Air Intake Control for NO Adsorber Regeneration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for controlling air intake flow in internal combustion engines, particularly for regenerating nitric oxide adsorbers, are ineffective due to reliance on fixed-duration and air-fuel ratio adjustments, which fail to achieve precise and fast variations necessary for efficient nitric oxide reduction and adsorber regeneration.
Innovation Solution
A method and device that utilize an electronic control system with a combination of feed-forward and feedback computing branches to precisely control air intake flow, incorporating an airflow computing block that adjusts the air-fuel ratio based on real-time exhaust gas oxygen concentration and engine conditions, enabling rapid and accurate switching between accumulation and regeneration steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fixed-duration and air-fuel ratio adjustments are used for nitric oxide adsorber regeneration, then the control system is simple to implement, but the precision and speed of air-fuel ratio variation are insufficient
Solution Approach 1:
The control system is segmented into two distinct computing branches: a feed-forward branch that pre-calculates the reference airflow based on engine operating parameters, and a feedback branch that measures actual exhaust oxygen concentration and adjusts the control signal accordingly. This segmentation allows each branch to specialize in specific tasks, achieving high precision without excessive overall system complexity.
Solution Approach 2:
The feed-forward computing branch performs preliminary calculations to determine the reference airflow value before the actual regeneration process begins. By pre-calculating the required air intake based on engine load, speed, and other parameters, the system prepares the optimal control signal in advance, enabling rapid response when regeneration is initiated without waiting for feedback loops to detect and react to changes.
2Speed
If conventional air intake control methods are used, then the control system is easy to operate, but the switching speed between accumulation and regeneration steps is too slow
Solution Approach 1:
The feed-forward computing branch continuously calculates the reference airflow value based on current engine operating conditions before regeneration is actually needed. This preliminary calculation ensures that when the control system decides to switch to regeneration mode, the optimal airflow setpoint is already prepared, enabling immediate switching without delay for calculation or adjustment.
Solution Approach 2:
The feedback computing branch continuously monitors the actual exhaust oxygen concentration and compares it with the target value. This real-time feedback allows the system to detect when regeneration should begin or end and immediately adjusts the air intake control signal accordingly, enabling rapid switching between accumulation and regeneration modes based on actual atmospheric conditions in the combustion chamber.
3Productivity
If precise and fast air-fuel ratio variation is implemented for nitric oxide reduction, then nitric oxide elimination efficiency is improved, but the control system becomes more complex
Solution Approach 1:
The control system is divided into two specialized computing branches that handle different aspects of air-fuel ratio control: the feed-forward branch handles pre-calculation based on engine parameters, while the feedback branch handles real-time adjustment based on exhaust oxygen measurement. This segmentation allows the system to achieve precise and fast air-fuel ratio variation for improved nitric oxide elimination while keeping each individual branch relatively simple in structure.
Solution Approach 2:
The system dynamically changes the reference airflow parameter based on engine operating conditions (load, speed, temperature) and exhaust oxygen concentration. By continuously adjusting this key parameter through the coordinated action of feed-forward and feedback computing, the system achieves high nitric oxide elimination efficiency while maintaining manageable control system complexity through parameter-based control rather than complex mechanical or electronic mechanisms.
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 highly precise and fast adjustment of the air-fuel ratio, effectively regenerating the nitric oxide adsorber and compensating for mechanical and electronic drifts, thereby improving nitric oxide reduction and adsorber efficiency.
Implementation Method 1
varying the air-fuel ratio in the combustion chamber (35) of the engine
Implementation Method 2
a fraction of the exhaust gas is known to be recirculated into the combustion chamber... Exhaust gas comprises carbon dioxide, which, having a high thermal capacity capable of reducing the temperature in the chamber
Implementation Method 3
nitrogen monoxide (NO) is converted to nitrogen dioxide (NO2) by an oxidizing element, e.g. platinum (Pt)
Implementation Method 4
trapped in an adsorbent compound, e.g. barium oxide (BaO)
Implementation Method 5
the barium oxide (BaO) is separated into nitrogen and carbon dioxide by a reducing element, e.g. rhodium (Rh)
Implementation Method 6
an airflow computing block (29) supplied with said injected fuel quantity and said exhaust gas oxygen concentration and calculating a reference airflow value
Data Source
AI summary
There is described a method of controlling air intake flow of an internal combustion engine (1), the method including the steps of calculating a reference airflow (AREF) as the sum of a feed-forward contribution (AFF), calculated as a function of the reference air/fuel ratio ((A/F)REF) to be obtained in the combustion chamber, and a feed-back contribution (AFB), calculated as a function of the oxygen concentration (% O2) of the exhaust gas; and closed-loop controlling the air intake flow of the engine so that it equals the reference airflow (AREF).