Methanol production system based on reaction-separation structure reconstruction and optimization design method and related device thereof

Abstract

The invention provides a methanol production system based on reaction-separation structure reconstruction as well as an optimization design method and related devices thereof. The methanol production system comprises a plurality of reactors, a plurality of separators, a heater and a cooler, the plurality of reactors and the plurality of separators are connected to form a plurality of reconfigurable reaction-separation structures; when the methanol production system operates, at least one reaction-separation structure is called. Reconstruction and time-sharing sharing are carried out on the reactor of the methanol production system under the condition of feeding fluctuation, the fluctuation adapting capacity of the methanol production system is improved, and high efficiency and high flexibility of the production system are guaranteed.

Description

Technical Field

[0001] The present invention relates to the fields of new energy and chemical engineering, and particularly to a methanol production system based on the reconstruction of reaction-separation structure, its optimization design method and related devices. Background Art

[0002] Vigorously developing renewable energy is the key way to promote the low-carbon transformation of the energy and power industry. However, renewable energy is volatile and intermittent, and its connection to the power grid will threaten the safe and stable operation of the power grid. The Power-to-Methanol (PtM) technology driven by renewable energy has become the key path to solve the large-scale consumption and medium- and long-term storage of renewable energy, providing a new solution for the consumption and storage of renewable energy. However, the volatility and intermittency of renewable energy are contrary to the requirements of the stable operation of conventional chemical production systems, making the design and operation of such methanol production systems still face challenges. Therefore, it is very necessary to develop a method to improve the operation flexibility and production quality of the methanol production system by optimizing the configuration or reconstructing the methanol reactor.

[0003] The research on how to improve the flexibility and production efficiency of the methanol production system has become a hot topic. At present, the flexibility and production efficiency of the methanol production system are mainly improved by setting up an energy storage unit and optimizing the configuration of the methanol production process. By adding an energy storage unit, the excess renewable energy is stored. When the supply of renewable energy is insufficient, the energy is released to smooth out the fluctuations of renewable energy and ensure the continuous and stable operation of the renewable methanol production system. At the same time, the problems of low production efficiency and frequent start-stop caused by supply fluctuations when the supply of renewable energy is insufficient are avoided. The commonly used energy storage units mainly include batteries and storage tanks. Among them, the battery energy storage has a faster response ability and can respond in a very short time. At the same time, the relatively stable operation of the electrolytic hydrogen production device can be ensured through battery energy storage, and the configuration and adjustment of the electrolytic hydrogen production device are simple. However, frequent charging and discharging will accelerate the battery degradation, and the battery cost is relatively high, and adding battery energy storage significantly reduces the economy of the system. The storage tank is another form of energy storage. By adding a storage tank, the hydrogen produced by electrolysis can be stored when the supply of renewable energy is high. When the hydrogen production rate is low, both electrolytic hydrogen production and hydrogen supply from the storage tank are used to ensure the stable operation of the backend production system. Compared with battery energy storage, the response speed of the storage tank is relatively slow and it is more inclined to long-term storage. Introducing a storage tank will additionally introduce additional facilities such as compressors and heat exchangers, increasing additional costs.

[0004] By optimizing the configuration or reconstructing the methanol reactor, the ability of the methanol production system to adapt to external fluctuations can be significantly improved while ensuring the production quality. The common structural configurations of methanol production systems mainly include single-stage reactors, multi-stage reactors, recycle reactors, pre-reforming reactors, and membrane reactors. By comparing the conversion rates and energy requirements for methanol production of several reactors, it is shown that pre-reforming reactors and recycle reactors are suitable for large-scale methanol production scenarios. The selective membrane of the membrane reactor can inhibit catalyst poisoning during the methanol production process and increase the service life of the catalyst. However, the methanol output of the membrane reactor is slightly lower than that of multi-stage reactors, and the cost of the membrane reactor is higher. Due to low energy requirements and high product yields, multi-stage reactors are the best process for producing methanol. However, the optimal number of stages of multi-stage reactors and the relationship between the number of stages and performance are not yet known. By constructing a superstructure model, the optimal configuration scheme of multi-stage reactors in the methanol production system can be determined. By setting different objective functions for solution, the methanol yield is optimal when two reactors are connected in parallel and each is connected in series with one reactor; the output of two reactors connected in parallel is higher than that of a single reactor, and the profit is the largest; the production scale range suitable for three-stage reactors is wider and the effect is better. The above studies mostly consider the performance of series reactors, but the structural configurations of parallel reactors, series-parallel reactors, and parallel-series reactors also have an impact on methanol production. Taking three reactors as an example, by changing the connection method, the flow rate ranges suitable for the structural configurations of the methanol production systems of series, parallel, series-parallel, and parallel-series reactors are determined. As the feed flow rate increases, the optimal structural configuration of the methanol production system will gradually transition from series reactors to parallel reactors, and the series-parallel reactor has the strongest anti-disturbance ability, while the series reactor has the weakest anti-interference ability.

