空分裝置空壓機同步電動機啟動方式計算和分析

1、2006年第4期總第135期228000Nm3/h空分裝置空壓機同步電動機啟動方式計算和分析228000Nm3/h空分裝置空壓機同步電動機啟動方式計算和分析李志慧(天津鋼鐵有限公司設計部,300301摘要天鋼228000Nm3/h空分裝置空壓機其驅(qū)動電動機為三相交流電動機,電動機啟動方式有三種。通過計算和分析,確定了13500kW同步電動機采取電液變阻啟動方式,10kV母線壓降為90.6%,符合空分工藝要求并有不產(chǎn)生諧波、調(diào)試方便和易于維護等優(yōu)點。關鍵詞空壓機電動機啟動短路容量母線壓降計算1概述天鋼228000Nm3/h空分裝置的空壓機為德國MAN透平公司產(chǎn)品。其驅(qū)動電動機為ABB公司三相交流

2、同步電動機。電動機參數(shù):Pe=13500kW Ue=10 000V Ie=882A Ne=1500r/min Mq/Me=0.96GD2= 10272N.m2。由于2x28000萬Nm3/h空分設備計算負荷為58620kW,直接從1#總降站供10kV電壓電源已經(jīng)不能滿足2x28000萬Nm3/h空分設備用電要求和13500kW同步電動啟動要求。因此需在氧氣廠建35 kV變電所,專為228000Nm3/h空分設備供電。目前,電動機啟動形式有三種:一是變頻軟啟動;二是全壓啟動;三是降壓啟動。對于大容量變頻軟啟動電氣設備需要進口,費用很高,如13500kW電動機配套的變頻軟啟動設備約2000萬元左右

3、,而電氣設備利用率又很低(每年13500kW同步電動機只啟動一到二次,因此變頻啟動方式不可取。下面僅計算和分析全壓啟動和降壓啟動兩種方式。對于特大型電動機很少采用自耦降壓啟動和串電抗降壓啟動方式,主要有三個原因;一是啟動切換時,產(chǎn)生二次沖擊電流;二是因為電氣設備龐大,安裝、運輸困難;三是控制誤差大不易調(diào)試、并且限制電動機單位時間內(nèi)啟動次數(shù)。電液變阻降壓啟動方式,是在電動機定子回路串接一特制可變液體電阻,啟動過程中該電阻在電動機啟動初始自動投入,利用液態(tài)電阻的熱容量大及可恢復性良好等特性,通過PLC程序控制動極板的運動,按一定規(guī)律改變動定極板的間距,從而達到在預定啟動時間內(nèi)均勻無級減少液阻阻值,

4、并在阻值幾近為零時切除,實現(xiàn)電動機轉(zhuǎn)速均勻上升、平穩(wěn)啟動,達到控制電動機啟動電流的目的。因此,本文僅就直接啟動和電液變阻降壓啟動方式進行計算和分析。2全壓啟動計算2.1短路容量計算1#總降站35kV母線短路容量:最大Smax=620MVA,最小Smin=415MVA35kV電纜長度L=1km變壓器容量Q=63000kVA變比35/10kVUk%=12計算電路和等值電路圖見圖1。圖1(1基準容量Sj=100MVA基準電壓Uj=10.5kV基準電流Ij=5.4986kA(2計算系統(tǒng)各元件標幺值最大方式35kV母線系統(tǒng)電抗:X*M=Sj/Smax=0.1613最小方式35kV母線系統(tǒng)電抗:X*m=S

5、j/Smin=0.24096電纜電抗:X*L=X2L2Sj/U D2=0.121100/372=0.0088變壓器電抗:Pe=135000kW氧氣廠35kV站35kV10kVBS m ax=620MVAS m in=415MVAL=1000mQ=63000kVAUk%=121#總降站35kVXsXLXb29X*b=Uk%/100Sj/Q=12/100100/63=0.19最大方式總電抗值:X*=0.1613+0.0088+0.19=0.360576最小方式總電抗值:X*m=0.24096+0.0088+0.19=0.43976最大方式I=Ij1/X*=15.249kASmax=1/X*MSj=

6、277.33MVA最小方式Im=Ij1/X*m=12.503kASmin=1/X*mSj=227.396MVA13500kW同步電動機10kV母線最大短路容量277.33MVA。最小短路容量227.396MVA。2.2全壓啟動計算KjqSe(Sd+Q fh母線允許85%電壓時613.50.175(227.4+4.28(U*m=0.85=1/0.85-1=0.1758140.544母線允許70%電壓時613.50.429(227.4+4.28(U*m=0.7=1/0.7-1=0.4298199.39式中:Kjq額定電壓,電動機啟動電流倍數(shù)。Se電動機額定容量,MVA。Q fh母線上負荷的無功功率

