Patent Application
20190203935
There are many technologies where heat is needed and the heat is often generated by burning fuel in a burner system. The fuel is delivered to the burner system and combustion occurs in a flame area (e.g., at the nozzle), resulting in a flame. In some instances, legacy burner systems may have lower efficiencies than newer burner systems, which may include various improvements over the legacy burner systems. Generally, increasing efficiency of the legacy burner systems may be desirable for any number of reasons, such as to reduce fuel cost, reduce emissions, increase output, etc.
In some instances, replacing a legacy burner system may be cost prohibitive or otherwise undesirable. For example, cost of a new system (even when amortized over its useful lifetime) may outweigh fuel savings. Sometimes, a legacy burner system may be updated or retrofitted to improve its efficiency, reduce emissions, and the like.
Accordingly, manufacturers and users of burner systems continue to seek improvements for modifying or retrofitting existing burner systems.
Embodiments disclosed herein relate to combustion systems, retrofit flame control systems, and methods for controlling a flame in a combustion or burner system. The burner system includes one or more burner components configured to control at least one of supply of fuel to a flame area or fuel mixture for forming the flame in the flame area. The burner system further includes one or more electrodynamic components including one or more electrodes configured to control one or more characteristics of the flame. The burner system additionally includes a data interface configured to receive a first command for controlling the burner components and to prepare a second command for controlling at least one of the one or more electrodynamic components, with the second command being at least partially based on the first command.
In an embodiment, a retrofit flame control system is disclosed. The retrofit flame control system includes one or more electrodynamic components configured for integration with an existing burner system capable of producing a flame. The one or more electrodynamic components include one or more electrodes configured to generate an electric field for controlling one or more characteristics of the flame and one or more chargers configured to charge the flame. The flame control system further includes a data interface configured to receive a first command for controlling the burner components and prepare a second command for controlling the one or more electrodynamic components, with the second command being at least partially based on the first command.
In an embodiment, a method for controlling a flame of a burner system is disclosed. The method includes receiving a first command from a control system, with the first command including information for controlling one or more of a burner or a fuel source. The method further includes preparing a second command at least partially based on the first command, with the second command including information for controlling one or more electrodynamic components that include at least one of one or more electrodes or a charger. The method additionally includes transmitting the second command to the one or more electrodynamic components.
Features from any of the disclosed embodiments may be used in combination with one another, without limitation. In addition, other features and advantages of the present disclosure will become apparent to those of ordinary skill in the art through consideration of the following detailed description and the accompanying drawings.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, which are not to scale or to proportion, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings and claims, are not meant to be limiting. Other embodiments may be used and/or and other changes may be made without departing from the spirit or scope of the present disclosure.
Embodiments disclosed herein relate to combustion systems, retrofit flame control systems, and methods for controlling a flame in a combustion or burner system. Embodiments disclosed herein further relate to a data interface configured to control a burner system. For example, the data interface may be integrated with burner systems including legacy burner systems and that may enable control of the burner system or control of components of the burner system.
In some instances, efficiency of a legacy burner system may be improved by controlling the flame. While the general direction of a flame may be controlled using the flame's momentum, controlling other aspects of the flame (e.g., the flame height) may further improve the efficiency of the legacy burner system. More specifically, in some embodiments, the retrofit flame control system may be easily integrated with an existing burner system to improve efficiency thereof.
An existing burner system may have several components that may be controlled by the retrofit flame control system. For instance, elements or components of the burner system may be controlled in a manner that impacts the efficiency and operation of the burner system. For example, a burner system typically has a fuel source. The operation of the burner system may be controlled by controlling various aspects or characteristics of the fuel source. Fuel flow rate, mixture ratios, fuel type, fuel temperature, fuel pressure, or the like are examples of characteristics of the fuel or of the fuel source that may be controlled. In some embodiments, the burner may also have controllable elements or components, such as valves and dampeners.
Flame geometry, flame combustion characteristics, flame chemistry, flame heat transfer (e.g., heat transfer to a surface, or non-transfer of heat to a surface), flame holding position, flame luminosity, or combinations thereof may be controlled in accordance with embodiments disclosed herein. A flame generally may include ionized gases or charged particles (ions) with the mix of positive and negative ions. Accordingly, in some instances, the flame has a net zero charge. In some embodiments, as described in more detail below, the flame may be charged to exhibit a net positive or net negative charge so that the charged flame may be manipulated via an electric field.
