4 research outputs found
Analysis of combustion performance and emission of extended expansion cycle and iEGR for low heat rejection turbocharged direct injection diesel engines
Increasing thermal efficiency in diesel engines through low heat rejection
concept is a feasible technique. In LHR engines the high heat evolution is
achieved by insulating the combustion chamber surfaces and coolant side of
the cylinder with partially stabilized zirconia of 0.5 mm thickness and the
effective utilization of this heat depend on the engine design and operating
conditions. To make the LHR engines more suitable for automobile and
stationary applications, the extended expansion was introduced by modifying
the inlet cam for late closing of intake valve through Miller’s cycle for
extended expansion. Through the extended expansion concept the actual work
done increases, exhaust blow-down loss reduced and the thermal efficiency of
the LHR engine is improved. In LHR engines, the formation of nitric oxide is
more, to reduce the nitric oxide emission, the internal EGR is incorporated
using modified exhaust cam with secondary lobe. Modifications of gas exchange
with internal EGR resulted in decrease in nitric oxide emissions. In this
work, the parametric studies were carried out both theoretically and
experimentally. The combustion, performance and emission parameters were
studied and were found to be satisfactory
Smart ceramic materials for homogeneous combustion in internal combustion engines: A review
The advantages of using ceramics in advanced heat engines include increased fuel efficiency due to higher engine operating temperatures, more compact designs with lower capacity cooling system. Future internal combustion engines will be characterized by near zero emission level along with low specific fuel consumption. Homogenous combustion which realized inside the engine cylinder has the potential of providing near zero emission level with better fuel economy. However, the accomplishment of homogeneous combustion depends on the air flow structure inside the combustion chamber, fuel injection conditions and turbulence as well as ignition conditions. Various methods and procedures are being adopted to establish the homogeneous combustion inside the engine cylinder. In recent days, porous ceramic materials are being introduced inside the combustion chamber to achieve the homogeneous combustion. This paper investigates the desirable structures, types, and properties of such porous ceramic materials and their positive influence on the combustion process