A combustion monitoring system for an engine

Abstract

The present invention relates to the technical field of diesel internal combustion engines, and particularly to a combustion monitoring system for an engine. The system includes: an engine data acquisition module for real-time acquisition of the combustion cylinder pressure, and also for periodic acquisition of the temperature data and exhaust gas data of the engine; a pressure characteristic analysis module for analyzing the pressure characteristics of the combustion cylinder; a temperature characteristic analysis module for analyzing the temperature characteristics of the combustion cylinder; an injection state monitoring module for analyzing the injection state and adjusting the injection advance angle of the next monitoring cycle according to the injection state; an exhaust gas monitoring module for analyzing the abnormal characteristics of the exhaust gas based on the nitrogen oxide concentration and particulate matter concentration collected within the management cycle; an injection management module for adjusting the adjustment process of the injection advance angle of the next management cycle; and a vibration monitoring module for adjusting the analysis process of injection abnormality within the management cycle. The present invention effectively improves the combustion monitoring efficiency of the engine.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel internal combustion engines, and particularly to a combustion monitoring system for an engine. Background Art

[0002] In recent years, with the increasingly strict environmental protection regulations and the increasing requirements for energy efficiency, traditional engine management systems have faced many challenges. In the current diesel engines, due to problems such as incomplete combustion, improper fuel injection advance angle setting, and uneven air-fuel mixture, fuel waste and excessive emissions have occurred during the combustion process.

[0003] Chinese Patent Publication No. CN116464565A discloses a combustion control method and a combustion system for an engine. The combustion control method for the engine includes: monitoring the real-time load output by the engine; dividing a plurality of fuel injection control states according to the real-time load of the engine; and in response to the fuel injection control state, adjusting the first moment when the main combustion mechanism of the engine starts fuel injection and the second moment when the disturbance mechanism of the engine starts fuel injection, so as to adjust the combustion speed of the air-fuel mixture in the engine, enable the engine to have different thermodynamic cycle modes during the power stroke, and increase the peak cylinder pressure and / or extend the duration of the peak cylinder pressure during the power stroke, so as to improve the thermal efficiency and power density, thereby enhancing the thermal conversion ability of the engine. The combustion system includes an engine, a collection unit, and a control unit. It can be seen that when controlling the combustion of the engine, this solution does not provide feedback on the combustion control process, and there are problems of low combustion control efficiency of the engine and low monitoring efficiency of the engine combustion. Summary of the Invention

[0004] The purpose of the present invention is to provide a combustion monitoring system for an engine to solve at least one of the problems existing in the prior art.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A combustion monitoring system for an engine includes:

[0007] An engine data acquisition module for real-time acquisition of the combustion cylinder pressure, and also for periodically acquiring the temperature data and exhaust gas data of the engine;

[0008] A pressure characteristic analysis module for analyzing the pressure characteristics of the combustion cylinder according to the combustion cylinder pressure acquired within a monitoring period;

[0009] A temperature characteristic analysis module for analyzing the temperature state of the combustion cylinder according to the intake temperature and outlet temperature of the combustion cylinder acquired within a monitoring period, and analyzing the temperature characteristics of the combustion cylinder according to the temperature state of the combustion cylinder;

[0010] An injection state monitoring module, which is used to analyze the injection state based on the pressure characteristics and temperature characteristics of the combustion cylinder within the monitoring period, and adjust the injection advance angle of the next monitoring period according to the injection state;

[0011] An exhaust gas monitoring module, which is used to analyze the abnormal characteristics of the exhaust gas based on the nitrogen oxide concentration and particulate matter concentration collected within the management period;

[0012] An injection management module, which is used to analyze the injection abnormality within the management period based on the analysis results of the injection state in each monitoring period within the management period, and adjust the adjustment process of the injection advance angle of the next management period according to the analysis results of the injection abnormality and the abnormal characteristics of the exhaust gas.

[0013] Further, the pressure characteristic analysis module includes a peak analysis unit, which is used to sort the combustion cylinder pressures collected within the monitoring period in descending order, record the maximum value of the combustion cylinder pressure as Fmax, and record the crankshaft angle corresponding to Fmax as D;

[0014] The peak analysis unit compares the maximum value Fmax of the combustion cylinder pressure with a preset peak value f to analyze the peak state of the combustion cylinder. The peak state includes normal and abnormal. If the peak state of the combustion cylinder pressure is abnormal, the peak characteristic is set as FT.

