5.16.1. Features of the device
The system of recirculation of the fulfilled gases serves for decrease in toxicity of an exhaust (due to reduction of formation of oxides of nitrogen). At high temperature of combustion of fuel-air mix in the combustion chamber a large amount of oxides of nitrogen is formed. Through system of recirculation a part of the fulfilled gases for their reburning comes back to cylinders of the engine that reduces concentration of fresh fuel-air mix and, therefore, temperature in the combustion chamber.
Basic element of system — the recirculation valve installed on an inlet pipe which at the big angles of opening of a butterfly valve allows for a dogoraniye into the inlet highway the fulfilled gases from a final collector on channels in a flange of a branch pipe of a final collector and in an inlet pipe. The electromagnetic valve which is operated, in turn, by the control unit of the engine operates the pneumatic valve.
The system of recirculation of the fulfilled gases does not work under following conditions:
– low temperature of cooling liquid of the engine;
– the engine idles;
– the engine works at full opening of a butterfly valve.
The failure of valves of system of recirculation leads to increase in toxicity of the fulfilled gases. Valves are non-demountable, at failure replace them assembled.