A thin instant water heater capable of preventing dry burning

Abstract

The present invention relates to electric heating technology, aiming to provide a thin quick-heat water heater that prevents dry burning. The product includes a top cover, a heating plate and a bottom shell; a plurality of vertical flow channel fins arranged in a staggered manner are arranged in the top cover to form a flow channel, the horizontal height of the top of the flow channel at the water outlet is higher than that at the water inlet, and the horizontal height of the top of the flow channel at any position is always not lower than the incoming flow direction; the heating plate includes a substrate and a heating element, the bottom shell is connected to the main body of the top cover, and a spacing is maintained between the bottom shell and the heating plate to accommodate the cables and supporting components of the heating plate. The present invention 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 fin and the heating plate to ensure that the bubbles in the water flow can flow out in the direction of the fluid, and the gap between the flow channel and the heating plate can always keep the water flow wet, avoiding uneven heating or local overheating that affects the heating efficiency and even causes safety hazards; the product is small in size, easy to assemble, and convenient to manufacture and assemble.

Description

Technical Field

[0001] The invention relates to electric heating technology, in particular to a thin instant water heater capable of preventing dry burning. Background Art

[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 fast water heaters that adapt to them are also increasingly developing and iterating towards small size, fast heating rate, and high safety requirements.

[0003] The common micro instant water heater solutions on the market are mainly aluminum die-cast heating blocks with heating tubes as the heat source, or ceramic heaters with heating layers attached to cylindrical surfaces as the heat source. Among them, using the heating layer as the heating source has the advantage of fast heating rate. However, when the instant heating plate or the instant heating layer is attached to a plane structure for fluid heating, it is easy to cause local dry burning due to gas residue, gas-liquid mixing, or insufficient thermal conductivity of the heating surface, which will not only affect the heating efficiency, but in severe cases, it will cause the instant heating plate or the instant heating layer to burn, thus posing a safety hazard.

[0004] For example, the Chinese invention patent application “Heater for heating fluid” (CN201910729035.1) discloses a heater for heating fluid, wherein the main body includes a plate-shaped partition wall portion and a flow path forming portion that forms a flow path on the other side of the partition wall portion, and the heating plate is arranged on the flow path forming portion in a plate shape, and includes a heating pattern of a shape corresponding to the flow path. However, if the straight section flow channel in the serpentine flow channel is placed tilted to the horizontal plane, gas is likely to remain in the bend at a high gravitational potential energy location; if the straight section flow channel in the serpentine flow channel is placed parallel to the horizontal plane, dry burning is likely to occur in the straight section flow channel at a high gravitational potential energy location. Both situations are likely to affect the heating performance and cause safety hazards.

[0005] Therefore, it is necessary to propose new solutions to solve the above problems. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a thin instant water heater that can prevent dry burning.

[0007] In order to solve the above technical problems, the solution adopted by the present invention is:

[0008] Provided is a thin instant water heater that prevents dry burning, comprising a top cover, a heating plate and a bottom shell arranged in sequence from top to bottom; wherein,

[0009] The main body of the top cover is a box-shaped structure with an opening at the bottom, and a plurality of vertical flow channel fins arranged in a staggered manner are arranged inside the top cover to form a flow channel, and the two ends of the flow channel are respectively connected to the water inlet and the water outlet arranged on the side of the top cover; the horizontal height of the top of the flow channel at the water outlet is higher than the horizontal height of the top of the flow channel at the water inlet, and the horizontal height of the top of the flow channel at any position between the water inlet and the water outlet is always not lower than the horizontal height of the top of the flow channel at other positions in the incoming flow direction;

[0010] The heating plate includes a substrate and a heating element; the side of the top cover is sealed to the substrate, and the end of each channel fin maintains a gap with the surface of the substrate; the heating element is arranged on the surface of the substrate opposite to the top cover;

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

[0012] As an improved solution, the water inlet and the water outlet are arranged on two opposite sides of the top cover; the flow channel is any one of the following forms: a serpentine flow channel, a meandering flow channel or a spiral flow channel.

[0013] As an improved solution, the supporting components include a heat spreader fitted in 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 through a wiring harness; there is at least one fuse, and its fixing method is any one of the following: structural extrusion fixing, threaded structure fixing, snap fixing or adhesive fixing.

[0014] As an improved solution, the side of the top cover has a circumferentially extending mounting portion, and two circumferential mounting grooves are coaxially arranged below the top cover, with sealing rings respectively provided in the grooves; a double-layer sealing ring is used to achieve sealing 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 fixing or riveting fixing.

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

[0016] As an improved solution, a plurality of protruding slot structures are provided on the inner bottom of the bottom shell, and the cables of the heating plate and the supporting components are clamped in the corresponding slot structures.

[0017] As an improved solution, at least one thermistor is provided at the water inlet of the top cover; at least one thermistor and at least one temperature controller are provided at the water outlet of the top cover.

[0018] As an improved solution, 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 a resistance heating wire as a heat source; the top cover, base plate and bottom shell are respectively an integrated structure made of any one of the following materials: plastic, cast iron, die-cast aluminum, ceramic, stainless steel.

[0019] As an improved solution, the gap distance between the end of each flow channel fin and the base plate is between 0.1 mm and 10 mm.

[0020] As an improved solution, a plurality of vertical supporting fins or supporting columns are provided inside the top cover, and the ends of the supporting fins or supporting columns are connected to the surface of the substrate; or, the flow channel fins are provided with a plurality of fins which are arranged alternately and have a supporting function, and their ends are extended to connect with the surface of the substrate.

[0021] Compared with the prior art, the technical effects of the present invention are:

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

[0023] 2. The instant water heater of the present invention has the advantages of small size and easy assembly structure; since the upper cover and the bottom shell can adopt an integrated structure, it can be easily manufactured and assembled.

[0024] 3. The instant water heater of the present invention adopts a heating plate as a heat source, and the bottom shell can be made very thin, with only the flow channel occupying the main thickness in the upper cover; therefore, compared with traditional aluminum die-cast heating blocks with heating tubes as heat sources, or ceramic heaters with a heating layer attached to a cylindrical surface as a heat source, the product appearance can be made very thin, which is very suitable for application scenarios with limited installation locations such as smart toilets. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall assembly structure of the medium-speed water heater of the present invention;

[0026] Figure 2 Schematic diagram of the internal structure of the bottom shell;

[0027] Figure 3 This is a schematic diagram of the assembly structure after removing the bottom shell;

[0028] Figure 4This is a schematic diagram of the internal structure of the upper cover after removing the heating layer, heat spreader and wiring harness tube;

[0029] Figure 5 It is a step cross-sectional schematic diagram of the flow channel structure;

[0030] Figure 6 It is a half-section schematic diagram of the medium-speed water heater of the present invention.

[0031] The figure numerals are as follows: upper cover 1; bottom shell 2; thermostat wiring harness 1 3; fuse wiring harness 1 4; thermistor wiring harness 5; screw 6; power wiring harness 7; bolt 8; nut 9; washer 10; base plate 11; heating element 12; heat spreader 13; inner ring sealing ring 14; outer ring sealing ring 15; seal 16; water inlet 17; water outlet 18; fuse 19; thermostat wiring harness 2 20; fuse wiring harness 2 21; flow channel fin 22; flow channel 23. DETAILED DESCRIPTION

[0032] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings.

[0033] 1. Product structure description

[0034] like Figure 1-6 As shown, the anti-dry-burning thin instant water heater of the present invention comprises a top cover 1, a heating plate and a bottom shell 2 arranged in sequence 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 extending mounting portion on its side. Two circumferential mounting grooves are coaxially arranged below the mounting portion, and an inner ring sealing ring 14 and an outer ring sealing ring 15 are respectively provided in the grooves to ensure a sealed connection between the top cover 1 and the base plate 11.

[0036] Inside the box body of the top cover 1, a plurality of vertical flow channel fins 22 are arranged in a staggered manner to form a flow channel 23, and the two ends of the flow channel 23 are respectively connected to the water inlet 17 and the water outlet 18 arranged on the side of the top cover 1. The horizontal height of the top of the flow channel at the water outlet 18 must be higher than the horizontal height of the top of the flow channel at the water inlet 17; and the horizontal height of the top of the flow channel at any position between the water inlet 17 and the water outlet 18 is always not lower than the horizontal height of the top of the flow channel at other positions in the incoming flow direction. The purpose of this design is to utilize the top of the flow channel to maintain an upward trend relative to the horizontal plane, to avoid the bubbles generated by turbulence or heat exchange of the water flow from being retained at the top of a certain area of ​​the flow channel for a long time, and to be quickly carried out of the water heater by the water flow. The shape of the top of the flow channel between the water inlet 17 and the water outlet 18 can be one that always maintains a balanced upward trend (such as Figure 6As shown in ). The top shape of the flow channel can also be partially horizontal or partially ascending curved, but a downward trend in the water flow direction should be avoided to cause bubble retention. The horizontal height difference between the top of the flow channel at the outlet 18 and the inlet 17 forms an angle α, which can be in the range of 0°<α≤45°; the specific value is determined by the thickness determined by the product installation environment, the product heat exchange effect, etc.

