Machines

Friday, January 21, 2011

Supercritical steam generators

      Supercritical steam generators (also known as Benson boilers) are frequently used for the production of  electric power. They operate at "supercritical pressure". In contrast to a "subcritical boiler" , a supercritical steam generator operates at such a high pressure (over 3,200psi/22.06MPa or 220.6bar) that actual boiling ceases to occur , and the boiler has no water - steam separation. There is no generation of steam bubbles within the water , because the pressure is above the "critical pressure" at which steam bubbles can form. It passes below the critical point as it does work in the high pressure turbine and enters the generator's condenser. This is more efficient , resulting in slightly less fuel use. The term "boiler" should not be used for a supercritical pressure steam generator , as no "boiling" actually occurs in this device.