The present disclosure relates generally to water/energy flow utility management in a water provision system, such as a heater arrangement system for a water provision system for supplying hot water to a plurality of water outlets (taps) in a building. In particular, the present disclosure relates to reducing water flow and/or energy flow to water outlets, in a water provision system to conserve water and/or energy.

BACKGROUND

Whether it is in a commercial or domestic setting, heated water is required throughout the day all year round. It goes without saying that the provision of heated water requires both clean water and a source of heat. To provide heated water, a heating system is provided to an often centralised water provision system to heat water up to a predetermined temperature e.g. set by a user, and the heat source used is conventionally one or more electric heating elements or burning of natural gas. Generally, during periods of high energy (e.g. gas or electricity) demand utilities providers would implement a peak tariff which increases the unit cost of energy, partly to cover the additional cost of having to purchase more energy to supply to customers and partly to discourage unnecessary energy usage. Then, during periods of low energy demand utilities providers would implement an off-peak tariff which lowers the unit cost of energy to incentivise customers to switch to using energy during these off-peak periods instead of peak periods to achieve an overall more balanced energy consumption over time. However, such strategies are only effective if customers are always aware of the changes in tariffs and in addition make a conscious effort to modify their energy consumption habits.

Clean water as a utility is currently receiving much attention. As clean water becomes scarcer, there has been much effort to educate the public on the conservation of clean water as well as development of systems and devices that reduce water consumption, such as aerated showers and taps to reduce water flow, showers and taps equipped with motion sensors that stop the flow of water when no motion is detected, etc. However, these systems and devices are restricted to a single specific use and only have limited impact on problematic water consumption habits.

With growing concerns over the environmental impact of energy consumption, there has been a recent growing interest in the use of heat pump technologies as a way of providing domestic heated water. A heat pump is a device that transfers thermal energy from a source of heat to a thermal reservoir. Although a heat pump requires electricity to accomplish the work of transferring thermal energy from the heat source to the thermal reservoir, it is generally more efficient than electrical resistance heaters (electrical heating elements) as it typically has a coefficient of performance of at least 3 or 4. This means under equal electricity usage 3 or 4 times the amount of heat can be provided to users via heat pumps compared to electrical resistance heaters.

The heat transfer medium that carries the thermal energy is known as a refrigerant. Thermal energy from the air (e.g. outside air, or air from a hot room in the house) or a ground source (e.g. ground loop or water filled borehole) is extracted by a receiving heat exchanger and transferred to a contained refrigerant. The now higher energy refrigerant is compressed, causing it to raise temperature considerably, where this now hot refrigerant exchanges thermal energy via a heat exchanger to a heating water loop. In the context of heated water provision, heat extracted by the heat pump can be transferred to water in an insulated tank that acts as a thermal energy storage, and the heated water may be used at a later time when needed. The heated water may be diverted to one or more water outlets, e.g. a tap, a shower, a radiator, as required. However, a heat pump generally requires more time compared to electrical resistance heaters to get water up to the desired temperature.

Since different households, workplaces and commercial spaces have different requirements and preferences for heated water usage, new ways of heated water provision are desirable in order to enable heat pumps to be a practical alternative to electrical heaters. Moreover, in order to conserve energy and water, it may be desirable to temporarily reduce the flow of water.

SUMMARY

The invention provides a heater arrangement system for a water provision system for controlling a water supply provided to a water outlet, as claimed in claim 1.

The invention also provides a method of controlling a water supply provided to a water outlet, as claimed in claim 10.

The invention further provides a corresponding computer program product and a control module, as claimed in claims 19 and 20.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described with reference to the accompanying drawings, in which: Fig. 1 is a schematic system overview of an exemplary water provision system;

Fig. 2 is a flowchart showing the steps involved in temporarily reducing the flow of energy, and/or water, in an exemplary water provision system.

DETAILED DESCRIPTION

In view of the foregoing, the present disclosure provides various approaches for controlling the use of utilities including water and energy in a household environment. According to one embodiment, a flow rate and/or temperature of heated water emerging from a water outlet is reduced when it is determined that there is an absence of any object beneath the water outlet, such that water (due to the lower flow rate of the water) and/or energy (due to the lower temperature of the water) usage may be reduced when it is not required. According to a complimentary embodiment, a warning such as a sound or flashing light is initiated when it is determined that a water outlet has been continuously providing heated water for a first period of time, and ceases provision of heated water when it is determined that the water outlet has been continuously providing heated water for a longer second period of time, such that water and/or energy usage may be reduced when it is deemed unnecessary and furthermore flooding is prevented. According to a further complimentary embodiment, a report may be generate based on collected heated water usage data, for example to prompt users to modify their usage habits.

