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

Author(s):  
Katherine R. Krueger ◽  
Jane H. Davidson ◽  
Wojciech Lipin´ski

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.

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
K. R. Krueger ◽  
J. H. Davidson ◽  
W. Lipiński

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.


Author(s):  
Katherine R. Krueger ◽  
Wojciech Lipiński ◽  
Jane H. Davidson

This paper presents measured performance of the University of Minnesota’s 45 kWe indoor high-flux solar simulator. The simulator consists of seven radiation units, each comprised of a 6.5 kWe xenon short arc lamp coupled to a reflector in the shape of a truncated ellipsoid of revolution. Data include flux distribution at the focal plane for all seven radiation units operating in tandem and for individual radiation units. The flux distribution is measured optically by acquiring the image of radiation reflected from a Lambertian target with a CCD camera equipped with neutral density optical filters. The CCD camera output is calibrated to irradiation using a circular foil heat flux gage. It is shown that accurate calibration of the heat flux gage must account for its response to the spectral characteristics of the radiation source. The simulator delivers radiative power of approximately 9.2 kW over a 60-mm diameter circular area located in the focal plane, corresponding to an average flux of 3.2 MW m−2, with a peak flux of 7.3 MW m−2.


2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Katherine R. Krueger ◽  
Wojciech Lipiński ◽  
Jane H. Davidson

The University of Minnesota's high flux simulator delivers radiative power of approximately 9.2 kW over a Ø60 mm circular area located in the focal plane, corresponding to an average flux of 3200 kW m−2, with a peak flux of 7300 kW m−2.


2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Shunzhou Chu ◽  
Fengwu Bai ◽  
Fuliang Nie ◽  
Zhifeng Wang

Abstract A high-flux solar simulator is essential for evaluating solar thermal components under controlled and adjustable flux input conditions. This study presents a newly built high-flux solar simulator composed of 19 individual units. Each unit includes a xenon short-arc lamp (each consuming up to 6 kW electricity power) coupled with a truncated ellipsoidal reflector, a cooling blower, and a power module. The power module yields a current in the range of 50–160 A. The number of lamps in use is flexible, which allows for a wide range of radiation flux (10%–100%) on the focal plane. The radiation power, peak value, flux distribution on the circular target plane, and conversion efficiency are evaluated based on a flux mapping method. The results indicate that the proposed solar simulator is capable of achieving thermal power of 23.3 kW, peak flux in excess of 1.78 MW/m2, a stagnation temperature exceeding 2360 °C, and average irradiance of 773.4 kW/m2 on the focal plane (diameter of 260 mm). The electro-thermal conversion efficiency of the simulator is 35.7%. A ray-tracing method was employed, and the simulation results were found to be in good agreement with those in the experiments. An experimental test of a volumetric ceramic receiver was conducted, and the results indicate the availability and applicability of the high-flux solar simulator when carrying out studies about solar receivers.


2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Xue Dong ◽  
Graham J. Nathan ◽  
Zhiwei Sun ◽  
Peter J. Ashman ◽  
Dahe Gu

This paper presents assessments of the sensitivity of the performance of high flux solar simulators to the key variables of conical secondary concentrators for metal halide lamps, which offer complementary benefits compared with xenon arc lamps. The assessment is performed for both a single-lamp configuration and a seven-lamp array, each lamp close-coupled with its own elliptical reflector, and then aligned with a common conical secondary concentrator. The simulation of heat flux from both the single- and the seven-lamp systems was performed with the Monte Carlo ray-tracing code, which was validated with the experimental results from the single-lamp system. The calculated heat flux at the focal plane agrees with the measured peak flux to within 5% and to within 13% of the measured half width. Calculated results also show that the addition of the secondary concentrator to the single-lamp system can increase the peak flux by 294% and the average flux by up to 93% within a target of 100 mm in diameter, with a corresponding reduction in total power by 15%. The conical secondary concentrator is less effective for a seven-lamp system, increasing the peak and average fluxes by 87.3% and 100%, respectively, within 100 mm diameter focal plane, with a corresponding reduction in total power by 48%. The model was then used to assess the sensitivity of the geometry of the secondary concentrators for both the single- and seven-lamp systems. The results show that the average heat flux is sensitive to the surface reflectance of the secondary concentrator, with the average flux decreasing almost linearly with the surface reflectance. The presence of the secondary cone greatly reduces the sensitivity of the concentrated heat flux to misalignment of the tilting angle of the elliptical reflector relative to the arc.


2019 ◽  
Vol 58 (10) ◽  
pp. 2605 ◽  
Author(s):  
Leopoldo Martínez-Manuel ◽  
Manuel I. Peña-Cruz ◽  
Carlos A. Pineda-Arellano ◽  
J. Gonzalo Carrillo-Baeza ◽  
Daniel A. May-Arrioja

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Cédric Ophoff ◽  
Nesrin Ozalp

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.


2003 ◽  
Vol 125 (1) ◽  
pp. 117-120 ◽  
Author(s):  
D. Hirsch, ◽  
P. v. Zedtwitz, and ◽  
T. Osinga ◽  
J. Kinamore ◽  
A. Steinfeld

A new high-flux solar simulator, capable of delivering up to 75 kW of continuous radiative power at peak fluxes exceeding 4250 kW/m2, is operational at the ETH-Zurich. Its optical design and performance are described. This unique facility serves principally as an experimental platform for investigating thermal and thermochemical processes at temperatures up to 3000°K.


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