What about the compressed air car?

[minguinhirigue]

I think the 300 bars are a major security problem, I just think that the main concern is the energy consumption to obtain them.

I believe that across the whole industry, on a large scale, between compression and transformation into useful energy (electrical or mechanical), there are 60% losses on German systems on a large scale.

I don't know if we can limit them, recover the heat produced by compression, it may be worth it.

Otherwise the danger of a cylinder is the same as for LPG ...

[Capt_Maloche]

Houlà, I must answer

All-electric vehicles would, for example, be three-carrier, of which only the central wheel would have an engine, limited to 80 or 120 km / h due to insufficient power, but having more than 90 km of range at speeds. urban and peri-urban averages (between 30 to 70 km / h with current batteries ...). These vehicles would reduce nuisance in the heart of the city, and would finally allow more suitable individual transport: stop moving 80 kilos in a vehicle that weighs 1100!

This same electricity can be used at home for a compressor, but as has been pointed out several times, it takes a trick to recover the heat "lost" during the compression of an air system, otherwise, it really holds. not the road, neither as a replacement for current cars, nor in competition with electric vehicles ... Otherwise, on solar concentrating systems or wind power systems, we can always directly produce compressed air to reduce compressor losses, but 300 bars, that's still problematic!

Sorting carriers? Too much trouble!

80 Kg, no, a little less

there are no tips to recover the waste heat, apart from preheating the DHW, on the other hand there is one to recover it when the pressure is reduced, by passing the relaxed air through an exchanger which will recover calories from the outside air

300bar tanks remain dangerous

It should be noted that the scuba diving tanks are inflated to comparable pressures, higher even during the testing and that at the moment there are thousands in use.

How is it that it is not prohibited?

This is not the issue, diving tanks are subject to regulations and must not be transported under pressure, moreover, they are subject to annual exams and re-tests (I am well placed to know)
on a vehicle, a shock can cause them to explode / tear with fatal consequences

I think the 300 bars are a major security problem, I just think that the main concern is the energy consumption to obtain them.

I believe that across the whole industry, on a large scale, between compression and transformation into useful energy (electrical or mechanical), there are 60% losses on German systems on a large scale.

I don't know if we can limit them, recover the heat produced by compression, it may be worth it.

Otherwise the danger of a cylinder is the same as for LPG ...

answered above

A+

[Leo Maximus]

There are CNG buses that carry high pressure gas cylinders, they are everywhere, it is marked "I drive on natural gas".

These high pressure gas cylinders for transport is not new, I have traveled hundreds or even thousands of km in Japan where taxis run on natural gas under pressure (and LPG also now) and I have never heard of a problem. The bottle occupies a good part of the trunk, this is the main drawback. There was an article about this in the Auto Journal in ... 1967.

There are forums on scuba diving and, apparently, the transport of inflated diving cylinders is not prohibited, it is regulated.

[jp_souq]

I even wonder how the next progress of electrical storage (nanotechnologies therefore increase in exchange surfaces at equivalent volume, key system for batteries, fuel cells and supercapacitors ...) could not authorize in 3 years the design of all-electric vehicles traveling at 130 km / h for two hours, after which a break is necessary ... But we are not there yet!

Regarding electricity production, without discussing too much about the current efficiency of photovoltaic panels, we know today that with a little ingenuity, the sensors can hope to progress up to 30% to 40% performance, and replace our old house covers, as well as paintings of our walls. MIT even develops solar windows... So the home charging from a renewable production system is already practiced and can continue to develop pleasantly ...

I have already said it here, but I doubt that electric technology is as economical as it seems to show for a motorization. This conceals the high cost of recycling accumulators / batteries, as well as photovoltaic sensors, which contain polluting metals (silicon, cadmium). Guy NEGRE's system may seem bizarre, lousy and rotten, but at least we don't have this additional cost linked to recycling. As for the cost per kilometer, it is close to that of electric vehicles (changing batteries is even more expensive than wearing parts of a compressed air engine).

On the other hand, on the solar energy side, energy production systems such as solar water heaters seem to me to be a very good economic and ecological compromise.

This same electricity can be used at home for a compressor, but as has been pointed out several times, it takes a trick to recover the heat "lost" during the compression of an air system, otherwise, it really holds. not the road, neither as a replacement for current cars, nor in competition with electric vehicles ... Otherwise, on solar concentrating systems or wind power systems, we can always directly produce compressed air to reduce compressor losses, but 300 bars, that's still problematic!

I wish to have more information on this subject. Compressing air can be done in several ways: electricity, fossil energy, renewable energy.

1) Fossil energy (petroleum, coal): a compressor which uses this type of energy would have good energy efficiency, but would remain fairly polluting. The cost to fill 300 bar cylinders remains modest for the moment, but that could evolve, and especially take another scale if the demand for compressed air skyrockets. in short, not necessarily ideal.

2) electricity: most of our electricity in France is of nuclear origin. It remains clean energy, apart from the risks associated with radioactive waste and accidents such as leaks or explosions. It is questionable, however, whether the price of nuclear power will increase sharply in the future as the countries in transition adopt this energy. Already in the past 5 years, the price of uranium has risen considerably on world markets, which is likely to cause tension downstream on electricity prices.

3) Renewable energies, which can produce electricity to make compressed air. It is a very ecological and inexpensive way to obtain compressed air, but one wonders if the production will be able to follow the needs in the future.


Are there systems for recovering the heat lost during compression? Physically, I don't see how it can exist ... However, MDI also seems to be working on this point, but I didn't understand the system used.

If not, why is compressing to 300 bars problematic? For reasons of energy efficiency? Technological capacity? Security (weak argument, given some answers on this thread)?

[minguinhirigue]

MDI when you hold us ...

I have no comparative values ​​on the initial costs and in uses of compressed air systems and battery systems. The question of the cost of one or the other, especially at the recycling level, can be very important, if some have lights on this subject?

For the question of compression at 300 bars, without being prohibitive, I find it a shame for the different reasons that we have been able to discuss:
- risk of explosion, even if it is low and different from the potential fire charge that is a car, it should not be overlooked, just as special arrangements are often
carried out for covered car parks in view of the risk of fire ...
- losses during compression, all the more important as the compression ratio is high. However, they are partially recoverable on cogeneration systems, with recovery of cooling water for domestic hot water for example (same problem for electricity with generators or cogeneration boilers).
- losses during expansion, the thermal losses can however be exploited in various ways, either as Capt Maloche says with an exchanger, or with the use of cold air relaxed in air conditioning of the passenger compartment.

One point on which electric and compressed air can be compared is that the two technologies are open to the recovery of braking energy ... Except that the efficiency can be more than 80% for electric (with supercapacitors), when it does not exceed 65% for current compressors ...

So, even if the air car has considerable cost advantages (to assess !?), I doubt that the air sector is an energy efficiency equivalent to that of the electric sector:
- production efficiency between 80 and 95% for the electric alternator, 60% for the compressor.
- operating efficiency of 80 to 95% for the electric motor, 65% for the negro guy's motor.
- braking recovery efficiency from 60 to 90% for the electric alternator, from 50 to 60% for the on-board compressor.

The data are on the ladder from various articles in economics, and Wikipedia. I have to check the sources or those who know them to correct ...
But still, is it that 20 to 30% of the available energy can escape the air system !?

[skyr81]

Just for info, the link to the page of the Dépèche de Toulouse of this day: http://www.ladepeche.fr/article/2008/07/25/465715-La-voiture-ecolo-attendue-a-Toulouse.html

I hope they will settle down quickly and that it is not a shot in the water or rather the air ;-)

As for those who doubt the performance, I could oppose them the fact that batteries, they must be recycled at one time or another while the air ...

Just that in the end, the ecological balance is perhaps in favor of the solution to Guy NEGRE.

But I am not an expert.

For the moment my choice would go towards the MDI solution, because to make the journey home-work (50 km / d) work-house 5 times a week, for a few euros / week and not 90 for theGO or the SP95. Even if the comfort is a bit basic.

A +

[Christophe]

We said: NEVER AGAIN MDI or air car on these forums...

In summary: MDI threatened this forum and defamation lawsuit site several times because they apparently don't like being reminded of certain truths and facts ... like those that minguinhirigue has just mentioned ...

For newcomers who don't understand what I'm talking about: https://www.econologie.com/forums/search.php

So do I lock or not?

[Mesh]

In the article, it is specified that the vehicle will be marketed first in India in 2009.

What about us? I think we are not yet ready to see it roll in France, unfortunately!

For rates ranging from 3500 to 9000 euros: 3500 will be for India and 9000 for France ... As usual!

Wait and see!

[skyr81]

We said: NEVER AGAIN MDI or air car on these forums...

In summary: MDI threatened this forum and defamation lawsuit site several times because they apparently don't like being reminded of certain truths and facts ... like those that minguinhirigue has just mentioned ...

For newcomers who don't understand what I'm talking about: https://www.econologie.com/forums/search.php

So do I lock or not?

Sorry, but I did not see in my research this ban on MDI, atso time for me.
I think it's a shame not to be able to discuss it freely while remaining respectful to the various parties. So well if they ever build this factory, only Toulouse and its region can discuss it. well yeah that's how it is.

Come on soon and my apologies again.

;-)

[Christophe]

Well, we were the first ones surprised by these virulent reactions from MDI ...

So I would prefer to keep the "promise" that we had self-suggested not to talk about this technology anymore on forums...