System and method for providing diesel-methanol emulsion for direct injection engine

Abstract

An internal combustion engine system (100) is described herein. The system (100) uses a mixer (126) to mix two fuels to provide a transition from using only one of the fuels to using only the other as power demand varies. The output of the mixer (126) is provided as main fuel to the engine (102). The controller opens and closes the throttle valve to adjust the relative concentration of a first fuel (104) (e.g., diesel) and a second fuel (108) (e.g., methanol) entering the mixer (126). In some examples, the systems described herein are not to remove desired performance and / or environmental benefits achieved by using the second fuel (108) at power demand levels greater than a maximum achievable by using only the second fuel (108), but to allow at least a portion of the second fuel (108) to be used in the primary fuel at these power demand levels.

Description

Technical Field

[0001] This disclosure generally relates to operating a prime mover, and more specifically, to using an emulsion to provide a transition power band between methanol-based and diesel-based operation of the prime mover. Background Technology

[0002] Prime movers for working machines, such as internal combustion engines, fuel cells, and batteries, are widely used across various industries. Internal combustion engines, for example, can operate using a variety of different liquid fuels, gaseous fuels, and various blends. Spark-ignition engines use an electric spark to ignite the combustion of fuel and air, while compression-ignition engines typically compress the gas in the cylinder to the auto-ignition threshold, allowing fuel ignition to begin without a spark. Furthermore, in ignition-ignition applications, including dual-fuel applications, a mixture of gaseous fuels (such as natural gas and air) is delivered to the cylinder, and ignition is triggered by a relatively small direct injection of a compressed ignition fuel (e.g., an ignition fuel), which automatically ignites to trigger the ignition of a relatively large main charge.

[0003] As part of efforts to improve the efficiency of these engines, researchers have explored various types of alternative fuel blends, including alcohol fuels such as methanol and ethanol, and other chemicals such as formaldehyde. In some examples, methanol is injected directly into the engine cylinders and ignited with an ignition fuel or spark. Using methanol offers several advantages compared to other alternative fuels. For example, methanol has a relatively low production cost, and its production cost may be even lower than other alternative fuels. Furthermore, methanol's availability is greater than other alternative fuel sources because it can be produced in various ways using materials ranging from natural gas to coal. Additionally, methanol is relatively safe to use, store, and transport due to its relatively low flammability risk. As mentioned above, an ignition fuel may be needed to assist in the ignition of the methanol. Diesel fuel is often used as an ignition fuel to ignite the low-hexadecyl methanol fuel used in methanol-powered engines. Typically, diesel fuel, as an ignition fuel, is injected into the combustion chamber before the methanol fuel is injected. The ignition of the diesel (or ignition fuel) causes the methanol fuel to ignite.

[0004] In some cases, it may be necessary to use both diesel and methanol in an engine. Some efforts have been made to provide methanol and / or diesel in different amounts based on engine status (i.e., startup) or power level. For example, U.S. Patent No. 4,499,862 (“'862 Patent”) to Baumer et al. describes a direct injection system configured to operate using both diesel and alcohol fuels. The '862 Patent system describes the use of separate valves for diesel and alcohol fuels, thereby allowing the opening time of each valve to be adjusted based on power demand. However, the system described in the '862 Patent has some drawbacks. For example, the '862 Patent system injects methanol into the combustion cylinder, meaning that the immersion and mixing of methanol with diesel fuel relies solely on turbulent airflow within a relatively small volume of space in the cylinder, which can lead to incomplete mixing. This potential incomplete mixing can result in a reduction in total available power when in diesel-methanol mode. Additionally, because the methanol portion of the '862 Patent system only injects methanol, a power band gap may exist between primarily using ethanol as the primary fuel and using diesel as the primary fuel.

[0005] The examples disclosed herein relate to overcoming the shortcomings of such systems. Summary of the Invention

[0006] In one aspect of the currently disclosed subject matter, a system includes: an engine that burns a primary fuel and an ignition fuel, wherein the engine is an internal combustion engine; a first fuel tank for storing a first fuel; a second fuel tank for storing a second fuel; a first fuel metering valve for controlling a first fuel flow rate of the first fuel through a three-way valve, wherein the output of the three-way valve flows into a mixer; a second fuel metering valve for controlling a second fuel flow rate of the second fuel through the three-way valve; and the mixer for mixing the output of the three-way valve, wherein the mixer output of the mixer flows into a primary fuel rail for the engine to use as the primary fuel, wherein the positions of the first fuel metering valve and the second fuel metering valve determine the concentrations of the first fuel and the second fuel in the primary fuel.

[0007] In another aspect of the currently disclosed subject matter, a method includes: a system monitored by a controller, the system comprising: an internal combustion engine that burns a primary fuel and an ignition fuel; a first fuel tank for storing a first fuel; a second fuel tank for storing a second fuel; a first fuel metering valve for controlling a first fuel flow rate of the first fuel through a three-way valve, wherein the output of the three-way valve flows into a mixer; a second fuel metering valve for controlling a second fuel flow rate of the second fuel through the three-way valve; and the mixer for mixing the output of the three-way valve, wherein the mixer output of the mixer flows into a main fuel rail for the engine to use as the primary fuel. The positions of the first fuel metering valve and the second fuel metering valve determine the concentrations of the first fuel and the second fuel in the main fuel; the controller receives a power demand input; the controller retrieves a first fuel flow rate and a second fuel flow rate from the engine map based on the power demand input; the controller sends a first fuel control signal to the first fuel metering valve to adjust the first fuel metering valve to the first fuel metering valve position to achieve the first fuel flow rate; and the controller sends a second fuel control signal to the second fuel metering valve to adjust the second fuel metering valve position to the second fuel metering valve based on the second fuel control signal.

