Electrothermal heater

Abstract

A partially or fully electrothermal heater (1) is disclosed, the heater being arranged to heat a fluid in a first circuit, the fluid comprising heated fluid or tap water. The heater includes a first electric heating element (8) arranged to heat the fluid in the first circuit. The first electric heating element is arranged to be powered by an AC power supply (22) and a DC power supply (20). The heater includes a controller (24) arranged to control the power distribution from the DC power supply and the AC power supply to the first heating element.

Description

Technical Field

[0001] This invention relates to electric heaters for fluid heating systems. Specifically, but not exclusively, this invention relates to electric boilers for wet heating systems or electric furnaces for air heating systems, both of which can supply heated fluid (e.g., via radiators) or heated tap water, or both, for heating a space. Background Technology

[0002] Gas-fired boilers can provide wet heating solutions that meet both hot water and heating needs. For example, a domestic gas-fired boiler typically supplies hot water to the heating radiators within the heating system and also provides on-demand hot water to taps (e.g., for drinking, cleaning, washing). The two supplies (heating and taps) are kept separate because the heated water can become contaminated as it travels through the radiator circuit, while tap water must be clean. Combination boilers are popular because they provide all these functions in a sealed, high-pressure environment within a single boiler casing, and have a relatively small physical footprint. Other types of boilers with separate water tanks or cylinders are also used.

[0003] Gas-fired boilers burn fossil fuels. Therefore, electric boilers are now emerging as an environmentally friendly alternative. Electric boilers deliver water via electrically heated elements.

[0004] Electric combination boilers use technology similar to electric kettles. The boiler is connected to a main power source and supplies cold water from the main pipe. When a hot water request is received (e.g., when a hot water tap is turned on or the heater is activated), a heating element inside the boiler heats the water and transfers that heat to the cold water. The heated water is then pumped to the desired tap or radiator.

[0005] Storage-type electric boilers include a hot water tank (either an internal or external tank within the unit). This allows for the heating and storage of water when energy costs are low (e.g., overnight) for subsequent use when energy costs are high (e.g., the following day). Such systems require more space.

[0006] Following the same theme, but offering some of the advantages of combined boilers, the combined main storage unit (CPSU) features a central heating boiler and hot water tank integrated into a single large casing – which can provide a large volume of hot water when needed. However, it requires a significant amount of space to house the system.

[0007] All of these electric boiler systems use heating elements powered by AC (alternating current).

[0008] The inventors have realized that better electric boilers can be produced and have created the solution for the claimed protection. Summary of the Invention

[0009] According to a first aspect of the present invention, a fluid heater as described in claim 1 is provided.

[0010] Advantageously, all-electric or hybrid fluid heaters are available that can use a combination of DC and AC power (i.e., without relying on AC input). This type of heater can intelligently utilize available power options, thus operating more efficiently while providing high performance and an environmentally friendly approach. The intelligent combination of AC and DC power reduces the risk of overwhelmed household power supplies or the local grid (e.g., during peak demand periods). Furthermore, fluid heaters with typically higher peak power can be provided. Moreover, the intelligent use of DC power is extremely useful in the event of a mainline AC power outage.

[0011] Optional features of the invention are claimed in the dependent claims—thereby providing various advantages as discussed in the detailed description. These optional features increase the efficiency and intelligence of the heater setup of the invention. As those skilled in the art will understand, any of these optional features can be combined with any other optional feature. Attached Figure Description

[0012] Embodiments will now be described by way of example only with reference to the accompanying drawings, in which:

[0013] Figure 1 A schematic diagram of a boiler according to a first aspect of the present invention is shown;

[0014] Figure 2 A schematic diagram of a boiler according to another aspect of the present invention is shown;

[0015] Figures 3 to 5 A schematic diagram of a boiler according to another aspect of the invention is shown; and

[0016] Figures 6a to 6d Rear view, side view, cross-sectional view (through DD shown in the side view), and perspective sectional view of a furnace according to another aspect of the invention are shown respectively. Detailed Implementation

[0017] The exemplary embodiments described in the detailed description and claims are not intended to be limiting. Other embodiments may be used and other changes may be made without departing from the scope of the invention. Various embodiments have been described. The specific embodiments are not intended as an exhaustive description or as a limitation on the broader discussion and claimed aspects. Features described in connection with particular embodiments are not necessarily limited to those embodiments and may be incorporated into any other embodiments. Any protection provided by applicable doctrines of equivalents is reserved to the fullest extent.

[0018] Terms such as upper, lower, top, bottom, left, right, inner, outer, vertical, and upright have been used to simply and clearly describe the present invention. These terms should not be interpreted in a limiting manner. Those skilled in the art will envision other suitable embodiments within the scope of this invention.

[0019] Reference Figure 1 This illustration schematically depicts a fluid heater (also referred to herein as a boiler) in the form of a water heater 1, used for heating water used in a standard fluid circuit (e.g., a radiator heating water circuit). Various aspects of the boiler and boiler system will be described in detail with reference to non-limiting examples. Other details will be apparent to those skilled in the art. In particular, those skilled in the art can incorporate and use known aspects of boiler systems (including those not described) into this invention.

[0020] Generally, a boiler can be a box-type boiler (also known as a system boiler), or a modular boiler, or any other known boiler type, or a furnace heater, such as a furnace air heater. Those skilled in the art will be able to adapt the described embodiments to boiler types other than those described. These boiler types are known to be used to supply heated water (e.g., to a radiator circuit) or drinking water (e.g., to a tap circuit) or both. In other examples, instead of heating radiator water, another type of heating fluid may be present flowing through the heating system, such as another fluid, another gas (e.g., air), or oil, or any combination thereof.

[0021] Such fluid circuits are well known in the art. Each or every fluid circuit can be substantially sealed during use and may optionally be pressurized. In drinking water circuits, pressure from a main pipe or gravity supply drives water so that water flows from the tap during normal use when the tap / faucet is turned on. Typically, radiator circuits are substantially sealed during normal use. Drain points or pressure relief points can be located in convenient locations to allow for inspection or pressure release or fluid release for maintenance and repair. Expansion tanks or expansion containers (small tanks used to protect closed (not open to atmospheric pressure) fluid heating systems and domestic hot water systems from overpressure) are known. Typically, expansion tanks are partially filled with air, whose compressibility cushions the impact of water hammer and absorbs excess water pressure caused by thermal expansion. In air heaters, the fluid circuit typically includes at least one vent through which heated air is exhausted into the space to be heated. In such circuits, the air within the circuit is not isolated from the environment—typically at atmospheric pressure or ambient pressure. In some of these systems, air is drawn into the furnace during normal operation, heated, and then blown around the heated network.

[0022] In this example, the water heater 1 is a system boiler and includes a boiler shell 2 to house its components. Typically, the boiler of the present invention needs to be installed in a confined space. In many examples, the invention includes features that make the boiler compact, allowing it to be installed within the same shell or space occupation as typical known boilers, even if the boiler of the present invention includes new components (described in more detail below).

[0023] Boiler 1 is arranged to heat water in a first loop, which is a heated water loop. The heated water loop includes several components, including, in addition to boiler 1, a standard domestic radiator (not shown). In this example, water is used as the heating fluid in the first loop; other known heating fluids may be used in other examples.

