CN-121978301-A - Natural gas engine gas component detection method, device and vehicle

CN121978301ACN 121978301 ACN121978301 ACN 121978301ACN-121978301-A

Abstract

The application discloses a method, a device and a vehicle for detecting the gas composition of a natural gas engine, which can comprehensively evaluate the gas composition of the natural gas engine through motor feedback torque, excess air coefficient and knocking signals, thereby more accurately judging the influence of the gas composition on knocking. The natural gas engine gas quality component detection method comprises the steps of obtaining a vibration signal of combustion of a natural gas engine cylinder, adjusting the natural gas engine to a preset gas quality detection point when the vibration signal is larger than or equal to a preset knock threshold value, obtaining motor feedback torque, an excess air coefficient and a knock signal when the vibration signal is at the preset gas quality detection point, calculating a gas quality knock influence coefficient based on the motor feedback torque, the excess air coefficient and the knock signal, and determining that the natural gas engine knocks due to gas quality influence when the gas quality knock influence coefficient is larger than or equal to the preset threshold value so as to determine the gas quality component difference of the natural gas engine.

Inventors

ZHAO XI
DONG WEITAO
ZHANG CHEN
ZHANG YAXIAO
ZHAN DONGHONG
LI WENDONG

Assignees

潍柴动力股份有限公司

Dates

Publication Date: 20260505
Application Date: 20251208

Claims (10)

1. The method for detecting the gas composition of the natural gas engine is characterized by comprising the following steps of: acquiring a vibration signal of combustion of a cylinder of a natural gas engine; When the vibration signal is larger than or equal to a preset knock threshold value, adjusting the natural gas engine to a preset gas detection point, and acquiring motor feedback torque, an excessive air coefficient and a knock signal when the natural gas engine is at the preset gas detection point; Calculating a gas knock influence coefficient based on the motor feedback torque, the excess air factor and the knock signal; And when the gas quality knocking influence coefficient is larger than or equal to a preset threshold value, determining that the natural gas engine knocks under the influence of the gas quality so as to determine the gas quality component difference of the natural gas engine.
2. The method for detecting a gas component of a natural gas engine according to claim 1, further comprising: When the natural gas engine knocks under the influence of gas, a lighting indication is sent out and low-knock power generation optimizing is carried out, wherein the low-knock power generation optimizing represents an adjustment working condition point.
3. The method for detecting a gas component of a natural gas engine according to claim 2, wherein performing low knock power generation optimizing comprises: Adjusting the current set working condition point until the vibration signal is smaller than a preset knock threshold value, and recording the adjusted first gas consumption rate; On the basis of the set working condition point, sequentially increasing the rotating speed and reducing the torque along a preset power line to obtain a second gas consumption rate of at least one second working condition point; when any second gas consumption rate is increased compared with the first gas consumption rate or the previous second gas consumption rate, taking the lowest point in the second gas consumption rates as a second working condition point; on the basis of the set working condition point, sequentially reducing the rotating speed and improving the torque along a preset power line to obtain a third gas consumption rate of at least one third working condition point; when any third gas consumption rate is increased compared with the second gas consumption rate or the previous third gas consumption rate, the lowest point in the third gas consumption rate is taken as the optimal power generation point under the current required power.
4. A method of detecting a gas composition of a natural gas engine according to claim 3, wherein when any of the second gas rates is higher than the first gas rate or the preceding second gas rate, the method includes the step of taking the lowest point of the second gas rates as the second operating point: When any second gas consumption rate is reduced compared with the first gas consumption rate, the rotating speed is increased and the torque is reduced along a preset power line until any second gas consumption rate is increased compared with the previous second gas consumption rate, and the lowest point in the second gas consumption rate is taken as a second working condition point; When any third gas consumption rate is higher than the second gas consumption rate or the previous third gas consumption rate, taking the lowest point in the third gas consumption rate as the optimal power generation point under the current required power, and comprising the following steps: And when any third gas consumption rate is reduced compared with the second gas consumption rate, reducing the rotating speed and improving the torque along the preset power line until any third gas consumption rate is increased compared with the previous third gas consumption rate, and taking the lowest point in the third gas consumption rate as the optimal power generation point under the current required power.
5. The natural gas engine gas composition detection method according to claim 1, wherein when the vibration signal is greater than or equal to a preset knock threshold, the natural gas engine gas composition detection method further comprises: detecting boundary conditions of a natural gas engine, wherein the boundary conditions of the natural gas engine comprise engine water temperature, intake manifold temperature and ambient temperature; the method for adjusting the natural gas engine to a preset gas quality detection point and obtaining the motor feedback torque, the excess air coefficient and the knocking signal when the natural gas engine is at the preset gas quality detection point comprises the following steps: When the boundary condition of the natural gas engine meets the following three conditions that the water temperature of the natural gas engine is in a preset water temperature range, the temperature of the air inlet manifold is in a preset temperature range and the ambient temperature is in a preset ambient temperature range, the natural gas engine is adjusted to a preset gas detection point, and motor feedback torque, an excessive air coefficient and a knocking signal at the preset gas detection point are obtained.
6. The natural gas engine gas composition detection method according to claim 1, wherein after adjusting the engine to a preset gas composition detection point, the natural gas engine gas composition detection method further comprises: Adjusting the electric control parameters of the natural gas engine to be within a preset electric control parameter range, wherein the electric control parameters comprise an advance angle, an EGR valve opening, a throttle valve opening and a bleed valve opening; The method for acquiring the motor feedback torque, the excess air coefficient and the knocking signal at the preset air quality detection point comprises the following steps: When the electric control parameters of the natural gas engine are adjusted to be within a preset electric control parameter range, the motor feedback torque, the excess air coefficient and the knocking signal at the preset gas detection point are obtained.
7. The natural gas engine gas composition detection method according to claim 1, wherein calculating a gas knock influence coefficient based on the motor feedback torque, the excess air coefficient, and the knock signal, comprises: Calculating a torque knock coefficient according to the feedback torque of the motor; calculating an excess air knock coefficient according to the excess air coefficient; Calculating an integral knock coefficient according to the knock signal; And calculating a gas knock influence coefficient according to the preset weight coefficients of the torque knock coefficient and the torque knock coefficient, the preset weight coefficients of the excessive air knock coefficient and the excessive air knock coefficient, and the preset weight coefficients of the integral knock coefficient and the integral knock coefficient.
8. The method for detecting a gas composition of a natural gas engine according to claim 7, further comprising: and determining a preset weight coefficient of the torque knocking coefficient, a preset weight coefficient of the excessive air knocking coefficient and a preset weight coefficient of the integral knocking coefficient according to the air inlet temperature and the water temperature.
9. A natural gas engine gas composition detection device, comprising: the acquisition module is used for acquiring vibration signals of combustion of the cylinder of the natural gas engine; The adjusting module is used for adjusting the natural gas engine to a preset gas quality detection point when the vibration signal is larger than or equal to a preset knock threshold value, and acquiring motor feedback torque, an excessive air coefficient and a knock signal when the natural gas engine is at the preset gas quality detection point; The calculation module is used for calculating a gas knocking influence coefficient based on the motor feedback torque, the excess air coefficient and the knocking signal; And the determining module is used for determining that the natural gas engine knocks under the influence of the gas quality when the gas quality knocking influence coefficient is larger than or equal to a preset threshold value so as to determine the gas quality component difference of the natural gas engine.
10. A vehicle, characterized by comprising: A natural gas engine; the natural gas engine gas composition detection apparatus of claim 9, wherein the natural gas engine gas composition detection apparatus is communicatively coupled to the natural gas engine.