In at least one embodiment, application of an electric field to one or more regions at least proximate to a flame via one or more electrodes enables influencing flame geometry, flame combustion characteristics, flame chemistry, flame heat transfer (e.g., heat transfer to a surface, non-transfer of heat to a surface), flame holding position, flame luminosity, or combinations thereof. For example, by controlling a timing, a direction, a strength, a location, a waveform, a frequency spectrum of the electric field, or combinations thereof, flame geometry, flame combustion characteristics, flame chemistry, flame heat transfer, flame holding position, flame luminosity, or combinations thereof may be controllably altered.
Flame geometry may be controlled, for example, by charging the flame or the flame area and then using one or more electrodes to apply the electric field to control the flame geometry. Causing a response in the flame via the electric field may include causing a visible response in the flame. Additionally or alternatively, causing a response in the flame via the electric field may include causing increased mixing of fuel and oxidizer in the flame. Causing the increased mixing of fuel and oxidizer may increase a rate of combustion. Additionally or alternatively, causing the increased mixing of fuel and oxidizer may increase fuel and air contact in the flame. Additionally or alternatively, causing the increased mixing of fuel and oxidizer may decrease a flame temperature. Additionally or alternatively, causing the increased mixing of fuel and oxidizer may decrease an evolution of oxides of nitrogen (“NOx”) by the flame. Additionally or alternatively, causing the increased mixing of fuel and oxidizer may decrease an evolution of carbon monoxide (“CO”) by the flame. Causing the increased mixing of fuel and oxidizer may increase flame stability and/or decrease a chance of flame blow-out. Additionally or alternatively, causing the increased mixing of fuel and oxidizer may increase flame emissivity. Additionally or alternatively, causing the increased mixing of fuel and oxidizer may decrease flame size for a given fuel flow rate.
Embodiments disclosed herein may inject charges (e.g., electrons, positive ions, negative ions, and/or radicals) into the flame (or the fuel or the flame area) such that the flame as a whole is electrically biased either positively or negatively (i.e., the flame may have a net negative or net positive charge). By adjusting the electrical bias of the flame, the flame's geometries may also be controlled by applying an appropriate electric field. More specifically, the geometry of the flame may be controlled using one or more electrodes that may have the same charge as the biased flame or a different charge from the biased flame. In some embodiments, the electrodes may be positively charged or negatively charged. Additional or alternative embodiments may include multiple electrodes, some of which may have a negative charge and other may have a positive charge. In some embodiments, the electrodes may include at least one counter electrode (e.g., at least one ground electrode) that may also be used to generate the electric fields and to control directions and configurations of the electric fields. The counter electrodes may be included in the burner system (or in a burner configuration) to establish a desired electric field relative to other electrodes that are at a different potential. The placement and bias of the electrodes may be placed and configured according to a desired flame shape or to enable control of the flame shape according to desired ranges. For example, one or more electrodes may be positioned in or near a buoyancy-dominated region of the flame which may not even be visible as opposed to a momentum-dominated region of the flame that is at or near the base of the flame.
The polarities (e.g., positive, negative, or neutral charge) of the electrodes may be controlled such that the flame is controlled by repulsion or attraction. For example, if the flame is provided with an overall positive charge by the injection or addition of positive ions, then positive electrodes may control the flame geometry or characteristic (e.g., flame height) by repelling the biased flame. More specifically, in an embodiment, positively charged electrodes may repel positive ions in the flame. In this manner, at least the height of the flame may be controlled. In an embodiment, the electrodes may be configured to control the chemical reactions that occur during combustion. For example, forming radicals with the electrodes may create new reaction pathways during combustion, such as creating new reactive species during combustion.
Controlling the flame geometry or other characteristics of the flame may be influenced by placement of the electrodes, size and shape of the electrodes, directions of electric fields, relative potentials of the electrodes or relative strengths of the corresponding electric fields, or the like or any combination thereof. Electrodes may be placed at any number of suitable locations relative to the flame. For example, one or more electrodes may be positioned above the flame, on the sides of the flame, within the flame, or the like or any combination thereof. The electrodes also may have any number of suitable shapes and/or sizes, which may vary from one embodiment to the next, and which may be shaped like rods, rings, partial-rings, plates, or the like or any combination thereof. Also, the electrodes may also be oriented in different directions or along one or more axes. The electrodes for a given burner system may have different shapes, orientations, sizes, or the like. The electrodes in a given burner system may be similarly configured or differently configured.
