電極蒸汽鍋爐系統(tǒng)安裝使用維護(hù)說明

1、WORD文檔下載可編輯輔助鍋爐房電鍋爐項目 系統(tǒng)安裝使用維護(hù)說明備注：階段設(shè)計礎(chǔ) 1出版日期2011-08-28ZANDER &INGESTRO 初包含項目設(shè)計說明文件審核圖紙或圖標(biāo)0批準(zhǔn)文件狀態(tài)CFC總數(shù)CAD管理版次0遞交文件號HYG-MB20-V7-YZDI024遞交文件號HYG-MB20-V7-YZDI014資料名稱系統(tǒng)說明版 次日期設(shè)計審核批準(zhǔn)CAD管理備注02011.08.28系統(tǒng)說明Table of Content 目錄1 Functions of the System 系統(tǒng)功能 61.1 Safety classified functions安全分類功能 61.2 Op

2、erational Functions運行功能 62 General Description of the System 系統(tǒng)般說明 72.1 System系統(tǒng)72.1.1 Feed water System (QHG)給水系統(tǒng) 72.1.2Evaporation System (QHA)汽化系統(tǒng) 72.1.3Blow down System (QHE) 排污系統(tǒng) 92.1.4Chemical Dosing System (QCC, QCF)化學(xué)加藥系統(tǒng) .92.1.5Sampling System (QUB) 取樣系統(tǒng) 102.1.6 Compressed / Instrument Air

3、System (QHP)壓縮空氣 / 儀表系統(tǒng) 102.2 Main Components 主要部件 112.2.1 Deaerator/Feed water tank 除氧器 / 給水箱 112.2.2 Feed water pumps 給水泵 112.2.3 Boilers 鍋爐112.2.4 Circulation pumps 循環(huán)泵 122.2.5 Make-up water pumps 補水泵 122.2.6 Blow down tank 排污罐123 Operation of the system系統(tǒng)運行 133.1 Normal system operating conditio

4、ns系統(tǒng)正常運行工況 133.2 Abnormal system operating conditions 系統(tǒng)異常運行工況 143.3 Normal plant operating conditions電站正常運行工況 153.4 Abnormal plant operating conditions電站異常運行工況 153.4.1 Effects on the ASGS at failure or malfunctions in associated systems因 ASG故障或輔助系統(tǒng)154 System Design 系統(tǒng)設(shè)計164.1 General Design Basis 總體

5、設(shè)計基礎(chǔ) 164.1.1 Codes and Standards 規(guī)范和標(biāo)準(zhǔn) 164.1.2 Safety Classification 安全等級 164.1.3 Safety related design criteria相關(guān)安全設(shè)計標(biāo)準(zhǔn) 164.1.4 Protection against Internal Hazards內(nèi)部危害防護(hù) 164.1.5 Protection against external hazards夕卜部危害防護(hù) 174.1.6 Ambient conditions環(huán)境條件 174.2 Component Design Basis 部件設(shè)計基礎(chǔ) 174.3 Insta

6、llation 安裝184.4 Materials 材料184.5 Electrical and Control Equipment 電氣和控制設(shè)備 184.5.1 Automatic Control and On/Off Functions自動控制和開關(guān)功能 194.5.1.1 Boiler 鍋爐：194.5.1.1.14.5.1.1.24.5.1.1.34.5.1.1.44.5.1.1.54.5.1.1.64.5.1.1.74.5.1.1.84.5.1.1.94.5.1.1.10Start & stop sequences 啟停順序 19Pressure, power and le

7、vel control of boiler鍋爐的壓力 20Circulation pump 循環(huán)泵 21Volume control of boiler鍋爐水量調(diào)節(jié) 22Feed water pump 給水泵 23Min. boiler pressure and reduced pressure最小鍋爐壓力和減壓 23Conductivity control導(dǎo)電性控制 24Bottom blow down (sludge removal)鍋爐底部排污(污泥清除) 25Deaerating the boiler鍋爐排氣 25Warm up valves steam line 蒸汽管道上的暖管閥

8、264.5.1.1.11 Cooling the protective cage安全箱的冷去卩 264.5.1.1.12 Heating of boiler during hot standby鍋爐熱備用期間加熱 27274.5.1.2 Feed water tank :除氧器：4.5.1.2.1 Pressure control of feed water tank除氧器壓力的控制 274.5.1.2.2 Level control of feed water tank and makeup water pumps除氧器和補水泵的液面控制284.5.1.2.3 Overflow contro

9、l of feed water tank除氧器的溢流控制 294.5.1.2.4 Standby operation 備用操作 294.5.1.2.5 Deaerating 排氣294.5.1.3 Water treatment (Dosing):水處理(加藥) 304.5.1.3.1 Hydrazine, (N2H)聯(lián)氨304.5.1.3.2 Trisodium Phosphate, (crystallized 98% Na3PO4 +12H2O)磷酸三鈉，(98%勺結(jié)晶 Na3PO4 +12H2O 304.5.1.3.3 Blow down tank cooling 排污罐冷去卩 314.

10、5.2 Measurements 其他314.5.3 Alarm functions 報警功能344.5.3.1 Common for ASGS ASGS 的常見狀況 374.532 Boilers 鍋爐374.533 Feed water tank 除氧器 374.534 Dosing tanks 力廿藥罐 374.5.4 Signal Exchange towards MCR 指向 MCR勺信號交換 394.6 Associated Systems 相關(guān)系統(tǒng) 495 General operational aspects般操作方面 506 Technical System Specific

11、ation系統(tǒng)技術(shù)規(guī)范 517 References 參考文獻(xiàn)538 Appendices 附錄54技術(shù)資料專業(yè)分享1.Fu nctio ns of the System系統(tǒng)功能描述? 1.1 peratio nal Fu nctio ns 使用功能The Auxiliary steam gen erat ing system (QH), by means of two medium voltage electrode boilers, supplies steam to the auxiliary steam system duri ng main pla nt outage, start-

12、up and shutdow n, whe n steam from the mainsteam system, or other sources, isnot available.本輔助蒸汽系統(tǒng)(QH系統(tǒng))采用兩臺中壓電極鍋爐在總電站運行中斷、開啟、停止期間，以及主蒸汽系統(tǒng)或其他來源的蒸汽不可用時，向輔助蒸汽系統(tǒng)提供蒸汽。In order to achieve the required fast startup and steam production,the system willno rmally be in sta ndby operati on, at no rmal operati

13、o nal pressure and temperature by means of low voltage electrical elements (immersion heaters) fitted in the boilers and feed water tank.為達(dá)到快速啟動和產(chǎn)生蒸汽要求，本系統(tǒng)通常會處于備用狀態(tài)，維持正常操作壓力和溫度。這些工作將由安裝在鍋爐和除氧器內(nèi)的380V氐壓電氣元件(備用加熱器)完成。? 2General Description of the System系統(tǒng)一般說明2.1 System系統(tǒng)說明? 2.1.1Feed water System (QHG)

14、鍋爐給水系統(tǒng)(QH(系統(tǒng))Make-up water, demineralized water (QHC) is fed to the feed water tank (00QHJ10 BB010) by make-up water pumps to the sprayer, which is part of the feed water tank.除氧器(00QHJ10 BB010)的補水是除鹽水(QH(系統(tǒng))，是由補水泵(00QHC11 AP001/00QHC12AP001和除氧器噴嘴之間的設(shè)備完成的。Excess steam/gas flows from the deaerator th

15、rough a pipe that conn ects with the safe ty valve ' s blow -off pipe. A manually shut-off valve (00QHJ10 AA002) on this pipe will be closed after when there is no filling of the tank. Two orifice plates (00QHJ10 BP003/004) is fitted to optimize the flow of the excess steam. During sta ndby oper

16、ati on the valve is closed, in order to save en ergy.除氧器內(nèi)的過量蒸汽及其他氣體通過排氣管道排出。在除氧器內(nèi)充水后，此管道上的手動切斷閥(00QHJ10 AA002)關(guān)閉。兩個孔板(00QHJ10 BP003/004)將調(diào)整成最有利于過量蒸汽 排出的狀態(tài)。為了節(jié)能，在設(shè)備備用期間此閥門將處于關(guān)閉狀態(tài)。The feed water tank ' s water level is maintained by regulating the control valve (00QHC10 AA003) for thedemineralized

17、 makeup water to the feed water tank.Controlsignal 0-100% regulates the makeup water valve 0-100%.除鹽補水在除氧器內(nèi)的水位是通過調(diào)節(jié)控制閥(00QHC10 AA003)來維持的。控制信號0-100%調(diào)節(jié)補水閥0-100%。The feed water tank ' s pressure, and in direct its temperature, is maintained by regulati ngthe con trol valve (00QHF30 AA004) for the

18、steam from the boilers to thefeed water tank.通過調(diào)節(jié)鍋爐供給除氧器蒸汽的調(diào)節(jié)閥，可保持除氧器的壓力及對應(yīng)的溫度。The steam is lead to the bottom of the tank and passed through spreader pipes which create a circulation and thus a good mixing in the tank.除氧蒸汽通過除氧器內(nèi)擴散器管道從除氧器底部進(jìn)入除氧器，這樣有利于蒸汽與水的充分混合。One pressure relief valve (safety valve

19、 00QHJ10 AA010) is fitted on the tank to preve nt an excess pressure in case there is a problem with the pressure con trol.除氧器安裝一個安全閥(安全閥00QHJ10 AA010),用于防止壓力控制出現(xiàn)問題時造成的超壓事故。The water is pumped from the feed water tank to the respective boiler by the feed water pumps.從除氧器內(nèi)出來的水再由給水泵輸送到各自應(yīng)流向的鍋爐內(nèi)。There

20、is one pump for each boiler (00QHG11 AP001 and 00QHA12 AP001). Each pump is designed for 100% of the flow.每臺鍋爐都配有一臺給水泵(00QHG11 AP001和00QHA12 AP001)，每臺泵都按100%的流量設(shè)計。The selected feed water pump is running continuously during normal operation. Ifthe selected pump fails and shuts down, the spare pump (0

21、0QHG13AP001) will automatically start. Correspondingly the on-off valve 00QHG14AA001)pens to boiler 00QHA10AC010 and on-off valve 00QHG15AA001 ope ns to boiler 00QHA20AC010.設(shè)備正常運行期間，給水泵是連續(xù)運行的。如果給水泵不能正常工作，則備用泵(00QHG13AP001會自動啟動。相對應(yīng)的，備用切換開關(guān)閥 00QHG14AA00為鍋爐00QHA10AC010 開啟，而備用切換開關(guān)閥00QHG15AA00對應(yīng)鍋爐00QHA20

22、AC01開啟。During standby or if the boiler pressure is below a set value the feed water control valve (00QHG11/12 AA006) is closed before a pump is started and the ope ning of the valve is reduced to a set value to remove the risk for cavitations in the pump due to high flow.在設(shè)備備用期間或當(dāng)鍋爐壓力低于設(shè)定值時，開啟另一個泵之前

23、，給水控制閥(00QHG11/12 AA006)將關(guān)閉，同時閥門的開度會調(diào)整到一個設(shè)定值，以避免給水泵帶來的汽 蝕危險。During sta ndby operatio n the feed water pump fills the boiler betwee n two water volume set poin ts.設(shè)備運行期間，給水泵的給水量處于兩個水量設(shè)定值之間。Each pump has a minimum flow valve (00QHG11/12/13 AA003), which secures the pumps minimum flows. The min flow va

24、lves will ope n automaticallyat set pressure and thewater is pumped back to the feed water tank.給水泵有最低流量閥(00QHG11/12/13 AA003)，用于維持泵的最小流量。在設(shè)定壓力下， 最低流量閥將自動開啟，然后水會被泵回除氧器內(nèi)。An on/off valve (00QHE16AA002), fitted below the tank, acts as overflow protection: 安裝在除氧器底部的開關(guān)閥(00QHE16AA002)起到溢流的作用：If the feed w

25、ater tank water level should reach the set high limit, this valve will open until the level is below the set value for closing the valve.如果除氧器內(nèi)的水位達(dá)到了最高上限，則此開關(guān)閥會開啟，直到水位低于設(shè)定值后再自動關(guān)閉。During sta ndby operatio n the feed water tank is kept warm and pressurized by two electric eleme nts (00QHJ10 AH001/AH00

26、2, 2x50% capacity), which are en gaged at the set limit (on/offcontrol).To ensure the fastest possible start-up, the set limitfor warm keeping will be equal to operational temperature.設(shè)備備用期間，除氧器的保溫和保壓工作由兩個電器元件(00QHJ10 AH001/AH002,2X50KW)完成，這兩個電加熱器溫控運行(開關(guān)控制)。為保證最快速度的開啟設(shè)備，保溫的設(shè)定限制將約等同于供氣溫度。The feed wat

27、er tank ' s pressure, and in direct its temperature, is maintained byregulati ngthe con trol valve (00QHF30 AA004) for the steam from the boilers to thefeed water tank.通過調(diào)節(jié)鍋爐供給除氧器蒸汽的調(diào)節(jié)閥，可保持除氧器的壓力及對應(yīng)的溫度。The steam is lead to the bottom of the tank and passed through spreader pipes which create a c

28、irculation and thus a good mixing in the tank.除氧蒸汽通過除氧器內(nèi)擴散器管道從除氧器底部進(jìn)入除氧器，這樣有利于蒸汽與水的充分混合。One pressure relief valve (safety valve 00QHJ10 AA010) is fitted on the tank to preve nt an excess pressure in case there is a problem with the pressure con trol.除氧器安裝一個安全閥(安全閥00QHJ10 AA010),用于防止壓力控制出現(xiàn)問題時造成的超壓事故。

29、The water is pumped from the feed water tank to the respective boiler by the feed water pumps.從除氧器內(nèi)出來的水再由給水泵輸送到各自應(yīng)流向的鍋爐內(nèi)。There is one pump for each boiler (00QHG11 AP001 and 00QHA12 AP001). Each pump is designed for 100% of the flow.每臺鍋爐都配有一臺給水泵(00QHG11 AP001和00QHA12 AP001)，每臺泵都按100%的流量設(shè)計。The select

30、ed feed water pump is running continuously during normal operation. If the selected pump fails and shuts down, the spare pump (00QHG13AP001) will automatically start.Correspondinglythe on-off valve 00QHG14AA001)pens to boiler00QHA10AC010 and on-off valve 00QHG15AA001 ope ns to boiler 00QHA20AC010.設(shè)備

31、正常運行期間，給水泵是連續(xù)運行的。如果給水泵不能正常工作，則備用泵 (00QHG13AP001會自動啟動。相對應(yīng)的，備用切換開關(guān)閥 00QHG14AA00為鍋爐00QHA10AC010 開啟，而備用切換開關(guān)閥00QHG15AA00對應(yīng)鍋爐00QHA20AC01開啟。During standby or if the boiler pressure is below a set value the feed water control valve (00QHG11/12 AA006) is closed before a pump is started and the ope ning of th

32、e valve is reduced to a set value to remove the risk for cavitations in the pump due to high flow.在設(shè)備備用期間或當(dāng)鍋爐壓力低于設(shè)定值時，開啟另一個泵之前，給水控制閥 (00QHG11/12 AA006)將關(guān)閉，同時閥門的開度會調(diào)整到一個設(shè)定值，以避免給水泵帶來的汽 蝕危險。During sta ndby operatio n the feed water pump fills the boiler betwee n two watervolume set poin ts.設(shè)備運行期間，給水泵的給

33、水量處于兩個水量設(shè)定值之間。Each pump has a minimum flow valve (00QHG11/12/13 AA003), which secures the pumpS minimum flows. The min flow valves will ope n automaticallyat set pressure and thewater is pumped back to the feed water tank.給水泵有最低流量閥(00QHG11/12/13 AA003)，用于維持泵的最小流量。在設(shè)定壓力下， 最低流量閥將自動開啟，然后水會被泵回除氧器內(nèi)。An on

34、/off valve (00QHE16AA002), fitted below the tank, acts as overflow protection: 安裝在除氧器底部的開關(guān)閥(00QHE16AA002)起到溢流的作用：If the feed water tank water level should reach the set high limit, this valve will open until the level is below the set value for closing the valve.如果除氧器內(nèi)的水位達(dá)到了最高上限，則此開關(guān)閥會開啟，直到水位低于設(shè)定值后再

35、自動關(guān)閉。During sta ndby operatio n the feed water tank is kept warm and pressurized by two electric eleme nts (00QHJ10 AH001/AH002, 2x50% capacity), which are en gaged at the set limit (on/offcontrol).To ensure the fastest possible start-up, the set limitfor warm keeping will be equal to operational te

36、mperature.設(shè)備備用期間，除氧器的保溫和保壓工作由兩個電器元件(00QHJ10 AH001/AH002,2X50KW)完成，這兩個電加熱器溫控運行(開關(guān)控制)。為保證最快速度的開啟設(shè)備，保溫的設(shè)定限制將約等同于供氣溫度。2.1.2Evaporation System (QHA) 蒸汽系統(tǒng)(QH系統(tǒng))The electrode boiler has an inner vessel moun ted on ceramic in sulators in side the shell (outer vessel). The three phase electrodes (00QHA10 AH1

37、01 for boiler 10 and 00QHA20AH101 for boiler 20), each consistingof a number of bars mounted on a singleelectrode plate, are located in the inner vessel. Each electrode is suspe nded inin sulated bush ings(hollow ceramic in sulators) at the top of the boiler. The innervessel, which also forms the ne

38、utral point of the electrical system, divides the boiler into two water chambers (inner and outer).鍋爐分為內(nèi)筒和外筒。電極鍋爐的內(nèi)筒通過陶瓷絕緣件安裝在外筒內(nèi)部上方。每個三相電極(三相電極00QHA10 AH101供鍋爐10所用，00QHA20 AH101供鍋爐20所用)包含若干 個安在單電極盤上的金屬電極棒，并被固定在內(nèi)筒上方。 電極被懸在鍋爐頂部的絕緣套管上(中空的陶瓷絕緣件)。鍋爐內(nèi)筒將成為電氣系統(tǒng)的中性點。Electric power is con verted directly int

39、o heat as the curre nt flows through the water. The current passing through the water is a function of the active surface area of the electrodes and the boiler water ' s con ductivity. The curre nt is con trolled by regulat ing the water level, thus vary ing the active electrode area. The level

40、is raised by closing the valve in the bottom of the inner vessel (00QHA10 AA101 for boiler 10 and 00QHA20 AA101 for boiler 20) and at the same time opening the valve in the circulation pipe (00QHM01 AA003 for boiler 10 and 00QHM02 AA003 for boiler20). The level is lowered by doing the in verse.爐水導(dǎo)電，

41、電能被轉(zhuǎn)化成熱能。爐水的電流與電極的有效表面積以及爐水電導(dǎo)率具有函數(shù)關(guān)系。電流的控制是通過水位的調(diào)節(jié)，進(jìn)而改變電極被浸沒的有效面積完成的。關(guān)閉內(nèi)筒底部閥門(00QHA10 AA101供鍋爐10用，00QHA20 AA101供鍋爐20用)，并同時開啟循環(huán) 管道上的閥門(00QHM01 AA003供鍋爐10用，00QHM02 AA003供鍋爐20用)，可使鍋爐水位 上升。反向操作則降低水位。As long as the load does not exceed the power set poin t (max. allowed powered), it is the boilers '

42、steam pressure that is con trolled.只要載荷不超過功率設(shè)定點(允許的最大功率)就可控制鍋爐的蒸汽壓力。The water volume in the respective boiler is kept constant at set level by regulating the control valves (00QHG11 AA006 for boiler 10 and 00QHG12 AA006 for boiler 20) on the boilers ' respective feed water inlet pipe. The volume

43、 is calculated from the levels of both the inner and outer (boiler) vessel.通過調(diào)節(jié)各鍋爐給水管上的控制閥(00QHG11 AA006供鍋爐10用，00QHG12 AA006供鍋爐20用)，即可使鍋爐內(nèi)水量保持設(shè)定值，恒定不變。水量可通過計算鍋爐內(nèi)、外筒的水 位得出。The water is circulated from the outer vessel (boiler vessel) to the inner vessel by a circulati on pump.鍋爐外筒的水通過循環(huán)泵泵入內(nèi)筒。There ar

44、e two circulation pumps (2x100%) for each boiler (00QHM11/12 AP001 and 00QHM21/22 AP001).每個鍋爐有兩個(2x100%)循環(huán)泵(00QHM11/12 AP001 和 00QHM21/22 AP001)。If the selected pump fails and shuts down, the other pump will automatically start. 如果一個泵因自身故障停止運行，則備用泵會自動啟動。The flow is approximately 180 m3/h. At operati

45、on, keeping the level of the innervessel steady,means that the controlvalves for inner vessel and circulation pipewill be approximately 50% ope n, which means there is always a reflow of water from the inner to the outer vessel.循環(huán)泵流量約為180 m3/h。運行時，保持內(nèi)筒水位恒定則意味著內(nèi)筒和循環(huán)管道上的控制閥需要打開 50%左右，以保持內(nèi)外兩筒始終有水流動。The

46、 forced circulati on system en sures a fast start-up and shut-dow n. The con sta nt mixing of water also eliminates the risk for a salt concentration at the surface, which otherwise would occur.強制循環(huán)系統(tǒng)可保證鍋爐快速調(diào)整功率。爐水的充分混合也避免了爐水表面含鹽濃度過咼的危險。After the pumps (00QHM11/12AP001 for boiler 10 and 00QHM21/22AP

47、001 for boiler 20) there is an orifice plate (00QHM11/12 BP001 forboiler 10 and 00QHM21/22 BP001 forboiler 20) for en sure that the pumps don't cavitate.循環(huán)泵(00QHM11/12AP001供鍋爐10用，00QHM21/22AP001供鍋爐20用)的出口裝有孔 板(鍋爐10的為00QHM11/12 BP001，鍋爐20的為00QHM21/22 BP001)，用于防止泵氣蝕。In the PLC program the outgoi n

48、g sig nal to con trol valve (00QHM01AA003 for boiler10 and 00QHM02AA003 for boiler 20) is minimized to 5 % to ensure the minimum water flow.在PLC程序中，向控制閥(鍋爐10的為00QHM01AA00,鍋爐20的為00QHM02AA003)發(fā) 出的信號最小值為 5%以保證最低流量。The boiler water' s con ductivity is main tai ned by regulat ing the in termitte nt b

49、low down valve (00QHE02AA001for boiler 10 and 00QHE22AA001or boiler 20), which blows water from the inner vessel to the blow down tank.爐水電導(dǎo)率的控制靠排污閥(鍋爐10為00QHE02AA001,鍋爐20為00QHE22AA001間歇調(diào)節(jié)實現(xiàn)。排污閥把內(nèi)筒排污水間歇性排放到排污罐內(nèi)。A conductivity meter (00QHM01CQ001 for boiler 10 and 00QHM02CQ001 for boiler 20)is fitted

