Transient Engine Control via Gas Density and EGR Rate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for controlling internal combustion engines during transient operation often result in increased NOx and particulate matter emissions due to reduced exhaust gas recirculation, which compromises engine response behavior.
Innovation Solution
A method that involves detecting an increase in target torque and increasing gas density and exhaust gas recirculation rate to maintain pollutant emission limits while ensuring rapid engine response, using an engine control unit to manage gas supply and recirculation, particularly through an electric compressor and variable turbine geometry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If exhaust gas recirculation rate is reduced to improve engine response behavior during transient operation, then engine response is improved, but NOx emissions increase
Solution Approach 1:
The patent changes the physical state of the intake charge by increasing its density through compression. This allows the engine to maintain high exhaust gas recirculation rates (improving NOx control) while still achieving rapid torque response, as the denser charge provides sufficient oxygen and combustion efficiency despite reduced fresh air intake.
2Object-generated harmful factors
If fuel injection quantity is limited to reduce particulate matter emissions, then soot emissions are reduced, but engine power output is limited
Solution Approach 1:
The patent increases the density of the intake charge through compression, which allows more oxygen to be packed into the combustion chamber. This enables higher fuel injection quantities (improving power output) while maintaining adequate oxygen supply for combustion, thereby reducing soot formation through improved air-fuel mixing and combustion efficiency.
3Object-generated harmful factors
If exhaust gas recirculation rate is increased to reduce NOx emissions, then NOx emissions are reduced, but engine response behavior deteriorates
Solution Approach 1:
The patent compensates for the negative effects of high exhaust gas recirculation rates by increasing the density of the intake charge. The compressed, denser charge provides sufficient oxygen and improves combustion efficiency, allowing the engine to maintain rapid torque response even with high EGR rates that would normally slow down the combustion process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces NOx emissions and maintains rapid engine response by increasing gas density and exhaust gas recirculation, allowing for quicker combustion chamber filling and minimizing the need for reduced fuel injection, thus achieving a balance between emission control and performance.
Implementation Method 1
increasing a density of gas to an increased density; supplying the increased density gas into a combustion chamber
Implementation Method 2
a respective exhaust gas flow through a turbine of a turbocharger
Implementation Method 3
recirculating exhaust gas discharged from the combustion chamber into the combustion chamber at an increased exhaust gas recirculation rate; In principle, NO x emissions can thus be reduced
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A method and an engine control unit for controlling an internal combustion engine (3) are provided, the method comprising: detecting (25) an increase of a target torque (82) to be provided by the internal combustion engine to an increased target torque (83); increasing (14, 16) a density of gas (11, 15, 23) to an increased density; supplying the gas (9) of the increased density into a combustion chamber of the internal combustion engine (3); and recirculating exhaust gas (19, 15) discharged from the combustion chamber into the combustion chamber at an increased exhaust gas recirculation rate (91, 92, 93) compared to a reference rate (98) applied during steady-state operation at the increased target torque.