AP1000機(jī)組小破口失水事故模擬分析

陳杰，周濤，劉亮，李宇

(華北電力大學(xué)a.核熱工安全與標(biāo)準(zhǔn)化研究所; b.非能動(dòng)核能安全技術(shù)北京市重點(diǎn)實(shí)驗(yàn)室，北京　102206)

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AP1000機(jī)組小破口失水事故模擬分析

陳杰a，b，周濤a，b，劉亮a，b，李宇a，b

(華北電力大學(xué)a.核熱工安全與標(biāo)準(zhǔn)化研究所; b.非能動(dòng)核能安全技術(shù)北京市重點(diǎn)實(shí)驗(yàn)室，北京102206)

摘要:采用美國MST公司核事故仿真軟件PCTRAN，對(duì)AP1000小破口失水事故進(jìn)行瞬態(tài)曲線分析，仿真結(jié)果表明:當(dāng)發(fā)生400 cm2小破口失水事故后，AP1000機(jī)組堆芯補(bǔ)水箱和堆芯安注箱水位隨反應(yīng)堆系統(tǒng)壓力下降而下降，反應(yīng)堆系統(tǒng)壓力降到13.09 MPa時(shí)，觸發(fā)AP1000機(jī)組非能動(dòng)余熱排出系統(tǒng)熱交換器導(dǎo)出堆芯余熱;當(dāng)反應(yīng)堆系統(tǒng)的壓力降到1.52 MPa時(shí)，堆芯水位開始上升;到反應(yīng)堆系統(tǒng)壓力達(dá)到0.29 MPa后，壓力開始趨于穩(wěn)定。計(jì)算后的反應(yīng)堆系統(tǒng)壓力在數(shù)值上與西屋公司用NOTRUMP軟件分析的結(jié)果大致一樣。

關(guān)鍵詞:AP1000機(jī)組;小破口失水事故; PCTRAN軟件;瞬態(tài)曲線;模擬分析

0　引言

核電機(jī)組安全問題不僅會(huì)影響其自身的發(fā)展，而且會(huì)波及周圍的環(huán)境，更為嚴(yán)重的是會(huì)引起人們的恐慌，因此，確保安全非常重要。由于機(jī)組小破口失水事故(SBLOCA)在冷卻劑喪失事故(LOCA)中發(fā)生頻率很高，而且SBLOCA會(huì)使反應(yīng)堆冷卻劑系統(tǒng)(RCS)降壓速率減慢，甚至?xí)尪研韭懵?，?dǎo)致燃料元件溫度過高，進(jìn)一步引起反應(yīng)堆發(fā)生一系列問題，如RCS喪失后壓力降低、冷卻能力降弱、放射性冷卻劑釋放等。目前，我國山東海陽核電站、浙江三門核電站正在建造AP1000機(jī)組［1］，因此，研究其SBLOCA對(duì)AP1000機(jī)組運(yùn)行的影響具有現(xiàn)實(shí)意義。

1　研究的幾何模型

AP1000核電機(jī)組是第3代壓水堆［2］，其非能動(dòng)RCS讓反應(yīng)堆保護(hù)系統(tǒng)的安全性能得到提高。AP1000有效地利用重力、自然循環(huán)和空氣壓縮膨脹等驅(qū)動(dòng)原理［3］，減少人為控制安全系統(tǒng)的次數(shù)，提高核電站運(yùn)行的安全性。AP1000 RCS是由2條并聯(lián)環(huán)路組成的反應(yīng)堆閉式循環(huán)回路［4］(如圖1所示)，其中RCS設(shè)計(jì)采用“4進(jìn)2出”布置的冷卻劑管道，即2條環(huán)路有4根冷管段和2根熱管段。

AP1000機(jī)組SBLOCA分為4個(gè)階段［5］:噴放階段、自然循環(huán)階段、自動(dòng)降壓系統(tǒng)階段和長期冷卻循環(huán)階段，4個(gè)階段AP1000設(shè)備工作狀態(tài)見表1。

