Fuel quality determination system and associated method of operation

Abstract

A system for determining a characteristic of fuel supplied to an internal combustion (IC) engine and for adjusting operation of the IC engine based on the determined characteristic. The system includes: an air flow throttle configured to control air supplied to the IC engine; a fuel flow throttle valve configured to control fuel supplied to the IC engine; an engine exhaust oxygen sensor; and a controller configured to receive readings from the throttle valve and control operation of the throttle valve. The controller is configured to execute a fuel-air determination procedure, wherein the controller determines a percentage error air-fuel ratio (AF) based on a comparison of a real AF ratio to an ideal AF ratio. The controller is configured to execute a fuel characteristic determination and adjustment procedure, wherein the controller is configured to adjust operation of the IC engine based on a fuel characteristic value determined using a percentage error AF ratio.

Description

[0001] Cross-references This application claims the benefit of U.S. Provisional Patent Application No. 63 / 487,638, filed March 1, 2023, with the United States Patent and Trademark Office, entitled "Fuel Quality Determination Systems and Associated Methods of Operation Application". The application cited above is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates primarily to throttle valves for natural gas engines, and particularly to throttle valves for large natural gas engines used in the oil and gas industry. More specifically, this disclosure relates to systems and methods that use throttle valves and engine control systems to control the mass flow rate to the combustion chamber of large gas-fuel spark-ignition internal combustion engines, particularly for stationary applications in the oil and gas industry. Background Technology

[0003] Throttling valves have long been used in natural gas engines in the oil and gas industry, where natural gas fuel typically has a less predictable quality because it is typically obtained directly or indirectly from the wellhead. The supply of fresh natural gas fuel from the wellhead can be delivered directly through pipelines, or it can first pass through a filter or dryer; however, the natural gas fuel used in the field of this disclosure is typically additionally unrefined.

[0004] Regardless of the variable mass of the fuel, precise flow control is required to ensure optimal and efficient combustion in natural gas engines based on the needs of the Engine Control Module (ECM). Precisely controlled mass flow rates are difficult to achieve, especially regarding non-blocking flow. Electronic throttle valves are commonly used in large engines to control the mass flow rates of fuel and air. Advances in ECM have significantly improved the ability to optimize efficiency and performance, as well as minimize emissions issues associated with spark-ignition internal combustion engines. By continuously monitoring numerous sensors and inputs, the ECM can balance current operator commands relative to performance conditions to determine the optimal supply flow rate required by the engine at any given moment.

[0005] Achieving such optimal control is more challenging when the fuel is unrefined natural gas. Given that natural gas engines in other fields typically have a fuel supply with known characteristics, such engines in other fields can be accurately tuned to achieve maximum power while maintaining compliance with emissions standards and other desirable performance characteristics. However, in cases where the quality and / or composition of the fuel is unknown or can vary over time, the process for tuning the engine can be difficult, and can often require manual sensing to ultimately provide an accurate fuel mass flow based on the engine’s demand. In this context, the disclosed systems and methods can provide greatly improved automatic tuning to the engine based on accurately determining the air mass flow and fuel mass flow at any given time during operation of the engine.

[0006] Accordingly, there has long been a need for an engine control system with a throttle that not only can accurately and consistently deliver the ECM’s demanded mass flow rate on site, but also can provide the user with an output regarding the quality of the natural gas being used as fuel, all while controlling non-choked flow, which is common with respect to low pressure supply flows, and also occurs in many high pressure scenarios. For more background information comparing choked mass flow control to mass flow determination tending to be more easily achieved, reference is made to U.S. Patent No. 9,957,920, a copy of which is incorporated by reference herein in its entirety. SUMMARY

[0007] It will become apparent to those skilled in the art that the judicious use of the disclosure and embodiments disclosed herein will address the above-mentioned and many other unmet difficulties, problems, obstacles, limitations, and challenges, particularly when conceived in light of the following further description considered in the context of a thorough understanding of the prior art.

[0008] By enabling real-time natural gas fuel quality determination through the combination of combustion data with mass flow data, the present disclosure enables this judicious use in connection with the use of fast-acting, highly accurate gaseous supply throttles for large spark-ignited internal combustion engines, which is particularly beneficial for engines using unrefined natural gas as a fuel source. While the preferred embodiments are typically often operated in low pressure applications to control non-choked flow, they enable highly accurate mass flow control. Our goals include achieving such flow control in response to instantaneous demand signals from the engine’s ECM, while maintaining extremely high accuracy at all times over a large dynamic power range, regardless of most upstream, downstream, and even midstream pressure fluctuations.

[0009] The disclosed embodiments include systems and methods using a combination of flow restrictors, whereby the combination involves a mass flow of air (MFA) restrictor and a mass flow of gas (MFG) restrictor according to the present disclosure, further combined with an oxygen sensor, wherein the mass flow of air and the mass flow of gas are determined. Moreover, with respect to the construction of the flow restrictors and other components of the disclosed systems, the specific properties of the fuel can be accurately inferred (including the British Thermal Unit (BTU) content of the fuel), whereby automatic calibration and other interventions of the engine are implemented as needed. This is particularly true in applications where the quality of the fuel is unknown and / or can vary over time.

[0010] Possible embodiments can manifest in many different combinations, as well as many different kinds of improved machines, internal combustion engines, gaseous supply control systems, etc. Other possible embodiments manifest in methods for operating and optimizing such machines, engines, systems, etc., as well as in other types of methods. All of the various aspects of the present disclosure, as well as all various combinations, substitutions, and modifications of these aspects, can all be individually conceived as disclosure if considered from the proper perspective.

[0011] The resulting combinations of the present disclosure are not only more versatile and reliable, but they are also capable of achieving greater accuracy over a larger dynamic power range, regardless of rapidly changing conditions, than ever achieved with such simple systems. Various embodiments improve the relevant art, including by optimizing reliability, manufacturability, cost, efficiency, ease of use, ease of repair, ease of adaptability, etc. While the embodiments mentioned below do not provide anything remotely close to an exhaustive list, the present description describes selected embodiments that are believed to implement many of the essential elements of the present disclosure.

[0012] In accordance with many of the teachings of the present disclosure, the flow restrictors are provided in a form that is readily adaptable to the power requirements of many applications, and readily capable of achieving highly accurate setpoint accuracy for controlling gaseous supply flow rates across a very large dynamic power range in an internal combustion engine. Such flow rate control flow restrictors and related fuel systems substantially depart from the conventional concepts and designs of the prior art, and in doing so provide many advantages and novel features that are not anticipated, made apparent, suggested, or even implied by any of the prior art, either alone or in any obvious combination thereof.

[0013] Through its innovative combination of features and elements, the throttle valve according to the teachings of this disclosure can consistently and reliably achieve highly accurate mass flow control for a wide range of large engine applications, even in non-blocked flow conditions. Some of the features and elements contributing to this result include the use of an integral block assembly for the throttle valve and a fast-acting actuator, coupled with a single integral and rigid rotating shaft for driving the throttle valve blades, supported by three different bearing assemblies along the length of the shaft, and an assembly that houses the control circuitry, the rotating actuator, and the throttle valve itself; all of these contribute to minimizing tilt in control. Furthermore, this disclosure preferably utilizes at least partially redundant multiple pressure sensors, enabling the controller to self-test various sensors in real time.

[0014] A particularly advantageous aspect achieved through the application of this disclosure is a system with a throttle valve having a controller adapted to infer fuel quality characteristics based on the teachings of the disclosed embodiments; and a method for controlling such a system. Such systems and methods preferably employ a combination of an MFG throttle valve and an MFA throttle valve, the MFG throttle valve being used to control the mass flow of fuel, and the MFA throttle valve being configured to control the mass flow of air or a mixture of air and fuel. This combination enables control of the throttle valve's operation such that the controller can reverse-interpolate the characteristics of the fuel flow controlled by the MFG throttle valve, thereby further enabling fine-tuning and other interventions of the throttle valve as needed.

[0015] To gain a deeper understanding of this determination, preferred embodiments deploy throttle valves with fast-acting and accurate control, enabling accurately controllable mass flow rates regardless of relatively low-pressure fuel supply and subsonic non-blocking throttle valve flow rates. The required accuracy is achieved in part by using embodiments with fast-response transducers integrated with the throttle valve position control panel, enabling rapid and accurate monitoring of the throttle valve shaft position almost as quickly as it is controlled. Furthermore, preferred embodiments also ensure rapid and accurate control in part by precisely measuring the flow pressure sampled upstream and downstream of the throttle valve (preferably via pressure ports less than half the throttle valve diameter, upstream and downstream of the central axis of the throttle valve blades), further enhanced by the use of a third pressure sensor (delta-P sensor). The upstream and downstream pressure sensors themselves, and preferably all three mentioned pressure sensors, are also preferably mounted on the same throttle valve position control panel. Other aspects of preferred embodiments include highly accurate fuel and airflow devices with particularly accurate inputs regarding the fuel characteristics of the fluid's specific heat ratio and specific gravity. The air-related characteristics mentioned above are unlikely to change (and can be monitored using Envirotech sensors or sensors with similar outputs), except for those related to the stoichiometric air-fuel ratio, which can be adjusted using an oxygen sensor if the airflow throttle valve (MFA) is positioned after the fuel inlet point. For a given calibrated engine, variations in closed-loop correction are related to changes in airflow or fuel flow / fuel characteristics. Since airflow for a given speed and load condition can now be measured, variations in closed-loop correction can be attributed to changes in fuel characteristics.

[0016] Furthermore, in equipment that monitors engine horsepower consumption (compressor bhp / generator kW), the standalone use of the MFG can be used to infer fuel characteristic changes (BTU / kW). Preferably, software adaptation is also included to automatically adjust the engine based on BTU changes. Changes can be made to the phi target (before and / or after the catalytic converter), spark timing, and / or maximum permissible load based on the BTU input. Phi is the ratio of the stoichiometric air-fuel ratio to the actual air-fuel ratio of an internal combustion engine. A second check can be used to adjust the spark timing and measure the knock level. This helps to correlate the expected relationship between BTU content and methane number. The engine ECM, or the controller of the air and fuel valves discussed in more detail below, can output fuel characteristic information to the gas compressor for more accurate prediction of compressor power and compressor (and internal stage) information. The engine ECM, or the controller of the air and fuel valves, can also output fuel characteristic information to aid in the caching and metering of fuel delivered through the pipeline.

[0017] Another important and advantageous aspect of the disclosed embodiments includes developing a method for minimizing damage caused by backfire events in an engine using a throttle valve according to the teachings of the appended disclosure. This method utilizes the currently disclosed throttle valve embodiment where, when a backfire event is detected via a pressure surge in a downstream pressure port (the pressure surge significantly exceeding levels expected from pressure fluctuations due to more normal engine operation, such as exceeding 50%), the microcontroller is programmed to instantaneously open the throttle valve vanes for at least 150 milliseconds. After maintaining the throttle valve vanes open for the duration specified, the microcontroller then returns to normal operation of the throttle valve. Due to the rapid-acting nature of the disclosed throttle valve embodiment, this method is found to minimize additional damage caused by backfire events, such as bending or other damage to the throttle valve vanes and / or the throttle valve shaft.

[0018] Another aspect of the disclosed embodiments is the use of a combination of MFA and MFG throttle valves, which can greatly shorten the development cycle of engines using such throttle valves.

[0019] For the sake of completeness, many other aspects, objects, features, and advantages of this disclosure will become apparent to those skilled in the art (all to a patentable extent) from the careful and comprehensive review of the following description and accompanying drawings in view of the prior art. Therefore, it is intended that such aspects, objects, features, and advantages also fall within the scope and spirit of this disclosure. However, it should be understood that the detailed description and specific examples are given by way of illustration only while indicating preferred embodiments of this disclosure, as various extensions, variations, and modifications within the spirit and scope of this disclosure will become apparent to those skilled in the art from the detailed description.

[0020] In fact, this disclosure is ultimately defined with respect to one or more patent claims or groups of claims that may be appended to this specification or to a specification claiming priority to this specification, as these claims may be modified, divided, refined, updated, replaced, supplemented, etc., over time. Even though the corresponding scope of this disclosure depends on those claims, for convenience, these descriptions will occasionally refer to “disclosure” or “this disclosure” as if that particular scope were fully understood at the time of drafting. In fact, based on this specification, multiple independent and distinct disclosures may suitably be claimed, such that references to “disclosure” are floating references to anything defined by the final form of the corresponding patent claim. Therefore, to the extent that these descriptions refer to aspects of the disclosure not individually claimed by the final patent claim, such references should not be considered as limiting or describing that variation of the disclosure.

[0021] Therefore, this disclosure is not limited in its application to the details of the construction and the arrangement of components set forth in the following description or shown in the accompanying drawings. Instead, the drawings are illustrative only, and changes may be made to any details shown or described, especially any details referred to as “preferred.” Such changes may be implemented while remaining within the spirit of this disclosure. Furthermore, it will be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting. Other terms and language used to describe this disclosure and its embodiments and their functions are to be considered within the spirit of this disclosure.

[0022] This disclosure is capable of having many other embodiments and can be practiced and performed in many other ways. It should also be understood that many other alternative embodiments, not shown or mentioned, will still be covered within the spirit of this disclosure, which will be limited only by the scope of the claims, which may be original, added, or modified in this patent application or any other patent application that may claim priority to this application in the future. Attached Figure Description

[0023] Various features and advantages of this disclosure will now be described with reference to the accompanying drawings, which are intended to illustrate rather than limit the disclosure, and the reference numerals may refer to similar elements.

[0024] Figure 1 This is a diagram illustrating a fuel quality determination and engine control system according to an embodiment of the present disclosure.

[0025] Figure 2A and Figure 2B This is a perspective view of a preferred mass flow throttle valve.

[0026] Figure 2C This is a front view of a preferred mass flow throttle valve.

[0027] Figure 2D Is it through Figure 2C The cutting plane BB cuts Figure 2C A cross-sectional view of the preferred mass flow throttle valve.

[0028] Figure 3A This is an exploded perspective view of the preferred mass flow throttle valve.

[0029] Figure 3B This is an exploded perspective view of a mass flow throttle valve according to another embodiment of the present disclosure.

[0030] Figure 4 This is a perspective view of a throttle valve body assembly according to an embodiment of the present disclosure.

[0031] Figure 5A This is an exploded perspective view of a spring assembly according to an embodiment of the present disclosure.

[0032] Figure 5B yes Figure 3B An exploded perspective view of the spring assembly of the mass flow throttle valve depicted in the image.

[0033] Figure 6 This is an exploded perspective view of a thermistor assembly according to an embodiment of the present disclosure.

[0034] Figure 7 This is an exploded perspective view of a motor and throttle valve shaft assembly according to an embodiment of the present disclosure.

[0035] Figure 8 This is an exploded perspective view of an intermediate housing assembly according to an embodiment of the present disclosure.

[0036] Figure 9 This is an exploded perspective view of a PCB assembly according to an embodiment of the present disclosure.

[0037] Figure 10 This is a block diagram illustrating a preferred embodiment of a gaseous fuel supply system with a large engine MFG throttle valve, according to various teachings of this disclosure, which is operatively integrated with an internal combustion engine to provide highly accurate control of the gaseous fuel supply to the engine.

[0038] Figure 11A A flow diagram is provided, which represents the use of fuel-air mass flow characteristics (such as those available using two throttle valves according to the teachings of this disclosure, such as...) Figure 10 The system implementation (shown in the diagram) of both the fuel throttle valve and the fuel-air throttle valve, along with combustion results (such as information from the exhaust oxygen sensor), determines the quality of the combusted fuel.

[0039] Figure 11B A flowchart is shown representing a method that utilizes air-fuel ratio characteristics (such as that which can be achieved using a system with two throttle valves according to the teachings of this disclosure). Figure 11B Intended to provide Figure 11A Further understanding of the methods described in [the document].

[0040] Figure 11C Showing an intention to further represent Figure 11A and Figure 11B A flowchart describing the method. Figure 11C It emphasizes the methods used to determine the characteristics of selected fuels and the control strategies used to adjust those characteristics.

