Combustion control method based on different fuel mix

Abstract

The present application relates to the technical field of fuel combustion, and particularly relates to a combustion control method based on mixed combustion of different fuels, which comprises the following steps: S1, feeding the fuel into corresponding pipelines and premixing according to an initial set proportion; S2, calculating a real-time heat value of the mixed fuel and calculating an hourly heat consumption according to a target heat load; S3, calculating a mixed fuel flow rate meeting the input heat demand; S4, analyzing the mass proportion of elements contained in the mixed fuel, calculating an ideal air-fuel ratio and a required air flow rate, and controlling the fuel to combust; S5, adjusting a proportion change period of corresponding components according to a change rate of nitrogen oxide and a first gaseous fuel content; and S6, adjusting parameters according to exhaust gas components measured in the combustion process.The present application calculates a mixed fuel heat value in real time, accurately matches a fuel flow rate required by a target temperature, calculates an ideal air-fuel ratio, reduces heat loss, and greatly improves combustion efficiency.

Description

Technical Field

[0001] This invention relates to the field of fuel combustion technology, and in particular to a combustion control method based on the mixing of different fuels. Background Technology

[0002] Driven by the "dual-carbon" strategy, the fuel combustion field is facing multiple challenges: the pressure to reduce carbon emissions from traditional fossil fuels is surging, while zero-carbon fuels such as ammonia and hydrogen are becoming alternatives due to their ease of storage and transportation. However, ammonia fuel has bottlenecks such as slow combustion speed and high ignition energy requirements, making it difficult for a single fuel to meet the industrial combustion temperature and stability requirements; existing technologies use fixed-ratio mixing and combustion, which cannot adapt to fluctuations in fuel calorific value; insufficient premixing of multi-layer fuels leads to the risk of backfire, and uneven atomization of liquid fuel results in localized high temperatures in the combustion chamber, accelerating equipment wear. Therefore, it is necessary to continue developing an integrated technology solution that can achieve dynamic optimization of multi-fuel ratios and a backfire-resistant, high-efficiency combustion structure.

[0003] Chinese Patent Publication No. CN118361733A discloses a combustion system and its control method based on ammonia mixed fuel combustion, comprising: a combustion chamber having a combustion cavity extending along the flame injection direction, the combustion chamber having a flame inlet and a flue gas outlet, the combustion chamber having a plurality of temperature sensors and a plurality of injection nozzles for injecting reducing agent evenly distributed; a burner located at the flame inlet; a flue pipe connected to the flue gas outlet, the flue pipe having a nitrogen oxide sensor and a hydrogen sensor; and a controller controlling the injection quantity and injection pressure of the plurality of injection nozzles.

[0004] This combustion system can be used for experimental research on the combustion of ammonia-mixed fuels, and its flame varies depending on the experimental conditions. However, this method fails to achieve dynamic optimization of multi-fuel ratios. When the gas content after ammonia cracking fluctuates, the conventional air-fuel ratio leads to a decrease in thermal efficiency, and NO... x The content increases sharply and cannot be automatically adjusted. Summary of the Invention

[0005] Therefore, the present invention provides a combustion control method based on different fuel mixtures to overcome the problems in the prior art that cannot adapt to fuel calorific value fluctuations and that insufficient premixing of multi-layer fuels can lead to backfire risk.

[0006] To achieve the above objectives, the present invention provides a combustion control method based on different fuel mixtures, comprising:

[0007] Step S1: The first gaseous fuel, the liquid fuel, and the second gaseous fuel are introduced into the corresponding fuel pipelines. The liquid fuel is atomized and premixed according to the initially set ratio to obtain a mixed fuel.

[0008] Step S2: Calculate the real-time calorific value of the mixed fuel based on the composition of the mixed fuel, and calculate the hourly heat consumption based on the target heat load;

[0009] Step S3: Calculate the flow rate of the mixed fuel that meets the input heat demand based on the hourly heat consumption and the real-time calorific value of the mixed fuel, and record it as the first parameter;

[0010] Step S4: Analyze the mass ratio of elements contained in the mixed fuel, calculate the ideal air-fuel ratio, calculate the required air flow rate based on the mixed fuel flow rate and the ideal air-fuel ratio, and record it as the second parameter. Control the combustion of fuel based on the first parameter and the second parameter.

