Dry-burning-resistant thin instant water heater

Abstract

The utility model relates to an electric heating technology, and aims to provide a thin instant water heater capable of preventing dry burning. The product comprises a top cover, a heating plate and a bottom shell, a plurality of vertical flow channel fins are arranged in the top cover in a staggered manner and form a flow channel, the horizontal height of the top of the flow channel at the water outlet is higher than that of the water inlet, and the horizontal height of the top of the flow channel at any position is not lower than the incoming flow direction all the time; the heating plate comprises a base plate and a heating element, the bottom shell is connected with a main body of the top cover, and a distance is kept between the bottom shell and the heating plate and used for containing cables and matched elements of the heating plate. By means of the design that the tops of the flow channels keep the rising trend relative to the horizontal plane and the design that gaps are kept between the tail ends of the flow channel fins and the heating plate, it is guaranteed that bubbles in water flow can flow out in the fluid direction, and water flow infiltration can be always kept between the flow channels and the heating plate due to the gaps. Influence on heating efficiency and even potential safety hazards caused by non-uniform heating or local overheating are avoided; the product is small in size, easy to assemble and convenient to manufacture and assemble.

Description

Technical Field

[0001] This utility model relates to electric heating technology, and in particular to a thin, fast-burning water heater that prevents dry burning. Background Technology

[0002] With the rapid development of the small household appliance industry, the demand for micro fluid heaters is increasing. For example, the market demand for smart flushing toilets is expanding, and the instant water heaters that are compatible with them are also evolving towards smaller size, faster heating rate, and higher safety requirements.

[0003] Currently, common micro instant water heater solutions on the market mainly use die-cast aluminum heating blocks with heating elements as the heat source, or ceramic heaters with heating layers attached to cylindrical surfaces as the heat source. Among these, using a heating layer as the heat source offers the advantage of a fast heating rate. However, when the rapid heating plate or layer is applied to a planar structure for fluid heating, it is prone to localized dry burning due to factors such as residual gas, gas-liquid mixing, or insufficient thermal conductivity of the heating surface. This not only affects heating efficiency but, in severe cases, can cause the rapid heating plate or layer to burn out, posing a safety hazard.

[0004] For example, Chinese invention patent application "Heater for Heating Fluids" (CN201910729035.1) discloses a heater for heating fluids. Its main body includes a plate-shaped partition wall portion and a flow path forming portion forming a flow path on the other side of the partition wall portion. A heating plate is disposed on the flow path forming portion in a plate shape, including a heating pattern with a shape corresponding to the flow path. However, if the straight sections of the serpentine flow path are placed inclined to a horizontal plane, gas is easily retained in the bends located at higher gravitational potential energy. If the straight sections of the serpentine flow path are placed parallel to a horizontal plane, dry burning is easily caused in the straight sections located at higher gravitational potential energy. Both situations easily affect heating performance and create safety hazards.

[0005] Therefore, it is necessary to propose new solutions to address the aforementioned problems. Utility Model Content

[0006] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a thin-type instant water heater that prevents dry burning.

[0007] To solve the above-mentioned technical problems, the solution adopted by this utility model is:

[0008] A thin, instantaneous water heater with anti-dry-burning features is provided, comprising a top cover, a heating plate, and a bottom shell arranged sequentially from top to bottom; wherein,

[0009] The main body of the top cover is a box-shaped structure with an opening at the bottom. Inside, there are several vertical flow channel fins arranged in an alternating manner to form flow channels. The two ends of the flow channels are connected to the inlet and outlet located on the side of the top cover, respectively. The horizontal height of the top of the flow channel at the outlet is higher than that at the inlet, and the horizontal height of the top of the flow channel at any position between the inlet and the outlet is never lower than the horizontal height of the top of the flow channel at other positions in the direction of the incoming flow.

[0010] The heating plate includes a substrate and a heating element; the side of the top cover is sealed to the substrate, and the ends of each flow channel fin maintain a gap with the surface of the substrate; the heating element is attached to the surface of the substrate on the opposite side of the top cover.

[0011] The bottom shell is connected to the main body of the top cover, and a gap is maintained between the bottom shell and the heating plate to accommodate the heating plate's cables and supporting components.

