SIST EN IEC 62862-3-2:2019

Solar thermal electric plants - Part 3-2: Systems and components - General requirements and test methods for large-size parabolic-trough collectors (IEC 62862-3-2:2018)

IEC 62862-3-2:2018 specifies the requirements and the test methods for the characterization of a large-size parabolic-trough collector. This document covers the determination of optical and thermal performance of parabolic-trough collectors, and the tracking accuracy of the collector one-axis tracking system. This test method is for outdoor testing only. This document applies to parabolic-trough collectors equipped with the manufacturer-supplied sun tracking mechanism.

Solarthermische Kraftwerke - Teil 3-2: Systeme und Komponenten - Allgemeine Anforderungen und Prüfverfahren für Parabolrinnenkollektoren (IEC 62862-3-2:2018)

Centrales électriques solaires thermodynamiques - Partie 3-2: Systèmes et composants - Exigences générales et méthodes d'essai des capteurs cylindro-paraboliques de grande taille (IEC 62862-3-2:2018)

L'IEC 62862-3-2:2018 spécifie les exigences et méthodes d'essai pour la caractérisation d'un capteur cylindro-parabolique de grande taille. Le présent document couvre la détermination des performances optiques et thermiques des capteurs cylindro-paraboliques et la précision du système de suiveur à un axe du capteur. Cette méthode ne concerne que les essais en extérieur. Le présent document s'applique aux capteurs cylindro-paraboliques équipés d'un mécanisme suiveur du soleil fourni par le fabricant.

Sončne termoelektrarne - 3-2. del: Sistemi in komponente - Splošne zahteve in preskusne metode za velika parabolična korita (IEC 62862-3-2:2018)

IEC 62862-3-2:2018 določa zahteve in preskusne metode za karakterizacijo velikih paraboličnih korit. Dokument zajema določanje optičnih in toplotnih lastnosti paraboličnih korit ter natančnost sledenja enoosnega sledilnega sistema kolektorja. Ta preskusna metoda je namenjena samo za preskušanje na prostem. Dokument se uporablja za parabolična korita, opremljena z mehanizmom za sledenje soncu, ki ga zagotavlja proizvajalec.

General Information

• Status: Published
• Publication Date: 18-Aug-2019
• ICS: 27.160 - Solar energy engineering
• Technical Committee: I09 - Imaginarni 09
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 24-Jul-2019
• Due Date: 28-Sep-2019
• Completion Date: 19-Aug-2019
• Ref Project: EN IEC 62862-3-2:2018 - Solar thermal electric plants - Part 3-2: Systems and components - General requirements and test methods for large-size parabolic-trough collectors

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 62862-3-2:2019
01-september-2019
Sončne termoelektrarne - 3-2. del: Sistemi in komponente - Splošne zahteve in
preskusne metode za velika parabolična korita (IEC 62862-3-2:2018)
Solar thermal electric plants - Part 3-2: Systems and components - General
requirements and test methods for large-size parabolic-trough collectors (IEC 62862-3-
2:2018)
Solarthermische Kraftwerke - Teil 3-2: Systeme und Komponenten - Allgemeine
Anforderungen und Prüfverfahren für Parabolrinnenkollektoren (IEC 62862-3-2:2018)
Centrales électriques solaires thermodynamiques - Partie 3-2: Systèmes et composants
- Exigences générales et méthodes d'essai des capteurs cylindro-paraboliques de
grande taille (IEC 62862-3-2:2018)
Ta slovenski standard je istoveten z: EN IEC 62862-3-2:2018
ICS:
27.160 Sončna energija Solar energy engineering
SIST EN IEC 62862-3-2:2019 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 62862-3-2:2019

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SIST EN IEC 62862-3-2:2019


EUROPEAN STANDARD EN IEC 62862-3-2

NORME EUROPÉENNE

EUROPÄISCHE NORM
October 2018
ICS 27.160

English Version
Solar thermal electric plants - Part 3-2: Systems and
components - General requirements and test methods for large-
size parabolic-trough collectors
(IEC 62862-3-2:2018)
Centrales électriques solaires thermodynamiques - Partie 3- Solarthermische Kraftwerke - Teil 3-2: Systeme und
2: Systèmes et composants - Exigences générales et Komponenten - Allgemeine Anforderungen und
méthodes d'essai des capteurs cylindro-paraboliques de Prüfverfahren für Parabolrinnenkollektoren
grande taille (IEC 62862-3-2:2018)
(IEC 62862-3-2:2018)
This European Standard was approved by CENELEC on 2018-08-14. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.


