HEATING ASSEMBLY FOR QUICK HEATING OF OCCUPIED SPACES

Abstract

A thermal system for the storage and release of heat is comprised of an electric heater in fluidic communication with a recirculation pump, a heat exchanger for transferring heat to a target space, and a plurality of control valves. The heater may act as its own reservoir, or a separate reservoir may be provided. Fluid within the reservoir is slowly heated at relatively low power levels and is then released quickly on demand just prior to occupying the target space.

Claims

1. A heating system for localized heating of a space comprising: an electric heater having an inlet and an outlet, the electric heater drawing from 300 to 300 1500 W; an expansion tank coupled to the outlet of the electric heater; a buffer tank having an inlet and an outlet; and a convector having an inlet and an outlet, the inlet of the convector coupled to the outlet of the buffer tank; a recirculation pump; and a diverter valve coupled to the outlet of the buffer tank, the diverter valve actuable to direct fluid flow from the buffer tank to one of the convector or the recirculation pump; wherein the heating system is operable in a charge mode and a discharge mode, in the charge mode, the diverter valve directing fluid flow from the buffer tank to the recirculation pump for recirculation through the electric heater, and in the discharge mode, the diverter valve directing fluid flow through the convector to heat a building space.

2. The heating system of claim 1, wherein the electric heater is an ohmic heater.

3. The heating system of claim 2, wherein the buffer tank is integrally formed with the electric heater.

4. The heating system of claim 1, wherein the electric heater is a resistive heater.

5. The heating system of claim 1, wherein the convector forms a component of an existing heating network.

6. The heating system of claim 1, wherein electric heater and the convector are configured such that the charge mode is substantially longer than the discharge mode.

7. The heating system of claim 1, wherein the volume of the buffer tank is from about 2 liters to about 10 liters.

8. The heating system of claim 1, further including a controller for activating the heater to maintain a set temperature within the heater assembly during the charge mode.

9. The heating system of claim 8, wherein the controller controls actuation of the diverter valve to change operation of the heating system between the charge mode and the discharge mode.

10. A method of supplementing an existing heating network with a heater assembly, the method comprising: providing the heating assembly with an electric heater for heating water, a buffer tank for storing the water, an expansion tank, a diverter valve, and a recirculation pump for recirculating the heated water through the electric heater and the buffer tank; connecting a fluid supply conduit of a convector of the existing heating network to an outlet of the buffer tank; connecting a fluid return conduit of the convector of the existing heating network to an inlet of the recirculation pump; and using the diverter valve to direct the heated water through a fluid circuit defined within the heating assembly to heat the water to a set temperature during a charge mode or directing the water to the convector of the existing heating network to supplement heat provided by the existing heating network to a building space to be heated during a discharge mode.

11. The method of claim 10, further including recirculating the water exiting the convector in the fluid return conduit back into the fluid circuit defined by the heater assembly during the discharge mode.

12. The method of claim 10, further including closing a flow control valve in the fluid supply conduit to the convector and in the fluid return conduit from the convector prior to connecting the fluid supply conduit to the outlet of the buffer tank and prior to connecting the fluid return conduit to the recirculation pump.

13. The method of claim 10, further including securing a housing of the heater assembly to a wall defining the building space to be heated.

14. The method of claim 10, further including automatically initiating the charge mode based upon factors including a power utilities rate schedule and the occupancy schedule for the building space.

15. The method of claim 10, further including integrating a controller of the heating system with building management system to optimize timing for initiating the charge mode.

16. The method of claim 10, further including isolating a fluidic circuit of the heating assembly from the existing heating network after the discharge mode.

17. The method of claim 10, further including initiating the discharge mode immediately prior to expected occupancy of the building space.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various aspects of the disclosed loading unit are described below with reference to the drawings, wherein:

[0029] FIG. 1 is a schematic diagram of a heating system in accordance with aspects of the disclosure;

[0030] FIG. 2 is a schematic diagram of an alternative version of the heating system shown in FIG. 1;

[0031] FIG. 3 is a schematic diagram of a portion of an existing heating network;

[0032] FIG. 4 is a side view of the portion of the existing heating network shown in FIG. 3 with the existing heating network modified to facilitate incorporation of the heating system shown in FIG. 2;

[0033] FIG. 4A is a side view of the portion of the existing heating network shown in FIG. 4 with the existing heating network modified to incorporate the heating system shown in FIG. 2; and

[0034] FIG. 5 is a side view of the portion of the existing heating network with the heating system shown in FIG. 2 incorporated into the network.

