A sensitivity-based safety control method for the hydraulic condition of urban heating networks

Abstract

The present invention discloses a safety control method for the hydraulic condition of an urban heating network based on sensitivity. The method comprises the following steps: Step S1, obtaining the operation state parameters of the hydraulic condition of the urban heating network; Step S2, calculating the sensitivity of the non-reference node pressure with respect to the reference node pressure, the frequency of the variable-frequency water pump, and the valve opening; Step S3, calculating the expected change amount and its weight of the non-reference node pressure; Step S4, calculating the adjustment amounts of the reference node pressure, the frequency of the variable-frequency water pump, and the valve opening. When there is a limit violation of the node pressure in the hydraulic condition of the urban heating network, the present invention can be used to obtain a safety control scheme, and the obtained scheme can alleviate the limit violation condition of the node pressure, providing strong support for improving the safety of the hydraulic condition of the urban heating network.

Description

Technical Field

[0001] The present invention belongs to the field of urban heating network applications, and particularly relates to a safety control method for the hydraulic condition of an urban heating network based on sensitivity. Background Art

[0002] As an important infrastructure to ensure the living needs of residents, the construction scale and energy consumption of urban heating networks have been increasing year by year. How to improve energy utilization efficiency and achieve clean heating under the premise of ensuring user thermal comfort is a challenge faced in the operation of urban heating networks. At the current stage, most urban heating networks adopt the quality regulation method, which not only leads to relatively large heat medium transportation energy consumption, but also fails to fully utilize the characteristics of the heating network to support the integrated energy system. If the heating network adopts variable flow regulation, it can improve the hydraulic characteristics, reduce the transportation energy consumption, and provide more flexibility for the integrated energy system, which is conducive to accommodating more renewable energy. It can be predicted that the hydraulic conditions of future urban heating networks will change more frequently, and the possibility of node pressure exceeding the limit will be greater. Therefore, there is an urgent need to propose a fast and effective calculation method for safety control strategies to ensure the safe operation of urban heating networks. Summary of the Invention

[0003] The purpose of the present invention is to provide a safety control method for the hydraulic condition of an urban heating network based on sensitivity, so as to provide a safety control strategy when the node pressure exceeds the limit in the urban heating network, relieve the situation of node pressure exceeding the limit, and improve the safety level of the urban heating network.

[0004] To solve the above technical problems, the present invention provides a safety control method for the hydraulic condition of an urban heating network based on sensitivity, including the following steps:

[0005] Step S1, obtaining the operation state parameters of the hydraulic condition of the urban heating network, where the operation state parameters include: the pressures of each non-reference node, the reference node pressure, the frequency of the variable-frequency water pump, the valve opening, and the branch flow;

[0006] Step S2, calculating the sensitivity of the non-reference node pressure with respect to the reference node pressure, the frequency of the variable-frequency water pump, and the valve opening;

[0007] Step S3, calculating the expected change amount and its weight of the non-reference node pressure;

[0008] Step S4, calculating the adjustment amounts of the reference node pressure, the frequency of the variable-frequency water pump, and the valve opening.

[0009] Further, the step S2 specifically includes the following steps:

[0010] Step S21, denoting the set composed of all non-reference nodes as Ω 1 , denoting Ω1 The number of elements in the medium is M; assuming that variable-frequency pumps and valves are not configured simultaneously in each branch, sort the frequencies of each variable-frequency pump and the valve openings according to the numbers of their respective branches, and together with the reference node pressure, form a control variable column vector denoted as x. Denote the number of elements in x as N; denote the sensitivity matrix of the non-reference node pressure with respect to x as S, and the number of rows and columns of S are M and N respectively; denote the Jacobian matrix corresponding to the hydraulic operating condition equation as J, and denote the partial derivative matrix of the hydraulic operating condition equation with respect to the control variable column vector x as B.

