Diesel Oxidation Catalyst Self-Diagnosis via Temperature Difference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The diesel oxidation catalyst in exhaust fluid treatment apparatuses often experiences unexpected performance due to deposits, leading to reduced hydrocarbon oxidation and unburnt fuel emissions, affecting downstream modules like the diesel particulate filter and selective catalytic reduction module.
Innovation Solution
A method for monitoring the diesel oxidation catalyst by injecting a first quantity of fuel for combustion, calculating the temperature difference, and adjusting fuel injection based on expected margins to ensure proper operation and prevent unburnt fuel passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If fuel is injected into the diesel oxidation catalyst for combustion to increase temperature or remove deposits, then the temperature in the diesel oxidation catalyst increases and deposits are removed, but fuel may pass through the diesel oxidation catalyst without combusting, leading to unburnt fuel emissions
Solution Approach 1:
The system measures the temperature difference across the diesel oxidation catalyst and uses this feedback to determine whether fuel combustion is occurring as expected. If the temperature difference indicates proper combustion, fuel injection continues; if not, the system responds by raising the temperature of exhaust gas upstream to ensure proper combustion conditions
Solution Approach 2:
Before injecting fuel into the diesel oxidation catalyst, the system performs a check by injecting a test quantity of fuel and measuring the resulting temperature difference. This preliminary action ensures that the catalyst is functioning properly and will combust injected fuel before committing to full fuel injection for deposit removal or temperature increase
2Reliability
If periodic checks are performed on individual modules to ensure expected performance, then module performance is monitored and maintained, but the complexity of the monitoring system increases
Solution Approach 1:
The diesel oxidation catalyst module performs its own performance check by combusting a known quantity of fuel and measuring the resulting temperature difference. This self-diagnosis capability allows the module to monitor its own performance without requiring external monitoring equipment, thereby maintaining reliability while minimizing system complexity
Solution Approach 2:
The system replaces complex mechanical monitoring equipment with a simple temperature measurement approach. By using temperature sensors to measure the temperature difference across the catalyst and comparing it to expected values, the system achieves reliable performance monitoring through a simple, elegant measurement technique rather than complex mechanical diagnostic equipment
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 method ensures the diesel oxidation catalyst operates within expected parameters, maintaining optimal temperatures and reducing unburnt fuel emissions, thereby enhancing the performance of downstream modules.
Implementation Method 1
a diesel oxidation catalyst comprising an inlet and an outlet
Implementation Method 2
injecting a first quantity of fuel upstream of the diesel oxidation catalyst for combustion in the diesel oxidation catalyst
Implementation Method 3
receiving an input temperature data value being indicative of temperature of fluid at the inlet; receiving an output temperature data value being indicative of temperature of fluid at the outlet; calculating a calculated temperature difference between the input temperature data value and the output temperature data value
Data Source
AI summary
An exhaust fluid treatment apparatus used to treat exhaust fluid emitted by a combustion engine includes a check of its functionality. A method of monitoring operation of an exhaust fluid treatment apparatus includes comparing a calculated temperature difference with an expected temperature difference associated with combustion of fuel. If the calculated temperature difference is within an acceptable margin of the expected temperature difference, further fuel injection may be permitted. If the calculated temperature difference is outside the acceptable margin of the expected temperature difference, a temperature of the exhaust gas upstream of the exhaust fluid treatment apparatus may be increased.