PELLET STOVE

Abstract

One or more techniques and/or systems are disclosed for a pellet stove system that incorporates a thermoelectric generator for efficient electricity generation. The system features a combustion chamber for burning pellet fuel, a heat exchanger to transfer generated heat to an external environment, a heat sink to transfer a portion of the generated heat to a thermoelectric generator comprising a first portion thermally coupled to the heat sink and a second portion designed to maintain a lower temperature. This arrangement allows the generation of electricity through the temperature difference, powering stove components. Additionally, the system can include mechanisms for remote monitoring and control, optimizing fuel consumption, and enhancing heat distribution, facilitated by a control unit and wireless communication module.

Claims

1. A pellet stove for providing heat to a heated space comprising: a heat exchanger; a combustion chamber for combusting pellet fuel to generate heat at the heat exchanger an auger that transports the pellet fuel to the combustion chamber from a storage hopper; an exhaust that removes combustion gas out of the pellet stove; an air intake that receives outside air due to convection from outside of the pellet stove and directs the outside air across the heat exchanger resulting in heated air; and air outlet that directs the heated air out of the pellet stove into a heated space; and a thermoelectric generator that generates electricity comprising: a first thermoelectric portion, wherein heat is transferred from the combustion chamber to a heat sink thermally coupled to the first thermoelectric portion; and a second thermoelectric portion thermoelectrically coupled to the first thermoelectric portion, wherein heat is removed from the second thermoelectric portion through a cool sink thermally coupled to the second thermoelectric portion, wherein a temperature difference between the first thermoelectric portion and the second thermoelectric portion generates electricity; and at least one cooling fan disposed within the pellet stove, wherein the cooling fan directs air across the cool sink resulting in a reduction of temperature of the second thermoelectric portion.

2. The pellet stove of claim 1, further comprising a sensor that detects one or more environmental conditions in the environment around the stove.

3. The pellet stove of claim 1, further comprising a sensor that detects one or more operating conditions of the stove.

4. A pellet stove system comprising: a combustion chamber for burning pellet fuel to generate heat; a heat sink configured to transfer heat from the combustion chamber; and a thermoelectric generator comprising: a first thermoelectric portion thermally coupled to the heat sink to receive heat therefrom; and a second thermoelectric portion thermoelectrically coupled to the first thermoelectric portion, wherein the second thermoelectric portion is operably cooler than the first thermoelectric portion, and wherein a temperature differential between the first and second thermoelectric portions results in generation of electricity.

5. The pellet stove system of claim 4, wherein the thermoelectric generator is configured to power at least one electrical component of the pellet stove.

6. The pellet stove system of claim 5, wherein the thermoelectric generator is in electric communication with an internal battery storage to charge the internal battery storage.

7. The pellet stove system of claim 4, further comprising a cool sink thermally coupled to the second thermoelectric portion for dissipating heat therefrom.

8. The pellet stove system of claim 7, wherein the cool sink is fluidly coupled with a cooling fan to facilitate heat dissipation from the cool sink.

9. The pellet stove system of claim 4, further comprising an auger mechanism that feeds pellet fuel from a storage hopper to the combustion chamber.

10. The pellet stove system of claim 4, further comprising a control unit programmed to adjust the operation of the stove based on detected environmental conditions outside of the pellet stove.

11. The pellet stove system of claim 10, wherein the control unit is wirelessly connected to a network allowing for remote monitoring and control.

12. A pellet stove comprising a thermoelectric generator, the thermoelectric generator comprising: a first thermoelectric portion configured to be receive by a combustion chamber of the pellet stove; a second thermoelectric portion configured to operate at a lower temperature than the first thermoelectric portion; and thermoelectric generation portion disposed between the first and second thermoelectric portions, wherein the thermoelectric generation portion operably generates electricity from a temperature differential between the first and second thermoelectric portions.

13. The pellet stove of claim 12, wherein the thermoelectric generator is configured to output electricity to external devices disposed in the pellet stove.

14. The pellet stove of claim 12, further comprising an exhaust system for venting combustion gases and drawing in outside air by convection across a heat exchanger disposed in the pellet stove.

15. The pellet stove of claim 12, wherein the thermoelectric generator portion comprise one or more of: bismuth telluride, lead telluride, or silicon germanium.

