AUX E Series, Service Manual

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AUX air conditioner service manual
The pressure is distinguished by gauge pressure and absolute pressure applied in the practice.
The gauge pressure is validated according to the numerical value shown on the pressure gauge. This
value, based on an atmospheric pressure (0), is the difference of the actual pressure of the tested gas
and the ambient atmospheric pressure. If the value is lower than the atmospheric pressure, then it will
be negative and called vacuum value (B).The surface pressure is applicable for the observation use
during the operation and running period of the refrigeration system. For example, when a negative
value appears to the pressure gauge of refrigerant, it means the refrigerant in the refrigeration system
totally leaks out.
The absolute pressure is the actual pressure value of the gas, which is equal to the sum of the surface
pressure and the atmospheric pressure, e.g. Pa= Po+Pg. Pa stands for the absolute pressure, “Po”
stands for the atmospheric pressure and “Pg” stands for the surface pressure.
The relation between the absolute pressure, the surface pressure and vacuum value are specified in the
below picture1-1:
Absolute Pressure upper limit line
One Atmospheric Pressure
2
Absolute Zero Pressure line
Positive
Pressure
Negative
Pressure
V
acuu
m
Va
lue
Su
rf
ace
Pr
essu
re
ABSOLUTE PRESSURE
⑶ Specific Volume
The specific Volume is the dimension for the substance with unit mass. υ stands for it and the unit is
meter
3
/ kilogram( m
3
/kg) or Liter/kilogram(L/Kg). The specific volume of the vapor refrigerant is the
key parameter in determining the cooling capacity of the compressor.
Specific Volume is the physics parameter in description of the compression level of the molecules in
the substance. For Gas, if more large space between the molecules is, the larger the specific volume
will be, consequently the compression level will be smaller and the compressibility will be more.
Otherwise, the specific volume will be smaller, and consequently the compression level will be larger
and the compressibility will be less.
The density (
ρ ), the reciprocal of the specific volume, is always being applied in the refrigeration
technology, e.g.:
υ =1/ ρ 或 υ • ρ =1
Density is the mass of the unit dimension of the substance with the unit of kg/m
3
(Kilogram/meter
3
).
The density of the liquid is higher than the one of the gas, which is the theory, sourced from and