[0008] In another aspect of the currently disclosed subject matter, a controller includes a memory storing computer-executable instructions and a processor communicating with the memory, the computer-executable instructions causing the processor to perform actions, the actions including: a monitoring system comprising: an internal combustion engine burning a primary fuel and an ignition fuel; a first fuel tank for storing a first fuel; a second fuel tank for storing a second fuel; a first fuel metering valve for controlling the first fuel flow rate through a three-way valve, wherein the output of the three-way valve flows into a mixer; a second fuel metering valve for controlling the second fuel flow rate through the three-way valve; and the mixer for mixing the output of the three-way valve. The mixer output of the mixer flows into the main fuel rail for the engine to use as the main fuel, wherein the positions of the first fuel metering valve and the second fuel metering valve determine the concentrations of the first fuel and the second fuel in the main fuel; and receives a power demand input; retrieves a first fuel flow rate and a second fuel flow rate from the engine profile based on the power demand input; issues a first fuel control signal to the first fuel metering valve to adjust the first fuel metering valve to the first fuel metering valve position to achieve the first fuel flow rate; and issues a second fuel control signal to the second fuel metering valve to adjust the second fuel metering valve to the second fuel metering valve position based on the second fuel control signal. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a combustion engine system according to one or more examples of the present disclosure, the combustion engine system using a mixer to mix one fuel into another fuel that is fed into the engine as the main fuel.

[0010] Figure 2 The diagram shows a combustion chamber of an engine according to some examples of this disclosure, in which the second fuel is the only component of the main fuel.

[0011] Figure 3 The diagram shows a combustion chamber of an engine according to some examples of this disclosure, wherein the first fuel is the only component of the main fuel.

[0012] Figure 4 The diagram illustrates the combustion chamber of an engine according to some examples of this disclosure, wherein a first fuel is mixed with a second fuel to produce a fuel mixture, which is the main fuel.

[0013] Figure 5This is an illustration of a combustion engine system according to one or more examples of the present disclosure, the combustion engine system using a controller to control the relative concentrations of a first fuel and a second fuel fed into the main fuel of the engine.

[0014] Figure 6 Methods for operating an internal combustion engine, according to various examples of the currently disclosed subject matter, are shown, wherein a controller controls the relative amounts of a first fuel and a second fuel in the main fuel.

[0015] Figure 7 This paper depicts a component-level view of controllers for use with the systems and methods described herein, based on various examples of currently published topics. Detailed Implementation

[0016] Wherever possible, the same reference numerals will be used throughout the accompanying drawings to denote the same or similar parts. Refer to the accompanying drawings. Figure 1 This is a schematic diagram of a combustion engine system 100 according to one or more examples of this disclosure, which uses a mixer to mix fuel into another fuel fed into the engine. System 100 includes an engine 102, which is an internal combustion engine. As used herein, engine 102 is a prime mover that can be used separately or in conjunction with other systems such as batteries, fuel cells, etc. Engine 102 is fueled by a first fuel 104 stored in a first fuel tank 106 and / or a second fuel 108 stored in a second fuel tank 110. The first fuel 104 may comprise a higher cetane / lower octane liquid fuel, and the second fuel 108 may comprise a lower cetane / higher octane liquid fuel. In this context, the terms "higher" and "lower" can be understood as relative terms relative to each other. Thus, the first fuel 104 may have a higher cetane number and a lower octane number than the second fuel 108. The first fuel 104 may include any one or more of the following fuel types: diesel distillate fuel, dimethyl ether, biodiesel, hydrotreated vegetable oil (HVO), gas-liquid (GTL) renewable diesel, and various liquid fuels with cetane enhancers. The second fuel 108 may include alcohol fuels, such as, for example, methanol or ethanol, naphtha, or other fuel types. Figure 1 For the purposes of this disclosure, the first fuel 104 is described as diesel fuel and the second fuel 108 is described as methanol, but as stated above, the present disclosure can be used with other fuel types.

[0017] In some examples, the first fuel 104 can be used as the ignition fuel for the engine 102. The ignition fuel is the fuel injected before or in combination with the second fuel. Figure 1In the example, compression from a piston (not shown) of engine 102 ignites a first fuel 104, which ignites due to its relatively high cetane number compared to other fuels. The relatively high temperatures generated during ignition and combustion of the first fuel 104 as an ignition fuel then provide sufficient pressure and temperature to burn a second fuel 108, which may not ignite compressibly due to its relatively low cetane number compared to the first fuel 104. The first fuel 104 is in fluid communication with and pumped by a first fuel pump 112 into cylinder block 114 and into one or more injectors (not shown) of engine 102. Cylinder block 114 is typically a ported device with an internal port that receives the first fuel 104 from the first fuel pump 112 and directs the first fuel 104 into the engine as an ignition fuel, or, if the first fuel metering valve 116 is open, directs it to the first fuel metering valve 116, thereby allowing fluid flow of the first fuel 104. The first fuel metering valve 116 prevents and throttles the flow of the first fuel 104 into a three-way valve 118.

[0018] A second fuel pump 120 is in fluid communication with a second fuel 108 in a second fuel tank 110. The second fuel pump 120 pumps the second fuel 108 from the second fuel tank 110 to a second fuel metering valve 122. The second fuel metering valve 122 prevents and throttles the flow of the second fuel 108 into a tee 118. One or more fluids entering the tee 118 exit the tee outlet 124 and enter a mixer 126. The mixer 126 is designed to mix the fluids entering the mixer 126 to produce an emulsion of the fluids entering the mixer 126. Depending on the volumetric flow rate of the one or more fluids entering the mixer 126, the mixer can be a low-shear / high-flow-rate mixer or a high-shear / low-flow-rate mixer. In some examples, the mixer 126 is a liquid-liquid mixer, a gas-liquid mixer, or a combination thereof. However, it should be noted that the present disclosure is not limited to any particular type or number of mixers, as more than one type, different types, or multiple mixers can be used, and they are considered to be within the scope of the present disclosure.