16. The pellet stove of claim 12, further comprising a power management unit configured to optimize generation of electricity for use or storage.

17. The pellet stove of claim 12, further comprising insulation materials disposed around the first thermoelectric portion resulting in an increase in heat retention and electrical generation efficiency.

18. The pellet stove of claim 12, wherein the thermoelectric generation portion is electrically coupled to at least one battery in a battery storage system, and generated electricity is stored in the at least one battery.

19. The pellet stove of claim 12, comprising a control unit that controls one or more portions of the pellet stove, and generated electricity operably powers the control unit.

20. The pellet stove of claim 19, wherein the control unit comprises a wireless communication module that operably provides operational data of the pellet stove to a remote user interface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIGS. 1A and 1B are component diagrams illustrating an example pellet stove where one or more portions of one or more techniques and/or one or more systems described herein may be implemented.

[0009] FIG. 2A is a component diagram illustrating an example pellet stove where one or more portions of one or more techniques and/or one or more systems described herein may be implemented.

[0010] FIG. 2B is a component diagram illustrating an example pellet stove where one or more portions of one or more techniques and/or one or more systems described herein may be implemented.

[0011] FIGS. 3A and 3B are diagrams illustrating an example implementation of a display screen where one or more portions of the systems described herein may be implemented.

[0012] FIG. 4 is a diagram illustrating an example implementation of the thermoelectric generator.

[0013] FIG. 5 is a circuit diagram illustrating an example implementation of the thermoelectric generator.

[0014] FIG. 6 is a diagram illustrating an example implementation of the thermoelectric generator module in an example pellet stove.

[0015] FIG. 7 is a flowchart diagram illustrating one implementation of the heat transfer process of the thermoelectric generator within the pellet stove.

DETAILED DESCRIPTION

[0016] The claimed subject matter is now described with reference to the drawings, wherein like reference numerals are generally used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. It may be evident, however, that the claimed subject matter may be practiced without these specific details. In other instances, structures and devices are shown in block diagram form in order to facilitate describing the claimed subject matter.

[0017] In one aspect, a pellet stove can be devised that operates to provide heat, and also generates electrical energy. In some implementations, in this aspect, typical pellet stove technology can be included, such as a stove that comprises a burner box, where combustion of the fuel takes place, a fuel feeder component that provides fuel to the burner box at a predetermined rate, a fuel hopper that stores bulk fuel, and an exhaust system that removes exhaust gases created by combustion.

[0018] Additionally, in some implementations, a control unit can be used to exercise fine-grained control over the functions of the stove, based at least on user input, environmental conditions, and data indicative of conditions of the stove. Further, in some implementations, the control unit may be communicatively coupled with a local and/or remote device/system to provide remote control and allow a user to view settings and use conditions.

[0019] In some implementations, a pellet stove comprises a combustion chamber, inside which is disposed a fire pot. Combustion occurs in the fire pot and is supported by outside air that is introduced into the combustion chamber and fuel introduced into the fire pot. In some implementations, combustion air will be introduced into the combustion chamber at the top of the stove door, for example, to help keep ash and debris from accumulating on the door, and obscure visibility. An exhaust blower draws combustion products from the combustion chamber and directs it out of venting, such as at the rear or top of the stove. The venting is typically coupled with a vent/chimney that leads to the outside of an occupied space.

[0020] A hopper or storage bin can be disposed in, or coupled with, the stove, where bulk fuel material can be stored. The hopper is typically tapered toward the bottom to allow the fuel pellets to flow downward. An auger is disposed in an auger tube, and rotation of the auger collects fuel from the hopper and transfers it to a fuel chute that leads to the fire pot. That is, fuel pellets can be lifted from the bottom of the hopper, and dropped into a fuel chute that leads to the fire pot. The pellets are dropped into the fire pot where combustion occurs and is sustained. In some implementations, a convection blower can propagate air (e.g., from outside, and/or recirculated from the occupied space) along the outside of the combustion chamber, where it is heated from the heat of the chamber and is directed into the occupied space to provide heat. The convection blown air is not mixed with combustion gases, and merely passes along heated places in the stove to become heated air.

