Exhaust system

An exhaust system for an engine, comprising:

• a first exhaust manifold configured to receive exhaust from the engine;
• a second exhaust manifold configured to receive exhaust from the engine in parallel with the first exhaust manifold;
• a plurality of turbochargers being driven by exhaust from the first and second exhaust manifolds;
• first and second turbocharger valves associated with a turbocharger of the plurality of turbochargers, the first turbocharger valve selectively fluidly connecting the turbocharger to the first and second exhaust manifolds, the second turbocharger valve selectively fluidly connecting the turbocharger to an intake manifold of the engine;
• a recirculation circuit in fluid communication with the first exhaust manifold;
• and
• first and second recirculation valves regulating passage of exhaust through the recirculation circuit, wherein the first and second turbocharger valves are controlled based on a characteristic of exhaust passing through the recirculation circuit, and wherein the first turbocharger valve is configured to block exhaust from entering the turbocharger in response to greater than or equal to approximately 20 percent of exhaust exiting the engine being directed to the recirculation circuit.

A method of handling exhaust from an engine, comprising:

• receiving exhaust from the engine;
• forming a first flow of exhaust, a second flow of exhaust, and a recirculation flow of exhaust with the exhaust received from the engine;
• removing energy from the first flow of exhaust with a turbocharger;
• removing energy from the second flow of exhaust in parallel with the removal of energy from the first flow of exhaust;
• directing the recirculation flow of exhaust back into the engine;
• determining a characteristic of the recirculation flow of exhaust;
• and
• blocking passage of the first flow of exhaust into the turbocharger based on the characteristic, wherein the characteristic is forming the recirculation flow of exhaust with greater than or equal to approximately 20 percent of the exhaust received from the engine.