Pressure wave supercharger
The Comprexlader (also called pressure wave supercharger ) is a type of forced induction of petrol and diesel engines.
Design and functional principle
The loader goes into a cylindrical housing with two openings on either side, a respective inlet and an outlet. Inside the case is a single bucket rotates. It is mechanically driven by a toothed belt or a chain, and thus runs either synchronously to the crankshaft or at a lower speed ( typically 1 /3).
The suction pressure build-up occurs abruptly by using the energy of the incoming exhaust gases. The exhaust gases are guided in a respective one or more cells of the cellular wheel and compress fresh air therein. By a suitable speed and translation timing of the cell wheel will cause the exhaust - pressure shock compresses a lot of fresh air in a straight each selected cell. Then, the fresh air pressure in the cell is maintained by further rotation of the cell wheel, and shortly after that the thus compressed air is supplied to the intake system.
The driving of the charger transfers as opposed to a compressor or Roots-type blower is no mechanical energy to the pressure build-up and has to overcome bearing friction than the no forces; it is in driving the Comprexladers only speed synchronization between the crankshaft and the induction strokes.
Thus, the Comprexlader is not strictly speaking a displacement as it transmits the power directly from the exhaust gas to the intake gas and the operation is controlled by the mechanism of the pressure cells only.
History
The Comprexlader was developed in the 1970s and 1980s by the firm of Brown, Boveri & Cie in Baden ( Aargau ).
The construction principle was built starting in 1985 for a short time at the manufacturer Opel in the past Senator diesel models. At that time other manufacturers have also had turbo - diesel engines in the sales program, so Opel with its 2.3 -liter naturally aspirated diesel engine, which carried only 71 hp ( 52 kW), was no longer competitive. The diesel engine range was expanded further: In model year 1984, the 86 hp ( 63 kW) turbo variant added, which was also available at the Senator. From 1985 there was a technical feature the 2.3-liter diesel with 95 comprex HP (70 kW) as an option. The Senator comprex diesel gave it exclusively with a 5- speed manual transmission. However, manufacturers nameplate was not Opel, but Irmscher. It only small numbers were manufactured.
The torque curve makes the advantage of Comprexladers against the turbocharger recognize: Unlike the turbocharger thrust sets even at very low speeds and especially a delay, since the acceleration of the exhaust turbine is eliminated. It allows for energy- efficient driving style at low engine speeds.
The first Comprexlader had the peculiarity that a singing, by some customers perceived as unpleasant sound produced by the same large cells whose pitch was followed by the speed. Remedy brought a new bucket that was no longer cells, but of a package with tubes of different diameters. Since the loader is made of thin-walled ceramics, became more expensive by this transformation the production costs.
BBC did not find the Comprexlader by the vehicle manufacturer in Europe, the desired resonance; it was after the merger of BBC with ASEA to form ABB also no new money for this project. The system was then sold to Mazda, where from 1988 to 1996 einbaute a comprex - charged 2.0 -liter diesel engine in the Model 626, which brought it to an output of 55 kW (75 hp). The 2.0 -liter naturally aspirated diesel engine 's performance in comparison to 44 kW (60 hp).
1996 was presented by Greenpeace Twingo Smile of the public. This prototype based on the Renault Twingo had a 358 cc gasoline engine with large Comprexlader. The engine developed 40 kW ( 55 hp ), giving a specific power output of 154 hp per liter of displacement. The Twingo Smile consumed less than 3.3 liters of fuel per 100 km, which is about half as much as the original vehicle with its outdated bumper engine.
Latest stage of the principle is the so-called Hyprex - pressure wave supercharger.
Pros and Cons
The exhaust gases transfer printing without delay to the fresh air, with the result that the Comprexlader no " turbo lag " is, but uses the charging effect directly.
The disadvantages include the fact that the Comprexlader is relatively difficult to tune a motor, which makes the development very expensive and complex. Furthermore, the Comprexlader both emission as well as the fresh air side against extremely sensitive to pressure, so that already attract small changes in the intake ( dirty air filter ) or exhaust system ( small hole in the exhaust ) strong repercussions. Such errors often had the problem of unwanted exhaust gas recirculation, which the engine receipted with strong stuttering and swallowing.