Using the interpolation-analytical approximation of the Iapws-95 equations in the flow calculation of the steam turbine flow part

• Datum: 2015
• Hauptverfasser: Русанов, Андрей Викторович, Пащенко, Н. В., Русанов, Р. А.
• Format: Artikel
• Sprache: Russian
• Veröffentlicht: Інститут енергетичних машин і систем ім. А. М. Підгорного Національної академії наук України 2015
• Schlagworte: turbine; flow part; spatial flow; equations of state of water and steam; УДК 621.165; 532.6
• Online Zugang: https://journals.uran.ua/jme/article/view/40248
• Назва журналу: Energy Technologies & Resource Saving

Paper introduced an approach to the approximation of the equations of state of water and steam (IAPWS-95) for the calculation of three-dimensional viscous flow of steam in the flow parts of turbomachines. This method based on an approximation of the complex thermodynamic functions IAPWS-95 more simple relationship with the compressibility factor, which is calculated using an interpolation polynomials of the third order. To verify the proposed method there are made test calculations of spatial flows in the five-stage flow part of the low-pressure cylinder of steam turbine with capacity 360 MW which is one of modification of the three-stage flow part of the low-pressure cylinder of steam turbine K-200-130 and medium pressure cylinder of cogeneration turbine T120 130-12,8. Presents a comparison of the numerical results with experimental data. The proposed method provides sufficient accuracy of determination of thermodynamic values throughout the operating range of modern and advanced steam turbines (the maximum error is not more than ± 0,1%), without the need for a substantial increase in the computational cost. Using of this approach allows for a more accurate modeling of three-dimensional flow of wet steam in flow parts of the turbines in comparison with models which use simple equation of state.