionally, the filler can also be a part with a certain structure and shape. For example, the filler is a hollow cylindrical structure provided between the sleeve 1 and the heating element 2.

[0062] Among them, the radiation rate of the thermal radiation coating 4 is greater than or equal to 0.9.

[0063] In this embodiment, when preparing the thermal radiation coating 4, a material with a relatively high radiation rate can be selected. For example, cerium oxide, zirconium oxide, carbon nanotube heat dissipation coating can be used to ensure the radiation rate of the thermal radiation coating 4. Among them, for ordinary metals, their thermal radiation rate is only about 0.5. It can be seen that setting the radiation rate of the thermal radiation coating 4 to be greater than or equal to 0.9 can ensure that the thermal radiation coating 4 has a relatively high radiation rate, so that the thermal radiation heating effect of the heating tube 100 can be significantly enhanced.

[0064] In any of the above embodiments, optionally, the thickness of the thermal radiation coating 4 is greater than or equal to 50 μm and less than or equal to 150 μm.

[0065] In this embodiment, the thickness of the thermal radiation coating 4 can be set as needed, but generally it cannot be set too thick, otherwise it is easy to fall off and be damaged, nor can it be set too thin, so that the radiation rate of the heating tube 100 cannot be effectively improved. Therefore, considering comprehensively, the thickness of the thermal radiation coating 4 can be set to be less than or equal to 150 μm, but preferably greater than or equal to 50 μm.

[0066] In any of the above embodiments, the filling medium 3 is a solid powder medium, and the solid powder medium has heat conduction and insulation properties.

[0067] In this embodiment, the filling medium 3 is a solid powder. For example, magnesium oxide powder. Meanwhile, a solid powder with heat conduction and insulation properties can be selected and filled into the heating tube 100, so that the filling medium 3 can not only conduct heat, but also achieve insulation between the sleeve 1 and the heating element 2. When the heating element 2 is an electrically energized heating part, the current on the heating element 2 can be prevented from being conducted to the sleeve 1 by the filling medium 3, thereby ensuring the insulation of the sleeve 1 and avoiding electric leakage of the sleeve 1.

[0068] In other embodiments, if the insulation of the filling medium 3 is not considered, other forms of media can also be used, such as liquids, gases, etc.

[0069] Optionally, the solid powder can be selected as low-temperature, medium-temperature, or high-temperature powder according to the heating temperature.

[0070] Exemplarily, the solid powder is magnesium oxide powder. Magnesium oxide powder has high heat resistance and excellent insulation properties, and can not only play an insulating role between the heating element and the sleeve 1, but also play a heat transfer role between the heating element and the sleeve 1.

[0071] In any of the above embodiments, optionally, the sleeve 1 includes a metal sleeve. Selecting a metal sleeve can ensure the heat conduction performance, strength, and high-temperature resistance of the sleeve 1. In other embodiments, a sleeve made of ceramics or other materials can also be selected.

[0072] Optionally, the metal sleeve includes at least one of the following or a combination thereof: stainless steel sleeve, red copper sleeve, and carbon steel sleeve. The materials of these sleeves are relatively inexpensive, so the cost of the metal sleeve can be reduced.

[0073] In any of the above embodiments, optionally, as Figure 2 shown, the heating element 2 is a resistance wire, that is, a part that can generate heat when energized. The form of resistance wire heating is relatively common, with low cost and good heating effect. Of course, in other embodiments, the heating element 2 can also be an electromagnetic heating element, a microwave heating element, an infrared heating element, etc.

[0074] In any of the above embodiments, optionally, considering that the heating efficiency and high-temperature resistance of the alloy wire are better, the resistance wire can be set as an electrothermal alloy wire.

[0075] In any of the above embodiments, optionally, the resistance wire includes iron-chromium-aluminum and / or nickel-chromium alloy wire. The above materials have high resistance, good plasticity, low cost, and are easy to produce, which can save more costs while ensuring the quality and working efficiency of the heating tube 100.

