Preloading Particulate Filter with Ash via Water Injection
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Solution Overview
Problem
New particulate filters in internal combustion engines lack initial ash loading, leading to insufficient filtration efficiency, and previous methods using ash-former additives in fuel have damaged catalytic converters and lambda probes at certain engine operating points.
Innovation Solution
A mixture of water and an ash former, such as metal salts, is injected into the combustion chamber to rapidly form ash particulates, optimizing filtration efficiency without impairing engine operation, using a water injection system with a control unit to manage injection based on exhaust-gas temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a new particulate filter is installed without preloading, then the installation process is simplified and error-free, but the filtration efficiency is insufficient initially
Solution Approach 1:
The patent applies preliminary action by injecting an ash-forming agent into the combustion chamber before normal operation to pre-load the particulate filter with ash particulates. This ensures the filter achieves sufficient filtration efficiency (minimum degree of loading) before actual use, resolving the contradiction between simplified installation and initial filtration performance.
2Productivity
If ash-former additive is introduced into the fuel, then the particulate filter is loaded with ash rapidly, but the catalytic converter and lambda probe are damaged at certain operating points
Solution Approach 1:
The patent uses an intermediary approach by injecting the ash-forming agent directly into the combustion chamber rather than mixing it with fuel. This intermediary method allows precise control over when and how the ash former is introduced, enabling rapid filter loading while avoiding the harmful effects of ash former-contaminated fuel that damage catalytic converters and lambda probes.
Solution Approach 2:
The patent applies parameter changes by controlling the injection timing and conditions of the ash-forming agent into the combustion chamber. By adjusting injection parameters (timing, quantity, conditions), the system achieves rapid ashing of the particulate filter while maintaining safe operating conditions that prevent damage to sensitive components like catalytic converters and lambda probes.
3Reliability
If the particulate filter is preloaded with ash prior to installation, then the filtration efficiency is optimized from the start, but the manufacturing process becomes more complex and error-prone
Solution Approach 1:
The patent applies self-service by enabling the particulate filter to load itself with ash particulates during the first operating cycles through controlled injection of an ash-forming agent. This eliminates the need for complex pre-loading processes during manufacturing, allowing the filter to achieve optimal filtration efficiency automatically during normal operation without increasing manufacturing 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
Rapidly achieves the desired filtration efficiency of 99% by loading the particulate filter with sufficient ash, minimizing damage to catalytic converters and lambda probes, and reducing harmful depositions within the engine.
Implementation Method 1
the ash former used can be, for example, a component which has a metal salt or is composed of the latter... which, in particular as a component of a water and ash-former mixture, forms ash particulates upon combustion in the combustion chamber
Data Source
AI summary
A method is provided for operating an internal combustion engine in a motor vehicle, The internal combustion engine has at least one cylinder with a combustion chamber, a water injection unit with a tank and at least one injection nozzle for directly or indirectly injecting water into the combustion chamber, an exhaust gas system with at least one exhaust gas catalytic converter and a particulate filter device which has a particulate filter for filtering particles out of an exhaust gas flow guided in the exhaust gas system. A control unit is provide for a state monitoring process and for controlling the combustion in the cylinder.