System and method for sequential energizing heating elements in an electrocatalytic unit for ammonia dissociation

Abstract

In a system of an electrocatalytic unit for ammonia dissociation, a method for energizing a heating element that can be operated on a vehicle is provided. [Solution] By utilizing output temperature readings from various sections within the electrocatalytic unit, the corresponding heating elements are sequentially energized only when the output temperature of the upstream section is below the threshold temperature required for ammonia dissociation to occur. This reduces the risk of degradation and failure of the vehicle's power system and other electrical components within the vehicle compared to fully energizing all heating elements.

Description

【Technical Field】 【0001】 The present invention generally relates to a system and method for sequentially energizing a heating element as needed within an electrocatalytic unit to promote ammonia dissociation. 【Background Art】 【0002】 In an on-board ammonia dissociation system for a vehicle, an electrocatalytic unit can be utilized when the temperature of the exhaust gas from the engine is relatively low, such as during a cold start of an internal combustion engine or during low-load engine operation. The electrocatalytic unit can heat the catalyst to a temperature sufficient to effect ammonia dissociation, but conventional electrocatalytic units require a large amount of power to do so. 【0003】 Commercially available catalytic units for ammonia dissociation are typically large and bulky industrial systems that use alternating current voltage, such as systems manufactured by Thermal Dynamix Inc. (trademark) of Westfield, Massachusetts. These industrial ammonia dissociation systems are not suitable for use on a vehicle considering their size, weight, and high voltage requirements. 【0004】 Conventional electrocatalytic units for vehicles, also referred to as catalytic converters, are well known. These catalytic units typically have a planar metal conductor through which an electric current passes. For example, Emitec Technologies GmbH (trademark) located in Lohmar, Germany, manufactures an electrocatalytic converter used for treating exhaust gas emissions and including a spiral planar conductor. Such planar conductors are used for exothermic reactions. 【0005】 The ammonia dissociation reaction is highly endothermic, meaning that a large amount of heating is required to break the chemical bonds of the ammonia molecules. The high temperature and therefore high energy required to crack ammonia can make the process of producing hydrogen within an onboard electrocatalytic unit inefficient and expensive. 【0006】 The energy to heat the electrocatalytic unit is typically supplied by the vehicle battery. Under continuous stop-and-go driving conditions, high currents are repeatedly drawn from the vehicle battery when the electrocatalytic unit is used to initiate hydrogen production. This continuous and repeated current drawing from the vehicle battery risks rapidly draining the battery, potentially rendering the vehicle unable to start, and in extreme cases, even damaging the battery itself due to excessive heat generated by the high current; this is a concern, especially if high current drawing persists for extended periods. Furthermore, drawing high currents can cause a significant drop in battery voltage, potentially affecting the performance of other electrical components in the vehicle. 【0007】 In addition, typically, an electrocatalytic unit has a single heating element that is always fully energized, meaning the heating element is either drawing its entire current or not drawing any current at all. This binary operation can result in excess or unnecessary current being drawn from the power supply when the heating element could provide sufficient heating with a lower heater percentage. 【0008】 Therefore, an electrocatalytic unit is needed that can reach temperatures sufficient to efficiently carry out ammonia dissociation on the vehicle, and that can address the challenges and drawbacks of repeated high-current drawing from the vehicle battery. [Overview of the Initiative] 【0009】 In one embodiment, the present invention relates to an electrocatalyst unit for ammonia dissociation, comprising: a housing having a first section and a second section, the first section including a first heating element and the second section including a second heating element; a first power feedthrough coupled to the first heating element and a power supply; a second power feedthrough coupled to the second heating element and the power supply; a first temperature sensor coupled to the first section; a second temperature sensor coupled to the second section; and a controller communicatively coupled to the power supply, the first temperature sensor, and the second temperature sensor, wherein the controller increases the heater percentage of the first heating element when the temperature detected by the first temperature sensor is below a threshold temperature, wherein the controller supplies power to the second heating element only when (i) the first heating element is operating at its maximum heater percentage and (ii) the temperature detected by the first temperature sensor is below the threshold temperature. 【0010】 In another embodiment, the present invention relates to an electrocatalytic unit for ammonia dissociation, comprising a housing having a first section and a second section, the first section comprising a first heating element and the second section comprising a second heating element; a first power feedthrough coupled to the first heating element and a power supply; a second power feedthrough coupled to the second heating element and the power supply; a first temperature sensor attached to the first section downstream of the first heating element; a second temperature sensor attached to the second section downstream of the second heating element; and a controller communicatively coupled to the power supply, the first temperature sensor and the second temperature sensor, wherein the controller increases the heater percentage of the first heating element when the temperature detected by the first temperature sensor is below a threshold temperature, wherein the controller supplies power to the second heating element only when (i) the first heating element is operating at its maximum heater percentage and (ii) the temperature detected by the first temperature sensor is below the threshold temperature. 