CN109472047B - Valve management function determining method based on reverse iteration - Google Patents

Abstract

The invention relates to a valve management function determining method based on reverse iteration, which comprises the steps of determining a comprehensive flow characteristic curve and obtaining an input-output sequence [ X, Y ]; modifying any one of the function principles to perform forward or reverse iteration according to the function block corner mark i under the assumption that two of the function block corner marks are unchanged, wherein i=1, and performing 2 times of reverse interpolation iteration; i=2, the forward and backward interpolation iterations are each performed 1 time; i=3, forward interpolation iteration is performed 2 times; and outputting a calculation result. The method is used for calculating the DEH system valve management function, and the parameter sequence of any one of the three function blocks in the DEH system valve management function composition can be determined by the method.

Description

Valve management function determining method based on reverse iteration

Technical Field

The invention belongs to the technical field of valve management of a DEH system of a thermal power plant, and particularly relates to a valve management function determining method based on reverse iteration.

Background

The DEH system is a core component of a steam turbine control system, wherein a valve management program is an important link of the function of the DEH system, and the main function of the DEH system is to continuously adjust and control the opening of each valve of a steam turbine through a designed comprehensive flow characteristic curve after a remote control instruction of the steam turbine sent by a coordination system is corrected through a load nonlinear function, so that the conversion of the power generation of the steam turbine is realized. Whether the matching degree of the comprehensive flow characteristic curve and the actual operation working condition of the turbine unit is in an optimal state determines key elements such as safety, economy and the like of the unit, and therefore, the comprehensive flow characteristic curve is often redesigned by the aid of the valve optimization test after overhaul of the unit or overhaul of a door adjusting part and modification of a DEH (deep h) system of the thermal power plant.

Typical valve management programs in DEH systems fall into two forms: 1) In brief, taking four high-voltage regulating gate (GV 1, GV2, GV3, GV 4) units as an example, taking a comprehensive flow instruction (the measuring range is 0-100) as a horizontal axis, taking the opening degree (the measuring range is 0-100) of each regulating gate of GV1, GV2, GV3, GV4 as a vertical axis, and taking an overall function formed by the abscissa and the ordinate as a vertical axis, wherein the overall function is limited by the number of DCS coordinate points and can only approximate a comprehensive flow characteristic curve (generally not more than 12 segmentation points) by using linear points; 2) The sectional function is composed of three parts, wherein the first part is a switching order opening function, the offset function is generally in the form of y=kx+b, the second part is an overlapping degree function, the third part is a switching flow characteristic function, the third part is a [ x, y ] coordinate set of 12 sectional points, and the like, the curve form approximates to a quadratic function.

The purpose of the valve optimization test is to re-acquire the comprehensive flow characteristic curve, and the parameters such as the main steam pressure, the pressure after the regulation stage, the main steam temperature, the temperature after the regulation stage and the like acquired through the test process can determine the actual comprehensive flow characteristic curve by using a typical friedel formula through the calculation of the front-back pressure ratio, and for the integrated valve management program, the result can be obtained according to the fitting point number, but for the sectional valve management program, three functions are formed, and the data result cannot be effectively and rapidly given.

Disclosure of Invention

The invention aims to provide a valve management function determining method based on reverse iteration, which aims to solve the problem of accurate fitting of a sectional type valve management program function block in a DEH system.

The invention provides a valve management function determining method based on reverse iteration, which is characterized by comprising the following steps of:

step one, determining a total curve of flow characteristics of a regulating gate by combining on-site regulating gate opening and closing stroke test data; the test data comprise main steam pressure, post-stage regulation pressure, main steam temperature and post-stage regulation temperature;

judging the valve management function type in the DEH system; aiming at the integral function type, determining the corresponding [ x ] of the output DCS according to the set fitting point number n of the total curve of the flow characteristic of the regulating gate determined in the step one ₁ ,y ₁ ；x ₂ ,y ₂ ；…；x _n ,y _n ]An array; for the piecewise function type, determine a modification F (x) i, (i=1, 2, 3);

step three, the following sub-steps are executed:

1) Combining the total curve of the flow characteristics of the regulating gate determined in the step two, and according to [ x ] in a piecewise function block F (x) i in the DCS _i1 ,y _i1 ；x _i2 ,y _i2 ；…；x _in ,y _in ]The maximum value n of the coordinate sequence confirms the number n-1 of the segmentation points, and the [ x ] is generated after data fitting ₁ ,y ₁ ；x ₂ ,y ₂ ；…；x _n ,y _n ]A coordinate sequence;

