Thermodynamic Model of the Loss Factor Applied to Steam Turbines

Authors : Alejandro ZALETAAGUİLAR, Javier ROYO, Antonio VALERO

Pages : 127-133

View : 22 | Download : 7

Publication Date : 2001-09-01

Article Type : Research Paper

Abstract :Erosion, roughness, steam path damage, etc., are factors that reduce power capacity in a steam turbine. Any power loss occurring locally in intermediate stages of a steam turbine results in more available energy in the downstream stages, this effect is well known as the Loss Factor insert ignore into journalissuearticles values(Salisbury, 1974; Stodola, 1927; Husain, 1984);. Currently, the Loss Factor is been calculated by graphical methods insert ignore into journalissuearticles values(Cotton, 1996);. In this work a new thermodynamic expression for the Loss Factor insert ignore into journalissuearticles values(LF); is introduced, in order to improve applications to evaluate malfunctions in the first and intermediate stages of steam turbines. The new thermodynamic expression for the Loss Factor, is based on Second Law Analysis; and concepts like the internal parameter θ, and the dissipation temperature Td; insert ignore into journalissuearticles values(Royo, 1992);. An Example of a steam turbine in a conventional power plant of 158 MW is analyzed by comparing a classical graphical method insert ignore into journalissuearticles values(ASME/ANSI PTC-6, 1970; and Cotton, 1993);, and the proposed expression of the Loss Factor insert ignore into journalissuearticles values(LF);. Special emphasis is made on the thermoeconomical deviations that could arise by an imprecise application of the Loss Factor Method, during an energy audit of the steam turbine internal parts.
Keywords : loss factor, steam turbine malfunctions