Experimental test of common rail diesel engine supplied with diesel fuel - rape seed oil mixtures

Abstract

In the next few decades, the resources of oil will be depleted. From the other hand, growing market and usage of oils cause increase of oil price. Additionally, only some countries have oil deposits large enough to be independent from foreign suppliers. All these reasons show need for searching and development of new fuels, which can replace traditional ones produced from oil. One of the solutions for Diesel engines are bio-fuels produced from various vegetable oils like rapeseed, coconut or palm oil. Nowadays, the majority of new Diesel engines are equipped with Common Rail fuel injections system. It enables to achieve higher power of the engine, lower emissions and lower fuel consumption. This suggests that the Common rail system should be also utilized in Diesel engines supplied with bio-fuels, produced from various plants, as it was mentioned above. However, the bio-fuels have some properties much different from those of conventional Diesel fuel, for example they usually have significantly higher viscosity. In consequence, the fuel supply and fuel injection systems require some modifications. The paper presents results of the experimental test of Common Rail Diesel engine supplied with four fuels: standard Diesel fuel, rapeseed oil and two mixtures of these fuels: 70 percent of Diesel with 30 percent of rape seed oil and 50 percent of Diesel fuel with 50 percent of rape seed oil. For the research, a new test bench was built in Faculty of Production Engineering, Warsaw University of Life Sciences. The main element of the test bench is one cylinder, direct injection engine Farymann Diesel 18W. Originally, the engine was equipped with mechanical Bosh direct injection system, which was replaced with Common Rail system. The test bench enables measurements of various parameters: torque, pressure inside the cylinder, temperature of cooling water and exhaust gases, emissions etc. The tests of the modified engine were conducted with use of several types of piston and injector