Heated Catalyst Temperature Control for Exhaust Aftertreatment
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Solution Overview
Problem
Existing methods for heating components of exhaust-gas aftertreatment devices in internal combustion engines face challenges in controlling heat introduction due to varying exhaust-gas mass flow and composition, leading to fluctuations and inefficiencies, particularly during dynamic operations, which can result in cooling and increased pollutant emissions.
Innovation Solution
A method involving a heated catalyst that reacts a partial exhaust-gas flow with fuel to generate heat, controlled by open-loop or closed-loop systems using reference variables like exhaust-gas temperature, fuel amount, and mass flow to maintain consistent temperature levels, potentially supplemented by electrical heating, and utilizing a heated catalyst characteristic map for rapid and efficient temperature regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heated catalyst is used to generate heat by reacting exhaust gas with fuel, then heat can be introduced into the exhaust-gas aftertreatment device, but large fluctuations in heat emission occur due to varying exhaust-gas mass flow and composition
Solution Approach 1:
The patent implements a control device that continuously monitors the actual temperature of the exhaust-gas aftertreatment device and adjusts the fuel supply to the heated catalyst accordingly. This closed-loop feedback system compensates for fluctuations caused by varying exhaust-gas conditions, maintaining stable heat emission and preventing both overheating and cooling of the aftertreatment components.
Solution Approach 2:
The control device dynamically adjusts the fuel supply parameter to the heated catalyst based on real-time temperature measurements and predicted temperature development. By changing the fuel amount as a control parameter, the system optimizes heat generation to match actual thermal needs, stabilizing the temperature despite variations in exhaust-gas flow and composition.
2Temperature
If internal engine measures are used to raise exhaust-gas temperature, then heat is introduced into the aftertreatment components, but engine efficiency and pollutant emissions are adversely affected
Solution Approach 1:
The patent introduces a heated catalyst as an intermediary device between the engine and the exhaust-gas aftertreatment components. This intermediary generates the required heat through controlled fuel combustion, acting as a thermal buffer that decouples the heating function from the engine's primary combustion process, thereby preserving engine efficiency while still achieving the necessary temperatures for aftertreatment.
Solution Approach 2:
The heating function is segmented from the engine's main combustion process and placed in a separate heated catalyst unit. This segmentation allows independent optimization of the heating process using minimal fuel amounts, while the engine continues to operate efficiently for its primary power generation function, reducing the trade-off between heating and engine performance.
3Temperature
If fuel is supplied to the heated catalyst to generate heat, then temperature can be maintained, but unnecessary energy is wasted when heating is not needed
Solution Approach 1:
The control device uses feedback from temperature sensors to monitor the actual temperature of the exhaust-gas aftertreatment device and adjusts fuel supply accordingly. When the temperature is sufficient, fuel supply is reduced or stopped, eliminating unnecessary energy consumption. The feedback mechanism ensures fuel is only consumed when and where heat is actually needed.
Solution Approach 2:
The fuel supply to the heated catalyst is made dynamic rather than static, continuously adapting to the actual thermal conditions of the exhaust-gas aftertreatment device. This dynamic adjustment allows the system to optimize fuel consumption by increasing supply only when temperature drops below required levels and reducing or stopping supply when temperature requirements are met, preventing energy waste.
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 allows for precise control of heat introduction, maintaining component temperatures within desired ranges, reducing energy waste, and minimizing emissions, even during dynamic engine operations, without adversely affecting engine efficiency.
Implementation Method 1
a partial flow of an exhaust-gas flow is at least partially reacted with fuel in a heated catalyst
Implementation Method 2
a partial flow of an exhaust-gas flow is at least partially reacted with fuel in a heated catalyst
Implementation Method 3
the actual temperature of the exhaust-gas aftertreatment device is determined and the fuel supply to the heated catalyst is adjusted on the basis of the actual temperature
Data Source
AI summary
A method for introducing heat into at least one component of an exhaust-gas aftertreatment device of an internal combustion engine (15). The method involves at least partially reacting a partial flow of an exhaust-gas flow with fuel in a heated catalyst (2) and then feeding back the resulting product to the exhaust-gas flow, The amount of fuel fed to the heated catalyst and/or the partial flow fed to the heated catalyst is controlled, by open-loop or closed-loop control, in accordance with the exhaust-gas temperature upstream and/or downstream of the component. The amount of fuel fed to the heated catalyst and/or the partial flow fed to the heated catalyst is determined by means of at least one heated-catalyst characteristic map. A computer readable medium stores a signal sequence representing data suitable for transmission by means of a computer network, to an open-loop or closed-loop control device to carry out the above-described method.