How does the EGR valve work?

How does the EGR valve work?
How does the EGR valve work?
Anonim

Few people know, but it is precisely thanks to exhaust gas recirculation that it is possible to significantly reduce the fuel consumption of a car, increase engine performance, normalize its operation and reduce detonation. There is such a system for a long time, and at the moment it is used on absolutely all vehicles. Even the domestic Niva has such a device.

EGR valve
EGR valve

What is this system for?

Exhaust gas recirculation is needed so that the engine does not lose its power when unburned fuel is emitted. And it happens in the following way. When the temperature in the combustion chamber rises, nitrogen together with oxygen begin to form nitrogen oxides. In a gasoline engine, O2 is needed for efficient fuel combustion, and since nitrogen reduces its amount, the liquid does not burn completely. As a result, gasoline simply flies out the pipe,fuel consumption increases, and the performance of the internal combustion engine decreases. The exhaust gas recirculation valve allows the fuel to burn out to the end, as a result of which the power and fuel consumption in the car are normalized.

What is this valve?

It looks like a small disc with a tube that connects to the intake manifold and is mounted on the cylinder head. In a calm state, the exhaust gas recirculation valve (including Audi) is closed. But as soon as fuel is supplied to the engine, it is activated. The vacuum formed in the manifold causes the membrane to move, and it, in turn, opens the EGR valve.

audi exhaust gas recirculation valve
audi exhaust gas recirculation valve

Varieties

At the moment there are several types of these devices. The exhaust gas recirculation valve can be mechanical (in turn, it is divided into 5 modifications) and electronic (there are 3 modifications).

What is he doing?

This mechanism is a key component of the recycling system. It returns part of the burnt substances back to the intake manifold and mixes them with air. The latter, in turn, increases the combustion temperature (due to oxygen - O2). Thus, due to the artificial reduction of its content in the composition of the fuel-air mixture, the degree of combustion decreases. At the same time, oxygen interacts with nitrogen, and as the temperature decreases, it becomes more, so gasoline burns completely in the chamber.

bmw exhaust gas recirculation valve
bmw exhaust gas recirculation valve

In addition, the EGR valve (including BMW) significantly reduces pumping losses, since there is no such a strong pressure drop across the throttle. The low combustion temperature reduces the level of detonation, and this is a big plus for the motor (no loss of torque). As for diesel installations, here the EGR valve normalizes the “hard” operation of the engine at idle: due to the lower combustion temperature, the pressure in the chamber decreases, so there are no strong vibrations.

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