Steam shedding is stimulated brace up the influence analysis to shafting stability

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The article offerred summary steam shedding is stimulated brace up new model, point out steam shedding is stimulated brace up will produce dynamic force and static power at the same time and action arrives on rotor, both will affect shafting stability. Static force and rotor become direct ratio in the eccentricity in cylinder, and dynamic force and eccentricity have nothing to do. After the effect that considers static force, shafting stability is possible poorer. This analysed steam shedding to stimulate from a new point of view brace up the influence to shafting stability. The article combined example of rotor of high pressure of homebred 200MW aircrew to undertake an analysis finally. Keyword steam flows stimulate brace up foreword of １ of vibration of stability turbogenerator group develops to the direction of tall parameter and high capacity as turbogenerator group, steam shedding is stimulated brace up the problem is more and more serious. For example 8 machine of ＃ of Xuzhou power plant (homebred 200MW aircrew) after heavying repair for the first time, once had happened 30 stimulate as a result of steam shedding for many times brace up those who cause is clonic oscillatory, maximum of vibration of plain bearing liner achieves 145 μ M, the aircrew inside the time that influences one year cannot take full load to move, caused very big pecuniary loss [１ ] . Begin from 60 time, stimulate domestic and internationally to steam shedding brace up the problem began a lot of development to consider [2 - 6] . Research thinks the different heart of rotor and cylinder will produce generally as a result perpendicular stimulate at the trends of rotor displacement direction brace up strength effect arrives on rotor, the steam that causes rotor bearing system thereby flows stimulate brace up. Alford derived the steam that is cited extensively by people later flows stimulate brace up the computation of force is formulary [2] . Because rotor moves what displacement place arises to stimulate,this formula considered brace up force, did not consider the impact of the power that the quiet prejudicial place between rotor and cylinder produces. According to this model, steam shedding is stimulated brace up should with rotor static state when prejudicial have nothing to do. This not as complete as the breakdown feature of spot happening conform to, accordingly this model cannot explain steam shedding is stimulated completely brace up phenomenon. The article built steam shedding to stimulate afresh on the foundation of Alford model brace up model, point out steam shedding is stimulated brace up in generation a dynamic force while, still will produce master piece of a static state to be used to rotor. Static force and rotor become direct ratio in the eccentricity in cylinder, dynamic force and rotor move displacement to become direct ratio, both metropolis affects shafting stability. More comprehensive ground mirrorred this model steam shedding is stimulated brace up problem. The article combines example of rotor of high pressure of group of homebred 200MW turbogenerator finally, analysed steam shedding to stimulate brace up the influence to stability, reached a few new with useful conclusion. 2 steam shed those who stimulate Zhenli model to establish a plan the structural concern Fig between 1 turbine rotor and cylinder.

1Center of rotor of Structure Relationship Between Rotor And Cylinder(o1- ; O2- cylinder center; Rotor of X, Y- moves displacement; δ Y- rotor is in in cylinder static prejudicial; δ θ - the clearance that rotor and cylinder are in in angle θ ) the steam that if the graph is shown 1 times,considers flows stimulate brace up model. Set rotor center O1 and cylinder center O2 to there is Y of δ of one static deviation on Y direction, rotor is in perpendicular the oscillatory displacement that goes up with horizontal way is Y and X respectively. Concern according to the geometry between variable, classics derivation can get rotor and cylinder the clearance δ θ that angle of the either on circumferential direction is in satisfies next type: The R in type and R are cylinder and rotor radius respectively, θ is angle. By turbine principle knowable, blade does work the relation between the clearance between efficiency and lamina, cylinder satisfies next type: Among them: η θ is the efficiency that blade some angle is in, η U rectifies Zhou Ping to all make result efficiency for blade, h is blade height, β is one coefficient, the effect that states unit clearance changes to be led to making effect. When operating mode is changeless, turbine lamina outputs torque direct ratio to be led at making effect, namely: Accordingly, the active force that the lamina that angle θ is in produces on direction of X, Y is respectively: Weeks of whole lamina is in perpendicular the total active force that arises up with water square is respectively: 3 pairs of steam shedding are stimulated brace up the analysis of the model from on type sees, steam shedding stimulates brace up the power that produces basically comprises by two parts: (1) dynamic force part. This part is (9) one of type, as identical as orthodox Alford model. By see in type, yu Zhen of dynamic force direct ratio moves displacement ｘ and ｙ , with rotor static state prejudicial δ Y has nothing to do. (2) static force part. This part is (9) the 2nd in type. By see in type, static force and rotor become direct ratio in the eccentricity in cylinder, move displacement to have nothing to do with rotor. Because coefficient Q and aircrew place take bear to become direct ratio, because force of this static state and bear also become direct ratio. This section force does not have a consideration in orthodox Alford model. When undertaking to rotor bearing system motivation is analysed, as a result of static force as static as rotor prejudicial about, and move displacement to have nothing to do with rotor, accordingly from theoretic tell only dynamic force can affect vibration, static force won't produce an effect to vibration. Steam shedding is stimulated brace up should be in with rotor in cylinder prejudicial have nothing to do. But a lot of field data make clear, steam shedding is stimulated brace up because rotor is prejudicial,often be those who cause [１ , 6] . Adjust the steam after rotor is prejudicial to flow stimulate brace up be reduced or disappeared. This phenomenon cannot explain with orthodox Alford model. The new steam that uses the article to build now flows stimulate brace up the model undertakes an analysis to this problem. By type (9) is knowable, rotor makes the same score direction to go up in water prejudicial will produce up static force. Same, what rotor makes the same score direction to go up in water is negative prejudicial the static power that will produce to be down. These two kinds of circumstances can affect a shafting the load of two upright bearing. Lubricate by bearing theory is knowable, the change of bearing load can affect shafting stability. Load is reduced, stability is reduced. Load increases, stability rises. Accordingly, exist on horizontal way when rotor prejudicial when, systematic stability will be stimulated at the same time by steam shedding brace up dynamic force is reduced with the influence of static force a lot of, the shafting that makes original stability better is in lose firm edge or lose firm status. Contrary, when rotor existence is lost prejudicial when, steam shedding is stimulated brace up static force can offset the dynamic force impact to stability partly, make thereby steam shedding is stimulated brace up the influence is reduced. 8 machine of ＃ of Xuzhou power plant produce steam shedding to stimulate brace up hind, stop machine undertake distensible a gender small long. Rotor of the actual measurement after opening a crock is in the clearance in cylinder, discover boiler side is more than another side, rotor puts on horizontal way in the position in cylinder deviation. The difference of two side clearance is on average 0.

