In scnne integrated energy conversion systems, automatic extraction steam turbines are used to provide low quality steam from the turbine for process use or district heating and cooling purposes. This paper presents a generalized mathematical model for steam turbine/generator based on the Rankine cycle. Also, simplified linear models are presented for pure condensing, single extraction and double extraction turbine/generators which could be adapted to optimization of integrated energy conversion systems. Energy conversion Extraction steam turbine Mathematical model Thermal/electric generation Total snergy systems NOMENCLATURE Correction factor for part load efficiency Enthalpy of the steam entering state i (i = 1, 2,
k) (B.t.u./lb) Enthalpy of the exhaust steam from the final stage (note that h, = h,,,) Enthalpy of the condensate leaving the turbine condenser (B.t.u./lb) Number of stages of the turbine Maximum throttle flow (lb/h) Maximum allowable steam flow through the 2nd section of the turbine (lb/h) Mass flow rate of steam through stage i (i = 1, 2,. k) Wh) Minimum exhaust flow (lb/h) Mass flow rate of extraction steam from the steam leaving stage i-l and entering stage i (i = 2, 3,. k) (lb/h), e.g. me2 is extracted between stage 1 and stage 2 Steam pressure (psi) Entropy (B.t.u./lb"R) Steam temperature ("F) Electricity output from the generator (kW) Generator rated capacity (kW) Electric output part load factor Mechanical efficiency of the generator Mechanical efficiency of stage i of the turbine Turbine overall mechanical efficiency Turbine maximum mechanical efficiency at rated output.