DPF Soot Bridge Detection via Dual-Threshold Regeneration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for estimating particulate deposition amount in diesel particulate filters (DPFs) fail to accurately distinguish between normal deposition and soot bridge occurrences, leading to inappropriate filter regeneration processes due to rapid pressure differences caused by clogging.
Innovation Solution
A particle deposition amount estimation device employing two determination techniques based on different thresholds and times to differentiate between normal and soot bridge states, allowing for timely and appropriate regeneration operations even when a soot bridge has occurred, and including a pressure detector for abnormality detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the PM deposition amount is estimated by the P method, then the regeneration timing can be determined, but the estimated value becomes greater than the actual amount when soot bridge occurs, making it difficult to perform appropriate filter regeneration
Solution Approach 1:
The patent segments the regeneration timing determination into two distinct determination techniques with different threshold criteria. The first determination technique uses a lower threshold (first threshold) for normal regeneration, while the second determination technique uses a higher threshold (second threshold greater than first threshold) for soot bridge conditions. This segmentation allows the system to differentiate between normal deposition and soot bridge scenarios, preventing premature or inappropriate regeneration operations.
Solution Approach 2:
The patent changes the threshold parameter values based on the operational state. By introducing two different threshold values (first threshold and second threshold) and selecting which one to apply based on detected conditions, the system adapts the measurement criteria to the current state of the particulate filter. This parameter change enables accurate distinction between normal operation and soot bridge conditions, improving both measurement precision and regeneration reliability.
2Ease of operation
If a single threshold is used for regeneration timing determination, then the control logic is simple, but the system cannot distinguish between normal deposition and soot bridge states
Solution Approach 1:
The control logic is segmented into multiple determination techniques with different threshold criteria. The first determination technique applies a lower threshold for normal regeneration timing, while the second determination technique applies a higher threshold for soot bridge conditions. This segmentation maintains relatively simple control logic for each individual determination path while enabling accurate state differentiation through the multi-threshold approach.
Solution Approach 2:
The threshold parameter is made dynamic rather than static. The system selects which threshold to apply (first threshold or second threshold) based on the detected operational state and conditions. This dynamic adjustment of the threshold parameter allows the system to adapt to different scenarios (normal operation vs. soot bridge) while maintaining clear and manageable control logic through state-based threshold selection.
3Productivity
If the pressure difference rapidly increases due to soot bridge, then the estimated PM deposition amount increases quickly, but this causes unnecessary engine stoppages and reduces system efficiency
Solution Approach 1:
The system performs preliminary determination of the operational state by monitoring pressure difference changes and comparing them against the differentiated threshold criteria before initiating regeneration. By using the first determination technique (lower threshold) for normal conditions and the second determination technique (higher threshold) for soot bridge conditions, the system can preliminarily identify the appropriate regeneration scenario, preventing premature or inappropriate regeneration operations that would cause unnecessary engine stoppages and maintain system efficiency.
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
Enables accurate differentiation between normal and soot bridge states, ensuring appropriate filter regeneration and detecting potential engine abnormalities, thereby preventing unnecessary engine stoppages and maintaining system efficiency.
Implementation Method 1
a pressure detector that detects a pressure difference between before and after the particulate filter
Implementation Method 2
a combination of a diesel oxidation catalyst (hereinafter DOC) and a diesel particulate filter (hereinafter DPF) has been known
Implementation Method 3
exhaust of a diesel engine
Data Source
AI summary
A control device is configured to estimate a soot deposition amount (PM deposition amount) in a DPF for an exhaust purification device that is configured to purify exhaust of a diesel engine using the DPF, and determine a regeneration timing for the diesel engine based on the estimated PM deposition amount. As a technique of determining the regeneration timing, the control device employs a first determination technique of detecting that the PM deposition amount is a first threshold or more and a state in which the PM deposition amount is the first threshold or more has continued for a first predetermined time and a second determination technique of detecting that the PM deposition amount is a second threshold (>the first threshold) or more and a state in which the PM deposition amount is the second threshold or more has continued for a second predetermined time.