ANSI ASME PTC 12.1-2015 Closed Feedwater Heaters.pdf

1、Closed Feedwater HeatersPerformance Test CodesAN AMERICAN NATIONAL STANDARDASME PTC 12.1-2015Revision of ASME PTC 12.1-2000 (R2005)ASME PTC 12.1-2015Revision of ASME PTC 12.1-2000 (R2005)Closed FeedwaterHeatersPerformance Test CodesAN AMERICAN NATIONAL STANDARDTwo Park Avenue New York, NY 10016 USAD

2、ate of Issuance: June 30, 2016This Code will be revised when the Society approves the issuance of a new edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of this Code.Interpretations are published on the Committee Web page and under go.asme.org/InterpsD

3、atabase.Periodically certain actions of the ASME PTC Committee may be published as Code Cases. Code Casesare published on the ASME Web site under the PTC Committee Page at go.asme.org/PTCcommitteeas they are issued.Errata to codes and standards may be posted on the ASME Web site under the Committee

4、Pages toprovide corrections to incorrectly published items, or to correct typographical or grammatical errorsin codes and standards. Such errata shall be used on the date posted.The PTC Committee Page can be found at go.asme.org/PTCcommittee. There is an option availableto automatically receive an e

5、-mail notification when errata are posted to a particular code or standard.This option can be found on the appropriate Committee Page after selecting “Errata” in the “PublicationInformation” section.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standar

6、d was developed under procedures accredited as meeting the criteria for American NationalStandards. The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate. The proposed code or st

7、andard was madeavailable for public review and comment that provides an opportunity for additional public input from industry, academia,regulatory agencies, and the public-at-large.ASME does not “approve,” “rate,” or “endorse” any item, construction, proprietary device, or activity.ASME does not tak

8、e any position with respect to the validity of any patent rights asserted in connection with anyitems mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent, nor assumes any such liability. Users of

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10、vernment or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued in accordance with the establishedASME procedures and policies, which precludes the issuance of interpretations by individuals.No part of this document may be

11、reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersTwo Park Avenue, New York, NY 10016-5990Copyright 2016 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U

12、.S.A.CONTENTSNotice . vForeword viCommittee Roster . viiCorrespondence With the PTC Committee viiiSection 1 Object and Scope . 11-1 General 11-2 Object . 11-3 Scope 11-4 Uncertainty 2Section 2 Definitions and Descriptions of Terms 32-1 Symbols . 32-2 Nomenclature 32-3 Subscripts . 3Section 3 Guiding

13、 Principles. 73-1 Items for Agreement . 73-2 Parameters Affecting Feedwater Heater Performance 73-3 Methods of Operating During the Test 73-4 Preparation for the Test 83-5 Duration of Runs and Frequency of Readings . 103-6 Steady-State Limits 103-7 Measurement Uncertainty 103-8 Location of Test Poin

14、ts . 11Section 4 Instruments and Methods of Measurement 224-1 General 224-2 Pressure Measurement . 224-3 Temperature Measurement . 224-4 Water Flow Measurement 234-5 Split Stream Feedwater Heater Testing 244-6 Multiple Inlet Steam Nozzles . 254-7 Instrument Uncertainties . 25Section 5 Computation of

15、 Results 265-1 Introduction . 265-2 Performance Calculation Procedures 265-3 Uncertainty Calculation Procedures . 38Section 6 Report of Results 40Section 7 References 42Figures3-3.2-1 Typical DCA and TTD Versus Heater Internal Liquid Level . 93-8-1 Three-Zone Heater Test Points: Desuperheating, Cond

16、ensing, and DrainCooling Zones . 123-8-2 Thermal Profile: Desuperheating, Condesing, and Drain Cooling Zones 133-8-3 Two-Zone Heater Test Points: Desuperheating and Condensing Zones . 143-8-4 Thermal Profile: Desuperheating and Condensing Zones 153-8-5 Two-Zone Heater Test Points: Condensing and Dra

17、in Cooling Zones 163-8-6 Thermal Profile: Condensing and Drain Cooling Zones 173-8-7 Single-Zone Heater Test Points: Condensing Zone Only . 18iii3-8-8 Thermal Profile: Condensing Zone . 193-8-9 Single-Zone Heater Test Points: External Drain Cooler 203-8-10 Thermal Profile: External Drain Cooler . 21

