Electric kettle

Abstract

The electric kettle comprises a kettle body, the kettle body comprises an inner container containing liquid, the inner container comprises a bottom plate and a side wall, the bottom plate is provided with a heating pipe which is continuously and integrally formed, the heating pipe comprises a heating inner ring, the heating inner ring is enclosed around the center of the bottom plate to form a closed first cold area, and the side wall is provided with a second cold area. A first cold area is defined by the heating outer ring and the heating inner ring, a first heat collection area is arranged at the attached position of the heating inner ring, the heating outer ring and the heating outer ring are bent from the first heat collection area to the two sides of the heating inner ring and extend along the edges of the two sides of the bottom plate to be attached to the outer side wall of the heating inner ring, a second cold area is defined by the heating outer ring and the heating inner ring, and a second heat collection area is arranged at the attached position of the heating outer ring and the heating inner ring. The second cold areas are located on the two sides of the first cold area. According to the electric kettle, the contact area of the heating pipe and the bottom plate is guaranteed, and meanwhile the technical problems that in the prior art, due to the fact that the overall temperature of the inner container bottom plate is uniform, liquid backflow is blocked, and convection heat exchange efficiency is low are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric kettles, and more particularly, to an electric kettle. Background Art

[0002] An electric kettle heats the water in the kettle through a heating tube. When the water boils, the steam generated causes the bimetal sheet of the steam temperature sensing element to deform. This deformation drives the power switch to cut off the power through the lever principle, thereby achieving boiling water.

[0003] With people's continuous pursuit of the boiling water speed, the heating power of electric kettles has been increasing. While accelerating the boiling water process, it also increases the noise during boiling. Therefore, the goal of research and development is to reduce the boiling water noise without reducing the boiling power.

[0004] In the early electric kettles (such as patent CN200310124536.6), the heating tube is bent in a C shape and installed at the bottom of the inner liner of the kettle body. When boiling water, the heating tube generates heat, thereby heating the nearby inner liner of the heating tube, and then heating the liquid in the inner liner. During use, the heat is concentrated on the inner liner near the heating tube, resulting in a large heat load on the heating tube and part of the inner liner, reducing the heat transfer efficiency; at the same time, the local temperature is too high, causing the bubbles to quickly expand and burst. Especially when the bubbles burst at the bottom of the inner liner, noise is formed.

[0005] For the existing solutions to the boiling water noise of electric kettles, the main improvement ideas are as follows:

[0006] 1. Increase the uniformity of heating and reduce heat concentration.

[0007] For example, the applicant proposed a vacuum insulation electric kettle in Chinese patent CN200920238872.6. The heat conducting plate 6 made of pure aluminum or aluminum alloy with good heat conducting performance is welded on the side of the outer surface of the inner liner 2. The heating tube 5 is welded around the heat conducting plate 6. The purpose of setting the heat conducting plate is to transfer the heat emitted by the heating tube 5 to the inner liner 2 and the water in the inner liner faster and more evenly.

[0008] Chinese patent CN201710578948.9 provides an integrated electric heater and an electric kettle equipped with the integrated electric heater. The electric heating tube is completely enclosed inside the aluminum seat, and the electric heating tube joint is placed outside the aluminum seat to increase the contact area between the electric heating tube and the aluminum seat, improve the heat transfer efficiency between the electric heating tube and the aluminum seat, and also make the temperature transferred from the aluminum seat to the inner liner more uniform, reducing the temperature difference between the inner liner and the water, thereby reducing the rupture of bubbles. Further, the existing technology bends the electric heating tube to increase the area of the electric heating tube inside the aluminum seat, thereby improving the heat transfer efficiency.

[0009] Recent technological improvements still follow this idea (increasing the heating uniformity) to improve electric kettles. For example, patents CN202222777056.0 and CN202222773165.5 provide liquid heating containers where both ends of the connecting part are fixedly connected to the heat-conducting part covering the first annular section and the heat-conducting part covering the second annular section, enabling heat transfer between the two heat-conducting parts and transferring the heat of the two heat-conducting parts to the area of the disc body where no heating tube is provided, further improving the heat transfer effect between the first annular section and the second annular section and the disc body, making the temperatures of all parts on the disc body consistent, ensuring that the liquid in contact with the disc body can be heated evenly. When the liquid heating container boils water, the situation of small bubbles aggregating locally will not occur, and the situation of small bubbles bursting concentratedly to generate noise is also avoided.

[0010] "Increasing the heating uniformity and reducing heat concentration" remains the mainstream improvement idea for electric kettles, and it is already very difficult to increase the uniformity at the bottom of the inner liner. At the same time, when bending the electric heating tube in the existing technology, the bending angle of the electric heating tube is small, which easily causes the electric heating tube to crack during the production and processing process; in some existing technologies, processes such as pouring are required after the heat pipe is bent, reducing the production yield rate, increasing the production and manufacturing costs of the electric heating tube and the electric kettle, and affecting consumers' purchase desire (taking 2022 as an example, the retail prices of many electric kettles ranked among the top 10 in the e-commerce market are less than 150 yuan).

[0011] It is also found during use that when the heat of the heating tube is transferred to the inner liner, the temperature difference between the inner liner and the water decreases. Although the probability of bubbles bursting on the surface of the inner liner can be reduced, in the water in the inner liner, the temperature difference between waters at different depths is still large. After the bubbles detach from the surface of the inner liner and float in the water, the probability of the bubbles bursting is still large, and it is difficult to reduce the noise generated by the bubbles bursting in the water.

[0012] Second, set a coating inside the inner liner to change the residence time of the bubbles in the inner liner.

[0013] One direction is to reduce the speed of the bubbles detaching from the inner liner. For example, the liquid heating container provided by patent CN201710761239.4 attaches a noise reduction layer that can reduce the bubble detachment speed on the inner surface of the bottom wall and the side wall of the inner liner. In this way, small bubbles can grow as large as possible before detaching from the bottom wall of the inner liner to aggregate with surrounding small bubbles into large bubbles. Since large bubbles need to rise a longer height before bursting, the energy absorbed by the surrounding liquid is also more, and the corresponding noise generated when bursting is also small. Thus, the sound generated by the bubble implosion is suppressed, and finally the noise generated when the liquid heater is heating is reduced, improving the user experience of the product.

