EP3037742A1

EP3037742A1 - Liquid heater, such as a boiler for warm, hot or boiling hot liquid

Info

Publication number: EP3037742A1
Application number: EP15202620.9A
Authority: EP
Inventors: Jeroen Paul Van Schieveen
Original assignee: Koninklijke Fabriek Inventum BV
Current assignee: INVENTUM BEHEER B.V.
Priority date: 2014-12-24
Filing date: 2015-12-23
Publication date: 2016-06-29
Also published as: NL2014057B1

Abstract

The invention relates to a liquid heater, comprising a heating chamber, configured to contain a volume of liquid and having an input port for supply of cold liquid and an output port to furnish heated liquid, at least one heater in thermal contact with the heating chamber to heat the liquid and an electronic control connected to the at least one heater and to at least one temperature sensor, to drive the heater in accordance with an algorithm based at least on temperature of the liquid in the heating chamber.

Description

The present disclosure relates to a liquid heater, such as a boiler for warm, hot or boiling hot liquid, such as water. Conventionally, such boilers comprise a heating chamber with an elongate electric heater extending into the heating chamber, an electromechanical relais connected to the electrical heater and at least connectable to a power supply, such as mains power, to switch power supply to the heater on and/or off, and a sensor, such as a temperature sensor to generate a switching signal based on which the relais switches the electrical heater on and/or off.
Such liquid heaters exhibit a number of drawbacks.
With power supply to the heater switched on through the relais, temperature of the heater is raised to extremes and then abruptly lowered again, for example with influx of new cold liquid to be heated. The extremely high temperatures and corresponding extreme temperature variations at or of the electrical heater cause increased calcium, limescale and other deposition from water onto the heater and that impairs long term function and reliability of the heater.
With or without calcium, limescale and other deposition, energy efficiency of known liquid heaters leaves a lot to be desired; these are simply energy inefficient.
Users of known liquid heaters are provided with often not more than a turning knob to adjust operation of the prior art liquid heaters, which contributes to inefficient power consumption, as adaptation of an operation of the prior art liquid heaters is limited to one parameter, after which the liquid heaters simply stay in a set operation mode. Such knobs moreover only allow for temperature sensitivity of the operation of the heater, to supply power to the heater from a lower or higher settable temperature of the liquid in the chamber.
Boilers are further often tucked away in kitchen cupboards or behind panels and/or doors, so that reaching a knob to adapt any setting manually is cumbersome and awkward. Likewise, to avoid any need for maintenance or repair at such an inconvenient location, the technical developments with respect to such liquid heaters have all been directed at enhancing robustness, which was considered by skilled persons to have been complied with if simplicity of the liquid heaters was kept at a near absolute maximum.
In an attempt to resolve or at least decrease at least one of these disadvantages or some other drawback, not recited above, and more generally is directed at a far more versatile liquid heater than those according to the prior art, the present disclosure provides a liquid heater, comprising: a heating chamber, configured to contain a volume of liquid and having an input port for supply of cold liquid and an output port to furnish heated liquid; at least one heater in thermal contact with the heating chamber to heat the liquid; and an electronic control connected to the at least one heater and to at least one temperature sensor, to drive the heater in accordance with an algorithm based at least on temperature of the liquid in the heating chamber.
Since prior art boilers and ones according to the present disclosure alike are arranged in hidden locations, there was in the prior art a tendency to keep operation of the prior art boilers as well as any possibility of control there over as simple as possible, with even a prejudice against any feature or measure that could potentially be considered to constitute an increase in complexity. The present disclosure is entirely contrary to such prejudices, to achieve and provide advantages over the prior art, that the skilled person might have been unwilling to face in view of those prejudices. Moreover, the present disclosure provides the means to pave the way for many additional beneficial technical possibilities, which run against the prejudice that simplicity is paramount, and simultaneously allow for reduction of power consumption or ease of operation and of operation adjustment or the like.
The present disclosure comprises many additional and alternative embodiments that fall within the definition of appended claims, in particular the appended independent claims. Some of the features of these embodiments are defined in more detail in dependent claims and/or will be described below referring to the appended drawing.
In a potential embodiment a liquid heater further comprises an inner wall of the heating chamber, which may comprise an inductively heatable material and at least one of the at least one heater element comprises an inductive heater, which is inductively coupled with the wall of the heating chamber. Preferably the material of the vessel or container wall is made from material having a high heat conducting characteristic, such as titanium. Through inductive heating of the wall of the vessel or container, making the entire inside wall, including the bottom and/or top of the vessel or container, function as a heater acting on the fluid in the interior of the vessel or container, heat is made to distribute very evenly, surprisingly allowing the use of thinner walls and enabling more cost efficient use of traditionally more expensive materials, like titanium, which would otherwise - in configurations having thicker wall thicknesses - not be commercially viable. Moreover, as a result of the consideration that extremely high temperatures can be avoided relative to prior art heaters, extending into the interior of liquid chamber 2, when the interior wall of the vessel or container is made to act as a heater, also deposition of calcium, limescale and other will be reduced in association with lower inner wall temperatures of the vessel, tank or container, than the temperatures associated with the prior art heaters. Also, there is no longer any need for a hole to be made in a wall of vessel, tank or container for accommodating a centrally extending heater, reducing manufacturing difficulties and costs, for example for creating water tight connections at the centrally extending prior art heaters, and structural integrity of the vessel tank or container is determined to a far lesser extent by such connections, again contributing to thinner wall thicknesses, and enabling use of more expensive materials in a commercially viable manner. Also, a higher effective volume is available inside the vessel, tank or container in the interior thereof.
