| 摘要 |
The present invention relates to a method for controlling the working cycle of a four-stroke internal combustion engine which is supercharged by means of at least one exhaust-driven turbo-compressor (4), and also to an arrangement for carrying out the method. Each cylinder of the engine is provided with an inlet valve (2) to which the compressor (5) of the turbo-compressor (4) delivers air through an inlet pipe (6), and also with an outlet valve (3) from which gases are passed from the cylinder to the turbine (7) of the turbo-compressor (4) through an outlet pipe (8). According to the invention each cylinder is further provided with a pressure control valve (9) which is connected to the outlet pipe (8) by means of a pressure control line (10), between the outlet valve (3) and the turbine (7) of the turbo-compressor (4). The pressure control valve (9) is intended to open when the piston, during the compression stroke of the engine cycle, is located in the cylinder in a first predetermined position (D) at a distance from the bottom-dead-centre position (C) of the piston, and is intended to close when the piston, during the compression stroke, is located in a second predetermined position (E) at a greater distance from its bottom-dead-centre position. The air flowing through the pressure control line (10) can be heated in a heat exchanger (23) by hot exhaust gases downstream of the turbine (7) such as to recover heat from these exhaust gases. |
