Structural Design and Analysis of the Toroidal Heliostat

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Chuncheng Zang ◽  
Zhifeng Wang ◽  
Wenfeng Liang ◽  
Xiaoyu Wang

Heliostat is an important component in the solar power tower station because its cost, optical performance, and mechanical performance have great influence on the overall property evaluation of the station. The T-shape heliostat tracking the sun in the azimuth-elevation mode has been commonly developed and successfully applied in many stations. In recent years, some researchers have developed spinning-elevation heliostats and have analyzed their optical performance. In this paper, the structure of a 16 m2 toroidal heliostat tracking the sun in the spinning-elevation mode is designed, and the mechanical performance of the structure under wind load is analyzed by means of the finite element method. The trends of force, moments, and vibration modes with the change in elevation have been presented, and the classic status is analyzed in detail when their maximum values occur. Furthermore, the advantages and disadvantages of a toroidal heliostat in reducing the cost are discussed compared with those of a traditional T-shape heliostat.

2013 ◽  
Vol 438-439 ◽  
pp. 819-823 ◽  
Author(s):  
Wen Feng Du ◽  
Zheng Hao Zhu ◽  
Li Ming Zhu

Basing on the practical engineering of elliptic paraboloid roof structural design in Qinyang Stadium, four structural schemes such as suspend-dome, single-layer latticed shell, double-layer latticed shell and rigid suspend-dome, are calculated and designed respectively. After satisfying the requirements of strength, stiffness and stability, the quantity of steel is compared. The advantages and disadvantages on mechanical performance, construction and cost of four schemes are discussed. Results of comparison provide the accordance for the final decision of structural schemes of Qinyang Stadium and can be referenced by other similar practical engineers.


2020 ◽  
Vol 26 (3) ◽  
pp. 685-697
Author(s):  
O.V. Shimko

Subject. The study analyzes generally accepted approaches to assessing the value of companies on the basis of financial statement data of ExxonMobil, Chevron, ConocoPhillips, Occidental Petroleum, Devon Energy, Anadarko Petroleum, EOG Resources, Apache, Marathon Oil, Imperial Oil, Suncor Energy, Husky Energy, Canadian Natural Resources, Royal Dutch Shell, Gazprom, Rosneft, LUKOIL, and others, for 1999—2018. Objectives. The aim is to determine the specifics of using the methods of cost, DFC, and comparative approaches to assessing the value of share capital of oil and gas companies. Methods. The study employs methods of statistical analysis and generalization of materials of scientific articles and official annual reports on the results of financial and economic activities of the largest public oil and gas corporations. Results. Based on the results of a comprehensive analysis, I identified advantages and disadvantages of standard approaches to assessing the value of oil and gas producers. Conclusions. The paper describes pros and cons of the said approaches. For instance, the cost approach is acceptable for assessing the minimum cost of small companies in the industry. The DFC-based approach complicates the reliability of medium-term forecasts for oil prices due to fluctuations in oil prices inherent in the industry, on which the net profit and free cash flow of companies depend to a large extent. The comparative approach enables to quickly determine the range of possible value of the corporation based on transactions data and current market situation.


2017 ◽  
Vol 31 (2) ◽  
pp. 82-89
Author(s):  
E. S. Epifanov

This article presents a classification of major factors that shape the cost of Internet site. Also discusses the limitations in determining the objectives of the web site; advantages and disadvantages of different factors.


2021 ◽  
Vol 11 (16) ◽  
pp. 7246
Author(s):  
Julius Moritz Berges ◽  
Georg Jacobs ◽  
Sebastian Stein ◽  
Jonathan Sprehe

Locally load-optimized fiber-based composites, the so-called tailored textiles (TT), offer the potential to reduce weight and cost compared to conventional fiber-reinforced plastics (FRP). However, the design of TT has a higher complexity compared to FRP. Current approaches, focusing on solving this complexity for multiple objectives (cost, weight, stiffness), require great effort and calculation time, which makes them unsuitable for serial applications. Therefore, in this paper, an approach for the efficient creation of simplified TT concept designs is presented. By combining simplified models for structural design and cost estimation, the most promising concepts, regarding the cost, weight, and stiffness of TT parts, can be identified. By performing a parameter study, the cost, weight, and stiffness optima of a sample part compared to a conventional FRP component can be determined. The cost and weight were reduced by 30% for the same stiffness. Applying this approach at an early stage of product development reduces the initial complexity of the subsequent detailed engineering design, e.g., by applying methods from the state of the art.


