Electric Drive Heating Circuit, Basic Function - GF83.20-P-1003A
Model All (CAR)
with electric drive
Example illustration of heating circuit in electric vehicles with high voltage PTC booster heater
Overview
This document contains information on:
- General
- Function requirement
- Function
General
The heating circuit is used to heat the vehicle interior at low outside temperatures. It is connected to the refrigerant circuit via condenser (1) and is operated as a heat pump heater.
During heating, the coolant volumetric flow can be routed with the condensation heat in the direction of the heater core (4) for the vehicle interior via a regulation valve. To dissipate the heat to the surroundings, the coolant is routed to the low-temperature cooler during cooling.
The blower only runs up after a defined coolant temperature is reached. This system delays the heating process being perceived in the vehicle interior.
Function requirement
- The high-voltage supply must be released.
Function
The following component parts are integrated into the heating circuit:
- Coolant circulation pump for heating circuit (5)
- (Water-cooled) condenser (1)
- PTC booster heater (installed on air side in air conditioner box)
- High voltage PTC heater (3) (depending on type)
- RSV valve (rotary slide valve)
- Heater core (4)
On vehicles with high voltage PTC heater (3): The coolant pump delivers coolant through the condenser (1). The coolant absorbs the condensation heat from the refrigeration circuit and warms up. The coolant then reaches the high voltage PTC heater (3) where it can be heated further. The coolant then flows through the heater core (4) where it dissipates the heat to the air flowing by for the vehicle interior.
If the heating output is not sufficient, heat can be transferred from the battery cooling circuit into the heating circuit by means of an active refrigerant circuit. An additional high voltage PTC booster heater is integrated into the battery cooling circuit. This controls the temperature of the coolant accordingly in the event of missing waste heat from the battery.
In vehicles with high voltage PTC booster heater, the electric refrigerant compressor is principally not active in heating mode.
In vehicles with low voltage PTC booster heater: The coolant pump delivers coolant through the condenser (1). The coolant absorbs the condensation heat from the refrigeration circuit and warms up.
The coolant then flows through the heater core (4) where it dissipates the heat to the air flowing by for the vehicle interior. For faster dynamics, the air is additionally heated up using a low voltage PTC booster heater in the air conditioner box.
A high-voltage heater is integrated into the battery cooling circuit; this temperature controls the coolant accordingly if there is a lack of waste heat from the electric motor or battery.
In order to transfer the heat from the battery cooling circuit into the heating circuit, the electric refrigerant compressor is always active in heating mode.
| Further basic function | |||
| Climate control, basic function | GF83.00-P-9901A | ||
| Detailed information | |||
| Heating circuit, detailed information | Model 243 | GF83.20-P-0008A | |
| Model 293 | GF83.20-P-0008B | ||
| Model 294, 295, 296, 297 | GF83.20-P-0008L |