Charging device for an internal combustion engine and operating method for the charging device
A charging device for an internal combustion engine, having an exhaust turbocharger and a recuperation-charger having a compressor-turbine and an electromechanical motor-generator coupled thereto. The high-pressure side of the compressor-turbine is connectable, by a valve arrangement, to the outside air supply line before the exhaust turbocharger on one side and on the other side, to the charge air supply line after the exhaust turbocharger. Outside air can be suctioned or charge air blasted via the low-pressure side of the compressor-turbine. The recuperation-charger is switched, by the valve arrangement and the motor-generator, between a standard mode, an amplifier mode and a recuperation mode, wherein the recuperation-charger operates on one side in the amplifier mode, driven by the motor-generator, as a compressor for pressure increase in the outside air supply line or, on another side, driven by the charge air flow, acts as a turbine for energy recovery by the motor-generator.
1. A supercharging device for an internal combustion engine having an intake tract and having an exhaust-gas tract, the supercharging device comprising:
an exhaust-gas turbocharger having an exhaust-gas turbine, which is arranged in the exhaust-gas tract, and a fresh-air compressor having a low-pressure side and a high-pressure side, which is arranged in the intake tract;
a fresh-air supply line to which the fresh-air compressor is connected on the low-pressure side thereof;
a charge-air feed line which connects the high-pressure side of the fresh-air compressor to a charge-air manifold of the internal combustion engine; and
a recuperation charger which has a compressor-turbine with a high-pressure side and a low-pressure side and which has an electromechanical motor-generator coupled to said compressor-turbine,
wherein the high-pressure side of the compressor-turbine is connectable by a valve arrangement at one side to the fresh-air supply line and at the other side to the charge-air feed line and a fresh-air mass flow is drawn in, or a charge-air mass flow is discharged, via the low-pressure side of the compressor-turbine, and
wherein the recuperation charger is operable firstly in a manner driven by the motor-generator as a compressor for increasing pressure of the fresh-air mass flow in the fresh-air supply line, and is operable secondly in a manner driven by the charge-air mass flow as a turbine for energy recovery by the motor-generator.
2. The supercharging device as claimed in claim 1 , wherein the compressor-turbine is, via a branching line which has a branching point, connected by a fresh-air branch to the fresh-air supply line at a fresh-air branch connection point and connected by a charge-air branch to the charge-air feed line at a charge-air branch connection point, and in each case one shut-off valve is arranged in the fresh-air branch and in the charge-air branch and also in the fresh-air supply line, upstream of the fresh-air branch connection point in a fresh-air mass flow, and flow direction of a fresh-air mass flow in the branching line and via the compressor-turbine is switched through corresponding valve settings of the shut-off valves.
3. The supercharging device as claimed in claim 1 , wherein the compressor-turbine is, via a branching line which has a branching point, connected by a fresh-air branch to the fresh-air supply line at a fresh-air branch connection point and connected by a charge-air branch to the charge-air feed line at a charge-air branch connection point, and the supercharging device further includes a switching valve disposed at the fresh-air branch connection point.
4. The supercharging device as claimed in claim 1 , wherein the compressor-turbine is, via a branching line which has a branching point, connected by a fresh-air branch to the fresh-air supply line at a fresh-air branch connection point and connected by a charge-air branch to the charge-air feed line at a charge-air branch connection point, and the supercharging device further includes a switching valve disposed at the branching point of the branching line.
5. The supercharging device as claimed in claim 2 , wherein a charge-air cooler is provided in the charge-air feed line, wherein the charge-air branch connection point of the charge-air branch is arranged downstream, in a fresh-air mass flow, of the charge-air cooler in the charge-air feed line.
6. The supercharging device as claimed in claim 2 , wherein a charge-air cooler is provided in the charge-air feed line, wherein the charge-air branch connection point of the charge-air branch is arranged upstream, in a fresh-air mass flow, of the charge-air cooler in the charge-air feed line.
7. The supercharging device as claimed in claim 1 , wherein the compressor-turbine of the recuperation charger is equipped with a fixed or variable guide vane arrangement in a compressor-turbine housing of the compressor-turbine for the purposes of improving the outflow behavior or inflow behavior of the fresh-air mass flow or of the charge-air mass flow.
8. The supercharging device as claimed in claim 1 , wherein the fresh-air supply line is connected via a first intake connector, and the low-pressure side of the compressor-turbine is connected via a further intake connector, to a fresh-air filter box.
9. The supercharging device as claimed in claim 1 , wherein the supercharging device is configured, during operation, to be switched between a standard operating mode, a booster operating mode, and a recuperation operating mode in a manner dependent on an operating behavior of the internal combustion engine and by the valve arrangement and the motor-generator of the recuperation charger.
10. The supercharging device as claimed in claim 2 ,
wherein the supercharging device is configured, during operation, to be switched between a standard operating mode, a booster operating mode, and a recuperation operating mode in a manner dependent on an operating behavior of the internal combustion engine and by the valve arrangement and the motor-generator of the recuperation charger,
wherein the valve arrangement has at least one of shut-off valves and a switching valve,
wherein, to implement the standard operating mode, the fresh-air supply line, upstream of the fresh-air branch connection point in the fresh-air mass flow direction, and the fresh-air branch are opened, the charge-air branch is closed, and the motor-generator is switched into a neutral state, and
wherein, to implement the booster operating mode, the fresh-air supply line, upstream of the fresh-air branch connection point in the fresh-air mass flow direction, and the charge-air branch are closed, the fresh-air branch is opened, and the motor-generator is switched into the motor mode so as to drive the compressor-turbine for the purposes of increasing pressure in the fresh-air supply line, and
wherein, to implement the recuperation operating mode, the fresh-air supply line, upstream of the fresh-air branch connection point in the fresh-air mass flow direction, and the charge-air branch are opened, the fresh-air branch is closed, and the motor-generator is switched into the generator mode so as to be driven by the compressor-turbine for the purposes of energy recovery.