Low-Pressure Exhaust Gas Recirculation Valve and Flap Control

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Solution Overview

Problem

There are no known control methods that effectively optimize the regulation of air flow and recirculation rate in engines with low-pressure exhaust gas recirculation systems, particularly in relation to the operating state of the recirculation valve and exhaust flap.

Innovation Solution

A method that exclusively controls the position of either the exhaust gas recirculation valve or the exhaust flap based on predetermined criteria, using a single regulator with automatically chosen amplification gains, to manage the exhaust gas recirculation rate and air flow, with the valve position being less than an estimated threshold value.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If a low-pressure recirculation loop is used to reduce harmful emissions, then nitrogen oxides and soot particles emissions are reduced, but no known control methods exist to optimize regulation of air flow and recirculation rate

Engineering Contradiction:
Improveharmful emissions (nitrogen oxides and soot particles)VSAvoidcontrol method availability
Core Design Contradiction:
Object-generated harmful factorsVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements a feedback control system that uses sensors to detect the actual position of the recirculation valve and exhaust flap, compares it with target positions, and adjusts the control signals accordingly. This closed-loop feedback mechanism enables optimization of air flow and recirculation rate regulation, resolving the issue that no control methods were previously available for low-pressure recirculation loops.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual or simple mechanical control with an electronic control system that uses regulators, sensors, and control units. This substitution enables precise measurement and regulation of the recirculation rate and air flow, providing the necessary control capability that was missing in previous low-pressure recirculation loop designs.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If the recirculation valve position is controlled to regulate air flow, then recirculation rate can be optimized, but the control system complexity increases

Engineering Contradiction:
Improverecirculation rate optimizationVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the control function into separate regulators for the recirculation valve and exhaust flap, with each regulator independently optimizing its parameter. This segmentation allows complex control to be divided into manageable parts, making the overall system more controllable and easier to implement while maintaining optimization capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs dynamic control where the target positions of the recirculation valve and exhaust flap are continuously adjusted based on real-time sensor feedback and changing engine operating conditions. This dynamic adaptation enables optimal recirculation rate control without requiring overly complex static control mechanisms.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If both recirculation valve and exhaust flap are controlled simultaneously, then comprehensive regulation is achieved, but control stability and responsiveness decrease

Engineering Contradiction:
Improveregulation comprehensive controlVSAvoidcontrol stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent separates the control of the recirculation valve and exhaust flap into independent regulation loops, with each component controlled by its own regulator. This segmentation prevents control conflicts and instability that would arise from simultaneous control, while maintaining comprehensive regulation capability through coordinated operation of the separate controllers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses preliminary action by pre-establishing target positions and control strategies for the recirculation valve and exhaust flap based on engine operating conditions. This allows the control system to respond more stably and reliably by having pre-planned control paths rather than reacting simultaneously to changing conditions.

Inventive Principle:
Principle #10Preliminary action

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 adaptive regulation of the engine's operating parameters, ensuring optimal air flow and recirculation rate control, improving engine performance and compliance with anti-pollution standards by adjusting control signals and gains based on the valve's position relative to its threshold.

Implementation Method 1

the exhaust manifold is in communication with a turbine of a turbocharger. The gases have an energy capable of rotating the turbine and a compressor to which it is integral.

Methodology Applied
Scientific EffectTurbine: Turbine

Implementation Method 2

a cooler advantageously lowers the temperature of the recirculated gases.

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP1957777B1Method for controlling an engine provided with an exhaust gas recycling loop
Publication Date: 2016.09.14 RENAULT SA
  • EP1957777B1 patent drawingFigure 1~3
  • EP1957777B1 patent drawingFigure 4~5

AI summary

The invention relates to engine control, in particular to a method for controlling an engine provided with a low-pressure exhaust gas (6) recycling loop (8) consisting in adjusting a predetermined engine operating parameter by controlling the position of an exhaust gas recycling valve (10), which is placed in the loop (8), for determining whether the predetermined measured quantity of said valve (10) respects a predetermined criteria and in controlling the position of an exhaust shutter (19), which is arranged outside the loop (8), when the quantity does not respect said criteria.