Audi Q7 e-tron quattro 4M - Coolant Circuits Explained

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Coolant circuits
The heating circuit is required for heating the cabin. It is a part of
the coolant circuit. It diers from the heating circuit in conven-
tional models in that it also includes the integrated high-voltage
heater (PTC)Z115 and the heat exchanger for heat pump opera-
tion. These components allow hybrid vehicles to be operated even
at low ambient temperatures and without comfort restrictions.
When operating the vehicle in electric mode, the cabin heating
circuit is disconnected from the cooling circuit of the internal
combustion engine by a valve circuit. In this way, the energy input
via the high-voltage heater (PTC) Z115 and the heat exchanger for
heat pump operation is made available to the cabin.
649_041
Cabin heating circuit
High-voltage heater (PTC)
Z115
Heat exchanger in air conditioner for cabin heating
ATF cooler
In addition to the refrigerant circuit, the AudiQ7e-tron quattro
has high- and low-temperature circuits. They are needed to meet
the temperature requirements of all components in a hybrid
vehicle. The temperature range extends from –30°C to +110°C.
The engine coolant circuit is used for cooling the internal combus-
tion engine and the gearbox and for heating the cabin. The coolant
circuit of the high-voltage system regulates the temperature of the
hybrid battery unit AX1 and high-voltage battery charger 1 AX4.
The components of the electric driveline, the three-phase AC drive
VX54 and the electric drive power and control electronics
moduleJX1 are also cooled via this circuit. The temperature of the
components is controlled via valve circuits. The hybrid battery can
be cooled both passively via the atmosphere and actively via the
refrigerant circuit. A heat pump integrated in the thermal manage-
ment system of the AudiQ7e-tronquattro systematically collects
the heat loss of the electrical components. The heat loss flows are
heated via the refrigerant circuit. After this, they are fed to the
vehicle heating circuit via the heat exchanger for heat pump
operation. This ensures highly ecient cabin heating while extend-
ing the electrical range of the vehicle.
Heat exchanger for heat pump operation
Rear charge air cooler:
Coolant pump 2 for
thermal management
V618
Coolant pump for
thermal management
V617
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