[0014] Through further development, it was found that by accelerating the speed of bubble detachment from the inner liner, the noise of the electric kettle could also be reduced, such as the inner liner assembly and liquid heater provided by patent CN201711173254.3. The inner surface of the bottom wall of this patent's inner liner is provided with a hydrophilic coating, and the bubble contact angle of the hydrophilic coating is θ, and 20° ≤ θ ≤ 75°. By selecting a hydrophilic coating with a suitable bubble contact angle, the patent accelerates the speed of bubble detachment from the bottom wall of the inner liner, thereby reducing the noise generated when the liquid heater is heating.

[0015] Changing the residence time of bubbles through the coating requires spraying the inner liner; compared with cooking utensils such as non-stick pans, consumers have a low acceptance of spraying coatings on electric kettles.

[0016] At the same time, boiling water pots often use hydrophobic coatings such as chemical coatings. In the case of high temperature and dry burning, the chemical coatings are more likely to peel off, affecting their non-stick effect and also causing certain impacts on human health.

[0017] Third, change the internal structure of the inner liner to reduce the residence time of bubbles in the inner liner.

[0018] The microstructure inside the inner liner can be improved. For example, the inner liner assembly and liquid heater provided by patent CN201711173198.3 have micro-protrusions on the inner surface of the bottom wall of the inner liner. It provides a gasification core for bubbles, accelerates the process of bubble formation and detachment from the bottom wall of the inner liner, shortens the time for bubbles to store energy on the bottom wall of the inner liner, the energy stored by the bubbles is smaller, and the corresponding noise generated when they burst is also small, thereby reducing the noise generated when the liquid heater is heating and improving the user experience of the product.

[0019] The bottom structure of the inner liner can also be improved. For example, a liquid heater provided by patent CN202222997552.7. The inner surface of the bottom wall of this patent includes a spherical surface extending outward from the center, which can ensure that the water in the inner liner can form a circulating convection after being heated. This is not only beneficial to improving the heating uniformity and heating efficiency, but also can utilize the circulating convection formed by heating, and then cooperate with the buoyancy of the gas and the viscosity of the water. The small bubbles generated on the spherical surface of the first region can stably move to the spherical surface of the second region instead of directly detaching from the spherical surface of the first region. Therefore, it is also beneficial to further reduce noise.

[0020] Existing inner liners are often made by die-casting and welding, etc. This method requires changing the structure of the inner liner, increasing the processing procedures of the inner liner, and also requires adapting modifications to the outer shell of the electric kettle, increasing the difficulty of production and processing of the electric kettle and having a great impact on the cost of the electric kettle.

[0021] Fourth, change the arrangement method of the double heat pipes to improve the heating efficiency of the liquid.

[0022] The existing patent CN201811486814.5 provides an electric kettle. In it, the area corresponding to the second heating element on the inner liner has concentrated heat (abbreviated as the second hot zone), while the area between the two ends of the second heating element forms a second opening, and the area where the second opening is located has a lower temperature (abbreviated as the second cold zone). Correspondingly, the area between the two ends of the first heating element forms a first opening, and the area where the first opening is located has a lower temperature (abbreviated as the first cold zone). At this time, when the first heating element and the second heating element are heating simultaneously, the water in the area close to the bottom of the inner liner is heated by the second heating element and rolls upward. The hot water rolling upward will reach the position where the first cold zone is located. When the heat flow generated by the lower second heating element rises, it mixes with the water at the first cold zone, greatly accelerating the heat exchange of the water flow. In the other direction, the heat flow generated by the hot end of the first heating element will exchange heat with the lower second cold zone. The alternating heat exchange between the hot and cold ends of the second heating element and the first heating element will greatly improve the heat exchange rate of the water in the kettle body, and will not cause a large amount of bubbles to burst due to heat concentration in a certain area, generating noise. Moreover, the water in the upper part of the inner liner can also be quickly heated, and the bubbles will not burst immediately due to too large a temperature difference, achieving a noise reduction effect. Furthermore, after the water in the inner liner boils, the rolling force generated by the side heating method buffers the upward rolling force generated by the bottom heating method on the water, preventing the water from splashing out from the spout or the steam hole.

[0023] This technical idea requires two heating tubes to be arranged longitudinally. One heating tube can be arranged on the bottom wall of the inner liner, and the other heating tube is arranged on the side wall of the inner liner. Arranging the heating tube on the side wall of the inner liner requires occupying the space on the periphery of the electric kettle, or requires tilting the side wall of the inner liner, increasing the manufacturing cost.

[0024] It is also found in use that the rolling force generated by the side heating method buffers the upward rolling force generated by the bottom heating method on the water, affecting the overall convection efficiency of the electric kettle.

[0025] Regarding the source of the noise during boiling water, the mainstream explanation is the bubble rupture caused by the temperature difference.

[0026] The specific noise mainly comes from the supercooled boiling stage, when the water is heated to above 50°C, obvious noise will appear. At this stage, the local activation energy on the surface of the heating plate (or heating wire, etc.) reaches the vaporization core requirements, and water vapor bubbles will be formed, that is, a small part of the water boils into water vapor, and then is wrapped by liquid water to form bubbles. But the water temperature around the heating plate is low, which is supercooled boiling. Water vapor bubbles can only break away from the surface of the heating plate when they grow large enough. Although the detachment diameter of supercooled boiling bubbles is smaller than that of saturated boiling, supercooled boiling bubbles grow slowly, and the size of the bubble after the two bubbles merge may not meet the conditions for leaving the heating plate. At this time, the small bubble is on the surface of the heating plate, the bottom absorbs heat and expands, and the top contacts the cold water to release heat and shrink, and oscillates on the surface of the heating plate, which may be the source of the noise.

