Combustion monitoring system for engine

Abstract

The invention relates to the technical field of diesel internal combustion engines, in particular to a combustion monitoring system for an engine, and the system comprises an engine data collection module which is used for collecting the pressure of a combustion cylinder in real time and also used for periodically collecting the temperature data and tail gas data of the engine; the pressure characteristic analysis module is used for analyzing the pressure characteristics of the combustion cylinder; the temperature characteristic analysis module is used for analyzing temperature characteristics of the combustion cylinder; the oil injection state monitoring module is used for analyzing the oil injection state and adjusting the oil injection advance angle of the next monitoring period according to the oil injection state; the tail gas monitoring module is used for analyzing the abnormal characteristics of the tail gas according to the nitrogen oxide concentration and the particulate matter concentration collected in the management period; the oil injection management module is used for adjusting the adjusting process of the oil injection advance angle in the next management period; and the vibration monitoring module is used for adjusting the analysis process of the fuel injection abnormity in the management period. The combustion monitoring efficiency of the engine is effectively improved.

Description

Technical Field

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

[0002] In recent years, with the increasingly stringent environmental regulations and the increasing requirements for energy efficiency, traditional engine management systems are facing many challenges. Current diesel engines suffer from fuel waste and excessive emissions due to incomplete combustion, improper injection advance angle setting, and uneven mixing of air and fuel during the combustion process.

[0003] Chinese patent publication number CN116464565A discloses a combustion control method and a combustion system of an engine, wherein the combustion control method of the engine includes: monitoring the real-time load output by the engine; dividing a plurality of injection control states according to the real-time load of the engine; and adjusting the first moment when the main combustion mechanism of the engine starts to inject fuel and the second moment when the disturbance mechanism of the engine starts to inject fuel in response to the injection control state, so as to adjust the combustion speed of the oil-gas mixture in the engine, so that the engine has different thermodynamic cycle modes in the power stroke, and increases the cylinder pressure peak value of the power stroke and / or prolongs the duration of the cylinder pressure peak value to improve the thermal efficiency and power density, thereby improving the thermal conversion capacity of the engine. The combustion system includes an engine, a collection unit and a control unit; it can be seen that when the scheme controls the combustion of the engine, it does not provide feedback on the control process of the combustion, and there are problems of low efficiency in engine combustion control and low efficiency in monitoring the engine combustion. Summary of the invention

[0004] An object 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 object, the present invention adopts the following technical solutions: A combustion monitoring system for an engine, comprising: 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 within the management cycle according to the analysis results of the fuel injection status of each monitoring cycle within 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 fuel injection abnormality and the abnormal exhaust gas characteristics.

[0006] Further, 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 the maximum value Fmax of the combustion cylinder pressure with the 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 feature is set to FT; The pressure characteristic analysis module also includes a hysteresis 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 characteristics, and the analysis results of the lag characteristics include ZH1 and ZH2.

[0007] Furthermore, the pressure characteristic analysis module also includes a pressure characteristic analysis unit, and the pressure characteristic analysis unit 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.

[0008] Furthermore, 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 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.

[0009] Further, the injection state monitoring module includes a state analysis unit, which is used to analyze the injection feature PT according to the pressure feature YT of the combustion cylinder and the temperature feature of the combustion cylinder during the monitoring period; The state analysis unit analyzes the injection state according to the injection feature PT, and the injection state includes normal and abnormal.

[0010] Furthermore, the injection status monitoring module also 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.

[0011] 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, 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.

[0012] Furthermore, the exhaust gas monitoring module also 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.

[0013] Further, 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.

[0014] Furthermore, 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 result, 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.

[0015] The beneficial effects of the present invention are as follows: by real-time monitoring and comprehensive analysis of the pressure, temperature and injection state of the combustion cylinder, the injection advance angle is dynamically optimized, so that the engine can achieve the best combustion efficiency under various working conditions, thereby effectively reducing fuel consumption. Secondly, through the cycle-by-cycle analysis of the pressure and temperature state of the combustion cylinder, the system can promptly detect abnormal phenomena in the combustion process, such as excessive pressure peak or abnormal lag angle, thereby improving the combustion monitoring efficiency of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 Schematic diagram of the structure of the combustion monitoring system for the engine according to this embodiment.

