Hydrogen internal combustion engine constant speed load adaptive method and application

Abstract

The application discloses a hydrogen internal combustion engine constant-speed load self-adaptive method and application independent of throttle control and belongs to the technical field of control of spark-ignition hydrogen internal combustion engines. The hydrogen internal combustion engine constant-speed load self-adaptive method independent of throttle control comprises the following steps: setting throttle opening degrees under starting conditions, warm-up conditions and power output conditions of the hydrogen internal combustion engine respectively; constant-speed operation control of the warm-up conditions; and constant-speed load self-adaptive control of the power output conditions. The hydrogen internal combustion engine constant-speed load self-adaptive method and application independent of throttle control realize constant-speed operation and load self-adaptation of the hydrogen internal combustion engine under the condition of not depending on throttle adjustment, make the intake air amount control of the hydrogen internal combustion engine under starting, warm-up and power output states more in line with the condition requirements, and make the hydrogen internal combustion engine respond to real-time changes of loads more quickly and have more stable rotating speeds.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of control of hydrogen internal combustion engine, and particularly relates to a hydrogen internal combustion engine constant speed load adaptive method independent of throttle control and application. BACKGROUND

[0002] Hydrogen is a clean fuel with zero carbon emissions, and is an ideal "green" fuel. In the future industrial power field, the development of hydrogen internal combustion engine has an important strategic position.

[0003] Due to the unique physical properties of hydrogen, its combustion characteristics are quite different from those of traditional internal combustion engines. Unlike the ignition method of traditional diesel engines, it is difficult to achieve compression ignition due to the high self-ignition temperature of hydrogen, and the ignition method of hydrogen internal combustion engine is mainly ignition. Unlike traditional gasoline and natural gas internal combustion engines, the three-way catalyst limits them to burning near the stoichiometric ratio. Due to the wide flammable range of hydrogen and the main pollutant emissions being nitrogen oxides, the hydrogen internal combustion engine can vary the concentration of the mixture in the cylinder within a wide range, and when the mixture is burned at a relatively dilute concentration, the nitrogen oxide emission level can be effectively reduced, and even zero nitrogen oxide emissions can be achieved. Therefore, based on the unique combustion characteristics of hydrogen internal combustion engine, its control method is also quite different from that of traditional internal combustion engine.

[0004] On the one hand, due to the characteristics of the ignition type internal combustion engine, the intake air quantity of the ignition type hydrogen internal combustion engine needs to be controlled by the throttle, so as to control the mixture concentration in the cylinder according to the working condition requirements. Especially at startup and small load conditions, in order to ensure the stability of startup and the stability of combustion at small load conditions, the throttle must be controlled to control the intake air quantity to ensure the appropriate mixture concentration. On the other hand, due to the wide flammable range of hydrogen and the emission advantage under lean burn conditions, the throttle can be kept open or fully open at medium and high load conditions. Therefore, when the hydrogen internal combustion engine needs to work under constant speed load adaptive conditions, the control method developed based on the existing compression ignition diesel engine or ignition type gasoline and natural gas internal combustion engine is not applicable to the hydrogen internal combustion engine. Because in the control method of compression ignition diesel engine, there is no control of the throttle, and in the ignition type gasoline and natural gas internal combustion engine, the method of realizing constant speed operation mainly depends on the feedback of the exhaust gas oxygen sensor and the control of the throttle.

[0005] To realize the control of hydrogen internal combustion engine constant speed load adaptation, a new control method must be relied on to realize its application. For example, through hydrogen internal combustion engine for constant frequency power generation, hydrogen energy is converted into high-quality electric energy, and then the hydrogen energy is converted into electric energy through the power grid to realize cross-regional transportation, thereby indirectly solving the problem of hydrogen energy storage and transportation due to its small density, thereby promoting the popularization and use of hydrogen energy and reducing carbon emissions. SUMMARY

[0006] The application aims to provide a hydrogen internal combustion engine constant speed load self-adaptive method and application which is independent of throttle control, realizes constant speed operation and load self-adaption of the hydrogen internal combustion engine under the condition of not relying on throttle adjustment, and makes the hydrogen internal combustion engine intake control more in line with the working condition requirements under the conditions of startup, warm-up and power output; the hydrogen internal combustion engine responds faster to real-time changes of the load and is more stable in speed.

[0007] To achieve the above-mentioned purpose, the application provides a hydrogen internal combustion engine constant speed load self-adaptive method which is independent of throttle control and comprises the following steps:

[0008] S1, setting the throttle opening degree under the conditions of startup, warm-up and power output of the hydrogen internal combustion engine respectively.