[0041] Figure 12 A representative fuel table is shown for inferring the characteristics of selected fuels.

[0042] Figure 13 Representative response curves are shown, which serve as a supplementary source for inferring the characteristics of selected fuels.

[0043] Figure 14 A fuel recovery system incorporated into the power system of this disclosure is shown.

[0044] Figure 15A and 15B Downstream and upstream perspective views of a throttle valve body assembly including an orifice annular sensing ring according to embodiments of the present disclosure are shown, respectively.

[0045] Figure 16A and 16B Show respectively Figure 15A and 15B The upstream sensing loop and downstream sensing loop are shown in the figure.

[0046] Figure 17 Show Figure 15A and 15B The image shows a cross-sectional view of the throttle valve body assembly. Detailed Implementation

[0047] The following examples are described to illustrate preferred embodiments for carrying out this disclosure in practice, as well as certain preferred alternative embodiments (to the extent that they appear particularly illustrative at the time of writing). In understanding these various descriptions of the preferred and alternative embodiments, those skilled in the art will be able to not only gain a greater understanding of this disclosure, but also a greater understanding of some of the various ways in which this disclosure and its embodiments are made and used.

[0048] Vocabulary Conventions For the purposes of these descriptions, minor simplifications of terminology should be understood as general, unless otherwise specified in the particular context of the specification or any claims. For the purpose of understanding what may be fundamental to this disclosure, the use of the term “or” should be assumed to mean “and / or”, unless explicitly indicated to refer only to alternatives, or unless the alternatives are inherently mutually exclusive. When referring to values, the term “about” may be used to indicate approximate values, generally including the standard deviation of the error of any particular embodiment disclosed or commonly used to determine or implement such values. Reference to an element (often beginning with an article like “a” or “an”) may mean one or more, unless explicitly indicated otherwise. Such “one or more” meanings are most specific when used in conjunction with open-ended terms such as “having,” “comprising,” or “including.” Similarly, “another” may mean at least a second or more. Other words or phrases may have limiting meanings herein or in the accompanying background or summary description, and those limiting meanings should be assumed to apply unless the context suggests otherwise.

[0049] These descriptions occasionally point out and offer perspectives on various possible alternatives to emphasize that this disclosure is not limited to any particular embodiment; however, the described alternatives remain merely selected examples and do not represent an exhaustive identification of possible alternatives known at the time of drafting. The descriptions may occasionally even rank certain alternatives by a level of preference such as “most” or “more” preferred, etc., but such ranking should not be taken seriously unless such a ranking is irrefutably required by the final claim disclosure. Indeed, in the context of the overall disclosure, none of the preferred embodiments or mentioned alternatives should be considered restrictive unless our final patent claims irrefutably claim a corresponding limitation without any possibility of further equivalents, recognizing that many of the specific elements of those final patent claims may not require infringement under the U.S. doctrine of equivalents or other equivalent legal principles. That said, even though the disclosure should be presumed to cover all possible equivalents of the claimed subject matter, it should also be recognized that one or more particular claims may not cover all described alternatives, as indicated by an explicit disclaimer during examination or by limitations required to maintain the validity of the particular claims in light of prior art.

[0050] As of the date of writing, the structural and functional combinations characterized by these examples are considered to represent effective preferred models for practicing this disclosure. However, in view of this disclosure, those skilled in the art should be able to fill in, correct, or otherwise understand any gaps, misstatements, or simplifications in these descriptions.

[0051] For descriptive purposes, if the supply flow rate setpoint accuracy consistently falls within 5% of the demand flow rate across its entire operating range, we classify the supply flow rate setpoint accuracy as "generally accurate." When it consistently falls within 3% of the demand flow rate across the entire range, the setpoint accuracy can be classified as "highly accurate." In the extreme case where the setpoint accuracy consistently falls within approximately 1% of the demand flow rate across the entire operating range, it can be classified as "extremely accurate."

[0052] It is also worth noting that while many embodiments can be used for mass flow control of air or fuel or a combination of air and fuel, these descriptions will generally refer to the control of the “supply flow,” which should be understood broadly to mean the control of any such supply flow, whether it is air, fuel, or a combination. Nevertheless, it will be understood that, according to these descriptions, a throttle valve designed for precisely controlling the fuel supply flow will be installed in a different location on the conduit than a throttle valve installed on the conduit for controlling only the air. Similarly, according to these descriptions, a throttle valve deployed for controlling the mass flow of air without fuel will be installed in a different location on the conduit than a throttle valve installed on the conduit for controlling the mixture of fuel and air. We currently tend to include one throttle valve for controlling only the gaseous fuel supply flow to achieve highly accurate control of the fuel mass flow (sometimes referred to as the gas mass flow or “MFG”), and another throttle valve further downstream for controlling the supply flow after the air and fuel supply flow have mixed (sometimes referred to as the air mass flow or “MFA,” regardless of whether fuel is included in the same flow). Nevertheless, complete and highly accurate mass flow control can be achieved by combining the MFG throttle valve with the MFA throttle valve installed in the air supply via a pipe upstream of the fuel-air mixer. Furthermore, if other reliable data is used to calculate the air mass flow (such as by using an oxygen sensor in conjunction with pressure, temperature, etc.), generally accurate overall control can be obtained by controlling only the fuel mass flow without actively controlling the air mass flow.

[0053] With respect to any valve, throttle valve, or actuator, "fast-acting" is a term generally understood by those skilled in the art, and the term should be assumed to generally mean that it is designed to act or respond much faster or more rapidly than most throttle valves, valves, or actuators. A more restrictive definition may be applied to the phrase to the extent that it is explicitly waived during examination, or to the extent necessary to maintain the validity of the particular claim in light of prior art. Regardless of the assumed broader meaning, the fast-acting actuators mentioned in these descriptions are preferably capable of moving the actuated throttle valve element through a large portion (preferably from 20% to 80% of that operational range) (if not the entire operational range) within fifty milliseconds or less, but many other types of actuators may still be suitable as alternatives, especially to the extent that the elements of the particular claim do not explicitly waive the requirement for a particularly fast-acting feature.

[0054] The term "large engine throttle valve" 10 is used herein to describe a mass flow throttle valve of many preferred embodiments, and refers to the throttle valve and the throttle valve control system, not just the throttle valve body assembly 20 or the butterfly valve (or throttle valve vane) 210 therein. Regardless of the description of the throttle valve 10 as "large engine," the reader should understand that various aspects of such a large engine throttle valve can also be beneficial to smaller engines, such that the reference to "large engine" should not be considered restrictive unless estoppel, given the effectiveness of the prior art, or other legal principles expressly require a limitation to the interpretation of large engines. The simpler term "throttle valve" 20 is used interchangeably herein with the term "throttle valve body assembly" 20. Regarding fuel, the term "fluid" means liquid or gas herein, but liquid fuel embodiments are preferably adapted to vaporize the liquid phase of the fuel before the flow reaches the large engine throttle valve 10. In the context of supply flow rate control, a "continuous fluid passage" refers to any kind of fluid channel, whether defined by a pipe, road, chamber, baffle, manifold, or any other fluid channel, which is not interrupted by a fully closed valve, piston, positive displacement pump, etc., during its normal operating mode for controlling fuel flow rate, such that gaseous fluid can flow substantially continuously through the continuous fluid passage (whenever a pressure gradient causes such flow). However, it should be understood that in this context, the continuous fluid passage can be adjusted to zero flow rate by reducing the effective area of ​​the opening to zero, and in this context, the passage will still be considered a continuous fluid passage. Furthermore, unless otherwise expressly disclaimed, equivalent structures can be completely closed when not operated to control flow rate, and equivalent structures may also have parallel or alternative channels, one or more of which can be interrupted without stopping the overall flow.

[0055] System Diagram Figure 1A system 1 is shown for making fuel quality determinations and providing mass flow control of fuel and air entering an internal combustion engine 102. Additionally, system 1 is configured to command the operation of engine 102 based on the made fuel quality determinations to improve the operation of engine 102 and / or exhaust emissions. System 1 includes: an MFG throttle valve 10 configured to provide mass flow control of a fuel supply 350; an MFA throttle valve 140 configured to provide mass flow control of a fuel-air mixture 150 delivered to engine 102; and an oxygen sensor 190 configured to measure the oxygen level in the exhaust gas produced by the combustion of the fuel-air mixture within engine 102. As will be discussed in more detail below, each throttle valve 10, 140 includes a microcontroller 930 for controlling the operation of the throttle valve 10, 140. The controller 930 for each throttle valve 10, 140 and the oxygen sensor 190 are interconnected by a controller area network (CAN) 195. In some embodiments, each microcontroller 930 and oxygen sensor 190 are interconnected in CAN 195 by a CAN hub, to which the controller 930 and oxygen sensor 190 of each throttle valve 10, 140 are connected. However, as Figure 1 As depicted, in other embodiments, CAN195 does not include a hub, and each of the controller 930 and oxygen sensor 190 is directly connected to each other via CAN195.

[0056] Additionally, the engine control module (ECM) 100 of engine 102 (discussed in more detail below) is communicatively connected to the controller 930 of each throttle valve 10, 140, as shown by lines 196, 197, to enable communication between the ECM 100 and the controller 930. In some embodiments, connections 196, 197 are wired connections (such as, for example, RS485 or RS232 connections), and in some embodiments, connections 196, 197 are wireless connections. In some embodiments, connections 196, 197 may be managed by an Ethernet protocol. In some embodiments, connections 196, 197 include portions of CAN 195. That is, in some embodiments, the controller 930 of each throttle valve 10, 140, the ECM 100, and the oxygen sensor 190 are all connected to each other via CAN 195. In addition, there are some embodiments in which the oxygen sensor is not connected to the throttle valves 10 and 140 via CAN195, but instead the oxygen sensor 190 is able to transmit readings to the ECM100, which is then configured to relay the oxygen sensor 190 readings to the controllers 10 and 140 via connections 196 and 197.

[0057] As will be discussed in more detail below, connections 196, 197 enable controller 930 to transmit fuel characteristic information determined by controller 930 to ECM 100 for use by ECM 100 when operating the engine. Furthermore, in some embodiments, controller 930 commands certain operations of engine 102 based on calculations and determinations performed by controller 930. Additionally, according to some embodiments of this disclosure, connections 196, 197 are used to transmit engine-specific data from ECM 100 to controller 930. For example, such engine-specific data may be used by controller 930 to make fuel characteristic determinations or to accurately provide mass flow control. In some embodiments, ECM 100 is configured to send engine 102 operating data (such as, for example, engine load and engine speed) to controller 930 via connections 196, 197 for use by controller 930 in determining whether engine 102 operating conditions are sufficient or suitable for determining fuel characteristics, as discussed in more detail below. Additionally, in some embodiments, connections 196 and 197 can be used to transmit operating commands for throttle valves 10 and 140 from ECM 100 to controller 930.

[0058] System 1 operates by first controlling the fuel supply 350 from fuel source 360. Using MFG 10, the fuel supply 350 discharged from MFG 10 to fuel-air mixer 161 is mixed with air supply 160 to produce fuel-air mixture 150 for powering engine 102. The fuel-air mixture 150 supplied to engine 102 is controlled by MFA 140. Although MFA 140 is depicted downstream of fuel-air mixer 161, such that fuel-air mixture 150 passes through MFA 140, according to other embodiments, MFA 140 is positioned upstream of fuel-air mixer 161, such that air supply 160 passes through and is controlled by MFA 140.

[0059] As will be discussed in more detail below, each throttle valve 10, 140 includes multiple different sensors (pressure sensors 950-952, thermistor 600, throttle valve vane position sensor 940), from which the controller 930 acquires and stores sensor readings. Each controller 930 and oxygen sensor 190 is configured to transmit and receive various information, such as sensor readings and commands, to another controller 930 and oxygen sensor 190 via CAN 195. Therefore, the controller 930 of MFG 10 can perform calculations for controlling MFG 10 and MFA 140 based on readings from MFG 10, MFA 140, and oxygen sensor 190. Similarly, the controller 930 of MFA 140 can perform calculations for controlling MFG 140 and MFA 10 based on readings from MFG 10, MFA 140, and oxygen sensor 190. Additionally, the controller 930 of throttle valves 10, 140 can perform calculations for controlling certain operations of engine 102.

[0060] As previously mentioned, the currently disclosed invention is that MFG10 and MFA140 are capable of providing mass flow control for the supply of 350, 150, and using readings from MFG10, MFA140 and oxygen sensor 190 to determine the fuel quality of the fuel supply, and controlling the operation of engine 102 based on the determined fuel quality. Although not referenced... Figure 1 The discussion will be further elaborated below, but the specific readings, operations, and calculations performed by the controller 930 when operating valves 10, 140 and engine 102 to provide mass flow control will be discussed in more detail below.

[0061] As discussed, the operation of each of MFA10 and MFG140 is performed entirely by any one of the controllers 930. Therefore, System 1 is capable of operating without control by a main controller (such as, for example, ECM). This allows System 1 to be easily incorporated into conventional or existing engine systems in a retrofit or "plug-and-play" manner. Therefore, an aspect of the invention of this disclosure is that engine 102 can be retrofitted using System 1 to provide mass flow control of fuel supply 350 and air-fuel mixture 150 without access to or control capability of ECM 100. While System 1 is described as including MFG10, MFA140, and oxygen sensor 190, those skilled in the art will understand that, according to other embodiments of this disclosure, System 1 includes, as discussed in more detail below, […]. Figure 1 and Figure 10 Other components shown in the image.

[0062] As will be discussed in more detail below, in addition to mass flow control of fuel and air supplied to engine 102, another inventive aspect of system 1 is its ability to determine the quality of the fuel supplied. Often, the fuel supply originates from a source in which the specific quality of the fuel is unknown. System 1 is configured to determine the amount of fuel advantageous to the operator. In some embodiments, system 1 is configured to determine various fuel characteristics, such as, for example, BTU value, methane value, and phi value. According to some embodiments, based on the determined fuel quantity, system 1 is further configured to adjust the operation of engine 102 based on the quality of the fuel supplied to engine 102 to optimize the performance and efficiency of engine 102. Additionally, as will be discussed below, according to some embodiments in which fuel supply 350 is a mixture of different fuels, system 1 is configured to determine the proportion of each of the different fuels within fuel supply 350. Again, these calculations can be performed by any one or both controllers 930. The controller 390 of each valve 10,140 may be referred to as a “computation controller” because any one or both of the controllers 930 are configured to perform calculations for controlling the fuel and air supply to the engine 102, and for calculating fuel characteristic values ​​for the ECM 100 for use in optimizing the performance and operation of the engine 100.

[0063] Exploded and unexploded views of the large engine throttle valve 10 Go to Figure 2A and 2B This image shows a perspective view of a preferred large engine throttle valve 10. Throttle valve 140 (generally described as MFA) is identical to throttle valve 10 (generally described as MFG), and those skilled in the art will understand that the descriptions and components of throttle valve 10 are the same as those of throttle valve 140. To reduce redundancy, throttle valve 10 is described, but those skilled in the art will understand that throttle valve 140 is identical to throttle valve 10. As shown, the large engine throttle valve 10 includes an inlet adapter 30 and an outlet adapter 40. The inlet adapter 30 partially defines a supply inlet 390 configured to allow a supply flow into the large engine throttle valve 10. The outlet adapter 40 partially defines a supply outlet 170. Figure 2D and 10 (As shown in the image), it is configured to allow supply flow to exit the large engine throttle valve 10. Mechanical screws 31-34 mate with mechanical nuts 31a-34a for securing the inlet adapter 30 to the housing assembly 20. Figure 2C-4 (As shown in more detail below). Similarly, machine screws 41-44 are paired with machine nuts 41a-44a for securing the outlet adapter 40 to the housing assembly 20. Detailed descriptions of the components and parts of the preferred embodiment are provided in the following paragraphs.

