Dual Loop Line-Focusing Solar Power Plants with Supercritical Brayton Power cycles

Coco Enriquez, Luis and Muñoz Antón, Javier and Martínez-Val Peñalosa, José María (2016). Dual Loop Line-Focusing Solar Power Plants with Supercritical Brayton Power cycles. In: "European Conference Renewable Energy ECRES 2016", Agosto 2016, Estambul, Turquia.

Description

Title: Dual Loop Line-Focusing Solar Power Plants with Supercritical Brayton Power cycles
Author/s:
  • Coco Enriquez, Luis
  • Muñoz Antón, Javier
  • Martínez-Val Peñalosa, José María
Item Type: Presentation at Congress or Conference (Article)
Event Title: European Conference Renewable Energy ECRES 2016
Event Dates: Agosto 2016
Event Location: Estambul, Turquia
Title of Book: Proceedings of European Conference Renewable Energy ECRES 2016
Date: August 2016
Subjects:
Freetext Keywords: Dual Loop Solar Field, Thermal Oil, Molten Salt, Supercritical Brayton
Faculty: E.T.S.I. Industriales (UPM)
Department: Energía y Combustibles
UPM's Research Group: Modelización de Sistemas Termoenergéticos
Creative Commons Licenses: None

Full text

[img]
Preview
PDF - Requires a PDF viewer, such as GSview, Xpdf or Adobe Acrobat Reader
Download (328kB) | Preview

Abstract

Most of the deployed commercial line-focusing solar power plants with Parabolic Troughs (PTC) or Linear Fresnel (LF) solar collectors and Rankine power cycles use a Single Loop Solar Field (SF), Configuration 1 illustrated in Fig. 2, with synthetic oil as Heat Transfer Fluid (HTF) [1, 2]. However, thermal oils maximum operating temperature should be below ~400ºC for assuring no oil degradation, hence limiting the power cycle gross efficiency up to ~38%. For overcoming this limitation Molten Salts (MS) as HTF in linear solar collectors (PTC and LF) were recently experimented in pilot facilities [3, 4]. Direct MS main drawbacks are the equipments and components material corrosion and the salts freezing temperature, requiring heat tracing to avoid any sald solidification, hence increasing the Solar Field (SF) capital investment cost and parasitic energy looses. Concentrated Solar Power plants (CSP) with Dual Loop SF are being studied since 2012 [5] for gaining the synergies between thermal oils and MS properties. In the Dual Loop SF the HTF in the primary loop is thermal oil (Dowtherm A) [6] for heating the Balance Of Plant (BOP) working fluid from ~300ºC up to ~400ºC, and a secondary loop with Solar Salt (60% NaNO3, 40% KNO3) as HTF, for boosting the working fluid temperature from ~400ºC up to 550ºC [7, 8, 9]. The CSP Dual Loop state of the art technology includes Rankine power cycles, the main innovation of this paper is the integration between Dual Loop SF and the supercritical Carbon Dioxide (s-CO2) Brayton power cycles [10], see Configurations 2 and 3 illustrated in Fig. 3a, Fig 3b. A secondary innovation studied in this paper is the integration between thermal oil HTF (Dowtherm A) in linear solar collectors, a widely validated and mature technology, with the s-CO2 Brayton power cycles. This technical solution is very cost competitive with carbon steel receiver pipes, low SF operating pressure, and no requiring any heat tracing. Two main conclusions are deducted from this researching study. Firstly we demonstrated the higher gross plant efficiency ~44.4%, with 550ºC Turbine Inlet Temperature (TIT), provided by the Dual Loop with the Simple recuperated s-CO2 Brayton cycle with reheating, in comparison with 41.8% obtained from the Dual Loop SF and subcritical water Rankine power cycle. And finally the second conclusion obtained is the selection of the most cost competitive plant configuration with a Single loop SF with Dowtherma A and a s-CO2 Brayton power cycle due to the receiver material low cost and no heat tracing for the thermal oil.

More information

Item ID: 43999
DC Identifier: http://oa.upm.es/43999/
OAI Identifier: oai:oa.upm.es:43999
Deposited by: Luis Coco Enriquez
Deposited on: 01 Dec 2016 08:41
Last Modified: 18 Aug 2017 11:15
  • Logo InvestigaM (UPM)
  • Logo GEOUP4
  • Logo Open Access
  • Open Access
  • Logo Sherpa/Romeo
    Check whether the anglo-saxon journal in which you have published an article allows you to also publish it under open access.
  • Logo Dulcinea
    Check whether the spanish journal in which you have published an article allows you to also publish it under open access.
  • Logo de Recolecta
  • Logo del Observatorio I+D+i UPM
  • Logo de OpenCourseWare UPM