Parametric Trough Solar Collector With Commercial Evacuated Receiver: Performance Comparison at Plant Level

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Juan Pablo Núnez Bootello ◽  
Markus Schramm ◽  
Manuel Silva Pérez ◽  
Manuel Doblaré Castellano

A new anidolic parametric trough solar collector (PmTC) having 8.12 m net width aperture has been recently proposed for a commercial evacuated receiver tube with an absorber diameter of 70 mm. Since the collector was designed ignoring transmission, absorption, and reflection optical losses, calculations of the optical efficiency and the incidence angle modifier (IAM) by means of Monte Carlo spectral raytracing simulations using real slope errors distributions and taking into account Fresnel reflection losses were done. Comparison with an Eurotrough parabolic trough collector (PTC) shows an optical penalization of 5.1% due to the reflectivity and additional soiling of the secondary mirror, to an increase in the end losses and to the Fresnel reflection losses. The National Renewable Energy Laboratory (NREL) system advisor model (SAM) was used to perform annual simulations of two commercial 50 MWe oil power plants without thermal energy storage located in Seville. A PTC solar field consisting of 90 loops, each one having four Eurotrough solar collector assemblies (SCA) with 150 m length was first modeled resulting in a gross production of 386 kWh/(m2 yr). A PmTC solar field with the same module length and similar SCA net aperture area was also simulated. A final configuration of 94 loops and four SCAs with 100 m length per loop yields a gross production of 379 kWh/(m2 yr) showing no improvement compared to the reference PTC plant. The present study allows to advance in the understanding of the potential of the anidolic optic to produce optical geometries able to effectively improve the PTC technology in the short-term projecting results at a commercial plant level.

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Jinping Wang ◽  
Jun Wang ◽  
Xiaolong Bi ◽  
Xiang Wang

Parabolic trough systems are the most used concentrated solar power technology. The operating performance and optical efficiency of the parabolic trough solar collectors (PTCs) are different in different regions and different seasons. To determine the optimum design and operation of the parabolic trough solar collector throughout the year, an accurate estimation of the daily performance is needed. In this study, a mathematical model for the optical efficiency of the parabolic trough solar collector was established and three typical regions of solar thermal utilization in China were selected. The performance characteristics of cosine effect, shadowing effect, end loss effect, and optical efficiency were calculated and simulated during a whole year in these three areas by using the mathematical model. The simulation results show that the optical efficiency of PTCs changes from 0.4 to 0.8 in a whole year. The highest optical efficiency of PTCs is in June and the lowest is in December. The optical efficiency of PTCs is mainly influenced by the solar incidence angle. The model is validated by comparing the test results in parabolic trough power plant, with relative error range of 1% to about 5%.


Author(s):  
A. Giostri ◽  
M. Binotti ◽  
P. Silva ◽  
E. Macchi ◽  
G. Manzolini

Parabolic trough can be considered the state of the art for solar thermal power plants thanks to the almost 30 years experience gained in SEGS and, recently, Nevada Solar One plants in US and Andasol plants in Spain. One of the major issues that limits the wide diffusion of this technology is the high investment cost of the solar field and, particularly, of the solar collector. For this reason, since several years research activity has been trying to develop new solutions with the aim of cost reduction. This work compares commercial Fresnel technology with conventional parabolic trough plant based on synthetic oil as heat transfer fluid at nominal conditions and evaluates yearly average performances. In both technologies, no thermal storage system is considered. In addition, for Fresnel, a Direct Steam Generation (DSG) case is investigated. Performances are calculated by a commercial code, Thermoflex®, with dedicated component to evaluate solar plant. Results will show that, at nominal conditions, Fresnel technology have an optical efficiency of 67% which is lower than 75% of parabolic trough. Calculated net electric efficiency is about 19.25%, while parabolic trough technology achieves 23.6%. In off-design conditions, the gap between Fresnel and parabolic trough increases because the former is significantly affected by high radiation incident angles. The calculated sun-to-electric annual average efficiency for Fresnel plant is 10.2%, consequence of the average optical efficiency of 38.8%, while parabolic trough achieve an overall efficiency of 16%, with an optical one of 52.7%. An additional case with Fresnel collector and synthetic oil outlines differences among investigated cases. Finally, because part of performance difference between PT and Fresnel is simple due to different definitions, additional indexes are introduced in order to make a consistent comparison.


