Coal chemical industry heat exchange network system optimization method and device and heat exchange network

Abstract

The invention discloses a coal chemical industry heat exchange network system optimization method and device and a heat exchange network. The method comprises the following steps: acquiring process logistics data of a coal chemical heat exchange network system; acquiring a flexible topological structure of the coal chemical heat exchange network system; according to the flexible topological structure, a coal chemical heat exchange network system model is established, model constraints of the model include mass balance constraints and energy balance constraints, and an objective function of the model is to minimize annual total cost; substituting process material data into a coal chemical heat exchange network system model, and solving an optimal heat exchanger matching mode of a flexible topological structure when an objective function is minimum under the condition that model constraints are met; and outputting the optimal heat exchanger matching mode and the annual total cost when the target function is minimized. By establishing the coal chemical industry heat exchange network system model, optimization of the flexible topological structure is achieved, and the purposes of efficient energy utilization in the heat exchange process in the coal chemical industry plant, investment cost reduction and adaptation to production fluctuation are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field related to coal chemical industry, and in particular to a method for optimizing a heat exchange network system of a coal chemical industry, electronic equipment, a storage medium, a computer program product and a heat exchange network system of a coal chemical industry. Background Art

[0002] In recent years, with the rapid development of the global economy, coal chemical industry, as an energy-intensive industry, has also faced problems such as the decline in coal resource quality, serious environmental pollution and imbalance between energy supply and demand. In the coal chemical industry, material processing and product conversion and utilization processes require a large amount of energy input and output. Therefore, improving the energy utilization efficiency of the coal chemical industry is of great significance to solving problems such as energy shortage, carbon dioxide emissions and imbalance between energy supply and demand.

[0003] In the coal chemical production process, the preheating and cooling of materials are crucial links. Some materials need to be preheated to a certain temperature before entering the reactor to ensure the smooth progress of the reaction process, while other products need to be cooled to a specific temperature before entering the storage tank to maintain their stability. A large amount of energy can be recovered by exchanging heat in the heat exchanger. If the heat exchange between logistics cannot meet the energy requirements, additional heaters or coolers need to be set at the end to achieve the energy target. The heat exchangers, heaters and coolers between these logistics constitute the heat exchange network in the coal chemical plant. However, the existing technology mainly focuses on the energy-saving optimization of the fixed-cycle heat exchange network in a single plant. In fact, the processing load in the coal chemical plant is often adjusted, and the logistics parameters usually vary within a certain range. In the face of this situation, the traditional heat exchange network design usually needs to leave a large margin to ensure that the plant can adapt to these changes and meet the temperature and pressure conditions required for heat exchange and each plant. However, this design method will greatly increase the investment cost, and at the same time make the network structure unable to adapt well to the production requirements under different working conditions, which is not conducive to improving the competitiveness of the coal chemical industry and the sustainable development of the entire society. Summary of the invention

[0004] Based on this, it is necessary to provide a coal chemical heat exchange network system optimization method, electronic equipment, storage medium, computer program product and coal chemical heat exchange network system to address the technical problem that the heat exchange network structure of the coal chemical heat exchange network system in the prior art cannot be changed in real time.

[0005] The present invention provides a method for optimizing a coal chemical heat exchange network system, comprising:

[0006] Acquire process logistics data of the coal chemical heat exchange network system, wherein the process materials flow and exchange heat through process logistics pipelines between plants and / or within plants;

[0007] Acquire a flexible topology structure of the coal chemical heat exchange network system, wherein the flexible topology structure at least includes a plurality of factories, a pipeline connection topology of a plurality of process streams in the factories, and a heat exchanger, a cooler and / or a heater between the process streams, wherein the heat exchanger, the cooler and / or the heater can be switched between different process streams;

[0008] According to the flexible topology structure, a coal chemical heat exchange network system model is established, wherein the model constraints of the model include: mass balance constraint and energy balance constraint, and the objective function of the model is an annual total cost calculation function;

[0009] Substituting the process material data into the coal chemical heat exchange network system model, and solving the optimal heat exchanger matching mode of the flexible topology structure when the objective function is minimized under the constraints of the model, the heat exchanger matching mode is the heat exchanger, cooler and / or heater connected to each process flow in each cycle;

[0010] The optimal heat exchanger matching method and the annual total cost when the objective function is minimized are output.

[0011] Furthermore, the coal chemical heat exchange network system model is established according to the flexible topological structure, including:

[0012] According to the flexible topological structure, a coal chemical heat exchange network system model is established, which includes a first sub-model and a second sub-model. The first sub-model includes inter-plant model constraints and inter-plant objective functions, and the second sub-model includes intra-plant model constraints and intra-plant objective functions.

[0013] Furthermore, the inter-plant model constraints include:

[0014]

[0015] th p,i,1 -(1-yh p,i ) · thout p,i =yh p,i ·thin p,i p∈PN,i∈HN;

[0016] tc p,j,K -(1-yc p,j )·tcout p,j =yc p,j tcin p,j p∈PN,j∈CN;

[0017]

[0018] th p,i,K ≥thout p,ip∈PN,i∈HN;

[0019] tcout p,j ≥tc p,j,1 p∈PN,j∈CN;

[0020] th p,i,k ≥th p,i,k+1 p∈PN,i∈HN,k∈ST;

[0021] tc p,j,k ≥tc p,j,k+1 p∈PN,j∈CN,k∈ST;

[0022]

[0023] q p,i -ech p,i ·zcu p,i ≤0 p∈PN,i∈HN;

[0024] q p,j -ecc p,j ·zhu p,j ≤0 p∈PN,j∈CN;

[0025]

[0027] Dout = 1.101·Din + 0.006349;

[0028] Wt=1330·Din 2 +75.18·Din+0.9268;

[0029] Pcul=A1·Wt+A2·Dout 0.48 +A3+A4·Dout;

[0030] Lmcost=L·Pcul;

[0031] Among them, yh p,i Indicates whether the hot process stream i is heat exchanged in plant p, yc p,j Indicates whether the cold process stream j is heat exchanged in plant p, thin p,i is the initial temperature of the hot process stream i in plant p, thout p,i is the target temperature of hot process stream i in plant p, tcin p,j is the initial temperature of the cold process stream j in plant p, tcout p,j is the target temperature of the cold process stream j in plant p, Fc p,jis the heat capacity flow rate of cold process stream j, Fh p,i is the heat capacity flow rate of hot process stream i in plant p, q p,i,j,k is the heat load of the heat exchanger exchanging heat between hot process stream i and cold process stream j in the kth stage of the superstructure of plant p, qcu p,i is the heat load of the cooler cooling the hot process stream i in plant p, qhu p,j is the heat load of the heater in plant p for adding cold stream process stream j, th p,i,1 is the temperature of the hot process stream i when it enters the superstructure of plant p, tc p,j,1 is the temperature of the cold stream process stream j when it leaves the superstructure of plant p, th p,i,K is the temperature of the hot process stream i when it leaves the superstructure of plant p, tc p,j,K is the temperature of the cold stream process stream j when it enters the superstructure of plant p, th p,i,k is the left temperature of the hot process stream i at the kth stage of the superstructure of plant p, th p,i,k+1 It is both the left temperature of the hot process stream i at the k+1th level of the superstructure of plant p and the right temperature of the hot process stream i at the kth level of the superstructure of plant p, tc p,j,k is the left temperature of the cold process stream j at the kth stage of plant p, tc p,j,k+1 It is both the left temperature of the cold process flow j at the k+1th level of the superstructure of the plant p and the right temperature of the kth level of the superstructure of the cold process flow j at the plant p, zp p,i,j,k Indicates whether the hot process stream i and the cold process stream j are heat exchanged in the kth stage of the superstructure of plant p, zcup p,i Indicates whether the hot process stream i of plant p uses cold utility heat exchange, zhup p,j Indicates whether the cold process stream j of plant p uses the heat utility for heat exchange, ech p,i is the upper bound of the heat load for heat exchange of hot process stream i in plant p, ecc p,j is the maximum heat load of the cold process stream j of plant p, Γ p,i,j is the upper bound of the heat transfer temperature difference between the hot process stream i and the cold process stream j of plant p, Γhu p,j is the upper bound of the heat transfer temperature difference of the cold process stream j in plant p, Γcu p,i is the upper bound of the heat transfer temperature difference of the hot process stream i in plant p, dt p,i,j,k is the heat transfer temperature difference of the heat exchanger connecting hot process stream i and cold process stream j at the kth stage of plant p, dthu p,j is the heat transfer temperature difference of the heater connecting the cold process stream j and the hot utility in plant p, dtcu p,iis the heat transfer temperature difference of the cooler connecting the hot process stream i and the cold utility in plant p, Tcuin i is the initial temperature of the cold utility for cooling the hot process stream i, Thuin j is the initial temperature of the heat utility for heating the cold process stream j, Tcuout i The outlet temperature of the cold utility that cools the hot process stream i, Thuout j is the outlet temperature of the heat utility for heating the cold process stream j, A p,i,j,k is the heat exchange area of ​​the heat exchanger connecting the hot process stream i and the cold process stream j of plant p, h p,i is the heat transfer coefficient of the hot process stream i of plant p, h p,j is the heat transfer coefficient of the cold process stream j in plant p, Ahu p,j is the heat exchange area of ​​the cooler connecting the cold process stream j of plant p, hhu j is the heat transfer coefficient of the heat utility exchanging heat with the cold process stream j, hcu i is the heat transfer coefficient of the cold utility exchanging heat with the hot process stream i, Acu p,i is the heat exchange area of ​​the heater connecting the hot process stream i of plant p, M is the flow rate of the stream in the pipeline, ρ is the density of the stream in the pipeline, Din is the inner diameter of the pipeline, Dout is the outer diameter of the pipeline, Wt is the weight of the pipeline per unit length, Pcul is the investment cost per unit length, L is the distance between plants, Lmcost is the pipeline cost of the process stream, A1 is the first given parameter for calculating the pipeline investment cost, A2 is the second given parameter for calculating the pipeline investment cost, A3 is the third given parameter for calculating the pipeline investment cost, A4 is the fourth given parameter for calculating the pipeline investment cost, PRN is the set of heat exchange cycles, PN is the set of plants, HN is the set of hot process streams, CN is the set of cold process streams, KN ​​is the set of heat exchange stages, SN is the set of heat exchangers, and ST is a subset of KN.

[0032] Furthermore, the inter-factory objective function includes:

[0033] The total annual cost between factories is calculated as:

[0034]

[0035] Where hucost is the cost coefficient of the heat utility project, cucost is the cost coefficient of the cold utility project, Af is the annualization factor of the investment cost, α is the first calculation factor of the heat exchanger cost, β is the second calculation factor of the heat exchanger cost, γ is the third calculation factor of the heat exchanger cost, Lmcosth p,i is the pipeline cost of hot process stream i in plant p, Lmcostc p,jis the pipeline cost of cold process stream j in plant p.

