Particulate Matter Measurement Device Heat Resistance
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Solution Overview
Problem
Existing particulate matter measurement devices face limitations due to inadequate heat resistance and pressure handling capabilities, leading to reduced measurable ranges and increased costs, especially when dealing with varying engine conditions and pressure differences across the exhaust gas pipe.
Innovation Solution
A modular particulate matter measurement device is designed with a first unit near the exhaust gas pipe, featuring a short metal sampling pipe, orifice parts, and pressure rising check valves to maintain high temperatures and control pressure, while a second unit handles dilution and measurement, allowing for expanded pressure range and cost-effective operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hot hose is used to connect the measurement unit to the exhaust gas pipe, then particulate matter loss is prevented, but heat resistance is insufficient and cost increases
Solution Approach 1:
The system is divided into two segments: a short sampling pipe directly connected to the exhaust gas pipe for high-temperature exhaust gas intake, and a connecting pipe connected to the measurement unit for diluted exhaust gas transport. This segmentation allows each segment to be optimized for its specific function, with the sampling pipe requiring minimal length to maintain temperature while the connecting pipe can use lower-cost materials.
Solution Approach 2:
The exhaust gas undergoes parameter changes through dilution with ambient air in the dilution mechanism. By changing the temperature and concentration parameters of the exhaust gas before it enters the measurement unit, the system can use lower-cost piping materials while maintaining measurement accuracy.
2Stress or pressure
If the orifice diameter is reduced to increase withstand pressure, then pressure handling capability improves, but flow rate control becomes difficult at low pressures
Solution Approach 1:
The system dynamically adapts to different pressure conditions by using a dilution mechanism that can adjust the mixing ratio of exhaust gas and ambient air. This dynamic dilution capability allows the system to maintain optimal flow rates across a wide pressure range, from high-pressure engine operation to low-pressure idle conditions, without requiring multiple fixed orifice sizes.
3Measurement precision
If the measurement unit is arranged separately from the exhaust gas pipe, then measurement accuracy improves, but heat loss and piping complexity increase
Solution Approach 1:
The dilution mechanism performs preliminary action by diluting the exhaust gas before it enters the measurement unit. This pre-dilution process reduces the temperature and particulate concentration of the exhaust gas, allowing the measurement unit to be positioned farther from the exhaust pipe without causing excessive heat loss or measurement errors.
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
The solution improves heat resistance and pressure handling capabilities, enabling accurate measurement across a wider range of pressures without increasing costs, and prevents particulate matter attachment in the sampling pipe, ensuring reliable and precise particulate matter counting.
Implementation Method 1
an orifice part arranged in a midst of the exhaust gas flow channel
Implementation Method 2
a pressure rising check valve that is connected to the exhaust gas flow channel and that prevents a rise of the pressure by letting a part of the exhaust gas escape with mechanically opened by the pressure
Implementation Method 3
a dilution gas flow channel that is connected to a downstream side of the orifice part in the exhaust gas flow channel and that introduces the dilution gas into the exhaust gas flow channel
Data Source
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AI summary
An object of this invention is to improve resistance to heat and to increase a measurable range of a pressure without increasing a cost In order to attain the object, a first unit (U1) arranged near an exhaust gas pipe (1) and a second unit (U2) arranged separately from the first unit (U1) and connected to the first unit (U1) through a connecting pipe (C1) are provided, and the first unit (U1) has an exhaust gas flow channel (L11) from one end of which an exhaust gas is introduced, an orifice part (O11) arranged in a midst of the exhaust gas flow channel (L11), a pressure rising check valve (V11) of a mechanically operating type that is connected to a downstream side of the orifice part (O11) in the exhaust gas flow channel (L11), and a dilution gas flow channel (L12) that is connected to a downstream side of the orifice part (O11) in the exhaust gas flow channel (L11) so that the diluted exhaust gas diluted by the dilution gas is derived from the other end of the exhaust gas flow channel (L11).