Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, during a cold start, a method may include adjusting a position of a first valve disposed in an exhaust gas recirculation (EGR) passage based on an engine operating condition, the EGR passage coupled between the first exhaust manifold coupled to a first set of exhaust valves and the intake passage, upstream of a compressor. As one example, the engine operating condition may include an engine temperature or a temperature of a catalyst disposed in the exhaust passage.

In an intake apparatus of an internal combustion engine, an EGR gas inlet port of each of plural EGR gas distribution pipes is provided at a position at which a volume of an intake port from a surge tank to the EGR gas inlet port is equal to or greater than a volume of an EGR gas introduced to an intake pipe from each of the EGR gas distribution pipes during one cycle of the internal combustion engine and at a position towards the surge tank relative to a center of the intake port in a flow direction thereof.

In an intake apparatus of an internal combustion engine, an EGR gas inlet port of each of plural EGR gas distribution pipes is provided at a position at which a volume of an intake port from a surge tank to the EGR gas inlet port is equal to or greater than a volume of an EGR gas introduced to an intake pipe from each of the EGR gas distribution pipes during one cycle of the internal combustion engine and at a position towards the surge tank relative to a center of the intake port in a flow direction thereof.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, exhaust from a first set of exhaust valves coupled to the first exhaust manifold may be selectively routed to the intake passage via each of a first EGR passage coupled to the intake passage upstream of a compressor driven by a turbine and a second EGR passage coupled downstream of an outlet of the compressor. A decision of whether to route exhaust gas to the intake passage via the first EGR passage, second EGR passage, or both passages may be based on engine operating conditions.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, exhaust from a first set of exhaust valves coupled to the first exhaust manifold may be selectively routed to the intake passage via each of a first EGR passage coupled to the intake passage upstream of a compressor driven by a turbine and a second EGR passage coupled downstream of an outlet of the compressor. A decision of whether to route exhaust gas to the intake passage via the first EGR passage, second EGR passage, or both passages may be based on engine operating conditions.

This intake apparatus for an internal combustion engine having a first bank and a second bank includes: an intake pipe including one new-air intake pipe, two branched pipes, and a junction connecting the new-air intake pipe to the two branched pipes; an EGR gas pipe connected to the junction; and a partitioning member placed around an opening in the EGR gas pipe that opens toward the intake pipe. The partitioning member defines an EGR gas storage chamber. The EGR gas storage chamber has first-bank and second-bank flow passages in which the EGR gas flows toward the first bank and the second bank. The first and second effective cross-sectional areas in the first-bank flow passage and the second-bank flow passage are smaller than the flow passage cross-sectional area in the opening of the EGR gas pipe.

This intake apparatus for an internal combustion engine having a first bank and a second bank includes: an intake pipe including one new-air intake pipe, two branched pipes, and a junction connecting the new-air intake pipe to the two branched pipes; an EGR gas pipe connected to the junction; and a partitioning member placed around an opening in the EGR gas pipe that opens toward the intake pipe. The partitioning member defines an EGR gas storage chamber. The EGR gas storage chamber has first-bank and second-bank flow passages in which the EGR gas flows toward the first bank and the second bank. The first and second effective cross-sectional areas in the first-bank flow passage and the second-bank flow passage are smaller than the flow passage cross-sectional area in the opening of the EGR gas pipe.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, during a cold start, a method may include adjusting a position of a first valve disposed in an exhaust gas recirculation (EGR) passage based on an engine operating condition, the EGR passage coupled between the first exhaust manifold coupled to a first set of exhaust valves and the intake passage, upstream of a compressor. As one example, the engine operating condition may include an engine temperature or a temperature of a catalyst disposed in the exhaust passage.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, during a cold start, a method may include adjusting a position of a first valve disposed in an exhaust gas recirculation (EGR) passage based on an engine operating condition, the EGR passage coupled between the first exhaust manifold coupled to a first set of exhaust valves and the intake passage, upstream of a compressor. As one example, the engine operating condition may include an engine temperature or a temperature of a catalyst disposed in the exhaust passage.

A control apparatus for an internal combustion engine according to the invention is applied to an internal combustion engine in which EGR gas and condensed water generated by an EGR cooler are supplied into a cylinder. The control apparatus calculates an equivalence ratio of the internal combustion engine, and controls an EGR valve and a condensed water supply valve such that, when the equivalence ratio is high, a supply rate of the condensed water increases and a supply rate of the EGR gas decreases relative to when the equivalence ratio is low.