Liquid heater

Abstract

The invention relates to the field of small household appliances, in particular to a liquid heater. The electric kettle comprises a kettle body with an inner container, a heating assembly is arranged on a base plate of the inner container and comprises a first heating piece, a second heating piece and a heat conduction plate, the heat conduction plate is provided with a first heat conduction area and a second heat conduction area, and the first heat conduction area is located on the outer side of the second heat conduction area in a horizontal space. The heat conduction coefficient of the heat conduction plate in the first heat conduction area is larger than that of the heat conduction plate in the second heat conduction area, the first heating piece is arranged in the first heat conduction area, the second heating piece is arranged in the second heat conduction area, and the power of the first heating piece is smaller than that of the second heating piece. On the basis that the number of the heating pieces is increased and the heating efficiency is improved, the base plate of the inner container is evenly heated, water boiling noise is reduced, and user experience is improved.

Description

Technical Field

[0001] The invention relates to the field of small household appliances, and in particular to a liquid heater. Background Art

[0002] For example, electric kettles and other liquid heaters are often used to boil water and make tea, and generally a heating component is set at the bottom of the inner tank. In order to increase the heating speed, the heating component usually uses a higher power. Some conventional liquid heaters with a capacity of 5L usually have a power of 1000W or even more than 1500W. For example, the Chinese patent authorization announcement number CN205697212U, named "A high-power electric kettle"; the Chinese patent authorization announcement number CN201481071U, named "A mineralized electric kettle" and other patents increase the power of the heating element to increase the water boiling efficiency, but the heating element has uneven heating and local overheating, resulting in excessive water boiling noise and affecting the user experience.

[0003] Some heating components also increase the power by increasing the number of heating parts, such as double heating tubes nested inside and outside, but the increase in the contact heat transfer area between the heating tubes and the aluminum plate is limited. It takes time for the part of the aluminum plate that is not in contact with the heating tube to transfer heat. Although there is some improvement, there is still a problem of local overheating, which leads to excessive noise when boiling water and affects the user experience. Summary of the invention

[0004] In view of the fact that existing liquid heaters use multiple heating elements, there is still a problem of local overheating, which leads to increased boiling water noise and affects the user experience. The purpose of the present invention is to provide a liquid heater that increases the number of heating elements and improves the heating efficiency, evenly heats the bottom plate of the inner tank, reduces the boiling water noise and improves the user experience.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a liquid heater, comprising a kettle body with an inner liner, a heating assembly is provided on the bottom plate of the inner liner, the heating assembly comprises a first heating element, a second heating element, and a heat conduction plate, the heat conduction plate has a first heat conduction zone and a second heat conduction zone, the first heat conduction zone is located outside the second heat conduction zone in the horizontal space, the thermal conductivity coefficient of the heat conduction plate in the first heat conduction zone is greater than the thermal conductivity coefficient of the heat conduction plate in the second heat conduction zone, the first heating element is arranged in the first heat conduction zone, the second heating element is arranged in the second heat conduction zone, and the power of the first heating element is less than the power of the second heating element.

[0006] In the technical scheme, the heating component adopts a double heating element structure, and two heating elements, the first heating element and the second heating element, are arranged on the heat conduction plate, so as to increase the total power of the heating component. Under the same conditions, the low-power heating element makes less noise when boiling water. The low-power first heating element is selected on the outside of the double heating element structure, and the high-power second heating element is selected on the inside when the total power remains unchanged. At the same time, the heat conduction plate has two partitions: the first heat conduction zone on the outside and the second heat conduction zone on the inside. The first heating element is arranged in the first heat conduction zone, and the second heating element is arranged in the second heat conduction zone. The first heating element on the outside has low power and high thermal conductivity coefficient in the first heat conduction zone, while the second heating element on the inside has high power and low thermal conductivity coefficient in the second heat conduction zone. After comprehensive analysis, the heat conducted by the heating component to the unit area of ​​the inner tank chassis is more uniform, the collision movement of the lateral conduction in the heat conduction of water molecules is reduced, the sharp vibration during heat release is slowed down, and the generation of bubbles is reduced, thereby reducing noise, achieving the purpose of reducing noise while increasing power.

