Cooling Device of Intake Air of Internal Combustion Engine

In the effort to improve vehicle fuel economy while maintaining or improving vehicle power to weight ratios, many automotive OEMs are opting to downsize and turbocharger ("boost") their new direct injection gasoline engines. This is a continuation of a trend which has already led to nearly 100% penetration of turbocharger systems on automotive diesel engines. As used herein, the terms "boost" and "boosting" should be taken to mean an apparatus and/or method for providing combustion air to an internal combustion engine at a supra-atmospheric pressure.

One disadvantage of downsized, turbocharged engines is that the available torque at or near idle is very low (sometimes even lower than a naturally-aspirated engine of the same displacement). This leads to the well-known "turbo lag" and to the trend to waste gate, variable geometry turbine, and even two-stage series/sequential turbocharger systems to mitigate such poor low-RPM and transient performance.

One prior art engine system that overcomes low-RPM and transient performance has been put into volume production by Volkswagen(R) in a 1.4L "twin-charged" direct injection gasoline engine offered in several of their models. This engine system uses a high speed ratio supercharger to supplement the turbocharger at low RPM as needed. The system then transitions to turbocharger-only operation, with the supercharger declutched, at high RPM.

Although, as noted above, the turbocharger is unable to boost an engine well at low RPM, the amount of available exhaust energy at high engine speed and load is often substantially above the level needed for boosting the engine. Therefore, a "waste gate", as the name implies, is often used at high engine speed and load to waste part of the exhaust energy by diverting a portion of the flow around the turbocharger turbine. A variable geometry turbine is somewhat more efficient, because it can modulate the kinetic energy of the exhaust at the turbine inlet; however, a variable geometry turbine tends to be more expensive and still suffers from some flow losses and thus still involves some level of parasitic energy loss in the system.

Another important aspect of engine boosting for both gasoline and diesel engines is charge-air cooling. Due to adiabatic compression, the compressed air temperature after a turbo-compressor or supercharger is significantly higher than ambient. An "intercooler", also known as a charge air cooler, typically is used to lower the temperature as much as possible to improve the volumetric efficiency and to reduce the propensity of engine "knock?

Inter cooling principal is widely used in many charger system. But it is low efficient solution because in hotter days the cooling is no enough to maintain the hot inlet air. That is why we apply a low temperature serpentine in air inlet pipe of ICE. The temperature serpentine (see the white star at video ) is cooling by heat pump and/ or by car air-conditioning system.

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Category:

Science & Technology

Tags:

• Cooling
• Device
• of
• Intake
• Air
• Internal
• Combustion
• Engine