A distributed acquisition method of heat network flow of a fourth-generation district heating system

Abstract

The application discloses a kind of distributed acquisition methods of heat network tide of fourth-generation district heating system, comprising the following steps: 1) construct the prosumer state model of 4G district heating system;2) construct the pipe flow model of 4G district heating system;3) construct the pipe water temperature variation model of 4G district heating system;4) construct the node temperature mixing model of 4G district heating system;5) distributed acquisition of heat network tide of 4G district heating system.The method of the application accelerates the calculation efficiency and the calculation speed by distributed algorithm, and protects the privacy of prosumer and heat network operator, has good expandability, and can adapt to the continuous joining of prosumer in district heating system.

Description

Technical Field

[0001] This invention relates to the field of district heating systems and heat network flow acquisition, and in particular to a distributed method for acquiring heat network flow in a fourth-generation district heating system. Background Technology

[0002] Faced with the increasingly severe energy crisis and environmental problems, fourth-generation (4G) district heating systems have received widespread research attention due to their advantages of low temperature, low energy consumption, and energy conservation. However, as more and more users participate in 4G district heating system transactions, the modeling and power flow calculation of the heat network system have become key research issues. A 4G district heating system has two pipes: a supply pipe and a return pipe. Heat is transported through the supply pipe using water as a medium. Upon reaching the user end, sufficient heat exchange occurs through a heat exchanger, thus providing heat to the user. The water is then returned to the heat source through the return pipe.

[0003] Traditional methods for obtaining heat network flow data require first acquiring information from all users, followed by calculations at a unified computing center. However, with more users transacting within the 4G heat network, the massive volume of information communication and data significantly increases computational difficulty and cost, and also compromises user privacy. D. Chen et al. proposed a directional nodal potential method to reduce the complexity of heat network flow calculations, thereby accelerating computation speed and efficiency. However, this method cannot protect the privacy of prosumers and heat network operators participating in the district heating system (Chen D, Li Y, Abbas Z, Li D, Wang R. Network flow calculation based on the directional nodal potential method for meshed heating networks[J]. Energy, 2022, 243:122729.). Summary of the Invention

[0004] This invention proposes a distributed method for acquiring heat network flow in fourth-generation district heating systems. First, it accurately models the heat network flow based on the bidirectional heat flow characteristics of 4G district heating systems. Since 4G district heating networks use distributed control of the working fluid, traditional centralized heat network flow acquisition methods are limited. Therefore, this invention employs a distributed method to acquire specific heat network flow information. This method only requires each producer and consumer to know the local heat network information of their area, and this is achieved through communication with neighboring producers and consumers, thus protecting the information privacy of each producer, consumer, and heat network operator. Therefore, the method of this invention not only improves computational speed and efficiency through distributed computing but also protects the information privacy of users and heat network operators, possessing practical engineering significance.

[0005] The present invention is achieved by at least one of the following technical solutions.

[0006] A distributed method for acquiring heat network power flow in a fourth-generation district heating system includes the following steps:

[0007] 1) Construct a producer-consumer state model for a 4G district heating system;

[0008] 2) Construct a pipeline flow model for a 4G district heating system, which includes the flow rate of the heat exchanger passing through each producer and consumer and the flow rate in the water supply pipeline;

[0009] 3) Construct a pipeline water temperature change model for a 4G district heating system. The pipeline water temperature change model includes the temperature loss during heat transmission and the actual heat that the heat exchanger needs to extract or inject.

[0010] 4) Construct a node temperature mixing model for the 4G district heating system. The node temperature mixing model includes the mixed water temperature of the supply pipe and the mixed water temperature of the return pipe.

[0011] 5) Obtain the heat network flow of the 4G district heating system through a distributed approach.

[0012] Furthermore, the producer-consumer state model of the 4G district heating system in step 1) includes:

[0013] Based on the transactions between prosumers at that moment, each prosumer is expected to inject energy into or absorb energy from the heating network:

[0014]

[0015] In the formula: H ij,t H represents the amount of heat flowing from producer i to producer j at time t. ji,t Let be the amount of heat flowing from producer j to producer i at time t. Let i be the set of producers and consumers adjacent to producer-consumer i; if This means that producer-consumer i is the heat source at time t, and vice versa. This means that producer i is a heat load at time t.

[0016] Furthermore, step 2) of constructing the pipe flow model for the 4G district heating system includes:

[0017] In the 4G district heating system model, the flow rate through the heat exchanger of each producer-consumer i is as follows:

[0018]

[0019] In the formula: Let i be the amount of water absorbed by its heat exchanger from the return water pipe when the consumer i acts as a heat source at time t. Let c be the amount of water absorbed by the heat exchanger from the water supply pipe when producer i acts as a heat load at time t. p The specific heat capacity of water, Let Ts be the energy that each producer or consumer is expected to inject into or absorb from the heating network at time t. nom Tr is the rated initial temperature of the water supply pipe. nom The rated initial temperature of the return water pipe;

[0020] The flow rate in the water supply pipeline is calculated using the following formula:

[0021]

[0022] in Let be the vector of flow rates between the supply pipes (i,j) at time t, where i < j. The relationship between the flow rate of the return pipe and the flow rate of the supply pipe is: It is a vector composed of the flow of each producer-consumer heat exchanger, and the correlation matrix A is defined as:

[0023]

[0024] In the formula: For the relationship matrix between prosumers and consumers, For the water supply pipe nodes of producer-consumer i, For the return water pipe node of producer j.

