Skip to main content
Disciplines
Automotive Business IT + Informatics Construction + Real Estate Electrical Engineering + Electronics Energy + Sustainability Insurance + Risk Finance + Banking Management + Leadership Marketing + Sales Mechanical Engineering + Materials
Events
DE
EN
Books
Journals
Topic Page
Marketing
Start single access now
Access for companies
EXTENDED SEARCH
Log in
Top

2016 | Book

Introduction Read chapter Read first chapter

Parabolic Trough Collector Prototypes for Low-Temperature Process Heat

Authors: Gianluca Coccia, Giovanni Di Nicola, Alejandro Hidalgo

Publisher: Springer International Publishing

Book Series : SpringerBriefs in Applied Sciences and Technology

Part of: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik" , Springer Professional "Wirtschaft"

Login to get access
insite
SEARCH

About this book

This book provides a technical overview of low-cost parabolic trough collector (PTCs) prototypes for low-temperature heat demand. It begins with a comprehensive but concise summary of the state-of-the-art in PTCs, and presents a detailed mathematical model of such systems. Subsequent chapters describe the construction and materials used in the manufacture of PTC prototypes, and offers technical solutions to overcome design problems. Finally, it provides an accessible guide to the standards used to test and evaluate the performance of PTCs. Offering a valuable resource to engineering researchers and practitioners, it is also suitable for students of solar thermal systems, renewable energy and applied physics.

Table of Contents

Frontmatter
Chapter 1. Introduction
Abstract
In this introductory chapter, fundamentals of solar thermal energy are discussed and some details concerning the sun, the star of our solar system and the source of solar energy on earth, are given. Further, solar thermal collectors available in the market are briefly presented, focusing in particular on concentrating collectors, systems able to concentrate and hence to increase the solar radiation. Among these, parabolic trough collectors (PTCs), which are the main subject of the present book, are described by dividing them into two different parts: the concentrator and the receiver. The materials used in such solar collector and their working principle are also discussed. Finally, typical solar thermal applications are presented, in particular as regards their utilization with PTCs.
Gianluca Coccia, Giovanni Di Nicola, Alejandro Hidalgo
Chapter 2. Mathematical Modeling
Abstract
This chapter presents a detailed mathematical analysis of PTCs. It is divided into three sections: tracking of the Sun, optical analysis and thermal analysis. The first section is an overview of equations and relationships used in solar geometry to determine the position of the Sun and, hence, the slope and the angle of incidence that in each instant must be assumed by a PTC to correctly follow the Sun. Since PTCs usually have one degree of freedom, correlations valid for east-west and north-south axis with continuous adjustment are discussed. The optical analysis starts by introducing the concentration ratio and continues presenting a thorough description of the geometry of a PTC. Optical errors and geometrical effects are also presented. Then, the optical analysis is concluded by taking into account the optical properties of the materials generally adopted in PTCs: the mirror, the cover and the absorber. The last section involves the thermal analysis of a PTC, i.e. the energy balance of the receiver. Each heat flux is described in detail, in order to determine the thermal efficiency of a PTC.
Gianluca Coccia, Giovanni Di Nicola, Alejandro Hidalgo
Chapter 3. Standards and Testing
Abstract
The performance of solar thermal collectors such as PTCs can be assessed by performing specific procedures described in standards. Standards generally followed in the solar energy field are the ISO 9806, the ANSI/ASHRAE 93 and the EN 12975-1, which will be presented in this chapter. The measurements and the procedures required for testing PTCs will be discussed in detail, in particular focusing the attention on the three most important parameters of a solar collector: the time constant, the thermal efficiency and the incident angle modifier. Due to its importance, uncertainty in thermal efficiency testing will be described extensively. Also, quality test methods will be briefly discussed.
Gianluca Coccia, Giovanni Di Nicola, Alejandro Hidalgo
Chapter 4. Concentrator
Abstract
PTCs are solar collectors made by several components, nonetheless they can be divided into two different parts which have distinct functions: the concentrator and the receiver. The former is the subject of the present chapter. The scope of PTC concentrators is to reflect the maximum amount of solar radiation to the receiver. In PTCs, concentrators have the shape of a cylindric parabola, a structure which has the property to reflect each normal incident solar ray to a line belonging to the parabola itself and called focal line, where the receiver is located. In order to correctly concentrate the solar radiation on the receiver, it is crucial to obtain a concentrator with good characteristics. This can be achieved by designing an accurate mold and by choosing appropriate materials for both the concentrator structure itself and the reflective foil attached to it. This chapter analyzes all the aforementioned aspects by discussing the manufacture of several concentrators of PTC prototypes available in literature. An overview on adopted materials is also presented.
Gianluca Coccia, Giovanni Di Nicola, Alejandro Hidalgo
Chapter 5. Receiver
Abstract
Receivers are the parts of a PTC where the solar radiation is concentrated and collected. PTC receivers are tubes of various diameters located in the focal line of the concentrator and can be distinguished into two parts: the absorber, i.e. the metallic tube in which the heat transfer fluid (HTF) flows, and the cover, an external tube generally made of glass, adopted to reduce convective and radiative thermal losses. The absorber collects the solar radiation reflected and focused by the concentrator, and it transfers the absorbed heat to the HTF by conduction and then by convection. Due to their function, receivers should have high thermal conductivity and present high absorptance to the solar spectrum. The latter condition is generally realized by painting the outer surface of the receiver with special black coatings. This chapter presents an overview of the receivers used in PTC prototypes, providing some characteristics about the adopted materials. The performance of the prototypes are also discussed. Finally, PTC protoypes using nanofluids, novel promising HTFs, are presented.
Gianluca Coccia, Giovanni Di Nicola, Alejandro Hidalgo
Metadata
Title
Parabolic Trough Collector Prototypes for Low-Temperature Process Heat
Authors
Gianluca Coccia
Giovanni Di Nicola
Alejandro Hidalgo
Copyright Year
2016
Electronic ISBN
978-3-319-27084-5
Print ISBN
978-3-319-27082-1
DOI
https://doi.org/10.1007/978-3-319-27084-5