2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Jürgen Dersch ◽  
Peter Schwarzbözl ◽  
Timo Richert

An existing software tool for annual performance calculation of concentrating solar power and other renewable energy plants has been extended to enable the simulation of solar tower power plants. The methodology used is shown and a demonstrative example of a 50 MWe tower plant in southern Spain is given. The influence of design power and latitude on solar field layout is discussed. Furthermore, a comparison of the tower plant with a 50 MWe parabolic trough and a Linear Fresnel plant at the same site is given.


Energies ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 37 ◽  
Author(s):  
Jose Rogada ◽  
Lourdes Barcia ◽  
Juan Martinez ◽  
Mario Menendez ◽  
Francisco de Cos Juez

Power plants producing energy through solar fields use a heat transfer fluid that lends itself to be influenced and changed by different variables. In solar power plants, a heat transfer fluid (HTF) is used to transfer the thermal energy of solar radiation through parabolic collectors to a water vapor Rankine cycle. In this way, a turbine is driven that produces electricity when coupled to an electric generator. These plants have a heat transfer system that converts the solar radiation into heat through a HTF, and transfers that thermal energy to the water vapor heat exchangers. The best possible performance in the Rankine cycle, and therefore in the thermal plant, is obtained when the HTF reaches its maximum temperature when leaving the solar field (SF). In addition, it is necessary that the HTF does not exceed its own maximum operating temperature, above which it degrades. The optimum temperature of the HTF is difficult to obtain, since the working conditions of the plant can change abruptly from moment to moment. Guaranteeing that this HTF operates at its optimal temperature to produce electricity through a Rankine cycle is a priority. The oil flowing through the solar field has the disadvantage of having a thermal limit. Therefore, this research focuses on trying to make sure that this fluid comes out of the solar field with the highest possible temperature. Modeling using data mining is revealed as an important tool for forecasting the performance of this kind of power plant. The purpose of this document is to provide a model that can be used to optimize the temperature control of the fluid without interfering with the normal operation of the plant. The results obtained with this model should be necessarily contrasted with those obtained in a real plant. Initially, we compare the PID (proportional–integral–derivative) models used in previous studies for the optimization of this type of plant with modeling using the multivariate adaptive regression splines (MARS) model.


2018 ◽  
Vol 10 (11) ◽  
pp. 3937 ◽  
Author(s):  
Sahar Bouaddi ◽  
Aránzazu Fernández-García ◽  
Chris Sansom ◽  
Jon Sarasua ◽  
Fabian Wolfertstetter ◽  
...  

The severe soiling of reflectors deployed in arid and semi arid locations decreases their reflectance and drives down the yield of the concentrating solar power (CSP) plants. To alleviate this issue, various sets of methods are available. The operation and maintenance (O&M) staff should opt for sustainable cleaning methods that are safe and environmentally friendly. To restore high reflectance, the cleaning vehicles of CSP plants must adapt to the constraints of each technology and to the layout of reflectors in the solar field. Water based methods are currently the most commonly used in CSP plants but they are not sustainable due to water scarcity and high soiling rates. The recovery and reuse of washing water can compensate for these methods and make them a more reasonable option for mediterranean and desert environments. Dry methods, on the other hand, are gaining more attraction as they are more suitable for desert regions. Some of these methods rely on ultrasonic wave or vibration for detaching the dust bonding from the reflectors surface, while other methods, known as preventive methods, focus on reducing the soiling by modifying the reflectors surface and incorporating self cleaning features using special coatings. Since the CSP plants operators aim to achieve the highest profit by minimizing the cost of cleaning while maintaining a high reflectance, optimizing the cleaning parameters and strategies is of great interest. This work presents the conventional water-based methods that are currently used in CSP plants in addition to sustainable alternative methods for dust removal and soiling prevention. Also, the cleaning effectiveness, the environmental impacts and the economic aspects of each technology are discussed.


