阅读说明：本技术 基于瞬变流的爆管直径反演方法 (Explosion diameter inversion method based on transient flow ) 是由 郑国磊 田一梅 彭森 李政翾 程景 梁建文 何楠 于 2021-06-26 设计创作，主要内容包括：发明涉及一种实现爆管直径反演的方法,为实现管网中的爆管定位,应用高频SCADA系统监测管网内的压力异常信号,在爆管定位的基础上,根据瞬变流的传播特征,将总的监测信号分解为来自每条传播路径的分支监测信号；将瞬变流的传播路径及特征逆向,即原传播过程中的局部损失和摩阻损失取其倒数,变为增益,反演来自每条路径的激励信号,将其叠加后形成总的反演激励信号；根据爆管激励信号与爆管直径的关系,激励信号取最大振幅,爆管直径取最大值,计算爆管直径。通过与爆管实际直径及瞬变流衰减法计算爆管直径对比,证实本发明定位精度较高,说明本发明能有效解决爆管直径反演的问题。(The invention relates to a method for realizing the inversion of the diameter of a burst pipe, in order to realize the location of the burst pipe in a pipe network, a high-frequency SCADA system is applied to monitor a pressure abnormal signal in the pipe network, and on the basis of the location of the burst pipe, a total monitoring signal is decomposed into branch monitoring signals from each propagation path according to the propagation characteristics of transient flow; inverting the propagation path and characteristics of the transient flow, namely taking the reciprocal of the local loss and the frictional resistance loss in the original propagation process to obtain gain, inverting the excitation signals from each path, and superposing the excitation signals to form a total inversion excitation signal; and according to the relation between the detonation excitation signal and the detonation diameter, the excitation signal takes the maximum amplitude, the detonation diameter takes the maximum value, and the detonation diameter is calculated. The comparison of the diameter of the detonation calculated by the method with the actual diameter of the detonation and the instantaneous flow attenuation method proves that the positioning precision of the method is higher, and the method can effectively solve the problem of the diameter inversion of the detonation.)

1. The method for inverting the diameter of the pipe burst based on the transient flow is characterized by comprising the following steps of:

s1, decomposing the total monitoring signal into branch monitoring signals from each propagation path according to the propagation characteristics of the transient flow;

s2, reversing the propagation path and the propagation characteristics of the transient flow, and inverting the excitation signal;

and S3, calculating the diameter of the detonator according to the relationship between the detonator excitation signal and the diameter of the detonator.

2. The transient flow-based method for retrieving the detonation diameter of the pipe in the step S1 is characterized in that the specific method for decomposing the total monitoring signal is as follows:

according to the propagation theory of the transient flow, calculating the propagating transient flow signals in each propagation path from the pipe explosion point to the monitoring point, called branch analog signals, and superposing the branch analog signals to form a total analog signal, called a total analog signal, wherein the amplitude of the monitoring signal from each propagation path can be expressed as:

in the formula (1), k is the propagation path number of the transient stream, E_k(t) the amplitude of the branched analogue signal at time t, M (t) the amplitude of the total monitored signal at time t, ε_k(t) is the ratio of the monitor signal in the kth path at time t.

3. The transient flow-based method for inverting the diameter of the pipe burst according to claim 1, wherein in step S2, the specific method for inverting the excitation signal is as follows:

and (3) reversely transmitting the signal in each path from the monitoring point to the tube explosion point according to the original path, taking the reciprocal of the local loss and the friction loss in the original transmission process, and changing the reciprocal into gain, wherein the amplitude expression of the excitation signal from each path is as follows:

in the formula (2), T_kIs the propagation time of the transient stream in the kth path, A_kiTransmission or reflection coefficient of i-th node, R_kjFriction factor per unit length of j-th section of pipe, e^-RkjFrictional drag loss per unit length of j-th section of pipe, L_kjIs the length of j-th section of pipeAnd superposing the excitation signals from each path, wherein the superposed signals are total excitation signals, and the amplitude expression of the superposed signals is as follows:

4. the transient flow-based method for inverting the detonation diameter of claim 1, wherein in step S3, the specific method for calculating the detonation diameter is as follows:

regarding the tube explosion surface as a circle, according to the relation between the excitation signal and the tube explosion diameter, the excitation signal takes the maximum amplitude, the tube explosion diameter takes the maximum value, and then the expression is:

in the formula (4), I_maxMu is the burst coefficient and D is the burst diameter for the maximum amplitude of the excitation signal.

