Kolbenschmidt Pierburg, a member of the Rheinmetall Group, has booked its first orders for the newly developed cooled exhaust gas recirculation module. Presently, this globally operating auto industry vendor has orders on hand from three renowned European carmakers, representing a total contract volume of around €300 million.
In future, both diesel and turbo-charged gas engines will be inconceivable without EGR cooling due to the ever stricter exhaust gas regulations. For diesel engines, whether in passenger or commercial vehicles, this is especially true of the further reduction of nitrogen oxides (NOx) Of special significance in this context is cooled exhaust gas recirculation enabling a drastic reduction of such emissions.
This exhaust gas recirculation module from Pierburg comprises a newly developed cooler made from die-cast aluminum-a low-cost and weight-saving alternative to today's commonly used stainless steel coolers, an option which, moreover, utilizes the better heat conductivity of aluminum.
In lowering exhaust gas temperature by over 600 °C, depending on the operating mode, the exhaust gas cooler therefore helps reduce combustion temperatures and hence nitrogen oxide emissions while also taking some of the heat off the downstream engine components.
The longstanding know-how of this Neuss-based auto industry vendor in terms of emission reduction has enabled the development team, with its aluminum EGR cooler, to design a product innovation for diesel engine vehicles, one characteristic for its excellent long-term cooling performance. This is achieved through innovative exhaust gas recirculation using specially shaped fins. The new cooler concept is suitable for both low- and high-pressure systems and can be integrated into the intake manifold of engines with matching design features.
To date, coolers have mainly consisted of welded stainless steel sheet metal with its comparably high production costs. Another advantage of aluminum is its much higher heat conductivity versus steel. Aluminum's excellent heat conductivity makes it possible to achieve a very high cooling effect even in a relatively small space.
Moreover, the patented discontinuous fin construction is ideal, since the turbulent mixing of the exhaust gas flow is enhanced by these breaks. It counteracts direct fouling, promotes convective heat exchange and permits an exchange of substances, pressure and heat transverse to the mainstream direction-this having a self-cleaning effect. This is where the so-called Kelvin-Helmholtz instabilities are exploited where a swirl occurs at the shear layer of two parallel-flow layers with varying flow velocities.
So that the engine reaches its operating temperature as quickly as possible, the new exhaust gas cooler has a bypass valve, actuated electrically or pneumatically. The exhaust gases are routed through this valve and the so-called bypass channel past the cooler, until the required engine operating temperature is reached.
With the engine at its operating temperature, the bypass is closed, so that the cooler can perform its actual task and reduce the temperature of the recirculated exhaust gases. The effective lowering of the combustion temperature achieved through this process combined with corresponding oxygen abatement reduces nitrogen oxide emissions to a maximum degree.
Another important advantage of the new EGR cooler is that it is an integrated assembly in which the individual components-EGR cooler with its coolant flow, bypass valve alternating on-demand between cooler and bypass operation, and EGR valve for controlling the EGR rate-merge into one EGR module. Moreover, aluminum makes it possible to combine the EGR module and intake manifold into one individual component. The result: an integrated intake manifold module with exhaust gas recirculation and cooling system.
By fine-tuning a new welding technique developed for die-cast aluminum parts, it is now possible to weld together all the internal interfaces of the module rather than use the type of temperature-resistant seals and supplementary fasteners employed until now.
Additionally to meeting the already mentioned strict criteria-for instance, high cooling performance, minimum cold fouling and good resistance to elevated exhaust gas temperatures-there is also the weight advantage of the new aluminum cooler. And because of the aluminum and its inherent corrosion protection, all requirements in terms of durability are likewise met.
In future, both diesel and turbo-charged gas engines will be inconceivable without EGR cooling due to the ever stricter exhaust gas regulations. For diesel engines, whether in passenger or commercial vehicles, this is especially true of the further reduction of nitrogen oxides (NOx) Of special significance in this context is cooled exhaust gas recirculation enabling a drastic reduction of such emissions.
This exhaust gas recirculation module from Pierburg comprises a newly developed cooler made from die-cast aluminum-a low-cost and weight-saving alternative to today's commonly used stainless steel coolers, an option which, moreover, utilizes the better heat conductivity of aluminum.
In lowering exhaust gas temperature by over 600 °C, depending on the operating mode, the exhaust gas cooler therefore helps reduce combustion temperatures and hence nitrogen oxide emissions while also taking some of the heat off the downstream engine components.
The longstanding know-how of this Neuss-based auto industry vendor in terms of emission reduction has enabled the development team, with its aluminum EGR cooler, to design a product innovation for diesel engine vehicles, one characteristic for its excellent long-term cooling performance. This is achieved through innovative exhaust gas recirculation using specially shaped fins. The new cooler concept is suitable for both low- and high-pressure systems and can be integrated into the intake manifold of engines with matching design features.
To date, coolers have mainly consisted of welded stainless steel sheet metal with its comparably high production costs. Another advantage of aluminum is its much higher heat conductivity versus steel. Aluminum's excellent heat conductivity makes it possible to achieve a very high cooling effect even in a relatively small space.
Moreover, the patented discontinuous fin construction is ideal, since the turbulent mixing of the exhaust gas flow is enhanced by these breaks. It counteracts direct fouling, promotes convective heat exchange and permits an exchange of substances, pressure and heat transverse to the mainstream direction-this having a self-cleaning effect. This is where the so-called Kelvin-Helmholtz instabilities are exploited where a swirl occurs at the shear layer of two parallel-flow layers with varying flow velocities.
So that the engine reaches its operating temperature as quickly as possible, the new exhaust gas cooler has a bypass valve, actuated electrically or pneumatically. The exhaust gases are routed through this valve and the so-called bypass channel past the cooler, until the required engine operating temperature is reached.
With the engine at its operating temperature, the bypass is closed, so that the cooler can perform its actual task and reduce the temperature of the recirculated exhaust gases. The effective lowering of the combustion temperature achieved through this process combined with corresponding oxygen abatement reduces nitrogen oxide emissions to a maximum degree.
Another important advantage of the new EGR cooler is that it is an integrated assembly in which the individual components-EGR cooler with its coolant flow, bypass valve alternating on-demand between cooler and bypass operation, and EGR valve for controlling the EGR rate-merge into one EGR module. Moreover, aluminum makes it possible to combine the EGR module and intake manifold into one individual component. The result: an integrated intake manifold module with exhaust gas recirculation and cooling system.
By fine-tuning a new welding technique developed for die-cast aluminum parts, it is now possible to weld together all the internal interfaces of the module rather than use the type of temperature-resistant seals and supplementary fasteners employed until now.
Additionally to meeting the already mentioned strict criteria-for instance, high cooling performance, minimum cold fouling and good resistance to elevated exhaust gas temperatures-there is also the weight advantage of the new aluminum cooler. And because of the aluminum and its inherent corrosion protection, all requirements in terms of durability are likewise met.
