ASME TDP-1-2013 Prevention of Water Damage to Steam Turbines Used for Electric Power Generation Fossil-Fueled Plants《发电用蒸汽涡轮机的水损坏预防 化石燃料厂》.pdf

1、AN AMERICAN NATIONAL STANDARD ASME TDP-12013(Revision of ASME TDP-12006)Prevention of Water Damage to Steam Turbines Used for Electric Power Generation: Fossil-Fueled PlantsASME TDP-12013(Revision of ASME TDP-12006)Prevention of WaterDamage to SteamTurbines Used forElectric PowerGeneration:Fossil-Fu

2、eled PlantsAN AMERICAN NATIONAL STANDARDTwo Park Avenue New York, NY 10016 USADate of Issuance: June 7, 2013This Standard 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 thisdocument.

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5、 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 standard was

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11、uced 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 2013 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.C

12、ONTENTSForeword ivCommittee Roster . v1 Scope 12 Criteria . 13 Design . 44 Operation 275 Testing, Inspection, Maintenance, and Monitoring. 296 Conclusion 30Figures1 Typical Flash Tank/Separators Arrangement: Local Control System 62 Typical Flash Tank/Separators Arrangement: Integrated Control System

13、 . 73 Typical Leveling System Arrangement: Integrated Control System . 84 Typical Attemperator System . 95 Typical Drain System With Redundant Level Elements 116 Typical Heater Steam Side Isolation System: Local Control System 147 Typical Heater Steam Side Isolation System: Integrated Control System

14、 . 158 Typical Heater Tube Side Isolation System: Local Control System . 169 Typical Heater Tube Side Isolation System: Integrated Control System . 1710 Typical Deaerator Arrangement With Drain System: Local Control System . 1911 Typical Deaerator Arrangement With Drain System: Integrated Control Sy

15、stem 2012 Typical Deaerator Arrangement With Inlet Isolation: Local Control System 2113 Typical Deaerator Arrangement With Inlet Isolation: Integrated Control System 2214 Main Turbine: Typical Steam Seal Arrangement . 26Tables1 Symbol Legend 42 Device Identification Letters . 5iiiFOREWORDIn the late

16、 1960s, a substantial increase in the number of reported occurrences of steam turbinedamage by water induction precipitated design recommendations from the two major U.S. steamturbine manufacturers in an attempt to reduce such incidents. Consequently, utilities and designersbegan formulating their o

17、wn design criteria because of the economic need to keep the generatingunits in service. Realizing the common need for a uniform set of design criteria to alleviate thisproblem, an American Society of Mechanical Engineers (ASME) Standards Committee was formed,consisting of representatives of utilitie

18、s, equipment manufacturers, and design consultants todevelop recommended practices for use in the electric generating industry.This Standard, resulting from the work and deliberation of the Turbine Water DamagePrevention Committee, was approved as a Standard of The American Society of MechanicalEngi

19、neers by the ASME Standardization Committee and the ASME Policy Board, Codes andStandards, on July 26, 1972.In 1979, the Committee proposed a revision to this Standard to include information on condensersteam and water dumps, direct contact feedwater heaters, and steam generators. This proposedrevis

20、ion was approved by the ASME Standardization Committee on April 25, 1980.The 1985 revision was approved as an American National Standard on September 13, 1985. In1994, the ASME Board on Standardization approved the disbandment of the Committee onTurbine Water Damage Prevention along with the withdra

21、wal of the standard TDP-1. This wasdue to perceived lack of interest and use by the industry.Subsequent interest from users and potential users for TDP-1 convinced ASME to reconstitutethe Committee under the Board on Pressure Technology Codes and Standards in June 1997. Asa result of this committees

22、 work, TDP-11985 was revised and approved as an American NationalStandard on June 17, 1998.Advances in power plant technology, most notably combined cycle, multiple steam generators,cycling, cogeneration technology, and modern plant instrumentation and control systems, con-vinced the Committee to ag

23、ain revise the Standard. The result was TDP-12006. This revisionwas approved as an American National Standard on November 6, 2006.The current Standard is a revision of TDP-12006. The broad acceptance that this Standard hasreceived caused ASME to decide to reissue it in mandatory language rather than

24、 a recommendedpractice. In addition to the change to mandatory language, this revision also includes minormodifications and clarifications to the previous revision. This revision was approved as anAmerican National Standard on February 5, 2013.ivASME TWDP COMMITTEETurbine Water Damage Prevention(The

25、 following is the roster of the Committee at the time of approval of this Standard.)STANDARDS COMMITTEE OFFICERSL. A. Kielasa, ChairR. G. Narula, Vice ChairT. W. Schellens, SecretarySTANDARDS COMMITTEE PERSONNELJ. C. Boyle, FM GlobalA. Atoui, Alternate, FM GlobalV. C. Buquoi, Siemens Power Generatio

26、n, Inc.M. Heue, Alternate, Siemens Power Generation, Inc.A. M. Donaldson, WorleyParsonsJ. C. Archer, Alternate, WorleyParsonsG. W. Doody, Nuclear Service Organization, Inc.G. M. Golden, ConsultantL. A. Kielasa, Detroit Edison Co.R. A. Masten, Sargent however, it isrecognized that under some conditio

27、ns it cannot beavoided. When this type of attemperator is required inthe motive steam line to control the temperature of thesteam entering a steam turbine, the following featuresshall be provided in addition to the other features listedin paras. 3.2.5 through 3.2.14:(a) The attemperators shall not b

28、e allowed to operatewhen the steam exiting the attemperator will containless than 50F (28C) of superheat unless a higher tem-perature is required by the turbine manufacturer.(b) The attemperator shall be located as far from thesteam turbine inlet as possible, but in no case closerthan 50 pipe diamet