[0015] The pressure characteristic analysis module further includes a lag analysis unit, which is used to compare the crankshaft angle D corresponding to the maximum value of the combustion cylinder pressure with a preset target angle d0 to analyze the abnormality of the cylinder pressure lag angle. The abnormality of the cylinder pressure lag angle includes normal and abnormal. If the cylinder pressure lag angle is abnormal, the lag analysis unit analyzes the lag characteristic, and the analysis result of the lag characteristic includes ZH1 and ZH2.

[0016] Further, the pressure characteristic analysis module further includes a pressure characteristic analysis unit, which is used to analyze the pressure characteristics of the combustion cylinder based on the analysis results of the peak characteristic and the lag characteristic within the monitoring period to obtain the pressure characteristic YT of the combustion cylinder.

[0017] Further, the temperature characteristic analysis module is used to analyze the temperature state of the combustion cylinder based on the intake temperature t0 and the outlet temperature t1 of the combustion cylinder collected within the monitoring period. The temperature state includes a low temperature state, a normal state, and a high temperature state; if the temperature state of the combustion cylinder in the current monitoring period is the low temperature state, the temperature characteristic of the combustion cylinder is set as WT1, if the temperature state of the combustion cylinder in the current monitoring period is the normal state, the temperature characteristic of the combustion cylinder is set as WT2, and if the temperature state of the combustion cylinder in the current monitoring period is the high temperature state, the temperature characteristic of the combustion cylinder is set as WT3.

[0018] Further, the fuel injection state monitoring module includes a state analysis unit, which is used to analyze the fuel injection characteristic PT according to the pressure characteristic YT of the combustion cylinder and the temperature characteristic of the combustion cylinder within the monitoring period;

[0019] The state analysis unit analyzes the fuel injection state according to the fuel injection characteristic PT, and the fuel injection state includes normal and abnormal.

[0020] Further, the fuel injection state monitoring module further includes a fuel injection adjustment unit, which is used to adjust the fuel injection advance angle of the next monitoring period according to the analysis result of the fuel injection state within the monitoring period. If the fuel injection state in the current monitoring period is abnormal, the fuel injection advance angle of the next monitoring period is set to K2.

[0021] Further, the exhaust gas monitoring module includes an abnormality monitoring unit, which is used to compare the nitrogen oxide concentration collected in each monitoring period within the management period with the first preset concentration n0, and analyze the abnormality of the nitrogen oxide concentration according to the comparison result. The abnormality of the nitrogen oxide concentration includes normal and abnormal;

[0022] The abnormality monitoring unit is further used to compare the particulate matter concentration collected in each monitoring period within the management period with the second preset concentration m0, and analyze the abnormality of the particulate matter concentration according to the comparison result. The abnormality of the particulate matter concentration includes normal and abnormal.

[0023] Further, the exhaust gas monitoring module further includes a feature extraction unit, which analyzes the exhaust gas abnormality feature according to the analysis results of the nitrogen oxide concentration abnormality and the particulate matter concentration abnormality in each monitoring period within the management period to obtain the exhaust gas abnormality feature QT.

[0024] Further, the fuel injection management module is used to analyze the fuel injection abnormality within the management period according to the analysis results of the fuel injection state in each monitoring period within the management period, and adjust the adjustment process of the fuel injection advance angle of the next management period according to the analysis results of the fuel injection abnormality and the exhaust gas abnormality feature, where:

[0025] If j3 / J ≤ α, the fuel injection management module determines that the fuel injection in the current management period is normal and does not make adjustments;

[0026] If j3 / J > α, the fuel injection management module determines that the fuel injection in the current management period is abnormal, and adjusts the preset adjustment range of the next management period to DCA1, where DCA1 = DCA × (1 + η × QT);

[0027] Where, j3 is the number of monitoring periods with abnormal fuel injection states within the management period, α is the preset abnormal ratio, η is the preset adjustment ratio, DCA is the preset adjustment range, and J is the number of monitoring periods within the management period.

[0028] Furthermore, it further includes a vibration monitoring module, which is used to analyze the vibration state of the engine based on the engine vibration acceleration collected within the management cycle, and adjust the analysis process of fuel injection abnormality within the management cycle according to the analysis result, where:

[0029] If zp ≤ z0, the vibration monitoring module determines that the vibration state of the engine in the current management cycle is normal;

[0030] If zp > z0, the vibration monitoring module determines that the vibration state of the engine in the current management cycle is abnormal, and sets the preset abnormal ratio to α'; where zp is the average value of the engine vibration acceleration collected within the management cycle, and z0 is the preset vibration acceleration threshold.

[0031] The beneficial effects of the present invention are as follows: By monitoring and comprehensively analyzing the pressure, temperature, and fuel injection state of the combustion cylinder in real time, the fuel injection advance angle is dynamically optimized, enabling the engine to achieve the best combustion efficiency under various working conditions, thereby effectively reducing fuel consumption. Secondly, through the per-cycle analysis of the pressure and temperature states of the combustion cylinder, the system can timely detect abnormal phenomena during the combustion process, such as excessive pressure peaks or abnormal lag angles, thereby improving the combustion monitoring efficiency of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1 It is a schematic structural diagram of the combustion monitoring system for the engine in this embodiment.

[0034] Figure 2 It is a schematic structural diagram of the pressure characteristic analysis module in this embodiment.

[0035] Figure 3 It is a schematic structural diagram of the fuel injection state monitoring module in this embodiment.

[0036] Figure 4 It is a schematic structural diagram of the exhaust gas monitoring module in this embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] In order to more clearly illustrate the present invention, the following further describes the present invention in conjunction with preferred embodiments and drawings. Similar components in the drawings are represented by the same reference numerals. Those skilled in the art should understand that the following specific description is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention.

[0038] It should be noted that although terms such as first, second, and third may be used in the embodiments of the present application for description, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, without departing from the scope of the embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0039] Please refer to Figure 1 as shown, which is a schematic structural diagram of a combustion monitoring system for an engine in this embodiment. The system includes

[0040] an engine data acquisition module, which is used to collect the combustion cylinder pressure in real time, and is also used to periodically collect the temperature data and exhaust gas data of the engine. The temperature data of the engine includes the intake temperature and the exhaust temperature of the engine. The exhaust gas data of the engine includes the concentration of nitrogen oxides and the concentration of particulate matter. The particulate matter is PM2.5. It can be understood that in this embodiment, the collection methods of the combustion cylinder pressure, the temperature data of the engine, and the exhaust gas data are not specifically limited, and those skilled in the art can freely set them as long as the collection requirements of the combustion cylinder pressure, the temperature data of the engine, and the exhaust gas data are met. Among them, the combustion cylinder pressure can be measured in real time by an in-cylinder pressure sensor, the intake temperature can be collected by a temperature sensor installed at the intake pipe, the exhaust temperature can be collected by a temperature sensor installed at the exhaust pipe, the concentration of nitrogen oxides can be collected by a gas analyzer, and the concentration of particulate matter can be collected by a particulate matter sensor.

[0041] Please continue to refer to Figure 1 as shown, the system further includes:

[0042] a pressure characteristic analysis module, which is connected to the engine data acquisition module. The pressure characteristic analysis module is used to analyze the pressure characteristics of the combustion cylinder according to the combustion cylinder pressure collected within a monitoring period.

[0043] Specifically, in this embodiment, the setting of the monitoring period is not specifically limited, and those skilled in the art can freely set it as long as the setting requirements of the monitoring period are met. For example, the duration of one intake, compression, power, and exhaust cycle of the engine can be used as a monitoring period.

[0044] Please refer to Figure 2 as shown, the pressure characteristic analysis module includes:

[0045] a peak analysis unit, which is used to sort the combustion cylinder pressure collected within a monitoring period in descending order, record the maximum value of the combustion cylinder pressure as Fmax, and record the crankshaft angle corresponding to Fmax as D;

[0046] The peak analysis unit compares the maximum value Fmax of the combustion cylinder pressure with a preset peak value f to analyze the peak state of the combustion cylinder and analyze the peak characteristics based on the peak state, where:

[0047] If Fmax ≤ f, the peak analysis unit determines that the peak state of the combustion cylinder pressure is normal;

[0048] If Fmax > f, the peak analysis unit determines that the peak state of the combustion cylinder pressure is abnormal, sets the peak characteristic as FT, and sets FT = -(Fmax - f) / f; by sorting in descending order and comparing with the preset peak value, the normal and abnormal states of the combustion cylinder pressure can be clearly determined, providing a quantitative basis for subsequent analysis. By analyzing the peak characteristic FT, the degree of abnormality can be quantified, making subsequent judgments more intuitive, thereby improving the combustion monitoring efficiency of the engine.

