BS IEC 60287-2-3-2017 Electric cables Calculation of the current rating Thermal resistance Cables installed in ventilated tunnels《电缆 当前评级的计算 热阻 通风隧道中安装的电缆》.pdf

1、Electric cables - Calculation of the current ratingPart 2-3: Thermal resistance - Cables installed in ventilated tunnelsBS IEC 60287-2-3:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06IEC 60287-2-3 Edition 1.0 2017-04 INTERNATIONAL STANDARD NORME INTERNATIONALE

2、Electric cables Calculation of the current rating Part 2-3: Thermal resistance Cables installed in ventilated tunnels Cbles lectriques Calcul du courant admissible Partie 2-3: Rsistance thermique Cbles poss dans les tunnels ventils INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQU

3、E INTERNATIONALE ICS 29.060.20 ISBN 978-2-8322-4221-6 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale Warning! Make sure that you obtained this publication from an authorized distributor. Attention! Veuillez vous ass

4、urer que vous avez obtenu cette publication via un distributeur agr. National forewordThis British Standard is the UK implementation of IEC 60287-2-3:2017.The UK participation in its preparation was entrusted to Technical Committee GEL/20/16, Electric Cables - Medium/high voltage.A list of organizat

5、ions represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISB

6、N 978 0 580 84968 8ICS 29.060.20Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2017.Amendments/corrigenda issued since publicationDate Text affectedBRIT

7、ISH STANDARDBS IEC 6028723:2017IEC 60287-2-3 Edition 1.0 2017-04 INTERNATIONAL STANDARD NORME INTERNATIONALE Electric cables Calculation of the current rating Part 2-3: Thermal resistance Cables installed in ventilated tunnels Cbles lectriques Calcul du courant admissible Partie 2-3: Rsistance therm

8、ique Cbles poss dans les tunnels ventils INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE ICS 29.060.20 ISBN 978-2-8322-4221-6 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale Warni

9、ng! Make sure that you obtained this publication from an authorized distributor. Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agr. BS IEC 6028723:2017 2 IEC 60287-2-3:2017 IEC 2017 CONTENTS FOREWORD . 4 INTRODUCTION . 6 1 Scope 7 2 Normative references

10、7 3 Terms, definitions and symbols 7 3.1 Terms and definitions 7 3.2 Symbols 7 4 Description of method 9 4.1 General description . 9 4.2 Basic formulae 10 4.2.1 General . 10 4.2.2 Radial heat transfer by conduction within the cable . 10 4.2.3 Heat transfer by radiation from the cable surface to the

11、inner wall of the tunnel 11 4.2.4 Heat transfer by convection from the cable surface to the air inside the tunnel 11 4.2.5 Heat transfer by convection from the air inside the tunnel to the inner tunnel wall . 12 4.2.6 Longitudinal heat transfer by convection resulting from the forced or natural flow

12、 of air along the tunnel. 13 4.2.7 Radial heat conduction in the soil surrounding the tunnel. 13 4.3 Set of formulae . 14 4.4 Solving . 14 4.5 Iterative process . 15 5 Formulae for air properties 16 6 Temperature profile . 16 Annex A (informative) Calculation example 17 A.1 Cable and installation .

13、17 A.2 Calculated values . 17 Annex B (informative) Delta-star transformation . 21 Annex C (informative) Calculation of Fmcoefficient . 22 C.1 Definition of spacing . 22 C.2 Calculation of Fmcoefficient . 22 Bibliography 24 Figure A.1 Temperature profile along a 1 km tunnel . 19 Figure A.2 Temperatu

14、re profile along a 10 km tunnel . 19 Figure B.1 Delta-star transformation 21 Figure C.1 Spacing definitions . 22 Table 1 Fmcoefficient for radiation thermal resistance calculation 11 Table 2 Value of parameter Kcv. 12 Table A.1 Installation data . 17 BS IEC 6028723:2017 2 IEC 60287-2-3:2017 IEC 2017

15、 CONTENTS FOREWORD . 4 INTRODUCTION . 6 1 Scope 7 2 Normative references 7 3 Terms, definitions and symbols 7 3.1 Terms and definitions 7 3.2 Symbols 7 4 Description of method 9 4.1 General description . 9 4.2 Basic formulae 10 4.2.1 General . 10 4.2.2 Radial heat transfer by conduction within the c

