ASME PTC 12 1-2000 Closed Feedwater Heaters (PTC 12 1 - 2000)《密封供水加热器》.pdf

1、 STD*ASME PTC 12.1-ENGL 2000 0759b70 ObZOi58 7l17 m ASME PTC 12.1 -2000 Revision of ANSVASME PTC 12.1-1978 (R 1987) Closed Feedwater Heaters STDOASME PTC 12*1-EMGL, 2000 W 0759b70 Ob20457 b53 Date of Issuance: December 29, 2000 This Standard will be revised when the Society approves the issuance of

2、a new edition. There will be no Addenda issued to ASME PTC 12.1-2000. Please Note: ASME issues written replies to inquiries concerning interpretation of technical aspects of this document. The interpretations are not a part of the document. ASME is the registered trademark of The American Society of

3、 Mechanical Engineers, This code or standard was developed under procedures accredited a5 meeting the criteria for American National Standards. The Standards Committee that approved the code or standard was balanced to assure that individuals from competent and concerned interests have had an opport

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5、 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 standard against liability for infringement of any applicable lett

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8、erpretations by individuals. 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 Three Park Avenue, New York, NY 1 O01 6-5990 Copyright O 2000 by TH

9、E AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A. STDmASME PTC LZ-L-ENGL 2000 D 0759b70 Ob204b0 375 W FOREWORD The Performance Test Code Committee 12.1 was assembled to review, edit, and update the existing 1978 Code edition. The Code has been extensively revised to co

10、mply with the latest requirements in the PTC 1-1 991, General Instructions, including the required uncertainty analysis. This Code incorporates a revised calculation procedure, including examples. The calculation method requires iterations and can be performed manually but is best done by using a co

11、mputer program. The Code also incorporates an alternative for using ultrasonic flow measurement techniques to test individual or split-string feedwater heaters, when flow nozzles are not available. This edition of the Code provides a relatively simple but accurate method of calculating the performan

12、ce of a heater utilizing the Code procedure with a minimum knowledge of the design characteristics of the heater. This version was approved by the Board on Performance Test Codes on February 23, 2000 and as an American National Standard by the ANSI Board of Standards Review on May 23,2000. iii STD-A

13、SflE PTC LZ*L-ENGL 2000 0759b70 Ob204bL 2OL 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 of the user of this Code. It is expected that th

14、e Code user is fully cognizant of Parts I and III 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 knowledge and practice currently available. They wer

15、e developed by balanced committees representing all concerned inter- ests. They specify procedures, instrumentation, equipment operating requirements, calcula- tion methods, and uncertainty analysis. When tests are run in accordance with a Code, the test results themselves, without adjustment for un

16、certainty, 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 commercial test agree before starting the test and

17、 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 comparisons shall be made. iv STD-ASME PTC 117-1-ENGL 2000 0759670 Ob204b2 148 PERSONNEL OF PERFORMANCE

18、 TEST CODES COMMITTEE NO. 12.1 ON FEEDWATER HEATERS (The following is a roster of the Committee at the time of approval of this Code.) OFFICERS Nelson Thompson, Chair Mark R. Biar, Vice Chair George Osolsobe, Secretary COMMITTEE PERSONNEL Carl F. Andreone, Consultant Mark R. Biar, EFCO John J. Elder

19、, Levitan and Associates Joseph V. Hoobler, Consultant, Utility Equipment (Struthers industries) Joseph W. Milton, Reliant Energy Jack L. Stellern, Oak Ridge National Laboratory Nelson Thompson, SEI John L. Tsou, Consultant Gerald E. Weber, Midwest Generation EME V STD*ASME PTC LZ*L-ENGL 2000 111 07

20、59670 Ob20463 084 BOARD ON PERFORMANCE TEST CODES OFFICERS P. M. Gerhart, Chair S. J. Korellis, Vice Chair W. O. Hays, Secretary COMMITTEE PERSONNEL R. P. Allen R. L. Bannister O. S. Beachler B. Bornstein J. M. Burns A. J. Egli J. R. Friedman G. J. Gerber Y. Goland R. S. Hecklinger T. C. Heil D. R.

