Compressed Air Metering System for SCR Reducing Agent Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing reducing agent metering systems for selective catalytic reduction in internal combustion engines face challenges with complex installation and high production costs due to the need for additional components and hoses for separate air compressors, especially at low engine rpm or load conditions where sufficient compressed air supply is not ensured.
Innovation Solution
An integrated metering system where the air compressor is mounted on a plate with integrated channels and pockets, allowing for simple and economical integration into the compressed air supply, using a pressure sensor to ensure efficient air supply from both the supercharger and electrical compressor, and a solenoid valve to prevent deposits by blowing free the reducing agent line during pauses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate air compressor is added to ensure sufficient compressed air supply at low engine rpm/load, then compressed air supply reliability is improved, but device complexity and installation cost increase due to additional components and hoses
Solution Approach 1:
The patent combines the separate air compressor with the existing supercharger by mounting the compressor on the supercharger housing and integrating its intake and pressure lines into the supercharger's existing air pathways. This merging eliminates the need for separate mounting structures and reduces the number of external hoses and connections required, thereby reducing system complexity while maintaining reliable compressed air supply at all engine operating points including low rpm/load conditions
2Reliability
If a separate air compressor is added to ensure sufficient compressed air supply at low engine rpm/load, then compressed air supply reliability is improved, but production and installation cost increase
Solution Approach 1:
The patent combines the separate air compressor with the existing supercharger by mounting the compressor on the supercharger housing and integrating its intake and pressure lines into the supercharger's existing air pathways. This merging eliminates the need for separate mounting structures and reduces the number of external hoses and connections required, thereby reducing system complexity while maintaining reliable compressed air supply at all engine operating points including low rpm/load conditions
Solution Approach 2:
The supercharger housing serves multiple functions: it acts as the housing for the supercharger itself, provides mounting structure for the additional compressor, and serves as the integration point for both compressors' air pathways. This multi-functionality reduces the need for additional components and reduces production and installation costs
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 simplifies the installation and operation of the metering system, ensuring consistent compressed air supply at all engine operating points, reducing production and installation costs, and preventing deposits by using integrated components and smart air management.
Implementation Method 1
there being an electrical air compressor
Implementation Method 2
the compressed air is available only after a certain length of operation. At other operating points, for example a low rpm and/or engine load, however sufficient compressed air supply is not ensured by the engine supercharger
Implementation Method 3
The compressed air is used as an energy supplier. This is advantageous for achieving small droplets
Implementation Method 4
In the exhaust gas the urea decomposes at temperatures above 150° C. into gaseous ammonia and CO2
Implementation Method 5
SCR catalytic converters are used to reduce nitrogen oxide emission of diesel engines. The emission of nitrogen oxides is reduced by roughly 90% in these SCR catalytic converters by selective catalytic reduction (SCR)
Data Source
AI summary
A metering system for injecting a reducing agent into the exhaust gas flow of an internal combustion engine for selective catalytic reduction, including a reducing agent tank, a metering pump, an air compressor for a compressed air supply, at least one nozzle which is in a flow connection to a pressure line of the compressed air supply and a pressure line of the metering pump and by which the reducing agent can be injected into the exhaust gas flow by means of compressed air, the air compressor being located on a mounting plate and having channels which form intake and pressure lines of the air compressor and which have connection regions at the outlets from the mounting plate and one or more pockets which are in a flow connection to the channels and which form the intake connection and/or the pressure connection of the air compressor.