[0064] Reference Figure 2CThis image shows a two-dimensional view of a large engine throttle valve 10. A coolant port 220 (shown in a dashed box) is visible at the front of the housing assembly 20, and another coolant port 221 (not shown) is located on the opposite side. Especially when the throttle valve 10 is used as an air-fuel (MFA) throttle valve, hot gases can flow through it. To cope with the temperature of such hot gases, and particularly to protect against thermal damage to the control circuitry associated with the PCB 900 or to the motor 700, a radiator (not labeled) is located within an integral block assembly 99 between the main throttle valve body assembly 20 and the motor 700 and PCB 900. The radiator is preferably in the form of an aluminum member that surrounds one or more flow channels with a relatively large surface area, allowing liquid coolant to circulate through it and thereby cool the aluminum member. As will be understood by those skilled in the art, radiators are commonly used in turbocharged applications, such as the large engine throttle valve 10. Coolant ports 220 and 221 allow coolant to enter and flow around the large engine throttle valve 10 to prevent the brushless motor 700 ( Figure 7 (Display in the middle) and main PCB900 ( Figure 9 (The text appears to be incomplete and contains errors. A more accurate translation would require the full context.)

[0065] Reference Figure 2D ,show Figure 2C The embodiment shown is a cross-section rotated 90 degrees clockwise (indicated by line BB). A throttle shaft 710 (sometimes referred to as the actuator "drive shaft") controls the movement of the throttle vane 210, minimizing the chance of deviation or other errors. The upstream pressure P1 (upstream of the throttle vane 210) is measured at port 230 by a pressure sensor 951 on the PCB 900, because the stovepipe of sensor 951 is in open fluid communication with port 230 via a pipe extending through an open passage (not shown) through the integral block assembly and between port 230 and the stovepipe of sensor 951. Similarly, the downstream pressure P2 (downstream of the throttle vane 210) is measured at port 240 by a pressure sensor 952 on the PCB 900, because the stovepipe of sensor 952 is in open fluid communication with port 240 via a pipe extending through an open passage (not shown) through the integral block assembly and between port 240 and the stovepipe of sensor 952.

[0066] Each of ports 230 and 240 has a fluid passage segment adjacent to the port, oriented perpendicular to the streamline of the throttle valve fluid passage of the throttle valve 10 to minimize stagnation or suction pressure due to their orientation relative to the flow. However, to minimize the risk of blockage, the next adjacent segment of each is oriented slightly upward relative to gravity. A thermistor 600 ( Figure 6(As shown in the image) The temperature of the fluid is measured at port 250. Mechanical screws 201-204 unite the throttle valve body assembly 20 with the intermediate housing assembly 80.

[0067] Reference Figure 3A The dashed box is used to depict embodiments of the integral block assembly 99 of the throttle valve 10 and some of the various components within it. While some (but not all) embodiments of the throttle valve 10 employ an integral block for each throttle valve 10, the components rigidly joined to form the integral block assembly 99 include the throttle valve body 22 of the central throttle valve body assembly 20, and the components facing... Figure 3A The spring return cover 550 of the spring return assembly 50 at the right end of the middle, facing... Figure 3A The control circuit cover 901 is located at the other end on the left side, where the intermediate housing 800 of the motor housing 80 is positioned between the throttle valve body assembly 20 and the PCB space. Additionally, as will be understood, numerous screws are used to... Figure 3A In this embodiment, the sub-blocks are rigidly joined together, preferably using insert seals to ensure a sealed joint between each of the various sub-blocks. Two additional sub-blocks (i.e., the inlet extension and the outlet extension) are also joined together. Figure 3A The overall block component 99. Similarly, Figure 3A The overall block component 99' shown in the embodiment also relates to Figure 3A The components are very similar.

[0068] More specifically, in a preferred embodiment, the integral block assembly is composed of various sub-blocks and caps, which are preferably all primarily made of aluminum. The resulting integral block assembly of the throttle valve 10 defines the inner and outer surfaces of the throttle valve 10. This integral block assembly is shown as a blank-type assembly of aluminum parts. Figure 1-4 While this is evident in the various views, it should be understood that preferred embodiments can also be formed by larger castings with fewer sub-blocks to reduce the cost of mass production. These components are shown in more detail in the figures below. Figure 3A The throttle valve body assembly 20 is shown in the image (more specifically in...). Figure 4 The inlet adapter 30 is shown above the throttle valve body assembly 20. Four screws 31-34, using a circular seal 35, unite the inlet adapter 30 to the throttle valve body assembly 20 to allow a sealed mass flow from upstream into the throttle valve body assembly 20. Similarly, the outlet adapter 40, using a circular seal 45 and screws 41-44, unites the throttle valve body assembly 20 to allow a sealed mass flow downstream of the throttle valve body assembly 20. Although minor, it is worth noting that the inlet adapter 30 and outlet adapter 40 are more advantageous when the throttle valve 10 is used as an MFG throttle valve (as opposed to when it is used as an MFA throttle valve).

[0069] Although each of the multiple spaces defined by the integral block assembly and collectively housing the rotating shaft 710 (i.e., the PCB space, the motor space of the intermediate housing 800, the throttle body space, and the spring return assembly space of the assembly 50) is formed by the sealed union of adjacent sub-blocks, leakage can still occur from one such space to the next due to imperfect sealing around the rotating shaft 710. Therefore, to protect the control circuitry of the PCB 900 from the corrosive effects of the gaseous fuel supply, the electronic components of the PCB 900 are coated with a coating that protects such electronic components from the additional corrosive properties of the gaseous fuel.

[0070] The right side of the throttle valve body assembly 20 is the spring assembly 50. Figure 5A (Details shown in the image). The spring assembly 50 operates as a torsion spring, which tightens when the block assembly 10 is energized. When the block assembly 10 is de-energized, the spring assembly 50 releases and returns to the closed position, or more preferably, to the substantially closed position. To the left of the throttle valve body assembly 20 is the temperature-sensing thermistor assembly 60 (…). Figure 6 (See details below). On the left side of the throttle valve body assembly 20, there is also a motor and throttle valve shaft assembly 70 (…). Figure 7 (details shown in the image), its control throttle valve ( Figure 4 The movement of the intermediate housing assembly 80 (as shown in the image). Figure 8 (As shown in detail) the motor and throttle valve shaft assembly 70 and the printed circuit board (PCB) assembly 90. Figure 9 (The details are shown in the text)

[0071] As an alternative to the embodiments of Figures 3 and 5, Figure 3A and 5A A comparable but alternative embodiment is shown. However, since throttle valve 10' is very similar to throttle valve 10, therefore... Figure 3A and 5A Each part in the diagram is labeled similarly to a considerable portion of Figures 3 and 5, with the main difference being... Figure 3A and 5A The components in the embodiment are marked with an apostrophe ("'"). Specifically, refer to... Figure 3B Almost all the sub-components of the throttle valve 10' are actually related to Figure 3A The components are similar to those of the throttle valve 10, with the most notable exception being the spring return assembly 50', which has components that are similar to but different from those of the spring return assembly 50.

[0072] despite this, Figure 5B Details and Figure 5A Those similar details are different enough that some descriptions can be useful. In particular, Figure 5BComponent 510' is a shaft seal. In this embodiment, seal retainers 511' and 512' are combined into one component. Part 501' is a bushing separator supporting spring 500', and screw 531' screws component 50' onto the end of throttle shaft 710. The D-shaped cut in screw 531' tends to orient the spring assembly to a desired orientation on shaft 710. Bearing assembly 513' is a conventional bearing assembly very similar to bearing assembly 513, and element 520' is a bearing free-load spring. Part 530' is a spring return element for returning throttle vane 210 to a position five degrees from full closure. Each end of spring 500' has a protruding flared end that engages a matching notch, etc., to drive the spring-biased return of throttle vane 210 in a manner generally common to many spring-biased return operations used in automotive throttle valves.

[0073] Throttling valve body assembly 20 Reference Figure 4 This image shows an isometric view of the throttle body assembly (also referred to as a "gas supply throttle valve") 20. As previously discussed, the throttle body assembly 20 can be used to control the flow rate of fuel, air, or a fuel-air mixture. The cylindrical volume of the space of the throttle body assembly 20 from top to bottom is defined herein as the throttle chamber 205. For a fuel throttle valve, the diameter of the throttle orifice 200 is preferably between 50 mm and 76 mm. For a fuel-air throttle valve, the diameter of the throttle orifice 200 is preferably between 60 mm and 120 mm. Note that while the throttle orifice 200 is circular in the preferred embodiment, other shapes, such as a square orifice, may be used in alternative embodiments.

[0074] Spring assembly 50 Reference Figure 5A This displays an exploded view of the spring assembly 50. Figure 5A On the upper left is the throttle valve shaft seal 510 (regarding insertion), which seals the throttle valve shaft 710 ( Figure 7 (As shown in the image). A throttle valve sealing spacer 511 separates the throttle valve shaft seal 510 from the seal retainer washer 512. A roller bearing 513 is located between the seal retainer washer 512 and the wave spring 520. A spring guide bearing 501 prevents the torsion spring 500 from contacting or rubbing against the body of the throttle valve 10. A larger spring guide bearing 502 separates the torsion spring 500 from the spring return flange 530. A helical vertical pin 531, located at the center of the flange 530 of the spring assembly 50, transmits the neutral bias pressure of the spring 500 to the shaft 710 and subsequently to the throttle valve vane 210. Screws 551-554 secure the spring return cap 550 to the throttle valve body assembly 20, and an O-ring 540 seals the assembly together. (See reference...) Figure 5BAn alternative embodiment shows another exploded view of the spring assembly 50', which has a similar structure and functions in a manner substantially similar to that of the spring assembly 50.

[0075] Thermistor assembly 60 Reference Figure 6 The image shows an exploded view of the thermistor assembly 60. In one embodiment, the thermistor 600 has a temperature measurement range from -70°C to 205°C. The thermistor assembly 60 has two O-ring gaskets 603 and 604 that function as a sealing layer. Leads 611 and 612 are soldered to the thermistor PCB 610, extend (not shown) through the intermediate housing assembly 80, and are also soldered to the main PCB 900. An epoxy resin overmolded part 620 protects the thermistor 600 and the thermistor PCB 610. A thermistor tube 630 surrounds the epoxy resin overmolded part 620, the thermistor 600, and the thermistor PCB 610. The thermistor tube 630 is joined to the throttle valve body assembly 20 using screws 640.

[0076] Motor and throttle valve shaft assembly 70 Reference Figure 7 The display shows the motor and throttle valve shaft assembly 70. The brushless motor 700 controls the movement of the throttle valve shaft 710. Figure 7 On the upper right is the throttle valve shaft seal (about the insertion) 711. The throttle valve seal spacer 712 separates the throttle valve shaft seal 711 from the throttle valve shaft 710. Four screws 701-704 (three shown) unite the brushless motor 700 and the throttle valve shaft 710 with the throttle valve body assembly 20. The throttle valve shaft 710 extends through the brushless motor 700 and connects to the rotor arm 720. Two rotary bearing assemblies 705 and 706 are present within the motor 700, such that the three bearing assemblies are connected to the rotary bearing assembly 513 (or... Figure 3A In the embodiment, 513' together support the rotatable movement of shaft 710. Screw 730 integrately fastens rotor arm 720 to the end of throttle shaft 710, which is located from the left side of brushless motor 700 (e.g., 513'). Figure 7 (See below) protrudes into the PCB space. The rotor arm 720 has a permanent magnet 740 permanently attached to the radially outward portion of the rotor arm 720, so that the arm 720 can be used in conjunction with the magnet 740 to indirectly measure the position of the throttle valve blade 210 within its rotatable range of motion.

[0077] Intermediate housing assembly 80 Reference Figure 8The intermediate housing assembly 80 is shown. A large open space 810 is used to accommodate the brushless motor 700. A smaller circular opening 820 at the lower left is used to accommodate the Controller Area Network (CAN) pin connector protruding from the main PCB 900. A small opening 830 at the top of the assembly 80 accommodates a reverse flow check valve 840 to protect the sensor from overpressure. Another smaller opening 850 accommodates a forward flow check valve 860 to protect the sensor from overpressure. A recessed seal 870, shaped to mate with the intermediate housing assembly 80, seals the assembly 80 to the throttle body assembly 20.

[0078] Printed Circuit Board (PCB) Assembly 90 Reference Figure 9 The image shows a PCB assembly 90, which hermetically houses a PCB 900. The PCB 900 is surrounded within a space (“PCB space”) defined between a PCB housing cover 901 and an intermediate housing 800, which are sealed together by screws 915-920. The sealed joint between the cover 901 and the intermediate housing 800 is partially achieved by an in-recessed resilient seal 902, which is positioned peripherally around the PCB space at the interface between the intermediate housing 800 and the PCB housing cover 901. Twelve screws 903-914 securely fasten the PCB 900 and pressure sensors 950-952 to the PCB housing 901. Six screws 915-920 (three shown) and the PCB housing seal 902 further secure the PCB assembly 90 to the intermediate housing assembly 80. Figure 8 (As shown in the image) a sealed joint. This type of seal integration enables optimal control and helps minimize external artifacts or other effects that could further affect its operation.

[0079] PCB900 includes microcontroller 930, which can be any commercially available microcontroller with memory capable of receiving machine-readable code (i.e., software). Microcontroller 930 provides the "brain" of the large engine throttle valve 10. Microcontroller 930 receives throttle valve position signals from Hall effect sensors 941a-e of sensor assembly 940, pressure signals from pressure sensors 950-952, temperature signals from thermistor 600, and control signals from ECM 100. Microcontroller 930 uses algorithms to calculate the throttle valve position to achieve the instantaneous desired mass flow rate, and then outputs pulse width modulation and H-bridge signals to motor 80 so that motor 700 correctly controls the position of throttle valve vane 210, while also outputting measurement data to ECM.

[0080] PCB900 has five pairs of identical Hall effect sensors 941a-e, which are part of the position sensor assembly for indirectly detecting the position of the throttle valve vane 210. (See reference...)Figure 10 These sensors are collectively referred to as "blade position sensors" 940. As the throttle valve shaft 710 rotates, the rotor arm 720, an integrated portion of the shaft 710, rotates within the PCB space, causing the magnet 740 to move relative to Hall effect sensors 941a-e, which are capable of detecting the resulting changes in the magnetic field. These sensors 941a-e change their output voltage in response to the changes in the magnetic field, and these electrical signals are processed by a microcontroller 930. Sensors 941a-e are used to calibrate the position of the throttle valve blade 210 relative to the magnetic field strength given by the magnet 740.

[0081] Delta-P sensor 950 is a bifacial pressure transducer that measures the pressure difference (“Delta-P”) between upstream pressure port 230 and downstream pressure port 240. Two pressure sensor gaskets 955 and 956 seal Delta-P sensor 950. Upstream pressure sensor 951 measures the absolute upstream pressure (“P1”) and has pressure sensor gasket 951a. Downstream pressure sensor 952 measures the absolute downstream pressure (“P2”) and has pressure sensor gasket 953. Delta-P sensor 950 is significantly more accurate in measuring pressure difference than simply subtracting the difference between P1 and P2 mathematically. However, a condition exists when the throttle valve operates at pressures outside the range of Delta-P sensor 950. When Delta-P sensor 950 begins to stabilize (peg) (i.e., approach its maximum reliability limit), microcontroller 930 will begin using pressure sensors 951 and 952 to calculate the pressure difference. Once the maximum pressure range is exceeded, the microcontroller 930 will stop using the Delta-P sensor 950 and switch entirely to pressure sensors 951 and 952. Additionally, the PCB 900 will troubleshoot other cases whenever P1, P2, and / or Delta-P fail the validity check. In such cases, error signals may be sent to the ECM 100 and / or controllers 930a and 930b.

[0082] Pressure sensors 951 and 952 are conventional pressure transducers, but unconventional pressure transducers (or even sensors for fluid conditions other than pressure) may be considered as alternatives for some of the same purposes. Pressure transducers 951 and 952 are preferably of a type that can be mounted to and installed on PCB 900, and have a rigid tube connector (sometimes called a "pressure tap") extending from their base through which the transducer obtains the pressure to be sensed.

