Patent Application
20240117966
The present disclosure relates generally to gas water heater appliances, and more particularly to a productive use of gas water heater flue gases.
Many households and buildings include water heaters that selectively provide heated water on demand via faucets, showers, and the like. Conventional water heaters include a tank storing a quantity of water, a temperature sensor to sense the temperature of the water, one or more heat sources burning natural gas or LPG (liquified petroleum gas) to provide heat to the water, piping or tubing to deliver heated water, and a flue pipe to exhaust hot combustion gases to the atmosphere.
However, environmental and efficiency concerns make exhausting combustion gases to the atmosphere undesirable. In this regard, the carbon monoxide in the flue gases may be harmful to the environment and may present serious health issues, particularly in confined spaces. In addition, the thermal energy within the heated flue gases is not harnessed but is instead transferred directly into the environment.
Accordingly, improvements in the use of gas water heater flue gases are desirable.
Aspects and advantages of the invention will be set forth in part in the following description, may be apparent from the description, or may be learned through practice of the invention.
In one exemplary aspect, provided is a gas water heater assembly including a gas water heater, a catalytic converter, and a bioreactor. The gas water heater comprises a tank defining an interior volume, a gas burner in a combustion chamber, the burner coupled to a gaseous combustible fuel supply for generating a combustion gas, and a flue pipe fluidly coupled to the combustion chamber to support the removal of combustion gas to a duct. The catalytic converter is fluidly coupled with the duct and the bioreactor is fluidly coupled to the catalytic converter. The bioreactor contains an aqueous solution comprising algae.
In another example aspect, a method of operation for an oxygen generating gas water heater assembly is provided. The gas water heater assembly includes a gas water heater, a catalytic converter, a heat exchanger, and a bioreactor. The gas water heater comprises a tank defining an interior volume, a gas burner in a combustion chamber, the burner coupled to a gaseous combustible fuel supply for generating a combustion gas, and a flue pipe fluidly coupled to the combustion chamber to support the removal of combustion gas to a duct. The catalytic converter is fluidly coupled with the duct, the heat exchanger is coupled to the duct, and the bioreactor is fluidly coupled to the heat exchanger. The bioreactor contains an aqueous solution comprising algae. The method of operation includes generating combustion gas at the gas water heater and inducing a draft of combustion gas to the catalytic converter; converting carbon monoxide (CO) to carbon dioxide (CO2) at the catalytic converter; forming a CO2-enriched flue gas that flows through the heat exchanger; reducing a temperature of the a CO2-enriched flue gas; and urging the a CO2-enriched flue gas into the bioreactors containing algae to capture and consume a CO2-enriched flue gas and emit oxygen.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). In addition, here and throughout the specification and claims, range limitations may be combined and/or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.
Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “generally,” “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components and/or systems. For example, the approximating language may refer to being within a 10 percent margin, i.e., including values within ten percent greater or less than the stated value. In this regard, for example, when used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction, e.g., “generally vertical” includes forming an angle of up to ten degrees in any direction, e.g., clockwise or counterclockwise, with the vertical direction V.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” In addition, references to “an embodiment” or “one embodiment” does not necessarily refer to the same embodiment, although it may. Any implementation described herein as “exemplary” or “an embodiment” is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
References to “fluid,” “fluidly,” and the like include liquids and gases, and may specifically refer to gases such as natural gas, vapors, and gaseous byproducts of combustion (i.e., combustion gas), and other substances that tend to flow and have no fixed shape, but conform to the shape of the container provided.
Turning to the figures,
Appliance 100 may also include an inlet conduit 112 and an outlet conduit 114 that are both in fluid communication with tank 104 within casing 102. Inlet conduit 112 may support the flow of a liquid from a source to the tank 104 for heating and outlet conduit 114 may support the flow of the heated liquid away from the tank 104. As an example, supply water from a water source, such as a municipal water supply or a well, enters appliance 100 through inlet conduit 112 at an upper portion of tank 104. From inlet conduit 112, such supply water enters interior volume 106 of tank 104 wherein the water is heated to generate heated water. Such heated water exits appliance 100 at outlet conduit 114 through a top portion of tank 108 and, for example, is supplied to fixtures requiring heated water.
From inlet conduit 112, supply water may travel into tank 104 through a dip tube 116 that generally extends along a vertical direction V towards the bottom portion 110 of tank 104. Inlet conduit 112 is fluidly coupled with dip tube 116. According to some embodiments, dip tube 116 extends a predetermined distance or length into interior volume 106 of tank 102. For instance, a lower end 118 of dip tube 116 may be located below a midpoint of tank 102 along the vertical direction V. Advantageously, supply water supplied via dip tube 116, which may be relatively colder that the heated water, may be directed to a lower portion of tank 102, thus allowing a high volume of heated water to be maintained at or near the top of tank 102 to be output via outlet conduit 114 to a network of hot water conduits (not shown).
