Internal combustion engine and method for starting an internal combustion engine

1. An internal combustion engine comprising:

a fuel source configured to provide fuel for the internal combustion engine;

an air source configured to provide air for the internal combustion engine;

a mixer coupled to the fuel source and to the air source, the mixer is configured to produce a flow of a fuel-air mixture, and wherein all of the fuel and the air delivered to the internal combustion engine flows through the mixer;

a main line configured to direct the fuel-air mixture to the internal combustion engine, wherein the mixer discharges the fuel-air mixture into the main line;

a first compressor coupled to the main line;

a second compressor coupled to the main line, wherein the second compressor is downstream from the first compressor;

a first cooler downstream from the first compressor and upstream from the second compressor, wherein the first cooler couples to the main line;

a second cooler downstream from the second compressor, wherein the second cooler couples to the main line;

a bypass line coupled to the main line at a first location and at a second location, wherein the first location is upstream from the first compressor and the second location is downstream from the second cooler, wherein the bypass line reduces the distance between the mixer and an inlet to the internal combustion engine, wherein the bypass line bypasses the first compressor, the first cooler, the second compressor, and the second cooler and directs the fuel-air mixture in a first flow direction from the first location to the second location and into the internal combustion engine during startup of the internal combustion engine, wherein the bypass line selectively recirculates a portion of the fuel-air mixture in a second flow direction from the second location to the first location after startup of the internal combustion engine;

a bypass valve coupled directly to the bypass line and configured to control the flow of the fuel-air mixture through the bypass line in the first and second flow directions; and

a controller coupled to the bypass valve, wherein the controller is configured to open or partially open the bypass valve during startup of the internal combustion engine to direct the fuel-air mixture in the first flow direction, wherein the controller is configured to open or partially open the bypass valve after startup to direct the fuel-air mixture in the second flow direction.

2. The internal combustion engine according to claim 1 , wherein the bypass line is connected to an outlet of the mixer.

3. The internal combustion engine according to claim 1 , wherein the internal combustion engine is a stationary gas engine.

4. The internal combustion engine according to claim 1 , comprising a first turbocharger, wherein the first turbocharger includes the first compressor.

5. The internal combustion engine according to claim 1 , comprising a second turbocharger, wherein the second turbocharger includes the second compressor.

6. A method for starting an internal combustion engine, comprising:

directing fuel from a fuel source to a mixer;

directing air into the mixer to form a fuel-air mixture;

directing the fuel-air mixture through a bypass line that couples to a main line at a first location and a second location, wherein the main line comprises a first compressor of a first turbocharger and a second compressor of a second turbocharger, wherein the first location is upstream from the first and second compressors, wherein the second location is downstream from the first and second compressors, wherein the bypass line reduces the distance between the mixer and an inlet to the internal combustion engine;

opening a bypass valve to direct a flow of the fuel-air mixture through the bypass line in a first flow direction from the first location to the second location to bypass the first and second compressors in response to starting the internal combustion engine; and

opening the bypass valve to direct a flow of the fuel-air mixture through the bypass line in a second flow direction from the second location to the first location to at least partially recirculate the fuel-air mixture through the first and second compressors after starting the internal combustion engine.

7. The method according to claim 6 , wherein the bypass valve is at least partly opened and/or at least partially kept open while starting the internal combustion engine to direct the flow in the first flow direction.

8. The method according to claim 6 , wherein the bypass valve is completely opened and/or completely kept open while starting the internal combustion engine to direct the flow in the first flow direction.

9. The method according to claim 6 , wherein a generator is driven by the internal combustion engine.

10. The method according to claim 6 , wherein a gas compressor is driven by the internal combustion engine after startup.