[0012] As an improvement, the inlet and outlet are located on two opposite sides of the top cover; the flow channel is any of the following forms: serpentine flow channel, loop flow channel, or spiral flow channel.

[0013] As an improvement, the supporting components include a heat spreader attached to the center of the heating element, and a fuse located below the heat spreader, the latter being connected to the outside of the top cover via a wiring harness; there is at least one fuse, and its fixing method is any one of the following: structural compression fixing, threaded structural fixing, snap-fit ​​fixing, or adhesive fixing.

[0014] As an improvement, the side of the top cover has a circumferentially extended mounting portion, and two circumferential mounting grooves are arranged coaxially below it, with sealing rings installed in each groove; the double-layer sealing rings are used to achieve a seal between the base plate and the mounting portion, and the two are fastened by any of the following methods: bolt and nut fixing, screw fixing, adhesive fixing, snap-fit ​​fixing or riveting fixing.

[0015] As an improvement, the bottom shell and top cover are fastened by any of the following methods: bolt and nut fixing, screw fixing, adhesive fixing, snap-fit ​​fixing, or riveting fixing.

[0016] As an improvement, the inner bottom of the bottom shell is provided with multiple protruding slot structures, and the cables of the heating plate and supporting components are clamped in the corresponding slot structures.

[0017] As an improvement, at least one thermistor is provided at the water inlet of the top cover; at least one thermistor is provided at the water outlet of the top cover, as well as at least one thermostat.

[0018] As an improvement, the heating element is any one of the following: a thick film heating plate, a ceramic heating plate, a PTC heating plate, or a die-cast heating plate with a heating tube or resistance heating wire as the heat source; the top cover, the base plate, and the bottom shell are all integral structures made of any one of the following materials: plastic, cast iron, die-cast aluminum, ceramic, or stainless steel.

[0019] As an improvement, the gap between the end of each flow channel fin and the substrate is between 0.1 mm and 10 mm.

[0020] As an improvement, several vertical support fins or support columns are provided inside the top cover, with the ends of the support fins or support columns in contact with the surface of the substrate; or, several fins arranged alternately in the flow channel fins have a supporting function, with their ends extending to contact the surface of the substrate.

[0021] Compared with the prior art, the technical effects of this utility model are:

[0022] 1. The instant water heater provided by this utility model utilizes the design of the top of the flow channel maintaining an upward trend relative to the horizontal plane and the design of maintaining a gap between the end of the flow channel fins and the heating plate to ensure that air bubbles in the water flow can flow out with the direction of the fluid, and the gap between the flow channel and the heating plate can always keep the water flow wetted, thus perfectly solving the problems existing in the prior art; avoiding uneven heating or local overheating caused by the heating plate not being completely submerged by the fluid or residual gas in the flow channel, thereby affecting the heating efficiency or even causing safety hazards.

[0023] 2. The instant water heater of this utility model has the advantages of small size and easy assembly; since the top cover and bottom shell can be made of one piece, it can be easily manufactured and assembled.

[0024] 3. The instant water heater of this utility model uses a heating plate as a heat source, and the bottom shell can be made very thin. Only the flow channel occupies the main thickness in the top cover. Therefore, compared with traditional aluminum die-cast heating blocks that use heating tubes as heat sources, or ceramic heaters that use heating layers attached to cylindrical surfaces as heat sources, this product can be made very thin, which is very suitable for application scenarios with limited installation space, such as smart toilets. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall assembly structure of the medium-speed water heater of this utility model;

[0026] Figure 2 This is a schematic diagram of the internal structure of the bottom shell;

[0027] Figure 3 This is a schematic diagram of the assembly structure after the bottom shell has been removed.

[0028] Figure 4 A schematic diagram of the internal structure of the top cover after removing the heating layer, heat spreader, and wire harness tube;

[0029] Figure 5 A stepped cross-section diagram of the flow channel structure;

[0030] Figure 6 This is a half-sectional schematic diagram of the medium-speed water heater of this utility model.

