Author Topic: Exploding CNG driven buss!  (Read 4818 times)

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Offline apis

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Re: Exploding CNG driven buss!
« Reply #25 on: March 11, 2019, 08:46:12 am »
Yeah, pretty amazing. They didn't begin using full electric drive until november last year, so probably why there haven't been more news about it yet. Norway also has an electric ferry:
https://www.theexplorer.no/solutions/ampere--the-worlds-first-electric-car-and-passenger-ferry/?gclid=EAIaIQobChMIq-__otn54AIVyYeyCh2DjgClEAAYASAAEgLNA_D_BwE
 

Offline janoc

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Re: Exploding CNG driven buss!
« Reply #26 on: March 11, 2019, 09:27:18 pm »
I think most city busses here have a round trip of less than 30km, a pantograph super charger at the end could easily charge it for around trip in a few minutes. Only infrastructure needed is enough power at the charging station and it could be used for charging cars when the bus isn't there

I was thinking more places like Paris where the bus is passing through the city center (otherwise no point bothering with an electric one) and spends a lot of time slowly advancing through traffic jams and navigating the dense traffic in the narrow city streets. The distance traveled may be even much less than those 30km or so but the energy requirements are high, especially in the summer where the requirement is to have AC in the new buses (you could literally die in the summer heat in Paris when the August heatwaves hit ...)

The termini typically serve many vehicles/lines at once, with rapid turnaround. So you can't just "put the bus on the charger" there for 15-20 minutes, the terminus would have to be enormous to accommodate this.  The same for the lines that have termini in the city center - trying to put overhead wires and what not there would cause a huge uproar (historic center and all that) - and that assumes you would have the space to begin with.

Parisian RATP (the transportation company) has, in fact, a huge headache with this now because Paris is progressively banning diesels from the city. And they still run a lot of buses that don't fulfill even the old Euro emission standards. We are talking a fleet of about 4000 buses in the streets every day, not counting private operators, tour buses and long distance transport (Eurolines, Flixbus and similar). That's an enormous amount of money required - which simply isn't there. AFAIK, they are putting more money into CNG buses and are investing into a common project with Enedis (French electricity distribution company) to develop electric buses suitable for these conditions but it is only just starting now.


 

Offline janoc

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Re: Exploding CNG driven buss!
« Reply #27 on: March 11, 2019, 09:40:48 pm »
Toyota Rav4 flaming out, is it the petrol tank or the bat electrolyte or both or neither?!

Battery electrolyte isn't flamable (at least if we are talking normal lead acid car battery) - that's sulfuric acid + water.

The video shows a bleve of a petrol tank. I had the "pleasure" to witness this first hand few times. Yobs love to set cars on fire for fun here (yay France) and when the car burns for a while, the tank will heat up and pressurize until it (or the fuel pipe) bursts - that's what you see. It is not really an explosion in true sense (detonation) but the pressurized fuel vapors escaping the ruptured tank and igniting with a large WHOOSH (and sometimes a bang of the tank bursting).

An even worse event that will eventually happen if the fire isn't extinguished rapidly is the tires bursting in the heat - that's an enormous BANG and it sends shrapnel all over the place.

These firemen have only themselves to blame there, IMO.

Here when the fire crew arrives on the scene and it is obvious that the car is burning for a while already, they will never approach the vehicle on foot. They can't know when will the tank or tires blow. That could cause a serious injury or even kill a man, despite full protective gear. They will always use the water cannon from the truck first to reduce the fire and to cool the vehicle down from distance.  Only then they approach on foot with the hoses to finish the job.
« Last Edit: March 11, 2019, 09:45:42 pm by janoc »
 

