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.

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.

scholarly journals Performance of Pulverized Coal Combustion under High Temperature Air Diluted by Steam

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mohsen Saffari Pour ◽  
Yang Weihong
Keyword(s):  
High Temperature ◽  
Coal Combustion ◽  
Fluid Dynamic ◽  
Flame Temperature ◽  
Experimental Tests ◽  
Injection Rate ◽  
Pulverized Coal ◽  
Injection Velocity ◽  
Pulverized Coal Combustion ◽  
Injection Speed

The high temperature air combustion (HiTAC) is an advanced promising technology for heat recovery, energy saving, and stability improvement of flame. Computational fluid dynamic (CFD) is known as an applied tool to execute HiTAC modeling. In this paper, performances of pulverized coal combustion under the high preheated and oxygen deficient air are studied by both experimental and numerical methodology. The experimental facilities have been accomplished in a HiTAC chamber with coal injection velocity that ranges from 10 to 40 m/s. In order to achieve different preheated temperatures, the combustion air in such system is diluted by variable steam percentages from 0 to 44%. Results of mathematical simulation and experimental tests present convincible agreement through whole region. It is concluded that NOX emission is reduced by increasing the steam percentage in the oxidizer due to decreasing the flame temperature. Besides, graphical contours show that by adding more steam to oxidizer composition, the oxygen concentration decreased. Additionally, results show that when the injection speed of fuel is increased, NOX emission is also increased, and when the injection rate of preheated air is increased, NOX emission shows decreasing trend. Further contribution in future is needed to investigate the performance of such technologies.

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 and Testing of Ejectors for High Temperature Fuel Cell Hybrid Systems

2006 ◽  
Vol 3 (3) ◽  
pp. 284-291 ◽  
Author(s):  
Mario L. Ferrari ◽  
Davide Bernardi ◽  
Aristide F. Massardo
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Hybrid Systems ◽  
Fluid Dynamic ◽  
Experimental Tests ◽  
Open Circuit ◽  
Secondary Flows ◽  
Atmospheric Conditions ◽  
Simplified Approach ◽  
Chamber Length

Our goal in this work is the improvement of the ejector performance inside hybrid systems supporting the theoretical activity with experimental tests. In fact, after a preliminary ejector design, an experimental rig has been developed to test single stage ejectors for hybrid systems at different operative conditions of mass flow rates, pressures, and temperatures. At first, an open circuit has been built to perform tests at atmospheric conditions in the secondary duct. Then, to emulate a SOFC anodic recirculation device, the circuit has been closed, introducing a fuel cell volume in a reduced scale. This configuration is important to test ejectors at pressurized conditions, both in primary and secondary ducts. Finally, the volume has been equipped with an electrical heater and the rig has been thermally insulated to test ejectors with secondary flows at high temperature, necessary to obtain values in similitude conditions with the real ones. This test rig has been used to validate simplified and CFD models necessary to design the ejectors and investigate the internal fluid dynamic phenomena. In fact, the application of CFD validated models has allowed us to improve the performance of ejectors for hybrid systems optimizing the geometry in terms of primary and secondary ducts, mixing chamber length, and diffuser. However, the simplified approach is essential to start the analysis with an effective preliminary geometry.

A New 75 kW High-Flux Solar Simulator for High-Temperature Thermal and Thermochemical Research

2003 ◽  
Vol 125 (1) ◽  
pp. 117-120 ◽  
Author(s):  
D. Hirsch, ◽  
P. v. Zedtwitz, and ◽  
T. Osinga ◽  
J. Kinamore ◽  
A. Steinfeld
Keyword(s):  
High Temperature ◽  
Optical Design ◽  
High Flux ◽  
Solar Simulator ◽  
Experimental Platform ◽  
Radiative Power ◽  
Thermochemical Processes ◽  
And Performance

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.

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 Greener Solution to Waste Corn Stalks and Shortage of Asphalt Resource: Hydrochar Produced by Hydrothermal Carbonization as a Novel Performance Enhancer for Asphalt Binder

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1427
Author(s):  
Xiaoming Wu ◽  
Chichun Hu
Keyword(s):  
High Temperature ◽  
Reaction Temperature ◽  
Storage Stability ◽  
Asphalt Binder ◽  
Aging Effect ◽  
Experimental Tests ◽  
Hydrothermal Carbonization ◽  
Modified Asphalt ◽  
Direct Combustion ◽  
Aging Property

Utilization of waste corn stalks (CS) has seized extensive attention due to high annual output and hazardous impact of piling aside or direct combustion on environment. However, previously there has been a lot of emphasis on improvement of its energy efficiency as solid fuel while limited investigations are available which explore the possibility of applying corn stalks as performance enhancer in asphalt binder. The purpose of this study is to examine the potential of employing hydrochar as modifiers in asphalt binder by a series of experimental tests. In this study, two hydrochar were produced from corn stalks by a novel process called hydrothermal carbonization at a different reaction temperature. The two hydrochar and their responding hydrochar-modified asphalt (HCMA) were tested by chemical and rheological tests. Chemical analysis detected the interaction between hydrochar and binder factions, resulting in poor compatibility but satisfying anti-aging property. Even though hydrochar increased the viscosity of bitumen, implying worse workability, and caused poor storage stability, ameliorated performance of asphalt binder at high temperature by incorporating hydrochar was verified by various criteria such as higher performance grade (PG) failure temperature and lower non-recoverable creep compliance (Jnr). Moreover, higher reaction temperature makes hydrochar’s particles smaller and more homogeneous, which results in slightly lower enhanced high temperature performance, more satisfying workability, better storage stability, and greater anti-aging effect of hydrochar-modified asphalt. Eventually, this study provided a promising win-win solution to environment problems concerning corn stalk treatment and shortage of asphalt binder. Further exploration of methods to improve HCMA’s storage stability, real-scale corroboration on trial section and life cycle assessment of asphalt pavement containing hydrochar modifiers will be followed in the future.

On-Site Experimental Testing to Study the Vibration of Composite Floors

2014 ◽  
Vol 601 ◽  
pp. 231-234
Author(s):  
Cristian Lucian Ghindea ◽  
Dan Cretu ◽  
Monica Popescu ◽  
Radu Cruciat ◽  
Elena Tulei
Keyword(s):  
Dynamic Characteristics ◽  
Experimental Testing ◽  
Concrete Slab ◽  
Human Perception ◽  
Experimental Tests ◽  
International Standards ◽  
Structural Element ◽  
Element Analysis ◽  
Floor Slabs ◽  
Composite Floors

As a general trend, in order to reduce material consumption or to reduce the mass of the structures, composite floor slabs solutions are used to achieve large spans floor slabs. This solutions led to floors sensitive to vibrations induced generally by human activities. As a verification of the design concepts of the composite floors, usually, it is recommended a further examination of the floor after completion by experimental tests. Although the experimental values of the dynamic response of the floor are uniquely determined, the processing can take two directions of evaluation. The first direction consist in determining the dynamic characteristics of the floor and their comparison with the design values. Another way that can be followed in the processing of the experimental results is to consider the human perception and comfort to the vibration on floors. The paper aims to present a case study on a composite floor, with steel beams and concrete slab, tested on-site. Both aspects of data processing are analyzed, in terms of the structural element, and in terms of the effect on human perception and comfort. Experimentally obtained values for the dynamic characteristics of the floor are compared with numerical values from finite element analysis, while the second type of characteristic values are compared with various human comfort threshold values found in international standards.

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