In a potential additional or alternative embodiment, a liquid heater further comprises a clock, a memory and a flow meter associated with the outflow port to measure instantaneous outflow of heated liquid from the heating chamber, wherein the control is connected to or comprises the memory and the clock, and is connected with the flow meter for registration in the memory of measurement results from the flow meter of instantaneous outflow of heated liquid from the chamber. Here, reference to a flow meter can encompass any type or kind of sensor, detector or the like in as far as such a device is intended which can register outflow of heated liquid from the chamber. Even temperature readings using a temperature sensor can yield detection results with respect to an intensity of usage of heated liquid in particular periods during day or night. In such an embodiment the control may be configured to determine usage patterns from the measurement results for storage of determined patterns in the memory, preferably cyclic patterns having a cycle of for example a day, week, month or year, and to drive the heater in correspondence with the determined and stored usage patterns. In such an embodiment determining the usage patterns, the control may be configured to, at least during an initial learning period, drive the heater to a constant liquid temperature and/or heating power, which is for example associated with a maximum outflow per unit of time of heated liquid from the heating chamber. In an embodiment with the control configured to determine the usage patterns, as an alternative for or in addition to the initial learning period with constant liquid temperature and/or heating power, the control may be configured to continuously determine usage patterns from the measurement results and adapt usage patterns stored in the memory based on newer usage patterns determined from the measurement results.
In a potential additional or alternative embodiment, the control may be configured to, in addition to measurements from the temperature sensor and optionally also from the outflow meter, take into account for driving the heater, at least one from a group of aspects comprising: fixed or semi-fixed parameters, such a night rate electricity; and momentaneous parameters, such as outside temperature and an available surplus of generated electrical solar energy.
In a potential additional or alternative embodiment, the control may be configured to deactivate the heater, when a temperature measured by the temperature sensor of liquid inside the heating chamber exceeds a predetermined threshold.
In a potential additional or alternative embodiment, the liquid heater may further comprise a user interface connected with the control, the user interface forming an input for user commands for the control. In such an embodiment, the user interface may be separate from a housing of the liquid heater and distant from the control. Having a separate user interface, the liquid heater may further exhibit the feature that the user interface is connected with the control via a wireless communication module, based on any one or more than one of wireless communications from a group, comprising: Wi-Fi, ZigBee, BlueTooth. Regardless of any arbitrary connection with the control, the user interface may comprise a mobile device or a computer, such as a smart phone, tablet, laptop, desktop or a smart thermostatic controller, which is provided with an app or computer program to configure to the mobile device or computer to function as the user interface.
In a potential additional or alternative embodiment, the liquid heater may further comprise a communication module, wherein the control is configured to communicate with a manufacturer's server, for any one or more than one of the aspects from a group, comprising: program updates; power consumption data; power saving data; self-diagnosis results.
In a potential additional or alternative embodiment, the liquid heater may further comprise a normally closed, controllable valve at the outflow port, which valve is under control of the control, and an authenticator configured to establish authorisation if not an identification of a person operating a tap to extract heated liquid from the heating chamber, wherein the control is configured to only enable opening of the valve, after the authorisation or identity of the person has been established. In such an embodiment the authenticator may be a device from a group, comprising at least: a code input pad, an iris scanner, a user interface at a distance from a housing of the liquid heater, and a fingerprint scanner. In an embodiment having at least the valve and authenticator in general, the authenticator may be integrated into the tap, which tap is in turn connected with the outflow port of the liquid heater.
In an embodiment comprising at least a user interface and a valve in the outflow port and an authenticator, the authenticator may be a part of the user interface.
In a potential additional or alternative embodiment, the liquid heater may further be a boiler having an electrical heater and the control is configured to modify power supply to the electrical heater relative to a maximum power supply, for instance associated with mains power supply. In such an embodiment, the control may be connected to a power regulator arranged between a power supply and the heater, wherein the power regulator is configured to, under control of the control, allow passage of at least one intermediate power level between full supply and disconnection from supply to the heater. In such an embodiment with a power regulator to set such an intermediate power level, the power regulator may be configured to at least approximately enable any desired power supply level between full supply and disconnection from supply to the heater. In an embodiment having a power regulator in general, the power regulator may be based on at least of the electrical components of a triac and a MOSFET, and be configured to modify frequency of a power signal or modify pulse durations of pulses in a power signal transmitted there through to the heater, under control of the control. In this sense it is noted that - as a possibly preferred alternative for frequency regulation - power to the heater may be regulated by adjusting pulse durations of pulses in a power signal. In case of fixed pulse duration, frequency adjustment may be an option, where pulses can be made to follow less or more quickly, to set power on average lower and higher, respectively.
In a potential additional or alternative embodiment, the liquid heater may further comprise two or more heater elements at different positions relative to a height of the heating chamber, wherein the control is configured to separately drive the two or more heater elements depending on the distinct positions thereof relative to the height of the heating chamber. In such an embodiment, the two or more heater elements may be arranged on an outside of an inner wall of the heating chamber. In a potential additional or alternative embodiment, the temperature sensor may be integrated in the heater. In such an embodiment, the liquid heater may further comprise a current source which is configured to be selectively connected with the heater, and wherein the control is configured to determine electrical resistance of the heater upon connection of the heater to the current source, and deduce a temperature of the liquid from a determined electrical resistance of the heater. In such an embodiment having the current source, the control may be configured to adjust a current value of a current from the current source and to be passed through the heater to at least one predetermined current value.