[0036] Furthermore, the in-plant model constraints include:

[0037]

[0038]

[0039] F i,pr (th i,K,pr -thout i,pr )=qcu i,pr i∈HN,pr∈PRN;Fc j,pr (tcout j,pr -tc j,1,pr )=qhu j,pr j∈CN,pr∈PRN;th i,k,pr ≥th i,k+1,pr i∈HN,k∈ST,pr∈PRN;

[0040] tc j,k,pr ≥tc j,k+1,pr j∈CN, k∈KN, pr∈PRN;

[0041] th i,K,pr ≥thout i,pr i∈HN,pr∈PRN;

[0042] tcout j,pr ≥tc j,1,pr j∈CN,pr∈PRN;

[0043] thin i,pr =th i,1,pr i∈HN,pr∈PRN;

[0044] tcin j,pr =tc j,K,pr j∈CN,pr∈PRN;

[0045]

[0046] q i,pr -ech i,pr zcup i,pr ≤0 i∈HN,pr∈PRN;

[0047] q j,pr -ecc j,pr zhup j,pr ≤0 j∈CN,pr∈PRN;

[0048]

[0049] dt i,j,k,pr ≥ΔTmin i∈HN,j∈CN,k∈KN,pr∈PRN;

[0050] dthu j,pr ≥ΔTmin j∈CN,pr∈PRN;

[0051] dtcu i,pr ≥ΔTmin i∈HN,pr∈PRN;

[0052]

[0053] As s ≤zas s AsMax s∈SN;

[0054]

[0055] As s ≤As s+1 s∈SN;

[0056] Among them, thin i,pr is the initial temperature of the hot process stream i in period pr, thout i,pr is the target temperature of the hot process stream i in period pr, tcin j,pr is the initial temperature of the cold process stream j at the cycle, tcout j,pr is the target temperature of the cold process stream j cycle, parameter Fc j,pr is the heat capacity flow rate of the cooling process stream j in period pr, Fh i,pr is the heat capacity flow rate of hot process stream i in period pr, q i,j,k,pr is the heat load of the heat exchange between hot process stream i and cold process stream j in the kth stage in the cycle pr, qcu i,pr is the utility load of the cooler for the hot process stream i in cycle pr, qhu j,pr is the utility load of the heater for the process stream j in the cycle pr, th i,k,pr is the temperature of the hot process stream i at the left side of the kth stage in the cycle pr, th i,k+1,pr It is the left temperature of hot process stream i at stage k+1 in cycle pr and the right temperature of stage k, tc j,k,pr is the left temperature of the cooling process stream j at the kth stage in the cycle pr, tc j,k+1,pr It is the left temperature of the cooling process stream j at the k+1th stage in the period pr and the right temperature of the kth stage. i,K,pr is the temperature of hot process stream i when it leaves the superstructure in period pr, th i,1,pris the temperature of hot process stream i when it enters the superstructure in period pr, tc j,K,pr is the temperature of the cooling process stream j when it enters the superstructure in period pr, tc j,1,pr is the temperature of the cooling process stream j when it leaves the superstructure in period pr, ech i,pr is the upper bound of the heat load for heat exchange of hot process stream i in period pr, ecc j,pr is the maximum heat load of the process flow j in the cycle pr, zp i,j, k ,pr Indicates whether heat exchange between hot process stream i and cold process stream j in the kth stage exists in the cycle pr, zcup i,pr Indicates whether heat exchange of hot process stream i exists in period pr, zhup j,pr Indicates whether heat exchange of cooling process stream j exists in period pr, Γ i,j,pr is the upper bound of the heat transfer temperature difference between the hot process stream i and the cold process stream j in period pr, Γhu j,pr is the upper bound of the heat transfer temperature difference of the cooling process stream j in the period pr, Γcu i,pr is the upper bound of the heat transfer temperature difference of hot process stream i in period pr, dt i,j,k,pr is the heat transfer temperature difference between the hot process stream i and the cold process stream j in the k-th stage heat exchanger in cycle pr, dthu j,pr is the heat transfer temperature difference of the heater connecting the cold process stream j and the hot utility in cycle pr, dtcu i,pr is the heat transfer temperature difference of the cooler connecting the hot process stream i and the cold utility in the period pr, ΔTmin is the minimum heat transfer temperature difference, Tcuout is the outlet temperature of the cold utility, Thuout is the outlet temperature of the hot utility, PRN is the set of heat exchange cycles, PN is the set of plants, HN is the set of hot process streams, CN is the set of cold process streams, KN ​​is the set of heat exchange stages, SN is the set of heat exchangers, ST is the sub-set of KN, and zps i,j,k,pr,s Indicates whether heat exchanger s is used for heat exchange between hot process stream i and cold process stream j in the kth stage of the superstructure in period pr, zhups j,pr,s Indicates whether the process flow j in the cycle pr is heated by the heater using the heat exchanger s, zcups i,pr,s Indicates whether heat exchanger s is used to cool the hot process stream i in cycle pr, As s is the heat transfer area of ​​heat exchanger s, zas s Indicates whether there is a heat exchanger s, AsMax is the maximum value of the heat exchange area, A i,j,k,pr Ahu is the heat exchange area of ​​the heat exchanger required for the heat exchange between the hot process stream i and the cold process stream j in the kth stage of the superstructure in the cycle pr, j,pris the heat exchange area of ​​the heater required for the process stream j to be heated by the heat utility in the cycle pr, Acu i,pr is the heat exchange area of ​​the cooler required for the hot process stream i to be cooled by the cold utility in the cycle pr, h i,pr is the heat transfer coefficient of hot process stream i in period pr, h j,pr is the heat transfer coefficient of the cold process stream j in period pr, hhu j is the heat transfer coefficient of the heat utility exchanging heat with the cold process stream j, hcu i is the heat transfer coefficient of the cold utility exchanging heat with the hot process stream i, Tcuin i is the initial temperature of the cold utility for cooling the hot process stream i, Thuin j is the initial temperature of the heat utility used to heat the cold process stream j.

[0057] Furthermore, the in-plant objective function includes:

[0058] The total annual cost of the factory is calculated as:

[0059]

[0060] Among them, Time pr is the cycle fraction, hucost is the cost coefficient of heat utilities, cucost is the cost coefficient of cold utilities, Af is the annualization factor of investment cost, α is the first calculation factor of heat exchanger cost, β is the second calculation factor of heat exchanger cost, and γ is the third calculation factor of heat exchanger cost.

[0061] The present invention provides an electronic device, comprising:

[0062] at least one processor; and,

[0063] a memory communicatively connected to at least one of the processors; wherein,

[0064] The memory stores instructions that can be executed by at least one of the processors, and the instructions are executed by at least one of the processors so that at least one of the processors can execute the coal chemical heat exchange network system optimization method as described above.

[0065] The present invention provides a storage medium, which stores computer instructions. When a computer executes the computer instructions, it is used to execute all the steps of the coal chemical heat exchange network system optimization method as described above.

[0066] The present invention provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the above-mentioned method for optimizing a coal chemical heat exchange network system.

[0067] The present invention provides a coal chemical heat exchange network system, comprising a plurality of factories, a plurality of process flow pipelines connected to the factories, heat exchangers, coolers and / or heaters. In each cycle, the heat exchangers, coolers and / or heaters are connected to the process flow pipelines indicated by the optimal heat exchanger matching method output by the coal chemical heat exchange network system optimization method as described above.

[0068] The present invention optimizes the flexible topology structure by establishing a coal chemical heat exchange network system model. By designing a flexible topology network and combining the characteristics of the coal chemical process, the goals of efficient energy utilization, reduced investment costs and adapting to production fluctuations in the heat exchange process in the coal chemical plant are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 This is a working flow chart of a method for optimizing a coal chemical heat exchange network system according to an embodiment of the present invention;

[0070] Figure 2 This is a work flow chart of a method for optimizing a coal chemical heat exchange network system according to another embodiment of the present invention;

[0071] Figure 3 This is a schematic diagram of the inter-plant heat exchange network structure of an example of the present invention;

[0072] Figure 4 This is a schematic diagram of a multi-cycle heat exchange network structure in a first plant according to an example of the present invention;

[0073] Figure 5 This is a schematic diagram of a multi-cycle heat exchange network structure in a second plant according to an example of the present invention;

[0074] Figure 6 This is a schematic diagram of a multi-cycle heat exchange network structure in the third plant according to an example of the present invention;

[0075] Figure 7 A stage-wise superstructure model of an example of the present invention;

[0076] Figure 8 The results obtained by optimizing the method proposed in the present invention and a comparative schematic diagram;

[0077] Fig. 9 The figure is a schematic diagram of the hardware structure of an electronic device of the present invention. DETAILED DESCRIPTION

[0078] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. The same components are represented by the same reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0079] like Figure 1 The figure shows a working flow chart of a method for optimizing a coal chemical heat exchange network system according to an embodiment of the present invention, comprising:

[0080] Step S101, obtaining process logistics data of a coal chemical heat exchange network system, wherein the process materials flow and exchange heat through process logistics pipelines between plants and / or within plants;

[0081] Step S102, obtaining a flexible topology structure of the coal chemical heat exchange network system, wherein the flexible topology structure at least includes a plurality of factories, a pipeline connection topology of a plurality of process streams in the factory, and a heat exchanger, a cooler and / or a heater between the process streams, wherein the heat exchanger, the cooler and / or the heater can be switched between different process streams;

[0082] Step S103, establishing a coal chemical heat exchange network system model according to the flexible topology structure, wherein the model constraints of the model include: mass balance constraints and energy balance constraints, and the objective function of the model is an annual total cost calculation function;

[0083] Step S104, substituting the process material data into the coal chemical heat exchange network system model, and solving the optimal heat exchanger matching mode of the flexible topology structure when the objective function is minimized under the constraints of the model, wherein the heat exchanger matching mode is the heat exchanger, cooler and / or heater connected to each process stream in each cycle;

[0084] Step S105, outputting the optimal heat exchanger matching method and the annual total cost when minimizing the objective function.

[0085] Specifically, the present invention can be applied to electronic devices having processing capabilities.

[0086] First, step S101 is executed to obtain process logistics data of the coal chemical heat exchange network system, wherein the process materials flow and exchange heat through process logistics pipelines between plants and / or within plants.

[0087] Specifically, according to the factories included in the coal chemical heat exchange network system, periodically changing process logistics parameters are collected, and the periodically changing process logistics parameters include: inlet temperature, outlet temperature, heat capacity flow rate, heat transfer coefficient, density and viscosity of the process logistics.

[0088] Among them, process logistics refers to cold logistics that need to be exchanged (such as crude oil that needs to be heated) and hot logistics (such as atmospheric side line oil that needs to be cooled), and utilities refer to the heat and cold provided by the factory. Commonly used cold utilities are water, and hot utilities are steam, thermal oil, etc.

[0089] like Figure 3 The figure shows the inter-plant heat exchange network structure of an example of the present invention. Figure 3 The results solved by the first model, i.e., the flow direction of process streams in each factory, are shown. As can be seen from the figure, in the three cycles, the cold process stream C4 in factory 2 and the cold process stream C6 in factory 3 went to factory 1 for heat exchange, and the remaining hot process streams H1, H2, H3, H4, H5, H6 and the cold process streams C1, C2, C3, C5 were all heat exchanged in the original factories.

[0090] Then, execute step S102 to obtain the flexible topology structure of the coal chemical heat exchange network system, wherein the flexible topology structure includes at least multiple factories, pipeline connection topologies of multiple process streams within the factory, and heat exchangers, coolers and / or heaters between process streams, and the heat exchangers, coolers and / or heaters can switch connections between different process streams.

[0091] Specifically, according to the data properties and optimization goals, a flexible topology network of the heat exchange system is designed. The equipment composition of the network includes: devices that complete coal chemical functions, inter-plant process logistics transportation pipelines, heat exchangers between process logistics, coolers, heaters and their network configurations. In the flexible topology network, all heat exchangers are designed as heat exchangers. When the process conditions change, the paths of some process logistics are switched to exchange heat with other process logistics to complete the heat exchange task. The heat exchange network designed in this way can not only reduce investment costs, but also adapt to production fluctuations to a certain extent.