As illustrated in
Gas control valve 123 may selectively control the flow of gas to the gas burner 122 as determined by controller 133 to allow the gaseous fuel to be burned. Controller 133 may be in communication with temperature sensors, flow sensors, and the like (not shown), and may also control the burner 122 cycling on and off as determined to maintain a preset water temperature, or temperature range, in tank 104.
Referring again to
Appliance 100 may further include or be in operative communication with a processing device or a controller 133 that may be generally configured to facilitate appliance operation. In this regard, control panel 127, user input devices 129, and display 131 may be in communication with controller 133 such that controller 133 may receive control inputs from user input devices 129, may display information using display 131, and may otherwise regulate operation of appliance 100. For example, signals generated by controller 133 may operate appliance 100, including any or all system components, subsystems, or interconnected devices, in response to the position of user input devices 129 and other control commands. Control panel 127 and other components of appliance 100 may be in communication with controller 133 via, for example, one or more signal lines or shared communication busses. In this manner, Input/Output (“I/O”) signals may be routed between controller 133 and various operational components of appliance 100.
As used herein, the terms “processing device,” “computing device,” “controller,” or the like may generally refer to any suitable processing device, such as a general or special purpose microprocessor, a microcontroller, an integrated circuit, an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field-programmable gate array (FPGA), a logic device, one or more central processing units (CPUs), a graphics processing units (GPUs), processing units performing other specialized calculations, semiconductor devices, etc. In addition, these “controllers” are not necessarily restricted to a single element but may include any suitable number, type, and configuration of processing devices integrated in any suitable manner to facilitate appliance operation. Alternatively, controller 166 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND/OR gates, and the like) to perform control functionality instead of relying upon software.
Controller 133 may include, or be associated with, one or more memory elements or non-transitory computer-readable storage mediums, such as RAM, ROM, EEPROM, EPROM, flash memory devices, magnetic disks, or other suitable memory devices (including combinations thereof). These memory devices may be a separate component from the processor or may be included onboard within the processor. In addition, these memory devices can store information and/or data accessible by the one or more processors, including instructions that can be executed by the one or more processors. It should be appreciated that the instructions can be software written in any suitable programming language or can be implemented in hardware. Additionally, or alternatively, the instructions can be executed logically and/or virtually using separate threads on one or more processors.
For example, controller 133 may be operable to execute programming instructions or micro-control code associated with an operating cycle of appliance 100. In this regard, the instructions may be software or any set of instructions that when executed by the processing device, cause the processing device to perform operations, such as running one or more software applications, displaying a user interface, receiving user input, processing user input, etc. Moreover, it should be noted that controller 133 as disclosed herein is capable of and may be operable to perform any methods, method steps, or portions of methods as disclosed herein. For example, in some embodiments, methods disclosed herein may be embodied in programming instructions stored in the memory and executed by controller 166.
The memory devices may also store data that can be retrieved, manipulated, created, or stored by the one or more processors or portions of controller 133. The data can include, for instance, data to facilitate performance of methods described herein. The data can be stored locally (e.g., on controller 133) in one or more databases and/or may be split up so that the data is stored in multiple locations. In addition, or alternatively, the one or more database(s) can be connected to controller 133 through any suitable network(s), such as through a high bandwidth local area network (LAN) or wide area network (WAN). In this regard, for example, controller 133 may further include a communication module or interface that may be used to communicate with one or more other component(s) of appliance 100, controller 133, an external appliance controller, or any other suitable device, e.g., via any suitable communication lines or network(s) and using any suitable communication protocol. The communication interface can include any suitable components for interfacing with one or more network(s), including for example, transmitters, receivers, ports, controllers, antennas, or other suitable components.
Air may travel into combustion chamber 120 through an air intake 124 in casing 102. The resulting mixture of air and gas may be ignited and burned to heat bottom portion 110 of tank 114 and the water contained therein. Hot combustion gas may exit combustion chamber 120 through flue pipe 126 fluidly coupled to the combustion chamber and centrally located within tank 104. The flue pipe 126 extends through the tank 104 at top portion 108 to support removal of hot combustion gas. After entering the flue pipe 126, combustion gas may be referred to as flue gas.
