Method and system for real-time online regulation of dual-fuel mixing ratio

Abstract

The application discloses a method and system for real-time online regulation of a dual-fuel mixing ratio, which simplifies a fuel supply system and reduces engine cost, and significantly improves injection atomization quality, improves combustion efficiency and reduces pollutant emission due to the use of the same injector for injection of two fuels with great differences in physical and chemical properties and the flash boiling phenomenon. In addition, the high-pressure injection system can greatly reduce excessively high injection pressure due to the flash boiling phenomenon, thereby reducing the driving power of the injection system and improving mechanical efficiency. In addition, due to the selection of high-viscosity and high-cetane-number fuel, the corrosion and abrasion of the mixed fuel in the high-pressure pump are greatly improved, and the reliability of the system is improved. Finally, due to the accurate control of the mixed fuel ratio, the substitution rate of low-carbon / zero-carbon fuel can be expanded, thereby significantly reducing greenhouse gas emission.

Description

Technical Field

[0001] This invention relates to the field of green fuel technology, and further to a method and system for real-time online control of the mixing ratio of two fuels. Background Technology

[0002] In recent years, with the intensification of global climate change and the increasing severity of the energy crisis, the development of low-carbon and zero-carbon fuels to completely or partially replace traditional fossil fuels has become a global focus. Among these, hydrogen, ammonia, and methanol have become the main areas of interest.

[0003] Hydrogen can be produced in many ways, including through water electrolysis and from fossil fuels. In internal combustion engine applications, due to its easy ignition and rapid flame propagation, it was initially used as a single fuel in spark-ignition engines. However, hydrogen-fueled spark-ignition engines suffer from problems such as low compression ratios, susceptibility to knocking, and backfire.

[0004] Methanol is a low-carbon fuel that can be produced through various methods. It is a liquid at room temperature and pressure, making it convenient to store and transport. Due to its high auto-ignition temperature and good anti-knock properties, methanol is used in spark-ignition engines.

[0005] Both methanol and hydrogen have low compression ratios in spark-ignition engines, resulting in low efficiency. Therefore, researchers have also attempted to apply hydrogen and methanol to compression-ignition engines. In this case, methanol or hydrogen is supplied through the intake manifold, and high-cetane fuel is directly injected near top dead center to ignite the hydrogen or ammonia. This intake manifold-supply method does not fundamentally solve the knocking problem, and the efficiency improvement is not significant, while pollutant emissions are relatively high.

[0006] Zero-carbon ammonia has gained widespread attention due to its convenient storage and transportation and mature production process. However, its high auto-ignition temperature, large ignition energy, narrow ignition limit, and slow combustion rate lead to the risk of incomplete combustion under high-load engine conditions, reducing thermal efficiency. Furthermore, ammonia has poor combustion stability; under low-load and low-temperature conditions, it is prone to flameout and unstable combustion. Pure ammonia fuel alone cannot be directly used in internal combustion engines. Therefore, two approaches have been adopted: one is to use hydrogen, which has excellent ignition and combustion characteristics, employing a hydrogen-ammonia fusion and spark ignition method; the other is to supply ammonia through the intake manifold combined with direct injection of highly reactive fuel for ignition. Both methods suffer from reduced efficiency, higher pollutant emissions, more complex fuel supply systems, and increased costs.

[0007] In addition, hydrogen, ammonia, and methanol can also be supplied via direct injection, with high-cetane fuel used for direct injection near top dead center to ignite the hydrogen or ammonia. This mode allows for a higher compression ratio and reduces pumping losses, resulting in higher engine efficiency. However, high-pressure direct injection systems for hydrogen, ammonia, and methanol suffer from poor lubrication and significant corrosion problems, leading to poor reliability, system complexity, and high cost.

[0008] Hydrogen, ammonia, and methanol have poor lubricating properties, easily causing wear on fuel injectors and affecting their service life. Liquid ammonia, in particular, readily evaporates into a gaseous state at room temperature and pressure, and its viscosity is lower than that of liquid fuels like diesel, making precise injection through traditional fuel injectors difficult. Furthermore, liquid ammonia is corrosive, requiring high-quality materials for metal pipelines and seals; prolonged use may lead to system leaks. Additionally, ammonia and methanol are toxic and hazardous substances, and leaks could harm operators and the environment. Therefore, the storage and transportation systems for liquid ammonia and methanol must be strictly sealed and equipped with efficient monitoring and early warning systems.

[0009] Ammonia, methanol, and diesel fuel have significantly different physicochemical properties. Liquid ammonia is a polar molecule, while diesel fuel is a non-polar molecule. They are difficult to mix uniformly at room temperature, easily forming stratification, which affects combustion consistency. Furthermore, controlling the mixing ratio is complex and requires dynamic adjustment based on engine operating conditions (speed, load, etc.) to achieve optimal combustion. Therefore, to achieve direct injection of fuels such as ammonia and methanol, a new high-pressure injection system needs to be developed. However, high-pressure injection systems for low-carbon / zero-carbon fuels are difficult to develop, have poor reliability, high cost, and are complex; to date, no mature commercial products exist. Summary of the Invention

[0010] To address the aforementioned technical problems, the present invention aims to provide a method and system for real-time online control of dual-fuel mixing ratio. This system achieves real-time online control of the dual-fuel mixing ratio, which not only simplifies the fuel supply system and reduces engine costs, but also significantly improves injection atomization quality by using the same injector to inject two fuels with vastly different physicochemical properties, thereby increasing combustion efficiency and reducing pollutant emissions through the flash boiling phenomenon.