[0007] The present invention is further configured as follows: the heat conducting plate includes a first heat conducting plate, a second heat conducting plate, and a third heat conducting plate, the first heat conducting plate is arranged at the lower end of the bottom plate of the inner tank, the first heat conducting plate, the second heat conducting plate, and the third heat conducting plate are stacked in sequence from top to bottom in the second heat conducting area to form a composite plate, the projection of the composite plate on the horizontal plane is located within the projection of the first heat conducting plate on the horizontal plane, the first heating element is arranged at the lower end of the first heat conducting plate and outside the composite plate, the second heating element is arranged at the lower end of the composite plate, and the thermal conductivity coefficients of the first heat conducting plate and the third heat conducting plate are the same and greater than the thermal conductivity coefficient of the second heat conducting plate. Through this configuration, the second heat-conducting zone on the inside is arranged with three layers of composite plates, wherein the upper plate is the first heat-conducting plate, the lower plate is the third heat-conducting plate, the second heat-conducting plate is sandwiched between the first and third heat-conducting plates, the first heat-conducting plate is attached to the bottom plate of the liner, the second heat-conducting member is arranged on the third heat-conducting plate, and the first heat-conducting zone on the outside is arranged with the first heat-conducting plate, which is also the part of the upper plate of the composite plate extending outward, and the first heat-conducting member is arranged on the extension of the first heat-conducting plate. The first heat-conducting plate and the third heat-conducting plate are made of the same material, and the second heat-conducting plate is made of another material with a lower thermal conductivity. The overall thermal conductivity of the composite plate is lower than that of the first heat-conducting plate, which delays the heat accumulation at the position above the composite plate corresponding to the second heating element. Since the upper plate of the composite plate is the first heat-conducting plate with good thermal conductivity, it also conducts heat to the center of the bottom plate of the liner, so that the bottom plate of the liner is heated evenly.

[0008] The present invention is further configured as follows: the heat conducting plate includes a first heat conducting plate and a second heat conducting plate, the first heat conducting plate is arranged at the lower end of the bottom plate of the inner pot, the second heat conducting plate is embedded in the first heat conducting plate to form a composite plate, the first heating element is arranged at the lower end of the first heat conducting plate and is located outside the second heat conducting plate, the second heating element is arranged at the lower end of the first heat conducting plate and is located below the second heat conducting plate, and the thermal conductivity of the first heat conducting plate is greater than the thermal conductivity of the second heat conducting plate. Through this configuration, the second heat conducting zone on the inner side is arranged with a composite plate, the composite plate is a double-layer plate composed of the first heat conducting plate and the second heat conducting plate, the thermal conductivity of the second heat conducting plate is smaller than the thermal conductivity of the first heat conducting plate, the second heat conducting plate is embedded in the first heat conducting plate, the second heating element is arranged at the lower end of the composite plate, the first heat conducting zone on the outer side is arranged with the first heat conducting plate, which is also the part of the outer layer of the composite plate extending outward, and the first heat conducting element is arranged on the extension of the first heat conducting plate. The overall thermal conductivity of the composite plate is lower than that of the first heat conducting plate. The composite plate delays the heat accumulation at the position above the composite plate corresponding to the second heating element. Since the outer layer of the composite plate is the first heat conducting plate with good thermal conductivity, it also conducts heat to the center of the inner tank chassis, so that the inner tank chassis is heated evenly.

[0009] The present invention is further configured as follows: the thermal conductivity of the heat conduction plate in the first heat conduction zone is K1, the thermal conductivity of the heat conduction plate in the second heat conduction zone is K2, the surface heat load of the first heating element is P1, the surface heat load of the second heating element is P2, (P1 / P2) = (K2 / K1). Through this configuration, during the operation of the heating component, by controlling the above variables, the heating temperature T1 of the inner liner chassis above the first heating element and the heating temperature T3 of the inner liner chassis above the second heating element are ensured to be as equal as possible, thereby achieving the purpose of noise reduction.

