Biogas Gas flow measurement by Thermal mass flow meters

The recycling of biogas is a systematic project to benefit the country and the people. This project can protect the environment and save resources. Many countries have invested a lot of manpower and material resources to research and develop biogas recycling technology. Biogas power generation technology is relatively advanced, and only a few countries have mastered this technology.

Biogas flow measurement is a problem that must be solved. The traditional gas flowmeters in biogas flow measurement applications have proven to be less than ideal. With the maturity of thermal gas mass flowmeter technology, more and more biogas power generation companies or biogas recovery companies are beginning to accept thermal gas mass flow meters. The successful use of the hot type has solved the problem of biogas flow metering that has long plagued the industry. A comparison of the thermal gas mass flow rate with the performance of other types of gas flow sensors is now available.


Vortex shedding flowmeter

Vortex flowmeter features: No moving parts, high measurement accuracy, low pressure loss

The vortex flow sensor detection element is not in contact with the fluid to be measured, and the output signal is independent of parameters such as temperature, pressure, density, composition, viscosity of the fluid.

The use of vortex flowmeter is relatively simple and easy to install. It is divided into plug-in type and duct type. When installing, be aware that the flow direction of the fluid should be the same as the direction indicated by the flow meter.

Disadvantages of vortex flowmeter: the ratio is smaller than the thermal gas flowmeter (mostly only 10:1); its performance is greatly affected by pipe line vibration; the size of the pipeline is proportional to the price cost; it needs to be compensated by external temperature pressure; small flow is not sensitive, unstable reading for gas flow .



Rotor flowmeter features: Local display, no power supply; the price is relatively cheap;

It is available in two materials, the glass tube rotor flow meter and the metal tube mass flow meter. Both local display and remote transmission display are available. The interface has HART, standard current signal, PROFIBUS and other forms.

Rotor flowmeter is convenient to use. It is ok to tighten the corresponding bolts during installation, but it should be noted that the direction of fluid flow must be vertical.

Rotor flowmeter shortcomings: the range ratio is 10:1; the pressure loss is relatively large; the dirt is easy to block the flowmeter; the installation and maintenance are relatively complicated; the vibration is greatly affected; the temperature and pressure compensation are required; the diameter of the pipe is proportional to the price. , generally below DN200.


Ultrasonic flow meter (gas)

Ultrasonic flowmeter features: no pressure loss; simple installation; independent of the fluid's temperature, pressure, viscosity and other properties; no moving parts; can measure dirt, corrosive gases and multi-component gases.

Disadvantages of ultrasonic flowmeter: The range ratio is slightly less than that of the thermal gas flowmeter, and the maintenance is relatively troublesome. The high gas precision is high, the metering requires external temperature and pressure compensation, and the equipment configuration is cumbersome and costly.


Thermal gas mass flow meter

Characteristics of thermal mass flowmeter: The range ratio is up to 1000:1; the small range is sensitive; the temperature is not directly affected by temperature and pressure; the pressure loss can be neglected; the large diameter and small flow can be measured with high precision. The price is not much different from the size of the pipeline; the high precision is up to 1%; the temperature range is as wide as -40 °C to 400 °C; it is not sensitive to dust and particulate matter.

The thermal mass flow meter is easy to use and install. It has two types: plug-in type and pipeline type. Whether it is plug-in or pipeline type, maintenance and operation are extremely simple. When installing, please note that the direction of the fluid should be the same as that indicated by the thermal flowmeter.

The disadvantages of the thermal mass flowmeter: It is not suitable for installation in an environment with high viscosity of the medium; it is not suitable for installation in a place where the water content is above 40%.

The advantages of thermal gas mass flow meters in gas measurement are particularly evident in the case of a large number of practical applications in many industries, especially in the case of low pressure and complex gas composition. Compared with other flowmeters, the thermal gas mass flowmeter has the advantages of small pressure loss, wide range ratio and sensitive small range, which is more conducive to energy conservation. Its successful application provides accurate metering equipment for future biogas flow measurement.




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