Injection system for tri-fuel engines with control of power by simultaneous use of CNG and ethanol or gasoline 2010-36-0195

Vehicles equipped with original tri-fuel engines are restricted to a few models. They can operate on blends of liquid fuels, but the use of CNG does not occur simultaneously. CNG is often used by converted vehicles and can be used with ethanol, gasoline or a mixture of both. The main disadvantages in the use of CNG are low volumetric efficiency, low autonomy, loss of power and the need for internal space to store the cylinder. However, they have great economic advantages. The main goal of this project is to build an electronic circuit able to efficiently manage the injection of CNG, increasing its volumetric efficiency and minimizing the loss of power through an automatic management of the power and economy ratio. When the power demand is low, the system operates only on CNG. When intermediate power is required, the system operates with different proportions of ethanol and CNG. For maximum power, only ethanol is used. Comparisons were made between the conventional and the proposed system through dynamometer tests, road tests and emission analyses. There was a significant increase in both power and consumption. The vehicle with its original system, using only ethanol, has 68 hp and 12.6 km /l consumption. With gasoline it has 66 hp and 16.4 km/l consumption. With the conventional aspirated CNG system, the maximum power reached was 55 hp, and the consumption on the road was 21 km/m₃. Using the proposed system, it was possible to achieve a power gain of 17.45%, reaching 64.6 hp, and an increase in autonomy of over 25%, reaching 26.4 km/m₃. The initial power using CNG was no higher than 44.7 hp. However, when the accelerator pedal is pressed above 50%, the system manages the simultaneous use of CNG and ethanol, returning its original power, which may reach 63.1 hp when using 100% of ethanol, if the angle of the throttle is above 90%.