power systems Samira Sayad Saravi, Savvas Tassou Brunel University - PowerPoint PPT Presentation

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Diffuser performance of centrifugal compressor in supercritical CO 2 power systems Samira Sayad Saravi, Savvas Tassou Brunel University London, Institute of Energy Futures, Centre for Sustainable Energy Use in Food Chains Uxbridge, Middlesex UB8 3PH, UK RCUK Centre for Sustainable Energy Use in Food Chains

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Layout • Background • Literature review • Real gas effect • Modelling setup • Results • Conclusions RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 2 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Background • energy and industry-related emissions are predicted to be more than double by 2050 compared to 1990 levels [1], • CO 2 is a high density working fluid and is CO 2 is a low-cost, non-flammable and non-toxic [2], • sCO 2 systems were originally conceived for nuclear and concentrated solar power generation applications [3, 4] RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 3 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Review (experiment) Tokyo Institute of Technology, 2012 [5] Sandia National Laboratories, 2010 [6] RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 4 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Review (modelling) Baltadjiev, Lettieri and Spakovszky, 2015 [7] Behafarid, Podowski, 2016 [8] Pecnik, Rinaldi and Colonna, 2012 [9] RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 5 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Real gas effect on one-dimensional flow 𝑣𝑒𝑣 + 1 𝑒 and 𝜍 𝑒𝑞 = −𝑒𝑥 𝑡ℎ𝑏𝑔𝑢 𝑒𝑦 𝜍𝑣𝐵 = 0 𝑒𝑁 2 𝑁 2 = −2 1 + Γ − 1 𝑁 2 𝑒𝑥 𝑡ℎ𝑏𝑔𝑢 𝑒𝐵 1 1 𝜖𝜑 Γ 𝐵 + 1 − 𝑁 2 1 − 𝑁 2 𝜑 𝜖𝑈 Γ − 1 𝐷 𝑞 𝑞 𝑒𝑥 𝑡ℎ𝑏𝑔𝑢 1 𝑒𝐵 1 1 𝑒𝜑 𝑒𝑦 → , 𝑁 → 1 ሻ 𝐵 2(Γ − 1 𝜑 𝑒𝑈 𝐷 𝑞 𝑒𝑦 Γ = 1 + 𝜍 𝜖𝐷 = 1 𝜑 𝜖𝑄 = −𝜑 2 𝜖𝑄 𝜖 2 𝜑 𝜖 2 𝑄 𝐷 2 = 2 𝜍 3 𝐷 4 ൗ = ൗ > 0 𝜖𝑄 2 𝜖𝜑 2 2𝐷 2 𝐷 𝜖𝜍 𝜖𝜍 𝜖𝜑 𝑡 𝑡 RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 6 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Modelling setup Γ Behaviour (Thompson, 1971 [10]) Γ > 1 Sound speed increases with P; behaviour of usual substances Γ = 1 Constant sound speed ; P a linear function of ρ 0 < Γ <1 Sound speed deceases with P Γ = 0 P a linear function of V Γ < 0 Negative curvature of isoentrope; behaviour of unusual substances RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 7 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Results RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 8 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Results (density and sound speed) (VN13:- - - , VN17: ̶ ̶ ̶ ) RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 9 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Conclusions • explicit representation and characterisation of the real gas effects of the fluid on the one-dimensional internal flow behaviour and related mechanisms • The changes in the flow properties have been examined by changing the cross-sectional area in a selected vaned diffuser • modelling is performed with ANSYS CFX 17.1, including a generated lookup table from REFPROP for CO 2 real gas properties • the results show that the model with 17 vanes has higher pressure drop in throat and can lead to flow instability • it confirms the fact that the higher number of vanes leads to smaller operation range for this specific diffuser design • further investigation is needed to confirm this outcome for higher and lower incidence angle in leading edge RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 10 Brunel University

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains Thank you Samira Sayad Saravi Savvas Tassou Brunel University London, Institute of Energy Futures, Centre for Sustainable Energy Use in Food Chains Uxbridge, Middlesex UB8 3PH, UK RCUK Centre for Sustainable Energy Use in Food Chains

2 nd International Conference on Sustainable Energy and Resource Use in Food Chains References [1] Marchal, V., Dellink, R., Vuuren, D. V., Clapp, C., Château, J., Lanzi, E., Magné, B., and Vliet, J. V., 2011, “OECD Environmental Outlook to 2050 ,” Accessed January 3, 2018, <https://www.oecd.org/env/cc/49082173.pdf>. [2] Kulhanek, M., and Dostal, V., 2011, “Supercritical carbon dioxide cycles thermodynamic analysis and comparison,” Supercritical CO2 Power Cycle Symposium, Boulder, Colorado, May 24 – 25. [3] Ahn, Y., Bae, S. J., Kim, M., Cho, S. K., Baik, S., Lee, J. I., and Cha, J. E., 2015, “Review of supercritical CO2 power cycle technology and current status of research and development,” Nuclear Engineering and Technology, 47(6), pp. 647 – 661. [4] Li, M., Wang, J., Li, S., Wang, X., He, W., and Dai, Y., 2014, “Thermo -economic analysis and comparison of a CO2 transcritical power cycle and an organic Rankine cycle,” Geothermics, 50, pp. 101 – 111. [5] Utamura, M., Fukuda, T. and Aritomi, M. 2012, “Aerodynamic Characteristics of a Centrifugal Compressor Working in Supercritical Carbon Dioxide,” 2nd International Conference on Advances in Energy Engineering (ICAEE 2011), Energy Procedia, pp. 1149 – 1155. [6] Wright, S., Radel, R., Vernon, M., Rochau, G., and Pickard, P., 2010, “Operation and Analysis of a Supercritical CO2 Brayton Cycle,” Sandia National Laboratories, Albuquerque, NM, Technical Report No. SAND2010-0171. [7] Baltadjiev, N. D., Lettieri, C., and Spakovszky, Z. S., 2015, “An Investigation of Real Gas Effects in Supercritical CO2 Centrifugal Compressors,” J. Turbomach., 137, pp. 091003(1 – 13). [8] Behafarid, F., Podowski, M. Z., 2016, “Modelling and Computer Simulation of Centrifugal CO2 Compressors at Supercritical Pressures,” J Fluids Eng, 138, pp. 061106 (1 – 9). [9] Pecnik, R., Rinaldi, E., and Colonna, P., 2012, “Computational Fluid Dynamics of a Radial Compressor Operating With Supercritical CO2 ,” J Eng Gas Turb Power, 134, pp. 122301(1 – 8). [10] Thompson, P.A., 1971, “A Fundamental Derivative in Gas Dynamics,” Physics of Fluids, 14 (1971): 1843 – 1849. RCUK Centre for Sustainable Energy Use in RCUK Centre for Sustainable Energy Use in Food Chains Food Chains (CSEF) 12 Brunel University