CEN TS 15548-1-2014 Thermal insulation products for building equipment and industrial installations - Determination of thermal resistance by means of the guarded hot plate method -.pdf

1、BSI Standards PublicationThermal insulation products for building equipment and industrial installations Determination of thermal resistance by means of the guarded hot plate methodPart 1: Measurements at elevated temperatures from 100 C to 850 CPD CEN/TS 15548-1:2014National forewordThis Published

2、Document is the UK implementation of CEN/TS 15548-1:2014. It supersedes DD CEN/TS 15548-1:2011 which iswithdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee B/540, Energy performance of materials components and buildings.A list of organizations represented on this com

3、mittee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2014.Published by BSI Standards Limited 2014ISBN 978 0 580 83310 6ICS 91.100.

4、60Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document was published under the authority of theStandards Policy and Strategy Committee on 31 August 2014.Amendments/corrigenda issued since publicationDate Text affectedPUBLISHED DOCUMENTPD CEN/TS 1554

5、8-1:2014TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 15548-1 August 2014 ICS 91.100.60 Supersedes CEN/TS 15548-1:2011English Version Thermal insulation products for building equipment and industrial installations - Determination of thermal resistance by means of the

6、 guarded hot plate method - Part 1: Measurements at elevated temperatures from 100 C to 850 C Produits isolants thermiques pour les quipements de btiments et les installations industrielles - Dtermination dela rsistance thermique par la mthode de la plaque chaudegarde - Partie 1: Mesurages haute tmp

7、erature entre 100 C et 850 C Wrmedmmstoffe fr die Haustechnik und fr betriebstechnische Anlagen - Bestimmung des Wrmedurchlasswiderstandes nach dem Verfahren mit dem Plattengert - Teil 1: Messungen bei erhhten Temperaturen von 100 C bis 850 C This Technical Specification (CEN/TS) was approved by CEN

8、 on 28 June 2014 for provisional application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard. CEN membe

9、rs are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the final decision about the p

10、ossible conversion of the CEN/TS into an EN is reached. 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, L

11、ithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17

12、, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TS 15548-1:2014 EPD CEN/TS 15548-1:2014CEN/TS 15548-1:2014 (E) 2 Contents Page Foreword 3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and defini

13、tions, symbols and units 5 3.1 Terms and definitions .5 3.2 Symbols and units .5 4 Principle 6 4.1 Apparatus .6 4.2 Measuring the density of heat flow rate 6 4.3 Measuring the temperature difference 6 4.4 Deriving the thermal resistance or transfer factor .6 4.5 Computing thermal conductivity or the

14、rmal transmissivity .6 4.6 Apparatus limits .7 4.7 Specimen limits7 5 Apparatus description and design requirement .7 5.1 General 7 5.2 Two specimen apparatus 8 5.3 Single specimen apparatus 8 5.4 Plates 8 5.5 Main heating unit 10 5.6 Edge insulation and auxiliary guards . 11 5.7 Cold plates . 11 5.

15、8 Thickness measurement system 11 5.9 Accuracy and repeatability 11 5.10 Uncertainty analysis and equipment performance checks 11 6 Test specimen . 12 6.1 General . 12 6.2 Selection and size . 12 6.3 Specimen preparation 12 7 Testing procedure. 13 7.1 General . 13 7.2 Conditioning 13 7.3 Measurement

16、s . 13 8 Calculations and test report 15 8.1 Density and mass changes 15 8.2 Heat transfer properties . 16 9 Test report . 17 Annex A (normative) Limits for equipment performance and test conditions 19 A.1 General . 19 A.2 Accuracy and repeatability, stability, uniformity . 19 A.3 Suggested apparatu

17、s sizes . 20 A.4 Equipment design requirements . 20 A.5 Acceptable specimen characteristics 21 A.6 Acceptable testing conditions . 22 PD CEN/TS 15548-1:2014CEN/TS 15548-1:2014 (E) 3 Foreword This document (CEN/TS 15548-1:2014) has been prepared by Technical Committee CEN/TC 89 “Thermal performance o