[0092] In the flexible heat exchange network structure, the path of the process logistics will change in different cycles. The coal chemical heat exchange network system optimization method of this embodiment is used for optimization to determine the pipelines of the process logistics connected to the heat exchanger, cooler and / or heater in different cycles.

[0093] like Figures 4 to 6 Shown is the multi-cycle heat exchange network structure of the present invention in different plants. Figures 4 to 6 The results of the second model are shown, namely the multi-cycle flexible heat exchange network structure diagrams of the three plants. Among them, the heat exchange network of Plant 1 has 2 hot process streams and 4 cold process streams, requiring 6 heat exchangers; the heat exchange network of Plant 2 has 2 hot process streams and 1 cold process stream, requiring 4 heat exchangers; the heat exchange network of Plant 3 has 2 hot process streams and 1 cold process stream, requiring 3 heat exchangers. Each heat exchange match corresponds to a heat exchanger allocation containing three cycles. Among them, S1-S6 represent the numbers of the heat exchangers used, and the values ​​thereafter represent the corresponding heat exchange energy load. Among them, the process streams are also connected to multiple devices, including but not limited to: atmospheric and vacuum units, catalytic cracking units, wax oil hydrogenation units, etc.

[0094] Then, step S103 is executed to establish a coal chemical heat exchange network system model according to the flexible topology structure. The model constraints of the model include: mass balance constraints and energy balance constraints. The objective function of the model is an annual total cost calculation function.

[0095] Specifically, according to the flexible topology, a coal chemical heat exchange network system model is designed. The model includes two sub-models. The first sub-model solves the heat exchange plant to which each process stream goes in each cycle, and then uses this as the input of the second model to optimize the multi-cycle heat exchange network. The model constraints include: mass balance, energy balance, and the model objective function is to minimize the total annual cost. The total annual cost (Total Annual Cost, TAC) includes: the investment cost of the heat exchanger, cooler, heater, and inter-plant process stream transportation pipeline between the process streams, and the operating cost of the cooler and heater.

[0096] After the model is constructed, step S104 is executed to substitute the process material data into the coal chemical heat exchange network system model, and to solve the optimal heat exchanger matching mode of the flexible topology structure when the objective function is minimized under the constraints of the model. The heat exchanger matching mode is the heat exchanger, cooler and / or heater connected to each process flow in each cycle;

[0097] Specifically, the initial conditions of the data preset model are determined, wherein the continuous variables of the model include: the temperature of the logistics at each level in the superstructure, the heat load of the heat exchanger, cooler and heater, the heat transfer temperature difference of the heat exchanger, cooler and heater, the heat exchange area of ​​the heat exchanger, cooler and heater, and the heat exchange area of ​​the heat exchanger; the binary variables of the model include: the existence of process logistics heat exchanger, the existence of cooler, the existence of heater, the existence of heat exchanger, inter-plant logistics distribution, and the matching of heat exchanger and heat exchange.

[0098] Among them, the superstructure is a mathematical model of a heat exchange network. Figure 7 Shown is a schematic diagram of a stage-wise superstructure model in an example of the present invention.

[0099] Then, the solution is continued according to the results obtained under the preset conditions to find the optimal network structure of the flexible topology network.

[0100] Finally, step S105 is executed to output the optimal heat exchanger matching method and the annual total cost when the objective function is minimized.

[0101] Specifically, the heat exchanger matching method is the heat exchanger, cooler and / or heater connected to each process stream in each cycle, which can be achieved by, zp i,j,k,pr 、zcup i,pr、zhup j,pr Indicates. Among them, zp i,j,k,pr Indicates whether heat exchange between hot process stream i and cold process stream j in the kth stage exists in the cycle pr, zcup i,pr Indicates whether heat exchange of hot process stream i exists in period pr, zhup j,pr Indicates whether heat exchange of cold process stream j exists in period pr.

[0102] The output results may specifically include: the investment cost and utility operation cost of the coal chemical heat exchange network system, the area and heat load of each heat exchanger in the flexible topology network, and the impact of the flexible network on the system layout and economy.

[0103] The present invention optimizes the flexible topology structure by establishing a coal chemical heat exchange network system model. By designing a flexible topology network and combining the characteristics of the coal chemical process, the goals of efficient energy utilization, reduced investment costs and adapting to production fluctuations in the heat exchange process in the coal chemical plant are achieved.

[0104] like Figure 2 The figure shows a working flow chart of a method for optimizing a coal chemical heat exchange network system in another embodiment of the present invention, comprising:

[0105] Step S201, obtaining process logistics data of a coal chemical heat exchange network system, wherein the process materials flow and exchange heat through process logistics pipelines between plants and / or within plants.

[0106] Step S202, obtaining the flexible topology structure of the coal chemical heat exchange network system, wherein the flexible topology structure includes at least multiple factories, pipeline connection topologies of multiple process streams within the factories, and heat exchangers, coolers and / or heaters between process streams, and the heat exchangers, coolers and / or heaters can switch connections between different process streams.

[0107] Step S203, based on the flexible topology structure, establish a coal chemical heat exchange network system model including a first sub-model and a second sub-model, wherein the first sub-model includes inter-plant model constraints and inter-plant objective functions, and the second sub-model includes intra-plant model constraints and intra-plant objective functions.

[0108] In one embodiment, the inter-factory model constraints include:

[0109]

[0110] th p,i,1 -(1-yh p,i ) · thout p,i =yh p,i ·thin p,i p∈PN,i∈HN;

[0111] tc p,j,K -(1 - yc p,j )·tcout p,j =yc p,j ·tcin p,j p ∈ PN, j ∈ CN;

[0112]

[0113] th p,i,K ≥ thout p,i p ∈ PN, i ∈ HN;

[0114] tcout p,j ≥ tc p,j,1 p ∈ PN, j ∈ CN;

[0115] th p,i,k ≥ th p,i,k+1 p ∈ PN, i ∈ HN, k ∈ ST;

[0116] tc p,j,k ≥ tc p,j,k+1 p ∈ PN, j ∈ CN, k ∈ ST;

[0117]

[0118] qcu p,i - ech p,i ·zcu p,i ≤ 0 p ∈ PN, i ∈ HN;

[0119] qhu p,j - ecc p,j ·zhu p,j ≤ 0 p ∈ PN, j ∈ CN;

[0120]

[0121]

[0122] Dout = 1.101·Din + 0.006349;

[0123] Wt = 1330·Din 2 + 75.18·Din + 0.9268;

[0124] Pcul = A1·Wt + A2·Dout 0.48 + A3 + A4·Dout;

[0125] Lmcost = L·Pcul;

[0126] where, yhp,i Indicates whether the hot process stream i is heat exchanged in plant p, yc p,j Indicates whether the cold process stream j is heat exchanged in plant p, thin p,i is the initial temperature of the hot process stream i in plant p, thout p,i is the target temperature of hot process stream i in plant p, tcin p,j is the initial temperature of the cold process stream j in plant p, tcout p,j is the target temperature of the cold process stream j in plant p, Fc p,j is the heat capacity flow rate of cold process stream j, Fh p,i is the heat capacity flow rate of hot process stream i in plant p, q p,i,j,k is the heat load of the heat exchanger exchanging heat between hot process stream i and cold process stream j in the kth stage of the superstructure of plant p, qcu p,i is the heat load of the cooler cooling the hot process stream i in plant p, qhu p,j is the heat load of the heater in plant p that adds cold stream process stream j, th p,i,1 is the temperature of the hot process stream i when it enters the superstructure of plant p, tc p,j,1 is the temperature of the cold stream process stream j when it leaves the superstructure of plant p, th p,i,K is the temperature of the hot process stream i when it leaves the superstructure of plant p, tc p,j,K is the temperature of the cold stream process stream j when it enters the superstructure of plant p, th p,i,k is the left temperature of the hot process stream i at the kth stage of the superstructure of plant p, th p,i,k+1 It is both the left temperature of the hot process stream i at the k+1th level of the superstructure of plant p and the right temperature of the hot process stream i at the kth level of the superstructure of plant p, tc p,j,k is the left temperature of the cold process stream j at the kth stage of plant p, tc p,j,k+1 It is both the left temperature of the cold process flow j at the k+1th level of the superstructure of the plant p and the right temperature of the kth level of the superstructure of the cold process flow j at the plant p, zp p,i,j,k Indicates whether the hot process stream i and the cold process stream j are heat exchanged in the kth stage of the superstructure of plant p, zcup p,i Indicates whether the hot process stream i of plant p uses cold utility heat exchange, zhup p,j Indicates whether the cold process stream j of plant p uses the heat utility for heat exchange, ech p,i is the upper bound of the heat load for heat exchange of hot process stream i in plant p, ecc p,j is the maximum heat load of the cold process stream j of plant p, Γ p,i,jis the upper bound of the heat transfer temperature difference between the hot process stream i and the cold process stream j of plant p, Γhu p,j is the upper bound of the heat transfer temperature difference of the cold process stream j in plant p, Γcu p,i is the upper bound of the heat transfer temperature difference of the hot process stream i in plant p, dt p,i,j,k is the heat transfer temperature difference of the heat exchanger connecting hot process stream i and cold process stream j at the kth stage of plant p, dthu p,j is the heat transfer temperature difference of the heater connecting the cold process stream j and the hot utility in plant p, dtcu p,i is the heat transfer temperature difference of the cooler connecting the hot process stream i and the cold utility in plant p, Tcuin i Initial temperature of the cold utility for cooling the hot process stream i, Thuin j is the initial temperature of the heat utility for heating the cold process stream j, Tcuout i is the outlet temperature of the cold utility for cooling the hot process stream i, Thuout j is the outlet temperature of the heat utility for heating the cold process stream j, A p,i,j,k is the heat exchange area of ​​the heat exchanger connecting the hot process stream i and the cold process stream j of plant p, h p,i is the heat transfer coefficient of the hot process stream i in plant p, h p,j is the heat transfer coefficient of the cold process stream j in plant p, Ahu p,j is the heat exchange area of ​​the cooler connecting the cold process stream j of plant p, hhu j is the heat transfer coefficient of the heat utility exchanging heat with the cold process stream j, hcu i is the heat transfer coefficient of the cold utility exchanging heat with the hot process stream i, Acu p,i is the heat exchange area of ​​the heater connecting the hot process stream i of plant p, M is the flow rate of the stream in the pipeline, ρ is the density of the stream in the pipeline, Din is the inner diameter of the pipeline, Dout is the outer diameter of the pipeline, Wt is the weight of the pipeline per unit length, Pcul is the investment cost per unit length, L is the distance between plants, Lmcost is the pipeline cost of the process stream, A1 is the first given parameter for calculating the pipeline investment cost, A2 is the second given parameter for calculating the pipeline investment cost, A3 is the third given parameter for calculating the pipeline investment cost, A4 is the fourth given parameter for calculating the pipeline investment cost, PRN is the set of heat exchange cycles, PN is the set of plants, HN is the set of hot process streams, CN is the set of cold process streams, KN ​​is the set of heat exchange stages, SN is the set of heat exchangers, and ST is a subset of KN.

[0127] In one embodiment, the inter-factory objective function includes:

[0128] The total annual cost between factories is calculated as:

[0129]

[0130] Where hucost is the cost coefficient of the heat utility project, cucost is the cost coefficient of the cold utility project, Af is the annualization factor of the investment cost, α is the first calculation factor of the heat exchanger cost, β is the second calculation factor of the heat exchanger cost, γ is the third calculation factor of the heat exchanger cost, Lmcosth p,i is the pipeline cost of hot process stream i in plant p, Lmcostc p,j is the piping cost of cold process stream j at plant p.