[0010] The present invention is further configured as follows: the thermal conductivity of the heat conduction plate in the first heat conduction zone is K1, the thermal conductivity of the heat conduction plate in the second heat conduction zone is K2, the surface heat load of the first heating element is P1, the surface heat load of the second heating element is P2, 1.2(K2 / K1)>(P1 / P2)>(K2 / K1). Through this configuration, the thermal conductivity of the composite plate is related to the plate thickness, material, and welding fixation method. Considering the actual thermal conduction gaps between the composite plates, and considering the actual production, the power of each heating element and the plate thickness of each layer should be rounded as much as possible to facilitate processing and production. The theoretical value of K2 should be greater than the actual value. Therefore, P1 / P2 is slightly greater than K2 / K1.

[0011] The present invention is further configured such that the first heat conducting plate, the second heat conducting plate and the third heat conducting plate completely overlap in the second heat conducting area. With this configuration, the first heat conducting plate, the second heat conducting plate and the third heat conducting plate have the same shape in the second heat conducting area, which can ensure uniform heat conduction of the composite plate and make the overall appearance more beautiful.

[0012] The present invention is further configured as follows: the first heat conducting plate and the third heat conducting plate are made of aluminum, and the second heat conducting plate is made of iron or steel. The first heat conducting plate and the third heat conducting plate are made of aluminum, and the thermal conductivity of aluminum is 237W / Mk, which has high thermal conductivity and is convenient for the heat of the heating element to diffuse to the inner tank chassis. The material of the second heat conducting plate can be iron or stainless steel, and the thermal conductivity of stainless steel is 17W / Mk, and the thermal conductivity of iron is 80W / Mk, which is used to reduce the overall thermal conductivity of the composite plate.

[0013] The present invention is further configured as follows: the first heat conducting plate, the second heat conducting plate, and the third heat conducting plate are all arranged concentrically in annular shapes, the outer diameter of the first heat conducting plate is larger than the outer diameter of the third heat conducting plate, the first heating element is arranged around the lower end of the first heat conducting plate and is located outside the second heat conducting plate, and the second heating element is arranged around the lower end of the third heat conducting plate and is located below the second heat conducting plate. Through this configuration, the first heating element and the second heating element are tubular, the first heating element is arranged on the first heat conducting plate and is located outside the third heat conducting plate, that is, the first heat conducting zone is annular, and the tubular first heat conducting element uniformly heats the first heat conducting plate, the second heat conducting element is arranged on the third heat conducting plate, that is, the second heat conducting zone is annular, and the tubular second heat conducting element uniformly heats the composite plate.

[0014] The present invention is further configured as follows: the material of the first heat conducting plate is an aluminum component, and the material of the second heat conducting plate is an iron or steel component. The first heat conducting plate is aluminum, and the thermal conductivity of aluminum is 237W / Mk, which has high thermal conductivity efficiency and facilitates the heat of the heating element to diffuse to the inner tank chassis. The material of the second heat conducting plate can be iron or stainless steel, and the thermal conductivity of stainless steel is 17W / Mk, and the thermal conductivity of iron is 80W / Mk, which is used to reduce the overall thermal conductivity of the composite plate.

[0015] The present invention is further configured as follows: the first heat conducting plate and the second heat conducting plate are both in the form of concentrically arranged rings, the outer diameter of the first heat conducting plate is larger than the outer diameter of the second heat conducting plate, the first heating element is arranged around the lower end of the first heat conducting plate and is located outside the second heat conducting plate, and the second heating element is arranged around the lower end of the first heat conducting plate and is located below the second heat conducting plate. Through this configuration, the first heating element and the second heating element are in the form of a tube, the first heating element is arranged on the first heat conducting plate and is located outside the second heat conducting plate, that is, the first heat conducting zone is in the form of a ring, the tubular first heat conducting element uniformly heats the portion of the first heat conducting plate outside the second heat conducting plate, the second heat conducting element is arranged on the first heat conducting plate and is located below the second heat conducting plate, that is, the second heat conducting zone is in the form of a ring, and the tubular second heat conducting element uniformly heats the composite plate.