[0076] In any of the above embodiments, as Figure 2As shown, the heating wire is spirally arranged along the axial direction of the sleeve 1. The spiral arrangement of the heating wire can make the length of the heating wire longer, thereby increasing the heating area of the heating wire and improving the heating efficiency. Of course, the heating wire can also be in a serpentine structure with back-and-forth bends.

[0077] In any of the above embodiments, as Figure 2 shown, the heating tube 100 further includes: two terminal posts 5, which are respectively arranged at both ends of the sleeve 1, and one end of the terminal post 5 is electrically connected to the heating element 2; two sealing members 6, which are respectively arranged at both ends of the sleeve 1 and seal both ends of the sleeve 1.

[0078] In this embodiment, the terminal post 5 is used to connect the heating tube 100 to an external power supply. In this way, the heating tube 100 can be conveniently powered on. Among them, the sealing member 6 is used to seal both ends of the sleeve 1 to prevent the substances inside the sleeve 1 from flowing out. For example, when a solid powder medium is filled between the sleeve 1 and the heating element 2, the sleeve 1 can be sealed by the sealing member 6 so that the solid powder medium can be filled inside the sleeve 1.

[0079] Among them, the sealing member 6 is a silica gel member formed by secondary solidification. When installing the heating tube 100, the heating element 2 can be first installed inside the sleeve 1, then the filling member or filling medium 3 is arranged between the sleeve 1 and the heating element 2, and then the terminal posts 5 at both ends of the sleeve 1 can be fixed. The combination can then solidify to form silica gel members at both ends of the sleeve 1 to achieve the sealing of both ends of the sleeve 1. This sealing method has a simple structure, low cost, and better sealing effect.

[0080] Optionally, as Figure 3 shown, at least part of the terminal post 5 is located outside the sleeve 1, and a pressing head 7 is installed on the part of the terminal post 5 located outside the sleeve 1 to press the sealing member 6 to prevent the sealing member 6 from falling off. For example, threads can be provided on the part of the terminal post 5 located outside the sleeve 1, and then the pressing head 7 is sleeved on the terminal post 5, and then the pressing head 7 is pressed by a nut 8 adapted to the threads on the terminal post 5. At the same time, in order to ensure strength, a gasket can also be provided between the pressing head 7 and the nut 8.

[0081] Exemplarily, the pressing head 7 can be a ceramic head.

[0082] As Figure 4 and Figure 5 shown, an embodiment of the second aspect of the present application provides a cooking device 200, which includes the heating tube 100 provided by the embodiment of the first aspect.

[0083] According to the cooking device 200 provided by the present application, since it includes the heating tube 100 provided by the embodiment of the first aspect, therefore, the cooking device 200 also has all the beneficial effects of the heating tube 100 provided by any embodiment of the first aspect, which will not be elaborated here.

[0084] In the above embodiments, optionally, the cooking device 200 includes at least one of the following: an oven, a microwave oven, and a rice cooker. Any cooking device that can be heated by a heating tube belongs to the scope of the cooking device in this application.

[0085] In this embodiment, the cooking device 200 includes the above-mentioned heating tube. Through the high-efficiency heating of the heating tube, compared with other cooking devices, when the cooking device is heated to the same heat, it consumes less electric energy and better completes the heating work.

[0086] In the above embodiments, optionally, as Figure 4 and Figure 5 shown, the cooking device 200 includes a box body 210. The box body 210 includes a cooking cavity. The heating tube is installed in the cooking cavity and is used to heat the cooking cavity. The cooking device 200 further includes a door body 220. The door body 220 is rotatably installed on the box body 210 and is used to open or close the cooking cavity.

[0087] As Figure 4 and Figure 5 shown, the door body 220 is a glass door body. The cooking device 200 may specifically be an oven.