[0011] Step S5: Based on the carbon monoxide and nitrogen oxide content in the exhaust gas after combustion, determine whether the actual air-fuel ratio deviates from the ideal value, adjust the ratio change cycle of the first gaseous fuel according to the rate of change of nitrogen oxide content, and adjust the ratio change cycle of air according to the rate of change of carbon monoxide content.

[0012] Step S6: Adjust the first parameter and the second parameter according to the deviation of the oxygen, carbon monoxide and nitrogen oxide content in the exhaust gas after the ratio change cycle is adjusted;

[0013] Wherein, the first gaseous fuel is ammonia, and the second gaseous fuel is any one of natural gas, biomass gasification gas, biogas, coalbed methane, coal gas, shale gas, petroleum gas, and landfill gas.

[0014] Furthermore, the combustion control method employs combustion equipment including a combustion chamber, a fuel mixing end with a four-layer coaxial sleeve structure, an igniter, a premixing chamber, and an exhaust pipe;

[0015] The four-layer coaxial sleeve structure is equipped with a mass flow meter to control the inflow of fuel. One end is connected to the premixing chamber, which extends into the combustion chamber. The side wall of the combustion chamber is equipped with an observation window and a temperature sensor. The igniter for ignition is also installed inside. The exhaust pipe is connected to the combustion chamber outlet through a flange and is equipped with a detector for detecting the content of oxygen, carbon monoxide, and nitrogen oxides.

[0016] Furthermore, the four-layer coaxial sleeve structure is provided with the following components from the inside to the outside:

[0017] The central ammonia cracking channel has a built-in nickel-based catalyst coating with a coating thickness of 100-200 μm, which is used to introduce a hydrogen-nitrogen mixture gas obtained by cracking ammonia, wherein the ammonia gas to be cracked is preheated to above 400°C.

[0018] A liquid fuel channel for introducing the atomized liquid fuel;

[0019] A gaseous fuel annular cavity is used to introduce the second gaseous fuel, and a premixed gas film is formed through circumferential microporous jet;

[0020] The outer axial flow air passage is used to introduce air and premix it with various fuels.

[0021] Furthermore, in step S4, the fuel volume flow rate entering the combustion chamber is adjusted to the first parameter by adjusting the mixed fuel flow controller; and the air flow rate is adjusted to the second parameter by adjusting the air valve.

[0022] Furthermore, in step S5, the contents of oxygen, carbon monoxide, and nitrogen oxides in the exhaust gas are acquired in real time to determine whether the actual air-fuel ratio deviates from the ideal value;

[0023] In step S6, the first parameter and the second parameter are adjusted according to the deviation of the oxygen, carbon monoxide and nitrogen oxide content in the exhaust gas.

[0024] Furthermore, in step S1, the liquid fuel is any one of gasoline, kerosene, diesel, or fuel oil.

[0025] Furthermore, before and after the igniter is ignited, air is introduced through the outer axial airflow channel to purge for 3 to 5 minutes to remove residual gas. The purging airflow velocity is greater than 15 m / s to prevent backfire.

[0026] Furthermore, the liquid fuel is atomized through a high-pressure swirl nozzle and then enters the premixing chamber. The atomization pressure is 0.5 to 1.0 MPa, and the preset atomization particle size is 30 μm. When the carbon monoxide concentration in the exhaust gas is higher than the preset threshold, the atomization pressure is increased to reduce the atomization particle size, with the minimum atomization particle size being 10 μm.

[0027] Furthermore, the surface of the gaseous fuel annular cavity is uniformly distributed with micropores in the circumferential direction. The pore diameter is 0.5 to 1 mm, the micropore jet direction is at an angle of 30° to 45° with the axis of the combustion chamber, and the spacing between adjacent micropores is 3 to 5 times the pore diameter.