圖1　RCS組成

表1　AP1000 SBLOCA的發(fā)展階段

2　PCTRAN/AP1000　仿真分析

采用美國MST公司PCTRAN［6］軟件對(duì)AP1000 SBLOCA進(jìn)行模擬分析，采用定性對(duì)比和定量分析相結(jié)合的方法，分事故發(fā)生時(shí)AP1000機(jī)組工作狀態(tài)和未發(fā)生事故時(shí)AP1000機(jī)組工作狀態(tài)來研究AP1000機(jī)組工作性能變化，然后通過PCTRAN導(dǎo)出事故發(fā)生后的瞬態(tài)曲線圖(如圖2～7所示)，當(dāng)冷管段發(fā)生400cm2的SBLOCA時(shí)，可通過PCTRAN主控頁面初步觀察失水事故發(fā)生后AP1000機(jī)組設(shè)備及系統(tǒng)之間的工作狀態(tài)變化(如圖8、圖9所示)。

圖2　A蒸汽發(fā)生器蒸汽和堆芯補(bǔ)水箱流量瞬態(tài)曲線

圖3　堆芯水位瞬態(tài)曲線

圖4　穩(wěn)壓器水位瞬態(tài)曲線

圖5　反應(yīng)堆RCS壓力的瞬態(tài)曲線

圖6　安全殼壓力的瞬態(tài)曲線

圖7　包殼峰值溫度、燃料峰值溫度和RCS平均溫度瞬態(tài)曲線

3　管段SBLOCA仿真過程分析

3.1設(shè)備水位及流量參數(shù)變化

通過圖8和圖9可知:在AP1000機(jī)組冷管段發(fā)生SBLOCA 1.5 s時(shí)，非能動(dòng)余熱排出流量并未開啟流動(dòng);當(dāng)事故發(fā)生300 s時(shí)，AP1000機(jī)組非能動(dòng)余熱排出系統(tǒng)啟動(dòng)，帶出堆芯和RCS的熱量以降低堆芯溫度，冷卻一回路系統(tǒng);當(dāng)事故發(fā)生1.5s時(shí)，堆芯補(bǔ)水箱水位和安注箱水位為100％，當(dāng)事故發(fā)生300 s時(shí)，堆芯補(bǔ)水箱水位降為93.80％、安注箱水位降為52.40％，說明事故發(fā)生一段時(shí)間后，堆芯補(bǔ)水箱和安注箱啟動(dòng)，為反應(yīng)堆冷卻系統(tǒng)注入低溫含硼水冷卻堆芯;化學(xué)容積系統(tǒng)在事故發(fā)生前段時(shí)間其流量為27.69 kg/s，并未發(fā)生改變，說明仍正常工作，但當(dāng)失水事故發(fā)生到300 s時(shí)，化學(xué)容積系統(tǒng)排出流量升高為68.55 kg/s，說明AP1000機(jī)組反應(yīng)堆中輔助系統(tǒng)開始啟動(dòng)，并對(duì)堆芯進(jìn)行反應(yīng)性控制，通過堆芯補(bǔ)水箱上的連接管調(diào)節(jié)硼的濃度來進(jìn)行補(bǔ)水，從而控制一路系統(tǒng)的堆芯裝水量，并向反應(yīng)堆冷卻劑泵提供含硼水。通過對(duì)圖3和圖4對(duì)比也可看出，在失水事故發(fā)生時(shí)，反應(yīng)堆控制棒插入堆芯使得反應(yīng)堆緊急停堆，非能動(dòng)冷卻系統(tǒng)提供的硼水為反應(yīng)堆提供額外的負(fù)反應(yīng)性，從而保證反應(yīng)堆在溫度較低時(shí)有充足停堆裕量。

圖8　事故剛發(fā)生1.5 s后AP1000機(jī)組的狀態(tài)

