ID 176

An Experimental Study on Sprays of Diesel from Direct Coal Liquefaction

 

Abstract:

Fuel spray is an important physical process that affects the combustion and emission characteristics of the engine. A fuel spray characteristics test system was constructed based on technologies of electronically controlled fuel injection and high-speed photography. The spray characteristics of Diesel from Direct Coal Liquefaction (DDCL) and petroleum-derived diesel were compared by experiments and then the effects of setting rail pressure, injection pulse width, ambient pressure and nozzle diameter on macro spray characteristics of DDCL were also studied and analyzed. Experimental results show that under the same injection condition, the spray penetration length of DDCL is slightly shorter and steady cone angle is slightly larger than petrodiesel, this is result from the combined effect of DDCL 3% higher in density and 32% lower in viscosity than petrodiesel. For DDCL, as the setting rail pressure raises, both the spray penetration length and steady cone angle increase. Increasing injection pulse width slightly increases the spray penetration length but has little effect on steady spray cone angle. The reduction of ambient pressure from 2 to 1 MPa leads to about 20% increase in spray penetration length and about 10% decrease in steady spray cone angle. Increasing the nozzle diameter from 0.28 to 0.34 mm results in about 10% increase in penetration length and about 35% increase in steady spray cone angle.