ANSI ASME PTC12.3-1997 Performance Test Code on Deaerators《除氧器性能试验规程》.pdf

1、Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ASME PTC 12.3-1 997 (REVISION OF ASME PTC 12.3-1977) Performance Test Code on Deaerators Copyright ASME International Provided by IHS under license w

2、ith ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Date of Issuance: October 31. 1997 This document will be revised when the Society approves the issuance of the next edition. There will be no Addenda issued to ASME PTC 12.3-1997. Please Note: ASME issues writ

3、ten replies to inquiries concerning interpretation of technical aspects of this document. The interpretations are not part of the document. PTC 12.3-1 997 is being issued with an automatic subscription service to the interpre- tations that will be issued to it up to the publication of the next editi

4、on. ASME is the registered trademark of The American Society of Mechanical Engineers. This code or standard was developed under procedures accredited as meeting the criteria for American National Standards. The Consensus Committee that approved the code or standard was balanced to assure that indivi

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6、oes not “approve,“ “rate,“ or “endorse“ any item, construction, proprietary device, or activity. ASME does not take any position with respect to the validity of any patent rights asserted in connection with any items mentioned in this document, and does not undertake to insure anyone utilizing a sta

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9、ies which preclude the issuance of interpretations by individual volunteers. No part of this document may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. The American Society of Mechanical Engineers 345 East 47th Stree

10、t New York. NY 1001 7 Copyright 0 1997 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A. Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FOREWORD (This Foreword

11、is not part of ASME PTC 12.3-1997.) On September 1, 1989, the Board on Performance Test Codes (BPTC) voted to reactivate the Performance Test Code committee, PTC 12.3, to undertake the revision of PTC 12.3- 1977, the Performance Test Code on Deaerators. Shortly thereafter, the Committee was reconsti

12、tuted, and had its first meeting on May 22-23, 1991, with 3 of the original members on the new Committee. One of the requirements for the satisfactory operation of the boiler feed system in a steam plant is high quality boiler feedwater, freefrom dissolved oxygen and carbon dioxide. To meet the diss

13、olved oxygen requirements of the steam generator, improvements in the design of mechanical deaerators have been made. Design requirements demand extreme reliability of oxygen testing of boiler feedwater. This Code was approved by the PTC 12.3 committee on May 31, 1996. It was then approved and adopt

14、ed by the Council as a Standard practice of the Society by action of the BPTC on October 25, 1996. This Performance Test Code was also approved as an American National Standard by the ANSI Board of Standards Review on February 6,1997. . Ill Copyright ASME International Provided by IHS under license

15、with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NOTICE All Performance Test Codes MUST adhere to the requirements of PTC 1, GENERAL INSTRUCTIONS. The following information is based on that document and is included here for emphasis and for the convenience

16、of the user of this Code. It is expected that the Code user is fully cognizant of Parts I and I11 of PTC 1 and has read them prior to applying this Code. ASME Performance Test Codes provide test procedures which yield results of the highest level of accuracy consistent with the best engineering know

17、ledge and practice currently available. They were developed by balanced committees representing all con- cerned interests. They specify procedures, instrumentation, equipment operating require- ments, calculation methods, and uncertainty analysis. When tests are run ih accordance with this Code, the

18、 test results themselves, without adjustment for uncertainty, yield the best available indication of the actual performance of the tested equipment. ASME Performance Test Codes do not specify means to compare those results to contractual guarantees. Therefore, it is recommended that the parties to a

19、 commercial test agree before starting the test and preferably before signing the contract on the method to be used for comparing the test results to the contractual guarantees. It is beyond the scope of any code to determine or interpret how such compari- sons shall be made. iv Copyright ASME Inter

20、national Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-PERSONNEL OF PERFORMANCE TEST CODE COMMITTEE NO. 12.3 ON DEAERATORS (The following is the roster of the Committee at the time of approval of this Code.) OFFICERS john j.