Embodiments disclosed herein may also contemplate other electrodes. Other electrodes (e.g., corona electrodes) may be used to generate the ions that are added to or injected into the flame to provide a charge to the flame.
Embodiments disclosed herein further relate to a data interface that may facilitate control of at least the above-described aspects of burner systems. In some embodiments, the data interface may cooperate with multiple controllers using minimal communication lines. In an embodiment, the data interface may be effectively placed between the controllable elements of the burner system and a control system. The data interface may be able to pass data/commands, generate data/commands, route data/commands, the like, or combinations thereof.
In an embodiment, the data interface may include a lookup table (“LUT”) stored in a memory. The lookup table may allow or facilitate certain actions to be performed even if not explicitly reflected in the original command. For example, a command to shut off the fuel to the burner may result in commands for other elements of the burner system. In some embodiments, the operational states of the electrodes and the charger may also be changed in response to a command to shut off the fuel to the burner.
The data interface may be configured to receive signals or commands from a control system, interpret the commands, and then route the commands as necessary to implement the original command. Some embodiments may include using the lookup table (e.g., stored in a memory), which may facilitate generating appropriate commands and sending commands to various elements or components of the burner system.
The burner system 100 further includes a control system 102 that is operably connected with electrodes 104, an optional charger 106, the burner 108, and the fuel source 110. In an embodiment, the electrodes 104 and the charger 106 are electrodynamic components 118, while the burner 108 and the fuel source 110 are burner components 120.
The charger 106 is configured to charge the flame 116 or to add charge to the flame 116 (or to a flame area 114). The charger 106 may charge the flame 116 using synchronized AC polarity. The charger 106 may add positive or negative ions (e.g., gaseous ions) or radicals to the flame 116, to the fuel flow, or to a flame area to produce a biased flame. As previously discussed, the flame may include ions of different charges, but the overall charge of the flame 116 may be substantially neutral. The charger 106 is configured to provide charge to or bias the flame 116. In some embodiments, the charger 106 may ensure that the overall or net charge of the flame 116 is positive or negative.
In some embodiments, the height of the flame 116 may be controlled using the existing charges in the flame and the charger 106 may not be required. Hence, in at least one embodiment, the charge and potential of the electrodes 104 may be varied and set at least partially based on the response of the flame that has not been charged by the charger 106. In some embodiments, the burner system 100 is configured to form radicals and the charger 106 may not be required. In additional or alternative embodiments the charger 106 may be omitted.
The electrodes 104 may be generally arranged relative to the flame 116 and/or to the charger 106 in a manner that the geometry of the flame 116 (e.g., the height) may be controlled. For example, the charger 106 may provide the flame 116 with a positive charge as previously stated. The electrodes 104 may also be positively biased in order to create an electric field that acts on the positively charged flame. By controlling the strength and/or direction of the electric field, the height, width, or other shape of the flame 116 may be adjusted by repelling the flame 116 with the electrodes 104, which act on the charges in the flame 116.
The electrodes 104 also may be turned off, or the potential of the electrodes 104 may be lowered in some embodiments, which would increase the height of the flame 116. In an embodiment, the potential or bias of the electrodes may be made negative, which may increase the height of the flame 116. Various other properties of the flame or related combustion characteristics other than flame geometry may also be controlled by the electric field applied via the electrodes 104 as previously discussed, such as flame combustion characteristics, flame chemistry, flame heat transfer (e.g., heat transfer to a surface, non-transfer of heat to a surface), flame holding position, flame luminosity, or combinations thereof. When controlling the flame, commands issued by the control system 102 may contemplate and account for situations where the polarity of the electrodes 104 is always positive or neutral, always negative or neutral, or where the polarity may change from positive to negative or from negative to positive.
The control system 102 may be configured to control at least one of the electrodes 104, the charger 106, the burner 108, or the fuel source 110. The control system 102 may control the potential and polarity of the electrodes 104, the amount of charge emitted or generated by the charger 106, the like, or combinations thereof. The control system 102 may also be able to control the burner 108 and the fuel source 110 (e.g., rate of fuel flow, pressure, or the like).
