Physical and chemical properties of natural gas: combustion heat
The composition of the gas includes combustible( carbon, hydrogen sulfide, hydrogen) and non-flammable( oxygen, carbon dioxide, vapor, nitrogen) constituents. Also, during the extraction of gas, a small percentage of toxic hydrogen sulphide comes from it, namely in a ratio of about 0.03 g / m3, but no more.
Heat of combustion means the heat that is produced by the complete combustion of 1 cubic meter of gas. Indicated in kcal / m3, kJ / m3.The heat that is expended during the condensation of fumes is called higher heat, while the lower heat, in turn, does not take account of heat.
When the calculation takes place, only the lowest heat is taken into account, because of the high temperatures of the outgoing gases of the devices using it.
How to calculate the density?
The value indicating the ratio of the mass of a substance to a volume is called the density( in kg / m3).Depends on what she has in the composition. The standard density for gas consuming appliances is 0.73-0.85 kg / m3
Heat output
The physicochemical properties of natural gas also take into account the quality, such as the heat output, where the maximum temperature of any fuel is the temperature reached during its complete combustion. It is fixed in the presence of a sufficient amount of combustion air and occurs when the complete combustion procedure is followed, although the air temperature itself may be zero. The approximate parameters of the heat output are 2 000-2 100 ° С.It also depends on the combustion conditions that will be provided.
Characteristically, the ignition temperature is one at which it can ignite without an ignition device. Therefore, the indices of this temperature fluctuate 650-700 ° C.
Explosion and explosion pressure
The composition, as already mentioned, is attributed to the physical and chemical properties of natural gas. It is non-uniform and it has certain burning characteristics:
- Up to 6% - does not burn.
- From 6-16% - does not break.
- From 16% - free-burning outdoors.
- Explosion pressure: 0.9 to 1.0 MPa.
Natural gas is odorless and it would be difficult to detect its leak. The blessing for it is audited, which provides a small but specific smell, according to which it is possible at this very moment to determine the leakage. Odirization uses a chemical element such as ethyl mercaptan, which sets the measure of the 17 g licensed for 1 thousand cubic meters. The process itself occurs at special stations of the GDS, which then distribute the odorisation hit on each% of the gas so that it has this specific odor.
Gas benefits of
Physico-chemical properties of natural gas are distinguished by a list of positive features:
- Cheap and easy to extract. It's easy to transport.
- Wasteless and does not throw solid particles into the air.
- Heat of combustion provides high performance in heating systems.
- There is no need to prepare the ignition of fuel.
- The high level of sanitary and hygienic standards of work and the labor of workers does not require much physical effort.
- The process of working in enterprises with its use is significantly automated.
If more than 20% of gas penetrates into a closed room, it will lead to suffocation, and even to an explosion. If the CO is not completely burned( carbon monoxide), then even in small concentrations this chemical element will serve as a poison for all workers.
To avoid leakage, often, the gas line at the junction of the valve is checked carefully and carefully.
