文稿案例成果

1、A全 issuestage2广西防城港核电厂一期(2x1000MW)PHASE I（2x1000MW）DOC.BLX17ACO005GJS045GN题SYSTEMDESIGNFEEDWATERHEATERSDRAINRECOVERYSYSTEM(ACO) CHAPTER 5 OPERATING PARAMETERS给水加热器疏水回收系统设计手参考电A:编B: C: Issued by设计院编-H0201S-J0210-Internal Identification This is the property of GEDI.It must not beused,reproduced,transm

2、itted or disclosed without the prior written permission of GEDI. 本文件之属于省电力。未获我院，任何人不得擅自使用、传递或该文件。准 核 张 对 郑 写 全控 CHAPTER 5 - OPERATING NORMAL OPERATING Normal operating conditions are at turbine rated continuous electrical output of 1086.0 MW with no section of the feed train bypassed.DrainstoLPheate

3、rdrainsflow(perDrainsfromLPheaterdrainsflow(perABCDEFGPARTICULAR STEADY OneBankofHeaters3and4One bank of LP heaters 3 and 4 isolated with 50% of flow through the active bank and 50% through the bypass. The turbine load is 1077.010 MW, the main turbine stop valves are considered to be wide open.Drain

4、sto LP heaterdrains receivers DrainsfromLPheaterdrainsreceiverTwoBanks of LPheaters1 and2 All banks of duplex heaters isolated. The reactor output is 100% and the turbine load is 1066.388 MW, the main turbine stop valves are considered to be wide open. Under this mode of operation the operator must

5、stop the LP heater drains pumps, all drainage is automatically diverted to the standpipe upon HHWL R in the LP drains receiver. Flow rate of the third bledhigh ,so this mode of operation can not be long.One HP Heater Bank ABCDEFGOne bank of HP heaters 6 and 7 isolated with the flow split 65% through

6、 the activebankand35%throughthebypass.Thereactoroutputis100%andthe main turbine stop valves are considered to be wide open.DrainstoLPheaterdrainsflow(perDrainsfromLPheaterdrainsflow(perABCDEFGPARTICULARTRANSIENTLoad Loadrejectionisdefinedasalargedropinturbinegeneratorloadwithoutturbinetrip Upon load

7、 rejection the pressures in the LP heaters will drop suddenly due to the drop in bledpressures. This may lead to cavitation and/or flashing in the heater drains pumps. The pumps are designed to withstand operation in the cavitating mode, but there should be a loss of generated head of 50% normal for

8、 greater than 1 minute, the pumps will trip automatically.Reverse flow due to the drop in pressure is prevented via the NRVs (GPV31 51 VV /GPV32 51 VV). The LP heater 3 and the LP heater 3 drains receiver are sustained at the same pressure via the interconnecting vent and drain pipework which also e

9、nsures that reverse flow will not take place.Load rejection results in the LP heater 3 and 4 drainage flow rate falling due to the reduced bledflow. Consequentially the LP heaters drains receiver level control valves will modulate to suit the lower flow rate as described in sections4.1.6.2andShould

10、LP heater drains pump ACO 301 PO (302PO) trip take place then the LP heaters drains receiver will flood to the HHWL R, automatic opening of the emergency overflow valve ACO 102VL (202VL) then takes place.TurbineNone of the components of the ACO system impose any limitations on the rates of turbine l

11、oading.BothBanksofLPHeaters3and4The automatic isolation of the LP heaters 3 and 4, due to fault conditions in the ABP system, also effectively isolates the ACO system by closing the pump discharge isolating valve ACO106VL (ACO206VL). Closure of this valve fully opens the drain pump recirculation con

12、trol valve leaving the pump running on recirculation flow. The LP drains pumps should be stopped by the operator if operation of the associated LP heater bank cannot be re-established within one hour. On restoration of the associatedLPheaterbankforwarddrainsflowisrestoredwhen theoperatorreopensABCDE

13、FGACO106VLABCDEFGNORMALSHUTDOWNAND START-Prior to start-up it is necessary to correctly position all the system valves as per flow diagram BLX17ACO501GJS045DD.OTHERLossofLPDrainsTheLPdrainspumpwilltripforthefollowingLoss of discharge head; if the developed head drops below 50% of normal in excess of

14、 1 minute duration. This may occur if the pumps are running in the cavitating mode during load rejection operation.LLWL F in the drains receiver; this may occur upon malfunction of the level control system.Turbine trip; this action occurs as part of the main turbine automatic shutdown. Should a drai

15、n pump trip then the drains receiver will flood to HWL R and initiate the alarm LP heater drains receiver ABP 301BA (302BA) HWL , hence warningtheoperatorofafaultcondition.Shouldtheoperatorbeunabletotake remedial action to restart the pump then the level in the drains receiver will achieve HHWL R.CO

16、NTROLControlThefollowingtextdescribeshigh water level indicates falling levelindicatesrisingindicatesLP Heater No. 3A Drains Receiver ACO 301BA (302BA identical) Level 2RD Alarm LWLStartassociatedACOdrainpump Level 3RD Alarm HWLStartACOdrainpump Level 4RD Alarm HHWLOpen emerge drain valve ACO 102VL

17、(202VL) Level3FD CloseemergedrainvalveACO102VL(202VL). Level 2FD Alarm LWL.NotpermittostartassociatedACOdrainpump Level 1FD Alarm LLWL.Stop associated ACO drain At level HHWL R the operator must associated LP Heater Drains pump to help maintain the emergency drain line flooded. The operator should s

18、top the LP Heater Drains pump to rectify the high drain level before restarting the associated LP Heater Drains pump.FunctionalRequirementsofControl ValvesforBankA(BankBidentical) Receives a modulating signal from LP heater drains receiver level controller which is located on the s of the vessel. Th

19、e flow discharges into the condensate discharge line from the LP heater 3 (ABP system).Risingcontrolsignaltendstoopenthevalve. Spring tends to close the valve.On control air failure valve closes. Onsupplyairfailurevalvefailsfixed.LP Heater Drains Pump A Recirculation Control Valve ACO 108VL Receives

20、 a modulating signal from LP heater drains receiver level controllerwhichislocatedonthesofthevessel.Theflowdischarges back into the LP heater ACO 301BA (302BA).Risingcontrolsignaltendstoclosethevalve. Spring tends to open the valve.On control air failure valve opens. Onsupplyairfailurevalvefailsfixe

21、d.Valveopenswhen106VL(206VL)isnotfullyLP Heater 4 Drain Control Valve ACO 109VL Receives a modulating signal from LP heaters 4 level controller which is located on the s of the vessel. The flow cascades to the LP heater No. 3 drains receiver ACO 301BA (302BA).Risingcontrolsignaltendstoclosethevalve.

22、 Spring tends to close the valve.On control air failure valve closes. Onsupplyairfailurevalvefailsfixed.LP Heater 4 Emergency Drain Control Valve ACO 110VL (210VL): ReceivesamodulatingsignalfromLPheaters4levelcontrollerwhichis located on the s of the vessel. The flow cascades to the condenser Risingcontrolsignaltendstoclosethevalve. Spring tends to open the valve.On control air failure valve opens. Onsupplyairfailurevalvefailsfixed.5.6.3.2 MotorizedLP Heater 3A