The burner system 100 further includes a data interface 150. The data interface 150 may be integrated in the burner system 100 to interface with the control system 102 and with the electrodynamic components 118 and the burner components 120.
The fuel source 110, for example, may include various components such as valves and dampeners. The control system 102 may issue a command to control the fuel source 110 (e.g., shut or partially close a valve or a dampener). The command may be formed as a set of bits (e.g., a command frame), for example, that may have predefined fields. The commands are received by the data interface 150 and converted into action. Thus, the interface is positioned in the burner system 100 to control the fuel source 110 in response to a command from the control system 102. Similarly, commands directed to the burner (e.g., related to fuel mixing, air flow, or the like) may be converted to action by the data interface 150. The data interface 150 may interpret commands, route commands, augment commands with additional instructions, modify commands, pass commands unmodified, the like, or any combination thereof.
In an embodiment, a communication line 122 may pass commands to the burner components 120 and to the electrodynamic components 118. One or more embodiments may allow incorporation of the electrodynamic components 118 into a legacy burner system without the need of separate control systems. The data interface 150 may generate commands for the electrodynamic components 118, which may be at least partially based on commands by the control system 102 issued to the burner components 120.
For instance, a command to reduce fuel flow may be modified by the data interface 150 to include a command to the electrodes 104 and/or the charger 106 that may be at least partially based on the command issued to the burner components 120. More generally, a command to the burner components 120 typically has a certain effect on the flame 116. The data interface 150 may issue commands to the electrodynamic components 118 that are consistent with such anticipated effect on the flame 116 (from the commands issued to the burner components 120). For example, a command to shut off the fuel flow may result in an additional command to shut off application of voltage to the electrodes 104.
In another example, a command directed to the electrodes 104 (e.g., changing a potential of an electrode, changing a direction or strength of an electric field) or a command directed to the charger 106 (e.g., controlling an amount of injected charge) may be sent on the line 122, which also may be used by the control system 102 for issuing commands to the burner components 120. The data interface 150 enables the same communication line to the control system 102 to be used for all components of the burner system 100 and may prevent commands that would not be understood or accepted by a particular component from reaching that component.
Thus, the data interface 150 may use existing communication line 122 (
The data interface 150 may include a connection configured to connect to one or more upline components such as the control system 102. The data interface 150 may also include a connection configured to connect to one or more downline components such as component controllers.
The data interface 150 may be embodied as a hardware device and/or as software programmed and/or stored on the hardware control system 102. The data interface 150 receives all data that originates upline. The data interface 150 may then pass data to one or more of the intended components, such as to fuel control components. The data may be reviewed prior to being passed, such that other correlated commands may be generated and sent downline to the electrodynamic control components. In some embodiments, the data interface 150 may have a multi-task operating system that may operate multiple controllers or that may control multiple components.
The data interface 250 may include a processor 210 and a lookup table (LUT) 208. The LUT 208 may be stored in a memory and may be updated over time. The data interface 250 also may include other circuitry and components that cooperate to receive/transmit data/signals in upline and downline directions. Additionally or alternatively, the data interface 250 may be configured to access the LUT 208, which may be stored and/or located remotely from the data interface 250.
The LUT 208 may be a database or table that stores information related to the control of the burner system 200. For instance, the LUT 208 may include one or more fields that may include information or parameters that may correlate one command with another. Hence, the LUT 208 may be accessed to prepare one or more commands at least partially based on the information contained in one or more other commands. Moreover, the LUT 208 may include specific information for preparing each new command at least partially based on the one or more other commands.
In an embodiment, the LUT 208 may be accessed based on an original command 202 received over a communication line 218 that is connected to a port 212. The LUT 208 may include other commands that correspond to the original command 202. For example, when the command 202 is received by the data interface 250 and processed by the processor 210, the LUT 208 may be accessed to obtain information or parameters from preparing one or more commands that may be based on or related to the original command 202. For instance, commands 204 and 206 may be associated with and/or based on the original command 202. In one or more embodiments, the data interface 250 may generate and/or transmit both the command 204 and the command 206 in response to receiving the command 202.
