Heating installation, method and system

Abstract

A heating installation for a house is provided, the installation comprising: a controller, and coupled to the controller: an air source heat pump; a house heating arrangement; and a local weather sensing arrangement. The controller is configured to receive weather forecast data from an external source, and to receive local weather status information from the local weather sensing arrangement. The controller is also configured to set a control algorithm based on both the weather forecast data and the local weather status information, and to control the energy supply from the air source heat pump to the heating arrangement based on the set control algorithm; and to increase the energy input to the heating arrangement when a predicted drop in the temperature of air from which the air source heat pump extracts energy is predicted. A method of controlling a house heating installation is also provided, the heating installation comprising an air source heat pump, the method comprising: receiving weather forecast data from an external source, and receiving local weather status information from the local weather sensing arrangement; setting a control algorithm based on both the weather forecast data and the local weather status information; controlling the air source heat pump based on the setting of the control algorithm; and to increase the energy input to the heating arrangement when a predicted drop in the temperature of air from which the air source heat pump extracts energy is predicted.

Description

Technical Field

[0001] The present disclosure, in various aspects, relates to heating installations for premises and related methods, systems, and apparatus. Background Art

[0002] According to Directive 2012 / 27 / EU, buildings account for 40% of final energy consumption and 36% of CO2 emissions in the EU. The European Commission’s 2016 report “Mapping and analyses of the current and future (2020-2030) heating / cooling fuel deployment (fossil / renewables)” concluded that heating and hot water alone account for 79% of total final energy use in EU households (192.5 Mtoe). The European Commission also reported that “according to Eurostat’s 2019 chart, around 75% of heating and cooling is still generated by fossil fuels, while only 22% is generated by renewable energy. To achieve the EU’s climate and energy goals, the heating and cooling sector must significantly reduce its energy consumption and cut its fossil fuel use. Heat pumps (which draw energy from the air, ground or water) have been identified as a potentially important contributor to addressing this problem.”

[0003] Many countries have policies and pressure to reduce their carbon footprint. For example, the UK government released the "Future Homes standard" white paper in the UK in 2020, which recommends reducing carbon emissions from new homes by 75% to 80% compared to current levels by 2025. In addition, it was announced in early 2019 that the installation of gas boilers in new homes would be banned from 2025. It is reported that as of the time of submission, 78% of the total energy used for heating buildings in the UK comes from gas, while 12% comes from electricity.

[0004] The UK has a large number of small, 2-3 bedroom or less properties with gas central heating systems, and most of these properties use so-called combination boilers, where the boiler acts as an instantaneous hot water heater and as a boiler for central heating. Combination boilers are popular because they combine a small form factor, provide an instant source of more or less "unlimited" hot water (with an output of 20kW to 35kW), and do not require hot water storage. Such boilers can be purchased relatively cheaply from reputable manufacturers. The small form factor and the ability to not require a hot water storage tank mean that such boilers can usually be accommodated even in small apartments or houses (usually mounted on the kitchen wall), and require one person's day's work to install a new boiler. Therefore, new combination gas boilers can be installed cheaply. With the upcoming ban on new gas boilers, there is a need to provide alternative heat sources to replace gas combination boilers. In addition, previously installed combination boilers will eventually need to be replaced with some alternative.

[0005] Although heat pumps have been proposed as a potential solution to reduce reliance on fossil fuels and reduce CO2 emissions, they are currently unsuitable for replacing gas boilers in smaller domestic (and small commercial) homes for several technical, commercial and practical reasons. They are typically very large and require a sturdy unit outside the property. Therefore, they cannot be easily retrofitted into a property with a typical combination boiler. Currently, units that can provide an output equivalent to a typical gas boiler are expensive and may require a large power requirement. Not only do these units themselves cost several times the cost of an equivalent gas unit, but their size and complexity mean that installation is technically complex and therefore expensive. A hot water storage tank is also required, and this is another factor that hinders the use of heat pumps in small domestic residences. Another technical problem is that heat pumps often take a long time to start producing heat in response to demand, it may take 30 seconds to self-check and then some time to heat, so there is a delay of 1 minute or more between requesting hot water and its delivery. For this reason, attempts to use renewable solutions using heat pumps and / or solar energy are generally suitable for large properties (with space requirements, heat losses and legionella risks) with rooms with hot water storage tanks.

[0006] Therefore, there is a need to provide a solution to the problem of finding a suitable technology to replace gas combination boilers, especially for smaller domestic residences.

[0007] More generally, there is a continuing need to improve the effective efficiency of heat pumps, particularly air source heat pumps which are the cheapest type of heat pump to install. Summary of the invention

[0008] According to a first aspect, a heating installation for a house is provided, the installation comprising: a controller, and coupled to the controller: an air source heat pump; a house heating arrangement; and a local weather sensing arrangement; wherein the controller is configured to: receive weather forecast data from an external source, and receive local weather status information from the local weather sensing arrangement; set a control algorithm based on both the weather forecast data and the local weather status information; control the supply of energy from the air source heat pump to the heating arrangement based on the set control algorithm; wherein the controller is configured to increase the energy input to the heating arrangement when a predicted drop in the temperature of air from which the air source heat pump extracts energy is predicted.

[0009] Preferably, the controller is configured to increase the energy input into the heating arrangement when a predicted drop in the temperature of air from which the air source heat pump extracts energy is predicted.

[0010] Preferably, the controller is configured to control the energy supply based on a predicted likelihood that the house heating arrangement will be activated or used or required during a forecast period of reduced temperature. Optionally, the controller is configured to predict the likelihood based on past household behavior of the house and / or past behavior of comparable households. Optionally, the controller may be configured to take into account the occupancy or predicted occupancy of the house when predicting the likelihood.

[0011] Optionally, the controller is configured to take into account scheduled activities of occupants of the premises when estimating the likelihood.

[0012] Optionally, the controller is configured to override the settings of the heating arrangement.

[0013] Optionally, the heating installation further comprises an energy storage arranged to receive energy from the heat pump, the controller being configured to control the supply of energy from the air source heat pump to the energy storage based on a set control algorithm. Preferably, the energy storage comprises a mass of phase change material for storing energy as latent heat. Optionally, the controller is configured to control the supply of energy to the energy storage to increase the amount of energy stored in the storage as sensible heat. Preferably, the energy storage is arranged to supply energy to a hot water system of the house.

[0014] According to a second aspect, there is provided a method for controlling a house heating installation comprising an air source heat pump, the method comprising: receiving weather forecast data from an external source and receiving local weather status information from a local weather sensing arrangement; setting a control algorithm based on both the weather forecast data and the local weather status information; controlling the air source heat pump based on the setting of the control algorithm; and increasing the energy input into the heating arrangement when a predicted drop in the temperature of air from which the air source heat pump extracts energy is predicted.

[0015] Preferably, the method further comprises controlling the energy supply based on a predicted likelihood that any of the premises heating arrangements will be activated, used or required during the forecast period of reduced temperature.

[0016] Optionally, the method further includes estimating the likelihood based on past household behavior of the home and / or past behavior of comparable households.

[0017] Optionally, the method further comprises taking into account the occupancy or projected occupancy of the premises when estimating the likelihood.

[0018] Optionally, the method further comprises taking into account scheduled activities of occupants of the premises in estimating the likelihood.

[0019] Optionally, the method further comprises overriding settings of the heating arrangement.