[0018] Figure 2 Schematic diagram of the structure of the pressure characteristic analysis module of this embodiment.

[0019] Figure 3 Schematic diagram of the structure of the fuel injection status monitoring module of this embodiment.

[0020] Figure 4 Schematic diagram of the structure of the exhaust gas monitoring module of this embodiment. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0022] It should be noted that, although the terms first, second, third, etc. may be used to describe in the embodiments of the present application, 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.

[0023] See also Figure 1As shown, it is a schematic diagram of the structure of the combustion monitoring system for the engine of this embodiment, and the system includes: 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's temperature data and exhaust gas data, wherein the engine's temperature data includes the engine's intake temperature and exhaust temperature, and the engine's exhaust gas data includes nitrogen oxide concentration and particulate matter concentration, wherein the particulate matter is PM2.5; it can be understood that in this embodiment, no specific limitation is made on the collection method of the combustion cylinder pressure, the engine's temperature data and the exhaust gas data, and those skilled in the art can freely set it, as long as the collection requirements of the combustion cylinder pressure, the engine's temperature data and the exhaust gas data are met, wherein 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 nitrogen oxide concentration can be collected using a gas analyzer, and the particulate matter concentration can be collected by a particulate matter sensor.

[0024] Please continue reading Figure 1 As shown, the system also includes: A pressure characteristic analysis module is connected to the engine data acquisition module, and is used to analyze the pressure characteristics of the combustion cylinder according to the combustion cylinder pressure acquired during a monitoring period.

[0025] Specifically, the setting of the monitoring cycle is not specifically limited in this embodiment, and technical personnel in this field can set it freely as long as the setting requirements of the monitoring cycle are met. For example, the duration of the engine completing the four stages of intake, compression, power and exhaust can be used as a monitoring cycle.

[0026] See also Figure 2 As shown, 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 the maximum value Fmax of the combustion cylinder pressure with the preset peak value f to analyze the peak state of the combustion cylinder, and analyzes the peak characteristics according to the peak state, wherein: If Fmax≤f, the peak analysis unit determines that the peak state of the combustion cylinder pressure is normal; If Fmax>f, the peak analysis unit determines that the peak state of the combustion cylinder pressure is abnormal, and sets the peak characteristic to FT, setting 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, and by analyzing the peak characteristic FT to quantify the degree of abnormality, subsequent judgments are more intuitive, thereby improving the combustion monitoring efficiency of the engine.

[0027] Specifically, the crankshaft angle corresponding to Fmax described in this embodiment can be obtained through a crankshaft position sensor.

[0028] It can be understood that the setting of the preset peak value is not specifically limited in this embodiment, and those skilled in the art can set it freely as long as the setting requirements of the preset peak value are met, wherein the optimal value of f is 100 bar.

[0029] Please continue reading Figure 2 As shown, the pressure characteristic analysis module also includes: A hysteresis analysis unit is used to compare the crankshaft angle D corresponding to the maximum value of the combustion cylinder pressure with the preset target angle d0 to analyze the abnormality of the cylinder pressure hysteresis angle, and analyze the hysteresis characteristics according to the abnormality of the cylinder pressure hysteresis angle to provide a basis for adjusting the injection advance angle, wherein: When D<d0, if d0-D≤LA, the hysteresis analysis unit determines that the cylinder pressure hysteresis angle is normal; if d0-D>LA, the hysteresis analysis unit determines that the cylinder pressure hysteresis angle is abnormal, and sets the hysteresis characteristic to ZH1, setting ZH1=-exp[3×(d0-D-LA) / DA-3]; When D≥d0, if D-d0≤LA, the hysteresis analysis unit determines that the cylinder pressure hysteresis angle is normal; if D-d0>LA, the hysteresis analysis unit determines that the cylinder pressure hysteresis angle is abnormal, and sets the hysteresis characteristic to ZH2, setting ZH2=exp[3×(D-d0-LA) / DA-3]; by quantifying the hysteresis characteristics ZH1 and ZH2, it is possible to directly reflect the deviation from the advance injection timing, provide intuitive feedback, and thus improve the combustion monitoring efficiency of the engine; Wherein, LA is a first preset angle, DA is a second preset angle, and LA<DA.