[0011] Step S22, the calculation method of J is as follows:

[0012] Step S221, denote the non-reference node-branch incidence matrix in the hydraulic operating condition of the urban heating network as A, and denote the element in the i-th row and j-th column of matrix A as a ij , a ij The assignment method of is as follows:

[0013] When the i-th non-reference node is the outlet node of the j-th branch, the value of a ij is 1;

[0014] When the i-th non-reference node is the inlet node of the j-th branch, the value of a ij is -1;

[0015] When the i-th non-reference node is not connected to the j-th branch, the value of a ij is 0;

[0016] Step S222, denote the number of branches in the urban heating network as K, denote D as a K-order diagonal matrix, and denote the element in the k-th row and k-th column of D as d kk , d kk The assignment method of is as follows:

[0017]

[0018] In the formula, f k is the flow rate in the k-th branch, k_in and k_out are the inlet node and outlet node of the k-th branch respectively, p k_in and p k_out are the pressures at node k_in and node k_out respectively;

[0019] Step S223, the assignment method of the initial value of J is as follows:

[0020] J = -ADA T

[0021] In the formula, the superscript T represents the transpose calculation of the matrix;

[0022] Step S224, denote the set composed of all branches with power-frequency pumps and variable-frequency pumps as Ω 2 , denote the number of elements in Ω 2 as L, and denote the initial value of the serial number l as 1;

[0023] Step S225, denote the inlet node and outlet node of the l-th branch in Ω 2 as l_in and l_out respectively, and the method for correcting the elements in J is as follows:

[0024] Step S2251, when both l_in and l_out are non-reference nodes, denote the serial numbers of l_in and l_out in Ω 1 as N l_in and N l_out respectively, denote the element in the N l_in -th row and N l_in -th column of J as Denote the element in the N l_in -th row and N l_out -th column of J as Denote the element in the N l_out -th row and N l_out -th column of J as Denote the element in the N l_out -th row and N l_in -th column of J as and are assigned as follows:

[0025] When the l-th branch is equipped with a power-frequency pump, and are assigned as follows:

[0026]

[0027]

[0028]

[0029]

[0030] In the formula, f l is the flow rate in the l-th branch, p l_in and p l_out are the inlet pressure and outlet pressure of the l-th branch respectively, C l is the hydraulic impedance of the l-th branch, a c0,l , a c1,l and a c2,l are the parameters of the characteristic curve of the power-frequency pump configured on the l-th branch, C l , a c0,l , a c1,l and ac2,l Provided by the operators of the urban heating network;

[0031] When a variable-frequency water pump is configured on the l-th branch, and The assignment method is as follows:

[0032]

[0033]

[0034]

[0035]

[0036] In the formula, a v0,l , a v1,l and a v2,l Are the parameters of the characteristic curve of the variable-frequency water pump configured on the l-th branch, provided by the operators of the urban heating network; f 0l and f 1l Are the rated frequency and operating frequency of the variable-frequency water pump configured on the l-th branch respectively, f 0,l Provided by the operators of the urban heating network;

[0037] Step S226, when l is less than L, let l = l + 1, and return to step S225; when l is equal to L, execute step S23;

[0038] Step S23, the calculation method of B is as follows:

[0039] Step S231, record the initial value of the serial number t as 1;

[0040] Step S232, record the t-th control variable in x as x t , record the branch number where x t Is located as u, record the inlet node and outlet node of branch u as u_in and u_out respectively, record the serial numbers of u_in and u_out in Ω 1 Are N u_in and N u_out , record the element in the t-th column of the N u_in Row and the element in the t-th column of the N u_out Row in B are respectively and and The assignment method is as follows:

[0041] When x t Is the valve opening, and The assignment method is as follows:

[0042]

[0043]

[0044] where f u is the flow rate in the u-th branch, and C u is the hydraulic impedance of the u-th branch; K u and R u are the flow capacity and adjustable ratio of the valve configured on the u-th branch respectively, and K u and R u are given by the urban heating network operator; o u is the opening of the valve configured on branch u;

[0045] When x t is the frequency of the variable-frequency water pump, and are assigned as follows:

[0046]

[0047]

[0048] Step S233, when t is less than N - 1, let t = t + 1, and return to step S232; when t is equal to N - 1, execute step S234;

[0049] Step S234, the calculation method of the N-th column in B is as follows:

[0050] Step S2341, denote the set composed of all non-reference nodes connected to the reference node as Ω 3 , denote the number of nodes in Ω 3 as Q; denote the initial value of the serial number q as 1;

[0051] Step S2342, denote the serial number of the q-th non-reference node in Ω 3 in Ω 1 as N q , denote the branch between the q-th non-reference node in Ω 3 and the reference node as y, and denote the element in the N q -th row and N-th column of B as and its assignment method is as follows:

[0052] When there is no industrial-frequency water pump and variable-frequency water pump configured on branch y, the assignment method is as follows:

[0053]

[0054] where f y is the flow rate in the y-th branch, p y_in and p y_outare the inlet and outlet pressures of the y-th branch, respectively;

[0055] When a power-frequency water pump is configured on branch y, The assignment method is as follows:

[0056]

[0057] where a c0,y 、a c1,y and a c2,y are the parameters of the characteristic curve of the power-frequency water pump configured on the y-th branch, provided by the operator of the urban heating network; C y is the hydraulic impedance of the y-th branch, C y is provided by the operator of the urban heating network;

[0058] When a variable-frequency water pump is configured on branch y, The assignment method is as follows:

[0059]

[0060] where a v0,y 、a v1,y and a v2,y are the parameters of the characteristic curve of the variable-frequency water pump configured on the y-th branch, provided by the operator of the urban heating network; f 0,y and f 1,y are the rated frequency and operating frequency of the variable-frequency water pump configured on the y-th branch, respectively, f 0,y is provided by the operator of the urban heating network;

[0061] Step S24, the assignment method of S is as follows:

[0062] S = -[J] -1 B

[0063] where the superscript -1 represents the inverse calculation of the matrix.

[0064] Furthermore, the specific steps of step S3 are as follows:

[0065] Step S31, the operator of the urban heating network provides 3 weight values w 1 、w 2 and w 3 ,w 1 、w 2 and w 3 satisfy the relationship w 1 <w 2 <w 3 ;

[0066] Step S32, record the initial value of the serial number z as 1;

[0067] Step S33, denote Ω 1 The pressure of the z-th non-reference node in it is p z , denote Ω 1 The upper pressure limit, lower pressure limit and pressure safety margin of the z-th non-reference node in it are p z,max , p z,min and p z,margin , p z,max , p z,min and p z,margin Provided by the urban heating network operator, denote the expected change amount of p z as Δp z , denote the weight of Δp z as w_p z , Δp z and w_p z are assigned as follows:

[0068] When p z is greater than the sum of p z,min and p z,margin , and p z is less than the difference between p z,max and p z,margin , Δp z takes the value of 0, and w_p z takes the value of w 1 ;

[0069] When p z is greater than p z,min , and p z is less than the sum of p z,min and p z,margin , Δp z takes the value of p z,min +p z,margin -p z , and w_p z takes the value of w 2 ;

[0070] When p z is greater than the difference between p z,max and p z,margin , and p z is less than p z,max , Δp z takes the value of p z,max -p z,margin -p z , and w_p z takes the value of w 2 ;

[0071] When p z is less than p z,min , Δp z takes the value of p z,min+p z,margin -p z ,w_p z takes the value of w 3 ;

[0072] When p z is greater than p z,max , Δp z takes the value of p z,max -p z,margin -p z ,w_p z takes the value of w 3 ;

[0073] Step S34, when z is less than M, let z = z + 1, and return to Step S33; when z is equal to M, execute Step S35;

[0074] Step S35, denote the column vector composed of the expected pressure change amounts of all non-reference nodes in Ω 1 as Δp, and denote the diagonal matrix composed of the weights of the expected pressure change amounts of all non-reference nodes in Ω 1 as W;

[0075] Furthermore, the specific steps of the said Step S4 are as follows:

[0076] Denote the column vector composed of the adjustment amounts of all control variables as Δx, and the calculation method of Δx is as follows:

[0077] Δx = ([S] T WS) -1 [S] T WΔp

[0078] The beneficial effects of the present invention are:

