Improvements in and relating to internal combustion engines

摘要

In an engine 1, Fig. 2, which fuel gas is subjected to partial combustion for the generation of a recoverable gas such as synthesis gas with the simultaneous performance of mechanical work, part of the combustion products are bled off from the exhaust pipe 11, as shown after passing through a smoothing container and waste heat recovery unit 12 and a gas purifier 14, and are returned to the engine 1 for cylinder scavenging, as shown via regulating valves 22, 23, a smoothing container 20, a cooler 21 and a blower 24 which may be omitted if a compressor is included in the pipe 11 between the purifier 14 and the bleed-off point. As used to produce synthesis gas, oxygen and methane are supplied directly to the engine induction manifold or past regulating valves 7, 8 to a mixer 4 delivering to the engine past a regulating valve 3. As applied to a four-stroke engine, a head 27, Fig. 4, for a cylinder 25, has a gas inlet valve 28, an exhaust valve 29 and a scavenging inlet valve 32 with a deflector 33, ignition being by spark plug or pilot oil injection. The scavenging valve 32 is opened towards the end of the exhaust stroke and closed simultaneously with the exhaust valve 29 just after T.D.C., the inlet valve 28 opening just before or after exhaust valve closure and preferably just before T.D.C. According to the invention, only one of the constituents of the combustion products, e.g. carbon monoxide, may be used for scavenging.