[0025] Furthermore, the temperature loss during the heat transfer process in step 3) of constructing the 4G district heating system includes:

[0026] When heat is generated from the water supply pipe node of producer-consumer i through the water supply pipe Water supply to producers and consumers After the heat exchanger extracts the heat, it returns to the consumer i via the return water pipe node. i Return water pipe node to consumer j j The temperature loss during transmission is:

[0027]

[0028]

[0029] In the formula: Te t For ambient temperature, λ b l is the roughness coefficient of the pipe. ij c is the length of the pipe. p The specific heat capacity of water, Let T be the outlet water temperature of the water supply pipe for consumer i at time t. out j ,t Let be the outlet water temperature of the return water pipe of the consumer j at time t. Let T be the water temperature at time t from the water supply pipe of producer i, which reaches the water supply pipe node of producer j due to losses. ji ,t Let t be the water temperature at which the water exiting the return water pipe of producer j reaches the node of the return water pipe of producer j due to losses. Let m be the flow rate from producer i to producer j through the water supply pipe at time t. ji ,t Let t be the flow rate of producer j to producer i through the return pipe.

[0030] Furthermore, the heat that the heat exchanger in step 3) needs to extract or inject to construct the 4G district heating system actually includes:

[0031] When producer i is a heat load, its heat exchanger absorbs heat from the water supply pipe. A certain amount of water, and extract from it The heat generated, therefore the water temperature injected into the return pipe is:

[0032]

[0033] In the formula: Let i be the amount of water absorbed by the heat exchanger from the water supply pipe when the producer-consumer i acts as the heat load at time t. For the energy that producer i is expected to inject into or absorb from the heating network at time t, At time t, Ts represents the outlet water temperature of the water supply pipe for producer i. nom Tr is the rated initial temperature of the water supply pipe. nom The rated initial temperature of the return water pipe;

[0034] When producer i is the heat source, the outlet water temperature of its water supply pipe at time t is... It should be Ts nom The heat exchanger absorbs heat from the return water pipe. A certain amount of water is heated and then injected into the water supply pipe. At time t, the actual amount of heat that the heat exchanger needs to inject is:

[0035]

[0036] In the formula: When the heat source is the producer i, the heat absorbed by its heat exchanger from the return water pipe, T out i ,t This represents the outlet water temperature of the return water pipe of the producer / consumer.

[0037] Furthermore, step 4) of constructing the nodal temperature hybrid model of the 4G district heating system includes:

[0038] The mixed water temperature in the water supply pipe meets the following requirements:

[0039]

[0040] In the formula: c p The specific heat capacity of water, Let be the outlet water temperature of the water supply pipe of consumer i at time t. This represents the set of prosumers adjacent to the water supply node i. i The return water pipe node representing consumer i, This represents the flow rate of the water supply pipe to producer-consumer i at time t. This represents the flow rate out of the water supply pipe node i at time t. Let t be the water temperature that reaches the water supply pipe node of producer-consumer i at time t;

[0041] The mixed water temperature in the return water pipe meets the following requirements:

[0042]

[0043] In the formula: This represents the set of prosumers adjacent to the return water pipe node of prosumer i. The water supply pipe node representing producer-consumer i, m j i ,t T represents the flow rate at time t towards the return water pipe node of producer-consumer i. j i ,t T represents the water temperature at time t that reaches the return water pipe node of producer-consumer i. out i ,t Let m be the outlet water temperature of the return water pipe of the consumer i at time t. j i ,t m represents the flow rate at time t towards the return water pipe node of producer-consumer i. i j,t This represents the flow rate out of the water supply pipe node i at time t;

[0044] Among them, the sign function sign(m) ij,t ) is defined as

[0045]

[0046] When sign(m) ij,t ) = 1, m ij,t >0 indicates that at time t, the water flowed from producer i to producer j.

[0047] Furthermore, the current heat network flow of the 4G heating district heating system is obtained. The acquisition of pipeline flow and node mixing temperature is characterized by the unknowns of the node itself and its neighboring nodes. Using this feature, a distributed method is used to sequentially solve the pipeline flow and node mixing temperature to obtain the current heat network flow.

[0048] The converged solution includes pipeline flow information and node mixed temperature information of the 4G heat network power flow. Based on the converged solution, the pipeline flow information of each node at each time period, and the outlet water temperature of the water supply pipe and return pipe are obtained.

[0049] Furthermore, in step 5), a distributed method is used to sequentially solve for the flow rate and node mixing temperature to obtain the heat network flow of the 4G district heating system.

[0050] The distributed method for obtaining the heat network power flow involves: distributively solving the following system of linear equations.

[0051] Ax = b

[0052] Furthermore, each intelligent agent i obtains the corresponding row's A based on the pipeline flow rate and node mixing temperature equations. i and b i First, initialize x according to the following formula. i (1)

[0053] A i x(1)=b i

[0054] Neighboring producers and consumers then communicate to exchange necessary information, and the system of linear equations converges quickly to the optimal solution using the following iterative formula:

[0055]

[0056] In the formula: Let P be the number of intelligent agents adjacent to intelligent agent i, x be the unknown to be solved, A be the coefficient equation of the unknown x, and b be the constant term of the linear equation system; i Defined as Where I is the identity matrix, A i For the intelligent subject i, the corresponding row; b i t represents the constant term of the linear equation system; t is the iteration number, x i (t) represents the value of the variable to be solved in the t-th iteration of the intelligent agent i, x. j (t) represents the value of the unknown to be solved by the intelligent agent i in the t-th iteration. When the value is sufficiently small, the system of linear equations essentially converges to the optimal solution.