【0011】 In yet another embodiment, the present invention relates to an electrocatalytic unit for ammonia dissociation, comprising: a housing having a first section and a second section; a first heating element disposed within the first section, the first heating element having a positive end coupled to a first power feedthrough and a negative end coupled to a first ground terminal; a second heating element disposed within the second section, the second heating element having a positive end coupled to a second power feedthrough and a negative end coupled to a second ground terminal; a first temperature sensor mounted on the first section downstream of the first heating element; a second temperature sensor mounted on the second section downstream of the second heating element; and a power supply, a controller communicatively coupled to the first temperature sensor and the second temperature sensor, wherein the controller increases the heater percentage of the first heating element when the temperature detected by the first temperature sensor is below a threshold temperature, wherein the controller supplies power to the second heating element only when (i) the first heating element is operating at its maximum heater percentage and (ii) the temperature detected by the first temperature sensor is below the threshold temperature. [Brief explanation of the drawing] 【0012】 These and other embodiments of the present invention will be discussed with reference to the following exemplary and non-limiting figures, where similar elements are numbered similarly. 【0013】 [Figure 1] A perspective view of an onboard ammonia dissociation system for an internal combustion engine; 【0014】 [Figure 2] A perspective view of an electrocatalytic unit according to one embodiment of the present invention; 【0015】 [Figure 3] This is a cross-sectional side view of an electrocatalytic unit according to one embodiment of the present invention; 【0016】 [Figure 4] A cross-sectional perspective view of an electrocatalyst unit according to an embodiment of the present invention; 【0017】 [Figure 5] A side side view of an electrocatalyst unit according to an embodiment of the present invention; 【0018】 [Figure 6] A perspective view of a section of the housing of an electrocatalyst unit according to an embodiment of the present invention; 【0019】 [Figure 7] An inlet end face view of an electrocatalyst unit according to an embodiment of the present invention; 【0020】 [Figure 8] An inlet end face view of an electrocatalyst unit with the cover removed according to an embodiment of the present invention; 【0021】 [Figure 9] A flowchart illustrating the sequential energization of heating elements when gas flows through an electrocatalyst unit according to an embodiment of the present invention; 【0022】 [Figure 10] A flowchart illustrating the sequential energization of heating elements when gas flows through an electrocatalyst unit according to an embodiment of the present invention; 【0023】 [Figure 11] A block diagram of a control system for an electrocatalyst unit according to an embodiment of the present invention. Definitions 【0024】 The following definitions are intended to aid in the explanation and understanding of the terms defined in the context of this invention. These definitions are not intended to limit these terms to a narrower scope than those described throughout this specification. These definitions are intended to encompass grammatical equivalents. 【0025】 As used herein, the term “vehicle” means any mobile vehicle capable of carrying one or more human occupants and / or cargo, or capable of performing work, and powered by any form of energy. The term "vehicle" includes, but is not limited to, (a) automobiles such as passenger cars, trucks, vans, minivans, sports utility vehicles, passenger transport vehicles, cargo transport vehicles, two-wheeled, three-wheeled, and four-wheeled vehicles, quadricycles, motorcycles, scooters, all-terrain vehicles, utility task vehicles, and the like; (b) aerial vehicles such as helicopters, aircraft, airships, drones, aerospace vehicles, and the like; (c) vessels such as dry cargo ships, liquid cargo ships, special cargo ships, tugboats, cruise ships, recreational boats, fishing boats, personal watercraft, jet skis, and the like; (d) locomotives; and (e) heavy machinery and equipment, generators, lawnmowers and tractors, agricultural equipment and machinery, forestry equipment and machinery, construction equipment and machinery, mining equipment and machinery, and the like. 【0026】 As used herein, the term “internal combustion engine” means any engine, spark-ignition gasoline engine, compression-ignition diesel engine, rotary, reciprocating, or other engine, in which combustion occurs in a combustion chamber, thereby performing work by the products of combustion, along with any other by-products, exerting a force on a moving surface, from which mechanical output from the engine is obtained. The term “internal combustion engine” includes, but is not limited to, hybrid internal combustion engines, two-stroke engines, four-stroke engines, six-stroke engines, and similar types. 【0027】 As used herein, the term “catalyst” refers to a material that facilitates a chemical reaction. The term “catalyst” includes, but is not limited to, one or more catalysts capable of facilitating dissociation reactions, such as ammonia cracking reactions, whether used as a basic catalyst and / or as an additive catalyst. For the purposes of the present invention, catalysts may include, but are not limited to, unstoichiometric lithium imide, nickel, iron, cobalt, iron-cobalt, ruthenium, vanadium, palladium, rhodium, platinum, sodium amide, and the like, as well as various combinations thereof. 【0028】 As used herein, the terms “dissociation” and “cracking” refer to a process or a series of processes in which ammonia is dissociated and / or decomposed on at least one catalyst into its constituent hydrogen and nitrogen components. 【0029】 As used herein, the term “nickel alloy” refers to pure nickel or an alloy containing nickel as a primary component. The term “nickel alloy” includes, but is not limited to, Inconel® products such as Inconel® 625, Inconel® 718, and Inconel® 725, and other composite metals having nickel as a primary component. Inconel® is a trademark of Special Metals Corporation, Huntington, West Virginia, and is a nickel-chromium superalloy often used in extreme environments where its components are exposed to high temperatures, high pressures, or mechanical loads. 【0030】 As used herein, the term "ceramic" refers to silicon nitride ceramics, steatite, and other non-conductive ceramic materials. 【0031】 As used herein, the term "lattice" refers to a structure in which unit cells are repeated at one or more points in a periodic arrangement, resulting in a structure that appears identical from any point. 【0032】 As used herein, the terms “three-dimensional print” and “three-dimensionally printed” refer to a three-dimensional object obtained through an additive manufacturing process, where the object has height, width, and length. An additive manufacturing process involves the computer-controlled deposition, bonding, or solidification of materials, typically with materials added together layer by layer. 【0033】 As used herein, the terms “seal” and “sealed” refer to protection from the harmful effects of ambient environmental conditions. Such protection includes protection against pressure differences, temperature, fluid / humidity, electric potential, shock, and gaseous composition. These terms also refer to enclosed, vacuum, airtight, and / or gastight environments within housings such as pressure vessels. [Modes for carrying out the invention] 【0034】 It should be understood that aspects of the present invention are described herein with reference to the figures illustrating exemplary embodiments. The exemplary embodiments herein are not necessarily intended to illustrate all embodiments of the present invention, but rather to illustrate a number of exemplary embodiments. Therefore, aspects of the present invention are not intended to be interpreted narrowly in view of the exemplary embodiments. In addition, although the present invention is described in terms of its application to an internal combustion engine of a vehicle, it should be understood that the system can be implemented in any engine-driven setting that can be powered by ammonia and / or hydrogen fuel. 