Exhaust Gas Bypass for Particle Filter Regeneration
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Solution Overview
Problem
Existing exhaust gas after-treatment systems face challenges in achieving sufficient exhaust gas temperatures, especially in engines with turbocharging and light loading, which hinders the effective operation of particle filters and catalysts, leading to incomplete regeneration and reduced pollutant conversion rates.
Innovation Solution
A method involving the removal of a partial exhaust gas stream upstream of an exhaust turbine, which is then fed back downstream, allowing for open-loop or closed-loop control to maintain high temperatures at the particle filter and optimize turbine efficiency, with the partial stream being reintroduced between an NO oxidation catalyst and a particle filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If exhaust gas is passed through an exhaust turbine for pressure charging, then engine power and efficiency are improved, but exhaust gas temperature downstream of the turbine decreases, hindering particle filter regeneration
Solution Approach 1:
The exhaust gas stream is divided into two separate streams: a main stream that passes through the exhaust turbine to provide pressure charging, and a partial stream that bypasses the turbine to maintain high temperature for particle filter regeneration. This segmentation allows independent optimization of both power generation and temperature maintenance
Solution Approach 2:
A bypass line acts as an intermediary pathway, allowing a portion of the exhaust gas to circumvent the exhaust turbine. This intermediary structure enables the hot exhaust gas to directly reach the particle filter without being cooled by the turbine, thus maintaining regeneration capability while preserving turbine-driven power charging
2Reliability
If the exhaust gas stream is divided into main and partial streams, then particle filter regeneration is enabled, but device complexity increases due to additional bypass lines and control systems
Solution Approach 1:
The bypass line is designed to serve multiple functions: it acts as a thermal pathway for particle filter regeneration, functions as an exhaust gas routing channel, and can be integrated with existing exhaust after-treatment components. This multi-functionality reduces the need for separate dedicated systems, thereby limiting the increase in device complexity
Solution Approach 2:
A control system continuously monitors exhaust gas temperature and particle filter state, dynamically adjusting the bypass line configuration to optimize regeneration while minimizing structural complexity. The feedback mechanism ensures the system adapts to varying operating conditions without requiring overly complex fixed infrastructure
3Temperature
If a partial exhaust gas stream is diverted upstream of the turbine, then high temperature can be maintained for after-treatment, but turbine efficiency and power output decrease
Solution Approach 1:
The bypass line configuration is made dynamic and adjustable, allowing the system to optimize the split between main and partial streams based on real-time operating conditions. This dynamic adjustment enables the system to maintain adequate temperature for after-treatment while preserving sufficient exhaust gas flow through the turbine to maintain power output
Solution Approach 2:
The system dynamically changes the parameter of exhaust gas flow distribution, adjusting the proportion of gas diverted through the bypass line based on temperature requirements and power demands. By varying this parameter, the system achieves optimal balance between maintaining high temperature for after-treatment and preserving turbine power output
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 ensures reliable operation of particle filters at higher temperatures, accelerates soot burnoff, and optimizes exhaust gas temperatures for efficient pollutant conversion, even in conditions where traditional methods fail to achieve sufficient temperatures.
Implementation Method 1
ensures reliable operation of particle filters at higher temperatures, accelerates soot burnoff
Implementation Method 2
A method involving the removal of a partial exhaust gas stream upstream of an exhaust turbine, which is then fed back downstream, allowing for open-loop or closed-loop control to maintain high temperatures at the particle filter
Implementation Method 3
oxidation catalysts are used to oxidize unburnt hydrocarbons and carbon monoxide
Implementation Method 4
These oxidation catalysts are used to oxidize unburnt hydrocarbons and carbon monoxide
Implementation Method 5
internal combustion engines with exhaust gas pressure charging... at least one exhaust turbine... A partial exhaust gas stream is removed from a main exhaust gas stream upstream of at least one exhaust turbine
Data Source
AI summary
A method of operating components for exhaust gas after-treatment disposed in the exhaust gas tract of a turbocharged internal combustion engine. A partial exhaust gas stream is removed from the main exhaust gas stream upstream of at least one exhaust gas turbine. The partial exhaust gas stream is fed back into the main exhaust gas stream downstream of the at least one exhaust gas turbine. The feed is located, in terms of exhaust flow, between an NO oxidation catalytic converter and a particle filter (i.e., the exhaust gas after-treatment component). That is, the at least one exhaust gas after-treatment component is arranged downstream of the feed. The quantity of exhaust gas branched off as a partial exhaust gas stream is controlled or closed-loop controlled as a function of at least one target temperature in at least one defined point in the exhaust gas tract, in particular in the partial exhaust gas stream and/or of the at least one exhaust gas after-treatment component.