Based on the above indication of different liquid heaters within the scope of the present disclosure, herein below more detailed description of several embodiments will follow, referring to the appended drawing. The scope of the present disclosure is exclusively to be determined on the basis of the appended independent claim(s), and includes any obvious alternatives for specific limiting features in the appended independent, and is not to be interpreted to be limited to any liquid heater having any particular feature from the following description or the appended drawing for whatever reason. The breadth and width of the disclosure and the scope of protection therefore are exclusively determined on the basis of the appended independent claim(s). Further it is noted that in distinct figures of the appended drawing, relating to different embodiments according to the present disclosure, the same or similar reference signs can be employed below to indicate for the different embodiments, the same or similar elements, components, (sub-) assemblies or aspects. In the drawing:

Figure 1 shows a schematic representation of a first embodiment of a liquid heater;
Figure 2 shows a schematic representation of a second embodiment;
Figure 3 shows a schematic representation of a third embodiment;
Figure 4 shows a schematic representation of a fourth embodiment;
Figure 5 shows a schematic representation of a fifth embodiment;
Figure 6 shows a vessel, tank or container in a further embodiment;
Figure 7 shows a potential realisation of the vessel, tank or container of figure 6; and
Figure 8 shows an alternative realisation relative to the one of Figure 7.

In figure 1, a schematic representation is shown of a liquid heater 1 in a first embodiment of the present disclosure. The embodiment could be considered a basic one, and includes a heating chamber 2 with an input port 3 for supply of cold liquid in the direction of arrow A and an output port 4 to furnish heated liquid in the direction of arrow B. Input port 3 comprises a pipe extending deep into the heating chamber 2, to introduce cold liquid into chamber at a low position therein, so that upon heating thereof, warmer liquid will rise through the heating chamber 2. After sufficient heating, in normal operation, the warmed liquid can be withdrawn from heating chamber 2 through output port 4.
It is noted here that an inverse configuration is also possible, where the input port 3 and the output port 4 extend into chamber 2 from below, and the input port 3 is short to introduce liquid low into chamber 2, and output port 4 is long to allow outflow of heated liquid from a higher level in the interior of chamber 2.
Couplings 5, 6 may be employed to connect input port 3 of the liquid heater 1 to a supply of fresh water (not shown) and to connect output port 4 to a warm, hot or boiling hot water tap (not shown in figure 1). The heating chamber 2 defines a space, into which the input port 3 and the output port 4 extend. Additionally, a heater 7 is provided to be in thermal contact with the heating chamber to heat the liquid. In more detail, heater 7 may be an electrical heater an be submerged into the heating chamber. Further, a temperature sensor 9 is provided in the space. The sensor could be integrated into an inner wall 8 of a container, barrel or the like, that forms the heating chamber 2, or into any the output port 4 (it hardly any use measuring the temperature of newly introduced liquid, when the output temperature is an objective), or into the heater 7.
The temperature sensor 9 is connected with a control, such as a micro-controller 10. The micro-controller is in turn connected with a power regulator 11, which is arranged between the heater 7 and a power source 12, which is an electric power source in this embodiment. In the present embodiment, the power regulator 11 could comprise a simple ON/OFF switch 13 or a more complex power regulator, for instance based on triac's or MOSFET's, as will be described in more detail below. The switch 13 could be a high speed switch controlled by the micro-controller 10. The heater 7 is an immersion heater, but could have any shape, form or embodiment conceivable to the skilled person.
Based on measurement results from the temperature sensor 9, the micro-controller 10 may determine a switching algorithm for driving the switch 13 of power regulator 11, in order to closely adjust and preferably considerably reduce power consumption of the liquid heater 1.
In a further embodiment, shown in figure 2, the liquid heater 1 additionally comprises a real time clock 14 and a memory 15 and a flow meter 16 associated with the outflow port 4 to measure instantaneous outflow of heated liquid from the heating chamber 2, wherein the control 10 is connected to or comprises the memory 15 and the clock 14, and is connected with the flow meter 16 for registration in the memory of measurement results from the flow meter 16 of instantaneous outflow of heated liquid from the chamber 2. Any other parameter indicative of outflow or liquid heater usage in general could be measured, using an appropriate measuring tool or instrument, instead of the flow meter 16. For instance, measurement results from temperature sensor 9 can be employed, or be combined with those of an additional temperature sensor (not shown). As a further addition or alternative, activation time of heater 7 can be registered. Any suitable alternative for measuring intensity of usage of the liquid heater 1 is likewise comprised within the scope of the present disclosure.
A portion of an amount of energy that is consumed by liquid heater 1 is necessary to keep liquid inside heating chamber 2 at a desired temperature. This portion of the energy compensates for still losses, which are caused by leakage of heat to an outside relative to the inside of heating chamber 2, even if no hot or warm liquid is tapped from liquid heater 1. A potential solution is, surprisingly enough and running against the expectations or experience of the skilled person, to lower the inside temperature of heating chamber 2. If the temperature inside heating chamber 2 is lowered, less losses are incurred through leakage of heat. However, lowering the inside temperature of heating chamber 2 may be unwanted, in particular in case where liquid heater 1 is designed to provide boiling hot water. Further, a lower inside temperature of heating chamber 2 results in a lower available amount of warm water, if heated water from the liquid heater 1 is mixed at a tap with cold water by a user, to tap combined heated and cold water at a desired resulting temperature. Heated water from liquid heater one runs out more quickly to provide the desired mixed warm water temperature if the inside temperature in heating chamber 2 is lowered. However, most users do not require a constant maximum amount of warm combined tapwater at every moment of the day. For instance at night warm water usage will diminish to practically zero. Likewise, particular end users may have a working job and be away from home during the day. In the long run, when an outside temperature is colder during winter, freshly introduced coldwater will also tend to be colder than during summer.
The embodiment of liquid heater 1 in figure 2 enables a self learning feature. In accordance with this self learning feature, micro-controller 10 is configured to determine usage patterns from the measurement results for storage of determined patterns in the memory, preferably cyclic patterns having a cycle of for example a day, week, month or year, and to drive the heater 7 via the power regulator 11 or in an alternative embodiment directly, in each case in correspondence with the determined and stored usage patterns.
To determine temporal usage of heated water, outflow measurements from flow meter 16 can be stored in memory 15, together with a time stamp originating from real time clock 14. Based on such temporal results, microcontroller 10 can initiate an analysis routine in correspondence with the program or algorithm loaded in microcontroller 10 or available for the microcontroller in memory 15. Such an analysis routine is designed to take the temporal results and distil usage patterns therefrom, to determine periods, in which the inside temperature of heating chamber 2 can be lowered. The objective here is to reduce electric power consumption without lowering convenience for users. This can be achieved in many different manners. For instance in case of an ON/OFF switch 13, microcontroller 10 can be driven to allow the temperature inside heating chamber 2 to drop to a lower level, before reactivating heater 7, in periods of which the analysis of measurement results indicates that there is a low usage intensity, at least normally. Under exceptional circumstances it must naturally be possible to override control over heater 7 when an extraordinary amount of heated water is necessary or required by a user, even though such extraordinary amounts of heated water are required in a period of the distilled pattern, in which normally a low usage intensity is determined.
The self learning functionality of the liquid heater 1 in the embodiment of figure 2 can be based on a limited learning period of for example a day, a week or even a year. During such period, the liquid heater 1 can be controlled in a conventional manner, in which no power is saved, and/or microcontroller 10 can be configured to continuously adapt distilled patterns on the basis of temporal measurements, even outside of an initial learning period. If an initial learning period having a limited length is employed, the microcontroller 10 may be configured to, at least during the initial learning period, drive the heater 7 to a constant liquid temperature and/or heating power, which is for example associated with a maximum outflow per unit of time of heated liquid from the heating chamber 2. Thereafter, when usage patterns have been determined, drive of the heater 7 can be adapted to be lowered in periods of less intense usage, corresponding with the usage patterns derived from measurement results.
Depending on the type of liquid heater 1 and its desired functionality, adaptation of activation patterns of heater 7 may differ. For instance, if liquid heater 1 is designed and intended for supply of boiling hot water, then detected periods of reduced usage intensity should very reliably be long, without hardly any withdrawal of heated liquid from heating chamber 2, for drive of heater 7 to be reduced, a user needing boiling water should only be disappointed not to get the desired boiling hot water at a very exceptional moment in time, corresponding with a distilled pattern. However, for a liquid heater designed and intended to furnish heated water at a temperature below boiling, the inside temperature of heating chamber 2 can be lowered easily also in periods of detected lower usage but in which periods some usage regularly occurs.
In addition to measured or detected usage, other parameters may also be taken into account when determining usage patterns, and for converting such usage patterns into drive patterns for driving heater 7. For example, activation of heater 7 may be promoted at the end of the night, which is the end of the period having hardly any usage normally, because at such a time night tariffs for energy may be charged by the utility companies. Likewise, any available amount of electric energy can at any time be used for heating the inside of heating chamber 2, if this is advantageous or convenient. For instance, an excessive amount of generated electric energy from an solar energy panel 17, which is not used for other purposes at any particular time, can be employed to activate heater 7. For example, at midday, when most people are at work, an optional solar panel 17 may generate electric energy, which is not used for any particular purpose around the house and could then be beneficially employed for activating heater 7. Therefore, the above referenced parameters, to take into account for determining usage intensity patterns, could also include excessive amounts of energy generated by a photovoltaic element or solar panel 17, to determine for the drive pattern of heater 7 that for instance at midday, heater 7 can be activated even though, when occupants of the house are all out at work and usage intensity is normally low or even absent, which should normally result, when only looking at usage measurements, in a period wherein the temperature in the interior of heating chamber 2 would be allowed to drop.
Consequently, it should be evident that there can therefore be a difference between usage patterns indicating expected heated liquid usage and activation patterns in which heater 7 is to be activated.
Further, an override should be provided, for example in the form of a user interface, to be described in more detail herein below, to increase or reduce temporarily amounts of heated water to be made available through liquid heater 1. For example, when occupants of the house go on holiday, liquid heater 1 should be allowed to enter into a state of low activity over the entire time length of a cycle, during which normally the pattern of usage or pattern of driving heater 7 is followed.
Any liquid heater 1 should have a safety to avoid excessive water temperatures. In prior art systems are separate, often mechanical safety against excessive temperatures is provided. In case of the present disclosure, where a microcontroller 10 is employed to drive heater 7, such a safety can be integrated or incorporated in an operation algorithm, which is followed by microcontroller 10. This avoids the need for a additional and often mechanical safety against excessive temperatures according to the prior art. Surprisingly, use of the microcontroller 10 can result in simplification of the resulting liquid heater 1.