[0024] Relatively cold water from the first circuit enters the boiler 1 through the cold water inlet pipe 4, is heated, and then relatively hot water leaves the boiler 1 through the hot water outlet pipe 6 and returns to the first circuit.

[0025] Boiler 1 includes an electric boiler container 10, which is located within a housing 2 between an inlet pipe 4 and an outlet pipe 6. The electric boiler container 10 is a closed and sealed container that contains a first electric heating element 8 arranged to heat water flowing through the container 10.

[0026] According to the present invention, the first electric heating element 8 communicates with both a DC power supply and an AC power supply, such that it can be powered by either or both of them.

[0027] In this example, the DC power supply is in the form of a battery pack 20, which is part of the heater 1 and also located inside the housing 2. In other examples, the DC power supply may be located outside the heater.

[0028] In this example, the AC power source includes mainline power 22 (also known as "utility power", "household power", "domestic electricity", "house current", "power line", "household power", "wall power", "line power", "AC power", "city power", "street power", "hydropower").

[0029] The boiler also includes a controller 24, which is arranged to control the power distribution from the DC and AC power supplies 20, 22 to the first heating element 8. The controller may be implemented in hardware or software, or a combination thereof, as will be apparent to those skilled in the art.

[0030] In some examples, the controller is computer-controlled and arranged to control the amount of heating supplied to the fluid based on or in response to any one or more control factors, including: the required amount of heating; the fluid input temperature at an input point in one or more fluid loops; the fluid output temperature at an output point in one or more fluid loops; the fluid temperature at any predetermined point in one or more fluid loops; the amount of heating capacity available from a first heating element; the amount of heating capacity available from a combustible fuel burner; the immediate demand for heated fluid or drinking water; the predicted demand for heated fluid or drinking water; and the flow rate of the fluid to be heated.

[0031] Furthermore, in some examples, the fluid heater includes one or more sensors (not shown) arranged to sense information related to one or more control factors and provide said control factor information to a controller. Some sensors are located inside the boiler casing (e.g., for measuring water temperature or flow rate within the boiler). Some sensors are located outside the boiler casing (e.g., for measuring water temperature or flow rate at a desired location in a first loop outside the boiler, such as in a room of a building). The controller responds to information from such sensors to instruct the fuel burner and electric heating elements to heat the fluid.

[0032] In some examples, the controller may have an associated (integral or separate) memory (not shown), arranged to store information about any or more aspects of the system, such as historical or sensing information related to any control factors, control factor information, sensing information from any sensors, or desired output information (e.g., desired room temperature). The controller is able to access the information from the memory in a known manner. The controller and memory can be implemented in standard computerized networks and systems.

[0033] In this example, controller 24 includes (not shown) a hardware thermostat and optionally an additional GUI thermostat, enabling users to easily input desired fluid heating requirements in a known manner and easily receive feedback on fluid heating operating parameters.

[0034] In this example, controller 24 also includes (not shown) an AC power adapter arranged to connect to an external AC power source 22 to deliver AC power to heating element 8 within a desired power configuration. Although not present in this embodiment, in some embodiments, similarly, a DC power adapter is arranged between the DC power source and the heating element to connect to the DC power source 22 to deliver DC power to the heating element within a desired power configuration.

[0035] The controller is configured to take several factors into account when distributing control power to the heating element. In some cases (at any given time), using only DC power will be preferable; in other cases (at any given time), using only AC power will be preferable; and in still other cases (at any given time), a combination of DC and AC power will be preferable.

[0036] The controller is configured to control the relative distribution of power from DC and AC power sources, taking into account any one or more of the following: the capacity of the individual or each heating element (e.g., the maximum safe load (e.g., peak power or continuous power supply duration) of a particular heating element); the capacity of the individual or each power source; the immediate demand for heated or tap water (e.g., a tap has just been turned on / a radiator has just started from a cold state); the predicted demand for heated or tap water; and the type of immediate or predicted supply available. The controller can also be configured to provide a seamless switching from primarily using DC power to primarily using AC power, for example, when the DC battery is depleted, the AC power gradually takes over while the power output remains substantially constant or at a desired level. The controller can also control the intelligent charging of the DC power source, taking into account the heat and charge level (of the DC battery) when controlling charging (e.g., whether to charge aggressively / fast or slower).

[0037] In some examples, the first heating element may have a preferred power requirement range, and the controller is arranged to supply power within that range while varying the AC / DC power ratio of the first heating element from AC:DC 0:100 to 100:0. A relatively large DC power supply may be required where the demand is met entirely or largely by the DC power supply. In some examples, the DC power supply is not large enough to meet 100% of the heating demand by DC power alone. In other examples, a large DC power supply is provided, and this demand can be met by DC power alone (see examples described later herein).

[0038] In this example, the boiler is an all-electric boiler, meaning the heat source is entirely electric. In other examples, the boiler may be partially electric, such as partially electric and partially gas-fired, or partially electric and partially fueled by other combustible fuels—suitable combustible fuels may be combustible fluids such as natural gas, hydrogen, or propane gas, or methane gas, or ethane gas, or butane gas, or suitable combustible oil or combustible solids or coverings, such as wood chips or wood pellets, or any combination thereof. Thus, some heating power is provided by electric (DC and AC) components, while some heating power is provided by more conventional combustion fuels. This helps to increase redundancy within the system, or allows for efficient operation in environments where one or more power sources are scarce. In this invention, the combined DC and AC power sources are large enough to supply the power output of all or almost all typical boilers, if desired.

[0039] Reference Figure 2 The illustration schematically depicts a water heater 31 used for heating water in a standard radiator heating water circuit. Various aspects of the boiler and boiler system will be described in detail with reference to non-limiting examples. Other details will be apparent to those skilled in the art. Specifically, those skilled in the art can incorporate and use known aspects of boiler systems (including those not described) in this invention.

[0040] Generally, a boiler can be a box-type boiler (also known as a system boiler), or a modular boiler, or any other known boiler type, or a furnace heater, such as a furnace air heater. Those skilled in the art will be able to adapt the described embodiments to boiler types other than those described. These boiler types are well known to be used to supply heated water (e.g., to a radiator circuit) or drinking water (e.g., to a tap circuit) or both. In other examples, instead of heating radiator water, another type of heating fluid may be present flowing through the heating system, such as another fluid, another gas (e.g., air), or oil, or any combination thereof. In some such examples,

[0041] In this example, the water heater 31 is a system boiler and includes a boiler shell 32 to house its components. Typically, the boiler of the present invention needs to be installed in a confined space. In many examples, the invention includes features that make the boiler compact, allowing it to be installed within the same shell or space footprint as typical known boilers, even if the boiler of the present invention includes new components (described in more detail below).

[0042] Boiler 31 is arranged to heat water in a first loop, which is a heated water loop. The heated water loop includes several components, including, in addition to boiler 31, a standard domestic radiator (not shown). In this example, water is used as the heating fluid in the first loop; other known heating fluids may be used in other examples.

[0043] Relatively cold water from the first circuit enters the boiler 31 via the cold water inlet pipe 34, is heated, and then relatively hot water leaves the boiler 31 via the hot water outlet pipe 36 and returns to the first circuit. A water pump (not shown) is also provided in this circuit.