[0016] The advantages of the present invention are: 1) The heating component adopts a double heating element structure, and two heating elements, the first heating element and the second heating element, are arranged on the heat conduction plate, thereby increasing the total power of the heating component. When the total power remains unchanged, the low-power first heating element is selected on the outside of the double heating element structure, and the high-power second heating element is selected on the inside. The thermal conductivity coefficient of the first heat conduction zone on the outside of the heat conduction plate is large, and the thermal conductivity coefficient of the second heat conduction zone on the inside is small. After integration, the heat conducted from the heating component to the unit area of ​​the inner tank chassis is more uniform, the collision movement of the lateral conduction of water molecules in the heat conduction is reduced, the rapid vibration during heat release is slowed down, and the generation of bubbles is reduced, thereby reducing noise, achieving the purpose of reducing noise while increasing power. 2) The second heat conduction zone is a composite plate with a small thermal conductivity formed by combining plates with different thermal conductivities, and the first heat conduction zone is a single plate with a large thermal conductivity. The composite plate can be two aluminum plates sandwiching a steel plate, or a steel plate wrapped in an aluminum plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the double heating tubes used in the existing liquid heater; Figure 2 It is a structural schematic diagram of a liquid heater in one embodiment of the present invention; Figure 3 for Figure 2 The enlarged view of point A in the middle; Figure 4 It is a structural schematic diagram of a heating component in one embodiment of the present invention; Figure 5 It is a schematic diagram of the local structure of the heating component in one embodiment of the present invention.

[0018] Reference numerals: heating tube 100 , inner container 200 , first heating element 300 , second heating element 301 , first heat conducting plate 400 , second heat conducting plate 401 , third heat conducting plate 402 , composite plate 403 . DETAILED DESCRIPTION

[0019] In the description of this embodiment, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "back", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore, cannot be understood as limiting the present invention. In addition, if the terms "first", "second", and "third" appear, they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] The existing liquid heater comprises a kettle body, which has an inner liner 200 for containing liquid. A heating component is arranged on the bottom plate of the inner liner 200 , and the heating component heats the liquid in the inner liner 200 .

[0022] The heating assembly in conventional technology has only a single heating tube 100. When only the power of the single heating tube 100 is increased, during operation, the heating tube 100 converts electrical energy into thermal energy, and the heat is concentrated and transferred through the aluminum plate, so that the heat near the aluminum plate above the heating tube 100 accumulates and rises, and it is easy to form a heat collection area corresponding to the shape of the heating tube 100 on the chassis, while the heat in the middle of the aluminum plate is less, forming a heat conduction area with less heat, and the heat is less transferred laterally. The temperature of the heat conduction area in the middle of the chassis is obviously lower than that of the heat collection area, resulting in obvious uneven heating. Heat transfer itself is molecular motion. Uneven heating causes water molecules to not only transfer heat up and down by convection, but also transfer heat laterally, which intensifies the relative motion of water molecules and increases the noise of boiling water.

[0023] In some technologies, the heating assembly uses a double heating tube 100. Figure 1 , the two heating tubes 100 are nested in a double C, close to the bottom of the aluminum plate. When the total power remains unchanged, compared with the single-tube structure, the contact area between the heating tube 100 and the aluminum plate increases, the power of the single tube decreases, and the heat generation per unit area is also reduced. In order to control the heat load of the two heating tubes 100 to be the same, the heat generation power per unit area of ​​the surface of the two heating tubes 100 is equal. Therefore, when the cross-sectional area of ​​the heating tubes 100 is the same, the outer heating tube 100 is longer, and the power of the outer heating tube 100 should be higher than that of the inner heating tube 100. However, in this scheme, the increase in the contact heat transfer area between the heating tube 100 and the aluminum plate is limited. It takes time for the part of the aluminum plate that is not in contact with the heating tube 100 to transfer heat, and the chassis of the inner tank 200 will still have the problem of local overheating.

[0024] In order to solve the problem that the existing liquid heater uses multiple heating elements but still has local overheating, resulting in increased water boiling noise and insufficient user experience, in one embodiment of the present invention, referring to Figure 2 , Figure 3 , Figure 4 , Figure 5The liquid heater includes a kettle body with an inner liner 200, and a heating assembly is provided on the bottom plate of the inner liner 200. The heating assembly includes a first heating element 300, a second heating element 301, and a heat conduction plate. The heat conduction plate has a first heat conduction zone and a second heat conduction zone. The first heat conduction zone is located outside the second heat conduction zone in the horizontal space. The thermal conductivity of the heat conduction plate in the first heat conduction zone is greater than the thermal conductivity of the heat conduction plate in the second heat conduction zone. The first heating element 300 is arranged in the first heat conduction zone, and the second heating element 301 is arranged in the second heat conduction zone. The power of the first heating element 300 is less than the power of the second heating element 301.