[0083] To mitigate some of the effects of pressure fluctuations (especially downstream pressure fluctuations), the control algorithm of microcontroller 930 preferably uses time-averaged pressure readings from pressure sensors 950-952, rather than instantaneous pressure readings. More specifically, based on the number of cylinders in the engine and the current RPM received by microcontroller 930 from ECM 100, microcontroller 930 continuously determines the stroke cycle time for the pistons in engine 102.

[0084] Figure 10 -block diagram Figure 10 A block diagram of a power system 1402 according to an embodiment of the present disclosure is shown. The power system 1402 includes the previously discussed system 1. Figure 10 In the illustrative block diagram, there are four main segments depicting the supply flow for the preferred embodiment: (1) an upstream gaseous fuel supply 350; (2) a large engine MFG throttle valve 10; (3) an MFA throttle valve 140; and (4) the depicted engine 102. According to the various teachings of this disclosure, the four segments 350, 10, 140, and 102 are operatively connected to provide rotating shaft power to any number of large engine applications, wherein the fuel supply 350 serves as the basic gaseous fuel supply for the engine 102, and wherein the large engine throttle valve 10 and the MFA 140 are used to provide accurate control of the gaseous fuel and air flow rates from the fuel supply 350 and the air supply 160 to the engine 102.

[0085] As previously discussed, the MFA140 is the same throttle valve as the MFG10, and its components are described in detail above. For clarity, see the reference... Figure 10 When applying for a specific application, the suffix "a" is used to describe and indicate the component markings for MFG10, and the suffix "b" is used to describe and indicate the component markings for MFA140.

[0086] Those skilled in the art will recognize that Figure 1 System 1 is utilized within power system 1402. As previously discussed, one aspect of the invention of this disclosure is the ability of system 1 to provide accurate mass flow control of the fuel supply 350 and air supply 160 to an existing engine system. Thus, according to various embodiments of this disclosure, many components shown (such as, for example, engine 102, fuel tank 360, air-fuel mixer 161, and many of their associated components) are existing parts that are modified using system 1 to provide accurate mass flow control of fuel and air to engine 102.

[0087] Upstream fuel supply 350 like Figure 10As shown, the fuel supply 350 preferably includes a fuel tank 360 as a fluid fuel source, a mechanical pressure regulator 370, and other conventional components such as a gate valve 380. Valve 380 is preferably controlled by an ECM 100, but in alternative embodiments, independent control (such as by controllers 930a, 930b) may be used. The gaseous fuel supply 350 is equipped and adapted to deliver a gaseous fuel supply to a supply inlet 390 at a desired pressure level.

[0088] More preferably, the gaseous fuel supply 350 is a natural gas or vaporized propane fuel supply, which delivers natural gas or propane stored in fuel tank 360. Although Figure 10 Not shown, but fuel tank 360 may be equipped with vaporization sub-assemblies and controls to manage the vaporization of LNG (liquefied natural gas) or propane and the resulting pressure within fuel tank 360 and associated pipelines 365, 375, and 376. Such vaporization sub-assemblies and controls for LNG preferably preheat tank 360 by passing some of the stored LNG through a heat exchange loop that increases the temperature of the pre-circulated LNG to a point of partial or complete vaporization, thereby generating a vapor phase with sufficient head within tank 360. Pipeline 365 preferably also includes a second heat exchanger downstream of fuel tank 360 to further assist in the complete vaporization of LNG or propane once gaseous fuel is allowed to flow from fuel supply 350 to large engine throttle valve 10.

[0089] Downstream of the heat exchanger in line 365, gaseous fuel is sequentially guided through a mechanical pressure regulator 370, a downstream fuel shut-off valve 380, and a line quick-disconnect assembly (not shown) before entering the large engine throttle valve 10. In this embodiment, the initial fuel pressure is supplied by tank 360, but the initial pressure from tank 360 is preferably regulated by the mechanical pressure regulator 370 before reaching the supply inlet 390 of the large engine throttle valve 10. The mechanical pressure regulator 370 is capable of managing the low pressure from tank 360 and includes one or more conventional pressure regulators that use a pressure-balancing diaphragm to change the effective orifice size, thereby controlling the pressure at the supply inlet 390 within a preferred range. The mechanical pressure regulator 370 preferably includes an integrated pressure sensor for providing upstream pressure data (i.e., equivalent to the pressure "P1" at the supply inlet 390) to the ECM 100. Regardless of whether the pressure sensor is integrated with the regulator 370, the preferred embodiment includes a pressure transducer 951 that measures the pressure at port 230 upstream of the throttle valve vane 210 and where the fluid is close to the supply inlet 390, such that it is the same as P1, for reliably inputting the actual pressure of the gaseous supply entering the throttle valve 10.

[0090] Assuming all lines 365, 375, and 376 are operatively sealed and connected to the direct supply flow passing through them, the supply flow from fuel supply 350 to the large engine throttle valve 10 is enabled or disabled by the opening / closing operation of mechanical shut-off valve 380. While a manual valve may be used in some alternative embodiments, valve 380 is preferably actuated by a motor or solenoid via supervisory control of ECM 100. When shut-off valve 380 is open, the gaseous supply flow is caused by an operable pressure gradient between tank 360 and supply inlet 390. Therefore, with valve 380 open, fuel first moves through the heat exchanger and (multiple) mechanical pressure regulators 370, and then is directed through valve 380 and into fuel inlet 390.

[0091] Regardless of the vaporization sub-assemblies and controls, the potential presence of vaporized natural gas or propane fuel, including droplets of liquid LNG or propane, can occur, for example, if the ports or conduits used for the heat exchange fluid are blocked. If any LNG or propane droplets remain in the fuel flow downstream of the (multiple) mechanical pressure regulators 370, their subsequent vaporization can introduce a large pressure spike into the large throttle valve engine 10, which would overwhelm it. To compensate for the possible introduction of LNG or propane droplets downstream of the heat exchanger, a pressure control loop can be inserted into the system at an intermediate location between the (multiple) pressure regulators 370 and the supply inlet 390 leading to the large engine throttle valve 10 (preferably downstream of the heat exchanger and the (multiple) mechanical pressure regulators 370).

[0092] In the event of any abnormal LNG or propane droplets entering the main engine throttle valve 10, delayed vaporization will likely result in a spike in pressure at the supply inlet 390 of the main engine throttle valve 10. If such a pressure spike occurs, the inserted pressure control loop preferably buffers the spike by venting back to the upstream side of the mechanical pressure regulator 370. As an alternative, one or more overpressure vents or bypass check valves may be included in lines 375 and / or 376 to help deflect vaporization spikes that would further propagate and disrupt the control of the main engine throttle valve 10. Similarly, pressure spikes resulting from fuel vaporization upstream of the mechanical pressure regulator may also be vented to the environment and / or diverted to other containers further upstream in the fuel supply 350.

[0093] By providing a variety of strategies for controlling such abnormal pressure spikes, namely by including a heat exchanger in line 365, and one or more of a vent, check valve, or similar as discussed above, the preferred embodiment controls and regulates the pressure introduced to supply inlet 390 to reduce or prevent the flow rate control of the large engine throttle valve 10 from becoming overwhelmed.

[0094] The fuel tank 360 may alternatively be any of many commonly available gaseous fuel sources, such as a stationary gas line, a compression cylinder, or other type of liquefied storage tank with vaporization control, as well as a conventional pressure regulator. Preferably, most of these alternatives still include some form of fuel storage tank 360 that supplies fuel to the large engine throttle valve 10 via a high-pressure mechanical pressure regulator 370, which regulates the pressure to a desired range for supply inlet 390.

[0095] Next, fuel is supplied from the high-pressure mechanical pressure regulator 370 through a fuel line or supply line 375, which preferably includes a shut-off gate valve 380 as shown. Downstream of the shut-off gate valve 380, the fuel supply line 376 is connected at a supply inlet 390 to the large engine throttle valve 10, at which point fuel is preferably introduced into the gas supply throttle valve 20 of the large engine throttle valve 10.

[0096] As will be understood by those skilled in the art, the supply line 375 may also include a fuel filter or other conventional systems for monitoring and / or optimizing fuel supply conditions prior to introduction into the large engine throttle valve 10. Such other systems may include, for example, a fuel quality sensor connected to the PCB 900 of the ECM 100 and / or the large engine throttle valve 10 for predicting operational needs. The fuel supply 350 may also include a combination of several independent pressure regulators 370 (instead of just one), or may include an additional pressure regulator integrated into the fuel reservoir 360.

[0097] Refer again as follows Figure 10 In the preferred embodiment shown, the large engine throttle valve 10 includes a fuel supply 350. Downstream of this large engine throttle valve 10, the supplied fuel flow is then mixed with air 160 for supplying a gaseous fuel-air mixture 150 to the internal combustion engine 102. Although Figure 10 The arrangement is preferred, but alternative embodiments conforming to some of the broader teachings of this disclosure may alternatively introduce some or all of the required air into the fuel upstream of the large engine throttle valve 10 (as suggested by alternative air mixing flow arrow 260'), but given that corresponding adjustments may be required to address the airflow introduction at any point, there are corresponding challenges and possible compromises.

[0098] Gas supply throttle valve 20 The gas supply throttle valve 10 is adapted to provide rapid and highly accurate control (in response to the ṁ flow rate signal) of the actual mass flow rate (“ṁ”) at the outlet 170 of the MFG 10 for fuel supply to the fuel-air mixer 161 and subsequently, the controlled delivery to the engine 102. By its nature, the gas supply throttle valve 10 is used to control the flow rate from the main fuel supply 350 (… Figure 10 (Middle left upper) to internal combustion engine 102 ( Figure 10 The gaseous supply flow is located on the upper right side of the engine 102. Therefore, the gaseous supply throttle valve 20 is operatively positioned downstream of the fuel supply 350 and upstream of the fuel-air mixer 161 and engine 102, such that it is fitted with conduit and sealed as part of a fluid continuous fuel supply system during operation of the engine 102, wherein the gaseous supply throttle valve 20 is located between the fuel supply 350 and the engine 102. A detailed description of the large engine throttle valve 10 is provided in the following paragraphs with reference to the accompanying figures.

[0099] According to some embodiments, the desired mass flow rate of fuel supply 350 is calculated by ECM 100. In these embodiments, a target air-fuel ratio (which in some embodiments is determined by a calibration table and other adjustments based on operating conditions) is stored in ECM 100. ECM 100 is configured to determine the desired mass flow rate of fuel supply 350 by multiplying the target air-fuel ratio by the mass flow rate of air traveling through MFA 140 (e.g., measured by MFA 140 and transmitted to ECM 100 via communication line 197, or commanded by ECM 100). However, in other embodiments, the desired mass flow rate of fuel supply 350 may be determined by controllers 930a, 930b. In these embodiments, the target air-fuel ratio may be transmitted from ECM 100 to controllers 930a, 930b via communication lines 196, 197 for use by controllers 930a, 930b in determining the desired mass flow rate. For example, controllers 930a and 930b can determine the desired mass flow rate of fuel supply 350 by multiplying the received target air-fuel ratio by the mass flow rate of the air traveling through MFA140.

[0100] For further optimization, the on-chip microcontrollers 930a, 930b and related control circuitry are preferably embodied in a single printed circuit board 900a, 900b (in... Figure 9(Also visible in the image). The on-board microcontrollers 930a and 930b are connected via previously discussed connections 196 and 197 to receive data signals from the ECM 100. Using the desired mass flow rate value received from the ECM 100 and the readings from the pressure / temperature sensor 121, the printed circuit board 900 controls the large engine throttle valve 10, preferably without requiring any external communication other than the power and data connection to the engine's ECM 100. Although "CAN" is technically an abbreviation for Controller Area Network, the term "CAN" is a commonly used technical term referring to a CAN network or data received via a CAN network. In this regard, it should be understood that while a CAN network is the preferred communication link for all commands, variables, and other data received by the microcontroller 930a from outside the throttle valve system 10, wireless, analog, digital, or other communication means may be used as alternatives, while still encompassing many aspects of this disclosure.

[0101] CAN network connector 960 (in) Figure 2D (As can be seen in the image) This is also located on PCBs 900a and 900b. As will be understood by those skilled in the art, the CAN network connector 960 is a five-pin connector. The five pins include a power pin, a ground pin, a CAN positive pin, a CAN negative pin, and a CAN termination pin. As will be understood by those skilled in the art, alternative embodiments may be direct (0-5V or 5-20mA) data connections, or any other known alternatives suitable for data connections in applications such as large engine throttle valves 10. Alternative embodiments may have an eight-pin connector instead of the five pins used for CAN networks.

[0102] In a preferred embodiment, the end of its pressure tapping tube (or, alternatively, a tube extending from it) is positioned relative to the throttle chamber 205. Figure 4 (As shown in the image) direct fluid contact, with the bases of transducers 950a,b directly mounted on PCB 900a,b, receiving optimal fluid condition feedback from the bifacial transducers (“Delta-P sensors”) 950a,b. (Cross-reference) Figure 2D Delta-P sensors 950a,b measure the pressure difference (“Delta-P”) between upstream pressure port 230 and downstream pressure port 240. Pressure sensors 951a,b measure the absolute upstream pressure (“P1”) from port 230. Pressure sensors 952a,b measure the absolute downstream pressure (“P2”) from port 240. Further cross-references Figure 2DThe pressure tapping ends of pressure sensors 951a,b and 952a,b extend from PCB 900a,b through suitably positioned sensor ports 230 and 240 in the side wall of throttle chamber 205. To minimize clogging or other contamination of transducers 950-952, ports 230 and 240 are preferably located in the side compartment of throttle chamber 205 and are shielded by using downwardly sloping passages or other measures known as contaminants.

[0103] Cross-reference Figure 6 By directly positioning the sensor end 601 of the thermistor 600 within the throttle chamber 205, and simultaneously soldering the base 602 of the thermistor 600 directly to the thermistor PCB 610, optimal fluid condition feedback is achieved. Thermistor 600 is a conventional thermistor that senses temperature at its end 601 and has leads extending to the sensor end 601; however, other forms of temperature sensors (or even sensors for fluid conditions other than temperature) may be considered as alternatives for some of the same purposes.

[0104] By controlling the on-chip microcontroller 930, embodiments of this disclosure address long-standing needs in the art through numerous innovative approaches that overcome the limitations and challenges of the prior art. Based on many of the teachings of this disclosure, the industry can provide solutions manifested in large engine control systems that are readily adaptable to the power requirements of many applications and readily capable of highly accurate and precise control of the supply flow across a considerable dynamic power range in internal combustion engines.

[0105] Engine 102 Refer again Figure 10 Engine 102 is a large spark-ignition internal combustion engine 102 that uses gaseous fuel as its primary energy source (most preferably, natural gas (NG) or vaporized propane (LPG) as its fuel). Large engine is defined herein as any engine of 30 liters or greater. Engine 102 is preferably used in stationary applications, such as generator sets (hereinafter “generator sets”) on natural gas compression skids. Alternatively, engine 102 can be used in large mobile applications, such as trains, ships, mining trucks, or other heavy vehicles. Conventionally, engine 102 has an ECM 100 or equivalent that continuously monitors the operation of various parts of engine 102 and its peripheral systems. Such engine 102 can be operatively incorporated in any number of power supply applications in alternative embodiments, and operatively incorporated in many other applications that are now or in the future known in the art to be powered by spark-ignition gaseous fuel internal combustion engines.

[0106] The ECM 100 of engine 102 is connected via data communication lines or other conventional means to monitor pressure, temperature, and operating conditions in or around a number of subsystems of engine 102, such as its fuel-air treatment system (which preferably includes a turbocharger 172), fuel-air throttle valve 140, its ignition system, its combustion chamber 180, its coolant system, its oil pressure system, and its exhaust system, in addition to other subsystems as known in the art. While alternative embodiments may use wireless connectivity for some or all of the data connections between ECM 100 and the various subsystems of engine 102, a preferred embodiment of ECM 100 is connected via wiring harnesses or other forms of communication lines to transmit and receive analog or digital signals. The communication lines are preferably embodied in the form of a conventional data network such as a controller area network.