2018 ◽  
Vol 44 ◽  
pp. 00008
Author(s):  
Nikolay Amosov ◽  
Alexander Andryushin ◽  
Edik Arakelyan ◽  
Anatoliy Kosoy

The results of the level analysis of intellectuality and efficiency of up-to-date automated process control systems (APCS) based on software and hardware systems (SHS) are presented. It was demonstrated that, despite the widespread implementation of modern software and hardware systems during the construction of new APCS and upgrading the existing ones for thermal power plants (TPP), improvement of the process control quality, optimization of their modes and parameters take place generally at the equipment and power unit level and to a far lesser extent – at the power plant level and as a result – insufficient level of automation and low technical and economic efficiency. Another conclusion from the performed analysis – when implementing control algorithms in the APCS based on the up-to-date SHS, their wide data and software capabilities are not fully used. The main ways of further APCS improvement for the purpose of further increasing of their efficiency and the level of intelligence of SHS based APCS of power plants are presented. The possibility of their implementation is considered with application of the basic principles laid in the concept Industry 4.0. The possible economic effect from the implementation of the proposed solutions for increasing the intelligence and efficiency of the SHS based APCS was assessed. A brief description of the configuration of the proposed SHS based control system is given.


Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 668
Author(s):  
Wael Al-Kouz ◽  
Ahmad Almuhtady ◽  
Nidal Abu-Libdeh ◽  
Jamal Nayfeh ◽  
Alberto Boretti

This paper aims to compute the performances of a smaller version of Solana power plant, with half the solar field, and 1 of 2 turbines in the power cycle, that can be built in Amman or Ma’an in Jordan. The climate conditions for both Amman and Ma’an are discussed thoroughly in the paper. Furthermore, a preliminary validation exercise performed by using measured monthly average values of electricity production from existing plants, a system advisor model (SAM) is used to predict the performances of the proposed Solana-like plants in Ma’an and Amman. The validation shows a good agreement with the measured data for different existing power plants. The simulation results including the monthly capacity factors suggest the annual operation in Ma’an maybe even better than the operation in Gila Bend, for an annual average capacity factor of about 41% for Ma’an vs. a capacity factor of about 39% for Gila Bend. This is mainly due to the best combination of direct normal irradiance (DNI) and the dry bulb temperature across the year in Ma’an versus Gila Bend.


1997 ◽  
Vol 119 (1) ◽  
pp. 52-60 ◽  
Author(s):  
A. Meaburn ◽  
F. M. Hughes

In recent years the problem of controlling the temperature of oil leaving an array of parabolic trough collectors has received much attention. The control schemes developed have in general utilized a feedback control loop combined with feedforward compensation. The majority of the published papers place the emphasis almost entirely on the design of the feedback control loop. Little or no attention has been paid to issues involved in the design of the feedforward controller. This paper seeks to redress this imbalance by concentrating upon the design and development of a feedforward controller for the ACUREX distributed solar collector field at the Plataforma Solar de Almeria. Different methods of combining feedback and feedforward will be assessed and experimental results will be presented in order to support any theoretical observations made.


Author(s):  
Joseph Kopp ◽  
R. F. Boehm

The performance of a solar thermal parabolic trough plant with thermal storage is dependent upon the arrangement of the heat exchangers that ultimately transfer energy from the sun into steam. An indirect two-tank molten salt storage system that only transfers heat with the solar field heat transfer fluid is the most commercially acceptable thermal storage design. Annual electricity generation from two differing indirect two-tank molten salt storage designs and a base case with no thermal storage were modeled. Four components were characterized in a quasi-steady state analysis dependent upon key ambient and operational parameters: solar field, storage, heat exchangers, and power block. The parameters for the collector field remained constant for all models and were based on the SEGS VI plant. The results of net power generation favor storage though the design that maximizes annual output depends on whether maximum power generation or power generation during the evening peak demand hours is desired. Additionally, the economic trade offs are discussed for the three arrangements.


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