[0037] The gap distance β between the end of each channel fin 22 and the substrate surface (eg Figure 6 ), can be controlled between 0.1mm and 10mm. If the gap is too large, the water will flow straight through and weaken the heat exchange effect. If the gap is too small, the installation error may cause the two to directly contact and affect the water immersion effect. The gap distance between the end of each flow channel fin 22 and the surface of the substrate does not need to be uniform. The error can be allowed according to the mold processing conditions, or a specific shape design can be given according to the needs.

[0038] In addition, several vertical supporting fins or supporting columns may be arranged alternately in each flow channel fin 22 inside the top cover 1, and the ends of the supporting fins or supporting columns may be in contact with the surface of the base plate 11 after the base plate 11 and the top cover 1 are fastened and installed. Alternatively, there may be several fins arranged alternately in the flow channel fin 22 and having supporting functions, and the ends of the fins may be extended to be in contact with the surface of the base plate. This design may 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 arranged on the surface of the substrate 11 on the opposite side of the top cover 1. The supporting components include a heat spreader 13 that is arranged in the center of the heating element 12, and a fuse 19 located below the heat spreader 13, which is connected to the outside of the top cover 1 through a wiring harness; there is at least one fuse 19, and its fixing method is any of the following: structural extrusion fixing, threaded structure fixing, snap 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 distance is maintained between the bottom shell 2 and the heating plate 12 to accommodate the cables and supporting components of the heating plate. A plurality of protruding slot structures are provided on the inner bottom of the bottom shell 2, and the cables of the heating plate and supporting components are clamped in the corresponding slot structures.

[0041] As an optional example, the top cover 1, the substrate 11 and the bottom shell 2 are respectively an integrated structure made of any of the following materials: plastic, cast iron, die-cast aluminum, ceramic, stainless steel. The flow channel 23 is any of the following forms: a serpentine flow channel, a meandering flow channel or a spiral flow channel. The water inlet 17 and the water outlet 18 are arranged 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 with a heating tube or a resistance heating wire as a heat source. The substrate 11 and the mounting part of the top cover 1 are fastened by any of the following methods: the fastening and sealing are achieved by any of the following methods: bolt and nut fixing, screw fixing, adhesive fixing, snap fixing or riveting fixing. The bottom shell 2 and the top cover 1 are fastened and installed by any of the following methods: bolt and nut fixing, screw fixing, adhesive fixing, snap fixing or riveting fixing. In the present invention, the cable connection and temperature control implementation of the heating element 12, fuse 19, thermistor, and thermostat all adopt the existing technology, so they are not described in detail.

[0042] 2. Product assembly method:

[0043] Thermistors and seals 16 are installed at the water inlet 17 and the water outlet 18 of the upper cover 1, respectively, and the thermostat 3 is installed at the water outlet 18, and they are fixed with screws 6. In the installation groove at the bottom of the upper cover 1, the inner ring seal 14 and the outer ring seal 15 are respectively placed. The power harness 7 is welded on the heating element 12, and the heat spreader 13 is attached to the surface of the heating element 12. The base plate 11 is fixedly installed on the bottom of the upper cover 1 with bolts 8, nuts 9, and washers 10 to achieve sealing. The fuse 19 and various cables are installed in the card slot structure of the bottom shell 2; finally, the upper cover 1 is buckled with the bottom shell 2.

[0044] As a specific example: using ceramic plate material as the substrate 11, the instant water heater has higher pressure resistance and safer insulation performance. Figure 5 The serpentine flow channel 23 shown in the figure makes the instant water heater heat more evenly and at a faster heating rate. Figure 6 The inclined flow channel design at an angle α shown in the figure makes it easy to discharge the residual gas in the flow channel 23 or the mixed gas in the fluid, thereby reducing the risk of local dry burning and explosion due to excessive pressure. Figure 6 The gap β shown in the design ensures that the fluid is always in contact with the heating plate and in a cooling and heat exchange state during the heating process, avoiding bubbles or interruptions, and eliminating the risk of dry burning. Thermistors 5 are provided at both the water inlet 17 and the water outlet 18, a thermostat 3 is additionally provided at the water outlet 17, and a fuse 19 is provided on the lower surface of the heat spreader 13, so that the temperature detection and control of the heater are more accurate, and the safety performance of the fast water heater is higher. Based on the above design, the fluid heater designed by the present invention can be used in a heating environment where the fluid directly contacts and acts on the human body.