Microcontroller 10 or memory 15 may contain a threshold value for an allowable temperature inside of heating chamber 2. When comparing such a threshold value with a measured temperature result from temperature sensor 9, microcontroller 10 can be configured to determine that power to heater 7 must be cut off, if an instantaneous temperature in heating chamber 2 exceeds the allowable threshold. Likewise, microcontroller 10 may include the diagnosis/detection module to shut down the liquid heater 1, if any other malfunction then an excessive temperature in heating chamber 2 occurs.
According to established standards, liquid heater 1 may comprise a plurality of microcontrollers, temperature sensors, power regulators, and the like, to ensure a safe operation of liquid heater 1. However, a control algorithm or associated software, based on which the microcontroller 10 is to function, could comply with safety class B or C and subsequently, duplicating essential components could be avoided, if desired, for example from a perspective of saving on costs relative to having to furnish such essential components in plural.
In prior art liquid heaters, a control interface is normally provided on a housing thereof. Often, such a control interface is nothing more than a turning knob to set temperature sensitivity or energy consumption of the prior art liquid heater. Such a knob often also allows a user to set a temporarily operation mode of higher or lower energy consumption, for instance when going on holiday or unexpectedly requiring more heated liquid.
Figure 3 shows an embodiment, where microcontroller 10 is connected with or incorporates a communication module 18 for wireless communication with a user interface 19. Any available or appropriate communication protocol could be employed, such as Wi-Fi, ZigBee, Bluetooth, and the like.
User interface 19 is, in the embodiment of figure 3, a smart phone or tablet computer on which an app runs to control communications with microcontroller 10 and/or to allow a user to adapt operation of the liquid heater 1. Alternatively, user interface 19 in the form of a smart phone or tablet computer could be replaced by a control panel, which is connected through cables or wireless with microcontroller 10, and could be placed or positioned in a convenient location, distant from where the actual heating chamber 2 is positioned, for instance in the inside of a kitchen cupboard. Consequently, adaptation of the operation of liquid heater through the shown user interface 19, or any other control panel remote from liquid heater 2 can be made available to an owner or user of the liquid heater in a much more convenient manner than having to actually get physically near to heating chamber and turning the prior art knob.
It should be noted, that even the rudimentary prior art turning knob can be omitted in accordance with this aspect of the present disclosure, essentially without having to provide any additional hardware, in particular if a smart phone or tablet computer is employed, since such a smart phone or tablet computer can already be owned by the owner or user of the liquid heater. Moreover, control possibilities and functionalities can be expanded tremendously relative to the rudimentary turning knob. Further, control possibilities and functionalities can be updated in time, by providing updates of apps, to be downloaded onto the smart phones or tablet computers, defining user interfaces 19.
User interface 19 may allow setting of many different parameters, such as water temperature in an inside of heating chamber 2, and adjustment of the usage pattern or a heater activation pattern, described herein above in relation to a self learning functionality. Likewise, user interface 19 can allow the user to force liquid heater into a kind of hibernation mode, for the duration of for instance a holiday. Also, the user interface 19 can be used as an instrument to import specific requirements and desires, that an owner or user of liquid heater 1 might have. Such information could also facilitate the self learning process, described herein above, for example by providing input about the number of people in a household, the number of showers, taken every day, and/or other information may be made available to microcontroller 10 to allow microcontroller 10 to determine more accurately either a heated water usage pattern and/or a heater activation pattern. At least a part of necessary calculations, normally attributed to microcontroller 10, could be executed on user interface 19, in as far as user interface 19 has calculation capacity, which is in particular the case if user interface is for instance a smart phone or a tablet computer. In addition to the possible embodiments of user interface 19 as a smart phone, tablet computer or control panel, interactivity of liquid heater 1 with a smart thermostatic controller of a central heating system could also be accomplished, where the user interface 19 is formed by the thermostatic controller.
In figure 3, a direct wireless communication between communication module 18 and user interface 19 is implied. However, such communications could also run via or through for example a Wi-Fi network in a home or office environment. Such an embodiment would allow a user interface 19 to be used even if user interface 19 is outside of an area available for direct communications. For instance, Bluetooth is normally limited to a communication distance of approximately 10 m. In contrast, if communications can also run through a network, such as the Internet, an owner or user of liquid heater 1 can adapt operation of liquid heater 1 from practically any remote location, provided his or her user interface 19 is connected to the Internet.
A combination of microcontroller 10 with communication module 18 and/or user interface 19 in isolation could also allow transmission of operational information to a manufacturer of liquid heater 1, for example over the Internet. Manufacturers could be provided with loss function information, information about a need to replace the component or element, such as heater 7, or the like, and this would enable such a manufacturer to contact the owner or user of liquid heater 1 and arrange for a repair or maintenance. Other operational information could be the power consumption of the liquid heater, which is also an aspect, that could be displayed on user interface 19. In the embodiment of figure 2, with the optional provision of a solar panel 17, user interface 19 could display the origin of electrical power used for activating heater 7; the electric power source 12 or solar panel 17. Further, a separate control of solar panel 17 could be made to interact with microcontroller 10 of liquid heater to determine if there is any surplus energy being generated by the solar panel 17, to make this surplus of energy available to heater 7.
Above, reference is made to standard communication protocols, like Wi-Fi and Bluetooth, but communications between user interface 19 and communication module 18 could be encrypted or based on an entirely independent protocol, in order to enhance security, for instance. Likewise, communications between liquid heater 1 and a manufacturer thereof over the Internet could be based on an independent protocol, where there would probably be the need for a separate gateway, connected to a router, providing access to the Internet to the communication module 18.