【0035】 Figure 1 is a perspective view of an onboard ammonia dissociation system 100 for an internal combustion engine. The onboard ammonia dissociation system 100 is described in the jointly owned U.S. Patent No. 11,981,562, issued on 14 May 2024, titled "Systems and Methods for the On-Board Catalytic Production of Hydrogen from Ammonia Using a Heat Exchange Catalyst Unit and an Electric Catalyst Unit Operating in Series," which is incorporated herein by reference. 【0036】 In one embodiment, the ammonia liquid tank 102 is attached to a motor vehicle or engine. The ammonia liquid tank 102 can be coupled to a pump. In one embodiment, the tank 102 is refillable and / or replaceable. 【0037】 In one embodiment, the temperature control valve 104 receives a temperature feedback signal, including a temperature reading from the electrocatalyst unit 106, during a cold start of the engine. The temperature feedback signal can be generated by a temperature sensor coupled to the electrocatalyst unit 106. When the electrocatalyst unit 106 reaches a threshold temperature suitable for carrying out the ammonia dissociation process (i.e., the temperature reading is equal to or greater than the threshold temperature), the temperature control valve 104 opens, allowing gaseous ammonia to pass through the heat exchange catalyst unit 108 and move downstream to the electrocatalyst unit 106, which is heated using power supplied from the power source. 【0038】 In one embodiment, a controller (not shown) is coupled to the components of the onboard ammonia dissociation system 100 to receive inputs from various sensors, such as a temperature sensor and a pressure transducer, and can control the operation of heating elements of, for example, a temperature control valve 104, a pressure control valve 110, and an electrocatalyst unit 106. 【0039】 In another embodiment, the controller can be integrated with the vehicle's electronic control unit (ECU) hardware and software. In this embodiment, the flow rate of hydrogen supplied to the engine's injection system can be measured and reported back to the ECU, which acts as a mechanism for controlling the injection method. 【0040】 If the electrocatalytic unit 106 has not reached the threshold temperature, the temperature control valve 104 continuously monitors the temperature feedback signal and prevents the gaseous ammonia from moving downstream to the electrocatalytic unit 106. 【0041】 In one embodiment, the temperature of the heated exhaust gas entering the heat exchange catalyst unit 108 is determined based on the current draw in the electrocatalyst unit 106, where the current draw indicates how effective the heat exchange catalyst unit 108 is in cracking gaseous ammonia. 【0042】 For example, if there is hydrogen and nitrogen passing from the heat exchange catalyst unit 108 to the electrocatalyst unit 106, the ammonia dissociation process is not necessary (except for residual ammonia flowing with the hydrogen and nitrogen), so the heating element of the electrocatalyst unit 106 draws only a minimal amount of current or no current at all. 【0043】 Conversely, when gaseous ammonia passes from the heat exchange catalyst unit 108 to the electrocatalyst unit 106, the heating element of the electrocatalyst unit 106 draws and conducts an electric current to generate heat for cracking. 【0044】 However, during normal or high-load engine operating conditions (i.e., not during cold starts or low-load operating conditions), the onboard ammonia dissociation system 100 does not utilize the electrocatalytic unit 106 to carry out the ammonia dissociation process, because the heat exchange catalytic unit 108 carries out the ammonia dissociation process, which is heated to a threshold temperature by the exhaust gas from the engine. 【0045】 In one embodiment, the pressure control valve 110 is arranged in series with the temperature control valve 104 and controls the amount of gaseous ammonia supplied to the heat exchange catalyst unit 108. 【0046】 In one embodiment, to facilitate a cold start of the onboard ammonia dissociation system 100 when the exhaust gas from the engine is not at a suitable threshold temperature for carrying out the ammonia dissociation process, an electrocatalytic unit 106 is used to heat the catalyst so that gaseous ammonia can be cracked, and the resulting hydrogen is supplied to the engine's downstream injection system as co-fuel along with the ammonia. The engine can then burn the hydrogen and ammonia as co-fuel, and by powering the engine, the heated exhaust gas is supplied to the onboard ammonia dissociation system 100. 【0047】 Figure 2 is a perspective view of an electrocatalytic unit 106 according to one embodiment of the present invention. The electrocatalytic unit 106 includes a housing 200, an inlet 202, an outlet 204, and covers 206 and 208 coupled to both ends of the housing 200. 【0048】 In one embodiment, the housing 200 includes a plurality of sections 210, such as four jointly connected sections 210a-d shown in Figure 2. The four sections 210a-d shown in Figure 2 are intended to be illustrative and not limiting, and the housing 200 may include any number of sections 210, from a minimum of two sections to any number of sections required based on a particular engine size, installation area and / or heating requirements. 【0049】 In one embodiment, each section 210 has the same dimensions, such as the same diameter and the same width. In another embodiment, the sections may have variable dimensions, so that the housing 200 can be formed by joining together sections having different widths. In yet another embodiment, the sections may have different diameters, so that the annular space within the housing varies based on the diameter of each section. For example, by utilizing sections with varying diameters, a variety of housing shapes can be formed, such as cones, dual-cone shapes, inverted dual-cone shapes, and other polyhedral shapes where the diameter is not constant along the length. 【0050】 In one embodiment, section 210 forms a circular cylindrical housing 200. In other embodiments, section 210 can form a housing having the shape of an elliptical cylinder, a polygonal cylinder, a cube, a rectangular parallelepiped, a triangular prism, a quadrilateral prism, and the like. 【0051】 In one embodiment, sections 210 are joined together at a joint 212. The joint 212 can be formed by welding, soldering, riveting, bolting, brazing, and / or by using mechanical fasteners to press-fit the opposing sections 210 together. In one embodiment, the joint 212 may include a gasket, such as a beaded gasket, which is intended to improve the seal between each of the opposing surfaces of sections 210. 