Two-stage turbocharged engine system
View Patent ↗A two-stage turbocharged engine system is provided. The two-stage turbocharged engine system includes an internal combustion engine, a high-pressure turbocharger having a high-pressure turbine for rotating a high-pressure compressor through a connecting shaft, and a low-pressure turbocharger having a low-pressure turbine for rotating a low-pressure compressor by a connecting shaft. The two-stage turbocharged engine system also includes a low-pressure intake line for fluidly connecting the outlet of low-pressure compressor to the inlet of high-pressure compressor, a high-pressure intake line for fluidly connecting the outlet of high-pressure compressor to an air cooler, and a bypass device for selectively fluidly connecting a first branching point located in low-pressure intake line to a second branching point located in high-pressure intake line to thereby bypass the high-pressure compressor. The bypass device is located closer to the low-pressure compressor than to the high-pressure compressor.
1. A two-stage turbocharged engine system, comprising:
an internal combustion engine;
a high-pressure turbocharger having a high-pressure turbine for rotating a high-pressure compressor through a connecting shaft;
a low-pressure turbocharger having a low-pressure turbine for rotating a low-pressure compressor by means of a second connecting shaft;
a low-pressure intake line for fluidly connecting the outlet of the low-pressure compressor to the inlet of the high-pressure compressor;
a high-pressure intake line for fluidly connecting the outlet of the high-pressure compressor to an air cooler; and
a bypass device for selectively fluidly connecting a first branching point located in the low-pressure intake line to a second branching point located in the high-pressure intake line to thereby bypass the high-pressure compressor, and
wherein the bypass device is located closer to the low-pressure compressor than to the high-pressure compressor.
2. The two-stage turbocharged engine system according to claim 1 , wherein the first branching point and the second branching point are located closer to the low-pressure compressor than to the high-pressure compressor.
3. The two-stage turbocharged engine system according to claim 1 , wherein the bypass device comprises:
a bypass housing,
wherein the first branching point and the second branching point are comprised as hydraulically interconnected conducts in the bypass housing.
4. The two-stage turbocharged engine system according to claim 3 , wherein the low-pressure compressor comprises:
a low-pressure compressor housing for accommodating a compressor wheel,
wherein the bypass housing is directly fixed to the low-pressure compressor housing.
5. The two-stage turbocharged engine system according to claim 4 , wherein at least a portion of the bypass housing is integral with the low-pressure compressor housing.
6. The two-stage turbocharged engine system according to claim 1 , wherein the high-pressure intake line comprises:
a first portion for channeling back an airflow from the outlet of the high-pressure compressor to a neighborhood of the low-pressure compressor.
7. The two-stage turbocharged engine system according to claim 6 , wherein the first branching point is located in the low-pressure intake line immediately downstream the outlet of the low-pressure compressor, and the second branching point is located at an end of the first portion of the high-pressure intake line.
8. The two-stage turbocharged engine system according to claim 7 , wherein the first branching point is defined by a three-way junction which directly communicates with the outlet of the low-pressure compressor.
9. The two-stage turbocharged engine system according to claim 7 , wherein the low-pressure intake line comprises:
at least a pipe for fluidly connecting the first branching point to the inlet of the high-pressure compressor,
wherein the high-pressure intake line comprises
a first pipe for fluidly connecting the outlet of the high-pressure compressor to the second branching point, and
a second pipe for fluidly connecting the second branching point to the inlet of the air cooler.
10. The two-stage turbocharged engine system according to claim 9 , wherein each of the second pipe of the low-pressure intake line and the first pipe of the high-pressure intake line has a cross section being smaller than a cross section of the second pipe of the high-pressure intake line.
11. The two-stage turbocharged engine system according to claim 1 , further comprising:
a single turbine housing for accommodating a turbine wheel of both the high-pressure turbocharger and the low-pressure turbocharger.
12. The two-stage turbocharged engine system according to claim 1 , further comprising:
a second air cooler which is located in the low-pressure intake line between the bypass device and the high-pressure compressor.
13. The two-stage turbocharged engine system according to claim 1 , wherein the bypass device comprises:
a bypass line for fluidly connecting the first branching point located in the low-pressure intake line to the second branching point located in the high-pressure intake line, and
a valve for selectively opening and closing the bypass line.
14. The two-stage turbocharged engine system according to claim 13 , wherein the valve comprises:
a movable flap for selectively opening and closing the bypass line.
15. The two-stage turbocharged engine system according to claim 14 , further comprising:
a pneumatic actuator for moving the movable flap between an open and a closed position.