7、,Mvar。Sde供電系統(tǒng)短路容量,MVA。U*m母線允許電壓標幺指。3串電液變阻啟動仿真3.1仿真基本數(shù)據(jù)電動機額定電壓:10kV電動機額定容量:13500kW電動機額定電流:882A電動機額定轉(zhuǎn)速:1500r/min電動機堵轉(zhuǎn)電流與額定電流比:設為3.28電動機額定電壓下空載定子電流:0.2Ie=176A電動機額定電壓下最大轉(zhuǎn)矩與額定值比:1.67電動機全壓啟動時電磁轉(zhuǎn)矩與額定值比:0.96電網(wǎng)額定電壓:10.5kV轉(zhuǎn)動慣量:10272N.m2仿真時間:50s電液箱電阻特性轉(zhuǎn)折時刻:35s對應每一時刻電阻值:(2.6,1.8,0$電動機允許堵轉(zhuǎn)時間:10s3.2計算結(jié)果電液最后溫升度數(shù):5

8、.699最大電流:1549A(約為1.8倍額定電流最大電網(wǎng)壓降:990.166V(約為9.4%啟動時間:27s電液變阻一次接線圖見圖2。圖24結(jié)論4.1通過計算,13500kW同步電動機全壓啟動時,10 kV母線壓降超過85%,達到70%以上。這在空分工藝上是不允許的,所以全壓啟動方式不可行。4.213500kW同步電動機采取電液變阻啟動方式, 10kV母線壓降90.6%,符合空分工藝。投資省(電液變阻成套電氣設備約40萬,并且有不產(chǎn)生諧波、調(diào)試方便和易于維護等優(yōu)點。4.2我公司228000Nm3/h萬空分裝置的空壓機同步電動機啟動方式采取電液變阻啟動方式是首選方式。(收稿2006-7-20責

9、編崔建華作者簡介李志慧,男,1980年8月畢業(yè)于天津冶金工業(yè)學校自動化專業(yè),工程師,現(xiàn)在天津鋼鐵有限公司設計部從事電氣工程設計工作。10kV1DL2DL1QK RSABSTRACTSInnovation Creates the Landmark of Tianjin Iron&Steel IndustryReport of Tiangang Moving Eastwards ProjectDiscussion of Technique Problems for SWRH82B Steel in SmeltingWang YongranAbstract:By analyzing the tech

10、nique data of SWRH82B steel making at Tianjin Iron&Steel Co.Ltd,some improving measurements on how to realize the high carbon and low phos-phor of the smelting end and optimize the procedure for con-verter have been put out.Key words:smelting;converter;composition;dephosphor; techniquePractice of De

11、velopment of Grade N80Non-quenching& Tempering Casing Steel for ConverterGao Shurong Wang YongranAbstract:The technical characteristics and technological flow of grade N80non-quenching&tempering casing steel produced by Tianjin Iron&Steel Co.,Ltd are introduced.The practice shows the chemical compos

12、ition and mechanical prop-erty reach the standard and make the users satisfactory.Key words:converter;non-quenching&tempering steel; casing;refined melting;chemical composition;technique;devel-opmentPractice of Intensified Smelting of2000m3BF at Tian-gangSu QingjieKey words:BF;burden;blast volumn;bl

13、ast temperature;coal injection;practiceCause Analysis and Improving Measurement of Low Temperature Storage Flow during Common Carbon Steel for Billet and Round Billet Continuous CastingWang Baoming Wang Wenhui Zhang Yuhai Abstract:By analyzing the storage flow at the beginning pro-duction of the ste

14、el making plant of Tianjin Iron and Steel Co. Ltd,the temperature drop and influencing factors are found out and the improving measurement is put forth leading to reduc-tion of out-casting from low temperature storage flow and age flow;temperature drop;continuous casting heatsAnalysis and Treatment

15、of Synchronous Hydraulic up and down Troubles of Intermediate Tundish Carriage for Billet CasterCui YidongAbstract:The cause of synchronous hydraulic up and down troubles of intermediate tundish carriage for billet caster is an-alyzed.The trouble is found by means of exclusive method and the resolvi

16、ng method is put forward.Key words:caster;intermediate tundish carriage;hydraulic cylinder;hydraulic motor;over flow valve;troubleTrial Rolling of Hot-rolled65Mn Narrow Strip Steel Cui XiaohangKey words:rolling;narrow strip steel;spring steel;techno-logical flowDiscussion of the BF Keeper Tapping Ma