Description

Natural gas engine gas component detection method, device and vehicle Technical Field The application relates to the technical field of natural gas engines, in particular to a method and a device for detecting gas components of a natural gas engine and a vehicle. Background Natural gas is widely used as a clean energy source in the fields of vehicles and power. Compared with gasoline or diesel engine, natural gas engine has the advantages of less pollutant emission, low running cost, etc. However, natural gas engines also face some unique technical challenges in actual operation, with knock issues during combustion being particularly pronounced. Currently, engines are typically equipped with a knock sensor for monitoring the vibration signal and determining therefrom whether knocking has occurred. However, it is difficult in the prior art to effectively distinguish and determine whether knocking is caused by a change in the composition of the gas. Conventional knock monitoring systems can only determine whether knocking has occurred, but cannot identify the cause of the knocking. Because of numerous factors that cause knocking, such as improper ignition angle, cooling system failure, carbon deposition, etc., if the influence of the gas component cannot be accurately identified, targeted control strategy adjustment cannot be performed. Disclosure of Invention The present application has been made to solve the above-mentioned technical problems. The embodiment of the application provides a method, a device and a vehicle for detecting the gas composition of a natural gas engine, which can comprehensively evaluate the gas composition of the natural gas engine through motor feedback torque, excess air coefficient and knocking signals, so that the influence of the gas composition on knocking can be accurately judged. According to a first aspect of the application, a natural gas engine gas quality component detection method is provided, and the method comprises the steps of obtaining a vibration signal of combustion of a cylinder of a natural gas engine, adjusting the natural gas engine to a preset gas quality detection point when the vibration signal is larger than or equal to a preset knock threshold value, obtaining motor feedback torque, an excessive air coefficient and a knock signal at the preset gas quality detection point, calculating a gas quality knock influence coefficient based on the motor feedback torque, the excessive air coefficient and the knock signal, and determining that the natural gas engine knocks under the influence of gas quality when the gas quality knock influence coefficient is larger than or equal to the preset threshold value so as to determine the gas quality component difference of the natural gas engine. As one possible implementation manner, the natural gas engine gas quality component detection method further comprises the steps of sending a lighting indication and performing low-knock power generation optimizing when the natural gas engine knocks under the influence of gas quality, wherein the low-knock power generation optimizing represents an adjustment working condition point. The low-knock power generation optimizing method comprises the steps of adjusting a current set working condition point until a vibration signal is smaller than a preset knock threshold value, recording the adjusted first gas consumption rate, sequentially increasing the rotating speed and reducing the torque along a preset power line on the basis of the set working condition point to obtain a second gas consumption rate of at least one second working condition point, taking the lowest point in the second gas consumption rate as the second working condition point when any second gas consumption rate is increased compared with the first gas consumption rate or the previous second gas consumption rate, sequentially reducing the rotating speed and increasing the torque along the preset power line on the basis of the set working condition point to obtain a third gas consumption rate of at least one third working condition point, and taking the lowest point in the third gas consumption rate as the optimal power generation point under the current required power when any third gas consumption rate is increased compared with the second gas consumption rate or the previous third gas consumption rate. As one possible implementation, when any second gas consumption rate is increased compared with the first gas consumption rate or the previous second gas consumption rate, the lowest point in the second gas consumption rate is taken as a second working condition point, and the method comprises the steps of increasing the rotating speed and the torque along a preset power line when any second gas consumption rate is reduced compared with the first gas consumption rate until any second gas consumption rate is increased compared with the previous second gas consumption rate, taking the lowest point in the second gas co