[0107] As will be understood by those skilled in the art, the ECM 100 is programmed to operate in part to determine the desired supply flow rate (“ṁ” or “mdot”) at any given moment based on the current operating conditions of the engine 102 compared with current user demand. When the ECM 100 determines the desired ṁ flow rate, the ECM generates a corresponding ṁ data signal representing the current ṁ flow rate demand of the engine 102. When the ECM 100 determines the desired ṁ flow rate, the corresponding ṁ data signal is transmitted via communication links 196, 197 to microcontrollers 930a and / or 930b, and controllers 930a and / or 930b control the large engine throttle valve 10 to operate operationally for instantaneously and accurately delivering the desired ṁ flow rate from the throttle valve system outlet 170. Therefore, according to some embodiments of this disclosure, controllers 930a, 930b are configured to determine the desired mass flow rate of fuel for the MFG 10.

[0108] Following flow control by the large engine throttle valve 10, a controlled flow of gaseous supply from the throttle valve system outlet 170 is directed to a fuel-air mixer 161, where it is preferably mixed with air 160 to produce a combustible fuel-air mixture 150. A preferred embodiment uses a flow of filtered air 160. In an alternative embodiment, the inlet air 160 directed to the fuel-air mixer 161 may be drawn from ambient air with or without (but with performance compromises) a pressure compensator. The fuel-air mixer 161 is preferably a Venturi mixer, or another type that does not use a moving portion in the supply flow, thereby maximizing the persistence of flow conditions actually delivered to the combustion chamber 180 and the homogeneity of the fuel / air mixture. Most preferably, the fuel-air mixer 161 is in the form of a fuel ring to help retain the benefits of accurate flow rate control provided by the throttle valve system 10.

[0109] Once a suitable fuel-air mixture 150 is provided by the fuel-air mixer 161, the mixture 150 flows toward the engine 102. The fuel-air mixture 150 passes through the turbocharger 172. The turbocharger 172 draws in recirculated gas from the turbine pre-exhaust port 171, mixes it with the fuel-air mixture 150, and compresses it. After leaving the turbocharger 172, the fuel-air mixture 150 passes through the turbo aftercooler 174. The turbo aftercooler 174 cools the fuel-air mixture 150 before it enters the engine 102. It is necessary to lower the temperature of the fuel-air mixture to allow for denser intake to the engine 102, thereby increasing the output of the engine 102. The turbine after-exhaust gas 173 flows past the oxygen sensor 190 and into the three-way catalytic converter (TWC) 175. In other embodiments, the oxygen sensor 190 is located in the turbine pre-exhaust port 171. As will be understood by those skilled in the art, the TWC175 reduces contaminants before the exhaust gas is released into the environment. Although not shown in the drawings, those skilled in the art will understand that preferred embodiments will include various components not shown. Furthermore, other components such as filters and pressure relief valves are also not shown. Regarding any such simplifications and omissions from the drawings, it should be understood that preferred embodiments include such features and constructions as will be substantially understood within the judgment of those skilled in the art.

[0110] The flow of the fuel-air mixture 150 is controlled by a fuel-air throttle valve 140, which is preferably an electronic throttle valve, further facilitating the maintenance of the flow of the fuel-air mixture 150. Figure 10 The supply throttle valve 10 provides highly accurate flow rate control. Therefore, the fuel-air throttle valve 140 is also preferably constructed with the same basic structure and software as the throttle valve 10, but preferably has modifications to accommodate different pressure ranges experienced downstream of the mixer 161, and perhaps less protection of internal components against the corrosive effects of more concentrated fuels encountered upstream of the mixer 161. Figure 10 The piping is installed and a throttle valve 10 is used to control the mass flow rate of the fuel itself, so this type of throttle valve deployment is sometimes referred to as a gas mass flow throttle valve (or "MFG" throttle valve). In contrast, a fuel-air throttle valve 140 used to achieve highly accurate control of the mass flow of the fuel-air mixture 150 is sometimes referred to as an air mass flow throttle valve or "MFA" throttle valve, regardless of whether the fuel is mixed with air at that control point.

[0111] Preferably, the fuel-air throttle valve 140 is also constructed according to the teachings of this disclosure, having the same basic structure as the supply flow throttle valve 10, which functions as an MFG throttle valve to independently control the mass flow of fuel. Therefore, the highly accurate fuel supply flow of the MFG throttle valve 10 is preferably combined with highly accurate air supply mass flow control achieved by the fuel-air throttle valve 140, constructed according to the same basic teachings as the MFG throttle valve 10. Alternatively, complete and highly accurate mass flow control can also be achieved by combining the MFG throttle valve with an MFA throttle valve (with a conduit installed upstream of the fuel-air mixer 161 in the air supply 160). Any such combination ( Figure 10 The combination shown, or alternative combinations using similar throttle valves to independently control the mass flow of air 160, achieves comprehensive mass flow control of all supply flows for combustion. Furthermore, if other reliable data is used to calculate this air mass flow (such as by using an oxygen sensor in conjunction with pressure, temperature, etc.), generally accurate overall control can also be achieved by controlling only the mass flow of fuel without actively controlling the mass flow of air. Regardless of the choice made for a particular application, we believe that those skilled in the art will understand where and how such throttle valves can be included for different purposes to achieve different combinations for overall mass flow control.

[0112] Regardless of the choice, the resulting fuel-air mixture 150 is then operatively introduced into the combustion chamber 180 of the engine 102 under the control of controller 930a or 930b. Within the combustion chamber 180, the fuel-air mixture 150 is then operatively spark-ignited to induce working combustion.

[0113] Surprisingly, the use of such MFG throttle valves in conjunction with such MFA throttle valves enables a significantly streamlined engine development cycle. While large natural gas spark-ignition internal combustion engines have historically required considerable time and expense to complete and validate engine designs before commercial release, the highly accurate mass flow control achieved by this disclosure greatly simplifies development, enabling design without the cost of any test cell. Although the industry will likely continue to use test cells to complete designs, the accurate control achieved by this disclosure allows for much more relaxed standards in the process, not to mention the ability to achieve highly accurate mass flow control regardless of highly variable mass factors such as fuel quality, air composition, and other environmental factors.

[0114] Fuel characteristics determined In cases where the quality and composition of the fuel supplied to the engine are known and consistent, the fuel flow is measured and is a known value, and the air flow is measured or inferred, among other variables. Based on these measurements or inferences, the engine can be precisely tuned to achieve maximum power while maintaining compliance with emission standards. However, in cases where the quality and / or composition of the fuel are unknown or can vary over time, the process for tuning the engine can be difficult and often requires manual sensing to ultimately provide an accurate fuel mass flow based on the engine's needs. In this context, the disclosed systems and methods provide significantly improved automatic tuning to the engine based on accurately determining the air mass flow and fuel mass flow at any given time during engine operation.

[0115] When fuel composition changes as fuel is supplied to engine 102 over time, immediate adjustments to maintain efficient operation and maximum power of engine 102, and to keep engine operation within emission compliance standards, can be difficult. To address this difficulty and more effectively adjust the engine in real time, two throttle valves, as shown and described herein, can be employed in a system configuration that provides the necessary data points to make real-time determinations for adjusting or calibrating the engine based on fuel quality. To achieve this real-time determination, the fuel supply microcontroller 930a or 930b (or, in an alternative embodiment, ECM 100 or another controller or group of controllers) is programmed to use... Figure 11A The flowchart illustrates the process of inferring fuel quality characteristics (described further below).

[0116] With Figure 10 The system shown is consistent in at least some aspects, providing two throttle valves: one as a gas mass flow (MFG) throttle valve 20 and the other as an air mass flow (MFA) throttle valve 140.

[0117] Looking Figure 11A This shows a simplified flowchart representing a method for inferring fuel characteristics from a fuel supply, where the fuel supply has unknown fuel characteristics. In some embodiments, Figure 11A The method is executed by controller 930a or 930b, or in some embodiments by ECM100. More specifically, Figure 11AThe diagram illustrates the determination of the mass flow of fuel (“MFG”) at step 420 and the determination of the mass flow of air (“MFA”) at step 415. Starting at point 400, the mass flow of air and gas is first determined (shown as step 410). At step 415, the actual mass flow of air is determined from a mass flow sensor located in the MFA throttle valve 140. Moving to step 420, the actual mass flow of gas is determined using an algorithm programmed in the microcontroller of the MFG throttle valve 20. At step 430, the exhaust gas oxygen level is read by the EGO sensor 190; this step provides the actual air-fuel ratio, from which an air-fuel ratio offset value can be determined. The process for determining the air-fuel ratio offset value and other engine operations will be discussed in later sections. Controllers 930a, 930b (or another controller or combination of controllers in alternative embodiments) are capable of determining the mass flow of both fuel and air using two throttle valves 10, 140 embodied in the teachings of this disclosure. Controllers 930a, 930b determine the combustion outcome by monitoring the oxygen sensor 190. Figure 10 In this configuration, oxygen sensor 190 is located in the exhaust manifold, downstream of MFA 140, and preferably in the form of an exhaust oxygen sensor. For this purpose, sensor 190 is positioned and configured to sense the oxygen content in the exhaust gas. Oxygen sensor 190 provides controllers 930a, 930b with a measurement of the oxygen concentration or deficiency in the gas. The oxygen level in the exhaust gas can be associated with a rich or lean air-fuel ratio. As is known to those skilled in the art, the term "rich" is used to describe an air-fuel ratio with more fuel than air. Conversely, the term "lean" is used to describe an air-fuel ratio with more air than fuel. A rich or lean air-fuel ratio may be desired for certain load limit applications in relation to engine performance requirements. The quality of the fuel can also determine whether the air-fuel ratio is rich or lean. Natural gas directly from the wellhead has an inconsistent chemical composition. Depending on the source, unrefined natural gas will have characteristics associated with the concentration of any of its constituent gases. Typically, natural gas has a high concentration of methane (CH4); however, certain amounts of ethane (C2H6), propane (C3H8), butane (C4H10), pentane (C5H12), and hexane (C6H14) may also be found. Methane (a lighter fuel) will show a lower oxygen level in the exhaust. Heavier fuels like propane and ethane will show a higher oxygen level in the exhaust. It should be noted that this mass flow determination is made by the throttle valve controller during operation. Figure 10 The process of determining throttle valves 20 and 140 in the preferred configuration shown is illustrated. At step 440, fuel characteristics can be interpolated based on the offset value. The feedback loop (shown as arrow 450) transmits the engine operating offset to the corresponding devices, where MFG throttle valve 10 and MFA throttle valve 140 are adjusted to meet engine requirements. At step 460, then based on a reference... Figure 11AThe methods described at the time, as well as the additional methods described in later chapters, are used to infer fuel properties.

[0118] Figure 11B This is intended to provide a more detailed explanation. Figure 11A The flowchart of the method described herein. As will become apparent in the following discussion, Figure 11A-11B Some of the methods described herein may be referred to as fuel-air deterministic loops. In some embodiments, Figure 11B The method is executed by controllers 930a and 930b, and in other embodiments, by ECM 100. Referring to start point 400', ECM 100 transmits a throttle valve angle position command or an air mass flow rate command to MFA 140. Initial fuel characteristics and variables are assumed at step 401. Specifically, various assumed characteristics of the fuel supplied from fuel tank 350 are programmed into the memory of controllers 930a and 930b. In some embodiments, the characteristics stored in controllers 930a and 930b include the stoichiometric air-fuel ratio, the specific gravity of the fuel, and the specific heat ratio of air to fuel. In other embodiments, these fuel characteristics are stored in ECM 100 and transmitted to controllers 930a and 930b via communication connections 196 and 197. In some embodiments, as will be discussed in more detail below, the fuel in tank 350 is supplied directly from a natural fuel source (such as, for example, a natural gas well). In these embodiments, various fuel characteristics of natural gas or other fuels are unknown because natural gas is largely unprocessed and delivered from a natural gas source. Therefore, the fuel characteristics of natural gas can be inconsistent and largely unknown. Thus, as will be discussed in more detail below, assumed characteristics of the fuel and air are programmed into controllers 930a and 930b, and are used by controllers 930a and 930b to determine the mass flow rates of air and fuel entering engine 102, which can then be used to determine certain fuel characteristics. Unlike fuel supplied to IC engine 102 from a natural source, the characteristics of ambient air are relatively determined and known, regardless of where the air is supplied. Therefore, in making various determinations and calculations regarding the determination of the mass flow rate of air, which will be discussed in detail below, the assumed characteristic values ​​of the ambient air programmed into controllers 930a and 930b can be regarded as the actual characteristic values ​​of the air supplied to engine 102.

[0119] At step 404, controllers 930a and 930b calculate the mass flow of air and the mass flow of fuel based on the current inputs 403 from MFG10 and MFA140, combined with the assumed fuel and air characteristics stored in controllers 930a and 930b in step 401. First, as previously mentioned, ECM100 commands the mass air flow to be provided by MFA140. Next, based on the commanded mass air flow rate or the measured mass air flow through MFA140, and based on the target air-fuel ratio, ECM100 or controllers 930a and 930b calculates the desired mass flow rate of fuel supply 350, and commands MFG10 to provide fuel supply at the desired mass flow rate. When providing fuel supply at the desired mass flow rate, controllers 930a and 930b use various readings 403 from MFG10 and the assumed fuel characteristics stored in controllers 930a and 930b to calculate the estimated mass flow of fuel through MFG10. Specifically, controllers 930a and 930b use assumed fuel characteristics programmed into their memory, plus pressure readings from pressure sensors 950a, 951a, and 952a, temperature readings from thermistor 600a, and / or position readings from blade position sensor 940a, to calculate the estimated mass flow rate. Controllers 930a and 930b calculate the mass flow rate of air flowing through MFA140 in substantially the same manner as calculating the mass flow rate of fuel flowing through MFG10. As previously described, MFA140 has substantially the same components and structure as MFG10 and is therefore configured to acquire pressure, temperature, and blade position readings of air flowing through MFA140, just as MFG10 is configured to acquire pressure, temperature, and blade position readings of fuel flowing through MFG10. Figure 10Those skilled in the art will understand that the air-fuel mixture passes through MFA140 (not just air). Because the mass flow rate of fuel passing through MFA140 is calculated using readings from MFG10, controllers 930a and 930b are configured to take into account the fuel passing through MFA140 and calculate the mass flow rate of air-only passing through MFA140. In addition to input 403, the offset correction values ​​applied to the MFG10 and MFA140 actuators, as shown at step 430', are also taken into account to determine the mass flow of air and fuel. At step 402, the true air-fuel ratio (displayed as AF ratio) is determined. The true air-fuel ratio is determined by controllers 930a and 930b using the mass flow rates of air and fuel determined in step 404. At step 405, as previously mentioned, the ideal air-fuel ratio (shown as the ideal AF ratio) is determined during IC engine 102 calibration based on the type of IC engine 102 and the catalytic converter used therewith, and is pre-programmed into ECM 100 or controller 930a, 930b for use by ECM 100 or controller 930a, 930b in making the determination and calculation, as will be discussed in more detail below.

