Datum - Rheinmetall Automotive



September 15, 2015

Pierburg

No pressure at all: electrically controlled bypass flaps for EGR modules

For decades now, Pierburg GmbH has specialized and been an international market leader in exhaust-gas recirculation (EGR) modules. As regards the pneumatic actuators of diesel engines, these will in future increasingly have to make do without vacuum as a source of energy. Standard practice so far has been a mixture of electrically and pneumatically actuated EGR modules. For a series project, Pierburg has now developed an all-electrically actuated EGR module that does without vacuum.

Unlike gasoline engines that need a throttle to control the air flow, diesels require an extra pump for producing the vacuum. This pump is mechanically connected to the engine and leads to a loss in performance since it increases CO2 emissions. Moreover, there is no possibility of putting this to use as and when required since the vacuum must be continuously available. The electric actuator developed by Pierburg makes it possible to dispense with vacuum and only requires the energy at the moment of actuation, in other words on demand.

The highly integrated cooler bypass module has been developed for a series-production project due to come on stream in 2016. The first pre-production units are currently being assembled.

As many as over six million EGR valves were supplied in 2014. Other valve and module production locations besides Germany, Spain, and the USA, are in the Czech Republic as well as India and China.

Exhaust gas recirculation reduces emissions

The effect of exhaust gas recirculation is to lower the combustion temperature in diesel and gasoline engines. The lower temperature leads to a reduction in nitrogen oxide emissions. With gasoline engines this is accompanied by a decrease in fuel consumption as the engine is being throttled back under part-load conditions. With turbocharged engines, in particular, the cooled recirculated gases reduce knocking susceptibility at high loads while, at the same time, helping to avoid increased fuel injection when both engine speed and load are high. This is one reason why external exhaust gas recirculation is regaining significance with gasoline engines, specifically in the shape of EGR modules. On account of their compact footprint, the latter are a particularly attractive option for auto manufacturers.

On the materials side, the punishing thermal, mechanical and chemical environments to which all EGR modules are exposed call for highly heat- and corrosion-resistant steels. Among the basic functional requirements to be met by the components themselves are low flow losses and good controllability of the recirculated exhaust gas, even in very small amounts.

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KSPG AG

Corporate Communications · Karl-Schmidt-Straße · 74172 Neckarsulm

Tel. +49 7132 33-3141 · Fax +49 7132 33-3150 · · A Rheinmetall Company

press release

KSPG AG

Corporate Communications · Karl-Schmidt-Straße · 74172 Neckarsulm

Tel. +49 7132 33-3141 · Fax +49 7132 33-3150 · · A Rheinmetall Company

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