[0044] Boiler 31 includes an electric boiler container 40 located within a housing 32 between inlet pipe 34 and outlet pipe 36. The electric boiler container 40 is a closed, sealed container containing a first electric heating element 38 arranged to heat water flowing through the container 40.

[0045] According to the present invention, the first electric heating element 38 is connected to both a DC power supply and an AC power supply, so that it can be powered by one or both of them.

[0046] In this example, the DC power supply is in the form of a battery pack 50, which is part of the heater 31 and also located within the housing 32. In other examples, the DC power supply may be located outside the heater.

[0047] In this example, the AC power supply includes mainline power 52.

[0048] The boiler also includes a controller 54, which is arranged to control the power distribution from DC and AC power supplies 50, 52 to the first heating element 38. The controller may be implemented in hardware or software or a combination thereof, as will be apparent to those skilled in the art.

[0049] In this example, controller 54 includes (not shown) a hardware thermostat and optionally an additional GUI thermostat, enabling users to easily input desired fluid heating requirements in a known manner and easily receive feedback on fluid heating operating parameters.

[0050] In this example, the controller 54 also includes (not shown) an AC power adapter, which is arranged to connect to an external AC power source 22 to deliver AC power to the heating element 8 within a desired power configuration.

[0051] The controller 54 also includes a DC-AC converter (not shown separately from the controller in the figures), which is located between the DC power supply and the heating element, and is arranged to convert the delivered AC to DC in a known manner before being connected to the AC power supply 22 to deliver power to the heating element within a desired power configuration.

[0052] In this example, the controller is arranged to control a combination of outputs from both AC and DC power sources to deliver only AC power to the heating element. The advantage of this feature is that it simplifies the input circuitry to the heating element compared to directly supplying both AC and DC power (thus reducing wet circuitry components, i.e., components containing fluid / water), leading to enhanced reliability, maintenance, and space savings).

[0053] In other examples, the controller can be configured to control a combination of outputs from AC and DC power sources to achieve different objectives.

[0054] In other examples, the heater may (instead of a DC-AC converter) include an AC-DC converter located between the AC power source and the heating element, and is arranged to convert the supplied AC to DC in a known manner before supplying only DC power to the heating element within a desired power configuration. Again, this feature has the advantage of simplifying the input circuitry to the heating element compared to when both AC and DC are supplied directly to the heating element. In this case, in some embodiments, the AC-DC converter may be located inside the boiler housing, and in other embodiments, it may be located outside the boiler housing.

[0055] The controller is configured to consider multiple factors when distributing control power to the heating element. In some cases (at any given time), using only DC power is preferable; in others (at any given time), using only AC power is preferable; and in still others (at any given time), a combination of DC and AC power is preferable. In one example, DC power is used most of the time, while AC power is used during periods of sustained cold. In some examples, when heating hot water for drinking, etc., DC power is ideally used (at least for initial heating to provide a rapid heating response time).

[0056] The controller is configured to control the relative distribution of power from DC and AC power sources, taking into account any one or more of the following: the capacity of the individual or each heating element (e.g., the maximum safe load (e.g., peak power or continuous power supply duration) of a particular heating element); the capacity of the individual or each power source; the immediate demand for heated or tap water (e.g., a tap has just been turned on / a radiator has just started from a cold state); the predicted demand for heated or tap water; and the type of immediate or predicted supply available. The controller can learn user behavior over time (e.g., when a shower occurs, when one or more users typically wake up, etc.), and one or more sensors can provide sensed information to feed data back to the controller to enhance the learning.

[0057] In some examples, the first heating element may have a preferred power requirement range, and the controller is arranged to supply power within that range while varying the AC / DC power ratio of the first heating element from AC:DC 0:100 to 100:0. A relatively large DC power supply may be required where the demand is met entirely or largely by DC power. In some examples, the DC power supply is not large enough to meet 100% of the heating demand by DC power alone. In other examples, a large DC power supply is provided, and this demand can be met by DC power alone (see examples described later herein).

[0058] In this example, the boiler is an all-electric boiler, meaning the heat source is entirely electric. In other examples, the boiler may be partially electric, such as partially electric and partially gas-fired, or partially electric and partially fueled by other combustible fuels—suitable combustible fuels could be natural gas, hydrogen, or propane gas, or methane gas, or ethane gas, or butane gas, or suitable combustible oil or wood chips or wood pellets, or any combination thereof. Thus, some heating power is provided by electric (DC and AC) components, while some heating power is provided by more conventional combustion fuels. This helps increase redundancy within the system, or allows for efficient operation in environments where one or more power sources are scarce. In this invention, the combined DC and AC power sources are large enough to supply, or nearly all, the power output of a typical boiler, if desired.

[0059] Reference Figure 1 and Figure 2 The features of the controller described, and the way it intelligently distributes power from AC and DC sources when powering the heating element, can be used in conjunction with the embodiments described later, and protection is sought specifically for such combinations.

[0060] Reference Figure 3 It shows the reference Figure 1 The described water heater is similar to water heater 100. Unless otherwise stated, the technical features are consistent with any previously described embodiment (e.g., reference 100). Figure 1 or Figure 2 The technical features described are similar. Heater 100 is used to heat water in a standard radiator heating water circuit. Various aspects of the boiler and boiler system will be described in detail with reference to non-limiting examples. Other details will be apparent to those skilled in the art. Specifically, those skilled in the art can incorporate and use known aspects of boiler systems (including those not described) in this invention.

[0061] In this example, the water heater 100 is a system boiler and includes a boiler shell 102 to house its components.

[0062] Boiler 100 is arranged to heat water in a first loop, which is a hot water loop. The hot water loop includes several components, including, in addition to boiler 100, a standard domestic radiator (not shown). In this example, water is used as the heating fluid in the first loop; other known heating fluids may be used in other examples.

[0063] Relatively cold water from the first circuit enters the boiler 100 through the cold water inlet pipe 104, is heated, and then relatively hot water leaves the boiler 100 through the hot water outlet pipe 106 and returns to the first circuit.

[0064] Boiler 100 includes an electric boiler container 110 located within a housing 102 between an inlet pipe 104 and an outlet pipe 106. The electric boiler container 110 is a closed, sealed container containing a first electric heating element 108 arranged to heat water flowing through the container 110.

[0065] According to the present invention, the first electric heating element 108 is a reference Figure 1 The described type is powered by a combination of DC and AC power supplies; in another example, the combination of DC and AC power supplies may be a reference. Figure 2 Or the type described in the relevant examples. For clarity, Figure 1 Most of the common components shown are not in Figure 3 Repeated in the middle (e.g., controllers and their associated circuitry).

[0066] In this example, the DC power supply in the form of battery pack 120 is also located within housing 102. In this example, the boiler is an all-electric boiler, meaning the heat source is entirely electric. In other examples, the boiler may be partially electric, such as partially electric and partially gas-fired, or partially electric and partially fueled by other combustible fuels—suitable combustible fuels may be natural gas, hydrogen, or propane gas, or methane gas, or ethane gas, or butane gas, or suitable combustible oil or combustible solids or coverings, or any combination thereof. Thus, some heating power is provided by the electric DC component, while some heating power is provided by more conventional combustion fuels. This helps to increase redundancy within the system, or can be used for efficient operation in environments where one or more power sources are scarce. In this invention, the DC power supply is large enough to supply the power output of all or almost all typical boilers, if desired.