18、f buildings and building components”, the secretariat of which is held by SIS. 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. This do

19、cument supersedes CEN/TS 15548-1:2011. Significant changes between this and the previous edition are: In clause 5.4.3, modifications of Figure 1 and Figure 2; now denoted Figure 1a and Figure 1b In A.4, for clause 2.1.4.1.2, the value for minimum numbers of sensors is changed to 10A or 2 In A.6, for

20、 clause 1.7.3, the values are changed to 20 K and 50 K respectively. In A.6, for clause 3.3.3, the lower and upper limits of temperature differences across the specimen have been changed to 30 K and 70 K respectively. According to the CEN-CENELEC Internal Regulations, the national standards organiza

21、tions of the following countries are bound to announce this Technical Specification: 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

22、, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. PD CEN/TS 15548-1:2014CEN/TS 15548-1:2014 (E) 4 Introduction This Technical Specification is an interim solution to the need for a standard to complement EN 12667:2

23、001 in the approximate temperature range 100 C to 850 C. The Technical Specification is chosen to publish the knowledge gained in the field of measuring thermal conductivity at elevated temperature now, as the finalisation of a standard is a complex matter requiring further investigations. Among exi

24、sting apparatus for steady state thermal testing, the guarded hot plate can be operated at selected mean temperatures over the temperature range -100 C to 850 C. In general these apparatus exist in three forms covering roughly the following temperature ranges -100 C to ambient, ambient to 100 C and

25、above 100 C. However it has been found that it is not possible to achieve the uncertainties of 2 % claimed as achievable for the low and ambient temperature forms when using the high temperature version in accordance with ISO 8302. More realistic figures adopting the method and procedures detailed i

26、n this document are 5 % up to 450 C and 7 % at temperatures above 450 C. Many issues are more difficult at high temperatures. There are design issues due to apparatus material stability, the level of temperature measurement uncertainty is higher than at ambient temperatures and there is also greater

27、 degradation in the performance of temperature sensors when operated at high temperatures, requiring calibration checks to be more frequent. At high temperature it is more likely to get hot spots on a plate due to non uniformity of a heater; these could be near temperature sensors and give false rea

28、dings. Any air gaps will have greater heat flow across them due to radiation heat exchange and finally provisions for specimen expansion or shrinkage are needed. Due to the above considerations the following clauses of EN 12667:2001 have been expanded and detailed: 5 Apparatus 5.1 General 5.2.4 Heat

29、ing Unit 5.2.5 Metering Area 5.2.6 Edge insulation and auxiliary guards 5.2.7 Cooling units 5.3.5 Accuracy and repeatability 6 Test specimens 6.2 Selection and size 7 Testing procedure 7.3.8 Settling time and measurement interval Annex A Annex B.2 PD CEN/TS 15548-1:2014CEN/TS 15548-1:2014 (E) 5 1 Sc

30、ope This Technical Specification provides the additional information to that given in EN 12667, EN 12664, EN 12939 and ISO 8302 on the design of apparatus and operational procedures required to determine the thermal resistance of thermal insulation products in the temperature range 100 C to 850 C us

31、ing the guarded hot plate method. 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 refere

32、nced document (including any amendments) applies. EN 1946-2, Thermal performance of building products and components - Specific criteria for the assessment of laboratories measuring heat transfer properties - Part 2: Measurements by guarded hot plate method EN 12664, Thermal performance of building

33、materials and products - Determination of thermal resistance by means of guarded hot plate and heat flow meter methods - Dry and moist products of medium and low thermal resistance EN 12667:2001, Thermal performance of building materials and products - Determination of thermal resistance by means of

34、 guarded hot plate and heat flow meter methods - Products of high and medium thermal resistance EN 12939, Thermal performance of building materials and products - Determination of thermal resistance by means of guarded hot plate and heat flow meter methods - Thick products of high and medium thermal

35、 resistance EN ISO 7345, Thermal insulation - Physical quantities and definitions (ISO 7345) EN ISO 9288, Thermal insulation - Heat transfer by radiation - Physical quantities and definitions (ISO 9288) ISO 8302:1991, Thermal insulation - Determination of steady-state thermal resistance and related

