Heating Assembly with Recirculation Loop for Storage of Heated Liquid

This application claims the benefit of the filing date of provisional U.S. Patent Application No. 63/568,740 filed on Mar. 22, 2024.

This disclosure is directed to electric water heaters, and more particularly to electric Point-Of-Use (“POU”) water heaters.

Water heaters intended for POU are known and are becoming more popular and pervasive. In particular, the ability to provide heated water across a wide temperature range is beneficial as it may obviate the need for a post-pour heater, such as a kettle, etc. In fact, POU water heaters can produce temperatures of water up to 100° C. Water temperatures in this range are conducive to the preparation of hot beverages, such as coffee or tea, directly from the faucet.

These POU water heaters can be found in top-end kitchens. They are typically installed beneath the sink, so they need to be relatively small. The use of electricity is prevalent as the heating energy. Since the electrical energy available in this location is limited, the heater operates in a storage mode. That is, there is a relatively long heating up period, after which hot water may be drawn at normal flow rates, to the extent of the volume of heated water already stored at the time of the pour.

illustrates a conventional water heaterthat includes a vesseldefining a volume into which a resistive heating elementis submerged. Representative examples of this can be found in the series of boiling water taps sold by Quooker UK LTD under the trademark QUOOKER®. The top of the water heateris provided with an upper flangethat is mounted to the upper end of the vessel, and a lower flangethat is mounted to the lower end of the vessel. The upper flangeand the lower flangeseal components of the water heaterto the vessel. The resistive heating elementextends from the upper flangeinto the vesseland includes a lower end that has a helical portionthat provides the majority of heating of the water within the vessel.

The operation of the water heateris relatively simple. It consists of filling the volume of the vesselwith cold water through a water inlet tube, then applying heat via the resistive heating elementto heat the water to some thermal setpoint. When a discharge valve of the faucet (not shown) is opened for a pour, cold water from a water main connected to the vesselpushes the hot water within the vesselthrough the faucet.

The helical portionof the resistive heating elementis located at the bottom of the vessel, ostensibly to effect some convective/buoyancy mixing of the water in the vessel. As the water in contact with the outer surface of the resistive heating elementheats up, the local density of the heated water decreases, and the heated water tends to rise within the vessel.

This type of heating water is random in nature. The buoyancy forces the heated water into indeterminate, unpredictable paths from the lower end of the vesseltowards the upper end of the vessel. The temperature within the vesselis therefor inconsistent. Provisions are made to selectively tap the hot water, but the thermal randomness of the volume precludes a consistent temperature during a pour from the faucet. The exclusive use of buoyancy forces for mixing hot water and cold water also constrains the operation of the water heaterto a vertical orientation.

Further, during the pour, cold water from the supply main is entrained into the vessel. Since mixing is inevitable, some cold water is delivered to the faucet along with the hot water. This adds further inconsistency to the pour temperature.

Finally, the static nature of the water in the vesselis conducive to overheating at the surface of the resistive heating element, accelerating scaling and degradation of the resistive heating element. Eventually the resistive heating elementwill burn out because the resistive heating elementwill not be able to conduct enough heat through the scaling.

Accordingly, further improvement in this area would be desired, including providing a POU water heater that has a more consistent water pour temperature.

Aspects of the disclosure are directed to a heater assembly for the heating a conductive liquid. The heater assembly includes a structure to define a circuitous fluidic circuit including a secures of baffles that define a first fluidic path of the fluidic circuit and an array of electrodes defining a second fluidic path of the fluidic circuit. The heater assembly includes a recirculating pump to continuously pump the liquid through the fluidic circuit during a heating stage of the heater assembly. The heater assembly also includes a fluid inlet and a fluid outlet to receive and discharge liquid from the heater assembly.

A further aspect of the disclosure provides for sufficient fluidic flow to result in a determinate, coherent flow to accommodate the heating within the electrode array. Such flow has sufficient ‘wash’ so that the thermal profile across the electrodes is essentially constant.