【0052】 In one embodiment, the sections 210 are detachably connected to one another so that different sections can be used to form a modular housing 200. The ability of the sections 210 to be detached from one another allows for maintenance, repair, and / or replacement of the sections 210 and / or the housing 200 as needed. 【0053】 In one embodiment, each section 210 is formed from a nickel alloy such as Inconel®. 【0054】 In one embodiment, the electrocatalytic unit 106 includes covers 206, 208 positioned at opposite ends of the housing 200. The covers 206, 208 are removably coupled to the housing 200 and can be removed for maintenance or replacement of components within the housing 200. In another embodiment, only one of the covers 206, 208 is removable. In one embodiment, the inner surfaces of the covers 206, 208 can be coated with a ceramic paste that forms a thermal barrier and increases the thermal efficiency of the electrocatalytic unit 106. In yet another embodiment, a gasket, such as a beaded gasket, is positioned between the two opposing components, the covers 206, 208 and the housing 200, to improve sealing. 【0055】 In one embodiment, the inlet 202 is located on cover 206, and the outlet 204 is located on cover 208. The inlet 202 and outlet 204 can be detachably attached to their respective covers 208, 208, thereby allowing different inlets and outlets with various dimensions, sizes, and flow characteristics to be used modularly with the electrocatalytic unit 106. 【0056】 In one embodiment, the inlet 202, outlet 204, and covers 206, 208 can be made from the same metallic material as section 210. In another embodiment, the inlet 202, outlet 204, and covers 206, 208 can be formed from stainless steel, silver, bronze, and equivalent alloys. In one embodiment, covers 206, 208 seal the electrocatalytic unit 106 in an airtight manner. 【0057】 Each section 210 of the electrocatalytic unit 106 includes at least one power feedthrough 214 and at least one temperature sensor 216 for supplying current to a heating element located within the housing 200. The power feedthrough 214 is described in U.S. Patent No. 12,009,650, co-owned, issued June 11, 2024, entitled “Apparatus for an Electric Feedthrough for High Temperature, High Pressure, and Highly Corrosive Environments,” which is incorporated herein by reference. 【0058】 Each power feedthrough 214 is coupled at one end to a power source, which can be a conventional 12V vehicle battery or a separate, dedicated power source. The power source provides current to a heating element located within the housing 200, as will be described in more detail herein in relation to Figure 3. 【0059】 In one embodiment, the dedicated power supply does not supply power to any other vehicle electrical system or internal combustion engine, but only to the electrocatalytic unit 106. 【0060】 In one embodiment, the power supply consists of one or more 8V, 12V, 24V, or 48V batteries connected in series or parallel. The multiple batteries share load requirements from each heating element located within the electrocatalytic unit 106. 【0061】 In yet another embodiment, the power source may be a power pack having multiple lithium-ion (Li-ion) batteries, nickel-metal hydride (NiMH) batteries, lead-acid batteries, ultracapacitors, and the like. 【0062】 In one embodiment, the battery management controller balances and optimizes the power output from each battery in the power supply. The battery management controller protects the power supply and each battery contained therein from various failure mode conditions such as overcurrent protection, overvoltage / undervoltage conditions, and overtemperature or undertemperature conditions. 【0063】 The battery management controller can also measure and estimate the status and parameters of each battery, such as charge status, power status, health status, internal resistance, usable capacity, operating temperature, estimated duty cycle, and similar values. 【0064】 In another embodiment, a battery management controller or its functions can be integrated into the vehicle ECU. 【0065】 Figure 3 is a cross-sectional side view of an electrocatalytic unit 106 according to one embodiment of the present invention. In one embodiment, each section 210 of the housing 200 includes a heating element 300, which is connected to its respective power feedthrough 214 (which is the positive terminal) and its respective ground / negative terminal 218. Current from the power supply is configured to flow from each power feedthrough 214 to its respective heating element 300. 【0066】 In one embodiment, each section 210 includes at least one temperature sensor 216 mounted on the section 210 via a radial mounting fixture. The temperature sensor 216 may be a thermocouple, a thermistor, a resistance temperature detector (RTD), a semiconductor-based sensor, an analog thermometer integrated circuit, or a digital thermometer integrated circuit. In a preferred embodiment, the temperature sensor 216 is a thermocouple. 【0067】 Since each section 210 includes its own heating element 300 and its own temperature sensor 216, the output gas temperature within each section 210 can be monitored, and the gas can be continuously heated as needed as it flows through each successive section 210 in the electrocatalytic unit 106. 【0068】 Arrow 302 indicates the direction of gas flow through the electrocatalytic unit 106, where the gas enters at inlet 202 and flows through sections 210a to d toward outlet 204. In each section 210, a temperature sensor 216 is positioned downstream of the heating element 300. This configuration allows for the detection of the output gas temperature in each section 210. 【0069】 For example, when a gas flows from section 210a to section 210b, the temperature sensor 216a in section 210a detects the temperature of the air, gas, and / or air-gas mixture (collectively referred to herein as "gas" or "gas flow") flowing through section 210a. Based on a comparison of the output gas temperature with a threshold temperature, the heater percentage of the heating element 300a in section 210a is adjusted, as will be described in more detail herein. 【0070】 The threshold temperature can be in the range of 400°C to 700°C, and in a preferred embodiment, the threshold temperature is at least 600°C. If the output gas temperature of the section is higher than or equal to the threshold temperature, this indicates that the gas flow contains little to no ammonia and mainly hydrogen and nitrogen, i.e., gaseous ammonia has been successfully cracked in the electrocatalyst unit 106, or gaseous ammonia has been previously cracked in the heat exchange catalyst unit 108 before flowing into the electrocatalyst unit 106. 【0071】 In this scenario, the heater percentage of the heating elements does not increase, and the downstream heating elements in the electrocatalytic unit 106 are not energized. However, if the output gas temperature of a section is below a threshold temperature, the heater percentage of that heating element is increased based on the temperature difference and gas flow rate, which is described in more detail herein in reference to Figure 9. This method prevents excess or unnecessary current from being drawn from the power supply and ensures that only the power necessary to maintain the output gas temperature at the threshold temperature is supplied throughout each section 210 of the electrocatalytic unit 106. This sequential energization of each heating element 300 in the electrocatalytic unit 106 helps maintain the charge of the power supply, reduces unnecessary power drawdown, and thereby contributes to maintaining the health and lifespan of the power supply. 