[0019] When the second fuel 108 is used as the primary fuel, the output 128 of the mixer 126 is primarily the second fuel 108. The second fuel pump 120 pumps the second fuel 108 from the second fuel tank 110. The second fuel metering valve 122 can be a proportional valve or a throttle valve, which changes the flow rate of the second fuel 108 into the three-way valve 118 based on the position of the second fuel metering valve 122. In the configuration where the second fuel 108 is the primary fuel, the three-way outlet 124 of the three-way valve 118 is for the second fuel 108 because the first fuel metering valve 116 is closed, thereby inhibiting the flow of the first fuel 104 from the first fuel pump 112 out of the cylinder block 114 at the first fuel metering valve 116. The first fuel 104 flows out of the first fuel pump 112, through the cylinder block 114, and flows into the engine 102 as ignition fuel. When the first fuel 104 is used as the primary fuel, the output 128 of the mixer 126 is primarily the first fuel 104. The first fuel pump 112 pumps the first fuel 104 from the first fuel tank 106. The first fuel metering valve 116 is a proportional valve or throttle valve that changes the flow rate of the first fuel 104 into the tee 118 based on the position of the first fuel metering valve 116. In this example, because the first fuel 104 is used as the main fuel, the tee outlet 124 of the tee 118 is for the first fuel 104, and because the second fuel metering valve 122 is closed, the flow of the second fuel 108 from the second fuel pump 120 is suppressed at the second fuel metering valve 122. In some examples where the first fuel 104 is used as the main fuel and the second fuel metering valve 122 is closed, the second fuel pump 120 may also be de-energized.

[0020] In addition to configurations where either the second fuel 108 or the first fuel 104 is used as the primary fuel, system 100 also includes configurations where the primary fuel can be a mixture (or emulsion) of the first fuel 104 and the second fuel 108. In these examples, as engine power demand increases when engine 102 transitions from using the second fuel 108 as the sole primary fuel to using the first fuel 104 as the sole primary fuel, the first fuel 104 and the second fuel 108 can be mixed at various concentrations as engine 102 transitions through and returns from the transition. For the configuration where engine 102 transitions from using the second fuel 108 as the sole primary fuel to using the first fuel 104 as the sole primary fuel, initially the first fuel metering valve 116 is closed, and the second fuel metering valve 122 is throttled to control the volumetric flow rate of the second fuel 108 into the three-way valve 118, the mixer 126, and ultimately into engine 102 as the primary fuel.

[0021] To increase the amount of first fuel 104 added to the main fuel, a first fuel metering valve 116 is throttled open based on the required amount of first fuel 104 to be added as a component of the main fuel. A first fuel pump 112 pumps the first fuel 104 into cylinder block 114, a portion of which continues to be used as ignition fuel. A second portion exits cylinder block 114 and flows through the first fuel metering valve 116 at a volumetric flow rate set by the position of the first fuel metering valve 116, which, as explained above, is a throttle valve. It should be understood that the use of a throttle valve is for illustrative purposes only, as other techniques (including variable speed pumps) for controlling the volumetric flow rate of the first fuel 104 may also be used, and such other techniques are considered to be within the scope of the currently disclosed subject matter. First fuel 104 and second fuel 108 enter a tee 118, exit at a tee outlet 124, and subsequently enter a mixer 126, where the two fuels are mixed. Depending on the type of fuel used, the mixture may be a solution, suspension, or colloid, and may be homogeneous or heterogeneous. The subject matter disclosed here is not limited to any particular type of mixture. In the example where the first fuel 104 is diesel (oil) and the second fuel 108 is methanol, the mixture can be an emulsion, a type of colloid, because methanol and diesel are practically immiscible. Mixer 126 mixes the first fuel 104 and the second fuel 108 before engine 102. As described above, mixer 126 can have various structural forms. The concentrations of the first fuel 104 and the second fuel 108 in the main fuel mixture are determined by the positions of the first fuel metering valve 116 and the second fuel metering valve 122.

[0022] To increase the relative concentration of the first fuel 104 with respect to the second fuel 108 (meaning the engine 102 is transitioning from a methanol-only primary fuel mode to a diesel-only primary fuel mode), the first fuel metering valve 116 further opens, while the second fuel metering valve 122 further closes. This process continues until the first fuel metering valve 116 is open and the second fuel metering valve 122 is closed, thereby inhibiting the flow of the second fuel 108. To decrease the relative concentration of the first fuel 104 with respect to the second fuel 108 (meaning the engine 102 is transitioning from a diesel-only primary fuel mode to a methanol-only primary fuel mode), the first fuel metering valve 116 further closes, while the second fuel metering valve 122 further opens. This process continues until the first fuel metering valve 116 is closed and the second fuel metering valve 122 is open, thereby inhibiting the flow of the first fuel 104. This transition is described below. Figure 2-4 Further details will be provided in the text.

[0023] Figure 2This is a diagram of the combustion chamber 202 of an engine 102 according to some examples of this disclosure, wherein the second fuel 108 is the sole component of the main fuel. In this configuration, the first fuel metering valve 116 is closed, and the second fuel metering valve 122 is positioned to control the flow rate of the second fuel 108 into the engine 102. Figure 2 In the combustion chamber 202, the main fuel and ignition fuel are received and burned to provide power. The main fuel and ignition fuel are compressed by a piston (not shown). Figure 2 In this combustion chamber 202, ignition fuel is supplied via ignition fuel rail 204. First fuel 104 is pumped into ignition fuel rail 204 via cylinder block 114. Main fuel is supplied via main fuel rail 206. Second fuel 108 is pumped through mixer 126 and into main fuel rail 206. As used herein, a "rail" is a fuel line that supplies fuel to one or more injectors, such as injector 208. It should be noted that injector 208 may be a single injector capable of receiving both first fuel 104 and second fuel 108, or multiple injectors, or a combination thereof, each capable of receiving either first fuel 104 or second fuel 108. Injector 208 injects ignition fuel (first fuel 104) and main fuel (second fuel 108) into combustion chamber 202 via injector port 210. The injected fuel 212 comprises an initial injection of ignition fuel (first fuel 104), followed by a second injection of main fuel (second fuel 108).

