HK1158735B - Water heating apparatus - Google Patents

Abstract

A water heating apparatus (10) includes a water tank and at least one heating member (12,112,212,312,412,512,612,712) mounted inside the water tank. Each heating member (12,112,212,312,412,512,612,712) includes a heating body, at least a multi-layer conductive coating (16, 16') of nano-thickness deposited on the heating body, and electrodes coupled to the multi-layer conductive coatings (16, 16'). The multi-layer conductive coating includes a structure and composition which stabilize performance of the heating member at high temperature. The heating body can be made of ceramic glass in the form of a flat plate.

Description

Water heating device

Related patent application

This application claims priority to U.S. provisional patent application 61/075,008, filed 24.6.2008, which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to heating devices, and more particularly, to a water heating device.

Background

U.S. patent application No. 12/026,724 discloses an integrated coating system, the relevant contents of which are incorporated in the entirety into the water heating device of the present application. The integrated coating system has reliable high temperature heating elements to perform reliable and continuous heating functions, with heating temperatures up to 600 ℃. The coating system is disposed on a flat ceramic glass substrate and includes multiple layers of nano-thickness conductive coatings whose properties are based on chemical doping elements and processing conditions. The coating system further includes tailored ceramic glass parallel electrodes that span the entire coating to ensure an optimal match between the electrodes and the coating and substrate, thereby reducing the resistance and improving the electrical conductivity of the heating element. The coating can be made using thermal spray cracking and controlled to a temperature of between about 650 c and 750 c while controlling the spray motion to form multiple layers of thin films between about 50nm and 70nm to improve stability at high temperatures.

The conductive coating material is used to convert electrical energy into thermal energy. The heat generation principle is different from that of the conventional heating coil, and the heat output comes from the resistance of the metal coil, thereby having low heating efficiency and high energy consumption. In contrast, by adjusting the composition and thickness of the multilayer coating, the electrical resistance of the coating system can be controlled and its electrical conductivity enhanced, resulting in efficient heating and minimal energy consumption. The integrated coating system has reliable high temperature heating elements to perform reliable and continuous heating functions, with heating temperatures up to 600 ℃. An intelligent power monitoring and control system using an analog-to-digital converter (ADC) and Pulse Width Modulation (PWM) drive is integrated with the heating membrane to provide smooth power to the heating element, optimizing its heating performance and energy efficiency depending on the desired water temperature and flow rate.

The above background description is provided to aid in the understanding of the water heating apparatus of the present invention, but is not admitted to be prior art to the water heating apparatus disclosed in the present application or to be taken as a material to be cited in the evaluation of the patentability of the claims of the present application.

Disclosure of Invention

The technical scheme adopted by the invention for solving the technical problems is as follows: constructing a water heating device comprising a water tank and at least one heating element disposed within the water tank, the heating element comprising a heating body, at least one set of multi-layer nano-thickness conductive coatings disposed on the heating body; and an electrode coupled to the multilayer conductive coating; wherein the multilayer conductive coating has a structure and composition that stabilizes the performance of the heating element under high temperature conditions.

The water heating apparatus includes a heating element to form an n-shaped water passage in the water tank.

The water heating apparatus includes a plurality of heating elements arranged in parallel with each other to form a circuitous water passage within the water tank.

The water heating device comprises a plurality of heating elements which are arranged in a criss-cross manner so as to form a circuitous water channel in the water tank.

The water heating device includes a plurality of heating elements electrically connected in series.

The water heating device includes a plurality of heating elements electrically connected in parallel.

The heating body of the heating element is a flat plate.

The heating body of the heating element is made of ceramic glass.

The electrode may be a ceramic frit.

The heating element includes a plurality of electrically conductive coatings electrically connected in series.

The heating element includes a plurality of electrically conductive coatings electrically connected in parallel.

The multilayer conductive coating is covered with an insulating material.

The water heating apparatus includes a power monitoring and control system having an analog to digital converter and a pulse width modulated drive.