21、 Eibl, Chair Thomas j. McAlee, Vice Chair lack H. Karian, Secretary COMMITTEE PERSONNEL Joseph H. Duff, Water Technology Services, Inc. Michael Dymarski, Ontario Hydro john 1. Eibl, E. 1. Dupont Carol S. Coolsby, Duke Power Company A. Scott Hamele, Kansas City Deaerator Company David Hickling, Ecody

22、ne Limited jack H. Karian, American Society of Mechanical Engineers Thomas 1. McAlee, The United Illuminating Company Scott D. Ross, Sterling Deaerator Company Dave A. Velegol, Weirton Steel Corporation Joseph H. Wilkinson, Royce Instrument The PTC 12.3 Committee wishes to acknowledge the contributi

23、ons of Robert J. Beckwith and the late James S. Poole. It is with regret that Mr. Poole did not live to see the result of his efforts for which the Committee is most grateful. V Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted

24、without license from IHS-,-,-R. P. Allen R. L. Bannister B. Bornstein J. M. Burns J. R. Friedman G. J. Gerber P. M. Gerhart R. S. Hecklinger BOARD ON PERFORMANCE TEST CODES OFFICERS D. R. Keyser, Chair P. M. Cerhart, Vice Chair W. 0. Hays, Secretary COMMITTEE PERSONNEL R. W. Henry D. R. Keyser S. J.

25、 Korellis J. W. Milton G. H. Mittendorf, Jr. S. P. Nuspl R. P. Perkins A. L. Plumley S. B. Scharp 1. Siegmund J. A. Silvaggio, Jr. R. E. Sornrnerlad W. G. Steele, Jr. 1. C. Westcott I. G. Yost vi Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or net

26、working permitted without license from IHS-,-,-CONTENTS Foreword CommitteeRoster BoardRoster Section . 0 1 2 3 4 5 6 7 introduction . Object and Scope . Guiding Principles . Instruments and Methods of Measurement . Computation of Results . ReportofTest Definitions and Rescription of Terms . Detailed

27、 Uncertainty Analysis for Dissolved Oxygen . Figures 1 Method and Apparatus for the Detection of Free Air . 2 500 mL Sample Flask for Dissolved Oxygen Determination 4 General Arrangement for Sampling Apparatus 5 Procedure for Preparation of Samples for Titration 3 MicroBuret . Tables 4.1 5.1 6.1 6.2

28、 6.3 D.l D.2 D.3 D.4 D.5 D.6 Reagents Required for Dissolved Oxygen Test Method General Information and Description of Equipment Illustration of Dissolved Oxygen Test Results . dias Limits and Precision indices Example of Outliers Determination Two-Tailed Students t Table for the 95% Confidence Leve

29、l Modified Thompson T (at the 5% Significance Level) . Approximate Effect of Various Interfering Compounds on Standard BiasLimit . Test Operating Conditions . Analytical Data . Breakdown of Measurement Component Errors into Elemental Errors . Appendices A Starch Titration . . Ill V vi 1 3 5 7 71 23

30、29 33 10 12 13 18 21 15 26 29 30 31 44 45 46 46 47 47 35 vii Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-B C D E F On-Line Analyzer Method . 39 Colorimetric Method . 41 Example Calculations 43

31、Typical Deaerator Sample Point Locations . 49 References 51 viii Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ASME PTC 12.3-1997 SECTION 0- 0.1 Deaerating equipment is designed to remove the dis

32、solved oxygen and carbon dioxide in boiler feed- water to reduce corrosion in boilers and associated equipment. Normally, dissolved oxygen levels of 7 pg/L (ppb) or less can be achieved. A deaerator is designed to heat feedwater to the temperature of saturated steam at the pressure within the deaera

33、tor. 0.2 Deaerators, or deaerating heaters, may utilize many different designs. In general, there is a first stage which involves spraying water into the steam space where it is heated and partially deaerated. Water is discharged from spray nozzles or other spray devices as thin films, sheets or dro