[0020] In the method according to the second aspect, the arrangement may include an energy storage arranged to receive energy from the heat pump, the method further comprising controlling the supply of energy from the air source heat pump to the energy storage based on a set control algorithm. Preferably, the energy storage comprises a mass of phase change material for storing energy as latent heat, the method further comprising controlling the supply of energy to the energy storage to increase the amount of energy stored in the storage as sensible heat.

[0021] According to a third aspect, there is provided a domestic green power generation installation, comprising: a controller, and coupled to the controller: a green energy source; an energy sink; and a local weather sensing arrangement; wherein the controller is configured to: receive weather forecast data from an external source, and receive local weather status information from the local weather sensing arrangement; set a control algorithm based on both the weather forecast data and the local weather status information; and control the supply of energy from the green energy source to the energy sink and / or energy storage based on the set control algorithm. Preferably, the energy input to the heating arrangement is also increased when a predicted drop in the temperature of the air from which the air source heat pump extracts energy is predicted.

[0022] Preferably, the green energy source is selected from the group comprising: an air source heat pump, a photovoltaic installation comprising one or more photovoltaic cells, and a wind turbine.

[0023] Preferably, the energy sink is selected from the group comprising: a heating installation for a house, an energy storage, and a hot water supply system.

[0024] According to a fourth aspect, there is provided a method of controlling a domestic heating installation comprising a green energy source, the method comprising: receiving weather forecast data from an external source, and receiving local weather status information from a local weather sensing arrangement; setting a control algorithm based on both the weather forecast data and the local weather status information; and controlling the supply of energy from the green energy source to the domestic heating installation based on the setting of the control algorithm. Preferably, the energy input to the heating arrangement is also increased when a predicted drop in the temperature of air from which the air source heat pump extracts energy is predicted. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Embodiments of various aspects of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0026] Figure 1 Schematically shows an overview of a system according to aspects of the present invention;

[0027] Figure 2 Roughly corresponds to Figure 1 , but includes more details;

[0028] Figure 3 Schematically showing details of a system according to aspects of the invention;

[0029] Figure 4 is a schematic timeline diagram illustrating the operation of a controller according to aspects of the present invention;

[0030] Figure 5 is a schematic diagram showing an energy accumulator including a phase change material and a heat exchanger coupled to a heat pump energy source, the energy accumulator including one or more sensors to provide measurement data indicative of an amount of energy stored in the phase change material as latent heat; and

[0031] Figure 6 is a schematic diagram showing a potential arrangement of components of an interface unit incorporating an energy reservoir according to aspects of the present disclosure. DETAILED DESCRIPTION

[0032] Figure 1An overview of a system 100 according to aspects of the present invention is schematically shown. The system includes a controller 102 coupled to a green energy source 104, an energy sink 106, and a local weather sensing arrangement 108. The controller 102 is configured to receive weather forecast data from an external source 110, for example via a wired or wireless connection, and to receive local weather status information from the local weather sensing arrangement 108. The system also optionally includes an energy storage 112 coupled to the green energy source 104, the controller 102, and the energy sink 106. The green energy source 104 may, for example, include a wind turbine 105, a photovoltaic arrangement 107, or more preferably an air source heat pump 109. The controller 102 is further configured to set a control algorithm based on both the weather forecast data and the local weather status information, and to control the energy supply from the green energy source to the energy sink and / or the energy storage based on the set control algorithm.

[0033] Figure 2 Roughly corresponds to Figure 1, but includes more details. The controller 102 operates the control algorithm based on the received weather forecast data and, if necessary, adjusts the control algorithm based on local weather state information from the local weather sensing arrangement 108. The purpose of operating the control algorithm 103 is to use the energy currently available, or the energy that is expected to become available, before a local change in the weather that predicts a reduction in the amount of energy available from the green energy source 104. For example, if the green energy source is an air source heat pump, and the local air temperature is expected to decrease, and / or the relative humidity is expected to decrease, the control algorithm can be used to extract energy and supply it to an energy sink (e.g., a house heating installation) and / or an energy storage (e.g., a thermal energy storage), predicting that the extracted energy will be useful later. Similarly, if the green energy source includes one or more photovoltaic cells or arrays, and it is predicted that a currently clear or substantially clear sky will be replaced by heavy clouds, the control algorithm can be used to divert energy from the photovoltaics to supply an energy sink (e.g., a house heating installation) and / or an energy storage (such as a battery or supercapacitor arrangement), rather than supplying all or most of the captured energy to the grid. In the case where the green energy source includes one or more wind turbines, and the windy day currently or in the near future is predicted to be replaced by a long period of no wind, the captured energy can be processed as just described with reference to the photovoltaic arrangement. For any of these alternatives, the controller algorithm can be arranged to increase the energy input to the house heating arrangement, the energy sink when the predicted decrease in air temperature is predicted. The forecast of air temperature may make it more likely that the occupants of the house will start using the heating installation and / or increase its temperature setting to offset the impact of the predicted decrease in air temperature. Therefore, the controller can be configured to control the energy supply based on the predicted possibility of activating / using / needing the house heating arrangement during the forecast period of reduced temperature. The controller can be configured to predict the possibility based on the past household behavior of the house and / or the past behavior of comparable households. The controller can be configured to use a machine learning algorithm to learn occupant behavior from the settings and operation of the house heating arrangement in particular. The controller can also be provided with data on the behavior of comparable households, for example, provided at the time of installation / initial configuration of the system or provided or updated from a supplier or operator server in the cloud.

[0034] The controller is also preferably configured to take into account the occupancy or expected occupants of the house when predicting the likelihood. To this end, the controller can be configured to take into account the daily activities of the occupants of the house when predicting the likelihood - the controller optionally has access to the schedule, calendar and / or appointment details about the occupants of the house, and the controller can operate in a "smart home" mode. The controller can also be supplied with information from presence detectors (e.g., motion sensors (e.g., PIR sensors) and / or door sensors that can be provided as part of a security monitoring system), and or alternatively supplied with information from house strikes of the electrical system, which can provide information about, for example, the activation of lighting circuits in the house. The use of the local weather sensing arrangement 108 enables more accurate prediction and detection of weather events affecting the house, thereby increasing the ability to achieve energy savings in system operation. The controller 102 can be configured to run a machine learning algorithm that is configured to understand the differences between the weather experienced by the house detected by the local weather sensing arrangement and the received weather forecast data, such as in terms of time delay and optional severity. Using such a machine learning algorithm, the controller 102 may be able to better anticipate when it may be beneficial to increase energy supply from green energy sources to local energy sinks and / or energy storage.

[0035] The local weather sensing arrangement 108 is preferably arranged to sense air temperature, air humidity and atmospheric pressure. The arrangement 108 may include separate sensors to detect each of these variables, but preferably the arrangement 108 is based on an integrated weather sensing device, such as a weather sensing chip. Such a chip is available as the Bosch Sensortec BME280 integrated environmental unit, which provides a humidity sensor, measures relative humidity, atmospheric pressure and ambient temperature, all with a high degree of accuracy: the humidity sensor accuracy is ±3% relative humidity, the pressure sensor accuracy is ±0.25%, and the temperature sensor accuracy is ±1°C over the range of 0-65°C. The BME280 has a weather monitoring mode that provides pressure, temperature and humidity readings once a minute, which is a sufficient frequency for our purposes. In addition, the local weather sensing arrangement 108 may include a wind speed sensor and a wind direction detector, as wind direction and wind speed can be very useful indicators of current and potentially upcoming weather conditions - such as indicating the possible arrival, passage and passing of a cold weather front.