2) Setting a comprehensive flow instruction input sequence X _in ＝[x ₁ ,x ₂ ,x ₃ ,…x _n ]The method combines the index function block F (x) 0= [ x ] in the DEH valve management program of each power plant ₀₁ ,y ₀₁ ；x ₀₂ ,y ₀₂ ；…；x _0n ,y _0n ]Via linear interpolation

Wherein i=1, 2,3 n. N then obtain output sequence Y _in ＝[y _in1 ,y _in2 …y _inn ]；

3) Judging the value of the function block corner mark i, if i=1, and Y _in Input X sequence as valve management program piecewise function F (X) 1, let Y _out ＝[y ₁ ,y ₂ ,…y _n ]Derived from F (x) 3

Wherein i=1, 2 (S.) n, obtaining X _out1 ＝[x _out11 ,x _out12 ,…x _out1n ]And then X is taken _out1 As output of the valve management program segmentation function F (x) 2 and substituting the output into F (x) 2 by +.>

Wherein i=1, 2 (S.) n, obtaining X _out2 ＝[x _out21 ,x _out22 ,…x _out2n ]Finally, determining the coordinate sequence of F (x) 1 as [ y ] _in1 ,x _out21 ；y _in2 ,x _out22 ；…y _inn ,x _out2n ]And outputting a result; if i=2, executing step four, and if i=3, executing step five;

step four, repeating the substeps 1) and 2) in the step three, and carrying out Y in the substep 2) _in ＝[y _in1 ,y _in2 …y _inn ]The first function block F (x) 1= [ x ] in the piecewise function substituted into the valve management program ₁₁ ,y ₁₁ ；x ₁₂ ,y ₁₂ ；…；x _1n ,y _1n ]According to

Wherein i=1, 2,3 (S.) n, obtaining y _out1 ＝[y _out11 ,y _out12 ,…y _out1n ]And taking the output sequence as an input X sequence of F (X) 2 to let Y _out ＝[y ₁ ,y ₂ ,…y _n ]Derived from F (x) 3

Wherein i=1, 2 (S.) n, obtaining X _out1 ＝[x _out11 ,x _out12 ,…x _out1n ]Finally, F (x) 2= [ y ] is obtained _out11 ,x _out11 ；y _out12 ,x _out12 ；…y _out1n ,x _out1n ]；

Step five, repeating the substeps 1) and 2) in the step three, and carrying out Y in the substep 2) _in ＝[y _in1 ,y _in2 …y _inn ]The first function block F (x) 1= [ x ] in the piecewise function substituted into the valve management program ₁₁ ,y ₁₁ ；x ₁₂ ,y ₁₂ ；…；x _1n ,y _1n ]According to

Wherein i=1, 2,3 (S.) n, obtaining y _out1 ＝[y _out11 ,y _out12 ,…y _out1n ]And substitutes this sequence as an input into the second function block F (x) 2= [ x ] in the piecewise function in the valve management program ₂₁ ,y ₂₁ ；x ₂₂ ,y ₂₂ ；…；x _2n ,y _2n ]According to->

Wherein i=1, 2,3 (S.) n, obtaining y _out2 ＝[y _out21 ,y _out22 ,…y _out2n ]Taking this as the input X sequence of F (X) 3, let Y _out ＝[y ₁ ,y ₂ ,…y _n ]As an input Y sequence of F (x) 3, F (x) 3= [ Y ] is finally obtained _out21 ,y ₁ ；y _out22 ,y ₂ ；…y _out2n ,y _n ]；

Step six, outputting a display sequence F (x) i= [ x ] _i1 ,y _i1 ；x _i2 ,y _i2 ；…；x _in ,y _in ]。

By means of the scheme, the parameter sequence of any one of the three function blocks in the DEH system valve management function composition can be determined through the valve management function determining method based on reverse iteration.

