6 results about "Mean effective pressure" patented technology

The invention relates to a cooperative control method and system for lean-burn emission of a marine low-zero carbon fuel engine. The method comprises the steps that real-time in-cylinder pressure and temperature data are collected, and an in-cylinder pressure curve and an in-cylinder temperature curve are obtained through time sequence alignment, filtering denoising and interpolation fitting processing; extracting time sequence data based on the curve, calculating average effective pressure and peak temperature in a cylinder to determine a current load interval, and marking a risk tag sequence; calculating the generation rate of the nitrogen oxides and the particulate matters by matching with reaction condition parameters, and extracting reverse variation characteristics to obtain strong mutual exclusion correlation of the nitrogen oxides and the particulate matters; and based on the associated starting model, predicting and controlling the output oil injection quantity and the air inflow adjusting quantity, calculating the transient time sequence lag quantity through a dynamic lag model, and after superposition, calibrating through a combustion phase matching algorithm to generate an oil injection timing and air inlet valve opening control instruction after transient adjustment. The method is adaptive to the combustion characteristics of low-zero-carbon fuel, emission contradictions are accurately captured, transient emission peak values are avoided, and multi-pollutant collaborative control is achieved.

The application discloses a lean-burn engine control method, device and engine system. The lean-burn engine control method comprises the following steps: obtaining a current torque and a target torque; when the current torque is less than the target torque, obtaining an average effective pressure and an excess air coefficient; when the average effective pressure is in a first pressure range and the excess air coefficient is in a first coefficient range, adjusting an ignition angle, increasing air content and combustible content in a cylinder, and increasing the current torque to the target torque. By using the above technical scheme, the current torque can be increased, the thermal efficiency can be ensured to be high, and the combustion center can be prevented from changing, the ignition angle can be prevented from being large, and the lean-burn engine can be prevented from being damaged by knocking.

The internal combustion engine (1) includes: an exhaust gas recirculation device having an exhaust gas recirculation control valve (9); a crankshaft angle sensor (11) for detecting the graphical mean effective pressure variation rate (cPi), which is an indicator of the combustion stability of the internal combustion engine (1); and a controller (10) for correcting the EGR rate of the exhaust gas recirculation device based on the combustion stability. If the graphical mean effective pressure variation rate (cPi) is less than a threshold for a specified number of cycles, the controller (10) increases the EGR rate by a specified amount. If the graphical mean effective pressure variation rate (cPi) is greater than or equal to the threshold, the EGR rate is immediately decreased.

An engine includes pistons, cylinders, a crankshaft, an intake manifold, an exhaust manifold, intake valves, exhaust valves, a fuel injector, and an Electronic Control Unit (ECU). The pistons actuate the crankshaft and are actuated by combustion reactions. Each cylinder houses a piston and contains a combustion reaction. The intake valves control a flow of a gas mixture to the cylinders. The fuel injector injects fuel into the cylinders that is combusted to create exhaust gases. The exhaust manifold includes a blowdown line and a scavenge line that deliver to a turbine and a catalytic conversion device, respectively. Each exhaust valve is disposed at a blowdown or scavenge line inlet and controls a flow of the exhaust gases to the exhaust manifold. The ECU deactivates exhaust valves associated with the blowdown line inlets when the engine operates with a Brake Mean Effective Pressure (BMEP) value less than a BMEP threshold.

The application discloses a diesel engine under-charge real-time monitoring and fault diagnosis method, which measures the parameters such as cylinder pressure and crank angle signals of the diesel engine by comprehensively applying various sensors, firstly reads or calculates the cylinder pressure at the top dead center, the maximum explosion pressure, the effective power feature and the average effective pressure, respectively, calculates the difference value of the above parameters and the threshold value of the corresponding normal working condition, respectively, and preliminarily diagnoses whether the diesel engine is under-charge; secondly, the fault degree of each parameter is judged by calculating the deviation rate of each parameter; finally, the overall fault degree is comprehensively analyzed according to the above fault degree; according to the fusion of the fault characteristic information, the typical fault characteristics are compared, so that the composite fault diagnosis of the diesel engine is realized, various characteristic information is fully utilized, the diagnosis speed and accuracy are improved, qualitative and quantitative analysis is realized, and the application of the diesel engine fault diagnosis level will be improved.

The application provides a combustion control method and system of an engine, the method comprising: obtaining a combustion fluctuation error of a plurality of combustion cycles after starting of the engine, the combustion fluctuation error being an absolute value of a difference between an actual combustion fluctuation amount determined by an average indicated mean effective pressure of a plurality of reference combustion cycles corresponding to the combustion cycle and a preset standard combustion fluctuation amount; calculating an EGR valve opening degree according to the combustion fluctuation error, a preset proportional link adjustment gain and a preset integral link adjustment gain; and controlling an actual EGR valve opening degree of the engine to be equal to the EGR valve opening degree. Based on this, the application can calculate the corresponding EGR valve opening degree in real time according to the actual operation condition of the engine, so that the application can obtain the EGR valve opening degree under various operation conditions of the engine in actual operation, and the overall performance of the EGR technology applied to the engine is improved.