[0079] The safety control method for the hydraulic condition of the urban heating network based on sensitivity proposed by the present invention uses sensitivity to quantify the influence of control variables such as the pressure of reference nodes, the frequency of variable-frequency water pumps, and the opening degree of valves on the pressure of non-reference nodes in the urban heating network, considers the expected adjustment amounts of the pressures of all nodes and weights their expected adjustment amounts according to the node pressure states. The obtained safety control scheme can give full play to the control ability of the urban heating network and adjust the pressures of multiple nodes with over-limit simultaneously within the operation limit values. The safety control scheme obtained by this method can provide strong support for improving the safety level of the urban heating network. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 is the implementation flowchart of the safety control method for the hydraulic condition of the urban heating network based on sensitivity. DETAILED DESCRIPTION OF THE INVENTION

[0081] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, only schematically showing the basic structure of the present invention, and therefore only showing the components related to the present invention.

[0082] As Figure 1 shown, the present invention provides a sensitivity-based safety control method for the hydraulic condition of an urban heating network, including the following steps:

[0083] Step S1, obtain the operation state parameters of the hydraulic condition of the urban heating network, where the operation state parameters include: the pressures of each non-reference node, the pressure of the reference node, the frequency of the variable-frequency water pump, the valve opening, and the branch flow rate;

[0084] Step S2, calculate the sensitivity of the non-reference node pressure with respect to the reference node pressure, the frequency of the variable-frequency water pump, and the valve opening;

[0085] Step S3, calculate the expected change amount and its weight of the non-reference node pressure;

[0086] Step S4, calculate the adjustment amounts of the reference node pressure, the frequency of the variable-frequency water pump, and the valve opening.

[0087] The specific steps of step S2 include the following steps:

[0088] Step S21, denote the set composed of all non-reference nodes as Ω 1 , denote the number of elements in Ω 1 as M; assume that the variable-frequency water pump and the valve are not configured in each branch at the same time, sort the frequencies of each variable-frequency water pump and the valve openings according to the numbers of the branches where they are located, and jointly form a control variable column vector with the reference node pressure and denote it as x, denote the number of elements in x as N; denote the sensitivity matrix of the non-reference node pressure with respect to x as S, the number of rows and columns of S are M and N respectively; denote the Jacobian matrix corresponding to the hydraulic condition equation as J, and denote the partial derivative matrix of the hydraulic condition equation with respect to the control variable column vector x as B;

[0089] The calculation method of J in step S22 is as follows:

[0090] Step S221, denote the non-reference node-branch incidence matrix in the hydraulic condition of the urban heating network as A, and denote the element in the i-th row and j-th column of matrix A as a ij , the assignment method of a ij is as follows:

[0091] When the i-th non-reference node is the outlet node of the j-th branch, the value of a ij is 1;

[0092] When the i-th non-reference node is the inlet node of the j-th branch, the value of a ij is -1;

[0093] When the $i$-th non-reference node is not connected to the $j$-th branch, the value of $a$ ij is 0;

[0094] Step S222: Denote the number of branches in the urban heating network as $K$, denote $D$ as a $K$-order diagonal matrix, and denote the element in the $k$-th row and $k$-th column of $D$ as $d$ kk , and the assignment method of $d$ kk is as follows:

[0095]

[0096] where $f$ k is the flow rate in the $k$-th branch, $k_{in}$ and $k_{out}$ are the inlet node and outlet node of the $k$-th branch respectively, and $p$ k_in and $p$ k_out are the pressures at node $k_{in}$ and node $k_{out}$ respectively;

[0097] Step S223: The assignment method of the initial value of $J$ is as follows:

[0098] $J = -ADA$ T

[0099] where the superscript $T$ represents the transpose calculation of the matrix;

[0100] Step S224: Denote the set composed of all branches equipped with industrial frequency pumps and variable frequency pumps as $\Omega$ 2 , denote the number of elements in $\Omega$ 2 as $L$, and denote the initial value of the serial number $l$ as 1;

[0101] Step S225: Denote the inlet node and outlet node of the $l$-th branch in $\Omega$ 2 as $l_{in}$ and $l_{out}$ respectively, and the correction method of the elements in $J$ is as follows:

[0102] Step S2251: When both $l_{in}$ and $l_{out}$ are non-reference nodes, the serial numbers of $l_{in}$ and $l_{out}$ in $\Omega$ 1 are denoted as $N$ l_in and $N$ l_out respectively, denote the element in the $N$ l_in -th row and $N$ l_in -th column of $J$ as Denote the element in the $N$ l_in -th row and $N$ l_out -th column of $J$ as Denote the element in the $N$ l_out -th row and $N$ l_out -th column of $J$ as Denote the element in the $N$ l_out -th row and $N$ l_in -th column of $J$ as and are assigned as follows:

[0103] When a power-frequency water pump is configured on the l-th branch, and are assigned as follows:

[0104]

[0105]

[0106]

[0107]

[0108] In the formula, f l is the flow rate in the l-th branch, p l_in and p l_out are the inlet pressure and outlet pressure of the l-th branch respectively, C l is the hydraulic impedance of the l-th branch, a c0,l , a c1,l and a c2,l are the parameters of the characteristic curve of the power-frequency water pump configured on the l-th branch, C l , a c0,l , a c1,l and a c2,l are provided by the operators of the urban heating network;

[0109] When a variable-frequency water pump is configured on the l-th branch, and are assigned as follows:

[0110]

[0111]

[0112]

[0113]

[0114] In the formula, a v0,l , a v1,l and a v2,l are the parameters of the characteristic curve of the variable-frequency water pump configured on the l-th branch, provided by the operators of the urban heating network; f 0,l and f 1,l are the rated frequency and operating frequency of the variable-frequency water pump configured on the l-th branch respectively, f 0,l is provided by the operators of the urban heating network;

[0115] Step S226: When l is less than L, let l = l + 1, and return to Step S225; when l is equal to L, execute Step S23;

[0116] Step S23: The calculation method of B is as follows:

[0117] Step S231: Denote the initial value of the serial number t as 1;

[0118] Step S232: Denote the t-th control variable in x as x t , denote the branch number where x t is located as u, denote the inlet node and outlet node of branch u as u_in and u_out respectively, and denote the serial numbers of u_in and u_out in Ω 1 as N u_in and N u_out respectively, and denote the element in the N u_in -th row and t-th column and the element in the N u_out -th row and t-th column in B as and and The assignment methods of

[0119] are as follows: When x t is the valve opening degree, the assignment methods of and are as follows:

[0120]

[0121]

[0122] In the formula, f u is the flow rate in the u-th branch, C u is the hydraulic impedance of the u-th branch; K u and R u are respectively the flow capacity and adjustable ratio of the valve configured on the u-th branch, and K u and R u are given by the urban heating network operators; o u is the opening degree of the valve configured on branch u;

[0123] When x t is the frequency of the variable-frequency water pump, the assignment methods of and are as follows:

[0124]

[0125]

[0126] Step S233, when t is less than N - 1, let t = t + 1, and return to Step S232; when t is equal to N - 1, execute Step S234;

[0127] Step S234, the calculation method of the Nth column in B is as follows:

[0128] Step S2341, denote the set composed of all non-reference nodes connected to the reference node as Ω 3 , denote Ω 3 the number of nodes in it as Q; denote the initial value of the serial number q as 1;

[0129] Step S2342, denote the serial number of the qth non-reference node in Ω 3 in Ω 1 as N q , denote the branch between the qth non-reference node in Ω 3 and the reference node as y, denote the element in the Nth q row and Nth column of B as The assignment method is as follows:

[0130] When there is no industrial-frequency water pump and variable-frequency water pump configured on branch y, The assignment method is as follows:

[0131]

[0132] In the formula, f y is the flow rate in the yth branch, p y_in and p y_out are the inlet and outlet pressures of the yth branch respectively;

[0133] When there is an industrial-frequency water pump configured on branch y, The assignment method is as follows:

[0134]

[0135] In the formula, a c0,y , a c1,y and a c2,y are the parameters of the characteristic curve of the industrial-frequency water pump configured on the yth branch, provided by the operators of the urban heating network; C y is the hydraulic impedance of the yth branch, C y provided by the operators of the urban heating network;