In the following embodiments, heated water is provided to a plurality of water outlets, including taps, showers, radiators, etc., in a building, such as a private residential house or commercial space, by a centralized water heating system. The water heating system may comprise one or more electric heating elements for directly heating cold water to a temperature controlled by the amount of energy supplied to the one or more electric heating elements. The water heating system may further comprise a less direct, slower acting but cost-saving and environmentally friendly heat source for heating water, for example in the form of a heat pump for extracting thermal energy from the surroundings and/or a thermal energy storage e.g. comprising phase change material for storing thermal energy as latent heat to be later extracted for heating cold water to a temperature determined by the amount of thermal energy stored within the thermal energy storage. The water heating system is controlled by means of a control module communicatively coupled to the water heating system configured for example to modulating power supplied to the one or more electric heating elements, to activate or otherwise control and modulate power supplied to the heat pump.

Water Provision System

In embodiments of the present techniques, cold and heated water is provided by a centralized water provision system to a plurality of water outlets, including taps, showers, radiators, etc., for a building in a domestic or commercial setting. An exemplary water provision system according to an embodiment is shown in Fig. 1. In the present embodiment, the water provision system 100 comprises a control module 110. The control module 110 is communicatively coupled to, and configured to control, various elements of the water provision system, including flow control 130 for example in the form of one or more valves arranged to control the flow of water internal and external to the system, a (ground source or air source) heat pump 140 configured to extract heat from the surroundings and deposit the extracted heat in a thermal energy storage 150 to be used to heat water, and one or more electric heating elements 160 configured to directly heat cold water to a desired temperature by controlling the amount of energy supplied to the electric heating elements 160. Heated water, whether heated by the thermal energy storage 150 or heated by the electric heating elements 160, is then directed to one or more water outlets as and when needed. In the embodiments, the heat pump 140 extracts heat from the surroundings into a thermal energy storage medium within the thermal energy storage 150. The thermal energy storage medium may in addition be heated by other sources. The thermal energy storage medium is heated until it reaches a desired operation temperature, then cold water e.g. from the mains can be heated by the thermal energy storage medium to the desired temperature. The heated water may then be supplied to various water outlets in the system.

In the present embodiment, the control module 110 is configured to receive input from a plurality of sensors 170-1, 170-2, 170-3, ..., 170-n. The plurality of sensors 170-1, 170-2, 170-3, ..., 170-n may for example include one or more air temperature sensors disposed indoor and/or outdoor, one or more water temperature sensors, one or more water pressure sensors, one or more timers, one or more motion sensors, and may include other sensors not directly linked to the water provision system 100 such as a GPS signal receiver, calendar, weather forecasting app on e.g. a smartphone carried by an occupant and in communication with the control module via a communication channel. The control module 110 is configured, in the present embodiment, to use the received input to perform a variety of control functions, for example controlling the flow of water through the flow control 130 to the thermal energy storage 150 or electric heating elements 160 to heat water.

While a heat pump is generally more energy efficient for heating water compared to an electrical resistance heater, a heat pump requires time to start up as it performs various checks and cycles before reaching a normal operation state, and time to transfer sufficient amount of thermal energy into a thermal energy storage medium before reaching the desired operation temperature. On the other hand, an electrical resistance heater is generally able to provide heat more immediately. Thus, a heat pump can take longer to heat the same amount of water to the same temperature compared to an electrical resistance heater. Moreover, in some embodiments, the heat pump 140 may for example use a phase change material (PCM), which changes from a solid to a liquid upon heating, as a thermal energy storage medium. Additional time may therefore be required to for the heat pump to first transferred a sufficient amount of heat to turn the PCM from solid to liquid, if it has been allowed to solidify, before it can further raise the temperature of the liquified thermal storage medium. Although this approach of heating water is slower, it consumes less energy to heat water compared to electric heating elements, so overall, energy is conserved and the cost for providing heated water is reduced.

