A step-by-step design method for hydrogen network based on linear mathematical model

Abstract

The present invention proposes a step-by-step design method for a hydrogen network based on a linear mathematical model, which includes five steps. S1: Extracting the process parameters of hydrogen utilities, hydrogen units and fuel systems, including the outlet pressure, purity and flow rate upper limit of the utilities; the inlet and outlet pressure, purity and flow rate of the hydrogen units; and the pressure of the fuel system; S2: Establishing a linear programming model with the goal of minimizing the flow rate of utilities, obtaining the minimum utilities usage, and calculating the total annual cost; S3: Fixing the utilities usage as the minimum value, establishing a mixed integer linear programming model with the goal of minimizing the compression cost, and calculating the total annual cost according to the optimization results; S4: Merging the compressors at the same outlet to reduce the number of compressors, obtaining the optimal design scheme, and calculating the total annual cost; S5: According to the results of merging the compressors, using Aspen Plus to simulate the compressor power consumption, recalculate the total annual cost, and draw the optimal design scheme.

Description

Technical field:

[0001] The invention relates to the field of hydrogen network design in the oil refining industry and proposes a step-by-step design method for a hydrogen network based on a linear mathematical model. Background technology:

[0002] With the rapid development of the world economy and society, the demand for energy is also growing at an alarming rate. The quantity and quality of traditional energy can no longer meet the needs of contemporary economic development. The deep processing of traditional energy and the development of new energy are constantly being explored. Among various forms of energy, hydrogen resources play a vital role in the deep processing of traditional energy, and the refining industry is the largest terminal market for hydrogen consumption, accounting for about 90% of the world's total hydrogen consumption. Due to the shortage of high-quality crude oil, the continuous increase of low-quality crude oil and the increasingly stringent environmental protection regulations, the requirements for oil quality are constantly increasing. Hydrogenation technology has been widely used in the refining industry, and the demand for hydrogen in refineries is increasing. Optimizing the hydrogen network of the refinery and improving the utilization rate of hydrogen resources have important theoretical value and practical application significance for energy conservation, emission reduction and production cost reduction in the refining industry. Hydrogen network design refers to the reasonable matching of all or part of the hydrogen supply devices and hydrogen consumption devices under the condition of meeting all production process standards, fully recovering and utilizing the hydrogen resources in the production process, and achieving the goals of maximizing the utilization rate of hydrogen in the entire production process and minimizing the cost of hydrogenation process. In this context, the present invention proposes a step-by-step design method for a hydrogen network based on a linear mathematical model.

[0003] Hydrogen network design can be viewed as an optimization problem whose objective function is to minimize the total annual cost. Existing hydrogen network design methods mainly include pinch analysis and mathematical programming. Pinch analysis is a graphical method that focuses on optimizing the use of utilities and cannot simultaneously consider multiple factors such as equipment investment. In contrast, mathematical programming methods can simultaneously consider the impact of multiple factors on the entire network design, including hydrogen utility operating costs, compressor operating electricity costs, compressor and pipeline equipment investment, etc. However, most of the hydrogen network models studied by previous researchers are mixed integer nonlinear programming (MINLP) models, which contain many nonlinear and nonconvex complex constraint equations. Most existing methods directly use commercial solvers or develop stochastic optimization algorithms to optimize and solve the model. This traditional method has two obvious defects: (1) The existing hydrogen network mathematical model is a mixed integer nonlinear programming (MINLP) problem with severe nonconvexity and nonlinearity. It is difficult to obtain high-quality feasible solutions by directly using commercial solvers for optimization and solving, and the design quality cannot be guaranteed. In particular, when dealing with industrial cases, even feasible solutions and design plans cannot be obtained.

[0004] (2) The mathematical model of the hydrogen network includes many mass conservation equations. The use of random optimization algorithms requires setting penalty terms for violating mass conservation constraints. This is highly dependent on the experience of designers, resulting in a long convergence time and the inability to guarantee the optimality and stability of the design results. Summary of the invention:

[0005] In view of the above-mentioned difficulties existing in the existing design technology, the technical problems to be solved by the present invention include: how to solve the problem of excessively large annual total cost of hydrogen network and long convergence time obtained by optimizing traditional deterministic algorithms (commercial solvers) and random algorithms, and obtain the optimal design solution that minimizes the use of hydrogen utilities and minimizes the annual total cost of hydrogen network.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is a step-by-step design method of hydrogen network based on linear mathematical model. This method decomposes the mixed integer nonlinear programming model (MINLP) of hydrogen network design into linear programming (LP), mixed integer linear programming model (MILP), etc., to obtain the optimal hydrogen network design scheme, which specifically includes the following five steps:

[0007] S1: Extract the process parameters (input data) of hydrogen utilities, hydrogen units (hydrogenation units) and fuel systems, including the pressure, purity and flow rate limit at the outlet of hydrogen utilities; the pressure, purity and flow rate at the inlet and outlet of hydrogen units; and the pressure of the fuel system.