[0021] In a further implementation, the combustion chamber can also transfer heat to a thermoelectric generator positioned within the stove. In such an implementation, the thermoelectric generator comprises a first thermoelectric portion and a second thermoelectric portion, wherein the heat from the combustion chamber is transferred to first thermoelectric portion, resulting in a temperature difference between the first thermoelectric portion and the second thermoelectric portion. The temperature difference creates a voltage difference by way of the Seebeck effect, resulting in electricity production. The first and second thermoelectric portions can be composed of high-efficiency thermoelectric materials, including but not limited to bismuth telluride, lead telluride, silicon germanium, carbon allotropes, copper chalcogenides and other half-Heusler compounds, specifically chosen for their superior thermoelectric performance and durability under high-temperature conditions. These materials can be arranged in a series of thermocouples which can convert heat directly into electrical power.

[0022] The first thermoelectric portion can be oriented near the stove's combustion chamber, where the temperatures are high, to exploit the thermal energy produced during pellet combustion. In a further implementation, the second thermoelectric portion can be thermally coupled to a heat dissipation system. The heat dissipation system can include a heat sink and a fan configured to cool the second thermoelectric portion, maintaining the desired temperature gradient for continuous and optimal electricity production between the first thermoelectric portion and the second thermoelectric portion (hereafter when together referred to as the TEG modules).

[0023] In one implementation, the control unit of the stove can be designed to manage the operation of the thermoelectric generator alongside the primary heating function. The control unit can monitor the temperature differential across the thermoelectric modules, adjusting the stove's combustion rate and the cooling system's activity to optimize electricity generation without compromising heating efficiency. This control unit functionality allows for a dynamic response to changes in stove usage or ambient conditions, ensuring that the electricity generation is optimized under varying operational conditions.

[0024] In further implementations, the electrical power generated by the TEG modules can be managed by a power management unit (PMU), which can include a microcontroller-based system for real-time monitoring and control. This unit can include maximum power point tracking (MPPT) technology to ensure that the TEG modules operate at their most efficient point despite fluctuations in the temperature gradient. Thus, the PMU can efficiently convert the generated power to the required voltage and current specifications for direct use in household applications, charging batteries, or powering the stove's internal components. The power management unit may include protective circuits to safeguard against overvoltage, overcurrent, and thermal overload conditions.

[0025] In one implementation, the hopper can be filled with appropriate fuel pellets, and power to the unit can be activated, such as by engaging a button or the like, to begin activation of the stove. In this implementation, the stove comprises a control unit that comprises a microcontroller, memory and at least one processor. Data indicative of one or more programs can be stored in the memory, where the programs are configured to operably direct the stove to perform specific functions, based on preprogrammed events, and/or data indicative of real-time information from the environment, the stove, and/or user input. The processor(s) can be configured to operably run the program(s) using input data, which may comprise timed events, sensor data, user input, etc. As an example, when the power button is operated, thereby powering up the stove, the following programs may be run, resulting in certain functions in the stove.

[0026] In some implementations, a cleaning cycle can be activated, where one or more components (e.g., fans, actuators, etc.) actively remove (e.g., draw out) dust, ash and other remnants from the fire pot. In this way, a substantially clean fire pot is positioned to begin a new combustion cycle. A fuel feeding cycle can begin, where the auger is operated to draw pellets from the hopper to the chute, and into the (clean) fire pot. As an example, depending on the type and size of stove, the cycle may run for a predetermined amount of time (e.g., 1-20 mins.) sufficient to provide enough pellets to the fire pots to begin and initially sustain combustion. A lighting cycle can operate, where an ignition source is provided to the fire pot.

[0027] As an example, an electrically powered hot surface can be operated to heat the pellets to their combustion point in the fire pot. In other example, a gas-powered flame, a plasma arc, or other ignition source may be provided. In this example, the ignition source can be operated for a sufficient amount of time to generate sufficient combustion of the fuel. In one implementation, the temperature of the exhaust gases (e.g., smoke) can be detected, and when a threshold temperature is met that is indicative of sufficient combustion (e.g., sufficient to continue to burn), the ignitor cycle may be ended. That is, for example, a temperature sensor may be disposed in the exhaust flue, and the temperature sensor can send data indicative of the temperature to the control unit. The control unit can use the data to determine when to turn the ignitor cycle off (e.g., using the program running on the processor). In some examples, the ignition cycle may run for about 8 minutes.