[0136] When there is a variable-frequency water pump configured on branch y, The assignment method is as follows:

[0137]

[0138] In the formula, a v0,y , a v1,y and av2,y The parameters of the characteristic curve of the variable-frequency water pump configured on the y-th branch are provided by the operators of the urban heating network; f 0,y and f 1,y are respectively the rated frequency and the operating frequency of the variable-frequency water pump configured on the y-th branch, f 0,y are provided by the operators of the urban heating network;

[0139] Step S24, the assignment method of S is as follows:

[0140] S = -[J] -1 B

[0141] In the formula, the superscript -1 represents the inverse calculation of the matrix;

[0142] The specific steps of the said step S3 are as follows:

[0143] Step S31, set three weight values w 1 、w 2 and w 3 ,w 1 、w 2 and w 3 satisfy the relational expression w 1 < w 2 < w 3 ,in this embodiment, the values of w 1 、w 2 and w 3 are respectively assigned as 0.1, 0.5 and 1;

[0144] Step S32, record the initial value of the serial number z as 1;

[0145] Step S33, record the pressure of the z-th non-reference node in Ω 1 as p z ,record the upper pressure limit, the lower pressure limit and the pressure safety margin of the z-th non-reference node in Ω 1 as p z,max 、p z,min and p z,margin ,p z,max 、p z,min and p z,margin are provided by the operators of the urban heating network, record the expected change amount of p z as Δp z ,record the weight of Δp z as w_p z ,the assignment methods of Δp z and w_p z are as follows:

[0146] When p z is greater than p z,min and p z,marginThe sum, and p z Less than p z,max And p z,margin The difference of, Δp z Takes the value of 0, w_p z Takes the value of w 1 ;

[0147] When p z Greater than p z,min , and p z Less than p z,min And p z,margin The sum of, Δp z Takes the value of p z,min +p z,margin -p z , w_p z Takes the value of w 2 ;

[0148] When p z Greater than p z,max And p z,margin The difference of, and p z Less than p z,max When, Δp z Takes the value of p z,max -p z,margin -p z , w_p z Takes the value of w 2 ;

[0149] When p z Less than p z,min When, Δp z Takes the value of p z,min +p z,margin -p z , w_p z Takes the value of w 3 ;

[0150] When p z Greater than p z,max When, Δp z Takes the value of p z,max -p z,margin -p z , w_p z Takes the value of w 3 ;

[0151] Step S34, when z is less than M, let z = z + 1, and return to step S33; when z is equal to M, execute step S35;

[0152] Step S35, denote the column vector composed of all the expected pressure change amounts of non-reference nodes in Ω 1 as Δp, and denote the one composed of Ω 1The diagonal matrix composed of the weights of the expected change amounts of the pressures of all non-reference nodes is W;

[0153] The step S4 specifically includes the following steps:

[0154] Denote the column vector composed of the adjustment amounts of all control variables as Δx, and the calculation method of Δx is as follows:

[0155] Δx = ([S] T WS)- 1 [S] T WΔp.