DETAILED DESCRIPTION

[0035] Although illustrative heating 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.

[0036] 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.

[0037] FIG. 1 illustrates a localized heating system according to aspects of the disclosure shown generally as heating system 10. The heating system 10 includes an electric heater 12, an expansion tank 14, a reservoir/buffer tank 16, and a convector 18 for exchanging heat with a target space (e.g., liquid-to-air heat exchanger, such as a fan coil unit). The heating system 10 also includes a recirculation pump 20, a three-way or diverter valve 22, and a network of pipes 24, and connectors 28 to provide a recirculating hydraulic path between the components of the heating system 10. In aspects of the disclosure, the outlet to the electric heater 12 is connected by pipes 24 to the expansion tank 14 and to the inlet of the reservoir/buffer tank 16, and the outlet to the reservoir/buffer tank 16 is connected to the convector 18 and to the inlet of the recirculation pump 20. The three-way or diverter valve 22 can be actuated to direct fluid flow to the convector 18 or to the inlet to the recirculation pump 20. This drawing is schematic and not necessarily to scale. The heating system 10 also includes temperature and pressure sensors that facilitate control of the fluid temperature and pressure within the heating system 10. In aspects of the disclosure, the components of the heating system 10 excluding the convector 18 are contained within a housing 60. Alternatively, the convector 18 may be positioned within the housing 60, and the housing 60 may include vent openings (not shown).

[0038] The electric heater 12 operates by directly heating the fluid, e.g., water flowing through the heater, specifically by directing electric current through the water itself so that the water is heated by conversion of electrical energy to heat within the water itself. In aspects of the disclosure, the electric heater 12 is an ohmic heater structured so that water flows through a series of channels including or defined by electrodes selectively connectible to poles of a power source, so that current can be directed through various current paths extending through the water. The electrodes may be graphite electrodes, and the series of channels may be surrounded by a core. Examples of ohmic heaters that can be used in conjunction with the heating system 10 include those disclosed in U.S. Pat. Nos. 7,817,906, 8,861,943, 11,353,241, 10,365,013, U.S. Pat. Appl. Pub. No. 2022/0268140, and U.S. Pat. Appl. Pub. No. 2021/0153302, the entire contents of each of which are incorporated herein by reference.

[0039] The ohmic heater 12 may include several baffles extending axially, external to the heating core, and internal to an outside shell of the heater 12, where such baffles desirably provide additional reservoir volume. Although aspects of the heating system 10 described here include a separate reservoir/buffer tank 16, it is envisioned that the ohmic heater 12 and the reservoir/buffer tank 16 could be integrated into a single unit having an expanded volume for containing an additional volume of water. In some aspects of the disclosure, the additional volume is defined between the baffles of the ohmic heater 12, so as to afford the required heating system volume within the ohmic heater 12 itself. An example of such an ohmic heater 12 is disclosed in the concurrently filed U.S. provisional application on even date herewith entitled Serpentine Recirculation Loop For Storage Of Heated Liquid and bearing Attorney Docket No. OHMIQ 3.8F-022, the entire disclosure of which is incorporated herein by reference.

[0040] In aspects of the disclosure, the reservoir/buffer tank 16 may be available off the shelf at minimal cost. Likewise, the convector 18 may be selected from one or more of a variety of commodity items readily and economically available. In some aspects of the disclosure, the convector 18 may be embodied by a fan coil unit, although the use of other types of convectors is envisioned. Further, the pipes 24, the three-way or diverter valve 22 and the connectors 28 may be selected from standard off-the-shelf items. In some aspects of the disclosure, the reservoir/buffer tank 16 (or the electric heater 12 itself) has a volume of between 2 and 10 liters. In certain aspects of the disclosure, the reservoir/buffer tank 16 has a volume of about 5 liters. However, the volume of the reservoir/buffer tank 16 is selected to meet a desired capacity of the heating system 10 and as such may be outside of this range (larger or smaller).