European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 62862-3-2:2018 E

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SIST EN IEC 62862-3-2:2019
EN IEC 62862-3-2:2018 (E)
European foreword
The text of document 117/87/FDIS, future edition 1 of IEC 62862-3-2, prepared by IEC/TC 117 "Solar
thermal electric plants" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC
as EN IEC 62862-3-2:2018.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2019-05-14
level by publication of an identical national
standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2021-08-14
document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 62862-3-2:2018 was approved by CENELEC as a
European Standard without any modification.

In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 62817:2014 NOTE Harmonized as EN 62817:2015 (not modified).

2

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SIST EN IEC 62862-3-2:2019
EN IEC 62862-3-2:2018 (E)
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.

Publication Year Title EN/HD Year
ISO 9488 1999 Solar energy - Vocabulary EN ISO 9488 1999
ISO 9806 2017 Solar energy - Solar thermal collectors - EN ISO 9806 2017
Test methods
IEC/TS 62862-1-1 2018  Solar thermal electric plants - Part 1-1: - -
Terminology

3

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SIST EN IEC 62862-3-2:2019




IEC 62862-3-2

®


Edition 1.0 2018-07




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside










Solar thermal electric plants –

Part 3-2: Systems and components – General requirements and test methods for

large-size parabolic-trough collectors



Centrales électriques solaires thermodynamiques –

Partie 3-2: Systèmes et composants – Exigences générales et méthodes d'essai


des capteurs cylindro-paraboliques de grande taille













INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 27.160 ISBN 978-2-8322-5790-6




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and symbols. 6
3.1 Terms and definitions . 6
3.2 Symbols . 7
4 Test requirements . 7
5 Instrumentation . 7
5.1 Solar radiation measurement . 7
5.2 Flow rate measurement . 7
5.3 Temperature measurements . 7
5.4 Wind speed measurement . 7
5.5 Data acquisition . 8
5.6 Tracking accuracy measurement . 8
6 Test procedure . 8
6.1 Sample description . 8
6.2 Test equipment (installation/mounting/cleanliness) . 8
6.2.1 Performance test . 8
6.2.2 Tracking error test . 10
6.3 Measurement procedure . 10
6.3.1 Performance test . 10
6.3.2 Tracking error test . 10
6.4 Calculation and test results . 11
6.4.1 General . 11
6.4.2 Useful power . 11
6.4.3 Incidence angle modifier (IAM) . 12
6.4.4 Validation performance test . 12
6.4.5 Tracking error test . 13
6.4.6 Uncertainty estimation . 14
7 Reporting format . 14
Annex A (informative) Parabolic-trough collector description/requirements . 15
A.1 General description . 15
A.1.1 General . 15
A.1.2 Bearing structure . 16
A.1.3 Drive pylon . 16
A.1.4 Middle, end and shared pylon . 16
A.1.5 Reflectors . 16
A.1.6 Receiver tube . 16
A.1.7 Tracking system . 17
A.2 Operation modes . 17
Annex B (normative) Documentation to be supplied by the collector manufacturer . 18
Annex C (normative) Test report . 21
C.1 General . 21
C.2 Collector characteristics . 21

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C.3 Parabolic-trough collector limitations. 22
C.4 Description of the experimental setup . 22
C.5 Results . 22
Bibliography . 24

Figure 1 – Test equipment installation. 9
Figure 2 – Structure sketch of one module of parabolic-trough collector – Gross
aperture area definition . 12
Figure A.1 – General view of a parabolic-trough collector . 15

Table C.1 – Alternate tracking accuracy reporting template . 22

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

SOLAR THERMAL ELECTRIC PLANTS –

Part 3-2: Systems and components – General requirements and
test methods for large-size parabolic-trough collectors

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62862-3-2 has been prepared by IEC technical committee 117:
Solar thermal electric plants.
The text of this International Standard is based on the following documents:
FDIS Report on voting
117/87/FDIS 117/89/RVD

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

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SIST EN IEC 62862-3-2:2019
IEC 62862-3-2:2018 © IEC 2018 – 5 –
A list of all parts in the IEC 62862 series, published under the general title Solar thermal
electric plants, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.