50、in the circulation pipe.循環(huán)管道上安有電導(dǎo)率儀(鍋爐10的為00QHM01CQ001鍋爐20的為00QHM02CQ001)For removing precipitated solids(sludge),the blow down valve (00QHE01 AA001/AA002 for boiler 10 and 00QHE11 AA001/AA002 for boiler 20), will ope n ma nually and blow water from the bottom of the boiler to the blow dow n tank.當(dāng)排

51、除鍋爐內(nèi)的沉淀物(污泥)時，手動開啟排污閥(鍋爐10的為00QHE01AA001/AA002, 鍋爐20的為00QHE11 AA001/AA002)后，爐水會從鍋爐底部被排到排污罐里。During sta ndbyoperatio n the boilers are kept warm and pressurized by two electricelements (00QHA10 AH001/AH002 for boiler 10 and 00QHA20AH001/AH002 for boiler 20, each with a capacity of 50%), which are en

52、gaged at the set limit (on/off con trol).To ensure the fastest possible start-up, the set limit for warm keeping will be 190 C . 設(shè)備備用期間，鍋爐的恒溫和恒壓由備用加熱器(鍋爐10的為00QHA10AH001/AH002,鍋爐20的為00QHA20AH001/AH002,各有50%勺容量)完成，以保證其處于設(shè)定限制內(nèi)(開關(guān)控制)。為保證設(shè)備的快速啟動，熱備用期間保溫的設(shè)定值為190C。For ventilatingthe protective casing (10k

53、V connection box), there is a fan (00QHA10AN001 for boiler 10 and 00QHA20 AN001 for boiler 20), which starts when the 10kV breaker is en gaged and stops whe n the 10kV breaker stops.關(guān)于保護(hù)罩(10kV接線盒)的通風(fēng)：兩鍋爐各有一風(fēng)扇(鍋爐10為00QHA10 AN001,鍋爐20為00QHA20 AN001),隨10kV斷路器的啟停而啟停。For deaerating (venting) during start

54、up sequence the boiler, there is a valve onthe steam outlet (00QHF12 AA001 for boiler 10 and 00QHF22AA001 for boiler 20), which ope ns whe n the boiler pressure is below the set ope n limit and closes whe n the pressure reaches the set close limit. The venting pipe conn ects with the safety valves b

55、low-off pipe. During sta nd-by operati on the valves are closed.在啟動順序中，鍋爐排廢氣：蒸汽出口處有一個閥門(00QHF12 AA001用于鍋爐10 ,00QHF22 AA001用于鍋爐20)，當(dāng)鍋爐壓力低于設(shè)定的開啟限值時閥門開啟，當(dāng)鍋爐壓力達(dá) 到設(shè)定的關(guān)閉限值時閥門關(guān)閉。排氣管道與安全閥排出管相連。備用期間，此閥門處于關(guān)閉狀態(tài)。Two pressure relief valves (safety valves 00QHF10AA001/002 for boiler 10 and 00QHF20 AA001/002) are

56、fitted on the respective outgo ing steam line to preve nt an excess pressure in case there is a problem with the pressure control.Each valve is designedfor 50% of the flow.鍋爐各有兩個安全閥 (安全閥00QHF10 AA001/002 (鍋爐10) , 00QHF20 AA001/002 (鍋 爐20)，用以防止壓力控制出現(xiàn)問題時產(chǎn)生超壓事故。各閥設(shè)計流量均大于最大排放量的 50%As the produced steam

57、has a higher pressure tha n what is required by the auxiliary steam system, the pressure is reduced by regulating the control valve (00QHF10 AA005 for boiler 10 and 00QHF20AA005 for boiler 20) on the steam outlet pipe. This controlvalve is also used for securing that theboiler pressure doesn' t fall below a setlimit (min. pressure). If the pressure falls below this limit, the valve will close in order to maintain boiler pressure. This is imp