Figure 4 shows a further embodiment of a liquid heater one according to the present disclosure, wherein output port 4 is connected, via a coupling 6 and appropriate plumbing, to a tap 22 extending above the kitchen work area 20. Tap 22 is provided with the camera 21, but alternatively, a fingerprint sensor or the like may be provided to establish authorisation of a person attempting to use tap 22. For example, in case of boiling water heaters, care should be taken in particular with children. Camera 21 or the fingerprint sensor can be connected through a wireless connection with microcontroller 10 to restrict access. For example, a motor valve 23 can be provided, also under control of microcontroller 10, to stay shut if no proper authorisation to use tap 22 is established. Alternatively, a code pad could be provided, instead of camera 21 and the fingerprint sensor, to allow a user to enter a code and there by establish his or her authorisation to use tap 22. It should be noted, that camera 21, when used, could be configured to execute facial recognition and/or an iris scan, and/or be used as the fingerprint scanner.
Traditionally, liquid heaters are provided with the highly reliable, extremely simplistic temperature control, based on ON/OFF switching employing for instance an electromechanical switch. There are a number of aspects to be noted in relation to such a prior art configuration. Although mechanical switches are robust, reliable and simple, mechanical switches are notoriously inaccurate. For example, use of mechanical switches can result in activating the heater 7, even when a temperature in the heating chamber 2 is only slightly below the desired temperature. As a consequence, temperature in heating chamber 2 can be increased considerably above the desired temperature, before heater 7 is deactivated again. This results in considerable temperature variations of liquid in heating chamber 2, as well as very high temperatures of the heater 7 itself which can result in an increase in calcium, limescale and other deposition onto heater 7.
Herein above, reference was already made to more complex controls and functionalities. In figure 5, an embodiment of a liquid heater 1 is shown, having a more complex power regulator 11, which is an electronic power regulator based on, for example, a triac or MOSFET 24. In such an embodiment, power regulator 11 can be configured to switch current to heater 7 at a high frequency, as a consequence of which average current and average furnished power can be reduced relative to the prior art configuration of a full on or full off drive algorithm for heater 7. Also, in a supplementary feature or alternative embodiment, the power regulator 11 can instantaneously set a current to be supplied to heater 7 at a level between zero and the maximum, furnished by the power source 12, instead of a reduction on average over time. However, care should in such an embodiment be taken not to incur any unnecessary energy losses.
Most prior art liquid heaters for generating heated or boiling water are provided with a heater 7 in the interior of the heating chamber 2. Interior dimensions of heating chamber 2 then impose considerable limitation on the size of heater 7, and consequently of the heat delivery capacity thereof. Further limitations thereon are imposed by the fact that there is a trade off between a volume of liquid in the interior of heating chamber 2 and the size of heating chamber 2 and allowable dimensions of heater 7 to secure, that sufficient amounts of liquid can be heated in heating chamber 2 sufficiently quickly in view of a demand for heated liquid. On the basis of such considerations, a heater 7 like the one in figures 1 - 5 was in prior art normally driven to generate very high temperatures, but such high temperatures promote calcium, limescale and other deposition on heater 7, and over time the efficiency or heat generating capacity of heater 7 would thereby be affected if not eventually compromised. In addition, assembly of heater 7 with a vessel, tank or container to define liquid chamber 2 is often cumbersome or at least contributes to considerable costs for manufacture of prior art liquid heaters. More in particular, such a heater 7 needs to extend through a hole in a side of the vessel, tank or container 25, which even after welding could result in weakening of the construction. If any leaks do occur, these would normally exhibit themselves precisely at those welds, where heater 7 wall of vessel, tank or container 25. Further, through holes for heaters first need to be provided by cutting into the wall of vessel, tank or container 25, to enable subsequent welding or soldering of heater 7 to an edge of a wall of vessel, tank or container 25. Further, cutting, welding, soldering, assembling, etc all require time and subsequently also money in the production process.
In the embodiment of figure 6, heating of liquid chamber 2 is achieved from the outside. The vessel, tank or container 25 in figure 6 is optionally divided into three zones 26, 27 and 28. Each of these zones 26, 27 and 28 has its own heater arranged in thermal contact with the outside wall of the vessel, tank or container 25. In a more basic embodiment, a single heater in thermal contact with a portion or the entirety of the exterior of vessel tank or container 25 may be provided. Optionally, relative to the configuration of figure 6, a heater can be omitted in top zone 28. Lower located zones 26 and 27 and possibly also top zone 28 have a heater arranged around the outer circumference thereof, which is why reference is made to heating from the outside. Heating from the outside, even without the division into zones 26, 27 and 28, in itself is considered to constitute an invention. However, in the framework of a more complex control over functioning of liquid heaters, it is noted that each heater, associated with each of zones 26, 27 and possibly also 28 is separately controlled to heat the interior of liquid chamber 2 through the wall of vessel, tank or container 25. A heater associated with a lower zone 26 can have a higher capacity to be driven to higher temperatures and/or higher power, since a lower zone 26 corresponds with the inflow of cold liquid, in particular water. As the cold liquid is heated in lower zone 26, it will rise. Middle zone 27 will take over heating of the water or other liquid, as it has been warmed or heated already to some extent in lower zone 26. A heater in association with zone 28 could be omitted, if heater in zone 27 suffices for adequate heating of the liquid or water in the lower zones 26 and 27 in combination. Omitting a division into zones with a single outside heater or division into two, or four or more zones could also be contemplated. Driving each heater, associated with one of the zones 26, 27 and 28 requires intelligent control, for which programming of a microcontroller or the like is extremely suitable. Any one of the heaters for any particular one of zones 26, 27 and 28 may have a functionality of keeping interior of heating chamber in the vessel, tank or container warm at relatively low temperatures, thereby reducing deposition of calcium, limescale and/or other depositions.