36、properties - Guarded hot plate apparatus 3 Terms and definitions, symbols and units 3.1 Terms and definitions For the purposes of this document the terms and definitions given in EN ISO 7345 and EN ISO 9288 apply. 3.2 Symbols and units Symbol Quantity Unit A metering area measured on a selected isot

37、hermal surface m2 d thickness; average thickness of specimen m e edge number ratio - m mass ( of the specimen ) kg m mass change kg q density of heat flow rate W/m2 R thermal resistance mK/W R increment of thermal resistance mK/W PD CEN/TS 15548-1:2014CEN/TS 15548-1:2014 (E) 6 r thermal resistivity

38、mK/W T1temperature of the warm surface of the specimen K T2temperature of the cold surface of the specimen K T3specimen edge temperature K Tmmean test temperature (usually (T1+ T2)/2) K T temperature difference (usually T1- T2) K t time interval s T transfer factor W/(mK) V volume m3 heat flow rate

39、W thermal conductivity W/(mK) tthermal transmissivity W/(mK) density kg/m3 4 Principle 4.1 Apparatus The principle of the guarded hot plate method is as described in subclause 1.6 of ISO 8302:1991.The guarded hot plate apparatus is intended to establish a unidirectional constant and uniform density

40、of heat flow rate within homogeneous specimens, in the form of slabs with flat parallel faces. The part of the apparatus where this takes place with acceptable accuracy is around its centre; the apparatus is therefore divided in a central metering section in which measurements are taken, and a surro

41、unding guard section. NOTE Specimen homogeneity is discussed in A.3.2 of EN 12667:2001. 4.2 Measuring the density of heat flow rate Following the establishment of steady state in the metering section, the density of heat flow rate, q, is determined from measurement of the heat flow rate, , and the m

42、etering area, A, that the heat flow crosses. 4.3 Measuring the temperature difference The temperature difference across the specimens, T, is measured by temperature sensors fixed on or in the surfaces of the plates in contact with the specimens and/or those fixed on/or in the surfaces of the specime

43、ns themselves, where appropriate. 4.4 Deriving the thermal resistance or transfer factor The thermal resistance, R, is calculated from q, A and T. From the additional knowledge of the thickness, d, of the specimen, the transfer factor, T, is computed; see A.2.8 of EN 12667:2001. 4.5 Computing therma

44、l conductivity or thermal transmissivity The mean thermal conductivity, or thermal transmissivity t, of the specimen may also be computed if the appropriate conditions to identify them and those given in A.4.3 of EN 12667:2001 are realised. PD CEN/TS 15548-1:2014CEN/TS 15548-1:2014 (E) 7 4.6 Apparat

45、us limits The application of the method is limited by the capability of the apparatus to maintain an unidirectional, constant and uniform density of heat flow rate in the specimen, coupled with the ability to measure power, temperature and dimensions to the limit of accuracy required, see Annex A. 4

46、.7 Specimen limits The application of the method is also limited by the shape of the specimen(s) and the degree to which they are identical in thickness and uniformity of structure (in the case of two specimen apparatus) and whether their surfaces are flat or parallel, see Annex A. 5 Apparatus descr

47、iption and design requirement 5.1 General A guarded hot plate apparatus used for measurements according to this document shall comply with the limits on equipment performance and test conditions given in Annex A and shall conform with the requirements concerning the assessment of equipment accuracy

48、given in EN 1946-2; this requires that the equipment design, error analysis and performance checks are according to Section 2 in ISO 8302. A guarded hot plate design for high temperature measurement needs detailed modelling of heater plates, gap, imbalance sensors, guard plates, edge insulation and

49、auxiliary guards and requires much more careful design than its ambient temperature counterpart for the following reasons: The heater plate material needs to retain its mechanical properties to the higher operating temperatures. Suitable materials with the higher strength requirements usually have a lower thermal conductivity than pure copper and aluminium alloys that are normally used at ambient temperatures. This can mean that the heater plates have to be thicker to ensure uniform temperature di