Analysis of Heliostats' Rotation Around the Normal Axis for Solar Tower Field Optimization

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Erminia Leonardi ◽  
Lorenzo Pisani
Keyword(s):  
Total Energy ◽  
Collection Efficiency ◽  
Field Performance ◽  
Power Losses ◽  
Systematic Analysis ◽  
Blocking Effects ◽  
Solar Plant ◽  
Low Coverage ◽  
Solar Field ◽  
Two Sides

The design of a solar field is one of the crucial aspects when a solar tower system is realized. In general, shading and blocking effects, which are the main causes of solar power losses, are minimized displacing the heliostats each other quite distant, with typical land coverage less than 20%, and thus, strongly limiting the construction of these plants to low value lands. A new method is proposed here to improve the collected energy for solar tower systems with high land coverage (greater than 30%), based on the chance for each heliostat to rotate about the normal passing through the center of its surface. Then, shading and blocking are minimized by optimization of the relative orientations. To this aim, a small solar field composed of 150 rectangular flat heliostats has been considered, and its performances with and without the proposed optimization have been computed and compared for a wide variety of cases. In particular, a systematic analysis is presented to study the effect of the shape of the heliostats on the solar field performance: in a series of simulations, maintaining constant the area of each heliostat, the ratio between its two sides has been varied in a range between 1 (squared heliostats) and 3 (very stretched heliostats), and optimized and nonoptimized systems have been compared. Also, the total energy collected by the solar field has been calculated for optimized and nonoptimized heliostats' orientations, considering towers of different heights. Finally, the real PS10 solar plant has been considered, demonstrating that also for an optimized, very low coverage plant (about 14%), heliostats rotation can still improve the energy collection efficiency by a non-negligible amount.

Thermoeconomic Analysis of Combined Cycle Coupled With Parabolic Trough Solar Plant

2013 ◽  
Author(s):  
M. D. Duran ◽  
E. A. Rincón ◽  
I. Martínez ◽  
A. Lentz
Keyword(s):  
Optimum Design ◽  
Combined Cycle ◽  
Working Fluid ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Thermal Systems ◽  
Load Variations ◽  
Solar Plant ◽  
Combined Cycle Plant ◽  
Solar Field

Parabolic trough technology is currently one of the most extended solar thermal systems for the production of electricity. This paper describes a thermo-economic study of an integrated, combined-cycle parabolic trough power plant. The parabolic trough plant is considered an economizer or a superheater of the HRSG (heat recovery steam generator). The main objective is to obtain the optimum design of the different sections of the boiler and the size of the parabolic field. The configurations analyzed are two pressure levels with and without a reheater. A Euro Trough (ET) concentrator was used in this study, the working fluid being water with direct steam generation. There will be no problem with the evaporation in the absorber, since the solar plant will be the economizer of the HRSG and an approach point greater than 3°C is considered. The methodology applied for the optimization is Genetic Algorithms. This methodology was employed in previous works developed by the authors and yielded good results. So that method is applied to the configurations analyzed but including the parabolic trough plant. As a result, a thermoeconomic optimum design of a parabolic trough plant used as the section of the HRSG is obtained. The results show that the solar field increases the power and efficiency of the combined-cycle plant during the operation and makes it less susceptible to load variations.

scholarly journals Concentrating solar power tower technology: present status and outlook

2019 ◽  
Vol 8 (1) ◽  
pp. 10-31 ◽  
Author(s):  
Albert Boretti ◽  
Stefania Castelletto ◽  
Sarim Al-Zubaidy
Keyword(s):  
Solar Power ◽  
Combined Cycle ◽  
Power Cycle ◽  
Power Block ◽  
Solar Plant ◽  
Thermal Desalination ◽  
Design Values ◽  
Solar Power Tower ◽  
Solar Field ◽  
Installed Capacity

Abstract The paper examines design and operating data of current concentrated solar power (CSP) solar tower (ST) plants. The study includes CSP with or without boost by combustion of natural gas (NG), and with or without thermal energy storage (TES). Latest, actual specific costs per installed capacity are high, 6,085 $/kW for Ivanpah Solar Electric Generating System (ISEGS) with no TES, and 9,227 $/kW for Crescent Dunes with TES. Actual production of electricity is low and less than the expected. Actual capacity factors are 22% for ISEGS, despite combustion of a significant amount of NG exceeding the planned values, and 13% for Crescent Dunes. The design values were 33% and 52%. The study then reviews the proposed technology updates to improve ratio of solar field power to electric power, capacity factor, matching of production and demand, plant’s cost, reliability and life span of plant’s components. Key areas of progress are found in materials and manufacturing processes, design of solar field and receiver, receiver and power block fluids, power cycle parameters, optimal management of daily and seasonal operation of the plant, new TES concepts, integration of solar plant with thermal desalination or combined cycle gas turbine (CCGT) installations and specialization of project.

