COMPARISON OF POTENTIALALLY DANGEROUS FACTORS WITH THE USE OF RARE AND GASILY VEHICLE

Abstract

A detailed analysis of the potentially dangerous factors in the use of diesel, gasoline, methane and propane-butane fuels was carried out in cars. A detailed analysis of potentially dangerous factors when using diesel, gasoline, methane and propane-butane fuels in automobiles has been carried out. 6 options of fuel usage are considered: a tank with g asoline and a system supplying it to the carburetor and further to the engine cylinders, a tank with diesel fuel and the system feeding it to the engine cylinders, gas cylinder installation when installing cylinders with methane on the roof of the car, gas cylinder installation when mounting cylinders with methane in the luggage compartment of the car, gas installation when installing cylinders with propane-butane mixture on the roof of the car, gas installation when installing cylinders with propane-butane mixture in the cargo compartment of the car. Meanwhile, the potential danger while the vehicle is in motion is analyzed, as well as while it is in the open parking lot and in the garage. As the initial data, the common operation period was taken - in summer with the temperature of 30°C and possible fuel leakage with the probability of formation of an explosive mixture. Nonane is taken as a model when considering gasoline, and Pentadecane is used for diesel fuel.

It was noted that the gasoline self-ignition temperature ranges from 255°С to 435°0С, the lower concentration limit of petrol explosiveness can be considered as 0.76% vol., while under selected conditions indoors, gasoline vapor can reach the concentration of up to 0.8 vol. %. The relative vapor density of diesel fuel betting the same conditions is 8.52 kg/m3. With the explosion, the pressure in the closed volume will reach 5.2 atm.

It was noted that the gasoline self-ignition temperature ranges from 210°С to 370°0С, the lower concentration limit of petrol explosiveness can be considered as in % vol., while under selected conditions indoors, gasoline vapor can reach the concentration of up to 0.13 vol. %. With the explosion, the pressure in the closed volume will reach 5.0 atm.

The self-ignition temperature of methane is 537°C, the lower concentration limit of explosiveness of this gas is 5.28% (vol). The vapor density of methane at the temperature of 300°C (303K) is 0.64 kg/m3, which is significantly less than the density of air. The explosion pressure in the closed volume will reach 7.7 atm.

The propane-butane mixture used in summer contains about 40% of propane and 60% of butane. Spontaneous ignition temperature of propane is 4700C, butane is 4050C. The calculated lower explosion limit of this mixture is 1.5% (vol), and the vapor density of mixture at the temperature of 300°C is 2.1 kg/m3, which is almost twice the density of air under the same conditions. The calculated explosion pressure in the closed volume will reach 8.3 atm.

It was concluded that when using certified equipment which is professionally installed, methane, which cannot accumulate in the lower part of the room or any compartment, is much safer than propane-butane and, especially, than gasoline or diesel fuel, as vapor densities of both are more than air density.