Technical Field

The invention relates to a method for inverting the diameter of a burst pipe, belongs to the field of engineering, and particularly relates to a method for inverting the diameter of the burst pipe based on transient flow.

Background

Water supply networks are an important component of the urban infrastructure, called the life line of the city. When the pipe burst happens, a decision is needed to be provided for pipe burst repair according to pipe burst information. In recent years, an SCADA system is widely introduced into a water supply network to monitor flow and pressure in real time, and a plurality of methods for positioning a burst pipe by using monitoring data cannot infer the burst pipe area, so that certain difficulty is brought to burst pipe repair decision. Therefore, the inversion of the caliber of the pipe burst is of great significance.

In recent years, high-frequency pressure monitoring in an SCADA system is introduced into a water supply pipe network, and the transient flow monitored by the system can realize accurate positioning of a complex pipe network, but pipe burst caliber information is difficult to infer. Therefore, it is necessary to research an inversion method of the pipe burst caliber to provide pipe burst repair decision.

Transient flow monitored by the SCADA system is formed by overlapping transient flow excited by pipe explosion and propagated to a monitoring point through multiple paths, and local loss and friction loss exist in the propagation process. On the basis of pipe burst positioning, the propagation path is reversed, two losses are converted into two gains, transient flow is propagated from a monitoring point to a pipe burst point through multiple paths and then overlapped to form an excitation signal, and the pipe burst caliber is calculated according to the corresponding relation between the excitation signal and the pipe burst caliber.

Disclosure of Invention

Aiming at the problem that the caliber of the pipe burst in the water supply network is difficult to invert, the invention provides a pipe burst diameter inversion method based on transient flow on the basis of pipe burst positioning, and the inversion of the caliber of the pipe burst in the water supply network is effectively realized. Therefore, the technical scheme of the invention is as follows:

a burst pipe diameter inversion method based on transient flow comprises the following steps:

s1, decomposing the total monitoring signal into branch monitoring signals from each propagation path according to the propagation characteristics of the transient flow;

s2, reversing the propagation path and the characteristics of the transient flow, and inverting the excitation signal;

and S3, calculating the diameter of the detonator according to the relationship between the detonator excitation signal and the diameter of the detonator.

Further, in step S1, the specific method of the total monitoring signal decomposition is:

according to the propagation theory of the transient flow, the propagating transient flow signals in each propagation path from the pipe explosion point to the monitoring point, called branch analog signals, are calculated and are superposed to form a total analog signal, called a total analog signal, and the amplitude of the monitoring signal from each propagation path can be expressed as:

in the formula (1), k is the propagation path number of the transient stream, E_k(t) the amplitude of the branched analogue signal at time t, M (t) the amplitude of the total monitored signal at time t, ε_k(t) is the ratio of the monitor signal in the kth path at time t.

Further, in step S2, the specific method for inverting the excitation signal is as follows:

and (3) reversely transmitting the signal in each path from the monitoring point to the tube explosion point according to the original path, taking the reciprocal of the local loss and the friction loss in the original transmission process, and changing the reciprocal into gain, wherein the amplitude expression of the excitation signal from each path is as follows:

in the formula (2), T_kIs the propagation time of the transient stream in the kth path, A_kiTransmission or reflection coefficient of i-th node, R_kjFriction factor per unit length of j-th section of pipe, e^-RkjFrictional drag loss per unit length of j-th section of pipe, L_kjIs the length of the j-th section of pipe.

And (3) superposing the excitation signals from each path, wherein the superposed signals are total excitation signals, and the amplitude expression of the superposed signals is as follows:

further, in step S3, the specific method of calculating the diameter of the squib is:

regarding the tube explosion surface as a circle, according to the relation between the excitation signal and the tube explosion diameter, the excitation signal takes the maximum amplitude, the tube explosion diameter takes the maximum value, and then the expression is:

in the formula (4), I_maxMu is the burst coefficient and D is the burst diameter for the maximum amplitude of the excitation signal.