[0009] Since the combustion characteristics of the hydrogen internal combustion engine are different from those of the traditional compression ignition diesel engine and the ignition type gasoline and natural gas and other internal combustion engines, the control of realizing constant speed operation and load self-adaption cannot completely be independent of the control of the throttle or completely rely on the control of the throttle, but needs to fix the throttle at a certain opening degree to control the intake of the hydrogen internal combustion engine according to different working conditions. Specifically, under the condition of startup of the hydrogen internal combustion engine, a small opening degree of the throttle needs to be maintained to ensure the stable startup of the hydrogen internal combustion engine. Under the condition of warm-up, the throttle maintains a small opening degree to control the dilution degree and reduce the cycle variation, thereby ensuring stable operation and rapid warm-up. Under the condition of power output, the throttle maintains a large opening degree to increase the intake, so that the hydrogen internal combustion engine works under the condition of dilute mixture as much as possible to reduce the generation and emission of nitrogen oxide pollutants.

[0010] Preferably, the throttle opening degree is fixed under the conditions of startup, warm-up and constant speed power output.

[0011] Preferably, the throttle opening degree is 5%-8% under the condition of startup, 10%-15% under the condition of warm-up, and 15%-100% under the condition of power output.

[0012] Preferably, under the condition of power output, the throttle opening degree is 15%-20% when the hydrogen internal combustion engine operates at a target speed of 25%-40% of the maximum speed, 20%-25% when the hydrogen internal combustion engine operates at a target speed of 40%-50% of the maximum speed, and 100% when the hydrogen internal combustion engine operates at a target speed of more than 50% of the maximum speed.

[0013] Under the conditions of warm-up and power output, the corresponding fixed throttle opening degree is maintained to control the constant speed operation and load self-adaption of the hydrogen internal combustion engine.

[0014] S2, constant speed operation control under the condition of warm-up.

[0015] In order to ensure that the hydrogen internal combustion engine has good lubricating effect between each friction pair during operation, thereby reducing mechanical wear, prolonging the service life of the hydrogen internal combustion engine and improving its reliability, the oil of the hydrogen internal combustion engine needs to be kept in a certain temperature range before the hydrogen internal combustion engine enters the power output condition. Therefore, during the process of starting to power output of the hydrogen internal combustion engine, a warm-up process needs to be carried out. At the same time, in order to make the hydrogen internal combustion engine run stably during the warm-up process and keep the noise level at a relatively stable state, the hydrogen internal combustion engine is controlled to run at a constant speed during the warm-up process.

[0016] Unlike traditional spark-ignition gasoline engines and natural gas internal combustion engines, the hydrogen internal combustion engine adjusts the throttle opening and fuel injection pulse width through the feedback of the exhaust gas oxygen sensor to realize constant speed control. Therefore, the speed needs to be feedback adjusted through the collection of other physical quantities to realize constant speed control.

[0017] Preferably, in S2, the constant speed control of the warm-up condition includes the following steps:

[0018] S21, the hydrogen internal combustion engine runs at the actual speed under the basis warm-up MAP and the warm-up throttle opening, and the actual speed is 80%-120% of the target speed;

[0019] S22, the PID control adjustment amount of the operating parameter is obtained through the speed difference between the actual speed and the target speed;

[0020] S23, the MAP execution parameter is obtained by combining the current actual speed of the hydrogen internal combustion engine and the oil temperature with the data in the calibrated basis warm-up MAP;

[0021] S24, the PID control adjustment amount and the MAP execution parameter are added to obtain the actual executed hydrogen internal combustion engine operating parameter, and a new actual speed is obtained;

[0022] S25, repeat S22-S24, the actual speed converges to the target speed, the hydrogen internal combustion engine runs stably at the target speed, and the warm-up process ends.

[0023] Preferably, in S21, the actual speed and the oil temperature are used as independent variables to calibrate the basis warm-up MAP, and the parameter data of the calibrated basis warm-up MAP includes hydrogen injection pulse width, ignition advance angle and hydrogen injection start time.

[0024] The parameter table of the MAP is expressed as:

[0025] y=f(n,T)

[0026] Wherein, y represents the hydrogen injection pulse width, the ignition advance angle or the hydrogen injection starting time, n represents the actual working speed of the hydrogen internal combustion engine, and T represents the oil temperature of the hydrogen internal combustion engine. The calibration independent variable T of the MAP replaces the throttle opening degree in the constant speed control of the traditional spark-ignition internal combustion engine, thereby eliminating the influence of the key control parameter, the throttle, on the warm-up MAP data.