[0045] It is understandable that, because the water flow itself has the characteristic of flowing and covering, the lower part of the upper cover 1 and the base plate do not need to be completely horizontal, and a slight tilt is allowed during design and manufacturing. However, when installing the thin instant water heater product in the application scenario, it should be ensured that the horizontal height of the top of the flow channel at the water outlet is higher than the horizontal height of the top of the flow channel at the water inlet, and avoid tilted installation resulting in the horizontal height of the top of the flow channel at the water inlet being higher than the horizontal height of the top of the flow channel at the water outlet, which will cause the bubbles to be unable to be discharged from the flow channel 23 normally.

[0046] When used for heating, water flows in from the water inlet 17 of the upper cover 1, and the temperature is detected by directly contacting the thermistor; when the water flows along the flow channel 23 in the upper cover 1, the top of the flow channel has a Figure 6 The angle α shown in FIG. 1 is used to utilize the property of bubbles to float above the fluid so that the gas can be discharged with the water flow. Furthermore, the plane where the end of the flow channel fin 22 is located does not directly contact the upper surface of the substrate 11, leaving a gap such as Figure 6 The gap β shown allows the water to preferentially spread and cover the surface of the substrate 11 when flowing, thereby avoiding dry burning.

[0047] The thin instant water heater designed by the present invention places the instant heating plate or the instant heating layer at the bottom and reserves a gap in the flow channel structure, so that the fluid can preferentially cover the heating surface to protect the heater; the flow channel structure is formed by die-casting or injection molding materials (such as plastic, cast aluminum, cast iron, etc.) through an integrated molding process; the fluid can be fully heated in the heating area through the serpentine flow channel; the distance between the flow channel and the instant heating plate or the heating layer at the bottom is designed so that a part of the fluid is diverted when the fluid flows along the flow channel to preferentially immerse the surface of the heating plate, so as to ensure that the instant heating plate or the instant heating layer will not burn in vain during heating; the layout structure of the flow channel is designed so that the initial residual gas in the flow channel or the tiny bubbles precipitated during heating can be carried out of the flow channel along with the fluid by the water flow, so as to prevent the gas from remaining in the flow channel and affecting the heating performance and heating uniformity, and to eliminate safety hazards such as burning or rupture.

Claims

1. A thin instant water heater that prevents dry burning, characterized in that: It includes a top cover, a heating plate and a bottom shell which are arranged in sequence from top to bottom; wherein, The main body of the top cover is a box-shaped structure with an opening at the bottom, and a plurality of vertical flow channel fins arranged in a staggered manner are arranged inside the top cover to form a flow channel, and the two ends of the flow channel are respectively connected to the water inlet and the water outlet arranged on the side of the top cover; the horizontal height of the top of the flow channel at the water outlet is higher than the horizontal height of the top of the flow channel at the water inlet, and the horizontal height of the top of the flow channel at any position between the water inlet and the water outlet is always not lower than the horizontal height of the top of the flow channel at other positions in the incoming flow direction; The heating plate includes a substrate and a heating element; the side of the top cover is sealed to the substrate, and the end of each channel fin maintains a gap with the surface of the substrate; the heating element is arranged on the surface of the substrate opposite to the top cover; The bottom shell is connected to the main body of the top cover, and a distance is maintained between the bottom shell and the heating plate to accommodate the cables and supporting components of the heating plate.

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

3. The anti-dry-burning thin instant water heater according to claim 1, characterized in that: The matching components include a heat spreader fitted in 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 through a wiring harness; there is at least one fuse, and its fixing method is any one of the following: structural extrusion fixing, threaded structure fixing, snap fixing or adhesive fixing.

4. The anti-dry-burning thin instant water heater according to claim 1, characterized in that: The side of the top cover has a circumferentially extending mounting portion, and two circumferential mounting grooves are coaxially arranged below it, with sealing rings respectively provided in the grooves; a double-layer sealing ring is used to achieve sealing 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 fixing or riveting fixing.

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

6. The anti-dry-burning thin instant water heater according to claim 1, characterized in that: A plurality of protruding slot structures are arranged on the inner bottom of the bottom shell, and the cables of the heating plate and the matching components are clamped in the corresponding slot structures.

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

8. The anti-dry-burning thin 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 a resistance heating wire as a heat source; the top cover, the base plate and the bottom shell are respectively an integrated structure made of any one of the following materials: plastic, cast iron, die-cast aluminum, ceramic, stainless steel.

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

10. The anti-dry-burning thin instant water heater according to claim 1, characterized in that: A plurality of vertical supporting fins or supporting columns are also provided inside the top cover, and the ends of the supporting fins or supporting columns are connected to the surface of the substrate; or, the flow channel fins are provided with a plurality of fins arranged alternately and having supporting functions, and their ends are extended to connect to the surface of the substrate.

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