[0005] In summary, there are many methanol production processes, the structural configurations of methanol production systems are variable, and the applicable scales, corresponding production efficiencies, and energy requirements of each structural configuration are different, ultimately resulting in differences in the economics of methanol production systems. Although fruitful explorations and research have been carried out on the performance of various types of methanol production systems, demonstrating the advantages of multi-stage reactors and reactor reconstruction in improving methanol production efficiency and system flexibility, the types of methanol production systems considered in current existing research are not yet complete, especially lacking the consideration of the coupling and connection methods of the methanol reaction-separation process. The introduction of a separator may change the applicable production range of multi-stage reactors and the existing reconstruction rules; in addition, existing research only focuses on the energy requirements and economics of methanol production systems under single feed conditions, lacking the analysis and evaluation of the comprehensive performance of the complete methanol production system under feed fluctuation conditions. Summary of the Invention

[0006] To solve the problems of the above-mentioned existing technologies, the present invention provides a methanol production system based on the reconstruction of reaction-separation structures, an optimization design method therefor, and related devices, which reconstruct and share the reactors of the methanol production system in a time-sharing manner under feed fluctuations, improve the ability of the methanol production system to adapt to fluctuations, and ensure the high efficiency and high flexibility of the production system.

[0007] The present invention is realized through the following technical solutions: In a first aspect, the present invention provides a methanol production system based on the reconstruction of reaction-separation structures, including a plurality of reactors, a plurality of separators, a heater, and a cooler; a plurality of reaction-separation structures that can be reconstructed are formed by connecting between the plurality of reactors and the plurality of separators; when the methanol production system operates, at least one reaction-separation structure is called; the output end of the reactor is connected to the input end of another reactor through the cooler, or the output end of the reactor is connected to the input end of the separator through the cooler, and the output end of the separator is connected to the input end of another reactor through the heater.

[0008] Preferably, the total feed flow rate of the methanol production system is obtained, and taking the total feed flow rate of the methanol production system as the input, the mathematical optimization design model of the methanol production system is solved to obtain a reconstruction plan for the reaction-separation structure and a feed flow rate distribution plan; the feed flow rate distribution plan refers to the distribution plan of the total feed flow rate of the methanol production system among different reaction-separation structures; the optimization objective of the mathematical optimization design model of the methanol production system is to maximize the annualized income.

[0009] Further, the objective function of the mathematical optimization design model of the methanol production system is: (1) Wherein, C re is the annualized income of the methanol production system, C inv is the investment cost of the methanol production system; C inv is the investment cost of the system, which can be expressed as (2) Wherein, i is the equipment type, is the basic cost of the equipment, is the reference feed of the equipment; is the maximum allowable feed of the equipment. is the maximum number of the equipment. is the equipment base number, α i and β i are respectively the scale factor and the quantity economic index factor of the equipment.

[0010] Annualization factor Af can be expressed as a discount rate r and the plant's expectations function of (3) C oper is the operating cost of the methanol production system, including the costs of cold and heat utility: (4) Among them, and are respectively the loads of cold utility and heat utility required for the reaction-separation structure selected for the t th time within the cycle m reaction-separation structure j , c cu and c hu are respectively the prices of cold utility and heat utility; DOP t and NOP are the cycle duration and the total time respectively.

[0011] C MeOH is the methanol sales revenue, expressed as: (5) Among them, c MeOH is the methanol selling price, d j,m,t is the methanol production volume of the reaction-separation structure selected for the t th time within the cycle m reaction-separation structure j .

[0012] Furthermore, the constraint conditions of the mathematical optimization design model of the methanol production system include: the inlet mass balance constraint of the methanol production system, the relationship constraint between the performance index of the methanol production system and the feed flow rate of the reaction-separation structure, the maximum load constraint of the unit equipment in the methanol production system, the upper and lower operation limits constraint of the reaction-separation structure, the quantity constraint of the reaction-separation structure, and the reactor number constraint in the reaction-separation structure; among them, the unit equipment includes coolers, heaters and separators.

[0013] Furthermore, the inlet mass balance constraint of the methanol production system is: (6) Among them, f j,m,t is for the cycle t th within the mThe second selected reaction-separation structure j The feed flow rate of q t is the cycle t The total feed flow rate provided to the methanol production system inward, T is the total number of cycles; The relationship constraint between the performance index of the methanol production system and the feed flow rate of the reaction-separation structure is: (7) (8) (9) (10) Among them, d j,m,t is in the cycle t The m The methanol production of the second selected reaction-separation structure j ; and are respectively in the cycle t The m The load of the cold utility and the load of the hot utility required by the second selected reaction-separation structure j ; is the cycle t The m The feed flow rate of the feed of the second selected reaction-separation structure j The n The feed flow rate of the separator; z j,m,t is a binary variable, indicating the reaction-separation structure in the cycle t The j The m Whether the second time is selected; f j,m,t is the cycle t The m The feed flow rate of the second selected reaction-separation structure j ; g d , g cu , g hu , g s Are respectively the independent variables , And the dependent variables , , And Function of; J is the type of reaction-separation structure; M is the number of times the same reaction-separation structure is selected in the cycle t , T is the total number of cycles; The relationship constraints between the performance indicators of the methanol production system and the feed flow rate of the reaction-separation structure are obtained by fitting the process simulation data of the methanol production system.

[0014] Furthermore, the maximum load constraints of the unit equipment in the methanol production system are as follows: (11) (12) (13) Wherein, , and respectively represent the maximum loads of the cooler, heater, and separator in all cycles; and are respectively the loads of the cold utility and the hot utility required for the reaction-separation structure t selected for the m th time in cycle j ; is the feed flow rate of the t th separator of the reaction-separation structure m selected for the j th time in cycle n .

[0015] Furthermore, the upper and lower operation limits of the reaction-separation structure are as follows: (14) Wherein, z j,m,t is a binary variable indicating whether the reaction-separation structure t is selected for the j th time in cycle m ; ψlow j and ψup j are respectively the lower and upper limits of the feed flow rate for the normal operation of the reaction-separation structure j ; f j,m,t is the feed flow rate of the reaction-separation structure t selected for the m th time in cycle j ; J is the type of the reaction-separation structure; M is the number of times the same reaction-separation structure is selected in cycle t , and T is the total number of cycles; The quantity constraint of the reaction-separation structure is: (15) The constraint on the number of reactors in the reaction-separation structure is: (16) Among them, is the number of reactors with a reaction-separation structure j and is the maximum value of the number of reactors in the methanol production system; The methanol product demand constraint of the reaction-separation structure is: The methanol products produced by the methanol production system should meet the minimum product demand.

[0016] (17) Among them, d j,m,t is the methanol production volume of the reaction-separation structure selected for the t th time within the cycle m and low j is the minimum product demand required by the methanol production system. d low

[0017] Secondly, the present invention provides an optimized design operation system for a methanol production system based on the reconstruction of a reaction-separation structure, including: A data acquisition module for acquiring the total feed flow rate of the methanol production system; A calculation module for solving a mathematical optimization design model of the methanol production system with the total feed flow rate of the methanol production system as the input to obtain a reconstruction plan for the reaction-separation structure and a feed flow rate distribution plan; the feed flow rate distribution plan refers to the distribution plan of the total feed flow rate of the methanol production system among different reaction-separation structures; the optimization objective of the mathematical optimization design model of the methanol production system is the highest annualized profit.

[0018] Thirdly, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that when the processor executes the computer program, it implements the optimized design method for the methanol production system based on the reconstruction of the reaction-separation structure as described above.

[0019] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, characterized in that when the computer program is executed by a processor, it implements the optimized design method for the methanol production system based on the reconstruction of the reaction-separation structure as described above.

