Exhaust Flow Modifier Reduces Reagent Impingement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exhaust aftertreatment systems face challenges in efficiently mixing reagents with exhaust gases, leading to reagent deposition and reduced effectiveness in NOx emission reduction, particularly due to high reagent injection pressures causing over-penetration and impingement on exhaust pipe surfaces.
Innovation Solution
An exhaust gas treatment system with a flow modifier positioned upstream of the reagent injector, featuring a diverter that increases exhaust gas velocity at a predetermined location to reduce reagent impingement on the pipe surface, enhancing mixing and distribution of the reagent within the exhaust stream.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high reagent injection pressures are used to improve atomization, then reagent mixing is improved, but over-penetration occurs causing impingement on exhaust pipe surfaces
Solution Approach 1:
The flow modifier is installed upstream of the reagent injector to pre-condition the exhaust gas flow before reagent injection. This preliminary action modifies the velocity profile and creates favorable flow conditions that prevent over-penetration and impingement, allowing effective reagent mixing at lower injection pressures
2Object-affected harmful factors
If reagent injection pressure is reduced to prevent over-penetration, then pipe impingement is reduced, but reagent mixing with exhaust gas becomes insufficient
Solution Approach 1:
The flow modifier acts as an intermediary between the exhaust gas flow and the reagent injection. It mediates the interaction by conditioning the exhaust flow to be more receptive to reagent mixing, enabling efficient mixing at lower pressures by improving flow structure and reducing adverse velocity profiles
3Quantity of substance
If reagent is deposited on pipe surfaces, then mixing efficiency is reduced, but reagent availability for NOx reduction decreases
Solution Approach 1:
The flow modifier converts the potentially harmful effect of high-velocity exhaust flow (which causes poor mixing and deposition) into a beneficial effect by using the flow energy to create favorable mixing conditions. The modified flow pattern enhances reagent distribution and prevents deposition, maximizing reagent utilization and vehicle range
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
The flow modifier significantly reduces reagent deposition on the pipe surface by over 50% and improves mixing, allowing for more efficient utilization of the reagent, thereby increasing the vehicle range and reducing the need for reagent replenishment.
Implementation Method 1
The flow modifier includes a diverter for increasing the velocity of the exhaust gas at a predetermined location within the conduit relative to the injected reagent
Implementation Method 2
The diverter is positioned upstream from the reagent injection aperture and inclined at an angle to increase a velocity of the exhaust at a predetermined location within the conduit
Data Source
AI summary
An exhaust gas treatment system for reducing emissions from an engine includes an exhaust conduit adapted to supply an exhaust stream from the engine to an exhaust treatment device. The conduit includes an aperture. An injector injects a reagent through the aperture and into the exhaust stream. A flow modifier is positioned within the exhaust conduit upstream of the injector. The flow modifier includes a diverter for increasing the velocity of the exhaust gas at a predetermined location within the conduit relative to the injected reagent.