[0025] In this embodiment, the heating assembly adopts a double heating element structure, and two heating elements, a first heating element 300 and a second heating element 301, are arranged on the heat conduction plate, thereby increasing the total power of the heating assembly. Under the same conditions, the noise of the heating element with low power when boiling water is smaller. The low-power first heating element 300 is selected on the outer side of the double heating element structure, and the high-power second heating element 301 is selected on the inner side when the total power remains unchanged. At the same time, the heat conduction plate has two partitions: the first heat conduction zone on the outer side and the second heat conduction zone on the inner side. The first heating element 300 is arranged in the first heat conduction zone, and the second heating element 301 is arranged in the second heat conduction zone. The first heating element 300 on the outer side has low power and a large thermal conductivity coefficient in the first heat conduction zone, and the second heating element 301 on the inner side has high power and a small thermal conductivity coefficient in the second heat conduction zone. After comprehensive analysis, the heat conducted by the heating assembly to the unit area of ​​the bottom plate of the inner liner 200 is more uniform, the collision movement of the lateral conduction in the heat conduction of water molecules is reduced, the sharp vibration during the heat release is slowed down, and the generation of bubbles is reduced, thereby reducing the noise, achieving the purpose of reducing the noise while increasing the power.

[0026] In order to realize the partition of the first heat conduction zone and the second heat conduction zone on the heat conduction plate, refer to Figure 2 , Figure 3In one embodiment of the present invention, the heat conducting plate includes a first heat conducting plate 400, a second heat conducting plate 401, and a third heat conducting plate 402. The first heat conducting plate 400 is arranged at the lower end of the bottom plate of the inner tank 200. The first heat conducting plate 400, the second heat conducting plate 401, and the third heat conducting plate 402 are stacked in sequence from top to bottom in the second heat conducting area to form a composite plate 403. The projection of the composite plate 403 on the horizontal plane is located within the projection of the first heat conducting plate 400 on the horizontal plane. The first heating element 300 is arranged at the lower end of the first heat conducting plate 400 and outside the composite plate 403. The second heating element 301 is arranged at the lower end of the composite plate 403. The thermal conductivity coefficients of the first heat conducting plate 400 and the third heat conducting plate 402 are the same and greater than the thermal conductivity coefficient of the second heat conducting plate 401. The second heat-conducting zone on the inner side is arranged with a three-layer composite plate 403, wherein the upper plate is the first heat-conducting plate 400, the lower plate is the third heat-conducting plate 402, the second heat-conducting plate 401 is sandwiched between the first heat-conducting plate 400 and the third heat-conducting plate 402, the first heat-conducting plate 400 is attached to the bottom plate of the liner 200, and the second heat-conducting member is arranged on the third heat-conducting plate 402, and the first heat-conducting zone on the outer side is arranged with the first heat-conducting plate 400, which is also the part of the upper plate of the composite plate 403 extending outward, and the first heat-conducting member is arranged on the extension of the first heat-conducting plate 400. The first heat conducting plate 400 and the third heat conducting plate 402 are made of the same material, and the second heat conducting plate 401 is made of another material with a lower thermal conductivity. The overall thermal conductivity of the composite plate 403 is lower than that of the first heat conducting plate 400, which delays the heat accumulation at the position above the composite plate 403 corresponding to the second heating element 301. Since the upper plate of the composite plate 403 is the first heat conducting plate 400 with good thermal conductivity, the heat is also conducted to the center of the bottom plate of the inner liner 200, so that the bottom plate of the inner liner 200 is evenly heated.

