Gas flow measurement unit introduction

Gas flow measurement unit
The gas flow measurement unit uses standard cubic meters. We often call it a mass-quality unit because it looks like a volume unit. It is actually a mass unit. It has nothing to do with the pressure at the place of use. If the gas is natural gas, 1 standard cubic meter. The quality is also related to the composition of natural gas. The use of energy units in the natural gas trade settlement measurement is more reasonable because the same natural gas quality, if its composition is different, its calorific value is also different.
Example: Air 1 standard cubic meter = 1.2041 kg (standard state is 101.325 kPa, 20 ° C)
Flow rate 100 m 3 /h (standard state) = 120.41 kg/h
Natural gas, the relative density of natural gas is d=0.6, then
1 standard cubic meter = 1.2041 × 0.6 = 0.7225 kg
Flow rate 100 m 3 /h (standard state) = 72.25 kg/h
In the standard state, the pressure is standard atmospheric pressure at home and abroad, that is, 101.325 kPa, but the temperature is not the same. I have two temperature standards, 20 ° C, 0 ° C.
Natural gas is 20 ° C, gas is 0 ° C or 20 ° C, which is caused by historical reasons. In trade settlement, both parties to the contract can negotiate any temperature, called the contract temperature. The meaning of gas flow measurement unit standard cubic meters
Internationally, 15.6 ° C ( 60 ° F ) or 15 ° C ( 59 ° F ).
The flowmeter measures the volumetric flow rate of the working condition, which is obtained by pressure and temperature conversion (using a flow calculator).
Its conversion formula is
formula
q vn , q v -- volume flow in standard state and working state, respectively, m 3 /h ;
p n , p —— the absolute pressure in the standard state and the working state, respectively; Pa;
T n , T —— respectively the thermodynamic temperature under standard state and working state, K;
Z n , Z —— The gas compression coefficients of the standard state and the working state, respectively.