Exhaust Heater for Engine Catalyst Light-Off
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Solution Overview
Problem
Catalytic converters in internal combustion engines are ineffective at reducing emissions at cold start due to requiring time to reach the 'light off' temperature, necessitating supplemental heating solutions that can be costly and space-intensive.
Innovation Solution
An internal combustion engine design featuring a heater assembly with a fuel-burning heater that selectively supplies heat energy to the exhaust gas from both banks of cylinders, merging the gas flow through a collector before it reaches a catalyst, allowing for efficient heating and emission reduction without the need for close-coupled catalysts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a supplemental heater is added to heat the exhaust gas quickly, then the catalyst reaches light off temperature faster, but the device complexity and space requirements increase
Solution Approach 1:
The patent combines the exhaust streams from both cylinder banks into a single collector before reaching the catalyst. This merging allows the heater assembly to heat a consolidated flow more efficiently and enables the catalyst to be positioned downstream where it can be shared by both banks, reducing overall system complexity and space requirements.
Solution Approach 2:
The catalyst is positioned downstream of the collector to serve both cylinder banks universally. Instead of requiring separate close-coupled catalysts for each bank, a single catalyst receives the merged exhaust flow and performs emission treatment for both banks, reducing device complexity and component count.
2Reliability
If close-coupled catalysts are used for each bank, then emission treatment is effective, but the space and cost increase
Solution Approach 1:
The exhaust streams from both cylinder banks are merged in a single collector before reaching the catalyst. This consolidation allows a single catalyst to effectively treat emissions from both banks, eliminating the need for separate close-coupled catalysts and thereby reducing the space occupied by the catalyst system.
Solution Approach 2:
The heater assembly acts as an intermediary by heating the merged exhaust flow in the collector before it reaches the catalyst. This ensures the catalyst receives sufficiently hot exhaust gas to maintain effective emission treatment, even though it is positioned downstream and shared by both banks.
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 effectively reduces emissions by ensuring the catalyst reaches operating temperature quickly, saving space and cost by locating the catalyst underfloor, where it can be shared by both banks and treated efficiently, while maintaining effective emission treatment.
Implementation Method 1
a heater assembly configured to selectively supply heat energy to the exhaust gas from the first pipe and the second pipe
Implementation Method 2
The heater assembly includes a fuel burning heater
Implementation Method 3
a catalyst configured to receive a merged flow of the exhaust gas from the outlet of the collector and configured to treat the exhaust gas from the first pipe and second pipe
Data Source
AI summary
An internal combustion engine including a first and a second manifold coupled to exhaust ports of a first and a second plurality of cylinders to receive exhaust gas therefrom. The engine includes a first and a second pipe configured to receive the exhaust gas from the manifolds. The engine includes a collector including a first and second inlet coupled to the pipes and an outlet configured to receive a merged flow of the exhaust gas from the first and second pipe. The engine includes a catalyst configured to receive a merged flow of the exhaust gas from the outlet and treats the exhaust gas and a heater assembly configured to selectively supply heat energy to the exhaust gas from the first pipe and the second pipe. The heater assembly includes a connecting portion coupled to the collector.