17、chine Modifica-tionZhang XiaomingAbstract:The cause of abnormal BF production pre-keeper tapping machine modification of2000m3BF at Tianjin Iron& Steel Co.Ltd is discussed.By modifying the rotating borer de-vice,pneumatic change valve,air tubes and aerial fog cooling system of drill rod,the trouble

18、rate of keeper tapping machine is greatly reduced and the good economic benefit gained.Key words:tapping machine;striking machine;impact power; rotating borer power;aerial fog cooling system;filteringAC-DC-AC Frequency Controlled Speed Regulating Sys-tem of Screwdown Motor of Plate Roughing Mill in

19、Tian-gang GroupYuan ShuningAbstract:The screwdown system of four-roll reversing roughing mill in Tiangang Group requires high control preci-sion,the speed control of screwdown motor is the key factor. The technological requirement and technical parameter of screwdown motor and AC-DC-AC frequency con

20、trolled speed regulating system are introduced.The system can meet the con-trol requirement of screwdown motor of roughing mill.Key words:roughing mill;screwdown device;motor;frequency controlled speed regulating system;vector control Calculation and Analysis of Starting Mode of Sychronous32006年第4期總

21、第135期Li ZhihuiAbstract:The drive motor of air compressor in228000 Nm3/h oxygenerator in Tiangang Group is three-phase AC motor with three starting modes.By calculating and analyzing,the starting mode of13500kW synchronous motor adopts electro-hydraulic rheostat and results in90.6percent of the volta

22、ge drop of10kV bus,that meets requirement of air seperation technology,and advantages,such as no harmonic wave and easy readjusting and maintaining.Key words:air compressor;motor;starting;short-circuit vol-ume;bus voltage drop;calculationAnalysis of Short-Circuit Accident of Transformer for 10kV BF

23、Converting StationChu AiqiuAbstract:In view of the three-phase short circuit accident resulted from mouse entering the transformer room,several rea-sons are analyzed.The short circuit current calculation shows the rated thermal stability current of former current mutual in-ductor is too small.Using

24、the new type current mutual inductor and enhancing the insulated protection of bus removes the trouble hidden and ensures the power running safety.Key words:tranformer;BF;short circuit current;heat effi-ciency;accident;analysisChecking and Calculating of Gear Intensity of Speed In-creasing Box for81

25、0DA3Air CompressorDai JunAbstract:According to the frequent oscillation of high-speed axle of speed increasing box,the gear strength is checked.The result shows that gear of speed increasing box can meet the re-quirement of contact strength and bend strength providing the reliable theoretic basis fo

26、r the removal of trouble hidden.Key words:air compressor;speed increasing box;gear; strength;checkingDiscussion on Application of the High Speed Steel Roll Ring and RollWei YixiangAbstract:The application of high speed steel roll ring in the High Speed Wire Rods Plant of Tiangang Group is introduced

27、. By comparison of merits and demerits of tungsten carbide roll ring with high speed steel one,the utilization possibility of high speed steel roll ring and roll in steel-rolling factories is put forth.Key words:mill;high speed steel;hard alloy;roll ring;rolling; applicationImplementation of Automat

28、ic Control Procedure for Full Fuel Industrial Steam BoilerYang ZhirongAbstract:Combined with the computerized control system of 14t/h boiler in Tianjin Iron&Steel Corporation,its working principle,the important control circuits and implementation methods for each control key are discussed.Key words:

29、industrial steam boiler;negative pressure of hearth;steam pressure;flux;frequency change control;computer matic Control System of Gas CleaningBing Jinwen Miao Zhijun Zhao YonggangAbstract:The structure of CITECT monitoring software and the realization of control functions of automatic control system

30、 of gas cleaning are introduced.After putting into operation,the system runs steadily with good effect.Key words:gas;cleaning;automatic control;monitoring soft-ware;functionStudy on Determination of Vanadium and Titanium Ele-ment in Vanadium Titano-magnetite with ICP-MES MethodYan Xuehui Zhang Qianl

31、inAbstract:The testing condition of vanadium and titanium ele-ment in vanadium titano-magnetite with ICP-MES method is studied during experiment.The sample is dissolved with the sealed high pressure resolution method and elements deter-mined by selecting the optimum analysis spectrum line and suitab

32、le apparatus.The result shows very small interference a-mong the co-existing elements and error less than2%to the standard and95%105%mark recovery rate.The method is rapid and simple with accurate analysis result.Key words:spectrograph;vanadium titano-magnetite;ele-ment;test;sample;analysis;studyProblems to Be Paid Attention in the Analysis of Suspen-sion of Metallurgical Waste WaterBian Lihuai Zhai RulingAbstract:The problems of representativity of water sample, constant weight of filter paper and absorption of salt in the analysis of suspension of metallurgical waste w