Engine Mode Control via Fuel-Air Ratio Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbocharged internal combustion engines face slow transient response times when switching from low to high loads due to the time lag in increasing boost pressure, leading to insufficient air for clean combustion and potential black smoke, and existing engine control methods do not effectively manage transitions between economy and performance modes to minimize this impact.
Innovation Solution
A method and system for automatically shifting the engine operating mode between economy and performance modes based on determining the current fuel-air ratio, comparing it to predetermined limits, and using time and intensity thresholds to decide when to switch modes, ensuring efficient fuel usage and reduced emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine operates in economy mode with low speed and low loads, then fuel efficiency is improved, but the transient response time to high loads becomes slow
Solution Approach 1:
The control system performs preliminary actions by predicting future load demands based on current operating conditions and driver behavior patterns. When a transient load increase is anticipated, the system proactively adjusts fuel injection and air supply parameters in advance, so that when the actual load demand occurs, the engine is already prepared to respond quickly without sacrificing economy mode fuel efficiency during steady-state operation.
Solution Approach 2:
The system dynamically adapts operating parameters based on real-time conditions. It continuously monitors engine load, speed, and other parameters to determine the optimal balance between economy and performance modes. The control strategy dynamically adjusts fuel-air ratio, injection timing, and turbocharger control to achieve quick transient response when needed while maintaining fuel-efficient operation during steady-state low-load conditions.
2Power
If additional fuel is injected to increase engine speed during transient loads, then engine power is improved, but insufficient air for clean combustion causes black smoke
Solution Approach 1:
The control system employs feedback mechanisms by continuously monitoring combustion quality, air supply conditions, and exhaust parameters. When a transient load increase is detected, the system adjusts fuel injection and air supply in a coordinated manner based on real-time feedback, ensuring that the fuel-air ratio remains within combustion limits. This feedback control prevents black smoke formation while maintaining the required engine power during transient operations.
Solution Approach 2:
The system changes multiple operating parameters simultaneously and coordinately during transient events. When engine speed needs to increase, the control strategy doesn't just increase fuel injection - it also adjusts air supply parameters, injection timing, and turbocharger control parameters in a coordinated fashion. This multi-parameter adjustment ensures that combustion remains clean while achieving the required power increase, avoiding black smoke formation.
3Stress or pressure
If the turbocharger compressor speed is increased to raise boost pressure, then intake manifold air pressure is improved, but the time lag reduces transient response performance
Solution Approach 1:
The control system performs preliminary actions by anticipating transient load demands and proactively adjusting turbocharger compressor speed and fuel injection in advance. When a transient event is predicted based on current operating conditions and driver behavior patterns, the system begins increasing boost pressure before the actual load demand occurs, reducing the perceived time lag while maintaining efficient operation during steady-state conditions.
Solution Approach 2:
The control system acts as an intermediary by coordinating multiple subsystems (turbocharger control, fuel injection, air supply) to work together harmoniously. During transient events, the control strategy mediates between the need for quick boost pressure increase and fuel injection timing, ensuring that all parameters are adjusted in optimal sequence and magnitude. This coordinated control reduces time lag while preventing combustion issues.
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 allows for seamless transitions between engine modes, improving fuel efficiency, reducing emissions, and maintaining performance by ensuring sufficient air for combustion, thus minimizing the impact on transient performance and operator experience.
Implementation Method 1
Exhaust gas drives a turbine of the turbocharger which, in turn, drives a compressor of the turbocharger
Implementation Method 2
A turbocharged engine may increase the intake manifold air pressure by controlling a compressor
Implementation Method 3
For engines that burn an air fuel mixture, whether gaseous or liquid fuel
Data Source
AI summary
This disclosure relates to a method of controlling an engine and more particularly for controlling the transition between operating modes of an internal combustion engine such as between an economy mode and a performance mode. The method comprising the steps of determining a current fuel-air ratio at which the engine is operating and comparing it with a predetermined fuel-air ratio limit. The time duration for which the current fuel air-ratio is below the fuel-air ratio limit is determined and compared with a predetermined waiting time threshold value. A count is triggered, which is based on a difference between the current fuel-air ratio and the fuel-air ratio limit when the engine is operating at a current fuel-air ratio which is below the fuel-air ratio limit and this is compared with an intensity threshold value. The operating mode is shifted from the performance mode to the economy mode when both the time duration and the count exceed the waiting time threshold value and the intensity threshold value respectively. The operating mode is automatically shifted back to the performance mode when the current fuel-air ratio reaches or exceeds the fuel ratio limit. The method alternatively comprises using the air-fuel ratio, instead of the fuel-air ratio, and the switch from performance mode to economy mode only occurs when the current air-fuel is above a predetermined air-fuel limit and it remains above the predetermined air-fuel limit until two other predetermined thresholds have been reached.