Claims

1. A safety control method for the hydraulic condition of an urban heating network based on sensitivity, characterized in that, it includes the following steps: Step S1, obtain the operation state parameters of the hydraulic condition of the urban heating network, and the operation state parameters include: the pressure of each non-reference node, the pressure of the reference node, the frequency of the variable-frequency water pump, the valve opening, and the branch flow rate; Step S2: Calculate the sensitivity of the non-reference node pressure with respect to the reference node pressure, the frequency of the variable-frequency water pump, and the valve opening; denote the set composed of all non-reference nodes as Ω 1 , denote Ω 1 The number of elements in is M; assume that each branch is not equipped with a variable-frequency water pump and a valve at the same time. Sort the frequencies of each variable-frequency water pump and the valve openings according to the numbers of their respective branches, and jointly form a control variable column vector with the reference node pressure and denote it as x. Denote the number of elements in x as N; denote the sensitivity matrix of the non-reference node pressure with respect to x as S. The number of rows and columns of S are M and N respectively; denote the Jacobian matrix corresponding to the hydraulic operating condition equation as J, and denote the partial derivative matrix of the hydraulic operating condition equation with respect to the control variable column vector x as B; the assignment method of S is as follows: S = -[J] -1 B In the formula, the superscript -1 represents the inverse calculation of the matrix; Step S3, calculate the expected change amount and its weight of the non-reference node pressure; Step S4, calculate the adjustment amounts of the reference node pressure, the variable-frequency water pump frequency, and the valve opening; the specific steps of Step S4 are as follows: Denote the column vector composed of the adjustment amounts of all control variables as Δx, and the calculation method of Δx is as follows: Δx = ([S] T WS) -1 [S] T WΔp Δp is the column vector composed of the expected pressure change amounts of all non-reference nodes in Ω 1 and W is the diagonal matrix composed of the weights of the expected pressure change amounts of all non-reference nodes in Ω 1 ​ 2. According to the safety control method for the hydraulic condition of an urban heating network based on sensitivity described in claim 1, characterized in that, the specific steps of Step S2 are as follows: The calculation method of J in Step S21 is as follows: Step S211, denote the non-reference node-branch incidence matrix in the hydraulic condition of the urban heating network as A, and denote the element in the i-th row and j-th column of matrix A as a ij , a ij is assigned as follows: When the i-th non-reference node is the outlet node of the j-th branch, the value of a ij is 1; When the i-th non-reference node is the inlet node of the j-th branch, the value of a ij is -1; When the i-th non-reference node is not connected to the j-th branch, the value of a ij is 0; Step S212, denote the number of branches in the urban heating network as K, denote D as a K-order diagonal matrix, and denote the element in the k-th row and k-th column of D as d kk , d kk is assigned as follows: where f k is the flow rate in the k-th branch, k_in and k_out are the inlet node and outlet node of the k-th branch respectively, p k_in and p k_out are the pressures at node k_in and node k_out respectively; The assignment method of the initial value of J in Step S213 is as follows: J = -ADA T In the formula, the superscript T represents the transpose calculation of the matrix; Step S214, denote the set composed of all branches configured with industrial frequency pumps and variable frequency pumps as Ω 2 , denote Ω 2 The number of elements in it is L, and denote the initial value of the serial number l as 1; Step S215, denote Ω 2 For the inlet node and the outlet node of the l-th branch in Step S2151, when both l_in and l_out are non-reference nodes, the sequence numbers of l_in and l_out in Ω 1 are respectively denoted as N l_in and N l_out . Denote the element in the N l_in -th row and N l_in -th column of J as Denote the element in the N l_in -th row and N l_out -th column of J as Denote the element in the N l_out -th row and N l_out -th column of J as Denote the element in the N l_out -th row and N l_in -th column of J as and are assigned as follows: When a power-frequency water pump is configured on the l-th branch, and The assignment method is as follows: where fl is the flow rate in the l-th branch, p l_in and p l_out are the inlet pressure and outlet pressure of the l-th branch respectively, C l is the hydraulic impedance of the l-th branch, a c0,l , a c1,l and a c2,l are the parameters of the characteristic curve of the power frequency water pump configured on the l-th branch, C l , a c0,l , a c1,l and a c2,l are provided by the operators of the urban heating network; When a variable-frequency water pump is configured on the l-th branch, and The assignment method is as follows: where a v0,l , a v1,l and a v2,l are the parameters of the characteristic curve of the variable-frequency water pump configured on the l-th branch, provided by the operators of the urban heating network; f 0,l and f 1,l are respectively the rated frequency and the operating frequency of the variable-frequency water pump configured on the l-th branch, and f 0,l is provided by the operators of the urban heating network; Step S216, when l is less than L, let l = l + 1, and return to Step S215; when l is equal to L, execute Step S22; The calculation method of B in Step S22 is as follows: In Step S221, denote the initial value of the serial number t as 1; Step S222, denote the t-th control variable in x as x t , denote x t The branch number where it is located as u, denote the inlet node and the outlet node of branch u as u_in and u_out respectively, and denote the sequence numbers of u_in and u_out in Ω 1 as N u_in and N u_out , denote the element in the N u_in -th row and the t-th column of B and the element in the N u_out -th row and the t-th column of B as and and The assignment methods are as follows: When x t is the valve opening degree, and are assigned as follows: where f u is the flow rate in the u-th branch, and C u is the hydraulic impedance of the u-th branch; K u and R u are respectively the flow capacity and the adjustable ratio of the valve installed on the u-th branch, and K u and R u are given by the operators of the urban heating network; o u is the opening degree of the valve installed on branch u; When x t is the frequency of the variable-frequency water pump, and are assigned as follows: Step S223, when t is less than N - 1, let t = t + 1, and return to Step S222; when t is equal to N - 1, execute Step S224; The calculation method of the Nth column in B in Step S224 is as follows: Step S2241, denote the set composed of all non-reference nodes connected to the reference node as Ω 3 , denote Ω 3 The number of nodes in is Q; Denote the initial value of the serial number q as 1; Step S2242, denote Ω 3 The sequence number of the q-th non-reference node in 1 is N in Ω q Denote that the branch between the q-th non-reference node and the reference node in Ω 3 is y. Denote that the element in the N-th row and N-th column of B is q The assignment method of is as follows: When no industrial frequency water pump and variable frequency water pump are configured on branch y, The assignment method is as follows: where f y is the flow rate in the y-th branch, p y_in and p y_out are the inlet and outlet pressures of the y-th branch, respectively; When a power frequency water pump is configured on branch y, The assignment method is as follows: Wherein, a c0,y , a c1,y and a c2,y are parameters of the characteristic curve of the power frequency water pump configured on the y-th branch, provided by the operator of the urban heating network; C y is the hydraulic impedance of the y-th branch, C y is provided by the operator of the urban heating network; When a variable-frequency water pump is configured on branch y, The assignment method is as follows: Where a v0,y , a v1,y and a v2,y are parameters of the characteristic curve of the variable-frequency water pump configured on the y-th branch, provided by the operators of the urban heating network; f 0,y and f 1,y are respectively the rated frequency and the operating frequency of the variable-frequency water pump configured on the y-th branch, and f 0,y is provided by the operators of the urban heating network.

