Basic characteristic of fuel control of a tractor diesel engine equipped with a fuel skipping system

The article discusses the problem of improving the efficiency of tractor diesel engines at low loads and rotations. An effective way is to prevent the cyclic fuel supply from decreasing as the load lowers. Practically this is done by turning off part of the cylinders (stopping the supply of fuel to part of the cylinders) as the load decreases. However, with this shutdown method, due to a stepwise change in the specific fuel consumption the unrealized zones appear, where additional fuel economy can be obtained. A smooth change in specific fuel consumption can be achieved by stopping (skipping) individual fuel supplies (injections) not in the same cylinders, but by distributing them across all cylinders. To implement this method of regulation, the fuel system must allow producing single stoppings of fuel injections with different intervals and in any cylinders, which is possible only in electronically controlled fuel systems. In the electronic unit the basic characteristic of the control of fuel supply must be incorporated. The goal is to develop a basic characteristic of diesel fuel supply control to regulate operating modes by skipping fuel supply. The basic characteristic of the fuel flow control was obtained using the speed and regulatory characteristics of the diesel fuel pump. The basic characteristic is a data matrix including the amount of supply actions (before the supply skip) and the number of supply action skipped after supply actions done. The results of experimental studies of the characteristics of the fuel pump of a 2CH105kh120 diesel engine confirmed the efficiency of the fuel system according to the basic characteristic obtained by the proposed method.

fuel supply skipping, speed characteristic, regulatory characteristic