16、able . 10 4.2.3 Heat transfer by radiation from the cable surface to the inner wall of the tunnel 11 4.2.4 Heat transfer by convection from the cable surface to the air inside the tunnel 11 4.2.5 Heat transfer by convection from the air inside the tunnel to the inner tunnel wall . 12 4.2.6 Longitudi

17、nal heat transfer by convection resulting from the forced or natural flow of air along the tunnel. 13 4.2.7 Radial heat conduction in the soil surrounding the tunnel. 13 4.3 Set of formulae . 14 4.4 Solving . 14 4.5 Iterative process . 15 5 Formulae for air properties 16 6 Temperature profile . 16 A

18、nnex A (informative) Calculation example 17 A.1 Cable and installation . 17 A.2 Calculated values . 17 Annex B (informative) Delta-star transformation . 21 Annex C (informative) Calculation of Fmcoefficient . 22 C.1 Definition of spacing . 22 C.2 Calculation of Fmcoefficient . 22 Bibliography 24 Fig

19、ure A.1 Temperature profile along a 1 km tunnel . 19 Figure A.2 Temperature profile along a 10 km tunnel . 19 Figure B.1 Delta-star transformation 21 Figure C.1 Spacing definitions . 22 Table 1 Fmcoefficient for radiation thermal resistance calculation 11 Table 2 Value of parameter Kcv. 12 Table A.1

20、 Installation data . 17 IEC 60287-2-3:2017 IEC 2017 3 Table A.2 Iterative process for a 1 km long tunnel 18 Table C.1 Expression for Fmcoefficient calculation . 22 BS IEC 6028723:2017 4 IEC 60287-2-3:2017 IEC 2017 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ELECTRIC CABLES CALCULATION OF THE CURRENT

21、 RATING Part 2-3: Thermal resistance Cables installed in ventilated tunnels 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 i

22、nternational 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 (here

23、after 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 part

24、icipate 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, a

25、n 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

26、 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 app

27、ly 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

28、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 pub

29、lication. 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

30、, 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 co

31、rrect 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 60287-2-3 has been prepar

32、ed by IEC technical committee 20: Electric cables. The text of this International Standard is based on the following documents: FDIS Report on voting 20/1707/FDIS 20/1720/RVD Full information on the voting for the approval of this International Standard can be found in the report on voting indicated

33、 in the above table. This document has been drafted in accordance with the ISO/IEC Directives, Part 2. BS IEC 6028723:2017 4 IEC 60287-2-3:2017 IEC 2017 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ELECTRIC CABLES CALCULATION OF THE CURRENT RATING Part 2-3: Thermal resistance Cables installed in vent

34、ilated tunnels 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 standar

35、dization 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

36、 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 th

37、e 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

38、 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 con

39、tent 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 possi

40、ble 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 conformi

41、ty 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 director

42、s, 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 ou

43、t 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

44、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 60287-2-3 has been prepared by IEC technical committee 20: Electric cables. The text o

45、f this International Standard is based on the following documents: FDIS Report on voting 20/1707/FDIS 20/1720/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 accord

46、ance with the ISO/IEC Directives, Part 2. IEC 60287-2-3:2017 IEC 2017 5 A list of all parts in the IEC 60287 series, published under the general title Electric cables Calculation of the current rating, can be found on the IEC website. The committee has decided that the contents of this document will

47、 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. BS IEC 6028723:2017 6 IEC 60287-2-3:2017 IEC 2017

48、INTRODUCTION In the IEC 60287 series, IEC 60287-1 provides general formulae for ratings and power losses of electric cables. IEC 60287-2 presents formulae or calculation methods for thermal resistances. IEC 60287-2-1 provides calculation methods for dealing with cables installed in free air (see IEC

49、 60287-2-1:2015,4.2.1). IEC 60287-2-2 provides a method and data for calculating reduction factors for cables in groups running horizontally in free air. IEC 60287-2-1 and IEC 60287-2-2 consider heat transfer only in a plane perpendicular to the cables; they assume there is no longitudinal heat transfer. This part of IEC 60287 deals with the rating for cables installed in ventilated tunnels. In such situations, cons