Catalyst operation

TOYOTA COROLLA cars are equipped with both adjustable and non-adjustable catalytic converters. A controlled catalyst requires a controlled blender.

A controlled air-fueler is a carburetor or injection system in which the fuel-to-air ratio can change depending on the driving conditions of the vehicle and the oxygen concentration in the exhaust gases. in conventional carburetors» that cannot be achieved, since they do not have a corresponding regulation node. For this purpose, carburetors or electronically controlled injection systems are used.

The mixer receives control commands depending on the oxygen sensor signal (lambda probe), which is located in front of the catalyst in the exhaust gas stream. The oxygen sensor is a sensor that generates an electrical signal depending on the oxygen content in the exhaust gases.

In a fraction of a second, the oxygen sensor sends a signal to the injection system control unit, which controls the desired fuel-to-air ratio. This is necessary, firstly, because the operating conditions of the engine are constantly changing (idle, full throttle), and secondly, because afterburning in the catalyst occurs when the exhaust gases contain a certain amount of gasoline.

To achieve optimal afterburning in the catalyst in the temperature range of +300-800°C, the fuel-air mixture must contain more fuel than is necessary for clean combustion of the fuel.

As a rule, so-called triple catalysts are used in cars. In such a catalyst, the control process simultaneously provides an oxidative reaction for the conversion of carbon monoxide (SO) and hydrocarbon (NS) into carbon dioxide and the reduction reaction of the conversion of nitric oxide (NOx) into ordinary nitrogen in the air.