[0031] The attached diagram shows the following reference numerals: 1. Top cover; 2. Bottom shell; 3. Thermostat wiring harness 1; 4. Fuse wiring harness 1; 5. Thermistor wiring harness; 6. Screw; 7. Power supply wiring harness; 8. Bolt; 9. Nut; 10. Washer; 11. Base plate; 12. Heating element; 13. Heat spreader; 14. Inner ring seal; 15. Outer ring seal; 16. Seal; 17. Inlet; 18. Outlet; 19. Fuse; 20. Thermostat wiring harness 2; 21. Fuse wiring harness 2; 22. Flow channel fins; 23. Flow channel. Detailed Implementation

[0032] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0033] I. Product Structure Description

[0034] like Figure 1-6 As shown, the anti-dry-burning thin-film instant water heater of this utility model includes a top cover 1, a heating plate, and a bottom shell 2 arranged sequentially from top to bottom; wherein:

[0035] The main body of the top cover 1 is a box-shaped structure with an opening at the bottom and a circumferentially extended mounting part on its side. Two circumferential mounting grooves are arranged coaxially below the mounting part. An inner ring sealing ring 14 and an outer ring sealing ring 15 are respectively provided in the grooves, so that the top cover 1 and the base plate 11 are sealed together.

[0036] Inside the housing of the top cover 1, several vertically arranged flow channel fins 22 are provided to form flow channels 23. The two ends of the flow channels 23 are connected to the inlet 17 and outlet 18 located on the side of the top cover 1, respectively. The horizontal height of the top of the flow channel at the outlet 18 is higher than that at the inlet 17; and the horizontal height of the top of the flow channel at any position between the inlet 17 and the outlet 18 is never lower than the horizontal height of the top of the flow channel at other positions in the direction of incoming flow. The purpose of this design is to utilize the upward trend of the top of the flow channel relative to the horizontal plane to prevent air bubbles generated by turbulence or heat exchange from lingering at the top of a certain area of ​​the flow channel, allowing them to be quickly carried out of the water heater by the water flow. The shape of the top of the flow channel between the inlet 17 and the outlet 18 can always maintain a balanced upward trend (e.g., Figure 6(As shown in the diagram). The shape of the top of the flow channel can also be partially horizontal or partially curved, but a downward trend in the water flow direction should be avoided to prevent air bubble retention. The difference in horizontal height between the top of the flow channel at the outlet 18 and the inlet 17 forms an angle α, which can range from 0° to 45°; the specific value is determined by factors such as the thickness of the product based on the installation environment and the heat exchange effect of the product.

[0037] The gap distance β between the end of each flow channel fin 22 and the substrate surface (e.g.) Figure 6 As shown in the diagram, the gap can be controlled between 0.1mm and 10mm. Excessive gap will cause water to flow directly through, weakening the heat exchange effect; insufficient gap may lead to direct contact between the two due to installation errors, affecting the water immersion effect. The gap distance between the ends of each flow channel fin 22 and the substrate surface does not need to be uniform; errors can be allowed depending on the mold processing, or specific shapes can be designed as needed.

[0038] Furthermore, several vertical support fins or support columns can be arranged alternately in each flow channel fin 22 inside the top cover 1. After the base plate 11 and the top cover 1 are fastened together, the ends of the support fins or support columns are in contact with the surface of the base plate 11. Alternatively, the flow channel fins 22 can have several fins arranged alternately and providing support, with their ends extending to contact the surface of the base plate. This design can further improve the installation stability between the base plate 11 and the top cover.

[0039] The heating plate includes a substrate 11 and a heating element 12; the heating element 12 is attached to the surface of the substrate 11 on the opposite side of the top cover 1. Supporting components include a heat spreader 13 attached to the center of the heating element 12, and a fuse 19 located below the heat spreader 13, the latter being connected to the outside of the top cover 1 via a wiring harness; there is at least one fuse 19, and its fixing method is any of the following: structural compression fixing, threaded structural fixing, snap-fit ​​fixing, or adhesive fixing. At least one thermistor (NTC) is provided at the water inlet 17 of the top cover 1; at least one thermistor and at least one thermostat are provided at the water outlet 18 of the top cover 1.