[0027] But water vapor bubbles will always leave the surface of the heating plate, especially as the water temperature rises, the number of bubbles will increase. Once the bubbles leave the heating plate and enter the cold water, the cold water will absorb the heat and the bubbles will burst. The bursting of the bubbles will vibrate the water body and form shock waves. The excess energy will be radiated in the form of sound energy, which is the source of noise. Summary of the invention

[0028] The purpose of the present invention is to provide an electric kettle, which ensures the contact area between the heating tube and the bottom plate, while solving the technical problems in the prior art that the overall temperature of the bottom plate of the inner tank is uniform, resulting in obstruction of liquid reflux and low convective heat transfer efficiency.

[0029] The embodiment of the present invention is achieved as follows:

[0030] An embodiment of the present application provides an electric kettle, comprising a kettle body, the kettle body comprising an inner liner for holding liquid, the inner liner comprising a bottom plate and side walls, the bottom plate being provided with a continuously integrally formed heating tube, the heating tube comprising a heating inner ring, the heating inner ring being enclosed around the center of the bottom plate to form a closed first cold zone, the joining portion of the heating inner ring being a first heat collection zone, a heating outer ring, the heating outer ring being respectively bent from the first heat collection zone to both sides of the heating inner ring and extending along the edges of both sides of the bottom plate to be joined to the outer side wall of the heating inner ring, the heating outer ring and the heating inner ring being enclosed to form a second cold zone, the joining portion of the heating outer ring and the heating inner ring being a second heat collection zone, there are at least two second cold zones, and the second cold zones are located on both sides of the first cold zone.

[0031] In some embodiments of the present invention, the heating tube includes two connecting ends located on the heating outer ring, an opening is formed between the two connecting ends, the heating inner ring is used to close the opening, and the second heat collection area is respectively provided on both sides of the opening, and the second heat collection area is relatively arranged on both sides of the first heat collection area.

[0032] In some embodiments of the present invention, the area of the above-mentioned first cold zone is larger than the area of any of the above-mentioned second cold zones.

[0033] In some embodiments of the present invention, the above-mentioned first cold zone is oval, and the short axis of the oval extends and contracts towards the above-mentioned first heat collection zone; the above-mentioned second cold zone is a curved water droplet shape, the large end of the water droplet shape is close to the above-mentioned first heat collection zone, and the small end of the water droplet shape bends along the arc of the oval of the above-mentioned first cold zone.

[0034] In some embodiments of the present invention, it further includes a thermostat. A heat transfer plate is provided on the side of the heating tube away from the bottom plate, and the thermostat is connected to the heating tube through the heat transfer plate.

[0035] In some embodiments of the present invention, the above-mentioned heat transfer plate completely covers the above-mentioned heating tube.

[0036] In some embodiments of the present invention, the above-mentioned inner heating ring and the above-mentioned outer heating ring are connected by a curved arc section. The diameter of the bottom plate is 110 mm to 130 mm, and the curvature radius of the curved arc is greater than or equal to 15 mm.

[0037] In some embodiments of the present invention, the tangency of two above-mentioned curved arc sections forms the above-mentioned first heat collection zone.

[0038] In some embodiments of the present invention, it further includes a steam outlet on the side wall. In the same horizontal projection, the above-mentioned first heat collection zone is located between the center of the bottom plate and the steam outlet.

[0039] In some embodiments of the present invention, it further includes a spout on the side wall, and the opening is arranged towards the spout.

[0040] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0041] While improving the heating efficiency of the electric kettle, it reduces the influence of the large temperature difference between the bottom plate and the liquid, and between the liquid at the bottom of the inner liner and the liquid in the upper and middle parts of the inner liner, which is likely to cause the bubbles to burst. In this embodiment, by bending a continuous whole heating tube, a cold zone and a heat collection zone are designed on the bottom plate to guide the liquid to convect and flow in the inner liner, improving the convective heat transfer efficiency of the liquid, making the temperature of the whole liquid (especially in the vertical direction) more uniform, and reducing the probability of bubbles bursting at the bottom and in the liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is an exploded structural schematic diagram of the inner liner, bottom plate, side wall, heating tube, heat transfer plate and thermostat in the present invention;

[0043] Figure 2 It is a structural schematic diagram of the inner liner, heating tube, heat transfer plate and thermostat in the present invention;

[0044] Figure 3 Structural schematic diagram of the heat - generating inner ring for closing the opening in the present invention;

[0045] Figure 4 Structural schematic diagram of the two end faces of the heat - generating outer ring in the present invention being fitted to form the first heat - collecting area;

[0046] Figure 5 Structural schematic diagram when there is one second heat - collecting area in the present invention.

[0047] Icon: 1 - heating tube, 100 - connection end, 101 - heat - generating outer ring, 102 - heat - generating inner ring, 103 - first heat - collecting area, 104 - second heat - collecting area, 110 - first cold area, 120 - second cold area, 130 - opening, 2 - bottom plate, 3 - inner container, 301 - side wall, 311 - spout, 4 - heat - transfer plate, 5 - temperature controller. Detailed implementation manners

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0049] Embodiment 1

[0050] As Figures 1-5 shown, this embodiment provides an electric kettle, including a kettle body. The kettle body includes an inner container 3 for containing liquid. The inner container 3 includes a bottom plate 2 and a side wall 301. The bottom plate 2 is provided with a continuously integrally formed heating tube 1. The heating tube 1 includes a heat - generating inner ring 102. The heat - generating inner ring 102 surrounds the center of the bottom plate 2 to form a closed first cold area 110. The joint of the heat - generating inner ring 102 is the first heat - collecting area 103; a heat - generating outer ring 101. The heat - generating outer ring 101 bends from the first heat - collecting area 103 to both sides of the heat - generating inner ring 102 and extends along the two - side edges of the bottom plate 2 to be fitted to the outer side wall 301 of the heat - generating inner ring 102. The heat - generating outer ring 101 and the heat - generating inner ring 102 enclose a second cold area 120. The joint of the heat - generating outer ring 101 and the heat - generating inner ring 102 is the second heat - collecting area 104. There are at least two second cold areas 120, and the second cold areas 120 are located on both sides of the first cold area 110.