[0027] Specifically, the first heat conducting plate 400, the second heat conducting plate 401, and the third heat conducting plate 402 are all in the form of concentrically arranged rings, the outer diameter of the first heat conducting plate 400 is larger than the outer diameter of the third heat conducting plate 402, the first heating element 300 is arranged around the lower end of the first heat conducting plate 400 and is located outside the second heat conducting plate 401, and the second heating element 301 is arranged around the lower end of the third heat conducting plate 402 and is located below the second heat conducting plate 401. The first heating element 300 and the second heating element 301 are tubular, the first heating element 300 is arranged on the first heat conducting plate 400 and is located outside the third heat conducting plate 402, that is, the first heat conducting area is annular, and the tubular first heat conducting element uniformly heats the first heat conducting plate 400, the second heat conducting element is arranged on the third heat conducting plate 402, that is, the second heat conducting area is annular, and the tubular second heat conducting element uniformly heats the composite plate 403. The first heat conducting plate 400 , the second heat conducting plate 401 , and the third heat conducting plate 402 have the same shape and completely overlap in the second heat conducting area, which can ensure that the composite plate 403 conducts heat evenly and has a more beautiful overall appearance.

[0028] The first heat conducting plate 400 and the third heat conducting plate 402 are made of aluminum, and the thermal conductivity of aluminum is 237W / Mk, which has high thermal conductivity efficiency. At the same time, the contact parts between the heat conducting plate and the heating element and the inner tank 200 chassis are all aluminum plates, which facilitates the heat of the heating element to diffuse to the inner tank 200 chassis. The material of the second heat conducting plate 401 can be iron or stainless steel. The thermal conductivity of stainless steel is 17W / Mk, and the thermal conductivity of iron is 80W / Mk, which is used to reduce the overall thermal conductivity of the composite plate 403.

[0029] It is understandable that the materials of the first heat conducting plate 400 , the second heat conducting plate 401 , and the third heat conducting plate 402 may also be other combinations, as long as the thermal conductivity of the composite plate 403 can be smaller than the thermal conductivity of the first heat conducting plate 400 .

[0030] like Figure 4 As shown, during the operation of the heating component, there are four temperature points, namely, temperature T1 at the joint of the first heat conduction plate 400 and the bottom plate of the inner liner 200 in the first heat conduction zone, temperature T2 at the joint of the first heat conduction plate 400 and the first heating element 300 in the first heat conduction zone, temperature T3 at the joint of the composite plate 403 and the bottom plate of the inner liner 200 in the second heat conduction zone, and temperature T4 at the joint of the composite plate 403 and the second heating element 301 in the second heat conduction zone.

[0031] Assuming that the two heating elements have the same cross-sectional area and different lengths, and the power of the first heating element 300 is smaller than that of the second heating element 301 , the surface heat load of the first heating element 300 is smaller than that of the second heating element 301 .

[0032] Under the same working time, it can be calculated that: T4>T2, T4>T3, T2>T1.

[0033] In order to achieve the purpose of noise reduction, T1 and T3 should be made equal as much as possible.

[0034] Assume that the thermal conductivity of the first heat conducting plate 400 is K1, the thermal conductivity of the composite plate 403 is K2, the surface heat load of the first heating element 300 is P1, and the surface heat load of the second heating element 301 is P2.

[0035] Theoretically, (P1 / P2)=(K2 / K1). During the operation of the heating assembly, by controlling the above variables, the heating temperature T1 of the bottom plate of the inner pot 200 above the first heating element 300 and the heating temperature T3 of the bottom plate of the inner pot 200 above the second heating element 301 are ensured to be as equal as possible, thereby achieving the purpose of noise reduction.

[0036] But in fact, the thermal conductivity of the three-layer composite plate 403 is related to the plate thickness, material and welding fixing method. Taking into account the thermal conductive gaps between the composite plates 403 and the actual production, the power of each heating element and the thickness of each layer of the plate should be rounded as much as possible to facilitate processing and production. The theoretical value of K2 should be greater than the actual value, so P1 / P2 is slightly greater than K2 / K1.

[0037] In fact, it satisfies: 1.2(K2 / K1)>(P1 / P2)>(K2 / K1). Thus, T1 and T3 are made as equal as possible, so that the heat per unit area conducted by the heating component to the bottom plate of the inner tank 200 is more uniform, the collision movement of water molecules in the lateral conduction of heat conduction is reduced, the rapid vibration during heat release is slowed down, and the generation of bubbles is reduced, thereby reducing noise, achieving the purpose of reducing noise while increasing power.