[0024] Figure 3 This is a diagram of the combustion chamber 202 of an engine 102 according to some examples of this disclosure, wherein the first fuel 104 is the sole component of the main fuel. In this configuration, a first fuel metering valve 116 is positioned to control the flow rate of the first fuel 104 into the engine, and a second fuel metering valve 122 is closed. The first fuel 104 is pumped through the cylinder block 114 into the ignition fuel rail 204. The main fuel is supplied through the main fuel rail 206. The first fuel 104 is pumped through the mixer 126 and into the main fuel rail 206. An injector 208 injects the ignition fuel (first fuel 104) and the main fuel (first fuel 104) into the combustion chamber 202 through injector port 210. The injected fuel 312 includes the initially injected ignition fuel (first fuel 104), followed by a second injection of the main fuel (first fuel 104). It should be noted that in some examples where the first fuel 104 is used as the main fuel, the controller of the system 100 (not shown) can stop or reduce the flow of the ignition fuel because the first fuel 104 is configured to burn without the use of ignition fuel.

[0025] Figure 4This is a diagram of the combustion chamber 202 of an engine 102 according to some examples of this disclosure, wherein a first fuel 104 is mixed with a second fuel 108 to produce a fuel mixture, which is the primary fuel. In this configuration, a first fuel metering valve 116 is positioned to control the flow rate of the first fuel 104 into the engine, and a second fuel metering valve 122 is positioned to control the flow rate of the second fuel 108 into the engine 102 through a mixer 126. The first fuel 104 is pumped through a cylinder block 114 into an ignition fuel rail 204 and through the cylinder block 114 and the first fuel metering valve 116 into a three-way valve 118. The second fuel 108 is pumped through the second fuel metering valve 122 into the three-way valve 118. The first fuel 104 and the second fuel 108 are mixed in the mixer 126 and provided to the primary fuel rail 206, whereby the mixture (emulsion) is the primary fuel. Injector 208 injects ignition fuel (first fuel 104) and main fuel (a mixture 402 of first fuel 104 and second fuel 108) into combustion chamber 202 through injector port 210. The injected fuel 412 comprises an initial injection of ignition fuel (first fuel 104), followed by a second injection of main fuel (a mixture 402 of first fuel 104 and second fuel 108). It should be noted that in some examples where first fuel 104 is used as a component of the mixture 402 forming the main fuel, system 100 may stop or reduce the flow of ignition fuel because first fuel 104 is configured to burn without the use of ignition fuel.

[0026] As described above, the positions of the first fuel metering valve 116 and the second fuel metering valve 122 determine the relative concentrations of the first fuel 104 and the second fuel 108 added to the main fuel of the engine 102. The positions of these valves (the first fuel metering valve 116 and the second fuel metering valve 122) can be controlled based on various inputs. In one example, the power demand of the engine 102, indicated by the position of a control input (e.g., the accelerator), can be used to determine the preferred relative concentrations of the first fuel 104 and the second fuel 108 added to the main fuel of the engine 102. A controller can be used to change the valve configuration, such as... Figure 5 A more detailed illustration is provided.

[0027] Figure 5This is an illustration of a combustion engine system 500 according to one or more examples of the present disclosure, which uses a controller to control the relative concentrations of a first fuel and a second fuel in the main fuel fed to an engine 502. System 500 includes an engine 502, which is an internal combustion engine. Engine 502 is fueled by a first fuel 504 stored in a first fuel tank 506, a second fuel 508 stored in a second fuel tank 510, or a mixture thereof. The first fuel 504 may comprise a higher cetane / lower octane liquid fuel, and the second fuel 508 may comprise a lower cetane / higher octane liquid fuel. In this context, the terms "higher" and "lower" can be understood as relative terms to each other. Thus, the first fuel 504 may have a higher cetane number and a lower octane number than the second fuel 508. The second fuel 508 may comprise an alcohol fuel, such as, for example, methanol or ethanol, naphtha, or other fuel types. Figure 5 For the purposes of this disclosure, the first fuel 504 is described as diesel fuel and the second fuel 508 is described as methanol, but as stated above, the present disclosure can be used with other fuel types.

[0028] In some examples, the first fuel 504 can be used as the ignition fuel for the engine 502. The first fuel 504 is in fluid communication with a first fuel pump 512 and is pumped by this pump into the cylinder block 514 and into the ignition fuel rail 505 of the engine 502 for use as ignition fuel. The cylinder block 514 is typically a ported device that receives the first fuel 504 from the first fuel pump 512 and directs the first fuel 504 as ignition fuel into the ignition fuel rail 505 of the engine 502, or, if the first fuel metering valve 516 is open, directs it into the first fuel metering valve 516, thereby allowing fluid flow of the first fuel 504. The first fuel metering valve 516 prevents and throttles the flow of the first fuel 504 through the check valve 519 into the three-way valve 518.

[0029] A second fuel pump 520 is in fluid communication with a second fuel 508 in a second fuel tank 510. The second fuel pump 520 pumps the second fuel 508 from the second fuel tank 510 to a second fuel metering valve 522. The second fuel metering valve 522 prevents and throttles the flow of the second fuel 508 through a check valve 521 into a three-way valve 518. A flow meter 523 for a fuel flow meter measures the flow rate of the second fuel 508 through the second fuel metering valve 522. Fluid entering the three-way valve 518 exits from the three-way outlet 524 and enters a mixer 526. In some examples, a mixing pump 511 may be used to provide additional power to the fluid exiting the three-way valve 518 at the three-way outlet 524. The mixer 526 is designed to mix the fluid entering the mixer 526 to produce an emulsion (or other mixture) of the fluid entering the mixer 526. The fluid exiting the mixer is directed to the main fuel rail 529 for use as the main fuel for the engine 502. Depending on the volumetric flow rate of one or more fluids entering mixer 526, mixer 526 can be a low-shear / high-flow mixer or a high-shear / low-flow mixer. In some examples, mixer 526 is a liquid-liquid mixer, a gas-liquid mixer, or a combination thereof. However, it should be noted that the present disclosure is not limited to any particular type or number of mixers, as more than one type, different types, or multiple mixers can be used, and they are considered to be within the scope of the present disclosure. Composition sensor 513 is used to measure the concentrations of the first fuel 504 and the second fuel 508 exiting the tee 518. In some examples, a flow meter (not shown) can be used at the output of the first fuel metering valve 516 to measure the flow rate of the first fuel 504 entering the tee 518. The relative concentrations of the first fuel 504 and the second fuel 508 exiting the tee 518 can be calculated based on the measured volumetric flow rates of the first fuel 504 and the second fuel 508. In another example, the volumetric flow rates of the first fuel 504 and the second fuel 508 can be pre-measured based on the pump speed and / or the position of their respective metering valves. These and other methods can be used to calculate the relative concentrations of the first fuel 504 and the second fuel 508 leaving the tee 518.