【0072】 Figure 4 is a cross-sectional perspective view of an electrocatalytic unit, and Figure 5 is a side view of an electrocatalytic unit 106 according to one embodiment of the present invention. In one embodiment, each section 210 is mounted at a different rotational angle (or offset) relative to its adjacent section. As a result of this mounting, the power feedthrough 214 and the temperature sensor 216 are offset from each other, as shown in Figure 5. 【0073】 Furthermore, as a result of this mounting, each heating element 300a-d is positioned in a different rotational direction relative to its adjacent heating elements. The offset arrangement of heating elements 300a-d results in a turbulent gas path as the gas passes through section 210 of the electrocatalytic unit 106. Due to the overlapping nature of the heating elements 300, the gas flowing from the inlet 202 to the outlet 204 of the electrocatalytic unit 106 cannot flow in a straight line; there is no straight line path or channel that provides an unobstructed flow of gas between the inlet 202 and outlet 204 of the electrocatalytic unit 106. Instead, when the gas comes into contact with and / or collides with the heating elements 300, the gas is forced to move around the heating elements 300, resulting in a randomized and nonlinear gas path throughout the electrocatalytic unit 106. 【0074】 In one embodiment, each section 210 is mounted with a rotational offset of 5 to 45 degrees relative to its adjacent section. In one embodiment, the degree of rotational offset between each adjacent section 210 is equal. In another embodiment, the degree of rotational offset between each adjacent section 210 varies. 【0075】 By mounting each section 210 with a rotational offset, the positions of the power feedthrough 214 and temperature sensor 216 vary along the length of the housing 200. This staggered arrangement of the power feedthrough 214 and temperature sensor 216 allows each heating element 300 within each section 210 to be energized at different angular positions inside the inner circumference of the housing 200, and similarly, allows temperature detection at different angular positions inside the inner circumference of the housing 200. 【0076】 Figure 6 is a perspective view of section 210 of the housing 200 of an electrocatalytic unit 106 according to one embodiment of the present invention. Section 210 includes a heating element 300 coupled to a power feedthrough 214 which is the positive terminal and to a ground / negative terminal 218 at the opposite end. In one embodiment, the heating element 300 is a wire heater having a meandering path as shown in Figure 5. The heating element 300 is not limited to the wire heater shown in Figure 5 and can take the form of an air process heater, cartridge heater, tube heater, band heater, strip heater, spiral heater, ribbon wire heater, etching foil heater (or thin film heater), ceramic heater, ceramic fiber heater, lattice heating element, and the like. 【0077】 In another embodiment, the opposite end of the heating element 300 can be directly connected to section 210 (i.e., housing 200) which functions as a negative terminal or ground terminal. 【0078】 In one embodiment, the heating element 300 is removably fixed to section 210, and various types, forms, and shapes of heating elements can be used interchangeably in a modular manner together with the electrocatalytic unit 106. In yet another embodiment, each section 210 of the housing 200 can utilize a different type of heating element. 【0079】 In another embodiment, the heating element 300 is a three-dimensionally printed lattice heating element described in U.S. Patent Application No. 18 / 827,074, co-owned, filed September 6, 2024, entitled "SYSTEM AND METHOD FOR A THREE-DIMENSIONALLY PRINTED LATTICE STRUCTURE FOR HEATING GAS IN A NON-LINEAR PATH," which is incorporated herein by reference. 【0080】 In one embodiment, section 210 may include at least one additional radial mount capable of receiving a temperature sensor 214 (not shown in Figure 6). The additional radial mount may be used for a variety of functions. For example, the additional radial mount may function as an inlet, an outlet, or be coupled to equipment for temperature, throughput, and / or pressure sensing, such as an additional temperature sensor, transducer, flow meter, and similar. 【0081】 In one embodiment, the surface of the heating element 300 is coated with a catalyst that facilitates the ammonia dissociation process. The catalyst can be coated onto the heating element 300 using a wash coating or deposition technique to bond or deposit the catalyst onto the surface of the heating element 300. In one embodiment, the inner surface 600 of section 210 can also be coated with a catalyst. The catalyst can be coated onto the inner surface 600 using a wash coating or deposition technique to bond or deposit the catalyst onto the inner surface 600. 【0082】 In one embodiment, the inner surface 600 is coated with ceramic, so that section 210 functions as an insulator, allowing heat to be focused and reflected and directed towards the heating element 300, which then promotes heating of the catalyst. 【0083】 Figure 7 is an inlet end view of an electrocatalytic unit 106 according to one embodiment of the present invention. Figure 7 illustrates that there is an exemplary rotational offset of 30 degrees between each section 210, so that there is a 90-degree gap between the mounting of section 210a and the rotational mounting of section 210d. 【0084】 Figure 8 is an inlet end view of the electrocatalytic unit 106 of Figure 6 with the cover 206 removed, according to one embodiment of the present invention. As shown, as a result of the rotational offset mounting of each section 210a-d, each heating element 300a-d is positioned in a different rotational direction relative to its adjacent heating elements, preventing a straight, linear path or channel for the gas flow through the electrocatalytic unit 106. 【0085】 In one embodiment, a separate catalyst medium or catalyst such as powder is deposited inside the housing 200 around the heating element 300. 【0086】 Figure 9 is a flowchart illustrating the sequential energization of the heating elements 300 as the gas flows through the electrocatalyst unit 106 according to one embodiment of the present invention. In one embodiment, the controller controls the power supplied to each heating element 300 using temperature feedback signals from the temperature sensors 216 of each section 210. The controller sequentially energizes each heating element 300 as needed to maintain the output gas temperature at a threshold temperature throughout the entire electrocatalyst unit 106. By maintaining the threshold temperature throughout the entire electrocatalyst unit 106, the endothermic reactions necessary for ammonia dissociation can occur continuously as the gas flow passes through each section 210. 【0087】 The threshold temperature is in the range of 400°C to 700°C, and in a preferred embodiment, the threshold temperature is at least 600°C. If the output gas temperature in section 210 is greater than or equal to the threshold temperature, this indicates that the gas flow contains little to no ammonia and mainly hydrogen and nitrogen (i.e., gaseous ammonia has been cracked). 【0088】 In step 900, the gas enters the electrocatalyst unit 106 via the inlet 202. If the ammonia dissociation process is successfully carried out in the heat exchange catalyst unit 108, the resulting gas stream of hydrogen and nitrogen gas (as well as residual ammonia gas) flows into the electrocatalyst unit 106. In this scenario, the gas stream causing cooling within section 210 of the electrocatalyst unit 106 contains little to no ammonia. Therefore, some or all of the heating elements 214 may not need to be energized at all, not at all, or not at all throughout the entire heating cycle. For example, if preheated residual ammonia needs to be cracked within the electrocatalyst unit 106, only the first heating element may be partially energized rather than fully energized, while the remaining downstream heating elements are left off (i.e., not energized and not drawing current). 【0089】 However, if the ammonia dissociation process is not carried out in the heat exchange catalyst unit 108, gaseous ammonia flows to the electrocatalyst unit 106. If the engine is operating under low-load conditions, gaseous ammonia may be preheated by the heat exchange catalyst unit 108, or if the engine is operating under cold start conditions, gaseous ammonia may be cold and not preheated. 【0090】 Referring to the electrocatalytic unit 106 having four sections 210a to d as illustrated in Figure 3, in step 902, the output gas temperature is detected by the temperature sensor 216a. In step 904, the controller receives a temperature feedback signal indicating the output gas temperature of section 210 and compares the output gas temperature with a threshold temperature. 【0091】 If the output gas temperature in section 210a is greater than or equal to the threshold temperature, the process continues to step 906, in which the controller does not adjust the heater percentage of heating element 300a and does not energize the remaining downstream heating elements 300b-d. The gas flow continues through the remaining sections of the electrocatalytic unit 106 (if any) and exits through outlet 204 in step 908. In this step, the gas flow contains the resulting gas mixture of hydrogen and nitrogen components, which, together with fuel or ammonia, is supplied as co-fuel to the injection system of the internal combustion engine. 【0092】 However, if in step 904 the output gas temperature of section 210a is below the threshold temperature, the process continues to step 910, where the controller determines whether the heater percentage of the heating element 300a is at its maximum value (i.e., fully energized and drawing its maximum current from the power supply). If the heating element 300a is not at its maximum heater percentage, the process continues to step 912, where the controller increases the heater percentage of the heating element 300a (i.e., supplies a higher current / more power). 【0093】 In one embodiment, the controller increases the heater percentage of the heating element 300a (i.e., the amount of current drawn by the heating element) in proportion to the magnitude of the difference between the output gas temperature and the threshold temperature, and the gas flow rate through section 210a. 【0094】 For example, during a cold start or low-load operating condition of the engine, the gas flow rate is relatively low, and the heating element 300a may heat section 210a to a threshold temperature, thereby causing ammonia cracking within section 210a. If the gas flow rate increases, the heating element 300a may not generate enough heat to completely crack all the gas entering the electrocatalyst unit 106. This causes the uncracking gaseous ammonia to move downstream to the next section 210b of the electrocatalyst unit 106. In this scenario, the heating element 300a acts as a preheater for the adjacent downstream heating element 300b. 【0095】 However, when the engine is operating under normal or high-load conditions, gaseous ammonia is cracked in the heat exchange catalyst unit 108, and residual ammonia flows from the heat exchange catalyst unit 108 to the electrocatalyst unit 106. Since this residual ammonia is preheated by the heat exchange catalyst unit 108, the heating element 300a may not need to be energized to its full heater percentage in order to maintain the output gas temperature of section 210a at the threshold temperature. 【0096】 In one embodiment, when the difference between the output gas temperature and the threshold temperature is relatively large, the controller increases the heater percentage of the heating element 300a by a proportionally larger amount. This results in the heating element 300a drawing a higher current from the power supply. 【0097】 However, when the temperature difference is relatively small, the controller proportionally increases the heater percentage of the heating element 300a by a smaller amount. This results in a relatively low current draw from the power supply by the heating element 300a. 【0098】 If the heater percentage of the heating element 300a increases, the process returns to step 902, where the output gas temperature of section 210a is detected by the temperature sensor 216a. 【0099】 However, if the heater percentage of heating element 300a is at its maximum value in step 910, the process continues to step 914, where the adjacent downstream heating element 300b is energized. In one embodiment, the heater percentage of the downstream heating element 300b is controlled based on the temperature difference and gas flow rate. The process returns to step 902, where the output gas temperature of section 210b is detected by the temperature sensor 216b. 【0100】 The heater percentage of heating element 300a is increased to its maximum value as needed based on the output gas temperature, and only when heating element 300a is unable to generate sufficient heat while operating at its maximum heater percentage is the downstream heating element 300b powered sequentially, thereby preventing excessive or unnecessary current from being drawn from the power supply. Therefore, the controller (a) does not supply power to the downstream heating element when the upstream heating element generates sufficient heat for cracking; and (b) applies only the heater percentage necessary for the upstream heating element to generate sufficient heat for cracking. Over time, this reduces power supply degradation and discharge, maintaining the health and lifespan of the power supply. 【0101】 In one embodiment, the controller determines the heater percentage of the heating element 300 using an algorithm that takes into account the temperature difference between the output gas temperature and the threshold temperature, as well as the gas flow rate. In one embodiment, the temperature difference and the heater percentage applied to the heating element 300 have an inverse relationship. 