[0067] In this example, the DC power supply has a capacity of 1 kWh.

[0068] In another example, for a small gas-electric hybrid boiler system setup, the battery capacity could be around 1 kWh – this could be useful in small homes (such as small apartments), or in larger homes, it could be used to increase the usual hot water supply.

[0069] In another example, for a larger gas-electric hybrid boiler system setup, the battery capacity could be around 3 to 5 kWh – which could be useful in larger residences.

[0070] In another example, for an all-electric boiler system setup, the battery capacity can be approximately 5 kWh or more. In most cases, a capacity of 15 kWh to 20 kWh is sufficient to meet the water heating needs using a boiler with DC power alone. For example, for an all-electric boiler in a small apartment, the battery capacity could be approximately 10 kWh, in a medium-sized house approximately 15 to 20 kWh, and in a large house approximately 25 to 30 kWh.

[0071] In some examples, the battery capacity can be around 90 kWh, for example, to supply heating fluids and heated drinking water to larger buildings.

[0072] In this example, the peak power output of the DC power supply is between 10kW and 20kW in some examples, and as high as 200kW in others. In circuits with low peak demand, the peak power output can be 1kW or 2kW. A suitable peak power output specification can be made according to specific circuit requirements and will be apparent to those skilled in the art. For example, in one example scenario, a 90kWh battery could provide 350kW of power for 10 minutes.

[0073] In this embodiment, the battery pack 120 includes a compactly configured battery stack.

[0074] In this example, the 1kWh DC battery pack 120 comprises one hundred replaceable or rechargeable cylindrical cells, such as standard-sized 18650 cells (18mm diameter and 65mm length), each with a capacity of approximately 10Wh. In this example, for compactness, the rechargeable cells are arranged in a 10x10 stack, and the entire stack can be removed from the battery pack 120 and recharged from outside the housing 102. In another example, the stack could be a 5x20 stack. Other suitable stacking configurations will be apparent depending on the available space in the battery pack. The battery stack is configured to provide substantially consistent use over time for each cell within the stack in a known manner, allowing the battery stack to operate effectively as a single cell. In some examples, the DC power source may also be charged from a renewable heat source, such as solar or wind power, a heat pump, or any other suitable source.

[0075] In other embodiments, the DC battery pack can be charged locally via a charging connection (not shown), i.e., without removing any batteries from the housing 102.

[0076] In this example, charging is performed via an AC-DC converter (not shown), and in an example where charging is performed in situ, the boiler also includes an AC-DC converter located within its casing.

[0077] A typical 18650 battery has a voltage of 3.6V. In this example, the batteries in battery pack 120 are arranged in series, meaning the effective voltage is approximately 3600V. The battery pack is well insulated. In other examples, the batteries may be arranged differently, for example, all in series (so that the maximum voltage in any single path is 3.6V) or in parallel paths with several series-connected batteries, such as 10 parallel paths, each with 10 series-connected batteries (36V).

[0078] In some embodiments, the battery can be arranged to provide substantially the same voltage as the AC input power supply voltage – which makes combining AC and DC easier and also makes charging easier. For example, in the UK, a 240V battery pack can be provided.

[0079] In some embodiments, multiple battery packs or stacks within battery packs are provided, rather than a single battery pack.

[0080] The boiler shell 100 uses its AC connection 130 to power small electronic components (which have relatively low power requirements compared to the power needed to heat water during normal boiler operation), such as switching circuits, boiler displays, boiler user interfaces, sensors, Wi-Fi, Bluetooth, sub-1GHz communication, LED lighting, and other standard boiler components. Other such components include: igniters or spark generators; ignition electrodes / ionization electrodes; pressure sensors / transmitters (water), as well as water pressure switches; flow sensors / switches (ensuring the gas / air mixture flows correctly before ignition); combustion sensors (thermal switches – sometimes manufacturers describe them separately from temperature sensors); thermostats; thermocouples / PRTs; control PCBs; multimedia interfaces; power electronics for the power supply; and pumps for water and gas (simple electric pumps or potentially more complex driven electronics). In some examples, this power may also be provided by a renewable heat source, such as solar or wind power, a heat pump, or any other suitable source. In some examples, these small electronic components are directly powered by a DC power supply.

[0081] In this example, boiler 100 also includes an electrical controller (not shown) arranged to control any one or more of the following: heating, battery charging, battery discharging, system requirements, and switching of DC power supply, as referenced. Figure 1 The example described.

[0082] The relatively large battery of this invention generates heat. Other electrical components of the boiler also generate heat. The inventors have recognized the need for a compact, efficient, non-standard cooling system.

[0083] The boiler 100 in this embodiment also includes a cooling system (not shown). Because it involves large DC battery power, and requires additional switching due to the intelligent use of the large-capacity DC battery, and the operation of the controller and its associated circuitry (due to the desire for intelligent DC-AC use), the electronic equipment can be hotter than a conventional boiler.

[0084] In some examples, the heater includes a high-power switching module arranged to efficiently switch high currents, allowing for power variation and smooth fluid temperature change within the same resistive heating element. This is particularly important in drinking water circuits. This feature allows for pulse width modulation within the control circuitry. The high-power switching module can be arranged to switch 30 amps or greater.

[0085] In examples incorporating a battery charging mechanism, the inventors further discovered that heat generation within the battery charging system can be a problem—particularly in AC-DC converter battery charging systems that allow voltage charging of DC battery packs / cells. This type of battery charging mechanism is not yet present in any boiler system or boiler housing and generates heat. Therefore, another advantage of some examples of the invention is the use of a cooling system (or providing another separate cooling system) as a radiator to cool the battery charging mechanism. A battery charging mechanism cooling system is particularly useful because charging can (and should) occur when the heating system is not turned on (i.e., when it is not heating the building or providing hot drinking water, e.g., at midnight). The cooling system of the present invention allows the heating system to be operated to filter heat during charging. Even when the fluid does not require heating, the controller can be arranged to allow fluid to flow through the fluid heater system to cool the battery charging mechanism; for example, the controller can react in response to prediction or being notified or sensing that the battery charging system should be cooled (e.g., by feedback from a temperature sensor located near the battery charger or after a minimum period of continuous battery charging threshold). This battery charging mechanism cooling feature can be implemented using any of the described embodiments incorporating a battery charger to create new embodiments of the invention.

[0086] In some examples (e.g., where the flow of heated fluid / drinking water is involved in cooling), cooling occurs by the flow of heated fluid / drinking water through the controller / battery / battery charger when the heating system is operating (e.g., when drinking water or heated radiator fluid is required). However, when the heating system is not operating, the present invention allows the charger cooling system to operate (either by the flow of heated fluid / drinking water or by its own dedicated coolant within its own dedicated coolant circuit) specifically for the purpose of cooling the battery charger.

[0087] In some examples, the cooling system uses water output from a radiator that reaches a cold input pipe 104 (typically at about 35-40°C) to cool hotter electronic components (ideally, the intention is to keep the electronic components well below 100°C). In some examples, elements of the cooling system include engineering to position a first-loop piping from the input 104 within the boiler 100 adjacent to or close to the components requiring cooling. Therefore, the overall efficiency of the fluid heater is improved, and its electronics can become more compact / simple due to the reduced need for full electronic efficiency in switching power.