[0036] Figure 3 Schematically shows details of a system according to an aspect of the invention, which corresponds very closely to Figure 2 , but wherein the green energy source is an air source heat pump 109 and the energy sink comprises a house heating installation 116, and preferably a thermal energy storage, ideally comprising a phase change material whose phase change is used to store energy as latent heat.

[0037] Figure 4 is a schematic timeline diagram illustrating the operation of the controller 102 according to aspects of the present invention.

[0038] At 400, the controller receives weather forecast data from an external source. The controller may be configured to periodically collect such data, or may periodically or more preferably push data to the controller whenever a significant change in the forecasted weather occurs. These weather forecast data may be provided, for example, by a national or regional meteorological department (such as the Met Office in the United Kingdom), a national or regional broadcaster (such as the BBC in the United Kingdom), or any other national, regional or local provider of weather forecast information, all of which provide data feeds via the Internet. Of course, these weather forecast data may also be provided by a data aggregator, a news agency, or any other intermediary or source.

[0039] At 402, the controller receives local weather status information from a local weather sensing arrangement, for example based on a device such as BME280. The controller may be configured to periodically collect such weather status information, or may push or otherwise supply the information to the controller periodically or more preferably whenever one or more signs of an upcoming significant change in weather are detected. Although the figure shows that the controller receives weather forecast data before receiving the local weather status information, the order may be reversed, with the controller receiving the local weather status information before receiving the weather forecast data. For example, the controller may be arranged to continuously receive and process local weather status information (e.g., once per minute, or once every few minutes), detecting indicators of upcoming or instantaneous significant changes in local weather. The local weather sensing arrangement 108 may and preferably includes processing capabilities that are arranged to process local weather status information to detect indicators of upcoming or instantaneous significant changes in local weather, notifications of which are then quickly delivered to the controller 102 or they are periodically read by the controller 102.

[0040] At 404, the controller processes the received weather forecast data and the received weather status information to determine whether to increase the energy input into the energy sink 106. In making this determination, the controller preferably considers the estimated probability that the additional energy supplied to the energy sink will be useful. For example, in the case where the energy sink includes a house heating arrangement, the controller is preferably configured to anticipate the likelihood that the house heating arrangement will be activated / used / needed during the forecast period of reduced temperature. In anticipating such a probability, the controller preferably considers the past household behavior of the house-for example, whether the heating arrangement is used under similar meteorological conditions, at the same or corresponding time of the year, and the nature of any such use, such as the period of use, the thermostat setting, etc. Optionally, the controller can consider the past behavior of comparable households, the relevant data being stored in the storage device 202 and optionally supplied / updated from a network-based resource associated with the manufacturer / supplier / operator of the system. Preferably, the controller is configured to consider the occupancy or estimated occupancy of the house when anticipating the probability, optionally considering the scheduled activities of the occupants of the house. The controller 102 may, for example, be part of or integrated with a "smart home" control system, and / or be coupled to a security monitoring system, such that occupancy and activity sensing / sensors may provide data to the controller 102 for anticipating possibilities. The controller may also be configured to override the settings of the heating arrangement, for example the heating arrangement may be set to switch on at a later time, and / or may be controlled by a thermostat set at a temperature higher than the current environment, such that the heating arrangement is currently off: the controller may override the timer and / or thermostat, such that additional energy may be input into the heating arrangement.

[0041] As a result of processing 404 and based on the weather forecast data with status information, the controller can establish a weather forecast window 406 with a start time 408 and an end time 410. At step 412, which can be performed before or after the weather forecast window start time 408, the controller checks the status of the green energy source 104. At step 414, the green energy source 104 provides a status update to the controller. At step 416, the controller checks the status of the energy sink, which optionally includes a heating arrangement and an energy storage device (such as a battery, or a PCM-based energy storage arrangement). At step 418, the energy storage device provides a status update to the controller. Based on the status update and the processing performed in step 404, the processor performs a second processing at step 420 to determine control parameters for controlling the green energy source (where appropriate) and the energy sink (optionally including both the heating arrangement and the energy storage arrangement). Then, based on the determined control parameters, the controller sends a control instruction to the green energy source 104 at 422, and sends a control instruction to the energy sink at 424. Optionally, the green energy source and the energy sink provide feedback information at steps 426 and 428. Thereafter, the controller issues appropriate control instructions to the green energy source and the energy sink, and receives feedback from the green energy source and the energy sink, as needed.

[0042] We will now consider why the method of the present invention is particularly attractive when applied to an installation in which the green energy source is an air source heat pump. Consider the characteristics of a cold front: before the arrival of the cold front, it may be warm, the atmospheric pressure is high, and the air may have a high relative humidity; as the cold front approaches, the atmospheric pressure begins to drop, and the clouds become denser; then, as the cold front passes, the pressure reaches a minimum, the temperature suddenly drops by more than 10°C, the clouds thicken, and heavy rain falls; after the cold front passes, the temperature may continue to drop, but the atmospheric pressure begins to rise, the heavy rain turns to showers and then clears, and the clouds tend to become sparse. Obviously, the ability to use the current air temperature (which may be 10°C or more higher than the expected arrival air temperature) to supply energy to the heating installation and / or charge the energy storage (charge) is advantageous. However, there is another very significant energy bonus that can be harvested, that is the energy stored as latent heat in the warm and humid air, which will be replaced by the colder, drier air brought by the cold front (and in some cases other meteorological phenomena). Note that air at 25°C and 80% RH contains about 16 g of water per kg of air, while air at 10°C and 80% RH contains about 6.3 g of water per kg of air.

[0043] The water vapor content in the atmosphere varies from 0-3% by mass. The enthalpy of moist air includes the enthalpy of dry air (sensible heat) and the enthalpy of evaporation of water in the air (latent heat). In fact, the energy stored in the form of latent heat from the evaporation of water greatly exceeds the energy stored in the form of sensible heat: for example, at 25°C and 80% RH, the enthalpy of moist air is about 66 kJ / kg, of which the latent heat from the evaporation of water contributes about 40 kJ / kg (about 60%).

[0044] If the air temperature in a cold front is 10°C, and still has 80% RH (equivalent to about 6.3 grams of water per kilogram of humid air), the enthalpy is about 26 kJ / kg. It is easy to understand that the additional 40 kJ / kg of energy available from the warmer air compared to the cooler air can potentially make a significant contribution to the effective efficiency of the heat pump - assuming the additional energy can be used for useful purposes - such as pre-heating or overheating the house, and / or charging or overcharging the thermal energy storage.

[0045] Figure 5 An energy accumulator 510 including a heat exchanger is schematically shown, the energy accumulator including a housing 512. Within the housing 512 is an input side loop 514 of the heat exchanger for connection to an energy source (here shown as an air source heat pump 109), an output side loop 516 of the heat exchanger for connection to an energy sink (here shown as a hot water supply system connected to a cold water supply 520 and including one or more outlets 522). Within the housing 512 is a phase change material for storing energy. The energy accumulator 510 also includes one or more state sensors 524 to provide a measurement indicating the state of the PCM. For example, one or more of the state sensors 524 can be a pressure sensor to measure the pressure within the housing. Preferably, the housing also includes one or more temperature sensors 526 to measure the temperature within the phase change material (PCM). Preferably, if multiple temperature sensors are provided within the PCM, these temperature sensors are preferably spaced apart from the structure of the input and output loops of the heat exchanger, and are appropriately spaced apart within the PCM to obtain a good "image" of the state of the PCM.