34、plets. This stage removes more than 90% of the dissolved oxygen. Venting of gases removed from the water may occur through an external shell and tube condenser or through an internal direct-contact vent condenser in the upper steam space on the deaerator. The condensing of steam in the apparatus red

35、uces its pressure progressively, as it travels upward, to a minimum pressure in the area of the vent condenser. Noncondensable gases plus a small amount of steam pass through the vent. The falling water, containing some dissolved gases, may be directed to a second stage which may be a tray section w

36、here it is mixed with, and mechanically scrubbed by, the heating steam. Thin films of water, formed by water overflowing the lips of the trays, are deaerated further by the incoming steam. Alternatively, the second stage may be a steam scrubber and/or reboiler. Here the water mixes with the incoming

37、 heating steam, with the water becom- ing slightly superheated during the heating and scrub- bing process. Some flashing takes place as it is discharged into the steam space where final deaera- tion takes place. There are other types of deaerators which use sprays or spray pipes of various types wit

38、h various types of packing such as packing rings, saddles, INTRODUCTION etc., on their own or in combination. There are also “integral“ and other types of deaerators. Deaerators may be designed to operate at any pressure. 0.3 Accurate measurements of dissolved oxygen are not obtained easily. Some te

39、st methods and proce- dures, while satisfactory for chemical control of the feedwater, are inadequate for guarantee-acceptance purposes. The fact that there are many test methods available and wide choices of apparatus and proce- dures which may be employed further complicates this problem. With the

40、 magnitude of permissible error of the test defined, it becomes apparent that the test method, test apparatus, and test procedure must be integrated and evaluated so that reliable measurement can be achieved. On-line analyzers and colorimetric test methods do not meet the methodology of measurement

41、uncertainty per PTC 19.1. The test methods and procedures described herein do meet the methodology of PTC 19.1 The Test described in Subsection 4.2 is the referee method because it provides a method which has been studied and tested for accuracy and reliability. 0.4 Before formulating a test to dete

42、rmine the perform- ance of deaerators, the Performance Test Code on General Instructions (PTC-1) should be studied and followed in detail. In particular, before any test is undertaken, the test objectives shall be defined and agreed by the parties to the test. The Code on Definitions and Values (PTC

43、-2) de- fines technical terms and numerical constants which are used throughout this Code with the meanings and values therein established. The PTC 19 Series Supplements (Instruments and Apparatus Supplements) gives descriptions of, and standard directions for, the use and calibration of measuring d

44、evices, including an estimate of the level 1 Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ASME PTC 12.3-1997 of accuracy obtainable. These supplements provide guidance on the application of some

45、 of the special- ized techniques used in this code. DEAERATORS 2 Copyright ASME International Provided by IHS under license with ASMENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DEAERATORS ASME PTC 12.3-1997 SECTION 1 - OBJECT AND SCOPE 1.1 Object The purpose of

46、 this Code is to provide rules and test procedures that are to be used to determine the performance of deaerators with regard to the following: (a) residual dissolved oxygen in the deaerated water, (b) terminal temperature difference (TTD), if any, between the deaerated water and the saturated steam

47、 temperature corresponding to the pressure in the steam zone adjacent to the interface between the steam and the collected deaerated water. 1.2 Scope 1.2.1 This Code applies to deaerating heaters and deaerators equipped with either shell-and-tube or direct contact, vent-condensing sections. 1.2.2 Th

48、e Code describes the test method and procedures for the determination of dissolved oxygen in water for deaerating equipment at concentrations up to 75 pg/L (ppb). This Code also describes the method for determining the terminal temperature difference (TTD). Other methods of dissolved oxygen measurem

49、ent are included in Appendices A, B and C. These may be used as an adjunct to the Code. 1.3 Uncertainty An uncertainty analysis of the test method for determination of dissolved oxygen in the deaerated water and terminal temperature difference is pro- vided. This uncertainty procedure serves as a guide for pretest and post-test uncertainty calculations wh