[0027] In the S23, the hydrogen injection pulse width, the ignition advance angle and the hydrogen injection time at different speeds and oil temperatures in the MAP data are obtained from the calibration process of the hydrogen internal combustion engine. Since only discrete values of the speed and the oil temperature can be taken in the calibration process, when the actual speed and the oil temperature are values other than the calibration points, the MAP execution parameters are determined by two-dimensional linear interpolation of the data of the nearest calibration points.

[0028] The speed is coarsely adjusted by querying the basic warm-up MAP, and finely adjusted by the PID control adjustment amount. The two work together to make the speed of the hydrogen internal combustion engine quickly converge to the warm-up target speed.

[0029] S3, constant speed load adaptive control in power output working condition.

[0030] Similar to the control of the constant speed operation in the warm-up working condition, the constant speed operation and the load adaptive control in the power output working condition also need to be adjusted by the feedback of other physical quantities.

[0031] Preferably, in the S3, the constant speed load adaptive control in the power output working condition comprises the following steps:

[0032] S31, determining the power output throttle opening degree by the target speed of the hydrogen internal combustion engine;

[0033] S32, operating the hydrogen internal combustion engine at the actual speed under the calibrated basic working MAP and the power output throttle opening degree, the actual speed being 80%-120% of the target speed;

[0034] S33, reading the transient speed for several times, and obtaining the average actual speed by averaging the transient speed results read for several times;

[0035] S34, obtaining the PID control adjustment amount of the operating parameter by the speed difference between the average actual speed and the target speed;

[0036] S35, obtaining the MAP execution parameter in the calibrated basic working MAP by combining the calibrated basic working MAP, the average actual speed and the load variable;

[0037] S36, adding the MAP execution parameter and the PID control adjustment amount to obtain the actual executed operating parameter of the hydrogen internal combustion engine, and obtaining the new actual speed;

[0038] S37, repeat S33-S36, the actual speed converges to the target speed, and the hydrogen internal combustion engine is kept stable at the target speed.

[0039] Preferably, in S32, the actual speed and the load variable are used as independent variables to calibrate the basic working MAP.

[0040] The basic working MAP data includes the hydrogen injection pulse width, the ignition advance angle, and the hydrogen injection start time, all of which are discrete functions of the speed and the load, and are expressed as:

[0041] y1 = f1(n, load)

[0042] wherein y1 represents the hydrogen injection pulse width, the ignition advance angle, or the hydrogen injection start time, n represents the speed of the hydrogen internal combustion engine, and load is a virtual variable.

[0043] In S35, the hydrogen injection pulse width, the ignition advance angle, and the hydrogen injection time at different speeds and loads in the MAP data are obtained from the calibration process of the hydrogen internal combustion engine. Since only discrete values of the speed and the load can be taken in the calibration process, when the actual speed and the load variable take values other than the calibration points, the data of the nearest calibration point is used for two-dimensional linear interpolation to determine the MAP execution parameters.

[0044] When the load of the hydrogen internal combustion engine changes, the speed of the hydrogen internal combustion engine changes, resulting in a large deviation of the obtained MAP execution parameters compared to the load before the change, thereby accelerating the rapid adaptation of the load and quickly achieving speed stability. Similarly, the speed is roughly adjusted by querying the basic working MAP, which can quickly change the load of the hydrogen internal combustion engine; the fine feedback adjustment is performed by the PID control adjustment amount, and the two work together to make the speed of the hydrogen internal combustion engine quickly converge to the target speed.

[0045] In the warm-up working condition, the hydrogen internal combustion engine only needs to overcome its own friction work and the work consumed by other accessories, and does not output power, so its load is basically stable, and the injection pressure of the nozzle is basically maintained unchanged. For the power output working condition, since the hydrogen internal combustion engine needs to face variable load working conditions, the demand for hydrogen is different, resulting in a much larger fluctuation range of the injection pressure of the hydrogen nozzle during load change than in the warm-up working condition. Therefore, in order to reduce the influence of rail pressure change on the constant speed operation and load adaptation of the hydrogen internal combustion engine, the load parameter considers the influence of the speed difference and the rail pressure deviation (i.e. the injection pressure deviation). In addition, in order to eliminate the influence of high transient speed of the hydrogen internal combustion engine on the control, the specific method is to take the average value of the multiple readings of the transient speed of the hydrogen internal combustion engine, and then calculate the speed deviation with the target speed.

[0046] Preferably, the load variable is a function of the speed difference between the average actual speed and the target speed, and the rail pressure difference between the actual rail pressure and the calibrated rail pressure, expressed as:

[0047] load = z (diff_a_n, diff_p)

[0048] wherein load represents the hydrogen internal combustion engine power generation load, diff_a_n is the speed difference between the average speed and the target speed, and diff_p is the difference between the calibrated rail pressure and the actual rail pressure.

