Ultrasonic Gas Meter Pulsation Error Reduction via Cycle Segmentation
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Solution Overview
Problem
Estimation gas meters employing the inverse transit time difference method face challenges in accurately measuring gas flow due to pulsation, especially when the pulsation cycle coincides with or is close to the sampling cycle, leading to significant errors in gas usage amount calculations.
Innovation Solution
A flow meter device that divides the sampling cycle into multiple equal measurement blocks and performs flow measurements within each block, calculating an average flow value across these blocks to reduce the influence of pulsation and enhance measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the sampling cycle coincides with or is close to the pulsation cycle, then the measurement process is simple and efficient, but the measurement precision deteriorates significantly due to capturing only peak or bottom values
Solution Approach 1:
The sampling cycle is divided into multiple measurement periods, and each measurement period is further divided into multiple sub-periods. This segmentation allows the system to capture multiple flow values within each measurement period, preventing the sampling cycle from coinciding with pulsation peaks or bottoms, thereby improving measurement accuracy while maintaining efficient operation
Solution Approach 2:
The invention implements periodic flow measurements at multiple time points within each sampling cycle. By performing measurements at different phases of the pulsation cycle across multiple measurement periods, the system captures a more representative sample of the actual flow conditions, reducing errors caused by pulsation-sampling cycle alignment
2Device complexity
If flow measurement is performed only once per sampling cycle, then the device complexity is reduced, but the reliability of gas usage amount calculation deteriorates when pulsation occurs
Solution Approach 1:
Each sampling cycle is segmented into multiple measurement periods, and each measurement period is divided into multiple sub-periods. This segmentation structure enables multiple flow measurements per sampling cycle without requiring complex additional hardware, as the divisions are implemented through control logic that manages the ultrasonic transducer operation and data collection timing
Solution Approach 2:
The system pre-divides the sampling cycle into measurement periods and sub-periods before actual measurement begins. This preliminary structuring allows the measurement control section to systematically execute multiple measurements at predetermined intervals, ensuring reliable data collection across different pulsation phases while maintaining organized and manageable measurement processes
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 effectively minimizes the impact of pulsation on gas flow measurements, resulting in higher accuracy and more precise gas usage amount calculations compared to conventional methods.
Implementation Method 1
ultrasonic transducers (transmitters/receivers) are provided at an upstream side and a downstream side, respectively, of a measurement fluid passage which is a measurement target, and alternately transmit and receive an ultrasonic wave pulse
Implementation Method 2
measure the flow velocity of the fluid by utilizing the transit time (propagation time) in a forward direction and the transit time in a reverse direction
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A measurement control section of a flow meter device causes a measurement block dividing section to divide a sampling cycle Tc into three or more, for example, four measurement blocks Tb of an equal length and causes the flow measuring section to measure the flow of a fluid in each of the measurement blocks Tb. A flow calculating section of the flow measuring section calculates an average value of flow values obtained in all of the measurement blocks in each sampling cycle Tc, as a flow value in each sampling cycle Tc. This configuration allows a flow meter device which employs an inverse transit time difference method, such as an estimation gas meter, to more effectively lessen the influence of a pulsation and to perform flow measurement with higher accuracy.