[0020] Compared with the prior art, the present invention has the following beneficial effects: In view of the problem that conventional chemical production processes are difficult to adapt to the volatility of renewable energy, the present invention proposes a methanol production system based on the reconstruction of the reaction-separation structure. The reaction-separation structure can be reconstructed according to the change of the feed flow rate. Under the condition of feed fluctuations, the reactor of the methanol production system can be reconstructed and time-shared, thereby improving the ability of the methanol production system to adapt to feed fluctuations and ensuring the high efficiency and high flexibility of the production system to meet the production task of methanol.

[0021] The method for optimizing the design of a methanol production system based on the reconstruction of a reaction-separation structure involved in the present invention takes the total feed flow rate of the methanol production system as input and adopts a mathematical optimization design model with the maximum annualized benefit as the optimization target, thereby realizing the integrated optimization of the design and operation of the methanol production system, obtaining the configuration scheme and reconstruction scheme of the reaction-separation structure in the methanol production system when the annualized benefit is maximized, and the distribution ratio of raw materials such as hydrogen and carbon dioxide in the system, thereby ensuring the production efficiency of the system and improving the economy of the system while improving the flexibility of the system.

[0022] Furthermore, the present invention combines process simulation with mathematical modeling methods, and uses process simulation to obtain the relationship between the performance indicators of the methanol production system and the feed flow rate of the reaction-separation structure, and then constructs a mathematical optimization design model of the methanol production system, thereby ensuring the accuracy of the mathematical optimization design model of the methanol production system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A conceptual diagram of a reconfigurable reaction-separation structure; Figure 2 is a flow chart of the method of the present invention; Figure 3 A reconstruction scheme for the reaction-separation structure of the methanol production system; Figure 4 The flow rate distribution scheme for the reaction-separation structure of the methanol production system. DETAILED DESCRIPTION

[0025] The following specific examples illustrate the implementation modes of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] It should be noted that the process equipment or devices not specifically noted in the following examples all adopt conventional equipment or devices in the art.

[0027] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices. Moreover, unless otherwise specified, the numbers of each method step are only convenient tools for identifying each method step, rather than restricting the arrangement order of each method step or limiting the scope of implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in technical content, should also be regarded as the scope of implementation of the present invention.

[0028] The methanol production system of the present invention includes a compressor, a heater, a cooler, a reactor, a separator, and a rectification column. Among them, the raw materials are pressurized by the compressor, the pressurized raw materials are preheated by the heater, and then enter the reactor to react and synthesize methanol. After that, they are cooled by the cooler and enter the separator for pre-separation. The separated crude methanol solution is purified by the rectification column to obtain refined methanol. Among them, multiple reactors and multiple separators are connected to form a reconfigurable variety of reaction-separation structures ( Figure 1 ), in the structure, the reactor can be connected to the reactor or to the separator. That is, the output end of each reactor can be selectively connected or not connected to the separator, and the number of reactors in each reaction-separation structure is not limited. If the output end of the reactor is directly connected to another reactor, the two reactors are connected by a cooler; if the output end of the reactor is directly connected to the separator, the reactor and the separator are connected by a cooler, and the separator and the subsequent reactor are connected by a heater.

[0029] The forms of the reaction-separation structures in the present invention can include RS, 2RS, R-RS, 3RS, R-2RS, RS-R-RS, 2R-RS, R 2 S, R 2 S-RS, R 2 -RS, RS-R 2 S, R-R 2 S and R 3S, RS represents a reactor in series with a separator; 2RS represents two reactors in series with the output of the reactors connected to the separator, R-RS represents two reactors in series with the output of the last reactor connected to the separator; 3RS represents three reactors in series with the output of the reactors connected to the separator, R-2RS represents three reactors in series with the outputs of the last two reactors connected to the separator, RS-R-RS represents three reactors in series with the outputs of the first and third reactors connected to the separator, 2R-RS represents three reactors in series with the output of the third reactor connected to the separator; R 2 S represents two reactors in parallel followed by a separator in series; R 2 S-RS represents two reactors in parallel followed by a separator, a reactor, and a separator in series in that order, R 2 -RS represents two reactors in parallel followed by a reactor and a separator in series in that order; RS-R 2 S represents the output of a reactor connected in series with a separator and then connected to two reactors in parallel, and finally a separator in series, R-R 2 S represents the output of a reactor connected to two reactors in parallel, and finally a separator in series; R 3 S represents three reactors in parallel followed by a separator in series.

[0030] When the methanol production system operates, at least one reaction-separation structure is called. According to the feed flow rate of the methanol production system, the reconstruction scheme of the reaction-separation structure and the feed flow rate distribution scheme of different reaction-separation structures are adjusted. Specifically, the reconstruction scheme of the reaction-separation structure is optimized through the following method ( Figure 2 ).

[0031] (1) Process simulation of the methanol production system Through research, all possible reaction-separation structures in the methanol production system are enumerated. The reaction-separation structure refers to the structural configuration of the reactor and the separator. Based on this, software such as Aspen Plus and UniSim is used to perform process simulation modeling and simulation on the corresponding methanol production system under the above reaction-separation structures. By analyzing the steady-state operation characteristics of the reactor under different system feed flow rates, the stable feed interval for the safe operation of the reactor is clarified. Then, according to the stable feed interval of the reactor, the infeasible reaction-separation structures are eliminated, and the safe fluctuation range of the feed flow rate of all selected feasible reaction-separation structures is determined. Finally, through sensitivity analysis, the input-output data corresponding to each feasible reaction-separation structure is obtained, and the relationships between the input and the system performance indicators of the feasible reaction-separation structures in the methanol production system are obtained by means of polynomial fitting, surrogate models, linear regression, etc., mainly including the relationship between methanol production and the system feed flow rate, and the relationships between the consumption of cold and heat utility in the methanol production system and the system feed flow rate, that is, the formulas (7)-(10) in the mathematical optimization design model of the corresponding methanol production system.

[0032] (2) Mathematical Modeling and Optimization Solution of Methanol Production System 1) Objective Function The optimization objective of the methanol production system is the annualized profit C re to be the highest, that is, the difference between the product profit and the total expenditure of the methanol production system is the largest, and the total expenditure of the methanol production system includes two parts: the investment and the operating cost of the methanol production system.

[0033] (1) C inv is the investment cost of the methanol production system and can be expressed as: (2) Among them, i is the equipment type, including reactors, separators, heaters, and coolers; is the basic cost of equipment i ; is the reference feed flow rate of equipment i ; is the maximum allowable feed flow rate of equipment i ; is the maximum number of equipment i ; is the base number of equipment i ; α i and β i are respectively the equipment iThe scale and the quantity economic index factor.

[0034] Annualization factor Af Can be expressed as the discount rate r And the plant expectation Function of: (3) C oper Is the operating cost of the methanol production system, including the costs of cold utility and heat utility: (4) Among them, And Are respectively the loads of cold utility and heat utility required for the reaction-separation structure selected for the t th m time within the cycle j Cold utility is the energy required for cooling, and heat utility is the energy required for heating. c cu And c hu Are respectively the prices of cold utility and heat utility; DOP t And NOP are respectively the cycle duration and the total time.

[0035] C MeOH Is the methanol sales revenue, which can be expressed as: (5) Among them, c MeOH Is the methanol selling price, d j,m,t Is the methanol production volume of the reaction-separation structure selected for the t th m time within the cycle j Volume.

[0036] 2) Constraints ① Mass balance at the inlet of the methanol production system The sum of the feed flow rates of all reaction-separation structures should exactly equal the total feed flow rate provided to the methanol production system.

[0037] (6) Among them, f j,m,t Is the feed flow rate of the reaction-separation structure selected for the t th m time within the cycle j Volume, q t Is the cyclet The total feed flow rate provided to the methanol production system.

[0038] ② Relationship between the performance indicators of the methanol production system and the inputs of the reaction-separation structure The relationships between the methanol production, cold utility consumption, hot utility consumption of the methanol production system, and the feed flow rates of each separator and the feed flow rate of the reaction-separation structure can be described as follows: (7) (8) (9) (10) Wherein, is the cycle t within the m th selected reaction-separation structure j of the n th separator feed flow rate, z j,m,t is a binary variable indicating whether the reaction-separation structure t within the cycle j the m th time is selected. g d , g cu , g hu , g s are respectively functions of the independent variables , and the dependent variables , , and . The specific expressions are obtained by fitting the process simulation data of the above methanol production system. J is the type of reaction-separation structure; M is the number of times the same reaction-separation structure is selected within the cycle t , and T is the total number of cycles.

