Window design for a Small Particle Solar Receiver

2011 ◽  
Author(s):  
Onkar Mande ◽  
Fletcher Miller
Keyword(s):  
Small Particle ◽  
Solar Receiver ◽  
Window Design

Three-Dimensional Fluid Dynamics and Radiative Heat Transfer Modeling of a Small Particle Solar Receiver

2013 ◽  
Author(s):  
Pablo Fernández del Campo ◽  
Fletcher Miller ◽  
Adam Crocker
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Small Particle ◽  
Radiative Heat ◽  
Three Dimensional ◽  
Solar Irradiation ◽  
Ansys Fluent ◽  
Solar Receiver

We present an investigation of the effects of the solar irradiation and mass flow conditions on the behavior of a Small Particle Solar Receiver employing our new, three-dimensional coupled fluid flow and radiative heat transfer model. This research expands on previous work conducted by our group and utilizes improved software with a set of new features that allows performing more flexible simulations and obtaining more accurate results. For the first time, it is possible not only to accurately predict the overall efficiency and the wall temperature distribution of the solar receiver, but also to determine the effect on the receiver of the window, the outlet tube, real solar irradiation from a heliostat field, non-cylindrical geometries and 3-D effects. This way, a much better understanding of the receiver’s capabilities is obtained. While the previous models were useful to observe simple trends, this new software is flexible and accurate enough to eventually act as a design and optimization tool for the actual receiver. The solution procedure relies on the coupling of the CFD package ANSYS Fluent to our in-house Monte Carlo Ray Trace (MCRT) software. On the one hand, ANSYS Fluent is utilized as the mass-, momentum- and energy-equation solver and requires the divergence of the radiative heat flux, which constitutes a source term of the energy equation. On the other hand, the MCRT software calculates the radiation heat transfer in the solar receiver and needs the temperature field to do so. By virtue of the coupled nature of the problem, both codes should provide feed-back to each other and iterate until convergence. The coupling between ANSYS Fluent and our in-house MCRT code is done via User-Defined Functions. After developing the mathematical model, setting up and validating the software, and optimizing the coupled solution procedure, the receiver has been simulated under fifteen different solar irradiation and mass flow rate cross combinations. Among other results, the behavior of the receiver at different times of the day and the optimum mass flow rate as a function of the solar thermal input are presented. On an average day, the thermal efficiency of the receiver is found to be over 89% and the outlet temperature over 1250 K at all times from 7:30 AM to 4:00 PM (Albuquerque, NM) by properly adapting the mass flow rate. The origin of the losses and how to improve the efficiency of the Small Particle Solar Receiver are discussed as well.

Theoretical analysis of a high-temperature small-particle solar receiver

1991 ◽  
Vol 24 (1-4) ◽  
pp. 210-221 ◽  
Author(s):  
Fletcher Miller ◽  
Roland Koenigsdorff
Keyword(s):  
High Temperature ◽  
Theoretical Analysis ◽  
Small Particle ◽  
Solar Receiver

scholarly journals Design Space Exploration of a 5 MWth Small Particle Solar Receiver

2014 ◽  
Vol 49 ◽  
pp. 344-353 ◽  
Author(s):  
P. Fernández ◽  
F. Miller ◽  
M. McDowell ◽  
A. Hunt
Keyword(s):  
Small Particle ◽  
Design Space Exploration ◽  
Design Space ◽  
Space Exploration ◽  
Solar Receiver

SREM observation of the interaction between the in-situ deposited Pd small particles and MgO cleavage surface

1986 ◽  
Vol 44 ◽  
pp. 382-383
Author(s):  
H.-J. Ou
Keyword(s):  
Electron Microscopy ◽  
Small Particle ◽  
Small Particles ◽  
Cleavage Surface ◽  
Metallic Particles ◽  
Microscopy Technique ◽  
Ceramic Surfaces ◽  
Reflection Electron Microscopy ◽  
New Perspective

The understanding of the interactions between the small metallic particles and ceramic surfaces has been studied by many catalyst scientists. We had developed Scanning Reflection Electron Microscopy technique to study surface structure of MgO hulk cleaved surface and the interaction with the small particle of metals. Resolutions of 10Å has shown the periodic array of surface atomic steps on MgO. The SREM observation of the interaction between the metallic particles and the surface may provide a new perspective on such processes.

Window design for a professional workstation in the office environment

1984 ◽  
Author(s):  
J. Thomas Murray ◽  
Markku T. Hakkinen ◽  
James D. Mackraz
Keyword(s):  
Office Environment ◽  
Window Design

Review of the Current State and Future Development in Standardizing Natural Lighting in Interiors

2018 ◽  
pp. 5-26 ◽  
Author(s):  
Stanislav Darula
Keyword(s):  
Human Life ◽  
Natural Light ◽  
Artificial Lighting ◽  
Computer Tools ◽  
Natural Lighting ◽  
Current State ◽  
Minimum Requirements ◽  
Life On Earth ◽  
Window Design

Three elements mainly wind, water and sun seemed to determine in ancient ages the basic phenomena of life on Earth. Architectural history documented the importance of sun influence on urban and building construction already in layouts of Mesopotamian and Greek houses. Not only sun radiation but especially daylight played a significant role in the creation of indoor environment. Later, in the 20th century, a search of interaction between human life in buildings and natural conditions were studied considering well­being and energy conscious design recently using computer tools in complex research and more detail interdisciplinary solutions. At the same time the restricted daytime availability of natural light was supplemented by more efficient and continually cheaper artificial lighting of interiors. There are two main approaches to standardize the design and evaluation of indoor visual environment. The first is based on the determination of the minimum requirements respecting human health and visibility needs in all activities while the second emphasizes the behaviour and comfort of occupants in buildings considering year­around natural changes of physical quantities like light, temperature, noise and energy consumption. The new current standardization basis for daylight evaluation and window design criteria stimulate the study of methodology principles that historically were based on the overcast type of sky luminance pattern avoiding yearly availability of sky illuminance levels. New trends to base the daylight standardization on yearly or long­term availability of daylight are using the averages or median sky illuminance levels to characterise local climatological conditions. This paper offers the review and discussion about the principles of the natural light standardization with a short introduction to the history and current state, with a trial to focus on the possible development of lighting engineering and its standards in future.

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