The heating element is detachably disposed in the water tank.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

fig. 1 is a schematic perspective view of a water heating apparatus according to an embodiment of the present invention;

FIG. 2 is a perspective view of a water heating device having multiple heating elements in accordance with one embodiment of the present invention;

FIG. 3 is a perspective view of a heating element having an electrically conductive coating;

FIG. 4 is a front view of the heating element shown in FIG. 3;

FIG. 5 is a cross-sectional view of a water heating device having a single heating element;

FIG. 6 is a cross-sectional view of a water heating device having four parallel heating elements;

FIG. 7 is a cross-sectional view of a water heating device having a plurality of criss-cross heating elements;

FIG. 8 is a perspective view of a first embodiment of a high volume water heating apparatus;

FIG. 9 is a perspective view of a second embodiment of a high volume water heating apparatus;

FIG. 10a is a schematic view of a heating element having five conductive coatings connected in parallel;

FIG. 10b is a schematic view of a heating element having five conductive coatings connected in series;

FIG. 11 is a schematic diagram of the increase in water temperature for a water having three heating elements, each heating element having an output of about 3kW and a total output of about 9 kW;

FIG. 12 is a schematic diagram of the increase in water temperature for a water having two heating elements, each heating element having an output of about 3kW and a total output of about 6 kW;

FIG. 13 is a block circuit diagram of a three-phase AC powered water heating system consisting of nine heating elements;

FIG. 14 is a circuit schematic of a monitor connected to a power supply;

fig. 15 is a circuit schematic of the ADC and PWM driving of the power monitoring and control system.

Detailed Description

Reference will now be made in detail to the preferred embodiments of the water heating apparatus disclosed in the present application, examples of which are also provided in the following description. Representative embodiments of the water heating apparatus disclosed in the present patent application will be described in detail, but it will be apparent to those of ordinary skill in the art that certain features that are not particularly important to an understanding of the water heating apparatus may not be shown for the sake of brevity.

Moreover, it should be understood that the water heating apparatus disclosed in the present application is not limited to the particular embodiments described below, and that various changes and modifications may be made by one of ordinary skill in the art without departing from the spirit or scope of the pending claims. For example, elements and/or features of different illustrative embodiments may be combined with and/or substituted for one another within the scope of this disclosure and the pending claims.

Furthermore, improvements and modifications that may be apparent to persons skilled in the art after reading this disclosure, the drawings and the appended claims are intended to be within the spirit and scope of the appended claims.

It should be noted that, for purposes of the specification and claims, when an element is described as being "coupled" or "connected" to another element, it is not necessary for the element to be fixed, bound, or otherwise connected to the other element. Conversely, the terms "coupled" or "connected" mean that an element is directly or indirectly connected to another element, or is mechanically or electrically connected to another element.

Fig. 1 is a schematic perspective view of a water heating apparatus 10 according to an embodiment of the present invention. Fig. 2 is a perspective view of a water heating apparatus having a plurality of heating elements according to an embodiment of the present invention. As shown in fig. 1 and 2, the water heating apparatus 10 includes at least one heating element 12 comprising a heating body made of ceramic glass or another suitable material, and a power supply and temperature monitoring and control system 14 for controlling and optimizing the water temperature and heating performance of the apparatus. A remote control using infrared or otherwise may be added to or integrated into the monitoring and control system 14 of the water heating apparatus 10 to perform its designed functions. According to the illustrated embodiment, the heating body of the heating element 12 may be designed as a flat plate structure to maximize the heating area for efficient heating of the water in the water heating apparatus 10 and to achieve a slim and compact design.

The heating body of the heating element 12 in this application may include a flat surface to maximize the heating area for efficient heating of the water in the water heating apparatus 10 and to achieve a slim and compact design of the apparatus. For example, the size is 10X 10cm²And a ceramic glass heating body with a thickness of 4mm can provide a heating surface of up to 200cm²Directly contacting with water and heating at both sides of the ceramic glass. In contrast, a tube heating element would require a diameter of 6.4cm in order to provide the same heating surface, which would limit the thin design achievable with the water heating device.