[0057] Furthermore, in step 5), the distributed method described above is used to solve for the flow rate in the water supply pipeline, and producer-consumer i obtains matrix A and The data in the i-th row, i.e., A i and Prosumer i retains a local copy Where k represents the iteration number, and each producer-consumer local copy is initialized according to the following formula:

[0058]

[0059] After initialization, the flow status of the heating network is obtained in a distributed manner using the following iterative formula:

[0060]

[0061] In the formula: P i Defined as I is the identity matrix. Let be the value of the local copy retained by producer i in the k-th iteration. For the k-th iteration, when If it is small enough, the pipeline flow converges to the optimal solution.

[0062] Furthermore, in step 5), a distributed method is used to solve for the mixing temperature of the supply and return water pipe nodes:

[0063] The equation for the mixing temperature of the supply and return water pipes for each producer and consumer is obtained by solving the following formula for the mixed water temperature at each 4G heating network node:

[0064] BT out n,t =c

[0065] In the formula: Let be a vector consisting of the outlet water temperatures of the supply and return water pipes at each node at time t, where T represents the outlet water temperature of the water supply pipe node at time t for producer-consumer n. out n ,t The matrix B represents the outlet water temperature of the return water pipe node at time t for producer n, and the matrix B is the solution to be solved for T. out n,t The coefficient matrix is ​​denoted by c, and c is a vector composed of constants in the equation.

[0066] Prosumer i obtains the flow rate flowing into the water supply node of its neighboring prosumers at time t. Water temperature reaching the water supply pipe node of the consumer water outlet temperature of the water supply pipe for producers and consumers The flow rate m from the adjacent producer-consumer into the return water pipe node of producer-consumer i j i ,t The water temperature T reaching the return water pipe node of the consumer ij i ,t The outlet water temperature T of the return water pipe of the consumer out i ,t Each prosumer retains a local copy. k represents the number of iterations; for Initialization is as follows:

[0067]

[0068] Among them B i Let c be the coefficient corresponding to the i-th row known to the producer-consumer i. i and the i-th row of the constant vector;

[0069] After initialization, the flow status of the heating network is obtained in a distributed manner using the following iterative formula:

[0070]

[0071] In the formula: The number of producers and consumers in a 4G district heating system. I is the identity matrix, when When the value is less than 0.01, the water supply pipe, return pipe, and outlet water temperature converge to the optimal solution.

[0072] Compared with existing technologies, the method for obtaining the heat network flow of a fourth-generation district heating system according to the present invention has the following beneficial effects:

[0073] (1) Accelerate computation efficiency and speed through distributed algorithms, and protect the privacy of producers, consumers and heat network operators.

[0074] (2) It has good scalability. The method of the present invention can adapt to the continuous addition of consumers to the district heating system. Attached Figure Description

[0075] Figure 1 This is a flowchart for obtaining the power flow of the heating network in this implementation;

[0076] Figure 2 This is a schematic diagram of the fourth-generation district heating system of the present invention;

[0077] Figure 3 This is a structural diagram of the internal structure of a certain product of the present invention;

[0078] Figure 4 This is a schematic diagram of the topology of four producers and consumers in the specific implementation of this example. Detailed Implementation

[0079] To make the objectives, technical solutions, and advantages of the present invention clearer and more explicit, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0080] Example 1

[0081] like Figure 1 As shown, this example uses a 4-node multi-producer / consumer scenario as the simulation object to specifically illustrate the distributed heat network flow acquisition method for the 4G district heating system provided by this invention. Its network topology is as follows: Figure 4 As shown, the specific steps are as follows:

[0082] Step S110: Obtain network data and transaction information of the heating network system, including: the total number of nodes in the heating network, the length of each pipe, etc. ij The heat source or load of producer-consumer i Pipe roughness coefficient λ b .

[0083] The total number of nodes in the heating network is 4 producers and consumers; the pipeline length is l 12 =3200m, l 23 =3600m and l 34 =3600m; Pipe roughness coefficient λ b =0.0003. The producers and consumers obtained in this embodiment are shown in Table 1.

[0084] Table 1 Heat source and heat load of the 4-node system of the heating network at 24 hours Data Information

[0085] Time period / h Prosumer 1 Prosumer 2 Producers and consumers 3 Prosumer 4 0-1 160.89 -160.87 278.74 -278.76 1-2 160.88 -160.87 278.76 -278.76 2-3 160.84 -160.84 278.75 -278.76 3-4 160.88 -160.87 278.75 -278.76 4-5 161.13 -157.44 275.08 -278.76 5-6 161.17 -150.91 269.43 -279.68 6-7 287.14 -345.27 335.13 -277.01 7-8 315.65 -370.26 307.47 -252.86 8-9 335.79 -395.27 287.30 -227.83 9-10 545.46 -575.27 267.24 -237.43 10-11 518.79 -689.95 297.21 -126.06 11-12 563.76 -630.27 322.24 -255.73 12-13 572.08 -680.27 397.24 -289.05 13-14 551.95 -655.27 407.23 -303.93 14-15 576.97 -630.27 282.24 -228.94 15-16 715.00 -830.27 267.23 -151.96 16-17 631.95 -720.27 297.24 -208.92 17-18 580.39 -650.27 312.24 -242.36 18-19 533.81 -620.27 392.24 -305.78 19-20 552.11 -665.27 427.24 -314.08 20-21 309.30 -410.27 440.28 -339.31 21-22 299.42 -375.27 385.16 -309.31 22-23 180.05 -180.05 289.31 -289.31 23-24 161.13 -156.19 273.82 -278.76