[0028] Furthermore, the constraints on the fuel combustion ratio include:

[0029] The calorific value provided by hydrogen in the ammonia cracking channel shall not be less than 20% of the total calorific value;

[0030] The calorific value ratio of liquid fuel to gaseous fuel is maintained between 1:0.5 and 1:2;

[0031] The proportional adjustment rate of the first parameter and the second parameter is limited to no more than 5% of the total fuel flow per second.

[0032] Compared with the prior art, the beneficial effects of the present invention are that it calculates the calorific value of the mixed fuel in real time, accurately matches the total fuel flow required for the target temperature, dynamically calculates the ideal air-fuel ratio based on fuel characteristics, reduces the fluctuation of the excess air coefficient, reduces heat loss, and greatly improves combustion efficiency.

[0033] Furthermore, the air-fuel ratio is corrected in real time using oxygen, carbon monoxide, and nitrogen oxide sensors; the proportion of ammonia cracked gas is greater than 20%, reducing the proportion of carbon-based combustion and reducing pollution emissions.

[0034] Furthermore, the gaseous fuel is jetted through micro-holes at 30°–45° to form a uniform premixed gas film, which homogenizes the flame temperature field and extends the burner's life; and after flameout, high-speed purging is performed to eliminate the risk of backfire.

[0035] Furthermore, the calorific value ratio of liquid fuel to gaseous fuel is limited, and the flow rate change rate is reduced to avoid deflagration caused by sudden fuel replacement; the four-layer coaxial sleeve structure used premixes liquid fuel, gaseous fuel, and pyrolysis gas in separate zones, improving combustion stability. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating a combustion control method based on different fuel mixtures according to an embodiment of the present invention;

[0037] Figure 2 This is a logic diagram of step S6 in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the combustion device structure in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the cross-section of the four-layer sleeve structure in an embodiment of the present invention;

[0040] Among them, 100 is a four-layer coaxial sleeve structure, 200 is a premixing chamber, 300 is a combustion chamber, 400 is an observation window, 500 is an exhaust channel, 600 is an igniter, 101 is an outer axial flow channel, 102 is a gaseous fuel annular cavity, 103 is a liquid fuel channel, and 104 is a central ammonia cracking channel. Detailed Implementation

[0041] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0042] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0043] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0044] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] Please see Figure 1 and Figure 2 As shown, this is a schematic diagram and logic diagram of the present invention. This embodiment provides a combustion control method based on different fuel mixtures. As a preferred embodiment of the present invention, the steps include:

[0046] Step S1: The first gaseous fuel, the liquid fuel, and the second gaseous fuel are introduced into the corresponding fuel pipelines. The liquid fuel is atomized under a certain pressure through a high-pressure swirl nozzle and premixed according to the initial ratio.

[0047] It is understood that in this embodiment, the first gaseous fuel is ammonia, and the second gaseous fuel can be any one of natural gas, biomass gasification gas, biogas, coalbed methane, coal gas, shale gas, petroleum gas, and landfill gas; the liquid fuel can be any one of gasoline, kerosene, diesel, and fuel oil; those skilled in the art can select the corresponding fuel according to the specific scenario, and the present invention does not limit it, all of which are within the protection scope of the present invention.

[0048] Step S2: Calculate the real-time calorific value of the mixed fuel based on the composition of the mixed fuel;

[0049]

[0050] Where HV is the real-time calorific value of the mixed fuel, q1 is the calorific value of hydrogen, q2 is the calorific value of liquid fuel, q3 is the calorific value of gaseous fuel, and V is the total volume of the mixed fuel.

[0051] Based on the target heat load, the required heat consumption per hour is calculated using the following formula:

[0052]

[0053] Among them, Q 输出 For the target heat load, Q 输入 The input heat is η, and the thermal efficiency is η. In this invention, the liquid fuel is atomized and released, and then mixed evenly with the gaseous fuel. The combustion efficiency is high, reaching more than 85%. Therefore, in this embodiment, the value of η is 0.85.