[0049] The load data is obtained from the hydrogen internal combustion engine calibration process. Since only discrete values of speed and rail pressure deviation can be taken during the calibration process, when the values of diff_a_n and diff_p are non-calibration point values, the load variable value is determined by two-dimensional linear interpolation of the nearest calibration point data.

[0050] The average speed eliminates the influence of instantaneous speed reading on constant speed operation control; by introducing the load virtual variable, not only the influence of the throttle on the calibration basis work MAP is eliminated, but also the throttle can always be kept open or in a certain state during power output, and the influence of the difference between the actual injection pressure and the injection pressure used during calibration on constant speed control is reduced; at the same time, the use of the load virtual variable makes the hydrogen internal combustion engine more accurate in the basis work MAP calibration under different load conditions, and makes the MAP execution parameters closer to the requirements of the target speed and target load, improving the accuracy of the rough feedback regulation; finally, through the combined adjustment of more accurate MPA execution parameters and PID control adjustment amount, the hydrogen internal combustion engine always maintains a constant speed during load change, ensuring its tolerance and dynamic response to load changes.

[0051] The above-mentioned hydrogen internal combustion engine constant speed load self-adaptive method without throttle control is applied to hydrogen internal combustion engine constant frequency power generation and driving propeller.

[0052] The hydrogen internal combustion engine constant speed load self-adaptive method without throttle control and its application have the advantages and positive effects that: combining the working characteristics of hydrogen internal combustion engine, the key control parameter of throttle in spark-ignition internal combustion engine is separated from the load of hydrogen internal combustion engine in control, so that the intake air control of hydrogen internal combustion engine in starting, warm-up and power output states is more in line with the working condition requirements; by introducing the load virtual control parameter, the relationship between the basis work MAP of hydrogen internal combustion engine and different loads is more accurate, and the response to the change of hydrogen internal combustion engine load is more accurate; through the real-time feedback and correction of load and PID control adjustment amount to the actual execution parameters, the hydrogen internal combustion engine responds faster to real-time changes in load, and the speed is more stable.

[0053] The technical solutions of the present application are described in further detail below with reference to the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 A control schematic diagram of an embodiment of the present application;

[0055] Figure 2 A throttle independent control flowchart of an embodiment of the present application;

[0056] Figure 3 A warm-up operating condition control flowchart of an embodiment of the present application;

[0057] Figure 4 A power output operating condition control flowchart of an embodiment of the present application;

[0058] Figure 5 A power output operating condition load calculation flowchart of an embodiment of the present application;

[0059] Figure 6 A propeller rotational speed and power and corresponding hydrogen internal combustion engine rotational speed and output power diagram of embodiment one of the present application. DETAILED DESCRIPTION

[0060] In the present application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. In case of conflict, the present specification, including the definitions herein, will control. In addition, the terms used herein are for the purpose of describing the embodiments of the present application only and are not intended to limit the present application. In order to accurately describe the technical content in the present application, and in order to accurately understand the present application, the following explanations or definitions of the terms used in the present specification are given before the specific embodiments are described:

[0061] 1) Hydrogen internal combustion engine: refers to an internal combustion engine that uses hydrogen gas as fuel, which drives the reciprocating motion of the piston by burning the mixture of hydrogen gas and air, and the piston pushes the connecting rod, which drives the rotation of the crankshaft, thereby outputting rotary power. Unlike a hydrogen fuel cell, a hydrogen fuel cell is an electricity generating device that directly converts the chemical energy of hydrogen and oxygen into electrical energy.

[0062] 2) Hydrogen internal combustion engine transient rotational speed: the rotational speed of the hydrogen internal combustion engine is collected multiple times in one working cycle, the instantaneous rotational speed is lower when the cylinders are working intermittently, and the rotational speed is higher when the cylinders are working, which varies within a certain range in the same cycle, and the variation range is related to the number of cylinders of the hydrogen internal combustion engine.

[0063] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0064] Embodiment one

[0065] Based on a 2.0L hydrogen internal combustion engine for driving propeller, the constant speed operation and load adaptive control of hydrogen internal combustion engine are realized. The hydrogen internal combustion engine is mechanically connected with the propeller through the transmission, the transmission ratio is 2.0, and the hydrogen internal combustion engine speed range is 0-6000r / min.