Offline Refrigerator

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Re: Exploding CNG driven buss!
« Reply #28 on: March 11, 2019, 10:00:41 pm »
I drive LPG and it's pretty safe unless you make it unsafe.
To get your LPG modded car through MOT you have to pay more and there are more tests to run.
But i love the fact that LPG is so cheap, around here it's 2.6x cheaper than gasoline (per liter) and you only burn about 30% more compared to gasoline, in the end it turns out to be significantly cheaper than even diesel.
To me personally the low-ish pressure of LPG is a bit of a problem since when my turbo spools up it tends to overpower the LPG system >:D ;D

Also if they want an electric bus then why not get a trolleybus?
We still have ancient trolleybuses making their way around the city here and the torque on those bastards, holy crap, when you get on board you better grab onto something before it starts moving or else your next destination is the floor  :-DD
I have a blog at http://brimmingideas.blogspot.com/ . Now less empty than ever before !
An expert of making MOSFETs explode.
 

Offline wraper

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Re: Exploding CNG driven buss!
« Reply #29 on: March 11, 2019, 11:49:54 pm »
Also if they want an electric bus then why not get a trolleybus?
Because you need to build infrastructure and they are way less versatile.
 

Offline MTTopic starter

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Re: Exploding CNG driven buss!
« Reply #30 on: March 12, 2019, 12:32:58 am »
Toyota Rav4 flaming out, is it the petrol tank or the bat electrolyte or both or neither?!
Battery electrolyte isn't flamable (at least if we are talking normal lead acid car battery) - that's sulfuric acid + water.
Yes electrolyte burns , look at the RAV4 picture, thats whats discussed, 386V lithium-ion battery of 4,500 cells rated at 41.8 kWh maximum power output of 129 kW. Similar tech as Tesla S.
« Last Edit: March 12, 2019, 12:41:29 am by MT »
 

Offline Berni

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Re: Exploding CNG driven buss!
« Reply #31 on: March 12, 2019, 06:10:20 am »
Battery electrolyte is always nasty stuff.

Most of the time its just corrosive as hell such as the sulfuric acid used in lead acid batteries. But for rechargeable lithium batteries its indeed very flammable too, to make it worse it also tends to have a fairly low flash point so any sort of battery failure is likely to ignite it on fire.

Hopefully a better battery technology will come around before electric cars really take off, but inherently anything storing a lot of energy inside of it is dangerous in some way (But some are more dangerous than others in a failure mode).
 

Offline apis

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Re: Exploding CNG driven buss!
« Reply #32 on: March 12, 2019, 12:54:11 pm »
Also if they want an electric bus then why not get a trolleybus?
Because you need to build infrastructure and they are way less versatile.
Trolleybuses are not so bad, especially if combined with a battery. Then you only need to invest in overhead wires for the busiest parts of the routes, you still have some flexibility to make route changes and the battery can be charged while driving.

They tested a trolleybus here as well, but settled on battery electric since it was cheaper and the battery busses have a range of 250 km which is good enough for the city buses anyway. (I assume they meant cheaper short term, because no one wants to plan ahead more than a few years these days and therefore the investment in infrastructure becomes cost prohibitive.)
« Last Edit: March 12, 2019, 03:11:17 pm by apis »
 

Offline Gromitt

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Re: Exploding CNG driven buss!
« Reply #33 on: March 13, 2019, 04:35:20 pm »
Also if they want an electric bus then why not get a trolleybus?
Because you need to build infrastructure and they are way less versatile.
Trolleybuses are not so bad, especially if combined with a battery. Then you only need to invest in overhead wires for the busiest parts of the routes, you still have some flexibility to make route changes and the battery can be charged while driving.

They tested a trolleybus here as well, but settled on battery electric since it was cheaper and the battery busses have a range of 250 km which is good enough for the city buses anyway. (I assume they meant cheaper short term, because no one wants to plan ahead more than a few years these days and therefore the investment in infrastructure becomes cost prohibitive.)

There is a city in Sweden that has trolleybusses, Landskrona. Has run since 2003.



 

Offline MTTopic starter

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Re: Exploding CNG driven buss!
« Reply #34 on: March 13, 2019, 05:03:28 pm »
Wire buss Gothembourg 1940!

 


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