1、Industrial Fired Boilers for General Refinery and Petrochemical ServiceAPI RECOMMENDED PRACTICE 538FIRST EDITION, OCTOBER 2015Special NotesAPI publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations shoul
2、d be reviewed.Neither API nor any of APIs employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or r
3、esponsibility for any use, or the results of such use, of any information or process disclosed in this publication. Neither API nor any of APIs employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.API publica
4、tions may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims a
5、ny liability or responsibility for loss or damage resulting from its use or for the violation of any authorities having jurisdiction with which this publication may conflict.API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. Thes
6、e publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publications should be utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.Any manufacturer
7、 marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such products do in fact conform to the applicable API standar
8、d.Users of this Recommended Practice should not rely exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.Where applicable, authorities having jurisdiction should be consul
9、ted.Work sites and equipment operations may differ. Users are solely responsible for assessing their specific equipment and premises in determining the appropriateness of applying the Recommended Practice. At all times users should employ sound business, scientific, engineering, and judgment safety
10、when using this Recommended Practice.API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations to comply with auth
11、orities having jurisdiction.All rights reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, A
12、PI Publishing Services, 1220 L Street, NW, Washington, DC 20005.Copyright 2015 American Petroleum InstituteForewordNothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product co
13、vered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.The following definitions apply.a) Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specifi
14、cation.b) Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the specification.This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental pr
15、ocess and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institu
16、te, 1220 L Street, NW, Washington, DC 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time e
17、xtension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 1220 L Street, NW, Washington, DC 20005.Suggested revisio
18、ns are invited and should be submitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20005, standardsapi.org. Reliable boiler operations are necessary to ensure steam production in refineries and petrochemical plants. Boilers are a critical component of U.S. commercial and indu
19、strial facilities and operations. Industrial boilers are also a major energy consumer. U.S. refineries and petrochemical plants employ approximately one-third of the total boiler heat input of all U.S. commercial and industrial facilities.This document is based on the accumulated knowledge and exper
20、ience of manufacturers and users of industrial fired boilers. This recommended practice (RP) addresses design, operating, maintenance, and troubleshooting considerations for industrial boilers that are used in refineries and chemical plants. This document directly reflects business needs by having A
21、PIs Subcommittee on Heat Transfer Equipment (SCHTE) membership, vendors, manufacturers, and contractors tailor these precise requirements. Manufacturers input from within and outside the SCHTE was sought and thus the final document reflects prevailing technical expertise. This RP could not have been
22、 developed in this manner by any other industry group. Manufacturers and contractors standards and requirements have individual differences that may not permit a purchaser to understand technical distinctions. ASME codes focus on a boilers mechanical construction and performance testing. National Fi
23、re Protection Association codes focus on a boilers burner management safety system. API standards applicable to boilers focus on fans/drivers and post-combustion oxides of nitrogen (NOx) control. This SCHTE RP complements rather than duplicates these requirements, focusing on refinery and petrochemi
24、cal boilers. API 538 includes information on boiler types, burner management, system reliability/availability, feedwater preparation, BFW and boiler water treatment, waterside control, steam purity, combustion control, boiler burners, emissions, tube cleaning, and more. The information contained in
25、API 538 is not covered by any other standards-writing body. By combining multiple technical subjects related to industrial fired boilers, the boiler user has the benefit of the collective industry experience that this RP provides, rather than having to rely on multiple technical documents.iiiContent
26、sPage1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27、 . . . . . . . . . . . . . . . . . . 13 Terms, Definitions, Acronyms, and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.1 Terms and Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28、. . . . . . . . . . . . . . . . . . . . . 33.2 Acronyms and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 BoilersEquipment Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29、 . . . . . . . . . . . . . . . . . . . . . . . 204.1 General Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.2 Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234.3 Boiler Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294.4 Fuels Fired in Industrial Steam Boilers. . . . . .
31、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414.5 Igniter Management System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414.6 Burner Management Systems . . . . . . . .
32、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434.7 Boiler Feedwater Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454.8 Boiler Water Quality and Intern
33、al Chemical Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454.9 Steam Purity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454.10 Boiler Performance .
34、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465 Water Tube Boiler Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495.1 Pre
35、ssure PartsSuperheaters/Attemperators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495.2 Pressure PartsSteam Generating Tubes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535.3 Pressure Parts of
36、Economizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555.4 Pressure PartsSteam Drum, Mud Drum, and Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585.5 Furnace Design . . . . . . . .
37、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 626 Combustion, Burners, and Igniters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 646.1 General Desc
38、ription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 646.2 Igniters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39、 . . . . . . . . . . 666.3 Burners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 696.4 CO Boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 776.5 Fuels Fired in Industrial Boilers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 806.6 Burner Arrangements . . . . . . . . . . . . . . . . . . . . . . . . .
41、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867 Instrumentation, Control, and Protective Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 887.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
42、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 887.2 Applying API 538 to Burner Management Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 887.3 Process Measurement . . . . . . . . . . . . . . . . .
43、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1047.4 Control Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1237.5 Protective Systems . . . . . .
44、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1477.6 Pre-ignition Purge Cycle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1697.7 Start
45、-up Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1707.8 Manual Trip (Shutdown) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
46、. . . . . . 1747.9 Safety Shutoff Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1747.10 Trips and Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47、. . . . . . . . . . . . . . . . . . . . . 1788 Centrifugal Fans and Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1798.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
48、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179vContentsPage8.2 Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1818.3 Steam Turbine and Electric Motor Drives
49、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1828.4 System Resistance Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1838.5 Control Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1859 Boiler Feedwater Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1869.1 M