Heat exchange with flue pipe 126 may also help heat water in tank 104. Flue pipe 126 is illustrated as a generally smooth and cylindrical shape directed in the vertical direction V for ease of illustration. In embodiments, flue pipe 126 may follow a circuitous path from the bottom portion 110 to the top portion 108, or may have external elements to facilitate heat transfer from the flue gas to help heat water in tank 104. The flue gas may then exit water heater 100 at the top portion 108 via duct 128 coupled to flue pipe 126.
As generally understood, catalytic converters, such as catalytic converter 130, may be useful in converting toxic combustion gases into less toxic gases. In some cases, catalytic converters can convert toxic gases to non-toxic gases. For example, in the present disclosure, catalytic converter 130 receives combustion gas (flue gas) from the flue pipe 126, and combines the carbon monoxide in the flue gas with oxygen to yield carbon dioxide (CO2) in an oxidation reaction.
As illustrated, appliance 100 includes a catalytic converter 130 which is fluidly coupled to duct 128 for lowering or removing volatile organic compounds (VOCs) and other harmful gases from the flow of flue gas. As used herein, “catalytic converter” or variations thereof may be used to refer to any component, machine, or device that is configured for removing or lowering volatile organic compounds (VOCs), toxic gases, harmful emissions, pollutants, or undesirable compounds from a flow of air and smoke. For example, according to the illustrated embodiment, catalytic converter 130 generally includes a catalytic element 142 and a catalyst heater 144. Although catalytic converter 130 is illustrated herein as being positioned within duct 128, it should be appreciated that according to other embodiments catalytic converter 130 may be positioned at any other suitable location, so long as catalytic converter 130 is in-line with the flow of flue gas, such that volatile organic compounds may be reduced.
In general, catalytic element 142 includes a material that causes an oxidation and a reduction reaction. For example, precious metals such as platinum, palladium, and rhodium are commonly used as catalyst materials, though other catalysts are possible and within the scope of the present subject matter. In operation, the catalytic element 142 may combine oxygen (O2) with carbon monoxide (CO) and unburned hydrocarbons to produce carbon dioxide (CO2) and water (H2O). In addition, according to exemplary embodiments, catalytic element 142 may remove nitric oxide (NO) and nitrogen dioxide (NO2).
Notably, catalytic converters typically require that the catalyst be heated to a suitably high temperature in order to catalyze the necessary chemical reactions. Therefore, catalyst heater 144 is in thermal communication with catalytic element 142 for heating it to a suitable temperature, such as approximately 800° F. According to the illustrated embodiment, catalyst heater 144 is positioned upstream of catalytic element 142 to provide thermal energy through convection. However, it should be appreciated that according to alternative embodiments, catalyst heater 144 may be in direct contact with catalytic element 142 to provide thermal energy through conduction, or may be thermally coupled to catalytic element 142 in any other suitable manner. In order to ensure a catalyst temperature of catalytic element 142 remains above a temperature suitable for controlling emissions, appliance 100 may further include a catalyst temperature sensor (not shown) that may be monitored by controller 133.
According to some embodiments of the present disclosure, induced draft blower 134 is coupled to both flue pipe 126 and duct 128 and selectively provided with electrical power. Controller 133 may selectively provide electrical power to induced draft blower 134 to beneficially induce a draft to urge flow of combustion gas in the flue pipe 126 and to ensure sufficient oxygen is provided to the burner 122. Induced draft blower 134 pulls ambient air through the combustion chamber 120, through the flue pipe 126, and into duct 128, supplementing the natural flow of combustion gas, or flue gas. The induced draft blower 134 may also beneficially direct ambient air, in particular oxygen, through the combustion chamber 120 to the catalytic converter 130 in sufficient quantity to support the oxidation reaction for converting carbon monoxide (CO) to carbon dioxide (CO2).
In some embodiments, the oxidized combustion gas, after passing through catalytic converter 130, may be considered CO2-enriched flue gas as some, or all, of the CO has been converted to CO2. In embodiments, the CO2-enriched flue gas is discharged from the catalytic converter 130 and directed to a heat exchanger 140 where residual heat in the flue gas may be transferred to supply water carried by inlet conduit 112. In the exemplary embodiment of
In the illustrative embodiment, the cooled CO2-enriched flue gas exits the heat exchanger through piping 136 and is directed to bioreactors 132 (three shown) via tubing 138. In alternate embodiments, fewer or more bioreactors 132 may be used. As illustrated, bioreactors 132 may be proximate to the water heater 100, or may be spaced away, or remote, from the water heater 100, and the assembly 200.
In embodiments, bioreactors 132 contain and aqueous solution comprising algae. Certain algae capture and consume carbon dioxide to conduct photosynthesis and, in the process, produce oxygen. In the present invention, carbon monoxide is converted to carbon dioxide in the catalytic converter 130. The carbon dioxide, in addition to being generally less harmful than carbon monoxide, can be used by algae in the bioreactors 132 during the photosynthesis process.