Instead of using a conventional metal heating element, the heating body of the heating element 12 is made of ceramic glass, and the surface thereof is provided with a plurality of layers of heating thin films of nanometer thickness. The ceramic glass is rigid and has a high temperature resistance. The ceramic glass can perform a reliable and continuous heating function at temperatures up to 600 c, the heating element in this application can reach 300 c in one minute, thereby providing very rapid immediate heating when water flows over the ceramic glass surface. The ceramic glass is non-corrosive and can be easily cleaned by flushing the heating system with a warm acid solution. Therefore, the heating element 12 can be used for a long time by easy maintenance.

Each heating element 12 may be between 10 x 10cm²Generating up to 5000W of power (at 220V ac). Has power density of 50W/cm²A compact and slim water heating device 10 of performance can be built with high power capacity, which other prior art heating elements cannot achieve.

Fig. 3 is a schematic perspective view of a heating element 12 having a heating body made of ceramic glass. As shown in fig. 3, the properties of the multi-layer nano-thick conductive coating 16, 16' are based on chemistry, doping elements and processing conditions, which maintain a stable structure and performance when heated at high temperatures, and a tailored ceramic glass electrode 18 spanning the entire coating is disposed on the ceramic glass body of the heating element 12. As shown in fig. 4, the coated area may be covered by another ceramic glass 20 or another suitable material for protection and insulation. The heating element 12 is sealed and water-tight, and it may be in direct contact with water.

As shown in fig. 3, each heating element 12 may include one or more conductive coatings 16, 16'. Each conductive coating 16, 16' includes a coating region that heats the film. If the heating element 12 includes multiple conductive coatings 16, 16 ', the conductive coatings 16, 16' may have the same or different size dimensions. These conductive coatings 16, 16' may have the same coating properties (e.g., structure, composition, thickness, etc.) or different coating properties. These conductive coatings 16, 16' may be connected to each other in parallel or in series. Based on all of the properties of the conductive coatings 16, 16 'and their electrical connection to each other, the conductivity of the conductive coatings 16, 16' can be improved and their resistance reduced to 10ohms, resulting in high power output over a large heating area or high power density (> 10W/cm) over a small area²) To perform efficient water heating in electric kettles, domestic and industrial heaters and other water heating devices.

Fig. 5-9 illustrate several embodiments of heating elements for water heating devices. Fig. 5 shows a water heating device 110 with only one heating element 112 and forming an n-shaped water channel. The heating device 110 has a water inlet 120 and a water outlet 122. Cold water enters the heating device 110 through the water inlet 120. The added cold water is heated by the heating element 112 as it flows along the water path indicated by the arrow. The heated water exits the heating device 110 through the water outlet 122.

Fig. 6 shows a water heating device 210 having four heating elements 212 and forming a circuitous water channel. Cold water flows into the heating device 210 through the water inlet 220. The added cold water is heated by the four heating elements 212 as it flows along the water path indicated by the direction of the arrows. The heated water exits the heating device 210 through the water outlet 222.

Fig. 7 shows a water heating device 210 having transverse heating elements 312 and longitudinal heating elements 314 and forming a circuitous water channel. Likewise, cold water flows into the heating device 310 through the water inlet 320. The added cold water is heated by transverse and longitudinal heating elements 312 as it flows along the water path indicated by the direction of the arrows. The heated water exits the heating device 310 through the water outlet 322.

Fig. 8 and 9 are high capacity water heating apparatuses 410, 510 for industrial applications. In these water heating devices 410, 510, the heating elements 412, 512 may be connected to a separate power supply. Alternatively, the heating elements 412, 512 may be electrically connected in parallel or series and connected to a single phase or three phase power supply.

As shown in FIGS. 5-9, by increasing or decreasing the number of heating elements 112, 212, 312, 412, 512, respectively, the power output or energy consumption of the water heating devices 110, 210, 310, 410, 510 may be increased or decreased accordingly. To achieve this, it is possible to simply add more heating elements to the water heating apparatus, or to remove some heating elements from the water heating apparatus, or to disconnect some heating elements from the power supply. In practical use, the water heating device can be provided with a smaller number of heating elements in a larger heating area or a larger number of heating elements in a smaller heating area, depending on the required heating output.

