Study On Spray Characteristicsof Diesel-Pine Oil Blendedfuel Based On Constant Volume Bomb

With the energy crisis, environmental pollution and increasingly stringent emission regulations, energy conservation and emissions reduction has become a hot issue around the world. Through looking for good efficient alternative fuel sources to improve fuel economy and reduce emissions, has become one of primary issues in the field of internal combustion engine and a urgent issue of diesel engines at present. Pine oil, as a kind of alternative fuel, is considered as a potential substitute, because it is of high oxygen content and caloric value, with low boiling point and viscosity, and reproducible. In diesel engines, the spray's quality affects the ignition, the burning rate, the stabilization, the distribution of temperature, and the exhaust gas pollutant. Therefore, the study of spray properties about diesel-pine oil with different mixing ratio is of great significance to the development of alternative fuels.In order to simulate the conditions of real engines, constant volume combustion bomb is an effective way to study the mechanism of the cylinder of diesel engine. This study first designs constant volume combustion bomb which pressure and temperature can be adjusted, the pure spray can be realized and spray combustion ca be freely chosen. By using the high pressure common rail fuel injection test bench and high-speed cameras and synchronous control, the study sets up the capacity Molotov cocktails spray the multi-function measurement system. Then, through using the MATLAB software programming to process spray images, the main spray parameters such as the spray cone angle, distance and relative area can be got. When temperature is 25 degrees, the ambient pressure is 1 MPa 2 MPa, and the nozzle aperture are 0.14 mm,0.17 mm,0.20 mm, five different mixing ratio of fuel (P0 P20 P40 P60 P100) in four different injection pressure (80 MPa to 100 MPa 100 MPa to 140 MPa) are numerically analyzed through the spray characteristics.The result shows:For the same proportion of fuel, in the case of the same injection pressure, the ambient pressure and nozzle hole diameter, the spray penetration increases as the time of spray increases and it finally tends to be a certain value. The spray cone angle increases rapidly first and then becomes stabilized, finally it falls slightly. The higher the ambient pressure increases, the more obvious the spray cone angle changes. In the case of the same nozzle hole diameter, the ambient pressure and the ratio of blending fuel, the spray penetration and the distance of the spray cone angle increase as the injection pressure rises. However, the higher the injection pressure increases, the less obvious the spray penetration shows. Under the same condition of the same nozzle hole diameter, injection pressure and the ambient pressure, the higher the proportion of the pine oil in the mixed oil, the faster the spray penetration and the spray angle increase. The spray penetration is P0<P20<P40<P60<P100, and the spray angle is P0<P20<P40< P60<P100. under the condition of the ratio of fuel, spray hole diameter and injection pressure, the smaller the ambient pressure is, the longer the spray penetration is; and the spray angle also decreases. As the diameter changes from 0.14 mm to 0.17mm and 0.20 mm, the spray cone angle decreases, and the spray penetration shows a certain degree of linear increase.