ICE fuel cell swaps
Discussion
I must say, I've been very impressed with the reviews of the Toyota Mirai and Hyundai Nexo. They appear to be coming down to a sensible price, too - at some point, they may be sold in reasonable numbers over here.
Now, this opens up a new opportunity AFAIC - disregarding people's opinions on EV converting ICE classics (IMO, for the record, fine as long as it's not a car where the engine is the star of the show!), what about FC conversions?
Once there's a couple of crashed FC cars in breakers yards, how cheap would the running gear be? How hard would it be to bolt in?
I ask because I'm in a quandry with one of my projects - I have a very thirsty old army lorry, but to EV convert it would need about 500kwh of batteries to get a sensible range, with the charging nightmare that would ensue. But if I could FC swap it, I get all of the benefit, plus I can fill up at one of the HGV/Bus hydrogen stations beginning to pop up. And if a new Mirai is only £50k, the fuel cell from a crashed one must surely be less, which instantly makes it less than the £60k of Tesla batteries I'd need for an EV swap....
I had a string of LPG cars back before the infrastructure started disappearing, so gas tanks and special filling rituals are nothing new to me either - indeed, my original plan for this truck was LPG....
What are people's thoughts?
Now, this opens up a new opportunity AFAIC - disregarding people's opinions on EV converting ICE classics (IMO, for the record, fine as long as it's not a car where the engine is the star of the show!), what about FC conversions?
Once there's a couple of crashed FC cars in breakers yards, how cheap would the running gear be? How hard would it be to bolt in?
I ask because I'm in a quandry with one of my projects - I have a very thirsty old army lorry, but to EV convert it would need about 500kwh of batteries to get a sensible range, with the charging nightmare that would ensue. But if I could FC swap it, I get all of the benefit, plus I can fill up at one of the HGV/Bus hydrogen stations beginning to pop up. And if a new Mirai is only £50k, the fuel cell from a crashed one must surely be less, which instantly makes it less than the £60k of Tesla batteries I'd need for an EV swap....
I had a string of LPG cars back before the infrastructure started disappearing, so gas tanks and special filling rituals are nothing new to me either - indeed, my original plan for this truck was LPG....
What are people's thoughts?
Not IMO doable. The Mirai is built round the hydrogen storage tanks. The entire car is engineered to fit them in and it still loses a chunk of space.
Mazda made (not for the public) a hydrogen RX-7 and RX-8, effectively it lost *all* of the boot space (and gave a fraction of the range and power of the "normal" ICE engine).
Hydrogen is light so the energy to weight is good but the energy density is terrible.
Mazda made (not for the public) a hydrogen RX-7 and RX-8, effectively it lost *all* of the boot space (and gave a fraction of the range and power of the "normal" ICE engine).
Hydrogen is light so the energy to weight is good but the energy density is terrible.
Engineering for hydrogen requires a specific knowledge and skillset.
Hydrogen has an ability to embrittle certain materials and/or migrate through many materials due to to its very small molecular size.
In other words, you can't just go to the catalogue and start buying any old stuff to plumb it in.
Assuming you are able to actually get hold of serviceable parts, you also need to be very aware of the pressure the system will be operating at.
Most likely it will be 700 bar, so any defects or damage to parts are liable to create a leakage point. Hydrogen cannot be detected by sight or smell, so you need to be 200% sure you are not allowing it to leak and collect in enclosed spaces. Even the flame if it ignites is almost invisible.
If it leaks, it will try to rise very quickly in air, so it's mostly enclosed spaces above the leak that matter.
If this happens, and it is unable to dissipate, it is almost guaranteed to ignite. The flammability range is very wide, this is combined with a very low ignition energy so even the slightest amount of static or other source of energy will probably set it off.
And when it does go, you are then dealing with the fastest flame speed known, about 10 times faster than natural gas, so the explosion creates a pressure wave that can be incredibly destructive to person, possession or other.
I suppose one of the biggest concerns would be that the carbon composite tanks/s have not been compromised by accident damage, as this is where the largest concentration of stored energy is (obviously). Note that many 700 bar H2 tanks have 'do not fill after' date stamped on them, as they cannot safely withstand more than certain number of refills and the resulting low-cycle fatigue that this causes.
Anyway, I could go on forever, I guess it's up to you if you want to take on something like this and take the right precautions, just wanted to make sure you are fully aware that large quantities of gaseous hydrogen can be incredibly dangerous to work with. Anyone who works in an industry that handles even a few kilograms of the stuff will tell you the same. Established safety procedures are far more stringent than for other combustible gases. Maybe read this wiki page first to understand it in a bit more detail: https://en.wikipedia.org/wiki/Hydrogen_safety
Hydrogen has an ability to embrittle certain materials and/or migrate through many materials due to to its very small molecular size.
In other words, you can't just go to the catalogue and start buying any old stuff to plumb it in.
Assuming you are able to actually get hold of serviceable parts, you also need to be very aware of the pressure the system will be operating at.
Most likely it will be 700 bar, so any defects or damage to parts are liable to create a leakage point. Hydrogen cannot be detected by sight or smell, so you need to be 200% sure you are not allowing it to leak and collect in enclosed spaces. Even the flame if it ignites is almost invisible.
If it leaks, it will try to rise very quickly in air, so it's mostly enclosed spaces above the leak that matter.
If this happens, and it is unable to dissipate, it is almost guaranteed to ignite. The flammability range is very wide, this is combined with a very low ignition energy so even the slightest amount of static or other source of energy will probably set it off.
And when it does go, you are then dealing with the fastest flame speed known, about 10 times faster than natural gas, so the explosion creates a pressure wave that can be incredibly destructive to person, possession or other.
I suppose one of the biggest concerns would be that the carbon composite tanks/s have not been compromised by accident damage, as this is where the largest concentration of stored energy is (obviously). Note that many 700 bar H2 tanks have 'do not fill after' date stamped on them, as they cannot safely withstand more than certain number of refills and the resulting low-cycle fatigue that this causes.
Anyway, I could go on forever, I guess it's up to you if you want to take on something like this and take the right precautions, just wanted to make sure you are fully aware that large quantities of gaseous hydrogen can be incredibly dangerous to work with. Anyone who works in an industry that handles even a few kilograms of the stuff will tell you the same. Established safety procedures are far more stringent than for other combustible gases. Maybe read this wiki page first to understand it in a bit more detail: https://en.wikipedia.org/wiki/Hydrogen_safety
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