Recent developments in High-Pressure Thermochemical Recuperation technology in the Technion – Israel institute of Technology, were first to allow engines to work on a hydrogen-rich reformate as a stand-alone fuel by its direct injection (DI) to the combustion chamber.This was achieved by using a Magneti Marelli gasoline direct injector, IHP072, modified to enable the gaseous reformate injection. However, this injector , under the used working conditions, suffered from a low flow cross section, non-reliable closure and a non-optimized jet structure, which had a detrimental effect on engine performance. In order to optimize engine performance, i.e. to achieve higher flow rate, shorter open-close timing and higher backward pressure resistance (in the cylinder), an improved injector is needed. In the present work, a novel DI injector was designed producing over expanded reformate jet.
One of the main features of the new injector is an outward-opening valve)POPPET valve) with a relatively high flow cross section.Furthermore, a number of elements have been incorporated in the injector design to allow rapid and convenient calibration of the valve lift, sealing force and the magnetic force. Those in turn, enable optimized injector configuration that is well-suited for different working conditions (such as different in-line pressure or flow rates).
In this work, the direct-gaseous-injector design process is reported, and its operation is optimized and investigated.