[0008] S2: Establish a linear programming model (LP) for hydrogen network design. This model includes formulas (1)-(6). Run this model to minimize the use of hydrogen utilities and calculate the total annual cost (TAC1) of the linear programming model:

[0009] In the linear programming model of hydrogen network design, the objective function is to minimize the hydrogen utility usage:

[0010]

[0011] Among them, Mtotal is the total amount of hydrogen utilities, Mo i is the total flow of hydrogen supplied by the i-th hydrogen utility, Mtotal and Mo i The unit is kmol / h, and IS is a collection of all hydrogen utilities.

[0012] Material balance of the ith hydrogen utility:

[0013]

[0014] Among them, M i,u is the gas flow from the i-th hydrogen utility to the u-th hydrogen unit, M iis the gas flow from the ith hydrogen utility to the fuel system, M i,u and M i The unit is kmol / h.

[0015] Material balance at the inlet of the uth hydrogen unit:

[0016]

[0017] in, is the total gas flow at the inlet of the u-th hydrogen unit, M u,u is the circulating hydrogen gas flow rate of the uth hydrogen-using unit, M u′,u is the gas flow from the u′th hydrogen-using unit to hydrogen-using unit u, M u,u and M u′,u The unit is kmol / h, and US is a collection of all hydrogen-using units.

[0018] Purity balance at the inlet of the uth hydrogen unit:

[0019]

[0020] in, is the hydrogen purity of the gas at the inlet of the u-th hydrogen-using unit, is the purity of hydrogen at the ith hydrogen utility, It is the hydrogen purity of the gas at the outlet of the u-th hydrogen-using unit.

[0021] Material balance at the outlet of the uth hydrogen unit:

[0022]

[0023] in, is the total gas flow at the outlet of the uth hydrogen unit, M u is the gas flow from the u-th hydrogen unit to the fuel system, and M u The unit is kmol / h.

[0024] Material balance at the fuel system inlet:

[0025]

[0026] Where MJ is the total gas flow rate entering the fuel system, in kmol / h.

[0027] S3: Based on the optimization results of the linear programming model (LP), the total amount of fixed hydrogen utilities is the minimum, and the minimization of compression costs is taken as the objective function to establish a mixed integer linear programming model (MILP) for hydrogen network design.

[0028] According to the optimization results of minimizing compression cost (MILP), the annual total cost TAC2 of the mixed integer linear programming model is calculated. The mixed integer linear programming (MILP) model of hydrogen network design includes formulas (2)-(6) and (7)-(17):

[0029] The objective function is to minimize the compression cost:

[0030]

[0031] Among them, Pw i,u is the power consumption of the gas compressor between the i-th hydrogen utility and the u-th hydrogen unit, Pw i is the power consumption of the gas compressor between the ith hydrogen utility and the fuel system, Pw u,u′ is the power consumption of the gas compressor between the uth hydrogen-using unit and the u′th hydrogen-using unit, Pw u,u is the power consumption of the circulating hydrogen compressor of the uth hydrogen-using unit, Pw u is the power consumption Pw of the gas compressor between the u-th hydrogen unit and the fuel system i,u , Pw i , Pw u,u , Pw u,u′ and Pw u The unit of z is kW; i,u is an integer variable indicating whether there is a gas compressor between the i-th hydrogen utility and the u-th hydrogen unit, z i is an integer variable indicating whether there is a gas compressor between the i-th hydrogen utility and the fuel system, z u,u′ is an integer variable indicating whether there is a gas compressor between the uth hydrogen-using unit and the u′th hydrogen-using unit, z u is an integer variable indicating whether a gas compressor exists between the u-th hydrogen unit and the fuel system. is the annual operating time (in hours), is the electricity price (in $ / kWh), is the equipment cost reduction factor, and It is the compressor equipment investment parameter.