[0066] As shown in Figure 1 A hydrogen internal combustion engine constant speed load adaptive control method independent of throttle control is used to control the hydrogen internal combustion engine driving propeller to provide power, comprising the following steps:

[0067] First, the independent control of the hydrogen internal combustion engine throttle opening is carried out, as shown in Figure 2 In the starting condition, in order to ensure the stable starting of the hydrogen internal combustion engine, a small throttle opening is selected, and the opening is 8%. In the warm-up condition, combined with the propeller speed characteristics as shown in Figure 6 , a small propeller speed is selected for warm-up to reduce the load and save fuel. The propeller speed is 600r / min, and the corresponding hydrogen internal combustion engine speed is 1200r / min, which is used as the warm-up condition. In order to realize stable combustion and rapid warm-up in the warm-up condition, a small throttle opening is selected, and the opening is 12% to ensure a small intake air amount and a thick in-cylinder mixture, reduce the combustion cycle variation, and reduce the heat of the excess heated air to speed up the oil warming process. In the power output condition, the propeller speed is in the range of 750r / min-2450r / min, and the corresponding hydrogen internal combustion engine speed range is 1500r / min-4900r / min. Under the restriction of combustion stability and reduction of nitrogen oxide emissions, the stable lean burn condition is maintained, and the throttle opening is 15%-20% in the speed range of 1500r / min-2500r / min; the throttle opening is 20%-25% in the speed range of 2500r / min-3000r / min, and the throttle opening is 100% when the speed is higher than 3000r / min.

[0068] Secondly, the hydrogen internal combustion engine constant speed operation control in the warm-up condition is carried out, as shown in Figure 3 . The warm-up target speed is 1200r / min. The throttle opening is kept at 12%, and the basic warm-up MAP is calibrated as shown in Table 1, wherein the top row represents the speed, the speed value is in the range of 1050r / min-1350r / min near the warm-up target speed, and the step is 10r / min. The leftmost column of numbers represents the oil temperature T, which ranges from -20-90℃ with a step of 5℃.

[0069] Table 1 shows the calibration content of the basic warm-up MAP

[0070]

[0071] The specific control method is: keeping the throttle opening degree at 12%, obtaining the MAP execution parameters by two-dimensional linear interpolation of the real-time speed n of the hydrogen internal combustion engine and the oil temperature T in the basic warm-up MAP, obtaining the rough adjustment parameters including the hydrogen injection pulse width, the ignition advance angle and the hydrogen injection time by the calibration MAP; obtaining the fine PID control adjustment amount including the fine adjustment amount of the hydrogen injection pulse width, the ignition advance angle and the hydrogen injection time by PID control calculation of the speed difference between the real-time speed n and the warm-up target speed 1200 r / min. Adding the PID control adjustment amount and the MAP execution parameters to obtain the actual execution control parameters, controlling the hydrogen internal combustion engine speed to converge to the warm-up target speed 1200 r / min and keep stable until the warm-up process is completed.

[0072] Finally, the hydrogen internal combustion engine speed load adaptive control in the power output condition is carried out, as shown in Figure 4 The hydrogen internal combustion engine speed range in the power output condition is 1500 r / min-4900 r / min, and according to the propeller speed characteristic as shown in Figure 6 When the propeller works in a certain state, the hydrogen internal combustion engine is required to stably operate at a certain speed and achieve corresponding power output, i.e. the load self-adaptation in the constant speed operation state. The state of the throttle valve in the power output condition is as described in the throttle valve independent control part. As shown in Table 2, the top row represents the speed, ranging from 1400 r / min to 5000 r / min with a step of 100 r / min; the leftmost column represents the virtual variable load, ranging from 0% to 100% with a step of 10%.

[0073] Table 2 shows the content of the calibrated basic working MAP

[0074]

[0075] The calculation method of the virtual variable load is as shown in Figure 5 The speed deviation and rail pressure deviation are determined, and the calibration table is shown in Table 3. Based on the reference speed and reference rail pressure (injection pressure), the speed deviation and rail pressure deviation are calibrated to ±50% as the calibration boundary, and the load variable is calibrated. The injection pressure is 100 bar in the calibration state. When the load of the hydrogen internal combustion engine changes with the working demand of the propeller, the hydrogen injection pressure fluctuates due to the change of the hydrogen consumption rate, and the hydrogen flow of the hydrogen nozzle is strongly related to the injection pressure, so the fluctuation of the injection pressure easily causes the change of the hydrogen injection amount, thereby causing large speed fluctuation. The load variable actively eliminates this influence.