[0051] In this embodiment, the electric kettle may include a kettle body and a heating base connected to the kettle body. The kettle body and the power base may be separately provided, or the power base may be integrated into the kettle body. The above-mentioned kettle body includes an inner container 3 for containing liquid. The inner container 3 includes a bottom plate 2 and a side wall 301. The side wall 301 may be provided with the above-mentioned spout 311 and the above-mentioned steam outlet. The heating tube 1 is installed outside the bottom plate 2. The contact surface between the heating tube 1 and the bottom plate 2 can be a flat surface, without the need for special modification of the bottom plate 2, which ensures the processing efficiency and does not additionally increase the cost of the inner container 3. The heating tube 1 is integrally formed continuously. That is, in the following regions such as the first heat collection area 103, the second heat collection area 104, the first cold area 110, and the second cold area 120, etc., can be bent from the same heating tube 1, without adding additional heating tubes 1, ensuring the controllability of the cost of the electric kettle.

[0052] When heating the liquid in the inner container 3, the temperature of the liquid near the bottom plate 2 at the bottom of the inner container 3 is relatively high, while the temperature of the liquid in the middle and upper parts of the inner container 3 is relatively low. There is a temperature difference between the liquids at different heights, which causes the bubbles to absorb energy when encountering cold water on the bottom plate and when the bubbles break away from the bottom plate and rise in the liquid, resulting in the bubbles bursting.

[0053] During the process of bending the heating tube 1, etc., on the bottom plate 2 of the same size, a longer heating tube 1 can be installed, increasing the contact area between the heating tube 1 and the bottom plate 2 and the heat transfer efficiency; but it also increases the overall temperature of the bottom plate 2 and the temperature difference between the bottom plate 2 and the liquid.

[0054] While improving the heating efficiency of the electric kettle, reducing the influence of the large temperature difference between the bottom plate 2 and the liquid, and between the liquid at the bottom of the inner container 3 and the liquid in the middle and upper parts of the inner container 3 on the easy bursting of bubbles, in this embodiment, cold areas and heat collection areas are designed on the bottom plate 2 to guide the liquid to conduct convection and flow in the inner container 3, improving the convective heat transfer efficiency of the liquid, making the temperature of the liquid as a whole (especially in the vertical direction) more uniform, and reducing the probability of bubbles bursting at the bottom and in the liquid.

[0055] During use, the above-mentioned spout 311, the above-mentioned steam outlet, and the center of the above-mentioned bottom plate 2 can be located on the same extension line. The heating tube 1 is bent to form a heating inner ring 102, and the above-mentioned heating inner ring 102 surrounds the center of the above-mentioned bottom plate 2. After surrounding, the heating inner ring 102 can be in a "C" shape and have an opening 130, and the direction of the opening 130 faces the steam outlet. During the extension of the heating inner ring 102, the two ends of the opening 130 of the heating inner ring 102 can approach the center of the opening 130, and finally the two ends of the opening 130 of the heating inner ring 102 are mutually attached to form a first heat collection area 103. Because the heating tubes 1 are mutually attached, the heat generated by the first heat collection area 103 during heating is more concentrated than the heat generated in other areas (such as the area not covered by the heating tube 1 and the area covered by only one section of the heat pipe). At the same time, the two ends of the opening 130 of the heating inner ring 102 approach each other, causing the opening 130 of the heating inner ring 102 to close, and finally causing the heating inner ring 102 to surround and form a first cold area 110. The heating tube 1 is located at the edge of the first cold area 110, and the center of the first cold area 110 is not covered by the heating tube 1. When the heating tube 1 works, the temperature at the center of the first cold area 110 is lower than the temperature at the edge of the first cold area 110 and much lower than that of the first heat collection area 103, resulting in a temperature difference between the first cold area 110 and the first heat collection area 103.

[0056] The heating tube 1 starts from the first heat collection area 103 and extends along the edges of the bottom plate 2 on both the left and right sides to form a heating outer ring. During actual use, the bottom plate 2 can be circular, and the heating outer ring can extend along the edge of the circular bottom plate 2 into an arc. During the extension of the heating outer ring and when the heating outer ring extends, it approaches the heating inner ring 102, and finally the heating outer ring 101 and the heating inner ring 102 approach and attach to each other to form a second heat collection area 104. The above-mentioned heating outer ring 101 and the above-mentioned heating inner ring 102 surround and form a second cold area 120, and there are at least two of the above-mentioned second cold areas 120, and the above-mentioned second cold areas 120 are located on both sides of the above-mentioned first cold area 110. When the electric kettle is heating and working, at the position of the bottom plate 2 corresponding to the second heat collection area 104, it is jointly heated by the heating outer ring 101 and the heating inner ring 102, and the temperature is relatively high; at the edge of the bottom plate 2 corresponding to the second cold area 120, there is only a single heating tube 1 (the heating outer ring 101 or the heating inner ring 102) covering it, and the temperature is lower than that of the second heat collection area 104 or the first heat collection area 103; there is no heating tube 1 covering the inside of the bottom plate 2 corresponding to the second cold area 120, and the temperature is relatively low.

[0057] In this embodiment, by bending the continuously integrally formed heating tube 1, a first heat collection area 103, a second heat collection area 104, a first cold area 110, and a second cold area 120 are formed. However, the temperature of the first heat collection area 103 and the second heat collection area 104 > the temperature at the edge of the first cold area 110 and the second cold area 120 > the temperature at the center of the first cold area 110 and the second cold area 120, resulting in a relatively large temperature difference at the corresponding positions of different heat collection areas and cold areas on the bottom plate 2, and the positions of the heat collection areas and the cold areas are staggered with each other.