[0028] Further, in some implementations, a stabilization cycle may begin. In this implementation, the stove/heater can use a preselected temperature (e.g., preprogrammed, and/or from user input) to fine tune the output of the stove/heater. That is, for example, the user may select a desired temperature output (e.g., using a remote, connected device, or on stove user interface (UI)), and/or a desired temperature for the occupied space, and the stove/heater can set operation of the stove components to settings that are configured to achieve the preselected temperature. For example, the flow rate of fuel, that is the amount of fuel moved from the hopper to the fire pot per time unit (e.g., pounds per hour) can be adjusted to meet the desired temperature (e.g., based on predetermined calibration); the flow rate/amount of combustion air introduced to the combustion chamber can be adjusted; the flow rate of the exhaust flow; and the flow rate of the convection air can all be adjusted to meet the desired temperature.

[0029] Powering down the unit can be undertaken, for example by engaging the power button or some other appropriate means, in order to power down the pellet stove. In some implementations, the stove can progress through a shut-down procedure, such as one stored in memory and processed by the processor on the control unit. In this example, fuel remaining in the fire pot can continue to burn and produce heat and flame. The auger that directs fuel to the fire pot from the hopper will discontinue operation so that no new fuel is added to the fire pot. After a period of time (e.g., 5-8 minutes) the fuel in the fire pot may be depleted, and the heat exchanger may begin to cool. Further, in this example, once the stove temperature has reached a predetermined threshold temperature (e.g., cooled to a desired point), a message can be displayed on the display screen that alerts the user that the shutdown has completed (e.g., shut down complete; goodbye; etc.).

[0030] In some implementations, the stove may be a smart stove with wireless communications capabilities. That is, for example, the stove may comprise a Wi-Fi (e.g., or Bluetooth, or other short-range communications protocol) communications module that is coupled with the control unit. In this way, for example, the stove can be communicatively coupled with a local and/or remote network to send and receive data from a coupled device (e.g., computer, portable smart device, server, cloud-based application, etc.). As an example, the local or remote communication may provide enhanced capabilities for the use of the stove by a user.

[0031] In one example, the stove may be monitored, controlled, and/or programmed by using a smart stove application on a user's smart device (e.g., phone). The application may be resident on a remote server and available for the user to download or access through a remote communications protocol (e.g., the Internet, cloud-based services, etc.). In this implementation, the user may be provided a unique identification (e.g., password) for the stove, which enables them to access features of the stove remotely. As an example, the communications module on the stove, in conjunction with the control unit, can help pair the stove with the local network, and with the local device using the unique identification.

[0032] Using the application, a user may be able to change the name and/or identification of the stove, which may be useful if the user has more than one stove or smart device connected in the application. In some implementations, the connection with the stove may be shared with other devices by sending the connection information to a third-party. Using the application, the user can select a predetermined temperature and/or operation setting for the stove, which can be programmed into the control unit remotely. For example, the user can select a desired room temperature, and the stove will be programmed to operate (e.g., feed fuel, run the fans, etc.) at least until the desired temperature is met (e.g., determined using a temperature sensor that communicates with the control unit). In some implementations the stove and application may have an ECO Mode that be selected to conserve fuel and/or electricity while maintaining the desired predetermined temperature. For example, selecting the ECO Mode button on the application (e.g., or external user interface of the stove) can put the stove into ECO Mode. In this made, the stove will shut off when the desired temperature is reached and turn back on when the temperature drops to a preset factory setting. In a second ECO mode, the stove can activate a minimum power setting that provides enough electrical power to minimally operate once the stove has reached the desired temperature. When it drops to the preset factory level, a higher power setting can be activated until the desired temperature is met once more.

[0033] In some implementations, the stove's setting using that remote communication may comprise a preset number of configurations. For example, the various configuration may adjust the speed of the combustion fan and the room air circulation fan to adjust the amount of power and fuel used. As one example, a preset #1 may comprise maximum power use; preset #2 may comprise medium power use; preset #3 may comprise low power use; and preset #4 may comprise minimum power use.