[0076] Table 3 shows the content of the virtual variable load calibration

[0077]

[0078] The specific control method is: the corresponding propeller speed is obtained from the power requirement of the propeller, so as to determine the target speed and output power of the hydrogen internal combustion engine, and the throttle state is determined according to the target speed of the hydrogen internal combustion engine. A hydrogen internal combustion engine speed is determined in combination with the basic working MAP. In order to eliminate the influence of the instantaneous speed of the hydrogen internal combustion engine on the constant speed control, the average value of the hydrogen internal combustion engine speed is taken, specifically, the average value of 50 instantaneous speeds, that is, M=50, to obtain the average speed a_n. The MAP execution parameter is obtained by two-dimensional linear interpolation of the average speed a_n and the load value in the calibrated basic working MAP, to make a rough correction to the speed in a large range. The PID control adjustment amount is obtained by the speed difference between the average speed a_n and the target speed of the hydrogen internal combustion engine, to determine the PID adjustment parameter and make a fine correction to the speed in a small range. Finally, the actual execution parameter is obtained by adding the MAP execution parameter and the PID control adjustment amount, to control the speed of the hydrogen internal combustion engine to converge to the power output target speed and keep stable.

[0079] When the demand for the propeller is to maintain constant power output, such as uniform speed propulsion of a ship or an aircraft, due to the working characteristics of the propeller, the output power is one-to-one corresponding to the speed, at this time, the hydrogen internal combustion engine is controlled according to the need to maintain constant power output. When the demand for the propeller is variable power output, such as acceleration and deceleration of a ship or an aircraft, the demand for the power of the propeller issues a variable command, causing the speed to change, so as to change the target speed of the hydrogen internal combustion engine. In this control method, the MAP execution parameter obtained by MAP interpolation quickly controls the speed of the hydrogen internal combustion engine to quickly change to the target speed, and the PID control adjustment amount quickly and stably converges to the target speed, so as to realize the load self-adaptation and constant speed operation control of the hydrogen internal combustion engine.

[0080] Through this control method, in the application of driving the propeller, the load and the throttle state of the hydrogen internal combustion engine are decoupled, so that the hydrogen internal combustion engine stably outputs power according to the demand in the lean burn working condition, and realizes constant speed operation and load self-adaptation.

[0081] Embodiment two

[0082] A hydrogen internal combustion engine generator set with a straight-4 cylinder, 1.0L naturally aspirated port injection is implemented with the control method described in the present application. The allowable speed range of the hydrogen internal combustion engine is 0-6000r / min, the target power generation frequency of the generator set is 50±0.2Hz, 50Hz corresponds to the power generation speed of 3000r / min, and the rated power generation power is 10kW.

[0083] As shown in Figure 1 A hydrogen internal combustion engine constant speed load self-adaptation control method independent of throttle control is used to control the hydrogen internal combustion engine to drive the propeller to provide power, which comprises the following steps:

[0084] First, the independent control of the throttle opening of the hydrogen internal combustion engine is carried out, as shown in Figure 2 In the starting condition, in order to ensure the stable starting of the hydrogen internal combustion engine, a small throttle opening is selected, and the opening is 8%. In the warm-up condition, the hydrogen internal combustion engine speed is selected as 1500 r / min as the warm-up condition. In order to realize stable combustion and rapid warm-up in the warm-up condition, a small throttle opening is selected, and the opening is 15%, so as to ensure a small intake air amount and a relatively thick in-cylinder mixture, reduce the combustion cycle variation, and reduce the heat of the excess heated air, and accelerate the oil warming process. In the power output condition, the frequency of the output alternating current is required by the fixed frequency generator set, the target speed of the hydrogen internal combustion engine is fixed as 3000 r / min, the throttle opening is always kept as 100% full opening, the in-cylinder mixture is controlled to be in a lean combustion state, and the generation and emission of nitrogen oxide pollutants are reduced to the maximum extent.

[0085] Secondly, the hydrogen internal combustion engine speed control in the warm-up condition is carried out, as shown in Figure 3 The warm-up target speed is 1500 r / min. The throttle opening is kept as 15%, and the basic warm-up MAP is labeled as shown in Table 4, wherein the uppermost row represents the speed, the speed is taken as being near the warm-up target speed, the range is 1450 r / min-1650 r / min, and the step is 10 r / min; the leftmost column of numbers represents the oil temperature T, the range is -20-90°C, and the step is 5°C.

[0086] Table 4 shows the labeled basic warm-up MAP

[0087]

[0088] The specific control method is that the throttle opening is kept as 15%, the two-dimensional linear interpolation of the real-time speed n of the hydrogen internal combustion engine and the oil temperature T in the basic warm-up MAP is used to obtain the MAP execution parameters, the rough adjustment parameters including the hydrogen injection pulse width, the ignition advance angle and the hydrogen injection time are obtained by relying on the labeled MAP; the speed deviation of the real-time speed n and the warm-up target speed 1500 r / min is used for PID control calculation to obtain the fine PID control adjustment amount, including the fine adjustment amount of the hydrogen injection pulse width, the ignition advance angle and the hydrogen injection time. The two are added to obtain the actual execution control parameters, the speed of the hydrogen internal combustion engine is controlled to converge to the warm-up target speed 1500 r / min and keep stable, and the warm-up process ends.