[0131] In one embodiment, the in-plant model constraints include:

[0132]

[0133] F i,pr (th i,K,pr -thout i,pr )=qcu i,pr i∈HN,pr∈PRN;Fc j,pr (tcout j,pr -tc j,1,pr )=qhu j,pr j∈CN,pr∈PRN;th i,k,pr ≥th i,k+1,pr i∈HN,k∈ST,pr∈PRN;

[0134] tc j,k,pr ≥tc j,k+1,pr j∈CN, k∈KN, pr∈PRN;

[0135] th i,K,pr ≥thout i,pr i∈HN,pr∈PRN;

[0136] tcout j,pr ≥tc j,1,pr j∈CN,pr∈PRN;

[0137] thin i,pr =th i,1,pr i∈HN,pr∈PRN;

[0138] tcin j,pr =tc j,K,pr j∈CN,pr∈PRN;

[0139]

[0140] q i,pr-ech i,pr zcup i,pr ≤0 i∈HN,pr∈PRN;

[0141] q j,pr -ecc j,pr zhup j,pr ≤0 j∈CN,pr∈PRN;

[0142]

[0143] dt i,j,k,pr ≥ΔTmin i∈HN,j∈CN,k∈KN,pr∈PRN;dthu j,pr ≥ΔTmin j∈CN,pr∈PRN;

[0144] dtcu i,pr ≥ΔTmin i∈HN,pr∈PRN;

[0145]

[0146]

[0147] As s ≤zas s AsMax s∈SN;

[0148]

[0149] As s ≤As s+1 s∈SN;

[0150] Among them, thin i,pr is the initial temperature of the hot process stream i in period pr, thout i,pr is the target temperature of the hot process stream i in period pr, tcin j,pr is the initial temperature of the cold process stream j at the cycle, tcout j,pr is the target temperature of the cold process stream j cycle, parameter Fc j,pr is the heat capacity flow rate of the cooling process stream j in period pr, Fh i,pr is the heat capacity flow rate of hot process stream i in period pr, q i,j,k,pr is the heat load of the heat exchange between hot process stream i and cold process stream j in the kth stage in the cycle pr, qcu i,pr is the utility load of the cooler for the hot process stream i in cycle pr, qhu j,pr is the utility load of the heater for the process stream j in the cycle pr, th i,k,pr is the temperature of the hot process stream i at the left side of the kth stage in the cycle pr, thi,k+1,pr It is the left temperature of hot process stream i at stage k+1 in cycle pr and the right temperature of stage k, tc j,k,pr is the left temperature of the cooling process stream j at the kth stage in the cycle pr, tc j,k+1,pr It is the left temperature of the cooling process stream j at the k+1th stage in the period pr and the right temperature of the kth stage. i,K,pr is the temperature of hot process stream i when it leaves the superstructure in period pr, th i,1,pr is the temperature of hot process stream i when it enters the superstructure in period pr, tc j,K,pr is the temperature of the cooling process stream j when it enters the superstructure in period pr, tc j,1,pr is the temperature of the cooling process stream j when it leaves the superstructure in period pr, ech i,pr is the upper bound of the heat load for heat exchange of hot process stream i in period pr, ecc j,pr is the maximum heat load of the process flow j in the cycle pr, zp i,j,k,pr Indicates whether heat exchange between hot process stream i and cold process stream j in the kth stage exists in the cycle pr, zcup i,pr Indicates whether heat exchange of hot process stream i exists in period pr, zhup j,pr Indicates whether heat exchange of cooling process stream j exists in period pr, Γ i,j,pr is the upper bound of the heat transfer temperature difference between the hot process stream i and the cold process stream j in period pr, Γhu j,pr is the upper bound of the heat transfer temperature difference of the cooling process stream j in the period pr, Γcu i,pr is the upper bound of the heat transfer temperature difference of hot process stream i in period pr, dt i,j,k,pr is the heat transfer temperature difference between the hot process stream i and the cold process stream j in the k-th stage heat exchanger in cycle pr, dthu j,pr is the heat transfer temperature difference of the heater connecting the cold process stream j and the hot utility in cycle pr, dtcu i,pr is the heat transfer temperature difference of the cooler connecting the hot process stream i and the cold utility in the period pr, ΔTmin is the minimum heat transfer temperature difference, Tcuout is the outlet temperature of the cold utility, Thuout is the outlet temperature of the hot utility, PRN is the set of heat exchange cycles, PN is the set of plants, HN is the set of hot process streams, CN is the set of cold process streams, KN ​​is the set of heat exchange stages, SN is the set of heat exchangers, ST is the sub-set of KN, and zps i,j,k,pr,s Indicates whether heat exchanger s is used for heat exchange between hot process stream i and cold process stream j in the kth stage of the superstructure in cycle pr, zhups j,pr,s Indicates whether the process flow j in the cycle pr is heated by the heater using the heat exchanger s, zcups i,pr,sIndicates whether heat exchanger s is used to cool the hot process stream i in cycle pr, As s is the heat transfer area of ​​heat exchanger s, zas s Indicates whether there is a heat exchanger s, AsMax is the maximum value of the heat exchange area, A i,j,k,pr Ahu is the heat exchange area of ​​the heat exchanger required for the heat exchange between the hot process stream i and the cold process stream j in the kth stage of the superstructure in period pr, j,pr is the heat exchange area of ​​the heater required for the process stream j to be heated by the heat utility in the cycle pr, Acu i,pr is the heat exchange area of ​​the cooler required for the hot process stream i to be cooled by the cold utility in the cycle pr, h i,pr is the heat transfer coefficient of hot process stream i in period pr, h j,pr is the heat transfer coefficient of the cold process stream j in period pr, hhu j is the heat transfer coefficient of the heat utility exchanging heat with the cold process stream j, hcu i is the heat transfer coefficient of the cold utility exchanging heat with the hot process stream i, Tcuin i is the initial temperature of the cold utility for cooling the hot process stream i, Thuin j is the initial temperature of the heat utility used to heat the cold process stream j.

[0151] In one embodiment, the in-plant objective function includes:

[0152] The total annual cost of the factory is calculated as:

[0153]

[0154] Among them, Time pr is the cycle fraction, hucost is the cost coefficient of heat utilities, cucost is the cost coefficient of cold utilities, Af is the annualization factor of investment cost, α is the first calculation factor of heat exchanger cost, β is the second calculation factor of heat exchanger cost, and γ is the third calculation factor of heat exchanger cost.

[0155] Step S204, substitute the process material data into the coal chemical heat exchange network system model, and solve the optimal heat exchanger matching method of the flexible topology structure when the objective function is minimized while satisfying the model constraints. The heat exchanger matching method is the heat exchanger, cooler and / or heater connected to each process flow in each cycle.

[0156] Step S205, outputting the optimal heat exchanger matching method and the annual total cost when minimizing the objective function.

[0157] Specifically, this embodiment can be applied to a client, a server, etc. The client can include a terminal device, such as a smart phone, a tablet computer, etc. The server can include a single computer device, or a server cluster composed of multiple servers, or a server structure of a distributed system, etc.

[0158] First, step S201 is executed to obtain process logistics data of the coal chemical heat exchange network system, wherein the process materials flow and exchange heat through process logistics pipelines between plants and / or within plants.

[0159] Specifically, according to the factories included in the coal chemical heat exchange network system, multi-cycle changing process logistics data are obtained; wherein the data include: inlet temperature, outlet temperature, heat capacity flow rate, heat transfer coefficient, density, and viscosity of the process logistics.

[0160] In some implementation scenarios, according to the target task requirements, data that changes periodically over time (year, month) can be collected, including temperature, density, and viscosity of process logistics.

[0161] In some implementation scenarios, according to the target task requirements, data changes caused by changes in operating conditions can also be collected, including the quantity of cold and hot process logistics, inlet and outlet temperatures, heat capacity flow rate, etc.

[0162] In some implementation scenarios, according to the target task requirements, data changes caused by market fluctuations can also be collected, including operating cost parameters, heat exchanger cost parameters, pipeline cost parameters, etc.

[0163] Of course, the above is only an exemplary description. The data in the embodiments of this specification are not limited to the above-mentioned example data, and the way the data changes in the embodiments of this specification are not limited to multi-period data. For example, the data can be distributed and changed according to a certain distribution function. Technical personnel in the relevant field may make other changes under the inspiration of the technical essence of this application, but as long as the functions and effects achieved are the same or similar to those of this application, they should be covered within the scope of protection of this application.

[0164] Then, step S202 is executed to obtain the flexible topological structure of the coal chemical heat exchange network system, wherein the flexible topological structure at least includes the connection topology of process flow pipelines, heat exchangers, coolers and / or heaters between process flows.

[0165] Specifically, according to the data properties and optimization objectives, a flexible topology network of the coal chemical plant multi-cycle heat exchange network system is designed. The network consists of: inter-plant process logistics transportation pipelines, heat exchangers, coolers, heaters and their network configurations between process logistics.

[0166] In some implementation scenarios, each process stream undergoes heat exchange in only one factory. It can exchange heat in the factory where the process stream is located, or it can go to another factory for heat exchange. At the same time, public works will be used to exchange heat for the process stream only after heat exchange in the factory.

[0167]

[0168] Z p,i ≤yh p,i p∈PN,i∈HN (3)

[0169] Zhu p,j ≤yc p,j p∈PN,j∈CN(4)

[0170] Among them, the binary variable yh p,i (yc p,j ) is used to indicate whether hot process stream i (cold process stream j) is heat exchanged in plant p. p,i (yc p,j ) is 1, the hot process stream i (cold process stream j) is heat exchanged in plant p; conversely, when yh p,i (yc p,j ) is 0, the hot process stream i (cold process stream j) does not undergo heat exchange in plant p. p,i (zhu p,j ) is used to indicate whether hot process stream i (cold process stream j) uses cold (hot) utility heat exchange. p,i (zhu p,j ) is 1, the hot process stream i (cold process stream j) uses the cold (hot) utility for heat exchange; conversely, when zcu p,i (zhu p,j ) is 0, hot process stream i (cold process stream j) does not use cold (hot) utility heat exchange.

[0171] In some implementation scenarios, a flexible topology network structure is adopted so that the network structure can be adjusted in different operation cycles. The heat exchanger in the flexible topology network is a shared heat exchanger, which is suitable for heat exchange between process streams and public works. In different cycles, the process stream flow direction of the heat exchanger needs to be changed to find a suitable heat exchanger. This design can make full use of the heat exchange area of ​​the heat exchanger, thereby reducing investment and operating costs.

[0172] The logical relationship between the heat exchange area between process streams, coolers and heaters and the heat exchanger area is calculated by the following formula:

[0173] As s +(1-zpsi,j,k,pr,s )·Γ i,j,pr ≥A i,j,k,pr

[0174] i∈HN,j∈CN,k∈ST,pr,PRN,s∈SN(5)

[0175] As s -Γhu j,pr ·(1-zhups j,pr,s )≥Ahu j,pr

[0176] j∈CN,pr∈PRN,s∈SN(6)

[0177] As s -Γcu i,pr ·(1-zcups i,pr,s )≥Acu i,pr

[0178] i∈HN,pr∈PRN,s∈SN(7)

[0179]

[0180] Among them, the variable As s Represents the area of ​​the heat exchanger. Variable A i,j,k,pr Indicates: In period pr, the heat exchange area of ​​the heat exchanger required for the heat exchange between hot process stream i and cold process stream j in the kth stage of the superstructure. j,pr Indicates: In period pr, the heat exchange area of ​​the heater required for the cold process stream j to be heated by the hot utility. i,pr Indicates: In period pr, the heat exchange area of ​​the cooler required for the hot process stream i to be cooled by the cold utility. Parameter Γ i,j,pr , Γhu j,pr and Γcu i,pr Represents an upper bound value.