[0011] To achieve the above objectives, the present invention provides a method for real-time online control of dual-fuel mixing ratio, comprising the following steps: Real-time acquisition of operating condition signals of the internal combustion engine, environmental parameter signals, parameter signals of the first fuel, and parameter signals of the second fuel; The first fuel supply mechanism is controlled to supply a first fuel with a high cetane number, and the second fuel supply mechanism is controlled to supply a second fuel with low viscosity and low boiling point, so that the two enter the fuel mixer in the initial ratio. The stirring mechanism is started to stir the first fuel and the second fuel to form a uniform and stable mixed fuel. The mixed fuel is pressurized by a high-pressure supply mechanism and then injected into the combustion chamber through a high-pressure injector; Based on real-time acquired signal data, the control mechanism calculates the optimal dual-fuel mixing ratio required at present and compares it with the current actual mixing ratio; By dynamically adjusting the fuel supply of the first and second fuel supply mechanisms and coordinating the opening and closing of the high-pressure oil rail drain valve in the high-pressure supply mechanism, the amount and composition of fuel returning to the fuel mixer can be adjusted, thereby achieving online precise adjustment of the dual-fuel ratio in the mixed fuel to bring it close to the optimal ratio.

[0012] In some embodiments, the step of dynamically adjusting the fuel supply of the first fuel supply mechanism and the second fuel supply mechanism specifically includes the following steps: The actual mixing ratio of the fuel is calculated based on the opening time of the first and second control valves, the physical property parameters of the two fuels, and the flow characteristics of the control valves. The actual mixing ratio is compared with the target mixing ratio corresponding to the current engine operating condition stored in the control mechanism to obtain the ratio deviation value; When the ratio deviation exceeds the set tolerance range, if the first fuel ratio is too high, the opening degree of the first control valve is reduced or closed, while the opening degree of the second control valve is maintained or increased; if the second fuel ratio is too high, the opening degree of the second control valve is reduced or closed, while the opening degree of the first control valve is maintained or increased.

[0013] In some implementations, the flow rate of the second control valve is greater than the flow rate of the first control valve.

[0014] In some implementations, the step of "when the proportional deviation value exceeds the set tolerance range" specifically includes the following steps: The opening and closing rates of the first control valve, the second control valve, and the high-pressure oil rail drain valve are dynamically optimized using a proportional-integral-derivative control algorithm to avoid mixed proportional fluctuations caused by over-adjustment or response lag.

[0015] In some embodiments, the method is characterized by controlling the first fuel supply mechanism to supply a first fuel with a high cetane number and controlling the second fuel supply mechanism to supply a second fuel with low viscosity and low boiling point, so that the two enter the fuel mixer in an initial ratio, and activating the stirring mechanism to stir the first fuel and the second fuel to form a uniform and stable mixed fuel, further comprising the step of: By controlling the opening of the high-pressure oil rail drain valve, fuel in the high-pressure common rail that does not meet the current ratio requirements, as well as excess mixed fuel, is returned to the fuel mixer through the high-pressure injector return pipe to participate in the mixing of the next working cycle.

[0016] In some implementations, when the engine is in a starting, idling, or low-load condition, the target mixing ratio is set to 80% to 100% of the total fuel in the cycle.

[0017] In some implementations, when the engine is under high or full load conditions, the target mix ratio is set to 60% to 98% of the total fuel in the cycle as the second fuel.

[0018] In some embodiments, a first fuel supply mechanism supplies first fuel via a first low-pressure pump, and a second fuel supply mechanism supplies second fuel via a second low-pressure pump. The flow rate of the second low-pressure pump is greater than that of the first low-pressure pump.

[0019] In some embodiments, the volume of the fuel mixer and the volume of the high-pressure common rail for the mixed fuel of the high-pressure supply mechanism are both set to be minimized; The connecting pipelines between the fuel mixer and the high-pressure fuel pump, the high-pressure fuel pump and the high-pressure fuel common rail, the high-pressure fuel pipe joint and the high-pressure injector, and the connecting pipeline between the high-pressure fuel rail drain valve and the fuel mixer are all set to the shortest path to improve the dynamic response speed of the system.

[0020] According to another aspect of the present invention, the present invention further provides a system for applying the method for real-time online control of dual-fuel mixing ratio as described in any one of the above, comprising: The first fuel supply unit is used to supply first fuel with a high cetane number. The second fuel supply mechanism is used to supply a second fuel with low viscosity and low boiling point. A fuel mixer, whose inlet is connected to the outlet of the first fuel supply mechanism and the outlet of the second fuel supply mechanism respectively, is used to receive the first fuel and the second fuel. The fuel mixer is provided with a stirring mechanism for stirring the first fuel and the second fuel evenly to form a mixed fuel. A high-pressure supply mechanism, whose inlet is connected to the outlet of the fuel mixer, is used to inject the mixed fuel into the combustion chamber at high pressure. The control mechanism is connected to the first fuel supply mechanism, the second fuel supply mechanism, the stirring mechanism, and the high-pressure supply mechanism respectively, and is used to adjust the ratio of the two fuels in the mixed fuel online according to the operating conditions of the internal combustion engine.

