Application of thermal gas mass flowmeter in high pressure natural gas measurement

Thermal gas mass flow meter is used to measure and control the gas mass flow meter, different from other gas flow meters, do not need to carry out pressure and temperature correction, directly measure the gas mass flow.

When selecting a thermal mass flowmeter, several important factors should be taken into consideration to ensure it meets the requirements of the application and provides accurate and reliable measurements. Here are key points to pay attention to:

In order to solve the problem of leakage caused by poor measurement accuracy or inability to measure below the lower limit of the instrument, a new type of thermal gas mass flowmeter is developed based on the theory of forced convection heat transfer and the principle of hot wire anemometer. The sensitivity of the instrument is greatly improved and the dead zone of the instrument is reduced by using microfilament structure in the sensitive element and the velocity measuring heating element.

One of the key advantages of thermal mass flow meters is their quick response time, enabling real-time monitoring and control of gas flow in dynamic processes. Moreover, these meters are known for their low pressure drop, minimizing energy consumption and preserving the efficiency of the overall system. With no moving parts, thermal mass flow meters also offer low maintenance requirements, reducing downtime and operational costs for industries relying on precise gas flow measurements.

Response speed: 1s
Output signal: 4-20mA (Photoelectric isolation, large load 500Ω)、
pulse、RS-485 (photoelectric isolation)、HART agreement
Alarm: 1-2 relay normally open contact、10A/220V/AC、*/30V/DC
Type of supply: Separate structure, integrated structure
Pipe material: Carbon steel, stainless steel, plastic, etc
Field display: Four lines of Chinese liquid crystal display
Display content: Mass flow, standard volume flow, cumulative flow, standard time, cumulative running time, standard flow rate, etc
Protection grade: IP65
Sensor material: Stainless steel Stainless steel, carbon steel

Thermal mass flowmeters offer several advantages and disadvantages, which are important to consider when selecting a flow measurement solution. Here are some of the key advantages and disadvantages:

Thermal gas mass flowmeter is the use of fluid flowing through the pipe heated by an external heat source when the temperature field changes, is a high-sensitivity, high-precision gas measurement instrument, in the gas flow measurement conditions, good stability, used for gas process control and gas flow measurement one of the most used instruments.

With the development of new energy technology, natural gas is more and more widely used in many new energy industries, and the thermal gas mass flowmeter has become a suitable instrument for measuring high pressure gas measurement. Below we analyze from the perspective of product performance and installation cost, why the thermal gas mass flowmeter can become a suitable low degree meter in high pressure natural gas measurement.

Direct measurement of gas mass, without temperature, pressure compensation of gas flow measurement instrument, it represents the development trend of gas flow measurement. The thermal mass flowmeter sensor part is composed of two reference platinum resistance temperature sensors, using a bridge loop, one sensor measures the fluid temperature, and the other sensor is a heating element, maintaining a constant temperature difference higher than the fluid temperature, that is, when the gas flows through the heating element, the heat is taken away, and the heat is proportional to the flow rate of the gas and the density of the gas. To maintain a fixed temperature difference between the two temperature sensors requires the circuit to provide more power to the heating element, and the amount of output power in the circuit is related to the mass of the fluid, thus measuring the flow rate.

Measuring medium: Various gases (except acetylene gas)
Pipe diameter range: DN10-2000mm
Accuracy Degree: ±1～2.5%
Pipe material: Carbon steel, stainless steel, plastic, etc

Thermal gas mass flowmeter as a gas flowmeter, the application is very wide, today we specifically understand the use of thermal gas mass flowmeter:

In practical applications, thermal mass flowmeters require careful attention to various factors to ensure accurate and reliable measurement of fluid flow rates. Here are some key considerations for the practical application of thermal mass flowmeters:

At the heart of a thermal mass flow meter is a sensor that heats up a portion of the gas stream while monitoring the temperature difference between the heated and unheated sections. As the gas flows over the heated sensor, it carries away heat, and the temperature difference provides a direct measurement of the mass flow rate. The beauty of this method lies in its ability to provide accurate readings across a wide range of flow rates, from low to high velocities, ensuring versatility and reliability in various industrial settings.

Structural form: plug-in pipelined
Measuring medium: All gases (except acetylene)
Pipe diameter range: Caliber DN32 or higher DN10～DN2000mm
Velocity range: 0.1～120Nm/s
Precision: ±1～2.5%
Operating temperature: Sensor：-40℃～+220℃
convertor：-20℃～+45℃
Working pressure: Medium pressure≤2.5Mpa
Medium pressure≤4.0Mpa
Power supply: DC24V or AC220V≤18W

How to improve the accuracy of thermal gas mass flow meter?