[0034] FIGS. 1A and 1B, and 2A and 2B, are component diagrams that illustrate one example implementation of a pellet stove, as described herein. In conjunction with the description above, the pellet stove 100 typically comprises an outer metal housing 102, and a door 104 that sometimes has a window 106. A fire pot 108 is disposed inside the combustion chamber 110 (e.g., or firebox), and the fuel chute 112 leads fuel pellets 150 from the auger 114 to the fire pot 108. The hopper 116 is used for bulk storage of fuel pellets 150 and has an opening in the bottom to release pellets from bulk storage to the auger 114, where they are taken up by the and dropped into the chute 112. The auger 114 is a rotating screw with thread-like protrusions to drive the fuel upward, which is operated by an electrically power motor 128. The hopper 116 can comprise a shape that tapers from the top to the bottom to provide for more reliable pellet transfer to the auger 114.

[0035] Further, in this implementation, combustion or intake air 152 can be drawn in to the combustion chamber 110 from an intake vent 118 that leads from outside the stove (e.g., from the surrounding environment (room) or outside the heated space). Exhaust gases 154 are expelled from the combustion and drawn out of the stove 100, and out of the heated space, to the outside (e.g., out of the building) through an exhaust vent 120. An exhaust fan 122 operates to help draw the exhaust gases 154 out through the exhaust vent 120. In some implementations, an exhaust sensor module can be configured to detect conditions of the exhaust gases 154, such as temperature, constituent chemicals (e.g., CO, CO.sub.2, O.sub.2, particulate, etc.). As an example, the collected sensor data may be used by the control unit 126 to update or alter stove settings, such as fuel consumption (e.g., auger motor speed/timing), fan speed (e.g., intake and exhaust), and other settings; and may be part of monitoring data (e.g., temperature of combustion) sent to the user's remote device. Additionally, the exhaust sensor data may provide early warning that combustion is not performing within a desired or predetermined manner (e.g., incomplete), which may indicate a problem with the stove's operation.

[0036] The stove can also comprise a convection or room air fan 130 that draws air in from the surrounding area (e.g., the heated space), such as through vents and openings in the housing 102 and directs it around the outside of the combustion chamber/firebox 110. In this way, for example, the room air becomes heated air 156 at a heat exchange area 132 and is directed out of heating vents 134 into the heated space. In some implementations, a room heat sensor module may be used to detect the temperature (e.g., and other characteristics such as constituents) of the heated air 156. As an example, the heated air data can be used to adjust settings of the stove, and/or be provided to the user on a display screen 138 or the remote device. In some implementations, door vents 140 can be disposed at a perimeter of the door 104 to allow make-up air 158 to be drawn over the inside of the door to mitigate buildup of soot, carbon, fly ash, smoke, etc.

[0037] FIGS. 3A and 3B are diagrams illustrating an example display screen 300 that may be disposed in/on a pellet stove described herein. In this example implementation, the display screen may be resident on a top or side portion of the stove such that a user may be able to readily access and view the screen 300. As an example, the display screen may be disposed proximate the control unit (e.g., 126 of FIG. 2) in an area of the stove that is subjected to less heat than other portions of the stove (e.g., above the hopper). In this example, a display screen 300 can comprise a touch-enabled screen that displays information, widgets, and other portions of a user interface (UI) that enables a user to view information and interact with elements on the screen. In other implementations, the screen may comprise a display portion and an interaction portion that utilizes physical buttons or switches instead of on-screen interactive elements.

[0038] As illustrated, a first display 302 on the screen 300 comprises a number of informational elements and some interactive elements. In this implementation, a desired temperature 306 (e.g., as preset by the user) can be displayed to show a temperature preference. In one example, to select the desired temperature 306 the user can press their finger on the outer ring of the temperature widget 304 (e.g., displaying the actual, current temperature) and rotate around the wheel to the selected, desired temperature. In this way, the desired temperature provides an interactive and informational element. Further, a power activation element 308 (e.g., button) can be pressed to power on the stove and pressed to power off the stove.

