Composition and state parameters of the hottest an

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Composition of wet air and its state parameters

I. composition of wet air:

the air layer surrounding the earth is called the atmosphere. The thickness of the earth's atmosphere measured by the earth's artificial satellite is about 3000km. The atmosphere is a mixture of dry air and water vapor, called wet air

dry air is a mixture of nitrogen, oxygen, argon, carbon dioxide, neon, helium and some other trace gases. Except for carbon dioxide, the content of other gases in dry air is very stable. The content of carbon dioxide changes greatly with the growth state of animals and plants, meteorological conditions, production emissions and other factors. Because its content is very small, it is allowed to consider dry air as a whole

the content of water vapor (water vapor for short) in wet air is very small. It comes from the evaporation of water on the surface of oceans, rivers and lakes, the metabolic processes of various organisms, and the production process. The percentage of water vapor in wet air is unstable and often changes with altitude, region, season, climate, wet source and other conditions. Although the water vapor content in wet air is small, it has a great impact on the state change of wet air. It can cause changes in the degree of dryness and wetness of wet air, and make the physical properties of wet air change accordingly, so as to have a direct impact on the comfort of human body to adapt to different consumers, product quality, technological process and equipment maintenance

second, the state parameters of wet air:

the majority of users of wet air can choose according to their own conditions in the selection process. The state is usually described by pressure, temperature, relative humidity and moisture content

according to the ideal gas equation of state:

pv=rt (1)

pV=mRT..................................... (2)

where p - pressure of gas, PA

v - specific volume of gas, m3/kg

r - gas constant, depending on the nature of the gas, j/(kg · K); R dry air =287 j/(kg · K)

r steam =461 j/(kg · K)

v - total volume of gas, m3

t - gas 2. Price: price is the thermodynamic temperature of one of the major factors considered by the purchaser, K

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m - total mass of gas, kg

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