Know the dry bulb temperature, the wet bulb temperature, the relative humidity, the partial pressure

Hello! dry-bulb temperature t;

Wet bulb temperature relative humidity

Saturated water vapor.

The partial pressure pq";

Find the density of air

Humidity content of the air.

x="/(p-φpq")

where p is atmospheric pressure;

Thermodynamic temperature.

t=t+partial pressure of water vapor: pq=xp (

Humid air density: =

kg/m^3)

If the atmospheric pressure in the equation is not informed, it can be calculated from the following equation:

p=（pt"-φpα"）/[

where pt"、pα"The saturated water vapor pressure at a temperature of t and is respectively.

It only represents a personal opinion, don't spray if you don't like it, thank you.

The density of air is divided into absolute density and relative density, absolute density is often referred to as air density, and the absolute density is the partial pressure of saturated water vapor 2 87 (273 degrees Celsius).

To be more precise, the air temperature is replaced by a virtual temperature, which is 1 0 378 (absolute humidity hPa saturated water vapor partial pressure hPa).

Relative Density (Absolute Density Standard Density) 100 Standard air density refers to the density of air at a pressure of 760 hPa and an air temperature of 15 degrees Celsius.

Looking at the enthalpy damp diagram, the wet bulb temperature refers to the air temperature when the water vapor in the air reaches saturation under the same enthalpy value, and the dry bulb temperature at the corresponding point is the corresponding point of the air state point along the isenthalpy line to the 100% relative humidity line in the air enthalpy diagram.

In other words, knowing the temperature and moisture content, we can determine the state point of the air on the enthalpy hygrogram, and make a straight line parallel to the isenthalpy line, the intersection point of this straight line and the 100% relative humidity line, and the temperature corresponding to this point is the desired wet-bulb temperature.

Of course, the easier way is to find the electronic enthalpy wet diagram on the Internet, click on one at random, and enter any two parameters to get out all the physical properties, which is very convenient.

Check the enthalpy wet diagram... If you want the formula, you can only fit it yourself.

The concepts of dry-bulb temperature and wet-bulb temperature are as follows:

Dry-bulb temperature. The temperature that only reflects the change in air temperature is called the dry-bulb temperature.

Wet-bulb temperature. The temperature that reflects both the change in air temperature and the effect of air humidity on temperature is called wet-bulb temperature.

Scale class of temperature:

1. Kelvin unit.

The temperature at which absolute zero is used as the starting point for calculation. That is, the temperature of the triple point of water is accurately defined as the temperature obtained later, which used to be called absolute temperature. Kelvin temperature is often represented by the symbol k, and the unit of hidden socks is Kelvin, which is defined as 1 ratio of the temperature of the water triphase point.

2. Fahrenheit temperature scale.

Fahrenheit and Celsius centigrade are both units used to measure temperature. Many countries around the world, including China, use Celsius, and the United States and some other English-speaking countries use Fahrenheit and less so Celsius. It is best known for its inventor, Gabriel D

Named by Fahrenheit (1681 to 1736), its freezing point is 32°F and its boiling point is.

3. Celsius temperature scale.

Its inventor was Anders Celsius (1701 to 1744), and its freezing point was 0 and its boiling point was focal. In 1740, the Swede Celsius proposed that the temperature of the ice-water mixture be set at 0 degrees and the boiling temperature of water should be set at a standard atmospheric pressure. The glass mercury thermometer is indexed according to the two fixed temperature points of water.

The formula for calculating relative humidity includes the air pressure, wind speed, and psychrometrobulb temperature, as well as the psychrometrobulb coefficient.

To measure the adiabatic saturation temperature t'w is impossible. Therefore, the reading TW of the wet-bulb thermometer in the dry and wet bulb thermometers is often used instead of T'W, although tw is not a state parameter, affected by wind speed and measurement conditions, but as long as the measurement method is correct, in the case of wind speed greater than 4 m s, the difference between the two is not big, in general engineering applications are completely allowed.

For sullen air at a given drybulb temperature, the lower its relative humidity is, the wet-bulb temperature ().

The higher. The lower (is slippery grinding to answer the letter laughing case).

No change. Indefinite, related to other factors.

For the air with a certain bright sparrow drybulb temperature, when its relative humidity tolerance is lower, the wet-bulb temperature ().

a.The higher. b.The lower.

c.No change. d.Not necessarily.

Correct Answer: The lower.

The formula for calculating water pressure E: E=ETW APH (T TW) ETW (HPA) is the saturated water pressure of the pure horizontal liquid level corresponding to the wet bulb temperature tw ( ), a is the wet gauge coefficient, the ventilation psychrometer when the wet bulb is not frozen (the ventilation speed coefficient is -1, and the ventilation psychrometer when the wet bulb is icing (the ventilation speed coefficient is -1, PH is the air pressure (HPA) of the station.

Relative humidity = (e ew) 100% ew is the saturated water pressure of the pure horizontal liquid (or ice surface) corresponding to the drybulb temperature t( ).

It can also be queried against the humidity chart.

The humid bulb temperature of the air is always less than the dry bulb temperature. （）

a.That's right. b.Mistake.

Correct answer: B