[0049] Specifically, the crankshaft angle corresponding to Fmax in this embodiment can be obtained through a crankshaft position sensor.

[0050] It can be understood that in this embodiment, the setting of the preset peak value is not specifically limited, and those skilled in the art can freely set it as long as the setting requirements of the preset peak value are met. Among them, the optimal value of f is 100 bar.

[0051] Please continue to refer to Figure 2 As shown, the pressure characteristic analysis module further includes:

[0052] A lag analysis unit, which is used to compare the crankshaft angle D corresponding to the maximum value of the combustion cylinder pressure with a preset target angle d0 to analyze the abnormality of the cylinder pressure lag angle and analyze the lag characteristic based on the abnormality of the cylinder pressure lag angle, so as to provide a basis for adjusting the fuel injection advance angle, where:

[0053] When D < d0, if d0 - D ≤ LA, the lag analysis unit determines that the cylinder pressure lag angle is normal; if d0 - D > LA, the lag analysis unit determines that the cylinder pressure lag angle is abnormal and sets the lag characteristic as ZH1, and sets ZH1 = -exp[3×(d0 - D - LA) / DA - 3];

[0054] When D ≥ d0, if D - d0 ≤ LA, the lag analysis unit determines that the cylinder pressure lag angle is normal; if D - d0 > LA, the lag analysis unit determines that the cylinder pressure lag angle is abnormal and sets the lag characteristic as ZH2, and sets ZH2 = exp[3×(D - d0 - LA) / DA - 3]; by quantifying the lag characteristics ZH1 and ZH2, the deviation from the fuel injection advance moment can be directly reflected, providing an intuitive feedback, thereby improving the combustion monitoring efficiency of the engine;

[0055] Wherein, LA is the first preset angle, DA is the second preset angle, and LA < DA.

[0056] It can be understood that in this embodiment, the settings of the preset angles and the preset target angle are not specifically limited, and those skilled in the art can freely set them as long as the setting requirements of the preset angles and the preset target angle are met. Among them, the best value of d0 is 355°CA, the best value of LA is 2°CA, and the best value of DA is 5°CA.

[0057] Please continue to refer to Figure 2 As shown, the pressure characteristic analysis module further includes:

[0058] A pressure characteristic analysis unit, which is connected to the peak analysis unit and the hysteresis analysis unit. The pressure characteristic analysis unit is used to analyze the pressure characteristic YT of the combustion cylinder according to the analysis results of the peak characteristic and the hysteresis characteristic within the monitoring period, and set YT = w1×FT + w2×ZHx; where, w1 is the peak weight, w2 is the hysteresis weight, w1 + w2 = 1, ZHx is the analysis result of the hysteresis characteristic, x = 1, 2. When the peak state is normal, the value of FT is 0, and when the cylinder pressure lag angle is normal, the value of ZHx is 0; by combining the analysis of the peak characteristic and the hysteresis characteristic, the pressure characteristic YT of the combustion cylinder is formed to improve the accuracy of the fuel injection advance angle adjustment, and further improve the combustion monitoring efficiency of the engine.

[0059] It can be understood that in this embodiment, the settings of the weights are not specifically limited, and those skilled in the art can freely set them as long as the setting requirements of the weights are met. Among them, the best value of w1 is 0.65, and the best value of w2 is 0.35.

[0060] Please continue to refer to Figure 1 As shown, the system further includes:

[0061] A temperature characteristic analysis module, which is connected to the engine data acquisition module. The temperature characteristic analysis module is used to analyze the temperature state of the combustion cylinder according to the intake temperature t0 and the exhaust temperature t1 of the combustion cylinder collected within the monitoring period, and analyze the temperature characteristic of the combustion cylinder according to the temperature state of the combustion cylinder, where:

[0062] If t1 - t0 ≤ Td, the temperature characteristic analysis module determines that the temperature state of the combustion cylinder in the current monitoring period is a low temperature state, and sets the temperature characteristic of the combustion cylinder as WT1, and sets WT1 = exp{lg(Td - t1 + t0) / Tj};

[0063] If Td < t1 - t0 < Tg, the temperature characteristic analysis module determines that the temperature state of the combustion cylinder in the current monitoring period is a normal state, and sets the temperature characteristic of the combustion cylinder as WT2, and sets WT2 = 0;

