An Investigation on the Spray Characteristics of DME Common Rail Fuel Injection System with Variation of Ambient Pressure

Abstract

: It is investigated of the DME spray characteristics about varied ambient pressure and fuel injection pressure using the common rail fuel injection system when the nozzle holes diameter is varied. The common rail fuel injection system and fuel cooling system is used since DME has compressibility and vaporization in atmospheric temperature. The fuel injection quantity and spray characteristics were measured. The spray was analyzed of spray shape, penetration length, and spray angle at the six nozzle holes. The 2 types injector were used, the one was 0.166 mm diameter the other one was 0.250 mm diameter. The ambient pressure which is based on gage pressure was 0 MPa, 2.5 MPa, and 5 MPa. The fuel injection pressure was varied by 5 MPa from 35 MPa to 70 MPa. When using the converted injector, compared to using the common injector, the DME injection quantity was increased 127 % but it didn't have the same heat release. Both of the common and converted injector had symmetric spray shapes. In case of converted injector, there were asymmetrical spray shapes until 1.2 ms, but after 1.2 ms the spray shape was symmetrical. Compared with the common and converted injector, the converted injector had shorter penetration length and wider spray angle than the common injector.

Experimental Research on the Injection Rate of DME and Diesel Fuel in Common Rail Injection System by Using Bosch and Zeuch Methods

“…The research on the effects of the spray angle and injection strategies (single injection, multi-injection, etc.) on the combustion characteristics [11][12][13][14] which are composed of particle size distribution [13], spray characteristics in a various pressure condition [14][15][16], combustion and emission performances, and EGR rate [17]-was investigated via numerical and experimental methodologies. Homogeneous charge compression ignition (HCCI) and bulk combustion were also investigated.…”