Basic characteristics of gas

- Mar 13, 2019-

1. Density: Refers to the weight contained in the unit volume.

2, specific gravity: the proportion of gas refers to the unit volume of gas has the density, the same state of air density ratio, also known as relative density or relative gravity.

3, Calorific Value: unit volume gas completely combustion of the heat released, become the calorific value of the gas.

4, the Theoretical Air volume: refers to the unit gas according to the combustion reaction equation of the complete combustion of the minimum amount of air required.

The amount of air required for LPG combustion is 3 times times that of natural gas; it is 6 times times that of artificial gas.

5. Expansion and compression

6, saturated vapor pressure

7. Gasification Latent heat

8. Classification of pressure

Relative pressure: The part of the pressure measured with a metering instrument, also known as table pressure, positive pressure, working pressure.

Absolute pressure: the sum of atmospheric pressure and table pressure, called absolute pressure, but also called actual pressure. Negative pressure: A metering instrument is used to measure that part of the pressure below the atmospheric pressure, at which point the relative pressure is less than the atmospheric pressure, because the value expressed is positive, called negative pressure.

9. Fire temperature The lowest temperature at which the fuel can burn continuously, called the ignition temperature. At atmospheric pressure (atmospheric pressure), the ignition temperature of LPG is 365-460 ℃, the ignition temperature of natural gas is 270-540 ℃, and the fire temperature of city gas is 270-605 ℃.

The ignition temperature is much lower than that of other fuels, so it is also called flammable gas.

10. Explosion limit: The range of combustible gas concentrations in the event of an explosion caused by an open fire in a mixture of combustible gases and air is called the explosion limit. 

 In this mixture, when the content of the combustible gas is reduced to the amount that cannot form an explosive mixture, it is called the lower limit of the explosion of the combustible gas, and when the content of the combustible gas has been increased to the amount that cannot form an explosive mixture, it is called the explosion limit.