Cost Optimum Parameters for Rock Bed Thermal Storage at 550–600 °C: A Parametric Study

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Kenneth Allen ◽  
Lukas Heller ◽  
Theodor von Backström
Keyword(s):  
Parametric Study ◽  
Particle Diameter ◽  
Thermal Storage ◽  
Design Parameters ◽  
Levelized Cost Of Electricity ◽  
United States Dollar ◽  
Capital Costs ◽  
Mass Fluxes ◽  
Rock Bed ◽  
Biot Numbers

A major advantage of concentrating solar power (CSP) plants is their ability to store thermal energy at a cost far lower than that of current battery technologies. A recent techno-economic study found that packed rock bed thermal storage systems can be constructed with capital costs of less than 10 United States dollar (USD)/kWht, significantly cheaper than the two-tank molten salt thermal storage currently used in CSP plants (about 22–30 USD/kWht). However, little work has been published on determining optimum rock bed design parameters in the context of a CSP plant. The parametric study in this paper is intended to provide an overview of the bed flow lengths, particle sizes, mass fluxes, and Biot numbers which are expected to minimize the levelized cost of electricity (LCOE) for a central receiver CSP plant with a nominal storage capacity of 12 h. The findings show that rock diameters of 20–25 mm will usually give LCOE values at or very close to the minimum LCOE for the combined rock bed and CSP plant. Biot numbers between 0.1 and 0.2 are shown to have little influence on the position of the optimum (with respect to particle diameter) for all practical purposes. Optimum bed lengths are dependent on the Biot number and range between 3 and 10 m for a particle diameter of 20 mm.

Parametric Study of an Innovative Counter-Flow Heat Exchanger

2010 ◽  
Author(s):  
Luciano Andrea Catalano ◽  
Fabio De Bellis ◽  
Riccardo Amirante
Keyword(s):  
Heat Exchanger ◽  
Parametric Study ◽  
Particle Diameter ◽  
Solid Particles ◽  
Sensitivity Analyses ◽  
Design Parameters ◽  
Counter Flow ◽  
Pipe Length ◽  
Specific Heats ◽  
High Efficient

An innovative Counter-Flow Sand Heat Exchanger (CFS-HX) is proposed, which makes use of very small solid particles as intermediate medium to perform heat transfer between two gas flows at different temperature. The potential of the CFS-HX was already demonstrated by the authors, both theoretically and experimentally. In this work, a parametric study has been employed in order to explore the capabilities of the proposed heat exchanger. A 1D model (validated by experiments) has been extensively used to perform sensitivity analyses with respect to the major design parameters, i.e.: specific heats, gas and sand densities, particle diameter, prescribed efficiency. Pipe length to obtain a prescribed heat exchanger efficiency has been calculated for a large number of configurations and results have been compared with a baseline case. The proposed computations show that a high efficient heat exchange can be obtained with relatively short pipes and with negligible pressure drop.

Modeling drive wheels of hoisting machines with rubber cables

2020 ◽  
pp. 105-114
Author(s):  
V. E. Perekutnev ◽  
V. V. Zotov
Keyword(s):  
Stress State ◽  
Safety Factor ◽  
Numerical Models ◽  
Design Parameters ◽  
Potential Range ◽  
Capital Costs ◽  
Reducing Gear ◽  
Reduce Risk ◽  
Steel Cables ◽  
Sidewall Surface

Upgrading of hoisting machines aims to improve their performance, to reduce risk of accidents, and to cut down operational and capital costs. One of the redesign solutions is replacement of steel cables by rubber cables. This novation can extend life of pulling members, decrease diameters of drive and guide wheels and, consequently, elements of the whole hoisting machines: rotor, reducing gear, motor. This engineering novation needs re-designing of hoisting machines; thus, the new design should be validated, in particular, strength characteristics of the machine members. This article considers a drive wheel of a hoisting machine with a pulling belt. In order to justify the potential range of design parameters with regard to safety factor, the numerical models of different-design drive wheels are developed and their operation with pulling belt (rubber cable) is simulated in the SolidWorks environment. The data on the stress state of the wheel elements are analyzed, the most loaded points are identified, and the maximal stresses on the sidewall surface and in the spokes of wheels of different designs are plotted.