[0030] It can be understood that, in this embodiment, the setting of each preset angle and the preset target angle is not specifically limited, and those skilled in the art can set it freely as long as the setting requirements of each preset angle and the preset target angle are met, among which the optimal value of d0 is 355°CA, the optimal value of LA is 2°CA, and the optimal value of DA is 5°CA.

[0031] Please continue reading Figure 2As shown, the pressure characteristic analysis module also includes: A pressure characteristic analysis unit 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; wherein 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 injection advance angle adjustment, thereby improving the combustion monitoring efficiency of the engine.

[0032] It is understandable that the present embodiment does not specifically limit the setting of each weight, and those skilled in the art can freely set it as long as the setting requirements of each weight are met, among which the best value of w1 is 0.65, and the best value of w2 is 0.35.

[0033] Please continue reading Figure 1 As shown, the system also includes: A temperature characteristic analysis module is connected to the engine data acquisition module, and is used to analyze the temperature state of the combustion cylinder according to the intake temperature t0 and the outlet temperature t1 of the combustion cylinder acquired during the monitoring period, and analyze the temperature characteristics of the combustion cylinder according to the temperature state of the combustion cylinder, wherein: 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 to WT1, setting WT1=exp{lg(Td-t1+t0) / Tj}; 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 normal, and sets the temperature characteristic of the combustion cylinder to WT2, setting WT2=0; If t1-t0≥Tg, the temperature characteristic analysis module determines that the temperature state of the combustion cylinder in the current monitoring period is a high temperature state, and sets the temperature characteristic of the combustion cylinder to WT3, setting WT3=-exp{lg(t1-t0-Tg) / Tj}; by monitoring the intake and exhaust temperatures, the temperature state of the combustion cylinder is comprehensively evaluated to improve the recognition and analysis capabilities of the temperature state, thereby improving the accuracy of the injection advance angle adjustment, and further improving the combustion monitoring efficiency of the engine; Wherein, Td is the first preset temperature, Tg is the second preset temperature, Td<Tg, and Tj is the preset adjustment temperature threshold.

[0034] It can be understood that in this embodiment, there is no specific limitation on the setting of each preset temperature and the preset adjustment temperature threshold. Those skilled in the art can set them freely as long as the setting requirements of each preset temperature and the preset adjustment temperature threshold are met. Among them, the optimal value of Td is 200°C, the optimal value of Tg is 400°C, and the optimal value of Tj is 50°C.

[0035] Please continue reading Figure 1 As shown, the system also includes: An injection status monitoring module is connected to the pressure characteristic analysis module and the temperature characteristic analysis module. The injection status monitoring module is used to analyze the injection status according to the pressure characteristics and the temperature characteristics of the combustion cylinder within a monitoring period, and adjust the injection advance angle of the next monitoring period according to the injection status.

[0036] See also Figure 3 As shown, the injection status monitoring module includes: A state analysis unit, which is used to analyze the injection characteristic PT according to the pressure characteristic YT and the temperature characteristic of the combustion cylinder during the monitoring period, and set PT=x1×YT+x2×the temperature characteristic of the combustion cylinder; The state analysis unit analyzes the injection state according to the injection characteristics. If |PT|≤u0, the state analysis unit determines that the injection state of the current monitoring cycle is normal; if |PT|>u0, the state analysis unit determines that the injection state of the current monitoring cycle is abnormal; by combining the pressure characteristics and the temperature characteristics, the injection characteristics PT are dynamically analyzed to achieve accurate analysis of the injection state, thereby improving the accuracy of the injection advance angle adjustment, and further improving the combustion monitoring efficiency of the engine; Among them, x1 is the pressure weight, x2 is the temperature weight, x1+x2=1, and u0 is the preset state threshold.