[0088] Next, taking a metal heating tube as an example, the high-efficiency heat-dissipating metal heating tube and the cooking device provided by this application will be further introduced.

[0089] The present utility model relates to a high-efficiency heat-dissipating metal heating tube, which can be used in an oven and the like to enhance radiation heat dissipation, accelerate the food cooking speed, and improve the heating efficiency.

[0090] As Figure 1 shown, in the related solution, the metal heating tube 100' has a metal tube as the outer shell (including stainless steel, copper tube, etc.), and spiral electric heating alloy wires (nickel-chromium, iron-chromium alloy) are evenly distributed along the central axis inside the tube. The voids are filled and compacted with magnesium oxide powder having good insulation and heat conduction performance, and both ends of the tube mouth are sealed with silica gel or other materials. It can be used to heat solids, air, metal molds, various liquids, etc.

[0091] Among them, the structure of the metal heating tube 100' is as Figure 1 shown. Its working principle is: by connecting the power supply to the terminal 5', then the current is conducted through the terminal 5' to the heating element 2' (such as a resistance wire). Both ends of the resistance wire are wound around two terminals inside the tube. The resistance wire generates heat when energized, and then the heat is conducted to the surface of the sleeve 1' of the electric heating tube through the magnesium oxide powder filler (the magnesium oxide powder filler serves as the filling medium 3') with very good heat conduction. A relatively high temperature will be generated on the surface of the sleeve 1', and finally the heat is conducted to solids, gases, and liquids through convective heat transfer and radiative heat transfer to achieve the purpose of heating.

[0092] Sheath 1': mainly includes stainless steel (SUS201, 304, 321, 316, 310, etc.), red copper, and carbon steel. Different metal sheaths can be selected according to different working environments.

[0093] Heating element 2' (resistance wire): mainly includes Fe-Cr-Al and Ni-Cr alloy wires, with electrical conductivity and heat generation properties.

[0094] Filler (filling medium 3'): generally magnesium oxide powder, a powdery filler that can insulate and conduct heat. Low-temperature, medium-temperature, and high-temperature powders can be selected according to the heating temperature. Its functions are: to insulate between the resistance wire and the metal outer tube, to transfer heat between the resistance wire and the metal outer tube, to fix the space position of the electric heating wire in the electric heating tube, and to ensure uniform heat generation of the electric heating tube.

[0095] Terminal 5': a threaded post made of iron, with good electrical conductivity.

[0096] Sealing piece 6': generally, silicone that can be solidified twice is selected, pressed tightly with a ceramic head, and then fastened with bolts and gaskets.

[0097] After the metal heating tube is powered on, a relatively high temperature will be generated on the surface of the metal sheath. Finally, heat is conducted to solids, gases, and liquids through convective heat transfer and thermal radiation to achieve the purpose of heating. Among them, thermal radiation refers to the way of heat transfer through electromagnetic wave radiation. The rate of thermal radiation depends on the temperature of the object, surface characteristics, and radiation wavelength. Thermal radiation follows the Stefan-Boltzmann law:

[0098] Q = εσA(T1 4 - T2 4 )

[0099] Among them, Q is the heat radiated by the object, ε is the emissivity or radiation rate of the radiating object, A is the surface area of the radiating object, σ is the Boltzmann constant, T1 is the temperature of the radiating object, and T2 is the temperature of the surrounding environment. It can be seen that the heat radiated by the object is related to the emissivity ε, surface area A, and temperature difference of the object's surface. The methods to increase the radiation heat dissipation can be summarized as: 1. Increase the emissivity of the object's surface; 2. Increase the heat dissipation surface area; 3. Increase the temperature difference between the object and the environment.

[0100] It can be seen from the Stefan-Boltzmann law that the higher the emissivity, the greater the radiant heat. The metal sheath outside the traditional metal heating tube is mainly made of stainless steel, and the emissivity of stainless steel is below 0.5, with a relatively low emissivity. The low emissivity of the traditional metal sheath limits the energy radiated outward by it, that is, it limits its heat dissipation ability and the ability to heat other objects.