[0046] The energy accumulator 510 has an associated system controller 102, which includes a processor 529. The controller can be integrated into the energy accumulator 510, but is more typically mounted separately. The controller 102 may also be provided with a user interface module 531, as an integrated or separate unit, or as a unit that can be removably mounted to a body containing the controller 102. The user interface module 531 typically includes a display panel and a keyboard, for example in the form of a touch-sensitive display. The user interface module 531, if separate or detachable from the controller 102, preferably includes wireless communication capabilities so that the processor 529 of the controller 102 and the user interface module can communicate with each other. The user interface module 531 can be used to display system status information, messages, suggestions and warnings to the user, and to receive user input and user commands - such as start and stop instructions, temperature settings, system overrides, etc.

[0047] The status sensor(s) are coupled to the processor 102, as are the temperature sensor(s) 526 (if present). The processor 102 is also coupled to a processor / controller 532 in the air source heat pump 109, either by a wired connection, or wirelessly using associated transceivers 534 and 536, or by both wired and wireless connections. In this way, the system controller 102 is able to send instructions, such as start instructions and stop instructions, to the controller 532 of the air source heat pump 109. In the same manner, the processor 102 is also able to receive information, such as status updates, temperature information, etc., from the controller 532 of the heat pump 109.

[0048] The hot water supply arrangement also includes one or more flow sensors 538 that measure the flow in the hot water supply system. As shown, such flow sensors may be provided on the cold water supply 520 to the system, and / or provided between the output of the output side loop 18 of the heat exchanger. Optionally, one or more pressure sensors may also be included in the hot water supply system, and (one or more) pressure sensors may be provided upstream of the heat exchanger / energy storage device and / or downstream of the heat exchanger / energy storage device - for example, next to one or more of the one or more flow sensors 538. The flow sensor or each flow sensor, the temperature sensor or each temperature sensor and the pressure sensor or each pressure sensor are coupled to the processor 529 of the system controller 102 via one or both of a wired or wireless connection, for example, using one or more wireless transmitters or transceivers 540. Depending on the nature of (one or more) of the various sensors 524, 526 and 538, they may also be interrogated by the processor 529 of the system controller 102.

[0049] An electrically controlled thermostatic mixing valve 560 is coupled between the outlet of the energy reservoir and one or more outlets of the hot water supply system and includes a temperature sensor 542 at its outlet. An additional tankless water heater 570, such as an electric heater (inductive or resistive) controlled by the controller 102, is preferably positioned in the water flow path between the outlet of the energy reservoir and the mixing valve 560. An additional temperature sensor may be provided to measure the temperature of the water output by the tankless water heater 570 and provide the measurement to the controller 102. The thermostatic mixing valve 560 is also coupled to the cold water supply 540 and may be controlled by the controller 102 to mix the hot and cold water to achieve a desired supply temperature.

[0050] Alternatively, as shown, the energy accumulator 510 may include an electrical heating element 514 within the housing 512 that is controlled by a processor 529 of the system controller 102 and may sometimes be used as a substitute for the heat pump 109 to recharge the energy accumulator.

[0051] The processor 102 is also coupled to a local weather sensing arrangement 108 and is configured to receive weather forecast data from an external source 110 , for example via a wired or wireless data link or supply.

[0052] Figure 5 This is merely a schematic diagram and only shows the connection of the heat pump to a hot water supply installation. It will be appreciated that in many parts of the world, space heating as well as hot water is required. Therefore, typically, the heat pump 109 will also be used to provide space heating. Reference will now be made to Figure 6 An exemplary arrangement is described in which an air source heat pump both provides space heating and works with an energy storage device for hot water heating.

[0053] Figure 6 A potential arrangement of components of an interface unit 10 according to aspects of the present disclosure is schematically shown. The interface unit interfaces between a heat pump (not shown in the figure) and a hot water system in a building. The interface unit comprises a heat exchanger 12, which comprises a housing (not separately numbered), within which is an input side loop (shown in very simplified form as 14) for connection to the heat pump, and an output side loop (also shown in very simplified form as 16) for connection to a hot water system in the building (not shown in the figure). The heat exchanger 12 also contains a thermal storage medium for storing energy, but this is not shown in the figure. Reference will now be made to the heat exchanger 12. Figure 6 In the described examples, the heat storage medium is a phase change material. It will be appreciated that the interface unit corresponds to the previously described energy accumulator. Throughout this specification, including the claims, references to energy accumulator, heat storage medium, energy storage medium and phase change material should be considered interchangeable unless the context clearly requires otherwise.

[0054] Typically, the phase change material in the heat exchanger has an energy storage capacity of 2MJoule to 5MJoule (in terms of energy stored through latent heat of fusion), although more energy storage is possible and can be useful. Of course, less energy storage is also possible, but generally one wishes to maximize (subject to practical limitations based on physical dimensions, weight, cost, and safety) the potential for energy storage in the phase change material of the interface unit 10. More will be described later in this specification regarding suitable phase change materials and their properties, as well as dimensions, etc.

[0055] The input-side loop 14 is connected to a pipe or conduit 18 which in turn is fed from a node 20 from a pipe 22 having a coupler 24 for connecting to a supply from a heat pump. The node 20 also feeds fluid from the heat pump to a pipe 26 which terminates in a coupler 28 which is intended to be connected to the heating network of the house or apartment - for example for piping to a floor heating or radiator network or both. Thus, once the interface unit 10 is fully installed and operational, the fluid heated by the heat pump (which is located outside the house or apartment) passes through the coupler 24 and along the pipe 22 to the node 20, part of the fluid flow flows from the node 20 along the pipe 18 to the input-side loop 14 of the heat exchanger, while another part of the fluid flow flows along the pipe 26 and out through the coupler 28 to the heating infrastructure of the house or apartment.

[0056] The heated fluid from the heat pump flows through the input side loop 14 of the heat exchanger and flows out of the heat exchanger 12 along the pipe 30. In use, in some cases, the heat carried by the heated fluid from the heat pump gives up some of its energy to the phase change material inside the heat exchanger and gives up some energy to the water in the output side loop 16. In other cases, as will be explained later, the fluid flowing through the input side loop 14 of the heat exchanger actually extracts heat from the phase change material.

[0057] Pipe 30 feeds the fluid leaving the input side circuit 14 to a motorized three-way valve 32 and then, depending on the state of the valve, flows out along pipe 34 to a pump 36. The pump 36 serves to push this flow via a coupling 36 to an external heat pump.

[0058] The motorized three-way valve 32 also receives fluid from a pipe 40 which receives fluid returning from the heating infrastructure of the house or apartment, such as a radiator, via a coupling 42 .

[0059] Three transducers are provided between the motorized three-way valve 32 and the pump 36: a temperature transducer 44, a flow transducer 46 and a pressure transducer 48. In addition, a temperature transducer 49 is provided in the conduit 22 leading to the fluid from the output of the heat pump. These transducers, like all other items in the interface unit 10, are operatively connected to or addressable by a processor not shown, which is typically provided as part of the interface unit, but may be provided in a separate module.

