navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address. Following continuous spam/hack attempts on the forum, "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1] 2   Go Down
  Print  
Author Topic: Air-powered Peugeot  (Read 6395 times)
dan_b
Hero Member
*****
Offline Offline

Posts: 5108

SW London


WWW
« on: January 23, 2013, 01:16:30 PM »

http://www.dailymail.co.uk/news/article-2266632/Peugeot-Citroen-Coming-soon-car-runs-air.html

 facepalm
Logged

3.06kWp SolarEdge system with a split array:
2.18kWp 10x South facing, plus 4x West facing 880W

Mk1 ImmerSUN DHW diverter
4kW PowerVault Battery

Tesla Model 3 Long Range
Sean
Hero Member
*****
Offline Offline

Posts: 641


« Reply #1 on: January 23, 2013, 01:36:51 PM »

It'll keep the banks and investors happy for just a little longer
Logged
dan_b
Hero Member
*****
Offline Offline

Posts: 5108

SW London


WWW
« Reply #2 on: January 23, 2013, 01:53:02 PM »

I think if they can make it work it's an environmentally less damaging means of adding energy recovery/hybrid power to cars than battery electric systems?
Logged

3.06kWp SolarEdge system with a split array:
2.18kWp 10x South facing, plus 4x West facing 880W

Mk1 ImmerSUN DHW diverter
4kW PowerVault Battery

Tesla Model 3 Long Range
Sean
Hero Member
*****
Offline Offline

Posts: 641


« Reply #3 on: January 23, 2013, 01:58:19 PM »

if they can make it work ....

no doubt they will be able to produce test models, fancy cut aways and lots of very good self congratulatory press releases - being able to produce a commercial viable product is a whole different task



Logged
smegal
Hero Member
*****
Offline Offline

Posts: 1615


« Reply #4 on: January 23, 2013, 02:31:49 PM »

Depending on the energy density of the air storage, this has potential. Especially if they use some waste heat to increase teh efficiency of the air powered drive.
Logged

When youíre thirsty, itís too late to dig a well. - Unknown
djh
Hero Member
*****
Offline Offline

Posts: 2128


« Reply #5 on: January 23, 2013, 02:37:18 PM »

It's not exactly a new idea. http://en.wikipedia.org/wiki/Compressed_air_car
Logged

Cheers, Dave
desperate
Hero Member
*****
Offline Offline

Posts: 3542


Backache stuff!!


WWW
« Reply #6 on: January 23, 2013, 07:21:12 PM »

Bloody shower of fools and dingbats in the PR dept band and The Heil fume   why o why do they keep calling it a car that runs on air, it effing doesn't, it runs on petrol with an air operated kinetic energy recovery system.Numpties need an airline up the rrrse, then we'll see something running on air. I like KERS and there certainly is a place for it, but this just reduces our dependance on fossil fuels a little bit. When you compress air it gets hot, do they recover that kinetic energy? IIRC it's about 15-20% of the energy you stuff into the compressor.

Desp
« Last Edit: January 23, 2013, 07:45:59 PM by desperate » Logged

www.jandhbuilders.co.uk

still a crazy old duffer!
spaces
Hero Member
*****
Offline Offline

Posts: 1179



« Reply #7 on: May 20, 2013, 12:25:09 AM »

Desperate, to accelerate a mass you must use some energy! Reducing our dependence on fossil fuels is about as good as it may get for a few years yet - it's more about how little we can use than going without complelety, at the moment.

Compared with an electrical KERS, Nitrogen (for that is what is being used, due to its safety) compressed with hydraulics in braking is many times more efficient that the sort of regen braking achieved by a Toyota Prius. The Prius achieves 35% efficiency when it is braking with electrics - which isn't so often since gentle braking doesn't use the electrics to recharge and heavy braking creates too much electricity for the battery to store in the time available. A Skoda Octavia uses its fuel more efficiently than a Prius, without any of the amazing engineering a Prius carries.

Compressing a bubble of gas is in the order of 80% efficient (chemistry.oregonstate.edu/courses/hc399/regen_braking_presentation.ppt‎, and a hydrostatic transmission brakes without the need for what we know as brakes - other than for emergencies and to keep legislators happy. So every time you brake, it is recovering in the order of 80% of the braking energy until the accumulator approaches a fully charged state.

Citroen, the company who developed machining technology which mass-produced suspension components to 1 micron tolerance back in the fifties, (and whose suspension systems were sold to Mercedes, Rolls-Royce and more recently JCB and Caterpillar, which inspired Formula 1 suspensions and the variable hydraulic anti-roll systems used in todays McLaren sports cars and upmarket Toyotas) were developing hydrostatic transmission cars from the end of WW2 for many years, clocking up over a million kilometres on the road and were only thwarted with excess noise from the pump and motors. This has since been solved. Efficiency was high because the heavy gearbox, differential, clutch and driveshafts can be thrown out to be replaced with hydraulic motors (six times lighter than equivalent electric motors) and the engine can run at the most efficient revs for a given output. The engine siting is not determined by solid drivetrain elements - it can go wherever is best.

Add gas accumulators to the system and you don't have to add much weight - the accumulators themselves and the regen pipework. Compared with a mass of batteries which can accept so small a percentage of charge in a limited range of braking effort, that is quite an improvement.