[0032] Constraint equations for the presence or absence of a compressor:

[0033]

[0034] in, is the compressor power consumption Pw i,u The upper limit of is the compressor power consumption Pw i The upper limit of is the power consumption of circulating hydrogen compressor Pwu,u The upper limit of is the compressor power consumption Pw u upper limit.

[0035] The calculation equation for compressor power consumption is:

[0036]

[0037] in, is the inlet pressure of the uth hydrogen-using unit, is the outlet pressure of the ith hydrogen utility, is the fuel system inlet pressure, is the inlet pressure of the u′th hydrogen unit, is the outlet pressure of the uth hydrogen unit, and The unit is kPa. is the compressor efficiency, is the gas compressibility factor, is the molar gas constant, is the gas temperature at the compressor inlet.

[0038] S4: Without considering the circulating hydrogen compressor of the hydrogen unit, the compressors at the entrance of the hydrogen unit and the fuel system are combined to reduce the number of compressors, reduce the equipment investment cost, obtain the optimal design plan, and calculate the third annual total cost TAC3.

[0039] For each hydrogen unit, the inlet pressure of the hydrogen production compressor after the compressor inlet is combined Take the hydrogen utility pressure of the supply gas and hydrogen unit outlet pressure The minimum value in:

[0040]

[0041] Combined compressor outlet pressure Pressure at the inlet of hydrogen extraction unit

[0042]

[0043] Gas flow of the combined compressor

[0044]

[0045] Combined compressor power consumption

[0046]

[0047] Whether the merged compressor exists or not is an integer parameter express:

[0048]

[0049] A similar method is used to merge the compressors at the inlet of the fuel system to reduce the number of compressors. S5: Based on minimizing the use of hydrogen utilities (LP) and minimizing the compression cost (MILP), the network design after merging the compressors in S4 is used as the scheme, and Aspen Plus is used to simulate the power consumption of all compressors to recalculate the annual total cost TAC4 of the hydrogen network design scheme based on process simulation.

[0050] Compared with the existing design technology, the present invention has at least the following advantages:

[0051] (1) The present invention aims at the problem of efficient utilization of hydrogen energy in refineries and develops a step-by-step design method for hydrogen networks based on linear mathematical models. Traditional hydrogen network design methods are all based on complex mixed-integer nonlinear programming models. These models contain a large number of nonlinear and non-convex constraint equations, which result in a large number of local optimal solutions in the model. Using a nonlinear solver can easily lead to local optimality, making it difficult to obtain high-quality feasible solutions and design schemes. In contrast, the step-by-step design method for hydrogen networks developed by the present invention uses a linear mathematical model, and there is no local optimal situation, so it can converge to high-quality feasible solutions and design schemes. The method first obtains the minimum hydrogen utility usage by establishing a linear programming model, then obtains the minimum compression cost by establishing a mixed-integer nonlinear programming model, and finally merges the hydrogen production compressors at the same outlet to reduce the number of compressors and the corresponding investment costs, so that a hydrogen network design scheme with a lower annual total cost can be obtained.

[0052] (2) The step-by-step design method developed by the present invention divides the refinery hydrogen network design into multiple steps, and the use of a linear mathematical model can avoid the use of a nonlinear commercial solver. Since the algorithm of the linear solver is relatively mature and highly stable, the linear mathematical model in each step has a high convergence performance and can be quickly run and solved. Therefore, the step-by-step design method for hydrogen network design can quickly obtain the optimal solution and design scheme, solve the problem of slow convergence of the hydrogen network mathematical model, and can quickly obtain the optimal solution for hydrogen network design within six seconds, thereby improving the efficiency of hydrogen network design. Description of the drawings:

[0053] Figure 1 It is the hydrogen network design step.

[0054] Figure 2 It is a comparison chart of the total annual cost of hydrogen network for various design steps.

[0055] Figure 3This is the optimal hydrogen network design diagram after the compressor is combined. Specific implementation method:

[0056] The present invention is described in further detail below.

[0057] See also Figure 1 , a step-by-step design method for hydrogen network based on linear mathematical model, decomposes the mixed integer nonlinear programming model (MINLP) of hydrogen network design into linear programming (LP), mixed integer linear programming model (MILP), etc., which specifically includes the following five steps:

[0058] S1: Extract the process parameters (input data) of hydrogen utilities, hydrogen units (hydrogenation units) and fuel systems, including the pressure, purity and flow rate limit at the outlet of hydrogen utilities; the pressure, purity and flow rate at the inlet and outlet of hydrogen units; and the pressure of the fuel system.

