ICS 77.010 CCS H 04 YB Industry standard for ferrous metallurgy industry of the People's Republic of China YB/T 4256.2—2016 Technical specification of seawater desalination for iron and steel industry -Part 2: Coupling joint production of desalted water and electricity for low temperature multiple effect distiｌlation 钢铁行业海水淡化技术规范第2部分：低 温多效水电耦合共生技术要求 (Eng/ish Trans/ation) Issue date: 2016-07-11 Implementation date:2017-01-01 Issued by Ministry of Industry and Information Technology of the People's Republic of China YB/T 4256.2—2016 Foreword SAc/TC183 is in charge of this English translation. In case of any doubt about the contents of English translation, the Chinese original shall be considered authoritative. The YB/T4256 Technica/ specification of seawater desalination for iron and stee/ industry consists of the following four parts under the general title: Part1:Lowtemperaturemu/tip/eeffectdisti//ation -Part2:Coup/ingjointproductionofdesa/tedwaterande/ectricityfor/owtemperature mu/tiple effect disti/lation -Part 3:Acidcleaningfor /owtemperaturemu/tip/eeffect seawater disti//ation -Part4:Comprehensiveutilizationof concentratedbrine This part is drafted in accordance with the rules given in the GB / T 1.1-2009 This part is part 2 of YB/T 4256. This part was proposed by China Iron and Steel Industry Association. This part was prepared by the Technical Committee on Steel of Standardization Committee of China(SAC/TC 183) - YB/T4256.2—2016 Technology specification of seawater desalination for iron and steel industry Part 2: Coupling joint production of desalted water and electricity for low temperature multiple effect distillation 1 Scope Thispart of YB/T4256 specifies the terms and definitions,processes and principles,media for low temperature multiple effect coupling joint production of desalted water and electricity for iron and steel industry. This part is applicable to the system of low temperature multiple effect coupling joint production of desalted water and electricity for iron and steel industry, and also can be the reference for other industries such as electric power and chemical industry. 2Normative references The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies GB/T1576 Water qua/ity for industria/ boilers GB/T5578Fixedpowerp/antturbinespecifications YB/T4256.1Technology specification of seawater desa/ination for ironand stee/ industry --Part1:Lowtemperaturemu/tip/eeffectdisti//ation 3 Terms and definitions For the purposes of this document, the terms and definitions given in the YB/T 4256.1, the GB/T 5578 and the following apply. 3. 1 negative pressure steam flow theatmosphericpressure,fromthemainsteamflowfinallyreachingtheIaststageofthe steam turbine after heat energy is converted into mechanical energy through driving the steam turbine blades 3. 2 2 YB/T4256.2—2016 closed-typeisolatingvalve valve that composed of sealedvalve shell and valve plate, which isused as the basic unit for pipelines sealing over tensioning the stretching with over designed force value is conducted on the cable, to make it keep in a stable and reliable state 4Processes and principles 4. 1 Processes The typical process flow diagram of low temperature multiple effect coupling joint production of desalted water and electricity is shown in Figure 1. 4.2 Principles The low temperature multiple effect coupling joint production of desalted water and electricitytechnologydirectlycouples thegenerator setwiththe lowtemperaturemultiple effect seawater desalination unit. The saturated steamwith pressureno lower than0.4 MPa from the boiler is first used for the steam turbine generator for power generation, after which the negative pressure steam flow of steam turbine is immediately sent to the Iowtemperaturemultiple effect seawater desalinationunit toproduced