Elsevier

Energy

Volume 73, 14 August 2014, Pages 192-203
Energy

A comparative analysis of configurations of linear Fresnel collectors for concentrating solar power

https://doi.org/10.1016/j.energy.2014.06.010Get rights and content

Highlights

  • An optical optimization of linear Fresnel collectors has been done.

  • The useful energy efficiency accounts for incident radiation and its concentration.

  • A comparative study between central Fresnel and compact Fresnel is carried out.

  • Compact Fresnel minimizes blocking/shading losses compared to central Fresnel.

  • This minimization does not overcome the greater dispersion of the rays in the receiver.

Abstract

Linear Fresnel collector arrays present some relevant advantages in the domain of concentrating solar power because of their simplicity, robustness and low capital cost. However, they also present important drawbacks and limitations, notably their average concentration ratio, which seems to limit significantly the performance of these systems.

First, the paper addresses the problem of characterizing the mirror field configuration assuming hourly data of a typical year, in reference to a configuration similar to that of Fresdemo. For a proper comparative study, it is necessary to define a comparison criterion. In that sense, a new variable is defined, the useful energy efficiency, which only accounts for the radiation that impinges on the receiver with intensities above a reference value. As a second step, a comparative study between central linear Fresnel reflectors and compact linear Fresnel reflectors is carried out. This analysis shows that compact linear Fresnel reflectors minimize blocking and shading losses compared to a central configuration. However this minimization is not enough to overcome other negative effects of the compact Fresnel collectors, as the greater dispersion of the rays reaching the receiver, caused by the fact that mirrors must be located farther from the receiver, which yields to lower efficiencies.

Section snippets

Introduction and background

Main advantages of LFC (linear Fresnel collectors) are its simplicity, robustness and low capital cost, as well as the degrees of freedom one finds in the design process, which must be analyzed in depth for reaching the maximum outcome in the variable representing the plant performance.

On the contrary, from the annual performance perspective they seem to reach lower efficiencies than parabolic trough collectors, as it is showed in the technical literature [1], [2], [3], [4]. Performance losses

Methodology for optical characterization of Fresnel collectors

The optical analysis has been approached by means of a detailed Ray tracing program for Fresnel collectors. There are several Ray tracing programs reported in bibliography [46], [47]. Nevertheless, it was decided to develop a new code, implemented in Matlab in order to provide the program of a great modularity. Therefore, complex sensitivity analysis may be carried out to identify the parameters that have a greater influence on optical losses, and new designs may be easily analyzed.

Fresnel

Comparative analysis between central linear Fresnel collectors and compact linear Fresnel collectors

This last section is devoted to a comparative analysis between the CLFC configuration and central LFC configuration. As mentioned in Section 1.1, the main advantage of the CLFC configuration versus central LFC is based on that blocking optical losses decrease drastically, thanks to the use of two receivers for each mirror array. The annual simulations show whether this advantage provides better annual performance of such systems.

The following configurations are considered: a Central LFC with

Summary and future work

The optical analysis of a linear Fresnel collector is a complex problem which must be properly featured before making comparisons with other devices. Efforts have been firstly aimed at the development of a Ray tracing program oriented to perform annual simulations based on hourly data. All relevant processes are studied in detail both in the incidence and reflection of solar beams on the mirrors for later concentration on the receiver. As the program has been provided with a great modularity,

Acknowledgments

Technical discussions with other members of the Group of Investigaciones Termoenergéticas (UPM) were essential for this work.

This work has been partially supported by the Institute for Advanced Sustainability Studies at Potsdam, Germany.

References (56)

  • J.D. Nixon et al.

    Cost-exergy optimization of linear Fresnel reflectors

    Sol Energy

    (2012)
  • R. Abbas et al.

    Solar radiation concentration features in linear Fresnel reflector arrays

    Energy Convers Manag

    (2012)
  • D. Mills et al.

    Compact linear Fresnel reflector solar thermal powerplants

    Sol Energy

    (2000)
  • D.R. Mills et al.

    Advances in solar thermal electricity technology

    Sol Energy

    (2004)
  • P. Garcia et al.

    Codes for solar flux calculation dedicated to central receiver system applications: a comparative review

    Sol Energy

    (2008)
  • R. Abbas et al.

    Steady-state thermal analysis of an innovative receiver for linear Fresnel reflectors

    Appl Energy

    (2012)
  • J. Muñoz et al.

    Thermal regimes in solar–thermal linear collectors

    Sol Energy

    (2011)
  • M.J. Montes et al.

    Proposal of a fluid flow layout to improve the heat transfer in the active absorber surface of solar central cavity receivers

    Appl Therm Eng

    (2012)
  • J. Dersch et al.

    Comparison of linear Fresnel and parabolic trough collector systems – system analysis to determine break even costs of linear Fresnel collectors

  • G. Morin et al.

    Comparison of linear Fresnel and parabolic trough collector systems – influence of linear Fresnel collector design variations on break even cost

  • M. Hoyer et al.

    Performance and cost comparison of linear Fresnel and parabolic trough collectors

  • G. Hautmann et al.

    First European linear Fresnel power plant in operation – operational experience & outlook

  • G. Morin et al.

    Operational results and simulation of a superheating Fresnel collector

  • M. Mertins et al.

    Experiences of operation of 30 MW solar thermal power station based on Fresnel collector technology

  • Novatec Solar, 2014....
  • Areva Solar, 2014....
  • CNIM, presentation of their activity in Concentrating Solar field:...
  • SolarPACES, 2014....
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