18、4-4-1 Typical Transducer Installation . 24Form6-1 Performance Testing of Closed Feedwater Heaters 41Tables2-1-1 Symbols . 42-2-1 Nomenclature 63-6-1 Deviation Limits of Parameters . 104-7-1 Maximum Uncertainty Values 255-2.1-1 Manufacturer Design Data . 27Nonmandatory AppendicesA Basic Heat Transfer

19、 Equations 43B Heater Performance Calculation Examples. 46C Uncertainty Considerations. 56D Principal Quantities and Commonly Used Conversion Factors in Heat Transfer(SI Units) . 61ivNOTICEAll Performance Test Codes must adhere to the requirements of ASME PTC 1, GeneralInstructions. The following in

20、formation is based on that document and is included here foremphasis and for the convenience of the user of the Code. It is expected that the Code user isfully cognizant of Sections 1 and 3 of ASME PTC 1 and has read them prior to applying thisCode.ASME Performance Test Codes provide test procedures

21、 that yield results of the highest levelof accuracy consistent with the best engineering knowledge and practice currently available.They were developed by balanced committees representing all concerned interests and specifyprocedures, instrumentation, equipment-operating requirements, calculation me

22、thods, and uncer-tainty analysis.When tests are run in accordance with a Code, the test results themselves, without adjustmentfor uncertainty, yield the best available indication of the actual performance of the tested equip-ment. ASME Performance Test Codes do not specify means to compare those res

23、ults to contractualguarantees. Therefore, it is recommended that the parties to a commercial test agree before startingthe test and preferably before signing the contract on the method to be used for comparing thetest results to the contractual guarantees. It is beyond the scope of any Code to deter

24、mine orinterpret how such comparisons shall be made.vFOREWORDThe Performance Test Code Committee 12.1 was assembled to review, edit, and update the1978 Code edition. The Code was extensively revised to comply with the requirements inASME PTC 1-1991, General Instructions, including the required uncer

25、tainty analysis. The 2000edition of this Code incorporated a revised calculation procedure including examples. The calcula-tion method requires iterations and may be performed manually but is best done by computer.The Code incorporated an alternative for using ultrasonic flow measurement techniques

26、to testindividual or split-string feedwater heaters when flow nozzles are not available.The PTC 12.1 Committee was once again assembled to review, edit, and update the 2000 edition.This Code has been extensively revised to make it more intuitive including more descriptivesubscripts, variable names,

27、modified figures, test forms, and notes, an expanded NonmandatoryAppendix A, and a general emphasis on educating the engineer on heater testing and performance.The uncertainty calculations have been updated to reflect the latest ASME PTC 19.1 terminology.The 2015 edition of the Code provides a relat

28、ively simple but accurate method of calculatingthe performance of a feedwater heater utilizing the Code procedure with a minimum knowledgeof the design characteristics of the feedwater heater.The PTC 12.1 Committee would like to acknowledge the contributions from Mr. George Osolsobeto this Performan

29、ce Test Code. This revision was approved by the Board on Performance TestCodes on June 25, 2015 and as an American National Standard on October 26, 2015.viASME PTC COMMITTEEPerformance Test Codes(The following is the roster of the Committee at the time of approval of this Code.)STANDARDS COMMITTEE O

30、FFICERSP. G. Albert, ChairJ. Milton, Vice ChairF. Constantino, SecretarySTANDARDS COMMITTEE PERSONNELP. G. Albert, ConsultantJ. Burns, Burns EngineeringA. E. Butler, GE Power however, they shouldnot contain proprietary names or information.Requests that are not in this format may be rewritten in the

31、 appropriate format by the Committeeprior to being answered, which may inadvertently change the intent of the original request.ASME procedures provide for reconsideration of any interpretation when or if additionalinformation that might affect an interpretation is available. Further, persons aggriev

32、ed by aninterpretation may appeal to the cognizant ASME Committee or Subcommittee. ASME does not“approve,” “certify,” “rate,” or “endorse” any item, construction, proprietary device, or activity.Attending Committee Meetings. The PTC Standards Committee and PTC Committees regularlyhold meetings and/o

33、r telephone conferences that are open to the public. Persons wishing to attendany meeting and/or telephone conference should contact the Secretary of the PTC StandardsCommittee. Future Committee meeting dates and locations can be found on the Committee Page atgo.asme.org/PTCcommittee.viiiASME PTC 12

