Problems of fuel consumption measurements in research of liquid phase LPG injection engine

In research of LPG fuelling engine, often used method of fuel consumption measurement is weighing of fuel tank. This method is not proper for fuelling system with fuel pump located in the tank. When LPG pump is working are generated vibration that introduce significant disturbance of fuel tank mass measurement. For test bed research of liquid LPG fuelling engine with sequential injection system (system of V generation), measurement of fuel consumption is very difficult because there are fuel vaporization problems in the fuel pipes, too. This paper presents LPG measurement system, with two of mass flow meters in differential configuration, proposed by authors. This system allow for accurate measurement of LPG fuel consumption. The described system was used for MD-111E engine in test bench research. This engine was fuelling with liquid phase sequential injection system into the suction manifold. Significant problem in the liquid phase injection system is the measuring of fuel consumption. This required of LPG pump installed of the proper rate of delivery to reduce vaporization of fuel. Average relative difference of measured fuel consumption per hour SGt,, for location of flowmeter sensors in the injectors circuit did not exceeded 2%.