Robert said: " All the big players like Siemens, GE etc are busy developing CO2 power plant machinery because it is more efficient, more compact, much cheaper and can withstand higher temperatures without the corrosion issues of steam. "
Do you have any evidence of this? I have been looking for confirmation they have jumped on this bandwagon, but so far have come up empty. On Mon, Feb 27, 2012 at 2:46 AM, Robert Lynn <robert.gulliver.l...@gmail.com > wrote: > That was my initial reaction too. But recuperated transcritical CO2 > Brayton can hit up to about 70-75% of Carnot efficiency (higher at higher > temperatures due to basically fixed temperature difference in > recuperation), and is actually more efficient than a practical Stirling can > manage (Stirling is only about 60-65% of Carnot at very best). > > Assuming 310K cold end (CO2 critical point is 304K) and 524K hot end the > Carnot efficiency would be 41%, and 70% of that would be 29%. So 30% > efficiency is within the realms of possiblity. > > All the big players like Siemens, GE etc are busy developing CO2 power > plant machinery because it is more efficient, more compact, much cheaper > and can withstand higher temperatures without the corrosion issues of steam. > > > On 27 February 2012 04:42, James Bowery <jabow...@gmail.com> wrote: > >> Can't be. Rossi's inlet temperature is 524K. With an outlet temperature >> at 373K (100C) the maximum Carnot efficiency is only 29%. >> >> >> On Sun, Feb 26, 2012 at 4:35 PM, Alan Fletcher <a...@well.com> wrote: >> >>> SST-040 looks a good candidate : 300kW from 1MW >>> >>> http://www.energy.siemens.com/hq/en/power-generation/steam-turbines/sst-040.htm >>> >>> The newly developed predesigned steam turbine SST-040 is a generator >>> drive specially designed for the 75-300 kW power range. This favorably >>> priced turbine features a simple, extremely compact design, short start-up >>> times and a high degree of operational reliability. >>> >>> Application area of the SST-040: >>> >>> * Waste-heat recovery e.g. behind gas engines and biogas engines >>> * Small CHP plants >>> * Decentralized solar facilities >>> >>> Inlet pressure 2 up to 40 bar (a) >>> Inlet temperature dry saturated steam up to 400 °C >>> >>> ----- Original Message ----- >>> > From: "Robert Lynn" <robert.gulliver.l...@gmail.com> >>> > This might be possible with supercritical CO2, though not in sizes >>> > less than about 100kW. Most definitely not steam >>> >>> >> >