[0181] Among them, HN, CN, PN, KN, PRN and SN represent the sets of hot process logistics, cold process logistics, heat exchange plants, heat exchange stages, heat exchange cycles and heat exchangers respectively; I, J, P, K, PR and S represent the total number of all elements in the corresponding sets respectively; i, j, p, k, pr and s represent the elements in the corresponding sets.

[0182] Among them, zp i,j,k,pr 、zcup i,pr and Zhup j,pr It is a binary variable, and its value can only be equal to 1 or 0. When the value is 0, it means that the corresponding heat exchange match does not exist, and when the value is 1, it means that the corresponding heat exchange match exists.

[0183] Binary variable zpsi,j,k,pr,s Indicates: In period pr, whether heat exchanger s is used for heat exchange between hot process stream i and cold process stream j in the kth stage of superstructure, when zps i,j,k,pr,s When the value of zps is 1, the hot process stream i and the cold process stream j use heat exchanger s in the kth stage of the superstructure; conversely, when zps i,j,k,pr,s When the value of is 0, the hot process stream i and the cold process stream j do not use heat exchanger s in the kth stage of the superstructure. Binary variable zhups j,pr,s Indicates: In period pr, the cold process stream j is heated by the heater whether heat exchanger s is used, when zhups j,pr,s When the value of is 1, the cold process stream j is heated by heat exchanger s; conversely, when zhups j,pr,s When the value of is 0, the cold process stream j is not heated by heat exchanger s. Binary variable zcups i,pr,s Indicates: In period pr, hot process stream i is cooled by the cooler whether heat exchanger s is used, when zcups i,pr,s When the value of is 1, the hot process stream i is cooled using heat exchanger s; conversely, when zcups i,pr,s When the value of is 0, the hot process stream i is not cooled using heat exchanger s. Binary variable zas s Indicates: whether heat exchanger s exists, when zas s When the value of is 1, the heat exchanger s exists; otherwise, when zas s When the value of is 0, the heat exchanger s does not exist.

[0184] Wherein, hot process stream i refers to the i-th hot process stream, cold process stream j refers to the j-th cold process stream, and heat exchanger s refers to the s-th heat exchanger.

[0185] If a heat exchanger is used in a heat exchange match (including between hot and cold process streams, hot process streams and cold utilities, cold process streams and hot utilities), the heat exchanger area required for this match should be less than or equal to the heat exchanger area used. In each cycle, all heat exchangers are used for at most one heat exchange match.

[0186] Of course, the above is only an exemplary description, and the flexible topological configuration of the heat exchange system in the embodiments of this specification is not limited to the above examples. For example, without considering the condition that the heater and the cooler are only used for the flexible topological network of heat exchange between process logistics, the public works based on this also change periodically, and the flexible topological network with short-period changes for small fluctuations. Technical personnel in the relevant field may make other changes under the inspiration of the technical essence of this application, but as long as the functions and effects achieved are the same or similar to those of this application, they should be covered within the scope of protection of this application.

[0187] Then, execute step S203, and establish a coal chemical heat exchange network system model including a first sub-model and a second sub-model according to the flexible topology structure, wherein the first sub-model includes inter-plant model constraints and inter-plant objective functions, and the second sub-model includes intra-plant model constraints and intra-plant objective functions.

[0188] Specifically, according to the flexible topological structure, a coal chemical heat exchange network system model is designed, and the model includes two sub-models. The model constraints include: mass balance, energy balance, temperature requirements, flow rate requirements, heat exchanger and pipeline size requirements, and the model objective function is to minimize the annual total cost. The annual total cost includes: the investment cost of heat exchangers, coolers, heaters between process logistics, and inter-plant process logistics transportation pipelines, as well as the operating costs of coolers and heaters.

[0189] In some embodiments, the model includes two sub-models. In the first sub-model, the heat exchange plant to which each process stream goes in each cycle is solved, and then this is used as the input of the second model to optimize the multi-cycle heat exchange network. Each sub-model is based on the stage-wise super-structure model commonly used in heat exchange networks. The general super-structure model is as follows Figure 5 As shown, in order to facilitate the description of the heat exchange system model with a flexible topology structure, the sets PRN, PN, HN, CN, KN and SN are defined, which represent the sets of cycles, plants, hot process logistics, cold process logistics, heat exchange stages and heat exchangers, respectively. The letters pr, p, i, j, k and s are defined to represent the elements in each set, respectively, and the parameter K represents the maximum value of the elements in the set KN.

[0190] The first sub-model is the inter-plant heat exchange model, which is used to describe the heat exchange of process logistics between plants. The constraints of the model mainly include the mass balance and energy balance within the system. The specific mathematical description can be referred to as follows:

[0191]

[0192]

[0193] As shown in equations (9) and (10), the parameters thin and thout represent the initial temperature and target temperature of the process stream, and the parameter Fc p,j and Fh p,i The variable q represents the heat capacity flow rate of the hot and cold process streams. p,i,j,k ,qcu p,i and qhu p,jRepresent the heat load of the heat exchanger, cooler and heater respectively. The present invention adopts the isothermal mixing assumption, that is, all sub-streams of the logistics must have the same temperature after transferring heat in the heat exchanger. The mixing of these sub-streams in the mixer before entering the next level of the superstructure is completed under isothermal conditions, thus eliminating the nonlinear constraints caused by energy balance. In the inter-plant heat exchange network model, in order to simplify the model and improve the solution efficiency, the present invention does not consider the diversion problem after the process logistics leaves the factory.

[0194] th p,i,1 -(1-yh p,i ) · thout p,i =yh p,i ·thin p,i p∈PN,i∈HN (11)

[0195] tc p,j,K -(1-yc p,j )·tcout p,j =yc p,j tcin p,j p∈PN,j∈CN (12)

[0196] As shown in equations (11) and (12), the variable th p,i,1 The variable tc represents the temperature of the hot process stream i when it enters the superstructure of plant p. p,j,K It represents the temperature of the cold process stream j when it enters the superstructure of plant p. In the inter-plant heat exchange model, the heat exchange model of each plant can be regarded as a hierarchical superstructure. If the process stream exchanges heat in the plant, the temperature of the hot process stream when it enters the superstructure is the initial temperature of the hot process stream, and the temperature of the cold process stream when it enters the superstructure is the target temperature of the cold process stream.

[0197] Wherein, plant p indicates the pth plant. A superstructure is a mathematical model of a heat exchange network, so, for example, "cold process stream j leaves the superstructure of plant p" can be understood as cold process stream j leaving the heat exchange network of plant p. The cold stream enters the superstructure in the opposite direction to the hot stream, the hot stream enters the superstructure from the first level and leaves the superstructure from the last level (K level), while the cold stream enters the superstructure from the last level (K level) and leaves the superstructure from the first level.

[0198]

[0199]

[0200] As shown in equations (13) and (14), the energy balance of the heat exchange between the hot process stream i and the cold process stream j at the kth stage of the superstructure is described. p,i,krepresents the temperature of the hot process stream i on the left side of the kth level of the superstructure. Since each level of the hierarchical superstructure is continuous, the variable th p,i,k+1 It is both the left temperature of hot process stream i at the k+1th level of the superstructure and the right temperature of the kth level of the superstructure. p,j,k Represents the temperature of the cold process stream j at the left side of the kth stage.

[0201] Among them, since each level of the super structure is connected, the left temperature of the next level is the left temperature of this level, and the temperature of the hot process logistics entering each level of the super structure is taken as the left temperature by default. At the same time, because it is a countercurrent heat exchange, the temperature of the hot process logistics entering this level is the left side, and the temperature of the cold process logistics entering this level is the right side.

[0202] th p,i,K ≥thout p,i p∈PN,i∈HN (15)

[0203] tcout p,j ≥tc p,j,1 p∈PN,j∈CN (16)

[0204] th p,i,k ≥th p,i,k+1 p∈PN,i∈HN,k∈ST (17)

[0205] tc p,j,k ≥tc p,j,k+1 p∈PN,j∈CN,k∈ST (18)

[0206] As shown in equations (15)-(18), it is described that the temperature of all logistics decreases or remains unchanged as the number of stages increases.

[0207]

[0208] q p,i -ech p,i ·zcu p,i ≤0p∈PN,i∈HN (20)

[0209] q p,j -ecc p,j ·zhu p,j ≤0 p∈PN,j∈CN (21)

[0210] As shown in equations (19)-(21), the logical relationship between the continuous variable heat load and its corresponding binary variable is described. p,i and ecc p,j Indicates the maximum heat load of logistics heat exchange, which is the variable q p,i,j,k,qcu p,i and qhu p,j Provides an upper bound.

[0211] dt p,i,j,k ≤th p,i,k -tc p,j,k +Γ p,i,j ·(1-zp p,i,j,k )

[0212] p∈PN,i∈HN,j∈CN,k∈ST (22)

[0213] dt p,i,j,k+1 ≤th p,i,k+1 -tc p,j,k+1 +Γ p,i,j ·(1-zp p,i,j,k )

[0214] p∈PN,i∈HN,j∈CN,k∈ST (23)

[0215] dthu p,j ≤Thuout j -tc p,j,1 +Γhu p,j (1-zhup p,j )

[0216] p∈PN,j∈CN (24)

[0217] dtcu p,i ≤th p,i,K -Tcuout i +Γcu p,i (1-zcup p,i )

[0218] p∈PN,i∈HN (25)

[0219] As shown in equations (22)-(25), the Big M method is used to calculate the heat transfer temperature difference between process flow heat exchangers, coolers and heaters. p,i,j , Γhu p,j and Γcu p,i Indicates the upper limit of the heat transfer temperature difference. The variable dt p,i,j,k 、dthu p,j and dtcu p,i They represent the heat transfer temperature differences of the process flow heat exchangers, coolers and heaters respectively, and the parameters Tcuout and Thuout represent the outlet temperatures of the hot and cold utilities.

[0220]

[0221] As shown in equations (26)-(28), an approximate formula is used to replace the logarithmic mean heat transfer temperature difference to calculate the heat exchange area between process streams, coolers and heaters. p,i,j,k , Ahu p,j and Acu p,i They represent the heat exchange areas of process stream heat exchangers, coolers and heaters respectively.

[0222]

[0223] Dout=1.101·Din+0.006349 (30)

[0224] Wt=1330·Din 2 +75.18·Din+0.9268 (31)

[0225] Pcul=A1·Wt+A2·Dout 0.48 +A3+A4·Dout (32)

[0226] Lmcost=L·Pcul (33)

[0227] As shown in equations (29)-(33), the investment cost of the pipeline is calculated. Among them, M represents the flow rate of the flow in the pipeline, ρ represents the density of the flow in the pipeline, Din represents the inner diameter of the pipeline, Dout represents the outer diameter of the pipeline, Wt represents the weight of the pipeline per unit length, Pcul represents the investment cost per unit length, L represents the distance between factories, and Lmcost represents the pipeline cost of process logistics. A1, A2, A3 and A4 are given parameters for calculating the pipeline investment cost.