[0021] Compared with the prior art, the method and system for real-time online control of dual-fuel mixing ratio provided by the present invention have at least one of the following beneficial effects: This invention achieves real-time online control of the dual-fuel mixing ratio, which not only simplifies the fuel supply system and reduces engine costs, but also significantly improves injection atomization quality by using the same injector for two fuels with vastly different physicochemical properties, thereby increasing combustion efficiency and reducing pollutant emissions through the flash boiling phenomenon. Furthermore, due to the flash boiling phenomenon, the high-pressure injection system can significantly reduce excessive injection pressure, thus reducing the driving work of the injection system and improving mechanical efficiency. In addition, the selection of high-viscosity, high-cetane number fuels greatly improves the corrosiveness and abrasiveness of the mixed fuels in the high-pressure pump, enhancing system reliability. Finally, precise control of the mixed fuel ratio expands the substitution rate for low-carbon / zero-carbon fuels, thereby significantly reducing greenhouse gas emissions. Attached Figure Description

[0022] The optional embodiments of the present invention will be described below in a clear and easy-to-understand manner, in conjunction with the accompanying drawings, to further illustrate the above-mentioned characteristics, technical features, advantages, and implementation methods of the present invention.

[0023] Figure 1 This is a schematic diagram of the structure of a system for real-time online control of the dual-fuel mixing ratio, which is an optional embodiment of the present invention.

[0024] Explanation of icon numbers: First fuel supply mechanism 1, first fuel tank 11, first pipeline 12, first low-pressure pump 13, first fuel filter 14, first control valve 15, first pressure sensor 16, first temperature sensor 17, first fuel return pipeline 18, second fuel supply mechanism 2, second fuel tank 21, second pipeline 22, second low-pressure pump 23, second fuel filter 24, second control valve 25, second pressure sensor 26, second temperature sensor 27, second fuel return pipeline 28, fuel mixer 3, stirring mechanism 31, fuel mixer pressure sensor 32, high-pressure supply mechanism 4, mixed fuel high-pressure oil pump 41, mixed fuel high-pressure oil pipe 411, mixed fuel low-pressure oil pipe 42, mixed fuel high-pressure common rail 43, high-pressure oil pipe connector 44, high-pressure oil rail pressure sensor 45, high-pressure injector 46, high-pressure injector return pipeline 461, high-pressure oil pipe 47, high-pressure oil rail drain valve 48, high-pressure oil rail return pipeline 481, control mechanism 5. Detailed Implementation

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0026] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0027] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] In one embodiment, refer to the appendix to the specification. Figure 1 The present invention provides a system for real-time online control of the dual-fuel mixing ratio, comprising: a first fuel supply mechanism 1, a second fuel supply mechanism 2, a fuel mixer 3, a high-pressure supply mechanism 4, and a control mechanism 5; wherein, the first fuel supply mechanism 1 is used to supply a first fuel with a high cetane number; the second fuel supply mechanism 2 is used to supply a second fuel with low viscosity and low boiling point; the inlet of the fuel mixer 3 is connected to the outlet of the first fuel supply mechanism 1 and the outlet of the second fuel supply mechanism 2 respectively, for receiving the first fuel and the second fuel, and the fuel mixer 3 is provided with a stirring mechanism 31 for stirring the first fuel and the second fuel evenly to form a mixed fuel; the inlet of the high-pressure supply mechanism 4 is connected to the outlet of the fuel mixer 3 for injecting the mixed fuel into the combustion chamber at high pressure; the control mechanism 5 is signal-connected to the first fuel supply mechanism 1, the second fuel supply mechanism 2, the stirring mechanism 31, and the high-pressure supply mechanism 4 respectively, for online control of the dual-fuel ratio in the mixed fuel according to the operating conditions of the internal combustion engine.

[0031] In this embodiment, the stirring mechanism 31 in the fuel mixer 3 is used to achieve uniform mixing of two fuels with large differences in physical and chemical properties, and the mixed fuel is injected into the combustion chamber in a high-pressure form through the high-pressure supply mechanism 4; the control mechanism 5 dynamically adjusts the mixing ratio of the two fuels based on the real-time operating conditions of the engine, thereby significantly improving combustion efficiency, reducing pollutant emissions, and effectively expanding the application ratio of low-carbon / zero-carbon fuels in the engine while ensuring combustion stability. It has the comprehensive advantages of simplified structure, flexible control, and strong adaptability.

[0032] In one embodiment, refer to the appendix to the specification. Figure 1The first fuel supply mechanism 1 includes: a first fuel tank 11, connected to a fuel mixer 3 via a first pipeline 12, for storing first fuel; a first low-pressure pump 13, disposed on the first pipeline 12; a first fuel filter 14, disposed on the first pipeline 12, located between the first fuel tank 11 and the first low-pressure pump 13, for filtering the first fuel; a first control valve 15, disposed on the first pipeline 12, located between the first low-pressure pump 13 and the fuel mixer 3, for controlling the flow rate of the first fuel to the fuel mixer 3; a first pressure sensor 16 and a first temperature sensor 17, disposed on the first pipeline 12, located between the first low-pressure pump 13 and the first control valve 15, for detecting the pressure and temperature of the first fuel; and a first fuel return pipeline 18, connecting the first control valve 15 and the first fuel tank 11. The first low-pressure pump 13, the first control valve 15, the first pressure sensor 16, and the first temperature sensor 17 are all signal-connected to the control mechanism 5.

