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Page 14 of 907 Results 131 - 140 of 9067

Y. W. Liu, L. Zhou, C. Li, S. Q. Fu, Z. X. Jin, Y. Chen
Exploration and Application of Opt-Sonic Correlation Measurement Technology to Realize Energy Determination for Naturl gas

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.

Gong Lei, Yang Lingshan, Yu Chunyang, Zhang Yue
Design of gas flow standard device for online or remote calibration of gas flow

Online/remote calibration is the transformation and expansion of traditional measurement. Its development will play a certain role in strengthening measurement management, improving the overall strength and level of measurement, and promoting trade and economic development. In this paper, a set of on-line/remote detection standard devices with a flow range of (0.4 ~ 400) m³/h, expanded uncertainty: U ≤ 0.33 %, k = 2 was designed and developed. Rely on the Internet + calibration mode, use the wireless Internet to send signals from the laboratory to the standard testing module, establish a remote service to send remote control commands, monitor the physical and electrical connections, and control the standard testing module. The program controls the calibration process automatically complete online /remote calibration.

C. Y. Yu, L. L. Zhang, H. J. Yang, X. Liu, X. Li
Standard Device of Natural Gas Real-flow Detection

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.

Huichao Shi, Lianfeng Cheng, Tao Meng, Wenlong Li
Simulation Study on Measurement Method of Flow Fluctuation Signal Based on Chaotic Oscillator

Based on the initial sensitivity of chaotic oscillator which is sensitive to regular signal and immune to noise simultaneously, the chaotic signal detection method can detect the signal submerged in the noise stronger than the measured signal, and relevant research has been applied to measure weak signals submerged by large noise. In this paper, chaotic oscillator is applied in flow fluctuation signal detection of a flow standard device, and a new detection model is proposed to detect the fluctuation signal using the maximum Lyapunov exponent to obtain the threshold value and monitor motions transition of detection system. The Holmes Duffing oscillator is chosen to work as the detection system. Fourth-order Runge-Kutta algorithm is used to solve the function of Holmes Duffing oscillator and to calculate maximum Lyapunov exponent. Simulation experiment on different frequencies fluctuation signal and under different levels of noises is conducted. Simulation results show that detection model can effectively detect the flow fluctuation signal output by flowmeter, and it is immune to the noises.

Huaiming Shen, Qing Guo, Xiaopeng Li, Tao Meng, Zhiming Yang, Huichao Shi
Research on monitoring method of flow field distribution based on multichannel ultrasonic flowmeter

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.

Xuemei Geng, Jieqiang Ji, Guofu Chen, Ningning Zhang, Yan Fang, Xiaojie Wu, Zhiyu Fang
Study on the influence factors of on-line measurement accuracy of portable clamp-on ultrasonic flowmeters

The portable clamp-on ultrasonic flowmeters are now widely used for on-line measurement in water resource systems, due to the advantages of convenience, economy and safety. However, the measurement accuracy of the clamp-on ultrasonic flowmeter is affected by various factors. During the on-line measurement process, the flow field distributions inside the pipeline have a greater impact on the measurement accuracy. The slope of the pipe and the opening degree of the valve are the two factors that affect the distributions of the flow field inside the pipe. To study the influences of these two factors, experimental tests are carried out on the water flow standard facility. The results show that the measurement errors obtained on the horizontal installation pipe are different from that obtained on the vertical installation pipe, and the absolute value of error deviation is 2.3 %. The change of valve opening degree will significantly affect the measurement accuracy of ultrasonic flowmeters. With the decrease of opening degree, the variation range of indication error increases, and the repeatability is difficult to meet the requirements. At the same opening of the valve, the variation range of indication error becomes larger when the measurement point is closer to the valve. The CFD method is applied to simulate the flow filed inside the testing pipeline, and the influence mechanism of the above two factors is analysed. An error calculation model based on the numerical simulation is proposed, which is in good agreement with the experimental results.

Min Wei, Zhu Rui
Study of Effect of Straight Pipe Length on Ultrasonic Flowmeter Measurement during Typical Baffle Interference

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.

Lide Fang, Bangbang Han, Cong Zhou
Study on a void fraction measurement method of gas-liquid two-phase stratified flow

Void fraction as one of the basic parameters of gas-liquid two-phase flow is of great significance to the development and transportation of petroleum pipelines and the design of nuclear reactor cooling towers. Thispaper proposes a void fraction detection method based on PIV technology, which can obtain the velocity distribution and void fraction of the cross-section at the same time. During the experiment, the truth-value of void fraction of the cross section is obtained by installing an endoscopic camera at the back of the test section. The deviation of the void fraction obtained by the two detection techniques is calculated and corrected, and the maximum deviation is only 0.0246. The results show that the method proposed is effective for measuring the void fraction of gas-liquid two-phase stratified flow.

Hong XU, Chunhua SHENG, Lin LI, Yu LIU, Xiaoyan Song
Comparative Analysis on the Electromagnetic Flowmeters Standards for Water Flow Measurement in closed conduits at Home and Abroad

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.

Xuejing Li, Xinhong Yao, Haiyang Li
A Numerical Study on the Influence of Temperature on the Measurement Performance of liquid lead-bismuth_x005f_x0002_eutectic (LBE) Electromagnetic-flowmeter

Liquid lead-bismuth eutectic (LBE) is one of the preferred materials for accelerator driven subcritical(ADS) transmutation targets and coolants in fourth-generation nuclear reactors. Due to the complex and interacting physical and chemical factors in the measurement process of LBE in high temperature operating environment, it is very difficult to control the flow and on-line calibration, resulting in the slow development of LBE flow meter technology, which hinders the fourth Generation nuclear reactor technology development. Electromagnetic flowmeter is currently recognized as one of the most suitable LBE flow measuring instruments in the world. In this paper, the measurement characteristics of LBE electromagnetic flowmeter at high temperature are numerically analyzed and studied, the influence of temperature on magnetic field strength and flow field distribution is quantitatively given, and the measurement linearity of LBE electromagnetic flowmeter is analyzed. The research conclusions provide a certain reference for the detection of lead-bismuth alloy flow parameters and the on-line calibration of LBE electromagnetic flowmeters in the nuclear industry control process.

Page 14 of 907 Results 131 - 140 of 9067