Reducing the toxicity of exhaust gases of diesel engines by disabling some of its cylinders

The main lines of constructive and technological improvement of motor vehicles are reducing fuel consumption and exhaust gas toxicity. One of the most effective measures to reduce fuel consumption and impact on the environment is to apply a complex method for full and partial shutdown of some cylinders when the engine operates at idle and low loads. This method limitedly applied for modern vehicles. However, it is complicated to develop and use the technical means for its implementation due to the distinctive features of operating modes of motor vehicles and the specifics of operating conditions. In the reviewed studies, the particularly developed measures for disabling fuel supply and timing drive were applied to the D-240 engine of an MTZ-80 tractor. To carry out the experiments, we used a KI-5543 roller-brake stand with measurement instruments, a D-240 diesel engine of an MTZ-80 tractor, an “Infrakar D1” opacimeter and an “Infralight 11P” gas analyzer. For the experiments, we selected three typical operating modes of a D-240 engine without load and under the load Ne = 0...35 kW: 1. a normal operating mode of all 4 cylinders; 2. an artificial operating mode created by switching off the fuel supply in 2 cylinders of a 4-cylinder engine; 3. an artificial operating mode created by switching off the fuel supply in 2 cylinders and gas distribution mechanism in 2 cylinders of a 4-cylinder engine. It was found that the shutdown of some diesel engine cylinders leads to a reduction in fuel consumption by an average of 25-27 %, in carbon-black content and smoke content of exhaust gases by 30-35 %, depending on the operating mode of the engine. We determined the dependences of the hourly fuel consumption, air consumption, air excess coefficient, carbon-black content and smoke content of exhaust gases of the four-cylinder diesel engine when switching off some of its cylinders at different loading modes.