【0102】 In yet another embodiment, the heater percentage can be adjusted in steps by a set amount for each heating iteration. For example, if the heater percentage of the heating element 300 is not at its maximum value, the controller can continuously increase the heater percentage by a set amount until it reaches the maximum value or until the output gas temperature of each section 210 reaches a threshold temperature. The set amount can be any increase, for example, from 0.5% to a maximum of 25%. 【0103】 In another embodiment, the heating cycle time of the heating element 300 is determined by the controller based on the magnitude of the temperature difference and / or the gas flow rate. For example, if the temperature difference is relatively large, the heating element can be energized for a proportionally longer period. Conversely, if the temperature difference is relatively small, the heating element can be energized for a proportionally shorter period (i.e., a period shorter than the entire heating cycle), thereby shortening the duration of current drawing by the heating element 300 from the power supply. 【0104】 In one embodiment, the controller can adjust both the heater percentage and heating cycle time of the heating element 300. Unnecessary power draw is prevented by optimizing the current draw percentage and duration to be as small and short as possible while still achieving the desired threshold temperature, thereby contributing to maintaining the health and lifespan of the power supply. 【0105】 In another embodiment, instead of separate power feedthroughs coupled to each section 210, a switching mechanism integrated or coupled to the electrocatalytic unit 106 can be used to supply current to multiple heating elements. For example, a single power feedthrough can supply power to a first heating element in a first section. A switching element, such as an electric relay, can be coupled between the first heating element and a second heating element in an adjacent second section. When the controller determines that power should be supplied to the second heating element, the electric relay can be closed, creating an electrical circuit between the two heating elements, thereby allowing current to be drawn by the second heating element. 【0106】 Figure 10 is a flowchart illustrating the sequential energization of the heating element as the gas flows through the electrocatalyst unit 106 according to one embodiment of the present invention. Figure 10 illustrates a similar process described with reference to Figure 9. However, in Figure 10, if the heater percentage of the heating element 300a is not adjusted in step 1006, the process continues to step 1008, where the controller determines whether a downstream section 210 exists within the housing 200 of the electrocatalyst unit 106. 【0107】 If the controller determines in step 1008 that there is no downstream section 210 within the housing 200, the gas flow exits the electrocatalytic unit 106 through the outlet 204 in step 1010. In this step, the gas flow contains a resulting gas mixture of hydrogen and nitrogen components, which, together with fuel or ammonia, is supplied as co-fuel to the injection system of the internal combustion engine. 【0108】 However, if the controller determines in step 1008 that a downstream section 210 exists within the housing 200, the process returns to step 1002, where the output gas temperature of the adjacent downstream section 210 is detected, and the heater percentage of the heating element 300a is increased, or, if the heating element 300a is already operating at its maximum heater percentage, the downstream heating elements 300b are sequentially energized. 【0109】 In this manner, the controller can continuously monitor the output gas temperature in each section 210 and sequentially energize the heating elements 300 in the electrocatalytic unit 106 as needed. For example, in scenarios where the output gas temperature suddenly drops, such as when the engine transitions from normal operating load to low-load operating conditions (i.e., idling during a stop signal or in stop-and-go traffic), the controller can sequentially energize additional heating elements or increase the heater percentage of one or more heating elements, thereby allowing the ammonia cracking process to continue without interruption. 【0110】 Conversely, in scenarios where the output gas temperature suddenly increases, such as when the engine transitions from low-load operating conditions to normal or high-load operating conditions (i.e., sudden acceleration after stopping at a stop signal or intersection), the controller can proportionally or gradually reduce the heater percentage of the heating element or stop supplying power to the heating element, thereby preventing excessive or unnecessary current from being drawn from the power source. 【0111】 Figure 11 is a block diagram of a control system for an electrocatalytic unit 106 according to one embodiment of the present invention. The controller 1100 receives a temperature feedback signal from the temperature sensor 216, as described herein, and compares the output gas temperature with a threshold temperature. Based on this comparison, the controller 1100 controls the heater percentage applied to the heating element 300. 【0112】 In one embodiment, the controller can control the heating element 300 more efficiently and quickly by collecting time-series data using the artificial intelligence engine 1102. For example, in addition to output gas temperature and temperature difference, data such as ambient temperature, engine temperature, time, weather conditions, road congestion and traffic, navigation and route data, driving behavior, and similar data can be stored in the learning database 1104. 【0113】 The large language model (LLM) 1106 can analyze data in the learning database 1004 and predict or forecast current and / or future power supply requirements based on past patterns. For example, if a vehicle driver travels daily on a route with multiple stop signs or traffic lights, or a route that is routinely heavily congested (i.e., stop-and-go traffic), the LLM 1106 can determine that the electrocatalytic unit 106 is likely to be used under low-load operating conditions of the engine while stopped, idling, or moving at low speed. Based on the analysis of the LLM 1106, the controller 1100 can proactively energize the heating element. 【0114】 Therefore, by predicting the power supply requirements of the heating element 300, the controller 1100 can quickly energize the heating element based on feedback from the artificial intelligence engine 1002 without requiring the controller to fully implement its temperature difference and power supply decisions as described herein. 【0115】 In one embodiment, the artificial intelligence engine 1102 is integrated with or coupled to the controller 1100. In another embodiment, the artificial intelligence engine 1102 is located remotely, such as on a cloud-based LLM or other cloud-based computing device or server. 【0116】 The principles of this disclosure are shown in connection with the exemplary embodiments described herein, but the principles of the present invention are not limited thereto and include modifications, variations, or substitutions thereof.