[0058] When heating the liquid, the liquid near the bottom plate 2 is heated by the heating tube 1, causing the density of the liquid to decrease and thus move upward to the upper side of the inner tank 3. In particular, the liquid in the first heat collection area 103 and the second heat collection area 104 has a relatively high temperature, and a large amount of liquid moves from the first heat collection area 103 and the second heat collection area 104 to the upper side of the inner tank 3. The liquid drives the bubbles to move upward in the inner tank 3, further improving the uniformity of the liquid temperature. After the heated liquid moves upward, the liquid with a lower temperature in the inner tank 3 has a larger density, so the colder liquid moves downward to the bottom of the inner tank 3 and continues to be heated by the heating tube 1 of the bottom plate 2, forming convective heat transfer. The central temperatures of the first cold area 110 and the second cold area 120 are relatively low, and the liquid with a lower temperature is more likely to flow to the bottom plate 2 corresponding to the first cold area 110 and the second cold area 120. Thus, the flow efficiency of the whole liquid (especially in the longitudinal direction) is accelerated, the temperature difference between the liquids at different heights is reduced, and the probability of the bubbles bursting during generation and floating is reduced.

[0059] When the colder liquid flows back to the first cold area 110 or the second cold area 120, when the colder liquid tends to flow to the heating tube 1, the first heat collection area 103 or the second heat collection area 104 where the density of the heated liquid is lower, after being heated, the density of the liquid decreases and it flows upward again. Therefore, the distances from the first cold area 110 and the second cold area 120 to the first heat collection area 103 and the second heat collection area 104 are shorter, which is beneficial to improving the convective heat transfer efficiency of the liquid; at the same time, the closer distance between the cold area and the heat collection area improves the moving efficiency of the bubbles on the bottom plate 2, facilitating the bubbles to converge and detach from the bottom plate 2 in a shorter time, and further reducing the probability of the bubbles bursting.

[0060] In some prior arts, the most common C-shaped or O-shaped heating tubes 1 are often used, and there are distances between the heating tube 1 and the edge of the bottom plate 2 and the center of the bottom plate 2. Heat differences can also be generated between the heating tube 1 and the edge of the bottom plate 2 and the center of the bottom plate 2 in the prior art, so convective heat transfer can also be generated in the common prior art. However, in this prior art, the contact area between the heating tube 1 and the bottom plate 2 is small, resulting in a low heat conduction efficiency between the heating tube 1, the bottom plate 2 and the liquid, affecting the normal boiling water efficiency. At the same time, the distances between the heating tube 1 and the edge of the bottom plate 2 and the center of the bottom plate 2 are far, the moving efficiency of the bubbles on the bottom plate 2 is low, and the bubbles are difficult to converge and detach from the bottom plate 2, resulting in the bubbles being easily broken on the bottom plate 2 and causing a relatively large noise in the electric kettle.

[0061] In this embodiment, the heating tube 1 is bent to increase the contact area between the heating tube 1 and the bottom plate 2 and the heat transfer efficiency. While improving the heating efficiency of the electric kettle, it reduces the influence of the large temperature difference between the bottom plate 2 and the liquid, and between the liquid at the bottom of the inner container 3 and the liquid in the upper and middle parts of the inner container 3, which easily causes the bubbles to burst. Cold areas and heat collection areas are designed on the bottom plate 2 to guide the liquid to conduct convection in the inner container 3, improve the convective heat transfer efficiency of the liquid, make the temperature of the whole liquid (especially in the vertical direction) more uniform, accelerate the efficiency of bubble convergence and detachment from the bottom plate 2, and reduce the probability of bubbles bursting at the bottom and in the liquid.

[0062] In some existing technologies, increasing the wrapping of the heat transfer member around the heating tube 1 also increases the coverage area of the heating tube 1 in the inner container 3. At the same time, the existing technology deliberately designs the same distance between the heating tubes 1, aiming to increase the heat transfer and boiling efficiency and make the whole bottom of the inner container 3 heat evenly. It is found in use that although the uniform heating of the bottom of the inner container 3 can reduce the temperature difference of the liquid in the horizontal direction, since there is no cold area or heat collection area at the bottom of the inner container 3, the liquid at the bottom of the inner container 3 is relatively uniform and there is no set flow direction of the liquid, resulting in disordered liquid flow. After the heated liquid moves upward, it is difficult for the colder liquid to flow back to the colder part of the bottom plate 2, which affects the convective heat transfer efficiency. This existing technology cannot solve the temperature difference that the bubbles are longitudinally subjected to, and may even cause a greater temperature difference of the liquid in the inner container 3 longitudinally, which is not conducive to reducing the noise during boiling water.

[0063] While improving the heat transfer and boiling efficiency, this embodiment sets the proximity and distance between the same heating tube 1, so that the cold areas and the heat collection areas cooperate with each other, deliberately guide the flow direction of the liquid, improve the convective heat transfer efficiency of the liquid, reduce the temperature difference that the bubbles are subjected to on the bottom plate 2 and in the liquid, reduce the probability of bubble rupture, and reduce the boiling noise of the electric kettle; the increase in the convective heat transfer efficiency also increases the flow velocity of the liquid on the surfaces of the inner container 3 and the bottom plate 2, facilitating the detachment of the bubbles from the surface of the bottom plate 2 and reducing the probability of bubbles bursting on the bottom plate 2, which can reduce the boiling noise of the electric kettle.

[0064] In some existing technologies, there is also double heat pipe heating. One heat pipe is arranged at the bottom of the inner container 3, and the other heat pipe is arranged on the side wall 301 of the inner container 3. The cold area positions and the hot area positions of the two heat pipes are arranged opposite to each other, and the boiling of the liquid is utilized to improve the convective efficiency of the electric kettle. However, the heating method on the side buffers the upward rolling force generated by the heating method on the bottom for the water, affecting the overall convective efficiency of the electric kettle. At the same time, the double heat pipe scheme also significantly increases the production cost of the electric kettle.

[0065] The heat collection area and the cold zone of this embodiment are both arranged on the bottom plate 2. Compared with the prior art, there is no side heating method to buffer the water. The layout of the heating pipe 1 of this embodiment improves the convective heat transfer of the liquid while preventing the liquid from being disturbed by the heating pipe 1 when flowing in the inner tank 3, further improving the efficiency of the convective heat transfer of the inner tank 3 and the noise reduction effect of the electric kettle. The heat collection area and the cold zone of this embodiment are formed by bending a continuous whole heating pipe 1, and compared with the prior art double heat pipe solution, there is no need to increase the manufacturing cost of the electric kettle.