[0040] The bottom shell 2 is connected to the main body of the top cover 1, and a gap is maintained between the bottom shell 2 and the heating plate 12 to accommodate the heating plate's cables and supporting components. The inner bottom of the bottom shell 2 is provided with multiple protruding slot structures, in which the cables of the heating plate and supporting components are secured.

[0041] As an optional example, the top cover 1, base plate 11, and bottom shell 2 are integral structures made of any of the following materials: plastic, cast iron, die-cast aluminum, ceramic, or stainless steel. The flow channel 23 is any of the following forms: serpentine flow channel, meandering flow channel, or spiral flow channel. The inlet 17 and outlet 18 are located on two opposite sides of the top cover 1. The heating element 12 is any of the following: a thick-film heating plate, a ceramic heating plate, a PTC heating plate, or a die-cast heating plate using a heating tube or resistance heating wire as the heat source. The mounting parts of the base plate 11 and the top cover 1 are fastened together by any of the following methods: bolt and nut fixing, screw fixing, adhesive fixing, snap-fit ​​fixing, or riveting fixing. The bottom shell 2 and the top cover 1 are fastened together by any of the following methods: bolt and nut fixing, screw fixing, adhesive fixing, snap-fit ​​fixing, or riveting fixing. In this utility model, the cable connection and temperature control implementation of the heating element 12, fuse 19, thermistor, and temperature controller all adopt existing technologies, so they will not be described in detail here.

[0042] II. Product Assembly Method:

[0043] A thermistor and a seal 16 are installed at the inlet 17 and outlet 18 of the upper cover 1, respectively. A thermostat 3 is installed at the outlet 18, and both are secured with screws 6. An inner ring seal 14 and an outer ring seal 15 are placed in the mounting groove at the bottom of the upper cover 1. A power harness 7 is soldered onto the heating element 12, and a heat spreader 13 is attached to the surface of the heating element 12. The base plate 11 is fixed to the bottom of the upper cover 1 using bolts 8, nuts 9, and washers 10 to achieve a seal. A fuse 19 and various cables are installed in the slot structure of the bottom shell 2. Finally, the upper cover 1 and the bottom shell 2 are fastened together.

[0044] As a specific example: using a ceramic plate as the substrate 11 gives the instant water heater higher pressure resistance and safer insulation performance. Figure 5 The serpentine flow channel 23 design shown makes the water heater heat more evenly and faster. Figure 6 The inclined flow channel design at angle α, as shown, facilitates the discharge of residual gas or mixed gases in the fluid within flow channel 23, reducing the risk of localized dry burning and explosion due to excessive pressure. Figure 6 The gap β design shown ensures that the fluid remains in contact with the heating plate and exchanges heat during the heating process, preventing bubbles or flow interruption and eliminating the risk of dry burning. The use of thermistors 5 at both the inlet 17 and outlet 18, an additional thermostat 3 at outlet 17, and a fuse 19 on the lower surface of the heat spreader 13 enhances the accuracy of temperature detection and control, resulting in higher safety performance for the instantaneous water heater. Based on these designs, the fluid heater of this invention can be used in heating environments where the fluid is in direct contact with and acts on the human body.

[0045] It is understandable that, due to the inherent flowable covering characteristics of water, the lower part of the top cover 1 and the base plate do not need to be perfectly horizontal, allowing for a slight tilt during design and manufacturing. However, in the application scenarios where this thin instantaneous water heater is installed, it should be ensured that the top level of the flow channel at the outlet is higher than the top level of the flow channel at the inlet. Tilting the installation to prevent the top level of the flow channel at the inlet from being higher than the top level of the flow channel at the outlet will prevent air bubbles from properly exiting the flow channel 23.

[0046] When heated, water enters through the inlet 17 of the top cover 1, and temperature is detected by direct contact with a thermistor; as the water flows along the flow channel 23 inside the top cover 1, the top of the flow channel has a... Figure 6 The tilt angle α shown utilizes the property that bubbles tend to float above the fluid, allowing the gas to be discharged with the water flow. Furthermore, the plane at the end of the flow channel fin 22 does not directly contact the upper surface of the substrate 11, leaving an opening such as... Figure 6 The gap β shown allows water to preferentially diffuse and cover the surface of the substrate 11 when it flows, thus preventing dry burning.