[0054] Step S3: Based on the total input heat and real-time fuel calorific value, calculate the real-time total fuel volume flow rate required to meet the heat input, and denot it as the first parameter; adjust the fuel flow regulator to adjust the total fuel volume flow rate entering the combustion chamber to the first parameter, the calculation formula is:

[0055]

[0056] Among them, Q 输入 HV represents the total input heat, HV represents the real-time fuel calorific value, and V represents the first parameter.

[0057] Step S4: Analyze the elemental proportions of the blended fuel and calculate the ideal air-fuel ratio;

[0058] Based on the proportions of the components in the mixed fuel, the mass percentages of the five elements C, H, O, N, and S are calculated. According to the complete combustion reaction equation, burning 12g of C requires 32g of oxygen, burning 4g of H requires 32g of oxygen, and burning 32g of S requires 32g of oxygen. The O in the fuel can substitute for some of the oxygen required and must be deducted. Under ideal conditions, N in the fuel will be converted into nitrogen gas; incomplete combustion will produce nitrogen oxides, which are not considered in the ideal calculation. The formula for the mass of oxygen required is summarized as follows:

[0059]

[0060] in, The mass of oxygen required for the combustion of 1 kg of mixed fuel (g), g C The mass of carbon element in 1 kg of blended fuel, in g H The mass of H element in 1 kg of blended fuel, in g S The mass of sulfur in 1 kg of blended fuel, in g O The mass of oxygen in 1 kg of mixed fuel;

[0061] The oxygen content in the incoming air is detected by an oxygen content detector and recorded as O2%.

[0062] The ideal air-fuel ratio formula is:

[0063]

[0064] Where A / F is the ideal air-fuel ratio, representing the amount of air (kg) required for the complete combustion of 1 kg of fuel mixture. The oxygen required for the combustion of 1 kg of mixed fuel is expressed in g, and O2% is the oxygen content in the air introduced.

[0065] Based on the total fuel volume flow rate and the ideal air-fuel ratio, the required total air flow rate is calculated and denoted as the second parameter. The total air flow rate is adjusted to the second parameter by regulating the air valve. The calculation formula is as follows:

[0066] Q = A / F·V·α

[0067] Where Q is the second parameter, A / F is the ideal air-fuel ratio, V is the first parameter, and α is the excess air coefficient. In actual combustion, excess air is required to ensure complete combustion, and its value is 1.2. The flow rate of the mixed fuel and the air flow rate are controlled according to the calculated first and second parameters to start combustion.

[0068] Step S5: Based on the rate of change of carbon monoxide and nitrogen oxide content in the exhaust gas after combustion, determine whether the actual air-fuel ratio deviates from the ideal value. When the actual air-fuel ratio deviates from the ideal value, adjust the ratio change cycle of the first gaseous fuel according to the rate of change of nitrogen oxide content, and adjust the ratio change cycle of air according to the rate of change of carbon monoxide content.

[0069] For example, when the nitrogen oxide detector detects a rapid increase in nitrogen oxide concentration (the rate of change of nitrogen oxide content is greater than 5% / s), it indicates a sudden increase in combustion temperature. At this time, the flow rate of the first gaseous fuel should be reduced to 0 at a constant rate of 5% per second, and then restored to the initial proportion of the first gaseous fuel. Each cycle of the proportional change is 10 seconds.

[0070] After one proportional change cycle, the rate of increase of nitrogen oxide concentration is detected again. If the rate of change of nitrogen oxide content is still greater than 5% / s, the proportional change cycle is increased by 1s, adjusted to every 11s, and this cycle is repeated until the rate of change of nitrogen oxide content is ≤5% / s, and the proportional change cycle is maintained at this time.

[0071] When the carbon monoxide detector detects a rapid increase in carbon monoxide concentration (the rate of change of carbon monoxide content is greater than 5% / s), it indicates that the oxygen concentration for combustion is insufficient. At this time, the air flow should be increased at a constant rate of 5% per second, and then restored to the initial air flow. This cycle repeats every 10 seconds.

[0072] After one proportional change cycle, the rate of increase in carbon monoxide concentration is detected again. If the rate of change in carbon monoxide content is still greater than 5% / s, the proportional change cycle is increased by 1 second, adjusted to every 11 seconds, and this cycle is repeated until the rate of change in carbon monoxide content is ≤5% / s.

