阅读说明：本技术 抑制汽轮发电机组激振的方法 (Method for inhibiting excitation of steam turbine generator unit ) 是由 邱哲人 张正贺 杨长庆 范黎鹏 肖健楠 姜燃 张仕刚 刘琦 于 2020-07-31 设计创作，主要内容包括：一种抑制汽轮发电机组激振的方法,先逐渐开启GV2；当GV2阀位开度达到K1时,逐渐开启GV3；GV2阀位开度到达K2时停止；在上述步骤中,GV3一直不间断地开启；GV3阀位开度达到K2时,GV3继续开启,而GV2保持当前阀位；当GV3阀位开度达到K3时,GV2继续开启,同时将GV3开阀速度降低；使GV2继续开启至K4,GV3继续开启至K5。本技术方案替换掉了传统顺阀控制,采用了交替阀控制模式,合理控制进汽阀门开启的时间和顺序,调节具有针对性,通过不断地修正DEH流量曲线走势,并比较激振值大小,然后得出最佳的DEH流量曲线,为以后调试提供基准依据,有效地减小了汽轮发电机组的激振值。(A method for inhibiting excitation of a steam turbine generator unit comprises the steps of gradually starting GV 2; when the valve position opening degree of the GV2 reaches K1, gradually opening the GV 3; the GV2 valve position opening degree stops when reaching K2; in the above steps, GV3 is turned on continuously; when the valve position opening of the GV3 reaches K2, the GV3 is continuously opened, and the GV2 keeps the current valve position; when the valve position opening degree of the GV3 reaches K3, the GV2 is continuously opened, and meanwhile, the valve opening speed of the GV3 is reduced; GV2 was allowed to continue to open to K4 and GV3 was allowed to continue to open to K5. The technical scheme replaces the traditional sequential valve control, adopts an alternate valve control mode, reasonably controls the opening time and sequence of the steam inlet valve, has pertinence in regulation, provides a reference basis for later debugging by continuously correcting the trend of the DEH flow curve and comparing the sizes of the excitation values to obtain the optimal DEH flow curve, and effectively reduces the excitation value of the turbo generator set.)

1. a method for inhibiting excitation of a steam turbine generator unit is characterized by comprising the following steps: reducing the excitation value of the steam turbine generator unit by adjusting the opening and the sequence of the valves GV2 and GV 3;

GV 2: a high-speed regulating valve positioned at the right lower part of the steam turbine;

GV 3: a high-speed governor positioned at the upper left of the steam turbine;

the method comprises the following steps:

s1.1: gradually turning on GV 2;

s1.2: when the valve position opening degree of the GV2 reaches K1, gradually opening the GV 3;

s1.3: the GV2 valve position opening degree stops when reaching K2; in the above steps, GV3 is turned on continuously;

s1.4: when the valve position opening of the GV3 reaches K2, the GV3 is continuously opened, and the GV2 keeps the current valve position;

s1.5: when the valve position opening degree of the GV3 reaches K3, the GV2 is continuously opened, and meanwhile, the valve opening speed of the GV3 is reduced;

s1.6: GV2 was allowed to continue to open to K4 and GV3 was allowed to continue to open to K5.

2. The method of suppressing excitation of a turbo unit according to claim 1, wherein: k1 takes 6% -7%; k2 takes 13% -15%; k3 takes 19% -20%; k4 takes 24% -26%; k4= K5.

3. The method of suppressing excitation of a turbo unit according to claim 2, wherein: k1= 6.3%; k2= 14%; k3= 19.17%; k4= 25%.

4. The method of suppressing excitation of a turbo unit according to claim 1, wherein: k1 takes 6% -7%; k2 takes 13% -15%; k3 takes 19% -20%; k4 takes a value of 34% -36%; k5 takes a value of 24% -26%.