[0041] The heating system 10 has two modes of operation including a charge mode and a discharge mode. In the charge mode of operation, the heating system 10 is filled with water and the water is heated to steady state at a set high temperature of between about 95 C. and 105 C. During the charge mode, the three-way or diverter valve 22 is actuated to allow water flow from the reservoir/buffer tank 16 to the inlet of the recirculation pump 20, and water is forced by the recirculating pump 20 through the fluidic circulation path defined by the pipes 24, and the connectors 28. While the water is circulated through the heating system 10, the ohmic heater 12 heats the water directly on each pass of the water through the ohmic heater 12 with the net effect of increasing the overall temperature of the water in the heating system 10. The water is continuously directed through the reservoir 16, then the three-way valve 22, and back to the recirculating pump 20 to raise the temperature of the water within the heating system 10. As the water is heated, the volume of the water expands and is taken up in the expansion tank 14. The charge mode of the heating system 10 is completed when the water is heated to the set steady state temperature. At this time, the heater 12 and the recirculating pump 20 can be deactivated. If the temperature of the water within the heating system 10 drops below the set steady state temperature, the heating system 10 can be reactivated to recirculate the water back through the fluidic recirculation path and heat the water back to the set temperature.

[0042] The power required to charge the heating system 10 to a set steady state temperature is desirably low, e.g., 150 to 1500 Watts. In some aspects of the disclosure, the power required to charge the heating system 10 to a set steady state temperature is 300 to 1500 Watts. Accordingly, the charge mode may take a relatively long time, possibly several hours. The low power consumption allows installation of the heating system 10 into existing low-power circuits in existing buildings without drawing significant capacity from that circuit.

[0043] When commanded or activated by a control system, possibly by the arrival of personnel on a particularly cold morning, the heating system 10 is designed to go into the discharge mode. In the discharge mode, the three-way valve 22 diverts the flow of water from the reservoir/buffer tank 16 to the convector 18, while still using the recirculation pump 20. Water exiting the convector 18 is directed by the pipes 24 back to the inlet of the recirculation pump 20 and is recirculated though the fluidic circulation path until the no more or only a minimal amount of heat can be extracted from the water. At this point, the heating system 10 is deactivated or returned to the charge mode in which the three-way valve 22 diverts water flow from the convector 18 back to the recirculation pump 20. Depending on the capacity of the convector 18, heat can be extracted from the heated water via the convector 18 and discharged very quickly into an occupied space or into a space to be occupied, possibly in minutes. It is envisioned that a heating assembly 10 having a reservoir/buffer tank 16 having a 5-liter volume of fluid has the capacity to raise the temperature of a room 17 ft.17 ft10 ft from 55 C to 70 C in 3 to 5 minutes given reasonable estimates of air density, efficiency, and convector size. Once the discharge mode of the heating assembly 10 is completed, a typical building heating network 200 (FIG. 3) can be used to maintain the temperature within the occupied space at a comfortable level.

[0044] The heating system 10 can be mounted in occupied spaces, or spaces to be occupied, to supplement an existing heating network such as a heating network having a heat pump or boiler. The heating assembly 10 provides a quick and efficient means of adding capacity to the existing heat pump network at selected times of need and at specific locations of need without having to oversize the existing heating network.

[0045] FIG. 2 illustrates an alternative version of the heating system 10 shown generally as heating system 100 that may be incorporated directly into an existing heat network 200 (FIG. 3) in a building such as a network including heating unit 250 having a heat pump or an electric boiler. The heating system 100 is substantially like heating system 10 but does not include a convector. In contrast, the heating system 100 provides heated fluid, e.g., water to a convector 212 (FIG. 3) of the existing heating network 200 to supplement the capacity of the existing heating network 200 in a particular location within the building.

[0046] The heating system 100 includes an electric heater 112, an expansion tank 114, a reservoir/buffer tank 116, a three-way or diverter valve 122, a recirculation pump 124, and a network of pipes 126, valves 128, and connectors 130 to provide a recirculating hydraulic path between the components of the heating system 10. The components included in the heating system 100 are as described above regarding heating system 10 and will not be described in further detail herein. The heating system 100 includes a coupling 132 on the outlet pipe 134 from the reservoir/buffer tank 116 and a coupling 136 on the inlet pipe 138 to the recirculation pump 124. The diverter valve 122 can be actuated to direct water flow from the reservoir/buffer tank 116 to the inlet of the recirculation pump 124 or to direct water flow from the inlet pipe 138 to the recirculation pump 124. In some aspects of the disclosure, the components of the heating system 100 are contained within a housing 140 and the outlet pipe 134 and the inlet pipe 138 extend from the housing 140 such that the couplings 132 and 136 are positioned externally of the housing 140 in a position to be coupled to an existing heating network 200.