Aspects of the disclosure are directed to a system for heating water including a heater assembly, a recirculation pump, and a controller. The heater assembly includes an electric heater, a housing defining a water reservoir, and a continuous fluidic circuit defined within the water reservoir. The continuous fluidic circuit includes a first fluidic path and a second fluidic path. The first fluidic path has an inlet. The second fluidic path communicates with the first fluidic path and has an inlet, an outlet, and a circuitous configuration. The electric heater is positioned to heat water passing along the second fluidic path within the fluidic circuit. The recirculation pump is coupled to the fluidic circuit and operable to recirculate the water through the fluidic circuit. The controller is operable to actuate the electric heater to supply heat to the water passing through the second fluidic path of the fluidic circuit.

In aspects of the disclosure, the circuitous configuration of the first fluidic path is a serpentine configuration.

In some aspects of the disclosure, the circuitous configuration of the second fluidic path is a serpentine configuration.

In certain aspects of the disclosure, the electric heater is an ohmic heater and includes two or more electrodes that define a portion of the second fluidic path.

In aspects of the disclosure, the housing includes a sleeve that defines a cavity, and further including a heater support received within the cavity.

In some aspects of the disclosure, the electric heater is supported within the heater support.

In certain aspects of the disclosure, the heater support includes baffles that define the first fluidic path.

In aspects of the disclosure, the first fluidic path encircles the second fluidic path, and the electric heater is centrally located with the water reservoir.

In some aspects of the disclosure, the inlet of the second fluidic path is connected to the outlet of the first fluidic path, and the outlet of the second fluidic path is connected to the recirculation pump and to a faucet.

In certain aspects of the disclosure, the inlet of the first fluidic path is adapted to be coupled to a water source.

In aspects of the disclosure, the housing includes a sleeve having a first end and a second end, a first pressure plate secured to the first end of the sleeve, a second pressure plate secured to the second end of the sleeve, a power cap secured to the first end of the sleeve, and an end cap secured to the second end of the sleeve.

In some aspects of the disclosure, the power cap and the end cap define portions of the first fluidic path and the second fluidic path.

In certain aspects of the disclosure, the heater assembly includes a temperature sensor, and the controller is electrically coupled to the heater, the temperature sensor, and the recirculation pump and is operable to maintain the fluid at a setpoint temperature.

In aspects of the disclosure, the second fluidic path includes channels, and the aspect ratios of each of the channels defining the second fluidic path is greater than 1.

In some aspects of the disclosure, the channels of the second fluidic path are configured such that the water flow through the second fluidic path has a Reynolds number of greater than 4000.

Other aspects of the disclosure are directed to a heater assembly including a housing defining a reservoir, a fluidic circuit, and an electric heater. The fluidic circuit is defined within the reservoir and has a first fluidic path and a second fluidic path. The first fluidic path has an inlet, and an outlet. The second fluidic path communicates with the first fluidic path and has an inlet, an outlet, and a circuitous configuration. The first fluidic path is connected to the second fluidic path to facilitate recirculation of fluid through the fluidic circuit. The electric heater is positioned to heat water passing along the second fluidic path. The inlet of the first fluidic path is adapted to be coupled to a water source and the outlet of the second fluid path is adapted to be connected to a faucet.

In aspects of the disclosure, the second fluidic path includes channels having an aspect ratio greater than 1 and is configured such that water flow through the second fluidic path has a Reynolds number greater than 4000.

In some aspects of the disclosure, the circuitous configuration of the second fluidic path is a serpentine configuration.

In certain aspects of the disclosure, the electric heater is an ohmic heater and includes two or more electrodes that define a portion of the second fluidic path.

In aspects of the disclosure, the housing includes a sleeve that defines a cavity, and the heater assembly includes a heater support that is received within the cavity

In some aspects of the disclosure, the electric heater is supported within the heater support.

In certain aspects of the disclosure, the heater support includes baffles that define the first fluidic path.

