New propulsion sytems for ships

That is very interesting, and covers many topics of recent weeks. Thanks Brian

 

From what you've said so far about this boat, I'm not convinced such an adjustment would be a bad thing. Granted, I haven't seen your actual hull shapes, but from what you've said so far I doubt you'll be getting much if any dynamic/planing lift at either L/B ratio. In fact, you may see an advantage going to the wider beam, in that the reduction in skin friction could more than offset the added wave drag. It may be worth calculating.

 

Thanks for the thought and ideas Matt, The model will be completed in about 2 weeks, try that, then see what has to be done & narrow the process a little.

A slow and careful progression is all I expect for the present.

 

An new engine was brought to my attention last night. It uses heat recovery------- Read about it here. http://www.cleanpowertech.co.uk/aboutus.htm

I think buying some shares might be sensible.

Pericles

 

To some extent, I agree with you, Brian. After all, bows and arrows are still with us. As well as square rigged ships.

What I meant is that the era of the automobile being the mainstay of personal transportation, as it is here in the United States, is, in my opinion, doomed. The average income will never keep up with the ever escalating costs of the vehicles themselves and the energy to run them. Already, here in the Detroit area, we have up to a third of the adult population with no cars at all. We have even more driving vehicles in various stages of disrepair and without proper insurance and plates. And this is an area where there really isn't a reliable alternative. Our bus system here sucks.

As fewer and fewer people own and drive cars, the economic and political clout to continually build, rebuild, and repair a vast network of roads will start to diminish. And without roads to drive them on, what good are cars? I can imagine existing roads being someday used as rail beds, crowding the cars out

In rural areas, I see the situation being somewhat different. It is notoriously difficult to set up mass transit systems for people who are widely scattered.

Here, a family car, truck, or even tractor could be used to go to town infrequently, or even less frequently, visit the big city. It is in this situation, the personal vehicle really shines and is probably irreplaceable.

As far as fuel cells on ships go, along with complicated systems to feed them, which will use energy themselves, not to mention space and cargo capacity, I just don't see the advantage. Why would any shipper in her/his right mind go to such trouble. Wouldn't it be better to just burn the fuel more efficiently directly?

I do see free hydrogen and fuel cells as a handy way to store excess electricity for short to moderate periods of time to be used later. Imagine if we had banks of them spread out through the power grid. They would be a fine hedge against blackouts in an increasingly electric economy.

Bob

 

A solid-oxide fuel cell is a solid state, ceramic device with no moving parts except for fuel and air pumps, and a few valves. Alone, they are expected to reach 50-60% efficiency soon. As part of a cogeneration system (the thing's 900 degree C exhaust can make a lot of steam to drive a conventional turbine) they can reach 85% net efficiency, in simulations (practical tests are in work now).

If you have to add on-board fuel reformation, as might be necessary to use conventional fossil fuels in a cell stack, these are of course substantially more complex and they do contain moving parts.

Compared to the best big-ship diesels on the market today, which are about 50% efficient and very close to the thermodynamic efficiency limits of their cycle, an equivalent SOFC cogeneration system would provide a significant (possibly up to 40%) reduction in fuel use - translating to an increase in range and/or speed, or a decrease in daily operating costs (given a comparable price per kilojoule of fuel energy in both cases), or both. (The fuel cell is an electrochemical device, not a thermal device, and so does not have the same hard caps on efficiency that fundamental thermodynamic laws place on all heat engines.) The downside is that the technology is still new and its long-term reliability unknown, and it is still expensive. When the systems can be proven reliable, then a very strong economic case for using fuel cells in new ships could be made.

Recovering the waste heat of a combustion engine is an interesting idea.

What temperature would our exhaust be? Let's say for the sake of this discussion we can get the exhaust right as it leaves the engine at, let's say, 700 Kelvin. (Input whatever your actual exhaust temperature is, make sure to convert to an absolute (Kelvin or Rankine) scale.)

Now, the best possible efficiency we could get from the heat recovery device would be with it operating in an isentropic (Carnot) condition. (Refer to a thermodynamics book if necessary.) The efficiency in this condition has an upper bound at
Max.Eff. = 1 - (Temp. at cold / Temp. at hot)
The air's around 300 Kelvin on a good summer day, so 1 - (300/700) = 0.57. So there is no way in hell you could ever extract more than 57% of the heat energy that's still there in the hot exhaust gas. In practice that value will be significantly less, typically about half of the Carnot efficiency.

But look at how much waste heat the engine makes in the condition you normally run it in. A lot of heat, right? So even trapping 25% of that waste heat, and getting useful work out of it, might be a worthwhile effort.