[0066] In some implementations, the heat collection area may be a surface contact or line contact section where the heating tubes 1 are attached to each other.

[0067] The first heat collection area 103 can be formed by bending the heating inner ring 102. Specifically, the two ends of the heating inner ring 102 can be bent into the first heat collection area 103 which are parallel and close to each other, so as to increase the length of the first heat collection area 103. The first heat collection area 103 and the heating inner ring 102 can be connected by a rounded corner or an oblique angle, so as to reduce the possibility of the heating tube 1 being broken and damaged when being bent.

[0068] The heating pipe 1 may include two connection ends 100, and the heating pipe 1 may be connected to a power supply device such as a power source through the connection ends 100. When in use, the two connection ends 100 may be led vertically to the bottom plate 2 to the lower side of the bottom plate 2, so that the heating pipe 1 is always in a continuous state on the bottom plate, further extending the heating pipe 1 and increasing the contact area between the heating pipe 1 and the bottom plate 2.

[0069] In some implementations, the two connection ends 100 can be led out vertically, or the two connection ends 100 can be set away from the heat collection area, so as to ensure the length of the heat collection area, increase the corresponding area of ​​the heat collection area, reduce the distance between the heat collection area and the cold area, and thus enhance the effect of convective heat transfer.

[0070] In some embodiments, the first heat collection area 103 and the second heat collection area 104 are respectively arranged on both sides of the bottom plate 2, and the first heat collection area 103 and the second heat collection area 104 are both located on the same straight line of the bottom plate 2. A spacing is left between the first heat collection area 103 and the second heat collection area 104 to prevent the heat collection area on one side of the inner tank 3 from being too concentrated, and to prevent the liquid on one side from tumbling upwards and easily overflowing; in this embodiment, the distance between the cold area (the first cold area 110 and the second cold area 120) and the heat collection area (the first heat collection area 103 and the second heat collection area 104) is not too far, which reduces the horizontal movement of the liquid on the bottom plate and ensures the overall flow efficiency of the liquid in the inner tank 3.

[0071] In some embodiments, when the heat pipe 1 is bent, the heat pipes 1 may not be substantially fitted together due to the different materials and manufacturing processes of the heat pipes 1. In some embodiments, when the diameter of the bottom plate 2 is 110 mm to 130 mm, the distance between the heat pipes 1 is less than or equal to 2.5 mm, which can be regarded as the heat pipes 1 fitting together, thereby forming a heat collection area. In some embodiments, the longitudinal section of the heat pipe 1 can be a trapezoidal section that is wide at the bottom and narrow at the top. The above-mentioned fitting of the heat pipes 1 in this article can be the lower ends of the heat pipes 1 fitting together.

[0072] In some implementations, when the heating tube 1 is extended around the edge of the bottom plate 2, due to the difference in the material and manufacturing process of the heating tube 1, the heating tube 1 may not be able to completely extend around the edge of the bottom plate 2. When the diameter of the bottom plate 2 is 110 mm to 130 mm, there may still be a gap of about 3 mm between the heating tube 1 and the edge of the bottom plate 2.

[0073] In some implementations, the electric kettle may be a liquid heater such as a health-preserving kettle.

[0074] In some embodiments, the heating inner ring 102 can be enclosed around the center of the bottom plate 2 to form a closed first cold zone 110, so that the first cold zone 110 covers the center of the bottom plate 2, and the horizontal distance from the center of the bottom plate 2 to any point of the bottom plate 2 is less than the radius of the bottom plate 2, which can reduce the distance that hotter water at different positions flows back to the first cold zone 110, thereby improving the uniformity of the return to the first cold zone 110.

[0075] In some embodiments, the first cold zone 110 may not cover the center of the bottom plate 2, and the first cold zone 110 may be offset in a direction away from the second cold zone 120 to reduce the squeezing of the first cold zone 110 on the space of the second cold zone 120, thereby increasing the area of ​​the second cold zone 120, increasing the flow rate returning to the second cold zone 120, balancing the flow rate difference between the first cold zone 110 and the second cold zone 120, reducing the flow rate difference returning to the first cold zone 110 and the second cold zone 120, and improving the uniformity of the overall reflux of the inner tank.

[0076] In some implementations of the present embodiment, the heating tube 1 includes two connecting ends 100 located on the heating outer ring 101, an opening 130 is formed between the two connecting ends 100, the heating inner ring 102 is used to close the opening 130, and the second heat collection area 104 is respectively provided on both sides of the opening 130, and the second heat collection area 104 is relatively arranged on both sides of the first heat collection area 103.

[0077] In the above-described embodiment, in order to reduce costs or facilitate wiring, a gap is left between the two connection ends 100, thereby creating an opening 130. The opening 130 is provided at the joint between the outer heating ring 101 and the inner heating ring 102, so that the second heat collection area 104 is divided into two, increasing the number of heat collection areas and enhancing the area where the liquid can rise after being heated, which is beneficial to improving the efficiency of convective heat transfer of the liquid, prompting the liquid to quickly drive the bubbles away from the surface of the bottom plate 2, thereby reducing noise.

[0078] The two second heat collection areas 104 are respectively located on both sides of the first heat collection area 103, and there is an opening 130 between the two second heat collection areas 104, such that the connection lines between the two second heat collection areas 104 and the first heat collection area 103 form a triangle, making the distribution between the heat collection areas more uniform, further reducing the horizontal flow distance of the liquid on the bottom plate 2, and ensuring the convective efficiency of the liquid.

[0079] In some embodiments of the present embodiment, the area of the above-mentioned first cold area 110 is larger than the area of any of the above-mentioned second cold areas 120.