For instance, the command 202 may be a command to change a pressurization of the fuel source and may be intended for the fuel source 110 or the fuel source controller 158 (
If the change in pressurization was to increase the fuel pressure, then the command 206 to the electrodes may have been made to ensure that the flame height did not change. This enables an increase in heat without changing the flame height. Other commands may be similarly implemented.
The contents of the LUT 208 may be changed as necessary or suitable. For instance, new data may be entered into the LUT 208. The LUT 208 may be configured such that the appropriate actions are taken in response to an initial command (e.g., a command that may be provided by a user). This advantageously relieves the user of having to control each component of the burner system 200 individually. In addition, the control of the burner system 200 may be more consistent or predictable.
The command 202 may have a format that may be interpreted by the data interface 250. The command 202, for example, may identify the component to control, the specific burner affected, a value to implement, a time stamp, other information, or combination thereof. In any event, the data interface 250 may receive the command 202 and may, at least partially based on the LUT 208, prepare new commands 204, 206 at least partially based on the command 202. It should be also appreciated that the data interface 250 may receive any number of commands and may prepare and send any number of commands that may be based at least in part on the received commands. Moreover, any of the sent commands may be similar to or the same as the received commands. In other words, the data interface 250 may generate additional commands (e.g., command 206) at least partially based on the information provided in the original command (e.g., command 202).
The LUT 208 enables the data interface 250 to coordinate control of the components in the burner system 200. The LUT 208 allows the data interface 250 to generate and transmit commands to components that may not be included in the original command. The LUT 208 may be arranged in a table format that may be indexed according to all available commands. Associated portions of the table may then identify the commands that may be generated and transmitted based on the command that was received.
For example, commands that affect the fuel or the fuel flow may be correlated with commands to the charger or electrodes that have a corresponding impact on what the original command intended to achieve. A command to shut off the valve may result in the electrodes and charger being turned off. A command to increase fuel flow rate or flow pressure may result in commands that change the magnitude and/or direction of the electric field or of the amount of charge (e.g., at least one of positive ions, negative ions, electrons, or radicals) injected into the flame area.
The LUT 208 also may include routing instructions, which may indicate the destination of the command. Hence, in some embodiments, the LUT 208 may be used to determine which component should receive the command 202. For example, the LUT 208 may contain one or more fields that may be identified using information contained in the command 202, and which may include instructions for routing the command 202 to a component and/or to a port of a component.
The data interface 250 may include multiple ports, illustrated as ports 212, 214, and 216. The port 212 is an input port that is connected to the communication line 218. Advantageously, the same line 218 may be used for communicating commands to all components of the burner system 200. The ports 214 and 216 are examples of output ports and are connected to respective lines 220 and 222. The data interface 250 may include more or fewer ports in other embodiments. As a result, the data interface 250 may be scalable and may accommodate as many components as may be necessary or suitable for a particular application or burner system. The data interface 250 also may facilitate control of multiple burner systems.
For a given command 202, the number of commands output may vary and may depend on the information in the LUT 208. In an embodiment, the data interface 250 may simply pass the command 202 directly through the data interface as the command 204. Alternatively, the command 202 may be changed into two commands, illustrated as the command 204 and the command 206. The lines 218, 220, and 222 may support unidirectional or bi-directional communication. This enables, for example, feedback to be received by the data interface 250 from the various components of the burner system 200.
In an embodiment, commands to the fuel component control 352 may be simply passed through by the electrodynamic component control 354 or vice versa if the commands travel in the other direction. The fuel component control 352 may recognize commands that are intended for the components 356 and cause the appropriate action (e.g., may send such commands to the electrodynamic component control 354). Similarly, the electrodynamic component control 354 may recognize commands that are intended for the components 358 and cause the appropriate action (e.g., may send such commands to the fuel component control 352).
The data interface 350 may have access to a LUT as previously described such that any command generated by the control system 102 may be correlated to the appropriate commands for the components 356 and/or the components 358. In this example, the electrodynamic component control 354 may pass a data stream to the fuel component control 352 while picking out the appropriate commands for the components 358. The fuel component control 352 may similarly pick out the appropriate commands for the components 356. Feedback from the electrodynamic component control 354 may be passed back to the data interface 350 through the fuel component control 352.