2021 ◽  
Vol 13 (6) ◽  
pp. 3535
Author(s):  
Byung-Ju Jeon ◽  
Byung-Soo Kim

The Korean government proposed a goal to reduce its greenhouse gas emissions by 37% compared to business-as-usual levels by 2030 and launched the Green Standard for Energy and Environmental Design (G-SEED) certification system. The certification requires meeting the required score and material selection with a secured economy and construction efficiency. However, most buildings only focus on obtaining the certification scores instead of choosing economical materials with high construction efficiency. This research focused on developing a material selection model that considers both the construction efficiency and economy of the materials and the acquisition of material and resource evaluation scores from the G-SEED certification. This research, therefore, analyzed actual data to automate the material selection and compare alternatives to using a genetic algorithm to obtain optimized alternatives. This model proposes an alternative to constructability and economy when the required score and material information is entered. When the model was applied to actual cases, the result revealed a reduction in construction costs of about 37% compared to the cost with the traditional methods. The material selection model from this research can benefit construction project owners in terms of cost reduction, designers in terms of structural design time, and constructors in terms of construction efficiency


2021 ◽  
Vol 22 (9) ◽  
pp. 4688
Author(s):  
Mootaz M. Salman ◽  
Zaid Al-Obaidi ◽  
Philip Kitchen ◽  
Andrea Loreto ◽  
Roslyn M. Bill ◽  
...  

Neurodegenerative diseases (NDs) including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and Huntington’s disease are incurable and affect millions of people worldwide. The development of treatments for this unmet clinical need is a major global research challenge. Computer-aided drug design (CADD) methods minimize the huge number of ligands that could be screened in biological assays, reducing the cost, time, and effort required to develop new drugs. In this review, we provide an introduction to CADD and examine the progress in applying CADD and other molecular docking studies to NDs. We provide an updated overview of potential therapeutic targets for various NDs and discuss some of the advantages and disadvantages of these tools.


Author(s):  
Daniel J. Chapman ◽  
Diego A. Arias

Solar brightness profiles were used to model the optical performance of a parabolic linear solar concentrator. A sensitivity analysis of the sun size on collector performance was completed using analytical methods. Ray traces were created for solar brightness profiles having circumsolar ratios from 0–40%, slope errors of the optical surface from 2–5 mrads, and angles of incidence varying from 0–60 degrees. Using typical meteorological data for two locations, the optical performance was calculated and averaged over a year. Intercept factors of these simulations were compared to simpler analytical models that cast the sun shape as a Gaussian function. Results showed that collector performance is relatively insensitive to solar profile, and that using a representative Gaussian solar profile will tend to underestimate collector performance compared to using exact weighted solar profiles by about 1%. This difference is within the uncertainty propagation of the intercept factor calculated with analytical methods.


Author(s):  
Hairui Wang ◽  
Chunfang Guo ◽  
Yujie Li ◽  
Yahua Liu ◽  
Minjie Wang ◽  
...  

With the advantage of high adaptability, Miura-origami structure with curvature shows various engineering applications such as a sandwich between two stiff facings with curvature requirements and structural support to form a circular tube. In this research, a forming method of polymer circular tube with single-curved surface origami expressed by five parameters was established and its corresponding theory was solved considering forming rationality in actual manufacturing. The components of circular tube were fabricated by the vacuum forming process and then spliced together. We conducted numerical simulation to analyze the structural performance of the tube with five parameters and shown that these parameters have a great influence on energy absorbed performance. Finally, a male mold of a part with Arc Miura-origami structure was designed and fabricated. The parts with Arc Miura-origami were manufactured using vacuum forming process and then spliced and bonded together into a two-layer tube. This research may provide a method to design and fabricate Miura-origami structure with high efficiency and quality.


2014 ◽  
Author(s):  
Upendra Malla ◽  
Krishna M. Karri

Floating Production Storage and Offloading (FPSO) sizing and cost estimation has become a challenging task at the early stages of offshore field development. During the early stages of field development designer needs to size and estimate cost in order to decide feasibility of the project. This paper describes a step by step method used to size and estimate the cost of a new built (or) converted FPSO based on basic engineering, existing FPSO data and corresponding metocean criteria for a particular location. This step by step approach covers FPSO sizing, hull structural design, mooring sizing, topsides support design and steel renewal using offshore classification rules and regulations. FPSO cost is estimated based on the design particulars (i.e. hull weights, FPSO particulars, mooring sizes etc.) and current market unit rates. This approach is an effective means to size and estimate cost of an FPSO at early stages of field development which saves overall time and cost for a client.


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