[0088] The cooling system in this example includes a coolant loop with a closed coolant piping system (not shown) through which coolant is pumped. The closed coolant piping system is configured to facilitate heat transfer between the coolant and the boiler's chilled water input to remove heat, and to facilitate heat transfer between the coolant and battery cells or other components to remove heat. This is achieved by directing the piping system to appropriate locations near any or more of the boiler components, battery cells, and chilled water input.

[0089] exist Figure 3 In this example, the boiler is configured to be compact. The housing has dimensions of 400 cm wide x 300 cm deep x 700 cm high and houses a first heater container 110 containing a first heating element 108, a DC power supply 102, and a cooling system (in this example). In other embodiments, the housing may have the following dimensions: 390 mm wide, 270 mm deep, 600 mm high; or 400 mm wide, 300 mm deep, 724 mm high; or 400 mm wide, 310 mm deep, 724 mm high; or 440 mm wide, 365 mm deep, 780 mm high; or 440 mm wide, 364 mm deep, 825 mm high; or 440 mm wide, 365 mm deep, 780 mm high; or any other suitable dimensions that are obvious to those skilled in the art.

[0090] Offering further compactness, the DC power supply is located at the front of the casing during use, essentially filling the space between the front and rear ends of the casing, and also essentially filling the space between the left and right sides of the casing. The left and right sides of the boiler have walls that are relatively difficult to access during use. The front is relatively easy to access and is typically used for accessing internal components during maintenance.

[0091] In some examples, housing 100 includes an access door arranged to allow access to internal components of the heater (e.g., for maintenance or repair), and the DC power supply is arranged within or integrally with the access door. This also increases overall compactness and ensures that no further removal or manipulation of the DC battery is required to access internal boiler components (e.g., for repair / maintenance).

[0092] In this example, boiler 100 also includes a thermal break or thermal shield (not shown) located between the DC power supply and the first heater container; and also between the controller and the first heater container. The thermal break or thermal shield may include any one or any combination of the following: an air gap; a gap filled (partially or completely) with insulating material; a gap filled (partially or completely) with infrared reflective material; a gap filled (partially or completely) with insulating or low thermal conductivity material.

[0093] In some examples, the heat shield may include an associated heat shield cooling mechanism arranged to transfer heat from the heat shield area to another area where the heat is safely dissipated, and includes any one or more of the following:

[0094] • Fluid materials that carry heat away from the area (e.g., from the heat shield area to the dissipation area (i.e., another area that is safer to dissipate heat than the heat shield area));

[0095] • Active cooling mechanisms, such as Peltier devices (actively transfer heat from one side to the other, for example, to another area where the heat dissipation is safer than the area of ​​the heat shield);

[0096] • The freezer (similar to a typical refrigerator) is located inside the boiler shell and is arranged to be essentially closed to DC power; and

[0097] • Airflow mechanisms, such as blowers, are arranged to draw in air from outside or inside the housing to provide the desired cooling effect.

[0098] The electric heating element can be wound around the pipe or component of the first circuit – benefits include ease of manufacture, reconfiguration, replacement / upgrade / repair (if needed) (because the heating element is located on the outside of the pipe / component (and the wet surface does not need to be in contact)). The heating element is easily visible and therefore easy to check (e.g., during regular maintenance) for degradation. This type of heating element is also easier to clean. This type of heating element is not affected by sludge in the water circuit (a problem that is common in radiator water circuits).

[0099] In other embodiments, the electric heating element can be placed inside the first loop conduit / pipe – benefits include compactness and less heat loss to the environment (heat is almost entirely retained in the desired water loop during normal heating operation).

[0100] In other embodiments, the electric heating element may be embedded in the wall of the water circuit conduit of the first loop - the advantage of which is that these elements are robust, less susceptible to damage from dirty water, and suffer less heat loss (compared to equivalent enclosed heating elements).

[0101] In other embodiments, heating may occur within a chamber (rather than within a tube). In such embodiments, the tube of the first circuit may lead to and exit the chamber, and one or more electric heating elements may be disposed anywhere within the chamber or embedded within the chamber wall or wrapped around the chamber wall, or any combination thereof. The advantage of using such a chamber, rather than heating the water / heating fluid simply as it passes through the fluid tube of the circuit, is that a longer or more circuitous path can be provided, and the heating fluid can be kept near the heating element for a longer period, during which more heat can be transferred (relative to a direct path through a straight section of tube).

[0102] In some other examples, depending on the specific application, there may be combinations of the types and arrangements of the electric heating elements used.

[0103] In another embodiment (not shown), the boiler comprises a hybrid electric-gas boiler vessel, rather than a vessel with only electric heating elements. In such an embodiment, multiple heating mechanisms are arranged within the same sealed boiler vessel chamber. One is an electric heating mechanism; another is a gas burner mechanism. Gas burner mechanisms are a known type. In addition to natural gas, another mechanism could be a burner for burning different fuels (e.g., hydrogen, propane, oil). The electric heating mechanism can be of any suitable form. In this example, it takes the form of an electric heating element. In such examples, the DC power supply will still be large enough to provide the electric heating element with enough power to provide all or most of the required heating of the fluid / water. In one example, the boiler can be arranged to heat water in a first circuit (e.g., for heating water to supply to a radiator circuit). The electric heating element or multiple such elements can be located anywhere within or around the burner vessel, such that the water can be heated by either or both of the gas and electric heating mechanisms. The heating element can be an electrical wire, which can be heated by allowing an electric current to flow through it and is appropriately arranged to transfer heat where needed (e.g., wrapped around a water pipe or baffle (or any other component within the burner vessel)).

[0104] A heat exchanger may be present within the gas burner container. The heat exchanger is arranged to concentrate heat from the combustion gases, heating electrical elements, or both onto the one or each water pipe. The heat exchanger may be made of metal or ceramic. In one example, the heat exchanger may be in the form of one or more plates (e.g., metal plates) arranged partially or completely around the water pipes. Electrical heating elements may be arranged between the plates. In another example, a large block of suitable material (e.g., a large block of ceramic) may be arranged around the water pipes.

[0105] Reference Figure 4 In another example, the water heater 200 includes a combined boiler arranged to heat water in a second loop (for heating and supplying drinking water) and a first loop (for heating and supplying heating fluid to the radiator network). The second loop has a different conduit arrangement, i.e., a different piping arrangement from the first loop, so that the fluids in the two loops do not meet (so that the drinking water is not contaminated by the radiator water).

[0106] Some components of boiler 200 are similar to those of boiler 100 and have similar reference numerals in the format 2xx instead of 1xx.

[0107] The boiler 200 includes a shell 202, which contains a first heater container 210, which contains a first heating element 208, a DC power supply 202, and a cooling system (not shown).

[0108] Relatively cold water from the first radiator circuit enters the boiler 200 via the cold radiator fluid inlet pipe 204, is heated, and then relatively hot water leaves the boiler 200 via the hot water outlet pipe 206 and reaches the first radiator network circuit.