[0030] When the second fuel 508 is used as the primary fuel, the output 528 of the mixer 526 is primarily the second fuel 508. The second fuel pump 520 pumps the second fuel 508 from the second fuel tank 510 through the second fuel metering valve 122, flow meter 523, check valve 521, and into the three-way valve 518. In the configuration where the second fuel 508 is the primary fuel, the three-way outlet 524 of the three-way valve 518 is for the second fuel 508 because the first fuel metering valve 516 is closed, thus inhibiting the flow of the first fuel 504 from the first fuel pump 512 out of the cylinder block 514 at the first fuel metering valve 516. The first fuel 504 flows out of the first fuel pump 512 through the cylinder block 514 and the ignition fuel rail 505, and flows into the engine 502 as ignition fuel. When the first fuel 504 is used as the primary fuel, the output 528 of the mixer 526 is primarily the first fuel 504. The first fuel pump 512 pumps the first fuel 504 from the first fuel tank 506. In this example, because the first fuel 504 is used as the main fuel, the three-way outlet 524 of the three-way 518 is for the first fuel 504. Since the second fuel metering valve 522 is closed, the flow of the second fuel 508 from the second fuel pump 520 is suppressed at the second fuel metering valve 522. In some examples where the first fuel 504 is used as the main fuel and the second fuel metering valve 522 is closed, the second fuel pump 520 may also be de-energized.

[0031] In addition to configurations where either the second fuel 508 or the first fuel 504 is used as the primary fuel, system 500 also includes configurations where the primary fuel can be a mixture (or emulsion) of the first fuel 504 and the second fuel 508. In these examples, as engine power demand increases when engine 502 transitions from using the second fuel 508 as the sole primary fuel to using the first fuel 504 as the sole primary fuel, the first fuel 504 and the second fuel 508 can be mixed at various concentrations as engine 502 transitions through and returns from the transition. For the configuration where engine 502 transitions from using the second fuel 508 as the sole primary fuel to using the first fuel 504 as the sole primary fuel, initially the first fuel metering valve 516 is closed, and the second fuel metering valve 522 is throttled to control the volumetric flow rate of the second fuel 508 into the three-way valve 518, the mixer 526, and ultimately into engine 502 as the primary fuel.

[0032] To control or change the relative amounts of the first fuel 504 and the second fuel 508 in the main fuel, a controller 530 may be used. The controller 530 may be a component of the engine control unit (ECU) or engine control module (ECM) ECU of an internal combustion engine, or another component for controlling various aspects of the internal combustion engine. The controller 530 controls the amount of main fuel entering the main fuel rail 529 and the concentration of the first fuel 504 and the second fuel 508 in the main fuel. The controller 530 includes one or more processors and a memory storing instructions therein, which, when executed by the processor of the controller 530, cause the controller 530 to control the various components of the system 500. These and other aspects of the controller 530 are described below. Figure 7 A more detailed explanation follows.

[0033] To transition from a configuration where the second fuel 508 is used as the primary fuel to a configuration where the primary fuel comprises a mixture of the second fuel 508 and the first fuel 504, the controller 530 is configured to control the position of the first fuel metering valve 516 using a first fuel control signal 532. The controller 530 is also configured to control the position of the second fuel metering valve 522 using a second fuel control signal 534. The controller 530 uses an engine power demand input 536 to determine the desired or required positions of the second fuel metering valve 522 and the first fuel metering valve 516 for engine power demand. As described above, the second fuel 508 can provide only the maximum power amount for a given system configuration. If the maximum power amount is less than the full power achievable by the engine 102, the first fuel 504 can be added to the second fuel 508 to provide additional power.

[0034] When the power demand increases beyond the maximum power that the second fuel 508 can provide for a given system configuration, it may be necessary to add an additional amount of the first fuel 504, possibly to the point that the first fuel 504 is the sole component of the main fuel. Therefore, the controller 530 uses the engine power demand input 536 to determine the desired relative amounts of the first fuel 504 and the second fuel 508 in the main fuel. For example, assuming that the second fuel 508, as the sole component of the main fuel, can provide 60 percent (50%) of the potential maximum power of the engine 102, and the first fuel 504 can provide up to 100 percent (100%) of the potential maximum power of the engine 102, then at power demand levels exceeding 50%, achieving greater than 50% engine power requires a combination of the first fuel 504 and the second fuel 508. The relative concentration may vary as the power demand level increases. For example, the relative concentration (or the ratio of the volumetric flow rate of the second fuel to the volumetric flow rate of the first fuel) can change from 100:0 at a 50% power demand level to 50:50 at a 75% power demand level, and continue to 0:100 at a 100% power demand level. It should be noted that these ratios are only used to illustrate how the ratios change based on the power demand level and should not be considered as limiting the scope of the present disclosure. The controller 530 may further adjust the positions of the second fuel metering valve 522 and the first fuel metering valve 516 using a composition input 548 received from the composition sensor 513 (if used), reflecting the concentrations of the first fuel 504 and the second fuel 508 exiting the tee 518.

