1、 Access to Additional Content for IEC 62097, Dated: February, 2009 (Click here to view the publication) This Page is not part of the original publication This page has been added by IHS as a convenience to the user in order to provide access to additional content as authorized by the Copyright holde
2、r of this document Click the link(s) below to access the content and use normal procedures for downloading or opening the files. IEC 62097 ed1.0 Scale Effect Calculation Information contained in the above is the property of the Copyright holder and all Notice of Disclaimer any IEC National Committee
3、 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 accord
4、ance 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 inte
5、rested 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 respons
6、ible 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
7、between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 6) All
8、 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
9、 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 publicati
10、on. 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 p
11、atent rights. International Standard IEC 62097 has been prepared by technical committee 4: Hydraulic turbines. The text of this standard is based on the following documents: FDIS Report of voting 4/242A/FDIS 4/243/RVD Full information on the voting for the approval of this standard can be found in t
12、he report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. This publication contains attached files in the form of Excel file. These files are intended to be used as a complement and do not form an integral part of this publ
13、ication. 6 62097 IEC:2009 The committee has decided that the contents of this publication will remain unchanged until the maintenance result data indicated on the IEC web site under “http:/webstore.iec.ch” in the data related to the specific publication. At this date, the publication will be recomme
14、nded; withdrawn; replaced by a revised edition; or amended. 62097 IEC:2009 7 INTRODUCTION 0.1 General remarks This International Standard establishes the prototype hydraulic machine efficiency from model test results, with consideration of scale effect including the effect of surface roughness. Adva
15、nces in the technology of hydraulic turbo-machines used for hydroelectric power plants indicate the necessity of revising the scale effect formula given in 3.8 of IEC 60193. 1 1The advance in knowledge of scale effects originates from work done by research institutes, manufacturers and relevant work
16、ing groups within the organizations of IEC and IAHR. 1 - 7 The method of calculating prototype efficiencies, as given in this standard, is supported by experimental work and theoretical research on flow analysis and has been simplified for practical reasons and agreed as a convention. 8 10 The metho
17、d is representing the present state of knowledge of the scale-up of performance from model to a homologous prototype. Homology is not limited to the geometric similarity of the machine components, it also calls for homologous velocity triangles at the inlet and outlet of the runner/impeller. 2 There
18、fore, compared to IEC 60193, a higher attention has to be paid to the geometry of guide vanes. According to the present state of knowledge, it is certain that, in most cases, the formula for the efficiency step-up calculation given in the IEC 60193 and earlier standards, overstated the step-up incre
19、ment of the efficiency for the prototype. Therefore, in the case where a user wants to restudy a project for which a calculation of efficiency step-up was done based on any previous method, the user shall re-calculate the efficiency step-up with the new method given in this standard, before restudyi
20、ng the project of concern. This standard is intended to be used mainly for the assessment of the results of contractual model tests of hydraulic machines. If it is used for other purposes such as evaluation of refurbishment of machines having very rough surfaces, special care should be taken as desc
21、ribed in Annex B. Due to the lack of sufficient knowledge about the loss distribution in Deriaz turbines and storage pumps, this standard does not provide the scale effect formula for them. An excel work sheet concerning the step-up procedures of hydraulic machine performance from model to prototype
22、 is indicated at the end of this Standard to facilitate the calculation of the step-up value. 0.2 Basic features A fundamental difference compared to the IEC 60193 formula is the standardization of scalable losses. In a previous standard (see 3.8 of IEC 60193:1999 1), a loss distribution factor V ha
23、s been defined and standardized, with the disadvantage that turbine designs which are not optimized benefit from their lower technological level. This is certainly not correct, since a low efficiency design has high non-scalable losses, like incidence losses, whereby the amount of scalable losses is
24、 about constant for all manufacturers, for a given type and a given specific speed of a hydraulic machine. This standard avoids all the inconsistencies connected with IEC 60193:1999. (see 3.8 of 1) A new basic feature of this standard is the separate consideration of losses in specific hydraulic energy, disc friction losses and leakage losses. 5, 8 10 1Numbers in square brackets refer to the bibliography.
