Different applications have different requirements.
See below:
What are the differences between the use of sonic, turbine and Roots gas flow meters in natural gas measurement?
Author: Shanghai Keqi Instrument Co., Ltd.
Currently, in natural gas flow meter measurement, the most widely used flow meters are: gas turbine flow meter, gas ultrasonic flow meter, gas flow meter Flowmeter etc. Each of these flow meters has its own advantages and disadvantages.
1. Gas ultrasonic flowmeter is a new flow measurement method that has emerged in recent years. Its design is relatively complex, so the price is relatively high. At present, there are relatively few manufacturers that can produce them, and their scope of use is only in natural gas transmission pipelines. Basically it is used by large enterprises. With the expansion of the scope of use, production costs are slowly decreasing, and there is a tendency to replace gas turbine flow meters. Its measurement accuracy is high and maintenance is low. Please visit.
2. Gas turbine flowmeter is a velocity type flow measurement instrument. When the fluid flows into the flowmeter, it is rectified and accelerated under the action of the leading fluid (or rectifier). Since the turbine blades are at a certain angle with the flow direction of the fluid, the turbine generates a rotational torque. After overcoming the friction torque and fluid resistance torque, the turbine starts Rotate. Within a certain flow range, the angular speed of turbine rotation is proportional to the fluid volume flow. According to the principle of electromagnetic induction, a magnetic sensor is used to induce a pulse signal proportional to the fluid volume flow from a synchronously rotating reference wheel. The signal is amplified, filtered, and shaped before being sent to the intelligent volume corrector, and is compared with signals such as temperature and pressure. The calculations are performed together and displayed on the LCD screen respectively. High accuracy and simple measurement. However, because of the impeller, there is a pressure difference between the upper and lower ends of the flow meter. The impeller is always under pressure, which places high demands on the bearings of the impeller. This is also the reason why turbine flow meters need to be replaced every 2-3 years. Moreover, the range ratio of the turbine flowmeter is too narrow, and measurement errors will occur during peak and underestimated gas consumption. Its price is relatively moderate. It is widely used in urban gas stations and other places.
3. The gas Roots flowmeter is a volumetric flow meter. When the gas passes through the flow meter, the pressure difference generated between the inlet and outlet acts on a pair of Roots wheels connected with high-precision synchronous gears, thereby driving the Roots wheels to rotate. During this period, the metering chamber, a closed space formed between the Roots wheel, the inner wall of the housing and the gland, is periodically inflated and exhausted. The number of revolutions of the Roots wheel is proportional to the volume of gas passing through the flow meter. The rotation of the Roots wheel is transmitted to the mechanical counter (or output flow pulse signal) through the magnetic coupler, thereby accumulating the volume flowing through the metering chamber to achieve metering purposes. The gas Roots flowmeter has a small initial flow rate and a wide range ratio, and is suitable for measuring gas flow rates with large load changes. And the measurement accuracy is not affected by pressure and flow changes, the performance is stable and the life is long. Generally used in large restaurants, star hotels and other civilian places. Its price is the cheapest among the three flow meters.
The three types of flow meters are used in different situations and have different prices, but they all measure accurately and have high precision.
Source: /NewsView.asp?ID=135&SortID=11