In aspects of the disclosure, the first fluidic path encircles the second fluidic path, and the electric heater is centrally located with the reservoir.

Although illustrative systems of this disclosure will be described in terms of specific aspects, it will be readily apparent to those skilled in this art that various modifications, rearrangements, and substitutions may be made without departing from the spirit of this disclosure.

For purposes of promoting an understanding of the principles of this disclosure, reference will now be made to exemplary aspects illustrated in the figures, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended. Any alterations and further modifications of this disclosure features illustrated herein, and any additional applications of the principles of this disclosure as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of this disclosure.

As used herein, a POU water heater is a compact heating device installed directly at the location where hot water is needed that allows for instantaneous hot water delivery.

illustrate a heater assemblyin accordance with aspects of the disclosure. The heater assemblyincludes a printed circuit board assembly (PCBA), electrodes(), a first pressure plate, a second pressure plate, a power cap, an end cap, and a sleeve. The first pressure platesupports the PCBAand defines a fluid inletfor introducing fluid, e.g., water, into the heater assembly. In aspects of the disclosure, the fluid inletis adapted to be connected to a fluid supply, e.g., a water main. The sleevedefines a cavity() and is configured to resist hoop stresses due to hydraulic pressure within the heater assembly. The sleevemay have a cylindrical configuration although other configurations are envisioned. The sleevemay include a first flangepositioned at the first end of the sleeveand a second flangepositioned at the second end of the sleeve. The first and second flangesandfacilitate securement of the sleeveto the first and second pressure platesand, the power cap, and the end cap. The power capis clamped between the first pressure plateand the first flange, and the end capis clamped between the second pressure plateand the second flange. In aspects of the disclosure, screwsare used to secure the power capand the first pressure plateto the first flangeand to secure the end capand the second pressure plateto the second flangealthough other securement devices and techniques are envisioned. The first and second pressure platesandresist axial reaction loads from hydraulic pressure within the sleeve. In aspects of the disclosure, the power capand the end capare configured to define a portion of a fluidic circuit “C” () defined within the heater assemblyas described in further detail below. In some aspects of the disclosure, the power capincludes structure to support the electrodessuch that the electrodesextend from the power capthrough the sleevetowards the end cap. The pressure platesand, the power cap, the end cap, and the sleeve, when secured together, define form a housing that defines a reservoir.

In some aspects of the disclosure, the sleevemay include or support mounting bracketsandthat are configured to support the heater assemblyto an adjacent structure. In certain aspects of the disclosure, the mounting bracketsandare formed integrally with the first and second flangesand. Alternately, the mounting bracketsandmay be formed independently of the flangesand.

illustrates a heater supportthat is received within the sleeve() and may have a configuration that corresponds to the configuration of the cavitydefined by the sleeve. Although the configuration of the cavityis shown to be cylindrical, other configurations are envisioned. The heater supportincludes an outer wall, internal bafflesthat extend from the outer wallinto the cavityof the sleeve, and a carrier. In aspects of the disclosure, the carrieris centrally located within the outer wallof the heater supportalthough other configurations in which the heater supportis not centered within the heater supportor within the reservoirare envisioned. In some aspects of the disclosure, the carrierdefines external channelsthat extend from the first end of the carrierto a second end of the carrierand receive ends of the internal bafflesto support the carrierwithin the sleeve. Alternatively, it is envisioned that components of the heater supportincluding the outer wall, the internal baffles, and the heater supportmay be integrally formed. The baffles, the power cap, and the end capare configured to define a first fluidic path “A” that is circuitous (). In some aspects of the disclosure, the first fluidic path “A” extends around or encircles the carrieras described in further detail below. In some aspects of the disclosure, the first fluidic path “A” has a serpentine configuration although other circuitous configurations are envisioned.