[0047] The thin-film instant water heater designed in this utility model places the instant heating plate or layer at the bottom and leaves gaps in the flow channel structure, allowing the fluid to preferentially cover the heating surface to protect the heater. The flow channel structure is formed by die casting or injection molding of materials (such as plastic, cast aluminum, cast iron, etc.) through an integral molding process. The serpentine flow channel ensures that the fluid is fully heated in the heating area. By designing the distance between the flow channel and the bottom instant heating plate or heating layer, a portion of the fluid is diverted along the flow channel to preferentially immerse the surface of the heating plate, ensuring that the instant heating plate or heating layer does not dry-burn during heating. The layout structure of the flow channel allows the initial residual gas or tiny bubbles released during heating to be carried out of the flow channel by the water flow, preventing gas residue in the flow channel from affecting heating performance and heating uniformity, and eliminating safety hazards such as burnout or breakage.

Claims

1. A thin, fast-burning water heater with anti-dry-burning features, characterized in that, It includes a top cover, a heating plate, and a bottom shell arranged from top to bottom; among which, The main body of the top cover is a box-shaped structure with an opening at the bottom. Inside, there are several vertical flow channel fins arranged in an alternating manner to form flow channels. The two ends of the flow channels are connected to the inlet and outlet located on the side of the top cover, respectively. The horizontal height of the top of the flow channel at the outlet is higher than that at the inlet, and the horizontal height of the top of the flow channel at any position between the inlet and the outlet is never lower than the horizontal height of the top of the flow channel at other positions in the direction of the incoming flow. The heating plate includes a substrate and a heating element; the side of the top cover is sealed to the substrate, and the ends of each flow channel fin maintain a gap with the surface of the substrate; the heating element is attached to the surface of the substrate on the opposite side of the top cover. The bottom shell is connected to the main body of the top cover, and a gap is maintained between the bottom shell and the heating plate to accommodate the heating plate's cables and supporting components.

2. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, The inlet and outlet are located on two opposite sides of the top cover; the flow channel is any of the following forms: serpentine flow channel, loop flow channel or spiral flow channel.

3. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, The supporting components include a heat spreader attached to the center of the heating element and a fuse located below the heat spreader, the latter being connected to the outside of the top cover via a wiring harness; there is at least one fuse, and its fixing method is any one of the following: structural compression fixing, threaded structural fixing, snap-fit ​​fixing or adhesive fixing.

4. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, The top cover has a circumferentially extended mounting portion on its side, and two circumferential mounting grooves are arranged coaxially below it, with sealing rings installed in each groove; the double sealing rings are used to seal the base plate and the mounting portion, and the two are fastened by any of the following methods: bolt and nut fixing, screw fixing, adhesive fixing, snap-on fixing or riveting fixing.

5. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, The bottom shell and top cover are fastened by any of the following methods: bolt and nut fixing, screw fixing, adhesive fixing, snap-on fixing or riveting fixing.

6. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, The inner bottom of the bottom shell is provided with multiple protruding slot structures, and the cables of the heating plate and supporting components are clamped in the corresponding slot structures.

7. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, At least one thermistor is provided at the water inlet of the top cover; at least one thermistor and at least one thermostat are provided at the water outlet of the top cover.

8. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, The heating element is any one of the following: a thick film heating plate, a ceramic heating plate, a PTC heating plate, or a die-cast heating plate with a heating tube or resistance heating wire as the heat source; the top cover, the base plate, and the bottom shell are all integral structures made of any one of the following materials: plastic, cast iron, die-cast aluminum, ceramic, or stainless steel.

9. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, The gap between the end of each flow channel fin and the substrate is between 0.1 mm and 10 mm.

10. The anti-dry-burning thin-film instant water heater according to claim 1, characterized in that, Inside the top cover, there are also several vertical support fins or support columns, the ends of which are in contact with the surface of the substrate; or, the flow channel fins have several fins arranged alternately and having a supporting function, the ends of which extend to be in contact with the surface of the substrate.

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