Influence of alternative fuel from waste plastic oil on the macroscopic spray parameters utilising a single injection strategy in a piezoelectric diesel injector

An alternative way to utilise waste plastics is to use waste plastic oil (WPO) in diesel engines. One way to explore the potential of WPO as an alternative fuel in diesel engines is by determining the spray macroscopic parameters. The present research will study the spray macroscopic characteristics utilising WPO and ultra-low sulphur diesel (ULSD) as the fuel baseline. To do so, the spray macroscopic parameters will be characterised in a constant volume chamber under non-evaporative and non-reactive conditions and using injection pressures ( p rail ) of 80, 100 and 120 MPa and a back pressure ( p b ) of 5 MPa. Among the main results reached, it can be highlighted that the spray tip penetration, spray cone angle, and spray area values of WPO are lower than those of ULSD in all injection pressure levels at the same time intervals after the start of injection. Moreover, analysing all macroscopic spray parameters and under the operating conditions studied, it can be concluded that the mixing process of WPO is faster than ULSD. Thus, WPO shows potential as an alternative fuel for diesel engines. Lastly, the present research provides useful information that may be used to support simulations of the injection process using WPO.