[0037] It can be understood that the present embodiment does not specifically limit the setting of each weight and the preset state threshold, and those skilled in the art can freely set them as long as the setting requirements of each weight and the preset state threshold are met, among which 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.

[0038] Please continue reading Figure 3 As shown, the injection status monitoring module also includes: The fuel injection adjustment unit is connected to the state analysis unit, and is used to adjust the fuel injection advance angle of the next monitoring cycle according to the analysis result of the fuel injection state in the monitoring cycle, wherein: If the injection status of the current monitoring cycle is normal, the injection advance angle of the next monitoring cycle will not be adjusted; If the injection state 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; the injection advance angle is adjusted according to the analysis result of the injection state to improve the accuracy of the injection advance angle adjustment, thereby improving the combustion monitoring efficiency of the engine; Among them, K1 is the injection advance angle of the current monitoring cycle, and DCA is the preset adjustment range.

[0039] It can be understood that the setting of the preset adjustment range is not specifically limited in this embodiment, and those skilled in the art can freely set it as long as the setting requirements of the preset adjustment range are met, wherein the best value of DCA is 6°.

[0040] Please continue reading Figure 1 As shown, the system also includes: An exhaust gas monitoring module is connected to the fuel injection status monitoring module, and is used to analyze abnormal exhaust gas characteristics according to nitrogen oxide concentration and particulate matter concentration collected during a management cycle.

[0041] Specifically, the present embodiment does not specifically limit the setting of the management period, and those skilled in the art can freely set it as long as the setting requirements of the management period are met. The management period can be set to 12 hours, 24 hours, etc.

[0042] See also Figure 4 As shown, the exhaust gas monitoring module includes: 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, wherein: If Nj≤n0, the abnormal monitoring unit determines that the nitrogen oxide concentration in the jth monitoring period within the management period is normal; If Nj>n0, the abnormal monitoring unit determines that the nitrogen oxide concentration in the jth monitoring period within the management period is abnormal, and Nj is the nitrogen oxide concentration in the jth monitoring period within the management period; 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, wherein: If Mj≤m0, the abnormal monitoring unit determines that the concentration of particulate matter in the jth monitoring period within the management period is normal; If Mj>m0, the abnormality monitoring unit determines that the concentration of particulate matter in the jth monitoring period within the management period is abnormal, and Mj is the concentration of particulate matter in the jth monitoring period within the management period.

[0043] It can be understood that the present embodiment does not specifically limit the setting of each preset concentration, and those skilled in the art can freely set it as long as the setting requirements of each preset concentration are met, among which the optimal value of n0 is 500 ppm, and the optimal value of m0 is 200 mg / m³.

[0044] Please continue reading Figure 4 As shown, the exhaust gas monitoring module also includes a feature extraction unit, which is connected to the abnormal monitoring unit. The feature extraction unit analyzes the exhaust gas abnormality feature QT according to the analysis results of the abnormality of nitrogen oxide concentration and the abnormality of particulate matter concentration in each monitoring period within the management period, and sets: QT=lg(6j1 / J+1)-3×(j2 / J) 2 -2×(j2 / J) 3 ; By combining the analysis results of nitrogen oxide concentration abnormality and particulate matter concentration abnormality to analyze the abnormal characteristics of exhaust gas, the abnormal degree of exhaust gas can be quantified, thereby improving the adjustment accuracy of injection advance angle, and finally improving the combustion monitoring efficiency of the engine; Among them, j1 is the number of monitoring cycles with abnormal nitrogen oxide concentration within the management period, j2 is the number of monitoring cycles with abnormal particulate matter concentration within the management period, and J is the number of monitoring cycles within the management period.