[0039] A temperature status button 310 can be used to view temperature readings of the stove, and can display the exhaust vent temperature, the hopper protection temperature, and a number of hours that the stove has run. A setting button 312 can be activated to enter a settings mode for the stove, described below. Further, when in the settings menu, the user can select between different modes of operation for the stove, such as ECO mode, set stir time for the hopper, along with exhaust fan and blower settings. A scheduling button 314 can be selected to enter desired run times for the stove, selected from a separate menu. A lock button 316 may be used to activate a lock screen, and/or may illuminate when the display 302 is locked in a programming mode. An Auger button 318 can be used to directly engage the auger, such as to add or stop adding more fuel to the fire pot, for example, to pre-feed the pot or load the auger with fuel prior to lighting. A wireless connection element 320 can be illuminated when the stove has a wireless connection with a local or remote network. A rate select element 322 can be used to toggle between a plurality of configurable heating presets, with the currently set preset displayed in the element between the up and down buttons. The up and down buttons may be used to alter settings of the heating presets, and/or select a desired preset.

[0040] FIG. 3B illustrates the screen 300 with a user menu 330. The user menu can display interactive elements and information that a user may utilize to adjust the settings of the stove, such as the temperature, mode of operation, battery usage, auger operation and stir times of the hopper, exhaust fan settings, convection blower setting, amongst others.

[0041] In some implementations, the stove can comprise local or remote network communications, such as to a local network and local smart device, and/or to a remote network (e.g., Internet, Wi-Fi, cellular network) for remote access using a computer or smart device. The stove may be networked to a local (e.g., or remote) network using one or more settings (e.g., presets) that can be accessed from the display screen 300. Once a network connection is established with the stove, a user can utilize an application on their smart device to control and adjust some functionality of the stove. For example, the name of the device can be edited to create one that the user may recognize or organize multiple stoves. Further, the connection with the stove can be shared with third parties by sending identification information to those parties, who could access the stove through the app using their own smart device.

[0042] FIGS. 2B, 4, 5, 6 illustrate one or more portions of one example of a thermoelectric generator 400 in an example pellet stove 100. In one implementation, heat generated in the combustion chamber 110 can be transferred to the thermoelectric generator 400 positioned within the stove. The thermoelectric generator 400 can be thermally coupled to (e.g., directed engaged with) a first heat sink 410 having a first surface 420, a second surface 430 opposite to the first surface 420, and a thickness 440 extending between the first surface 420 and the second surface 430, wherein the first surface 420 is thermally coupled to and configured to receive heat from the combustion chamber 110. During operation the first heat sink 410 can transfer heat conductively from the first surface 420 through the thickness 440 and to the second surface 430. In a further implementation, a first thermoelectric portion 445 can be thermally coupled to the second surface 430 wherein the first thermoelectric portion is configured to conductively receive heat from the second surface 430.

[0043] In some implementations, the first heat sink 410 can be made from one or more materials with high thermal conductivity. Such materials can include but are not limited to aluminum, copper, brass, iron, steel, zinc, nickel, tungsten, silver, alloys thereof, or other metals or alloys with high thermal conductivity. In some implementations the first heat sink 410 can be partially surrounded by insulation 411 to isolate or focus heat transfer from the first heat sink 410 to the first thermoelectric portion 445, and to mitigate loss of heat energy. Such insulation 411 can include Manniglas insulation, fiberglass insulation, mineral wool, ceramic insulation or other high heat insulators.

[0044] In some implementations, the first heat sink 410 can further comprise an extender 450 connected to the second surface 430. The extender can comprise a first extender surface 460, a second extender surface 470 opposite to the first extender surface 460, and an extender thickness 480 therebetween the first extender surface 460 and the second extender surface 470. The first extender surface 460 is thermally coupled to and configured to receive heat from the second surface 430. During operation, the heat can transfer conductively from the second extender surface 470, through the extender thickness 480, and to the second extender surface 470. In such an implementation, the first thermoelectric portion 445 can be thermally coupled to the second extender surface 470, where the first thermoelectric portion 445 is configured to conductively receive heat from the second extender surface 470.

[0045] In further implementations, the thermoelectric generator 400 can further comprise a second thermoelectric portion 490 thermoelectrically coupled to the first thermoelectric portion 445. During operation, in this implementation, some of the heat from the combustion chamber 110 is transferred to the first thermoelectric portion 445, resulting in a temperature difference between the first thermoelectric portion 445 and the second thermoelectric portion 490. The temperature difference creates a voltage difference by way of the Seebeck effect, resulting in electricity production. The first and second thermoelectric portions 445, 490 can be thermoelectrically coupled to positive elements 495 and negative elements 496 comprising high-efficiency thermoelectric materials, including but not limited to bismuth telluride, lead telluride, silicon germanium, carbon allotropes, copper chalcogenides and other half-Heusler compounds, specifically chosen for their superior thermoelectric performance and durability under high-temperature conditions. These materials can be arranged in a series of thermocouples 497 which can convert heat directly to electricity.

