Tianchen Borui Mass Flowmeter can not only measure the quality of liquids, but also measure the quality of natural gas. However, in the measurement of natural gas, there are not many applications. For example, in the long-distance pipeline trading of refined oil, filling stations and other gas stations. The following will introduce Tianchen Bo Rui mass flowmeter, how to apply to natural gas metering. 1, the characteristics of the mass flow meter 1.1, advantages According to the working principle and structure, compared with other flowmeters, mass flowmeters for measuring natural gas have the following advantages: (1) The measurement accuracy is high, the stability is good, and a high-precision direct flow measurement is truly realized. (2) The high range ratio can generally reach 20!1 to 50!1, and some mass flow meters have a range of up to 100!1 or more. (3) It is not necessary to set a straight pipe section upstream and downstream of the flow meter without being influenced by the fluid flow state in the pipe. (4) There are no moving parts in the test tube, and there are no parts that impede the flow of the fluid. This makes the flow meter easier to maintain and clean and has a longer service life. (5) It has wide adaptability to media and can be applied to the measurement of dirty gas or moisture that is difficult to maintain. Can be applied to gas components and changes in density. (6) Especially applicable to quality-based custody transfer metering and process control applications. 2.2, disadvantages Of course, the mass flowmeter also has its disadvantages. When selecting it, pay attention to the following points: (1) It cannot be used to measure natural gas with low density. (2) Sensitive to external vibration interference, mass flow meter has higher requirements for installation and fixation. (3) It cannot be used for large-diameter flow measurement. (4) Larger volume and weight; greater pressure loss. (5) The price is expensive. 2, mass flow metering method At present, there are three types of systems for international gas trade custody transfer: one is volumetric measurement under standard reference conditions, the other is mass measurement, and the third is energy measurement under standard reference conditions; these three measurement methods, mass flow The meters can be completed alone or with other equipment; the existing relevant standards are the international AGA11# report and the domestic SY/T6659-2006, which uses the Coriolis mass flowmeter to measure the natural gas flow#. 2.1, quality measurement Because the mass flow meter can directly measure the instantaneous mass flow of natural gas, it has unique advantages in quality measurement and can be completed independently without the need of other measuring equipment. 3. Application scope in natural gas metering 3.1. Application of Mass Flowmeter in Natural Gas Transmission Although the mass flowmeter has many advantages, it can not be used for large diameter flow measurement, large pressure loss, high price and other shortcomings, limiting its measurement applications in long-distance pipelines for natural gas; currently, mainstream gas metering for long-distance pipelines. The instrument is an ultrasonic flowmeter, turbine flowmeter, and orifice flowmeter. Orifice plate flowmeter has many disadvantages such as low accuracy, small range ratio, large pressure loss, long straight pipe section requirements before and after the flowmeter, large area, and many components involved in the inspection. The ultrasonic flowmeter has high accuracy, large range ratio, no pressure loss and energy saving. Without moving parts and small maintenance, it can save a lot of manpower and material resources. Therefore, the performance and price ratio of ultrasonic flowmeters is much higher than that of orifice flowmeters. At present, ultrasonic flowmeters have gradually replaced orifice flowmeters as ideal products for natural gas trade handover. Gas turbine flowmeters have a long history of application, and their technologies are relatively mature. At present, they are also widely used in the field of international gas metering. Its characteristics are high accuracy, good stability, wide range, the required straight pipe section is short, and the floor space is small. However, the gas turbine flowmeter requires a relatively high cleanliness of the measured medium. Since the impeller of the turbine flowmeter is easily damaged, it is generally required to install a filter before the flowmeter, and there are also high requirements in the operation of the turbine. As a result, the turbine meter has a large amount of post-maintenance maintenance. Although the ultrasonic flowmeter has many advantages, but because the measurement principle of the ultrasonic flowmeter is the propagation time difference method, when the aperture of the ultrasonic flowmeter becomes smaller, the acoustic path of acoustic wave propagation becomes shorter and the propagation time becomes shorter accordingly, and the propagation time difference will be very small. It is difficult to obtain accurate measurements, which will reduce the range ratio and accuracy of small-diameter ultrasonic flowmeters. Therefore, in the pipeline natural gas metering, the space left for the mass flowmeter basically has only a small diameter (below DN100) and dirty natural gas. In these two cases, the mass flowmeter can be fully utilized. Its advantages. In addition, there will be excellent performance in the self-consumption gas metering of the flaring gas compressor station. The frequency of gas supply and shutdown for domestic gas and compressor fuel gas