34、.1-2015CLOSED FEEDWATER HEATERSSection 1Object and Scope1-1 GENERAL(a) For the purpose of this Code, a closed feedwaterheater is a power plant heat exchanger designed to heata given quantity of feedwater through a specified tem-perature range. The heating medium is steam or conden-sate at a specifie

35、d temperature and pressure. Infeedwater heaters, the feedwater and heating mediumtypically are routed through the tubes and shell, respec-tively. Feedwater heaters are typically designed to beconfigured in one of the following ways:(1) horizontal(2) vertical channel down(3) vertical channel up(4) du

36、plex (two separate tube bundles in a singledivided shell)(b) In some cases, more than one feedwater heater isrequired for a given feedwater flow and extraction steamsource. In such instances, the feedwater heater is dividedinto two or three parallel heaters, which constitute amultiple string arrange

37、ment.The shell side of the heater may be constructed withone, two, or three independent zones and arranged invarious combinations:(1) desuperheating zone(2) condensing zone(3) drain cooling zoneEach zone is considered to be an independent heattransfer entity contained within the same shell.Extractio

38、n steam from the turbine is the heatingmedium in the desuperheating zone. Depending on theheater design, extraction steam from the turbinetogether with other possible energy sources such asincoming drains are the heating medium in the condens-ing zone. Condensate is the heating medium in the drainco

39、oling zone.(c) This Code is written in accordance with theASME PTC 1, General Instructions. ASME PTC 2,Definitions and Values, defines certain technical termsand numerical constants which are used in this Codewith the significance and value therein established. ThePTC 19 Series, Supplements on Instr

40、uments and1Apparatus, which covers the instruments prescribed inthis Code, should be used for reference.1-2 OBJECTThe object of this Code is to provide the procedures,direction, and guidance for determining the thermo-hydraulic performance of a closed feedwater heater. Itcan be utilized to verify co

41、ntractual performance for anew heater or to calculate performance of an existingheater in comparison to the design point. The overallperformance parameters utilized to accomplish this arethe following:(a) terminal temperature difference (TTD), which isthe difference between the saturation temperatur

42、e cor-responding to the steam inlet pressure and the feedwateroutlet temperature(b) drain cooler approach (DCA), which is the differ-ence between drain outlet temperature and feedwaterinlet temperature(c) tube-side (feedwater) pressure loss through theheater(d) shell-side pressure loss through the d

43、esuperheat-ing zone(e) shell-side pressure loss through the drain cool-ing zoneThe Code methodology adjusts the manufacturersguaranteed performance parameters to the actual testconditions, for a comparison to as-tested performance.1-3 SCOPEThis Code applies to all horizontal and vertical heatersexce

44、pt those with partial pass full-length drain coolingzones. The heater design is based on a specific operatingcondition that includes flow, temperature, and pressure.This specific condition constitutes the design point thatis found on the manufacturers feedwater heater specifi-cation sheet.Generally,

45、 it is not possible to conduct the test at theexact design point. Therefore, it is necessary to predictthe heater performance by adjusting the design parame-ters for the actual test conditions. Methods of calculatingASME PTC 12.1-2015the predicted heater performance are presented in thisCode. These

46、predicted values shall then be comparedto corresponding measured test values.Horizontal heaters with partial pass submerged draincooling zones and vertical channel-up heaters with par-tial pass drain cooling zones are not applicable to thisCode. In those designs, only a portion of the feedwaterpasse

47、s through the drain cooling zones, therefore thereare two flow streams with different temperature profiles.Duplex heaters are applicable as long as the feedwatertemperatures, including the temperature betweenstages, are measurable, and the shell sides are isolatedfrom each other and verified to be a

48、t different stagepressures.This Code is applicable for multitube pass heaters ofsingle zone design. Multizone partial pass heaters can-not be tested under this Code, unless the entire firstpass is contained in a single zone. This Code also doesnot apply to header type heaters.1-4 UNCERTAINTYThis Cod

49、e provides recommendations on instrumen-tation, procedures, and accuracies required for data col-lection. An example of an uncertainty analysis is2provided in Nonmandatory Appendix C, which is basedon the recommended instrumentation accuraciesdescribed in Section 4 of this Code and the method ofcalculation described in Section 5.The uncertainties in Nonmandatory Appendix C areprovided as typical values using the instrumentationaccuracies, locations, and techniques recommended bythis Code. The uncertainties may be reduced throughcareful placement of alternative or redundant instru-m