A new type of internal combustion engine based on the porous-medium combustion technique

Abstract

At present, the emissions of internal combustion engines can only be improved by catalytic treatments of the exhaust gases. Such treatments, however, result in high costs and relatively low conversion efficiency. This suggests that a new combustion technique should be developed to yield improved primary combustion processes inside the engine with drastically reduced exhaust gas emissions. In this paper, the authors report on such a technique that is applicable to direct injection, internal combustion engines, either diesel or gasoline fuelled. This technique is based on the porousmedium (PM) combustion technology previously developed in the authors’ laboratory for steady state household and industrial combustion processes. It is shown that the PM combustion technique can be applied to internal combustion engines, i.e. it is demonstrated that improvements obtained in steady state combustion are also realizable in unsteady combustion processes. Theoretical considerations are presented for internal combustion engines, indicating that an overall improvement in thermal efficiency can be achieved for the PM engine. This is explained and the general performance of the new PM engine is demonstrated for a single-cylinder, air-cooled, direct injection diesel engine. Verification experiments are described that were carried out as part of the present study. Initial results are presented and an outlook is given on how the present developments might continue in the future.