[0064] If \(t1 - t0\geq Tg\), the temperature characteristic analysis module determines that the temperature state of the combustion cylinder in the current monitoring period is in a high-temperature state, sets the temperature characteristic of the combustion cylinder as WT3, and sets WT3 = -exp{lg(t1 - t0 - Tg) / Tj}; by monitoring the intake and exhaust temperatures, comprehensively evaluate the temperature state of the combustion cylinder to improve the recognition and analysis ability of the temperature state, thereby improving the accuracy of fuel injection advance angle adjustment, and further improving the combustion monitoring efficiency of the engine;

[0065] Among them, Td is the first preset temperature, Tg is the second preset temperature, Td < Tg, and Tj is the preset adjustment temperature threshold.

[0066] It can be understood that in this embodiment, the settings of each preset temperature and the preset adjustment temperature threshold are not specifically limited, and those skilled in the art can freely set them as long as the settings of each preset temperature and the preset adjustment temperature threshold meet the requirements. Among them, the best value of Td is 200 °C, the best value of Tg is 400 °C, and the best value of Tj is 50 °C.

[0067] Please continue to refer to Figure 1 As shown, the system further includes:

[0068] An injection state monitoring module, which is connected to the pressure characteristic analysis module and the temperature characteristic analysis module. The injection state monitoring module is used to analyze the injection state according to the pressure characteristic and the temperature characteristic of the combustion cylinder in the monitoring period, and adjust the fuel injection advance angle of the next monitoring period according to the injection state.

[0069] Please refer to Figure 3 As shown, the injection state monitoring module includes:

[0070] A state analysis unit, which is used to analyze the injection characteristic PT according to the pressure characteristic YT of the combustion cylinder and the temperature characteristic in the monitoring period, and set PT = x1×YT + x2×the temperature characteristic of the combustion cylinder;

[0071] The state analysis unit analyzes the injection state according to the injection characteristic. If \(|PT|\leq u0\), the state analysis unit determines that the injection state in the current monitoring period is normal; if \(|PT|>u0\), the state analysis unit determines that the injection state in the current monitoring period is abnormal; by combining the pressure characteristic and the temperature characteristic, dynamically analyze the injection characteristic PT to achieve accurate analysis of the injection state, thereby improving the accuracy of fuel injection advance angle adjustment, and further improving the combustion monitoring efficiency of the engine;

[0072] Among them, x1 is the pressure weight, x2 is the temperature weight, x1 + x2 = 1, and u0 is the preset state threshold.

[0073] It is understandable that in this embodiment, the setting of each weight and the preset state threshold is not specifically limited, and those skilled in the art can set them freely as long as the setting requirements of each weight and the preset state threshold are met. Among them, the optimal value of x1 is 0.4, the optimal value of x2 is 0.6, and the optimal value of u0 is 0.18.

[0074] Please continue to refer to Figure 3 As shown, the fuel injection state monitoring module further includes:

[0075] A fuel injection adjustment unit, which is connected to the state analysis unit. The fuel injection adjustment unit is used to adjust the fuel injection advance angle of the next monitoring cycle according to the analysis result of the fuel injection state within the monitoring cycle, where:

[0076] If the fuel injection state in the current monitoring cycle is normal, the fuel injection advance angle of the next monitoring cycle is not adjusted;

[0077] If the fuel injection state in the current monitoring cycle is abnormal, the fuel injection advance angle of the next monitoring cycle is set to K2, and it is set that K2 = K1 + DCA × PT; the fuel injection advance angle is adjusted according to the analysis result of the fuel injection state to improve the accuracy of the fuel injection advance angle adjustment, thereby improving the combustion monitoring efficiency of the engine;

[0078] Among them, K1 is the fuel injection advance angle of the current monitoring cycle, and DCA is the preset adjustment amplitude.

[0079] It is understandable that in this embodiment, the setting of the preset adjustment amplitude is not specifically limited, and those skilled in the art can set it freely as long as the setting requirements of the preset adjustment amplitude are met. Among them, the optimal value of DCA is 6°.

[0080] Please continue to refer to Figure 1 As shown, the system further includes:

[0081] An exhaust gas monitoring module, which is connected to the fuel injection state monitoring module. The exhaust gas monitoring module is used to analyze the exhaust gas abnormal characteristics according to the nitrogen oxide concentration and particulate matter concentration collected within the management cycle.

