Gas Sensor Viscosity Measurement Differential Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas sensors for measuring viscosity and Wobbe index are complex, costly, unreliable, and prone to drift, making them unsuitable for accurate and efficient combustion optimization in natural gas applications, particularly in varying gas compositions.
Innovation Solution
A compact, economical gas sensor that measures viscosity and additional parameters like thermal conductivity and carbon dioxide content to improve the accuracy of Wobbe index measurement, using a differential pressure system with capillary channels and a signal processing circuit to calculate the Wobbe index, allowing for real-time adjustment of air-fuel ratios before ignition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing gas sensors are used to measure viscosity and Wobbe index, then measurement capability is provided, but device complexity and cost increase while reliability decreases
Solution Approach 1:
The sensor is divided into functionally independent modules: a measuring chamber for viscosity measurement, a reference chamber for pressure compensation, and a gas interface portion for gas introduction. This segmentation allows each module to be optimized independently and simplifies the overall system architecture, reducing complexity while maintaining measurement accuracy.
Solution Approach 2:
A reference chamber is introduced as an intermediary element to compensate for pressure variations affecting the viscosity measurement. The reference chamber receives the same gas through a second capillary and provides a reference pressure signal that is used to correct the measurement from the measuring chamber, thereby improving reliability without adding complex measurement systems.
2Reliability
If existing gas sensors are used for combustion optimization, then gas parameter measurement is enabled, but reliability and stability deteriorate due to drift
Solution Approach 1:
The sensor incorporates a feedback mechanism where the pressure difference between the measuring chamber and reference chamber is continuously monitored and used to compensate for drift. The reference chamber provides a stable reference that allows the system to detect and correct deviations in the measuring chamber, ensuring long-term reliability and measurement stability.
Solution Approach 2:
The reference chamber is pre-configured with a second capillary of identical dimensions to the measuring chamber capillary. This beforehand preparation ensures that both chambers respond identically to pressure variations, providing a built-in compensation mechanism that cushions against measurement drift before it affects the Wobbe index calculation.
3Ease of manufacture
If compact and economical sensor design is implemented, then ease of manufacture and assembly improve, but measurement precision may be compromised
Solution Approach 1:
The measuring chamber, reference chamber, and gas interface portion are merged into a single integrated sensor assembly. The capillaries are formed as integral parts of the chamber structures, and the pressure sensor serves both chambers simultaneously. This merging reduces the number of separate components, simplifies assembly, and lowers manufacturing costs while maintaining measurement precision through the differential measurement approach.
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 sensor provides reliable, robust, and cost-effective measurement of the Wobbe index, enabling efficient combustion optimization and reducing ignition problems by adjusting air-fuel ratios in real-time, suitable for various natural gas applications including appliances, engines, and biogas production.
Implementation Method 1
a first capillary channel fluidically connecting the measuring chamber to the gas interface portion, a second capillary channel fluidically interconnecting the reference chamber to the gas interface portion
Implementation Method 2
a pressure sensor configured to measure a time dependent variation in pressure of gas in the measuring chamber, the time dependent variation of pressure in the measuring chamber due to flow of gas through the resistive passage being correlated to a viscosity of the gas
Data Source
Figure 1
Figure 2a~2b
Figure 3a~3b
AI summary
Gas sensor (2) for measuring properties of a gas (1), including a gas viscosity sensor (4) comprising a gas interface portion (20) in contact with the gas (1) to be measured, and a measuring chamber system (15) comprising a measuring chamber(16), a first resistive passage (18) fluidically connecting the measuring chamber (16) to the gas interface portion (20), a pressure generator (25) configured to generate a change in pressure in the measuring chamber, and a pressure sensor (28) configured to measure a time dependent variation in pressure of gas in the measuring chamber, the time dependent variation of pressure in the measuring chamber due to flow of gas through the resistive passage being correlated to a viscosity of the gas. The gas viscosity sensor further comprises a reference chamber system (21) comprising a reference chamber and a second resistive passage (24) fluidically interconnecting the reference chamber (22) to the gas interface portion (20), the reference chamber (22) being coupled to the pressure sensor (28) of the measuring chamber such that the pressure sensor is configured to measure a differential pressure between a pressure in the measuring chamber and a pressure in the reference chamber.