FLOW METERS for Natural Gas

by Hei White Heiwhite

The thermal mass flow meter is a brand-new flow meter used to measure the flow of Natural gas. It consists of an assembly of several other devices that combined together. The assembly consist of Coriolis flow meter, magnetic device, and vortex meters. Over the past few decades use of Thermal mas flow meter has increased rapidly. According to a research it is found that it has increased to 7.5% through year 2018 and continue to increase compared to other flow meters. Primarily they are used in markets of China, Middle East, and developing nations.

Why does natural gas need to be measured?

The presence of several elements can cause variation in content energy of natural gas. The elements like water vapor, chemicals, and many other gases. Presence of elements like the Ethane, Butane, Propane, etc. and several other hydrocarbons increase the content energy of gas. This change in energy tells that the elements are present in high quantity. If elements like carbon dioxide, sulfides, hydrogens, and similar gases are present the energy content will be low.

If we want to increase the content energy of natural gas then we need to know the heating value. And To fulfill this need Natural Gas mass flow meters are used. Flow meters can measure the direct mass flow and demonstrates the pressure-drop accurately. But it cannot measure Volumetric flow of natural gas. We need high energy content in natural gas to increase its efficiency Which in turn increases the efficiency of boilers and burners. The more efficient your natural gas will be the more time and money it can save. Not only Natural gas but thermal mass flow meters can be used to measure the mas flow of liquified gases.

Why choose thermal mass flow meter for natural gas?

As we have discussed Thermal dispersion mass flow meters measures the mass flow rather than volume of natural gas. It uses heat to calculate the measurement. Unlike other flow meter, it does not affect by the physical properties of a liquid. They are used to measure the mass flow 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.

Natural gas basically works upon the thermal properties so that their physical properties does not such matter as compare to its heat dispersion while measuring.

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 each of these methods briefly in the section below:

1- Constant temperature differential:

In this method, the thermal mass flow meter (natural gas) 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.

2- Constant current:

The same two sensors are used in this method; however, the power which is delivered to the heated sensor is kept constant. The mass flow is calculated based on the difference in the temperatures of 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:

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

Disadvantages of thermal mass flow meter:

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

After getting all required information, now you can opt for best thermal mass flow meters ensuring accuracy and safety first at:https://www.silverinstruments.com/