[0109] Boiler 200 includes an electric boiler container 210 located within a housing 202 between an inlet pipe 204 and an outlet pipe 206. The electric boiler container 210 is a closed, sealed container containing a first electric heating element 208 arranged to heat water flowing through the container 210.

[0110] According to the invention, the first electric heating element 208 is powered by a combined DC-AC power supply. In this illustrative example, the combined power supply (similar to any previously described embodiment) is not shown in addition to the DC power supply; the combined power supply is in the form of a battery pack 220, which is also located within the housing 202. In this example, the boiler is an all-electric boiler, i.e., the heat source is entirely electric. In other examples, the boiler may be partially electric, for example, partially electric and partially gas-fired, or partially electric and partially fueled by other combustible fuels—suitable combustible fuels may be hydrogen or propane gas or suitable combustible oil or combustible solids or wood chips or any combination thereof. Thus, part of the heating power is provided by the (combined DC-AC) power supply, while part of the heating power is provided by a more conventional combustion fuel. This helps to increase redundancy within the system or can be used for efficient operation in environments where one or another power source is scarce. In the invention, the (combined AC-DC) power supply is large enough to supply the power output of all or almost all typical boilers, if desired.

[0111] In some such examples, such as those where the air intake is used to assist the combustion process (e.g., when burning gases or combustible fuels), the cooling system may include using the air intake to cool the battery pack and / or electronic components because the intake air is relatively cold; simultaneously, the air will be heated, making the combustion process more efficient. This can be achieved by positioning the air intake path near the battery pack or the components requiring cooling.

[0112] In this example, the DC power supply has a capacity of 5 kWh.

[0113] Other examples of modifications (e.g., hybrid electric power, AC-DC control, cooling configuration, etc.) are similar to the embodiments described previously (e.g., reference to...). Figure 3 The similarities described.

[0114] exist Figure 4 In this example, the hot water in the first boiler container 210 is also arranged to heat the water in the second circuit (without directly heating the water in the second circuit). The second circuit includes a drinking water circuit (e.g., supplying tap water for washing, bathing, drinking, etc.). Relatively cold water from the second circuit enters the boiler 200 via the main cold water inlet pipe 205 (which is supplied via the main water pipe), is heated, and then the relatively hot drinking water leaves the boiler 200 via the hot water outlet pipe 207 to reach the second tap circuit.

[0115] Between its input 205 and output 207, the second loop includes a tube section configured to transfer heat from the first container 210 to it. In this example, this is achieved by positioning the tube section adjacent to the container 210, allowing heat to be efficiently transferred to the tube section during use. The tube section includes a helical tube wound around the container 210 to further facilitate heat transfer therebetween. In another example, instead of the helical tube wound around the container, or in addition to the helical tube wound around the container, water is heated via a wet heat transfer chamber. This avoids the need to heat radiator water each time drinking water is heated. In such examples, water in either loop can be heated independently—tubes from both loops enter the heat exchanger container, where heating can occur in either or both loops.

[0116] The battery pack 220 is located on top of the housing 202, away from the heating container 210, and is isolated from the heating container 210 by a thermal shield (not shown), as described with respect to other examples.

[0117] Reference Figure 5 In another example, the water heater 300 includes a combined boiler arranged to heat water in a second circuit (for heating and supplying drinking water) and a first circuit (for heating and supplying heating fluid to the radiator network). Figure 5 The system and Figure 4 The system is similar (with similar reference numerals in the 3xx format instead of 2xx), except that the drinking water in the second loop is heated primarily by a different mechanism. The combined boiler 300 includes an electric boiler container 310, which is located within a housing 302 between an inlet pipe 304 and an outlet pipe 306. The electric boiler container 310 is a closed, sealed container containing a first electric heating element 308 arranged to heat the water flowing through the container 310.

[0118] According to the invention, the first electric heating element 308 is powered by a combined DC-AC power supply, which, apart from the DC power supply (not shown), takes the form of a battery pack 220, also located within the housing 202. In this example, the boiler is an all-electric boiler, meaning the heat source is entirely electric. In other examples, the boiler may be partially electric, such as partially electric and partially gas-fired, or partially electric and partially fueled by other combustible fuels—suitable combustible fuels may be hydrogen or propane, or suitable combustible oil or combustible solids or coverings, or any combination thereof. Thus, part of the heating power is provided by the (combined AC-DC) power supply, while part of the heating power is provided by a more conventional combustion fuel. This helps to increase redundancy within the system, or can be used for efficient operation in environments where one or another power source is scarce. In the invention, the (combined AC-DC) power supply (in fact, only the DC power supply) is large enough to supply the power output of all or almost all typical boilers, if desired.

[0119] In this example, the DC power supply has a capacity of 20 kWh.

[0120] and Figure 4 The opposite of the example, Figure 5 The example electric heating mechanism includes a second electric heating element arranged to efficiently transfer heat to water in a second circuit. In this example, boiler 300 includes a second electric boiler container 311 containing a second electric heating element 309 within the path of the second circuit between inlet pipe 305 and outlet pipe 307. In this example, a DC battery pack also powers the second electric heating element 309.

[0121] Various modifications can be made to this invention without departing from its scope.

[0122] Optionally, in examples where the heater comprises two (or more) heating elements (whether the heating elements heat fluids in a single loop or in different loops; or whether the heating elements are housed in the same heater container or in different heater containers), the controller is arranged to power the first heating element only via DC power and the second heating element only via AC power, or vice versa. This feature reduces the need for more complex loops, thereby reducing the risk of loop failure. Furthermore, if one source fails, the other source can still operate.

[0123] Optionally, in an example where the heater serves two (or more) loops, where fluid is heated (whether there are multiple heating elements or only a single heating element), the controller is arranged to use only DC power to power that one or each associated heating element when heating fluid in the first loop, and only AC power to power when heating water in the second loop, or vice versa. This feature takes into account that a particular power supply (AC or DC) is often more efficient for a particular fluid loop or fluid loop type (e.g., a radiator loop or a drinking water loop), and reduces the need for more complex loops, thereby reducing the risk of loop failure.

[0124] While examples of the invention have been described with respect to water boilers, the same inventive concept can be applied to other (partial or full) fluid heaters, such as air heaters (also called furnaces) common in North America. Such systems typically include a fan for blowing heated air—which is not shown in any of the figures for clarity. Systems for heating other fluids will be apparent to those skilled in the art.

[0125] Figures 6a to 6d An example of this is shown – according to this embodiment, the furnace heater 400 is arranged to provide heated (or cooled) air. The furnace 400 includes a housing 402, an air inlet 404, and a fan 406 located near the air inlet to draw air from the environment into the furnace housing 402. The housing also has an air outlet 408 through which the heated air exits the furnace housing. An air duct 410 is located between the inlet 404 and the outlet 408. Those skilled in the art will appreciate variations in this furnace air heater.

[0126] The furnace includes a heat exchanger 412 arranged to provide heat to air passing through duct 410. In this example, the heat exchanger is located inside the duct (but in other examples it may be located outside the duct). In this example, multiple electric heating elements 414 are located inside the body of the heat exchanger 412. The electric heating elements 414 are arranged to supply heat when powered by an electric current. The furnace includes a large DC power supply, in this example in the form of a six-cell DC battery pack (other configurations will be apparent). The DC power supply in this example includes a power supply of the type previously described with respect to the boiler. An AC power supply (not shown) is also arranged to power the heating elements. A controller (not shown) is arranged to control the power distribution from the DC and AC power supplies to the heating elements in a manner similar to that described above with respect to the boiler embodiment. In this example, the battery capacity is approximately 5 kWh – this value may differ in other examples discussed in relation to the previous examples. In this example, the power supply pack provides surge and steady-state power to the heating elements within the heated air delivery system.

