Exhaust Spark Ignition Using Secondary Air During Engine Cold Start
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Solution Overview
Problem
Existing internal combustion engines face challenges in effectively combusting unburned and combustible fuel components during cold starts, leading to excessive emissions and slow heating of exhaust aftertreatment devices.
Innovation Solution
A secondary air line is fluidically connected to the intake manifold downstream of the compressor and upstream of the throttle valve, diverting a portion of fresh air into the exhaust manifold to act as secondary air, which is then ignited by spark plugs to combust unburned fuel components, integrated with a bypass air system to prevent compressor wheel deceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a separate secondary air supply system is used to combust unburned fuel components during cold starts, then emissions are reduced and aftertreatment device heating is improved, but device complexity and cost increase
Solution Approach 1:
The secondary air line is integrated with the bypass air system, allowing the same air supply pathway to serve dual purposes: providing bypass air during normal operation and supplying secondary air for combustion during cold starts. This eliminates the need for a completely separate secondary air supply system, reducing device complexity while maintaining emissions reduction capability
Solution Approach 2:
The invention merges the secondary air line with the bypass air system by connecting the secondary air line to the intake manifold at a branch point located downstream of the compressor and upstream of the throttle valve. This integration combines two previously separate functions into a unified system, reducing the number of components and simplifying the overall air supply architecture
2Temperature
If a separate secondary air supply system is used to combust unburned fuel components during cold starts, then aftertreatment device heating is improved, but device complexity and cost increase
Solution Approach 1:
The integrated air supply system serves multiple functions including bypass air provision during normal operation and secondary air supply for aftertreatment device heating during cold starts. This multi-functionality eliminates the need for separate dedicated systems, reducing device complexity while maintaining effective heating capability
Solution Approach 2:
By merging the secondary air line with the bypass air system at a strategic branch point in the intake manifold, the invention creates a unified air supply pathway that can be selectively utilized for different purposes. This integration reduces component count and simplifies system architecture while ensuring adequate air supply for aftertreatment device heating
3Productivity
If a spark plug is used to ignite the fuel-air mixture in the exhaust system, then rapid combustion and emissions reduction are achieved, but additional components are required
Solution Approach 1:
The spark plug is integrated into the existing exhaust system architecture, utilizing the naturally formed fuel-air mixture in the exhaust tract. The system leverages available components and natural processes, requiring only the addition of a single spark plug element rather than a complex ignition system, thereby achieving rapid combustion with minimal increase in device complexity
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
Facilitates rapid combustion of unburned fuel components, reduces emissions, quickly heats the exhaust aftertreatment device, and optimizes engine operation with low costs and complexity.
Implementation Method 1
a mixture can be ignited that comprises the secondary air introduced into the exhaust tract and, in particular, unburned and combustible fuel components
Implementation Method 2
the ignition device is designed as a spark plug, by means of which the fuel components in the mixture comprising the secondary air can be ignited
Data Source
Figure 1~2
AI summary
The invention relates to an internal combustion engine (10), comprising an exhaust tract (18) through which exhaust gas can flow from a combustion chamber (16), comprising a secondary air line (20), through which secondary air can flow and by means of which the secondary air flowing through the secondary air line (20) can be introduced into the exhaust tract (18), comprising at least one ignition device (22, 24) arranged in the exhaust tract (18), by means of which ignition device a mixture comprising the secondary air introduced into the exhaust tract (18) and fuel components is to be ignited in the exhaust tract (18), and comprising an intake tract (26) through which fresh air can flow. The secondary air line (20) is fluidically connected to the intake tract (26) at a branch point (A) arranged downstream of a compressor (30) arranged in the intake tract (26) and upstream of a throttle valve (38) arranged in the intake tract (26), at which branch point at least some of the fresh air can be branched off from the intake tract (26) by means of the secondary air line (20) and can be introduced as the secondary air into the exhaust tract (18). The ignition device (22, 24) is a spark plug (22, 24).