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SOLAR THERMAL ELECTRIC PLANTS –

Part 3-2: Systems and components – General requirements and
test methods for large-size parabolic-trough collectors



1 Scope
This part of IEC 62862 specifies the requirements and the test methods for the
characterization of a large-size parabolic-trough collector.
This document covers the determination of optical and thermal performance of parabolic-
trough collectors, and the tracking accuracy of the collector one-axis tracking system. This
test method is for outdoor testing only.
This document applies to parabolic-trough collectors equipped with the manufacturer-supplied
sun tracking mechanism.
The test method in this document does not apply to any collector under operating conditions
where phase-change of the fluid occurs.
This document applies to the whole collector.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC TS 62862-1-1, Solar thermal electric plants – Terminology
ISO 9488:1999, Solar energy – Vocabulary
ISO 9806:2017, Solar energy – Solar thermal collectors – Test methods
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9488, ISO 9806 and
IEC 62862-1-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp

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3.2 Symbols
The following symbols are used in this document:
β elevation (measured by an inclinometer) (º)
real
ρ reflectance measured during the test (-)
test
reference value of the reflectance of the reflectors installed in the collector (-)
ρ
nom
θ

tracker elevation error (°)
T
F ratio between the product of the reflectors' reflectance and the glass envelope transmittance
c
during the test and the product of the reflectance and transmittance nominal values
ratio between the measured specular reflectance of reflector to the nominal specular
χ
reflector

reflectance of reflector

4 Test requirements
The parabolic-trough collector should be equipped with all the components supplied by the
manufacturer (such as bearing structure, reflector facets, receiver tubes, actuator system and
control) and mounted according to the manufacturer's instructions.
The different components/elements (such as the receiver, reflector, tracker, structure) should
be previously tested separately by current test methods or standards when available.The
documentation to be supplied by the manufacturer shall be according to Annex B.
5 Instrumentation
5.1 Solar radiation measurement
Solar radiation measurement shall be performed according to 21.1 of ISO 9806:2017.
Incidence angles will be determined by calculation or with sun position sensors with an
accuracy equal to or higher than ± 0,1º. In the case they are calculated from the sun position
equation, the accuracy of the calculation algorithm shall be equal to or higher than 0,025°.
5.2 Flow rate measurement
Flow rate measurement shall be performed according to 21.4.1 of ISO 9806:2017.
5.3 Temperature measurements
Temperature measurements (inlet, outlet and ambient temperature) shall be performed
according to ISO 9806:2017.
The collector inlet and outlet positions shall be defined by the manufacturer and the
temperature sensors shall be installed at no more than 200 mm from this point.
NOTE The problems caused by the concentrated light on the sensors if the sensors are mounted in the focus
zone are taken into consideration.
5.4 Wind speed measurement
The mean wind speed in the horizontal plane shall be determined with a standard uncertainty
< 0,5 m/s. The sensor shall be installed at (10 ± 0,1) m height from the ground. The sensor
shall be installed at a distance from the collector extremity (end pylon as shown in Figure A.1)
not higher than 100 m. If there is no wind speed sensor close enough to the meteorological
station of the plant, one temporary sensor should be added close to the collector.

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5.5 Data acquisition
Data acquisition shall be according to 23.5.3 of ISO 9806:2017.
5.6 Tracking accuracy measurement
Experimental tracking accuracy measurements can be obtained using inclinometers. Accuracy
of the inclinometers shall be better than 0,1° over the whole range of tracking angles.
Combination of two or more inclinometers often solves this requirement.
The true tracking angle is measured at two locations of the collector, one near the centre
(where the drive system is usually located) and another one at one of the collector's end.
6 Test procedure
6.1 Sample description
A general description and requirements of the parabolic-trough collector are given in Annex A.
The collector description should be supplied by the manufacturer according to Annex B.
All the components of the tested collector (reflectors, receiver, structure, etc.) shall be
representative of the product. The components shall be selected randomly from the
production.
All the serial numbers and identification of those components should be reported in the test
report.
6.2 Test equipment (installation/mounting/cleanliness)
6.2.1 Performance test
The sensors shall be mounted according to ISO 9806:2017. A basic diagram of the test
installation is presented in Figure 1.