By increasing or decreasing the power capacity of each heating element 112, 212, 312, 412, 512, respectively, the heating device 110, 210, 310, 410, 510 may also increase or decrease its power output or energy consumption, respectively. The power capacity of each heating element can be increased by changing the composition, coating area, processing conditions and connections of the conductive coating 16, 16' to increase its conductivity. Power output at high power density in a small area is achieved using a separate coating area and electrode connection method, using a.c. power supply. Thereby developing a heating element with high power density. By arranging the conductive coatings 16, 16' in a parallel connection, the heating element and its power output can be improved. For example, the heating element comprises five conductive coatings 16, 16', each of which may be powered using a.c. power, generating a power rating of approximately 1000W. Each conductive coating 16, 16' can be used alone or together to generate a total power output of about 5000W. These conductive coatings 16, 16' in the form of sealing plates are waterproof and can perform efficient water heating in electric kettles and hot water heaters, which is superior to conventional hot water heaters.

Fig. 10a shows five conductive coatings 614, 616, 618, 620 and 622 connected in parallel in the heating element 12, which can reduce the resistance of the heating element 612 below 10 ohms. For a resistance of 10ohms and an a.c. voltage of 220V, a single heating element can generate 4840W rated power. As shown in fig. 6, a total power output of 19kW can easily be achieved for 4 such heating elements in a water heating device.

The conductive coatings may also be connected in series. Fig. 10b shows five electrically conductive coatings 714, 716, 718, 720, 722 connected in series in a heating element 712. The resistance for each conductive coating is 2ohms, so that in 5 conductive coatings connected in series, a resistance of 10ohms is achieved. For a.c. voltage of 220V, the heating element of the unit may generate a 4840W rated power. As shown in fig. 6, for a water heating device having 4 such heating elements, a total power output of 19kW may be achieved.

Due to the ceramic glass heating element in the present application, a fast water heating can be achieved in the device. As shown in fig. 11 and 12, the water temperature rises at different water flow rates and power ratings. Figure 11 shows the results produced with a total power output of about 9kW with three heating elements, each heating element having a power output of about 3 kW. Figure 12 shows the results produced with a total power output of about 6kW with two heating elements, each heating element having a power output of about 3 kW. It can be obtained that for a three phase power output of about 9kW, the temperature can be raised by 20 ℃ in 20 seconds at a water flow rate of 6 litres per minute. Then the water temperature of 44 ℃ can be realized. The increase in water temperature is affected by the water flow rate. For higher water flow rates of 10 liters per minute, the temperature can be raised by 12 ℃ in 20 seconds, and then the water temperature will stabilize at 36 ℃. Some heating performance variation was observed for two single phase heating elements with a total power output of about 6 kW. For a water flow rate of 6 litres per minute, the water temperature can be raised by 13 ℃ in 20 seconds, and then the water temperature will stabilize at 40 ℃. For a water flow rate of 10 litres per minute, the water temperature can be raised by 8 ℃ in 20 seconds, and then the water temperature will stabilize at 35 ℃. For most of the commercially available hot water heaters, a water temperature of 40 ℃ for a single phase power of 6kW at a lower water flow rate of 3 litres per minute can be achieved to suit kitchen use. Typically, showers require a minimum water flow rate of 5 liters per minute.

The power monitoring and control system 14 using ADC (analog to digital converter) and PWM (pulse width modulation) driving can be integrated with the conductive coating, thereby providing a smooth power supply to the heating element and optimizing the heating performance and energy saving efficiency of the heating element according to the water flow rate and water temperature.

