WK-TMF-F Pipeline Thermal Gas Mass Flow Meter

summary:

The thermal gas mass flowmeter is designed based on the principle of thermal diffusion, and uses the constant temperature difference method to accurately measure gases. It has the advantages of small size, high degree of digitization, easy installation, and accurate measurement.

The sensor part consists of two reference level platinum resistance temperature sensors. When the instrument is working, one sensor continuously measures the medium temperature T1; the other sensor self heats up to a temperature higher than the medium temperature T2 and is used to sense fluid flow velocity, known as a velocity sensor. The temperature Δ T=T2-T1, T2>T1. When a fluid flows through, the gas molecules collide with the sensor and take away the heat of T2, causing the temperature of T2 to decrease. To keep Δ T constant, the power supply current of T2 needs to be increased. The gas flow rate is faster, and the more heat is taken away. There is a fixed functional relationship between the gas flow rate and the increased heat, which is the principle of constant temperature difference.

（1）

of which- Fluid specific gravity (related to density)

V - Flow velocity

K - Balance coefficient

Q - Heating capacity (related to specific heat and structure)

Δ T - temperature difference

Due to the fact that the temperature of the sensor is always automatically and consistently higher than the temperature of the medium (environment) by about 30 ℃, thermal gas flow meters do not require temperature compensation in principle.

Thermal gas qualityThe flowmeter is suitable for medium temperatures ranging from -40 to 250 ℃. Below, the medium temperature is -40-350 ℃. below

(1) The specific gravity and density of the fluid in the equation are related

（2）

of which- Medium density under working condition volume (kg/m3)

ρ n - Density of medium under standard conditions (101.325 Kpa, 20 ℃) (kg/m3)

P - Operating pressure (kPa)

T - Operating temperature (℃)

From equations (1) and (2), it can be seen that the functional relationship between flow rate, operating pressure, gas density, and operating temperature has been determined.

The constant temperature differential thermal gas mass flowmeter is not only unaffected by temperature, but also by pressure. The thermal gas mass flowmeter is a true direct mass flowmeter, and users do not need to adjust pressure and temperature.

Technical parameters:

The thermal gas mass flowmeter has the following technical advantages:

◀A true quality flowmeter does not require temperature and pressure compensation for gas flow measurement, making the measurement convenient and accurate. The mass flow rate or standard volume flow rate of the gas can be obtained.

◀ Wide range ratio, capable of measuring gases with flow rates ranging from 100Nm/s to 0.1Nm/s, and can be used for gas leak detection.

◀ Good seismic performance and long service life. The sensor has no moving parts or pressure sensing components, and is not affected by vibration on measurement accuracy.

◀ Easy installation and maintenance. If on-site conditions permit, non-stop installation and maintenance can be achieved. (Special customization required)

◀ Digital design. The overall digital circuit measurement is accurate and easy to maintain.

◀ By using RS-485 communication or HART communication, factory automation and integration can be achieved.