圖9　事故發(fā)生后300 s AP1000機(jī)組的狀態(tài)

3.2部分系統(tǒng)參數(shù)的變化

通過分析瞬態(tài)曲線圖各因素變化及瞬態(tài)曲線數(shù)據(jù)異常情況并仿真分析得到:當(dāng)發(fā)生400 cm2小破口時(shí)，RCS壓力快速下降，當(dāng)其壓力下降到13.09 MPa時(shí)，觸發(fā)AP1000機(jī)組非能動(dòng)余熱排出系統(tǒng)熱交換器導(dǎo)出堆芯余熱。安全殼壓力隨著RCS壓力下降而增加，在RCS壓力降到大約1.81 MPa后其壓力趨于穩(wěn)定(約0.29 MPa)。隨著溫度和穩(wěn)壓器水位的下降，堆芯補(bǔ)水箱(CMT)相關(guān)系統(tǒng)啟動(dòng)，堆芯補(bǔ)水箱以水循環(huán)模型進(jìn)行:冷管段的熱水開始進(jìn)入堆芯補(bǔ)水箱，將部分冷的含硼水排出，補(bǔ)水箱的冷水則注入RCS。由于安全殼壓力升高而觸發(fā)非能動(dòng)安全殼冷卻劑系統(tǒng)(PCS)信號(hào)，當(dāng)RCS壓力降至比安全殼壓力略高時(shí)，安全殼內(nèi)置換料水箱(IRWST)開始向堆芯提供冷卻水，導(dǎo)出安全殼熱量，降低安全殼壓力和溫度，使堆芯保持在冷卻狀態(tài)。通過圖7可以看出:包殼峰值溫度、燃料峰值溫度在15s之前迅速下降，之后下降趨勢變緩，但隨著堆芯再次被淹沒，燃料峰值溫度再一次降低。堆芯的水位因?yàn)镾BLOCA而逐漸下降，直到反應(yīng)堆系統(tǒng)的壓力降到1.51 MPa時(shí)，堆芯水位開始上升(如圖3所示)。

3.3冷管段小破口失水事故參數(shù)變化

根據(jù)圖5 RCS壓力趨勢變化，可得到冷管段SBLOCA前2個(gè)階段RCS壓力瞬態(tài)曲線。

3.3.1噴放階段

當(dāng)穩(wěn)壓器壓力高于10.65 MPa(事故發(fā)生后10 s左右)時(shí)，該階段反應(yīng)堆冷卻劑壓力迅速下降，當(dāng)RCS壓力降到9.62 MPa(約事故發(fā)生15s)時(shí)觸發(fā)反應(yīng)堆緊急停堆。同時(shí)，堆芯補(bǔ)水箱開始向堆芯注水，非能動(dòng)余熱排出系統(tǒng)熱交換器帶走堆芯余熱。穩(wěn)壓器水位開始由原來的100％降為0(如圖4所示)，堆芯補(bǔ)水箱通過直接管線開始向堆芯注入含硼水。非能動(dòng)系統(tǒng)通過自然循環(huán)將RCS冷卻，并通過再循環(huán)流流向堆芯補(bǔ)水箱。

3.3.2自然循環(huán)階段

當(dāng)穩(wěn)壓器壓力從10.65 MPa開始下降到1.98 MPa(大約事故發(fā)生165 s)時(shí)，冷卻劑系統(tǒng)向外排水，流出的冷卻劑流體帶走一部分衰變熱，使堆芯冷管段和熱管段溫度下降，同時(shí)堆芯補(bǔ)水箱和非能動(dòng)余熱排出系統(tǒng)熱交換器也通過再循環(huán)進(jìn)一步導(dǎo)出堆芯熱量，讓穩(wěn)壓器壓力進(jìn)一步下降。當(dāng)RCS壓力下降到1.65 MPa，堆芯水位下降到最低(約為44.99％)時(shí)，堆芯補(bǔ)水箱和安注箱繼續(xù)向堆芯注水導(dǎo)致堆芯水位開始上升(如圖2和圖3所示)。