[0059] S2: Establish a linear programming model (LP) for hydrogen network design. This model includes formulas (1)-(6). Run this model to minimize the use of hydrogen utilities and calculate the total annual cost (TAC1) of the linear programming model:

[0060] In the linear programming model of hydrogen network design, the objective function is to minimize the hydrogen utility usage:

[0061]

[0062] Among them, Mtotal is the total amount of hydrogen utilities, Mo i is the total flow of hydrogen supplied by the i-th hydrogen utility, Mtotal and Mo i The unit is kmol / h, and IS is a collection of all hydrogen utilities.

[0063] Material balance of the ith hydrogen utility:

[0064]

[0065] Among them, M i,u is the gas flow from the i-th hydrogen utility to the u-th hydrogen unit, M i is the gas flow from the ith hydrogen utility to the fuel system, M i,u and M i The unit is kmol / h.

[0066] Material balance at the inlet of the uth hydrogen unit:

[0067]

[0068] in, is the total gas flow at the inlet of the u-th hydrogen unit, M u,u is the circulating hydrogen gas flow rate of the uth hydrogen-using unit, M u′,u is the gas flow from the u′th hydrogen-using unit to hydrogen-using unit u, M u,u and M u′,u The unit is kmol / h, and US is a collection of all hydrogen-using units.

[0069] Purity balance at the inlet of the uth hydrogen unit:

[0070]

[0071] in, is the hydrogen purity of the gas at the inlet of the u-th hydrogen-using unit, is the purity of hydrogen at the ith hydrogen utility, It is the hydrogen purity of the gas at the outlet of the u-th hydrogen-using unit.

[0072] Material balance at the outlet of the uth hydrogen unit:

[0073]

[0074] in, is the total gas flow at the outlet of the uth hydrogen unit, M u is the gas flow from the u-th hydrogen unit to the fuel system, and M u The unit is kmol / h.

[0075] Material balance at the fuel system inlet:

[0076]

[0077] Where MJ is the total gas flow rate entering the fuel system, in kmol / h.

[0078] S3: Based on the optimization results of the linear programming model (LP), the total amount of fixed hydrogen utilities is the minimum, and the minimization of compression costs is taken as the objective function to establish a mixed integer linear programming model (MILP) for hydrogen network design.

[0079] According to the optimization results of minimizing compression cost (MILP), the annual total cost TAC2 of the mixed integer linear programming model is calculated. The mixed integer linear programming (MILP) model of hydrogen network design includes formulas (2)-(6) and (7)-(17):

[0080] The objective function is to minimize the compression cost:

[0081]

[0082] Among them, Pw i,u is the power consumption of the gas compressor between the i-th hydrogen utility and the u-th hydrogen unit, Pw i is the power consumption of the gas compressor between the ith hydrogen utility and the fuel system, Pw u,u′ is the power consumption of the gas compressor between the uth hydrogen-using unit and the u′th hydrogen-using unit, Pw u,u is the power consumption of the circulating hydrogen compressor of the uth hydrogen-using unit, Pw u is the power consumption Pw of the gas compressor between the u-th hydrogen unit and the fuel system i,u , Pw i , Pw u,u , Pw u,u′ and Pw u The unit of z is kW; i,u is an integer variable indicating whether there is a gas compressor between the i-th hydrogen utility and the u-th hydrogen unit, z i is an integer variable indicating whether there is a gas compressor between the i-th hydrogen utility and the fuel system, z u,u′ is an integer variable indicating whether there is a gas compressor between the uth hydrogen-using unit and the u′th hydrogen-using unit, z u is an integer variable indicating whether a gas compressor exists between the u-th hydrogen unit and the fuel system. is the annual operating time (in hours), is the electricity price (in $ / kWh), is the equipment cost reduction factor, and It is the compressor equipment investment parameter.

[0083] Constraint equations for the presence or absence of a compressor:

[0084]

[0085] in, is the compressor power consumption Pw i,u The upper limit of is the compressor power consumption Pw i The upper limit of is the power consumption of circulating hydrogen compressor Pw u,u The upper limit of is the compressor power consumption Pw u upper limit.

[0086] The calculation equation for compressor power consumption is:

[0087]

[0088] in, is the inlet pressure of the uth hydrogen-using unit, is the outlet pressure of the ith hydrogen utility, is the fuel system inlet pressure, is the inlet pressure of the u′th hydrogen unit, is the outlet pressure of the uth hydrogen unit, and The unit is kPa. is the compressor efficiency, is the gas compressibility factor, is the molar gas constant, is the gas temperature at the compressor inlet.

