Research on On-Line Calculating Methods of Steam-Gas Power Ratio for Single-Shaft Gas-Steam Combined-Cycle Unit

Steam-gas power ratio for single-shaft combined-cycle unit is an important parameter required for the performance calculation of the entire unit, which can not be measured directly by far. The mathematic models of performance indexes, such as steam turbine output power, gas turbine output power and steam-gas power ratio etc., are established based on the mass-energy balance principles. The on-line performance calculating software of the unit is developed with the support of the integrated modular modeling software. The software has been applied to supervisory information system of the STAG 109FA single-shaft gas steam combined-cycle unit power plant, it operates steadily and the results are exact and credible, and can meet the need of supervisory information system of the plant.