1、TECHNICALREPORTIECTR 62140-2First edition2002-10Fossil-fired steam power stations Part 2:Drum-level controlCentrales vapeur consommant des combustibles fossiles Partie 2:Contrle du niveau deau des ballonsReference numberIEC/TR 62140-2:2002(E)LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL US
2、E AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.Publication numberingAs from 1 January 1997 all IEC publications are issued with a designation in the60000 series.For example,IEC 34-1 is now referred to as IEC 60034-1.Consolidated editionsThe IEC is now publishing consolidated versions of its
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8、er Service Centre:Email:custserviec.chTel:+41 22 919 02 11Fax:+41 22 919 03 00LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.TECHNICALREPORTIECTR 62140-2First edition2002-10Fossil-fired steam power stations Part 2:Drum-level controlCe
9、ntrales vapeur consommant des combustibles fossiles Partie 2:Contrle du niveau deau des ballonsPRICE CODE IEC 2002 Copyright-all rights reservedNo part of this publication may be reproduced or utilized in any form or by any means,electronic ormechanical,including photocopying and microfilm,without p
10、ermission in writing from the publisher.International Electrotechnical Commission,3,rue de Varemb,PO Box 131,CH-1211 Geneva 20,SwitzerlandTelephone:+41 22 919 02 11 Telefax:+41 22 919 03 00 E-mail:inmailiec.ch Web:www.iec.chPFor price,see current catalogueCommission Electrotechnique InternationaleIn
11、ternational Electrotechnical Commission LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.2 TR 62140-2 IEC:2002(E)CONTENTSFOREWORD.3INTRODUCTION.51Scope.62Controlled system.62.1Description of controlled system.62.2Structure and design.62
12、.3Position of the water-level set point in the drum.62.4Steady-state and transient behaviour.73Formulation of control task.83.1Control set point.83.2Control performance requirements.94Configurations of the control circuits.94.1Single-element control.104.2Three-element control.104.3Three element cont
13、rol as cascade circuit.105Realization of the control circuit.115.1Measuring element.115.2Actuators for regulating feed-water flow.12Figure 1 Control behaviour of water level l.7Figure 2 Disturbance behaviour of water level l.8Figure 3 Measuring and control ranges on the drum.9Figure 4 Configurations
14、 of the control circuit.10Figure 5 System and pump characteristic at constant speed and with the pumpminimum flow valve closed.13Figure 6 Family of characteristics with alteration of pump speed.14Figure 7 Family of characteristics with throttling.14LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTE
15、RNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.TR 62140-2 IEC:2002(E)3 INTERNATIONAL ELECTROTECHNICAL COMMISSION_FOSSIL-FIRED STEAM POWER STATIONS Part 2:Drum-level controlFOREWORD1)The IEC(International Electrotechnical Commission)is a worldwide organization for standardization compr
16、isingall national electrotechnical committees(IEC National Committees).The object of the IEC is to promoteinternational co-operation on all questions concerning standardization in the electrical and electronic fields.Tothis end and in addition to other activities,the IEC publishes International Standards.Their preparation isentrusted to technical committees;any IEC National Committee interested in the subject dealt with mayparticipate in this preparatory work.International,governmental and non-g