[0082] Specifically, in this embodiment, the setting of the management cycle is not specifically limited, and those skilled in the art can set it freely as long as the setting requirements of the management cycle are met. Among them, the management cycle can be set to 12h, 24h, etc.

[0083] Please refer to Figure 4 As shown, the exhaust gas monitoring module includes:

[0084] Anomaly monitoring unit, which is used to compare the nitrogen oxide concentration collected in each monitoring period within the management period with the first preset concentration n0, and analyze the abnormality of the nitrogen oxide concentration according to the comparison result, where:

[0085] If Nj ≤ n0, the anomaly monitoring unit determines that the nitrogen oxide concentration in the j-th monitoring period within the management period is normal;

[0086] If Nj > n0, the anomaly monitoring unit determines that the nitrogen oxide concentration in the j-th monitoring period within the management period is abnormal, where Nj is the nitrogen oxide concentration in the j-th monitoring period within the management period;

[0087] The anomaly monitoring unit is also used to compare the particulate matter concentration collected in each monitoring period within the management period with the second preset concentration m0, and analyze the abnormality of the particulate matter concentration according to the comparison result, where:

[0088] If Mj ≤ m0, the anomaly monitoring unit determines that the particulate matter concentration in the j-th monitoring period within the management period is normal;

[0089] If Mj > m0, the anomaly monitoring unit determines that the particulate matter concentration in the j-th monitoring period within the management period is abnormal, where Mj is the particulate matter concentration in the j-th monitoring period within the management period.

[0090] It can be understood that in this embodiment, the setting of each preset concentration is not specifically limited, and those skilled in the art can freely set it as long as the setting requirements of each preset concentration are met. Among them, the best value of n0 is 500 ppm, and the best value of m0 is 200 mg / m³.

[0091] Please continue to refer to Figure 4 As shown, the tail gas monitoring module further includes a feature extraction unit, which is connected to the anomaly monitoring unit. The feature extraction unit analyzes the tail gas anomaly feature QT according to the analysis results of the nitrogen oxide concentration abnormality and the particulate matter concentration abnormality in each monitoring period within the management period. It is set that: QT = lg(6j1 / J + 1) - 3×(j2 / J) 2 -2×(j2 / J) 3 ; By combining the analysis results of the nitrogen oxide concentration abnormality and the particulate matter concentration abnormality to analyze the tail gas anomaly feature, thereby quantifying the anomaly degree of the tail gas, and then improving the adjustment accuracy of the fuel injection advance angle, and finally improving the combustion monitoring efficiency of the engine;

[0092] Among them, j1 is the number of monitoring periods with abnormal nitrogen oxide concentration within the management period, j2 is the number of monitoring periods with abnormal particulate matter concentration within the management period, and J is the number of monitoring periods within the management period.

[0093] Please continue to refer to Figure 1As shown, the system further includes:

[0094] An injection management module, which is connected to the exhaust gas monitoring module. The injection management module is used to analyze the injection abnormality within the management cycle based on the analysis results of the injection status in each monitoring cycle within the management cycle, and adjust the adjustment process of the injection advance angle in the next management cycle according to the analysis results of the injection abnormality and the exhaust gas abnormality characteristics, where:

[0095] If j3 / J ≤ α, the injection management module determines that the injection in the current management cycle is normal and does not make adjustments;

[0096] If j3 / J > α, the injection management module determines that the injection in the current management cycle is abnormal, and adjusts the preset adjustment range in the next management cycle to DCA1, where DCA1 = DCA × (1 + η × QT); by combining the monitoring results of the injection status in each monitoring cycle within the management cycle and the analysis of the exhaust gas characteristics, the injection advance angle in the next cycle is dynamically adjusted to improve the accuracy of the injection advance angle adjustment, thereby improving the combustion monitoring efficiency of the engine;

[0097] Wherein, j3 is the number of monitoring cycles with abnormal injection status within the management cycle, α is the preset abnormal ratio, and η is the preset adjustment ratio.

[0098] It can be understood that in this embodiment, the settings of the preset abnormal ratio and the preset adjustment ratio are not specifically limited, and those skilled in the art can freely set them as long as the setting requirements of the preset abnormal ratio and the preset adjustment ratio are met. Among them, the best value of α is 0.15, and the best value of η is 0.3.