[0035] To increase the amount of first fuel 504 added to the main fuel, controller 530 issues a first fuel control signal 532 to open the first fuel metering valve 516 to increase the flow rate of first fuel 504 through the first fuel metering valve 516. Furthermore, if it is necessary to maintain or achieve a specific total volumetric flow rate of the main fuel entering the engine 102, controller 530 issues a second fuel control signal 534 to close or open the second fuel metering valve 522. To decrease the amount of first fuel 504 added to the main fuel, controller 530 issues a first fuel control signal 532 to close the first fuel metering valve 516 to a certain position, and if it is necessary to maintain or achieve a specific total volumetric flow rate of the main fuel entering the engine 102, issues a second fuel control signal 534 to close or open the second fuel metering valve 522. It should be understood that the use of a throttle valve is for illustrative purposes only, as other techniques (including variable speed pumps) for controlling the volumetric flow rate of the first fuel 504 may also be used, and said other techniques are considered to be within the scope of the currently disclosed subject matter.

[0036] In some examples, engine 502 may not use all the main fuel. In these examples, excess main fuel 540, i.e., unburned main fuel that is not injected into the combustion chamber of engine 502, may need to be recycled back into engine 502 or stored in a tank. Figure 5 In this process, because the main fuel may be at a high temperature, excess main fuel 540 from engine 502 enters cooler 542. Cooler 542 reduces the temperature of excess main fuel 540 or cools it. Excess main fuel 540 leaves cooler 542 and enters flow meter 544, which measures the volumetric flow rate of excess main fuel 540 and outputs an excess flow rate signal 546 to controller 530. If the flow rate exceeds a set point, controller 530 may issue an updated first fuel control signal 532 to reduce the flow rate of first fuel 504 and an updated second fuel control signal 534 to reduce the flow rate of second fuel 508 entering mixer 526. Mixing pump 511 can be used to pump at least a portion of excess main fuel 540 back to mixer 526 through check valve 549. Additional excess main fuel 540 can be stored in mixing tank 550 by opening mixing tank valve 552.

[0037] Figure 6 A method 600 for operating an internal combustion engine 502, according to various examples of the currently disclosed subject matter, is illustrated, wherein a controller 530 controls the relative amounts of a first fuel 504 and a second fuel 508 in the main fuel. The method 600 and other processes described herein are shown as exemplary flowcharts, each operation of which may represent a sequence of operations that can be implemented in hardware, software, or a combination thereof. In the context of software, an operation represents computer-executable instructions stored on one or more tangible computer-readable storage media, which, when executed by one or more processors, perform the operation. Typically, computer-executable instructions include routines, programs, objects, components, data structures, etc., that perform a particular function or implement a particular abstract data type. The order in which the operations are described is not intended to be construed as limiting, and any number of the operations may be combined in any order and / or in parallel to implement the process.

[0038] Method 600 begins at step 602, where controller 530 is monitoring system 500. At step 602, controller 530 is operating and receiving various inputs, such as, but not limited to, engine power demand input 536, excess flow rate signal 546, and composition input 548. Controller 530 uses these inputs to control the flow rates of first fuel 504 and second fuel 508 entering engine 502.

[0039] At step 604, controller 530 receives an updated engine power demand input 536. Engine power demand input 536 is communication with controller 530, informing controller 530 of the expected power demand of engine 502. While not limited to any particular source, engine power demand input 536 can be generated and received from various sensors or inputs associated with engine 502, including engine control unit (ECU), engine control module (ECM) ECU of an internal combustion engine, or another component used to control various aspects of the internal combustion engine.

[0040] At step 606, controller 530 retrieves the flow rates of first fuel 504 and second fuel 508 to meet the demand. While not limited to any specific source for the flow rates of first fuel 504 and second fuel 508, in some examples, an engine profile may be accessible to controller 530. As used herein, an "engine profile" is a set of data providing various engine settings, such as the flow rates of first fuel 504 and second fuel 508, to achieve one or more desired engine outputs (e.g., torque or power). Therefore, controller 530 uses data such as an engine profile to determine the desired relative amounts of first fuel 504 and second fuel 508 in the main fuel using engine power demand input 536. For example, an engine profile may have a table stating that at 80% power demand, the flow rate of first fuel 504 should be 265 ml / min, and the flow rate of second fuel 508 should be 265 ml / min. Controller 530 may have stored, or be able to access, settings for first fuel metering valve 516 and second fuel metering valve 522 to achieve these corresponding flow rates.

[0041] At step 608, controller 530 transmits a first fuel control signal 532 to first fuel metering valve 516, causing first fuel metering valve 516 to adjust to the position based on the first fuel control signal 532 to achieve a first fuel flow rate. Similarly, controller 530 transmits a second fuel control signal 534 to second fuel metering valve 522, causing second fuel metering valve 522 to adjust to the position based on the second fuel control signal 534 to achieve a second fuel flow rate. As first fuel 504 and second fuel 508 flow through tee 518, the first fuel 504 and second fuel 508 flows are ultimately mixed in mixer 526 to be delivered to engine 502 as main fuel.

[0042] Figure 7A component-level view of a controller 530 for use with the systems and methods described herein is depicted, according to various examples of the currently disclosed subject matter. The controller 530 can be any means capable of providing functionality associated with the systems and methods described herein. The controller 530 may include several components to perform the aforementioned functions. The controller 530 may include hardware, software, or various combinations thereof. As discussed below, the controller 530 may include a memory 702, which includes an operating system (OS) 704 and one or more standard applications 706. The standard applications 706 may include applications that provide a first fuel control signal 532, a second fuel control signal 534, and receive and store signals such as an engine power demand input 536 and an excess flow rate signal 546.

[0043] The controller 530 may also include one or more processors 710 and one or more of a removable storage device 712, a non-removable storage device 714, a plurality of transceivers 716, a plurality of output devices 718, and a plurality of input devices 720. In various embodiments, the memory 702 may be volatile (such as random access memory (RAM)), non-volatile (such as read-only memory (ROM), flash memory, etc.), or some combination of both. The memory 702 may include data related to signals such as engine power demand input 536 and excess flow rate signal 546, as well as other information, and may be stored on a remote server or server cloud accessible to the controller 530.