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IEC 62862-3-2:2018 © IEC 2018 – 9 –
7 8 9
2 3 4 5 6
1
Power block / Balance of plant

IEC
Key
1 pump 6 temperature sensor (t )
out
2 flow meter (test) 7 ambient temperature sensor (t )
a
3 temperature sensor 8 pyrheliometer
4 temperature sensor (t ) 9 anemometer
in
5 parabolic-trough collector unit
Figure 1 – Test equipment installation
During the tests of a parabolic-trough collector it will be necessary to guarantee that the
reflectors and glass envelopes of the receivers are kept clean. It shall be ensured that the
< 1,0. For testing purposes, the
collector’s cleanliness factor is within the range 0,95 < F
c
cleanliness factor is defined as the ratio between the product of the reflectors reflectance and
the glass envelope transmittance during the test and the product of the reflectance and
transmittance nominal values.
There is currently no field instrumentation available to determine the degree of dirt in the
receiver cover once installed in the collector; a good approach is to assume that the same
percentage of reduction in the reflectors reflectance and in transmittance of the glass
envelope is produced due to dirt. The reflectors cleanliness factor χ will be measured
reflector
with a portable reflectometer in each sequence of the test, at least in five positions per
module. The number and position of points measured should be reported in the test report. If
the mean cleanliness factor is lower than 0,95, the collector (both reflectors and glass tube)

should be cleaned.

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Therefore, the global cleanliness is given by Equation (1):
3
2
 ρ 
1,5
test
F χ (1)
( )
 
C reflector
ρ
 nom 
where ρ is the specular reflectance measured during the test and ρ is the reference
test nom
value of the specular reflectance of the reflectors installed in the collector.
ρ and ρ should be measured with the same equipment.
nom test
6.2.2 Tracking error test
The solar tracker should be installed according to the manufacturer's recommendations. The
collector should have all the necessary components (receiver tube, reflector, structure, etc.).
One inclinometer or other angular sensor should be mounted on the centre of the parabola or
on the reflector, close to the drive pylon.
The minimum number of measurement devices is two, one close to the drive pylon and one
mounted in the collector end. It is recommended to install an additional sensor in the other
collector end. If the sensor is not perfectly parallel to the concentrator aperture an offset
should be subtracted to the tracking error calculated.
6.3 Measurement procedure
6.3.1 Performance test
The thermal performance test to determine peak optical efficiency, heat losses and incidence
angle modifier shall be performed according to ISO 9806:2017 using the quasi-dynamic test
method. The wind speed shall be less than 5,5 m/s for each point measured.
6.3.2 Tracking error test
The tracking test is performed over the full available tracking range (e.g. from sunrise to
sunset), by manually set tracking angles in steps of 10 degrees. The data shall be recorded
and evaluated for all the steps. Deviations between measured values and set values at the
drive have to be analysed. Also deviation between measured values at collector end and
collector centre have to be analysed. The recorded data should include:
• the tracker elevation error recorded in 1 min average intervals and calculated as
Equation (2):
θ ββ− (2)
T set
with the set tracking angles β and the real β (measured with an inclinometer);
set
• direct normal irradiance (DNI) recorded in 1 min average intervals (only if tracking system
with sun sensor);
• wind speed reported in 1 min increments for the 10 min mean speed at 10 m height
(terrain for the wind measurement and tracker location shall have a slope of less than
3 %);
• date and time.
The date and location of the test should be reported to facilitate assessment of adequacy of
the data collection, particularly with respect to the range of motion.
=
==

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6.4 Calculation and test results
6.4.1 General
Calculation of the test results shall be performed according to Clause 24 of ISO 9806:2017 for
the quasi-dynamic test method.
The increase of specific enthalpy of the fluid Δh is equal to ∆=hh − h . Polynomial
out in
approximations or interpolation of tabulated values can be used for the specific enthalpy h(T)
of the heat transfer fluid.
It is not recommended to use the specific heat capacity, because it depends on both inlet and
outlet temperature.
The fluid data table of the specific enthalpy (or specific heat capacity) depending on the
temperature shall be measured in the entire working range by a laboratory or any other
independent body. This data shall be perfectly documented and referenced.
6.4.2 Useful power
The model of the collector should be according to Formula (13) from ISO 9806:2017.
Additional requirements are set for collectors with a transparent cover and a concentration
ratio higher than 3, or for evacuated concentrating collectors: the wind speed dependency can
be neglected. So, some p
...