[0033] The second fuel supply mechanism 2 includes: a second fuel tank 21, connected to the fuel mixer 3 via a second pipeline 22, for storing second fuel; a second low-pressure pump 23, mounted on the second pipeline 22; a second fuel filter 24, mounted on the second pipeline 22, located between the second fuel tank 21 and the second low-pressure pump 23, for filtering the second fuel; a second control valve 25, mounted on the second pipeline 22, located between the second low-pressure pump 23 and the fuel mixer 3, for controlling the flow rate of the second fuel to the fuel mixer 3; a second pressure sensor 26 and a second temperature sensor 27, mounted on the second pipeline 22, located between the second low-pressure pump 23 and the second control valve 25, for detecting the pressure and temperature of the second fuel; and a second fuel return pipeline 28, connecting the second control valve 25 and the second fuel tank 21. The second low-pressure pump 23, the second control valve 25, the second pressure sensor 26, and the second temperature sensor 27 are all signal-connected to the control mechanism 5.

[0034] In this embodiment, by setting up sensors, the physical state of the fuel can be monitored in real time, providing key data for the control mechanism 5 to calculate fuel quality and flow rate; the control valve can quickly respond to adjustment commands and accurately control the fuel flow rate entering the fuel mixer; the entire mechanism is reasonably laid out and works in coordination with the control mechanism 5 to ensure that the fuel can be supplied stably, reliably and accurately.

[0035] It should be noted that the specific structures of the first fuel supply mechanism 1 and the second fuel supply mechanism 2 are described with reference to the accompanying drawings. In actual use, other structures or devices may be used according to actual needs, as long as the above functions can be achieved. This is only for better illustrating the present invention and should not be construed as a limitation of the present invention.

[0036] In one embodiment, refer to the appendix to the specification. Figure 1 The high-pressure supply mechanism 4 includes: a mixed fuel high-pressure oil pump 41, whose inlet is connected to the outlet of the fuel mixer 3 via a mixed fuel low-pressure oil pipe 42, for pressurizing the mixed fuel; a mixed fuel high-pressure common rail 43, whose inlet is connected to the outlet of the mixed fuel high-pressure oil pump 41 via a mixed fuel high-pressure oil pipe 411, and the mixed fuel high-pressure common rail 43 is provided with several high-pressure oil pipe joints 44; a high-pressure oil rail pressure sensor 45, which is installed on the mixed fuel high-pressure common rail 43, for real-time detection of fuel pressure in the mixed fuel high-pressure common rail 43, and for transmitting the signal to the control mechanism 5; and several high-pressure injectors 46, which are respectively connected to the corresponding high-pressure oil pipe joints 44 via high-pressure oil pipes 47, for injecting high-pressure mixed fuel into the engine combustion chamber.

[0037] Furthermore, a high-pressure oil rail drain valve 48 is also provided on the high-pressure common rail 43 for the mixed fuel. The high-pressure oil rail drain valve 48 is connected to the fuel mixer 3 through a high-pressure oil rail return pipe 481. The high-pressure injector 46 is also connected to a high-pressure injector return pipe 461 for returning any uninjected excess mixed fuel to the fuel mixer 3. The fuel mixer 3 is also provided with a fuel mixer pressure sensor 32, which is connected to the control mechanism 5 for detecting the pressure signal inside the fuel mixer 3. The control mechanism 5 is configured to receive the first fuel pressure and temperature signals from the first fuel supply mechanism 1. The control mechanism 5 uses the second fuel pressure and temperature signal from the second fuel supply mechanism 2, the common rail pressure signal from the high-pressure oil rail pressure sensor 32, and the operating condition signal and environmental parameter signal of the internal combustion engine. Combined with the flow characteristic parameters of the first control valve 15, the second control valve 25, and the high-pressure oil rail drain valve 48, the control mechanism 5 calculates the opening and closing sequence of the first control valve 15, the second control valve 25, and the high-pressure oil rail drain valve 48 in real time to dynamically adjust the amount and composition of fuel returning to the fuel mixer 3, thereby achieving online precise control of the dual-fuel mixing ratio in the high-pressure common rail 43.

[0038] In this embodiment, excess or mismatched mixed fuel is returned to the fuel mixer 3 for reuse through the high-pressure fuel rail drain valve 48 and the high-pressure injector return pipe 461. This not only creates an efficient fuel cycle, but more importantly, it provides a direct means for real-time adjustment of the mixing ratio. The control mechanism 5 comprehensively processes multiple signals from the first fuel supply mechanism 1, the second fuel supply mechanism 2, the mixed fuel high-pressure common rail 43, and the engine operating conditions. Based on the flow characteristics of each valve, it accurately calculates and coordinates the timing of the actions of the two fuel control valves and the drain valve. By dynamically adjusting the amount and composition of the returned fuel, it can quickly respond to changes in engine operating conditions, achieve online precise correction and stable control of the mixed fuel ratio in the mixed fuel high-pressure common rail 43, and ensure that the combustion process is always in the optimal state.

