Compressed air car
A compressed-air motor (English: Compressed air CAR) is a motor vehicle which is driven by means of compressed air and a gas expansion engine. The compressed air is carried in pressure containers and is supplied to the motor from the outside.
Therefore, there is a zero-emission vehicle in accordance with California emission standards with alternative drive technology.
Compressed air cars for use on public roads will be introduced since the 1990s under the heading of alternative vehicle technology over again, a series production was not yet taken. The Indian vehicle manufacturer Tata Motors has been working for several years until today together with MDI ( Motor Development International) at the production stage.
Also, there are trends for compressed air hybrid engines to use in motor vehicles.
- 9.1 Manufacturer
Pneumatic drive generally
Stationary air motors can be found in diverse machinery and tools.
Various niche applications with pneumatic drive, such as trams in Bern, studs locomotives in the construction of the Gotthard tunnel or mine locomotives have been realized in the past. Many of these special use areas have today been replaced by electric drive systems, which are simpler and also emission-free.
Industrially used memory steam locomotives have a similar approach and similar techniques.
History
In 1838 was constructed a compressed air car from Adraud and Tessie you Motay in Paris and introduced in 1840. In rail transport, this form of propulsion was first used in 1879 at the Tramway in Nantes ( France). The systems were developed by the French engineer Louis Mekarski Polish descent.
To race Paris -Rouen in 1894 six vehicles from France were reported with pneumatic drive, but none appeared at the start:
The U.S. manufacturer MacKenzie & McArthur in New Haven ( Connecticut ) and the Autocrat Manufacturing Company in Hartford (Connecticut ) dealt with the compressed air car. The name American Pneumatic should wear a compressed air driven with automobile whose design was announced in February 1900 by the American Vehicle Company. Were also not marketed compressed air vehicles from Automatic Air, Carrol, Meyers, Muir and Pneumatic.
Properties
The pneumatic drive operates without combustion and without the risk of sparking as it exists on electrical systems. It is therefore very well suited for use in explosive environments, such as in underground mining.
However, is offset by constraints that militate against use as a means of mass transportation. To carry a sufficient amount of drive energy, are large (heavy ) Compressed air tanks necessary. The energy density of the drive system is already unfavorable when compared with simple lead-acid batteries.
Compressed air is one of the most expensive energy sources. Your generation is energetically associated with very large losses. When formed in the heat of compression can not be used, it is lost for the energy balance. An efficient compressed air motor requires a multi-stage relaxation with intermediate heating and is therefore expensive ( engine design ). By expansion of the compressed air, there is a cooling of the engine. It has to be supplied from the ambient heat. Is not that enough to ensure the performance of the expander motor decreases. This effect is increased at low ambient temperatures.
The developments of Nègre
Through his company, MDI of France, the French Formula 1 engine engineer Guy Nègre started in the early 1990s to develop a special compressed-air motor for vehicle propulsion. These efforts led to the concept vehicle Tata OneCat.
Press releases announced since 1995 and the planned production and sales start on, and for years a series production will be announced in each case for the next year. In collaboration with the Indian vehicle manufacturer Tata Motors will continue working on the development. In Europe, a new concept for the production will be announced in which the vehicles are to be produced directly from the merchants.
Guy Nègre was nominated in 2002 for the Euro Solar Prize for alternative transport systems. The nomination was withdrawn after questions about operating experience of the prototypes could not be answered. The published performance figures have not yet been independently verified. A crash test is also not yet occurred in practice.
The advantages of low maintenance cost and long life can be provided by the developer. The functionality of the developed by Nègre engine is not fundamentally different from the well-known principle of a gas expansion engine: compressed air expands in two cylinders driving the piston of the car. The engines of only 500 to 700 kilogram vehicles will have an output of 30 hp (22 kW). A lubricant feed oil is used.
For a tank of 90,000 liters of air ( about 110 kg) are compressed to a pressure of 300 and stored in four sheathed with Kevlar compressed air bottles with a total volume of 300 liters. According to the manufacturer the charging process takes on a 230 -volt outlet for about four to six hours at a corresponding compressor station two minutes.
According to the manufacturer fall for operation on only cost of electrical energy, wearing parts, lubricants and taxes, for a full tank were only 20 kWh required (depending on electricity rates about 3-6 euros ). In the past, the manufacturer of 240 km range spoke at a constant 60 km / h with a top speed of 110 km / h 100 km should be possible. To permit higher ranges, there will be models with an internal combustion engine which generates more compressed air. Currently a range of about 70 kilometers, is specified by the manufacturer. These values were considered by professionals to be clearly too optimistic. An independent reference for the manufacturer's data does not exist.
Other models
At the Geneva Motor Show 2009, two new models of MDI, AirPod and Oneflowair presented.
In the Airpod it is a little more than two meters long four-seater with 220 kg curb weight. According to the specification data is the front suspension consists of a vertical single-axis controller with wheelbarrow wheels in double version (also known as " castor control"), with the size of 10 × 4.00-5 (excerpt from the published technical. "Train avant Diabolo deux roue, pneumatiques Avant: 10 x 4.00-5 ").
The Oneflowair is a 3.40 m long and up to five seater convertible, which is similar to the Citroën Mehari in shape. The Oneflowair is next to the air drive containing an internal combustion engine for range extension.
Criticism
In a study by the University of California, Berkeley, a comparison between gasoline car, battery-electric cars and compressed air car in terms of greenhouse gas emissions, fuel costs, primary energy consumption and tank volume was hired. As a comparison, a conventional Objects Smart Fortwo, a battery- electric Smart Fortwo ED and a hypothetical compressed air car served. The technical parameters of the compressed air cars were, if unknown, optimistic appreciated. In the points greenhouse gas emissions, fuel costs and the tank volume compressed air car fared significantly worse than the gasoline or the car battery. Only in the point of primary energy consumption resulted in an advantage over the petrol car, but only when operated with renewable energy. The battery car cut off in all respects much better than the compressed air car.
Other criticisms of MDI is currently practiced by current and former business partners, mainly with regard to services promised and technology transfers that were never executed.