[0039] ③ Maximum load of unit equipment in the methanol production system The maximum loads for calculating the investment costs of coolers, heaters, and separators should be greater than the maximum loads corresponding to each cycle.

[0040] (11) (12) (13) Wherein, , and respectively represent the maximum loads of the cooler, heater, and separator in all cycles, i.e., the maximum cold utility consumption, hot utility consumption, and separator feed flow rate.

[0041] ④ Operating upper and lower limit constraints of the reaction-separation structure If the reaction-separation structure j is selected, the feed flow rate of this reaction-separation structure should satisfy its flow rate boundary limit constraint, and the feed flow rate should be within the safe fluctuation range.

[0042] (14) Among them, z j,m,t is a binary variable representing whether the reaction-separation structure t in cycle j the m th time is selected, ψlow j and ψup j are respectively the lower and upper limits of the feed flow rate for the normal operation of the reaction-separation structure j .

[0043] ⑤ Number constraint of the reaction-separation structure Within the same cycle t the number of times the same reaction-separation structure is selected cannot exceed M times.

[0044] (15) ⑥ Reactor number constraint in the reaction-separation structure The number of reactors in the reaction-separation structure should not exceed the maximum value of the allowable number of reactors, i.e.: (16) Among them, is the number of reactors of the reaction-separation structure j , is the maximum value of the number of reactors in the methanol production system.

[0045] ⑦ Methanol product demand The methanol production of the methanol production system should at least meet the minimum production demand.

[0046] (17) Among them, d low is the minimum methanol production demand required by the methanol production system.

[0047] The reaction-separation structure of the present invention can be reconstructed according to the change of the feed flow rate to meet the methanol production task. The present invention combines process simulation and mathematical modeling methods to construct a mathematical optimization design model of the methanol production system based on the reconstruction of the reaction-separation structure, and obtains the design scheme of the methanol production system to cope with feed fluctuations, including the number of reactors, the number of separators, the methanol production, the required cooling and heating utility consumption, and the maximum profit of the optimized methanol production system. At the same time, this method can also obtain the reconstruction and flow rate allocation scheme of the reaction-separation structure in the methanol production system. As Figure 3 and Figure 4 are the reconstruction schemes of the corresponding optimal reaction-separation structure and the feed flow rate allocation scheme in the 3-stage methanol production system under 5 different feed flow rates.

[0048] Figure 3 represents the reconstruction scheme of the reaction-separation structure in the methanol production process obtained in the embodiment of the present invention, and a total of 5 reaction-separation structures are called. Among them, 3RS means that three reactors are connected in series and a separator is set behind the reactor, 2RS means that two reactors are connected in series and a separator is set behind the reactor, RS means that one reactor is connected in series with one separator, R 2 S-RS means that two reactors are connected in parallel first and then one reactor is connected in series, and a separator is set behind the reactor, R 2 S means that two reactors are connected in parallel and then one separator is connected in series. It can be seen from the figure that the call number of the 3RS structure increases from 1 to 3 with the increase of the feed flow rate. When the 3RS structure cannot meet the production task and continuing to increase the call number will increase the investment cost, consider using other structures to replace 3RS, and first consider using a series structure to replace it. When the feed cannot be completely consumed, then consider other types of structures.

[0049] Figure 4 represents the flow rate allocation scheme in different cycles obtained in the embodiment of the present invention. The solid line represents the upper limit of the feed of the reaction-separation structure, the short dash line represents being in the feed interval, and the dotted line represents the lower limit of the reaction-separation feed flow rate of the structure. In the same cycle, when choosing the same reaction-separation structure, on the basis of ensuring that the feed flow rates of all reaction-separation structures reach the operation lower limit, make as many reaction-separation structures as possible reach the feed flow rate upper limit; in the same cycle, when choosing different reaction-separation structures, on the basis of ensuring that the feed flow rates of all reaction-separation structures reach the operation lower limit, make the reaction-separation structures with better performance as much as possible reach the feed flow rate upper limit.