[0039] According to another aspect of the invention, reference is made to the appended specification. Figure 1 This invention provides a method for real-time online control of dual-fuel mixing ratio, comprising the following steps: real-time acquisition of operating condition signals of an internal combustion engine, environmental parameter signals, parameter signals of a first fuel, and parameter signals of a second fuel; controlling the first fuel supply mechanism 1 to supply a first fuel with a high cetane number, and controlling the second fuel supply mechanism 2 to supply a second fuel with low viscosity and low boiling point, so that the two enter the fuel mixer 3 in an initial ratio; activating the stirring mechanism 31 to stir the first fuel and the second fuel to form a uniform and stable mixed fuel; pressurizing the mixed fuel through the high-pressure supply mechanism 4, and then injecting it into the combustion chamber through the high-pressure injector 46; based on the real-time acquired signal data, the control mechanism 5 calculates the current optimal dual-fuel mixing ratio and compares it with the current actual mixing ratio; by dynamically adjusting the fuel supply amount of the first fuel supply mechanism 1 and the second fuel supply mechanism 2, and coordinating the opening and closing of the high-pressure oil rail drain valve 48 in the high-pressure supply mechanism 4, the amount and composition of fuel returning to the fuel mixer 3 are adjusted, thereby achieving online precise adjustment of the dual-fuel ratio in the mixed fuel to approach the optimal ratio.

[0040] In this embodiment, by sensing the engine operating condition and environmental status in real time, intelligent decision-making and dynamic optimization of the dual-fuel mixing ratio are achieved. The real-time data is compared with the target ratio, and the fuel supply and recirculation system are dynamically adjusted to actively and accurately control the mixing ratio. This not only ensures that the engine can obtain the most suitable fuel composition under different operating conditions, improving combustion efficiency and stability, but also significantly enhances the system's adaptability to changes in operating conditions through a flexible online adjustment mechanism.

[0041] In one embodiment, refer to the appendix to the specification. Figure 1 The method involves dynamically adjusting the fuel supply of the first fuel supply mechanism 1 and the second fuel supply mechanism 2, specifically including the following steps: calculating the actual mixing ratio of the current fuel based on the opening time of the first control valve 15 and the second control valve 25, the physical property parameters of the two fuels, and the flow characteristics of the control valves; comparing the actual mixing ratio with the target mixing ratio corresponding to the current engine operating condition stored in the control mechanism 5 to obtain the ratio deviation value; when the ratio deviation value exceeds the set allowable error range, if the first fuel ratio is too high, reducing or closing the opening degree of the first control valve 15 while maintaining or increasing the opening degree of the second control valve 25; if the second fuel ratio is too high, reducing or closing the opening degree of the second control valve 25 while maintaining or increasing the opening degree of the first control valve 15.

[0042] When the proportional deviation value exceeds the set allowable error range, the specific steps include: using a proportional-integral-derivative control algorithm to dynamically optimize the opening and closing rates of the first control valve 15, the second control valve 25, and the high-pressure oil rail drain valve 48, in order to avoid mixed proportional fluctuations caused by over-adjustment or response lag.

[0043] Furthermore, it also includes the steps of: when the engine is in start-up, idling or low-load conditions, setting the target mixture ratio to 80% to 100% of the total fuel in the cycle as the first fuel; and when the engine is in high-load or full-load conditions, setting the target mixture ratio to 60% to 98% of the total fuel in the cycle as the second fuel.

[0044] Furthermore, the first fuel supply mechanism 1 supplies a first fuel with a high cetane number, and the second fuel supply mechanism 2 supplies a second fuel with low viscosity and low boiling point, so that the two enter the fuel mixer 3 in the initial ratio. The stirring mechanism 31 is started to stir the first fuel and the second fuel to form a uniform and stable mixed fuel. The process also includes the step of: by controlling the opening of the high-pressure oil rail drain valve 48, the fuel in the high-pressure common rail 43 that does not meet the current ratio requirements and the excess mixed fuel through the high-pressure injector return pipe 461 are returned to the fuel mixer 3 to participate in the mixing of the next working cycle.

[0045] In this embodiment, when the fuel composition in the high-pressure common rail 43 does not meet the current operating conditions or there is excess fuel, the control mechanism 5 actively controls the high-pressure fuel rail drain valve 48 to open, returning this fuel to the fuel mixer 3 for remixing. This not only accelerates the transition from the current mixing ratio to the target ratio and reduces adjustment lag, but also realizes closed-loop fuel management, effectively avoiding waste. The returned fuel participates in the mixing of the next cycle, enabling the system to continuously optimize based on real-time feedback, thereby ensuring that the engine always obtains the most accurate and suitable mixed fuel composition, guaranteeing the instantaneous optimization and continuous stability of the combustion process.

[0046] In one embodiment, refer to the appendix to the specification. Figure 1 The functions of each key component in the system are described in detail below to more clearly demonstrate the specific implementation of this system: The first fuel tank 11 is used to store primary fuels, such as diesel, biodiesel, aviation kerosene, coal-to-oil, and other synthetic fuels with high cetane numbers and high viscosity. It is made of materials with excellent corrosion resistance, such as aluminum alloy or stainless steel, and the inner wall is coated with an anti-corrosion coating to adapt to the corrosiveness and oxidation resistance of different fuels. The first fuel tank 11 is equipped with baffles and a venting device to reduce air bubbles and pressure fluctuations caused by fuel sloshing during vehicle operation.

[0047] The first fuel filter 14 filters impurities and particulate matter from the first fuel, preventing them from clogging lines or damaging other components after entering the fuel system. It uses high-precision filter materials, such as composite cellulose or metal mesh, which are resistant to diesel fuel corrosion and have a long service life. The housing of the first fuel filter 14 is designed to withstand pressure, ensuring stable operation under high-pressure environments, with a filtration accuracy of less than 10 microns.