[0120] At step 406, the percentage error of the air-fuel ratio is calculated by comparing the true AF ratio from block 402 with the ideal AF ratio from step 405. At step 408, the offsets of MFG10 and MFA140 used in step 430' are determined. The MFG10 and MFA140 offsets are determined based on input 407 from the oxygen sensor 190 measurement. Specifically, the oxygen sensor 190 reading in step 407, provided to controllers 930a, 930b via CAN 195, is used to provide an independent measurement of the true air-fuel ratio based on the oxygen concentration in the exhaust gas. If the air-fuel ratio result determined in step 402 is the same as the oxygen sensor AF ratio result from 407, then the percentage error in 409 should be 0%. However, if a difference exists, for example due to variations in actual fuel characteristics that deviate significantly from the input at step 401, the percentage error will be something other than 0%. This percentage error is based on the variation described in step 440', as will be discussed in more detail below. If no correction is required, such as for direction at step 409, the fuel characteristics can be interpolated using a calibrated lookup table (referred to as the fuel table in step 440') and the percentage error of the air-fuel ratio. At step 440', it can be said that controllers 930a and 930b perform a fuel characteristic determination and adjustment procedure, wherein the ECM 100 is configured to adjust the operation of engine 102 based on the fuel characteristic values ​​of the fuel supplied to engine 102, wherein the fuel characteristic values ​​are determined by controllers 930a and 930b and sent to the EMC via communication connections 196 and 197. Figure 11CThe text displays an example of performing fuel characteristic determination and adjustment procedures, and can be viewed... Figure 12 The fuel gauge associated with the program is then viewed. The fuel characteristics can then be used as desired (shown at step 460'). For example, in some embodiments discussed in more detail below, in step 460', the fuel characteristics determined by controllers 930a, 930b in step 440' can be sent to pump 1404 (see reference). Figure 14 Pump 1404 pumps natural gas fuel from natural gas well 1408, and pump 1404 can use certain characteristics to pump fuel more efficiently.

[0121] If correction is required (shown as No at step 409), the MFG10 and MFA140 actuators need to be adjusted (shown at step 430'), and controllers 930a and 930b restart the fuel-air determination loop. For example, if the percentage error value in step 406 is compared with the input from sensor 190 in step 407, and controllers 930a and 930b determine that the air-fuel ratio is too rich on fuel, controllers 930a and 930b may control MFG10 to constrain the amount of fuel supplied and / or open MFA140 to mix more air with the supplied fuel. Similarly, if the percentage error value in step 406 is compared with the input from sensor 190 in step 407, and controllers 930a and 930b determine that the air-fuel ratio is insufficient on fuel, controllers 930a and 930b may control MFG10 to increase the amount of fuel supplied and / or constrain MFA140 to mix less air with the supplied fuel.

[0122] Controllers 930a and 930b are linked to a database program that includes calibrable manufacturer-recommended engine ratings. The database allows controllers 930a and 930b access to numerous manufacturer-recommended engine specifications. To further elaborate on how the database is used in this disclosure, there are specific fuel characteristics that can be maintained to ensure optimized engine performance. To simplify the concept, fuels with properties similar to gasoline would have adverse effects on engines designed to operate with fuels having properties similar to diesel. Furthermore, gasoline and diesel can have various octane numbers, which are associated with improved engine performance levels. The engines associated with this disclosure are designed to operate with natural gas, which is very similar to natural gas in terms of octane number, which can be evaluated using methane number or BTU content. The fuel characteristics of the fuel supply can be compared to manufacturer-recommended fuel characteristics, thus enabling controllers 930a and 930b to calculate associated offset values. The stoichiometric air-fuel ratio is a theoretical value, using known or estimated air mass flow, which can be used to calculate the theoretical gas mass flow. As is known to those skilled in the art, a simple method for calculating the air-fuel ratio is to divide the estimated air mass flow by the gas mass flow. This practice is consistent with the ability of controllers 930a and 930b to instantaneously demand a specific gas mass flow depending on performance requirements. To obtain a value for the desired gas mass flow rate, controllers 930a and 930b perform a percentage error analysis (in... Figure 11B (As shown at step 406 in the diagram), this percentage error analysis quantifies the accuracy of the actual air-fuel ratio compared to the ideal air-fuel ratio. This analysis is used to determine the closeness of the actual mass flow value to the desired mass flow value, where an offset value is determined (shown in box 408). The offset value is requested by controllers 930a, 930b, thereby adjusting the MFG throttle valve 10 to meet said offset value. Similarly, the mass flow of air can be determined such that the MFA throttle valve 140, located downstream of the MFG 10, provides a mass flow rate of air to the controllers 930a, 930b. For the purposes of describing the present disclosure, the mass flow of air will be mathematically considered as a known or estimated constant, and therefore the adjustment of MFA 140 will not be explicitly described. However, the adjustment of MFA 140 is within the capabilities of this disclosure. The method for implementing the adjustment of MFA 140 is the same as or similar to the method for implementing the adjustment of MFG 10. It should be understood that when positioned downstream of the air inlet and downstream of the air / fuel mixer 161 (where air is mixed with fuel), the MFA throttle valve 140 will actually measure the mass flow of the air and fuel mixture, such that the mass flow of air will be determined by subtracting the mass flow of fuel from the mass flow of the mixture. Nevertheless, it should be understood that in some alternative embodiments, the second throttle valve may be positioned upstream of the fuel-air mixer 161 in the air supply, such that it directly determines and controls the mass flow of air, rather than the mass flow of the mixture.

[0123] As previously mentioned, unrefined natural gas has a discontinuity in its chemical composition. If delivered directly from the wellhead to an on-sight engine, this discontinuity leads to variable engine performance due to inconsistent fuel quality. In addition to performing air-fuel ratio error analysis (as described at step 440'), controllers 930a and 930b also perform closed-loop error correction, which can then be used to infer fuel characteristics. Closed-loop error correction is performed using the percentage error value obtained as described at step 440'. By utilizing closed-loop correction, fuel tables (including those in a database of the manufacturer's recommended engine ratings) can be used to infer fuel characteristics. Figure 12 (displayed in the middle) or response curve ( Figure 13 The exact fuel characteristic values, such as BTU content "BTU" and methane number "MN", are interpolated using the data displayed in the diagram. Due to the precise control of the mass flow rates of fuel and air controlled by MFG10 and MFA140, the exact fuel characteristics can be determined. Therefore, since the mass flow rates of air and fuel are precisely controlled and known, controllers 930a and 930b can infer that the only factor preventing an ideal air-fuel ratio is that the fuel characteristic values ​​(such as BTU levels) differ from the assumed BTU levels used to create the assumed characteristic values ​​stored in controllers 930a and 930b (in step 401).

[0124] Looking Figure 11B At step 440', fuel quality can be inferred from the air-fuel ratio closed-loop error correction, which is generated from controllers 930a and 930b. Assuming the engine is calibrated to operate with certain fuel specifications, fuel characteristics can be efficiently interpolated from a characteristic table known to be associated with the calculated error range. At step 420', fuel specifications recommended by the engine manufacturer are accessed using a database program (such as, for example, GERP) and used to infer fuel characteristics based on the closed-loop error. For example, if the engine is calibrated to operate using propane as the base fuel, there will be a closed-loop error associated with the characteristics of the incoming fuel source. The closed-loop error determines the amount of correction required to achieve characteristics similar to the base fuel. In this disclosure, corrections made to the throttle positions of MFG10 and MFA140 are described; however, corrections for other device settings may be applied to alternative embodiments.

[0125] It should also be understood that, as by Figure 11A The feedback path 450 suggests that the inference about fuel quality can be iteratively improved by using the inferred fuel quality characteristics when determining the mass flow in step 410.

[0126] Typically, during engine operation, if measurements determine that the air / fuel ratio has changed from a preferred ratio (rich, lean, or stoichiometric) based on a particular application, the change can be expected to be due to variations in air or fuel. More specifically, for a given calibrated engine 102, changes in closed-loop correction are likely related to variations in airflow or fuel flow / fuel characteristics. Since airflow for a given speed and load condition can now be measured, changes in closed-loop correction are more likely to be attributed to variations in fuel characteristics. Therefore, characteristics related to airflow are unlikely to change and can be monitored using the oxygen flow sensor 190. However, given the parameters identified above based on the construction of the MFG throttle valve 20, the MFA throttle valve 140, and the oxygen sensor 190, variations in fuel, more specifically variations in fuel composition or fuel characteristics, can be inferred more accurately. Many fuel characteristics can be inferred based on known data related to the mass flow of fuel, the mass flow of air, and the air / fuel ratio. These fuel characteristics may include, but are not limited to, British thermal unit (BTU) content, Wobbe index, methane number, stoichiometric fuel / air ratio, fuel specific gravity, hydrogen / carbon ratio, and fuel specific heat ratio. While the following description specifically mentions BTU content, it should be understood that any of these fuel characteristics can be inferred. Nevertheless, the terms "fuel characteristics" or "fuel quality" are sometimes used generally, and this should be interpreted as a comprehensive and general reference to any of the fuel characteristics mentioned above, as well as any other fuel quality characteristics characterizing natural gas quality in the field related to natural gas engines.

[0127] By knowing the mass flow of air, the mass flow of gas, and the air / fuel ratio, the disclosed system 10 can infer the BTU content of the gas. All these parameters are then supplied to the ECM 100. Knowing the BTU content of the gas, the ECM 100 is then programmed to automatically adjust specific engine settings to maintain effective engine operation, resulting in appropriate power output, and preferably maintaining engine operation in compliance with applicable emission standards. For example, the phi target (before or after the catalytic converter), spark timing, and / or maximum permissible load can be changed based on the BTU input. Furthermore, another check can be used, thereby adjusting the spark timing, and the knock level can be measured using a knock sensor (not shown). This can help correlate the expected relationship between BTU content and methane number.

[0128] One particularly advantageous application of the above principles and system configurations is the integration of engines into various applications within oil and gas fields. This includes, but is not limited to, generator sets driving downhole electric pumps, engines integrated into gas compression systems, and other similar uses. For example, some applications in oil and gas fields where internal combustion engines are integrated can be supplied with fuel, where the fuel is gas from a gas well. Because the composition of the gas leaving the well varies over time, the BTU content of such gases is typically unknown without field measurements (e.g., using gas chromatography) to determine it. Alternatively, as with the systems and methods described herein, the ability to more accurately determine the BTU content of gases leaving the well, without the need for physical measurements, but relying on information gathered using the systems and methods described herein, represents a significant improvement, especially when it is crucial to be able to distinguish between purchased and sold gases, at least in part, based on the gas composition.

[0129] To elaborate further, for a typical system of an internal combustion engine supplied with gas directly from the well, personnel will have to physically visit the site to input specific setpoints for engine operation. Measuring the gas, determining its methane number, allows for spark timing setting based on this information, and based on all this information, the engine can be drated. Because the composition of the gas leaving the well often fluctuates, personnel may need to physically visit the site and adjust the engine to ensure it operates within emission standards. Using publicly available systems and methods, particularly those providing MFG and MFA throttle valves that allow for very accurate measurement of fuel and air, the gas composition (BTU content) can be accurately inferred, and the internal combustion engine can be adjusted in this scenario without physical intervention.

[0130] In specific applications, when system 10 infers one or more fuel characteristics and, based on this determination, requires correction, an immediate closed-loop correction can be made regarding the fuel supplied to engine 102. The fuel flow is measured and is a known value. The air / fuel ratio is determined using oxygen sensor 190, and this value is transmitted to controllers 930a and 930b. Therefore, the fuel flow and air flow are known. To accurately determine whether closed-loop correction is necessary, alarm faults are set in controllers 930a and 930b. These alarm faults are calibrable. For example, if the closed-loop correction value is zero, this indicates that no intervention to change the fuel flow is necessary. However, if the closed-loop correction value is -15, this indicates that system 10 must withdraw 15% of the energy or BTU content or fuel flow rate. In other words, to maintain sufficient power, controllers 930a and 930b command a 15% reduction in fuel mass flow to maintain the preferred air / fuel ratio. In this given example, a + / -15% alarm fault can be set in controllers 930a and 930b, such that if the indicated air / fuel ratio deviates by + / -15%, controllers 930a and 930b will command an increase or decrease in the fuel mass flow to return the air / fuel ratio to a preferred value. The fault alarm setting depends on the specific application in which the MFG throttle valve 10 and MFA throttle valve 140 are used. Furthermore, because the fuel mass flow, air mass flow, and air / fuel ratio are known, the known closed-loop correction value (especially a value other than zero) indicates a change in fuel characteristics to the operator.

[0131] It will be understood that another proposed application of the system described herein is the precise use of large engine throttle valves as metering devices, such as those applicable to gas pipelines. Given the accuracy of large engine throttle valves in measuring flow, particularly in low-pressure applications (such as large pipelines) where the pressure difference between upstream and downstream is small, using large engine throttle valves as flow metering devices can replace more complex and / or more expensive devices and technologies.

[0132] It will be understood that another application from which the systems and methods disclosed herein can benefit is their use in gas compression systems in oil and gas fields. More specifically, once fuel characteristic information is determined, controllers 930a and 930b can output that fuel characteristic information for a variety of other important applications, such as in... Figure 11A The flowchart is presented at step 460. As an example, fuel characteristic information can be sent to the compressor of the same general supply of compressed natural gas for more accurate prediction and control of compressor power, as well as compressor and internal stage information. [Go to...] Figure 11C This displays the strategy used to determine fuel characteristics (such as fuel quality, load limit offset, phi offset, and spark offset) by performing fuel characteristic determination and adjustment procedures. Figure 11C Further details are needed to determine Figure 11Aand Figure 11B The method of conception in [the text]. Although Figure 11C The methods used to determine fuel quality, load limits, phi offset, and spark offset are clearly described, but other characteristics (such as BTU content) can be determined using similar methods. For illustrative purposes, Figure 11C Includes various sections enclosed in parentheses for quick reference. The section shown in parentheses 1050 includes the process for determining the closed-loop error associated with the air-fuel ratio of a fuel supply with unknown characteristics. The section shown in parentheses 1051 includes interpolation methods for determining fuel quality, spark advance, and load limits.

[0133] Looking at starting point 1000, the actual air mass flow 1001 (displayed as mdot_a_i) is determined from the mass flow sensor in the MFA140 throttle valve, represented in box 1002. Various alternative embodiments may utilize only one mass flow throttle valve. To the extent that corresponding assumptions can be made about the air mass flow, some of those alternative embodiments will use an MFG to control the gas mass flow. Looking at box 1003, based on the sensed readings from the MFG10 throttle valve control algorithm 990, represented in box 1002', the actual air mass flow 1001 is divided by the actual gas mass flow, displayed as 1 / mdot_g_i. The output from box 1003 is the actual air-fuel ratio 1004 (displayed as AF_i). The actual air-fuel ratio 1004 is subtracted from the ideal air-fuel ratio 1005 (displayed as AF_stck). The ideal air-fuel ratio 1005 is determined using the method shown in box 1028, which is part of the engine calibration process. Specifically, the ideal air-fuel ratio for the IC engine 102 is determined based on the type of IC engine 102 used and the specific catalytic converter paired with it. Therefore, when the type of IC engine 102 and its catalytic converter are known, the ideal air-fuel ratio is known based on a calibration process performed during testing and can be pre-programmed into the ECM 100 and / or controllers 930a, 930b for use when performing the determinations and calculations described herein. The air-fuel difference 1007 (shown as delta_AF_i) between the actual air-fuel ratio 1004 and the ideal air-fuel ratio 1005 is calculated. Then, as shown in box 1008, the air-fuel difference 1007 is divided by the ideal air-fuel ratio and multiplied by 100, resulting in a percentage error value 1009. The percentage error value 1009 (shown as + / -e) branches out to determine fuel characteristics (which will be discussed later) and to determine the adjustment for the MFG throttle valve 20. Using the percentage error value to determine the throttle valve calibration will be referred to as closed-loop calibration, and the representative “loop” process is enclosed by dashed box 1014. The percentage error is multiplied (shown as box 1010) by the true air-fuel ratio 1004, resulting in an air-fuel ratio adjustment value 1011 (shown as + / -AF_adj). The air-fuel ratio adjustment value is transmitted to the throttle valve microcontroller 930. As previously mentioned, if the mass flow of air is known, estimated, or kept constant, the air-fuel ratio can be effectively adjusted by adjusting the mass flow of the gas. For the purpose of describing the present disclosure in terms of simple inputs and outputs, the throttle valve control algorithm 990... Figure 11CThe air-fuel adjustment is shown as mdot_g_0, where the required gas mass flow value 1012 is received. The throttle control algorithm 990 uses a formula described later to associate the required mass flow with a specific blade angle 1013, which the MFG throttle valve 20 will adjust accordingly.