[0060] although Figure 6 Not shown, but an additional electric heating element may also be provided in the flow path of the fluid receiving the output from the heat pump between the couplers 24. The additional electric heating element may also be an induction or resistive heating element and is provided as a means of compensating for potential failure of the heat pump, and may also be used to add energy to the thermal storage unit (e.g. based on current energy costs and projections for heating and / or hot water). The additional electric heating element may of course also be controlled by the processor of the system.

[0061] An expansion vessel 50 is also coupled to the pipe 34, and a valve 52 is connected to the expansion vessel 50, through which a filling circuit can be connected to top up the fluid in the heating circuit. Also shown as part of the heating circuit of the interface unit is a pressure relief valve 54 located between the node 20 and the input side circuit 14, and a filter 56 located between the coupler 42 and the three-way valve 32 (to capture particulate contaminants).

[0062] The heat exchanger 12 is also provided with a number of transducers, including at least one temperature transducer 58, (although preferably more (e.g., up to 4 or more) are provided, as shown), and a pressure transducer 60. In the example shown, the heat exchanger includes 4 temperature transducers, evenly distributed within the phase change material, so that temperature changes can be determined (and knowledge can therefore be gained about the state of the phase change material throughout its volume). This arrangement can be particularly beneficial during the design / implementation phase as a means of optimizing the design of the heat exchanger - including optimizing additional heat transfer arrangements. But such an arrangement can also continue to be beneficial in a deployed system, as having multiple sensors can provide useful information to the processor and the machine learning algorithm employed by the processor (either the interface unit alone and / or the processor of the system including the interface unit).

[0063] The arrangement of the cold water supply and hot water circuit of the interface unit 10 will now be described. A coupler 62 is provided for connection to a cold supply from the main water. Typically, before the water from the main water reaches the interface unit 10, the water will have passed through the anti-siphon check valve and may have reduced its pressure. The cold water passes through the output side circuit 16 of the heat exchanger 12 along the pipe from the coupler 62. In view of the fact that we provide a processor that monitors numerous sensors in the interface unit, the same processor can optionally be given another task to do. That is, monitor the pressure of delivering cold water from the main water supply. To this end, additional pressure sensors can be introduced into the cold water supply line upstream of the coupler 62, and in particular upstream of any pressure reduction arrangement in the house. The processor can then monitor the water supply pressure continuously or periodically, and even if the main water is supplied at a pressure lower than the legal minimum, the owner / user is prompted to seek compensation from the water supply company.

[0064] Water, which may have been heated by passing through a heat exchanger, passes from the output side circuit 16 along a conduit 66 to an electric heating unit 68. The electric heating unit 68, under the control of the previously mentioned processor, may comprise a resistive or inductive heating arrangement, the heat output of which may be modulated according to instructions from the processor.

[0065] The processor is configured to control the electric heater based on information about the state of the phase change material and the state of the heat pump.

[0066] Typically, the electric heating unit 68 has a rated power of no more than 10 kW, but in some cases a more powerful heater may be provided, for example 12 kW.

[0067] Hot water now passes from the electric heater 68 along the pipe 70 to the coupler 74 to which the hot water circuit of the house or apartment (including controllable outlets such as taps and showers) will be connected.

[0068] A temperature transducer 76 is provided after the electric heater 68, for example at the outlet of the electric heater 68, to provide information about the water temperature at the outlet of the hot water system. A pressure relief valve 77 is also provided in the hot water supply, and although the pressure relief valve 77 is shown as being located between the electric heater 68 and the outlet temperature transducer 76, its exact location is not important - as Figure 6 The same is true for many of the components shown in FIG.

[0069] In addition, somewhere in the hot water supply line there is a pressure transducer 79 and / or a flow transducer 81, either of which the processor can use to detect the need for hot water - i.e., to detect the opening of a controllable outlet such as a faucet or shower. The flow transducer is preferably a flow transducer without moving parts, for example based on acoustic flow detection or magnetic flow detection. The processor can then use information from one or both of these transducers and their stored logic to decide whether to signal the heat pump to start. It should be understood that the processor can call the heat pump to start based on the need for space heating (e.g., based on a program stored in the processor or an external controller, and / or based on a signal from one or more thermostats, such as room statistics, external statistics, floor heating statistics) or the need for hot water. The control of the heat pump can be in the form of a simple on / off command, but can also or alternatively be in the form of modulation (using, for example, ModBus).

[0070] As in the case of the heating circuit of the interface unit, three transducers are provided along the cold water supply pipe 64: a temperature transducer 78, a flow transducer 80 and a pressure transducer 82. A further temperature transducer 84 is also provided in the pipe 66 between the outlet of the output side circuit 16 of the heat exchanger 12 and the electric heater 68. These transducers are likewise all operatively connected to or addressable by the aforementioned processor.

[0071] Also shown on the cold water supply line 64 is a magnetic or electric water regulator 86, a motorized modulatable valve 88 (which like all motorized valves can be controlled by the aforementioned processor), a check valve 90, and an expansion vessel 92. The modulatable valve 88 can be controlled to adjust the flow of cold water to maintain a desired temperature of the hot water (e.g., as measured by the temperature transducer 76).

[0072] Valves 94 and 96 are also provided for connection to external storage tanks for storing cold and hot water, respectively. Finally, a double check valve 98 connects the cold supply pipe 64 to another valve 100 which can be used with a filling loop to connect to the previously mentioned valve 52 for charging the heating circuit with more water or a mixture of water and corrosion inhibitor.

[0073] It should be noted that Figure 6 Various conduit intersections are shown, but unless those intersections are shown as nodes (such as node 20), two conduits shown as intersecting are not in flow communication with each other, as should now be clear from the foregoing description of the figures.

[0074] although Figure 61, but the heat exchanger 12 may include one or more additional electrical heating elements configured to put heat into the thermal storage medium. While this may seem counterintuitive, it allows the use of electrical energy to pre-charge the thermal storage medium when it makes economic sense to do so, as will now be explained.

[0075] It has long been the practice of energy supply companies to set electricity prices in which the cost per unit of electricity changes depending on the time of day to take into account times when demand increases or decreases and to help shape customer behavior to better balance demand with supply capacity. Historically, electricity price plans have been fairly crude, reflecting the technology that generates and consumes electricity. However, the increasing incorporation of renewable energy sources of electricity—such as solar (e.g., from photovoltaic cells, panels, and farms) and wind—into countries' generation mix has spurred the development of more dynamic energy pricing. This approach reflects the inherent variability of such weather-dependent generation. Initially, such dynamic pricing was primarily limited to large-scale users, but now more and more dynamic pricing is being offered to household customers.

[0076] The degree to which pricing is dynamic varies from country to country, and also between different producers in a given country. At one extreme, “dynamic” pricing is little more than offering different prices for electricity at different time windows throughout the day, and such prices may apply for weeks, months or seasons without changing. But some dynamic pricing regimes enable suppliers to change prices a day or less in advance – so a customer might be quoted a price today for a half-hour time slot tomorrow, for example. Some countries quote time slots as short as six minutes, and it is conceivable that the lead time for notifying customers of impending tariffs could be further reduced by including “intelligence” in the equipment that consumes energy.

[0077] Because short- and medium-term weather forecasts can be used to estimate both the amount of energy that solar and wind installations might produce and the likely size of electricity demand for heating and cooling, periods of extreme demand can be anticipated. Some power companies with large amounts of renewable generation capacity even offer negative electricity charges—effectively paying customers for using excess electricity. More often, electricity quotes may be a fraction of normal rates.