[0086] Step S120: Modeling and solving the flow rate in the heating network pipeline:

[0087] Based on the transactions between prosumers at that moment, the energy that each prosumer is expected to inject into or absorb from the heating network at time t is:

[0088]

[0089] In the formula: H ij,t For the heat flowing from producer-consumer i to producer-consumer j, similar to H ji,t The heat flowing from producer j to producer i Let i be the set of producers and consumers adjacent to producer-consumer i. It is worth noting that if... This means that at time t, producer i is the heat source, and vice versa. This represents the heat carrier i at time t.

[0090] In the 4G district heating system model, the flow rate through the heat exchanger of each producer-consumer i at time t is as follows:

[0091]

[0092] In the formula: Let i be the amount of water absorbed by the heat exchanger from the return water pipe when the producer-consumer i acts as the heat source at time t. Let c be the amount of water absorbed by the heat exchanger from the water supply pipe when the producer i acts as the heat load at time t. p Ts is the specific heat capacity of water. nom The rated initial temperature of the water supply pipe is generally taken as Ts. nom =50℃-60℃. Tr nom The rated initial temperature of the return water pipe is typically taken as approximately Tr. nom =25℃.

[0093] The flow rate in the pipe can be further obtained using the heat exchanger flow model described above. Taking a water supply pipe as an example, the flow rate in the water supply pipe can be calculated using the following formula:

[0094]

[0095] in Let be the vector consisting of the flow rates between the supply pipes (i,j) at time t, where i < j. The relationship between the flow rate of the return pipe and the flow rate of the supply pipe is as follows: Let A be a vector consisting of the flow rates through each producer-consumer heat exchanger at time t. The definition of matrix A is:

[0096]

[0097] Prosumer i can easily obtain matrix A and 2 from step 2. The data in the i-th row, i.e., A i and Prosumer i retains a local copy Where k represents the iteration number. Each producer-consumer local copy is initialized to satisfy the following equation:

[0098]

[0099] After initialization, the flow status of the heating network is obtained in a distributed manner using the following iterative formula:

[0100]

[0101] In the formula: P i Defined as I is the identity matrix. The value of the local copy retained by producer i in the k-th iteration. For the k-th iteration. When When the value is sufficiently small, typically less than 0.01, the pipeline flow converges to the optimal solution.

[0102] Table 2 Example 1 Pipeline Flow Data Information

[0103] Time period / h <![CDATA[m 12 ]]> <![CDATA[m 23 ]]> <![CDATA[m 34 ]]> 0-1 1.09 0.00 1.90 1-2 1.09 0.00 1.90 2-3 1.09 0.00 1.90 3-4 1.09 0.00 1.90 4-5 1.10 0.03 1.90 5-6 1.10 0.07 1.90 6-7 1.95 -0.40 1.88 7-8 2.15 -0.37 1.72 8-9 2.28 -0.40 1.55 9-10 3.71 -0.20 1.62 10-11 3.53 -1.16 0.86 11-12 3.84 -0.45 1.74 12-13 3.89 -0.74 1.97 13-14 3.75 -0.70 2.07 14-15 3.92 -0.36 1.56 15-16 4.86 -0.78 1.03 16-17 4.30 -0.60 1.42 17-18 3.95 -0.48 1.65 18-19 3.63 -0.59 2.08 19-20 3.76 -0.77 2.14 20-21 2.10 -0.69 2.31 21-22 2.04 -0.52 2.10 22-23 1.22 0.00 1.97 23-24 1.10 0.03 1.90

[0104] Step S130: Modeling the temperature change model of the heating network working fluid:

[0105] When heat travels through the water supply pipes from producers to consumers Delivered to producers and consumers After the heat exchanger extracts the heat, then from... i Returned through the return pipe j The temperature loss during this transmission process is:

[0106]

[0107]

[0108] In the formula: Let T be the outlet water temperature of the water supply pipe for consumer i at time t. out j ,t Let t be the outlet water temperature of the return water pipe of the consumer j. Let T be the water temperature at time t that reaches consumer j after losses during the water supply process through the pipeline. ji ,t Let t be the water temperature at which producer j reaches producer j after losses during the pipeline transmission process. Let m be the flow rate from producer i to producer j through the water supply pipe. ji ,t The flow rate from producer j to producer i via the return water pipe. t For ambient temperature, λ b l is the roughness coefficient of the pipe. ij This represents the length of the pipe.

[0109] When the producer-consumer i is a heat load, the heat exchanger will absorb heat from the water supply pipe. A certain amount of water, and extract from it The heat. Therefore, the water temperature injected into the return pipe at time t is...

[0110]

[0111] When the heat source is the producer i, the outlet water temperature of its water supply pipe should be Ts. nom The heat exchanger absorbs heat from the return water pipe. A certain amount of water is heated and then injected into the water supply pipe. Therefore, the actual amount of heat that the heat exchanger needs to inject at time t is:

[0112]

[0113] In the formula: When the heat source is the producer i, the heat absorbed by its heat exchanger from the return water pipe, T out i This represents the outlet water temperature of the return water pipe of producer i. Due to losses during transmission, T... out i than Tr nom It needs to be small, therefore the actual amount of heat that the heat exchanger needs to inject is... It is more than expected Big ones.