[0228] The objective function of the first sub-model mainly includes the operating cost of utilities, the investment cost of inter-plant pipelines, and the investment cost of heat exchangers. The specific mathematical description can be referred to as follows:

[0229] (34)

[0231] As shown in formula (34), the parameters hucost and cucost represent the cost coefficients of hot utilities and cold utilities respectively, the parameter Af represents the annualization factor of the investment cost, and α, β and γ are the heat exchanger cost calculation factors.

[0232] The second sub-model is the multi-cycle heat exchange model within the plant, which is used to describe the heat exchange of process logistics within the plant. The constraints of the model mainly include the mass balance and energy balance within the system. The specific mathematical description can be referred to as follows:

[0233]

[0234] As shown in equations (35) and (36), the overall energy balance is described. Among them, the parameters thin and thout represent the initial temperature and target temperature of the process flow, and the parameter Fc j,pr and Fh i,pr The variable q represents the heat capacity flow rate of the hot and cold process streams. i,j,k,pr represents the heat load of the heat exchange between hot process stream i and cold process stream j in period pr, and the variable qcu i,pr represents the utility load of the cooler for hot process stream i, the variable qhu j,pr represents the utility load for the heater of cold process stream j.

[0235]

[0236] As shown in equations (37) and (38), the energy balance of the heat exchange of the hot process stream i at the kth stage and the energy balance of the heat exchange of the cold process stream j at the kth stage in the cycle pr are described. i,k,pr represents the temperature of the hot process stream i at the left side of the kth stage in the period pr. Since each stage of the hierarchical superstructure is continuous, the variable th i,k+1,pr It is the temperature on the left side of the hot process stream i at stage k+1 in period pr and also the temperature on the right side of stage k. Similarly, the variable tc j,k,pr It represents the temperature on the left side of the cooling process stream j at the kth stage in the cycle pr.

[0237] F i,pr (th i,K,pr -thout i,pr )=qcu i,pr i∈HN,pr∈PRN (39)

[0238] Fc j,pr (tcout j,pr -tc j,1,pr )=qhu j,pr j∈CN,pr∈PRN (40)

[0239] As shown in equations (39) and (40), the utility heat load for hot process stream i and cold process stream j is described by the variable th i,K,pr represents the temperature of hot process stream i when it leaves the superstructure in period pr, and the variable tc j,1,pr represents the temperature of the cold process stream j when it leaves the superstructure in period pr, and is also the temperature when it enters the cooler and heater.

[0240] th i,k,pr ≥th i,k+1,pr i∈HN,k∈ST,pr∈PRN (41)

[0241] tc j,k,pr ≥tc j,k+1,pr j∈CN,k∈KN,pr∈PRN(42)

[0242] th i,K,pr ≥thout i,pr i∈HN,pr∈PRN (43)

[0243] tcout j,pr ≥tc j,1,pr j∈CN,pr∈PRN (44)

[0244] As shown in equations (41)-(44), it is described that the temperature of all logistics decreases or remains unchanged as the number of stages increases.

[0245] thin i,pr =th i,1,pr i∈HN,pr∈PRN (45)

[0246] tcin j,pr =tc j,K,pr j∈CN,pr∈PRN (46)

[0247] As shown in equations (45) and (46), the temperatures of all streams when they enter the superstructure are described.

[0248] q i,j,k,pr -min(ech i,pr ,ecc j,pr )·zp i,j,k,pr ≤0

[0249] i∈HN,j∈CN,k∈ST,pr∈PRN (47)

[0250] q i,pr -ech i,pr zcup i,pr ≤0 i∈HN,pr∈PRN (48)

[0251] q j,pr -ecc j,pr zhup j,pr ≤0j∈CN,pr∈PRN(49)

[0252] As shown in equations (47)-(49), the continuous

[0253] The logical relationship between the variable heat load and its corresponding binary variable. i,pr and ecc j,pr Indicates the maximum heat load of logistics heat exchange, which is the variable q i,j,k,pr ,qcu i,prand qhu j,pr Provides an upper bound, binary variable zp i,j,k,pr 、zcup i,pr and Zhup j,pr Indicates whether the corresponding heat exchange match exists.

[0254] dt i,j,k,pr ≤th i,k,pr -tc j,k,pr +Γ i,j,pr (1-zp i,j,k,pr )

[0255] i∈HN,j∈CN,k∈ST,pr∈PRN (50)

[0256] dt i,j,k+1,pr ≤th i,k+1,pr -tc j,k+1,pr +Γ i,j,pr (1-zp i,j,k+1,pr )

[0257] i∈HN,j∈CN,k∈ST,pr∈PRN (51)

[0258] dthu j,pr ≤Thuout-tc j,1,pr +Γhu j,pr (1-zhup j,pr )

[0259] j∈CN,pr∈PRN (52)

[0260] dtcu i,pr ≤th i,K,pr -Tcuout+Γcu i,pr (1-zcup i,pr )

[0261] i∈HN,pr∈PRN (53)

[0262] As shown in equations (50)-(53), the Big M method is used to calculate the heat transfer temperature difference between process flow heat exchangers, coolers and heaters. i,j,pr , Γhu j,pr and Γcu i,pr The variable dt represents the upper limit of the heat transfer temperature difference. i,j,k,pr 、dthu j,pr and dtcu i,pr They represent the heat transfer temperature differences of the heat exchangers, coolers and heaters between process streams respectively, and the parameters Tcuout and Thuout represent the outlet temperatures of the hot and cold utilities.

[0263] dt i,j,k,pr≥ΔTmin i∈HN,j∈CN,k∈KN,pr∈PRN (54)

[0264] dthu j,pr ≥ΔTmin j∈CN,pr∈PRN (55)

[0265] dtcu i,pr ≥ΔTmin i∈HN,pr∈PRN (56)

[0266] As shown in equations (54)-(56), in order to avoid the situation where the heat exchanger area is infinite, it is stipulated that the heat transfer temperature difference of these heat exchangers must be greater than or equal to the minimum heat transfer temperature difference ΔTmin, where the minimum heat transfer temperature difference is preferably 10°C.

[0267]

[0268]

[0269] As shown in equations (57)-(59), the heat exchange between process streams, the heat exchange between coolers and heaters, and the matching of heat exchangers are described. If a heat exchange match exists (including between cold and hot process streams, between hot process streams and cold utilities, and between cold process streams and hot utilities), there will be a heat exchanger for this heat exchange match.

[0270]

[0271] As shown in equations (60)-(62), the heat exchange areas between process streams, coolers, and heaters are calculated.

[0272] As s ≤zas s ·AsMax s∈SN (63)

[0273]

[0274]

[0275] As s ≤As s+1 s∈SN (65)

[0276] As shown in equations (63)-(65), the logical relationship between the heat exchanger area and its corresponding binary variable is described. In each cycle, each heat exchanger can only be used by one heat exchange match (including between cold and hot process streams, hot process streams and cold utilities, and cold process streams and hot utilities) at the same time.

[0277] The objective function of the second sub-model mainly includes the operating cost of the utility and the investment cost of the heat exchanger. The specific mathematical description can be referred to as follows:

[0278]

[0279] As shown in formula (66), Time pr is the cycle fraction, that is, the proportion of time of each cycle in the total cycle, the parameters hucost and cucost represent the cost coefficients of hot utilities and cold utilities respectively, the parameter Af represents the annualization factor of the investment cost, and α, β and γ are the heat exchanger cost calculation factors.

[0280] In some embodiments, based on the optimization of the heat exchange system, the composition of the heat exchange system can be used to calculate other items of the total cost. Among them, other expenses may include equipment wear, maintenance, and repair costs, and water and electricity prices in different regions. Of course, the above is only an exemplary description. The method of generating a flexible topology network model in the embodiments of this specification is not limited to the above examples. Technical personnel in the relevant field may make other changes under the inspiration of the technical essence of this application, but as long as the functions and effects achieved are the same or similar to those of this application, they should be covered within the scope of protection of this application.

[0281] Then execute step S204, substitute the process material data into the coal chemical heat exchange network system model, and solve the optimal heat exchanger matching method of the flexible topology structure when the objective function is minimized while satisfying the model constraints. The heat exchanger matching method is the heat exchanger, cooler and / or heater connected to each process flow in each cycle.

[0282] The initial conditions of the model are preset based on the data, wherein the continuous variables of the model include: the temperature of the logistics at each level in the superstructure, the heat load of the heat exchanger, cooler and heater, the heat transfer temperature difference of the heat exchanger, cooler and heater, the heat exchange area of ​​the heat exchanger, cooler and heater, and the heat exchange area of ​​the heat exchanger. The binary variables of the model include: the existence of process logistics heat exchanger, the existence of cooler, the existence of heater, the existence of heat exchanger, inter-factory logistics distribution, and the matching of heat exchanger and heat exchange.

[0283] In some embodiments, the parameters of the initial conditions may include: boundary parameters such as the upper limit of the heat load of the hot and cold process logistics, the upper limit of the heat transfer temperature difference, and the minimum heat transfer temperature difference, and equipment cost coefficients such as the cost coefficient of the hot and cold utility engineering, the pipeline cost coefficient, and the heat exchanger cost coefficient. The variables of the initial conditions may include: the temperature of the hot and cold process logistics at each level in the superstructure, the heat load of the heat exchange between the hot and cold process logistics, the heat load of the heat exchange between the hot and cold process logistics and the utility engineering, the heat transfer temperature difference of the heat exchange between the hot and cold process logistics, the heat transfer temperature difference of the heat exchange between the hot and cold process logistics and the utility engineering, the heat exchange area of ​​the heat exchange between the hot and cold process logistics, the heat exchange area of ​​the heat exchange between the hot and cold process logistics and the utility engineering, the heat exchange area of ​​the heat exchanger, the existence of heat exchange between the hot and cold process logistics, the existence of heat exchange between the hot and cold process logistics and the utility engineering, the existence of heat exchange between the hot and cold process logistics in the factory, the matching of heat exchange between the heat exchanger and the process logistics, the existence of the heat exchanger, etc. It should be noted that the variables related to existence are all binary variables, such as, and.

[0284] Of course, the above is only an exemplary description. The variables of the heat exchange system in the embodiments of this specification are not limited to the above examples. Technical personnel in the relevant field may make other changes based on the technical essence of this application. However, as long as the functions and effects achieved are the same or similar to those of this application, they should be included in the scope of protection of this application.

[0285] Then, according to the preset model initial conditions, the objective function and constraints of the model are iteratively calculated to obtain the optimization results, wherein the results include: the optimal flexible topology network structure, the minimum cost investment and optimal operating conditions of the coal chemical heat exchange network system, the network structure formed by changing the flexible nodes in each cycle in the flexible topology network, the heat exchange area and heat load required for each heat exchange matching, the heat exchange area of ​​all heat exchangers, and the impact of the flexible topology structure on the network layout and economy.

[0286] Finally, step S205 is executed to output the optimal heat exchanger matching method and the annual total cost when the objective function is minimized.

[0287] This embodiment collects periodically changing process logistics parameters based on the factories included in the coal chemical heat exchange network system, designs a flexible topology network of the coal chemical heat exchange network system, constructs an optimization model of the coal chemical heat exchange network system, uses process logistics and other parameters as input data of the model, uses mathematical programming to iteratively calculate the constraints and objective functions of the model, obtains optimization results, finds the best network structure of the flexible topology network, performs sensitivity analysis, and analyzes the impact of the flexible network on system layout and economy. Increasing the flexibility of the entire coal chemical heat exchange system through the configuration of the heat exchanger can not only improve the adaptability of the heat exchange system, but also improve the economy and energy-saving ability of the system.