[0078] By incorporating an electric heater into an energy storage unit, such as a heat exchanger according to the system of the present disclosure, customers can take advantage of low cost supply periods and reduce their reliance on electricity during times of high energy prices. This not only benefits individual customers, but also has wider benefits as it can reduce demand when excess demand must be met by burning fossil fuels.

[0079] The processor of the interface unit has a wired or wireless connection (or both) to a data network such as the Internet to enable the processor to receive dynamic pricing information from the energy supplier. The processor also preferably has a data link connection (e.g., ModBus) to the heat pump to send instructions to the heat pump and receive information (e.g., status information and temperature information) from the heat pump. The processor has logic that enables it to understand the behavior of the household, and using this and the dynamic pricing information, the processor is able to determine whether and when to use cheaper electricity to pre-charge the heating system. This can be achieved by using electrical elements inside the heat exchanger to heat the energy storage medium, but alternatively this can be achieved by driving the heat pump to a higher than normal temperature - for example 60 degrees Celsius instead of between 40 and 48 degrees Celsius. When the heat pump is operated at higher temperatures, its efficiency will be reduced, but the processor can take this into account when deciding when and how to best use cheaper electricity.

[0080] Since the system processor is connectable to a data network, such as the Internet and / or a provider's intranet, the local system processor can benefit from external computing power. Thus, for example, the manufacturer of the interface unit may have a cloud presence (or intranet) where computing power is provided for, for example, calculating predicted: occupancy; activity; electricity prices (short / long); weather forecasts (which may be preferred over generally available weather forecasts, as they may be pre-processed for use by the local processor, and they may also be very specifically tailored to the conditions, location and exposure of the property where the interface unit is installed); identifying false positives and / or false negatives.

[0081] In order to protect users from the risk of scalding from overheated water in a hot water supply system, it is advisable to provide a scalding protection feature. This may take the form of providing an electrically controllable (modulatable) valve (such as Figure 5 A valve 560 is provided to mix cold water from the cold water supply into hot water as the hot water leaves the output loop of the heat exchanger.

[0082] Figure 6Parts of what may be considered the "gut" of the interface unit are schematically shown, but any containers of these "guts" are not shown. An important application of the interface unit according to the present disclosure is as a means to enable a heat pump to be used as an actual contributor to the space heating and hot water requirements of a residence previously provided with a gas combination boiler (or which may be equipped with such a boiler), but it will be appreciated that it is often convenient to provide a container for aesthetics and safety, as is conventionally the case with combination boilers. Furthermore, preferably, the dimensions of any such container will be designed to fit the form factor that can directly replace the combination boiler - which is usually wall-mounted, usually in a kitchen where they coexist with a kitchen cabinet. Based on the shape of a generally rectangular cuboid with height, width and depth (of course, curved surfaces may be used for any or all surfaces of the container for aesthetics, ergonomics or safety), suitable dimensions may be in the approximate range: height 650mm to 800mm; width 350mm to 550mm; depth 260mm to 420mm; for example, 800mm high, 500mm wide and 400mm deep.

[0083] One significant difference of an interface unit according to the present disclosure relative to a gas combination boiler is that the container of the latter must generally be made of a non-combustible material (e.g. steel) (due to the presence of the hot combustion chamber), whereas the internal temperature of an interface unit will generally be well below 100 degrees C, typically below 70 degrees C, and frequently below 60 degrees C. Therefore, it becomes practical to use combustible materials such as wood, bamboo, or even paper in the manufacture of the container for the interface unit.

[0084] Lack of combustion also opens the possibility of installing the interface unit in a position that would never normally be considered suitable for installing a gas combination boiler - of course, unlike a gas combination boiler, the interface unit according to the present disclosure does not require an exhaust flue. Thus, for example, the interface unit can be configured to be installed below the kitchen countertop, and even the notorious dead corner represented by the corner under the counter can be used. In order to be installed in such a position, the interface unit can actually be integrated into the cabinet under the counter - preferably by working with a kitchen cabinet manufacturer. However, by effectively being located behind an interface unit of some form of cabinet, the maximum flexibility of deployment can be retained, which is configured to allow access to the interface unit. The interface unit will then preferably be configured to allow the circulation pump 36 to slide out and away from the heat exchanger 12 before the circulation pump 36 is decoupled from the flow path of the input side circuit.

[0085] Consideration may also be given to utilising other often wasted space in fitted kitchens, namely the space beneath under-counter cupboards. There are often larger spaces with a height of over 150mm, a depth of around 600mm and a width of 300, 400, 500, 600mm or more (but allowance needs to be made for any legs supporting the cabinet). Particularly for new installations, or where a combination boiler is being replaced at the same time as a kitchen refit, it may make sense to use this space to accommodate at least the heat exchanger for the interface unit, or to use more than one heat exchanger unit for a given interface unit.

[0086] Particularly for interface units designed for wall mounting, it is often desirable to design the interface unit as a plurality of modules, although this is potentially advantageous regardless of the application of the interface unit. With such a design, it may be convenient to include a heat exchanger as one of the modules, since the presence of the phase change material may result in the heat exchanger alone weighing more than 25 kg. For health and safety reasons, and to facilitate installation by a single person, it is desirable to ensure that the interface unit can be delivered as a set of modules, none of which weighs more than about 25 kg.

[0087] This weight restriction may be supported by making one of the modules a chassis for mounting the interface unit to the structure. For example, where the interface unit is to be wall mounted to replace an existing gas combination boiler, it may be convenient if the chassis supporting the other modules can first be fixed to the wall. Preferably, the chassis is designed to work with the location of the existing fixing points used to support the combination boiler to be replaced. This could potentially be done by providing a "universal" chassis with fixing holes pre-made according to the spacing and location of popular gas combination boilers. Alternatively, it may be cost effective to produce a range of chassis, each with hole locations / sizes / spacing that matches the hole locations / sizes / spacing of a particular manufacturer's boiler. The boiler of the relevant manufacturer can then be replaced by simply specifying the correct chassis. This approach has multiple benefits: It avoids the need to drill further holes for the plugs to secure the bolts - this not only eliminates the time required for marking, drilling and cleaning, but also avoids the need to further weaken the structure of the home being fitted - this may be an important consideration given the low-cost construction techniques and materials often used in "starter homes" and other low-cost housing.

[0088] Preferably, the heat exchanger module and the chassis module are configured to be coupled together. In this way, the need for separable fasteners can be avoided, again saving installation time.

[0089] Preferably, the add-on module includes a first interconnect, such as 62 and 74, to couple the output side loop 16 of the heat exchanger 12 to the building's in-building hot water system. Preferably, the add-on module also includes a second interconnect, such as 38 and 24, to couple the input side loop 14 of the heat exchanger 12 to a heat pump. Preferably, the add-on module also includes a third interconnect, such as 42 and 28, to couple the interface unit to the thermal circuit of the premises in which the interface unit is to be used. It will be appreciated that by mounting the heat exchanger to a chassis that is itself directly connected to the wall, rather than first mounting the connector to the chassis, the weight of the heat exchanger is held closer to the wall, thereby reducing the effect of cantilever loads on the wall fixtures that secure the interface unit to the wall.

