ANSI ASME PTC 12.4-1992 Moisture Separator Reheaters.pdf

1、ASME PTC 12.4-1 992 I AN AMERICAN NATIONAL STANDARD THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS United Engineering Center 345 East 47th Street New York, N.Y. 10017 Date of Issuance: May 24, 1993 This Standard will be revised when the Society approves the issuance of a new edition. There will be no

2、addenda or written interpretations of the require- ments of this Standard issued to this edition. 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.

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7、ibility for only those interpretations issued in accordance with governing ASME procedures and policies which preclude the issuance of interpretations by individual vol- unteers. No part of this document may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior

8、 written permission of the publisher. Copyright 0 1993 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A. FOREWORD (This Foreword is not part of ASME PTC 12.4-1 992.) Moisture Separator Reheaters (MSRs) were introduced to steam power cycles after the advent of comm

9、ercial nuclear power. A moisture separator, with no reheat was first added to nuclear power cycles to minimize the low pressure (LP) turbine erosion caused by wet steam prevalent in those cycles and improve turbine cycle performance. Steam reheat was added later to reduce further the quantity of moi

10、sture in the steam passing through the LP turbine and to increase further the efficiency of the LP turbine. The first MSRs were susceptible to many modes of failure. Great technological advances have occurred over the past 30 years with respect to MSR design and operation. These advances increased t

11、he reliability and enhanced the performance of the MSR which pro- vided the momentum and justification for MSR upgrades. During the 1970s and early 1980s an increasing number of utilities were involved in MSR upgrades which included replacing portions of or their entire MSRs. The ASME Board on Perfo

12、rmance Test Code was notified in June 1984 that no code existed for the testing and analysis of MSRs. PTC-6 (1982) on steam turbines treated the MSR as an integral part of a turbine generator, which it is when purchased as a package. The Board authorized the formation of a new performance test code

13、committee to develop a code for the treatment of the MSR as a separate component. A new committee was formed and first met in December 1985. Numerous drafts were developed over the next 4 years, each more detailed than the previous. Upon the comple- tion of appendices containing a set of sample calc

14、ulations and a complete uncertainty analysis, the draft was released for the industry review in July of 1990. The comment resolution process, completed in April 1991, strengthened the document. The committee was balloted and approved the code draft in July 1991. The Board on Performance Test Codes a

15、pproved the code in January 1992. This test code has been approved as an Amer- ican National Standard by the ANSI Board of Standards Review on November 24, 1992. PERSONNEL OF P,ERFORMANCE TEST CODE COMMITTEE No. 12.4 ON MOISTURE SEPARATOR REHEATERS (The following is the roster of the Committee at th

16、e time of approval of this Standard.) OFFICERS Samuel J. Korellis, Chairman W. Cary Campbell, Vice Chairman Geraldine A. Omura, Secretary COMMITTEE PERSONNEL Paul G. Albert, General Electric Co. George L. Amodeo, Virginia Power Peter Von Bockh, lngenierschule Beider Basel W. Cary Campbell, Southern

17、Company Services H. Gay Hargrove, Westinghouse Electric Corp. Edwin W. Hewitt, Condenser (d) Testing and calculational techniques; and (e) Information contained in the test report. rating and steam reheating components located between the high pressure and low pressure steam turbine. The purpose of

18、the Code is to determine the performance of the MSR and to provide guidance in the evaluation of its performance effect on the turbine cycle heat rate with regard to: (a) Moisture Separator Outlet Quality; (b) Reheater Terminal Temperature Difference (c) Cycle Steam pressure drop across applicable (

19、d) Excess heating steam flow. (TTD) per stage; component(s); and 1.2 SCOPE Requirements are specified by this Code for appli- cation on MSR testing in the following areas: (a) Pretest arrangements and agreements; (b) Instrumentation types and accuracies; 1.3 EXPECTED MEASUREMENT UNCERTAINTY By satis

20、fying the instrument accuracy criteria spec- ified in Section 4 and complying with the balance of procedural requirements of this Code, a test will gen- erally provide 95 percent or greater confidence that the measurement of the required performance param- eters will yield results for which the boun

21、ds of the difference between the final test results and the true value is within (b) reference values (or defining equations) for use in Table 5.1, for calculation of MSR performance; (c) frequency of observations, method of recording data, number, and duration of test runs; (d) system alignment and

22、 verification during the test; (e) determination of parameters not measured (e.g., inlet cycle steam moisture content and heating steam inlet quality); (0 test objectives; (g) method of comparing test results to perfor- mance guarantee(s), including considerations for test- ing MSRs individually or

23、simultaneously; (h) provisions for maintaining stable test condi- tions; (i) that MSR components, system piping, and inter- nal structures have been installed as required or spec- ified (j) cleanliness conditions of the MSR (e.g., exis- tence of fouling and debris); (k) identification of any known d

24、amage or defi- ciency (e.g., missing tubes, plugged tubes, and bro- ken welds); (I) number, use, installation, and location of tem- perature, pressure, and flow sensors, including redun- dant measurements of critical test parameters; (m) location and use of any station instrumentation for balance of

25、 plant (BOP) or auxiliary components testing; (n) method of determining cycle steam, excess steam and drain flow rates (e.g., sensor design, loca- tion); (0) radioactive tracer application techniques, in- cluding location of injection and sample taps; 7 PRINCIPLES (p) responsibility for licensing an

26、d handling radio- active tracers, if used; (q) accountability of all extraneous and abnormal flows (see para. 3.3.4, System Alignment Require- ments); (r) adjustment of the excess steam flow rate, if ad- justable; (s) instrument accuracy and calibration; (t) use of vendor thermal kit or previous pre

27、cision (u) time limits (see para. 3.4.5, Calibration of In- turbine test data; strumentation). 3.1.2 Acceptance Test Scheduling Note: This paragraph lnay be disregarded if the MSR test is part of the initial turbine acceptance test. The MSR should be in an as-new condition. An ac- ceptance test shou

28、ld be conducted as soon as practic- able but not later than 12 weeks after the initial oper- ation of the new or modified MSR, providing no serious MSR operating difficulty has occurred. If sta- tion conditions or licensing limitations make it impos- sible to conduct the test within the prescribed t

29、ime frame, then it may have to be postponed until imme- diately following an internal inspection. In lieu of an internal inspection, the condition may be considered as-new if the MSRs performance does not differ from that determined in the initial benchmark, observed in a trend of the MSRs performan

30、ce parameters. 3.1.3 Performance Benchmark Determination. A performance benchmark should be established with plant instrumentation immediately after the MSRs are first placed in service at stable unit conditions, so that if the Code test is delayed by more than 12 weeks, there can be reasonable assu

31、rance that there has been no change in the MSR performance during the inter- vening period of operation by comparing measure- ments. This eliminates the need for an internal inspection prior to Code testing. Required measure- ments and information include: (a) reactor power level; ASME PTC 12.4-1992

32、 MOISTURE SEPARATOR REHEATERS (b) MSR cycle steam outlet temperature; (c) reheaterb) heating steam pressure(s1 and flow(s); (d) MSR steam outlet pressure or LP Turbine bowl (e) MSR cycle steam pressure drop. pressure; 3.2 GENERAL TEST REQUIREMENTS 3.2.1 Preliminary Test Runs. Preliminary test runs s

33、hould be conducted for the purpose of (a) checking all instrumentation; (b) orienting test personnel; (c) establishing the required duration and fre- (d) making minor operational and test adjustments; (e) determining whether the MSR(s) and plant are (f) establishing the operating conditions at which

34、 (g) achieving proper valve and system alignment; (hl ensuring proper conditions can be met to per- (i) preliminary determination of test uncertainties; (j) if tracer is-used, determination of the required concentration levels, injection and sampling rates, and equilibrium/lag rates. quency of obser

35、vations for the actual test runs; in a suitable condition for the test; to conduct the test; form the test; 3.2.2 Responsibilities of Parties. The responsibilities of the parties to the test are: (a) to ensure that the test report reflects if alterna- tive methods within the guidelines of this Code

36、are employed; (b) to designate a mutually acceptable third party to direct and mediate disputes; (c) to witness the test and verify that it is conducted in accordance with this Code and the pretest agree- ments. All data logs will be made available to all par- ties at the conclusion of each test run

37、. Copies of the entire data collection will be distributed upon the conclusion of the test. 3.3 TEST OPERATING CONDITIONS 3.3.1 Operating Conditions. Test runs should be con- ducted under specified operating conditions, or as close to specified operating conditions as possible, in order to minimize

38、corrections to the test results. The variation of any condition which may influence the results of the test run shall be minimized before the test run begins and maintained so during the test run. (Refer to paras. 3.3.3 and 3.3.4.) The testing should be commenced at 95 percent rated thermal power or

39、 above. The licensee technical specifications, NRC regula- tions, and turbine manufacturer specifications should not be violated. 3.3.2 Constancy of Test Conditions. Prior to any test run, the unit shall be operated for a sufficient time to attain steady state conditions and shall be kept at steady

40、state throughout the test run. Steady state con- ditions will have been attained when the unit operat- ing conditions and permissible deviation criteria of Table 3.1 have been met. When a tracer is used, the injection should com- mence sufficiently prior to the start of the test run to attain concen

41、tration equilibrium. As a guide, it may be conservatively expected that equilibrium is at- tained when a time period, equal to four times the calculated transport time through both the longest in- jection line and the longest sample line, has passed following the commencement of injection. All ele-

42、ments of the system (eg, tanks) shall be considered. Concentration equilibrium is verified when the tracer concentration of two consecutive samples taken dur- ing the test run differ by no greater than three percent. 3.3.3 Deviations. Deviations of the variables in ex- cess of the limits prescribed

43、in Table 3.1, or as other- wise agreed upon, may occur during a test run. If such deviations are observed during a test run, the cause shall be eliminated or corrected and the test run con- tinued, if possible, until all variables are within the specified limits for the duration of the test run. The

44、 test run may be extended in order to make up for the time and data lost during the correction of the cause of the deviation, but shall not exceed a two-hour total duration. If the cause of the deviations cannot be eliminated or corrected during the test run, or if devia- tions are discovered during

45、 the computation of results from a completed test run, that run shall be rejected in whole, or in part, and repeated as necessary after the cause of the deviations has been eliminated. Any rejected portions of the test run shall not be used in computing the overall averages. The results of that test

46、 run may then be acceptable, provided that the re- maining valid periods aggregate to one hour or more and the quantity of readings obtained during the valid periods satisfies the criteria of Table 3.1. a MOISTURE SEPARATOR REHEATERS ASME PTC 12.4-1992 TABLE 3.1 PERMISSIBLE DEVIATION OF VARIABLES Un

47、it Permissible System Operating Deviation Variable Conditions During Each Test Run Unit Conditions Thermal power 95% or greater t 0.5% Main steam or steam generator pressure 2 2% of expected 21% MSR Measurements Heating Steam Flow t 3% Cycle Steam Outlet Temperature ? 2F Reheater Drain Temperature t

48、 2F Shell Pressure Drop ? 5% Heating Steam Pressure t 2% Drains Flow t 5% Excess Steam Flow t 10% Cycle Steam Pressure tl% NOTE: (I) Each observation of an operating condition during a test run shall not vary from the reported aver- age for that operating condition during the complete run by more th

49、an the amount shown, except by mutual agreement between the parties to the test. 3.3.4 System Alignment Requirements The MSR System should be aligned for normal op- eration as per plantlvendor procedures. In addition, the following should be addressed: (a) In order to attain typical flow rates through the MSR shell and reheaters, all extraneous and abnormal flows which may significantly affect cycle steam flow or heating steam flow should be eliminated. Prepara- tions shall be made prior to the test to eliminate or account for any extraneous flows. (b) System alignment shall be made so