Flow measurement is widely applied across various fields, including industrial and agricultural production, national defense, scientific research, foreign trade, and daily life. In the petroleum industry, flow measurement is integral to the entire process-from extraction, transportation, and refining to commercial sales; no single stage can function without it, as doing so would jeopardize normal production and trade operations. In the chemical industry, inaccurate flow measurement can lead to imbalances in chemical composition ratios and compromise product quality; in severe cases, it can even result in safety accidents. In the power generation industry, the measurement and regulation of fluids-such as liquids, gases, and steam-play a crucial role. The accuracy of flow measurement is not only economically significant for ensuring power plants operate at optimal parameters, but-with the development of high-temperature, high-pressure, and large-capacity units-it has also become vital for safe operation. For instance, an interruption or reduction in the instantaneous feedwater flow to a large-capacity boiler could cause serious incidents, such as boiler dry-out or tube bursts. Consequently, flow measurement devices must not only provide accurate readings but also issue timely alarm signals. In the iron and steel industry, measuring the flow of circulating water and oxygen (or air) during steelmaking is a key parameter for ensuring product quality. Flow measurement is equally indispensable in sectors such as light industry, food processing, and textiles.
Clamp-on and insertion-type transducers are the most commonly used varieties. While single-path ultrasonic flow meters feature simple structures and ease of use, they lack adaptability to changes in flow profile distribution; however, rapid advancements in microelectronics and computer technology have driven the upgrading of instrumentation, leading to a proliferation of new flow meter models. To date, reportedly over a hundred types of flow meters have been introduced to the market, offering solutions to many previously intractable field application challenges. my country began developing modern flow measurement technology relatively late. [The system includes] a component positioned at the upstream end of the flow channel (6) relative to apertures (11) and (12) to reduce the inflow of the measured fluid into said apertures; a measurement control unit (19) for measuring the ultrasonic propagation time between ultrasonic transducers (8) and (9); and a calculation unit (20) for calculating the flow rate based on signals from the measurement control unit (19). Flow meters should be kept away from ferromagnetic objects and equipment generating strong electromagnetic fields (such as large motors or transformers) to prevent magnetic interference with the sensor's operating magnetic field and flow signals. Analysis of component failures caused by lightning strikes reveals that the induced high voltages and surge currents responsible for these failures primarily enter via the control room power supply lines, with other entry points being less common. Since electromagnetic flow meters are frequently used to measure fluids containing suspended solids or contaminants, there is a relatively high probability of malfunctions caused by the buildup of deposits on the inner walls-particularly if the conductivity of the deposit layer is similar to that of the fluid itself. Common malfunctions during the commissioning phase are usually attributable to improper installation.