The foregoing description illustrates that a single set of wires or lines may be used to convey commands to all components in a burner system and ensure that each component receives the appropriate commands. It should be appreciated that embodiments may include any suitable number of sets of wires, which may vary from one embodiment to the next. Hence, additional or alternative embodiments may include multiple sets of wires, some of which may be dedicated to transmitting data between certain ones of one or more controls and/or one or more components.
Generally, the data interface may be viewed as a wedge data interface that, in an embodiment, may be inserted into legacy systems. The existing communication lines may be used to convey commands while providing a way to control new components that may be added to the system. In addition, the interface may facilitate new components to be properly controlled with legacy commands and/or with commands particular to the new components. For instance, as previously described, the LUT may ensure that commands to a fuel source results in additional commands to the electrodes or charger such that the intended result is achieved by all of the components operating appropriately in the context of the original command.
In an act 406, new commands (e.g., commands that correlate with the original command) may be generated. The new commands may include the original command as well as other additional commands. For example, the intent of an original command that is achieved by controlling a fuel source may be implemented with commands to the fuel source and other components that are operated to achieve the same intent as discussed herein. Moreover, in the act 406, the new commands may be transmitted to the appropriate components.
The one or more electrodes 504 may be dielectric barrier discharge electrodes that are configured to produce cold plasma discharge (a.k.a., photonic discharge or low temperature discharge). The one or more electrodes 504 may include at least one first electrode 504a (e.g., a plurality of first electrodes 504a) and at least one second electrode 504b (e.g., a plurality of second electrodes 504b) positioned proximate to the at least one first electrode 504a. During operation, the first and second electrodes 504a, 504b have different polarities. In an example, during operation, the first electrode 504a may have a positive polarity while the second electrode 504b has a negative polarity. In an example, during operation, the first electrode 504a may have a negative or positive polarity while the second electrode 504b has neutral polarity (i.e., the second electrode 504b is a ground electrode).
In an embodiment, the at least one first electrode 504a includes a plurality of first electrodes 504a and the at least one second electrode 504b includes a plurality of second electrodes 504b. In such an embodiment, the first and second electrodes 504a, 504b, are alternatively positioned in a plane which allows the first and second electrodes 504a, 504b to affect a large percentage of the fuel and/or flame.
The one or more electrodes 504 may exhibit any suitable shape. For example, as illustrated, each of the one or more electrodes 504 may exhibit a generally elongated shape. The elongated shape may include, for example, a rod-like shape since the rod-like shape forms a more uniform electric fields than a shape that includes a corner. In an embodiment, the elongated shape of the electrodes 504 may extend in a direction that is generally perpendicular to the flow of fuel from the nozzles 508 (shown with an arrow) which allows the electrodes 504 to affect a larger quantity of the fuel and/or flame with fewer electrodes than if the elongated shape of the electrodes 504 extended in a non-perpendicular direction relative to the flow of the fuel.
The core 530 may be at least partially surrounded by a dielectric layer 532 (e.g., a dielectric coating). The dielectric layer 532 may be formed on the core 530 such that the dielectric layer 532 is positioned between the core 530 and a core of an adjacent electrode. It is noted that the adjacent electrode may or may not include a dielectric layer positioned between the core of the adjacent electrode and the core 530 of the electrode 504. In an example, the dielectric layer 532 may completely surround the core 530, thereby ensuring that the dielectric layer 532 is positioned between the core 530 and the core of the adjacent electrode. Due to the temperatures generated by the burner system 500, the dielectric layer 532 may also be formed from a material exhibiting a high melting point, such as zirconium oxide or another oxide. Forming the dielectric layer 532 from an oxide may prevent oxygen radicals that are formed during operation from corroding the dielectric layer 532.
In an embodiment, the electrode 504 may include a tie layer 534 disposed between the core 530 and the dielectric layer 532. The tie layer 534 may improve adhesion between the core 530 and the dielectric layer 532. The tie layer 534 may include, for example, titanium, molybdenum, chromium, aluminum, yttrium, nickel, cobalt, oxides thereof, or combinations thereof.