[0090] Phase change materials

[0091] One class of suitable phase change materials is paraffin wax, which has a solid-liquid phase transition at the target temperatures for domestic hot water supply and use in conjunction with heat pumps. Of particular interest are paraffin waxes that melt at temperatures in the range of 40 to 60 degrees Celsius, and waxes in this range can be found melting at different temperatures to suit specific applications. Typical latent heat capacities are between about 180 kJ / kg and 230 kJ / kg, and specific heat capacities are about 2.27 Jg in the liquid phase. -1 K -1 , about 2.1 Jg in the solid phase -1 K -1 It can be seen that very large amounts of energy can be stored by using the latent heat of fusion. Even more energy can also be stored by heating the phase change liquid above its melting point. For example, when electricity costs are relatively low and hot water can be expected to be needed soon (at a time when electricity is likely or known to cost more), then it may make sense to run the heat pump at a higher than normal temperature to "superheat" the thermal energy store.

[0092] A suitable choice of wax may be a wax having a melting point of about 48 degrees Celsius, such as n-tricosane. 23 or chain alkane C 20 -C 33. Applying a standard 3K temperature difference across the heat exchanger (between the liquid supplied by the heat pump and the phase change material in the heat exchanger) gives the heat pump liquid temperature of approximately 51 degrees Celsius. And similarly, on the output side, allowing the temperature to drop by 3K, we get a water temperature of 45 degrees Celsius, which is satisfactory for general domestic hot water - hot enough for a kitchen tap, but potentially a little too hot for a shower / bathroom tap - but obviously cold water can always be added to the flow to lower the water temperature. Of course, if a household is trained to accept lower hot water temperatures, or if they are acceptable to this for some other reason, then potentially using a phase change material with a lower melting point could be considered, but generally a phase change temperature in the 45 to 50 range is likely to be a good choice. Obviously, we need to consider the Legionella risk of storing water at such temperatures, and the disinfection techniques described earlier provide a means by which this risk can be managed.

[0093] Heat pumps (such as ground source heat pumps or air source heat pumps) operate at temperatures up to 60 degrees Celsius (however, using propane as a refrigerant, the operating temperature may be as high as 72 degrees Celsius), but their efficiency tends to be much higher when the operating temperature range is 45 to 50 degrees Celsius. Therefore, our 51 degrees Celsius obtained from the phase change temperature of 48 degrees Celsius may be satisfactory.

[0094] The temperature performance of the heat pump also needs to be considered. Typically, the maximum ΔT (the difference between the input and output temperatures of the fluid heated by the heat pump) is preferably kept in the range of 5 to 7 degrees Celsius, although it can be as high as 10 degrees Celsius.

[0095] Although paraffins are the preferred material for use as energy storage media, they are not the only suitable material. Salt hydrates are also suitable for latent thermal energy storage systems, such as existing ones. In this case, salt hydrates are mixtures of inorganic salts and water, whose phase change involves the loss of all or most of their water. During the phase change, the hydrate crystals separate into anhydrous (or less water-containing) salt and water. The advantages of salt hydrates are that their thermal conductivity is much higher than that of paraffin (2 to 5 times higher) and the volume change during the phase change is much smaller. A salt hydrate suitable for the current application is Na2S2O3.5H2O, which has a melting point of about 48 to 49 degrees Celsius and a latent heat of 200 / 220 kJ / kg.

[0096] In terms of energy storage, one could also consider using PCMs with phase transition temperatures well above the 40-50 degrees Celsius range. For example, paraffin waxes have a wide range of melting points:

[0097] n-henicosane C 24 , the melting point is about 40 degrees Celsius;

[0098] n-docosane C21 , melting point is about 44.5 degrees Celsius;

[0099] n-Tetracosane C 23 , the melting point is about 52 degrees Celsius;

[0100] n-pentacosane C 25 , the melting point is about 54 degrees Celsius;

[0101] n-hexacosane C 26 , the melting point is about 56.5 degrees Celsius;

[0102] n-heptacosane C 27 , the melting point is about 59 degrees Celsius;

[0103] n-octacosane C 28 , the melting point is about 64.5 degrees Celsius;

[0104] n-nonacosane C 29 , the melting point is about 65 degrees Celsius;

[0105] n-triacosane C 30 , the melting point is about 66 degrees Celsius;

[0106] n-hentriacosane C 31 , the melting point is about 67 degrees Celsius;

[0107] n-dotriacosane C 32 , the melting point is about 69 degrees Celsius;

[0108] n-Triatriacosane C 33 , the melting point is about 71 degrees Celsius;

[0109] Paraffin C 22 -C 45 , the melting point is about 58 to 60 degrees Celsius;

[0110] Alkanes C 21 -C 50 , the melting point is about 66 to 68 degrees Celsius;

[0111] RT 70HC, melting point is about 69 to 71 degrees Celsius.

[0112] Alternatively, a salt hydrate may be used, such as CH3COONa.3H2O, which has a melting point of about 58 degrees Celsius and a latent heat of 226 / 265 kJ / kg.

[0113] Thermal energy stores have hitherto been described mainly as having a single mass of phase change material within a heat exchanger having input and output circuits each in the form of one or more coils or loops. However, it may also be advantageous in terms of heat transfer rate, for example, to enclose the phase change material in a plurality of sealed bodies - for example metal (e.g. copper or copper alloy) cylinders (or other elongated forms) - which are surrounded by a heat transfer liquid from which the output circuit (preferably for providing hot water for a (domestic) hot water system) extracts heat.

[0114] With such a configuration, the heat transfer liquid can be sealed in the heat exchanger, or more preferably, the heat transfer liquid can flow through the energy storage and can be the heat transfer liquid that transfers heat from the green energy source (e.g., a heat pump) without the need for input heat transfer coils in the energy storage. In this way, the input loop can be simply provided by one (or more generally multiple) inlets and one or more outlets, allowing the heat transfer liquid to freely pass through the heat exchanger without the constraints of coils or other conventional conduits, the heat transfer liquid transferring heat into or out of the encapsulated PCM and then to the output loop (and therefore to the water in the output loop). In this way, the input loop is defined by one or more inlets and one or more outlets for the heat transfer liquid and the free-form path(s) through the encapsulated PCM and through the energy storage.

[0115] Preferably, the PCM is enclosed in a plurality of elongated closed-end tubes arranged in one or more spaced apart arrangements (such as staggered rows of tubes, each row comprising a plurality of spaced apart tubes), with a heat transfer fluid preferably arranged to flow laterally over the tubes (or transversely to the length of the tubes or other encapsulating enclosure) - either in a route from an inlet to an outlet, or if an input coil is used, directed by one or more impellers provided within the thermal energy storage.

[0116] Alternatively, the output circuit may be arranged on top of the energy store and positioned above and above the encapsulated PCM - its reservoir may be arranged horizontally and located above the input loop or coil (so that convection supports energy transfer upward through the energy store) or the incoming heat transfer liquid is directed against the encapsulated PCM through the inlet and optionally towards the output circuit above. If one or more impellers are used, preferably the or each impeller is magnetically coupled to an externally mounted motor so that the integrity of the housing of the energy store is not compromised.

[0117] Alternatively, the PCM may be encapsulated in an elongated tube, typically of circular cross-section, with a nominal outer diameter in the range of 20 to 67 mm, for example 22 mm, 28 mm, 35 mm, 42 mm, 54 mm or 67 mm, and typically these tubes will be formed of copper suitable for use in piping systems. Preferably, the outer diameter of the pipe is between 22 mm and 54 mm, for example between 28 mm and 42 mm.