Seismic stability analyses of reinforced tapered landfill cover systems considering seepage forces

2018 ◽  
Vol 36 (4) ◽  
pp. 361-372 ◽  
Author(s):  
Afshin Khoshand ◽  
Ali Fathi ◽  
Milad Zoghi ◽  
Hamidreza Kamalan
Keyword(s):  
Parametric Study ◽  
Limit Equilibrium ◽  
Practical Method ◽  
Seismic Stability ◽  
Design Parameters ◽  
Cover System ◽  
Landfill Cover ◽  
Cover Systems ◽  
Landfill Cover System ◽  
The Stability

One of the most common and economical methods for waste disposal is landfilling. The landfill cover system is one of the main components of landfills which prevents waste exposure to the environment by creating a barrier between the waste and the surrounding environment. The stability and integrity of the landfill cover system is a fundamental part of the design, construction, and maintenance of landfills. A reinforced tapered landfill cover system can be considered as a practical method for improving its stability; however, the simultaneous effects of seismic and seepage forces in the reinforced tapered landfill cover system have not been studied. The current paper provides a solution based on the limit equilibrium method in order to evaluate the stability of a reinforced tapered landfill cover system under seismic and seepage (both horizontal and parallel seepage force patterns) loading conditions. The proposed analytical approach is applied to different design cases through parametric study and the obtained results are compared to those derived from literature. Parametric study is performed to illustrate the sensitivity of the safety factor (FS) to the different design parameters. The obtained results reveal that parameters which describe the geometry have limited effects on the stability of the landfill cover system in comparison to the rest of the studied design parameters. Moreover, the comparisons between the derived results and available methods demonstrate good agreement between obtained findings with those reported in the literature.

scholarly journals ARMOUR UNIT STRUCTURAL RESPONSE - A PARAMETRIC STUDY

1988 ◽  
Vol 1 (21) ◽  
pp. 176
Author(s):  
C. David Anglin ◽  
William F. Baird ◽  
Etienne P.D. Mansard ◽  
R. Douglas Scott ◽  
David J. Turcke
Keyword(s):  
Wave Height ◽  
Parametric Study ◽  
Structural Integrity ◽  
Design Procedure ◽  
Structural Response ◽  
Design Parameters ◽  
Coastal Structures ◽  
Log Normal ◽  
Wave Induced ◽  
Hydraulic Stability

There is a general lack of knowledge regarding the nature and magnitude of loads acting on armour units used for the protection of rubblemound coastal structures. Thus, a comprehensive design procedure incorporating both the hydraulic stability and the structural integrity of the armour units does not exist. This paper presents the results of a detailed parametric study of the structural response of armour units to wave-induced loading in a physical breakwater model. The effect of the following design parameters is investigated: breakwater slope, armour unit location, wave period and wave height. This research has made a number of significant contributions towards the development of a comprehensive design procedure for concrete armour units. It has identified a linear relationship between the wave-induced stress in the armour units and the incident wave height. In addition, it has shown that the conditional probability of waveinduced stress given wave height can be estimated by a log-normal distribution. Finally, a preliminary design chart has been developed which incorporates both the structural integrity and the hydraulic stability of the armour units.

Parametric Design of a Waterjet Pump by Means of Inverse Design, CFD Calculations and Experimental Analyses

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Duccio Bonaiuti ◽  
Mehrdad Zangeneh ◽  
Reima Aartojarvi ◽  
Jonas Eriksson
Keyword(s):  
Flow Field ◽  
Parametric Study ◽  
Parametric Design ◽  
Inverse Design ◽  
Design Parameters ◽  
Pump Design ◽  
Hydrodynamic Efficiency ◽  
Numerical Predictions ◽  
High Level ◽  
Suction Performance