Calling it a car which runs on air is no sillier than saying a car runs on electricity. Still silly, though.
Logged

Simplicity, the ultimate refinement
biff
Global Moderator
Hero Member
*****
Online Online

Posts: 12302


An unpaid Navitron volunteer who lives off-grid.


« Reply #8 on: May 20, 2013, 09:46:30 AM »

I would not blame anyone for thinking that compressed gas/air is a good idea
                                      It is only when one gets serious and involved in the design that the problems spring to the surface and unfortunatly there are too many problems with compressed gas/air.Safety and getting certs for the containers. Heat and finding a way to shake it off. Reliability and finding a way to keep this type of conglomerate running would be a job in itself.
        Whoever brought this old puzzle out of the cupboard did nobody any favours.Its a bit like the brilliant Wankle engine. It should be a winner but its not.
                 Biff
Logged

An unpaid Navitron volunteer,who has been living off-grid,powered by wind and solar,each year better than the last one.
dhaslam
Hero Member
*****
Offline Offline

Posts: 6775



« Reply #9 on: May 20, 2013, 11:43:48 AM »

There may be life in the  rotary engine yet.    The ability to  make lighter and more compact rotary engines  would allow  much more compact cars.  However  it isn't clear how the transmission would work. 




Logged

DHW 250 litre cylinder  60 X 47mm tubes
Heating  180,000 litre straw insulated seasonal store, 90X58mm tubes + 7 sqm flat collectors, 1 kW VAWT, 3 kW heatpump plus Walltherm gasifying stove
knighty
Hero Member
*****
Offline Offline

Posts: 2874


« Reply #10 on: May 20, 2013, 12:55:50 PM »

The Prius achieves 35% efficiency when it is braking with electrics - which isn't so often since gentle braking doesn't use the electrics to recharge and heavy braking creates too much electricity for the battery to store in the time available

I think that must be a limit of the prius system because it's not the limit of the technology available

my bodged together electric bike is about 85% efficient, and re-gen breaking is just as efficient as accelerating :-o
Logged
spaces
Hero Member
*****
Offline Offline

Posts: 1179



« Reply #11 on: May 20, 2013, 02:12:00 PM »

Knighty, I think the commonly-recognised problem with regenerative braking with an electric/ICE car is that the batteries cannot accept the energy quickly enough. Maybe the Prius is particularly bad at this, I don't know. Presumably a car equipped with a big enough battery bank could convert more braking energy to electricity. And back. But everything I read suggests that converting braking energy into electricity and back is significantly less efficient than compresisng a gas, from roughly half as efficient to a third as efficient. UPS have been using hydraulic hybrids in the States for a few years now, very successfully.

Biff - with your concerns over developing a newish technology, we wouldn't have any form of tech at all unless it jumped straight into its engineer's arms, ready to go with all the glitches ironed out, and working to its best efficiency. Not sure if your juxtapostion with the Wankel engine which you say is brilliant and should be a winner is deliberate or not - but that engine has had very little development compared with the reciprocating ICE. I wonder how good it would be if it had developed over more than a century?

You mention "too many problems" and "safety... heat". As we all know, a petrol engined car wastes 70% of the energy you pour into it, mostly as heat - and the fuel tank is a mobile bomb. Remarkable, given its contents aren't protected other than the container itself. And the battery bank - sat in a shed, trickle storing energy from wind or PVs then releasing it slowly it is reasonably efficient but bolted to a motor vehicle it is hardly an ideal (or efficient) method of storing electricity for a means of repeatedly accelerating a tonne and more - let alone trying to store much braking energy.
Logged

Simplicity, the ultimate refinement
desperate
Hero Member
*****
Offline Offline

Posts: 3542


Backache stuff!!


WWW
« Reply #12 on: May 20, 2013, 09:11:49 PM »

Spaces, I am well aware that you need to expend* energy to do work, what gets on my tits is the stupid blockheads who write the headlines such as "runs on air"
They patently DONT know the difference between an energy source and a storage medium.

*or to be presact^convert one form of energy to another.

^ precise or exact..............you choose Smiley

Drape tees
Logged

www.jandhbuilders.co.uk

still a crazy old duffer!
spaces
Hero Member
*****
Offline Offline

Posts: 1179



« Reply #13 on: May 20, 2013, 10:16:28 PM »

Reset pead, I took your comment in the wrong way last night - was a little worse for wear after a friend's homemade cider.  Roll Eyes

I agree, it is vexing how terms are bandied about so loosely. 'Hydrogen economy' always gets my goat.
Logged

Simplicity, the ultimate refinement
biff
Global Moderator
Hero Member
*****
Online Online

Posts: 12302


An unpaid Navitron volunteer who lives off-grid.


« Reply #14 on: May 21, 2013, 12:12:48 AM »

You need to get involved,
                            To really understand the complex problems involved in working with either compressed gas or air.
   Even if you managed to build a working model you have to obtain too many different safety certs.Just imagine trying to get an M.O.T on such a vehicle over 4 years old.
  Spaces,I know you are one smart guy and I bet you gave the idea a lot of thought but one thing becomes very clear when working on such a vehicle.It gets heavy,very heavy,No matter how you do it the weight build up to a totally unacceptable level.I discovered this the hard way.Been there and worn the teashirt,
              Biff
Logged

An unpaid Navitron volunteer,who has been living off-grid,powered by wind and solar,each year better than the last one.
Pages: [1] 2   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!