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If racing is trying to be green minimum weight rules are wrong


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#51 bigleagueslider

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Posted 28 July 2012 - 00:57

I do like your outside the box thinking. And as a bonus, ammonia is the most efficient refrigerant around, so you could use it in the A/C before it goes to the engine to be burned. But, I'm not sure of the chemistry on this one. Since NH3 is non-flammable, I'm assuming that your plan is to reform it into N2 and H2 between the tank and the engine. They naturally dissociate at 850F, so that might be a use for the waste heat of the engine. Although it would probably require the use of a suitable catalyst to bring that temp down a little bit. Running the fuel lines through/around the exhaust system sounds a bit complicated. On the downside, ammonia is VERY dangerous.


blkirk,

Anhydrous ammonia will combust, and there have been recip engines converted to run on anhydrous ammonia fuel. The problem is that ammonia has a very high ignition temperature, around 1200degF I believe. So it is difficult to use in CI engines without a pilot fuel.

Ammonia has average energy density, but it is easy to store since it becomes liquid at less than 10bar and RT. As for being hazardous, ammonia spills can be diluted with water. The only danger it presents is vapor toxicity to humans in higher concentrations. Anhydrous ammonia is also widely used as an agricultural fertilizer.


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#52 Wolf

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Posted 29 July 2012 - 13:30

(I'm on a short break in my vacation, so I hope you'll pardon a possibly not very thought through post.) IMHO the way to go green would be if legislators were to limit (absolute) amount of emissions. instead of relative amount within exhaust gases... This would hopefully lead not only to cleaner engines but to downsizing the engines to keep within limits, which would hopefully lead to downsizing the existing cars to maintain their performance. Let's face it, today's cars have grown ridiculously too big (just the other day, a Volvo SUV was parked next to my car, and lower edge of it's side window was so high that I couldn't see a roof mounted luggage rack on my car* :eek:). That's my 2c worth, anyway...

* and my car is by no means a sports car... although it does have the engine and driven wheels at proper end of the car

#53 rachael

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Posted 29 July 2012 - 20:15

This is a good one. The worst thing you do to your car's fuel economy is start it up on a cold morning and drive reasonably slowly out of your drive and into your local street, where you probably don't tear off at full throttle. Meanwhile you've got your heater on full heat, attempting to bring the interior temp up to nice and toasty. All that heat comes from the cooling system where it should be warming the engine up.

If you have electric seats then (a) you can and will settle for a cooler cabin (b) the electrical load helps to heat the engine up faster. (a) is far more important.

There' also a benefit for cooled seats in hot climates, but they are more difficult to make


Following on from Greg's electric seats improving fuel economy, at the end of any significant journey the engine is up to temperature but then loses all this heat to the atmosphere - why not convert this heat to electricity and store it in a battery. This energy could be used to rapidly heat the engine at the next cold start so improving fuel economy - is this possible / does anybody do this already?


#54 desmo

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Posted 29 July 2012 - 23:33

"why not convert this heat to electricity and store it in a battery."

How practically?

#55 Greg Locock

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Posted 29 July 2012 - 23:52

Following on from Greg's electric seats improving fuel economy, at the end of any significant journey the engine is up to temperature but then loses all this heat to the atmosphere - why not convert this heat to electricity and store it in a battery. This energy could be used to rapidly heat the engine at the next cold start so improving fuel economy - is this possible / does anybody do this already?


Already in production, some VW and all current Prius syphon off their engine coolant into a thermos flask. I don't know much about this system, but here's the gen

http://www.google.co...CcWLhrsHtZ4mhXA



#56 Wolf

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Posted 30 July 2012 - 00:27

"why not convert this heat to electricity and store it in a battery."

How practically?


Small Stirling engine driving a generator?

#57 bigleagueslider

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Posted 30 July 2012 - 00:30

Already in production, some VW and all current Prius syphon off their engine coolant into a thermos flask. I don't know much about this system, but here's the gen......


I believe those thermal storage devices are geared more towards reducing emissions than improving efficiency. Modern SI auto engines have incredibly low emissions under most operating conditions. But the one operating condition that is hard to deal with is a cold start. Combustion is not real stable, fuel/air mixing is not so good, and the exhaust catalysts are cold. Lots of unburned HC.

It's similar to the reason cars have vapor recovery and sealed fuel systems. Exhaust catalysts are so effective that the HC emissions from refueling your car can exceed those produced while the engine is running.


#58 Powersteer

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Posted 02 August 2012 - 02:31

The great thing about racing is its development speed especially Formula 1. Something from nowhere can spawn, I read somewhere of a lightweight carbon fibre wing that acts as a battery too..not radical in battery storage capacity nor mass but certainly in power/weight. KERS technology hit development ceiling pretty quickly. In a small way weight limitation does contradict efficiency but race cars already very light weight which shows that selection of weight limit is within the standards. Maybe weight limitation on safety monocoque cell only. Aerodynamics or the lack of it can play a huge part, turbocharging, direct injection and variable technology..I think the challenge of making racing green is fascinating...just look at AUDI Ultra E-Tron. Technically it looks like something far more expensive to develop than a Formula 1 car...but in reality, maybe not.

:cool: