Thermal Gas Mass Flow Meter Working Principle

Thermal gas mass flow meter is an instrument that uses the principle of thermal diffusion to measure gas flow. Shanghai Cixi Instrument and Meter Co., Ltd. introduces to you that the sensor is composed of two reference thermal resistance (RTD). One is the speed sensor RH, and the other is the temperature sensor RMG that measures the temperature change of the gas. When the two RTDs are placed in the measured gas, the sensor RH is heated, and the other sensor RMG is used to sense the temperature of the measured gas. As the gas flow rate increases, the gas flow takes away more heat, and the temperature of the sensor RH decreases.

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According to King's law of thermal effect, heating power P, temperature difference △T (TRH-TRMG) and mass flow Q have a definite mathematical relationship. P/△T=K1+K2 f(Q)K3 K1, K2, and K3 are constants related to the physical properties of the gas. The unique temperature difference measurement method of the thermal gas mass flowmeter overcomes the large zero drift caused by the water, oil and impurities in the gas when the thermal gas mass flowmeter adopts the principle of constant temperature difference to measure the gas flow, resulting in unmeasured Disadvantages. It can also be used to measure the mass flow of wet gas, such as real-time detection of the air volume (speed) in the mine gas drainage, air supply, and exhaust system.

 

Convenient installation, simple maintenance, two-way detection, anti-vibration

Up to 24 points of flow measurement

Correction of output analogue multi-point non-linear curve correction

Wide range ratio 100:1

Simultaneous detection of flow and temperature, switch display

Large diameter and small flow measurement, can be used for leak detection

Adopt proprietary technology "double balance structure" package sensor

Proprietary high humidity and high temperature algorithm, medium temperature can reach 500℃

Direct mass flow detection without temperature and pressure compensation

 

 

The thermal flow meter is a flow meter designed based on the principle of thermal diffusion. That is, when the fluid flows through the heating object, the heat loss of the heating object is proportional to the flow rate of the fluid. The sensors of this series of flow meters have two standards Grade RTD, one is used as a heat source, and the other is used to measure the temperature of the fluid. When the fluid flows, the temperature difference between the two has a linear relationship with the flow rate. Converted to a linear output measuring flow signal.

 

 

Thermal gas mass flow meters are divided into installation methods: plug-in type and pipe segment type.

Plug-in

The plug-in sensor can be installed and maintained online. The installation process is to first weld a base with external threads on the outer wall of the pipeline, install a 1-inch stainless steel ball valve on the base, and then use a special tool to drill a 22mm diameter hole in the pipeline. After the drilling is completed, remove the special tool, and finally connect the sensor Install on the valve and insert the sensor into the center of the pipe (the insertion position of the sensor has been determined at the factory). The plug-in sensor is suitable for pipe diameter: DN80～6000mm.

 

 

Pipe segment

The pipe segment thermal gas mass flowmeter is equipped with process pipes with the same inner diameter as the on-site pipes when they leave the factory. The connection with the on-site pipeline is flange connection or threaded connection. The flange standard complies with the national standard GB/T9119-2000. Pipe section sensor is suitable for pipe diameter: DN15～2000mm.

 

 

The sensor is made of stainless steel, and the pipe is made of carbon steel or stainless steel.

 

Application field editing Voice

● Oxygen, nitrogen, hydrogen, chlorine and multi-component gas measurement.

● Measurement of blast furnace gas and coke oven gas.

● Flue gas measurement.

● Aeration and chlorine measurement in biogas and water treatment.

● Compressed air measurement.

● Flow measurement of natural gas, liquefied gas, flare gas, etc.

● Primary air and secondary air flow measurement of power plant blast furnace

● Flow measurement of underground ventilation or exhaust system

●Air flow measurement during gas process

●Measurement of flue gas flow rate (velocity) discharged from the chimney (CEMS)

●Calciner flue gas flow measurement

●Gas flow measurement in the production process of cement, cigarette and glass factories

●Gas flow measurement in solvent recovery system

●Gas flow measurement during semiconductor chip manufacturing

●Measurement of carbon dioxide gas flow during beer production

●Gas flow (speed) measurement in heating, ventilation and air conditioning systems

●Measurement of combustion gas flow in coal-fired boilers

●Real-time detection of flow rate (speed) in underground ventilation or exhaust system

 

Applicable medium: all gases compatible with stainless steel.

If you need to know more,please contact winny: sales01@cxflowmeter.com