4　冷管段SBLOCA仿真結(jié)論

(1)用PCTRAN模擬后誤差分析。對(duì)于AP1000機(jī)組所屬的工況III(稀有事故)標(biāo)準(zhǔn):受損的燃料元件不應(yīng)超過規(guī)定值，保持正常堆芯冷卻功能;燃料元件要能保持在正常溫度值，其中燃料包殼溫度值低于1204℃;一回路壓力邊界值低于120％設(shè)計(jì)值。

(2)在冷管段小破口事故發(fā)生300 s后，燃料包殼峰值溫度728.15℃低于AP1000機(jī)組規(guī)定值;其中一回路壓力在300 s后降至0.73 MPa，遠(yuǎn)遠(yuǎn)低于120％設(shè)計(jì)值，大致符合AP1000機(jī)組設(shè)定值。通過對(duì)比分析，本文計(jì)算的結(jié)果在時(shí)間和數(shù)值上與西屋公司用NOTRUMP分析的結(jié)果［5］大致一樣(如圖10所示)。

圖10　PCTRAN與NOTRUMP分析AP1000機(jī)組小破口對(duì)比分析(前300 s分析)

(3)當(dāng)發(fā)生SBLOCA時(shí)，AP1000機(jī)組的非能動(dòng)余熱排出系統(tǒng)啟動(dòng)，導(dǎo)出堆芯和RCS產(chǎn)生的熱量，降低反應(yīng)堆系統(tǒng)壓力，冷卻堆芯。當(dāng)反應(yīng)堆系統(tǒng)壓力下降到一定值時(shí)，堆芯補(bǔ)水箱啟動(dòng)，為反應(yīng)堆冷卻系統(tǒng)注入低溫含硼水。隨著反應(yīng)堆壓力進(jìn)一步降低，AP1000機(jī)組非能動(dòng)安注箱開始向堆芯注入含硼水進(jìn)一步冷卻堆芯。當(dāng)堆芯水位降到一定程度時(shí)，AP1000機(jī)組輔助系統(tǒng)(化學(xué)容積系統(tǒng))開始控制反應(yīng)堆反應(yīng)性，輔助系統(tǒng)通過堆芯補(bǔ)水箱上的連接管調(diào)節(jié)硼的濃度來進(jìn)行補(bǔ)水，控制一路系統(tǒng)的水裝量，并向反應(yīng)堆冷卻劑泵提供軸封水。為了避免反應(yīng)堆受損，AP1000機(jī)組的控制棒會(huì)插入堆芯使反應(yīng)堆緊急停堆，非能動(dòng)冷卻系統(tǒng)提供的硼水為反應(yīng)堆提供額外的負(fù)反應(yīng)性，從而保證反應(yīng)堆在溫度較低時(shí)有足夠停堆裕量。

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(本文責(zé)編:白銀雷)

陳杰(1991—)，男，湖南衡陽人，在讀碩士研究生，從事核熱工水力與安全方面的研究(E-mail: 805072298 @ qq.com)。

周濤(1965—)，男，陜西西安人，教授，博士生導(dǎo)師，從事反應(yīng)堆熱工水力與安全方面的研究工作(E-mail: zhoutao @ ncepuedu.cn)。

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2016－01－45 2×150 MW generator ends winding loose and corona treatment

HUANG Yijin(Huadian Sichuan Power Generation Company Limited Panzhihua Branch，Panzhihua 617065，China)

2016－01－47Reason analysis and preventive measures of tripping caused by 600 MW steam turbine fuel injection test

ZHANG Xuehai (Huaneng Tongchuan Zhaojin Power Plant，Tongchuan 727100，China)

2016－01－49The reasonable application of frequency converter in coal-fired power plant

CHEN Lixin，SUN Jianbang，CHEN Rui(Harbin Thermal Power Company Limited，Harbin 150046，China)

