Aftertreatment Decomposition Chamber for Low-Backpressure NOx Reduction
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Solution Overview
Problem
Existing aftertreatment systems for internal combustion engines face challenges in uniformly distributing reductant within the exhaust, leading to increased backpressure and reduced engine performance due to the configuration of mixing components, which can cause deposits and inefficient NOx emission reduction.
Innovation Solution
A decomposition chamber with a conduit, doser mount, mixing plate, vane mixer, and baffle are configured to improve reductant distribution by orienting the mixing plate and vane mixer perpendicular to the conduit axis, with specific angles and positions to enhance mixing and reduce backpressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If mixing components are configured to facilitate chemical reaction between exhaust and reductant, then NOx emission reduction is improved, but back pressure on the internal combustion engine increases
Solution Approach 1:
The mixing plate is oriented at a specific angle (10-80 degrees) relative to the conduit axis, creating a three-dimensional mixing structure that enhances reductant distribution without increasing back pressure. This angular orientation allows the mixing components to function in multiple dimensions, improving chemical reaction efficiency while maintaining acceptable pressure characteristics
Solution Approach 2:
The doser mount is positioned at a specific location on the conduit wall with the injection opening oriented at 100-170 degrees relative to the conduit axis. This localized positioning and angular orientation ensure optimal reductant injection and distribution at the specific mixing zone, improving NOx reduction efficiency without requiring system-wide pressure increases
2Productivity
If mixing components are configured to enhance reductant distribution, then chemical reaction efficiency is improved, but engine performance decreases due to increased back pressure
Solution Approach 1:
The vane mixer is positioned at a specific distance downstream from the mixing plate, creating a staged mixing approach that enhances reductant distribution efficiency. This spatial arrangement allows thorough mixing to occur without creating excessive back pressure that would reduce engine power output
Solution Approach 2:
The mixing plate is positioned upstream to pre-distribute the reductant before it reaches the vane mixer. This preliminary action ensures that the reductant is already well-distributed when it reaches the main mixing zone, improving overall chemical reaction efficiency without requiring additional pressure buildup
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 configuration enhances reductant distribution, reducing backpressure and improving NOx emission reduction efficiency by optimizing the mixing process within the decomposition chamber.
Implementation Method 1
The vane mixer includes a plurality of vanes. The vanes define a plurality of vane apertures therebetween.
Implementation Method 2
The mixing plate includes a plurality of lateral crossmembers, a plurality of transverse crossmembers, and a plurality of deflectors.
Data Source
AI summary
A decomposition chamber for an aftertreatment system includes a conduit centered on a conduit axis extending in a reference plane and a doser mount. The doser mount includes an injection opening centered on an injection axis. The injection axis extends in the reference plane. In the reference plane, the injection axis is oriented at an injection angle between 100 degrees and 170 degrees, inclusive, relative to the conduit axis. The decomposition chamber includes a mixing plate having plurality of lateral crossmembers, a plurality of transverse crossmembers, and a plurality of deflectors. In the reference plane, an orientation of a plate plane in which the plurality of lateral crossmembers extend is at a plate angle between 10 and 80 degrees, inclusive, relative to the conduit axis. The decomposition chamber includes a vane mixer disposed in the conduit downstream of the mixing plate and a baffle.