In reply to Alan J Fletcher's message of Wed, 25 May 2011 13:59:30 -0700: Hi, [snip] >At 01:24 PM 5/25/2011, you wrote: >HARD CURRENCY ENERGY- how the thermal energy of the active core can be >converted in electric energy in an economical way? > > >I don't think that's going to (or needs to) happen any time soon --- it only >delivers 500C (limited by the nickel powder degrading?) at 50 bar. >Electrical conversion efficiency at that level is less than 20% (??) -- times >the 6x factor is barely over unity. >I'm probably too conservative there. 40% ? 60% ? >(Way out of my expertise, anyway.)
The Carnot efficiency at 500 C is 52% (assuming the steam is condensed at 100 C, 61% if at room temperature). 50% of 6 = 3, which implies that 1/3 of the electrical power is used to run the device, and 2/3 is available for external use. However no device ever actually achieves Carnot efficiency, so this may be a bit less. OTOH, if this is real then the factor of 6 is likely to grow with time as better methods of control are developed. > > >But the working fluid doesn't have to be water. >I'm not sure that a http://en.wikipedia.org/wiki/Mercury_vapour_turbine would >get approval for domestic use, though !!!! I don't think the working fluid makes much difference when the operating temperature is way above the boiling point of water, so you might as well use water. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