Referring back to
In an embodiment, as previously discussed, the electrode controller may be or include a nanosecond signal generator. The nanosecond signal generator is configured to cause the electrodes to emit an electric field having a nanosecond pulse length. As used herein, a nanosecond pulse length refers to a pulse length of about 0.1 nanoseconds (“ns”) to about 100 ns, such as in ranges of about 0.1 ns to about 1 ns, about 0.5 ns to about 5 ns, about 1 ns to about 10 ns, about 5 ns to about 15 ns, about 10 ns to about 30 ns, about 20 ns to about 40 ns, about 30 ns to about 50 ns, about 40 ns to about 60 ns, about 50 ns to about 70 ns, about 60 ns to about 80 ns, about 70 ns to about 90 ns, or about 80 ns to about 100 ns. The nanosecond pulse length causes the first and second electrodes 504a, 504b to generate cold plasma discharge instead of, for example, hot plasma discharge.
Not wishing to be bound by theory, during operation, electrical charges are provided to at least one of the first electrode 504a or the second electrode 504b. For example, the electrical charges may be provided to the first electrode 504a while the second electrode remains neutral. The electrical charges collect on the surface of the dielectric layer 532 before discharging. Discharging the electrical charges may result in electrons being released from the electrodes 504. The electrons may react with gas molecules to form radicals. For example, the electrons may react with oxygen gas to form an oxygen radical.
The presence of the radical may affect the combustion reaction of the fuel thereby making the fuel combustion more stable. For example, the presence of the radical may reduce the minimum stable fuel rate. Further, the presence of the radicals may increase the turndown ratio of the burner system 500 by at least 5% (e.g., at least about 10%, at least about 30%, at least about 50%, about 20% to about 60%, or about 20% to about 50%) compared to a substantially similar burner system that is configured to form ions or hot plasma discharge. Turndown ratio is the maximum stable fuel rate minus the minimum stable fuel rate all divided by the maximum stable fuel rate. However, it is noted that the radicals may not have sufficient energy to ignite the fuel (e.g., the burner system 500 may need an ignition source other than the electrodes 504) though the radicals may have sufficient energy to maintain ignition of the fuel.
Forming radicals with the electrodes 504 instead of forming ions or hot plasma discharge may be more energy efficient. Further, forming radicals may increase the lifespan of the electrodes 504 since the discharge is less intense than other types of discharge (e.g., discharge caused by corona electrodes).
The burner system 500 includes a combustion chamber 538 defined by one or more walls 540. The combustion chamber 538 is configured to receive the fuel from the nozzles 508 and have the fuel combust therein. In an embodiment, the electrodes 504 are at least partially disposed in the combustion chamber 538. In such an embodiment, the walls 540 may define one or more openings 548 therein that allow the electrodes 504 to be electrically coupled (e.g., via one or more wires 549) to the electrode controller.
The burner system 500 may include a perforated flame holder 544 disposed in the combustion chamber 538. The perforated flame holder 554 may be attached to the walls 540, thereby allowing the perforated flame holder 554 to be supported above the nozzles 508. In an embodiment, the perforated flame holder 544 may be supported above the nozzles 508 by one or more support structures 542. For example, the support structure 542 may be blocks or other structure that are attached to or otherwise protrudes from the walls 540. In such an example, the perforated flame holder 544 may rest on or be otherwise attached to the support structures 542.
The perforated flame holder 544 is configured to facilitate combustion of the fuel. For example, the perforated flame holder 544 defines a plurality of passageways 546 extending therethrough. The fuel may be dispensed from the nozzles 508 towards the perforated flame holder 544. The passageways 544 may receive the fuel and may increase mixing of the fuel and an oxidant source thereby resulting in better combustion of the fuel. The passageways 544 may also decrease the speed of the fuel thereby decreasing the odds of blowout. Further, the passageways 544 may have at least some of the fuel combust therein which may result in a more stable flame and more efficient transfer of heat from the flame. Examples of perforated flame holders are disclosed in U.S. patent application Ser. No. 15/521,011 filed on Apr. 21, 2017, the disclosure of which is incorporated herein, in its entirety, by this reference. In an embodiment, the perforated flame holder 544 is omitted from the burner system 500.