[0089] S4: Without considering the circulating hydrogen compressor of the hydrogen unit, the compressors at the entrance of the hydrogen unit and the fuel system are combined to reduce the number of compressors, reduce the equipment investment cost, obtain the optimal design plan, and calculate the third annual total cost TAC3.

[0090] For each hydrogen unit, the inlet pressure of the hydrogen production compressor after the compressor inlet is combined Take the hydrogen utility pressure of the supply gas and hydrogen unit outlet pressure The minimum value in:

[0091]

[0092] Combined compressor outlet pressure Pressure at the inlet of hydrogen extraction unit

[0093]

[0094] Gas flow of the combined compressor

[0095]

[0096] Combined compressor power consumption

[0097]

[0098] Whether the merged compressor exists or not is an integer parameter express:

[0099]

[0100] A similar method is used to merge the compressors at the inlet of the fuel system to reduce the number of compressors. S5: Based on minimizing the use of hydrogen utilities (LP) and minimizing the compression cost (MILP), the network design after merging the compressors in S4 is used as the scheme, and Aspen Plus is used to simulate the power consumption of all compressors to recalculate the annual total cost TAC4 of the hydrogen network design scheme based on process simulation.

[0101] Implementation case: A step-by-step design method for hydrogen network based on linear mathematical model, the specific steps are as follows: S1: Extract the process parameters (input data) of hydrogen utilities, hydrogen units and fuel systems, including the pressure, purity and flow rate upper limit of the hydrogen utilities outlet; the pressure, purity and flow rate of the hydrogen unit inlet and outlet; the pressure of the fuel system, see Table 1 and Table 2. Other parameters are:

[0102] Table 1 Hydrogen source data

[0103]

[0104] Table 2 Hydrogen trap data

[0105]

[0106] S2: Establish a linear programming model (LP) for hydrogen network design, obtain the minimum utility usage of 4710.316 kmol / h, and calculate the total annual cost (TAC1) of the linear programming model as 4,068,120.3$ / year.

[0107] S3: Fixed utility usage (minimum flow), with minimization of compression cost as the objective function. A mixed integer linear programming model (MILP) of the hydrogen network was established, the hydrogen network design scheme was obtained, and the total annual cost (TAC2) of the mixed integer linear programming model was calculated to be 3,704,310.3$ / year.

[0108] S4: Combine the compressors in the optimization results to reduce the number of compressors. Reduce the equipment investment cost and obtain the optimal design solution. The third annual total cost (TAC3) is calculated to be 3,637,729.1$ / year.

[0109] S5: Based on minimizing the use of hydrogen utilities (LP) and minimizing the compression cost (MILP), the network design after merging the compressors in S4 is used as the scheme, and Aspen Plus is used to simulate the power consumption of all compressors. The GAMS calculation and Aspen Plus simulation results of the compressors are shown in Table 3. The annual total cost (TAC4) based on the process simulation is recalculated to be 3,639,652.9$ / year. The five steps of this design method take a total of 5.6 seconds, and the annual total cost obtained in each step is as follows Figure 2 As shown, the optimal design solution is Figure 3 shown.

[0110] Table 3 Compressor power consumption of hydrogen network design scheme

[0111]

