Exhaust Gas Analysis Device Viscosity Correction
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Solution Overview
Problem
The dilution sampling method in exhaust gas analysis systems leads to measurement errors due to changes in viscosity of the diluted exhaust gas, resulting in lower calculated concentrations of components compared to direct sampling methods.
Innovation Solution
The exhaust gas analysis device corrects measured values by accounting for the concentration of viscous components like oxygen in the diluted exhaust gas, which affects the flow rate and sensitivity of the analysis, using the dilution ratio calculated from carbon component concentrations to accurately determine the component concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If exhaust gas is diluted with atmosphere using dilution sampling method, then moisture concentration is reduced and dew condensation is prevented, but the viscosity of the diluted exhaust gas increases causing measurement errors
Solution Approach 1:
The patent changes the physical parameter of viscosity by introducing a viscosity correction factor that accounts for the increased viscosity of diluted exhaust gas. The correction factor is calculated based on the ratio of actual viscosity to reference viscosity, allowing the system to compensate for viscosity changes and maintain measurement accuracy while still using the dilution sampling method to prevent dew condensation.
Solution Approach 2:
The patent implements a feedback mechanism where the viscosity correction factor is continuously calculated and applied to correct the measured concentration values. The system uses the relationship between dilution ratio, viscosity changes, and measurement results to iteratively refine the correction, ensuring accurate measurements despite the harmful effect of increased viscosity.
2Object-affected harmful factors
If dilution sampling method is used to reduce moisture content, then dew condensation is restrained, but the calculated concentration of components becomes lower than actual values
Solution Approach 1:
The patent replaces the need for mechanical or physical correction methods by using a computational approach. Instead of physically adjusting the diluted exhaust gas to compensate for viscosity changes, the system substitutes a mathematical correction model that calculates and applies the viscosity correction factor to the measured concentration values, thereby recovering accurate component concentrations.
Solution Approach 2:
The patent transforms the concentration measurement from a direct physical measurement affected by viscosity into a corrected parameter by applying the viscosity correction factor. This parameter change allows the system to report accurate concentration values that reflect the actual exhaust gas composition despite the dilution-induced viscosity increase.
3Ease of operation
If fluid resistor part is used to limit flow rate, then flow rate control is achieved, but increased viscosity causes increased fluid resistance and decreased flow rate into analyzing part
Solution Approach 1:
The patent introduces the viscosity correction factor as an intermediary element that mediates between the fluid resistor's flow rate control function and the analyzing part's sensitivity requirements. By calculating and applying this correction factor, the system compensates for the reduced flow rate caused by increased viscosity, ensuring that the analyzing part receives sufficient corrected data for accurate measurements.
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 approach allows for more accurate calculation of component concentrations in exhaust gases by mitigating the impact of viscosity changes, reducing measurement errors and maintaining high accuracy without the need for additional sensors, thereby reducing costs.
Implementation Method 1
the viscosity of the diluted exhaust gas becomes higher than the viscosity of the fluid (namely, the exhaust gas) prior to dilution
Implementation Method 2
the fluid resistance that the diluted exhaust gas receives from the fluid resistor part such as the capillary increases
Data Source
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AI summary
The present claimed invention provides an exhaust gas analysis system using a dilution sampling method with an exhaust gas analysis device that can calculate a measured value such as a concentration of a component to be measured in an exhaust gas with higher accuracy. The exhaust gas analysis device analyzes a diluted exhaust gas as being a mixture of an exhaust gas and a dilution gas that dilutes the exhaust gas, and comprises an analyzing part that measures a component to be measured in the diluted exhaust gas, an introducing path that introduces the diluted exhaust gas into the analyzing part and that has a resistance part as being a flow resistance of the diluted exhaust gas, a viscous component concentration determining part that determines a concentration of a viscous component that is in the diluted exhaust gas and that is different from the component to be measured, and a correction part that corrects the measured value measured by the analyzing part in accordance with the concentration of the viscous component determined by the viscous component concentration determining part.