[0089] Finally, the hydrogen internal combustion engine speed load adaptive control in the power output condition is carried out, as shown in Figure 4As shown in the figure. The target speed of the hydrogen internal combustion engine under power output conditions is 3000 r / min, with the throttle always kept at 100% full opening. The calibrated baseline MAP is shown in Table 5, where the top row represents the engine speed, ranging from 2850 r / min to 3150 r / min, with a step size of 10 r / min; the leftmost column represents the dummy variable load, ranging from 0% to 100%, with a step size of 5%.

[0090] Table 5. Basic work for MAP calibration: Schematic diagram

[0091]

[0092] The calculation method of the dummy variable load is as follows: Figure 5 As shown, the load variable is determined by the speed deviation and rail pressure deviation, and its calibration table is shown in Table 6. Based on the reference speed and reference rail pressure (injection pressure), the calibration boundaries are ±10% for speed deviation and ±50% for rail pressure deviation, and the load variable is calibrated accordingly. The reference speed is 3000 r / min, and the calibrated rail pressure is 6 bar. When the load demand of the hydrogen internal combustion engine fixed-frequency generator set changes, the hydrogen injection pressure fluctuates due to changes in the hydrogen consumption rate. Since the hydrogen flow rate of the hydrogen nozzle is strongly correlated with the injection pressure, fluctuations in injection pressure easily cause changes in the hydrogen injection quantity, resulting in significant speed fluctuations. The load variable calculation fully considers rail pressure changes, thereby eliminating this effect and improving the stability of the power generation frequency.

[0093] Table 6. Illustration of load variable calibration content

[0094]

[0095] The specific control method is as follows: The throttle state is determined by the target speed of the hydrogen internal combustion engine (3000 r / min), and the throttle state is kept at 100% fully open. A hydrogen internal combustion engine speed is determined based on the baseline MAP (Modular Mapping). To eliminate the influence of the instantaneous speed of the hydrogen internal combustion engine on constant speed control, the average speed of the engine is calculated, specifically the average of 20 instantaneous speeds (M=20), resulting in the average speed a_n. Two-dimensional linear interpolation is performed on the average speed a_n and the load value in the calibrated baseline MAP to obtain the MAP execution parameters, which provide a coarse correction to the speed over a large range. The speed deviation between the average speed a_n and the target speed of the hydrogen internal combustion engine is used to obtain the PID control adjustment amount, determining the PID adjustment parameters for a fine correction to the speed over a small range. Finally, the actual execution parameters are obtained by adding the MAP execution parameters and the PID control adjustment amount, controlling the hydrogen internal combustion engine speed to converge towards and stabilize towards the power output target speed, thus achieving constant-speed operation of the hydrogen internal combustion engine fixed-frequency generator set.

[0096] When the power supply load corresponding to the hydrogen internal combustion engine constant frequency generator set remains constant, under this control method, the set maintains constant rotating speed and power generation power, and outputs stable current; when the demand of the load for power generation power changes, it will cause disturbance of the rotating speed of the hydrogen internal combustion engine, under this control method, the hydrogen internal combustion engine set quickly responds to the disturbance, so that the rotating speed is always maintained at the target power generation rotating speed 3000r / min, ensuring the stability of the power generation frequency, and the power generation power is quickly adjusted to the power matched with the demand of the load, realizing the self-adaptation of the power generation power of the hydrogen internal combustion engine set, that is, the self-adaptation of the load of the hydrogen internal combustion engine.

[0097] Through this control method, in the application of driving propeller, the load and throttle state of the hydrogen internal combustion engine are decoupled, so that the hydrogen internal combustion engine stably outputs power according to the demand under the lean burn condition, and realizes constant speed operation and load self-adaptation.

[0098] Through this control method, in the application of controlling the hydrogen internal combustion engine constant frequency power generation, the load of the hydrogen internal combustion engine generator set is self-adapted in the power range of 0-10kW, when the load changes, the frequency of the output three-phase alternating current is always controlled at 50±0.2Hz, realizing the control of the dynamic load constant frequency power generation of the hydrogen internal combustion engine generator set.

[0099] Therefore, by adopting the hydrogen internal combustion engine constant speed load self-adaptation method and application decoupled from the throttle control, the constant speed operation and load self-adaptation of the hydrogen internal combustion engine under the condition of not depending on the throttle adjustment are realized, so that the intake air amount control of the hydrogen internal combustion engine under the conditions of starting, warming up and power output is more in line with the working condition demand; the hydrogen internal combustion engine responds faster to the real-time change of the load, and the rotating speed is more stable.