5. The method of suppressing excitation of a turbo unit according to claim 4, wherein: k1= 6.3%; k2= 14%; k3= 19.17%;

in step S1.6, the valve opening speed of GV2 is increased; k4=35%, K5= 25%.

6. The method for suppressing excitation of a turbo unit according to claim 3 or 5, wherein:

s2-1: under the downstream valve control mode, when the excitation phenomenon of the steam turbine generator unit occurs, the opening degree of the GV2 valve is gradually reduced, the GV2 is gradually adjusted from an initial valve position to a fully closed valve position, the excitation value of the steam turbine generator unit is observed, the excitation value comprises an X axial vibration value and a Y axial vibration value, and the maximum excitation value is defined as L_maxAnd record L_maxA change curve;

s2-2: when L is_maxWhen the change curve has a low valley value, the GV2 stops acting, and the temperature T of the bearing bush at the moment is recorded; when T is at a normal value, recording the valve position opening of GV 2;

s2-3: if T exceeds the early warning value, the valve opening degree of GV2 is adjusted back, and when T is lower than the early warning value, the GV2 stops acting and records the valve position opening degree of GV 2.

7. The method of suppressing excitation of a turbo unit according to claim 6, wherein: in step S2-3, L_maxWhen the inhibition can not be effectively inhibited, the following steps are adopted:

s3-1: continue to decrease GV2 valve opening and increase GV3 valve opening and increase GV3 opening rate while observing L_maxValue of L_maxRegulation was within the normal range, GV2 valve opening and GV3 valve opening were recorded.

Technical Field

The invention belongs to the technical field of suppression of vibration of a steam turbine, and particularly relates to a method for suppressing vibration excitation of a steam turbine generator unit.

Background

When the turbo generator set normally operates, the DEH high-speed regulating valve is adopted for load or pressure control, the DEH high-speed regulating valve mainly has two control modes of single valve control and sequential valve control, when the turbo generator set operates, in order to reduce throttling loss and improve economic benefit, a sequential valve control mode is generally adopted, 4 DEH high-speed regulating valves are sequentially opened in the sequential valve control mode, and a curve for controlling the opening degree of the 4 DEH high-speed regulating valves is called a DEH flow curve. When the turbine is excited (for 670MW supercritical coal-fired power generator set, the vibration value is more than 150um, the excitation is considered to be the excitation), the excitation phenomenon is controlled by optimizing the DEH flow curve (namely adjusting the opening of a high regulating valve). At present, no complete and effective scheme exists for a method for controlling a high-speed adjusting door.

Disclosure of Invention

In view of the technical problems in the background art, the method for inhibiting the excitation of the turbo generator set replaces the traditional sequential valve control, adopts an alternate valve control mode, reasonably controls the opening time and the opening sequence of the steam inlet valve, and has pertinence in adjustment, wherein the valve opening corresponds to a comprehensive valve instruction, namely the valve opening corresponds to the steam inlet quantity; by continuously correcting the trend of the DEH flow curve and comparing the sizes of the excitation values, the optimal DEH flow curve is obtained, a reference basis is provided for later debugging, and the excitation value of the steam turbine generator unit is effectively reduced.

In order to solve the technical problems, the invention adopts the following technical scheme to realize:

a method for inhibiting the excitation of a steam turbine generator unit reduces the excitation value of the steam turbine generator unit by adjusting the opening degree and the sequence of valves GV2 and GV 3;

GV 2: a high-speed regulating valve positioned at the right lower part of the steam turbine;

GV 3: a high-speed governor positioned at the upper left of the steam turbine;

the method comprises the following steps:

s1.1: gradually turning on GV 2; observing a DEH flow curve;

s1.2: when the valve position opening degree of the GV2 reaches K1, gradually opening the GV 3;

s1.3: the GV2 valve position opening degree stops when reaching K2; in the above steps, GV3 is turned on continuously;

s1.4: when the valve position opening of the GV3 reaches K2, the GV3 is continuously opened, and the GV2 keeps the current valve position;

s1.5: when the valve position opening degree of the GV3 reaches K3, the GV2 is continuously opened, and meanwhile, the valve opening speed of the GV3 is reduced;

s1.6: GV2 was allowed to continue to open to K4 and GV3 was allowed to continue to open to K5.

