Engine Control Device for Alcohol Fuel Hydrogen Interference
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Solution Overview
Problem
The existing control devices for internal combustion engines face challenges in accurately determining the atmosphere inside a catalyst when alcohol-mixing fuel is supplied, leading to potential false detections and reduced purification efficiency due to increased hydrogen concentration, which can result in unburned emissions flowing out.
Innovation Solution
A control device that includes hydrogen concentration detection and correction means to adjust the target air-fuel ratio based on detected hydrogen levels, along with intake air flow rate detection to optimize the amplitude of air-fuel ratio changes, ensuring proper atmosphere determination and enhanced catalyst purification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If alcohol-mixing fuel is supplied to increase hydrogen concentration in the exhaust gas, then the reducing atmosphere in the catalyst is enhanced, but false detection of oxidation atmosphere occurs due to downstream air-fuel ratio sensor errors
Solution Approach 1:
The patent introduces a correction value as an intermediary element to mediate between the downstream air-fuel ratio sensor output and the actual catalyst atmosphere determination. The correction value compensates for the sensor's measurement errors caused by high hydrogen concentration, allowing accurate atmosphere detection despite sensor inaccuracies
Solution Approach 2:
The patent changes the parameter of the air-fuel ratio feedback amount by applying a correction value that adjusts the downstream air-fuel ratio sensor output. This parameter modification accounts for hydrogen's interfering effect on sensor measurements, enabling reliable catalyst atmosphere determination under alcohol-mixing fuel conditions
2Ease of operation
If the downstream air-fuel ratio sensor is used to determine catalyst atmosphere, then feedback control can be performed, but false detection occurs when hydrogen concentration is high
Solution Approach 1:
The patent employs feedback control by using the corrected downstream air-fuel ratio sensor output to determine catalyst atmosphere and adjust the air-fuel ratio feedback amount accordingly. The correction value ensures that this feedback loop remains reliable even when hydrogen concentration interferes with sensor measurements
Solution Approach 2:
The correction value serves as an intermediary that bridges the gap between the imperfect sensor measurement and the required accurate atmosphere determination for feedback control, maintaining both ease of operation and reliability
3Quantity of substance
If alcohol concentration in fuel is increased, then hydrogen concentration in exhaust gas increases, but sensor detection accuracy deteriorates
Solution Approach 1:
The patent applies parameter changes by modifying the air-fuel ratio feedback amount through a correction value that compensates for hydrogen's interfering effect on sensor measurements, allowing high hydrogen concentration to coexist with accurate measurements
Solution Approach 2:
The patent converts the harmful effect of high hydrogen concentration (which causes sensor errors) into a benefit by using the correction value to accurately determine catalyst atmosphere, thereby enabling effective feedback control that leverages hydrogen's reducing properties while maintaining measurement 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
This solution effectively prevents false atmosphere detection and maintains high purification efficiency by adjusting the air-fuel ratio to leverage hydrogen's reducing properties, reducing NOx and other emissions, and ensuring the catalyst operates optimally.
Implementation Method 1
a downstream air-fuel ratio sensor that generates an output value in accordance with the air-fuel ratio of exhaust gas passing through the exhaust passage
Implementation Method 2
Since hydrogen acts as a so-called strongly reducing agent, by increasing the hydrogen concentration in the interior of the catalyst, the atmosphere in the interior of the catalyst becomes the reduction atmosphere
Implementation Method 3
a catalyst arranged in an exhaust passage through which an exhaust gas discharged from the combustion chamber passes
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
When alcohol mixing fuel is supplied to an internal combustion engine, an intake air flow rate Ga is detected (Step 1005), and a basic amplitude amount α of an upstream target air-fuel ratio abyfr corresponding to this detected intake air flow rate Ga is calculated (Step 1010). Next, alcohol concentration in the fuel (in more detail, ethanol concentration Cetha) and a cooling water temperature THW (or an intake air temperature THA) are detected (Step 1015), hydrogen concentration Ch in a mixing exhaust gas is calculated based on the detected ethanol concentration Cetha and the detected cooling water temperature THW (or the detected intake air temperature THA) (Step 1020), amplitude gain β corresponding to the calculated hydrogen concentration Ch is calculated (Step 1025), and finally, an amplitude amount (α x β) of the upstream target air-fuel ratio abyfr is calculated (Step 1030).