[0045] Please continue reading Figure 1 As shown, the system also includes: The fuel injection management module is connected to the exhaust gas monitoring module, and is used to analyze the fuel injection abnormality in the management cycle according to the analysis results of the fuel injection state in 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 exhaust gas abnormal 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); by combining the monitoring results of the injection state of each monitoring cycle in the management cycle with the analysis of the exhaust gas characteristics, the injection advance angle of 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; Among them, j3 is the number of monitoring cycles with abnormal injection status within the management cycle, α is the preset abnormality ratio, and η is the preset adjustment ratio.

[0046] It can be understood that, in this embodiment, there is no specific limitation on the setting of the preset abnormality ratio and the preset adjustment ratio, and those skilled in the art can set them freely as long as the setting requirements of the preset abnormality ratio and the preset adjustment ratio are met, where the optimal value of α is 0.15, and the optimal value of η is 0.3.

[0047] Please continue reading Figure 1 As shown, the system also includes: A vibration monitoring module connected to the fuel injection management module, the vibration monitoring module 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 fuel injection abnormality during the management period according to the analysis result, 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', setting: α'=α×exp[-(zp-z0) / z0]; Among them, zp is the average value of engine vibration acceleration collected during the management period, , zs is the sth engine vibration acceleration data collected during the management cycle, S is the number of engine vibration acceleration data collected during the management cycle, and z0 is the preset vibration acceleration threshold; by setting the preset vibration acceleration threshold to improve the accuracy of engine vibration state analysis, the accuracy of injection advance angle adjustment is improved, and finally the combustion monitoring efficiency of the engine is improved.

[0048] Specifically, this embodiment is applied to combustion monitoring of commercial diesel engines. By collecting in-cylinder pressure, intake and exhaust temperature and exhaust gas data and performing data analysis on the collected data, the injection advance angle is dynamically adjusted, thereby improving the combustion monitoring efficiency of the engine.

[0049] It can be understood that the present embodiment does not specifically limit the setting of the preset vibration acceleration threshold, and those skilled in the art can freely set it as long as the setting requirements of the preset vibration acceleration threshold are met, wherein the best value of z0 is 2g.

[0050] Specifically, the present embodiment does not specifically limit the method for collecting the engine vibration acceleration, and those skilled in the art can freely set it as long as the requirements for collecting the engine vibration acceleration are met, wherein the vibration acceleration can be collected through a vibration sensor.

[0051] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection 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 within the management cycle according to the analysis results of the fuel injection status of each monitoring cycle within 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 fuel injection abnormality and the abnormal exhaust gas characteristics.

2. The combustion monitoring system for an engine according to claim 1, characterized in that: 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 the maximum value Fmax of the combustion cylinder pressure with the 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 feature is set to FT; The pressure characteristic analysis module also includes a hysteresis 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 characteristics, and the analysis results of the lag characteristics include ZH1 and ZH2.

3. The combustion monitoring system for an engine according to claim 2, characterized in that: 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.

4. The combustion monitoring system for an engine according to claim 3, characterized in that: 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 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, and 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.

5. The combustion monitoring system for an engine according to claim 4, characterized in that: The injection state monitoring module includes a state analysis unit, which is used to analyze the injection feature PT according to the pressure feature YT of the combustion cylinder and the temperature feature of the combustion cylinder during the monitoring period; The state analysis unit analyzes the injection state according to the injection feature PT, and the injection state includes normal and abnormal.

6. The combustion monitoring system for an engine according to claim 5, characterized in that: The injection status monitoring module also 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 in 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.

7. The combustion monitoring system for an engine according to claim 6, characterized in that: 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, 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.

8. The combustion monitoring system for an engine according to claim 7, characterized in that: The exhaust gas monitoring module also 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.

9. The combustion monitoring system for an engine according to claim 8, 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.

10. The combustion monitoring system for an engine according to claim 1, 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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