[0080] In the above-described embodiment, the joint between the outer heating ring 101 and the inner heating ring 102 is the second heat collection area 104, and at the same time, the first cold area 110 is surrounded by the inner heating ring 102, which is equivalent to the second heat collection area 104 extending along the edge of the first cold area 110, so that the contact area between the second heat collection area 104 and the first cold area 110 is large; compared with the second cold area 120, the liquid is more inclined to flow from the first cold area 110 into the second heat collection area 104. The first cold area 110 is also located between the first heat collection area 103 and the second heat collection area 104, so that in the actual operation of the electric kettle, the amount of liquid flowing out of the first cold area 110 can be greater than the amount of liquid in the second cold area 120. In order to increase the amount of liquid flowing into the first cold area 110, the area of the first cold area 110 is increased, ensuring the efficiency of liquid convection, especially liquid reflux, and reducing the noise during boiling water.

[0081] In some embodiments of the present embodiment, the above-mentioned first cold area 110 is oval, and the short axis of the oval extends and contracts towards the first heat collection area 103; the above-mentioned second cold area 120 is a curved water droplet shape, the large end of the water droplet shape is close to the first heat collection area 103, and the small end of the water droplet shape bends along the arc of the oval of the first cold area 110.

[0082] In the above-described embodiment, the first cold zone 110 may include a wide portion, and both ends of the wide portion gradually narrow to form an oval-shaped main body. Specifically, one end of the first cold zone 110 may contract towards the middle of the second heat collection zone 104 (in the case of only one second heat collection zone 104) or the opening 130 between the second heat collection zones 104 (in the case of two second heat collection zones 104), increasing the contact length between the first cold zone 110 and the second heat collection zone 104, thereby facilitating the liquid in the first cold zone 110 to flow to the second heat collection zone 104.

[0083] During the actual heating process, the liquid located in the first cold zone 110 is more inclined to flow to the higher-temperature first heat collection zone 103 than to flow to the heat-generating inner ring 102. In this embodiment, the narrowed other end extends towards the first heat collection zone 103 and contracts into a sharp corner. When the liquid in the first cold zone 110 flows to the sharp corner, it can promote the contact between the liquid and the heat-generating inner ring 102 on both sides of the sharp corner, and the temperature of the bottom plate 2 through which the liquid flows gradually increases, improving the heat exchange efficiency during liquid flow.

[0084] In a conventional electric kettle, the bottom plate 2 is often circular. When bending the heat-generating outer ring 101, it is laid as close as possible to the edge of the bottom plate 2. Ideally, the shape of the second cold zone 120 complementary to the first cold zone 110 is as close to circular as possible, thereby increasing the length of the heating tube 1 and reducing the heat load of the heating tube 1 and the bottom plate 2 corresponding to the heating tube 1. The second cold zone 120 can be a curved water droplet shape. The water droplet-shaped second cold zone 120 may include a large end, and the large end is close to the first heat collection zone 103. The edge of the large end can be fitted with the sharp corner of the first cold zone 110. The second cold zone 120 starts from the large end and extends along the edge of the first cold zone 110 and the bottom plate 2. During the extension process, the width of the second cold zone 120 narrows and finally extends to the second heat collection zone 104. The large end of the second cold zone 120 is close to the first heat collection zone 103, facilitating the liquid in the second cold zone 120 to flow to the first heat collection zone 103. The liquid in the second cold zone 120 also flows to the second heat collection zone 104 through the first cold zone 110 and the extended section of the bottom plate 2, driving the liquid to contact the corresponding positions of the heat-generating inner ring 102 (the edge of the first cold zone 110) and the heat-generating outer ring 101 (the edge of the bottom plate 2). Compared with the design without a heat collection zone or the design without width narrowing, this embodiment enhances the liquid flow on the bottom plate 2 and is conducive to driving the bubbles to fall off from the bottom plate 2.

[0085] In some embodiments of this embodiment, a thermostat 5 is further included. A heat transfer plate 4 is provided on the side of the heating tube 1 away from the bottom plate 2, and the thermostat 5 is connected to the heating tube 1 through the heat transfer plate 4.

[0086] In the above embodiment, depending on the diameter of the bottom plate 2 and the area of the cold zone, and at the same time, the volume of some of the temperature controllers 5 is too large, and it is possible that the temperature controller 5 cannot be directly installed on the surface of the chassis. In this embodiment, a heat transfer plate 4 is provided on the side of the heating tube 1 away from the bottom plate 2. The heat transfer plate 4 can be an aluminum plate or a cast iron plate, etc. The heat transfer plate 4 provides an installation space for the temperature controller 5. When the heating tube 1 is working, the heat transfer plate 4 conducts part of the heat to the temperature controller 5. When the temperature received by the temperature controller 5 is higher than the set temperature, the temperature controller 5 can cut off the power supply to prevent the electric kettle from dry burning.

[0087] In the actual production and processing process, the stud can be first installed on the bottom plate 2, and the heat transfer plate 4 can be provided with an opening for the stud to pass through. When installing the heat transfer plate 4, the stud passes through the opening of the heat transfer plate 4, and the stud restricts the horizontal movement of the heat transfer plate 4, thus facilitating the installation and assembly of the heat transfer plate 4.

[0088] In some embodiments of this embodiment, the above heat transfer plate 4 completely covers the above heating tube 1.

[0089] In the above embodiment, the temperature difference between the heat collection zone, the inner heating ring 102, the outer heating ring 101 and the cold zone is relatively large (compared with the electric kettle in which the heating tube 1 is uniformly arranged). If the heat transfer plate 4 only covers the cold zone or the heat collection zone, it will cause the temperature controller 5 to be too cold or too hot, affecting the normal use of the electric kettle. In order to ensure that the heat received by the temperature controller 5 is close to the heat of the bottom plate 2 for the liquid, the heat transfer plate 4 can completely cover the heating tube 1. At this time, the temperature of the heat transfer plate 4 is relatively uniform, ensuring the normal operation of the temperature controller 5 and the electric kettle.

[0090] In some embodiments of this embodiment, the above inner heating ring 102 is connected to the above outer heating ring 101 through a curved arc section, the diameter of the above bottom plate 2 is 110 mm to 130 mm, and the curvature radius of the above curved arc is greater than or equal to 15 mm.