[0112] Finally, it should be noted that the above implementation cases are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred implementation cases, ordinary technicians in this field should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A step-by-step design method for hydrogen network based on linear mathematical model, characterized in that The hydrogen network design is divided into five steps, each of which is described as follows: S1: Process parameters of hydrogen extraction utilities, hydrogen units and fuel systems, including pressure, purity and flow rate limit of utilities outlet; pressure, purity and flow rate of hydrogen units inlet and outlet; pressure of fuel system; S2: Establish a linear programming model LP for hydrogen network design; this model includes formulas (1)-(6). Run this model to minimize the use of hydrogen utilities and calculate the total annual cost TAC1 of the linear programming model: In the linear programming model of hydrogen network design, the objective function is to minimize the hydrogen utility usage: Among them, Mtotal is the total amount of hydrogen utilities, Mo i is the total flow of hydrogen supplied by the i-th hydrogen utility, Mtotal and Mo i The unit of is kmol / h, IS is the set of all hydrogen utilities; Material balance of the ith hydrogen utility: Among them, M i,u is the gas flow from the i-th hydrogen utility to the u-th hydrogen unit, M i is the gas flow from the ith hydrogen utility to the fuel system, M i,u and M i The unit of is kmol / h; Material balance at the inlet of the uth hydrogen consumption unit: in, is the total gas flow at the inlet of the u-th hydrogen unit, M u,u is the circulating hydrogen gas flow rate of the uth hydrogen-using unit, M u′,u is the gas flow from the u′th hydrogen-using unit to hydrogen-using unit u, M u,u and M u′,u The units are all kmol / h, and US is the set of all hydrogen-using units; Purity balance at the inlet of the uth hydrogen unit: in, is the hydrogen purity of the gas at the inlet of the u-th hydrogen-using unit, is the purity of hydrogen at the ith hydrogen utility, is the hydrogen purity of the gas at the outlet of the u-th hydrogen-using unit; Material balance at the outlet of the uth hydrogen unit: in, is the total gas flow at the outlet of the uth hydrogen unit, M u is the gas flow from the uth hydrogen unit to the fuel system, and M u The unit of is kmol / h; Material balance at the fuel system inlet: Where MJ is the total gas flow rate entering the fuel system, in kmol / h; S3: According to the optimization results of the linear programming model LP, the total amount of hydrogen utilities is fixed as the minimum value, and the minimization of compression cost is taken as the objective function to establish a mixed integer linear programming model MILP for hydrogen network design; according to the optimization results of minimizing compression cost, the annual total cost TAC2 of the mixed integer linear programming model is calculated; the mixed integer linear programming model for hydrogen network design includes formulas (2)-(6) and (7)-(17): The objective function is to minimize the compression cost: Among them, Pw i,u is the power consumption of the gas compressor between the i-th hydrogen utility and the u-th hydrogen unit, Pw i is the power consumption of the gas compressor between the ith hydrogen utility and the fuel system, Pw u,u′ is the power consumption of the gas compressor between the uth hydrogen-using unit and the u′th hydrogen-using unit, Pw u,u is the power consumption of the circulating hydrogen compressor of the uth hydrogen-using unit, Pw u is the power consumption of the gas compressor between the u-th hydrogen unit and the fuel system, Pw i,u , Pw i , Pw u,u , Pw u,u′ and Pw u The unit of z is kW; i,u is an integer variable indicating whether there is a gas compressor between the i-th hydrogen utility and the u-th hydrogen unit, z i is an integer variable indicating whether there is a gas compressor between the i-th hydrogen utility and the fuel system, z u,u′ is an integer variable indicating whether there is a gas compressor between the uth hydrogen-using unit and the u′th hydrogen-using unit, z u is an integer variable indicating whether a gas compressor exists between the u-th hydrogen unit and the fuel system. is the annual operating time in hours, is the electricity price in $ / kWh, is the conversion factor of equipment cost, and It is the compressor equipment investment parameter; Constraint equations for the presence or absence of a compressor: in, is the compressor power consumption Pw i,u The upper limit of is the compressor power consumption Pw i The upper limit of is the power consumption of circulating hydrogen compressor Pw u,u The upper limit of is the compressor power consumption Pw u The upper limit of The calculation equation for compressor power consumption is: in, is the inlet pressure of the uth hydrogen-using unit, is the outlet pressure of the ith hydrogen utility, is the fuel system inlet pressure, is the inlet pressure of the u′th hydrogen unit, is the outlet pressure of the uth hydrogen unit, and The unit is kPa. is the compressor efficiency, is the gas compressibility factor, is the molar gas constant, is the gas temperature at the compressor inlet; S4: Without considering the circulating hydrogen compressor of the hydrogen unit, the compressors at the entrance of the hydrogen unit and the fuel system are combined to reduce the number of compressors, reduce the equipment investment cost, obtain the optimal design scheme, and calculate the third annual total cost TAC3; For each hydrogen unit, the inlet pressure of the hydrogen production compressor after the compressor inlet is combined Take the hydrogen utility pressure of the supply gas and hydrogen unit outlet pressure The minimum value in: Combined compressor outlet pressure Pressure at the inlet of hydrogen extraction unit Gas flow of the combined compressor Combined compressor power consumption Whether the merged compressor exists or not is an integer parameter express: A similar method is used to merge the compressors at the inlet of the fuel system to reduce the number of compressors; S5: On the basis of minimizing the use of hydrogen utilities and minimizing compression costs, the network design after merging the compressors in S4 is used as the scheme, Aspen Plus is used to simulate the power consumption of all compressors, and the annual total cost TAC4 based on process simulation of the hydrogen network design scheme is recalculated.

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