The research is devoted to possibility of mineral diesel fuel with mixed biodiesel fuel partial replacement, which contains the vegetable oil as a biological component (such as: rapeseed, camelina, radish, mustard, colza, soybean, etc.). Constructive versions of bi-fuel supply system and mixers for diesel engines adaptation for their operation by biodiesel fuel are offered. The advantages of the developed bi-fuel systems and mixers are: universality in relation to different types of diesel engines; polyfuelness; availability of components; competitiveness; possibility of production in the plant conditions, no requirement of big capital investments, the small term of payback. The application of the offered system by the diesel-powered machinery provides the necessary percentage ratio of mixed fuel components depending on the load-speed mode without its essential constructive changes. The using of the mixed biodiesel fuel containing for example 50% of mineral fuel and 50% of camelina oil allows to save 50% of petroleum diesel fuel, to reduce smoke of the exaust gases by 17-20%, to reduce the content of carbon oxide by 35-40% in comparison with the work of the diesel engine on mineral diesel fuel, by insignificant decreasing of the effective power (no more than 6%) and by some increasing of specific fuel consumption of mixed fuel (to 14%).

The goal of the research is constructive adaptation of automotive diesel engines working by diesel mixed fuel. A perspective kind of an alternative motor fuel is biodiesel blend produced with mixing of vegetable oil and conventional diesel fuel in different percentages. The present diesel-powered machinery is not adapted to work on such kind of fuel because of the different properties of biodiesel and diesel fuels. Applying of the invented devices (such as dual-fuel supply system, the mixer-filter and ultrasonic fuel mixer) allows to adapt automotive diesel engines for work on biodiesel blend. The dual-fuel supply system performs engine start, warm-up and stop modes on mineral diesel fuel, and its work on biodiesel blend on other modes. The original design of the fuel mixer-filter provides effective mixing of components and filtration from contaminants. Due to the high frequency vibrations the ultrasonic mixer provides the obtaining of homogeneous fuel composition and molecular splitting of higher fatty acids contained in vegetable oil.

The mode of independent idling, characterized by an impaired process flow, unproductive fuel consumption and increased emissions of harmful substances into the atmosphere, is the most unfavorable mode of the diesel engine operation. Therefore, the aim of the research is to reveal the peculiarities of the tractor diesel engine operation by the camelina-mineral fuel in the mode of independent idling. Camelina-mineral fuel is a mixture of camelina oil and mineral diesel fuel in certain ratio of these components. To assess the possibility of using the camelina oil as biological component of diesel mixed fuel, an experimental study of the D-243 diesel engine in idling mode was carried out, and the degree of influence of the different ratio of the components of the mixed fuel on its parameters was determined. The researches were carried out with the diesel fuel on the L-0.2-62 mineral fuel and the camelina-mineral fuel with a ratio of the biological and mineral components: 25% RyzhM + 75% DT; 50% RyzhM + 50% DT; 75% RyzhM + 25% DT; 90% RyzhM + 10% DT and 90% RyzhM + 10% DT (US). For the parameters of the diesel, the excess air factor, the filling ratio of the diesel cylinder with fresh charge, the maximum cycle pressure, the hourly fuel consumption, smoke and carbon monoxide content in the exhaust gases are taken. It is established that when the diesel engine works on camelina-mineral fuel mode the minimum sustainable speed of the crankshaft idle speed 800 min-1 the values of maximum cycle pressure (6.3 MPa) and the filling ratio of the cylinders of a diesel engine the fresh charge (0,87) remain unchanged. The coefficient of excess air, increasing in mixed fuel shares of camelina oil to 90%, reduced from 7.187 to 4.619, while fuel consumption increases of 1.1 kg/h 2 kg/h. The best environmental indicators are observed when working on red-and-mineral fuel 50% RyzhM + 50% DT. Handling mixed fuel with ultrasound reduces fuel consumption, smoke and content of carbon oxide in the exhaust gas relative to the mixed fuel not treated with ultrasound.