[0091] In the above embodiment, when the heating tube 1 needs to be bent during the production and processing of the heating tube 1, sometimes the heating tube 1 will break or crack due to reasons such as material or process when the heating tube 1 is bent. Therefore, when the heating tube 1 is bent in this embodiment, the heating tube 1 is bent in the form of a curved arc, avoiding stress concentration of the heating tube 1. During the bending process of the heating tube 1, the curvature radius of the curved arc is controlled to prevent the curvature radius of the curved arc from being too small and causing damage to the heating tube 1.

[0092] The second cooling area 120 is formed by enclosing the heating outer ring 101 and the heating inner ring 102. When restricting the minimum curvature radius of the bending arc, the minimum distance at the connection between the heating outer ring 101 and the heating inner ring 102 is ensured, thereby ensuring the minimum area of the second cooling area 120, preventing the area of the second cooling area 120 from being too small, ensuring a large temperature difference between the center of the second cooling area 120 and the heat collection area, and further ensuring the convective circulation of the liquid.

[0093] In some embodiments of the present embodiment, the tangency of the two above-mentioned bending arc segments forms the above-mentioned first heat collection area 103.

[0094] In the above embodiment, the first heat collection area 103 is, in this embodiment, the contact surface or contact line between the two bending arc segments. The length of the first heat collection area 103 is shortened, preventing the length of the first heat collection area 103 from being too long. While ensuring the convective circulation efficiency of the liquid in the inner container 3, the surging degree of the liquid on the upper side of the first heat collection area 103 is reduced, and the probability of liquid overflow is decreased.

[0095] In this embodiment, the length of the first heat collection area 103 can be less than the length of the second heat collection area 104, that is, the heat at the second heat collection area 104 is greater than the heat at the first heat collection area 103, making the liquid more inclined to flow from the second heat collection area 104 into the first cooling area 110 and the second cooling area 120; and the second heat collection area 104 is closer to the edge of the bottom plate 2, which is beneficial to driving the liquid to flow from the edge of the bottom plate 2 towards the center of the bottom plate 2, increasing the overall circulation efficiency of the liquid.

[0096] In some embodiments of the present embodiment, it further includes a steam outlet on the side wall 301. In the same horizontal projection, the above-mentioned first heat collection area 103 is located between the center of the above-mentioned bottom plate 2 and the above-mentioned steam outlet.

[0097] In the above embodiment, the bottom plate 2 of the inner container 3 is generally placed horizontally. According to the different product forms of the electric kettle, the side wall 301 of the inner container 3 can be inclined or perpendicular to the bottom plate 2. In different installation methods of the side wall 301, in the same horizontal projection, the first heat collection area 103 is between the center of the bottom plate 2 and the steam outlet, that is, there is a spacing between the steam outlet and the first heat collection area 103 in the horizontal projection, which can reduce the probability of liquid overflow from the steam outlet when the electric kettle is boiling water; combined with the first heat collection area 103 with a shorter length, the probability of liquid overflow can be further reduced, ensuring the use experience.

[0098] In some embodiments of the present embodiment, it further includes a spout 311 on the side wall 301, and the above-mentioned opening 130 is arranged towards the above-mentioned spout 311.

[0099] In the above-described embodiment, the temperature at the opening 130 is lower than the temperature of the second heat collection area 104. By arranging the opening 130 towards the spout 311, it is possible to prevent the liquid that tumbles upwards in the second heat collection area 104 from overflowing at the opening 130, preventing the user from being scalded and ensuring the use experience.

[0100] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electric kettle, characterized in that: it includes a kettle body, the kettle body includes an inner container for containing liquid, the inner container includes a bottom plate and a side wall, and the bottom plate is provided with a continuously integrally formed heating tube; the heating tube includes, a heating inner ring, the heating inner ring surrounds the center of the bottom plate to form a closed first cold zone, and the joint of the heating inner ring is the first heat collection zone; a heating outer ring, the heating outer ring bends from the first heat collection zone to both sides of the heating inner ring and extends along the two side edges of the bottom plate to fit with the outer side wall of the heating inner ring, the heating outer ring and the heating inner ring enclose a second cold zone, and the joint of the heating outer ring and the heating inner ring is the second heat collection zone; there are at least two second cold zones, and the second cold zones are located on both sides of the first cold zone.

2. The electric kettle according to claim 1, characterized in that: the heating tube includes two connection ends located on the heating outer ring, an opening is formed between the two connection ends, the heating inner ring is used to close the opening, the second heat collection zones are respectively arranged on both sides of the opening, and the second heat collection zones are oppositely arranged on both sides of the first heat collection zone.

3. The electric kettle according to claim 1, characterized in that: the area of the first cold zone is larger than the area of any one of the second cold zones.

4. The electric kettle according to any one of claims 1, 2 or 3, characterized in that: the first cold zone is oval, the short axis of the oval extends and contracts towards the first heat collection zone; the second cold zone is a curved water droplet shape, the large end of the water droplet shape is close to the first heat collection zone, and the small end of the water droplet shape bends along the arc of the oval of the first cold zone.

5. The electric kettle according to claim 1, characterized in that: it further includes a thermostat, a heat transfer plate is provided on the side of the heating tube away from the bottom plate, and the thermostat is connected to the heating tube through the heat transfer plate.

6. The electric kettle according to claim 5, characterized in that: the heat transfer plate completely covers the heating tube.

7. The electric kettle according to claim 1, characterized in that: the heating inner ring and the heating outer ring are connected by a curved arc section, the diameter of the bottom plate is 110mm - 130mm, and the curvature radius of the curved arc is greater than or equal to 15mm.

8. The electric kettle according to claim 7, characterized in that: the tangency of the two curved arc sections forms the first heat collection zone.

9. The electric kettle according to any one of claims 1 or 8, characterized in that: it further includes a steam outlet on the side wall, and in the same horizontal projection, the first heat collection zone is located between the center of the bottom plate and the steam outlet.

10. The electric kettle according to claim 2, characterized in that: it further includes a spout on the side wall, and the opening faces the spout.

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