1、DocumentNo.：SHANGHAI ELECTRIC POWER GENERATION EQUIPMENT CO.，SHANGHAI TURBINE PLANTS.This document contains proprietary information owned by Shanghai Electric Power GenerationEquipment Co,. Shanghai Turbine Plants. Use this document solely for the purpose given. Donot reproduce, disclose or use othe

2、rwise without written consent of Shanghai Electric PowerGeneration Equipment Co,. Shanghai Turbine Plants.GFEDCBA04/2011CFC楊照國蔣Rev.DateStatusDrafted byChecked byReviewed byApproved byModifications-observation防城港核電廠一期（2×1000MW）工程FANGCHENGGANG NUCLEAR POWER PLANT PHASE I (2×1000MW)DOC.NOBLX1

3、7CET006S40B45GNGLAND STEAM SEALING SYSTEM (CET) SYSTEM DESIGN MANUALCHAPTER 6Reference DocumentRev.C A T E G O RYAIdentical×BModifiedCNewDocumentNo.：COMPILINGDEPT.：編制部 門 ：設計COMPILED編BY：制 ： 楊照國 04/2011CHECKED校BY：對 ：04/2011REVIEWED審BY：核 ：04/2011APPROVED審BY：定 ： 蔣04/2011STANDARDIZED標 準化 BY： COUNTER

4、SIGN：會簽 ：04/2011 04/2011RATIFIED批BY:準： Document No.：CHAPTER 6 CONTROL6.1Control BasesThe seal steam system serves to prevent steam leaving or air entering the turbine via the shaft seals. Provision is also made for the leak-off steam from the glands of large turbine valves to be drawn off by the lea

5、k-off steam system.As steam flow conditions across the glands change substantially during start-up, shut-down, and turbine running load variations, it is normal to have the gland sealing system under continuous automatic pressure control.The sealing line pressure is monitored to maintain the desired

6、 system pressure by modulating steam supply and overflow valve positions to meet the variations in steam flow as running and load conditions change.The admission of steam to the shaft seal is not to be started until the hydraulic turning gear has set the turbine shaft in rotation. This means that th

7、e lubricant supply system must be in operation as well. This is intended to prevent uneven thermal stress in the shafts. The gland steam exhaust fan is started up and the seal steam controller switched on.The seal steam system is shut down at the same time as the air removal system. Before the seal

8、steam pressure controller is switched off, the pressure in the condenser is raised with the aid of the vacuum breakers to prevent an ingress of air that cools the shafts down too rapidly in the area of the labyrinth glands.Startup and shutdown can be performed automatically for all components associ

9、ated with the seal steam system. This ensures less coordinated operation of components.6.1.1Seal steam pressure controller with pneumatic actuators and opening interlockPerformance of the turbine seals is at its optimum when seal steam which is held at a constant pressure level is admitted to these.

10、 This pressure setpoint is selected such as to ensure that steam cannot escape into the atmosphere. Seal steam supply to the shaft sealsis implemented veal steam header.Under certain operating conditions, it is necessary to admit additional steam to the seal steam header using the seal steam supply

11、valve to maintain pressure. Under other conditions excess steam has to be dumped from the seal steam header.Seal steam quality is monitored continuously for fulfillment of set pressure andDate of Issue04/2011ABCDEFGHIShanghai Electric Power Generation Equipment Co.Turbine WorksSYSTEM DESIGN MANUAL G

12、LAND STEAM SEALING SYSTEM (CET)Chapter 6Sheet 1 of 11Document No.：temperature conditions. The seal steam valve can be locked in the CLOSED status where necessary to rule out admission of steam with inadequate quality to the turbine.The task of the seal steam pressure control system is to prevent esc

13、ape of steam to the atmosphere under all operating conditions, and likewise to prevent the ingress of air into the turbines and thereby into the condenser.For this, a seal steam header is provided to which all shaft seals are linked. A pressure controller modulates the seal steam supply and leak-off

14、 valves appropriately to hold pressure in the seal steam header and thereby the shaft seals at the setpoint. The seal steam supply valve serves to admit additional steam to the seal steam header. The seal steam leak-off valve serves for dumping of excess steam from the seal steam header (as appropri

15、ate for the operating conditions).6.1.2 Subloop control and drive control gland steam exhausters (2x 100%)The task of the gland steam exhausters is to produce a slight vacuum in the gland steam condenser and to remove the air that is carried over into the gland steam condenser with the leak-off stea

16、m from the shaft glands.To give high availability, two gland steam exhausters are provided with only one in operation at any time. In the event of a demand, automatic changeover to the standby exhauster is implemented.To protect the gland steam exhauster, water level in the gland steam condenser ism

17、onitored by means of a level detector connected to I&C system. If the set limit is violated, any operating gland steam exhauster is stopped automatically.umDate of Issue04/2011ABCDEFGHIShanghai Electric Power Generation Equipment Co.Turbine WorksSYSTEM DESIGN MANUAL GLAND STEAM SEALING SYSTEM (C

18、ET)Chapter 6Sheet 2 of 11Document No.：6.2Logic DiagramsBLX17CET016S40B45GNSheet 1-54Rev.ADate of Issue04/2011ABCDEFGHIShanghai Electric Power Generation Equipment Co.Turbine WorksSYSTEM DESIGN MANUAL GLAND STEAM SEALING SYSTEM (CET)Chapter 6Sheet 3 of 11Document No.：6.3Analogue DiagramsDate of Issue

19、04/2011ABCDEFGHIShanghai Electric Power Generation Equipment Co.Turbine WorksSYSTEM DESIGN MANUAL GLAND STEAM SEALING SYSTEM (CET)Chapter 6Sheet 4 of 11Document No.：6.4Controls available to the operatorDate of Issue04/2011ABCDEFGHIShanghai Electric Power Generation Equipment Co.Turbine WorksSYSTEM D

20、ESIGN MANUAL GLAND STEAM SEALING SYSTEM (CET)Chapter 6Sheet 5 of 11Document No.：6.5Information available to the operatorDate of Issue04/2011ABCDEFGHIShanghai Electric Power Generation Equipment Co.Turbine WorksSYSTEM DESIGN MANUAL GLAND STEAM SEALING SYSTEM (CET)Chapter 6Sheet 6 of 11Document No.：6.

21、6Operating Principles6.6.1Start-Up OperationThe task of the subgroup control (SGC) is to assure supply of seal steam at appropriate temperature and pressure to the shaft seals under all operating conditions. Automatic startup and shutdown of this SGC is initiated by the higher-level group control. A

22、utomatic control is configured such as to allow manual control of the relevantcomponents when this SGC is deactivated.The SGC Seal steam supply implements startup and shutdown of all subsystemsassignedtosealsteamsupplyautomaticallyandinpropersequence(STARTUP/SHUTDOWN program for this SGC). Before a

23、switching operation is implemented, the SGC first checks that all conditions for this are fulfilled. It is likewise checked whether all the necessary checkbacks are received within the set monitoringtime.The group control Evacuation initiates the STARTUP and SHUTDOWN programs for this SGC as appropr

24、iate. The condition that must be fulfilled for startup of seal steamsupply is turbine operation at a speed of n>0.25 rev/s.The start-up operation program comprises 5 steps:Step 1:The following switching operations are initiated: The vacuum breaker is closed and theassociated subloop control switc

25、hed to MANUAL.As step criterion for switching to the next step, fulfillment of the following criteria is then interrogated: Vacuum breaker closed Condenser vacuum < 0.8 Bar (abs.) Steam pressure upstream of seal steam supply valve > 2 bar. Pressure of control air supply > 4 bar. Differentia

26、l pressure for Filter in control air supply < 1 bar. If the seal steam pressure controller is already in AUTO mode (bypass criterion), the criterion"Condenser vacuum < 0.8 bar (abs.)" is then no longer relevant.Step 2:Date of Issue04/2011ABCDEFGHIShanghai Electric Power Generation Eq

27、uipment Co.Turbine WorksSYSTEM DESIGN MANUAL GLAND STEAM SEALING SYSTEM (CET)Chapter 6Sheet 7 of 11Document No.：The following switching operations are initiated: The turbine drains are activated.As step criterion for switching to the next step, fulfillment of the following criteria is then interroga

28、ted: Turbine drains have been activated Adequate degree of superheat for seal steam or warm-up upstream of the seal steam supply valve has been activated At least one of the condensate pumps must be have been switched on Cooling of the gland steam condenser must be assured - Pressure in condensate s

29、upply line must be > 13 barLevel in gland steam condenser must be < MAX.Step 3:The following switching operations are initiated: The seal steam system is activated.As step criterion for switching to the next step, fulfillment of the following criteria is then interrogated: The seal steam syste

30、m is in operation. Adequate degree of superheat for seal steam upstream of seal steam supply valve Turbine speed is on turning speedCondenser pressure is < 0.8 bar (abs.).Step 4:The following switching operations are initiated: The seal steam pressure controller isswitched on.As step criterion fo

31、r switching to the next step, fulfillment of the following criterion isthen interrogated: The seal steam pressure controller is in operation.Step 5:On reaching step 5, a checkback is issued to signal that the seal steam system is inoperation.Date of Issue04/2011ABCDEFGHIShanghai Electric Power Gener

32、ation Equipment Co.Turbine WorksSYSTEM DESIGN MANUAL GLAND STEAM SEALING SYSTEM (CET)Chapter 6Sheet 8 of 11Document No.：6.6.2Shutdown OperationThe shutdown operation program comprises 5 steps:Step 51:As step criterion for switching to the next step, fulfillment of the following criterion isthen inte

33、rrogated: Vacuum pumps have been switched off.Step 52:The following switching operations are initiated: The vacuum breaker is opened As step criterion for switching to the next step, fulfillment of the following criteria is then interrogated: The vacuum breaker is 100% open Condenser vacuum is >0

34、.8 bar (abs.)Turbine speed is below 9 rev/sStep 53:The following switching operations are initiated: The seal steam pressure controller isswitched offAs step criterion for switching to the next step, fulfillment of the following criterion is then interrogated: The seal steam pressure controller has

35、been switched off (MANUALmode) AND the seal steam supply valve is closed.Step 54:The following switching operations are initiated: The vacuum breaker is closed againThe seal steam system is deactivatedAs step criterion for switching to the next step, fulfillment of the following criteria isthen inte

36、rrogated: The vacuum breaker is closed The warm-up valve is closed The seal steam system is not in operationStep 55:On reaching step 55, a checkback is issued to signal that proper shutdown of the sealDate of Issue04/2011ABCDEFGHIShanghai Electric Power Generation Equipment Co.Turbine WorksSYSTEM DE

37、SIGN MANUAL GLAND STEAM SEALING SYSTEM (CET)Chapter 6Sheet 9 of 11Document No.：steam system has taken place.6.6.3Operation in Case of Incident and/or AccidentAn interlock is provided for the seal steam supply valve to protect the turbine shaft and shaft seals against the admission of seal steam at t

38、oo high or too low temperatures. Interlocking against the admission of seal steam at too high temperatures may benecessary in the event of a too hot steam source.Disabling of opening of the seal steam supply valve or closing of this if already open is performed by the interlock in response to a numb

39、er of conditions. These comprise: Steam temperature upstream of seal steam supply valve is only slightly above theassociated saturation temperature or pressure upstream of seal steam supply valve isbelow a set minimum limit, or seal steam temperature is above aum value. Thesaturation temperature is derived as a function of pressure upstream of the seal steam supply