[0047] FIG. 3 illustrates a schematic diagram of a portion of a typical existing heating network 200. The heating network 200 includes a fluid supply conduit 202, a convector 204, and a fluid return conduit 206. The fluid supply conduit 202 delivers a heated fluid to the convector 204 where heat is extracted from the hot fluid and delivered to an occupied space or a space to be occupied to heat the space. The cooled fluid exits the convector 204 and is returned to the heating network 200 through the fluid return conduit 206. The network 200 includes an inlet flow control valve 210 in the fluid supply conduit 202 and an outlet flow control valve 212 in the fluid return conduit 206.

[0048] The heating system 100 (FIG. 2) is configured to be incorporated into an existing heating network 200 (FIG. 3) to supplement the heating capacity of the heating network 200 at a specific location within a building as described above. FIGS. 4 to 5 illustrate a method according to aspects of the disclosure for supplementing the heating capacity of an existing heating network 200 at a specific location within a building. To incorporate the heating system 100 into the existing heating network 200, the flow control valves 210 and 212 are closed to isolate the convector 204 from the network 200, and power to the convector 204 is disconnected. The fluid supply conduit 202 and the fluid return conduit 206 are cut (FIG. 4) and a valve 220 having an actuator 222 and a T-fitting 224 are installed into the fluid supply conduit 202 upstream of the convector 204. In addition, a T-fitting 226 is installed into the fluid return conduit 206 (FIG. 4A). Next, the outlet pipe 134 of the heating system 100 is connected to the T-fitting 224 in the fluid supply conduit 202 of the network 200, and the inlet pipe 138 of the heating system 100 is connected to the T-fitting 226 of the fluid return conduit 206 of the network 200.

[0049] The housing of the heating assembly 100 may be secured to a support structure of the building or structure near the convector 204 within the space to be heated using mounting brackets 260. For example, the mounting brackets 260 can be secured to studs in a wall or ceiling of the space to be heated.

[0050] Once the heating system 100 is incorporated into the existing heating network 200, the heating system 100 can operate in the charge mode to heat the fluid within the heating system 100. In the charge mode, the valve 128 is closed, and the diverter valve 122 directs fluid exiting the reservoir/buffer tank 116 into the recirculation pump 124 to recirculate the water through the electric heater 112 and the reservoir/buffer tank 116 to be heated to the set temperature. When the set temperature within the heating system 100 is reached, the recirculation pump 124 and the electric heater 112 are deactivated. During this period, the heating network 200 continues to deliver heating fluid to the convector 204. When additional heating is needed in a location within the building in which the heating assembly 100 is mounted, the heating system 100 switches to discharge mode to provide additional heat to the space in a fast and efficient manner. This switch from the charge mode to the discharge mode can be accomplished automatically with the controller described below. In the discharge mode, the valve 220 is actuated to close fluid flow from the fluid supply conduit 202 of the network 200, the valve 128 is actuated to allow water to flow through the outlet pipe 134, and the diverter valve 122 is actuated to direct flow from the reservoir/buffer tank 116 into the convector 204 of the network 200 via outlet pipe 134, and direct return flow from the convector 204 into the recirculation pump 124 via inlet pipe 138. The recirculation pump 124 recirculates fluid from within the heating system 100 through the convector 204 to quickly heat the space.

[0051] After the heating system 100 has completed the discharge mode, the valve 128 is closed, the valve 220 is opened to allow flow from the fluid supply conduit 202 of the network 200 back into the convector 204, and the diverter valve 122 is actuated to direct flow back to the recirculation pump 124 to recirculate the water though the heating assembly 100 when the charge mode is initiated.

[0052] A heater system 10, 100 in accordance with aspects of the disclosure depicted in FIGS. 1 and 2 may include a printed circuit board assembly (PCBA) configured to receive electrical power and control signals and to distribute power to the electrodes within the heater 12, 112 and to actuate the valves in the system. In aspects of the disclosure, rather than receiving control signals, the PCBA can include components that provide control functionality to provide power to the electrodes to operate the heater 12, 112, and to provide power to actuate the valves. This PCBA may 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.

[0053] In some aspects of the disclosure, the PCBA may 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.

[0054] In certain aspects of the disclosure, the PCBA may 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.

