AUX air conditioner service manual
5
impacted by force, for example the convection of the refrigerant inside the pipes caused by the impact
from the compressor of the refrigerator and air-conditioner, and the forced convection to the condenser
and evaporator impacted by the fan. The heat transfer coefficient is directly proportional to the flow
speed of the forced convection. So, the fan can be utilized as a forced convection tool for creating the
effective heat transfer.
⑶Heat Radiation
Heat radiation represents the transmission of the radiation energy turned from the heat energy existing
in the space between two indirect touching objects. Any objects continuously emit the radiation energy
and absorb the radiation energy so as to turn it into the heat energy. Comparing with the heat
conduction and heat convection, heat radiation can be realized through the vacuum space without any
heat and middle medium. The heat transmitting process from the Sun to the Earth is by the way of
heat radiation.
The intensity of the object’s radiation energy is directly proportional to the forth power of the absolute
temperature value. In this case, the final efficient result of the radiation is that the object at higher
temperature will loss energy and the one at lower temperature will receive energy. Despite of the
above factor, the intensity of the radiation energy is also relative to the property of the object’s surface.
More black or rough the surface is, more easy in radiating or absorbing heat. The white and smooth
object can hardly absorb the heat, but be good at heat reflection. Because of this, the condenser of the
refrigerator is painted in black color for strengthening the capability of radiation, and the shell surface
of the refrigerator is light and brilliant so as to reduce the absorbance caused by the radiation from
other objects.
3. The State Parameter of air
⑴ The temperature of air
The temperature of air represents the heat extent of the air. Usually Celsius temperature scale t（℃）
was introduced to stand for it.
⑵ The pressure of air
The pressure of air in the nature is atmosphere pressure. Since the air is the mixture of dry air and
water vapor, the air pressure is the sum of the pressures of dry air and water vapor. The value of the
water vapor pressure is a parameter reflecting the quantity of the water vapor in the air.
The total air dimension is always full of the water vapor molecules. The temperature value we
obtained is not only the one of the dry air but also the water vapor’s. In this case, the volume or the
temperature of the water vapor is equal to the volume or the temperature of the air respectively. The
weight of the air is the sum of the dry air and the water vapor.
⑶ Humidity
Humidity is one of the physical parameter for representing the quantity of the water contained in the
air. There are absolute humidity and relative humidity as the specific definition for it. The absolute
humidity(kg/m
3
或g/kg) means the weight of the water contained in 1kg air. The relative humidity (RH
%) means the percentage ratio of the current absolute humidity to the saturated absolute humidity
under a certain ambiance temperature. It’s difficult to measure the water weight directly in the air in
practice. Since the pressure created by the water in the air is in direct proportion to the quantity of the
To Next Page
Loading...
Need help?
General