Algae can be found in marine environments (i.e., salt water or saline water) and in freshwater environments (i.e., non-saline or fresh water). Algae may be green in marine and freshwater forms, although other colors of algae exist and may be beneficially used in embodiments. In the present disclosure, either saltwater or freshwater form algae may be used. Salt water and freshwater bioreactors are anticipated, and either may be used to practice the present disclosure.
Although discussed in terms of algae-containing bioreactors, other photosynthetic organisms or plants may be used in bioreactors in embodiments of this disclosure. As would be obvious to one of normal skill in the art, in addition to algae, plants and cyanobacteria consume CO2 and produce oxygen during photosynthesis. Accordingly, algae, plants, and cyanobacteria may be used, together or separately, to capture and consume CO2 and produce oxygen in embodiments of this disclosure.
In an embodiment, CO2-enriched flue gas flows from the catalytic converter 130 in piping 136 under the positive pressure of the outlet of the induced draft blower 134. Piping 136 is reduced to tubing 138 to distribute the CO2-enriched flue gas to the plurality of bioreactors 132. In embodiments, the tubing 138 extends to the bottom of the bioreactors 132 and the CO2-enriched flue gas bubbles up through the aqueous solution to disperse the CO2 in the solution. Under operational conditions, the algae in the aqueous solution within the bioreactors 132 captures and uses the CO2 in photosynthesis and produces oxygen, among other things. The oxygen may be dispersed within the structure. As discussed above, multiple bioreactors 132 may be used, some proximate to the gas water heater 100 and others remote from the water heater 100. According to embodiments, remotely located bioreactors 132 may be located in one or more enclosed spaces (e.g., rooms) in which increased oxygen may be beneficial (e.g., frequently occupied or crowded rooms).
The system 300 comprises an induced draft blower 134 fluidly coupled to a duct 128. Induced draft blower 134 may be controlled by controller 133 for selective operation between a powered condition in which induced draft blower 134 urges combustion gas to flow through the flue pipe 126, and a non-powered condition in which such flow is not urged. A catalytic converter 130 is fluidly coupled with the duct 128 for receiving the combustion gas and converting carbon monoxide in the combustion gas to carbon dioxide at the catalytic converter 130. A CO2-enriched flue gas is formed at, and discharged from, the catalytic converter 130.
A bioreactor 132 containing an aqueous solution comprising algae is fluidly coupled to the catalytic converter 130, downstream from the catalytic converter 130 with respect to the flow of combustion gas. The algae in the bioreactor captures the carbon dioxide from the CO2-enriched flue gas and consumes the carbon dioxide in a photosynthetic process, producing oxygen.
In the exemplary embodiment of
Now that the construction of a gas water heater assembly in accordance with this disclosure has been presented, an exemplary method 200 of operation for an oxygen generating water heater will be described with reference to
At 204, induced draft blower 134 facilitates the flow of combustion gas from the combustion chamber 120 to the catalytic converter 130. The induced draft blower 134 provides a positive pressure to the catalytic converter 130 to facilitate flow of the combustion gas through the catalytic converter. Induced draft blower 134 also pulls ambient air from the combustion chamber 120 to provide an adequate flow to the catalytic converter.
At 206, the catalytic converter 130 converts CO in the combustion gas to CO2 with the flow of combustion gas urged by the induced draft blower 134 to support the oxidation reaction converting CO to CO2 to produce a CO2-enriched flue gas.
At 208, the CO2-enriched flue gas from 206 flows through a heat exchanger 140. Some of the heat present in the CO2-enriched flue gas is extracted and transferred to supply water flowing in inlet conduit 212. This allows the supply water entering the tank 104 through the inlet conduit 112 to be pre-heated, increasing the efficiency of the water heater 100.
At 210, the CO2-enriched flue gas with reduced temperature passes through piping 136 and tubing 138 to the bioreactors 132. The CO2-enriched flue gas is urged by the induced draft blower 134 to enter the aqueous solution comprising algae in the bioreactors 132 and is dispersed throughout the solution through bubbling action. In some embodiments, the aqueous solution is saline, in others, the aqueous solution is freshwater.
At 212, algae in the bioreactors 132 capture and consume CO2 from the CO2-enriched flue gas in the photosynthesis process and emit oxygen to the ambient air as a product of the process. According to an embodiment, the algae are green algae.
Steps 202 through 210 proceed when controller 133 determines the induced draft blower 134 should be operating, for example when the gas control valve 123 is opened and burner 122 is ignited. Step 212 can continue independently of the induced draft blower 134.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
