A Novel Iris Mechanism for Solar Thermal Receivers

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Cédric Ophoff ◽  
Nesrin Ozalp
Keyword(s):  
High Temperature ◽  
Power Systems ◽  
Experimental Testing ◽  
Absorption Efficiency ◽  
Careful Consideration ◽  
Solar Thermal ◽  
Area Measurement ◽  
Solar Simulator ◽  
Variable Aperture ◽  
Solar Reactors

Variable aperture mechanisms are being used in many fields including medicine, electronics, fluid mechanics, and optics. The main design characteristics of these aperture concepts are the use of multiple blades regulating aperture area and consequently the incoming medium flow. Manufacturing complexities primarily depend on the concept geometry, material, and the process application requirements. Design of a variable aperture demands meticulous methodology and careful consideration of the application field. This paper provides an in-depth methodology on the design of a novel iris mechanism for temperature control in high temperature solar thermal receivers and solar reactors. Such methodology can be used as a guideline for iris mechanisms implemented in other applications as well as in design of different apparatuses exposed to high temperature. Optical simulations in present study have been performed to demonstrate enhanced performance of the iris mechanism over conventional Venetian blind shutter serving as optical attenuators in concentrating solar power systems. Results showed that optical absorption efficiency is improved by 14% while reradiation loss through the aperture is reduced by 2.3% when the iris mechanism is used. Correlation for adaptive control of aperture area was found through computational surface area measurement. Experimental testing with a 7 kW solar simulator at different power levels demonstrated the performance of the mechanism to maintain stable temperature under variable flux.

Design of a New 45 kWe High-Flux Solar Simulator for High-Temperature Solar Thermal and Thermo-Chemical Research

2010 ◽  
Author(s):  
Katherine R. Krueger ◽  
Jane H. Davidson ◽  
Wojciech Lipin´ski
Keyword(s):  
High Temperature ◽  
Focal Plane ◽  
Flux Distribution ◽  
Solar Thermal ◽  
Optimized Design ◽  
High Flux ◽  
Chemical Research ◽  
Solar Simulator ◽  
Peak Flux ◽  
The Common

In this paper, we present a systematic procedure to design a solar simulator for high-temperature concentrated solar thermal and thermo-chemical research. The 45 kWe simulator consists of seven identical radiation units of common focus, each comprised of a 6.5 kWe xenon arc lamp close-coupled to a precision reflector in the shape of a truncated ellipsoid. The size and shape of each reflector is optimized by a Monte Carlo ray tracing analysis to achieve multiple design objectives, including high transfer efficiency of radiation from the lamps to the common focal plane and desired flux distribution. Based on the numerical results, the final optimized design will deliver 7.5 kW over a 6-cm diameter circular disc located in the focal plane, with a peak flux approaching 3.7 MW/m2.

Compound Parabolic Concentrators in Solar Thermal Applications: A Review

2013 ◽  
Author(s):  
Donghao Xu ◽  
Ming Qu
Keyword(s):  
High Temperature ◽  
Cost Effectiveness ◽  
Power Systems ◽  
Solar Power ◽  
Solar Thermal ◽  
Thermal System ◽  
Solar Collectors ◽  
Basic Concepts ◽  
Solar Thermal Applications ◽  
Solar Thermal System

Among all types of concentrators, compound parabolic concentrators (CPCs) have been designed as stationary solar collectors for relative high temperature operations with high cost effectiveness. The CPCs are potentially the favorable option for solar power systems and high temperature solar thermal system. This paper provided a review on studies of CPCs in solar thermal applications. It covered basic concepts, principles, and design of CPCs. It also reviewed optical models and thermal models of CPCs, as well as the thermal applications of CPCs. The challenges were also summarized.

Design of a New 45 kWe High-Flux Solar Simulator for High-Temperature Solar Thermal and Thermochemical Research

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
K. R. Krueger ◽  
J. H. Davidson ◽  
W. Lipiński
Keyword(s):  
High Temperature ◽  
Focal Plane ◽  
Flux Distribution ◽  
Circular Disk ◽  
Solar Thermal ◽  
Optimized Design ◽  
High Flux ◽  
Solar Simulator ◽  
Peak Flux ◽  
The Common

In this paper, we present a systematic procedure to design a solar simulator for high-temperature concentrated solar thermal and thermochemical research. The 45 kWe simulator consists of seven identical radiation units of common focus, each comprised of a 6.5 kWe xenon arc lamp close-coupled to a precision reflector in the shape of a truncated ellipsoid. The size and shape of each reflector is optimized by a Monte Carlo ray tracing analysis to achieve multiple design objectives, including high transfer efficiency of radiation from the lamps to the common focal plane and desired flux distribution. Based on the numerical results, the final optimized design will deliver 7.5 kW over a 6 cm diameter circular disk located in the focal plane, with a peak flux approaching 3.7 MW/m2.

scholarly journals Development of a High-Flux Solar Simulator for Experimental Testing of High-Temperature Applications

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3124
Author(s):  
Marco Milanese ◽  
Gianpiero Colangelo ◽  
Arturo de Risi
Keyword(s):  
High Temperature ◽  
Horizontal Plane ◽  
Scientific Literature ◽  
Experimental Testing ◽  
Fluid Dynamic ◽  
Experimental Tests ◽  
Maximum Temperature ◽  
High Flux ◽  
Solar Simulator ◽  
Concentrated Solar Radiation

In the last few years, several studies have been carried out on concentrating solar thermal and thermochemical applications. These studies can be further enhanced by means of high-flux solar simulators (HFSS), since they allow the development of experimental tests under controlled irradiance conditions, regardless of sunshine. In this work, a new high-flux solar simulator, capable of reaching levels of irradiance higher than 100 W/cm2 (1000 suns), has been designed, built and characterized. This simulator is composed of 8 ellipsoidal specular reflectors, arranged face-down on a horizontal plane, in order to irradiate from the upper side any system requiring the simulation of concentrated solar radiation; differently from the HFSSs described in the scientific literature, this configuration allows the avoidance of any distortion of fluid-dynamic or convective phenomena within the system under investigation. As a first step, a numerical analysis of the HFSS has been carried out, simulating each real light source (Xe-arc), having a length of 6.5 mm, as a line of 5 sub-sources. Therefore, the HFSS has been built and characterized, measuring a maximum irradiance of 120 W/cm2 and a maximum temperature of 1007 °C; these values will be enough to develop experimental tests on lab-scale thermal and thermochemical solar applications.

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