BMW Hydrogen 7

The Hydrogen 7 (E68)

The Hydrogen 7 is a hydrogen-powered car . It bears the internal designation E68 and is based on the 760Li ( E66 ) model from the 7 series from the German manufacturer BMW .

As a special feature, the Hydrogen 7 is powered by a hydrogen combustion engine. In addition, it can be converted to petrol drive, which should make the vehicle more suitable for everyday use, as there were only 14 publicly accessible hydrogen filling stations in Germany in 2012. For this he has an additional fuel tank. In the BMW plant in Dingolfing, 100 copies of this model were produced, which were not sold, but only leased.

This article or the following section is not adequately provided with supporting documents ( e.g. individual evidence ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.

The Hydrogen 7 has two predecessors: Among the first hydrogen-powered vehicles worldwide were the 15 individual models of the 750hL type built in 2000 based on the 750i ( E38 ) from that time . They were demonstrated at the Expo 2000 , among others . Experience with the hydrogen prototype H2R from 2004 was also incorporated into the development of the Hydrogen 7.

engine

Hydrogen 7 engine (E68)

The hydrogen combustion engine of the Hydrogen 7 is technically almost identical to the engine of the 760i. However, it had to be modified to use hydrogen as a fuel. The modifications mainly affect the engine's intake system . In addition to direct injection for gasoline, a feed line to the hydrogen tank was integrated. Special injection valves always ensure the right amount of hydrogen in the intake air.

The sealing of the piston rings also had to be improved in order to prevent the hydrogen from escaping. This had repeatedly led to explosions in earlier stages of development. Since hydrogen burns up to 100 times faster than conventional fuels, the engine control had to be adapted. This was achieved with variable valve control ( Valvetronic ) and double camshaft adjustment ( VANOS ).

The engine of the Hydrogen 7 191 kW (260 hp) and has a torque of 390 Nm (Comparative "normal" 760i: 327 kW / PS 445 and 600 Nm). The car takes 9.5 s from 0 to 100 km / h. The performance is lower than that of the 760i due to the bivalent design of the engine. A tank of 8 kg allows a range of around 200 km. The content of the petrol tank (74 l) increases the range by a further 500 km. When designing future engines for hydrogen only, potential for improvement is expected through the elimination of suitability for gasoline.

Other modifications

In addition to the changes to the engine, the trunk also had to be changed: an additional cryotank had to be installed to store the hydrogen . The development and subsequent series production of the tank was carried out by Magna Steyr Fahrzeugtechnik in Graz / Austria . The cryotank reduces the usable trunk from 500 l to 250 l. In this tank, the hydrogen is stored in liquid form at around 20 K in the low pressure range (the boiling point of hydrogen is −252.882 ° C). The development was characterized, among other things, by the use of media-compatible materials for cryogenic operating conditions. The permeation of hydrogen also posed a major challenge. To isolate the tank, a high vacuum was drawn between the inner and outer tanks. The inner walls are covered with a suitable insulating material. Production was carried out under clean room conditions, among other things. The associated electronics and sensors for measuring the filling mass and for monitoring the safety-relevant filling level during refueling posed a challenge in the development. The company Atena Engineering (today: Silver Atena Electronic Systems Engineering ) therefore developed the control unit, which takes over the safety functions, according to the safety standard DIN IEC 61508 . The phase referred to as the idle time until the controlled emptying (the discharged hydrogen is catalytically oxidized to water) of a half-filled hydrogen tank begins after 17 hours and lasts about 9 days. After that, enough hydrogen would remain in the tank to cover another 60 kilometers in hydrogen mode. This insulation corresponds to approximately 17 m thick polystyrene foam .

The interior also had to be changed a little: the rear bench was moved 12 cm forwards and there is only room for two people on it, as the center armrest is firmly locked. Furthermore, frames and crash zones have been reinforced with composite materials.