3. According to the safety control method for the hydraulic condition of an urban heating network based on sensitivity described in claim 2, characterized in that, the specific steps of Step S3 are as follows: Step S31, three weight values w 1 , w 2 and w 3 are provided by the urban heating network operator, where w 1 , w 2 and w 3 satisfy the relationship w 1 < w 2 < w 3 ; In Step S32, denote the initial value of the serial number z as 1; Step S33, denote Ω 1 The pressure of the z-th non-reference node in z is p 1 Denote the upper pressure limit, lower pressure limit and pressure safety margin of the z-th non-reference node in Ω z,max as p z,min , p z,margin and p z,max respectively. p z,min , p z,margin and p z are provided by the operators of the urban heating network. Denote the expected change of p z as Δp z . Denote the weight of Δp z as w_p z . The assignment methods of Δp z and w_p When p z is greater than p z,min and the sum of p z,margin and, and p z is less than p z,max and the difference between p z,margin and, then Δp z takes the value of 0, and w_p z takes the value of w 1 ; When p z is greater than p z,min , and p z is less than the sum of p z,min and p z,margin , Δp z takes the value of p z,min + p z,margin - p z , and w_p z takes the value of w 2 ; When p z is greater than p z,max by the difference from p z,margin and p z is less than p z,max at this time, Δp z takes the value of p z,max - p z,margin - p z , w_p z takes the value of w 2 ; When p z is less than p z,min , Δp z takes the value of p z,min +p z,margin -p z , w_p z takes the value of w 3 ; When p z is greater than p z,max , Δp z takes the value of p z,max - p z,margin - p z , w_p z takes the value of w 3 ; Step S34, when z is less than M, let z = z + 1, and return to Step S33; when z is equal to M, execute Step S35; Step S35, denote the column vector composed of the expected pressure change amounts of all non-reference nodes in Ω 1 as Δp, and denote the diagonal matrix composed of the weights of the expected pressure change amounts of all non-reference nodes in Ω 1 as W.

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