Pilot injection engine

from Wikipedia, the free encyclopedia

A pilot injection engine is a diesel engine construction that is operated with biogas. The system's own injection system only supplies a small amount of liquid fuel required to ignite the gas-air mixture, which in the highly compressed mixture ignites by itself. The driving energy comes mainly as a gas mixture via the intake system, so the system works as a gasoline engine with external mixture formation and external ignition.

Pilot injection engines are used in combined heat and power plants to burn lean gases (mainly biogas , see also biogas engine ). The relatively knock-resistant biogas can be sucked into high-compression engines without the risk of spontaneous ignition. The pilot injection engine then adds a small amount of pilot oil , for example diesel fuel, at the ignition point in order to initiate the combustion of the entire combustible mixture including the biogas. Optimized pilot injection engines today get by with an amount of 2% pilot oil, older systems still require up to 10%.

In principle, every diesel engine can be converted to a pilot injection engine. Pump-nozzle injection systems and common rail injection systems are particularly suitable for this . These can be electronically adjusted to the operating conditions through different biogas qualities and are also suitable for the use of vegetable oils. The biogas as the actual fuel gas is added to the intake duct via an electronically controlled metering system (principle as with gasoline injection).

Within the framework of the law for the priority of renewable energies (EEG 2009), biogas plants that went into operation before January 1, 2007 may be operated with fossil ignition oil ( heating oil ). Plants commissioned later must use biodiesel (PME) or vegetable oil for the necessary start-up, ignition and support firing .

literature

  • Richard van Basshuysen, Fred Schäfer: Handbook Internal Combustion Engine Basics, Components, Systems, Perspectives. 3rd edition, Friedrich Vieweg & Sohn Verlag / GWV Fachverlage GmbH, Wiesbaden, 2005, ISBN 3-528-23933-6
  • "Pilot injection engines" - efficient combustion of biogas and lean gases in combined heat and power plants was published in the series "Die Bibliothek der Technik". Verlag Onpact GmbH ISBN 978-3-86236-008-6 .