in the station is high, especially the flow fluctuation range is large ( The stations with the largest fluctuations reach 5 to 20000 Nm3/h, causing a greater impact on the flow meter. In terms of current technology, it is difficult to accurately measure the entire range. The mass flowmeter has a 50:1 range ratio (value range up to 500!1), which is much larger than other types of flowmeters, plus there are no moving parts inside the test tube, and there are no obstructing fluid flow components. Straight section before and after, saves the area and so on. It is suitable for the total measurement of self-consumption gas flow. 3.2. Application of mass flowmeters in the measurement of natural gas production wells In the pipelines outside the natural gas production wells, the density of pressure, temperature, and impurities, as well as the production conditions, are variable. Accurate measurement is very difficult. This condition is not suitable for conventional flowmeters. Mass flowmeters can solve these problems due to the above characteristics. problem. 3.3. Application of Mass Flow Meter in Measurement of LNG Liquefied natural gas (LNG) is an important part of the energy structure. Many LNG projects in China have been put into operation or under construction; the volume of liquefied LNG is approximately 1/600 of the gas under standard conditions, and the transportation cost is only for pipeline transportation. About 1/6, but LNG transportation generally uses high pressure, low temperature (about -160%), the entire storage and transportation process has high requirements for equipment, production processes, personnel. From the perspective of the LNG production process, its measurement can be divided into three types: before liquefaction, after liquefaction and after gasification. Before and after liquefaction, it is in the state of gas. There are comprehensive standards and mature flowmeters for the measurement of natural gas at home and abroad. Type, here only talk about LNG liquefaction measurement. The liquefaction of LNG is similar to that of oil, and the mass (t) is the transfer unit; due to the poor self-lubrication of LNG, dynamic measurement using a volumetric or turbine flowmeter will result in rotor shaft and stator bearing, rotor and metering. The serious wear between the inner walls of the chamber directly affects the life of the flowmeter. There are no moving parts in the metering chamber of the mass flowmeter, which overcomes the influence of the poor self-lubrication of LNG. At the same time, it directly measures the LNG transfer quality. While other types of flowmeters measure volume flow, parameters such as temperature, pressure, and density must be measured to convert the quality of the transaction. If density measurement is used in online density meters, the price is similar to that of mass flowmeters. Off-line analysis, due to high pressure and low temperature, the representativeness of sampling is not good. At the same time, due to the high saturation vapor pressure of LNG, the density cannot be detected under normal pressure, and it can only be detected by chromatographic analysis. Not only is the detection cost high, the operation is complicated, and the detection Accuracy is hard to guarantee. It can be seen that the mass flow meter is an ideal flow meter for measuring LNG; at present, the biggest problem is the lack of on-line flow verification data to verify that the actual measurement uncertainty meets the measurement requirements. 4, structural problems Due to the small natural gas density, at the same flow rate, the mass flow rate is much smaller than that of the liquid, and the detected phase difference caused by the Coriolis force is also much smaller. In order to ensure the measurement accuracy, it should be selected when the quality of the measurement is the same. Mass flowmeter structure with large deformation; Under the same Coriolis force, the longer the radial distance, the larger the deformation of the structure. According to the data, at the maximum flow rate, the measured phase difference of the U-shaped measuring tube It is 5 times that of the straight tube measuring tube. Therefore, when measuring natural gas, the mass flow meter of the U-shaped measuring tube should be preferred. 5, calibration / verification issues The SY/T6659-2006 requires that the mass flow meter used for natural gas trade measurement be verified before use, after repair, and after it reaches the verification cycle, and that real flow verification should be performed. However, the AGA11# report clearly states that the Coriolis force mass flowmeter uses liquid instead of gas for calibration, and uses liquid calibration for gas metering. It has the same indicator, that is, after research, domestic and international standards are in place. Under the condition of benchmarking, then, the mass flow meter for natural gas measurement can be calibrated on the common liquid standard device, which will greatly improve the current inspection cost of natural gas trade. 6 Conclusion In short, mass flow meters are among the best in metering. Although the application and natural gas trade are still relatively rare in the measurement, they have good applications in the measurement of refined oil trades and natural gas production wells, including dirty natural gas. Other flow meters are still inadequate compared to mass flow meters. Roll To Roll Fabric Printing Machine Roll To Roll Fabric Printing Machine,Small Size Printing Equipment,Cloth Printing Machines,Direct Textile Printer Shenzhen Textalk Graphic Technology Co.,Ltd , https://www.textalkdigital.com