[0288] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0289] The above-mentioned heat exchange system optimization method or factory based on flexible topology network provided in the embodiments of this specification can be implemented by a processor in a computer executing corresponding program instructions, such as using GAMS software and DICOPT solver of Windows operating system on PC side, Linux system, or other methods such as using Android and iOS system programming languages ​​on smart terminals, as well as processing logic based on quantum computers, etc.

[0290] In one of the embodiments, the method further includes: analyzing the flexible topology structure based on the optimal heat exchanger matching method and the annual total cost when minimizing the objective function.

[0291] Specifically, based on the flexible topology network and model settings, a sensitivity analysis is performed to analyze the impact of the flexible network on system layout and economy.

[0292] In order to more intuitively illustrate the effect achieved by the present invention, the present invention will use the following examples to conduct comparative analysis of the results: This example optimizes a heat exchange network including three factories. The factories have a total of 12 cold and hot process logistics that change periodically in three cycles per year.

[0293] The results and comparisons obtained by optimizing the method proposed in this invention are shown in Table 1. Figure 8 As shown in Figure 2, the inter-plant heat exchange network structure is as follows: Figure 3 As shown, the multi-cycle heat exchange network structure of each factory is as follows Figures 4 to 6 shown.

[0294] Table 1 Optimization results and comparison

[0295] Traditional methods Method of the present invention Cycle 1 Fee (RMB / year) <![CDATA[5.54×10 5 ]]> <![CDATA[7.76×10 5 ]]> Cycle 2 Fee (RMB / year) <![CDATA[5.79×10 5 ]]> <![CDATA[3.13×10 5 ]]> Cycle 3 Fee (RMB / year) <![CDATA[6.01×10 5 ]]> <![CDATA[4.40×10 5 ]]> Total cost (RMB / year) <![CDATA[1.73×10 6 ]]> <![CDATA[1.53×10 6 ]]>

[0296] like Figure 8 As shown in Table 1. In the existing heat exchange network design, in the face of multi-cycle logistics changes, the design method based on single cycle data is usually adopted. Then, when the cycle changes, the current heat exchange network is adjusted by adding heat exchangers, heaters, coolers and other equipment to meet the heat exchange needs of logistics in different cycles. Figure 8 A graph showing total cost over time. Figure 8 The horizontal axis represents the time of three cycles, and the vertical axis represents the cumulative cost that changes with the cycles. The method of the present invention is represented by a broken line 81, and the traditional method is represented by a broken line 82.

[0297] from Figure 8 It can be seen that at the beginning of the first cycle, the method of the present invention requires 5.64×10 5 The cost of heat exchanger and transportation pipeline investment is only 3.42×10 5 However, when the first cycle ends and the second cycle begins, the heat exchange network structure of the traditional method can no longer meet the energy demand of logistics due to the change in logistics parameters, so an additional 7.59×10 4 The investment cost of RMB 1000 is used to add heat exchangers, and the investment cost of utilities is also gradually increasing. However, the flexible topology network structure designed by the present invention can adjust the network structure to meet the energy target by changing the flow direction through valves. As can be seen from the figure, during the second cycle of operation, the cumulative cost of the traditional method exceeds that of the present invention. Similarly, the investment in heat exchangers and utilities also needs to be increased in the third cycle. Finally, at the end of the third cycle, the total cost of the two methods is 1.73×10 6 Yuanhe 1.53×10 6 The cumulative cost of the traditional method is 13.4% higher than that of the method of the present invention. Therefore, it can be seen that the flexible topological structure designed by the present invention has better economy and long-term investment return than the traditional method.

[0298] like Fig. 9 The figure shows a hardware structure diagram of an electronic device of the present invention, including:

[0299] at least one processor 901; and,

[0300] A memory 902 that is communicatively connected to at least one of the processors 901; wherein:

[0301] The memory 902 stores instructions that can be executed by at least one of the processors, and the instructions are executed by at least one of the processors so that at least one of the processors can execute the coal chemical heat exchange network system optimization method as described above.

[0302] Fig. 9 A processor 901 is taken as an example.

[0303] The electronic device may further include: an input factory 903 and a display factory 904 .

[0304] The processor 901, the memory 902, the input factory 903 and the display factory 904 may be connected via a bus or other means, and the figure takes the connection via a bus as an example.

[0305] The memory 902 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as program instructions / modules corresponding to the coal chemical heat exchange network system optimization method in the embodiment of the present application, for example, Figure 1 , Figure 2 The processor 901 executes various functional applications and data processing by running the non-volatile software programs, instructions and modules stored in the memory 902, that is, the method for optimizing the coal chemical heat exchange network system in the above embodiment is implemented.

[0306] The memory 902 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required by at least one function; the data storage area may store data created according to the use of the coal chemical heat exchange network system optimization method, etc. In addition, the memory 902 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 902 may optionally include a memory remotely arranged relative to the processor 901, and these remote memories may be connected to a factory that executes the coal chemical heat exchange network system optimization method via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0307] The input factory 903 can receive input user clicks and generate signal inputs related to user settings and function control of the coal chemical heat exchange network system optimization method. The display factory 904 can include display devices such as display screens.

[0308] The one or more modules are stored in the memory 902, and when executed by the one or more processors 901, the coal chemical heat exchange network system optimization method in any of the above method embodiments is executed.

[0309] The present invention optimizes the flexible topology structure by establishing a coal chemical heat exchange network system model. By designing a flexible topology network and combining the characteristics of the coal chemical process, the goals of efficient energy utilization, reduced investment costs and adapting to production fluctuations in the heat exchange process in the coal chemical plant are achieved.

[0310] An embodiment of the present invention provides a storage medium, which stores computer instructions. When a computer executes the computer instructions, it is used to execute all the steps of the coal chemical heat exchange network system optimization method as described above.

[0311] In the context of the present disclosure, a storage medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, a factory, or a device. The storage medium may be a machine-readable signal medium or a machine-readable storage medium. Alternatively, the storage medium may be a non-temporary computer-readable storage medium, for example, a non-temporary computer-readable storage medium may be a ROM, a random access memory (Random Access Memory, RAM), a compact disc read-only memory (Compact Disc ROM, CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0312] An embodiment of the present invention provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the above-mentioned method for optimizing a coal chemical heat exchange network system.

[0313] The above-mentioned heat exchange system optimization method or factory based on flexible topology network provided in the embodiments of this specification can be implemented by a processor in a computer executing corresponding program instructions, such as using GAMS software and DICOPT solver of Windows operating system on PC side, Linux system, or other methods such as using Android and iOS system programming languages ​​on smart terminals, as well as processing logic based on quantum computers, etc.

[0314] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for optimizing a coal chemical heat exchange network system, characterized in that: include: Acquire process logistics data of the coal chemical heat exchange network system, wherein the process materials flow and exchange heat through process logistics pipelines between plants and / or within plants; Acquire a flexible topology structure of the coal chemical heat exchange network system, wherein the flexible topology structure at least includes a plurality of factories, a pipeline connection topology of a plurality of process streams in the factories, and a heat exchanger, a cooler and / or a heater between the process streams, wherein the heat exchanger, the cooler and / or the heater can be switched between different process streams; According to the flexible topology structure, a coal chemical heat exchange network system model is established, wherein the model constraints of the model include: mass balance constraint and energy balance constraint, and the objective function of the model is an annual total cost calculation function; Substituting the process material data into the coal chemical heat exchange network system model, and solving the optimal heat exchanger matching mode of the flexible topology structure when the objective function is minimized under the constraints of the model, the heat exchanger matching mode is the heat exchanger, cooler and / or heater connected to each process flow in each cycle; The optimal heat exchanger matching method and the annual total cost when the objective function is minimized are output.

2. The method for optimizing the coal chemical heat exchange network system according to claim 1, characterized in that: The method of establishing a coal chemical heat exchange network system model according to the flexible topology structure includes: According to the flexible topological structure, a coal chemical heat exchange network system model is established, which includes a first sub-model and a second sub-model. The first sub-model includes inter-plant model constraints and inter-plant objective functions, and the second sub-model includes intra-plant model constraints and intra-plant objective functions.

3. The method for optimizing the coal chemical heat exchange network system according to claim 2, characterized in that: The inter-factory model constraints include: th p,i,1 -(1-yh p,i )·thout p,i =yh p,i ·thin p,i p∈PN,i∈HN; tc p,j,K -(1-yc p,j )·tcout p,j =yc p,j ·tcin p,j p∈PN,j∈CN: th p,i,K ≥thout p,i p∈PN,i∈HN; tcout p,j ≥tc p,j,1 p∈PN,j∈CN; th p,i,k ≥th p,i,k+1 p∈PN,i∈HN,k∈ST; tc p,j,k ≥tc p,j,k+1 p∈PN,j∈CN,k∈ST; q p,i,j,k -me(me) p,i etc. p,j )·zp p,i,j,k ≤0 p∈PN,i∈HN,j∈CN,k∈ST; qcu p,i -I p,i ·zcu p,i ≤0 p∈PN,i∈HN; q p,j -ecc p,j ·zhu p,j ≤0 p∈PN,j∈CN; dt p,i,j,k ≤th p,i,k -tc p,j,k +Γ p,i,j ·(1-zp p,i,j,k ); p∈PN,i∈HN,j∈CN,k∈ST dt p,i,j,k+1 ≤th p,i,k+1 -tc p,j,k+1 +Γ p,i,j ·(1-zp p,i,j,k ); p∈PN,i∈HN,j∈CN,k∈ST dthu p,j ≤Output j -tc p,j,1 +Γhu p,j (1-zhup p,j ); p∈PN,j∈CN dtcu p,i ≤th p,i,K -Tcuout i +Γcu p,i (1-zcup p,i ); p∈PN,i∈HN Dout = 1.101·Din + 0.006349; Wt=1330·Din 2 +75.18·From+0.9268; <h2 style=";text-align:left;direction:ltr">Pcul=A1·Wt+A2·Dout<h2 style=";text-align:left;direction:ltr"> 0.48 <h2 style=";text-align:left;direction:ltr"> +A3+A4·Dout; Lmcost=L·Pcul; Among them, yh p,i Indicates whether the hot process stream i is heat exchanged in plant p, yc p,j Indicates whether the cold process stream j is heat exchanged in plant p, thin p,i is the initial temperature of the hot process stream i in plant p, thout p,i is the target temperature of hot process stream i in plant p, tcin p,j is the initial temperature of the cold process stream j in plant p, tcout p,j is the target temperature of the cold process stream j in plant p, Fc p,j is the heat capacity flow rate of cold process stream j, Fh p,i is the heat capacity flow rate of hot process stream i in plant p, q p,i,j,k is the heat load of the heat exchanger exchanging heat between hot process stream i and cold process stream j in the kth stage of the superstructure of plant p, qcu p,i is the heat load of the cooler cooling the hot process stream i in plant p, qhu p,j is the heat load of the heater in plant p that adds cold stream process stream j, th p,i,1 is the temperature of the hot process stream i when it enters the superstructure of plant p, tc p,j,1 is the temperature of the cold stream process stream j when it leaves the superstructure of plant p, th p,i,K is the temperature of the hot process stream i when it leaves the superstructure of plant p, tc p,j,K is the temperature of the cold stream process stream j when it enters the superstructure of plant p, th p,i,k is the left temperature of the hot process stream i at the kth stage of the superstructure of plant p, th p,i,k+1 It is both the left temperature of the hot process stream i at the k+1th level of the superstructure of plant p and the right temperature of the hot process stream i at the kth level of the superstructure of plant p, tc p,j,k is the left temperature of the cold process stream j at the kth stage of plant p, tc p,j,k+1 It is both the left temperature of the cold process flow j at the k+1th level of the superstructure of the plant p and the right temperature of the kth level of the superstructure of the cold process flow j at the plant p, zp p,i,j,k Indicates whether the hot process stream i and the cold process stream j are heat exchanged in the kth stage of the superstructure of plant p, zcup p,i Indicates whether the hot process stream i of plant p uses cold utility heat exchange, zhup p,j Indicates whether the cold process stream j of plant p uses the heat utility for heat exchange, ech p,i is the upper bound of the heat load for heat exchange of hot process stream i in plant p, ecc p,j is the maximum heat load of the cold process stream j of plant p, Γ p,i,j is the upper bound of the heat transfer temperature difference between the hot process stream i and the cold process stream j of plant p, Γhu p,j is the upper bound of the heat transfer temperature difference of the cold process stream j in plant p, Γcu p,i is the upper bound of the heat transfer temperature difference of the hot process stream i in plant p, dt p,i,j,k is the heat transfer temperature difference of the heat exchanger connecting hot process stream i and cold process stream j at the kth stage of plant p, dthu p,j is the heat transfer temperature difference of the heater connecting the cold process stream j and the hot utility in plant p, dtcu p,i is the heat transfer temperature difference of the cooler connecting the hot process stream i and the cold utility in plant p, Tcuin i is the initial temperature of the cold utility for cooling the hot process stream i, Thuin j is the initial temperature of the heat utility for heating the cold process stream j, Tcuout i is the outlet temperature of the cold utility for cooling the hot process stream i, Thuout j is the outlet temperature of the heat utility for heating the cold process stream j, A p,i,j,k is the heat exchange area of ​​the heat exchanger connecting the hot process stream i and the cold process stream j of plant p, h p,i is the heat transfer coefficient of the hot process stream i of plant p, h p,j is the heat transfer coefficient of the cold process stream j in plant p, Ahu p,j is the heat exchange area of ​​the cooler connecting the cold process stream j of plant p, hhu j is the heat transfer coefficient of the heat utility exchanging heat with the cold process stream j, hcu i is the heat transfer coefficient of the cold utility exchanging heat with the hot process stream i, Acu p,i is the heat exchange area of ​​the heater connecting the hot process stream i of plant p, M is the flow rate of the stream in the pipeline, ρ is the density of the stream in the pipeline, Din is the inner diameter of the pipeline, Dout is the outer diameter of the pipeline, Wt is the weight of the pipeline per unit length, Pcul is the investment cost per unit length, L is the distance between plants, Lmcost is the pipeline cost of the process stream, A1 is the first given parameter for calculating the pipeline investment cost, A2 is the second given parameter for calculating the pipeline investment cost, A3 is the third given parameter for calculating the pipeline investment cost, A4 is the fourth given parameter for calculating the pipeline investment cost, PRN is the set of heat exchange cycles, PN is the set of plants, HN is the set of hot process streams, CN is the set of cold process streams, KN ​​is the set of heat exchange stages, SN is the set of heat exchangers, and ST is a subset of KN.

