Parabolic Trough Collector

Prinsloo, G.J., Dobson, R.T. (2015). Solar Tracking: High precision solar position algorithms, programs, software and source-code for computing the solar vector, solar coordinates & sun angles in Microprocessor, PLC, Arduino, PIC and PC-based sun tracking devices or dynamic sun following hardware. Stellenbosch: SolarBooks. ISBN 978-0-620-61576-1, p 1-542.
Using solar equations in an electronic circuit for solar tracking is quite simple, even if you are a novice, but mathematical solar equations are over complicated by academic experts and professors in text-books, journal articles and internet websites. In terms of solar hobbies, scholars, students and Hobbyist's looking at solar tracking electronics or PC programs for solar tracking are usually overcome by the sheer volume of scientific material and internet resources, which leaves many developers in frustration when search for simple experimental solar tracking source-code for their on-axis sun-tracking systems. This booklet will simplify the search for the mystical sun tracking formulas for your sun tracker innovation and help you develop your own autonomous solar tracking controller.

By directing the solar collector directly into the sun, a solar harvesting means or device can harness sunlight or thermal heat. This is achieved with the help of sun angle formulas, solar angle formulas or solar tracking procedures for the calculation of sun's position in the sky. Automatic sun tracking system software includes algorithms for solar altitude azimuth angle calculations required in following the sun across the sky. In using the longitude, latitude GPS coordinates of the solar tracker location, these sun tracking software tools supports precision solar tracking by determining the solar altitude-azimuth coordinates for the sun trajectory in altitude-azimuth tracking at the tracker location, using certain sun angle formulas in sun vector calculations. Instead of follow the sun software, a sun tracking sensor such as a sun sensor or webcam or video camera with vision based sun following image processing software can also be used to determine the position of the sun optically. Such optical feedback devices are often used in solar panel tracking systems and dish tracking systems.

Dynamic sun tracing is also used in solar surveying, DNI analyser and sun surveying systems that build solar infographics maps with solar radiance, irradiance and DNI models for GIS (geographical information system). In this way geospatial methods on solar/environment interaction makes use use of geospatial technologies (GIS, Remote Sensing, and Cartography).
Climatic data and weather station or weather center data, as well as queries from sky servers and solar resource database systems (i.e. on DB2, Sybase, Oracle, SQL, MySQL) may also be associated with solar GIS maps. In such solar resource modelling systems, a pyranometer or solarimeter is normally used in addition to measure direct and indirect, scattered, dispersed, reflective radiation for a particular geographical location. Sunlight analysis is important in flash photography where photographic lighting are important for photographers. GIS systems are used by architects who add sun shadow applets to study architectural shading or sun shadow analysis, solar flux calculations, optical modelling or to perform weather modelling. Such systems often employ a computer operated telescope type mechanism with ray tracing program software as a solar navigator or sun tracer that determines the solar position and intensity.

The purpose of this booklet is to assist developers to track and trace suitable source-code and solar tracking algorithms for their application, whether a hobbyist, scientist, technician or engineer. Many open-source sun following and tracking algorithms and source-code for solar tracking programs and modules are freely available to download on the internet today. Certain proprietary solar tracker kits and solar tracking controllers include a software development kit SDK for its application programming interface API attributes (Pebble). Widget libraries, widget toolkits, GUI toolkit and UX libraries with graphical control elements are also available to construct the graphical user interface (GUI) for your solar tracking or solar power monitoring program.

In this paper, the mathematical modelling of a novel Electrical Energy Storage (EES) Receiver for Solar Parabolic Trough Collector (PTC) is presented. The EES receiver is essentially a Heat Collecting Element (HCE) with built in storage in the form of thermal batteries such as the Sodium Sulphur (NaS) battery. The conceptual design and mathematical models describing the operation of the receiver are presented along with important results of model validation. When held under adiabatic conditions (a primary indicator of model validity), results were highly consistent with established PTC, models and with National Renewable Energy Laboratory (NREL, USA) experimental data for existing SCHOTT PTR-70 and Solel UVAC3 receiver tubes, currently being used in existing PTC power plants.

Since usage of fossil fuels for producing electricity causes climate change, renewable energy options have become one of the best substitution for fossil fuels. Solar energy promises high amount of resources for producing electricity. Among solar energy alternatives, Photovoltaic (PV) and Parabolic Trough Collectors (PTC) are dominant in the market. This paper compares middle size of PV and PTC power plant for the electricity need of Middle East Technical University Northern Cyprus Campus. Based on the maximum hourly demand of METU NCC, both PV and PTC are sized to 3 MWe. The simulations were performed via SAM software using the hourly values from typical meteorological data, which include solar irradiation, wind speed, dry and wet bulb temperatures, relative humidity and pressure. For the PTC and PV plants, commercially available components are used. The scenario assumes METU NCC to be a grid-connected micro-grid with one-way tariff, so that any deficit energy can be met by the utility and any excess energy produced by the suggested renewable energy systems will be given to the grid for free. The results indicate that 3 MW PV plant would generate annual energy of about 4.95 GWh with a capacity factor of 18.9%. These numbers would yield to a LCOE value of 2.60 ¢/kWh. On the other hand, the suggested 3 MW PTC plant with 2 solar multiple would supply about annual energy of 6.3 GWh at a capacity factor of 24.0%. The LCOE of the energy from PTC plant was estimated to be 8.47 ¢/kWh due to high capital and operation cost of PTC plants compared to PV plants. However, over years the cost of PTC power plants has been decreasing. Additionally, both PTC plant and PV plant would consume water only for cleaning purposes that makes them suitable for Cyprus water scarcity conditions. Overall, this study shows pros and cons of middle-sized PV and PTC plants with the case study of METU NCC.