The carrieris illustrated as having a rectangular configuration and includes internal walls. In aspects of the disclosure, the internal wallsdefine longitudinal channelsthat receive and support the electrodeswithin the carrierin spaced relationship to each other. Alternatively, it is envisioned that the electrodescan be supported within the carrierin a variety of manners. The electrodesare spaced from each other to form channels that define a second fluidic path “B” () through the carrierthat is circuitous. In some aspects of the disclosure, the second fluidic path “B” may have a serpentine configuration although other configurations are envisioned. In aspects of the disclosure the first circuitous path “A” and the second circuitous path “B” define the fluidic circuit “C” within the heater assembly. It is envisioned that the carriercan have a variety of different configurations.

The heater supportprovides electrical isolation, and in that regard is desirably constructed from a dielectric or electrically-insulative material. The carrierprovides structural support for the electrodesto position the electrodesin an array for supplying electricity to the fluid, e.g. water, to thereby heat the water.

In some aspects of the disclosure, the heater assemblyincludes a PCBAas depicted in. The PCBAis configured to receive electrical power and control signals and to distribute power to the electrodes. In certain aspects of the disclosure, rather than receiving control signals, the PCBAcan include components that provide control functionality to provide power to the electrodesto operate the heater assembly. The PCBAmay include various electrical components, such as power management circuitry, sensing circuitry, relay or switching circuitry, one more controller(s), one or more memory, and/or communication circuitry, among other possible components.

In aspects of the disclosure, the PCBAmay include power management circuitry which manages voltage and/or current, such as AC/DC converters, step-up converters, step-down converters, and/or waveform shaping circuitry (e.g., pulse width modulation circuitry), among other possibilities.

In aspects of the disclosure, the PCBAmay include sensing circuitry such as voltage sensors, current sensors, and/or circuitry that interfaces with sensors in the heater, such as circuitry that interfaces with temperature sensors in the heater, for example. The sensing circuitry may include, for example, amplifiers and/or analog-to-digital converters, among other possibilities.

In aspects of the disclosure, the PCBAmay include relay or switching circuitry such as switches that connect and disconnect power to various electrodesin the array of electrodes. The relay or switching circuitry may include switches that connect to different electrical potentials from a power source, or solid-state switches, among other possibilities.

In aspects of the disclosure, the PCBAmay include one or more controller(s), which may include any type of device that can provide control and/or computing functionality, such as microcontrollers, microprocessors, central processing units, and/or digital signal processors, among other possibilities. In some aspects of the disclosure, the controller(s) may include and may execute firmware instructions. In certain aspects of the disclosure, the controller(s) may execute machine-readable instructions accessed from the one or more memories, which may include volatile memory (e.g., random access memory, etc.) and/or non-volatile memory (e.g., EEPROM, etc.). The machine-readable instructions may implement control functionality, such as controlling operations of the heater assembly. In aspects of the disclosure, the control functionality may connect power to various electrodesof the array of electrodes at various times according to a predetermined operation. The control functionality may also process sensing signals provided by the sensing circuitry to perform various computations and may connect power to various electrodesof the array of electrodes based on the computations. For example, the one or more controller(s) may operate to direct power to various electrodesof the array of electrodes in different cycles. As another example, the controller(s) may receive an input reflective of a set point temperature and receive sensing signals reflective of measured temperatures in the heater assembly. The controller may direct or not direct power to various electrodesof the array of electrodesbased on the set point temperature and the sensing signals reflective of the measured temperatures. Various other operations are described below herein. All such operations are contemplated to be within the scope of the present disclosure.

In aspects of the disclosure, the PCBAmay include communication circuitry, such as wireless communication circuitry enabling communication using technologies such as Wi-Fi, Bluetooth, and/or cellular communications, among other wireless communication technologies. In some aspects of the disclosure, the communication circuitry may communicate with a user device, such as a smartphone, tablet, or other user device. In certain aspects of the disclosure, the communication circuitry may transmit information to and/or receive information from a cloud system. The information communicated by the communication circuitry may be used in various ways, such as used by a user app to control operation of the heater and/or to view performance of the heater, or use to update firmware within the heater, among other possibilities. Such and other embodiments are contemplated to be within the scope of the present disclosure.