Phase Change Materials

In the present embodiments, a phase change material may be used as a thermal storage medium for the heat pump. One suitable class of phase change materials are paraffin waxes which have a solid-liquid phase change at temperatures of interest for domestic hot water supplies and for use in combination with heat pumps. Of particular interest are paraffin waxes that melt at temperatures in the range 40 to 60 degrees Celsius (°C), and within this range waxes can be found that melt at different temperatures to suit specific applications. Typical latent heat capacity is between about 180kJ/kg and 230kJ/kg and a specific heat capacity of perhaps 2.27Jg ^-1 K ¹ in the liquid phase, and 2.1Jg ^-1 K ¹ in the solid phase. It can be seen that very considerable amounts of energy can be stored taking using the latent heat of fusion. More energy can also be stored by heating the phase change liquid above its melting point. For example, when electricity costs are relatively low during off-peak periods, the heat pump may be operated to "charge" the thermal energy storage to a higher-than-normal temperature to "overheat" the thermal energy storage. A suitable choice of wax may be one with a melting point at around 48°C, such as n- tricosane C23, or paraffin C20-C33, which requires the heat pump to operate at a temperature of around 51°C, and is capable of heating water to a satisfactory temperature of around 45°C for general domestic hot water, sufficient for e.g. kitchen taps, shower/bathroom taps. Cold water may be added to a flow to reduce water temperature if desired. Consideration is given to the temperature performance of the heat pump. Generally, the maximum difference between the input and output temperature of the fluid heated by the heat pump is preferably kept in the range of 5°C to 7°C, although it can be as high as 10°C.

While paraffin waxes are a preferred material for use as the thermal energy storage medium, other suitable materials may also be used. For example, salt hydrates are also suitable for latent heat energy storage systems such as the present ones. Salt hydrates in this context are mixtures of inorganic salts and water, with the phase change involving the loss of all or much of their water. At the phase transition, the hydrate crystals are divided into anhydrous (or less aqueous) salt and water. Advantages of salt hydrates are that they have much higher thermal conductivities than paraffin waxes (between 2 to 5 times higher), and a much smaller volume change with phase transition. A suitable salt hydrate for the current application is Na2S2O3-5H2O, which has a melting point around 48°C to 49°C, and latent heat of 200-220 kJ/kg.

Fig. 2 shows an embodiment of a method for controlling utility usage, for example in a home environment. The method begins at S2001 when a water outlet (for example, a bathroom sink tap) is activated or turned on by a user to receive heated water supplied by a water heating system disposed remotely from the water outlet, the water heating system being controlled by a control module 110 of Fig. 1, disposed remotely from the water outlet and in communication with a sensor (for example, one of the sensors 170-n, shown in Fig. 1) disposed at or near the water outlet for sensing the presence of an object (for example, a hand of the person who is washing his hands) below the water outlet. At S2002, the control module 110 receives a signal from the sensor and determines at S2003 whether an object is present below the water outlet. If the control module determines that an object is present, the method returns to S2002 and the control module continues to monitor signals from the sensor. If the control module determines that there is no object below the water outlet, at S2004, the control module controls the water heating system to reduce the temperature of the heated water supplied to the water outlet and/or reduce the flow rate of the heated water supplied to the water outlet. The method then returns to S2002 and the control module continues to monitor signals from the sensor. In doing so, heated water may continue to be supplied to the water outlet but with reduced energy and/or water usage. For example, when the user is washing their hands with heated water under a tap, when the user removes their hands from under the tap to e.g. reach for the soap, the control module can reduce the temperature and the flow of heated water to conserve energy and water, then once the user return their hands to the tap, the temperature and the flow of heated water can be brought back to the initial level.