2016－01－51Economy improvement analysis during hot start of 6FA gas turbine combined cycle unit

TANG Mingfeng，WU Minjie (Hangzhou Huadian Xiasha Thermal Power Company Limited，Hangzhou 310018，China)

2016－01－54Domestic 600 MW supercritical coal-fired unit“near zero emission”reconstruction

YIN Pengfei(Guangdong Zhuhai Jinwan Power Plant Company Limited，Zhuhai 519050，China)

2016－01－59Low NOxcombustion retrofit of boilerand its effect analysis for 330 MW power unit

FAN Aibing (Jiangsu Huadian Yangzhou Power Generation Company Limited，Yangzhou 225007，China)

2016－01－62The application of selective noncatalytic reduction denitration technology in garbage incineration power plant

ZHANG Hui(Shenzhen Energy Environmental Protection Company Limited，Shenzhen 518052，China)

2016－01－64 Failure analysis and design optimization of non-metallic expansion joint at inlet duct of denitrification device

WANG Sen1，AN Hong2，ZHU Bin2，WANG Shushan2(1.Shenghua Guohua(Beijing) Electric Power Research Institute Company Limited，Beijing 100025，China; 2.Shenhua Guangdong GuohuaYuedian Taishan Power Generation Company Limited，Taishan 529228，China)

Abstract: Some faults are existed in the non-metallic expansion joint at inlet duct of denitrification device for a certain 1000 MW power unit，such as the lower skin cracking and serious deformation of flange etc.Through the analysis，the failure reason is considered as the unreasonable structure design of double-wave type middle flange hinge of expansion joint.In this paper，the original expansion joint was replaced by single-wave structural non-metallic expansion joint，and some structural optimizations of expansion joint frame，thermal-protective coating and skin were also conducted.More than two years of operation shows that the expansion joint works well and the surface temperature is less than 50℃under full load condition.

2016－01－68Simulation analysis of small break loss of coolant accident of AP1000 power unit

CHEN Jiea，b，ZHOU Taoa，b，LIU Lianga，b，LI Yua，b(North China Electric Power University，a.Institute of Nuclear Thermalhydraulic Safety and Standardization; b.Beijing Key Laboratory for Passive Safety Technology of Nuclear Energy，Beijing 102206，China)

2016－01－72Anemometer monitoring method based on adjacent wind turbines correlation model

WU Lizeng(China Huadian Corporation，Beijing 100031，China)

2016－01－01 Research of one-dimensional shielding calculationusing finite element method

ZHAO Jingchang，ZHANG Bin，CHEN Yixue(School of Nuclear Science and Engineering，North China Electric Power University，Beijing 102206，China)