[0073] Step S6: Adjust the first parameter and the second parameter according to the deviation of the oxygen, carbon monoxide and nitrogen oxide content in the exhaust gas after the ratio change cycle is adjusted;

[0074] For example, after the ratio change cycle is adjusted, the oxygen, carbon monoxide, and nitrogen oxide content in the exhaust gas is detected. If the oxygen content is higher than the preset threshold (preferably 15%), the second parameter is decreased; if the carbon monoxide content is higher than the preset threshold (preferably 800 ppm), the second parameter is increased; if the nitrogen oxide content is higher than the preset threshold (preferably 2500 ppm), the proportion of hydrogen in the mixed fuel is decreased, natural gas is used to supplement it, and the first parameter is recalculated. The adjustment range of the first and second parameters is less than 5% each time. Every 10 minutes, it is confirmed whether further adjustment is needed based on the current exhaust gas.

[0075] It is understandable that the oxygen, carbon monoxide, and nitrogen oxide contents mentioned above refer to the volume percentage of the corresponding components in the exhaust gas.

[0076] Specifically, please refer to Figure 3 As shown, the combustion device includes: a combustion chamber, a four-layer coaxial sleeve structure, an igniter, an injection pipe, and an exhaust pipe;

[0077] The four-layer coaxial sleeve structure has valves to control the flow of fuel entering the combustion chamber. One end extends into the combustion chamber, and the side wall of the combustion chamber is equipped with observation windows and temperature sensors. Inside, there is also an igniter and injection pipe for ignition. The exhaust pipe is connected to the combustion chamber outlet through a flange and is equipped with oxygen, carbon monoxide, and nitrogen oxide content detectors.

[0078] Specifically, please refer to Figure 4 As shown, the four-layer coaxial sleeve structure includes:

[0079] The central ammonia cracking channel is preferably coated with a built-in nickel-based catalyst with a coating thickness of 150 μm and a cracking efficiency of 98% at 850 °C.

[0080] The liquid fuel channel, preferably, has a swirl angle of 60°, an atomization pressure of 0.8 MPa, and an atomization particle size of 30 μm. It is premixed with gaseous fuel. When the carbon monoxide concentration in the exhaust gas is higher than a preset threshold (preferably 800 ppm), the atomization pressure is increased to reduce the atomization particle size, with a minimum atomization particle size of 10 μm.

[0081] The gaseous fuel annular cavity preferably has a micropore diameter of 0.8 mm, a micropore jet direction at a 40° angle to the combustion chamber axis, and a micropore spacing of 3 mm to form a swirling premixed gas film.

[0082] The external axial flow air duct is preferably supplied with a direct current air velocity of 20 m / s to suppress flame spread; it is purged for 4 minutes before ignition and after extinguishing to remove residual gas.

[0083] Specifically, the fuel blending ratio can be adjusted according to constraints such as target calorific value and pollutant emissions, and step S2 can be repeated after adjustment.

[0084] Specifically, the fuel combustion ratio is subject to the following constraints:

[0085] The calorific value of the hydrogen-nitrogen mixture in the ammonia cracking channel shall account for no less than 20% of the total calorific value;

[0086] The calorific value ratio of liquid fuel to gaseous fuel is maintained between 1:0.5 and 1:2;

[0087] The proportional adjustment rate is limited to no more than 5% of the total fuel flow per second.

[0088] Example:

[0089] Step S1: Ammonia, diesel, and natural gas are introduced into the corresponding fuel pipelines. Ammonia is cracked into hydrogen and nitrogen in the pipelines. They are premixed in the premixing chamber according to the initial ratio of 10:20:70. The flow rate is adjusted by a mass flow meter. Diesel is atomized at a pressure of 0.8 MPa through a high-pressure swirl nozzle.

[0090] Step S2: Calculate the real-time calorific value based on the mixed fuel composition;

[0091] The calorific value of hydrogen is 120.0 MJ / kg; the calorific value of diesel is 42.7 MJ / kg; the calorific value of natural gas is 50.0 MJ / kg; after mixing, the calorific value of the mixed fuel is 55.5 MJ / kg.