[0118] The heat transfer liquid is preferably water or a water-based liquid, such as water mixed with one or more of a flow additive, a corrosion inhibitor, an antifreeze agent, a biocide, and may, for example, contain an inhibitor of the type designed for use in central heating systems - such as Sentinel X100 or Fernox Fl (both RTM) - appropriately diluted in water.

[0119] Therefore, throughout the specification and claims of this application, unless the context clearly requires otherwise, the expression input circuit should be interpreted as including the arrangement just described and in which the liquid flow path from the input of the input circuit to its output is not defined by conventional conduits, but involves essentially free flow of liquid within the housing of the energy storage device.

[0120] The PCM may be encapsulated in a plurality of elongated cylinders having a circular or substantially circular cross-section, the cylinders preferably being spaced apart and arranged in one or more rows. Preferably, the cylinders in adjacent rows are offset relative to each other to facilitate heat transfer from and to the heat transfer liquid. Optionally, an input arrangement is provided in which the heat transfer liquid is introduced into the space around the encapsulated body through one or more input ports, which may be in the form of a plurality of input nozzles that direct the input heat transfer liquid toward and onto the encapsulated body supplied by an input manifold. The cross-section of the orifice of the nozzle at its output may be substantially circular or may be elongated to produce a jet or stream of liquid that more effectively transfers heat to the encapsulated PCM. The manifold may be supplied from a single end or from opposite ends to increase flow rate and reduce pressure losses.

[0121] The heat transfer liquid can be pumped into the energy storage 12 as a result of the action of a pump of a green energy source (e.g., a heat pump or a solar water heating system) or another system pump, or the thermal energy storage may include its own pump. After flowing out of the energy storage at one or more outlets of the input loop, the heat transfer liquid can be returned directly to the energy source (e.g., a heat pump), or it can be switched by using one or more valves to first pass through a heating installation (e.g., floor heating, radiator, or other form of space heating) before returning to the green energy source. The package body can be arranged horizontally, with the coil of the output loop positioned above and above the package body. It should be understood that this is only one of many possible arrangements and orientations. The same arrangement can also be well positioned to arrange the package body vertically.

[0122] Alternatively, an energy store using PCM encapsulation may again use a cylindrical elongate encapsulation body such as those previously described, but in this case with an input circuit in the form of a conduit, for example in the form of a coil. The encapsulation body may be arranged with its long axis arranged vertically, and with the input coil 14 and output coil 18 arranged on either side of the energy store 12. But equally, this arrangement may also be used for alternative orientations, such as with the input circuit at the bottom and the output circuit at the top, with the long axis of the encapsulation body arranged horizontally. Preferably, one or more impellers are arranged within the energy store 12 to push the energy transfer liquid from around the input coil 14 towards the encapsulation body. The or each impeller is preferably coupled to an externally mounted drive unit (e.g. an electric motor) via a magnetic drive system, so that the housing of the energy store 12 does not need to be perforated to receive a drive shaft - thereby reducing the risk of leakage where such a shaft enters the housing.

[0123] The fact that the PCMs are encapsulated makes it easy to construct energy storage devices that use more than one phase change material for energy storage, and in particular allows the creation of energy storage cells in which PCMs with different transition (e.g. melting) temperatures can be combined, thereby extending the operating temperature of the energy storage device.

[0124] It will be appreciated that in embodiments of the type just described, the energy storage 12 includes one or more phase change materials to store energy as latent heat in combination with a heat transfer liquid such as water or a water / inhibitor solution.

[0125] A plurality of elastomers configured to reduce volume in response to an increase in pressure caused by a phase change of the phase change material and to expand again in response to a decrease in pressure caused by a reverse phase change of the phase change material are preferably provided together with the phase change material within the packaging body (they may also be used in energy accumulators using "bulk" PCMs, as described elsewhere in this specification).

Claims

1. A heating installation for a house, the installation comprising: Controller; and coupled to the controller: air-source heat pumps, which extract energy from the surrounding air; House heating arrangements; as well as Local weather sensing deployment; The controller is configured as follows: receiving weather forecast data from an external source via a wired or wireless connection, and receiving local weather status information from said local weather sensing arrangement; setting a control algorithm based on both the weather forecast data and the local weather status information; controlling the supply of energy from the air source heat pump to the house heating arrangement based on a set control algorithm; determining, based on the weather forecast data, a forecast period of time during which the temperature of air from which the air source heat pump extracts energy decreases; estimating a likelihood that the home heating arrangement will be used during the forecast period of reduced temperature, wherein the controller is configured to take into account occupancy or projected occupancy of the home and to take into account scheduled activities of occupants of the home in estimating the likelihood; and The energy supply is controlled based on a predicted likelihood that the home heating arrangement will be used during the forecast period of reduced temperature and energy input to the home heating arrangement is increased prior to the forecast period of reduced temperature of air from which the air source heat pump extracts energy.

2. A heating installation according to claim 1, wherein the controller is configured to estimate the likelihood based on past household behavior of the house and / or based on past behavior of comparable households.

3. A heating installation according to any one of the preceding claims, wherein the controller is configured to control the heating arrangement to enable additional energy to be input into the heating arrangement.

4. The heating installation according to claim 1, further comprising an energy storage arranged to receive energy from the heat pump, the controller being configured to control the supply of energy from the air source heat pump to the energy storage based on the set control algorithm.

5. A heating installation according to claim 4, wherein the energy storage comprises a phase change material for storing energy as latent heat.

6. A heating installation according to claim 5, wherein the controller is configured to control the supply of energy to the energy storage to increase the amount of energy stored in the storage as sensible heat.

7. A heating installation according to any of claims 4 to 6, wherein the energy store is arranged to supply energy to a hot water system of the house.

8. A method of controlling a home heating installation, the home heating installation comprising a controller and coupled to the controller: an air source heat pump that extracts energy from ambient air; a home heating arrangement; and a local weather sensing arrangement, the method comprising performing, by the controller: receiving weather forecast data from an external source via a wired or wireless connection, and receiving local weather status information from said local weather sensing arrangement; setting a control algorithm based on both the weather forecast data and the local weather status information; controlling a supply of energy from the air source heat pump to the house heating arrangement based on the settings of the control algorithm; determining, based on the weather forecast data, a forecast period of time during which the temperature of air from which the air source heat pump extracts energy decreases; an estimated likelihood that the home heating arrangement will be used during the forecast period of reduced temperature, taking into account occupancy or expected occupancy of the home and taking into account scheduled activities of occupants of the home in estimating the likelihood; as well as The energy supply is controlled based on a predicted likelihood that the home heating arrangement will be used during the forecast period of reduced temperature and energy input to the home heating arrangement is increased prior to the forecast period of reduced temperature of air from which the air source heat pump extracts energy.

9. The method of claim 8, further comprising estimating the likelihood based on past household behavior of the house and / or based on past behavior of comparable households.

10. A method according to claim 8 or claim 9, further comprising controlling the heating arrangement to enable additional energy to be input into the heating arrangement.

11. The method of claim 8, wherein the installation comprises an energy storage arranged to receive energy from the heat pump, the method further comprising controlling the supply of energy from the air source heat pump to the energy storage based on a set control algorithm.

12. The method of claim 11, wherein the energy storage comprises a phase change material for storing energy as latent heat, the method further comprising controlling the supply of energy to the energy storage to increase the amount of energy stored in the storage as sensible heat.

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