[0127] In some examples, a second fluid loop for hot water is also provided—in such examples, on-demand hot water can be managed within the furnace via power electronics (used to power the furnace's electronics). The number / combination power of the DC power supply units is adjustable to meet specific installation requirements. In some examples, the power electronics are cooled by circulating air or other fluids and can be used to preheat airflow through ducts. Modular DC power supply units are designed for easy replacement and are located on an easily accessible side of the housing.

[0128] There is very little wasted space inside the furnace shell 402. The battery pack is both useful and fills what is usually empty space.

[0129] In other examples, the fluid heater includes a portable air heater (similar to the furnace described above but smaller). In such examples, the first circuit (as described in claim 1) is located within the standalone fluid heater itself. In such examples, the portable air heater includes a small blower connected to one or more electric heating elements (of the type described in relation to the previous examples), which are powered by a DC battery pack and an AC power source (e.g., mainline AC). The controller is arranged to control the power distribution from the DC and AC power sources to the heating elements in a manner similar to those described in the previously described embodiments. In some other examples, the portable heater does not have a blower; instead, the heater includes a natural convection heater or a radiation heater. In some such examples, the AC power source can be disconnected (or unavailable, e.g., during a power outage), and the heater can only be operated by DC power.

[0130] In such examples, the DC battery capacity can be at least 0.2 kWh, for example, about 0.5 kWh or about 1 kWh. In some examples, the peak power output can be a combination of a DC power supply of about 3 kW and an AC power supply of 3 kW.

[0131] The casing of this portable air heater is smaller than that of a typical furnace, for example, about 20 cm in diameter and about 35 cm in height.

[0132] In an example with multiple fluid loops, such as in a combined boiler example, in addition to the combined AC-DC power supply, there are other power sources. The first heating element can be arranged to heat the fluid in one of the first and second loops, and the combustion heater can be arranged to heat the fluid in the other loop of the first and second loops. For example, tap water is heated by the power source only, while hot water is heated by a combustible fuel source.

[0133] Each heater container can be equipped with more than one heating element.

[0134] For any embodiment described as purely electric, those skilled in the art will understand that it may be provided in the form of a partially electric – partially combustible fuel.

[0135] Any example may include a DC power interface arranged to receive DC power, wherein the DC power interface is configured to receive more than one type of DC power, such as nickel-metal hydride battery cell banks, nickel-cadmium battery cell banks, and lithium battery cell banks, or any hybrid bank containing a mixture of any of these cell types. Alternatively, or in addition to conventional DC battery banks, supercapacitors may be used to provide DC power.

[0136] Any example of a battery that includes a DC power supply may include a safety disconnect mechanism arranged to disconnect the battery from the power supply to the electric heating element. The safety disconnect mechanism may include a main switch or an automatic main switch; in some examples, the safety disconnect mechanism includes a contactor. Advantageously, this provides a safe and simple DC switching mechanism.

[0137] An electric heating element or battery, or both, together with a control mechanism (e.g., control electronics and / or software) for controlling the amount of heating provided by direct current, alternating current, or a combination thereof, can be modified into an existing electric, gas (or other combustible fuel), or gas-electric hybrid fluid heater to provide a fluid heater within the scope of this invention.

[0138] Compared to the aforementioned fluid heaters, the fluid heater of the present invention can be more powerful and efficient. Such examples are particularly suitable for retrofitting existing AC or gas boilers with electric heating capabilities. For example, the electric heating element can be coated, coated therein, sprayed, contained therein, wrapped around therein, partially or completely embedded therein, or otherwise associated with a conduit portion or nearby pipe portion: from its outlet to the combustible fuel burner container; to its inlet to the burner container; or both. The heating element can be powered by DC, AC, or a combination thereof. In some examples, a battery, such as a large battery of the aforementioned type, can be attached to the burner container along with a control mechanism (e.g., control electronics and / or software) to control the amount of heating provided by the electric heating element compared to the combustible fuel source. When attached to an AC boiler, a DC power supply and suitable control electronics can be added to use DC and AC power according to demand requirements and / or supply balance.

[0139] In examples where the circuit includes a heating water circuit such as a radiator circuit, the boiler / heater also includes a pump as known in the art, such as a water pump (not shown in any of the figures for clarity).

[0140] In examples where the circuit includes a drinking water circuit, the input typically comes from the main water supply, which is pressurized, and therefore a pump is not required. In some examples, a pump may be provided when the input comes from an unpressurized clean water source.

[0141] In any, all, or some embodiments, the battery charging mechanism is arranged to charge the DC power source in consideration of and in response to any one or more of the following: the current DC power source battery charge level; the capacity of the individual or each power source; the immediate demand for hot water or tap water; the predicted demand for heated water or tap water; the type of immediate or predicted available supply; and household demand, local demand, national demand, international demand, or any combination thereof.

[0142] Typically, battery packs are charged during off-peak hours, such as in the middle of the night or at midday (when the controller is informed that demand is generally low, or in some cases when the controller knows that demand is low).

[0143] In any of the described examples, the heating element can be any element that generates heat when an electric current passes through it, such as any resistance wire or arrangement of wires that generates heat when an electric current passes through it, for example (but not limited to):

[0144] Thin film (polyimide on a conductive metal);

[0145] Ceramic (ceramic sheath with embedded nickel-chromium-aluminum, etc.) wire;

[0146] Bare wire (nickel, nickel-chromium alloy, Kanthal, Stellite alloy, etc., tungsten);

[0147] Encapsulation lines - such as silicone sleeves and nickel-chromium alloys;

[0148] Mineral-insulated wires – copper-sheathed / nickel-chromium alloy, cupronickel / chromium-nickel-iron alloy, steel-sheathed / nickel, chromium-nickel-iron alloy-sheathed / nickel alloy wires, and various mixtures thereof. Components can be drawn to size or manufactured to final dimensions, etc. The insulation material is typically Al2O3 or MgO;

[0149] Ordinary electrical wires, spiral wires, and busbars with winding elements in the middle.

[0150] In any example describing a single heating element, it may be replaced by one or more different heating elements, as will be apparent to those skilled in the art. For example, one or more electric heating elements may be included on any one or more of the following conductive heating element coatings: the inner surface of at least one pipe wall; the outer surface of at least one pipe wall; and the surface of a combustion fuel heat exchanger, baffle, or any other component. One or more of the electric heating elements may include induction heating elements, for example, so that it / they can be powered by induction (without direct contact).

[0151] In some cases, multiple different electric heating elements are arranged to heat fluid in different sections of a conduit. In some examples, multiple different sections of the heating elements are positioned within the fluid conduit, and each section can be controlled together or separately, for example, providing different levels of heating at different locations. This is effective when the degree of combustion heating varies at different locations within the burner vessel—the electric heating element can provide less heating in sections where the burner can provide more heating, and vice versa. In another application, providing different levels of heating at different sections of the fluid path can be desirable, for example, during initial heating startup, when the fluid is first heated from cold, such as when a tap is first turned on. Because the initial input fluid is particularly cold, a stronger heating can be provided at the beginning of the fluid path than at the end.

