Examinando por Autor "Ortega, Guillermo"

Mostrando 1 - 3 de 3
  • Miniatura
    Publicación
    Comparison of Different Technologies for Integrated Solar Combined Cycles: Analysis of Concentrating Technology and Solar Integration
    (MDPI, 2018-04-25) Sánchez, Consuelo; Abbas, Rubén; Muñoz Antón, Javier; Ortega, Guillermo; Rovira de Antonio, Antonio José; Valdés Fernández, Manuel Tomás; Barbero Fresno, Rubén; Montes Pita, María José; Muñoz Domínguez, Marta; Varela Díez, Fernando
    This paper compares the annual performance of Integrated Solar Combined Cycles (ISCCs) using different solar concentration technologies: parabolic trough collectors (PTC), linear Fresnel reflectors (LFR) and central tower receiver (CT). Each solar technology (i.e. PTC, LFR and CT) is proposed to integrate solar energy into the combined cycle in two different ways. The first one is based on the use of solar energy to evaporate water of the steam cycle by means of direct steam generation (DSG), increasing the steam production of the high pressure level of the steam generator. The other one is based on the use of solar energy to preheat the pressurized air at the exit of the gas turbine compressor before it is introduced in the combustion chamber, reducing the fuel consumption. Results show that ISCC with DSG increases the yearly production while solar air heating reduces it due to the incremental pressure drop. However, air heating allows significantly higher solar-to-electricity efficiencies and lower heat rates. Regarding the solar technologies, PTC provides the best thermal results.
  • Miniatura
    Publicación
    A new method for the selection of candidates for shading and blocking in central receiver systems
    (Elsevier, 2020-01-28) Ortega, Guillermo; Rovira de Antonio, Antonio José
    This paper presents a method for the selection of candidates for shading and blocking in central receiver systems (CRS). The main advantage of this algorithm is that it produces a reduced list of candidates with no upper limit on the total number, and it selects only those heliostats which produce real shading or blocking, eliminating redundant candidates. The objective is to contribute to a reduction in the execution times of the shading and blocking efficiency calculation in CRS, without a significant drop in accuracy. The method consists of three filtering levels, which progressively reduce the number of candidates, and it is specifically designed for use in performance simulation and optimisation applications for CRS. Its performance in this context has been compared with that of other selection algorithms, in terms of the number of selected candidates for each method and the execution times for determining the annual shading and blocking efficiency. The results indicate that the proposed method reduces the list of selected candidates to nearly 23% of those selected by other methods (spheres method) and up to 22% the execution times without affecting the numerical efficiency results.
  • Miniatura
    Publicación
    Towards high solar contribution in hybrid CSP-combined cycle gas turbine plants
    (Hindawi, 2023) Ortega, Guillermo; Rovira de Antonio, Antonio José; Barbero Fresno, Rubén; Subires Tejedor, Antonio Jesús; Muñoz Domínguez, Marta
    This paper proposes and analyses several configurations for hybridising concentrating solar power (CSP) plants with combined cycle gas turbines (CCGT). The objective is to increase the solar contribution to a large extent, much higher than those obtained in integrated solar combined cycles but maintaining synergies, which are usually lost when increasing the solar share. For that, two thermal energy management systems are introduced at different temperature levels. First, a configuration with only the low-temperature system is proposed. Then, an enhanced configuration with the low- and high-temperature systems is conceived. These configurations are compared to reference CSP and CCGT state-of-the-art plants. The analyses include different strategies of operation and two sizes for the thermal energy storage system. The results show that the first proposed configuration introduces some synergies but cannot improve the performance of the reference CSP and CCGT working separately, due to an issue with the solar dumping on days with high solar irradiation. The enhanced configuration overcomes this problem and maintains the synergies, leading to an improvement from both the thermodynamic and economic points of view, increasing the solar contribution and decreasing the levelized cost of energy over the reference plants.