Short-Duration Performance Acceptance Test of Parabolic Trough Solar Field: A Case Study

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Ali Elmaihy ◽  
Ahmed El Weteedy
Keyword(s):  
Renewable Energy ◽  
Steady State ◽  
Short Duration ◽  
Field Performance ◽  
Acceptance Test ◽  
National Renewable Energy Laboratory ◽  
Parabolic Trough ◽  
Short Period ◽  
Technical Specifications ◽  
Solar Field

Extensive solar field performance testing is often required as part of the plant commissioning process in order to ensure that actual solar field performance satisfies both technical specifications and performance guarantees between the involved parties. In this study, short duration (15 min) steady state performance acceptance test for Kuraymat integrated solar combined cycle (ISCC) solar field was carried out in agreement with the general guidelines of the earlier National Renewable Energy Laboratory (NREL) report on parabolic trough (PT) collector fields (Kearney, 2011, “Utility-Scale Parabolic Trough Solar Systems—Performance Acceptance Test Guidelines,” National Renewable Energy Laboratory, Golden, CO, NREL Report No. SR-5500-48895 and Kearney, 2010, “Development of Performance Acceptance Test Guidelines for Large Commercial Parabolic Trough Solar Fields,” National Renewable Energy Laboratory, Golden, CO, NREL Report No. SR-5500-49367) which is in full agreement with the plant documentations provided by FLAGSOL (2010, “Specification: Performance Test Procedure. Plant Documentations,” Customer Doc-ID: KU1-FLG-000-QP-M-001). This work includes measurement of the thermal power output of PT system under clear sky conditions over a short period during which thermal steady state conditions exist. The methodology of the solar field testing is presented while a special consideration is provided for the model formulation and uncertainty associated with the measured data. The measured results together with the associated uncertainties were compared with model predictions. All tests for both northern and a southern collector subfields that satisfy the test conditions are accepted based on acceptance test evaluation criteria.

scholarly journals Protein intake trends and conformity with the Dietary Reference Intakes in the United States: analysis of the National Health and Nutrition Examination Survey, 2001–2014

2018 ◽  
Vol 108 (2) ◽  
pp. 405-413 ◽  
Author(s):  
Claire E Berryman ◽  
Harris R Lieberman ◽  
Victor L Fulgoni ◽  
Stefan M Pasiakos
Keyword(s):  
Total Energy ◽  
Protein Intake ◽  
Ideal Body Weight ◽  
The United States ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Systematic Analysis ◽  
Demographic Groups ◽  
Dietary Reference Intakes ◽  
The Us

ABSTRACT Background Systematic analysis of dietary protein intake may identify demographic groups within the American population that are not meeting the Dietary Reference Intakes (DRIs). Objective This cross-sectional study analyzed protein intake trends (2001–2014) and evaluated recent conformity to the DRIs (2011–2014) according to age, sex, and race or ethnicity in the US population. Design Protein intakes and trends during 2-y cycles of NHANES 2001–2014 (n = 57,980; ≥2 y old) were calculated as absolute (grams per day) and relative [grams per kilogram of ideal body weight (IBW) per day] intakes and as a percentage of total energy. Sex and race or ethnicity [Asian, Hispanic, non-Hispanic black (NHB), and non-Hispanic white (NHW)] differences were determined for protein intake and percentage of the population below the Estimated Average Requirement (EAR) and Recommended Dietary Allowance, and above and below the Acceptable Macronutrient Distribution Range (AMDR). Results Usual protein intakes (mean ± SE) averaged from 55.3 ± 0.9 (children aged 2–3 y) to 88.2 ± 1.1 g/d (adults aged 19–30 y). Protein comprised 14–16% of total energy intakes. Relative protein intakes averaged from 1.10 ± 0.01 (adults aged ≥71 y) to 3.63 ± 0.07 g · kg IBW–1 · d–1 (children aged 2–3 y), and were above the EAR in all demographic groups. Asian and Hispanic populations aged >19 y consumed more relative protein (1.32 ± 0.02 and 1.32 ± 0.02 g · kg IBW–1 · d–1, respectively) than did NHB and NHW (1.18 ± 0.01 g · kg IBW–1 · d–1). Relative protein intakes did not differ by race or ethnicity in the 2–18 y population. Adolescent (aged 14–18 y) females and older (aged ≥71 y) NHB men had the largest population percentages below the EAR (11% and 13%, respectively); <1% of any demographic group had intakes above the AMDR. Conclusions The majority of the US population exceeds minimum recommendations for protein intake. Protein intake remains well below the upper end of the AMDR, indicating that protein intake, as a percentage of energy intake, is not excessive in the American diet. This trial was registered at www.isrctn.com as ISRCTN76534484.