29、ers.ASME TDP-12013Fig. 4 Typical Attemperator SystemFTSteam pipeBlockvalveSpraycontrolvalveTell-talevalveAttemperatorFlow elementFIFrom attemperatorwater sourceFor details ofcontrolling functionsrefer to para. 3.2(c) The attemperator shall be located such that anyassociated water accumulation will d

30、rain in the directionof steam flow to a drain pot located at an elevationlower than the connection to the steam turbine. Thus,the piping shall be sloped toward the drain pot, and thedrain pot shall be located between the attemperator andthe steam turbine. This will result in the intentionalcreation

31、of a low point to allow steam separation andwater collection in the bottom of the pipe. An oversizeddrain pot shall be considered to enhance water collectionat high steam velocity.(d) The design of this type of attemperator systemshall be coordinated with the steam turbinemanufacturer.3.2.4 The use

32、of motive steam attemperators shallprohibit activation or increase in spray when the steamconditions downstream of the attemperator are within25F (14C) of saturation temperature.3.2.5 A power-operated block valve shall beinstalled upstream of the attemperator spray controlvalve. This valve provides

33、tight shutoff to prevent waterleaking past the spray control valve and provides abackup in the event that the spray control valve fails toclose when required (see Fig. 4). The spray control and9block valves constitute a double line of defense againstthe inadvertent introduction of spray water into t

34、hesteam lines. Because spray control valves are susceptibleto leakage, an additional block valve may be installedto provide additional protection.3.2.6 The control system shall automatically closeand override all manual and automatic settings of thespray control and block valves when the associateds

35、team generator or the gas turbine trips.3.2.7 The control valve shall be kept in the closedposition until the block valve has reached the full openposition. This will prevent wire drawing of the blockvalve seat and subsequent leakage through the blockvalve.3.2.8 The block valve shall be automaticall

36、y closedbelow a predetermined minimum boiler load and anytime the demand signal to the control valves does notcall for spray. Sprays shall not be released for automaticcontrol at loads where it can be determined that it isrelatively ineffective in reducing final steam tempera-ture. The loads used sh

37、all be in accordance with theboiler/bypass valve manufacturers recommendations.Manual control shall not prevent operation of the auto-matic protection features specified in para. 3.2.6. AfterASME TDP-12013a steam generator trip, operator intervention should berequired to reset and reopen the attempe

38、rator blockvalves.3.2.9 The attemperator shall be designed to achievesuitable atomization at the lowest and highest steamflow rates expected. Operation of the attemperator out-side the range of suitable atomization is prohibited.3.2.10 The control system for opening the spraycontrol valve shall be d

39、esigned to prevent the suddeninjection of large quantities of water.3.2.11 A manually operated drain valve shall beinstalled between the power-operated block valve andthe spray control valve. This connection can be used asa telltale for periodically testing for block valve leakage.3.2.12 If a bypass

40、 valve around spray controlvalves is used, it shall be power operated and actuatedto close when the block valve is closed. Use of manualbypass valves around spray control valves is not recom-mended. If a manual bypass is used, a second power-operated block valve shall be provided as a second lineof

41、defense. If a manual bypass is used, the inherentpossibilities of water induction shall be reduced throughadministrative control.3.2.13 A bypass of the block valve shall not beprovided under any circumstances.3.2.14 Instrumentation shall be supplied as shownin Fig. 4 to indicate the flow rate of the

42、 spray watergoing to the attemperator.3.3 Motive Steam SystemsMotive steam piping systems are defined in para.2.2. Motive steam systems include systems traditionallyreferred to as Main Steam, Hot Reheat Steam, ColdReheat Steam, and Boiler Feed Pump Turbine SteamSupplies for conventional steam cycles

43、. Also includedare systems referred to as High Pressure, IntermediatePressure, Reheat, and Low Pressure Steam for combinedcycle units. Generally, a motive steam system can bethought of as any steam line normally carrying steamto or from a steam turbine that is not an extraction lineas covered in par

44、as. 3.5 and 3.6. Steam seal lines are notconsidered to be motive steam lines and are covered inpara. 3.9.3.3.1 Because of the lack of detection instrumenta-tion that will close steam turbine stop valves in timeto prevent damage during steam turbine operation, noisolation recommendations are provided

45、 for the preven-tion of damage by water passing through the motivesteam piping and into the steam turbine. If such devicesare developed and marketed, consideration should begiven to including this instrumentation. Rapid closureof steam turbine valves should not be considered as a10method of preventi

46、ng water induction into the steamturbine from a motive steam line.3.3.2 Normal closure of the steam turbine admis-sion stop and control valves with the opening of appro-priate drains is considered a suitable method forisolating the steam turbine during start-up and othertimes when condensate might b

47、e present and the valvesare already closed.3.3.3 A drain shall be installed at each low pointin motive steam piping. The review for low points shallconsider all portions of the lines from the steam sourceoutlet to the connection on the steam turbine, includingany branches or dead legs (including tho

48、se caused byvalve closure). Each drain shall consist of a drain lineconnection or a drain pot connected directly to the bot-tom of the motive steam line. As a minimum, drain potsshall be used for the following lines (other lines do notrequire drain pots, but this Standard does not prohibittheir use)

49、:(a) motive steam lines that are prone to water accu-mulation during operation for which large drain collec-tion areas and/or water detection devices are desired.(b) cold reheat line at first low point downstream ofthe steam turbine exhaust (this application requiresredundant level elements; see Fig. 5).(c) motive steam lines that will be under vacuumduring steam turbine start-up and shutdown.(d) motive steam lines that operate (admit steam tothe steam turbine continuously) with less than 100F(56C) superheat unless a continuous drain has beenprovided (this application