Granted, this is a substantially oversimplified analysis (for someone seriously considering this, you'd want to analyze the exergy balance of the complete system, from fuel to exhaust pipe, including what the cooling water takes away). But it gets the point across and illustrates the hard, temperature-dependent cap on efficiency that is inherent to all thermodynamic systems.

 

I have to agree with Brian. Gasoline has hit $9.00 in some European markets recently; has been over $5.00 for decades; yet the bottom has not dropped out of the market for individually-owned autos

 

Regenerative Braking 'Power'

Here is a question I would like to ask, why did they find it necessary to use such large HP motors in each wheel?? Was it for 'show', or was it because they needed them to generate large amounts of power in the regenerative (braking) mode?? Remember this car has no other 'brakes'.

 

Nano Li-ion Batteries from Altair

And my second question, does anyone have specific info as to the 'exclusiveness' claim that Altair-nanotechnologies appears to have in this new generation of lithium-ion battery development??....and in particular their nano-titanate materials as the negative electrode.

In my brief studies of the subject it would appear they have a real advantage in their technology over that of several other competing companies. But it appears as though they don't have their 'foot in the door' of potential users to the extent that some of their competitors have.

So what I am asking is do you think they will ultimately trump their competitors, or will some other competitor find a way around their electrode technology??

Any battery experts out there??

 

This had nothing to do with necessity it was simply to demonstrate that electric propulsion can blitz internal combustion engines. This was really a demonstation of top of the line EV technology.

If you are looking at more economic solutions with battery powered EVs then there are a wide range of examples here:
http://www.austinev.org/evalbum/

I am still looking for a retailer of Perm PMS motors and PGS generators. THese will give efficiencies better than 90%. On paper they look better than the Etek motors.

Rick W.

 

This is dandy, Marshmat, but with ship diesels already at 50% and at least 3 orders of magnitude cheaper than the fuel cells you suggest, plus diesel ships are *already* using exhaust gas heat recovery systems, good for an additional 20%, we've got pretty much what your fuel cells suggest are possible, yet industry can actually afford them today. Actually, add the losses due to onboard fuel reformation and I expect it's a push. And literally thousands of times cheaper.

FWIW, the newly-marketed exhaust heat recovery systems cost, on a per-kilowatt basis, about 3 times as much as a kite delivering the same amount of power...

KiteShip

 

You're trying to sell something, aren't you KiteShip... and I think it's a freighter-size kiteboarding rig. It's too bad so many of the big shipping companies are blind to the enormous amount of free energy that crosses their bows as wind. Why add expensive sails when bunker sludge can be had for a pittance, with no cumbersome regulations to control its use. It's not like sails are an incredibly simple source of virtually unlimited free energy, after all.
Wait, they are.

I agree with you that fuel cells are still far too expensive to compete against diesels- they are, after all, a relatively new and undeveloped technology. I don't have a clue where you got the "3 orders of magnitude" from. We will see where economic forces lead; we all know that they are unpredictable and go in directions we don't expect (if it were otherwise, we'd all be millionaires and able to afford being out on our yachts!)

 

You've got the point, Dave.
Cheers.

 

Thanks, Marsh. Sure, selling something that's obviously needed, pays for itself and lets shippers meet ever tougher regulations is a gas. Then again, the industry is more aware than we often give them credit for. There's just a lot of inertia there.

Fuel cells are hardly "new and undeveloped" they've been in commercial usage since the early 60's; they were developed more than a century ago (I read about them in my Weekly Reader in grade school). Until very recently (like, last year) fuel cells cost on the order of $1000/watt, installed. There is a company advertising them today, for $5500/kw, installed, though it isn't clear whether they've actually delivered any at that price. There are lots of web sites touting "eventual" costs of $1000-1500/kw, but of course that's just wishful thinking. In the meantime, big diesels cost between $150 and $200/kw, so I'm mistaken (if the single company touting big fuel cells is actually delivering). I apologize. They're only 30 times as expensive as diesel engines, and that's before the engine turns a generator, to keep things equivalent. (I'm talking about equipment costs only, not per delivered kW-Hr)

Remember, they don't save a dime of fuel costs. Under *any* scenario, hydrogen will cost more--many times more, per joule of available energy--than residual oil. All the more so, packaged for marine application.

KiteShip

(I was quoting a speaker I heard a couple of years ago, quoting "more than $50,000/kw" for fuel cells)

 

Brian,

Here are some other battery websites.

http://www.a123systems.com/#/home/heavy-duty

http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

I have realised that conventional traction batteries for marine use are reasonably priced for a 5 - 7 years life http://www.barden-uk.com/marine-leisure-batteries.html and when they are due for replacement, perhaps the new technologies will be less expensive?

In the UK, 1200 AH capacity from 12 volt AGM batteries costs about $4600-00.

Pericles