The diameter of the detonation tube can be calculated by the formula (4).

Drawings

FIG. 1 is a schematic diagram of an experimental pipe network;

FIG. 2 is a graph of a total monitoring signal;

FIG. 3 is a graph of the inverted total excitation signal;

FIG. 4 is a flow chart of the present invention.

Detailed Description

The invention is further illustrated with reference to the following figures and specific examples, which are not intended to limit the invention in any way.

The method comprises the following steps of realizing pipe explosion diameter inversion in an experimental pipe network, and specifically comprises the following operation steps:

s1, decomposition of monitoring signal

The experimental equipment mainly comprises: the water pump, water tank, high frequency pressure sensor (3), DN100, DN50, DN25 steel pipe, DN50PVC pipe, water valve, each pipe section makes up the pipe network that has 2 rings, and high frequency pressure sensor acquisition frequency is 10000 Hz. Each node in the pipe network is numbered with a letter "B" and a number, for example: b1, B5 and B10. Each pipe section number is numbered with a letter "T" and the number of the node at both ends of the pipe section, for example: t2-3, T10-13 (FIG. 1). In an experimental pipe network, a water valve is quickly opened to manufacture a primary pipe explosion event, pressure signals (shown in figure 2) before and after the event are monitored, and a pipe explosion point is positioned on a T9-10 pipe section and 2.3m away from a B9 node by applying a pipe explosion positioning method based on transient flow.

According to the propagation theory of the transient flow, the propagating transient flow signals in each propagation path from the pipe explosion point to the monitoring point, called branch analog signals, are calculated and are superposed to form a total analog signal, called a total analog signal, and the amplitude of the monitoring signal from each propagation path can be expressed as:

in the formula (1), k is the propagation path number of the transient stream, E_k(t) the amplitude of the branched analogue signal at time t, M (t) the amplitude of the total monitored signal at time t, ε_k(t) is the ratio of the monitor signal in the kth path at time t.

S2 inversion of excitation signal

And (3) reversely transmitting the signal in each path from the monitoring point to the tube explosion point according to the original path, taking the reciprocal of the local loss and the friction loss in the original transmission process, and changing the reciprocal into gain, wherein the amplitude expression of the excitation signal from each path is as follows:

in the formula (2), T_kIs the propagation time of the transient stream in the kth path, A_kiTransmission or reflection coefficient of i-th node, R_kjFriction factor per unit length of j-th section of pipe, e^-RkjFrictional drag loss per unit length of j-th section of pipe, L_kjIs the length of the j-th section of pipe.

And (3) superposing the excitation signals from each path, wherein the superposed signals are total excitation signals, and the amplitude expression of the superposed signals is as follows:

the monitoring signal from each propagation path obtained in step S1 is propagated in reverse direction, and then the excitation signal from each path is obtained by equation (2), and then the total excitation signal is obtained by equation (3) (fig. 3).

S3, calculating the diameter of the pipe explosion

Regarding the tube explosion surface as a circle, according to the relation between the excitation signal and the tube explosion diameter, the excitation signal takes the maximum amplitude, the tube explosion diameter takes the maximum value, and then the expression is:

in the formula (4), I_maxMu is the burst coefficient and D is the burst diameter for the maximum amplitude of the excitation signal.

The maximum amplitude (1.617MPa) in FIG. 3 was taken, and the squib diameter of 32.92mm was calculated by equation (4).

Table 1: comparison table of diameter inversion results of pipe explosion by using transient current attenuation method

As can be seen from Table 1, the pipe burst diameter inversion of the invention has an absolute error of 0.92mm and a relative error of 2.88%; compared with a transient flow attenuation method, the absolute value of the inversion accuracy of the diameter of the burst pipe is improved by 4.52mm, and the relative value is improved by 14.12%; in conclusion, the absolute error and the relative error of the reversal of the pipe burst diameter are small, and the problem that the pipe burst diameter in a pipe network is difficult to reverse is solved.