Abstract:In this paper，the shielding calculations of one-dimensional plate and one-dimensional sphericity using deterministic method were studied and a one-dimensional steady-state neutron transport calculation program DONTRAN1D using discrete SNfinite element method (FEM) was developed.In the calculations，a virtual point setting method was proposed when processing the model boundary conditions.In addition，a zeroing modification and a neutron balance calculation using transporte quation were adopted for negative flux.At last，a comparative analysis was conducted between DONTRAN1D and other mature program in the world using calculation examples.The results show that the solving accuracy of DONTRAN1D could be guaranteed well.Besides that，a mount of functional module interfaces were reserved for future development in DONTRAN1D program. In order to stabilize the power grid fluctuation due to the grid-connection of wind and photovoltaicenergies and realize the combined operation of scale small hydropower stations group witha variety ofnew energies，this paper aimed at the characteristics of stability，adjustability and rapid regulation of scale small hydropower stations group，developed an embedded controller integrating the rapid regulating functions of active power and reactive power for hydropower station，which could make small hydropower stations have the ability of power rapid regulation.In addition，in order to realize the closed-loop control of scale small hydropower stations group according to the remote control strategies，a closed-loop control telecontrol channelamong remote hoststation and hydropower stations must be built.Therefore，this paper proposed two solutions that based on the dispatching data network and wireless communication that taking the practical features of small hydropower station into consideration.The demonstration plants shows that the power rapid regulating system and the closed-loop control of scale small hydropower stations group was realized successfully. Automatic generation control(AGC) has become increasingly important with the development of power industry.Based on a gas and steam combined cycle power plant in Malaysia，an AGC system had been designed.This paper introduces the control pattern of AGC system，load limit，load rate of change and design content of operation procedure of AGC.The practical application indicates that the application effect of AGC system turns out good and meet the technical requirements of electric power control center. In winter，the ambient temperature is relatively low and the fan below the direct air-cooling condenser is forced to run at low flow rate or shutdown in order to prevent the finned tube bundlesfrozen under low heat load conditions.Therefore，it is necessary to study the heat transfer and flow resistance characteristics of finned tubesat low wind speed，as well as the air cooling system status under natural ventilation condition.This paper simulated the influence rules of ambient temperature，wall temperature of finned tubes and inlet velocity of air to the velocity and temperature fields of finned tubes using Fluent，and built a driving force generation model of airflow for direct air-cooling condenser under natural ventilation condition.On the basis of numerical simulation，this paper analyzed the heat transfer and flow resistance characteristics of single row snake-likefinned tubes，obtained the natural ventilation air flow rate under certain condition through the balance of the lift and drag，and calculated the corresponding heat transfer coefficient.It provided a reference for the optimization design of direct air-cooling condenserthat operating at low wind speed. Based on the fact that a trip failure occurred to a M701D gas turbine，this paper concludes that the cause of this failure is because the potential transformer is inconsistent with original design on the actual wiring and the logic of power control of turbine control system (TCS) is unreasonable.To overcome this problem，this paper suggests to take action by reconnecting，adding power controller and optimizing logic of TCS.After these modification，under the circumstances that each power transmitter and TCS are consistent on channel and adopted value，and one or three phase of fuse of power transmitter is fusing，the result showed that the logic of TCS is calculated correctly，which effectively improved circuit fault of control system. In coal-fired power plants，the economic benefits of medium and small sized condensing power units are not as ideal as expected due to existing problems，such as low efficiency，high coal consumption and large-scale pollution etc.In addition to the shutdown of medium and small sized cogeneration units，the formed heating gap is in urgent needsto be filled.Therefore，a large number of condensing power units has been transformed to extraction condensing cogeneration units gradually in recent years in order to meet the changing situation.Taking the 2×225 MW +2×300 MW units of a certain power plant as an example and aiming at the problems that exist in the heating transformation of subcritical condensing power units，this paper analyzed the design of control system and control logic and provided corresponding recommendations. Taking 2×1 000 kN platform hoist at Xijiang Changzhou hub ship lock project for example，the method how to use absolute value encoder，Siemens S120 inverter and Siemens S7－300 PLC to realize electrical synchronization with double lifting point of platform hoist was introduced in this paper.The synchronous system save the project cost，make the manual more flexible，simple and reliable. This paper analyzed the necessity of water wash to boiler air pre-heater and feasibility of on-line water wash，indicated two methods to water wash air pre-heater，and descried the process of air pre-heater on-line water wash.The operation parameter and waste water parameter indicated that water wash is effective and secured the safety and stability of unit operation. Two ball valves with diameter1 720 mm were installed in Fujian Muyangxi Zhouning Hydropower Station.The overall operation of No.2 ball valve run well when it was first put into use，while seal cast back problem which affected automatic boot occurred at later stage.After analysis，the main reasons were seal damage and congenital design deficiency.The problems were solved by modifying the open process of No.2 ball valve，replacing the three D type seal and redesigning the package D type sealing packing. After years of operation，many defects appeared on the booster pump of Huaneng Tongchuan Zhaojin Power Plant，such as abrasion of pump cover interface，serious axial movement while low load，damage of bearings，leakage of mechanical sealed cooling jacket and etc.After analyzation，solutions and suggestions to those defects was indicated，which