A High-Pressure Window for Volumetric Solar Receivers

1998 ◽  
Vol 120 (2) ◽  
pp. 101-107 ◽  
Author(s):  
J. Karni ◽  
A. Kribus ◽  
B. Ostraich ◽  
E. Kochavi
Keyword(s):  
High Pressure ◽  
Thermal Analyses ◽  
Life Time ◽  
Elevated Pressure ◽  
Fused Silica ◽  
Working Fluid ◽  
Operating Pressure ◽  
Accelerated Life ◽  
Solar Receiver

The absorbing matrix of a volumetric (directly irradiated) solar receiver must be exposed to the concentrated incoming sunlight. Most applications require that the receiver operates at an elevated pressure and in many cases the working fluid is not air. These requirements can be met only if the receiver is equipped with a transparent window. A novel frustum-like high-pressure (FLHiP) window, made of fused silica, is presented. Optical, mechanical, and thermal analyses, over 1,000 hours of accelerated life-time tests and several hundred hours of tests in a solar receiver, show that this window satisfies the required criteria for operation in a volumetric solar receiver, whose operating pressure and peak absorber temperature reach 30 bar and 1700°C, respectively.

The DIAPR: A High-Pressure, High-Temperature Solar Receiver

1997 ◽  
Vol 119 (1) ◽  
pp. 74-78 ◽  
Author(s):  
J. Karni ◽  
A. Kribus ◽  
P. Doron ◽  
R. Rubin ◽  
A. Fiterman ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
High Performance ◽  
Fused Silica ◽  
Solid Particles ◽  
Working Fluid ◽  
Thermochemical Process ◽  
Working Medium ◽  
Main Components ◽  
Solar Receiver

A solar central receiver absorbs concentrated sunlight and transfers its energy to a working medium (gas, liquid or solid particles), either in a thermal or a thermochemical process. Various attractive high-performance applications require the solar receiver to supply the working fluid at high temperature (900–1500°C) and high pressure (10–35 bar). As the inner receiver temperature may be well over 1000°C, sunlight concentration at its aperture must be high (4–8 MW/m2), to minimize aperture size and reradiation losses. The Directly Irradiated Annular Pressurized Receiver (DIAPR) is a volumetric (directly irradiated), windowed cavity receiver that operates at aperture flux of up to 10 MW/m2. It is capable of supplying hot gas at a pressure of 10–30 bar and exit temperature of up to 1300°C. The three main innovative components of this receiver are: • a Porcupine absorber, made of a high-temperature ceramic (e.g., alumina); • a Frustum-Like High-Pressure (FLHIP) window, made of fused silica; • a two-stage secondary concentrator followed by the KohinOr light extractor. This paper presents the design principles of the DIAPR, its structure and main components, and examples of experimental and computational results.

Accelerated life time testing of fused silica upon ArF laser irradiation

2008 ◽  
Author(s):  
Ch. Mühlig ◽  
W. Triebel ◽  
S. Kufert ◽  
U. Natura
Keyword(s):  
Laser Irradiation ◽  
Life Time ◽  
Fused Silica ◽  
Accelerated Life ◽  
Arf Laser

Numerical Design of a High-Flux Microchannel Solar Receiver

2013 ◽  
Author(s):  
Charles J. Rymal ◽  
Sourabh V. Apte ◽  
Vinod Narayanan ◽  
Kevin Drost
Keyword(s):  
Pressure Drop ◽  
Cross Section ◽  
Thermal Stresses ◽  
Computational Study ◽  
Rectangular Cross Section ◽  
Working Fluid ◽  
Operating Pressure ◽  
Pin Fin ◽  
Fin Design ◽  
Solar Receiver

This computational study investigates design of microchannel based solar receiver for use in concentrated solar power. A design consisting of a planar array of channels with solar flux incident on one side and using supercritical carbon dioxide as the working fluid is sought. Use of microchannels is investigated as they offer enhanced heat transfer in solar receivers and have the potential to dramatically reduce the size and increase the performance. Designs are investigated for an incident heat flux of 1 MW/m2, up to 3.3 times that of current solar receivers [1], resulting in significant reduction of size and cost. The goal is to design a microchannel receiver with inlet and outlet temperatures of the working fluid of 500°C and 650°C, operating pressure of 100 bar, pressure drop less than 0.35 bar and surface efficiency greater than 90% defined by radiation and convection losses to the environment. Three micro-channel designs are considered: rectangular cross section with high and low aspect ratio (designs A and B) and rectangular cross section with an array of micro pin-fins of various shape spanning the height of the channel (design C). Numerical simulations are performed on individual channels and on a unit cell of the pin-fin design. Structural analysis is performed to ensure that the design can withstand the operating pressure and thermal stresses. The effects of flow maldistribution and header system in an array of channels are also investigated. Preliminary results show that all three designs are capable of meeting the requirements, with the pin-fin design having the lowest pressure drop and highest efficiency.

INFLUENCE OF WORKING FLUID ON THERMAL PERFORMANCE OF THERMOSYPHONS FOR APPLICATION IN HIGH PRESSURE VACUUM TUBE SOLAR COLLECTORS

2020 ◽  
Author(s):  
Guilherme Antonio Bartmeyer ◽  
Victor Vaurek Dimbarre ◽  
Pedro Leineker Ochoski Machado ◽  
PAULO HENRIQUE DIAS DOS SANTOS ◽  
Thiago Antonini Alves
Keyword(s):  
High Pressure ◽  
Thermal Performance ◽  
Working Fluid ◽  
Solar Collectors ◽  
Vacuum Tube

scholarly journals The effect of high pressure treatment on the quality of chicken breast meat

2020 ◽  
Vol 14 (3-4) ◽  
pp. 76-81
Author(s):  
Nives Marušić Radovčić ◽  
Damir Ježek ◽  
Ksenija Markov ◽  
Jadranka Frece ◽  
Duška Ćurić ◽  
...  
Keyword(s):  
High Pressure ◽  
Treatment Time ◽  
Elevated Pressure ◽  
Quality Parameters ◽  
High Pressure Processing ◽  
Chicken Breast ◽  
Moisture Uptake ◽  
Breast Meat ◽  
Chicken Breast Meat ◽  
Cooking Yield

In the present work, the effect of high pressure processing (HPP) (0, 100, 200 and 300 MPa) and different treatment time (5 and 10 minutes) on the moisture uptake, cooking yield, colour and texture, as well as microbial population of chicken breast fillets was investigated. The application of high hydrostatic pressure resulted in a modification of quality parameters of chicken breast meat. By increasing pressure and time of the treatment the moisture uptake was reduced: samples treated with 300 MPa for 10 min had the lowest moisture uptake values. Cooking yield was not affected by HPP treatments. Increased pressure affected the colour by increasing L*, a* and b* values (only HPP treatment of 100 MPa in duration of 5 and 10 minutes did not affect colour of chicken breast meat). Lower pressures (100 and 200 MPa) tenderized, whereas elevated pressure (300 MPa) increased hardness in chicken breast fillets. Higher level of pressure (300 MPa) reduced bacteria count by about 3.0 – 5.3 log (CFU/g), depending on the microorganism and duration of the process.

Experimental and Numerical Analyses of a Pressurized Air Receiver for Solar-Driven Gas Turbines

2010 ◽  
Author(s):  
Illias Hischier ◽  
Pascal Leumann ◽  
Aldo Steinfeld
Keyword(s):  
Power Generation ◽  
Monte Carlo ◽  
Steady State ◽  
Gas Turbines ◽  
Porous Ceramic ◽  
Operating Pressure ◽  
Radiative Fluxes ◽  
Monte Carlo Techniques ◽  
Concentrated Solar Radiation ◽  
Solar Receiver

A high-temperature pressurized air-based receiver for power generation via solar-driven gas turbines is experimentally and theoretically examined. It consists of an annular reticulate porous ceramic (RPC) foam concentric with an inner cylindrical cavity-receiver exposed to concentrated solar radiation. Absorbed heat is transferred by combined conduction, radiation, and convection to the pressurized air flowing across the RPC. The governing steady-state mass, momentum and energy conservation equations are formulated and solved numerically by coupled Finite Volume and Monte Carlo techniques. Validation is accomplished with experimental results using a 1 kW solar receiver prototype subjected to average solar radiative fluxes in the range 1870–4360 kW m−2. Experimentation was carried out with air and helium as working fluids, heated from ambient temperature up to 1335 K at an absolute operating pressure of 5 bars.

scholarly journals In situ observation of phase changes of a silica-supported cobalt catalyst for the Fischer–Tropsch process by the development of a synchrotron-compatible in situ/operando powder X-ray diffraction cell

2018 ◽  
Vol 25 (6) ◽  
pp. 1673-1682 ◽  
Author(s):  
Adam S. Hoffman ◽  
Joseph A. Singh ◽  
Stacey F. Bent ◽  
Simon R. Bare
Keyword(s):  
High Pressure ◽  
Elevated Pressure ◽  
Phase Changes ◽  
In Situ Observation ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
X Ray ◽  
And Performance ◽  
Co Nanoparticles

In situ characterization of catalysts gives direct insight into the working state of the material. Here, the design and performance characteristics of a universal in situ synchrotron-compatible X-ray diffraction cell capable of operation at high temperature and high pressure, 1373 K, and 35 bar, respectively, are reported. Its performance is demonstrated by characterizing a cobalt-based catalyst used in a prototypical high-pressure catalytic reaction, the Fischer–Tropsch synthesis, using X-ray diffraction. Cobalt nanoparticles supported on silica were studied in situ during Fischer–Tropsch catalysis using syngas, H2 and CO, at 723 K and 20 bar. Post reaction, the Co nanoparticles were carburized at elevated pressure, demonstrating an increased rate of carburization compared with atmospheric studies.

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