[0134] Looking back at the percentage error value 1009, this value is also used to determine fuel characteristics. The percentage error value 1009 is associated with the instantaneous air-fuel ratio. To determine the fuel characteristics of the fuel supply, a calibration lookup table (represented by box 1006) can be used, thereby interpolating fuel characteristics. An example of a calibration lookup table can be seen as follows... Figure 12 Table 1200 in the present disclosure. The calibration method associated with the present disclosure includes determining a percentage error value associated with a known fuel type. For example, assuming an engine is designed for propane operation, the calibration process would involve operating the engine with other known types of fuel, the properties of which are already known. As the fuel type deviates further from propane, there will be a percentage error in the air-fuel ratio associated with that fuel type; propane will have 0% error. To elaborate further, if a fuel like butane is used in the calibration process for an engine designed for propane operation, there will be a percentage error in the air-fuel ratio associated with butane. Outside of the calibration process, if the percentage error value 1009 falls between the values ​​for butane and propane, the characteristics of an unknown fuel can theoretically be interpolated with a certain degree of accuracy. Moving forward, the percentage error value 1009 is entered into a calibration lookup table. The result is then used in a standard interpolation equation (shown in box 1018a), where the variable y represents the fuel mass. It will be apparent to those skilled in the art how the equations shown in 1018a, 1018b, and 1018c are applied. The interpolation equations also relate to other inputs used to determine the engine's spark advance (as seen in box 1018b) and load limits (as seen in box 1018c). Although not shown, the BTU content of the fuel supply is determined using a method similar to or the same as that used to determine fuel quality. The equation shown in box 1018b is used to solve for the required spark advance. The inputs used for equations 1018a, 1018b, and 1018c (except for the percentage error value 1009) are determined from calibration lookup table 1006. Looking back at equation 1018b, the output is the spark advance 1027 adjustment for combustion chamber 180, which will be required by ECM 100. Those skilled in the art will understand that spark advance refers to a combination of ignition timing related to piston position and crankshaft angle, and can also be referred to as a spark timing sequence.

[0135] Looking at the output of the equation in box 1018c, where y represents the ideal load limit. The value of the ideal load limit 1019 (displayed as LL_0) is used to determine the maximum blade angle of the MFA throttle valve 140; the method for determining the maximum blade angle is represented in box 1024. The output of box 1024 is supplied to the throttle valve algorithm 990, where the blade angle 1013' of the MFA throttle valve 140 will not violate the maximum blade angle value. That is, the load limit of the internal combustion engine 102 is adjusted by the ECM 100 by setting the maximum throttle valve blade limit of the MFA 140. By setting the maximum limit, the load limit of the IC engine 102 is limited by the amount of air allowed to enter the combustion chamber 180. For example, in some embodiments, to reduce the load limit of the IC engine 102, the ECM 100 may adjust the MFA 140 to limit air entering the IC chamber 180. Furthermore, according to other embodiments of this disclosure, in order to limit the load limit of IC chamber 180, ECM 100 may similarly set a limit on the angle of the throttle valve blade of MFG 10. As discussed, according to some embodiments, controllers 930a, 930b are configured to control the adjustments made to the above-described engine 102, MFG 10, and MFA 140 based on determined fuel characteristic values.

[0136] Referring back to equation 1018a, the determined fuel quality 1025 of the fuel supply is used to determine the ideal phi value 1028, or it can be reported 1034. Fuel quality can be reported as BTU content or methane number. It should be noted that... Figure 11C The purpose is to assist in describing the currently disclosed concepts, where the methods used to determine other associated fuel properties are beyond the scope of the description.

[0137] Fuel quality control strategy Looking Figure 12 and Figure 13 , Figure 12This is a representative fuel table 1200, as previously described in the example of the calibration process from a previous chapter. Table 1200 is programmed into the memory of controllers 930a, 930b, or EMC100, such as controllers 930a, 930b, or ECM100, for reference when performing fuel characteristic determination and adjustment procedures. Referring to the calibration example, the estimated closed-loop error associated with propane and the fuel characteristics are shown in row 1201. If the system closed-loop error calculated by controllers 930a, 930b, or ECM100 in step 406 described above falls between two known closed-loop errors (shown as 1203 for illustrative purposes), the rows above and below the system value are used to interpolate any desired fuel characteristics. Manufacturer specifications are shown in column 1202. In the example shown, 0% closed-loop error corresponds to an ideal BTU value of 900 BTU / scf and an ideal methane value of 98 MN, and in this ideal scenario, the spark advance and load limits of engine 102 do not need to be adjusted by ECM 100. However, as Figure 12 As seen in the diagram, when the BTU and MN values ​​deviate from the ideal values, the ECM100 adjusts the spark advance and load limits proportionally to the amount of the difference between the BTU and MN values ​​and the ideal values. According to some embodiments, those skilled in the art will understand that columns 1-3 of Table 1200 are stored to controllers 930a and 930b when calculating the BTU / MN values, while columns 4 and 5 are stored to the ECM100 for use in adjusting the engine 102 based on fuel characteristic information delivered to the ECM100 by controllers 930a and 930b.

[0138] According to some embodiments, MN acts as a substitute for the phi target (specifically, the phi target after the catalytic converter), wherein as the MN value increases, the phi target increases from a lean value to a richer value. In other words, the smallest MN value corresponds to the leanest phi target, and the largest MN value corresponds to the richest phi target. Therefore, the spark advance and load limits of engine 102 can be adjusted based on a determined phi value to optimize fuel emissions over a wide range of fuel compositions. Traditionally, this is done within a relatively narrow BTU input range when manufacturers certify engines for EPA compliance. According to various embodiments of this disclosure, this range can be a wide BTU range when compared to a typical engine BTU range.

[0139] The estimated BTU value can be used in a variety of applications. For example, according to some embodiments, controllers 930a and 930b are configured to estimate the fuel mixture of fuel supply 350 based on the estimated BTU. Often, fuel supply 350 is a mixture of two different fuels, but the proportion of each fuel in the mixture is unknown. By using the BTU, the proportion of each fuel in the mixture can be estimated. For example, in some embodiments, the fuel supply may be a mixture of natural gas and liquefied petroleum gas (LPG). In some embodiments, controllers 930a and 930b are programmable to recognize through adaptive learning that a BTU value of around 930 or lower corresponds to 100% natural gas, a BTU value of around 1380 corresponds to a 50 / 50 mixture of natural gas and LPG, and a BTU value of around 2300 corresponds to 100% LPG. Those skilled in the art will understand that this is only one of many instances in which controllers 930a and 930b can be used to estimate the fuel mixture of fuel supply 350.

[0140] Figure 13 The response curve 1300 used to determine the fuel quality of the fuel source is displayed. Depending on the load limit values ​​calculated using the previously described interpolation method, the maximum load limit is associated with 100% to 75% natural gas 1303, where the fuel quality will be reported as 100% to 75%. The minimum load limit is associated with 0% natural gas and 100% propane 1304. Because there is no slope for fuel quality between 100 and 75, the load limit between points 1301 and 1302 will result in an observable fuel quality. Point 1301 is at 75% fuel quality, and point 1302 is at 0% fuel quality.

[0141] The currently disclosed fuel quality control features use the database of controllers 930a and 930b to determine simplified fuel quality data that is useful to field personnel. Controllers 930a and 930b have interactive software that allows technicians to input fuel characteristic values ​​for calibration. The software also allows technicians to manipulate the operating modes of controllers 930a and 930b. Depending on whether the fuel quality control feature is in static or dynamic mode, the fuel quality data can also be used to determine the aforementioned adjustments to the MFG throttle valve 20 or MFA throttle valve 140 required to maintain engine performance.

[0142] Common methods for determining the quality of fuel from natural gas wellheads involve measuring BTU content and methane number; however, inexperienced technicians or other personnel may find these measurements difficult to interpret. Utilizing the teachings of this disclosure, the quality of fuel from natural gas wellheads can be described using a simple 0-100 percentage scale. Figure 13The simplified response curves shown illustrate the relationship between fuel quality and engine load limits. The 0-100 rating effectively represents the ratio of natural gas to propane content in the fuel supply, where natural gas “NG” represents 100% of the fuel quality and liquefied propane gas “LPG” represents 0% of the fuel quality. For example, a reading of 25% fuel quality indicates that the fuel produced at the wellhead is a mixture of 25% natural gas and 75% propane.

[0143] The utilization of the fuel quality control features disclosed herein depends on the AFR closed-loop error offset value. The closed-loop error offset value is input to a value similar to... Figure 12 The table shown is part of the fuel calibration table, and block multiplication is used to interpolate the values ​​for BTU content, AFR "phi", spark advance, and fuel quality. The interpolated values ​​are used to determine the offset values ​​required by the ECM100. (The last sentence appears to be incomplete and possibly refers to a different topic.) Figure 11B The conceptual path used to interpolate the values ​​is seen in the diagram. When controllers 930a and 930b are started, the base fuel BTU value is used to initialize the system. If the incoming fuel is natural gas, the fuel quality control characteristics are automatically activated; however, if the incoming fuel type is different or manually switched, the closed-loop error generated from the NG calibration will remain constant; in other words, any fuel error adjustments will remain unchanged with respect to the NG characteristics.

[0144] As previously mentioned, the fuel quality control features have the ability to operate in either dynamic or static mode. When dynamic mode is enabled, the closed-loop error offset value is used to initialize the fuel block multiplier of controllers 930a and 930b, and the BTU content and MN are continuously updated with respect to the mass flow readings provided by MFG10 and MFA140. Interpolated values ​​of the manufacturer-recommended spark / phi / load limits calculated from the updated BTU content and MN are used to automatically adjust the associated equipment. If static mode is enabled, controllers 930a and 930b are initialized in the same manner as in dynamic mode, but the values ​​of BTU content, MN, and the manufacturer-recommended spark / phi / load limits remain constant with respect to the base fuel. Static mode allows equipment adjustment, determined by the characteristics of the one-time base fuel used to initialize the system. To simplify design differences, static mode allows observation of wellhead fuel quality without adjustment based on said wellhead fuel quality. The application of static mode is valuable once the characteristics of the fuel source are determined and a base fuel is available for calibration. For example, natural gas wells in the Permian Basin of Texas can supply fuel of a different quality than those from another geographic source (such as the Eagle Ford Group in Texas). To elaborate further, system calibration can be based on geographic fuel supply; in connection with the previous example, natural gas from the Permian Basin or Eagle Ford could be used as the calibration base fuel.

[0145] If the methane number fuel trimming function is enabled, the air-fuel ratio, or "phi," can be adjusted accordingly. In dynamic mode, phi is adjusted based on the MN interpolated using the closed-loop error value and the fuel calibration table. If the interpolated MN is greater than or equal to the MN associated with the manufacturer's recommended spark / phi specification, phi is adjusted. The adjusted phi value generated from the system is used to correct the mass flow rate of the gas or air. Controllers 930a and 930b require correction values ​​for the MFG10 and MFA140 throttle valves. In static mode, the interpolated MN value of the fuel source can be simply looked up from the fuel calibration table.

[0146] The spark advance value is controlled by the previously mentioned database program compensation mode. When the database program is enabled, the controllers 930a and 930b can use the manufacturer-recommended values ​​for spark advance, phi, and load limits. The database program interpolates the spark advance value from the fuel gauge using a closed-loop error input. After determining the spark advance, the adjustment offset applied by the ECM100 and the resulting spark advance from said adjustment offset can be observed.

[0147] The methods described above for determining spark advance are only enabled when the fuel quality control system is active. If the fuel quality control system is not active, the database program determines spark advance based on a 0 to 100% range from a one-time calibration; natural gas has a database program value of 0%, and liquefied propane has a value of 100%. The database program percentage value depends on whether the fuel supply behaves more like natural gas or propane.

[0148] To control engine load limits, the fuel type can be NG, and the fuel quality control system can be enabled. A fuel gauge interpolation method is also used to determine the load limits. The closed-loop error is input as an input value, and the load limits are interpolated based on the manufacturer's recommended values ​​for engine load limits. After determining the load limits, a method based on similar... Figure 13 The response curves shown in the figure are used for interpolation to determine fuel quality.

[0149] Throttling valve control strategy As will be understood by those skilled in the art, the following mass flow rate equations are used to describe the non-obstructed gas flow through an orifice. Equation (1) is the mass flow rate equation for an ideal gas, and Equation (2) uses the gas compressibility factor “Z” to correct for the mass flow rate of a real gas.

[0150] In these equations, “ṁ” is the desired mass flow rate required by the ECM100; “C” is the dimensionless orifice flow coefficient; “A2” is the cross-sectional area of ​​the orifice (“effective area”); “ρ1” is the upstream actual gas density; “P1” is the upstream gas pressure; “k” is the specific heat ratio; “P2” is the downstream gas pressure; “M” is the gas molecular weight; “T1” is the upstream gas absolute temperature; “Z” is the dimensionless gas compressibility factor at “P1” and “T1”; and “R” is the universal gas law constant. The values ​​for “Z” and “R” are unique for a specific gas, or, in the present disclosure, unique for a specific fuel type. These values ​​are kept constant with respect to the calibration base fuel. The value for “C” can be found using the pressure differential “deltaP” in the MFA or MFG throttle valve.

[0151] Reference Figure 10 The throttle valve control algorithm 990 uses equation (2) to determine the "effective area" A2 required to achieve the desired mass flow rate. The algorithm essentially rearranges equation (2) so that the effective area is calculated and associated with the throttle valve blade angle. P2, P1, and T1 are measured as previously described, and these values ​​are used in equation (2). The correction of the mass flow can be associated with the correction of the "effective area" required to achieve the desired mass flow. The microcontroller 930 continuously utilizes the throttle valve control algorithm 990 to obtain the accurate mass flow rate as parameters change. Once the "effective area" A2 is determined by the throttle valve control algorithm 990, a signal is transmitted to the brushless motor 700. The brushless motor 700 is an actuator that controls the movement of the throttle valve shaft 710, thereby adjusting the throttle valve blade 210 of the gas supply throttle valve 20 until the desired "effective area" A2 is achieved. The brushless motor 700 is preferably a fast-acting actuator, preferably operable to move the throttle valve vane 210 through its entire range of motion in fifty milliseconds or less. The fast-acting actuator is preferably operable to move the actuated element through most of its operable range of motion (preferably from 20% to 80% of the stroke) (if not the entire operable range) in fifty milliseconds or less, but many other types of actuators may still be suitable as alternatives, especially to the extent that the particular claim element does not explicitly waive the requirement for a particularly fast-acting feature.

[0152] Operating pressure – low pressure While it will be understood that changes can be made for other upstream conditions, the pressure at the supply inlet 390 of the supply line 376 is preferably controlled by the mechanical pressure regulator 370 to a gauge pressure approximately slightly above one atmosphere, but when the throttle valve 10 is used as an MFG throttle valve, the pressure can be as high as 2.5 bar absolute pressure, or in the case of an MFA application, as high as four bar absolute pressure.

[0153] While not essential for highly accurate mass flow control, some methods for controlling the large engine throttle valve 10 can be further tuned to achieve desired control (partly dependent on actual or estimated fluid conditions even further downstream), such as monitoring pressure via a downstream sensor 121 (designated "P3" for our purposes), which monitors pressure via the ECM 100 and is continuously available to the controllers 930, 930b (or from the data network associated with the controllers 930a, 930b). The specific P3 value from sensor 121 represents any available data stream from engine 102, characterizing the pre-combustion fluid pressure within engine 102. Such a downstream sensor 121 can be a conventional temperature and manifold absolute pressure (TMAP) sensor module located downstream of the fuel-air throttle valve 140 in the engine intake manifold. In addition to or as an alternative to the conventional TMAP sensor 121, downstream data can also be collected from a conventional throttle valve inlet pressure (TIP) sensor module upstream of the fuel-air throttle valve 140. Furthermore, although knowing the downstream pressure P3 may be beneficial for some variations of this disclosure, most preferred embodiments of the throttle valve 10 omit the consideration of P3 data from sensor 121 as unnecessary, opting instead for simplicity and cost savings.