[0046] In various implementations, the first thermoelectric portion 445 can be located near or proximate to the stove's combustion chamber 110, where the temperatures are higher, in order to take advantage of the thermal energy produced during pellet combustion. In other implementations, the first thermoelectric portion and 445 can be positioned in or proximate to the exhaust vent 120 wherein the first thermoelectric portion can receive heat from the hot exhaust gasses instead of directly from the combustion chamber 110.

[0047] In some implementations, the second thermoelectric portion 490 can be thermally coupled to a heat dissipation system 500. The heat dissipation system 500 can further comprise a cooling sink 510 in thermodynamic fluid communication with a cooling fan 520. The cooling fan 520 can draw air in from the surrounding area (e.g., the heated space) such as through vents and openings in the housing 102 and direct cool air through the cooling sink 510 in order to facilitate convective heat transfer. In this way, for example, the room air becomes heated air 156 and is directed out of heating vents 134 into the heated space.

[0048] In operation, this action dissipates heat from the second thermoelectric portion 490 in order to maintain a desired temperature differential between the first thermoelectric portion 445 and the second thermoelectric portion 490 for continuous electricity production. Furthermore, after the cool air passes through the cooling sink 510 and undergoes heat transfer with the cooling sink 510, the air becomes heated air 156 that can be directed out of the stove and into the external environment through the heating vents 134 and into the heated space.

[0049] Further, the cooling sink 510 can be comprised of various types and shapes including but not limited to active flow, flat plate, flat fin, pin fin, vortex. Additionally, the cooling sink 510 can be made out of materials including but not limited to: aluminum, copper, composite materials, copper metal alloys, alloys thereof, or other aluminum metal alloys. The cooling sink 510 may be configured to operate in a temperature range between 100 and 500 degrees Celsius. Furthermore, the cooling fan 520 can be mounted directly on the cooling sink 510 (e.g., top mounted or inline mounted), or in other implementations the cooling fan 520 can be positioned upstream of the heat sink such that it directs air through a duct and through the cooling sink 510. In other implementations the cooling fan 520 can be positioned downstream of the cooling sink 510 such that it pulls air through a duct and through the cooling sink 510.

[0050] In implementations the cooling sink 510 can be coupled to the second thermoelectric portion 490 by a fastener 526. Further, the cooling sink 510 can comprise at least one opening 530 to receive the fastener 526. The fastener 526 can further include a screw 540, a spring washer 550, a flat washer 560, and a nylon or PTFE shoulder washer 570 rated for high temperatures. In some implementations the cooling sink 510 may be coupled to the second thermoelectric portion 490 using thermally conductive tape, epoxy, wire-form z clips, flat spring clips, standoff spacers, push pins, or spring-loaded screws and clips.

[0051] In a further implementation, the control unit 126 can be configured to manage the operation of the thermoelectric generator 400 along with (e.g., or separate from) the primary heating function. The control unit 126 can be in electrical communication with various temperature and voltage sensors to monitor the status and temperature differential across the thermoelectric portions 445, 490, wherein the control unit 126 can adjust the stove's combustion rate and/or the heat dissipation system's 500 activity (e.g., the cooling fan speed) to improve electricity generation without compromising the overall heating efficiency. The control unit 126 allows for a dynamic response to changes in stove usage or ambient conditions, providing for a high electricity generation under varying operational environments.

[0052] In some implementations, the stove can include a battery management system 580 in electrical communication with the control unit 126. The battery management system 580 can be in electrical communication with at least one battery 590, wherein the battery management system 580 controls and monitors the charging and discharging of rechargeable batteries, for example. At least one battery 590 can be of various types and compositions, including but not limited to: non-rechargeable, lithium ion, sodium-ion, lithium-sulfur, lithium-metal, and liquid electrolyte flow batteries.