4mm, some places are achieved 0.

5mm. Small in repairing, according to the overhaul regulations is adjusted clearance and change after 3 oily wedge cover with tiles better for stability ellipse covers with tiles, steam shedding is stimulated brace up disappeared, safe all the time stability runs unit up to now. Graph Fig of sketch map of structure of rotor of 2 high pressure.

2Steam of Structure Of High Pressure Rotor4 flows stimulate brace up analyse here to be with rotor of high pressure of some homebred 200MW aircrew to the influence of stability of rotor of 200MW aircrew high pressure exemple will analyse steam shedding to stimulate brace up the influence to stability. Gross weight of rotor of this aircrew high pressure is 6800kg, prop up by the elliptical bearing of two end, the span between bearing is 1.

41m. ＃ 1 with ＃ 2 bearing load is 3840kg and 12400kg respectively. High-pressured rotor shares 12 class lamina. Various lamina parameter and stimulate brace up if coefficient expresses 1 to show [5] . Differentiate high-pressured rotor now for 34 node, use Riccatti to deliver matrix and Newton-Bairstow method to seek rate of attenuation of solution system logarithm, decide systematic stability. Graph 3 gave out consideration and stability of the shafting when taking no account of static strength effect (high-pressured rotor is first-order) stimulate along with steam shedding brace up the metabolic circumstance of force. The ordinate in the graph represents logarithm attenuation rate, the abscissa is stimulated on behalf of steam shedding brace up coefficient. The number on the abscissa 1 state various lamina parameter mixes rotor of high pressure of aircrew of firm watch 200MW stimulate brace up coefficient [5] Tab.

H(mm) of Xie Gao of D(mm) of diameter of pitch circle of P(kW) of power of level of size of class of Wheel Demensions And Induced Vibration Coefficents Of The High Pressure Rotor In The Sample 200MW Turbogenerator is stimulated brace up coefficient Q(N/m)18153.

11100034152655024781.

898615169325234939.

40864.

554.

566738945085.

93868.

558.

563725255134.

508746458435065211.

968786855573175040.

458847449051585201.

498918145960395399.

1289888434941105171.

77902.

592.

5394382115636.

73912.

5102.

5383652125914.

What use when 07923113360972 qualitative computation is to go up the watch is shown stimulate brace up coefficient, number 2 - 10 express what use when computation to stimulate respectively brace up coefficient is to go up the watch gives out of the number 2 - 10 times. Curvilinear Ⅰ expresses to take no account of the computational result when the action of static force, the effect that curvilinear Ⅱ and Ⅲ show to consider static force respectively and high-pressured rotor has in cylinder, the computational result when negative level is prejudicial. Graph rate of attenuation of 3 shaftings logarithm follows steam shedding to stimulate brace up the metabolic circumstance Fig of force.

3Influence Of Steam Force On The Systems Logarithmetic Decrement Ratio can see from inside the graph: 1.

The shafting stability below 3 kinds of circumstances is stimulated along with steam shedding brace up the accretion of force and reduce;2.

The shafting stability after the effect that considers static force and take no account of from time to tome;3 of very big difference.

In cylinder when rotor existence is lost prejudicial when, logarithm attenuation rate is stimulated along with steam shedding brace up the trend that force increases and drops is the slowest. Contrary, exist when rotor prejudicial the downtrend when is the fastest;4.

Below 3 kinds of circumstances, rotor existence is lost prejudicial the stability when is best, rotor exists prejudicial the stability when is the poorest. That is to say, steam shedding is stimulated brace up the prejudicial position in cylinder concerns the influence to shafting stability and rotor, compare sometimes apparent, sometimes not apparent. 5 conclusion can reach through above analysis the following conclusion: 1.

Steam shedding is stimulated brace up will produce force of a static state and effect of a dynamic force to arrive on rotor at the same time. Both and bear become direct ratio. Static force and rotor are concerned in the eccentricity in cylinder, move displacement to have nothing to do with rotor. Contrary, dynamic force and rotor move displacement to concern, as static as rotor prejudicial have nothing to do. 2.

Dynamic force passes alternate stiffness influence shafting stability, static force affects stability through changing bearing load. Both must consider the influence of stability. 3.

Steam shedding is stimulated brace up to the influence degree of rotor stability and rotor the prejudicial position in cylinder is concerned. Rotor exists prejudicial the stability when is lost than rotor existence prejudicial the stability when should be gotten badly much. 4.

New steam flows stimulate brace up more comprehensive ground mirrorred the model steam shedding is stimulated brace up characteristic. CNC Milling