[0099] Please continue to refer to Figure 1 As shown, the system further includes:

[0100] A vibration monitoring module, which is connected to the injection management module. The vibration monitoring module is used to analyze the vibration state of the engine based on the engine vibration acceleration collected within the management cycle, and adjust the analysis process of the injection abnormality within the management cycle according to the analysis results, where:

[0101] If zp ≤ z0, the vibration monitoring module determines that the vibration state of the engine in the current management cycle is normal;

[0102] If zp > z0, the vibration monitoring module determines that the vibration state of the engine in the current management cycle is abnormal, and sets the preset abnormal ratio to α', where:

[0103] α' = α × exp[-(zp - z0) / z0];

[0104] Wherein, zp is the average value of the engine vibration acceleration collected within the management cycle, , zs is the s-th engine vibration acceleration data collected within the management period, S is the number of engine vibration acceleration data collected within the management period, and z0 is the preset vibration acceleration threshold; by setting the preset vibration acceleration threshold, the accuracy of engine vibration state analysis is improved, thereby improving the accuracy of fuel injection advance angle adjustment and ultimately improving the combustion monitoring efficiency of the engine.

[0105] Specifically, this embodiment is applied to the combustion monitoring of commercial diesel engines. By collecting in-cylinder pressure, intake and exhaust temperatures, and tail gas data, and performing data analysis on the collected data, the fuel injection advance angle is dynamically adjusted, improving the combustion monitoring efficiency of the engine.

[0106] It can be understood that in this embodiment, the setting of the preset vibration acceleration threshold is not specifically limited, and those skilled in the art can freely set it as long as the setting requirements of the preset vibration acceleration threshold are met. Among them, the optimal value of z0 is 2g.

[0107] Specifically, in this embodiment, the collection method of engine vibration acceleration is not specifically limited, and those skilled in the art can freely set it as long as the collection requirements of engine vibration acceleration are met. Among them, it can be collected by a vibration sensor.

[0108] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is impossible to enumerate all the implementation manners here. Any obvious changes or variations derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A combustion monitoring system for an engine, characterized in that: include: The engine data acquisition module is used to collect the combustion cylinder pressure in real time, and is also used to periodically collect the engine temperature data and exhaust data; A pressure characteristic analysis module, used to analyze the pressure characteristics of the combustion cylinder according to the combustion cylinder pressure collected during the monitoring period; A temperature characteristic analysis module is used to analyze the temperature state of the combustion cylinder according to the intake temperature and the outlet temperature of the combustion cylinder collected during the monitoring period, and to analyze the temperature characteristic of the combustion cylinder according to the temperature state of the combustion cylinder; The fuel injection state monitoring module is used to analyze the fuel injection state according to the pressure characteristics and temperature characteristics of the combustion cylinder in the monitoring cycle, and adjust the fuel injection advance angle of the next monitoring cycle according to the fuel injection state; Exhaust gas monitoring module, used to analyze abnormal exhaust gas characteristics based on the nitrogen oxide concentration and particulate matter concentration collected during the management cycle; The fuel injection management module is used to analyze the fuel injection abnormality in the management cycle according to the analysis results of the fuel injection status of each monitoring cycle in the management cycle, and adjust the adjustment process of the fuel injection advance angle in the next management cycle according to the analysis results of the fuel injection abnormality and the abnormal exhaust gas characteristics; The pressure characteristic analysis module includes a peak analysis unit, which is used to sort the combustion cylinder pressures collected during the monitoring period in descending order, and record the maximum value of the combustion cylinder pressure as Fmax, and record the crankshaft angle corresponding to Fmax as D; The peak analysis unit compares Fmax with a preset peak value f to analyze the peak state of the combustion cylinder, the peak state includes normal and abnormal. If the peak state of the combustion cylinder pressure is abnormal, the peak characteristic is set to FT, FT=-(Fmax-f) / f; The pressure characteristic analysis module further includes a hysteresis analysis unit, which is used to compare the crankshaft angle D corresponding to Fmax with the preset target angle d0 to analyze the abnormality of the cylinder pressure hysteresis angle. If the cylinder pressure hysteresis angle is abnormal, the hysteresis analysis unit analyzes the hysteresis characteristics, and the analysis results of the hysteresis characteristics include ZH1 and ZH2, ZH1=-exp[3×(d0-D-LA) / DA-3], ZH2=exp[3×(D-d0-LA) / DA-3]; Wherein, LA is the first preset angle, and DA is the second preset angle; The pressure characteristic analysis module further includes a pressure characteristic analysis unit, which is used to analyze the pressure characteristic of the combustion cylinder according to the analysis results of the peak characteristic and the hysteresis characteristic in the monitoring period to obtain the pressure characteristic YT of the combustion cylinder, YT=w1×FT+w2×ZHx; wherein w1 is the peak weight, w2 is the hysteresis weight, w1+w2=1, and ZHx is the analysis result of the hysteresis characteristic; The injection state monitoring module includes a state analysis unit, which is used to analyze the injection characteristics according to the pressure characteristics and temperature characteristics of the combustion cylinder during the monitoring period, and analyze the injection state according to the injection characteristics, and the injection state includes normal and abnormal.