There may be instances when the user may forget to turn off the tap. Thus, in an alternative embodiment or in addition to the previous embodiment, upon the water outlet being activated to supply heated water, a timer in communication with the control module is activated to record an elapsed time. At S2005, the control module receives signals from the timer to determine the elapsed time T for the continuous provision of heated water from the water outlet. If the control module determines at S2006 that the elapsed time T does not exceed a predetermined first threshold Tl, the method returns to S2005 and the control module continues to monitor signals from the timer. If the control module determines at S2006 that the elapsed time T exceeds the first threshold Tl, the control module initiate a warning sequence at S2007, which may include producing a sound or activating a light signal at or near the water outlet to warn the user that the water outlet has been continuously on for a time Tl to prompt the user to turn the water outlet off if heated water is no longer needed. At S2008, the control module determines whether the elapsed time T exceeds a predetermined second threshold T2, which is higher than the first threshold Tl. If it is determined that the elapsed time T does not exceed the second threshold T2, the method returns to S2005 and the control module continues to monitor signals from the timer. If the control module determines at S2008 that the elapsed time T exceeds the second threshold T2, the control module then controls the water heating system such that the water outlet is completely closed, thereby ceasing provision of heated water to the water outlet at S2009. In doing so, energy and water are not wasted when heated water is no longer required. For example, if the user forgets to turn off the tap after washing hands, or if a child has left the tap on for play, provision of heated water can stop automatically to conserve energy and water. In an embodiment, heated water usage data (S2010) collected over time can be used to generate a usage report (S2011) as a tool to prompt a user to review and potentially modify their usage habits to reduce energy and water usage.

The control module 110 is programmed in software to carry out the functions described above and illustrated in the steps of Fig. 2. Alternatively, the control module is hardwired in hardware logic to perform the functions described above.

As will be appreciated by one skilled in the art, the present techniques may be embodied as a system, method or computer program product. Accordingly, the present techniques may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware.

Furthermore, the present techniques may take the form of a computer program product embodied in a computer readable medium having computer readable program code embodied thereon. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

Computer program code for carrying out operations of the present techniques may be written in any combination of one or more programming languages, including object-oriented programming languages and conventional procedural programming languages.

For example, program code for carrying out operations of the present techniques may comprise source, object or executable code in a conventional programming language (interpreted or compiled) such as C, or assembly code, code for setting up or controlling an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), or code for a hardware description language such as VerilogTM or VHDL (Very high-speed integrated circuit Hardware Description Language).

Code components may be embodied as procedures, methods or the like, and may comprise sub-components which may take the form of instructions or sequences of instructions at any of the levels of abstraction, from the direct machine instructions of a native instruction set to high-level compiled or interpreted language constructs.

It will also be clear to one of skill in the art that all or part of a logical method according to the preferred embodiments of the present techniques may suitably be embodied in a logic apparatus comprising logic elements to perform the steps of the method, and that such logic elements may comprise components such as logic gates in, for example a programmable logic array or application-specific integrated circuit. Such a logic arrangement may further be embodied in enabling elements for temporarily or permanently establishing logic structures in such an array or circuit using, for example, a virtual hardware descriptor language, which may be stored and transmitted using fixed or transmittable carrier media.

The examples and conditional language recited herein are intended to aid the reader in understanding the principles of the present technology and not to limit its scope to such specifically recited examples and conditions. It will be appreciated that those skilled in the art may devise various arrangements which, although not explicitly described or shown herein, nonetheless embody the principles of the present technology and are included within its scope as defined by the appended claims.

Furthermore, as an aid to understanding, the above description may describe relatively simplified implementations of the present technology. As persons skilled in the art would understand, various implementations of the present technology may be of a greater complexity.

In some cases, what are believed to be helpful examples of modifications to the present technology may also be set forth. This is done merely as an aid to understanding, and, again, not to limit the scope or set forth the bounds of the present technology. These modifications are not an exhaustive list, and a person skilled in the art may make other modifications while nonetheless remaining within the scope of the present technology. Further, where no examples of modifications have been set forth, it should not be interpreted that no modifications are possible and/or that what is described is the sole manner of implementing that element of the present technology.

Moreover, all statements herein reciting principles, aspects, and implementations of the technology, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof, whether they are currently known or developed in the future. Thus, for example, it will be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative circuitry embodying the principles of the present technology. Similarly, it will be appreciated that any flowcharts, flow diagrams, state transition diagrams, pseudo-code, and the like represent various processes which may be substantially represented in computer-readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown. The functions of the various elements shown in the figures, may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor or control module, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), read-only memory (ROM) for storing software, random access memory (RAM), and non-volatile storage. Other hardware, conventional and/or custom, may also be included.

Software modules, or simply modules which are implied to be software, may be represented herein as any combination of flowchart elements or other elements indicating performance of process steps and/or textual description. Such modules may be executed by hardware that is expressly or implicitly shown.

It will be clear to one skilled in the art that many improvements and modifications can be made to the foregoing exemplary embodiments without departing from the scope of the present techniques.