DME엔진 구동 25㎾급 열병합엔진의 성능향상

Dimethyl ether(DME) is an oxygenated fuel with a cetane number higher than that of diesel oil. It meet the ULEV emission regulation and reduce the smoke to almost zero when used in a diesel engine. Cogeneration is an energy conversion process, where electricity and useful heat are produced simultaneously in one process. Also, carbon dioxide emissions can be substantially reduced. Cogeneration heat can be used either for district heating or for industrial processes. Furthermore, the heat by-product is available for use without the need for the further burning of a primary fuel. The cogeneration process may be based on the use of steam or gas turbines or combustion engines. However, there have been few models with an output of less than 100 kilowatt. In the present study, conventional DI diesel engine by using DME fuel with generation output of 25 kilowatts was developed for micro cogeneration package. Test results showed that the torque and power with DME were same as those of pure diesel oil, but the brake thermal efficiency decreased a little. Also, smoke index from DME engine showed nearly zero level and NOX was decreased a little compared to diesel oil. The EGR system was the very effective method to reduce the NOX emission in case of DME fuel in diesel engine.