— In recent years, the world as a whole tend to extract energy from renewable energy resources and fit it to the supply-demand chain due to the current resources coming to an end and harming the environment with CO2 emissions. In this paper, we present the solar opportunity as a renewable energy resource for Northern Cyprus, and based on measured data we compare two different solar energy collectors: Parabolic Trough and Fresnel systems. Depending on the beam and diffuse insolation and the topography, these systems’ advantages and disadvantages will be discussed, and a cost analysis will be presented throughout this paper.

This work presents an algorithm able to simulate the heating of a solar collector throughout the day. The discussed collector is part of a solar adsorption refrigerator, and is used to regenerate the activated carbon contained inside a cylindrical recipient (absorber), which is located in the focal line of a parabolic trough concentrator. The developed algorithm takes into account all the transfer mechanisms when analyzing the heat transfers taking place between the collector's components and the environment, as well as the transfer mechanisms towards the absorber's interior. The temperature evolution for the collector's elements is obtained, and the model is validated by comparing the experimentally measured surface temperature of the absorber with the one determined by the algorithm. The experimental data were gathered from similar collectors in two different scenarios: Santo Domingo (Dominican Republic) and Buenos Aires (Argentina). The model is satisfactorily validated with experimental data.

The computer program called Solar_PVHFC has been modified to model a compound parabolic concentrator (CPC) that uses photovoltaic cells to produce electrical energy. This program was used to study the effects of concentration ratio, truncation height ratio, and photovoltaic cell efficiency on electrical power output and relative levelized cost of energy (LCE) of a fixed CPC photovoltaic device. Comparisons are made to fixed, conventional flat photovoltaic panels. This study indicates that CPCs can reduce the levelized cost of electrical energy produced by high efficiency, high cost photovoltaic cells, but provides no advantages for lower efficiency, lower price photovoltaic cells.

In this paper, we have studied numerically thermal performances of a parabolic trough collector (PTC) working with different nanofluids. Simulations are carried out for 5% nanoparticles' volume concentration. The ultrafine particles that have been suspended in the base fluid (Syltherm800) are the aluminum oxide (Al2O3), the copper (Cu), the cupric oxide (CuO) and the silver (Ag). The results show that the convection heat transfer coefficient increased with the suspension of the nanoparticles. The overall heat loss coefficient of the PTC has been found to decrease when using nanofluids. The maximum enhancement in thermal performances of the PTC has been recorded for the silver nanoparticles which reach approximately 36% increase in the convection heat transfer coefficient and 21% decrease in overall heat loss coefficient.

Se propone adaptar, innovar y desarrollar la tecnología de diseño y producto necesaria para confeccionar un  concentrador solar tipo CPC utilizable en la separación molecular de contaminantes en aguas jabonosas.  La construcción del prototipo se justifica, en términos de que las  las aguas residuales jabonosas constituyen un grave problema de contaminación nacional. Prácticamente ninguna región, estado, municipio o comunidad del país está libre de su presencia y efectos negativos. Es imperativo efectuar los desarrollos tecnológicos, eficientes y confiables, que contribuyan a solucionarlo. Es en esta dirección que, desde febrero del 2000, un grupo de tecnólogos de la UNAM realizan en el Centro de Investigaciones en Energía en Temixco Morelos, progresos en el campo. En particular, el Dr. Camilo Arancibia realiza actualmente bajo los auspicios del CONACyT el proyecto “Estudio de la fotocatálisis para el tratamiento de contaminantes en solución acuosa utilizando energía solar”.  En la Universidad de Quintana Roo, el M. en C. Roberto Acosta, Profesor-Investigador de la carrera de ingeniería en Sistemas de energía impulsa la realización de proyectos  puntuales que coinciden con la preocupación de CIE-UNAM. Posibilitó la participación del bachiller Ricardo Xavier Gamboa Rocha egresado de la carrera mencionada en la “4a Escuela de Investigación en Energía” realizada durante abril del 2004 precisamente en el CIE-Temixco. Esta circunstancia permitió que, durante estas fechas, el bachiller Gamboa contactara al Dr. Camilo Arancibia quien gentilmente aceptó dirigir la Tesis cuya realización aquí se propone.

This paper presents an exergy analysis to study the effects of operational and environmental parameters on the performance of Parabolic Trough Collectors. The exergy analysis is based on a previous heat transfer model published by the authors. The main parameters considered for the analysis are: inlet temperature and mass flow rate of heat transfer fluid, wind speed, pressure or vacuum in annulus and solar irradiance. The results showed that inlet temperature of heat transfer fluid, solar irradiance, and vacuum in annulus have a significant effect on the thermal and exergetic performance, but the effect of wind speed and mass flow rate of heat transfer fluid is negligible. It was obtained that inlet temperature of heat transfer fluid cannot be optimized to achieve simultaneously maximum thermal and exergetic efficiency because they exhibit opposite trends. Finally, it was found that the highest exergy destruction is due to the heat transfer between the sun and the absorber while for exergy losses is due to optical error.