2. The combustion monitoring system for an engine according to claim 1, characterized in that: The temperature characteristic analysis module analyzes the temperature state of the combustion cylinder based on the intake temperature t0 and the outlet temperature t1 of the combustion cylinder collected during the monitoring period, and the temperature state includes a low temperature state, a normal state and a high temperature state; if the temperature state of the combustion cylinder in the current monitoring period is a low temperature state, the temperature characteristic of the combustion cylinder is set to WT1; if the temperature state of the combustion cylinder in the current monitoring period is a normal state, the temperature characteristic of the combustion cylinder is set to WT2; if the temperature state of the combustion cylinder in the current monitoring period is a high temperature state, the temperature characteristic of the combustion cylinder is set to WT3.

3. The combustion monitoring system for an engine according to claim 2, characterized in that: The injection status monitoring module includes an injection adjustment unit, which is used to adjust the injection advance angle of the next monitoring cycle according to the analysis result of the injection status within the monitoring cycle. If the injection status of the current monitoring cycle is abnormal, the injection advance angle of the next monitoring cycle is set to K2, and K2=K1+DCA×PT is set, K1 is the injection advance angle of the current monitoring cycle, and DCA is the preset adjustment range.

4. The combustion monitoring system for an engine according to claim 3, characterized in that: The exhaust gas monitoring module includes an abnormality monitoring unit and a feature extraction unit, wherein the abnormality monitoring unit is used to compare the nitrogen oxide concentration collected in each monitoring period within the management period with the first preset concentration n0, and analyze the abnormality of the nitrogen oxide concentration according to the comparison result, and the abnormality of the nitrogen oxide concentration includes normal and abnormal; The abnormality monitoring unit is also used to compare the particle concentration collected in each monitoring period within the management period with the second preset concentration m0, and analyze the abnormality of the particle concentration according to the comparison result, and the abnormality of the particle concentration includes normal and abnormal.

5. The combustion monitoring system for an engine according to claim 4, characterized in that: The feature extraction unit analyzes the abnormal exhaust gas feature according to the analysis results of the abnormal nitrogen oxide concentration and the abnormal particulate matter concentration in each monitoring period within the management period to obtain the abnormal exhaust gas feature QT.

6. The combustion monitoring system for an engine according to claim 5, characterized in that: The injection management module is used to analyze the injection abnormality in the management cycle according to the analysis results of the injection state of each monitoring cycle in the management cycle, and adjust the adjustment process of the injection advance angle of the next management cycle according to the analysis results of the injection abnormality and the abnormal exhaust gas characteristics, wherein: If j3 / J≤α, the fuel injection management module determines that the fuel injection in the current management cycle is normal and does not make any adjustments; If j3 / J>α, the injection management module determines that the injection in the current management cycle is abnormal, and adjusts the preset adjustment range of the next management cycle to DCA1, setting DCA1=DCA×(1+η×QT); Among them, j3 is the number of monitoring cycles with abnormal injection status within the management cycle, α is the preset abnormality ratio, η is the preset adjustment ratio, DCA is the preset adjustment amplitude, and J is the number of monitoring cycles within the management cycle.

7. The combustion monitoring system for an engine according to claim 6, characterized in that: It also includes a vibration monitoring module, which is used to analyze the vibration state of the engine according to the engine vibration acceleration collected during the management period, and adjust the analysis process of the injection abnormality during the management period according to the analysis results, wherein: If zp≤z0, the vibration monitoring module determines that the vibration state of the engine in the current management period is normal; If zp>z0, the vibration monitoring module determines that the vibration state of the engine in the current management period is abnormal, and sets the preset abnormal proportion to α'; wherein zp is the average value of the engine vibration acceleration collected in the management period, and z0 is the preset vibration acceleration threshold.

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