Exhaust Pre-Catalyzer Warming via Flow Partialization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Saddle-ride type vehicles face challenges in reducing hydrocarbon emissions during the engine warm-up phase due to the time required for the main catalyzer to reach operating temperature, which does not comply with increasingly stringent emission regulations without altering the size or materials of existing catalyzers.

Innovation Solution

The implementation of partializing means in the exhaust line between the pre-catalyzer and main catalyzer to temporarily increase exhaust gas pressure and temperature by reducing the passage area for exhaust gases, utilizing an electrical control unit to activate or deactivate these means based on the pre-catalyzer's temperature, ensuring rapid warming of the pre-catalyzer and efficient catalytic reaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the main catalyzer is made large to ensure pollutant abatement at maximum engine performance, then the catalysis temperature is maintained at low load, but the catalyzer cannot be installed close to the heat engine and requires longer time to reach operating temperature

Engineering Contradiction:
Improvecatalysis temperatureVSAvoidtime to reach operating temperature
Core Design Contradiction:
TemperatureVSLoss of time

Solution Approach 1:

The exhaust gas treatment system is divided into two separate catalyzers: a main catalyzer for pollutant abatement and a pre-catalyzer for rapid warming. This segmentation allows each component to be optimized for its specific function, with the pre-catalyzer positioned close to the heat engine to quickly reach operating temperature and the main catalyzer sized appropriately for its location in the exhaust line.

Inventive Principle:
Principle #1Segmentation

2Object-generated harmful factors

If a pre-catalyzer is installed close to the combustion chamber to reduce emissions during cold engine conditions, then hydrocarbon emissions are reduced, but the pre-catalyzer has markedly smaller volume and cannot compensate for the main catalyzer's slow warming

Engineering Contradiction:
Improvehydrocarbon emissionsVSAvoidpre-catalyzer volume
Core Design Contradiction:
Object-generated harmful factorsVSQuantity of substance

Solution Approach 1:

The system dynamically changes the passage area parameter of exhaust gases directed to the main catalyzer using partializing means. By temporarily reducing the passage area, exhaust gas pressure and temperature increase, enabling the pre-catalyzer to rapidly reach operating temperature and effectively reduce hydrocarbon emissions during the warm-up phase.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the passage area to the main catalyzer is reduced to increase exhaust gas pressure and temperature, then the pre-catalyzer warms up rapidly, but the main catalyzer receives less exhaust gas flow

Engineering Contradiction:
Improvepre-catalyzer temperatureVSAvoidexhaust gas flow to main catalyzer
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The partializing means are activated temporarily during the warm-up phase to increase pre-catalyzer temperature, then deactivated once the pre-catalyzer reaches operating temperature. This periodic action ensures the main catalyzer receives sufficient exhaust gas flow during normal operation while enabling rapid pre-catalyzer warming when needed.

Inventive Principle:
Principle #19Periodic 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 solution significantly reduces hydrocarbon emissions during the warm-up phase while maintaining the structure and materials of the catalyzers, ensuring compliance with emission standards and reliable, cost-effective manufacturing.

Implementation Method 1

temporarily increasing the exhaust gas pressure in the part of the exhaust line comprising the pre-catalyzer and thus rapidly increasing the temperature of the pre-catalyzer by effect of the stagnation of hot gases inside the pre-catalyzer

Methodology Applied
Scientific EffectStagnation of hot gases: Convection

Implementation Method 2

temporarily increasing the exhaust gas pressure in the part of the exhaust line comprising the pre-catalyzer

Methodology Applied
Scientific EffectPressure increase: Pressure Increase

Implementation Method 3

the pre-catalyzer has a volume, and thus a footprint, which is markedly smaller than the main catalyzer and can thus be installed close to the combustion chamber. In this manner, the higher-temperature exhaust gases cross the pre-catalyzer and quickly activate the catalytic reaction.

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP3771811A1Saddle-ride type vehicle having low hydrocarbon emissions during the warm-up phase
Publication Date: 2021.02.03 PIAGGIO & C SPA
  • EP3771811A1 patent drawingFigure 1
  • EP3771811A1 patent drawingFigure 2
  • EP3771811A1 patent drawingFigure 3

AI summary

The present invention relates to a saddle-ride type vehicle (1) comprising an engine (10) provided with a combustion chamber (5) and a treatment unit (15) of the exhaust gases generated in said chamber (5) Said treatment unit (15) comprises an exhaust line (20) communicating with said chamber (5), a main catalyzer (21) and a pre-catalyzer (25) arranged along said exhaust line (20) upstream of the main catalyzer (21). According to the invention, the treatment unit (15) comprises partializing means (8) which, when activated, partialize the flow rate of said exhaust gases directed to said main catalyzer (21) to a predetermined percentage. Such partializing means (8) are operatively arranged along said exhaust line (20) between the pre-catalyzer (25) and the main catalyzer (21) and are activated/deactivated as a function of the temperature of said pre-catalyzer (25).