英文版DL T 5068　火力发电厂化学设计技术规程.pdf

ICS 27 100 P 20 REG No J 542 2006 ELECTRIC POWER INDUSTRY STANDARD OF THE PEOPLE S REPUBLIC OF CHINA 中华人民共和国电力行业标准中华人民共和国电力行业标准 P DL T 5068 2006 Replace DL T 5068 1996 Technical Code for Designing Chemistry of Thermal Power Plants 火力发电厂化学设计技术规程火力发电厂化学设计技术规程 Issued on September 14 2006 Implemented on March 1 2007 Issued by National Development and Reform Commission of the People s Republic of China D DL L Contents 1 Scope 1 2 Normative References 2 3 Terms and Definitions 3 4 General Provisions 6 5 Water Pretreatment 8 5 1 System Design 8 5 2 Equipment Selection 10 5 3 Layout Requirement 16 6 Water Pre desalinization 18 6 1 General Provisions 18 6 2 System Design 19 6 3 Layout Requirement 21 7 Boiler Feedwater Treatment 22 7 1 System Design 22 7 2 Equipment Selection 25 7 3 Layout Requirement 26 8 Precision Process for Condensed Water of Steam Turbine Set 28 8 1 General Provisions 28 8 2 System Design 29 8 3 Arrangement Requirement 31 9 Cooling Water Treatment 32 10 Thermodynamic System Chemical Dosing 35 11 Water Vapor Sampling 38 12 Heat Net Makeup Water and Production Backwater Treatment 40 13 Hydrogen Station 41 13 1 General Provisions 41 13 2 System Design 42 13 3 Layout requirement 43 14 Transformer Oil Purification 46 15 Chemical Storage and Dosing Implement 47 15 1 General Provisions 47 15 2 Lime System 47 15 3 Coagulant Agent and Coagulant System 48 15 4 Acid and Alkali System 48 15 5 Salt System 49 15 6 Chlorination System 49 15 7 Water Quality Stabilizing Agent System 51 15 8 Dosing System for Ultra Macro Filtration Equipment and Reverse Osmosis Unit 52 15 9 Steam Condenser Copper Pipe Film forming System 52 16 Design and Corrosion Protection for Tank Gutter Tubing and Valve 53 17 Instrument and Control of Water Treatment System 57 18 Chemical Laboratory and Instrument 59 Appendix A Complete Water Quality Examination Report Normative 60 Appendix B Reference Data for Clarification Tank Design Normative 61 Appendix C Water Disposal System Selection Normative 66 Appendix D Reference Data for Ion exchanger Design Normative 69 Appendix E Reference Data for Filter Design of Condensed Water Precision Process Normative 73 Appendix F Design Reference Data for Condensed Water Precision Process Ion exchange Unit Normative 75 Appendix G Control Standards for Water Quality of Open Circulatory Cooling System Normative 80 Appendix H Water Volume Calculation for Flow By pass Filtration and Softening Treatment Normative 81 Appendix I Disposal of Water Vapor Sample Point and In line Meter in Thermodynamic System Normative 83 Appendix J Minimum Clear Distance of Overhead Hydrogen Gas Pipe and Other Overhead Pipes in Plant Site Hydrogen Station and Workshop Normative 85 Appendix K Minimum Clear Distance of Overhead Hydrogen Gas Pipe and Building or Structures on Plant Site Normative 86 Appendix L Minimum Clear Distance of Hydrogen Gas Pile Buried on Plant Site and Buildings or Structures Normative 87 Appendix M The minimum clear distance of directly buried hydrogen gas pipe and other buried pipe Normative 88 Appendix N Selection of Monitoring Instrumentation for Water Disposal System On line Normative 89 Appendix O Usable Area and Instrument and Equipment Rating for Chemical Laboratory Normative 90 1 Foreword According to the requirements of Document Fa Gai Ban Gong Ye 2003 NO 873 issued by National Development and Reform Commission Notice on issuing the Supplementation Plan of Professional Standards in 2003 this code is revised from Technical Code for Designing Chemistry of Thermal Power Plants DL T 5068 1996 Following contents are revised and adjusted in this code Applicable scope of this code is revised as Level 125MW Level 1000MW Original pretreatment is replaced by water pretreatment and contents about circulating water blow off water reclaimed water seawater mine drainage and etc are added processing schemes such as hyperfiltration microfiltration and biological filter are added The chapter on water pre desalinization which contents are about reverse osmosis and seawater desalination is added Relevant clauses on electrodialysis are canceled and the content about electric demineralization is added Relevant clauses on steam turbine oil oil purification room and open air oil storage are canceled Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Appendix G Appendix H Appendix I Appendix J Appendix K Appendix L Appendix M Appendix N and Appendix O of this code are informational Appendixes This code replaces the standard DL T 5068 DL T 5068 1996 from the implementation date This code is proposed by China Electricity Council CEC This code is under and explained by the jurisdiction of Electric power planning and design standardization technical committee This code is prepared by Shandong Electric Power Engineering Consulting Institute This code is jointly drafted by Xibei Electric Power Design Institute Henan electric power Survey Design Institute North China Power Engineering Beijing Co Ltd Southwest Electric Power Design Institute China Hydropower Engineering Consulting Group Co and Guangdong Electric Power Design Institute This code is drafted by Hu Tingqian Yuan Pingfan Tao Fengchun Zhang Fuli Li 2 Chengrong Yu le and Tang Dongsheng This code was firstly issued in 1985 secondly in 1996 and revised secondly this time 3 1 1 Scope This code specifies the basic technical contents on chemistry designing of thermal power plants The standard is applicable to chemistry designing for thermal power plants which steam turbine generator capacity is 125MW 1000MW and chemistry designing for plant unit combustion engine and other modes of plant unite which capacity is less than 125MW may comply with this code 2 2 Normative References The following standards contain provisions which through reference in this text constitute provisions of this standard For dated reference subsequent amendments excepting corrigenda content to or revisions of any of these publications do not apply Parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below For undated references the latest edition of the normative document referred to applies GB 50013 Code for Design of Outdoor Water Supply Engineering GB 50061 Code for Design of 66 kV or Under Over head Electrical Power Transmission Line GB T 6907 Methods for Analysis of Water for boiler and for Cooling the Sampling Method for Water GB 18918 Sewage Disposal Standards for Urban and Rural Treatment Plant GB 50016 Code for Fire Protection Design of Buildings GB 50046 Code for Anticorrosion Design of Industrial Construction GB 50050 Code for Design of Industrial Recirculating Cooling Water Treatment GB 50177 Design Code for Hydrogen Station DL T 502 2 Analytical Methods of Steam and Water in Power Plants Part 2 Sampling Method for Steam DL T 712 Guide Rules for Material Selection of Thermal Power Plants Condenser Tube DL T 912 Quality Criterion of Water and Steam for Supercritical Pressure Units in Thermal Power Plant DL T 5054 Code for Design of Thermal Power Plant Steam water Piping DL 5053 Design Code of Labor Safety and Industrial Hygiene for Thermal Power Plants CJJ 40 Code for Design of Water supply for Muddy Water HG T 20677 Rubber Lining Chemical Equipment 3 3 Terms and Definitions This following terms and definitions are applicable to this code 3 0 1 All volatile Treatment Reduction AVT R It is referred to the treatment that boiler feed water is dosed with Ammonia and reducer also named as deoxidizer e g hydrazine 3 0 2 All volatile Treatment Oxidation AVT O It is referred to the treatment that supplied water is dosed with only ammonia but deoxidizer 3 0 3 Oxygenated Treatment OT It is referred to the treatment that boiler feed water is oxygenated 3 0 4 Direct Dry Cooling System Air cooled heating radiator that is disposed outside of the workshop building replaced the traditional water cooled steam condenser disposed under the motor dom 3 0 4 Indirect Dry Cooling System The steam condenser is always disposed under the motor dom heated cooling water is conveyed into exterior circle of natural draught tower air inlet or enclosed cooler in tower and then cooled and reflows to steam condenser for reusing 3 0 6 Mixing Condenser It is used in Indirect Dry Cooling System and squirts circulating cooling water through nozzle to form a water film and to directly contact with turbine exhaust steam for heat exchanging It is also named as ejector condenser Indirect Dry Cooling with mixing condenser is also called as Heller System 3 0 7 Surface Condenser It is used in Indirect Dry Cooling System and basically the same to traditional steam condenser Indirect Dry Cooling system with surface condenser is also called Harmon system 3 0 8 Advanced Treatment It refers the purification process of further eliminating impurities that still exist after the 4 secondary normal treatment 3 0 9 Reclaimed Water Recycled Water It means the water that can reach certain quality standard and satisfy certain use requirement and be used safely after appropriate treatment 3 0 10 Flocculation It refers to the process that finely ground particles agglomerate into larger separable particles through mechanical physical chemical or biologic methods 3 0 11 Filtration It is refers to the process that suspended particle in water is removed through porous material layer or filter gauze with proper bore diameter 3 0 12 Ultrafiltration The filtration precision is between microfiltration to nanofiltration and normally within 0 01 m 0 1 m 3 0 13 Microfiltration It refers to the filtration which precision is between filtration to hyperfiltration and the filtration precision is normally within 0 1 mm 1 0 m 3 0 14 Water Pretreatment It refers to the rough treatment before advanced treatment 3 0 15 Gain Operation Ratio GOR It refers to the ratio of water production and heating steam amount kg kg 3 0 16 Multistage Flash type Distillation Unit MSF It refers to the instillation equipment that many single stage flash evaporators are connected in series to compose the composing level reaches as many as 30 40 and the gain operation ratio reaches 10 14 Based on its structure type it may be classified as cross tube type stub tube long tube type and standpipe type The maximum temperature of its salt solution should be less than 120 to prevent scale formation 3 0 17 Flame Spot It refers to the place where revealed flame and red heat or heat surface exist 5 3 0 18 Spray Flake Spot It refers to fixing positions for grinding wheel electric welding gas welding cutting electric saw or handsaw non blast protection electric utilities and switches and chimney with spotting fire 3 0 19 Wet Hydrogen It refers to the hydrogen gas that the liquid water content is saturated or hypersaturated under the existing temperature and pressure 3 0 20 Electrodeionization It refers to the method that negative and positive composite ions are filled in the fresh water room of the electrodialyzer and the electrodialysis is combined with ion exchange to remove ions in the water Meanwhile polarization phenomenon during the electrodialysis process is utilized to regenerate electrochemically ion exchange resin 6 4 General Provisions 4 0 1 Selection and layout of chemical systems shall be considered comprehensively in accordance with the planning capacity of the thermal power plant and that facilities of the thermal power plant shall be built up in phases or at once shall be identified in accordance with plant unit by phase construction and Technical and Economic Comparison The design of chemical water treatment process shall enable to select water supply reasonably save water reduce the energy consumption protect the environment and to facilitate installation operation and maintenance of the process 4 0 2 Materials on complete examination of water quality of available water supply shall be gained before the design and the copy number shall meet following requirements For surface water recycle water reclaimed water etc the month by month materials of whole year shall be available and the copy number shall be 12 For underground water mine drainage and seawater quarterly materials of whole year shall be available and the copy number shall be 4 Obtained materials on water quality shall be analyzed and verified analytical error shall meet the requirements and the design water quality and the checked water quality shall be proposed The pattern for complete water quality examination report is detailed in Appendix A 4 0 3 For surface water past year water quality change of high water period and low water period and possible pollution condition shall be known and corresponding materials on complete water quality examination shall be gained for water resources affected by salt water encroachment or agricultural irrigation and drainage water quality change condition caused by these factors shall be grasped for underground water in limestone terrene area the stability of the water shall be known for recycle water like reclaimed water and mine drainage the source and the composition shall be known for seawater in taking mode and surrounding environmental change shall be known 4 0 4 For designing thermoelectric plant materials on heat supply load backwater volume backwater quality backwater temperature and the amount of out supplied water for chemical treatment and water quality requirement shall be grasped 4 0 5 The supply including quality price package and shipment method of selected implement material including antiriot materials chemicals padding and so on shall be grasped in the design 4 0 6 In the design conditions like structural feature of thermodynamic system furnace implement and relative peripheral machines and cooling mode and parameter of electric generator shall be known Structure and Material requirement may be proposed to the 7 equipment manufacturer through relative profession in case of need 4 0 7 For extension and reconstructed project conditions like original systems equipment arrangement and operation shall be known 8 5 Water Pretreatment 5 1 System Design 5 1 1 Water resource selection shall abide by following principles 1 Reliable water supply shall be available for the power plant water supplies such as reclaimed water seawater and mine drainage may be adopted except surface water underground water If several water supplies are available the selection shall be identified in accordance with Technical and Economic Comparison 2 If the reliability of reclaimed water and single water supply cannot be guaranteed standby water supply shall be arranged Once the seasonal exacerbation of water quality occurs whether standby water supply or faculties shall be disposed shall be determined in accordance with Technical and Economic Comparison When reclaimed water is adopted as make up water for circulating cooling water of power station the discharged water of the sewage disposal plant shall reach at least Level 2 in standard GB 18918 3 Clean water supplies shall be selected for boiler feed water as much as possible and sewage may be adopted only under specified conditions 5 1 2 The preprocess system shall be identified through Technical and Economic Comparison in accordance with raw water quality water quality requirements of later processing treating water volume and test data and combined with operating experience of similar power stations and local conditions 5 1 3 When the temperature of boiler feed water is lower and may affect pretreatment effect raw water auto regulation heating measures shall be taken out 5 1 4 Pretreatment mode shall be identified in accordance with following principles 1 For pretreatment for surface water and seawater precipitation coagulation defecation and filtration should be adopted If the suspension content is lower contact coagulation filtration or membrane treatment shall be adopted 2 If the suspended solid and burden contents of surface water and seawater exceed the water inlet requirement of adopted defecator pool standby water supply and pre sedimentation facility that can reduce the sediment content shall be disposed in water supply system Requirement on inlet water turbidity of defecator pool are detailed in Appendix B 3 For reclaimed water sources like reclaimed water and mine drainage processes such as biochemical treatment sterilization filtration petrifaction flocculation defecation and ultra macro filtration treatment shall be adopted in accordance with water quality For 9 reclaimed water with high carbonate hardness if the water treatment capacity is larger petrifaction flocculation defecation treatment should be adopted and the petrifaction chemical should be slaked lime powder 4 The inactivated silica content of water supply is higher the influence of silica to steam quality shall be considered methods such as contact coagulation filtration or precipitation coagulation defecation and filtration and ultra macro filtration shall be adopted to remove inactivated silica The removing ratio of inactivated silica shall be identified through experiments and according to experience of similar power plants 5 If the raw water organic content is higher chlorination coagulation defecation and filtration treatments may be adopted to remove organic matter If above treatments cannot satisfy inlet water quality requirement of next stage implement active carbon occluded resin biochemical treatment or other methods may be adopted simultaneously to remove organic matter If the dissociated residual chlorine content of water after pretreatment exceeds the inlet water quality requirements of after treatment active carbon absorption or sodium sulfite dosing and other methods should be adopted to dechlorinate 5 1 5 Design parameters of activated charcoal filter shall be identified in accordance with inlet water quality treatment requirements and active carbon type and based on operating experiences