Coupled optical and CFD parametric analysis of an open volumetric air receiver of honeycomb type for central tower CSP plants

The performance of an open volumetric solar air receiver of honeycomb type (multiple parallel channels) for central tower CSP plants is evaluated numerically. A parametric study is conducted at the single channel level in order to investigate the influence of the main geometrical variables and of the air mass flow rate on the receiver performance. The adopted methodology consists of two steps: the first one is the optical analysis that is conducted using Tonatiuh, an open-source Monte-Carlo based ray-tracing software, providing the distribution of the absorbed heat flux on the channel inner surfaces, to be finally exploited as input data in the second step, i.e. the numerical evaluation of the thermal fluid dynamic performance of the channel. Using the commercial CFD software ANSYS Fluent, the convective heat transfer between the air flow and the absorber and the radiative heat transfer among the absorber inner walls and the channel aperture are simulated, computing the heat losses to the ambient. Different channel configurations are simulated, identifying the influence of the three key-parameters (the tilt angle with respect to the horizontal, the channel size and the air mass flow rate) on the receiver performance, in terms of solar-to-electricity efficiency

Towards standard testing materials for high temperature solar receivers

This is an open access article under the CC BY-NC-ND licenseSolar thermal technology for the production on electricity is one of the current technological challenges. In concentrating solar power (CSP) plants, in order to achieve high power it is required to use a high operating temperature to reach high conversion efficiencies. The majority of today's commercial solar thermal power plants are based on the parabolic trough collector technology with operating temperature around 400 °C. However, the technology of solar tower is used in order to maximize the efficiency of the CSP plants. This technology reaches an operating temperature higher than 1000 °C and the development of high temperature receivers that work in this temperature ranges is still in its early stages. The fundamental problems observed are related to materials durability and reliability. The main objective of this paper has been to develop testing methods for solar receivers which guarantee their reliability and durability under demanding working conditions of high solar concentrating technology. Based on a revision of published or draft Standards, a qualification test methodology for durability tests has been developed.This paper has been funded by the project MIRASOL, ref ENE2012-39385-C03-01 (CENER) and ENE2012-39385-C03-03 (CSIC), within the framework “Subprograma de Proyectos de Investigación Fundamental no orientada (2012)”, MINECO (Spanish Government).Peer Reviewe

ScienceDirect-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer review by the scientific conference committee of SolarPACES 2014 under responsibility of PSE AG Towards standard testing materials for high temperature solar receivers

Abstract Solar thermal technology for the production on electricity is one of the current technological challenges. In concentrating solar power (CSP) plants, in order to achieve high power it is required to use a high operating temperature to reach high conversion efficiencies. The majority of today's commercial solar thermal power plants are based on the parabolic trough collector technology with operating temperature around 400ºC. However, the technology of solar tower is used in order to maximize the efficiency of the CSP plants. This technology reaches an operating temperature higher than 1000 ºC and the development of high temperature receivers that work in this temperature ranges is still in its early stages. The fundamental problems observed are related to materials durability and reliability. The main objective of this paper has been to develop testing methods for solar receivers which guarantee their reliability and durability under demanding working conditions of high solar concentrating technology. Based on a revision of published or draft Standards, a qualification test methodology for durability tests has been developed