Theoretical basis and experimental facility for parabolic trough collectors at high temperature using gas as heat transfer fluid

The efficiency of any thermal power plant is related to the maximum working temperature that some components can reach. Examples of material constraints are the first stage blades of a gas turbine or the receiver of a solar tower plant, but there are other temperature constraints, such as the ones related with the heat transfer fluid. Nowadays, this happens in the most common solar technology: parabolic trough collectors that use synthetic oil. This fluid must work below 400°C. This limitation affects the power plant efficiency due to a poor Rankine cycle yield. To avoid this problem and go to higher temperatures, a gas can be used as heat transfer fluid, providing at the same time other significant advantages over synthetic oil: non-flammability and no environmental threats. The purpose of this paper is to justify the theoretical basis of the gas use in parabolic troughs and the problems related, and also to describe the test loop built at the PSA (Plataforma Solar de Almeria) in order to demonstrate the technical feasibility of this new technology, testing all components required to build a pre-commercial power plant. This paper describes the main features of this technology, the theoretical basis, the validation of the design tools and the results of the operation. Of them, the more important aspects are that high working pressure can reduce pumping power to adequate levels, that good controllability of the technology with hard solar transients can be achieved and that ball joints leaks problems detected appeared as the main inconvenience, but promising solution has been found.

[1]  Antonio L. Avila-Marin,et al.  Volumetric receivers in Solar Thermal Power Plants with Central Receiver System technology: A review , 2011 .

[2]  S. Iniyan,et al.  A review of solar thermal technologies , 2010 .

[3]  Y. Kato,et al.  Medium temperature carbon dioxide gas turbine reactor , 2004 .

[4]  M. Berenguel,et al.  Thermo-economic design optimization of parabolic trough solar plants for industrial process heat applications with memetic algorithms , 2014 .

[5]  E. Zarza,et al.  INDITEP: The first pre-commercial DSG solar power plant , 2006 .

[6]  Eduardo Zarza,et al.  Parabolic-trough solar collectors and their applications , 2010 .

[7]  K. R. Kumar,et al.  Thermal analysis of solar parabolic trough with porous disc receiver , 2009 .

[8]  Soteris A. Kalogirou,et al.  Solar thermal collectors and applications , 2004 .

[9]  Changying Zhao,et al.  A review of solar collectors and thermal energy storage in solar thermal applications , 2013 .

[10]  Roberto Grena,et al.  Solar linear Fresnel collector using molten nitrates as heat transfer fluid , 2011 .

[11]  W. Beckman,et al.  Solar Engineering of Thermal Processes , 1985 .

[12]  Robert L. Mott,et al.  Applied Fluid Mechanics , 1972 .

[13]  D. Mills.  Advances in solar thermal electricity technology , 2004 .

[14]  Massoud T. Simnad.  The early history of high-temperature helium gas-cooled nuclear power reactors , 1991 .

[15]  Manuel Berenguel,et al.  Control scheme for direct steam generation in parabolic troughs under recirculation operation mode , 2006 .

[16]  M. J. Montes,et al.  Performance of a direct steam generation solar thermal power plant for electricity production as a function of the solar multiple , 2009 .

[17]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .

[18]  Gang Xu,et al.  Efficient, low-cost solar thermoelectric cogenerators comprising evacuated tubular solar collectors and thermoelectric modules , 2013 .

[19]  A. J. Goodjohn.  Summary of Gas-Cooled reactor programs , 1991 .

[20]  Roland Span,et al.  A Reference Equation of State for the Thermodynamic Properties of Nitrogen for Temperatures from 63.151 to 1000 K and Pressures to 2200 MPa , 2000 .

[21]  Gitanjali Yadav,et al.  Performance study of a linear Fresnel concentrating solar device , 1999 .

[22]  Markus Eck,et al.  Direct steam generation in parabolic troughs: Final results and conclusions of the DISS project , 2004 .

[23]  R. D. McCarty,et al.  A New Wide Range Equation of State for Helium , 1990 .

[24]  Aránzazu Fernández-García,et al.  Modeling and co-simulation of a parabolic trough solar plant for industrial process heat , 2013 .

[25]  Markus Eck,et al.  Saturated steam process with direct steam generating parabolic troughs , 2006 .

[26]  Michael J. Driscoll,et al.  Gas cooled fast reactor for generation IV service , 2005 .

[27]  Ya-Ling He,et al.  A new modelling method and unified code with MCRT for concentrating solar collectors and its applications , 2013 .

[28]  Masud Behnia,et al.  Performance evaluation of solar thermal electric generation systems , 2003 .

[29]  José M. Martínez-Val,et al.  A conceptual design of solar boiler , 2009 .

[30]  W. Wagner,et al.  A New Equation of State for Carbon Dioxide Covering the Fluid Region from the Triple‐Point Temperature to 1100 K at Pressures up to 800 MPa , 1996 .

[31]  Robert Pitz-Paal,et al.  Influence of Measurement Equipment on the Uncertainty of Performance Data from Test Loops for Concentrating Solar Collectors , 2010 .

[32]  J. Muñoz,et al.  Analysis of internal helically finned tubes for parabolic trough design by CFD tools , 2011 .

[33]  Chang Xu,et al.  Numerical study of heat transfer enhancement in the receiver tube of direct steam generation with parabolic trough by inserting metal foams , 2013 .

[34]  María José Montes,et al.  Performance analysis of an Integrated Solar Combined Cycle using Direct Steam Generation in parabolic trough collectors , 2011 .

[35]  G. Morrison,et al.  Compact Linear Fresnel Reflector solar thermal powerplants , 2000 .