METHOD FOR OPERATING A RECIPROCATING PISTON INTERNAL COMBUSTION ENGINE WITH INTERNAL EXHAUST GAS ENERGY RECUPERATION AND RECIPROCATING PISTON INTERNAL COMBUSTION ENGINE

摘要

In a method for operating a reciprocating-piston internal combustion engine having internal exhaust gas energy recuperation, a cylinder head recuperator is heated up during an exhaust cycle by hot exhaust gas flowing through the cylinder head recuperator prior to being exhausted from the cylinder via an exhaust valve. During an intake cycle, fresh charge flows into the power chamber of the cylinder by passing around a cylinder head recuperator. During the subsequent compression stroke, the cylinder head recuperator is moved out of a recess formed in the cylinder head such that some of the compressed charge can flow into the recess. Near the end of the compression stroke, the cylinder head recuperator is moved back into the recess so that compressed charge located in the recess is forced to flow through the hot cylinder head recuperator and thereby be heated up immediately before ignition of the compressed charge.

主权项

1. A method for operating a reciprocating-piston internal combustion engine having internal exhaust gas energy recuperation, the engine comprising a cylinder having a power chamber delimited by a piston, which is reciprocally movable in an axial direction of the cylinder, and by a front wall provided with at least one intake valve and at least one exhaust valve, in which power chamber a cylinder head recuperator is reciprocally movable in the axial direction of the cylinder and covers only a portion of the cross-section of the power chamber that is not covered by the at least one intake valve, the method comprising:
flowing-in fresh charge by moving the piston from its top dead center (TDC) to its bottom dead center (BDC) with the at least one intake valve open and the at least one exhaust valve closed, wherein the cylinder head recuperator is located in a top dead center (TDCR) during the flowing-in, so that the fresh charge flows into the power chamber by passing around the cylinder head recuperator, compressing the fresh charge by moving the piston from the BDC to the TDC with the at least one intake valve closed and the at least one exhaust valve closed, wherein the cylinder head recuperator is moved during the compression from its TDCR to its bottom dead center (BDCR) with a stroke between the TDCR and the BDCR that is smaller than the stroke of the piston between the TDC and BDC, and wherein the cylinder head recuperator is moved back into its TDCR at the end of the compression, combusting the compressed fresh charge with the at least one intake valve closed and the at least one exhaust valve closed and thereby causing the piston to move from the TDC to the BDC, wherein the cylinder head recuperator (remains in the TDCR during the combustion, and exhausting the combusted charge with the at least one exhaust valve open and the at least one intake valve closed by moving the piston from the BDC to the TDC, wherein the cylinder head recuperator is moved away from its TDCR with opening of the at least one exhaust valve and, when closing the at least one exhaust valve at the end of the exhausting, the cylinder head recuperator is moved back into the TDCR with closing of the at least one exhaust valve.