[0100] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for adaptive speed and load control of a hydrogen internal combustion engine without throttle control, characterized in that, Includes the following steps: S1. Set the throttle opening for the hydrogen internal combustion engine under the starting, warm-up, and power output conditions respectively. S2, Constant speed operation control during warm-up; S3, Constant speed load adaptive control under power output conditions; In S1, the throttle opening is kept constant under the conditions of starting, warm-up, and constant speed power output. In step S2, the constant-speed operation control during warm-up includes the following steps: S21. Under the calibrated basic warm-up MAP and warm-up throttle opening, the hydrogen internal combustion engine runs at the actual speed, which is 80%-120% of the target speed. S22. The PID control adjustment amount of the operating parameters is obtained by using the speed difference between the actual speed and the target speed. S23. Obtain the MAP execution parameters by combining the current actual speed and oil temperature of the hydrogen internal combustion engine with the data in the calibrated basic warm-up MAP. S24. Add the PID control adjustment to the MAP execution parameters to obtain the actual hydrogen internal combustion engine operating parameters and obtain the new actual speed. S25. Repeat S22-S24. The actual speed converges to the target speed. The hydrogen internal combustion engine maintains stable operation at the target speed until the warm-up process ends. In step S3, the constant-speed load adaptive control for power output conditions includes the following steps: S31. Determine the throttle opening for power output based on the target speed of the hydrogen internal combustion engine; S32. Under the calibrated basic working MAP and power output throttle opening, the hydrogen internal combustion engine operates at the actual speed, which is 80%-120% of the target speed. S33. Perform several readings of the transient speed and calculate the average value of the transient speed readings to obtain the average actual speed; S34. The PID control adjustment value of the operating parameters is obtained by the speed difference between the average actual speed and the target speed. S35. Combine the calibrated basic working MAP, average actual speed, and load variable to obtain the MAP execution parameters in the calibrated basic working MAP; the load variable is a dummy variable. S36. Add the MAP execution parameters and the PID control adjustment to obtain the actual hydrogen internal combustion engine operating parameters and obtain the new actual speed. S37. Repeat S33-S36 until the actual speed converges to the target speed, and the hydrogen internal combustion engine maintains stable operation at the target speed.

2. The method for adaptive constant speed and load of a hydrogen internal combustion engine without throttle control according to claim 1, characterized in that: The throttle opening is 5%-8% during startup, 10%-15% during warm-up, and 15%-100% during power output.

3. The method for adaptive constant speed load of a hydrogen internal combustion engine without throttle control according to claim 2, characterized in that: Under the aforementioned power output conditions, when the hydrogen internal combustion engine is running at a target speed of 25%-40% of its maximum speed, the throttle opening is 15%-20%; when the hydrogen internal combustion engine is running at a target speed of 40%-50% of its maximum speed, the throttle opening is 20%-25%; and when the hydrogen internal combustion engine is running at a target speed of more than 50% of its maximum speed, the throttle opening is 100%.

4. The method for adaptive constant speed load of a hydrogen internal combustion engine without throttle control according to claim 3, characterized in that: In S21, the actual engine speed and oil temperature are used as independent variables to calibrate the basic warm-up MAP. The parameter data of the calibrated basic warm-up MAP include hydrogen injection pulse width, ignition advance angle and hydrogen injection start time. In step S23, when the actual speed and oil temperature are values ​​that are not at the calibration point, the MAP execution parameters are determined by two-dimensional linear interpolation using the data from the nearest calibration point.

5. The method for adaptive constant speed load of a hydrogen internal combustion engine without throttle control according to claim 4, characterized in that: In S32, the actual rotational speed and load variables are used as independent variables to calibrate the basic working MAP. The parameter data of the calibrated basic working MAP include the hydrogen injection pulse width, ignition advance angle and hydrogen injection start time. In step S35, when the actual rotational speed and load variable values ​​are not the values ​​of the calibration point, the MAP execution parameters are determined by two-dimensional linear interpolation using the data from the nearest calibration point.

6. The method for adaptive constant speed load of a hydrogen internal combustion engine without throttle control according to claim 5, characterized in that: The load variable is a function of the speed difference between the average actual speed and the target speed, and the rail pressure difference between the actual rail pressure and the calibrated rail pressure. When the speed difference and rail pressure difference are values ​​from non-calibration points, the load variable value is determined by two-dimensional linear interpolation using data from the nearest calibration point.

7. An adaptive method for constant speed load of a hydrogen internal combustion engine, as described in any one of claims 1-6, is applied in the constant frequency power generation and propeller driving of a hydrogen internal combustion engine.

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