[0053] In some implementations, the electrical power generated by the thermoelectric generator 400 can be managed or controlled by a power management unit 600 (PMU) within the control unit 126, wherein the power management unit 600 further comprises a microcontrollerfor real-time monitoring and control. The PMU 600 can be in electrical communication with various temperature and voltage sensors and can implement maximum power point tracking (MPPT) technology to ensure that the TEG modules operate at their most efficient point despite fluctuations in the temperature gradient. Furthermore, the PMU 600 can convert the thermoelectrically generated power to the required voltage and current specifications for charging the at least one battery 590, and/or powering the stove's internal componentsincluding but not limited to the control unit 126, the battery management system 580, the pellet auger 114, and the heat dissipation system 500. Additionally, the PM U 600 can also include protective circuits to safeguard against overvoltage, overcurrent, and thermal overload conditions.

[0054] In some implementations, thermal compound 660 can be added for enhanced heat transfer between the surface interfaces. The thermal compound 660 can include various types of thermal paste including but not limited to metal-based thermal paste with metals such as aluminum and silver, liquid metal-based thermal paste such as gallium, ceramic-based thermal paste, carbon-based thermal paste, diamond-carbon based thermal paste, and silicon-based thermal paste.

[0055] FIG. 5 illustrates schematic of an example implementation of a thermoelectric generation circuit for a thermoelectric generator 400. In some implementations, the first thermoelectric portion 445 and the second thermoelectric portion 490 can be thermoelectrically coupled to a plurality of thermoelectric materials including positive elements 495 and negative elements 496, wherein negative elements 496 can comprise a negative charge carrier semiconductor and a positive element 495 con comprise a positive charge carrier semiconductor.

[0056] FIG. 7 is a flow diagram illustrating the heat transfer process 700 of a pellet stove with thermoelectric generation for an example pellet stove implementation. In this example process 700, the transfer of heat to and from the thermoelectric generator (e.g., 400) is highlighted. In this example process 700, as described above, the first thermoelectric portion (e.g., 445) can be disposed proximate the stove's combustion chamber (e.g., 110), such as where the produced heat temperatures are highest, to exploit the thermal energy produced during pellet combustion. As such, the heat from the combustion chamber is transferred to the heat sink (e.g., 410), at 702. Further, at 704, the heat may be conductively transferred through the heat sink to the first thermoelectric portion (e.g., 445), which is thermally coupled to the heat sink. The heat transfer to the first thermoelectric portion can induce a voltage potential, at 706, due to the temperature difference between the first thermoelectric portion and the second thermoelectric portion (e.g., 490), such as using the Seebeck effect).

[0057] Further, in this example process 700, the second thermoelectric portion can be thermally coupled (e.g., engaged with) to the cooling sink (e.g., 510). As such, the at 708, conduction cooling can occur between the second thermoelectric portion and the cooling sink. Additionally, the cooling sink is in fluid communication with a cooling fan (e.g., 520), such that the cooling fan can direct cool air to cool the second thermoelectric portion, at 710, providing conductive cooling to the cooling sink. This can help maintain the desired temperature gradient for continuous and optimal electricity production between the first thermoelectric portion and the second thermoelectric portion. In this example process 700, the cooling fan can be configured to direct air from the cooling sink and to the external environment, at 712.

[0058] The word exemplary is used herein to mean serving as an example, instance or illustration. Any aspect or design described herein as exemplary is not necessarily to be construed as advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion. As used in this application, the term or is intended to mean an inclusive or rather than an exclusive or. That is, unless specified otherwise, or clear from context, X employs A or B is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then X employs A or B is satisfied under any of the foregoing instances. Further, at least one of A and B and/or the like generally means A or B or both A and B. In addition, the articles a and an as used in this application and the appended claims may generally be construed to mean one or more unless specified otherwise or clear from context to be directed to a singular form.

[0059] Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0060] Also, although the disclosure has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based upon a reading and understanding of this specification and the annexed drawings. The disclosure includes all such modifications and alterations and is limited only by the scope of the following claims. In particular regard to the various functions performed by the above described components (e.g., elements, resources, etc.), the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the disclosure. In addition, while a particular feature of the disclosure may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms includes, having, has, with, or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term comprising.

[0061] The implementations have been described, hereinabove. It will be apparent to those skilled in the art that the above methods and apparatuses may incorporate changes and modifications without departing from the general scope of this invention. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof.