Diesel Oxidation Catalyst Rapid Heating Strategy

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Solution Overview

Problem

Diesel engine oxidation catalysts age due to high operating temperatures and fuel components, leading to decreased efficiency and increased emissions, necessitating higher precious metal usage or fuel consumption to maintain pollutant treatment below regulatory thresholds.

Innovation Solution

A rapid heating strategy for diesel engine oxidation catalysts during start-up, involving controlled adjustments to air flow, fuel injection, and exhaust gas recirculation, optimized through engine control systems to maintain emissions within regulatory limits without degrading engine performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the quantity of precious metals in the catalyst is increased to compensate for aging, then the catalyst efficiency is maintained, but the cost increases significantly

Engineering Contradiction:
Improvecatalyst efficiencyVSAvoidprecious metals quantity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by implementing a rapid heating strategy during engine start-up to pre-heat the catalyst before it enters its aging phase. This proactive approach ensures the catalyst reaches optimal operating temperature quickly, maintaining its efficiency without requiring excessive precious metals. The heating strategy is activated based on detected catalyst aging level, allowing the system to prepare the catalyst in advance for optimal performance throughout its service life.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the exhaust gas temperature is increased rapidly during start-up to compensate for catalyst aging, then the catalyst efficiency is maintained, but fuel consumption increases

Engineering Contradiction:
Improvecatalyst efficiencyVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by implementing a adaptive heating strategy that adjusts exhaust gas temperature control based on real-time detection of catalyst aging level. The system dynamically modifies heating intensity and duration according to the actual aging state, rather than using a fixed high-temperature approach. This dynamic adjustment maintains catalyst efficiency while minimizing unnecessary fuel consumption during start-up phases.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback by using a sensor to detect the aging level of the oxidation catalyst and using this information to control the rapid heating strategy. The control unit receives signals from the aging detection sensor and adjusts the heating parameters accordingly, creating a closed-loop system that optimizes both catalyst performance and fuel consumption based on actual catalyst condition.

Inventive Principle:
Principle #23Feedback

3Reliability

If the exhaust gas temperature is increased rapidly during start-up, then the catalyst efficiency is maintained, but other engine performances such as nitrogen oxide and particulate emissions degrade

Engineering Contradiction:
Improvecatalyst efficiencyVSAvoidnitrogen oxide and particulate emissions
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies partial action by implementing a measured, controlled heating strategy rather than excessive heating. The system uses precise control to apply just enough heat to compensate for catalyst aging without over-heating. This partial approach maintains catalyst efficiency while avoiding the negative side effects of excessive temperature increases, such as increased nitrogen oxide and particulate emissions that would result from aggressive heating strategies.

Inventive Principle:
Principle #16Partial or excessive 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

Effectively compensates for catalyst aging by quickly raising exhaust gas temperature to maintain efficiency without increasing pollutant emissions or degrading engine performance, thus reducing the need for excessive precious metal usage.

Implementation Method 1

These catalysts which burn the hydrocarbons and carbon monoxide contained in the exhaust gases are composed of a ceramic impregnated with materials based on precious metals such as platinum or palladium.

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

These catalysts which burn the hydrocarbons and carbon monoxide contained in the exhaust gases

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

a strategy for rapidly heating, when the vehicle is started, of the oxidation catalysts used for depolluting diesel engines

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

a circuit exhaust gas recirculation positioned between the exhaust duct and the intake duct

Methodology Applied
Scientific EffectExhaust gas recirculation: Convection

Data Source

PatentEP2078839B1Quick-heating strategy to compensate for the aging of an oxidation catalyst in a diesel engine.
Publication Date: 2011.07.20 PEUGEOT CITROEN AUTOMOBILES SA
  • EP2078839B1 patent drawingFigure 1~4
  • EP2078839B1 patent drawingFigure 2

AI summary

Rapid heating strategy to compensate for the aging of an oxidation catalyst 8 integrated into the exhaust line of a Diesel engine 1. During an engine start-up phase, the instructions concerning the setting of the air circuit are modified firstly, i.e., the air flow entering the circuit, the pressure of the gases at the intake and the flow of the exhaust gas recirculation circuit (10) and secondly the instructions concerning the injection of fuel into the cylinders (15).