A Study on the Analysis of Airtightness Performance of Dilapidated Dwelling According to the Application of Windbreak

2017 ◽  
Vol 865 ◽  
pp. 200-205
Author(s):  
Su In Lee ◽  
Hyun Jung Choi ◽  
Gyeong Seok Choi ◽  
Jae Sik Kang
Keyword(s):  
Performance Evaluation ◽  
Energy Loss ◽  
Total Energy ◽  
Field Performance ◽  
Infiltration Rate ◽  
Measurement Result ◽  
Before And After

The airtightness performance of dilapidated dwellings is low. Infiltration occurs due to such low airtightness performance, causing the energy loss. Energy loss due to infiltration accounts for more than 30% of total energy loss in a building. Therefore, the airtightness performance should be considered by priority when retrofit of dilapidated dwelling is carried out. To improve the airtightness performance, numerous studies are underway. As a result, various products have been developed. The purpose of this study is to evaluate the performance of windbreak for improving the airtightness performance of dwelling and analyze the improvement level of airtightness performance of the room quantitatively after the windbreak is actually applied to dilapidated dwelling. In order to measure the airtightness performance of window where windbreak was applied, we measured the airtightness performance of window before and after windbreak was applied. Also, for the field performance evaluation, 27 dwellings were selected to measure the airtightness performance of the windbreak applied room. The measurement result showed that the infiltration rate of window where windbreak was applied decreased by approximately 48.66% in comparison to that before the windbreak was applied. And, The ACH50 (Air Change per Hour at 50 pascals of pressure) of the room where the windbreak was applied decreased by approximately 31.61%, confirming that the airtightness performance of window was improved through the application of windbreak.

scholarly journals The efficiency of linear Fresnel reflectors in producing superheated steam for power plant drive

2021 ◽  
Vol 323 ◽  
pp. 00011
Author(s):  
Mokhtar Ghodbane ◽  
Marek Majdak ◽  
Boussad Boumeddane
Keyword(s):  
Superheated Steam ◽  
Low Cost ◽  
Field Performance ◽  
Electricity Production ◽  
Weather Data ◽  
Direct Production ◽  
Superheated Steam Temperature ◽  
A Value ◽  
Linear Fresnel Reflector ◽  
Solar Field

Solar energy is one of the most important sources of renewable energies, which is widely used in many fields, such as electricity production through direct production of superheated steam based on Linear Fresnel Reflector. This study aims to show the optical and thermal behavior of linear Fresnel solar reflectors field directed to the electricity production in El-Oued region at Algeria. Four days of different weather data have been selected to track the change in solar field performance. Numerical optical modeling has shown that the optical performance of the solar field has reached 53.60 %, while the thermal study based on the numerical solution of the energy balance equations of the receiver tube proved that the thermal efficiency was 37.3 % and the average thermal loss coefficient was limited between 5.72 and 5.98 W/m²K. As for the superheated steam temperature, the lowest value was recorded in December with a value of 501 K. The results obtained are very compelling and encouraging to invest in this low-cost technology.

scholarly journals Adaptive control systems for solar collectors

Athenea ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 19-25
Author(s):  
Omar Flor Unda
Keyword(s):  
Predictive Control ◽  
Neural Model ◽  
Simulation Software ◽  
Engineering Practice ◽  
Control Engineering ◽  
Supervisory System ◽  
Adaptive Control Systems ◽  
Advanced Control ◽  
Solar Plant ◽  
Solar Field

