Exhaust Purification Catalyst Temperature Estimation Correction
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Solution Overview
Problem
Existing exhaust purification devices face challenges in accurately estimating catalyst temperature during NOx and SOx purge processes due to individual differences in heat generation and aging degradation, which affects the estimation accuracy and efficiency of catalyst regeneration.
Innovation Solution
An exhaust purification device with a catalyst temperature estimation system that uses unburnt fuel amounts and heat generation data, combined with an exhaust temperature detection system and correction values to improve temperature estimation accuracy, includes a control unit for catalyst regeneration and heat generation amount correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If catalyst temperature is estimated using heat generation amount and unburnt fuel amount, then catalyst regeneration can be controlled, but estimation accuracy deteriorates due to individual differences and aging degradation
Solution Approach 1:
The patent implements feedback control by detecting the actual exhaust temperature downstream of the catalyst and using this information to correct the heat generation amount. The corrected heat generation amount is then used to improve the accuracy of catalyst temperature estimation, creating a closed-loop control system that compensates for individual differences and aging effects.
Solution Approach 2:
The patent replaces direct catalyst temperature measurement (which would require complex contact sensors) with an indirect estimation method using exhaust temperature detection and heat generation correction. This substitution allows for easier implementation while maintaining control capability.
2Measurement precision
If heat generation amount correction is performed using exhaust temperature detection, then temperature estimation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent uses the exhaust temperature detected downstream of the catalyst as an intermediary parameter to infer and correct the catalyst's heat generation amount. This intermediary measurement provides indirect information about catalyst performance without requiring direct contact with the catalyst, simplifying the overall system while improving accuracy.
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
Enhances the accuracy of catalyst temperature estimation, ensuring effective regeneration and maintaining purification capacity, thereby improving the overall efficiency of the exhaust purification process.
Implementation Method 1
a catalyst provided in an exhaust system of an internal combustion engine and configured to generate heat and to purify an exhaust by unburnt fuel in the exhaust
Implementation Method 2
to purify an exhaust by unburnt fuel in the exhaust
Implementation Method 3
an exhaust temperature detection means that is arranged at a further exhaust downstream side than the catalyst and detects an exhaust temperature emitted from the catalyst
Data Source
AI summary
The present invention is provided with: a SOx purge control unit that executes catalyst regeneration processing that maintains the temperature of a NOx occlusion/reduction catalyst at a prescribed recovery temperature; a catalyst temperature estimation unit that estimates catalyst temperature on the basis of the amount of unburnt fuel contained in exhaust and of a catalyst heat generation amount; a second exhaust temperature sensor that is arranged further to an exhaust downstream side than the catalyst and that detects exhaust temperature; and a heat generation amount correction value setting unit that, during the execution of the catalyst regeneration processing, on the basis of an estimated catalyst temperature estimated by the catalyst temperature estimation unit and of an actual exhaust temperature detected by the second exhaust temperature sensor, obtains a heat generation amount correction value that is used to correct the heat generation amount of the catalyst.