A Low Heat Rejection Lean Burn Genset Engine

This thesis describes how to utilize the embedded energy that’s hiding inside the old cylinder block of an engine into something that not only provides electric energy, but also has a low manufacturing cost. Internal combustion engine powered generator sets are used worldwide to provide electricity in restricted areas. An automobile engine is designed with different design criteria than a generator engine. To get the best efficiency out of a current automobile engine while making electricity, the engine must be modified during remanufacturing. This research effort investigates the feasibility of using engine parts from multiple engines (a Nissan KA24 block and a Nissan Z20 cylinder head to create a crossbred engine the “ZKA2.6L”) to operate with a lean mixture of LPG at a compression ratio of 14.6:1. The attempt is to create a new engine designed specifically for use in a generator set, with a constant engine speed of 1800 RPM. The combustion chamber is hemispherical, resulting in low surface area to volume ratios, which combined with the lack of appreciable swirl and squish results in minimal heat losses compared with previous research engines. 3-D scanning was used to precisely calculated surface area of the hemispherical combustion chamber. This thesis shows the critical steps and modifications that are needed to obtain a maximum brake thermal efficiency of 38.8%