Using the wall of vessel, tank or container 25 for transmission of heat into the interior of liquid chamber 2 results in a large surface for heating liquid in liquid chamber 2, as the entire inside of the wall of vessel, tank or container 25 is made to act as a heater, already in a more basic embodiment having a single heater on the exterior of vessel, tank or container 25. Preferably, for this, the wall of vessel, tank or container 25 is made from a highly heat conducting material, such as metal, in particular copper, but specific reference is made here to titanium, which is also renowned for its heat transfer capacity. As a result of the consideration that extremely high temperatures can be avoided of prior art heaters, extending into the interior of liquid chamber 2, also deposition of calcium, limescale and other will be reduced in association with lower inner wall temperatures of the vessel, tank or container 25. Also, there is no longer any need for a hole to be made in a wall of vessel, tank or container 25 for a centrally extending heater 7 like in the preceding figures 1 - 5. As a consequence, vessel, tank or container 25 is weakened less, and can therefore be constructed from thinner sheet or plate material.
Essentially, heating through a wall of the vessel, tank or container 25 can be achieved on the basis of anyone of two currently eligible principles; resistive or inductive heating. Embodiments of both principles or any other suitable principle to become available in the future are intended to be encompassed within the scope of protection for the present disclosure.
Figure 7 shows a highly simplified cross-sectional view of a portion of a wall 29 of vessel, tank or container 25. On the outside of wall 29, and electrically isolating sheet or foil 31 is provided, over which resistive wiring 30 is arranged. Sheet or foil 31 should not be electrically conductive but isolating, to avoid a short circuit. Further, the sheet or foil 31 must be highly heat transmissive, to allow heat generated by resistive wiring 30 to be passed into the interior of liquid chamber 2. An isolating layer 32 is provided on top of the resistive wiring 30. In itself, such a isolating layer 32 is normally already arranged on the outside of vessel, tank or container 25, but not in combination with an accommodation for resistive wiring 30. In a further embodiment, a heat resisting layer of for example silicon rubber can be provided between resistive wiring 30 and isolating layer 32, for protection of the isolating layer 32. In an alternative embodiment, resistive wiring can be replaced by silicone heating mats or any other suitable flat type of heating element, which should preferably be capable of being bent easily onto the outer surface of the vessel, tank or container 25.
Figure 8 exhibits an example of inductive heating, wherein at least one loop 33 of electrical wiring is arranged on an outside of vessel, tank or container 25. When current I is passed through the at least one loop 33 of electrical wiring, preferably at a high frequency, an alternating magnetic field will be generated to cause flow of current in walls, potentially including the bottom and top of vessel, tank or container 25, which results in heating of the walls, potentially including the bottom and top of the vessel, tank or container itself, as well as heating of liquid inside the vessel, tank or container 25. Such direct heating of the wall of the vessel, tank or container 25 results in very efficient heating. A separate control 34 can be provided, in addition to or instead of the microcontroller 10 referred to in relation to above described embodiments. Inductive heating may be performed in more than one separate zone, for example by arranging inductive heating elements at different heights of the vessel, tank or container 25, or even on bottom or top of the vessel, tank or container 25. The advantage of thinner wall thicknesses, associated with using the walls of the vessel, tank or container 25, apply in particular for inductive heating with a wall material having a high heat transfer characteristic, enabling the cost efficient use of more expensive materials such as titanium.
According to a further aspect of the present disclosure, the temperature of any heater in any one or more than one of the preceding embodiments can be indicative of liquid temperature inside liquid chamber 2. By taking the temperature of a heater as an indication of liquid temperature in the interior of liquid chamber 2, a need for arranging a temperature sensor in the interior of liquid chamber 2 is obviated. Moreover, the temperature sensor according to prior art configurations must be provided, arranged and assembled, as a consequence of which there is a price to pay in terms of complexity and costs, which is avoided in this aspect of the present disclosure. Normally, an electrical resistance of an material can be directly related to a temperature of that material. By very accurately measuring electrical resistance of a heater, the temperature thereof can be determined. Taking into account that temperature, that the heater should have as a consequence of activation thereof and current flowing through, the difference between the expected temperature and a determined temperature must be caused by the liquid to be heated and consequently, the temperature of the liquid to be heated in the interior of heating chamber 2 may also be deduced. To facilitate such an approach, a material for a heater can be selected to exhibit an electrical resistance with a high temperature dependency. To determine a resistance of the heater, a current source can be connected thereto, in order to generate a current at a predetermined intensity. By measuring a voltage over such a heater, the electrical resistance thereof can easily be calculated.
In the preceding description of several embodiments, specific features are referred to and it should be emphasised here that the scope of protection for the present disclosure is by no means limited to any one or combination of specific features in as far as the appended independent claims are not likewise limited. Even unforeseen alternatives and equivalents of specifically defined limiting features in the appended independent claims lie within the scope of protection. For example, reference to a flow meter in the preceding description should be allowed a broad interpretation, where any type or kind of sensor, detector or the like is intended which can register outflow of heated liquid from the chamber. Even temperature readings using a temperature sensor can yield detection results with respect to an intensity of usage of heated liquid in particular periods during day or night. After having been confronted with the preceding description and the appended drawings of particular embodiments, many additional and/or alternative embodiments will become immediately clear and apparent to the skilled person, and each and every one of such additional and/or alternative embodiments is also within the scope of protection for the present disclosure.