When selecting a thermal mass flowmeter, several important factors should be taken into consideration to ensure it meets the requirements of the application and provides accurate and reliable measurements. Here are key points to pay attention to:

In-line thermal mass flowmeter is equipped with the same process pipe with the same inner diameter as the field pipe. The connection with the field pipe is flange connection or thread connection. Pipe segment sensor applicable pipe diameter: DN15 ~ 2000mm.

Measuring medium: Various gases (except acetylene gas)
Pipe diameter range: DN10-2000mm
Accuracy Degree: ±1～2.5%
Pipe material: Carbon steel, stainless steel, plastic, etc

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

The thermal gas mass flowmeter is an instrument for measuring fluid flow by using the principle of heat conduction. The instrument uses constant temperature difference method to accurately measure the gas mass flow.

The thermal gas flowmeter has many remarkable characteristics, which make it widely used in the field of gas flow measurement. The following are the main features of thermal gas flowmeters:

Common faults encountered with thermal mass flowmeters can disrupt their accurate measurement capabilities. Here are some typical issues along with potential solutions:

Thermal gas mass flowmeter has a wide range of applications in many fields, its high precision, rapid response and stability characteristics make it in a variety of gas flow measurement occasions can play an excellent performance, for the development of various industries to provide more reliable technical support.

Thermal gas mass flowmeter is the use of fluid flowing through the pipe heated by an external heat source when the temperature field changes, is a high-sensitivity, high-precision gas measurement instrument, in the gas flow measurement conditions, good stability, used for gas process control and gas flow measurement one of the most used instruments.

At present, oxygen generator in the production process will be affected by external influences, more and more enterprises for fine management, energy consumption, cost accounting and other requirements for the loss of this part of the oxygen measurement.

The thermal mass flowmeter is an device for measuring gas flow by using the principle of thermal diffusion. The sensor consists of two reference thermal resistors (RTDS). One is the speed sensor RH, and the other is the temperature sensor RMG, which measures the temperature change of the gas. When the two RTDS are placed in the measured gas, one sensor RH is heated and the other sensor RMG is used to sense the measured gas temperature. As the gas flow rate increases, the airflow carries away more heat, and the temperature of the sensor RH drops.

Measuring medium: Various gases (except acetylene gas)
Pipe diameter range: DN10-2000mm
Accuracy Degree: ±1～2.5%
Pipe material: Carbon steel, stainless steel, plastic, etc

1. Principle of thermal gas mass flowmeter

Thermal gas mass flowmeter The thermal distributed flowmeter uses the flow fluid to transfer heat to change the heat conduction distribution effect of measuring the temperature distribution of the tube wall. 2) King’s Law using the heat dissipation (cooling) effect. And because the structure of the detection element extends into the measuring tube, also known as immersion or intrusion type. Some instruments that are inserted from outside the tube into the process tube when in use are called plug-in.

The thermal gas mass flowmeter is an instrument that uses the principle of heat conduction to measure flow. The instrument adopts constant temperature difference method for gas mass flow sensor part consists of two reference platinum resistance temperature sensors. Using a bridge loop, one sensor measures the flow temperature and the other maintains a constant temperature difference above the fluid temperature, allowing flow measurement under high temperature and high pressure conditions.

Due to the continuous development of thermal gas mass flow meter is based on the principle of thermal diffusion, that is, the use of fluid flow through the heated object, the heated object of the heat dissipation of how much with the fluid flow rate into a certain proportional relationship. Specifically, the flow meter’s sensor has two standard and the RTD, has been used as a heat source, has been used to measure the fluid temperature, the fluid flows through, the heat loss of the heat source and the size of the flow into a non-linear relationship, the thermal gas mass flowmeter can be converted into a measurement of this relationship to measure the flow rate of the signal of the linear output.

The origin of the thermal gas mass flowmeter is from the hot wire anemometer. The temperature of the platinum heating wire has a proportional relationship with the change in the flow rate of the fluid: the faster the flow rate, the more heat is taken away.

Thermal gas mass flowmeters are a type of mass flowmeter specifically designed for measuring the flow rate of gases, while mass flowmeters, in a broader sense, can measure the flow rate of both gases and liquids. Here are some key differences between thermal gas mass flowmeters and other types of mass flowmeters:

Installing and debugging a thermal mass flowmeter correctly in the early stages is crucial to ensure accurate and reliable measurements. Here are some precautions to take during installation and debugging:

Thermal gas mass flowmeter adopts the principle of thermal diffusion, and thermal diffusion technology is a technology with excellent performance and high reliability under harsh conditions.

The thermal gas mass flowmeter is an instrument for measuring fluid flow by using the principle of heat conduction. The instrument uses constant temperature difference method to accurately measure the gas mass flow.