What is the Kruse Limited-Temperature Cycle?
The Kruse Limited Temperature Cycle is an improvement on the Otto and Diesel Cycle processes. By controlling (limiting) peak combustion temperatures in direct injection gasoline (petrol) and diesel engines, the Limited Temperature Cycle allows compression ratios to be increased with appreciable gains in volumetric efficiency for spark-ignition engines and lowers peak temperatures to significantly reduce the creation of Nitrogen Oxides (NOx) in exhaust gas emissions in compression-ignition engines.
Environment and Economics
It would appear that one of the many challenges facing automotive manufacturers is:
"The production of conventionally powered automobiles and trucks that meet the needs of their customers, while evolving towards high-economy, eco-friendly (zero emission) platforms that will meet the needs of their customers in the years to come."
Understandably, there are several points of view regarding the timescales involved in reaching universal zero emission modes of transport, such as that offered by the hydrogen fuel-cell. However, the likely reality is that these are still several decades away from mass production and will need significant investment in terms of distribution infrastructure to make them a viable alternative to fossil and alternative fuels, even in metro areas.
In the meantime, manufacturers are faced with the business of building affordable vehicles with the performance that their customers need, while incrementally reducing emissions and improving fuel economy. This is where the Kruse Limited Temperature Cycle will be of benefit.
Wide Application of Use
The Kruse Limited Temperature Cycle may be used in all forms of direct injection, spark-ignition and compression-ignition engines and is completely independent of fuel type. It is therefore effective for engines using liquid fuels, such as; gasoline (petrol), diesel, methanol and bio-fuels, as well as gaseous fuels, such as; compressed natural gas (CNG), liquefied petroleum gas (LPG) and hydrogen.
The Limited Temperature Cycle provides benefits to the following groups:
- Automotive - Cars, Sport Utility Vehicles and Light Trucks.
- Transportation (Road) - Medium, Light-Heavy and Heavy Duty Trucks and Buses.
- Transportation (Rail) - Locomotives.
- Transportation (Sea) - Marine engines.
- Off-Road (Mobile and Stationary) - Mining, Earth Moving, Farming, Power Generation, Pumps, etc.
There are a number of immediate benefits to be derived from the implementation of the Kruse LTC:
- Improved efficiency - Controlling peak combustion temperature allows for higher compression ratios and greater thermal efficiency. This results in increased fuel economy for a given power output.
- Increased power - Conversely, higher compression ratios result in greater power for a given fuel economy.
- Reduced NOx emissions - The control and reduction of peak combustion temperature by approximately 500 Rankine (260 Kelvin) from current unregulated levels results in as much as an 80% reduction in the generation of NOx.
- Reduced CO emissions - The ability to run lean-burn engines (i.e. more air) will have a significant effect in reducing the generation of carbon monoxide.
Implementation leads to a number of secondary benefits:
- Lower peak temperatures result in a reduction of cooling equipment and fluid, which translates into lower weight.
- Less NOx creation reduces the cost of exhaust gas after treatment.
- Improved efficiency allows for engine downsizing without a loss of performance.
Although it's expected that benefits will be applicable across the spectrum of applications, some fuel types will realise more particular benefits than others:
- Gasoline - Improved efficiency, reduction of carbon monoxide emissions.
- Diesel - Improved fuel economy and as much as an 80% reduction in NOx generation levels.
- Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG) - A 10 to 15% increase in power, as there's no displacement of charge air during injection.
- Methanol - Improved fuel economy and better cold starting.
It is hoped that by the time you have reviewed the material on this web site you will have an understanding of the Kruse Limited Temperature Cycle and will appreciate that its application will make the achievement of better fuel economy and less pollution a near-term reality.
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