[0055] In aspects of the disclosure, the PCBA may include relay or switching circuitry such as switches that connect and disconnect power to various of the electrodes of the heater. In other aspects of the disclosure, the relay or switching circuitry may include switches that connect to different electrical potentials from a power source. The relay or switching circuitry may include solid-state switches, among other possibilities.

[0056] In other aspects of the disclosure, the PCBA may 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. The controller(s) may include and may execute firmware instructions. In some 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 or the valves of the heater system 10, 100. The control functionality may connect power to various of the electrodes at various times according to a predetermined operation, and/or process sensing signals provided by the sensing circuitry to perform various computations and may connect power to various of the electrodes based on the computations. For example, the one or more controller(s) may operate to direct power to various of the electrodes 2 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. The controller may direct or not direct power to various of the electrodes based 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.

[0057] In certain aspects of the disclosure, the PCBA may 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. The communication circuitry may communicate with a user device, such as a smartphone, tablet, or other user device, and/or 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 assembly and/or to view performance of the heater assembly, or use to update firmware within the heater assembly, among other possibilities. Such and other aspects are contemplated to be within the scope of the present disclosure.

[0058] In certain aspects of the disclosure, the software in the Ohmic heater's power supply controller is configured to determine the best strategy (subset of charged electrodes) for heating. The software will access a sorted table of strategies along with the conductivity required to achieve the desired current for each strategy. When heating begins, the software will start with the strategy generating the least amount of current and increment until a level just below the current limit is found. At this point, the software will collect metrics based on the actual current versus the expected current for that strategy to estimate the conductivity of the water. Once the software has confidence in the conductivity estimate, it will iterate through the strategies and pick one that will generate the current closest to the limit based on that conductivity of the water. If the controller is capable of utilizing a PWM duty cycle on the AC (current) signal, the software will calculate the strategy and duty cycle to achieve the current limit with the highest thermal in/out energy efficiency.

[0059] The software can initiate the charge mode of the heater assembly 10 to maximize energy and cost savings. If occupancy is set on a known schedule, the firmware may delay charge until several hours (the amount of time estimated to reach the temperature setpoint for the heater assembly 10) before occupancy to prevent the heating assembly 10 from maintaining the temperature setpoint within the heater assembly 10 for an extended period before initiating the discharge mode. If the power utility's TOU (Time of Use) rate schedule is known in addition to occupancy schedule, the software can schedule heating during the lowest available TOU rates (e.g., Off-Peak) balanced against the cost of maintaining heat during higher TOU rates. The software could also determine if it's more cost efficient to split heating across multiple TOU rate periods. If the occupancy schedule is not known, the software could track the pattern of when thermal energy is released and create a predictive heating schedule to operate the heating assembly 10.

[0060] The software can also integrate with other systems to use that data to optimize heating, such as the Building Management System (BMS). If the software has access to peak demand data of the building or facility, the software will optimize and adapt the heating schedule for one or more heaters to minimize the cost due to the utility charges demand rates. The software can additionally provide metrics to external services for analytics and further optimization of heating.

[0061] In aspects of the disclosure, the heating system 10 can be incorporated into an existing or new heat pump network. It is also envisioned that the heating system 10 can provide heating independently of an existing or new heat pump network.

[0062] In some aspects of the disclosure, the ohmic heater 12 can be supplanted by a heater of different technology, for example, a resistive heater.

[0063] In certain aspects of the disclosure, the heat pumps are supplanted by another centralized technology, for example, an electric boiler.

[0064] In aspects of the disclosure, the low power heating of the reservoir can develop significant heat that can be discharged quickly on demand to rapidly heat an occupied space when the outside temperature prohibits the heat pump or existing network from developing suitable inside temperatures.

[0065] It is a further aspect of this disclosure that the circulation loop of the heating system 10 can be tied to the main heat pump or existing network.

[0066] It is a further aspect of this disclosure that the volume required to house the heating system 10 is minimal, such that the heating system 10 could fit in a small enclosure, or in the walls of the building.

[0067] It is a further aspect of this disclosure that the charging power requirement is minimal.

[0068] Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary aspects of the disclosure. It is envisioned that the elements and features illustrated or described in connection with one exemplary aspect of the disclosure may be combined with the elements and features of another without departing from the scope of the disclosure. One skilled in the art will appreciate further features and advantages of the disclosure based on the above-described aspects of the disclosure. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.