Fig. 13 shows a system block diagram of a three-phase a.c. powered water heating system 700 with nine heating elements 712. The temperature sensors and flow meters 730 may be connected to the system controller 732 of the power control 734 depending on preset conditions of water temperature and water flow rate in use. In particular, the power monitoring and control system 14 using ADC and PWM driving can be integrated with a heating film of nanometer thickness, thereby providing smooth power supply to the heating element and optimizing its heating performance and energy saving efficiency. The power monitoring and control system 14 may be integrated with the conductive coating to optimize temperature and energy saving control. The use of an ADC for temperature measurement and PWM driving software and controller for precise power control is integrated with the heating element into the circuit shown in fig. 14 and 15. Using the monitoring and control system 14, a heating servo system can be developed that can be matched and optimized to the rapid and efficient heating performance of a nano-thick conductive coating to achieve rapid heating (within 1 minute), precise temperature targets (+/-2 c) and maximum energy savings (energy savings efficiency of 95%). When the water temperature reaches the preset target temperature, the ADC and the PWM control system immediately respond and cut off the power supply so as to achieve the purpose of energy conservation and limit the branch flow of the temperature of the conductive coating. When the water temperature drops below the preset temperature, the ADC and the PWM respond, and meanwhile, the power supply is switched on to heat. Thus, the servo system can provide continuous monitoring and control and fast response, thereby providing smooth power supply to the heating element while optimizing heating performance and energy saving efficiency.

While the invention has been described with reference to several particular embodiments, it will be apparent to those skilled in the art that various changes in form and detail can be made therein without departing from the scope of the invention.

Claims (16)

1. A water heating apparatus, comprising:

a water tank;

a plurality of heating elements forming a bypass water channel disposed within the tank, the plurality of heating elements being electrically connected to each other, each of the heating elements comprising:

a heating body made of ceramic glass and forming a flat panel;

at least one set of multi-layer nano-thickness conductive coatings disposed on the heating body; and

a ceramic frit electrode coupled to the multilayer conductive coating; wherein the multilayer conductive coating has a structure and composition that stabilizes the performance of the heating element under high temperature conditions;

the plurality of heating elements includes transverse heating elements and longitudinal heating elements, which are arranged in a criss-cross manner to form a circuitous water channel.

2. A water heating apparatus, comprising:

a water tank;

a plurality of heating elements forming a bypass water channel disposed within the tank, the plurality of heating elements being electrically connected to each other, each of the heating elements comprising:

a heating body forming a flat panel;

at least one set of multi-layer nano-thickness conductive coatings disposed on the heating body; and

an electrode coupled to the multilayer conductive coating; wherein the multilayer conductive coating has a structure and composition that stabilizes the performance of the heating element under high temperature conditions; the plurality of heating elements includes transverse heating elements and longitudinal heating elements, which are arranged in a criss-cross manner to form a circuitous water channel.

3. The water heating apparatus according to claim 2, wherein the plurality of heating elements are electrically connected in series with each other.

4. The water heating apparatus according to claim 2, wherein the plurality of heating elements are electrically connected in parallel with each other.

5. The water heating apparatus according to claim 2, wherein the heating element comprises a plurality of electrically conductive coatings electrically connected in series with one another.

6. The water heating apparatus according to claim 2, wherein the heating element comprises a plurality of electrically conductive coatings electrically connected in parallel with each other.

7. A water heating apparatus, comprising:

a water tank;

at least one heating element disposed within the tank, the heating element comprising:

heating the body;

at least one set of multi-layer nano-thickness conductive coatings disposed on the heating body; the heating elements comprise transverse heating elements and longitudinal heating elements, and the transverse heating elements and the longitudinal heating elements are arranged in a criss-cross mode to form a circuitous water channel; the heating body of the heating element is a flat plate.

8. The water heating apparatus according to claim 7, comprising a plurality of heating elements electrically connected in series.

9. The water heating apparatus according to claim 7, comprising a plurality of heating elements electrically connected in parallel.

10. The water heating apparatus according to claim 7, wherein the heating body of the heating element is made of ceramic glass.

11. The water heating apparatus according to claim 7, wherein the electrode comprises a ceramic frit.

12. The water heating apparatus according to claim 7, wherein the heating element comprises a plurality of electrically conductive coatings electrically connected in series.

13. The water heating apparatus according to claim 7, wherein the heating element comprises a plurality of electrically conductive coatings electrically connected in parallel.

14. The water heating apparatus according to claim 7, wherein the multi-layer conductive coating is covered with an insulating material.

15. The water heating apparatus of claim 7, further comprising a power monitoring and control system including an analog to digital converter and a pulse width modulated drive.

16. The water heating apparatus according to claim 7, wherein the heating element is detachably provided in the water tank.