Electric Additional Compressor, Basic Function - GF09.50-P-1002A
Engine All In Model All
Example illustration: turbocharging
Overview
This document contains information on:
- General
- Function
General
The electric additional compressor (1) is downstream of the conventional exhaust gas turbocharger (3) and is located between the exhaust gas turbocharger (3) and throttle valve actuator (5).
The electric additional compressor (1) has the following tasks:
- Increase engine torque in lower rpm range.
- Improve combustion engine response time.
- Increase cylinder charge level.
Function
The electric additional compressor (1) basically consists of an electric motor which drives a compressor wheel via a shaft.
The combustion engine control unit calculates the specified boost pressure according to the engine speed depending on the following factors:
- Load request.
- Operating status of combustion engine.
- Pressure ratio downstream of exhaust gas turbocharger.
- Pressure ratio upstream of throttle valve.
- Coolant temperature downstream of charge air cooler.
The combustion engine control unit calculates the pressure differential between the actual boost pressure and the specified boost pressure. If the actual boost pressure does not match the specified boost pressure, the electric additional compressor (1) is actuated by the combustion engine control unit. The corresponding rpm of the electric additional compressor (1) is calculated by the combustion engine control unit based on the pressure difference. The electric additional compressor (1) is actuated by the combustion engine control unit up to an engine speed of 3000 rpm, with a maximum boost pressure that can be generated of up to 400 mbar.
Power is supplied to the electric additional compressor (1) via the 48 V on-board electrical system.
The electric additional compressor (1) is connected to the charge air path of the conventional exhaust gas turbocharger (3) via the check valve (6). The two air paths can be connected and disconnected via the check valve (6).
The check valve (6) is designed as a passive mushroom valve that blocks flows in the opposite direction to the charge air flow direction (uncooled) (C) of the charge air main line (7) between the exhaust gas turbocharger (3) and throttle valve actuator (5). It is required to allow the electric additional compressor (1) to build up pressure. The electric additional compressor (1) runs at low engine speeds and high load requirements where the exhaust gas turbocharger (3) provides little boost pressure or would need a very long time to build up sufficient pressure.
The electric additional compressor (1) sucks in the charge air downstream of the exhaust gas turbocharger (3) or upstream of the check valve (6) via the bypass line (8), compresses it, and routes it via the bypass line (9), back into the charge air main line (7) in the direction of the throttle valve actuator (5). The check valve (6) is closed as long as the pressure downstream of the electric additional compressor (1) is greater than the pressure downstream of the exhaust gas turbocharger (3). As soon as the exhaust gas turbocharger (3) provides the same boost pressure as the electric additional compressor (1), the actuation is interrupted.
If, for example, a high load request is made of the combustion engine at low engine speed, depending on the pressure ratios in the charge air path, the charge air path is opened to the electric additional compressor (1) via the check valve (6). The electric additional compressor (1) is briefly actuated and can thus compensate for the missing output of the conventional exhaust gas turbocharger (3) as well as cover the cylinder charge level in an adequate manner.
If faults occur on the electric additional compressor (1), these are stored in the combustion engine control unit as faults. The XENTRY Diagnosis COM Kit enables specified speeds to be configured manually.
The check valve (6) is designed as a passive component part and cannot be electrically actuated. The opening or closing of the check valve (6) is regulated via the pressure ratios in the charge air path.
| Component descriptions | |||
| Electric additional compressor, component description | Model 223 | GF09.50-P-1001A | |
| Model 206 | GF09.50-P-1001C | ||
| Model 254 | GF09.50-P-1001H | ||
| Model 214 | GF09.50-P-1001K | ||
| Model 167 as of model year 2023 | GF09.50-P-1001M |