En este trabajo se presentan las estrategias de control del flujo de aceite mediante la técnica de Control Predictivo basado en Modelo, para el mecanismo de control del campo de colectores solares cilindros parabólicos. Se analiza el comportamiento dinámico del sistema con el uso del modelo matemático, una técnicade control self-tunning y controlador predictivo basado en modelo para el control de plantas tipo ACUREX. Keywords: Automation, Modernization, ControlLogix, Supervisory System, Mimic Panel. References [1]Arahal, M. R., Berenguel, M. & Camacho, E. F., 1997. Nonlinear neural model-based predictive control of a solar plant. In Proc. European Control Conf. ECC'97. Brussels, Belgium, Volumen TH-E I2, p. paper 264. [2]Arahal, M. R., Berenguel, M. & Camacho, E. F., 1998a. Comparison of RBF algorithms for output temperature prediction of a solar plant.. In Proc. CONTROLO'98, 9-11 September. [3]Arahal, M. R., Berenguel, M. & Camacho, E. F., 1998b. Neural identification applied to predictive control of solar plant. Control Engineering Practice, Volumen 6, pp. pp. 333-344. [4]Aström, K. J. & Wittenmark, B., 1989. Adaptative Control. Aström, K. J. & Wittermark, B., 1984. Computed controlles Systems, Theory and Design. Englewood Cliffs, NJ: Prentice Hall. [5]Barão, M., 2000. Dynamic and no-linear control of a solar collector field. Thesis (in Portuguese). Universidade Técnica de Lisboa, Instituto Superior Técnico. [6]Barão, M., Lemos, J. M. & Silva, R. N., 2002. Reduced complexity adaptative nonlinear control of a distribuited collector solar field. J. of Process Control, Volumen 12(1), pp. pp. 131-141. [7]Berenguel, M., Arahal, M. R. & Camacho, E. F., 1998. Modeling free responses of a solar plant for predictive control. Control Engineering Practice, Volumen 6, pp. pp. 1257-1266. [8]Berenguel, M., Camacho, E. F. & Rubio, F. R., 1994. Simulation software package for the Acurex field.. Departamento de Ingeniería y Automática. [9]Berenguel, M., Camacho, E. F. & Rubio, F. R., 1997. Advanced Control of Solar Plants. Londres: Springer-Verlag.  

scholarly journals Long time series solar spectra used for solar field performance evaluation

2020 ◽  
Author(s):  
Antoine Grosjean ◽  
Estelle Le Baron ◽  
Anne-Claire Pescheux ◽  
Angela Disdier
Keyword(s):  
Time Series ◽  
Performance Evaluation ◽  
Field Performance ◽  
Long Time Series ◽  
Long Time ◽  
Solar Field

Demonstrating SolarPILOT’s Python API Through Heliostat Optimal Aimpoint Strategy Use Case

2021 ◽  
Author(s):  
William T. Hamilton ◽  
Michael J. Wagner ◽  
Alexander J. Zolan
Keyword(s):  
User Interaction ◽  
Field Performance ◽  
Use Case ◽  
Hermite Expansion ◽  
File Formats ◽  
Expansion Technique ◽  
Model Instance ◽  
Scripting Language ◽  
Multiple Receiver ◽  
Solar Field

Abstract SolarPILOT is a software package that generates solar field layouts and characterizes the optical performance of concentrating solar power (CSP) tower systems. SolarPILOT was developed by the National Renewable Energy Laboratory (NREL) as a stand-alone desktop application but has also been incorporated into NREL’s1 System Advisor Model (SAM) in a simplified format. Prior means for user interaction with SolarPILOT have included the application’s graphical interface, the SAM routines with limited configurability, and through a built-in scripting language called “LK.” This paper presents a new, full-featured, Python-based application programmable interface (API) for SolarPILOT, which we hereafter refer to as CoPylot. CoPylot provides access to all SolarPILOT’s capabilities to generate and characterize power tower CSP systems seamlessly through Python. Supported capabilities include (i) creating and destroying a model instance with message reporting tools; (ii) accessing and setting any SolarPILOT variable including custom land boundaries for field layouts; (iii) programmatically managing receiver and heliostat objects with varied attributes for systems with multiple receiver or heliostat types; (iv) generating, assigning, and modifying solar field layouts including the ability to set individual heliostat locations, aimpoints, soiling rates, and reflectivity levels; (v) simulating solar field performance; (vi) returning detailed results describing performance of individual heliostats, the aggregate field, and receiver flux distribution; and, (vii) exporting Python-based model instances to multiple file formats. CoPylot enables Python users to perform detailed CSP tower analysis utilizing either the Hermite expansion technique (analytical) or the SolTrace ray-tracing engine. In addition to CoPylot’s functionality, Python users have access to the over 100,000 open-source libraries to develop, analyze, optimize, and visualize power tower CSP research. This enables CSP researchers to perform analysis that was previously not possible through SolarPILOT’s existing interfaces. This paper discusses the capabilities of CoPylot and presents a use case wherein we demonstrate optimal solar field aiming strategies.

Sign in / Sign up

Export Citation Format

Share Document