Measurement and Calculation of Bulk Modulus for DME

Abstract DME(Di-methyl Ether) has been expected to be one of the promising alternative fuels for compression ignition engines due to its low emission characteristics for particulate matter. However, its physical properties such as density, bulk modulus and viscosity are not comparable to those of conventional diesel fuel. Especially, problems caused by low lubricity and high compressibility need to be understood more thoroughly, when a DME fuel is used for compression ignition engine, especially with mechanical fuel supply system. In this study, measurement and calculation of DME's bulk modulus were carried out over the range of temperatures from -3℃ to 53℃, and pressures from 50 bar to 250 bar using an experimental apparatus built in this work. The results show that DME is prone to be compressed more easily compared to diesel fuel. A comparison of bulk modulus with butane and propane were also made in this work. 1. 서 론 최근 자동차로 인한 대기오염이 나날이 심각해지고 있으며, 전 세계적으로 환경에 대한 관심이 증대하고 있는 시점에서 대기질을 향상할 수 있는 대책 마련이 시급한 상황이다. 디젤엔진은 열효율이 높고, 온실가스인 이산화탄소의 배출이 상대적으로 적다는 장점을 가지고 있는 반면, 질소산화물(NO