Asynchronous Reductant Injection for SCR Systems

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Solution Overview

Problem

Conventional exhaust aftertreatment systems for IC engines face challenges in synchronously delivering reductant to multiple SCR systems, leading to potential degradation in catalytic conversion efficiency due to lag in reductant delivery.

Innovation Solution

A reductant insertion assembly with dedicated injectors for each SCR system, controlled by a controller to asynchronously deliver reductant from a single storage tank, allowing sequential and simultaneous activation of injectors for brief delivery times, ensuring near-simultaneous reductant delivery to both systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If reductant is delivered to multiple SCR systems using a single storage tank and insertion assembly, then system complexity and cost are reduced, but reductant delivery timing precision deteriorates causing degradation in catalytic conversion efficiency

Engineering Contradiction:
Improvenumber of storage tanks and insertion assembliesVSAvoidreductant delivery timing precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The single reductant insertion assembly is segmented into multiple independent injectors, each capable of being activated independently to deliver reductant to different SCR systems at different times. This allows precise control over delivery timing to each SCR system while using a single storage tank and insertion assembly structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically controls the activation timing of each injector based on the specific requirements of each SCR system. The controller can activate injectors sequentially or simultaneously, adjusting delivery timing dynamically to maintain catalytic conversion efficiency while using a single storage tank.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If reductant is delivered asynchronously to multiple SCR systems, then delivery timing precision is improved, but system complexity increases

Engineering Contradiction:
Improvereductant delivery timing precisionVSAvoidcontrol mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The single reductant insertion assembly is designed to perform multiple functions by incorporating multiple independent injectors that can operate independently. This universal structure can deliver reductant to multiple SCR systems with different timing requirements, achieving precise delivery control without requiring separate insertion assemblies for each system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The controller acts as an intermediary that manages the complex timing coordination between multiple injectors. It receives signals from various sensors and systematically controls each injector's activation timing, simplifying the overall control architecture while achieving precise asynchronous delivery to multiple SCR systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If multiple independent reductant insertion assemblies are used for each SCR system, then reductant delivery reliability is improved, but system complexity and cost increase

Engineering Contradiction:
Improvereductant delivery reliabilityVSAvoidnumber of insertion assemblies
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The single insertion assembly is segmented into multiple independent injector units, each dedicated to a specific SCR system. This segmentation provides the reliability of independent delivery control for each SCR system while avoiding the complexity and cost of having completely separate insertion assemblies, as all injectors share the same storage tank and control architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple injector functions are merged into a single insertion assembly structure that shares common components such as the storage tank connection, control electronics, and mounting infrastructure. This combining approach maintains the reliability benefits of dedicated injectors for each SCR system while reducing overall system complexity and cost compared to fully independent assemblies.

Inventive Principle:
Principle #5Merging (Combining)

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 prevents degradation in catalytic conversion efficiency by ensuring reductant is delivered to both SCR systems quickly, maintaining system performance without the need for multiple reductant storage tanks or complex assemblies, thus reducing costs and complexity.

Implementation Method 1

at least one reductant insertion assembly is fluidly coupled to the reductant storage tank. The at least one reductant insertion assembly is also fluidly coupled to the first SCR system and the second SCR system

Methodology Applied
Scientific EffectFluid communication:

Data Source

PatentEP3470642B1Asynchronous reductant insertion in aftertreatment systems
Publication Date: 2020.11.18 CUMMINS EMISSION SOLUTIONS INC
  • EP3470642B1 patent drawingFigure 1
  • EP3470642B1 patent drawingFigure 2
  • EP3470642B1 patent drawingFigure 3

AI summary

A system for asynchronously delivering reductant from a reductant storage tank to a first selective catalytic reduction system and a second selective catalytic reduction system included in an aftertreatment system. The system comprises: a reductant insertion assembly fluidly coupled to the reductant storage tank, the reductant insertion assembly configured to be fluidly coupled to each of the first selective catalytic reduction system and the second selective catalytic reduction system, the reductant insertion assembly including a first injector fluidly coupled to the first selective catalytic reduction system, and a second injector fluidly coupled to the second selective catalytic reduction system; and a controller communicatively coupled to the reductant insertion assembly. The controller comprises a timing determination module configured to determine: a first activation time at which the first injector is to be activated, a first delivery time for which the first injector is to be selectively activated for delivering a first amount of reductant into the first selective catalytic reduction system, a second activation time at which the second injector is to be activated, and a second delivery time for which the second injector is to be selectively activated for delivering a second amount of reductant into the second selective catalytic reduction system. The controller is configured to: instruct the reductant insertion assembly to insert the first amount of reductant into the first selective catalytic reduction system for the first delivery time and the second amount of reductant into the second selective catalytic reduction system for the second delivery time, such that the controller inserts into only one of the first selective catalytic reduction system or the second selective catalytic reduction system at any given time, wherein the first delivery time is equal to the second delivery time and/or the first amount of reductant is equal to the second amount of reductant. There is also a method and control module.