[0048] The first low-pressure pump 13 increases the pressure of the filtered first fuel and uses the first pressure sensor 16 and the first temperature sensor 17 to transmit the temperature and pressure of the pressurized first fuel to the control mechanism 5. This is used to calculate and calibrate the mass of the first fuel entering the fuel mixer 3 and output an open or close signal to the first control valve 15. The first fuel, pressurized by the first low-pressure pump 13, is connected to the fuel mixer 3 through the first control valve 15, which receives the open or close signal from the control mechanism 5.

[0049] The secondary fuel tank 21 stores secondary fuels, such as ammonia, hydrogen, methanol, and other low-carbon / zero-carbon fuels. The main characteristics of these secondary fuels are low cetane number, high octane number, low boiling point, and low viscosity. The tank body has excellent corrosion resistance and can withstand low temperatures and chemical erosion during high-pressure storage.

[0050] After being filtered by the second fuel filter 24, the second fuel enters the second low-pressure pump 23 to increase the pressure of the second fuel. The second pressure sensor 26 and the second temperature sensor 27 transmit the temperature and pressure of the pressurized second fuel to the control mechanism 5 for calculating and calibrating the mass of the second fuel entering the fuel mixer 3, and output an open or close signal to the second control valve 25.

[0051] Key components of the second low-pressure pump 23, such as the pump casing and seals, are made of corrosion-resistant materials to ensure long-term operational reliability. It employs an electric plunger or gear pump, and the pump outlet pressure can be dynamically adjusted according to operating conditions. The second fuel, pressurized by the second low-pressure pump 23, is connected to the fuel mixer 3 via the second control valve 25, which receives opening or closing signals from the control mechanism 5. Both the pressurized first and second fuels enter the fuel mixer 3. Additionally, fuel flowing from the high-pressure fuel rail drain valve 48, through the high-pressure fuel rail return pipe 481 and the high-pressure injector return pipe 461, also enters the fuel mixer 3.

[0052] The fuel mixer 3 is equipped with a stirring mechanism 31 and a fuel mixer pressure sensor 32. The stirring mechanism 31 ensures stable and uniform fuel mixing. The volume of the fuel mixer 3 should be as small as possible, and it should not be too large. The uniformly mixed fuel enters the mixed fuel high-pressure oil pump 41 through the mixed fuel low-pressure oil pipe 42. After pressurizing the mixed fuel, it is sent to the mixed fuel high-pressure common rail 43 through the mixed fuel high-pressure oil pipe 411. The pump body and key components are made of high-strength alloy steel, which is corrosion-resistant and wear-resistant, ensuring stability and durability under high-pressure conditions. The mixed fuel high-pressure oil pipe 411 should be as short as possible, and the volume of the mixed fuel high-pressure common rail 43 should be as small as possible.

[0053] The high-pressure common rail 43, serving as the primary storage location for high-pressure stable mixed fuel, is equipped with several high-pressure oil pipe joints 44, a high-pressure oil rail pressure sensor 45, and a high-pressure oil rail drain valve 48. The high-pressure oil rail pressure sensor 45, mounted on the high-pressure common rail 43, monitors the internal pressure and feeds the data back to the control mechanism 5 to ensure pressure stability. The high-pressure oil pipe joints 44 are connected to the high-pressure injector 46 via a section of high-pressure oil pipe 47, with the middle section of the high-pressure oil pipe 47 being as short as possible. The high-pressure oil rail drain valve 48 is connected to the fuel mixer 3 via a high-pressure oil rail return pipe 481. The high-pressure oil rail drain valve 48 opens when the pressure in the high-pressure common rail 43 exceeds the allowable value or when the fuel composition in the high-pressure common rail 43 does not meet the current engine requirements; otherwise, the high-pressure oil rail drain valve 48 remains closed.

[0054] The high-pressure injector 46 injects high-pressure mixed fuel into the combustion chamber for efficient combustion. The nozzle and needle valve are made of wear-resistant alloy material, and their surfaces are specially treated to adapt to the corrosiveness and abrasiveness of different fuels. The opening pressure and injection angle of the needle valve are optimized to accommodate different proportions and types of mixed fuels, preventing clogging and leakage problems. When the amount of fuel supplied by the high-pressure fuel line 47 exceeds the injection volume of the high-pressure injector 46 itself, the excess fuel enters the fuel mixer 3 through the high-pressure injector return line 461.

[0055] The control mechanism 5 receives pressure and temperature signals from the first low-pressure pump 13 and the second low-pressure pump 23, as well as pressure signals from the fuel mixer 3 and the high-pressure common rail 43. Simultaneously, based on the internal combustion engine's operating conditions, ambient temperature / pressure / humidity / altitude signals, and the fuel information and calibration data stored in the control mechanism 5, it calculates the current fuel ratio in the fuel mixer 3 in real time. Then, it controls the opening or closing signals of the first control valve 15, the second control valve 25, and the high-pressure fuel rail drain valve 48 to adjust and correct the fuel ratio in the fuel mixer 3. Based on the internal combustion engine's operating conditions, ambient temperature / pressure / humidity / altitude signals, and the fuel ratio in the fuel mixer 3, the control mechanism 5 calculates and corrects the start time, injection frequency, and injection pulse width of the high-pressure injector 46.

