Preliminary Design Development, Laboratory Testing, and Optimization of a 6.6 MW-Thermal All-Refractory Particle Heating Receiver

Heat receiver design is an essential portion of Concentrating Solar Power (CSP) plants, particularly within CSP systems that are particle based. Particle based CSP promises higher operating temperatures and more cost-effective thermal energy storage than existing systems. Two general types of Particle Heat Receivers (PHR) are under development, variations of the free-falling curtain concept being developed by Sandia National Labs and an obstructed flow concept being developed by King Saud University (KSU) and Georgia Institute of Technology (GIT)[1, 2]. The obstructed flow design utilizes specifically engineered obstacles placed in the flow path of the particles to remove momentum and kinetic energy and promote lateral and depth-wise mixing. This design is named the discrete structure or DS-PHR. This paper focuses on development and design work that has been done with the existing DS-PHR developed by GIT and KSU. Previous iterations of the DS-PHR have utilized obstruction materials that include simple metal meshes, and ceramic formed into an inverted V-shapes or chevrons. However, these previous designs have some shortfalls. The metallic mesh design has structural integrity issues under intense radiation, inherent in a DS-PHR. The ceramic chevrons have a disadvantageously thick leading edge, which may intercept too much radiation and overheat. Current development has continued with improvements to remedy the issues of the previous design work. Experience, modeling, and testing have shown that a cavity receiver is preferred to reduce heat and particle loss in the system. Recent work has been devoted to developing a Discrete Structure Refractory Particle Heat Receiver (DS-RPHR) suitable for cavity installation working with a north-located field. The simplest suitable configuration is 5 flat ceramic plates, or absorber panels, arranged in an arc, forming a 15° angle of inclination, to improve particle retention in the system. To increase particle residence time, quartz rods are placed onto the back plane of the DS-PHR, in a hexagonal configuration. These serve as the momentum scrubbing obstructions as mentioned above. The performance of this design will be discussed in the following paper. This design has been extensively modeled using NREL’s Soltrace to evaluate thermal and optical performance. Modeling has shown high thermal efficiency in the design, as well as promising heat flux profiles across the receiver. Currently at KSU, a 300 kW-thermal testing facility has been constructed and used for high temperature testing. The final proposed 6.6 MW-thermal design, called the pre-commercial demonstration, will be built at a site owned and operated by Saudi Electric Company, in Waad Al-Shamal, 20 kilometers east of Tuarif, Saudi Arabi.

Artistic features of discrete structure in german novel

The article deals with the key stages of the formation and development of German fragmentary prose in the 19th–20th centuries. Using the materials from German novels of the 20th century, the authors analyze the artistic devices that motivate the discreteness of the narrative and determine their artistic function – the manifestation and structuring of aesthetic information. Based on the analysis of artistic devices, the aesthetic content of the discrete novel structure is identified which depends on the writers' worldview. The discrete structure has proven to be a universal art form that has shaped the typological features of the modern novel.

COMPOUND PROPOSITIONAL LAW FOR LOGICAL EQUIVALENCE, TAUTOLOGY AND CONTRADICTION

This paper presents a Compound Propositional Law for Logical Equivalence, Tautology and Contradiction. The proposed Law is developed with the help of negation, disjunction, conjunction, exclusive or, conditional statement and bi-conditional statement. The idea of research is taken from de-Morgan law. This proposed law is important and useful for Logical Equivalence, Tautology and Contradiction for the research purpose because these are the rare cases in the field of research. This article aims to help readers understand the compound proposition and proposition equivalence in conducting research. This article discusses propositions that are relevant for proposition equivalence. Six main compound propositions are distinguished and an overview is given in the article. Hence, it is observed from the result and discussion that the compound proposition law is a good achievement in discrete structure for the logical Equivalence, Tautology and Contradiction purpose.

Use of Physical Concepts in Musical Instruments and their Use in Cinema

Cinema without music is now a days beyond imagination. Whatever musical instruments used in the making of Cinema are based on Physical Concepts. One of the concepts is frequency. Frequency is nothing but the number of vibrations per second. Different frequencies forms melodious compositions. There are many musical instruments like Pan flute, Sitar, Violin, Harmonium etc are all Physical Concepts dependent musical instruments. How Physical Concepts play important role in the making of such musical instruments is presented in this paper. Unwanted continuous disturbance due to vibrations in air is noise and composition disturbance of different frequencies called sound. Music is sound with a discrete structure. Noise is sound with a continuous structure. Music is composed of sounds with a fundamental frequency and overtones. Noise is composed of sounds with frequencies that range continuously in value from as low as you can hear to as high as you can hear — not necessarily at equal intensity

Multi-Objective Optimization of Spatially Truss Structures Based on Node Movement

This paper discusses the solutions for topology optimization of spatially discrete structures. The optimization objects are the structural weight and the maximum displacement. The optimization variables include structural node coordinates, and the improved MOEA (Multi-objective Evolutionary Algorithm) method is used to optimize the structure. The innovation of this study is that it breaks through the shortage of constant node position in the optimization thought of traditionally discrete structure in the “Ground Structure Approach” and uses the coordinate of the node as the optimization variable for the optimization calculation. The result is not a single one but a set of optimal solutions through the evolution (i.e., Pareto optimal solutions); on this basis, the most suitable solution can be found according to the boundary conditions or other related requirements. Using the C# language to compile the calculation program, ANSYS finite element software is used to analyze the structure, and the Pareto front surface was automatically drawn to determine the optimal layout form of the discrete structure. The analysis results show that the improved MOEA method can provide an effective method to solve such optimization problems.

Preliminary Design of an All-Ceramic Discrete-Structure Particle Heating Receiver

Discrete structure particle heating receivers (DS-PHR), as used in concentrated solar power (CSP) systems, employ suitable discrete porous structures to intermittently halt the falling particles to control the speed and increase the residence time of falling particulates, thereby increasing the temperature rise of particulates exiting the DS-PHR. Previous designs of DS-PHRs have considered both porous foam structures, which have mass flux limits, and metal wire meshes, which are effective but have temperature and other functional limitations. This paper recounts recent studies at Georgia Tech and King Saud University that have investigated the use of ceramic tiles made porous by discrete slot-shaped passages in place of previous metal wire meshes. Currently, for experimental use, the slot-like passages are cut into the tiles by water jet, but operational units are expected to be formed into shape and fired by more economical conventional ceramic techniques. Benefits of ceramic and other refractory materials include higher temperature and heat flux limits at a reasonable cost. The tiles are expected to be installed in chevron configuration, which have been shown by experience to be especially effective, and these so-called ceramic chevrons have been shown to deliver adequate mass flux densities while still removing most of the kinetic energy from the particles. In addition, the thickness of the tile allows the incorporation of angled slots capable of redirecting the particle flow, adding a method to control particle mixing by purposefully directing the particulate streams. These enhanced slots are typically arranged with adequate spacing to allow for increased penetration of concentrated light into the depth of the falling bed of particles and may be angled to redirect hot particles toward the back plane of the DS-PHR. Both of these features should help minimize depthwise temperature variation. The testing reported here will focus on the degree of velocity and flow control that can be achieved by proper design of these ceramic chevrons as well as demonstrate the effectiveness of different designs on light penetration. Prior to this research, the effectiveness of ceramic obstructions might have been properly doubted because of the very high coefficient of restitution (COR) for the impact of ceramic particles on ceramic solids. In reality, it will be shown that a layer of particulates will form on a chevron, which effectively dissipates the kinetic energy of the impacting particles. Overall, this paper will report improvements in DS-PHR designs that can withstand high temperatures and fluxes, achieve additional control of particle flow, enhance particle mixing, and allow deeper penetration of light into the depth of the falling bed.

DEVELOPMENT OF A MODIFIED SELF-EXTENDING MIXTURE FOR INCREASING STABILITY OF ROCKS

Purpose. Search and analysis of rational forms of bottom rock strengthening at their block-discrete structure in the conditions of intensive raising in underground mine roadways. Method. The research methods used are a comprehensive approach, which includes: laboratory research on structural models, computer processing, analysis and interpretation of the results. Results. The urgency of the direction of increasing the stability of the rocks in bottom of the mine roadways by their local directional strengthening is indicated. The method of structural modelling conducted a series of studies on the installation, which was designed and assembled for the research. The influence of different schemes of strengthening block rocks in bottom of the mine roadways on the rock raising, vertical and horizontal convergence is determined. By comparing the areas of displaced rocks, calculated using a graphical editor, a conclusion was made about the effectiveness of each of the comparative hardening schemes. As a result, the scheme of hardening is determined, which allows restraining as much as possible the displacement of rocks into the roadway cavity. Scientific novelty. As a result of research it was found that when creating a bottom of the mine roadways, which is maintained in the conditions of repeated violation of its equilibrium state, a fortified zone in the form of a straight prism with the triangle of its base facing the bottom of the roadways, the volume of rocks extruded less than for the no-action model. The given form of the strengthened zone is the most effective. Practical meaning. A new method of local strengthening of bottom rocks, which can be represented by a block inhomogeneous medium, has been developed.