Fluid Transit Time Estimation in Distribution Grids
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for tracking fluid transit times and fractions in fluid distribution networks, such as natural gas grids, face challenges in accurately validating gas transit times and fractions from feed-in points to exit points, especially with varying calorific values due to mixed gas compositions, leading to complex and costly invoicing processes.
Innovation Solution
A method utilizing sensor elements to collect data on fluid properties at upstream and downstream nodes, with a finite state machine for aligning measurements and minimizing alignment errors, to estimate transit times and fractions, allowing for direct validation and efficient calorific value allocation without requiring detailed network topology data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If calorific value adjustment by adding LPG is performed to maintain grid calorific value within 2% tolerance, then invoicing compliance is improved, but system costs increase significantly (around €15,000 per year per 100 m³)
Solution Approach 1:
The patent replaces the mechanical/chemical approach of physically adding LPG to adjust calorific values with an information-processing approach using sensor data, signal processing, and computational algorithms to track and allocate calorific values. This substitution eliminates the need for costly physical adjustments while maintaining invoicing compliance.
Solution Approach 2:
The patent creates a virtual copy of the physical gas flow through digital signal processing. By measuring physical properties (temperature, pressure, flow rate) and creating corresponding digital representations, the system can track calorific values without physically manipulating the gas. This allows for accurate invoicing allocation without the costs of physical adjustment.
2Measurement precision
If mobile process gas chromatograph (PGC) is used to collect measurement data for validation, then measurement precision is improved, but device complexity and operational complexity increase
Solution Approach 1:
The patent introduces simple infrared sensors as intermediary devices that continuously measure gas properties without requiring complex mobile PGC equipment. These sensors act as mediators between the gas flow and the validation system, providing sufficient data for validation while dramatically reducing system complexity and operational burden.
Solution Approach 2:
The patent replaces the complex mechanical mobile PGC system with simpler sensor-based measurement and digital signal processing. Instead of physically transporting and analyzing gas samples with complex instrumentation, the system uses fixed sensors and computational algorithms to achieve validation, reducing both device complexity and operational complexity.
3Ease of operation
If time-invariant signal propagation model is used to determine transit times from signal trajectories, then ease of operation is improved, but measurement precision deteriorates due to inability to handle varying flow conditions
Solution Approach 1:
The patent transitions from a static time-invariant model to a dynamic time-variant model for signal propagation. The system continuously adapts to changing flow conditions by updating propagation characteristics in real-time, allowing accurate transit time calculation under varying operational conditions while maintaining ease of operation through automated adaptation.
Solution Approach 2:
The patent implements feedback mechanisms where measured signal characteristics are continuously fed back into the propagation model to refine transit time calculations. This feedback loop allows the system to automatically adjust to changing conditions, maintaining both operational simplicity and measurement precision by letting the data drive the model updates.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention is related to a method for the estimation of transit times τo,q(t), of fluids between a first number Q ≥ 1 of upstream network nodes q = 1,2, ..., Q interconnected with a second number 0 ≥ 1 of downstream network nodes o = 1,2, ..., O, and corresponding fractions αo,q(t) of the fluids, which E properties e = 1,2, ..., E are sampled utilizing suited sensors at each upstream network node of said first number Q of the upstream network nodes, composing the fluids which said E properties e = 1,2, ..., E are sampled utilizing suited sensors at each downstream node of said second number O of the downstream network nodes in at least one part of a fluid distribution network.