[0154] Alternative fuels For these purposes, gaseous fuel means fuel that is in a gaseous state at standard operating temperatures and pressures. In the presently preferred embodiment, the gaseous fuel is natural gas, derived from liquefied natural gas (LNG) or compressed natural gas (CNG) storage conditions. While the most preferred embodiments are suitable for use with these fuels, variations will be apparent to those skilled in the art with respect to alternative fuels in alternative embodiments. Such alternative embodiments are, for example, suitable for use with hydrogen or other gaseous fuels such as propane, butane, or other gas mixtures (including those commonly found with liquefied petroleum gas (LPG) mixtures). Indeed, while this disclosure focuses on the particular field to which the preferred embodiments apply, it may also be found that some aspects of this disclosure are revolutionary in other fields as well.

[0155] Power systems in use Figure 14A hydrocarbon recovery system 1400 is shown, in which the power unit system 1402 previously discussed is utilized. Specifically, the engine 102 of system 1402 is operatively coupled to pump 1404 via shaft 1406 to provide power to pump 1404. Pump 1404 is configured to pump hydrocarbons from a natural hydrocarbon source 1408 via source line 1409. Specifically, in some embodiments, hydrocarbon source 1408 is a natural gas well located underground, and pump 1404 is configured to pump natural gas from well 1408. While those skilled in the art will understand that hydrocarbon source 1408 can be any well or natural hydrocarbon source, throughout this application, hydrocarbon source 1408 will refer to a natural gas well from which pump 1404 is configured to pump natural gas.

[0156] Pump 1404 is configured to pump natural gas from well 1408 to destination 1410 via destination line 1412. Those skilled in the art will understand that destination 1410 can be any of many points in the natural gas recovery system 1400. For example, in some embodiments, destination 1410 is a storage tank for natural gas from well 1408. In other embodiments, destination 1410 is a facility for refining natural gas from well 1408. In some embodiments, pump 1404 is also configured to pump natural gas via supply line 1414, which is configured to supply fuel to fuel supply system 1402 to power engine 102. For example, in some embodiments, supply line 1414 is connected to fuel tank 360 and is therefore configured to maintain a certain level of natural gas fuel in fuel tank 360 for supplying fuel to engine 102. Thus, in some embodiments, 360 may be filled with a small amount of “starting fuel” to start the operation of engine 102 to operate pump 1404. Once pump 1404 is started, the natural gas fuel level in fuel tank 360 is adequately maintained by the natural gas supplied to fuel tank 360 by pump 1404.

[0157] In some embodiments, pump 1404 further includes a pump control module (PCM) 1416 configured to control the operation of pump 1404. PCM 1416 is configured to communicate with controllers 930a, 930b via wired or wireless communication. As discussed, controllers 930a, 930b are configured to transmit various determinations to PCM 1416 so that PCM 1416 can use the transmitted determinations to more effectively control the operation of pump 1404. For example, in some embodiments, in Figure 11B In the method described herein, at step 460', controllers 930a, 930b are configured to transmit the inferred fuel characteristics to PCM1416. As discussed in more detail previously, and referring to... Figure 11A-13The controllers 930 and 930b are configured to determine a certain fuel characteristic value (such as, for example, the BTU value) of the natural gas passing through MFG10. (See reference...) Figure 14 The gas supplied to MFG10 is ultimately provided by pump 1404, which pumps natural gas from well 1408. Therefore, controllers 930a and 930b are configured to determine the BTU value of the natural gas in well 1408. The BTU value of the natural gas in well 1408 is accessed via PCM 1416, which can control pump 1404 based on characteristic values ​​(such as the BTU value) received from controllers 930a and 930b. Those skilled in the art will understand that it is desirable to know the characteristics of the fuel pumped by pump 1404 so that the settings and operation of pump 1404 can be adjusted to pump natural gas most efficiently.

[0158] Throttling valve body assembly with annular sensing ring According to various embodiments of this disclosure, the previously detailed throttle body assembly 20 also includes annular sensing rings 1500, 1510, which, as will become apparent, further improve the accuracy of pressure sensors 950-952. Figure 15A and Figure 15B Downstream and upstream perspective views of the body assembly 20 are shown, respectively. An upstream sensing ring 1500 is disposed on the upstream side of the valve body 22 within the flow opening 24, and a downstream sensing ring 1510 is disposed on the downstream side of the valve body 22 within the flow opening 24. As will be discussed in more detail below, rings 1500 and 1510 are configured to form an annular portion between the outer portions of rings 1500 and 1510 and the opening 24, and fluid flowing through the opening 24 fills the annular portion. Pressure ports 230, 240 are fluidly connected within the annular portion, and thus allow sensors 950-952 to obtain readings of the fluid within the annular portion, providing pressure readings that are less location-dependent than readings directly from the fluid as it flows through the flow opening 24.

[0159] Figure 16A A perspective view of the upstream sensing ring 1500 is shown. The sensing ring 1500 has a shoulder portion 1502 disposed within an opening 24, and a recessed portion 1504 having a smaller outer diameter compared to the outer diameter of the shoulder portion 1502. The sensing ring 1500 further includes a plurality of notches 1506 formed on the outer edge of the recessed portion 1504, which, as discussed in more detail below, allow fluid to flow between the fluid passing through the opening 24 and the annular portion formed between the sensing ring 1500 and the wall of the opening 24.

[0160] Figure 16BA perspective view of the downstream sensing ring 1510 is shown. The sensing ring 1510 has a shoulder portion 1512 disposed within an opening 24, and a recessed portion 1504 having a smaller outer diameter compared to the outer diameter of the shoulder portion 1512. The sensing ring 1510 further includes a plurality of through holes 1506 formed in the recessed portion 1504, which, as discussed in more detail below, allow fluid to flow between the fluid passing through the opening 24 and the annular portion formed between the sensing ring 1510 and the wall of the opening 24.

[0161] Figure 17 A cross-sectional view of the body assembly 20 is shown, in which sensing rings 1500 and 1510 are mounted within the opening 24. Specifically, sensing ring 1500 is mounted in an upstream sensing ring seat 1530 of the opening 24. As previously mentioned, when sensing ring 1500 is positioned in place within seat 1530, the upstream annular portion 1520 is formed by the wall of seat 1530, the outer wall of recess 1504, and the downstream-facing edge wall of shoulder 1502. Fluid flowing through the opening 24 flows into and out of annular portion 1520 through the opening formed by recess 1506 and seat 1530. As shown, sensor port 230 is in direct fluid communication with upstream annular portion 1520.

[0162] Sensing ring 1510 is mounted in downstream sensing ring seat 1532 of opening 24. As previously mentioned, when sensing ring 1510 is positioned in seat 1532, downstream annular portion 1522 is formed by the wall of seat 1532, the outer wall of recessed portion 1514, and the upstream-facing edge wall of shoulder 1512. Fluid flowing through opening 24 flows into and out of annular portion 1520 through through hole 1516. As shown, sensor port 240 is in direct fluid communication with downstream annular portion 1522.

[0163] Those skilled in the art will understand that the annular portions 1520, 1522 provide the sensors 950-952 with the benefit of obtaining accurate pressure readings. The annular portions 1500, 1520 create a cavity for relatively "still" working fluid with a uniform pressure gradient for measurement by the sensors 950-952. Without the sensing rings 1500, 1510, the pressure reading would be obtained directly from the fluid flowing through the opening 24, which has a variable pressure gradient across the cross-section of the opening 24, and thus could cause the pressure reading to be location-dependent and inaccurately represented by the fluid flowing through the opening 24.

[0164] Although sensing rings 1500 and 1510 are shown as different from each other, those skilled in the art will understand that in other embodiments, the upstream sensing ring and the downstream sensing ring may be identical to each other. Furthermore, in some embodiments, the upstream sensing ring 1500 is incorporated into orifice 1516, and in some embodiments, the downstream sensing ring 1510 is incorporated into recess 1506. In still other embodiments, rings 1500 and 1510 may incorporate different types of channels to allow fluid communication to annular portions 1520, 1522. Although Figure 17 The cross-section shown is not illustrated, but those skilled in the art can refer to it. Figure 2D It will be understood that, according to some embodiments, the temperature sensor port 250 is also configured to be in fluid communication with the annular portion 1520. Furthermore, according to other embodiments, the port 250 is also configured to be in fluid communication with the annular portion 1520.

[0165] General alternatives While the foregoing description and figures should enable those skilled in the art to make and use things that are currently considered to be the best mode of this disclosure, they should be viewed in all respects in an illustrative rather than restrictive manner. Those skilled in the art will understand and recognize that numerous modifications, alterations, variations, combinations, rearrangements, substitutions, alternatives, design choices, and equivalents (“Alternatives”) exist, most (if not all) of which can be made without departing from the spirit and scope of this disclosure.

[0166] Therefore, this disclosure is not limited to the described embodiments and examples, but rather covers all possible embodiments within the effective scope and spirit of the claimed disclosure, where the claims may be amended, replaced, or otherwise altered during the relevant examination process. Any current, amended, or added claim should be construed as including all additional modifications, alterations, rearrangements, substitutions, alternatives, design choices, and embodiments that may be apparent to those skilled in the art, whether now known or later discovered. For example, another alternative associated with the current disclosure, having a mass flow throttle valve, may use a mass flow throttle valve for controlling the mass flow of the air-fuel mixture, which may be referred to as an MFA / MFG for convenience. Other alternatives will be apparent to those skilled in the art. In any case, all equivalents should be considered within the scope of this disclosure to the extent expressly waived during examination or to the extent necessary to maintain the validity of the particular claim in view of prior art.

Claims

1. A system for determining the fuel characteristics of fuel supplied to an internal combustion (IC) engine and for providing mass flow control of a fuel-air mixture supplied to the IC engine, comprising: A fuel control valve configured to control the delivery of fuel from a fuel source to the IC engine, and including a fuel controller for controlling the operation of the fuel control valve; An air control valve configured to control the air delivered to the IC engine, and including an air controller for controlling the operation of the air control valve; as well as The engine control module (ECM) of the IC engine, One or both of the air controller and the fuel controller are the computing controller of the system, and the computing controller is configured to: Determine the current side value of the mass flow input to the IC engine, wherein the mass flow is a mixture of fuel and air; The current air-fuel ratio of the mass flow is determined based on the current side value of the mass flow; Determine the target air-fuel ratio for the IC engine; The error value is calculated based on the difference between the current air-fuel ratio and the target air-fuel ratio; A fuel characteristic determination procedure is performed based on known fuel characteristics associated with interpolation and corresponding error side values ​​to determine the characteristics of the fuel corresponding to the error side values; as well as The characteristics of the fuel are transmitted to the ECM for use when operating the IC engine based on the characteristics of the fuel, and The ECM is configured as follows: Receive the characteristics of the fuel from the computing controller; and The operation of the IC engine is controlled based on the characteristics of the fuel.

2. The system according to claim 1, wherein, The fuel control valve further includes a plurality of fuel pressure sensors configured to obtain pressure readings from a fluid passage through which the fuel flows, and a fuel temperature sensor configured to obtain temperature readings from the fluid passage, wherein: The estimated characteristics of the fuel are stored in the fuel controller for use when the fuel controller operates the fuel control valve, and The fuel controller is configured to use the estimated characteristics of the fuel and readings from the plurality of fuel pressure sensors and the fuel temperature sensor to calculate the throttle valve opening to provide the desired fuel mass flow rate.

3. The system according to claim 1, wherein, The air control valve further includes a plurality of air pressure sensors configured to obtain pressure readings from a fluid passage through which the air flows, and an air temperature sensor configured to obtain temperature readings from the fluid passage, wherein: The properties of air are stored in the air controller for use when the air controller operates the air control valve, and The air controller is configured to use the characteristics of the air and readings from the plurality of air pressure sensors and the air temperature sensor to calculate the mass flow rate of the air.

4. The system of claim 1, further comprising an oxygen sensor configured to obtain an oxygen level reading from the exhaust gas of the IC engine, and The computing controller is configured to: Receive the oxygen level reading; and The calibration of the air control valve and one or both of the air control valves is determined based on the oxygen level reading and the error measurement value.

5. The system according to claim 4, wherein, Two or more of the fuel controller, air controller, oxygen sensor, and ECM of the IC engine are configured to communicate with each other via a communication network.

6. The system according to claim 1, wherein, The operation of the IC engine includes spark advance of the IC engine, and the ECM is configured to: The target spark advance corresponding to the fuel characteristics is determined based on the known fuel characteristics associated with the corresponding spark advance of the IC engine through interpolation; and The spark advance of the IC engine is controlled to achieve the target spark advance.

7. The system according to claim 1, wherein, The operation of the IC engine includes a load limit for the IC engine, and the ECM is configured to: The target load limit corresponding to the fuel characteristics is determined based on the known fuel characteristics associated with the corresponding load limit of the IC engine through interpolation; and The load limit of the IC engine is controlled to achieve the target load limit.

8. The system according to claim 1, wherein, The ECM is configured to adjust the operation of the IC engine when the characteristics of the fuel require adjustment of the operating conditions of the IC engine.

9. The system according to claim 8, wherein, The ECM is configured to adjust the operation of the IC engine to achieve the target phi value.

10. The system according to claim 1, wherein, The characteristics of the fuel include one or more of the British thermal unit (BTU) value, methane number (MN), or phi value.

11. The system according to claim 1, wherein, The known fuel characteristics associated with the corresponding error measurements are stored in a fuel characteristic database, and the calculation controller is configured to store the fuel characteristic database.

12. The system according to claim 1, wherein, The system is calibrated using a calibration method that generates a fuel characteristic database, and the fuel characteristic database includes the known fuel characteristics associated with corresponding error measurements.

13. The system according to claim 1, wherein, The system is calibrated using a calibration method that generates a fuel characteristic database, and the fuel characteristic database includes the known fuel characteristics associated with the corresponding operating parameters of the IC engine.

14. The system according to claim 13, wherein, For the known fuel characteristics, the operating parameters of the IC engine include the spark advance and load limit of the IC engine.

15. The system according to claim 14, wherein, The fuel characteristics database is stored in the ECM.

16. The system according to claim 1, wherein, The current measurement of the mass flow includes one or both of the mass flow rate of the air and the mass flow rate of the fuel.

17. The system according to claim 1, wherein, The target air-fuel ratio for the IC engine is determined based on the type of IC engine and the catalytic converter paired with the IC engine.

18. The system according to claim 1, wherein, The ECM is configured to send engine operating data to the computing controller, and the computing controller is configured to: Receive the engine operation data; and Determine whether the operating conditions of the IC engine are suitable for determining the characteristics of the fuel.

19. A method for determining the fuel characteristics of fuel supplied to an internal combustion (IC) engine and for providing mass flow control of a fuel-air mixture supplied to the IC engine, comprising: The current measurement of the mass flow input to the IC engine is determined by the computational controller, wherein the mass flow is a mixture of the fuel and the air, and the computational controller is one or both of a fuel controller configured to control a fuel control valve for delivering fuel from a fuel source to the IC engine and an air controller configured to control an air control valve for delivering air to the IC engine. The current air-fuel ratio of the mass flow is determined by the computational controller based on the current measurement of the mass flow; The target air-fuel ratio for the IC engine is determined by the computational controller; The calculation controller calculates the error measurement value based on the difference between the current air-fuel ratio and the target air-fuel ratio; The calculation controller performs a fuel characteristic determination procedure based on known fuel characteristics associated with interpolated and corresponding error measurements to determine the characteristics of the fuel corresponding to the error measurements. as well as The characteristics of the fuel are transmitted by the computing controller to the engine control module (ECM) of the IC engine for use when operating the IC engine based on the characteristics of the fuel.

20. The method of claim 19, further comprising: The characteristics of the fuel are received by the ECM from the computing controller; as well as The ECM controls the operation of the IC engine based on the characteristics of the fuel.

Images