On Saturday, 22 April 2017 09:45:40 UTC+1, Nightjar wrote:
On 21-Apr-17 6:46 PM, harry wrote:
On Friday, 21 April 2017 09:58:50 UTC+1, Nightjar wrote:
On 21-Apr-17 8:47 AM, harry wrote:
On Thursday, 20 April 2017 19:24:26 UTC+1, Nightjar wrote:
On 20-Apr-17 6:18 PM, Tim Streater wrote:
In article , Nightjar
wrote:

On 20-Apr-17 8:18 AM, harry wrote:
On Wednesday, 19 April 2017 19:47:29 UTC+1, Murmansk wrote:
I've just been for a ride in someone's Nissan Leaf - it was
impressive, so
quiet and amazing acceleration.

Do electric cars have a gearbox (an automatic one I presume)? Or
does the
motor just run faster the faster you go? I was told by the owner the
optimum speed for economy of battery usage is about 55mph.

It doesn't sound like it's changing gear.

Internal combustion engines are inherently unsuitable for traction,
hence
the need for gearboxes/clutches etc.
Electric motors can be designed to be ideal for traction.
Max torque at zero rpm.

I could get that with a steam engine.

And a small one at that for a car. But AIUI, it's the condenser that's
the problem.


With a 24 gallon water tank, the 1924 Doble E had a 1500 mile range and
it could move off from cold in under 30 seconds.

Drivel.
Water is not fuel.

I was answering the point about the condenser. However, recent advances
in catalytic splitting of water could make it feasible to use water as
fuel, if you really wanted to.

Drivel.
Have you never heard of the Law of Conservation of Energy?

The principle has been demonstrated. A few years ago the Japanese
demonstrated a fuel cell car that ran entirely on water.

All steam engines and boilers are inherently inefficient.
They will never come anywhere near the ICE efficiency wise.

Petrol cars achieve a tank to wheel thermal efficiency of about 16%.
Non-condensing third generation steam locomotives achieve a drawbar
thermal efficiency of about 16%.

I spent forty years running them. And getting rid of them where possible.

I suspect that the boilers and engines you are familiar with are more
nineteenth century technology than twenty-first century. A titanium tube
flash boiler can supply steam at up to 4,000 psi and 650C. Ceramics
allow engines to work at those temperatures and pressures and achieve
efficiencies not even dreamed of with conventional materials.

Total drivel.
Steam locomotive efficiency, typically 5%.

The most efficient power stations use rejected heat for district heating. But that only applies in Winter. In Summer the heat is dumped.
And it only works if the heat is needed nearby.
Higher steam temperatures results in less efficient boilers because the exiting combustion gases can be at no lower temperature than the stem.

If you look at the picture, there are cooling towers. What do you suppose they are for? (Clue,dumping excess heat)
http://cornerstonemag.net/setting-th...-power-plants/

The problem of what to do with rejected low grade heat has proved insurmountable.

Flash steam boilers are suited for rapid start up, cheapness and low weight. But are notoriously inefficient, high maintenance and short life.
Yes,I have run these too.