[0038] In addition to the above three-layer composite plate 403, in order to realize the partition of the first heat conduction zone and the second heat conduction zone on the heat conduction plate, refer to Figure 5 In one embodiment of the present invention, the heat conducting plate includes a first heat conducting plate 400 and a second heat conducting plate 401. The first heat conducting plate 400 is arranged at the lower end of the bottom plate of the inner tank 200, and the second heat conducting plate 401 is embedded in the first heat conducting plate 400 to form a composite plate 403. The first heating element 300 is arranged at the lower end of the first heat conducting plate 400 and is located outside the second heat conducting plate 401. The second heating element 301 is arranged at the lower end of the first heat conducting plate 400 and is located below the second heat conducting plate 401. The thermal conductivity of the first heat conducting plate 400 is greater than the thermal conductivity of the second heat conducting plate 401. The second heat-conducting zone on the inside is arranged with a composite plate 403, which is a double-layer plate composed of a first heat-conducting plate 400 and a second heat-conducting plate 401. The thermal conductivity of the second heat-conducting plate 401 is smaller than the thermal conductivity base of the first heat-conducting plate 400. The second heat-conducting plate 401 is embedded in the first heat-conducting plate 400. The second heating element 301 is arranged at the lower end of the composite plate 403. The first heat-conducting zone on the outside is arranged with the first heat-conducting plate 400, which is also the part of the outer plate of the composite plate 403 extending outward. The first heat-conducting element is arranged on the extension of the first heat-conducting plate 400. The overall thermal conductivity of the composite plate 403 is lower than that of the first heat-conducting plate 400. The composite plate 403 delays the heat accumulation of the second heating element 301 at the position above the composite plate 403. Since the outer plate of the composite plate 403 is the first heat-conducting plate 400 with good thermal conductivity, the heat is also conducted to the center of the bottom plate of the inner liner 200, so that the bottom plate of the inner liner 200 is heated evenly.

[0039] The first heat conducting plate 400 is made of aluminum, and the thermal conductivity of aluminum is 237W / Mk. The material of the second heat conducting plate 401 can be iron or stainless steel, and the thermal conductivity of stainless steel is 17W / Mk, and the thermal conductivity of iron is 80W / Mk, which is used to reduce the overall thermal conductivity of the composite plate 403. The aluminum plate has high thermal conductivity efficiency. Since the steel plate is wrapped in the aluminum plate, it can ensure that the contact parts between the heat conducting plate and the heating element and the inner tank 200 chassis are all aluminum plates, which facilitates the heat of the heating element to diffuse to the inner tank 200 chassis. The steel plate can be formed in the aluminum plate by die casting.

[0040] It is understandable that the materials of the first heat conducting plate 400 and the second heat conducting plate 401 may also be other combinations, as long as the thermal conductivity of the composite plate 403 can be smaller than the thermal conductivity of the first heat conducting plate 400 .

[0041] Specifically, the first heat conducting plate 400 and the second heat conducting plate 401 are both in the shape of a concentric ring, the outer diameter of the first heat conducting plate 400 is larger than the outer diameter of the second heat conducting plate 401, the first heating element 300 is arranged around the lower end of the first heat conducting plate 400 and is located outside the second heat conducting plate 401, and the second heating element 301 is arranged around the lower end of the first heat conducting plate 400 and is located below the second heat conducting plate 401. The first heating element 300 and the second heating element 301 are in the shape of a tube, the first heating element 300 is arranged on the first heat conducting plate 400 and is located outside the second heat conducting plate 401, that is, the first heat conducting zone is in the shape of a ring, and the tubular first heat conducting element uniformly heats the portion of the first heat conducting plate 400 outside the second heat conducting plate 401, the second heat conducting element is arranged on the first heat conducting plate 400 and is located below the second heat conducting plate 401, that is, the second heat conducting zone is in the shape of a ring, and the tubular second heat conducting element uniformly heats the composite plate 403.

[0042] The specific description of the present invention in the above embodiments is only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Technical engineers in this field may make some non-essential improvements and adjustments to the present invention based on the contents of the above invention, which fall within the scope of protection of the present invention.