[0101] The embodiment of the present application provides a metal heating tube with high heat dissipation. Similar to the related technical solutions, it includes a sleeve 1, a heating element 2, a filling medium 3, a terminal 5 and a sealing member 6. However, in this application, a coating with a high emissivity (such as a thermal radiation coating 4) is also coated on the surface of the metal heating tube in the related solution, which improves the radiation heat transfer ability of the metal heating tube and the ability to dissipate heat outward and heat other objects, and speeds up the heating rate.

[0102] The emissivity of the traditional metal heating tube is relatively low (the traditional metal outer sleeve is made of stainless steel, and the emissivity is less than 0.5), which limits its ability to radiate heat transfer outward, thus limiting its ability to heat other objects and the heating efficiency. The Stefan-Boltzmann law shows that the radiation heat transfer and heat dissipation ability of an object can be improved by increasing the emissivity, thereby improving the ability to heat other objects. This solution proposes to coat a high-temperature resistant coating with a high emissivity on the surface of the traditional heating tube (the required emissivity ε is as high as above 0.9, and the coating thickness <150 μm). This coating can be cerium oxide, zirconium oxide, yttrium oxide, silicon oxide, or a yttrium niobate-based ceramic coating or other high-emissivity ceramic coatings, or a carbon nanotube high-emissivity heat dissipation coating, or a graphene high-radiation heat dissipation coating, as well as other high-emissivity coatings. The structure of the metal heating tube proposed in this solution is as Figure 2 shown. Among them, the emissivity of the high-emissivity coating is higher than 0.9.

[0103] The proposed metal heating tube with high heat dissipation coats a layer of high-emissivity coating (such as a thermal radiation coating 4) on the metal sheath of the metal heating tube, which can significantly enhance the ability of the traditional metal heating tube to radiate heat outward, thereby increasing the heating rate of other objects and improving the heating efficiency of the heating tube, which is of great significance.

[0104] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0105] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A heating tube, characterized in that: For use in cooking equipment, including: casing; A heating element is arranged in the sleeve; A thermal radiation coating is disposed on the outer side wall of the sleeve, wherein the emissivity of the thermal radiation coating is greater than the emissivity of the sleeve; A filling medium is filled between the sleeve and the heating element; The thickness of the heat radiation coating is greater than or equal to 50 μm and less than or equal to 150 μm.

2. The heating tube according to claim 1, characterized in that: The emissivity of the thermal radiation coating is greater than or equal to 0.

9.

3. The heating tube according to claim 1, characterized in that: The thermal radiation coating comprises at least one of the following or a combination thereof: Cerium oxide coating, zirconium oxide coating, yttrium oxide coating, silicon oxide coating, ceramic coating and carbon nanotube heat dissipation coating.

4. The heating tube according to claim 1, characterized in that: The filling medium is a solid powder medium, and the solid powder medium has thermal conductivity and insulation properties.

5. The heating tube according to claim 1, characterized in that: The sleeve comprises a metal sleeve; and / or The heating element is a resistance wire.

6. The heating tube according to claim 5, characterized in that: The metal casing comprises at least one of the following or a combination thereof: a stainless steel casing, a copper casing and a carbon steel casing; and / or The resistance wire comprises iron-chromium-aluminum and / or nickel-chromium alloy wire.

7. The heating tube according to any one of claims 1 to 6, characterized in that: Also includes: Two terminals are respectively arranged at two ends of the sleeve, and one end of the terminal is electrically connected to the heating element; Two sealing members are respectively arranged at two ends of the sleeve and seal the two ends of the sleeve.

8. A cooking device, characterized in that: The invention comprises the heating tube according to any one of claims 1 to 7.

9. The cooking device according to claim 8, characterized in that The cooking equipment includes at least one of the following: an oven, a microwave oven, and an electric rice cooker.

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