[0044] The memory 702 may also include an operating system 704. The operating system 704 varies depending on the manufacturer of the controller 530. The operating system 704 contains modules and software that support the basic functions of the controller 530, such as scheduling tasks, executing applications, and controlling peripheral devices. The operating system 704 may also enable the controller 530 to send and retrieve other data and perform other functions, such as engine power demand input 536 and excess flow rate signal 546, as well as instructions, a first fuel control signal 532, and a second fuel control signal 534.

[0045] The controller 530 may also include one or more processors 710. In some embodiments, the processors 710 may be one or more central processing units (CPUs), graphics processing units (GPUs), both CPUs and GPUs, or any other combination and number of processing units. The controller 530 may also include additional data storage devices (removable and / or non-removable), such as, for example, disks, optical discs, or magnetic tapes. Such additional storage devices... Figure 7 The image is shown by a removable storage device 712 and a non-removable storage device 714.

[0046] Non-transitory computer-readable media can include volatile and non-volatile, removable and non-removable tangible physical media implemented with technologies used for storing information such as computer-readable instructions, data structures, program modules or other data. Memory 702, removable storage device 712 and non-removable storage device 714 are examples of non-transitory computer-readable media. Non-transitory computer-readable media include, but are not limited to, RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory or other memory technologies, optical disc ROM (CD-ROM), digital universal disc (DVD) or other optical storage devices, magnetic tape cassettes, magnetic tape, disk storage devices or other magnetic storage devices, or any other tangible physical media that can be used to store desired information and is accessible by controller 530. Any such non-transitory computer-readable media may be part of controller 530 or may be a separate database, data bank, remote server or cloud-based server.

[0047] In some implementations, transceiver(s) 716 includes any transceiver known in the art. In some examples, transceiver(s) 716 may include multiple wireless modems to facilitate wireless connectivity with other components (e.g., between controller 530 and one or more pumps or valves), the Internet, and / or intranets. Specifically, transceiver(s) 716 may include one or more transceivers that enable controller 530 to send and receive data. Thus, transceiver(s) 716 may include multiple single-channel transceivers or multi-frequency multi-channel transceivers to enable controller 530 to send and receive video calls, audio calls, messaging, etc. Transceiver(s) 716 may enable controller 530 to connect to multiple networks, including but not limited to 2G, 3G, 4G, 5G, and Wi-Fi networks. Transceiver(s) 716 may also include one or more transceivers to enable controller 530 to connect to future (e.g., 6G) networks, Internet of Things (IoT), machine-to-machine (M2M) networks, and other current and future networks.

[0048] (Multiple) transceivers 716 may also include functions that can be performed via an antenna (e.g., Wi-Fi or Bluetooth). ® This refers to one or more radio transceivers capable of transmitting and receiving radio frequency communications. In other examples, transceiver(s) 716 may include wired communication components, such as wired modems or Ethernet ports, for communicating via one or more wired networks. Transceiver(s) 716 may enable controller 530 to facilitate audio and video calls, file downloads, access to web applications, and other communications associated with the systems and methods described above.

[0049] In some embodiments, the output device(s) 718 includes any output device known in the art, such as a display (e.g., a liquid crystal or thin-film transistor (TFT) display), a touchscreen, a speaker, a vibration mechanism, or a haptic feedback mechanism. Therefore, the output device(s) may include a screen or display. The output device(s) 718 may also include a speaker or similar device to play sound or a ringtone upon receiving an audio or video call. The output device(s) 718 may also include ports for one or more peripheral devices, such as headphones, peripheral speakers, or peripheral displays.

[0050] In various embodiments, the input device(s) 720 includes any input device known in the art. For example, the input device(s) 720 may include a camera, microphone, or keyboard / keyboard. The input device(s) 720 may include a touch-sensitive display or keyboard to enable a user to input data and make requests and receive responses via a web application (e.g., in a web browser), make audio and video calls, and use standard application 706, etc. The touch-sensitive display or keyboard / keyboard may be a standard button alphanumeric keypad (such as a conventional QWERTY keyboard), virtual controls on a touchscreen, or one or more other types of keys or buttons, and may also include joysticks, wheels, and / or designated navigation buttons, etc. The touch-sensitive display may function as both input device 720 and output device 718.

[0051] Industrial applicability

[0052] This disclosure generally relates to internal combustion engines that use a mixer (e.g., mixer 126 or 526) to mix a first fuel (e.g., diesel) with a second fuel (e.g., methanol) to provide a transition from the maximum power provided using only the second fuel to the maximum power provided using only the first fuel. In some engines (e.g., engines 102 or 502), the second fuel (e.g., methanol) is used to achieve performance and / or environmental improvements compared to using the first fuel (e.g., diesel). However, the energy content of a fuel such as methanol may be half or one-third that of diesel. Therefore, in some systems, the flow rate of methanol may be insufficient to provide a certain power requirement. A power requirement gap may exist between the maximum power achievable using the second fuel and the maximum power achievable using the first fuel.

[0053] Systems 100 and 500 described herein provide a transition from the maximum available power of the second fuel 508 to a given power demand exceeding that maximum power. To maintain at least some of the benefits of using the second fuel 508, systems 100 and 500 do not switch from the second fuel 508 to the first fuel 504 when the power demand exceeds the maximum power; instead, they use a mixer to mix the first fuel 504 with the second fuel 508. The ratio of the second fuel to the first fuel in the mixture varies with the power demand, wherein the concentration of the second fuel 508 decreases relative to the concentration of the first fuel 504 as the power demand increases, and increases relative to the concentration of the first fuel 504 as the power demand decreases. Therefore, in some examples, systems 100 and 500 do not eliminate the desired performance and / or environmental benefits achieved by using the second fuel, but rather allow at least a portion of the second fuel 508 to be used in the primary fuel mix.