are effective to improve the unit operation. While Guangdong Zhuhai Jinwan Power Plant Company Limited No.3 unit overhauling，site test found there is trace of turn-to-turn short circuit at rotor winding.Turn-to-turn short circuit was determined by two-pole voltage balance test.Winding alternating voltage distribution test determined the coil with failure.After the rotor was sent back to factory to repair，failure was analyzed and repaired.The overhaul duration was secured. The author studied on a generator outage，which caused by plant transformer LV side non-segregated enclosed busbar failure.Based on the treatment of this accident and record analysis，the author indicated that the direct reason of this accident is the enclosure of LV side non-segregated busbar was not well-sealed，and insulator was damped.This paper also included the preventive measurement based on aspects of operation and equipment maintenance. Panzhihua Power Plant 2×150 MW generator stator winding end part bearing fixing structure，lashing rope and a su-book=78,ebook=82pport ring and supporting plate loosening effect，stator winding surface potential distribution is not uniform，in the high voltage，resulting in the big local potential gradient winding end part fixed and banding of tip and burr discharge phenomenon.In order to improve the life safety operation of generator，generator stator end winding were processed，and used the Harbin motor factory research obtains the reliable anti corona technology and anti corona treatment experience of winding of corona treatment，to take measures and through long－term monitoring on line partial discharge monitoring of generator stator winding insulation，can timely evaluation the state of generator stator winding fault，found early signs of early，to avoid the occurrence of accidents.After four years of operation，has achieved remarkable results. The process and principles of the injection test of a 600 MW steam turbine were introduced in this paper.Taking the tripping accident of turbine caused by the injection test for example，the causes were confirmed，the jam of the electromagnetic valve and the logic blocking of the DEH tripping were main reasons for the accident.Through the analysis above，preventive measures were put forward，which provided a good guidance to prevent the failure of units akin to the above. In order to achieve the goal of saving energy and reducing consumption of 300 MW coal-fired unit，additional frequency converter was installed on auxiliary electric motor in a certain power plant.After the installation，a tracking analysis of equipment running status was conducted and the corresponding treatment methods of problems occurred were given in this paper，which provided a reference for the energy saving and consumption reducing work of similar units. To reduce the gas consumption of natural gas during the host start of combined cycle unit and improve the economy of plant operation，several measures such as appropriate impulse starting parameter and reference datum selection，as well as the cylinder temperature reduction are performed to achieve lower plant operation costs.After optimization，the gas consumption during hot start has a significant descent and the plant operation has obvious economic benefits. To realize“near zero emission”，Guangdong Zhuhai Jinwan Power Plant Company Limited’s No.3 and No.4 unit took reconstruction.This paper introduced the reconstruction of desulfurization system，adding wet ESP(electrical precipitator)，classification of economizer，denitration system adding catalyst，combination of duct fan and booster fan.After reconstruction，the emission concentration of dust，SO2and NOxis lower than gas turbine unit，“near zero”emission was realized. The NOxemission concentration of an air preheater is up to 655.7mg/m3for the No.6 unit of a certain power plant.In order to meet the emission requirement of new standard，a low NOxcombustion retrofit of boiler burners conducted using a multi air stereo-staged and horizontal bias coal combustion technology，which carries out a multi air stereo-staged combustion along the vertical direction and horizontal direction in the chamber of a stove.The performance test of the retrofitted boiler shows that the retrofit effect is significant with the NOxemission concentration of an air preheater could be kept below 300mg/m3for a long time，and the boiler efficiency and combustible matter content in flue dust are also meeting the requirements. SNCR is characteristic of a short-term construction，minor investment and medium efficiency for denitration，which is fit for the medium scale or small-scale power plant，especially the waste incineration plant.Combined with the examples，the theory for the SCNR was introduced.The cases that should be paid more attention to are put forward.The conclusion are draw that SNCR technology，together with other denitration technologies can drop the NOxemissions at the low investment. Using the nuclear accident simulation software PCTRAN of MST Company，this paper carried out a transient curve analysis of small break loss of coolant accident (SBLOCA) of AP1000 power unit.The simulation results are as follows: After the occurrence of 400 cm2SBLOCA of AP1000 power unit，the water levels of makeup tank and safety injection tank of reactor core fall with the pressure decrease of reactor system.When the pressure drops to 13.09 MPa，the heat exchanger of passive residual heat removal system is triggered to remove the residual heat of reactor core.When the pressure continues to drop to 1.52 MPa，the water level of reactor core begins to rise.After the pressure reaches to 0.29 MPa，it begins to be stabilizing.The calculated system pressure is in concordance with the results that obtained using the software NOTRUMP by Westinghouse Corporation in time and number. It has important significance for real-time monitoring of wind turbine anemometer due to its high failure probability.This paper proposed an anemometer monitoring method based on adjacent wind turbines correlation model for the high correlation of operation conditions and measured values of anemometers among adjacent wind turbines.This paper processed the normal measured data of anemometers of adjacent wind turbines using particle swarm optimization (PSO) algorithm and built a correlation model.In this model，the real-time measured wind velocities of anemometers are considered as the inputs.When a certain wind turbine anemometer is abnormal，the correlation among adjacent wind turbines is destroyed and the predicted residual of the certain wind turbine anemometer will increase significantly，which indicates that anemometer may have a fault.Hence this method could realize the real-time monitoring of anemometer.The practical operation data of a certain wind farm verified the effectiveness of this method.