In an embodiment, as illustrated, the electrodes 504 may be disposed in the combustion chamber 538 between the nozzles 508 and the perforated flame holder 544. In other words, the electrodes 504 may be disposed below the perforated flame holder 544. Disposing the electrodes 504 below the perforated flame holder 544 may allow the radicals to be formed in the fuel before the fuel reaches the perforated flame holder 544. In an embodiment, the fuel may combust at or near the perforated flame holder 544. In such an embodiment, disposing the electrodes 504 below the perforated flame holder 544 may affect the combustion reaction, such as affect the combustion reactions that occur at or near the bottom of the flame (e.g., the portion of the flame closest to the nozzles 508).
It is noted that the electrodes may have other positions relative to the perforated flame holder other than the position shown in
In the illustrated embodiment, the one or more electrodes 604 are disposed in the perforated flame holder 644. For example, the perforated flame holder 644 may define one or more conduits therein that are configured to have the one or more electrodes 604 disposed therein or the perforated flame holder 644 may be formed from two or more components with the one or more electrodes 604 disposed between the two or more components. Disposing the electrodes 604 in the perforated flame holder 644 may cause the electrodes 604 to be disposed in the flame. Disposing the electrodes 604 in the perforated flame holder 644 may allow the electrodes 604 to affect the combustion reactions, such as when at least a portion of the fuel combusts within or directly above the perforated flame holder 644.
In the illustrated embodiment, the one or more electrodes 704 are disposed above the perforated flame holder 744. In other words, the perforated flame holder 744 is positioned between the electrodes 704 and the nozzles 708. The electrodes 704 that are disposed above the perforated flame holder 744 may be positioned in the flame or above the flame. The electrodes 704 may be disposed above the perforated flame holder 744, for example, to affect combustion of at least a portion of the fuel that combusts above the perforated flame holder 744. Further, positioning the electrodes 704 above the perforated flame holder 744 may facilitate combustion of fuel that, except for the electrodes 704, would not have combusted.
The electrodes 504, 604, and 704 of
The electrodes 804 extend in a longitudinal direct. In an embodiment, each of the electrodes 804 are generally parallel to each other thereby facilitating a uniform electric field therebetween. Each of the plurality of electrodes 804 may be electrically coupled together using any suitable technique. For example, as illustrated, the electrodes 804 may be electrically coupled together using an electrically conductive support 862 attached to or integrally formed with the electrodes 862. In such an example, the electrodes 804 may extend longitudinally from the support 862. However, the electrodes 804 may be electrically coupled together using other techniques, such as with electrically conductive wires.
In an example, as illustrated, at least a portion of the electrodes 804 may extend in a longitudinal direction that is generally parallel to the flow of the fuel. In such an example, the electrodes 804 may eject ions, electrons, and/or radicals into the fuel and/or flame along a longer path of the fuel and/or flame. In an example (not illustrated), at least a portion of the electrodes 804 may extend in at an oblique angle relative to the flow of the fuel.
The embodiments disclosed herein, including the control system and/or the data interface, may comprise a special purpose or general-purpose computer including various computer hardware or other hardware including duplexers, amplifiers, or the like, as discussed in greater detail below.
Embodiments disclosed herein also include computer-readable media for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable media may be any available media that may be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which may be used to carry or store desired program code means in the form of computer-executable instructions or data structures and which may be accessed by a general purpose or special purpose computer. Combinations of the above should also be included within the scope of computer-readable media.
Computer-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. 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.
While various aspects and embodiments have been disclosed, other aspects and embodiments may be contemplated. The various aspects and embodiments disclosed here are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
This application is a continuation-in-part of U.S. application Ser. No. 15/654,026 filed on Jul. 19, 2017, which is a division of U.S. application Ser. No. 14/206,919 filed on 12 Mar. 2014 (now U.S. Pat. No. 9,732,958), which is a continuation-in-part of U.S. application Ser. No. 12/753,047 filed on 1 Apr. 2010 (now U.S. Pat. No. 8,851,882 issued on 7 Oct. 2014) and claims priority to U.S. Provisional Patent Application No. 61/806,480 filed on 29 Mar. 2013. The disclosure of each of the foregoing applications, to the extent not inconsistent with the disclosure herein, is incorporated by reference, in its entirety, by this reference.
| Number | Date | Country | |
|---|---|---|---|
| 61806480 | Mar 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14206919 | Mar 2014 | US |
| Child | 15654026 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15654026 | Jul 2017 | US |
| Child | 16296623 | US | |
| Parent | 12753047 | Apr 2010 | US |
| Child | 14206919 | US |
