Experimental Investigation of Performance Combustion and Emission Characteristics in an HCCI Engine Fuelled Isopropanol and Heptane Fuel Mixtures

Abstract

In this study, the effect of isopropanol on combustion and exhaust emissions was investigated experimentally in a single cylinder HCCI engine with port injection system. The experiments were carried out at 1000 min-1 engine speed and 60 oC intake air temperature. Pure n-heptane and n-heptane isopropanol fuel mixtures (ip25 and ip50) were used in the study. In-cylinder pressure, heat release rate, start of combustion, combustion duration, pressure rise rate and exhaust emissions were examined. It was determined that in-cylinder pressure and rate of heat release decreased while the mixture getting leaner with all test fuels. The addition of isopropanol to nheptane fuel led to delayed start of combustion and prolonged combustion duration. The maximum indicated thermal efficiency was obtained as 43.27 % at 2.4 lambda with ip25 fuel. The use of ip25 and ip50 fuels compared to n-heptane, the CO emissions worsened by 22.7% and 62.1%, respectively. However, HC emissions increased by 8.8% and 12%, respectively. The addition of isopropanol to the n-heptane fuel resulted in reduced pressure rise rate. Thus, spontaneous HCCI combustion is controlled.

Keywords

• hcci
• low temperature
• combustion engine performance
• exhaust emissions
• combustion