In a preferred scheme, the value of K1 is 6-7%; k2 takes 13% -15%; k3 takes 19% -20%; k4 takes 24% -26%; k4 ═ K5.

In a preferred scheme, the K1 is 6.3%; k2 ═ 14%; k3 ═ 19.17%; k4 ═ 25%.

In a preferred scheme, the value of K1 is 6-7%; k2 takes 13% -15%; k3 takes 19% -20%; k4 takes a value of 34% -36%; k5 takes a value of 24% -26%.

In a preferred scheme, the K1 is 6.3%; k2 ═ 14%; k3 ═ 19.17%;

in step S1.6, the valve opening speed of GV2 is increased; k4-35%, K5-25%.

In a preferred embodiment, the ratio of S2-1: under the downstream valve control mode, when the excitation phenomenon of the steam turbine generator unit occurs, the opening degree of the GV2 valve is gradually reduced, the GV2 is gradually adjusted from an initial valve position to a fully closed valve position, the excitation value of the steam turbine generator unit is observed, the excitation value comprises an X axial vibration value and a Y axial vibration value, and the maximum excitation value is defined as L_maxAnd record L_maxA change curve;

s2-2: when L is_maxWhen the change curve has a low valley value, the GV2 stops acting, and the temperature T of the bearing bush at the moment is recorded; when T is at a normal value, recording the valve position opening of GV 2;

s2-3: if T exceeds the early warning value, the valve opening degree of GV2 is adjusted back, and when T is lower than the early warning value, the GV2 stops acting and records the valve position opening degree of GV 2.

In a preferred embodiment, in step S2-3, L_maxWhen the inhibition can not be effectively inhibited, the following steps are adopted:

s3-1: continue to decrease GV2 valve opening and increase GV3 valve opening and increase GV3 opening rate while observing L_maxValue of L_maxRegulation was within the normal range, GV2 valve opening and GV3 valve opening were recorded.

This patent can reach following beneficial effect:

rotor stress imbalance is the root cause of long-term high vibration, but the main problem of sudden vibration rise at elevated loads is steam flow shock. Due to the steam inlet position, when the opening degree of GV2 is increased, the lower steam inlet is increased, the shaft system is raised, the tile shaft vibration is raised, when the opening degree of GV3 is increased, the upper steam inlet is increased, the tile shaft vibration is reduced, but the tile temperature is raised. Therefore, the key to solve the excitation is to solve the problem of steam admission balance, and the running conditions of the units with the same size are different due to the difference of the installed capacities of the different units and the difference of the installation errors. The technical scheme replaces the traditional sequential valve control, adopts an alternate valve control mode, reasonably controls the opening time and sequence of the steam inlet valve, and has pertinence in adjustment, wherein the valve opening corresponds to a comprehensive valve instruction, namely the valve opening corresponds to the steam inlet quantity; by continuously correcting the trend of the DEH flow curve and comparing the sizes of the excitation values, the optimal DEH flow curve is obtained, a reference basis is provided for later debugging, and the excitation value of the steam turbine generator unit is effectively reduced.

Drawings

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

FIG. 1 is a diagram of the GV1, GV2, GV3 and GV4 installation positions of the present invention;

FIG. 2 is a graph of the synthetic valve command of the present invention in example 1;

FIG. 3 is a graph of the synthetic valve command of the present invention in example 2;

FIG. 4 is a graph of the synthetic valve command of the present invention in example 3;

FIG. 5 is a graph of the synthetic valve command of the present invention in example 4;

FIG. 6 is an X-axis vibration diagram in example 2.

Detailed Description