[0114] Step S140: Modeling and solving the mixed temperature model of the heating network nodes.

[0115] The mixed water temperature in the water supply pipes can meet the following requirements:

[0116]

[0117] In the formula: c p The specific heat capacity of water, Let t be the outlet water temperature of the water supply pipe for consumer i. This represents the set of prosumers adjacent to the water supply node i. i The return water pipe node representing consumer i, This represents the flow rate of the water supply pipe to the producer-consumer i at time t. The flow rate at time t represents the flow rate out of the water supply pipe node of producer-consumer i. Let t be the water temperature reaching the water supply pipe node of producer i at time t.

[0118] Similarly, the mixed water temperature of the return water pipe can be satisfied as follows:

[0119]

[0120] In the formula: This represents the set of prosumers adjacent to the return water pipe node of prosumer i. Water supply pipe nodes representing producers and consumers, m j i ,t T represents the flow rate at time t towards the return water pipe node of producer-consumer i. j i ,t T represents the water temperature at time t that reaches the return water pipe node of producer i. out i ,t Let m be the outlet water temperature of the return water pipe of the consumer at time t. j i ,t m represents the flow rate at time t towards the return water pipe node of producer-consumer i. i j,t m represents the flow rate (m) from the water supply pipe node to producer-consumer i at time t. i j,t This represents the flow rate out of the water supply pipe node i at time t.

[0121] The sign function sign(m) ij,t ) is defined as

[0122]

[0123] When sign(m) ij,t ) = 1, m ij,t >0 indicates that at time t, the water flows from producer i to producer j.

[0124] Based on the mixing equation of the supply and return water pipe temperatures for each producer and consumer in step S140, the mixed water temperature of the 4G heating network node can be obtained by solving the following formula:

[0125] BT out n,t =c

[0126] In the formula: Let be a vector consisting of the outlet water temperatures of the supply and return water pipes at each node, where T represents the outlet water temperature of the n-th water supply pipe node representing the producer and consumer at time t. out n ,t Let T represent the outlet water temperature at node n of the return water pipe, which is the producer-consumer junction, at time t. Matrix B represents the unknown variable T to be solved. out n,t The coefficient matrix is ​​denoted by c, and c is a vector of constants.

[0127] Prosumer i can obtain the flow rate from its neighboring prosumers into the water supply node of prosumer i at time t. Water temperature reaching the water supply pipe node of the consumer water outlet temperature of the water supply pipe for producers and consumers The flow rate m from the adjacent producer-consumer into the return water pipe node of producer-consumer i j i ,t The water temperature T reaching the return water pipe node of the consumer i j i ,t The outlet water temperature T of the return water pipe of the consumer out i ,t Each prosumer retains a local copy. k represents the number of iterations. For Initialization is as follows:

[0128]

[0129] Among them B i Let c be the coefficient corresponding to the i-th row known to the producer-consumer i. i The i-th row of the constant vector.

[0130] After initialization, the flow status of the heating network is obtained in a distributed manner using the following iterative formula:

[0131]

[0132] In the formula: The number of consumers in a 4G district heating system. I is the identity matrix. When the value is less than 0.01, it can be considered that the water supply pipe, return pipe, and outlet water temperature have converged to the optimal solution.

[0133] Step S150: Obtain the current heat network flow of the 4G heating area heating system. The pipeline flow and the node mixing temperature can be characterized by the unknowns of the node itself and its neighboring nodes. Using this feature, a distributed method is used to sequentially solve the pipeline flow and the node mixing temperature to obtain the current heat network flow.

[0134] The converged solution contains accurate pipeline flow information and node mixing temperature information for the 4G heat network power flow. Based on this converged solution, the outlet water temperature of the supply and return pipes of each node at each time period can be obtained. In the example, the converged solution contains the outlet water temperatures of the supply and return pipes of the four prosumers at 24 times throughout the day. As shown in Table 3:

[0135] Table 3 shows the outlet water temperatures of the supply and return water pipes at different times in Example 1.

[0136]

[0137] This value can provide an accurate reference for the actual operation of the heating network.

[0138] Example 2

[0139] In Example 2, the pipe and other parameters are the same as in Example 1, but the heat source and heat load data used in the four nodes of the heat network are different from those in Example 1. The heat source and heat load data of the heat network are shown in Table 4.

[0140] Table 4 shows the heat source and heat load of the 4-node system of the heating network in Example 2 at 24 hours. Data Information

[0141] Time period / h Prosumer 1 Prosumer 2 Producers and consumers 3 Prosumer 4 0-1 160.74 -123.18 287.95 -325.51 1-2 160.79 -134.87 299.60 -325.51 2-3 160.83 -128.87 293.55 -325.51 3-4 160.81 -139.78 304.48 -325.51 4-5 198.89 -146.68 257.10 -309.31 5-6 285.55 -208.20 248.25 -325.59 6-7 345.26 -345.26 326.36 -326.36 7-8 370.26 -370.26 307.27 -307.27 8-9 399.88 -395.49 287.14 -291.53 9-10 506.80 -575.26 267.24 -198.78 10-11 420.49 -518.66 297.24 -199.07 11-12 493.70 -604.37 322.24 -211.57 12-13 533.03 -680.44 397.19 -249.78 13-14 404.87 -558.04 407.24 -254.07 14-15 436.19 -526.86 282.24 -191.57 15-16 508.14 -591.31 267.24 -184.07 16-17 590.29 -688.46 297.24 -199.07 17-18 592.84 -650.26 312.24 -254.81 18-19 549.77 -620.26 392.21 -321.72 19-20 567.95 -665.26 427.21 -329.90 20-21 362.06 -410.26 387.52 -339.31 21-22 352.11 -375.26 332.47 -309.31 22-23 247.19 -214.90 257.03 -289.31 23-24 224.89 -161.77 236.20 -299.31

[0142] Table 5 shows the distributed data obtained from pipeline flow based on heat source and heat load data.