4. The method for optimizing the coal chemical heat exchange network system according to claim 3, characterized in that: The inter-factory objective function includes: The total annual cost between factories is calculated as: Where hucost is the cost coefficient of the heat utility project, cucost is the cost coefficient of the cold utility project, Af is the annualization factor of the investment cost, α is the first calculation factor of the heat exchanger cost, β is the second calculation factor of the heat exchanger cost, γ is the third calculation factor of the heat exchanger cost, Lmcosth p,i is the pipeline cost of hot process stream i in plant p, Lmcostc p,j is the pipeline cost of cold process stream j in plant p.

5. The method for optimizing the coal chemical heat exchange network system according to claim 2, characterized in that: The in-plant model constraints include: Fh i,pr (th i,K,pr -thout i,pr )=qcu i,pr i∈HN,pr∈PRN; Fc j,pr (tcout j,pr -tc j,1,pr )=smile j,pr j∈CN, pr∈PRN; th i,k,pr ≥th i,k+1,pr i∈HN,k∈ST,pr∈PRN; tc j,k,pr ≥tc j,k+1,pr j∈CN,k∈KN,pr∈PRN; th i,K,pr ≥thout i,pr i∈HN,pr∈PRN; tcout j,pr ≥tc j,1,pr j∈CN,pr∈PRN; thin i,pr =th i,1,pr i∈HN,pr∈PRN; tcin j,pr s tc j,K,pr j∈CN,pr∈PRN. q i,j,k,pr -me(me) i,pr etc. j,pr )·zp i,j,k,pr ≤0; i∈HN,j∈CN,k∈ST,pr∈PRN qcu i,pr -I i,pr zcup i,pr ≤0i∈HN,pr∈PRN; qhu j,pr -ecc j,pr zhup j,pr ≤0j∈CN,pr∈PRN. dt i,j,k,pr ≤th i,k,pr -tc j,k,pr +Γ i,j,pr (1-zp i,j,k,pr ); i∈HN,j∈CN,k∈ST,pr∈PRN dt i,j,k+1,pr ≤th i,k+1,pr -tc j,k+1,pr +Γ i,j,pr (1-zp i,j,k+1,pr ); i∈HN,j∈CN,k∈ST,pr∈PRN dthu j,pr ≤Output-tc j,1,pr +Γhu j,pr (1-zhup j,pr ); j∈CN,pr∈PRN dtcu i,pr ≤th i,K,pr -Tcuout+Γcu i,pr (1-zcup i,pr ); i∈HN,pr∈PRN dt i,j,k,pr ≥ΔTmin i∈HN,j∈CN,k∈KN,pr∈PRN; dthu j,pr ≥ΔTmin j∈CN,pr∈PRN; dtcu i,pr ≥ΔTmin i∈HN,pr∈PRN; As s ≤zas s ·AsMax s∈SN; As s ≤As s+1 s∈SN; Among them, thin i,pr is the initial temperature of the hot process stream i in period pr, thout i,pr is the target temperature of the hot process stream i in period pr, tcin j,pr is the initial temperature of the cold process stream j at the cycle, tcout j,pr is the target temperature of the cold process stream j cycle, parameter Fc j,pr is the heat capacity flow rate of the cooling process stream j in period pr, Fh i,pr is the heat capacity flow rate of hot process stream i in period pr, qi ,j, k ,pr is the heat load of the heat exchange between hot process stream i and cold process stream j in the kth stage in the cycle pr, qcu i,pr is the utility load of the cooler for the hot process stream i in cycle pr, qhu j,pr is the utility load of the heater for the process stream j in the cycle pr, th i,k,pr is the temperature of the hot process stream i at the left side of the kth stage in the cycle pr, th i,k+1,pr It is the left temperature of hot process stream i at stage k+1 in cycle pr and the right temperature of stage k, tc j, k ,pr is the left temperature of the cooling process stream j at the kth stage in the cycle pr, tc j,k+1,pr It is the left temperature of the cooling process stream j at the k+1th stage in the period pr and the right temperature of the kth stage. i,K,pr is the temperature of hot process stream i when it leaves the superstructure in period pr, th i,1,pr is the temperature of hot process stream i when it enters the superstructure in period pr, tc j,K,pr is the temperature of the cooling process stream j when it enters the superstructure in period pr, tc j,1,pr is the temperature of the cooling process stream j when it leaves the superstructure in period pr, ech i,pr is the upper bound of the heat load for heat exchange of hot process stream i in period pr, ecc j,pr is the maximum heat load of the process flow j in the cycle pr, zp i,j,k,pr Indicates whether heat exchange between hot process stream i and cold process stream j in the kth stage exists in the cycle pr, zcup i,pr Indicates whether heat exchange of hot process stream i exists in period pr, zhup j,pr Indicates whether heat exchange of cooling process stream j exists in period pr, Γ i,j,pr is the upper bound of the heat transfer temperature difference between the hot process stream i and the cold process stream j in period pr, Γhu j,pr is the upper bound of the heat transfer temperature difference of the cooling process stream j in the period pr, Γcu i,pr is the upper bound of the heat transfer temperature difference of hot process stream i in period pr, dt i,j,k,pr is the heat transfer temperature difference between the hot process stream i and the cold process stream j in the k-th stage heat exchanger in cycle pr, dthu j,pr is the heat transfer temperature difference of the heater connecting the cold process stream j and the hot utility in cycle pr, dtcu i,pr is the heat transfer temperature difference of the cooler connecting the hot process stream i and the cold utility in the period pr, ΔTmin is the minimum heat transfer temperature difference, Tcuout is the outlet temperature of the cold utility, Thuout is the outlet temperature of the hot utility, PRN is the set of heat exchange cycles, PN is the set of plants, HN is the set of hot process streams, CN is the set of cold process streams, KN ​​is the set of heat exchange stages, SN is the set of heat exchangers, ST is the sub-set of KN, and zps i,j,k,pr,s Indicates whether heat exchanger s is used for heat exchange between hot process stream i and cold process stream j in the kth stage of the superstructure in period pr, zhups j,pr,s Indicates whether the process flow j in the cycle pr is heated by the heater using the heat exchanger s, zcups i,pr,s Indicates whether heat exchanger s is used to cool the hot process stream i in cycle pr, As s is the heat transfer area of ​​heat exchanger s, zas s Indicates whether there is a heat exchanger s, AsMax is the maximum value of the heat exchange area, A i,j,k,pr Ahu is the heat exchange area of ​​the heat exchanger required for the heat exchange between the hot process stream i and the cold process stream j in the kth stage of the superstructure in period pr, j,pr is the heat exchange area of ​​the heater required for the process stream j to be heated by the heat utility in the cycle pr, Acu i,pr is the heat exchange area of ​​the cooler required for the hot process stream i to be cooled by the cold utility in the cycle pr, h i,pr is the heat transfer coefficient of hot process stream i in period pr, h j,pr is the heat transfer coefficient of the cold process stream j in period pr, hhu j is the heat transfer coefficient of the heat utility exchanging heat with the cold process stream j, hcu i is the heat transfer coefficient of the cold utility exchanging heat with the hot process stream i, Tcuin i is the initial temperature of the cold utility for cooling the hot process stream i, Thuin j is the initial temperature of the heat utility used to heat the cold process stream j.

6. The method for optimizing the coal chemical heat exchange network system according to claim 5, characterized in that: The in-plant objective function includes: The total annual cost of the factory is calculated as: Among them, Time pr is the cycle fraction, hucost is the cost coefficient of heat utilities, cucost is the cost coefficient of cold utilities, Af is the annualization factor of investment cost, α is the first calculation factor of heat exchanger cost, β is the second calculation factor of heat exchanger cost, and γ is the third calculation factor of heat exchanger cost.

7. An electronic device, characterized in that: include: at least one processor; as well as, a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by at least one of the processors, and the instructions are executed by at least one of the processors so that at least one of the processors can execute the coal chemical heat exchange network system optimization method as described in any one of claims 1 to 6.

8. A storage medium, characterized in that: The storage medium stores computer instructions, and when a computer executes the computer instructions, it is used to execute all steps of the coal chemical heat exchange network system optimization method as described in any one of claims 1 to 6.

9. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the method for optimizing the coal chemical heat exchange network system as described in any one of claims 1 to 6 is implemented.

10. A coal chemical heat exchange network system, characterized in that: It comprises a plurality of factories, a plurality of process flow pipelines connected to the factories, heat exchangers, coolers and / or heaters. In each cycle, the heat exchangers, coolers and / or heaters are connected to the process flow pipelines indicated by the optimal heat exchanger matching method output by the coal chemical heat exchange network system optimization method as described in any one of claims 1 to 6.

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