Porsche P-80 2005, Руководство пользователя

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Air Conditioning Basics
Climate Control Systems Diagnosis & Repair
Page 1.7
The Refrigeration Cycle
As we have said, air conditioning is the process of moving
heat energy from one place in the vehicle to another. The
A/C system is a closed system in which the compressor
pumps the refrigerant through the circuit over and over
whenever the A/C is ON.
While it is being pumped, the refrigerant changes state
from liquid to gas and back again. The refrigerant changes
from liquid to gas in the evaporator as it removes heat
from the passenger compartment. Then the refrigerant
gas condenses back to liquid in the condenser, giving up
heat to ambient (outside) air. The refrigerant does not get
worn out or used up unless there is a mechanical problem
or a leak.
The amount of heat moved from inside to outside the
vehicle determines the heat load. Both temperature and
humidity affect the heat load. The refrigerant circulates in
the closed circuit made up of these components:
• Compressor
• Condenser
• Receiver/Dryer
• Thermostatic Expansion Valve
• Evaporator
• Lines and Hoses
• Refrigerant
• Regulation and Control Devices
High and Low Pressure Sections
The system is divided into high pressure and low pressure
sections. They are the "high side" or discharge (D), and
"low side" or Suction (S). The compressor is the pump that
raises refrigerant pressure on the high side of the system
and reduces pressure on the low side.
• The compressor and the expansion valve separate the
two sides of the system.
• The condenser and receiver dryer are always on the
system high side.
• The evaporator is always on the system low side.
Notes: