Engine minimum ignition density calculation method, engine control method and engine

Abstract

The invention relates to the field of engines, and discloses an engine minimum ignition density calculation method, an engine control method and an engine. The engine minimum ignition density calculation method comprises the following steps: calculating the engine minimum air inlet circulation total amount enabling the engine not to generate surge under the actual working condition according to a supercharger surge curve; and obtaining the single-cylinder circulation air inflow of the engine, and calculating the minimum ignition density of the engine according to the minimum total air inflow circulation amount of the engine, the single-cylinder circulation air inflow of the engine and the total cylinder number of the engine. According to the engine minimum ignition density calculation method, the engine control method and the engine, the minimum ignition density of the engine is calculated through the supercharger surge curve, the calibrated surge curves of an engine system adopting the same type of superchargers are the same, it is not needed to determine a MAP graph between the rotating speed and the ignition density of the engine under different working conditions through multiple repeated tests, the calibration workload is greatly reduced, and rack resources are saved; and the calculation precision of the ignition density is high, the robustness is improved, and the development cost and calibration cost of the engine are reduced.

Description

technical field [0001] The invention relates to the field of engines, in particular to a method for calculating the minimum ignition density of an engine, an engine control method and an engine. Background technique [0002] With the upgrading of emission regulations and the requirements for carbon dioxide emission and economy, engine technology is gradually applied to diesel and gasoline engines. Engines use VVA (Variable Valve Technology) to achieve cylinder deactivation to improve combustion efficiency, reduce pumping losses, and improve Thermal management efficiency, resulting in lower emissions and improved fuel economy. Cylinder deactivation refers to the operation of the engine to stop the intake, exhaust and fuel injection ignition of one or more cylinders. For the engine, both the deactivation time and the number of deactivated cylinders affect the engine control effect and overall machine performance. [0003] When the engine is deactivated, the more deactivated ...

AI Technical Summary

Problems solved by technology

[0007] 1. Because under the medium and low working conditions, each working condition will start the cylinder deactivation operation, so the minimum intake air volume that the supercharger can withstand in each working condition is different, which also requires that in all the ten thousand cylinder deactivation Under certain working conditions, the above-mentioned MAP maps are calibrated, and the workload of calibration is relatively large.

[0008] 2. After the engine is turned on and the cylinders are deactivated, the fuel injection volume of the single cylinder needs to be increased. In order to avoid the extreme deterioration of the single cylinder combustion, the intake air volume and intake pressure of the single cylinder will be increased, but increasing the intake air volume of the single cylinder cannot make up for the cylinder deactivation The resulting decrease in the total intake air volume, so the total intake air volume is reduced, will increase the pressure ratio, reduce the flow rate, and the operating efficiency point of the supercharger will approach the surge line. The more the total volume is reduced, the greater the pressure increase, so for a supercharger already perfectly matched to the full cylinder of the engine, the supercharger surges

However, it is more difficult to judge the surge of the platform, which makes the calibration of each working condition extremely difficult

[0009] 3. It is impossible to perform offline calibration, and must rely on the actual bench for calibration, which consumes a lot of bench resources and fuel resources

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