[0143] Table 5 Example 2 Pipeline Flow Data Information

[0144] Time period / h <![CDATA[m 12 ]]> <![CDATA[m 23 ]]> <![CDATA[m 34 ]]> 0-1 1.09 0.26 2.21 1-2 1.09 0.18 2.21 2-3 1.09 0.22 2.21 3-4 1.09 0.14 2.21 4-5 1.35 0.36 2.10 5-6 1.94 0.53 2.21 6-7 2.35 0.00 2.22 7-8 2.52 0.00 2.09 8-9 2.72 0.03 1.98 9-10 3.45 -0.47 1.35 10-11 2.86 -0.67 1.35 11-12 3.36 -0.75 1.44 12-13 3.63 -1.00 1.70 13-14 2.75 -1.04 1.73 14-15 2.97 -0.62 1.30 15-16 3.46 -0.57 1.25 16-17 4.02 -0.67 1.35 17-18 4.03 -0.39 1.73 18-19 3.74 -0.48 2.19 19-20 3.86 -0.66 2.24 20-21 2.46 -0.33 2.31 21-22 2.40 -0.16 2.10 22-23 1.68 0.22 1.97 23-24 1.53 0.43 2.04

[0145] Based on the current pipeline parameters and flow information in the pipeline, the outlet water temperatures of the supply and return water pipe nodes of each producer and consumer in the 4G district heating system in Example 2 are shown in Table 6.

[0146] Table 6 shows the water outlet temperatures of the supply and return pipes at different times in Example 2.

[0147]

[0148] This value can provide an accurate reference for the actual operation of the heating network.

[0149] Example 3

[0150] In Example 3, the pipe and other parameters are still the same as in Example 1. The heat source and heat load data used in the four nodes of the heat network are different from those in Example 1 and Example 2. The heat source and heat load data of Example 3 are shown in Table 7.

[0151] Table 7 shows the heat source and heat load of the 4-node system of the heating network in Example 3 at 24 hours. Data Information

[0152] Time period / h Prosumer 1 Prosumer 2 Producers and consumers 3 Prosumer 4 0-1 160.78 -123.11 236.72 -274.38 1-2 160.83 -134.80 248.36 -274.38 2-3 160.86 -128.81 242.33 -274.38 3-4 160.85 -139.70 253.23 -274.38 4-5 198.87 -146.81 222.33 -274.38 5-6 285.61 -208.25 197.11 -274.47 6-7 345.26 -345.26 267.21 -267.21 7-8 386.57 -370.14 75.31 -91.74 8-9 420.97 -395.03 51.35 -77.30 9-10 467.88 -467.88 27.24 -27.24 10-11 356.36 -364.33 63.24 -55.27 11-12 447.17 -470.14 93.24 -70.27 12-13 505.72 -573.69 183.24 -115.27 13-14 353.04 -427.01 195.24 -121.27 14-15 392.25 -392.25 45.24 -45.24 15-16 468.05 -468.05 27.24 -27.24 16-17 558.43 -566.40 63.24 -55.27 17-18 604.78 -621.75 81.24 -64.27 18-19 571.27 -620.27 177.25 -128.26 19-20 607.67 -665.26 219.23 -161.63 20-21 410.27 -410.26 261.24 -261.24 21-22 375.85 -375.07 279.36 -280.13 22-23 282.26 -207.24 206.95 -281.97 23-24 224.91 -161.90 211.37 -274.38

[0153] Table 8 shows the distributed data obtained from pipeline flow based on heat source and heat load data.

[0154] Table 8 Example 3 Pipeline Flow Data Information

[0155] Time period / h <![CDATA[m 12 ]]> <![CDATA[m 23 ]]> <![CDATA[m 34 ]]> 0-1 1.09 0.26 1.87 1-2 1.09 0.18 1.87 2-3 1.09 0.22 1.87 3-4 1.09 0.14 1.87 4-5 1.35 0.35 1.87 5-6 1.94 0.53 1.87 6-7 2.35 0.00 1.82 7-8 2.63 0.11 0.62 8-9 2.86 0.18 0.53 9-10 3.18 0.00 0.19 10-11 2.42 -0.05 0.38 11-12 3.04 -0.16 0.48 12-13 3.44 -0.46 0.78 13-14 2.40 -0.50 0.82 14-15 2.67 0.00 0.31 15-16 3.18 0.00 0.19 16-17 3.80 -0.05 0.38 17-18 4.11 -0.12 0.44 18-19 3.89 -0.33 0.87 19-20 4.13 -0.39 1.10 20-21 2.79 0.00 1.78 21-22 2.56 0.01 1.91 22-23 1.92 0.51 1.92 23-24 1.53 0.43 1.87

[0156] Based on the current pipeline parameters and flow rate in the pipeline, the outlet water temperatures of the supply and return water pipe nodes of each producer and consumer in the 4G district heating system in Example 3 are as follows.