[0056] Control mechanism 5 is a key component for achieving precise control of the mixing ratio of the first and second fuels and stable combustion. It employs a control strategy based on real-time monitoring and closed-loop regulation. The operating logic of control mechanism 5 is as follows: The control mechanism 5 processes fuel flow and pressure data at high speed and executes complex control algorithms. The sensor module includes various sensors for pressure, temperature, position, humidity, altitude, etc. These sensors are connected to the control mechanism 5 via RS232 or CAN bus to collect various key data in real time. The execution module includes the execution commands for the first low-pressure pump 13, the second low-pressure pump 23, the first control valve 15, the second control valve 25, the mixed fuel high-pressure oil pump 41, the high-pressure fuel rail drain valve 48, and the high-pressure injector 46. The communication interface is between the control mechanism 5 and the engine ECU via CAN bus.

[0057] The control mechanism 5 adopts a closed-loop adjustment strategy to achieve dynamic control of the fuel mixing ratio through the following steps: The control mechanism 5 calculates the current fuel mixing ratio based on the opening time of the first control valve 15 and the second control valve 25, as well as the physical property parameters of the two fuels and the flow characteristics of the control valves, and compares it with the mixing ratio required for the current operating condition stored in the control mechanism 5. The engine ECU sets the fuel mixing ratio under the current operating condition to a certain value, and the control mechanism 5 calculates the difference (ΔP) between the current mixing ratio and the set ratio. When ΔP exceeds the set allowable error range (±1%), the control mechanism 5 adjusts the opening time of the first control valve 15 and the second control valve 25 according to the following rules: (1) If the first fuel ratio is too high, the opening cross-sectional area of ​​the first control valve 15 is reduced or even directly cut off, while keeping the second control valve 25 in the normally open state; (2) If the second fuel ratio is too high, the opening cross-sectional area of ​​the second control valve 25 is reduced or even directly cut off, while keeping the first control valve 15 in the normally open state. The PID (proportional-integral-derivative) algorithm is used to dynamically optimize the pressure control valve to avoid mixing ratio fluctuations due to over-adjustment or lag.

[0058] Control mechanism 5 dynamically optimizes the fuel mixing strategy based on engine operating conditions (speed, load, injection timing, etc.): Under low load, control mechanism 5 sets a higher first fuel ratio (e.g., 60%-100%) to ensure combustion stability and starting performance. Under high load, control mechanism 5 gradually increases the second fuel ratio (e.g., 60%-98%) to reduce carbon emissions and improve combustion efficiency. Rapid response adjustment: When engine operating conditions change (e.g., sudden acceleration or deceleration), the control mechanism quickly adjusts the pump's on / off state to ensure timely fuel ratio adjustment, avoiding unstable combustion or fuel stratification.

[0059] The safety protection and alarm functions mainly include abnormal pressure protection and leakage detection. When the rail pressure exceeds the safe range, the control mechanism 5 issues an alarm signal and automatically adjusts the pump's operating status to restore pressure balance. Leakage detection involves comparing data from the flow meter and rail pressure sensor to identify fuel leakage risks and trigger a safety shutdown procedure. The control mechanism 5 supports optimized mixing ratios for various fuel combinations and achieves matching of combustion characteristics for different fuels by adjusting algorithm parameters. The control mechanism 5 has a reserved remote communication interface, allowing for monitoring of equipment status, fault diagnosis, and fuel strategy adjustment via an IoT platform.

[0060] Through the above control method, the present invention achieves precise mixing ratio control of the two fuels, ensuring combustion stability and efficiency, significantly improving the ignition performance of the mixed fuel and the lubrication of the fuel supply system, and providing a reliable guarantee for engine performance optimization and emission control.

[0061] This application utilizes a high-pressure common rail system to achieve high-pressure uniform mixing of low-carbon and zero-carbon fuels with diesel fuels, offering several advantages: 1. By monitoring the flow data of both fuels in real time and employing a closed-loop control system, the mixing ratio is automatically adjusted, ensuring the stability and efficiency of the combustion process. 2. Addressing the low viscosity and high volatility of low-carbon and zero-carbon fuels, diesel fuels are used to enhance lubricity and reduce wear, minimizing fuel leakage losses, extending equipment life, and improving injection accuracy. 3. Due to the low boiling point of low-carbon and zero-carbon fuels and the two-phase emulsion state of the mixed fuels, flash boiling occurs upon injection into the cylinder, greatly promoting fuel injection and atomization. 4. By using real-time control of the fuel mixing ratio, the substitution ratio of low-carbon and zero-carbon fuels can be significantly expanded, reducing greenhouse gas emissions. 5. Due to the existence of flash boiling, good atomization can be achieved without excessively high injection pressure, thus significantly reducing common rail pressure and the driving work of the fuel system. 6. By precisely controlling the fuel mixing ratio and combustion temperature, NO during combustion is reduced. x The generation of [fuels] simultaneously provides more stable front-end conditions for after-treatment systems (such as SCR). In summary, this invention not only solves the key technical bottlenecks of low-carbon and zero-carbon fuels, but also provides an economical and efficient solution for their application in internal combustion engines and other fields.