The foregoing description is only an overview of the present invention, and is intended to provide a better understanding of the present invention, as it is embodied in the following description, with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is an Ovation 6 shutter DEH system valve management function [ X, Y ] coordinate set 1;

FIG. 2 is an Ovation 6 shutter DEH system valve management function [ X, Y ] coordinate combination 2;

FIG. 3 is a combination of the Xinhua XDPS 4 gate valve management function [ X, Y ] coordinates;

FIG. 4 is a graph of the result of an XDPS system overlap function fit curve;

FIG. 5 is a graph of the result of an XDPS system overlap function fit curve;

FIG. 6 is a graph of the result of an XDPS system overlap function fit curve;

FIG. 7 is a composite flow characteristic diagram 1;

FIG. 8 is a composite flow characteristic diagram 2;

fig. 9 is a comprehensive flow rate characteristic diagram 3.

Detailed Description

The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.

The embodiment provides a valve management function determining method based on reverse iteration, which mainly comprises the following steps:

step one: main steam pressure and regulated stage post pressure by test dataDetermining comprehensive flow characteristic curves by parameters such as force, main steam temperature, temperature after regulation stage and the like, and obtaining a coordinate set { [ x ] by performing linear approximation by a least square method through the set limit coordinate points n ₁ ,y ₁ ],[x ₂ ,y ₂ ]…[x _n ,y _n ]}；

Step two: determining a function sequence number i (i can be 1,2 and 3) to be reconstructed, and executing different calculation programs according to the value of i, wherein the principle is as follows: it is sufficient to modify either function assuming that both are unchanged. If i=1, taking a Y sequence in the coordinate sequence of the comprehensive flow characteristic curve as output, and carrying out 3-i times of reverse linear interpolation to sequentially substitute 1) a regulating gate flow characteristic function F (x) 3; 2) The overlapping degree function F (X) 2 is used for assigning a result to a Y sequence of the gate sequence opening function F (X) 1, assigning an X sequence in the coordinate sequence of the comprehensive flow characteristic curve to an X sequence of the gate sequence opening function F (X) 1, outputting the gate sequence opening function F (X) 1, and jumping to the third step if i=2;

step three: i=2, taking a Y sequence in the comprehensive flow characteristic curve coordinate sequence as output, carrying out i-1 times of reverse linear interpolation, sequentially substituting the Y sequence into a gate flow characteristic function F (X) 3, assigning the result to a Y sequence of an overlap degree function F (X) 2, taking the X sequence in the comprehensive flow characteristic curve coordinate sequence as input, carrying out i-1 times of forward linear interpolation, sequentially substituting the Y sequence into a gate sequence opening function F (X) 1, assigning the result to an X sequence of an overlap degree function F (X) 2, outputting the overlap degree function F (X) 2, and jumping to the fourth step if i=3;

step four: i=3, taking an X sequence in the coordinate sequence of the comprehensive flow characteristic curve as output, and carrying out i-1 times of forward linear interpolation to sequentially substitute 1) a gate regulating sequence opening function F (X) 3; 2) The overlapping degree function F (X) 2 is used for assigning a result to an X sequence of a gate flow characteristic function F (X) 3, assigning a Y sequence in a comprehensive flow characteristic curve coordinate sequence to a Y sequence of the gate flow characteristic function F (X) 3, and outputting the gate flow characteristic function F (X) 3;

step five: and (5) ending the program, exiting the operation, and displaying the result.

Referring to fig. 1 to 9, the specific steps of the present invention include:

step one: determining a total curve of flow characteristics of a throttle valve by combining on-site throttle valve opening/closing stroke test data (comprising main steam pressure TP1, main steam temperature TT1, first-stage pressure IMP1 and first-stage temperature IMT 1);

step two: firstly, judging the valve management function type in a DEH system, 1) aiming at the integral function type, setting fitting points n according to the total curve of the flow characteristics of the regulating gate determined in the step one, and determining the corresponding [ x ] of the output DCS ₁ ,y ₁ ；x ₂ ,y ₂ ；…；x _n ,y _n ]An array; 2) For a piecewise function type (typically consisting of three function blocks F (x) 1, F (x) 2,F (x) 3), a modification F (x) i is determined, (i=1, 2, 3), going down to step three.