The present paper describes the parametric design of a mixed-flow water-jet pump. The pump impeller and diffuser geometries were parameterized by means of an inverse design method, while CFD analyses were performed to assess the hydrodynamic and suction performance of the different design configurations that were investigated. An initial pump design was first generated and used as baseline for the parametric study. The effect of several design parameters was then analyzed in order to determine their effect on the pump performance. The use of a blade parameterization, based on inverse design, led to a major advantage in this study, because the three-dimensional blade shape is described by means of hydrodynamic parameters, such as blade loading, which has a direct impact on the hydrodynamic flow field. On the basis of this study, an optimal configuration was designed with the aim of maximizing the pump suction performance, while at the same time, guaranteeing a high level of hydrodynamic efficiency, together with the required mechanical and vibrational constraints. The final design was experimentally tested, and the good agreement between numerical predictions and experimental results validated the design process. This paper highlights the contrasting requirements in the pump design in order to achieve high hydrodynamic efficiency or good cavitation performance. The parametric study allowed us to determine design guidelines in order to find the optimal compromise in the pump design, in cases where both a high level of efficiency and suction performance must simultaneously be achieved. The design know-how developed in this study is based on flow field analyses and on hydrodynamic design parameters. It has therefore a general validity and can be used for similar design applications.

Parametric Study on the Fluid Elastic Instability Factor of the Fuel Rod for a PWR Plant

2010 ◽  
Author(s):  
Hyeong Koo Kim ◽  
Sang Youn Jeon ◽  
Kyou Seok Lee ◽  
Jeong Ha Kim ◽  
Sang Jong Lee
Keyword(s):  
Parametric Study ◽  
The Other ◽  
Design Parameters ◽  
Elastic Instability ◽  
Direct Relation ◽  
Spacer Grid ◽  
Fuel Rod ◽  
Flow Mixing ◽  
Fuel Design ◽  
Instability Factor

The main objective of this study is to estimate the effects of some considerable fuel design parameters on the fluid elastic instability behavior of the fuel rod. For the estimation, 6 fuel design parameters which seem to have direct relation with fluid elastic instability behavior of the fuel rod have been selected and examined using the PLUS7 fuel rod for OPR1000 PWR plants in Korea. Those are fuel rod creep-down, spacer grid stiffness, spacer grid spring relaxation, inactive spacer grid spring, intermediate flow mixing grid effect and fuel rod damping. As a result, the fluid elastic instability factors are insensitive with spacer grid stiffness, relaxation and intermediate flow mixing grid effect, but the other parameters need to be controlled and evaluated appropriately to maintain stability with proper margins.

Parametric study of a solar air heater with and without thermal storage for solar drying applications

2000 ◽  
Vol 21 (3-4) ◽  
pp. 505-522 ◽  
Author(s):  
S. Aboul-Enein ◽  
A.A. El-Sebaii ◽  
M.R.I. Ramadan ◽  
H.G. El-Gohary
Keyword(s):  
Parametric Study ◽  
Thermal Storage ◽  
Solar Air Heater ◽  
Solar Drying ◽  
Air Heater

Computational models of a rock-bed thermal storage unit

1987 ◽  
Vol 4 (2) ◽  
pp. 215-218 ◽  
Author(s):  
Omar Zarty ◽  
Awatef El Juddaimi
Keyword(s):  
Computational Models ◽  
Thermal Storage ◽  
Storage Unit ◽  
Rock Bed

Optimal Design of a Rotating Bar for Kinetic Energy Storage

1989 ◽  
Vol 111 (1) ◽  
pp. 94-99
Author(s):  
M. Berger ◽  
I. Porat
Keyword(s):  
Optimal Design ◽  
Kinetic Energy ◽  
Upper Bound ◽  
Parametric Study ◽  
Optimal Designs ◽  
Design Parameters ◽  
A Value ◽  
Optimal Profile ◽  
Thin Ring ◽  
General Configuration

A thin homogeneous rotating bar of variable width is considered for the purpose of storing kinetic energy. The objective of the design is to find the shape of the bar for which, in the presence of constraints on the geometry and strength of the bar, the Specific Kinetic Energy (SKE) is maximal. An upper bound for the SKE of a finite length bar is derived and a discrete formulation is presented by which an approximate optimal profile for arbitrary design parameters and rotational speeds can be obtained numerically. Applying a parametric study, in which optimal designs for a sequence of rotational speeds were observed, a general configuration of the exact optimal profile was concluded. The parametric study reveals the existence of three speed intervals, each characterized by a common type of optimal design. The optimal SKE corresponding to the ultimate rotational speed reaches a value very close to the theoretical upper bound, namely, that of a thin ring. The model gives insight into the nature of optimal designs and serves as a simple and rapid computational tool for finding the optimal profile for arbitrary bar parameters and rotational speeds.

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