[0054] Unless explicitly excluded, the use of the singular to describe a component, structure, or operation does not preclude the use of multiple such components, structures, or operations or their equivalents. As used herein, the word “or” refers to any possible permutation of a set of items. For example, the phrase “A, B, or C” refers to at least one of A, B, C, or any combination thereof, such as any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C; or multiple items such as A and A; B, B, and C; A, A, B, C, and C, etc.

[0055] While aspects of this disclosure have been specifically shown and described with reference to the foregoing embodiments, those skilled in the art will understand that various other embodiments can be conceived through modifications to the disclosed machines, systems, and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of this disclosure as defined by the claims and any equivalents.

Claims

1. A system (100) comprising: An engine (102) that burns primary fuel and ignition fuel, wherein the engine (102) is an internal combustion engine (102). First fuel tank (106) for storing first fuel (104); The second fuel tank (110) is used to store the second fuel (108); A first fuel metering valve (116) is used to control the first fuel (104) flow rate through a three-way valve (118), wherein the output (124) of the three-way valve (118) flows into a mixer (126); A second fuel metering valve (122) is used to control the flow rate of the second fuel (108) through the three-way valve (118); and The mixer (126) is used to mix the output (124) of the three-way valve (118), wherein the mixer output (128) of the mixer (126) flows into the main fuel rail (206) for the engine (102) to use as the main fuel, wherein the positions of the first fuel metering valve (116) and the second fuel metering valve (122) determine the concentration of the first fuel (104) and the second fuel (108) in the main fuel.

2. The system (100) according to claim 1 further includes: A first fuel pump (112) is in fluid communication with the first fuel (104), wherein the first fuel pump (112) pumps the first fuel (104) from the first fuel tank (106) to the cylinder block (114). The cylinder block (114) has an internal port for guiding a first portion of the first fuel (104) to an ignition rail, wherein the first portion of the first fuel (104) is ignition fuel for use by the engine (102), and wherein a second portion of the first fuel (104) is guided to the first fuel metering valve (116); and A second fuel pump (120) is in fluid communication with a second fuel (108) in a second fuel tank (110), wherein the second fuel pump (120) pumps the second fuel (108) into the tee (118).

3. The system (100) according to claim 1 further includes: A first fuel metering valve (116) is used to measure the flow rate of the first fuel (104) through the first fuel metering valve (116); and The second fuel flow meter is used to measure the flow rate of the second fuel (108) through the second fuel metering valve (122).

4. The system (100) of claim 1 further includes a component sensor (513) configured to measure the concentration of the first fuel (104) and the concentration of the second fuel (108) in the mixer output (128).

5. The system (100) according to claim 1 further includes: A cooler (542) for cooling excess main fuel (540), wherein the excess main fuel (540) is unburned main fuel that is not injected into the combustion chamber of the engine (102); An excess main fuel flow meter (544) is used to measure the flow rate of the excess main fuel (540); A mixing pump for pumping at least a portion of the excess main fuel (540) and the output of the three-way valve (118) into the mixer (126); as well as A mixing tank for receiving and storing excess main fuel (540) that has not been pumped back into the mixer (126).

6. The system (100) according to claim 1 further includes a controller, the controller comprising: Memory that stores executable instructions for a computer; as well as A processor communicating with the memory, wherein the computer executes instructions to cause the processor to perform actions, the actions including: Monitor the system (100); Receive power requirement input (536); Based on the power demand input (536), a first fuel flow rate and a second fuel flow rate are retrieved from the engine map; A first fuel control signal (532) is sent to the first fuel metering valve (116) to adjust the first fuel metering valve (116) to the first fuel metering valve (116) position to achieve the first fuel flow rate; and A second fuel control signal (534) is sent to the second fuel metering valve (122) so that the second fuel (108) metering valve adjusts the position of the second fuel metering valve (122) to the position based on the second fuel control signal (534).

7. A method for an operating system (100), the method comprising: The system (100) is monitored by a controller, the system (100) comprising: An internal combustion engine (102) that burns main fuel and ignition fuel; First fuel tank (106) for storing first fuel (104); The second fuel tank (110) is used to store the second fuel (108); A first fuel metering valve (116) is used to control the first fuel (104) flow rate through a three-way valve (118), wherein the output of the three-way valve (118) flows into a mixer (126); A second fuel metering valve (122) is used to control the flow rate of the second fuel (108) through the three-way valve (118); and The mixer (126) is used to mix the output of the three-way valve (118), wherein the mixer output (128) of the mixer (126) flows into the main fuel rail (206) for the engine (102) to use as the main fuel, wherein the positions of the first fuel metering valve (116) and the second fuel metering valve (122) determine the concentrations of the first fuel (104) and the second fuel (108) in the main fuel; and The controller receives the power demand input; The controller retrieves a first fuel flow rate and a second fuel flow rate from the engine map based on the power demand input. The controller sends a first fuel control signal (532) to the first fuel metering valve (116) to adjust the first fuel metering valve (116) to the first fuel metering valve (116) position to achieve the first fuel flow rate; and The controller sends a second fuel control signal (534) to the second fuel metering valve (122) so that the second fuel metering valve (122) adjusts its position to the position based on the second fuel control signal (534).

8. The method according to claim 7, further comprising: The controller receives a component input (548) indicating the concentrations of the first fuel (104) and the second fuel (108) in the output of the three-way valve (118); and The controller adjusts the position of the first fuel metering valve (116) or the position of the second fuel metering valve (122) to achieve the first fuel flow rate and the second fuel flow rate.

9. The method of claim 7, wherein the first fuel flow rate and the second fuel flow rate transition from the following: In the first configuration, the second fuel (108) is the sole component of the main fuel; In a second configuration, the first fuel (104) and the second fuel (108) are mixed in the mixer (126) to form the main fuel, wherein the main fuel comprises an emulsion of the first fuel (104) and the second fuel (108); and The third configuration, wherein the first fuel (104) is the sole component of the main fuel.

10. The method of claim 7, further comprising: Measure the flow rate of the first fuel (104) through the first fuel metering valve (116); as well as Measure the flow rate of the second fuel (108) through the second fuel metering valve (122).

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