[0157] Table 9 shows the outlet water temperatures of the water supply and return pipes at different times in Example 3.

[0158]

[0159] This value can provide an accurate reference for the actual operation of the heating network.

[0160] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A distributed method for acquiring heat network power flow in a fourth-generation district heating system, characterized in that, Includes the following steps: 1) Construct a producer-consumer state model for a 4G district heating system; 2) Construct a pipeline flow model for a 4G district heating system, which includes the flow rate of the heat exchanger passing through each producer and consumer and the flow rate in the water supply pipeline; 3) Construct a pipeline water temperature change model for a 4G district heating system. The pipeline water temperature change model includes the temperature loss during heat transmission and the actual heat that the heat exchanger needs to extract or inject. 4) Construct a node temperature mixing model for the 4G district heating system. The node temperature mixing model includes the mixed water temperature of the supply pipe and the mixed water temperature of the return pipe. 5) Obtain the heat network flow of the 4G district heating system through a distributed method, wherein the distributed method is used to sequentially solve the flow rate and the node mixing temperature to obtain the heat network flow of the 4G district heating system. The distributed method for obtaining the heat network power flow involves: distributively solving the following system of linear equations. And each intelligent agent i Obtain the corresponding row based on the equations for pipe flow rate and node mixing temperature. and First, initialize according to the following formula. Neighboring producers and consumers then communicate to exchange necessary information, and the system of linear equations converges quickly to the optimal solution using the following iterative formula: In the formula: To interact with intelligent entities i The number of adjacent intelligent agents, The unknown to be solved The unknown to be solved The coefficient equation, b These are the constant terms of the system of linear equations; Defined as ,in It is the identity matrix. For matrix A The i OK; These are the constant terms of the system of linear equations; t For the number of iterations, For intelligent subjects i No. t The value of the variable to be solved in the next iteration. To interact with intelligent entities i The adjacent intelligent agents in the first t The value of the unknown to be solved in the next iteration, when If the value is less than 0.01, the linear equation system has basically converged to the optimal solution.

2. The distributed acquisition method for heat network power flow in a fourth-generation district heating system according to claim 1, characterized in that, The producer-consumer state model of the 4G district heating system in step 1) includes: Based on the given day-ahead planned trading volume, the energy that each producer-consumer is expected to inject into or absorb from the heating network is: In the formula: In order to be in t Producers and consumers at all times i Flow to producers and consumers j Calories, In order to be in t Producers and consumers at all times j Flow to producers and consumers i Calories, To connect with consumers i A set of adjacent producers and consumers; if This represents producers and consumers. i exist t Always a heat source, and vice versa This represents the producer-consumer. i exist t The time is hot load.

3. The distributed acquisition method for heat network power flow in a fourth-generation district heating system according to claim 1, characterized in that, Step 2) of constructing the pipe flow model for the 4G district heating system includes: In the 4G district heating system model, through each producer and consumer... i The flow rate of the heat exchanger is as follows: In the formula: For consumers in production i exist t The amount of water absorbed by its heat exchanger from the return water pipe when it acts as a heat source. In order to be in t Producers and consumers at all times i When used as a heat transfer fluid, it absorbs water from the water supply pipe. The specific heat capacity of water, In order to be in t At any given moment, each producer or consumer is expected to inject energy into or absorb energy from the heating network. The rated initial temperature of the water supply pipe. The rated initial temperature of the return water pipe; The flow rate in the water supply pipeline is calculated using the following formula: in Is t Water supply pipes The vector formed by the flows between them, and The relationship between the flow rate of the return water pipe and the flow rate of the supply water pipe is as follows: = , It is a vector composed of the flow of each producer-consumer heat exchanger, and the correlation matrix A is defined as: In the formula: For the relationship matrix between prosumers and consumers, For producers and consumers i Water supply pipe nodes, For producers and consumers j The return water pipe node.

4. The distributed acquisition method for heat network power flow in a fourth-generation district heating system according to claim 1, characterized in that, The temperature loss during the heat transfer process in step 3) of constructing the 4G district heating system includes: When heat travels through the water supply pipes from producers to consumers i Water supply pipe nodes Water supply to producers and consumers After the heat exchanger extracts the heat, it is then transferred from the producer to the consumer. i return water pipe node Return to consumer j return water pipe node The temperature loss during transmission is: In the formula: For ambient temperature, The roughness coefficient of the pipe. The length of the pipe, The specific heat capacity of water, In order to be in t Producers and consumers at all times i The outlet water temperature of the water supply pipe, In order to be in t Producers and consumers at all times j The outlet water temperature of the return water pipe In order to be in t Producers and consumers at all times i Water from the water supply pipe reaches consumers due to losses. j The water temperature at the water supply pipe node is similar. In order to be in t From the perspective of producers and consumers j The return water pipe outlet water reaches the consumer due to loss. j Water temperature at the return water pipe node; for t Producers and consumers at all times i Water flows to producers and consumers through water supply pipes. j The same applies to traffic. for t Producers and consumers at all times j The water flows to the producers and consumers through the return pipe. i Traffic.