[0152] In some of these examples, the components may be completely embedded in the fluid conduit, such that no part of them is exposed or protruding from the conduit (e.g., no external electrical connection points).

[0153] In some examples where the heating element is positioned in different areas (discontinuously along the entire length of the pipe), the gaps between the different areas can be created by covering the gap portions of the pipe during the coating / spraying process (e.g., using a spray mask).

[0154] In some examples, the present invention provides a single-shell fluid heater with an electrically heated element, which is arranged to be powered by both a large DC power supply and an AC power supply, and has an onboard controller and a controller cooling system. The inventors recognized that the components of this type of system have significantly different cooling requirements.

[0155] In examples incorporating a battery charging mechanism, the inventors further discovered that heat generation within the battery charging system can be a problem—particularly in AC-DC converter charging systems that allow voltage charging of DC battery packs / cells. This type of battery charging mechanism is not yet present in any boiler system or boiler housing and generates heat. Therefore, another advantage of some examples of the invention is the use of a cooling system (or providing another separate cooling system) as a radiator to cool the battery charging mechanism. A battery charging mechanism cooling system is particularly useful because charging can (and should) occur when the system is not heating the building or providing hot drinking water (e.g., at midnight). The cooling system of the present invention allows the operation of a heating system to filter out heat during charging. Even when the fluid does not require heating, the controller can be arranged to allow fluid to flow through a fluid heater system to cool the battery charging mechanism; for example, the controller can react in response to prediction or notification or sensing that the battery charging system should be cooled (e.g., through feedback from a temperature sensor located near the battery charger or after a minimum period of continuous battery charging threshold).

[0156] In some examples, the controller may be configured to provide a shower saving algorithm that switches to AC power only for the heating element if DC power is unavailable (e.g., if the battery is low or zero). Hot water (i.e., on demand when the tap is turned on) is supplied only by AC power; the supplied power is less than what a large DC power supply could provide. Therefore, the controller is programmed to ensure that there is always a minimum threshold of remaining DC capacity, for example, to allow for high-power showers. The user can selectively activate or deactivate this feature via a user interface that sends commands to the controller. In some examples, the minimum threshold of DC capacity may be 5% of the total backup battery capacity.

[0157] In some examples, the present invention provides a fluid heater that enables the safe supply of a large, modular power supply unit, which can be easily replaced within the heater housing. The large power supply unit has sufficient capacity to supply the entire heating load of a typical home. As previously mentioned, a power supply unit of this size is safely housed within the housing using thermal shielding. Because the battery charger cooling mechanism can typically operate at different times than the controller and battery cooling mechanism, it can include or incorporate a cooling mechanism separate from or different from the controller and battery cooling mechanism.

[0158] In some cases, there may be multiple cooling mechanisms, such as at least one cooling mechanism associated with the controller, at least one cooling mechanism associated with the battery, and at least one cooling mechanism associated with the battery charger.

[0159] In some examples, the cooling system may be a passive cooling system (instead of or in addition to the aforementioned cooling systems), arranged to remove heat from the component to be cooled (e.g., boiler electronics, DC power supply, battery charger, or any combination thereof). Passive cooling systems may not include flowing fluid. Passive cooling systems may include heat sinks (e.g., aluminum blocks, such as 20mm x 40mm x 80mm blocks with natural convection fins for dissipating heat into the environment). Passive cooling systems may include large thermal masses, such as heater housings.

Claims

1. A partially or fully electrothermal heater, said heater being arranged to heat fluid in a first circuit and a second circuit, the first circuit and the second circuit being separate configurations independent of each other, wherein, The fluid in the first circuit includes a heating fluid for a radiator, and the fluid in the second circuit includes tap water, wherein the heater includes a heater housing arranged to accommodate: A first heating element is arranged to heat a fluid in the first circuit and / or the second circuit; wherein the first heating element is arranged to be powered by an AC power source and a DC power source having a capacity of at least 1 kWh. A controller, configured to control the power distribution from a pulse-width modulated DC power supply and the AC power supply to the first heating element; and A cooling system that provides cooling to the controller. The controller is adapted to control the combination of the AC power supply and the DC power supply outputs in different ratios and distribute them to the first heating element. The heater housing is arranged to house the DC power supply, and the cooling system is arranged to provide cooling to both the controller and the DC power supply.

2. The heater according to claim 1, wherein, The DC power supply includes a battery pack.

3. The heater according to claim 1, wherein, The DC power supply has a capacity of at least 5 kWh.

4. The heater according to claim 1, wherein, The AC power source includes an AC power adapter arranged to connect to an external AC power source.

5. The heater according to claim 1, wherein, At any given time, the first heating element is arranged to be powered only by the DC power supply or the AC power supply.

6. The heater according to claim 1, comprising: A DC-AC converter between the DC power supply and the first heating element, such that the first heating element is arranged to receive AC power only from the AC power supply, or only from the DC power supply, or both; or An AC-DC converter is provided between the AC power source and the first heating element, such that the first heating element is arranged to receive DC power only from the AC power source, or only from the DC power source, or both.

7. The heater according to claim 1, wherein, The controller is configured to use only the DC power supply to power the first heating element when heating fluid in the first circuit, and to use only the AC power supply to power the first heating element when heating water in the second circuit, or vice versa.

8. The heater of claim 1 further comprises a second heating element arranged to heat the fluid in the first circuit, the second circuit, or both.

9. The heater according to claim 1, wherein, The controller is configured to take into account any one or more of the following when controlling power distribution: The capacity of each heating element, the capacity of each power source, the immediate demand for heated or tap water, the forecasted demand for heated or tap water, and the type of immediate or forecasted supply available.

10. The heater of claim 1, further comprising a battery charging mechanism in communication with the controller, wherein the battery charging mechanism is arranged to charge a DC power supply considering any one or more of the following: Current DC power supply battery charge level, capacity of each power source, immediate demand for heated or tap water, forecasted demand for heated or tap water, types of immediate or forecasted available supply, and household demand.

11. The heater of claim 1, further comprising a combustion heater arranged to heat the fluid in the first circuit, the second circuit, or both.

12. The heater according to claim 11, wherein, The first heating element is arranged to heat the fluid in the first circuit, and the combustion heater is arranged to heat the fluid in the second circuit.

13. The heater according to claim 1, wherein, The heater housing is arranged to house a first boiler vessel containing the first heating element, and the heater housing has dimensions of 390 to 440 cm wide, 270 to 365 cm deep, and 600 to 825 cm high.

14. The heater according to claim 13, wherein, The first boiler container includes a second heating element.

15. The heater according to claim 14, wherein, The shell is also arranged to house a second boiler vessel containing a second heating element.

16. The heater according to claim 1, wherein, The controller includes a hardware thermostat and an additional graphical user interface (GUI) thermostat.

17. A method of using a partial or complete electrothermal heater according to any one of claims 1-16 for heating a fluid, the method comprising controlling the power distribution from a pulse-width-adjustable DC power supply and the AC power supply to the first heating element.

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