[0062] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0063] It should be noted that the above embodiments can be freely combined as needed. The above are merely optional embodiments of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for real-time online control of dual-fuel mixing ratio, characterized in that, Including the following steps: Real-time acquisition of operating condition signals of the internal combustion engine, environmental parameter signals, parameter signals of the first fuel, and parameter signals of the second fuel; The first fuel supply mechanism is controlled to supply a first fuel with a high cetane number, and the second fuel supply mechanism is controlled to supply a second fuel with low viscosity and low boiling point, so that the two enter the fuel mixer in the initial ratio. The stirring mechanism is started to stir the first fuel and the second fuel to form a uniform and stable mixed fuel. The mixed fuel is pressurized by a high-pressure supply mechanism and then injected into the combustion chamber through a high-pressure injector; Based on real-time acquired signal data, the control mechanism calculates the optimal dual-fuel mixture ratio required at the moment and compares it with the current actual mixture ratio. By dynamically adjusting the fuel supply of the first and second fuel supply mechanisms and coordinating the opening and closing of the high-pressure oil rail drain valve in the high-pressure supply mechanism, the amount and composition of fuel returning to the fuel mixer can be adjusted, thereby achieving online precise adjustment of the dual-fuel ratio in the mixed fuel to bring it close to the optimal ratio.

2. The method for real-time online control of dual-fuel mixing ratio according to claim 1, characterized in that, The step of dynamically adjusting the fuel supply of the first and second fuel supply mechanisms specifically includes the following steps: The actual mixing ratio of the fuel is calculated based on the opening time of the first and second control valves, the physical property parameters of the two fuels, and the flow characteristics of the control valves. The actual mixing ratio is compared with the target mixing ratio corresponding to the current engine operating condition stored in the control mechanism to obtain the ratio deviation value; When the ratio deviation exceeds the set tolerance range, if the first fuel ratio is too high, the opening degree of the first control valve is reduced or closed, while the opening degree of the second control valve is maintained or increased; if the second fuel ratio is too high, the opening degree of the second control valve is reduced or closed, while the opening degree of the first control valve is maintained or increased.

3. The method for real-time online control of dual-fuel mixing ratio according to claim 2, characterized in that, The flow rate of the second control valve is greater than that of the first control valve.

4. The method for real-time online control of dual-fuel mixing ratio according to claim 2, characterized in that, When the proportional deviation value exceeds the set allowable error range, the specific steps include: The opening and closing rates of the first control valve, the second control valve, and the high-pressure oil rail drain valve are dynamically optimized using a proportional-integral-derivative control algorithm to avoid mixed proportional fluctuations caused by over-adjustment or response lag.

5. The method for real-time online control of dual-fuel mixing ratio according to claim 1, characterized in that, The method of controlling the first fuel supply mechanism to supply a first fuel with a high cetane number and controlling the second fuel supply mechanism to supply a second fuel with low viscosity and low boiling point, so that the two enter the fuel mixer in an initial ratio, and activating the stirring mechanism to stir the first fuel and the second fuel to form a uniform and stable mixed fuel, further includes the following steps: By controlling the opening of the high-pressure oil rail drain valve, fuel in the high-pressure common rail that does not meet the current ratio requirements, as well as excess mixed fuel, is returned to the fuel mixer through the high-pressure injector return pipe to participate in the mixing of the next working cycle.

6. The method for real-time online control of dual-fuel mixing ratio according to claim 1, characterized in that, When the engine is starting, idling, or under low load, set the target mixture ratio to 80% to 100% of the total fuel in the cycle.

7. The method for real-time online control of dual-fuel mixing ratio according to claim 1, characterized in that, When the engine is under high or full load conditions, the target mixture ratio is set to 60% to 98% of the total fuel in the cycle.

8. The method for real-time online control of dual-fuel mixing ratio according to claim 1, characterized in that, The first fuel supply unit supplies the first fuel through the first low-pressure pump, and the second fuel supply unit supplies the second fuel through the second low-pressure pump. The flow rate of the second low-pressure pump is greater than that of the first low-pressure pump.

9. The method for real-time online control of dual-fuel mixing ratio according to claim 1, characterized in that, The volume of the fuel mixer and the volume of the high-pressure common rail for the mixed fuel of the high-pressure supply mechanism are both set to be minimized; The connecting pipelines between the fuel mixer and the high-pressure fuel pump, the high-pressure fuel pump and the high-pressure fuel common rail, the high-pressure fuel pipe joint and the high-pressure injector, and the connecting pipeline between the high-pressure fuel rail drain valve and the fuel mixer are all set to the shortest path to improve the dynamic response speed of the system.

10. A system for applying the method of real-time online control of dual-fuel mixing ratio as described in any one of claims 1-9, characterized in that, include: The first fuel supply unit is used to supply first fuel with a high cetane number. The second fuel supply mechanism is used to supply a second fuel with low viscosity and low boiling point. A fuel mixer, whose inlet is connected to the outlet of the first fuel supply mechanism and the outlet of the second fuel supply mechanism respectively, is used to receive the first fuel and the second fuel. The fuel mixer is provided with a stirring mechanism for stirring the first fuel and the second fuel evenly to form a mixed fuel. A high-pressure supply mechanism, whose inlet is connected to the outlet of the fuel mixer, is used to inject the mixed fuel into the combustion chamber at high pressure. The control mechanism is connected to the first fuel supply mechanism, the second fuel supply mechanism, the stirring mechanism, and the high-pressure supply mechanism respectively, and is used to adjust the ratio of the two fuels in the mixed fuel online according to the operating conditions of the internal combustion engine.

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