The Hydrogen 7 can be recognized by a more curved engine hood, the missing fog lights and the additional filler neck on the C-pillar.

Field trial

BMW Hydrogen 7 (E68) in Berlin

In 2002 BMW announced series production as a “0-liter car”, which was classified as greenwashing . So wrote Der Spiegel 46/2006:

"The supposed eco-vehicle is very thirsty - and pollutes the climate like a heavy truck."

Because in the BMW statement, in addition to the unavailability of hydrogen filling stations, the effort involved in generating and liquefying the hydrogen is completely disregarded. A gasoline equivalent of 13.3 l / 100 km is given for H ₂ consumption (3.6 kg / 100 km). However, in addition to the above-mentioned expenses for energy supply (hydrogen generation currently almost exclusively through steam reforming from natural gas ), it also goes unmentioned that the tank empties automatically when the vehicle is not used (see downtime until emptying ).

The 100 units produced were not sold, but some were sold to celebrities (e.g. Plácido Domingo , Daniel Barenboim , Katja Riemann , Florian Henckel von Donnersmarck ), politicians (e.g. Günter Verheugen , Christian Ude , Guido Westerwelle ) and business representatives ( e.g. Roland Berger , Wolfgang Reitzle ) for use on a leasing basis. Part of the fleet was used as a driving service at high-profile events. During the field test in Berlin , between five and ten vehicles were constantly in use, and they were refueled at the two existing hydrogen filling stations on Messedamm and Heerstraße. On special occasions, such as during the Berlinale , the number of Hydrogen 7 in Berlin rose to around 20.

The field test was ended at the end of 2009; nothing is known about the whereabouts of the 100 vehicles. A vehicle is in the outdoor exhibition of the Chemnitz Industrial Museum (status 10/2015).

Further development

The then BMW development director Klaus Draeger announced at the end of 2009 that there would be no new hydrogen test fleet for the time being.

In 2015 there were signs that BMW (supported by a cooperation with Toyota ) could bring a production vehicle with hydrogen drive onto the market in 2020.

Web links

Commons : BMW Hydrogen 7  - collection of images, videos and audio files

• OptiResource online software for direct comparison of different drive systems is available at www2.daimler.com, January 3, 2018.
• BMW Hydrogen 7: a new era of mobility begins
• General information and technical data Hybrid-Autos.info ( http://www.hybrid-autos.info/Wasserstoff-Fahrzeuge/BMW/hydrogen-7-2006.html ) available on January 3, 2018.
• With Zisch into the Future SPIEGEL ONLINE, January 3, 2018 available.
• 7 Series BMW relies on hydrogen propulsion ( Memento from November 24, 2006 in the Internet Archive ) Financial Times Deutschland, January 3, 2018 available.

Individual evidence

1. ^ Federal government and industry set up a network of 50 hydrogen filling stations. (No longer available online.) Federal Ministry of Transport, Building and Urban Development , June 20, 2012, archived from the original on January 2, 2015 ; accessed on January 2, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , January 3, 2018 no longer available.  
2. ↑ David Talbot: On the way in the hydrogen 7 Series. Heise online , November 22, 2006, accessed January 2, 2015 . 
3. ↑ The "0-liter car". Hydrogen BMW goes into series production. Auto Bild , April 15, 2002, accessed January 2, 2015 . 
4. ^ Christian Wüst: Green swallowing woodpecker . In: Der Spiegel . No. 46 , 2006, p. 184 ( online ). , available on January 3, 2018.
5. ↑ BMW Hydrogen 7. (PDF) In: BMW Media Information 11/2006. BMW Group , November 2006, p. 76 , accessed on January 2, 2015 . 
6. ↑ Markus Fasse: Car manufacturer: BMW is losing faith in hydrogen propulsion. Handelsblatt , December 7, 2009, accessed January 2, 2015 . 
7. ↑ BMW electric car with hydrogen drive will appear in 2020. In: Future Trends. June 30, 2015, accessed April 19, 2019 .