[0092] Step S3: The target heat load is 500kW, the thermal efficiency is 0.85, and the calculated input power is 588.24kW, requiring 2117664KJ of heat to be consumed per hour; based on the input power and the real-time fuel calorific value, the real-time fuel flow rate required to meet the heat input is calculated to be 38.15kg / h, which is denoted as the first parameter;

[0093] Step S4: Analyze the elemental composition of the blended fuel. The blended fuel consists of: hydrogen (H2), diesel (C2), and carbon dioxide (C4). 11 H 21 Using approximate natural gas (CH4), the oxygen content of the introduced air was detected by an oxygen content detector as 20.2%, and the ideal air-fuel ratio was calculated to be 18.34. Based on the ideal air-fuel ratio, the required airflow rate was calculated to be 839.60 kg / h; fuel was introduced according to the calculated data, and combustion began.

[0094] Step S5: Detect the emission rates of carbon monoxide and nitrogen oxides in the exhaust gas after combustion to determine whether the actual air-fuel ratio deviates from the ideal value. The detection results are as follows:

[0095] Table 1. Step S5: Detection of carbon monoxide and nitrogen oxide content in exhaust gases.

[0096]

[0097]

[0098] As can be seen from Table 1 above, the nitrogen oxide emission rate exceeds the standard by 673 ppm, and the hydrogen flow rate needs to be reduced to 0 at a constant rate within 10 seconds, and then the initial hydrogen flow rate needs to be restored.

[0099] In step S6, during the cycle of step S5, after the hydrogen content decreases by 10%, the nitrogen oxide content is found to be within acceptable limits. Based on this, the parameters of the subsequent combustion process are optimized, and the fuel mixture ratio is changed to hydrogen:diesel:natural gas = 9:20:71.

[0100] Table 2 shows the detection of oxygen, carbon monoxide, and nitrogen oxide content in the exhaust gas in step S6.

[0101] Testing items Qualification Standard Detection value oxygen 3％～15％ 7％ carbon monoxide 10ppm~800ppm 498ppm nitrogen oxides 1000ppm~2500ppm 2176ppm

[0102] As can be seen from Tables 1 and 2 above, the regulating system of the present invention effectively optimizes the fuel blending ratio, reduces nitrogen oxide emissions, accurately matches the total fuel flow required for the target temperature, dynamically calculates the ideal air-fuel ratio based on fuel characteristics, reduces excess air coefficient fluctuations, reduces heat loss, greatly improves combustion efficiency, and reduces the proportion of carbon-based combustion, thereby reducing pollution emissions.

[0103] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A combustion control method based on different fuel mixtures, characterized in that, Control methods include: Step S1: The first gaseous fuel, the liquid fuel, and the second gaseous fuel are introduced into the corresponding fuel pipelines. The liquid fuel is atomized and premixed according to the initially set ratio to obtain a mixed fuel. Step S2: Calculate the real-time calorific value of the mixed fuel based on the composition of the mixed fuel, and calculate the hourly heat consumption based on the target heat load; Step S3: Calculate the flow rate of the mixed fuel that meets the input heat demand based on the hourly heat consumption and the real-time calorific value of the mixed fuel, and record it as the first parameter; Step S4: Analyze the mass ratio of elements contained in the mixed fuel, calculate the ideal air-fuel ratio, calculate the required air flow rate based on the mixed fuel flow rate and the ideal air-fuel ratio, and record it as the second parameter. Control the combustion of fuel based on the first parameter and the second parameter. Step S5: Based on the carbon monoxide and nitrogen oxide content in the exhaust gas after combustion, determine whether the actual air-fuel ratio deviates from the ideal value, adjust the ratio change cycle of the first gaseous fuel according to the rate of change of nitrogen oxide content, and adjust the ratio change cycle of air according to the rate of change of carbon monoxide content. Step S6: Adjust the first parameter and the second parameter according to the deviation of the oxygen, carbon monoxide and nitrogen oxide content in the exhaust gas after the ratio change cycle is adjusted; Wherein, the first gaseous fuel is ammonia, and the second gaseous fuel is any one of natural gas, biomass gasification gas, biogas, coalbed methane, coal gas, shale gas, petroleum gas, and landfill gas.