Claims

Liquid heater, comprising:
- a heating chamber, configured to contain a volume of liquid and having an input port for supply of cold liquid and an output port to furnish heated liquid;

- at least one heater in thermal contact with the heating chamber to heat the liquid; and

- an electronic control connected to the at least one heater and to at least one temperature sensor, to drive the heater in accordance with an algorithm based at least on temperature of the liquid in the heating chamber.
Liquid heater according to any claim 1, wherein the wall of the heating chamber comprises an inductively heatable material and at least one of the at least one heater element comprises an inductive heater, which is inductively coupled with the wall of the heating chamber.
Liquid heater according to claim 1 or 2, further comprising a clock, a memory and a flow meter associated with the outflow port to measure instantaneous outflow of heated liquid from the heating chamber, wherein the control is connected to or comprises the memory and the clock, and is connected with the flow meter for registration in the memory of measurement results from the flow meter of instantaneous outflow of heated liquid from the chamber.
Liquid heater according to claim 3, wherein the control is configured to determine usage patterns from the measurement results for storage of determined patterns in the memory, preferably cyclic patterns having a cycle of for example a day, week, month or year, and to drive the heater in correspondence with the determined and stored usage patterns, wherein preferably the control is configured to, at least during an initial learning period, drive the heater to a constant liquid temperature and/or heating power, which is for example associated with a maximum outflow per unit of time of heated liquid from the heating chamber.
Liquid heater according to claim 4, wherein the control is configured to continuously determine usage patterns from the measurement results and adapt usage patterns stored in the memory based on newer usage patterns determined from the measurement results.
Liquid heater according to any one or more than one of the preceding claims, wherein the control is configured to, in addition to measurements from the temperature sensor and optionally also from the outflow meter, take into account for driving the heater, at least one from a group of aspects comprising: fixed or semi-fixed parameters, such a night rate electricity; and momentaneous parameters, such as outside temperature and an available surplus of generated electrical solar energy.
Liquid heater according to any one or more than one of the preceding claims, wherein the control is configured to deactivate the heater, when a temperature measured by the temperature sensor of liquid inside the heating chamber exceeds a predetermined threshold.
Liquid heater according to any one or more than one of the preceding claims, further comprising a user interface connected with the control, the user interface forming an input for user commands for the control, wherein the user interface is preferably separate from a housing of the liquid heater and distant from the control, and is for example connected with the control via a wireless communication module, based on any one or more than one of wireless communications from a group, comprising: Wi-Fi, ZigBee, BlueTooth
Liquid heater according to claim 8, wherein the user interface comprises a mobile device or a computer, such as a smart phone, tablet, laptop, desktop or a smart thermostatic controller, which is provided with an app or computer program to configure to the mobile device or computer to function as the user interface.
Liquid heater according to any one or more than one of the preceding claims, further comprising a communication module, wherein the control is configured to communicate with a manufacturer's server, for any one or more than one of the aspects from a group, comprising: program updates; power consumption data; power saving data; self-diagnosis results.
Liquid heater according to one or more than one of the preceding claims, further comprising a normally closed, controllable valve at the outflow port, which valve is under control of the control, and an authenticator configured to establish authorisation if not an identification of a person operating a tap to extract heated liquid from the heating chamber, wherein the control is configured to only enable opening of the valve, after the authorisation or identity of the person has been established, wherein the authenticator is preferably a device from a group, comprising at least: a code input pad, an iris scanner, a user interface at a distance from a housing of the liquid heater, and a fingerprint scanner, and is, for example, integrated into the tap, which tap is in turn connected with the outflow port of the liquid heater.
Liquid heater according to one or more than one of preceding claims 8, 9 and claim 11, wherein the authenticator is a part of the user interface.
Liquid heater according to one or more than one of the preceding claims, wherein the liquid heater is a boiler having an electrical heater and the control is configured to modify power supply to the electrical heater relative to a maximum power supply, for instance associated with mains power supply, wherein the control is preferably connected to a power regulator arranged between a power supply and the heater, wherein the power regulator is configured to, under control of the control, allow passage of at least one intermediate power level between full supply and disconnection from supply to the heater, wherein the power regulator is for example configured to at least approximately enable any desired power supply level between full supply and disconnection from supply to the heater.
Liquid heater according to claim 13, wherein power regulator is based on at least of the electrical components of a triac and a MOSFET, and is configured to modify frequency of a power signal or modify pulse durations of pulses in a power signal transmitted there through to the heater, under control of the control.
Liquid heater according to any one or more than one of the preceding claims, wherein the heater comprises two or more heater elements at different positions relative to a height of the heating chamber, wherein the control is configured to separately drive the two or more heater elements depending on the distinct positions thereof relative to the height of the heating chamber, wherein the two or more heater elements are arranged on an outside of an inner wall of the heating chamber.
Liquid heater according to any one or more than one of the preceding claims, wherein the temperature sensor is integrated in the heater, further preferably comprising a current source which is configured to be selectively connected with the heater, and wherein the control is configured to determine electrical resistance of the heater upon connection of the heater to the current source, and deduce a temperature of the liquid from a determined electrical resistance of the heater, wherein the control is preferably configured to adjust a current value of a current from the current source and to be passed through the heater to at least one predetermined current value.