I am something of an expert in heat engines, I've worked in IC engine development, Brayton development, have built (for fun) Rankine cycle engines, and even an engine that ran on the expansion and contraction of solid metal.
I've also been involved in the development of hydrogen working fluid stirling engines, and while they might look attractive there are big problems: -Very expensive and heavy ($1000/kW, 5-10kg/kW for kinematic engines (ie with crankshaft), $3000/kW, 20-30kg/kW for free piston engines that don't require external hydrogen seals) -Don't scale well to large sizes - as bigger means must run slower to keep gas flow losses the same. -Work best at much higher pressures than suitable for LENR (from what we know of Rossi) ie 150bar vs 25bar. Lower pressures mean much bigger heavier and less efficient engines. -Cannot have any powder or other detritus mixed in with the hydrogen working fluid - as it will quickly abrasively destroy your seals regenerators and coolers. -Seals for kinematic designs are unreliable and only last for a few 1000 hours at best. I don't think that stirling will be competitive with rankine or brayton cycles in terms of overall size, weight and cost for LENR applications. On 6 February 2012 17:35, Alain Sepeda <[email protected]> wrote: > Interesting idea. > Maybe when we master the ignition condition we could do something like a > family "explosion engine", > based Piston technology. > > I can anticipate the 2 mode of ignition : > > - self ignition by pressure and temperature, like diesel > - triggered ignition by "catalyser" (RF, manetic field, chemical > injection, local temperature), like otto engine > > however the speed of the cycle might be much slower that diesel/otto IC > engine > (few turns per minutes) > > anyway maybe future LENr reactors will be very difefrents from now... > > should tell defkalion and rossi 8-) > > > 2012/2/6 Roarty, Francis X <[email protected]> > > I think one of the little sterling models would make an interesting >> reactor platform where the Ni foam or skeletal cat is captive at the bottom >> of the cylinder and the hydrogen gas is sealed inside like the Papp engine >> – a sort of hybrid between only using exotic gases like Papp and the >> present Rossi or Mills device using pressurized gas with Ni powder or >> skeletal cat. The shaft of the sterling engine would be externally driven >> to vary the pressure and then measure the temp variation of the cooling >> system. **** >> >> Fran >> > >
