An Experimental Study on the Macroscopic Spray Characteristics of Biodiesel and Diesel in a Constant Volume Chamber

Hongzhan Xie,Yizhi Xie,Lanbo Song,Dong Pi,Chunyu Shao,Qizhao Lin

doi:10.3390/en8065952

Abstract

The objective of this study was to investigate the macroscopic spray characteristics of different 0%–100% blends of biodiesel derived from drainage oil and diesel (BD0, BD20, BD50, BD80, BD100), such as spray tip penetration, average tip velocity at penetration, spray angle, average spray angle, spray evolution process, spray area and spray volume under different injection pressures (60, 70, 80, 90, 100 MPa) and ambient pressures (0.1, 0.3, 0.5, 0.7, 0.9 MPa) using a common rail system equipped with a constant volume chamber. The characteristic data was extracted from spray images grabbed by a high speed visualization system. The results showed that the ambient pressure and injection pressure had significant effects on the spray characteristics. As the ambient pressure increased, the spray angle increased, while the spray tip penetration and the peak of average tip velocity decreased. As the injection pressure increased, the spray tip penetration, spray angle, spray area and spray volume increased. The increasing blend ratio of biodiesel brought about a shorter spray tip penetration and a smaller spray angle compared with those of diesel. This is due to the comparatively higher viscosity and surface tension of biodiesel, which enhanced the friction effect between fuel and the injector nozzle surface and inhibited the breakup of the liquid jet.

Highlights

Traditional fossil fuels are non-renewable and expected to eventually be exhausted in a few decades.In addition, burning fossil fuels generates a large amount of pollutants exacerbating environmental degradation [1]
Experimental macroscopic spray characteristics of biodiesel derived from drainage oil and its biodiesel–100% diesel fuel (BD0), BD20, BD50, BD80, BD100 blends with diesel were obtained under different injection pressures and ambient pressure conditions in a constant volume spray chamber
Based on the results of this study, we can make the following observations: (1) The spray tip penetration, peak of average tip velocity, spray area and spray volume increased with the increase of the injection pressure

Summary

Introduction

Traditional fossil fuels are non-renewable and expected to eventually be exhausted in a few decades.In addition, burning fossil fuels generates a large amount of pollutants exacerbating environmental degradation [1]. Traditional fossil fuels are non-renewable and expected to eventually be exhausted in a few decades. Among the various alternative fuels, biodiesel is the most popular [2]. Both the academic and industrial worlds have paid great attention to biodiesel fuels—produced from animal fats, vegetable oils and discarded biological oil (drainage oil) [3]—because is a clean and renewable fuel with reduced soot and nitrogen oxides (NOx) emissions by virtue of its high oxygen content [4]. In comparison to conventional diesel biodiesel is hardly atomized because of its intrinsic higher surface tension and viscosity. To improve these properties, biodiesel is currently blended with diesel

Objectives

Results

Conclusion