Claims

[Claim 1] An electrocatalyst unit for ammonia dissociation used in an onboard ammonia dissociation system for an internal combustion engine, A housing having a first section and a second section, the first section including a first heating element, and the second section including a second heating element; A first power feedthrough coupled to the first heating element and power supply; A second power feedthrough connected to the second heating element and the power supply; A first temperature sensor coupled to the first section; A second temperature sensor coupled to the second section; and, A controller that is communicatively coupled to the power supply, the first temperature sensor, and the second temperature sensor. Equipped with, Here, the controller increases the heater percentage of the first heating element when the temperature detected by the first temperature sensor is below the threshold temperature. Here, the controller supplies power to the second heating element only when (i) the first heating element is operating at the maximum heater percentage and (ii) the temperature detected by the first temperature sensor is below the threshold temperature. Electrocatalytic unit. [Claim 2] The electrocatalyst unit according to claim 1, wherein the threshold temperature is a temperature sufficient to carry out ammonia dissociation. [Claim 3] The electrocatalyst unit according to claim 1, wherein the threshold temperature is at least 600°C. [Claim 4] The electrocatalytic unit according to claim 1, wherein the first heating element and the second heating element are selected from the group consisting of an air process heater, a cartridge heater, a tube heater, a band heater, a strip heater, a spiral heater, a ribbon wire heater, an etched foil heater, a ceramic heater, a ceramic fiber heater, and a lattice heating element. [Claim 5] The electrocatalytic unit according to claim 1, wherein the first heating element and the second heating element are coated with a catalyst that promotes ammonia dissociation. [Claim 6] The electrocatalytic unit according to claim 1, wherein the first heating element and the second heating element are mounted in the housing with rotational offset from each other. [Claim 7] The electrocatalytic unit according to any one of claims 1 to 6, wherein the first temperature sensor and the second temperature sensor are mounted in the housing with rotational offset from each other. [Claim 8] An electrocatalyst unit for ammonia dissociation used in an onboard ammonia dissociation system for an internal combustion engine, A housing having a first section and a second section, the first section including a first heating element, and the second section including a second heating element; A first power feedthrough coupled to the first heating element and power supply; A second power feedthrough connected to the second heating element and the power supply; A first temperature sensor attached to the first section downstream of the first heating element; A second temperature sensor attached to the second section downstream of the second heating element; and, A controller that is communicatively coupled to the power supply, the first temperature sensor, and the second temperature sensor. Equipped with, Here, the controller increases the heater percentage of the first heating element when the temperature detected by the first temperature sensor is below the threshold temperature. Here, the controller supplies power to the second heating element only when (i) the first heating element is operating at the maximum heater percentage and (ii) the temperature detected by the first temperature sensor is below the threshold temperature. Electrocatalytic unit. [Claim 9] The electrocatalyst unit according to claim 8, wherein the threshold temperature is a temperature sufficient to carry out ammonia dissociation. [Claim 10] The electrocatalyst unit according to claim 8, wherein the threshold temperature is at least 600°C. [Claim 11] The electrocatalytic unit according to claim 8, wherein the housing is hermetically sealed. [Claim 12] The electrocatalytic unit according to claim 8, wherein the power source is a vehicle battery. [Claim 13] The electrocatalytic unit according to claim 8, wherein the first heating element and the second heating element are mounted in the housing with rotational offset from each other. [Claim 14] The electrocatalytic unit according to any one of claims 8 to 13, wherein the first temperature sensor and the second temperature sensor are mounted in the housing with rotational offset relative to each other. [Claim 15] An electrocatalyst unit for ammonia dissociation used in an onboard ammonia dissociation system for an internal combustion engine, Housing having a first section and a second section, A first heating element is disposed within the first section, the first heating element having a positive terminal coupled to a first power feedthrough and a negative terminal coupled to a first ground terminal; A second heating element is located within the second section, the second heating element having a positive terminal connected to a second power feedthrough and a negative terminal connected to a second ground terminal; A first temperature sensor attached to the first section downstream of the first heating element; A second temperature sensor attached to the second section downstream of the second heating element; and, A power supply, the first temperature sensor, and a controller that is communicatively coupled to the second temperature sensor. Equipped with, Here, the controller increases the heater percentage of the first heating element when the temperature detected by the first temperature sensor is below the threshold temperature. Here, the controller supplies power to the second heating element only when (i) the first heating element is operating at the maximum heater percentage and (ii) the temperature detected by the first temperature sensor is below the threshold temperature. Electrocatalytic unit. [Claim 16] The electrocatalyst unit according to claim 15, wherein the threshold temperature is a temperature sufficient to carry out ammonia dissociation. [Claim 17] The electrocatalyst unit according to claim 15, wherein the threshold temperature is at least 600°C. [Claim 18] The electrocatalyst unit according to claim 15, wherein the temperature detected by the first temperature sensor provides an indicator of whether ammonia dissociation is occurring as the gas flows through the first section. [Claim 19] The electrocatalytic unit according to claim 15, wherein the first heating element and the second heating element are coated with a catalyst that promotes ammonia dissociation. [Claim 20] The electrocatalytic unit according to any one of claims 15 to 19, wherein the first heating element and the second heating element are mounted in the housing with rotational offset from each other.

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