2. The combustion control method based on different fuel mixtures according to claim 1, characterized in that, The combustion control method employs combustion equipment including a combustion chamber, a fuel mixing end with a four-layer coaxial sleeve structure, an igniter, a premixing chamber, and an exhaust pipe. The four-layer coaxial sleeve structure is equipped with a mass flow meter to control the inflow of fuel. One end is connected to the premixing chamber, which extends into the combustion chamber. The side wall of the combustion chamber is equipped with an observation window and a temperature sensor. The igniter for ignition is also installed inside. The exhaust pipe is connected to the combustion chamber outlet through a flange and is equipped with a detector for detecting the content of oxygen, carbon monoxide, and nitrogen oxides.

3. The combustion control method based on different fuel mixtures according to claim 2, characterized in that, The four-layer coaxial sleeve structure is provided with, from the inside to the outside: The central ammonia cracking channel has a built-in nickel-based catalyst coating with a coating thickness of 100-200 μm, which is used to introduce a hydrogen-nitrogen mixture gas obtained by cracking ammonia, wherein the ammonia gas to be cracked is preheated to above 400°C. A liquid fuel channel for introducing the atomized liquid fuel; A gaseous fuel annular cavity is used to introduce the second gaseous fuel, and a premixed gas film is formed through circumferential microporous jet; The outer axial flow air passage is used to introduce air and premix it with various fuels.

4. The combustion control method based on different fuel mixtures according to claim 3, characterized in that, In step S4, the fuel volume flow rate entering the combustion chamber is adjusted to the first parameter by adjusting the mixed fuel flow controller; the air flow rate is adjusted to the second parameter by adjusting the air valve.

5. The combustion control method based on different fuel mixtures according to claim 4, characterized in that, In step S5, the contents of oxygen, carbon monoxide, and nitrogen oxides in the exhaust gas are acquired in real time to determine whether the actual air-fuel ratio deviates from the ideal value. In step S6, the first parameter and the second parameter are adjusted according to the deviation of the oxygen, carbon monoxide and nitrogen oxide content in the exhaust gas.

6. The combustion control method based on different fuel mixtures according to claim 1, characterized in that, In step S1, the liquid fuel is any one of gasoline, kerosene, diesel, or fuel oil.

7. The combustion control method based on different fuel mixtures according to claim 3, characterized in that, Also includes: Before ignition and after extinguishing the igniter, air is introduced through the outer axial airflow channel and purged for 3 to 5 minutes to remove residual gas. The purging airflow velocity is greater than 15 m / s to prevent backfire.

8. The combustion control method based on different fuel mixtures according to claim 2, characterized in that, The liquid fuel is atomized through a high-pressure swirl nozzle and then enters the premixing chamber. The atomization pressure is 0.5 to 1.0 MPa, and the preset atomization particle size is 30 μm. When the carbon monoxide concentration in the exhaust gas is higher than the preset threshold, the atomization pressure is increased to reduce the atomization particle size, with the minimum atomization particle size being 10 μm.

9. The combustion control method based on different fuel mixtures according to claim 3, characterized in that, The surface of the gaseous fuel annular cavity is uniformly distributed with micropores in the circumference. The pore diameter is 0.5 to 1 mm. The micropore jet direction is at an angle of 30° to 45° with the axis of the combustion chamber, and the spacing between adjacent micropores is 3 to 5 times the pore diameter.

10. The combustion control method based on different fuel mixtures according to any one of claims 1-9, characterized in that, The constraints on the fuel combustion ratio include: The calorific value provided by hydrogen in the ammonia cracking channel shall not be less than 20% of the total calorific value; The calorific value ratio of liquid fuel to gaseous fuel is maintained between 1:0.5 and 1:2; The rate of adjustment of the first parameter and the second parameter is limited to no more than 5% of the total fuel flow per second.

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