Step three: 1) Firstly, combining the total curve of the flow characteristics of the regulating gate determined in the step two, and according to [ x ] in a piecewise function block F (x) i in the DCS _i1 ,y _i1 ；x _i2 ,y _i2 ；…；x _in ,y _in ]The maximum value n of the coordinate sequence can confirm the number n-1 of the segmentation points, and the [ x ] is generated after data fitting ₁ ,y ₁ ；x ₂ ,y ₂ ；…；x _n ,y _n ]A coordinate sequence; 2) Secondly, setting an integrated flow instruction input sequence X _in ＝[x ₁ ,x ₂ ,x ₃ ,…x _n ]The method combines the index function block F (x) 0= [ x ] in the DEH valve management program of each power plant ₀₁ ,y ₀₁ ；x ₀₂ ,y ₀₂ ；…；x _0n ,y _0n ](the signature function is determined to be data after the unit is put into operation and does not need to be changed) through linear interpolation

Wherein i=1, 2,3 n. N the output sequence Y can be obtained _in ＝[y _in1 ,y _in2 …y _inn ]The method comprises the steps of carrying out a first treatment on the surface of the 3) Then, the value of the function block corner mark i needs to be judged, if i=1, Y is determined _in Input X sequence as valve management program piecewise function F (X) 1, let Y _out ＝[y ₁ ,y ₂ ,…y _n ]Derived from F (x) 3>

Wherein i=1, 2 (S.) n, obtaining X _out1 ＝[x _out11 ,x _out12 ,…x _out1n ]And then X is taken _out1 As output of the valve management program segmentation function F (x) 2 and substituting the output into F (x) 2 by +.>

Wherein i=1, 2 (S.) n, obtaining X _out2 ＝[x _out21 ,x _out22 ,…x _out2n ]Finally, the coordinate sequence of F (x) 1 can be determined to be [ y ] _in1 ,x _out21 ；y _in2 ,x _out22 ；…y _inn ,x _out2n ]And outputting the result. If i=2, go to step four, if i=3, go to step five.

Step four: repeating the steps 1) and 2) in the third step, and Y in the step 2) _in ＝[y _in1 ,y _in2 …y _inn ]The first function block F (x) 1= [ x ] in the piecewise function substituted into the valve management program ₁₁ ,y ₁₁ ；x ₁₂ ,y ₁₂ ；…；x _1n ,y _1n ]According to

Wherein i=1, 2,3 (S.) n, availability y _out1 ＝[y _out11 ,y _out12 ,…y _out1n ]And taking the output sequence as an input X sequence of F (X) 2 to let Y _out ＝[y ₁ ,y ₂ ,…y _n ]Derived from F (x) 3

Wherein i=1, 2 (S.) n, obtaining X _out1 ＝[x _out11 ,x _out12 ,…x _out1n ]Finally, F (x) 2= [ y ] is obtained _out11 ,x _out11 ；y _out12 ,x _out12 ；…y _out1n ,x _out1n ]。

Step five: repeating the steps 1) and 2) in the third step, and Y in the step 2) _in ＝[y _in1 ,y _in2 …y _inn ]Score substituted into valve management programThe first function block F (x) 1= [ x ] in the segment function ₁₁ ,y ₁₁ ；x ₁₂ ,y ₁₂ ；…；x _1n ,y _1n ]According to

Wherein i=1, 2,3 (S.) n, availability y _out1 ＝[y _out11 ,y _out12 ,…y _out1n ]And substitutes this sequence as an input into the second function block F (x) 2= [ x ] in the piecewise function in the valve management program ₂₁ ,y ₂₁ ；x ₂₂ ,y ₂₂ ；…；x _2n ,y _2n ]According to->

Wherein i=1, 2,3 (S.) n, availability y _out2 ＝[y _out21 ,y _out22 ,…y _out2n ]Taking this as the input X sequence of F (X) 3, let Y _out ＝[y ₁ ,y ₂ ,…y _n ]As an input Y sequence of F (x) 3, F (x) 3= [ Y ] is finally obtained _out21 ,y ₁ ；y _out22 ,y ₂ ；…y _out2n ,y _n ]。

Step six: the operation procedure is ended, and the display sequence F (x) i= [ x _i1 ,y _i1 ；x _i2 ,y _i2 ；…；x _in ,y _in ]。

By the valve management function determining method based on reverse iteration, which is provided by the embodiment, the parameter sequence of any one of three function blocks in the DEH system valve management function composition can be determined.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, and it should be noted that it is possible for those skilled in the art to make several improvements and modifications without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims (1)

1. The valve management function determining method based on reverse iteration is characterized by comprising the following steps of:

step one, determining a total curve of flow characteristics of a regulating gate by combining on-site regulating gate opening and closing stroke test data; the test data comprise main steam pressure, post-stage regulation pressure, main steam temperature and post-stage regulation temperature;

judging the valve management function type in the DEH system; aiming at the integral function type, determining the corresponding [ x ] of the output DCS according to the set fitting point number n of the total curve of the flow characteristic of the regulating gate determined in the step one ₁ ,y ₁ ；x ₂ ,y ₂ ；…；x _n ,y _n ]An array; for the piecewise function type, determine a modification F (x) i, (i=1, 2, 3);

step three, the following sub-steps are executed:

1) Combining the total curve of the flow characteristics of the regulating gate determined in the step two, and according to [ x ] in a piecewise function block F (x) i in the DCS _i1 ,y _i1 ；x _i2 ,y _i2 ；…；x _in ,y _in ]The maximum value n of the coordinate sequence confirms the number n-1 of the segmentation points, and the [ x ] is generated after data fitting ₁ ,y ₁ ；x ₂ ,y ₂ ；…；x _n ,y _n ]A coordinate sequence;

2) Setting a comprehensive flow instruction input sequence X _in ＝[x ₁ ,x ₂ ,x ₃ ,…x _n ]The method combines the index function block F (x) 0= [ x ] in the DEH valve management program of each power plant ₀₁ ,y ₀₁ ；x ₀₂ ,y ₀₂ ；…；x _0n ,y _0n ]Via linear interpolation

Wherein i=1, 2,3 … n gives the output sequence Y _in ＝[y _in1 ,y _in2 …y _inn ]；

3) Judging the value of the function block corner mark i, if i=1, and Y _in Input X sequence as valve management program piecewise function F (X) 1, let Y _out ＝[y ₁ ,y ₂ ,…y _n ]Derived from F (x) 3

Where i=1, 2 … n, gives X _out1 ＝[x _out11 ,x _out12 ,…x _out1n ]And then X is taken _out1 As output of the valve management program segmentation function F (x) 2 and substituting the output into F (x) 2 by +.>

Where i=1, 2 … n, gives X _out2 ＝[x _out21 ,x _out22 ,…x _out2n ]Finally, determining the coordinate sequence of F (x) 1 as [ y ] _in1 ,x _out21 ；y _in2 ,x _out22 ；…y _inn ,x _out2n ]And outputting a result; if i=2, executing step four, and if i=3, executing step five;

step four, repeating the substeps 1) and 2) in the step three, and carrying out Y in the substep 2) _in ＝[y _in1 ,y _in2 …y _inn ]The first function block F (x) 1= [ x ] in the piecewise function substituted into the valve management program ₁₁ ,y ₁₁ ；x ₁₂ ,y ₁₂ ；…；x _1n ,y _1n ]According to

Where i=1, 2,3 … n, gives y _out1 ＝[y _out11 ,y _out12 ,…y _out1n ]And taking the output sequence as an input X sequence of F (X) 2 to let Y _out ＝[y ₁ ,y ₂ ,…y _n ]Derived from F (x) 3

Where i=1, 2 … n, gives X _out1 ＝[x _out11 ,x _out12 ,…x _out1n ]Finally, F (x) 2= [ y ] is obtained _out11 ,x _out11 ；y _out12 ,x _out12 ；…y _out1n ,x _out1n ]；

Step five, repeating the substeps 1) and 2) in the step three, and carrying out Y in the substep 2) _in ＝[y _in1 ,y _in2 …y _inn ]The first function block F (x) 1= [ x ] in the piecewise function substituted into the valve management program ₁₁ ,y ₁₁ ；x ₁₂ ,y ₁₂ ；…；x _1n ,y _1n ]According to

Where i=1, 2,3 … n, gives y _out1 ＝[y _out11 ,y _out12 ,…y _out1n ]And substitutes this sequence as an input into the second function block F (x) 2= [ x ] in the piecewise function in the valve management program ₂₁ ,y ₂₁ ；x ₂₂ ,y ₂₂ ；…；x _2n ,y _2n ]According to->

Where i=1, 2,3 … n, gives y _out2 ＝[y _out21 ,y _out22 ,…y _out2n ]Taking this as the input X sequence of F (X) 3, let Y _out ＝[y ₁ ,y ₂ ,…y _n ]As an input Y sequence of F (x) 3, F (x) 3= [ Y ] is finally obtained _out21 ,y ₁ ；y _out22 ,y ₂ ；…y _out2n ,y _n ]；

Step six, outputting a display sequence F (x) i= [ x ] _i1 ,y _i1 ；x _i2 ,y _i2 ；…；x _in ,y _in ]。

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