Speed characteristics of automobile diesel engine operating on natural gas

The article presents the graphs of the D-245.7 diesel engine's high-speed characteristics during gas-diesel operation. One of the ways to improve the efficiency of road transport is now to convert vehicle engines into alternative, cheaper fuels. Among various alternative fuels, natural gas is very attractive. If the diesel engine is to be converted to natural gas, then the implementation of the gas-diesel process will be the best method of transfer. There is not enough information in the literature on this issue, so research on this topic is relevant. In the Vyatka State Agricultural Academy research was carried out on the transfer of diesel D-245.7 to the gas-diesel process, the parameters of the combustion process, heat release characteristics, and effective indicators were determined. Work on the gas-diesel process leads to increase in the values of the parameters of the combustion process and the characteristics of heat release in the cylinder of the diesel engine. At the same time, thermal and mechanical loads increase slightly. In the initial periods of combustion in the cylinder, the speed and the value of the active heat release increase. This change indicates that combustion takes place by a three-dimensional mechanism. On the gas-diesel process, as compared to the diesel process, the hourly air consumption decreases, the temperature of the exhaust gases decreases, the boost pressure decreases, the effective efficiency decreases slightly, but the power and torque do not decrease. On the basis of the research, the following conclusions are drawn: 1) during the transition to the gas-diesel process, the pressure, the temperature in the cylinder, the rate of pressure increase rises, but the maximum values of these parameters do not exceed the permissible limits of diesel engines; 2) in the gas-diesel process, combustion in the cylinder occurs by a volumetric mechanism, most of the fuel burns in the rapid combustion phase; 3) the engine power parameters at the gas-diesel process in the entire speed range fully correspond to the diesel process; 4) when the diesel engine operates on an external high-speed characteristic on a gas-diesel process compared to a diesel process, a reduction of diesel fuel consumption by at least 83 % is achieved by replacing it with natural gas.

gas diesel, natural gas, alternative fuel