Keywords:one-dimension; shielding calculation; finite element method; neutron transport calculation scale small hydropower stations group; dispatching data network; wireless communication; telecontrol channel gas and steam combined cycle power plant; AGC; load air-cooling unit; numerical simulation; snake-like finned tubes; heat transfercharacteristic; flow resistance characteristic TCS; trip failure; PT; power transmitter; wiring; power control logic; optimization coal-fired power plant; condensing power units; heating transformation; cogeneration; control system absolute value encoder; inverter; programmable logic controller; electrical synchronization; hydraulic grab beam 600 MW unit; air pre-heater; on-line water wash; waste water ball valve; seal; cast back problem; gland packing booster pump; bearing; axial movement; mechanical sealed cooling jacket generator; rotor; turn-to-turn short circuit; coil non-segregated enclosed busbar; single-phase ground failure; damp; room temperature vulcanized silicone rubber; busbar heat tracing generator; winding; corona; online inspection injection test; DEH; tripping; jam; logic blocking; preventive measures coal-fired power plant; electric motor; frequency converter; energy saving and consumption reducing 6FA gas turbine; combined cycle; hot start; economy near zero emission; gas dust; SO2; NOx; wet electric precipitator; desulfurization; denitration; economizer classification burner; low NOxcombustion; NOx; air stereo-staged combustion; horizontal bias MSW incineration; flue gas denitrification; selective non-catalytic reduction technology; ammonia injection denitrification device; inlet duct; non-metallic expansion joint; skin; flange; thermal-protective coating AP1000 power unit; small break loss of coolant accident; PCTRAN; transient curve; simulation analysis wind turbine; anemometer; correlation model; condition monitoring; particle swarm optimization algorithm; back propagation neural network; residual

作者簡介:

基金項(xiàng)目:中央高校基本科研業(yè)務(wù)專項(xiàng)資金項(xiàng)目(2014BJ0086) ;國家重點(diǎn)實(shí)驗(yàn)室開發(fā)課題(2014BJ0041)

收稿日期:2015－09－28;修回日期:2015－12－20

中圖分類號(hào):TL 33

文獻(xiàn)標(biāo)志碼:B

文章編號(hào):1674－1951(2016)01－0068－04