BorgWarner Electric Butterfly EGR Valve to Debut with Diesel Engine OEM in 2010
15 June 2009
| BorgWarner’s new electric butterfly EGR valve technology will debut with a leading commercial engine manufacturer in 2010. Click to enlarge. |
BorgWarner is introducing an electric butterfly EGR (exhaust gas recirculation) valve for diesel applications. The EGR valve was developed to deliver precise, responsive flow control combined with high flow capability, excellent sealing, corrosion resistance and reliable operation in the most severe operating environments. The technology will debut with a leading commercial engine manufacturer in 2010.
Recirculating exhaust gas and combining it with an air and fuel mixture reduces the combustion temperatures that produce NOx emissions. New engine concepts for commercial diesel vehicles require greater use of state-of-the-art EGR systems to meet ever stricter emissions standards, according to Roger Wood, BorgWarner Engine Group President.
BorgWarner’s electric butterfly EGR valve features a brushless DC motor actuator with a gear train that has already proven its robustness and reliability in turbocharger applications. The brushless motor offers high durability and enhanced power-to-weight ratio.
Sensors within the motor provide feedback to a closed-loop control system to position the valve and ensure precise control of recirculated exhaust gas. All major components, including the housing and valve, are built with stainless steel to resist corrosion. The butterfly valve design provides excellent sealing and reliable operation within the harsh diesel exhaust system environment.
In addition to commercial diesel engine and vehicle applications, BorgWarner’s butterfly EGR valve can also be applied to diesel passenger car applications and is easily integrated with an EGR cooler and cooler bypass valve.
BorgWarner Turbo & Emissions Systems is a leading global producer of turbochargers, exhaust gas recirculation valves and other engine air management systems for passenger cars, light trucks and commercial vehicles. These systems are designed to improve fuel economy, reduce emissions and enhance vehicle performance.
"for diesel applications"
OK, so would this give any benefit to gasoline engine applications which also use exhaust gas recirculation?
Posted by: ai_vin | 15 June 2009 at 08:28 AM
ai vin,
EGR valves have been in common use in gasoline engines for decades. This product is tougher and more corrosion resistant so that it can survive commercial diesel applications.
Posted by: Bernard | 15 June 2009 at 02:12 PM
And costs $2k+ at the parts counter.
Posted by: ToppaTom | 15 June 2009 at 08:57 PM
EGR on gasoline engine is pretty straightforward thing: cooled exhaust gases are sucked into intake manifold at part throttle. On diesel engine it is much trickier. Diesel engines are universally turbocharged, and pressure in intake manifold after turbocharger is higher than in exhaust manifold. Admission of exhaust gases before turbocharger is problematic, because diesel soot and traces of engine oil precipitate on exhaust turbine and cause turbine disbalance. It is very undesirable thing – disbalance on a part which rotates at up to 120 000 RPM.
Most modern diesel EGR systems avoid such problem by sucking in purified exhaust gases after diesel particulate filter.
Posted by: Andrey Levin | 15 June 2009 at 10:17 PM
Andrey, pressure in intake manifold after turbocharger cannot be higher than in exhaust manifold, because that would mean that the power given to the intake air is greater than the power of the exhaust gases in the exhaust manifold.
The EGR valve can help to control in a more precise way the recirculation of gases helping with NOx reduction, Achilles' heel of diesel engines (diesel soot is diesel fuel problem, not engine's)
Posted by: Felipe | 16 June 2009 at 07:48 PM
Felipe, it is BACK pressure in exhaust manifold, which has one open end – exhaust pipe. And on average it is smaller than what impeller is pushing into CLOSED cylinder. It is possible to use high pressure PULSES of exhaust gases to charge EGR, but it is very difficult to control.
Posted by: Andrey Levin | 16 June 2009 at 09:18 PM
You mean after turbocharger? Because flow in=flow out (ideally) and you must take power from exhaust gases to increase pressure for the flow entering intake manifold.
I see your point about closed cylinder because that generates back pulses in the intake runners, when intake valves close. Is that what you mean?
Posted by: Felipe | 17 June 2009 at 08:14 PM
Felipe: energy of compressing or expanding of gases is roughly pressure multiplied by delta volume (for simplicity say that temperature of gases does not change in compression/expansion). Because exhaust gases have much higher temperature, their volume is much higher, and it is possible to extract part of energy of expanding hot exhaust gases to compress cold intake air to pressure higher than pressure of exhaust gases.
For simplicity take gas turbine: compressor (powered by exhaust turbine on same shaft as compressor) compress intake air to pressure higher than it is found in combustion chamber (other vice gas turbine engine would not work). But because volume of exhaust gases is much higher (due to higher temperature) than volume of intake air, it is possible to extract useful power, aside from what it is used to compress intake air.
Posted by: Andrey Levin | 17 June 2009 at 10:34 PM
Felipe: Andrey is right.
Posted by: Engineer-Poet | 19 June 2009 at 10:41 AM
I was thinking based on P-V diagram for Diesel cycle, which shows that pressure at EVO (exhaust valve opening) is clearly higher than intake pressure, but seems that you are taking about intake pressure vs exhaust presure at IVO, used for scavenging.
I understand what you mean, instant pressure in exhaust manifold is not always higher than intake manifold pressure specially in turbocharged diesel engines.
Don't compare with gas turbines, gas turbines use only 1 compresor (the turbocompressor) to take the intake air to combustion pressure. Turbocompresors in car's engines does only part of the job, if the intake valve(s) were open at combustion pressure it will be instant surging.
Posted by: Felipe | 21 June 2009 at 03:24 PM