Claims

1. A liquid heater, comprising a kettle body with an inner liner, a heating assembly being arranged on the bottom plate of the inner liner, characterized in that: The heating assembly includes a first heating element, a second heating element, and a heat conduction plate. The heat conduction plate has a first heat conduction zone and a second heat conduction zone. The first heat conduction zone is located outside the second heat conduction zone in a horizontal space. The thermal conductivity of the heat conduction plate in the first heat conduction zone is greater than the thermal conductivity of the heat conduction plate in the second heat conduction zone. The first heating element is arranged in the first heat conduction zone, the second heating element is arranged in the second heat conduction zone, and the power of the first heating element is less than the power of the second heating element.

2. A liquid heater according to claim 1, characterized in that: The heat conducting plate comprises a first heat conducting plate, a second heat conducting plate and a third heat conducting plate, wherein the first heat conducting plate is arranged at the lower end of the bottom plate of the inner tank, and the first heat conducting plate, the second heat conducting plate and the third heat conducting plate are stacked in sequence from top to bottom in the second heat conducting area to form a composite plate, wherein the projection of the composite plate on the horizontal plane is located within the projection of the first heat conducting plate on the horizontal plane, the first heating element is arranged at the lower end of the first heat conducting plate and outside the composite plate, the second heating element is arranged at the lower end of the composite plate, and the thermal conductivity coefficients of the first heat conducting plate and the third heat conducting plate are the same and greater than the thermal conductivity coefficient of the second heat conducting plate.

3. A liquid heater according to claim 1, characterized in that: The heat conducting plate includes a first heat conducting plate and a second heat conducting plate. The first heat conducting plate is arranged at the lower end of the bottom plate of the inner pot, and the second heat conducting plate is embedded in the first heat conducting plate to form a composite plate. The first heating element is arranged at the lower end of the first heat conducting plate and is located outside the second heat conducting plate. The second heating element is arranged at the lower end of the first heat conducting plate and is located below the second heat conducting plate. The thermal conductivity of the first heat conducting plate is greater than the thermal conductivity of the second heat conducting plate.

4. A liquid heater according to claim 1, 2 or 3, characterized in that: The thermal conductivity of the heat conduction plate in the first heat conduction zone is K1, the thermal conductivity of the heat conduction plate in the second heat conduction zone is K2, the surface heat load of the first heating element is P1, the surface heat load of the second heating element is P2, (P1 / P2)=(K2 / K1).

5. A liquid heater according to claim 1, 2 or 3, characterized in that: The thermal conductivity of the heat conduction plate in the first heat conduction zone is K1, the thermal conductivity of the heat conduction plate in the second heat conduction zone is K2, the surface heat load of the first heating element is P1, the surface heat load of the second heating element is P2, 1.2(K2 / K1)>(P1 / P2)>(K2 / K1).

6. A liquid heater according to claim 2, characterized in that: The first heat conducting plate, the second heat conducting plate and the third heat conducting plate completely overlap in the second heat conducting area.

7. A liquid heater according to claim 2, characterized in that: The first heat conducting plate and the third heat conducting plate are made of aluminum, and the second heat conducting plate is made of iron or steel.

8. A liquid heater according to claim 2, characterized in that: The first heat conducting plate, the second heat conducting plate and the third heat conducting plate are all concentrically arranged in annular shapes, the outer diameter of the first heat conducting plate is larger than the outer diameter of the third heat conducting plate, the first heating element is arranged around the lower end of the first heat conducting plate and is located on the outside of the second heat conducting plate, and the second heating element is arranged around the lower end of the third heat conducting plate and is located below the second heat conducting plate.

9. The liquid heater according to claim 3, characterized in that: The first heat conducting plate is made of aluminum, and the second heat conducting plate is made of iron or steel.

10. The liquid heater according to claim 3, characterized in that: The first heat conducting plate and the second heat conducting plate are both concentrically arranged rings, the outer diameter of the first heat conducting plate is larger than the outer diameter of the second heat conducting plate, the first heating element is arranged around the lower end of the first heat conducting plate and is located on the outside of the second heat conducting plate, and the second heating element is arranged around the lower end of the first heat conducting plate and is located below the second heat conducting plate.

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