21、Keyser P. M. McHale J. W. Milton G. H. Mittendorf, Ir. S. P. Nuspl A. L. Plumley HONORARY MEMBERS R. R. Priestley J. Siegmund J. A. Silvaggio, Jr. W. G. Steele, Ir. J. C. Westcott I. G. Yost F. H. Light C. B. Scharp vi STD-ASME PTC L2.L-ENGL i000 0759b70 0620464 TLO CONTENTS . Foreword III Committee

22、Roster V Board Roster vi Section O Introduction 1 1 Object and Scope 3 2 Definitions and Description of Terms . 5 3 Guiding Principles . 17 4 Instruments and Methods of Measurement 27 5 Computation of Results 33 6 Report of Results 55 7 References . 57 Figures 3.3.1 Typical DCA and TTD versus Intern

23、al Liquid Level . 3.8.1 Desuperheating, Condensing, and Drain Cooling Zones . 22 3.8.2 Desuperheating and Condensing Zones . 23 3.8.3 Condensing and Drain Cooling Zones 24 3.8.4 Condensing Zone 25 3.8.5 External Drain Cooler . 26 4.4.1 Typical Transducer Installation 29 19 Tables 3.3.1 4.6 5.1.1 5.1

24、.2 5.1.3 5.1.4 5.1.5 5.1.6 Deviation Limits of Parameters Three-Zone Heater . Two-Zone Heater Desuperheating and Condensing . Two-Zone Heater Condensing and Drain Cooling Condensing Only Heater External Drain Cooler . PTC 12.1 Heater Test Report Form . Maximum Uncertainty Values Nonmandatory Appendi

25、ces A B D Basic Heat Transfer Equations . Heater Performance Calculation Examples . C Uncertainty Considerations . Principal Quantities and Commonly Used Conversion Factors In Heat Transfer (SI Units) 18 31 34 36 38 40 42 44 59 61 73 81 vii STD-ASME PTC LZ*L-ENGL 2000 0759b70 Ob204b5 e157 CLOSED FEE

26、DWATER HEATERS ASME PTC 12.1 -2000 SECTION O - INTRODUCTION 0.1 For the purposes of this Code, a closed feedwater heater is a power plant component designed to heat a given quantity of feedwater through a specified temperature range. The heating medium is steam or condensate at a specified enthalpy

27、and pressure. In such heaters, the feedwater and heating medium typically are routed through the tubes and shell, respectively. Feedwater heaters are designed to be on the design conditions, the heat transfer surface area within the feedwater heater may be configured as follows: (a) desuperheating z

28、one (b) condensing zone (c) drain cooling zone Steam is the heating medium in the condensing and desuperheating zones. Condensate is the heating medium in the drain cooling zone. “ configured in one of the following ways: (a) horizontal (b) vertical channel down (c) vertical channel up (ci) duplex (

29、two separate tube bundles in a single divided shell) In some cases, more than one feedwater heater is required for a given feedwater flow and heat source. In such instances, the feedwater heater is divided into two or three parallel heaters which constitute a multiple string arrangement. Depending 0

30、.2 This Code is written in accordance with the PTC-1, General instructions. PTC-2, Definitions and Values defines certain technical terms and numerical con- stants which are used in this Code with the signifi- cance and value therein established. The PTC-19 series Supplements on Instruments and Appa

31、ratus, covering the instruments prescribed in this Code, should be used for reference. 1 STD-ASME PTC 12.1-ENGL 2000 0759b70 Ob204bb 893 CLOSED FEEDWATER HEATERS ASME PTC 12.1 -2000 SECTION 1 - OBJECT AND SCOPE 1.1 OBJECT The object of this Code is to provide the proce- dures, direction, and guidanc

32、e for determining the performance of a closed feedwater heater with regard to the following: (a) Terminal Temperature Difference (7TD), which is the difference between the saturation temperature corresponding to the steam inlet pressure and thefeed- water outlet temperature; (b) Drain Cooler Approac

33、h (DCA), which is the difference between drain outlet temperature and feed- water inlet temperature; (c) tube side (feedwater) pressure loss through the heater; and (d) shell side pressure loss through the desuper- heating zone, and through the drain cooling zone. 1.2 SCOPE This Code applies to all

34、horizontal and vertical heaters except those with partial pass drain cooling zones. Designs with partial pass drain cooling zones are horizontal heaters with submerged drain cooling zones, and vertical channel-up heaters with drain cooling zones. In those designs, only a portion of the feedwater pas

35、ses through the drain cooling zones; therefore, there are two feedwater flow streams with different temperature profiles. A feedwater heater is designed to accomplish heat transfer between fluids. The heater design is based on a specific operating condition that includes flow, temperature, and press

36、ure. This specific condition constitutes the design point that is found on the manufacturers feedwater heater specification sheet. It is not feasible to expect that the test will be conducted at the design point. Therefore, it is neces- sary to predict the heater performance by adjusting the design

37、parameters for the test conditions. Meth- ods of calculating the predicted heater performance are presented in the Code. These predicted values shall then be compared to corresponding measured test values. 1.3 UNCERTAINTY This Code provides recommendations on instru- mentation, procedures, and accur

38、acies required for data collection. An example of an uncertainty analy- sis is provided in Appendix C. When the recom- mended instrumentation accuracies are employed as described in Section 4, and the method of calcula- tion described in Section 5 is used, the expected total uncertainties in the tes

39、t results will be as follows: Difference between predicted TTD and measured TTD: 10.36“F Difference between predicted DCA and measured DCA 50.32OF Difference between predicted and measured tube side pressure loss Difference between predicted and measured shell side pressure loss through the desuperh

40、eating zone Difference between predicted and measured shell side pressure loss through the drain cooling zone (per- (percent of predicted): 23.1% (percent of predicted): 112.2% cent of predicted): 2 l .8% These uncertainties are provided as typical values using the instrumentation accuracies, locati

41、ons, and techniques recommended by this Code. The uncer- tainties may be reduced through careful placement of alternative or redundant instrumentation. The total uncertainties presented above were calculated using the procedure described in Subsection 5.3. The bias uncertainties were determined by t

42、he judgment of this committee for a test adhering to the procedures of this Code. A post-test uncertainty analysis is recommended. However, a post-test uncertainty analysis is optional if parties to the test agree that the test adhered to all instrumentation requirements and procedures contained in

43、this Code. 3 Previous page is blank. STD.ASME PTC 12-1-ENGL ZOO0 W 0759670 Ob20467 72T CLOSED FEEDWATER HEATERS ASME PTC 12.1 -2000 SECTION 2 - DEFINITIONS AND DESCRIPTION OF TERMS 2.1 SYMBOLS Units U.S. Symbol Term Description Cusomary SI Al Drain cooling zone or Based on outside of tubes in drain

44、sq ft m2 external drain cooler cooling zone or external drain heat transfer surface area cooler (effective surface only), pro- (design) vided by heater designer A* Condensing zone heat Based on outside of tubes in con- transfer surface area densing zone (effective surface (design) only), provided by

45、 heater designer A3 Desuperheating zone Based on outside of tubes in desu- perheating zone (effective surface only), provided by heater designer heat transfer surface area (design) Cl * Hourly heat capacity By computation flow rate of steam con- densate in drain cooling zone or external drain cooler

46、 (computed) C3* Hourly heat capacity By computation flow rate of steam in desuperheating zone (computed) c1 * Hourly heat capacity By computation flow rate of feedwater in drain cooling zone or external drain cooler (computed) sq ft m2 m2 B tu/(h r-0 F) WIC Btu/( hr-“F) WIC Btu/( h r-OF) Previous pa

47、ge is blank. WIC 5 ASME PTC 12.1 -2000 CLOSED FEEDWATER HEATERS Units U.S. Customary SI Btu/( h r-OF) WIC Symbol c2 * c3 * DCA DCA DCA * Hd Hl * H3 hl h4 * (NTU)i* Term Descriotion Hourly heat capacity flow rate of feedwater in condensing zone (com- puted) By computation B t u/( h r-O F) WIC Hourly

48、heat capacity flow rate of feedwater in desuperheating zone (computed) By computation Drain cooler approach (actual) Ti -ti (measured values) OF “C Drain cooler approach (design) Provided by heater designer “F “F “C “C Predicted drain cooler approach (computed) Ti *-ti Drains inlet enthalpy (compute

49、d) From ASME Steam Tables at Td for each saturated liquid Btullbm Btullbm Btullbm Drain outlet enthalpy (computed) From ASME Steam Tables at Pl and Tia* for compressed liquid Steam inlet enthalpy (computed) From ASME Steam Tables at P3 and T3 for dry or superheated steam. Otherwise from steam quality mea- surement, if possible, or from per- forming a turbine heat balance. Feedwater inlet enthalpy (computed) From ASME Steam Tables at pi and ti for compressed liquid Btullbm Btullbm Feedwater outlet en- t h a I py (computed) From ASME Steam Tables