Analysis of Pressure Drop in a Concentrated Solar Collector with Direct Steam Production
Solar thermal power plants using parabolic trough collectors (PTC) are currently a powerful technology for generating electricity. Most of these solar power plants use thermal oils as heat transfer fluid. The latter is heated in the solar field and transfers the heat absorbed in an oil-water heat exchanger for the production of steam driving the turbines of the power plant. Currently, we are seeking to develop PTCs with direct steam generation (DSG). This process consists of circulating water under pressure in the receiver tube to generate steam directly into the solar loop. This makes it possible to reduce the investment and maintenance costs of the PTCs (the oil-water exchangers are removed) and to avoid the environmental risks associated with the use of thermal oils. The pressure drops in these systems are an important parameter to ensure their proper operation. The determination of these losses is complex because of the presence of the two phases, and most often we limit ourselves to describing them by models using empirical correlations. A comparison of these models with experimental data was performed. Our calculations focused on the evolution of the pressure of the liquid-vapor mixture along the receiver tube of a PTC-DSG for pressure values and inlet flow rates ranging respectively from 3 to 10 MPa, and from 0.4 to 0.6 kg/s. The comparison of the numerical results with experience allows us to demonstrate the validity of some models according to the pressures and the flow rates of entry in the PTC-DSG receiver tube. The analysis of these two parameters’ effects on the evolution of the pressure along the receiving tub, shows that the increase of the inlet pressure and the decrease of the flow rate lead to minimal pressure losses.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3346738Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 73
 R. W. Lockhart and R. C. Martinelli, “Proposed correlation of data for isothermal two-phase, two-component in pipes,” Chem. Eng. Process, vol. 45(1), pp. 39–48, 1949.
 R. Gronnerud, “Investigation of liquid hold-up, flow resistance and heat transfer in circulation type evaporators. 4. Two-phase flow resistance in boiling refrigerants,” Annex. 1972-1, Bull. l’Inst. du Froid, pp. 127–138, 1972.
 D. Chisholm, “Pressure gradients due to friction during the flow of evaporating two-phase mixtures in smooth tubes and channels.,” Int. J. Heat Mass Transf., vol. 16, no. 29, pp. 347–358, 1973.
 L. Friedel, “Improved friction pressure drop correlations for horizontal and vertical two-phase pipe flow,” Eur. Two-phase Flow Gr. Meet. Ispra, Italy, vol. 18, no. 2, pp. 485–492, 1979.
 H. Muller steinhagen and K. HECK, “A Simple Friction Pressure Drop Correlation for Two-Phase Flow in Pipes,” vol. 20, no. 1, pp. 297–308, 1986.
 B. K. Hardik and S. V Prabhu, “International Journal of Thermal Sciences Boiling pressure drop and local heat transfer distribution of water in horizontal straight tubes at low pressure,” Int. J. Therm. Sci., vol. 110, pp. 65–82, 2016.
 M. B. O. Didi, N. Kattan, and J. R. Thome, “Prediction of two-phase pressure gradients of refrigerants in horizontal tubes´ vision des gradients de pression des frigorige ` nes en Pre ´ coulement diphasique dans des tubes horizontaux e,” Int. J. Refrig., vol. 25, pp. 935–947, 2002.
 L. Wojtan, T. Ursenbacher, and J. R. Thome, “Investigation of flow boiling in horizontal tubes : Part I — A new diabatic two-phase flow pattern map,” vol. 48, pp. 2955–2969, 2005.
 J. M. Quibén, L. Cheng, R. J. da S. Lima, and J. R. Thome, “International Journal of Heat and Mass Transfer Flow boiling in horizontal flattened tubes : Part I – Two-phase frictional pressure drop results and model,” Int. J. Heat Mass Transf., vol. 52, no. 15–16, pp. 3634–3644, 2009.
 Z. Yang, M. Gong, G. Chen, X. Zou, and J. Shen, “Two-phase flow patterns, heat transfer and pressure drop,” Appl. Therm. Eng., 2017.
 D. Steiner, VDI-Wärmeatlas (VDI Heat Atlas), Verein Deutscher Ingenieure, VDI-Gesellschaft Verfahrenstechnik und Chemieingenieurwesen (GCV), Düsseldorf. 1993.
 H. Lobón David, B. Emilio, V. Loreto, and Z. Eduardo, “Modeling direct steam generation in solar collectors with multiphase CFD,” vol. 113, pp. 1338–1348, 2014.
 M. Biencinto, L. González, and L. Valenzuela, “A quasi-dynamic simulation model for direct steam generation in parabolic troughs using TRNSYS,” Appl. Energy, vol. 161, pp. 133–142, 2016.
 M. Eck and W.-D. Steinmann, “ISEC2004-65040 Modeling and Design of Direct Solar Steam Generating Collector Fields,” ASME, pp. 1–10, 2004.
 A. Amine, I. Rodríguez, and C. Ghenai, “Thermo-hydraulic analysis and numerical simulation of a parabolic trough solar collector for direct steam generation,” Appl. Energy, vol. 214, no. January, pp. 152–165, 2018.