SIST EN ISO 22975-1:2017

SLOVENSKI STANDARD
SIST EN ISO 22975-1:2017
01-januar-2017
6RQþQDHQHUJLMD6HVWDYQLGHOLLQPDWHULDOLVSUHMHPQLNRYVRQþQHHQHUJLMHGHO
9DNXXPVNHFHYL7UDMQRVWLQ]PRJOMLYRVW,62
Solar energy - Collector components and materials - Part 1: Evacuated tubes - Durability
and performance (ISO 22975-1:2016)
Solarenergie - Kollektorbauteile und -materialien - Teil 1: Vakuumröhren - Beständigkeit
und Leistungsfähigkeit (ISO 22975-1:2016)
Energie solaire - Composants et matériaux du collecteur - Partie 1: Tubes sous vide -
Durabilité et performance (ISO 22975-1:2016)
Ta slovenski standard je istoveten z: EN ISO 22975-1:2016
ICS:
27.160 6RQþQDHQHUJLMD Solar energy engineering
SIST EN ISO 22975-1:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 22975-1:2017

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SIST EN ISO 22975-1:2017


EN ISO 22975-1
EUROPEAN STANDARD

NORME EUROPÉENNE

October 2016
EUROPÄISCHE NORM
ICS 27.160
English Version

Solar energy - Collector components and materials - Part 1:
Evacuated tubes - Durability and performance (ISO 22975-
1:2016)
Énergie solaire - Composants et matériaux du Solarenergie - Kollektorbauteile und -materialien - Teil
collecteur - Partie 1: Tubes sous vide - Durabilité et 1: Vakuumröhren - Beständigkeit und
performance (ISO 22975-1:2016) Leistungsfähigkeit (ISO 22975-1:2016)
This European Standard was approved by CEN on 12 September 2016.

CEN 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 CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 22975-1:2016 E
worldwide for CEN national Members.

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SIST EN ISO 22975-1:2017
EN ISO 22975-1:2016 (E)
Contents Page
European foreword . 3

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SIST EN ISO 22975-1:2017
EN ISO 22975-1:2016 (E)
European foreword
This document (EN ISO 22975-1:2016) has been prepared by Technical Committee ISO/TC 180 "Solar
energy" in collaboration with Technical Committee CEN/TC 312 “Thermal solar systems and
components” the secretariat of which is held by ELOT.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2017, and conflicting national standards shall be
withdrawn at the latest by April 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 22975-1:2016 has been approved by CEN as EN ISO 22975-1:2016 without any
modification.

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SIST EN ISO 22975-1:2017

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SIST EN ISO 22975-1:2017
INTERNATIONAL ISO
STANDARD 22975-1
First edition
2016-10-01
Solar energy — Collector components
and materials —
Part 1:
Evacuated tubes — Durability and
performance
Énergie solaire — Composants et matériaux du collecteur —
Partie 1: Tubes sous vide — Durabilité et performance
Reference number
ISO 22975-1:2016(E)
©
ISO 2016

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SIST EN ISO 22975-1:2017
ISO 22975-1:2016(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved

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SIST EN ISO 22975-1:2017
ISO 22975-1:2016(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification and test list . 2
5 Testing of material . 3
5.1 Inspection for stones and knots . 3
5.1.1 General. 3
5.1.2 Test conditions. 3
5.1.3 Apparatus . 3
5.1.4 Procedure . 3
5.1.5 Results . 4
5.2 Inspection for scratches . 4
5.2.1 General. 4
5.2.2 Test conditions. 4
5.2.3 Apparatus . 4
5.2.4 Procedure . 4
5.2.5 Results . 5
5.3 Testing of solar transmittance . 5
5.3.1 General. 5
5.3.2 Test conditions and apparatus . 5
5.3.3 Procedure . 5
5.3.4 Results . 5
5.4 Testing of solar absorptance . 5
5.4.1 General. 5
5.4.2 Test conditions and apparatus . 5
5.4.3 Procedure . 5
5.4.4 Results . 6
5.5 Testing of hemispherical emittance . 6
5.5.1 General. 6
5.5.2 Test conditions. 6
5.5.3 Apparatus and procedure . 6
5.5.4 Results . 7
6 Durability testing of evacuated tube . 7
6.1 Vacuum performance . 7
6.1.1 General. 7
6.1.2 Test conditions and apparatus . 7
6.1.3 Procedure . 8
6.1.4 Results . 8
6.2 Resistance to thermal shock . 8
6.2.1 General. 8
6.2.2 Test conditions and apparatus . 9
6.2.3 Procedure . 9
6.2.4 Results . 9
6.3 Resistance to impact . 9
6.3.1 General. 9
6.3.2 Principle . 9
6.3.3 Procedure . 9
6.3.4 Results . 9
6.4 Resistance to internal pressure .10
6.4.1 General.10
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SIST EN ISO 22975-1:2017
ISO 22975-1:2016(E)

6.4.2 Test conditions and apparatus .10
6.4.3 Procedure .10
6.4.4 Results .10
7 Performance testing of evacuated tube .10
7.1 Tests for determination the exposure parameter .10
7.1.1 General.10
7.1.2 Test conditions.11
7.1.3 Apparatus .11
7.1.4 Procedure .12
7.1.5 Results .13
7.2 Tests for determination of sum of solar irradiation for temperature increase of
double-glass evacuated tube .13
7.2.1 General.13
7.2.2 Test conditions.13
7.2.3 Apparatus .13
7.2.4 Procedure and results .13
7.3 Tests to determine the average heat loss coefficient of a double-glass evacuated tube .13
7.3.1 General.13
7.3.2 Test conditions.14
7.3.3 Apparatus .14
7.3.4 Procedure .14
7.3.5 Results .15
Annex A (informative) Configuration schemes of evacuated tubes .16
Annex B (normative) Test report .18
Annex C (normative) Determination of the external surface area of absorber tube for
double-glass evacuated tubes .25
Bibliography .27
iv © ISO 2016 – All rights reserved

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SIST EN ISO 22975-1:2017
ISO 22975-1:2016(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 180, Solar energy.
ISO 22975 consists of the following parts, under the general title Solar energy — Collector components
and materials:
— Part 1: Evacuated tubes — Durability and performance
— Part 2: Heat-pipes for solar thermal application — Durability and performance
— Part 3: Absorber surface durability
The following parts are under preparation:
— Part 5: Insulation material durability and performance
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SIST EN ISO 22975-1:2017
ISO 22975-1:2016(E)

Introduction
This part of ISO 22975 is applicable to all categories of evacuated tubes, including double-glass
evacuated tubes and glass-metal sealed evacuated tubes.
This part of ISO 22975 provides test methods for inspecting stones and knots in envelope glass tubes.
This part of ISO 22975 also provides test methods for determining durability of evacuated tubes,
including vacuum performance, thermal shock resistance, external impact resistance and internal
pressure resistance. For each durability test, this part of ISO 22975 specifies general, apparatus,
procedure and results of the test.
This part of ISO 22975 also provides test methods for measuring performance of evacuated tubes,
including exposure parameter, solar irradiation for temperature increase of double-glass evacuated
tube and average heat loss coefficient. For each performance test, principle, test conditions, apparatus,
procedure and results of the test are specified.
vi © ISO 2016 – All rights reserved

