The thermal mass flow meter is considered as one of the new types of mass flow meters. These devices have rapidly grown over the past few decades. Research has it that they have raised over 7.5% through the year 2018. Their primary markets are China, the Middle East, and other developing Asian countries.

Why does natural gas need to be measured?

The content energy of natural gas varies due to the presence of several additives such as other gases, water vapor, chemicals, and likewise. When the energy content of natural gas is high, it implies that the Ethane, Butane, Propane, and similar heavier hydrocarbons are present in a high ration in that natural gas. If the traces of carbon dioxide, sulfides, hydrogens, and similar gases are found in the natural gas, it implies that its energy content is low. Once the heating value of gas is determined, its energy content can be increased. For this exclusive purpose, mass flow meters are used. Flow meters can measure the flow of natural gas as it accurately demonstrates the pressure-drop and reads the direct mass flow. The gas with high-quality energy contents can increase the boilers’ or burners’ efficiency. The more accurate your measurements regarding the natural gas you are using, the more time and money you will save. Natural gas flow meters can be used to handle liquified gases as well.

Why choose thermal mass flow meter for natural gas?

How theramal mass flow meter work for natural gas measurement

Thermal thermal dispersion mass flow meters are used to measure the mass flow of natural gas. They are not used to measure the volume of natural gas. It uses heat to compute the overall measurement. It is highly dependable on the thermal properties and heat conductivity of the natural gas. It involves two distinct processes to determine how the heat is dispersing in the gas, which is based on the primary physics principle, i.e., “Higher velocity results in cooling in the flow stream of the gas.” Let us discuss  these methods briefly in the section below
Constant temperature differential

In this method, the thermal mass flow meter uses two sensors. The first sensor is heated while the second sensor controls, measures, and maintains the gas temperature. The mass flow of natural gas is determined by calculating the electrical power that is required to maintain the heat between the two sensors.

Advantages and disadvantages of thermal mass flow meter

There are several advantages and disadvantages to using thermal mass flow meters for the calculation of the mass flow of natural gas.

Let us discuss the pros first,

Advantages of thermal mass flow meter

• 1.  It has a fast response time
• 2.  It can measure gases which have low pressure
• 3.  It is an ideal method for monitoring, emissions, and stack flow management
• 4.  It facilitates the measurements of a larger pipe size, insertion type thermal mass flow meter can work on large size natural gas pipelines.
• 5.  They are cost-effective as compared to other natural gas flow meters,such as gas turbine flow meter, Coriolis flow meter

Let us look at some disadvantages now

• 1.  These natural gas flow meters cannot measure steam
• 2.  Their accuracy varies based on the coating material of the sensors
• 3.  They usually fluctuate between +/-0.5% to +/- 1% accuracy.
• 4.  They are used to calculate the mass of gases with known composition
• 5.  The readings are affected by moisture or vapor presence as they influence the heat transfer.

Here are the technical parameters of the thermal gas flowmeter for measuring natural gas

• Measuring range: It can measure natural gas flow rates from a few cubic meters per hour to several thousand cubic meters per hour, suitable for different flow scenarios.
• Below is the table for different natural gas flow sensor for different flow range

• - Accuracy: Usually has an accuracy level of ±1% to ±2% of the measured value,
• - Repeatability: The repeatability is within ±0.5%, which means that it can provide stable and reliable measurement results under the same conditions.
• - Operating temperature: Generally, it can work in the temperature range of - 20℃ to 80℃, and some models can even adapt to more extreme temperatures,but for natural gas measurement, the temperature should not be very high
• - Pressure range: It can withstand pressures from low pressure to several MPa, meeting the requirements of different natural gas pipeline pressures. Standard pressure rating is 16 bar.
• - Output signal: It provides various output signals such as 4 - 20mA analog signal and RS485 digital signal, which is convenient for connecting with other equipment for data acquisition and control.
• - Material: The mass flow sensor materials are selected to be corrosion - resistant (stainless steel 316L) and suitable for the characteristics of natural gas, ensuring long - term stable operation.
• - Option with 1-2 relay outputs , 3A/220VAC, 3A/30VAC settable
• - Protection Level : IP65
• - Hazardous area classification :Exd II 2G Ex db IIC T6-T2,ATEX approved