Newsgroup: it.discussioni.energie-alternative
Titolo: Nuova turbina?

http://www.gereports.com/this-scientists-got-the-power-plant-in-his-hands/
 
 


 
"Toshiba to supply supercritical CO2 turbine"
 
Qualche dettaglio:
 
http://gasturbineworld.com/gearing-up.html
 
 
(attenzione, sono 3 pagine, cliccare per le successive)
 
The turbine and combustor, being designed and built by Toshiba, 
essentially combine gas turbine and steam turbine technologies, with the 
potential to deliver a power plant with:
 
● Efficiency of about 59% (LHV) when running on natural gas
 
● Efficiency of 51-52% (LHV) when running on gasified coal (syngas)
 
● Full 100% carbon capture at 300 bar without any efficiency penalty.
 
 
Following a Brayton Cycle-like expansion across its turbine, CO2 is 
recirculated back to the beginning of the cycle in a highly recuperative 
process. The system eliminates the expensive steam cycle components and 
avoids the inefficiencies of traditional Rankine cycles.
 
The working fluid is expanded through a turbine that has an inlet 
pressure in the range of 200 bar to 400 bar and a pressure ratio between 
6 and 12. It is then cooled through a heat exchanger, and H2O is 
separated from it to create a CO2 stream. The CO2 stream is pressurized 
and a major part of this flow is fed back to the combustor to begin the 
cycle anew.
 
The operating temperature at the hot end of the heat exchanger is thus 
in the range of 700°C to 750°C. This leads to a typical turbine inlet 
temperature constraint in the range of 1100°C to 1200°C.
 
The turbine inlet temperature of the cycle is not high for gas turbines, 
but it is very high for steam turbines. Similarly, the pressure of this 
cycle does not surpass that of advanced steam turbines, but it is 
extremely high for gas turbines. The combustor has been designed to cope 
with a gas pressure of 300 bar, which is more than 10 times the gas 
pressure utilized in conventional gas turbines.
 
 
The easiest way to describe the turbine is that we need only a single HP 
turbine for this cycle. Since the pressure at the exhaust end of the 
turbine is 30 bar, we don’t need an IP or LP. In a coal-fired plant, the 
steam turbine consists of HP, IP and LP sections. In a combined cycle 
plant, there’s a gas turbine and a steam turbine with HP, IP and LP 
sections.
 
 
Notare: il comburente e' ossigeno, non aria. Quindi occorre produrre 
ossigeno in quantita' industriali ...
 
E poi:
 
https://en.wikipedia.org/wiki/Allam_power_cycle
 
 
 


 
The net result is a simpler turbine that can be 10 times smaller than 
its steam equivalent. A steam turbine usually has between 10 and 15 
rotor stages. A supercritical turbine equivalent would have four.
 
"We're looking at a turbine rotor shaft with four stages on it that's 4 
inches in diameter, 4 feet long and could power 1,000 homes," said 
Richard Dennis, turbine technology manager at the National Energy 
Technology Laboratory.
 
E 4 stadi sono quelli che vediamo nella foto dell'articolo proposto dall'OP.
 
 
Beneficiari ?
 
"Such a device would be a boon for nuclear power stations, concentrating 
solar farms, geothermal installations, combined heat and power systems, 
and fossil fuel-fired power plants."
 
 
E poi:
 
"In addition, a supercritical turbine could fit into a directly heated 
cycle, where a fuel like natural gas burns in the presence of pure 
oxygen inside the turbine, creating only water and carbon dioxide as waste."
 
 
 


 
"NET Power, LLC, recently announced that it built a power plant that 
will validate a new natural gas power system producing low-cost 
electricity with zero atmospheric emissions, including carbon dioxide. 
The 50MW demonstration plant is being built in La Porte, Texas.
 
The plant will demonstrate NET Power’s Allam Cycle technology, which 
uses carbon dioxide as a working fluid to drive a combustion turbine, 
eliminates all atmospheric emissions without requiring expensive, 
efficiency-reducing carbon capture equipment, and ultimately produces 
pipeline-quality CO2 that can be sequestered or used in various 
industrial processes, including enhanced oil recovery."