5. The distributed acquisition method for heat network power flow in a fourth-generation district heating system according to claim 1, characterized in that, The heat that the heat exchanger in step 3) needs to extract or inject to construct the 4G district heating system actually includes: When producers and consumers i When it is a heat load, its heat exchanger absorbs heat from the water supply pipe. A certain amount of water, and extract from it The heat generated, therefore the water temperature injected into the return pipe is: In the formula: In order to be in t Producers and consumers at all times i The amount of water absorbed by the heat exchanger from the water supply pipe when used as a heat load In order to be in t Producers and consumers at all times i The energy expected to be injected into or absorbed from the heating network, exist t Always representing prosumers i The outlet water temperature of the water supply pipe, The rated initial temperature of the water supply pipe. The rated initial temperature of the return water pipe; When producers and consumers i When used as a heat source, its water supply pipe is in t Water temperature at all times Should be The heat exchanger absorbs heat from the return water pipe. A certain amount of water, heated, is then injected into the water supply pipe. t The actual amount of heat that the heat exchanger needs to inject is: In the formula: Representative of producers and consumers i When it acts as a heat source, the heat exchanger absorbs heat from the return water pipe. Representative of producers and consumers i The outlet water temperature of the return water pipe.

6. The distributed acquisition method for heat network power flow in a fourth-generation district heating system according to claim 1, characterized in that, Step 4) of constructing the nodal temperature hybrid model of the 4G district heating system includes: The mixed water temperature in the water supply pipe meets the following requirements: In the formula: The specific heat capacity of water, In order to be in t Producers and consumers at all times i The outlet water temperature of the water supply pipe, Representatives and Producers / Consumers i The set of producers and consumers adjacent to the water supply pipe node. Representative of producers and consumers i return water pipe node, Representative at t Flowing constantly to producers and consumers i The flow rate of the water supply pipe node, Representative at t Consumers are constantly emerging i The flow rate of the water supply pipe node, In order to be in t Time to reach consumers i Water temperature at the water supply pipe node; The mixed water temperature in the return water pipe meets the following requirements: In the formula: Representatives and Producers / Consumers i The set of producers and consumers adjacent to the return water pipe node. Representative of producers and consumers i Water supply pipe nodes, Representative at t Flowing constantly to producers and consumers i The flow rate of the return water pipe node, Representative at t Time to reach consumers i Water temperature at the return water pipe node In order to be in t Producers and consumers at all times i The outlet water temperature of the return water pipe Representative at t Flowing constantly to producers and consumers i The flow rate of the return water pipe node, Representative at t Consumers are constantly emerging i The flow rate of the water supply pipe node; Among them, the sign function Defined as when , Representative at t Water flows constantly from producers to consumers i Flow to producers and consumers j .

7. The distributed acquisition method for heat network power flow in a fourth-generation district heating system according to claim 1, characterized in that, To obtain the current heat network flow of the 4G heating district heating system, the pipeline flow rate and the node mixing temperature are both characterized by the unknowns of the node itself and its neighboring nodes. Using this feature, a distributed method is used to sequentially solve the pipeline flow rate and the node mixing temperature to obtain the current heat network flow. The converged solution includes pipeline flow information and node mixed temperature information of the 4G heat network power flow. Based on the converged solution, the pipeline flow information of each node at each time period, and the outlet water temperature of the water supply pipe and return pipe are obtained.

8. The distributed acquisition method for heat network power flow in a fourth-generation district heating system according to claim 1, characterized in that, In step 5), the distributed method described above is used to solve for the flow rate in the water supply pipeline, and the producers and consumers... i Get matrix A and The i The data in the row, that is and ; Producers and consumers i Keep a local copy ,in k This represents the number of iterations. Each producer-consumer's local copy is initialized according to the following formula: After initialization, the flow status of the heating network is obtained in a distributed manner using the following iterative formula: In the formula: Defined as , I It is the identity matrix. For the first k Sub-iteration prosumers i The value of the retained local copy, For the first k In the next iteration, when If it is small enough, the pipeline flow converges to the optimal solution.

9. A distributed acquisition method for heat network power flow in a fourth-generation district heating system according to claim 1, characterized in that, In step 5), a distributed method is used to solve for the mixing temperature of the supply and return water pipe nodes: The equation for the mixing temperature of the supply and return water pipes for each producer and consumer is obtained by solving the following formula for the mixed water temperature at each 4G heating network node: In the formula: In order to be in t The vector composed of the outlet water temperatures of the water supply and return pipes at each node at any given time, where Representative of producers and consumers n exist t The outlet water temperature at each water supply pipe node. Representative of producers and consumers n exist t The outlet water temperature of the return water pipe node at any time, matrix B To be solved The coefficient matrix, c Let the vector be composed of the constants in the equation; Producers and consumers i Get in t At any given moment, neighboring prosumers flow into prosumers. i Flow rate of water supply pipe nodes Reaching consumers i Water temperature at water supply pipe node Producers and consumers i Water outlet temperature of water supply pipe Adjacent prosumers flow into prosumers i Flow rate of return water pipe node Reaching consumers i Water temperature at return pipe node and consumers i water temperature at the return water pipe Each prosumer retains a local copy. , k Indicates the number of iterations; right Initialization is as follows: in For the consumer of this product i The known corresponding number i The coefficient of the row, and the first constant vector i OK; After initialization, the flow status of the heating network is obtained in a distributed manner using the following iterative formula: In the formula: The number of producers and consumers in a 4G district heating system. , I For the identity matrix, when When the value is less than 0.01, the water supply pipe, return pipe, and outlet water temperature converge to the optimal solution.

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