The traditional volume measurement method of natural gas is greatly affected by changes in temperament conditions, thus affecting the normal trade measurement, and can no longer adapt to the current domestic gas transmission status of multiple gas sources.In this context, this study proposes a Sound and light association method measurement technology not limited by the natural gas component to directly determine the natural gas heat generation, thus realizing energy measurement. Combined to the actual operation of natural gas station, the data of multiple multi- component gas standard substances and comparison with the results of chromatographic analyzer are analyzed, The accuracy of the sound and Sound and light association method for heat generation measurement and energy measurement is verified. Finally, the stability of heat measurement was verified by a 5-month interval test. The experimental results show that this technique is extremely useful in the field of energy measurement.

In my country's primary energy consumption structure, the proportion of natural gas is increasing. Accurate and reasonable measurement of natural gas is one of the important links in natural gas utilization, which has huge social and economic benefits. The Chongqing branch of the National Petroleum and Natural Gas Large-flow Detection Station has established a set of standard equipment for real-flow detection of natural gas. The device uses 10 critical flow venturi nozzles with different throat diameters in parallel, and uses the 1.6 MPa natural gas stored in the upstream 5500 m³ spherical tank as the verification gas. One of the biggest advantages of this device is that the pressure of the upstream natural gas source is relatively stable and the gas quality is clean. There is no need to add a voltage stabilizer and a purification device, and it can realize the verification of gas flow meters such as ultrasonic, turbine, and waist wheel. The working pressure of the device is (0.1 ~ 1.2) MPa, and the standard flow qN is (14 ~ 19000) m³/h. The measurement uncertainty of the device is evaluated, and the uncertainty of the device is Ur = 0.28 %, k = 2. A SICK DN200 gas ultrasonic flowmeter was calibrated using this testing standard device and the uncertainty of the measurement results was analyzed, and Ur = 0.32 %, k = 2.

In order to solve the problem that it is difficult to monitor the flow field state in the pipeline during thecalibration process of the flowmeter, this paper proposes a method to monitor the symmetrical state of theflow field in the pipeline by using the cross four-channel flowmeter with different sound channel velocity. The signal decomposition method based on singular value decomposition (SVD) is separate the noise signal from the single of channel measurement result, the velocity distribution curve of the medium in the pipeline is obtained by using 8 acoustic channel velocities lo quantitatively monitor the flow field distribution. in view of the above flow field monitoring methods, a real flow experimental platform based on water flow standard device and cross four channel flowmeter is built to verify the flow field symmetry state monitoring method in the water flow standard device pipeline, the experimental results show that the method can be used to monitor the symmetrical state of flow field in the pipe of water flow standard device.

On the current domestic market, a variety of ultrasonic flowmeters, including those with four (sound) channels, six channels, and eight channels, either through-beam and retro-reflective in channel arrangement, are all claimed to be extremely adaptable to baffle interference and have shorter straight pipes than required by the national standard. To observe and study the tolerance of these gas ultrasonic flowmeters to typical baffle interference and the requirements on the length of the front straight pipe segment, our technical team, according to the process installation requirements of GB/T18604-2014 measurement of natural gas flow by gas ultrasonic flow meters, as well as the AGA NO.9 -2017 report, use the turbine working standard combination system as a flow measurement standard device to test the real flow of natural gas for representative DN100 gas ultrasonic flowmeters with A, B, C, and D channels and different arrangements. Testing process: First, basic data were obtained by testing under ideal pipeline conditions, and then a flow regulator is installed under the interference conditions of typical flow blocking parts (space elbow and manifold are located 30D, 20D and 15D upstream of ultrasonic flowmeter), and see whether the main technical indicators can meet the requirements of trade handover. The technical team of the author designed the test of the effect of different process installation conditions on the measurement accuracy of the gas ultrasonic flowmeter and put forward their own views on the basis of analyzing the test data.

The electromagnetic flowmeter is one of the most important hydraulic structures to measure the water flow in closed conduits. Based on the collected current and latest electromagnetic flowmeter standards at home and abroad, this paper gives a comparative analysis of the technical parameters of electromagnetic flowmeters, including product parameters, measurement parameters and metrological parameters, classified by product standards, measurement standards and metrological standards. The results show that there are some differences among the technical parameters of these standards at home and abroad. It provides helpful and reference value for understanding the requirements of revising standards.