Wobbe Index Sensor for Variable-Blend Natural Gas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Natural Gas Vehicles (NGVs) face challenges in accepting a broader range of Renewable Natural Gas (RNG) fuels due to high CO2 levels, which necessitate costly EGR systems for NOx emission control, and existing Wobbe Index measurement techniques are bulky, complex, and not suitable for real-time, on-board applications.
Innovation Solution
A rugged, cost-effective online Wobbe Index sensor using thermal conductivity and infrared sensors, combined with temperature and pressure measurements, to estimate the Wobbe Index in real-time, enabling NGVs to operate with variable RNG fuels without EGR technology and providing accurate fuel analysis for engine parameter configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing Wobbe Index measurement techniques are used, then measurement accuracy is achieved, but device complexity and size increase making them unsuitable for on-board applications
Solution Approach 1:
The patent segments the Wobbe Index measurement into two separate measurement components: thermal conductivity measurement and infrared measurement. Each sensor type measures specific gas composition parameters independently, and the results are combined through calculation to derive the Wobbe Index. This segmentation allows use of simpler, more reliable sensor technologies while maintaining measurement accuracy.
Solution Approach 2:
The patent replaces complex mechanical Wobbe Index measurement systems with a combination of thermal and optical field-based sensors. Instead of using bulky mechanical calorimetric devices, the invention uses thermal conductivity sensors and infrared sensors that have no moving parts, are compact, and suitable for on-board vehicle installation.
2Object-generated harmful factors
If EGR technology is used to control NOx emissions with RNG fuel, then emission control is achieved, but system cost and complexity increase
Solution Approach 1:
The patent converts the harmful effect of high CO2 content in RNG fuel into a beneficial feature. Instead of treating CO2 as merely an impurity to be removed or managed through complex EGR systems, the invention uses the CO2 content as a measurement parameter to calculate the Wobbe Index. This allows the engine control system to adapt to the fuel's actual composition and optimize combustion, thereby controlling NOx emissions without requiring EGR technology.
3Adaptability or versatility
If RNG fuel with high CO2 content is used, then renewable fuel usage increases, but measurement and control difficulty increases
Solution Approach 1:
The patent creates a universal measurement system that can handle various RNG fuel compositions with different CO2 contents. The dual-sensor approach (thermal conductivity + infrared) provides multi-functional capability to measure different gas components (CH4, CO2, N2, O2) and calculate multiple parameters including Wobbe Index, methane content, and inert gas percentage. This universal system accepts a broad range of RNG fuels from different sources without requiring source-specific measurement 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
The sensor achieves ±1% accuracy in Wobbe Index measurement, allowing NGVs to efficiently combust unprocessed RNG, reducing engine costs and increasing RNG usage, while ensuring reliable and safe operation in harsh environments.
Implementation Method 1
A rugged, cost-effective online Wobbe Index sensor using thermal conductivity and infrared sensors
Implementation Method 2
A rugged, cost-effective online Wobbe Index sensor using thermal conductivity and infrared sensors
Data Source
AI summary
A system and method for configuring parameters for a variable gaseous appliance, comprise a sensor for detecting a composition of the gaseous fuel in a fuel tank. A first set of instructions are executable on a processor for receiving a signal from the sensor and analyzing the gaseous fuel based on the Wobbe Index, methane index, and inert gas percentage, to produce a gaseous fuel analysis. A second set of instructions are executable on the processor for producing a signal for configuring parameters of the engine for running the engine based on the gaseous fuel analysis.