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SIST EN ISO 22975-1:2017
INTERNATIONAL STANDARD ISO 22975-1:2016(E)
Solar energy — Collector components and materials —
Part 1:
Evacuated tubes — Durability and performance
1 Scope
This part of ISO 22975 specifies definitions and test methods for materials, durability and performance
of evacuated tubes.
This part of ISO 22975 is applicable to all types of evacuated tubes.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 9488, Solar energy — Vocabulary
ISO 9845-1, Solar energy — Reference solar spectral irradiance at the ground at different receiving
conditions — Part 1: Direct normal and hemispherical solar irradiance for air mass 1,5
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9488 and the following apply.
3.1
double-glass evacuated tube
component of an evacuated tube solar collector, of which both the inner tube and the envelope tube are
made of glass
3.2
glass-metal sealed evacuated tube
component of an evacuated tube solar collector, in which the absorber is affixed to a metal fluid channel,
that is sealed into the envelope glass tube through a specific glass-metal sealing process
3.3
stone
opaque inclusions in the glass of the evacuated tube
3.4
knot
transparent inclusions in the glass of the evacuated tube
3.5
scratch
abraded area where the surface of the glass is torn or worn off
3.6
vacuum jacket
space between envelope glass tube and absorber in an evacuated tube, wherein air pressure is
sufficiently low that thermal conduction and convection of air can be ignored
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SIST EN ISO 22975-1:2017
ISO 22975-1:2016(E)

3.7
stagnation
state where no working fluid passes through the evacuated tube and the temperature of the evacuated
tube is determined by the solar irradiance
3.8
exposure temperature
maximum temperature at an accessible part of an evacuated tube with specified irradiance under
stagnation (3.7) conditions
Note 1 to entry: For double glass evacuated tubes, the temperature with only air in the tube is measured. For
direct flow tubes, the measurement is done in the air-filled flow channel within the vacuum tube. For glass-metal
sealed tubes with heat pipe, the well-insulated condenser surface temperature is measured.
3.9
exposure parameter
ratio of the difference between exposure temperature (3.8) and ambient temperature to the solar
irradiance
3.10
sum of solar irradiation for temperature increase
sum of solar irradiation for a certain preset temperature rise range of the water in a double-glass
evacuated tube (3.1)
Note 1 to entry: This term applies only to double-glass evacuated tubes.
3.11
average heat loss coefficient
ratio of heat loss per m² defined external surface area of absorber tube, without irradiance, to
temperature difference between water content of vacuum tube and ambient air
Note 1 to entry: This term applies only to double-glass evacuated tubes (3.1).
4 Classification and test list
According to material category of absorber, evacuated tubes can be substantially classified into two types:
a) double-glass evacuated tube, see Figure A.1;
b) glass-metal sealed evacuated tube, see Figure A.2.
Tests for the two categories of evacuated tubes are summarized in Table 1.
Table 1 — Test list
Category of evacuated tube Test
Double-glass, Glass-metal sealed 5.1 Inspection for stones and knots
Double-glass, Glass-metal sealed 5.2 Inspection for scratches
Double-glass, Glass-metal sealed 5.3 Testing of solar transmittance
Double-glass 5.4 Testing of solar absorptance
Double-glass 5.5 Testing of hemispherical emittance
Double-glass 6.1 Vacuum performance
Double-glass 6.2 Resistance to thermal shock
Double-glass, Glass-metal sealed 6.3 Resistance to Impact
Double-glass, Glass-metal sealed direct flow 6.4 Resistance to internal pressure
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SIST EN ISO 22975-1:2017
ISO 22975-1:2016(E)

Table 1 (continued)
Category of evacuated tube Test
Double-glass, Glass-metal sealed 5.1 Inspection for stones and knots
7.1 Tests for determination of exposure
Double-glass, Glass-metal sealed
parameter
7.2 Tests for determination of sum of solar
Double-glass irradiation for temperature increase of
double-glass evacuated tube
7.3 Tests for determination the average heat loss
Double-glass
coefficient of double-glass evacuated tube
5 Testing of material
5.1 Inspection for stones and knots
5.1.1 General
This test is intended to check the uniformity of the tube glass by visual inspection.
5.1.2 Test conditions
The test room/table for taking observations shall have a minimum illuminance of 1 500 lx.
5.1.3 Apparatus
The dimension measurement instrument shall have an accuracy of ±0,1 mm.
5.1.4 Procedure
a) Draw
...