[0050] By adopting an optimized design method, the present invention constructs a mathematical optimization design model of a methanol production system considering the reconstruction of the reaction-separation structure, and realizes the reconstruction scheme and scheduling strategy of the reaction-separation structure in the methanol production system under feed fluctuations. Through the optimized configuration or reconstruction of the reaction-separation structure, the flexible absorption of feed fluctuations is achieved, and the goals of improving the system flexibility and system production efficiency are reached. Through the integrated optimization method of design and operation, the selection priority of the reaction-separation structure of the methanol production system and the reconstruction rules when the feed flow rate changes are determined, providing guidance for the safe and stable operation of the subsequent methanol production system.

[0051] The following is the device embodiment of the present invention, which can be used to execute the method embodiment of the present invention. For the details not disclosed in the device embodiment, please refer to the method embodiment of the present invention.

[0052] In one embodiment of the present invention, an optimized design operation system of a methanol production system based on the reconstruction of the reaction-separation structure is provided, including: A data acquisition module for acquiring the total feed flow rate of the methanol production system; A calculation module for taking the total feed flow rate of the methanol production system as an input, solving the mathematical optimization design model of the methanol production system, and obtaining a reconstruction scheme of the reaction-separation structure and a feed flow rate distribution scheme; the feed flow rate distribution scheme refers to the distribution scheme of the total feed flow rate of the methanol production system among different reaction-separation structures; the optimization goal of the mathematical optimization design model of the methanol production system is the highest annualized profit.

[0053] In another embodiment of the present invention, a computer device is provided. The computer device includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method process or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the design method of the methanol production system based on the reconstruction of the reaction-separation structure.

[0054] In another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. Moreover, one or more instructions suitable for being loaded and executed by the processor are stored in this storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the design method of the methanol production system based on the reaction-separation structure reconstruction in the above embodiments.

[0055] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0056] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0057] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the process inFigure 1 one process or multiple processes and / or blocks Figure 1 the functions specified in one block or multiple blocks.

[0058] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A methanol production system based on the reconstruction of the reaction-separation structure, characterized in that, It includes multiple reactors, multiple separators, a heater and a cooler; a reconfigurable variety of reaction-separation structures are formed by connecting the multiple reactors and the multiple separators; when the methanol production system operates, at least one reaction-separation structure is called; the output end of the reactor is connected to the input end of another reactor through the cooler, or the output end of the reactor is connected to the input end of the separator through the cooler, and the output end of the separator is connected to the input end of another reactor through the heater.

2. The optimization design method of the methanol production system based on the reconstruction of the reaction-separation structure according to claim 1, characterized in that Obtain the total feed flow rate of the methanol production system, use the total feed flow rate of the methanol production system as the input, solve the mathematical optimization design model of the methanol production system, and obtain the reconstruction plan of the reaction-separation structure and the feed flow rate distribution plan; the feed flow rate distribution plan refers to the distribution plan of the total feed flow rate of the methanol production system among different reaction-separation structures; the optimization objective of the mathematical optimization design model of the methanol production system is to maximize the annualized profit.

3. The optimization design method of the methanol production system based on the reconstruction of the reaction-separation structure according to claim 2, characterized in that The objective function of the mathematical optimization design model of the methanol production system is: （1） Among them, C re is the annualized income of the methanol production system, C inv is the investment cost of the methanol production system; C inv The investment cost of the system, expressed as （2） Among them, i is the device type, is the basic cost of the device, is the reference feed of the device; is the maximum allowable feed of the device, is the maximum number of devices, is the device base number, α i and β i are the scaling factor and the economies of scale index factor of the device respectively; Annualization factor Af Expressed as a discount rate r and plant expectations Function of: （3） C oper is the operating cost of the methanol production system, including the costs of cold and heat utility: （4） Among them, and are respectively the loads of cold utility and hot utility required for the t th m selection of the reaction-separation structure j within the cycle, c cu and c hu are respectively the prices of cold utility and hot utility; DOP t and NOP are the cycle duration and the total time respectively; C MeOH For the methanol sales revenue, expressed as: （5） Among them, c MeOH is the selling price of methanol, d j,m,t is within the cycle t the m th selected reaction-separation structure j methanol production.

4. The optimization design method of the methanol production system based on the reconstruction of the reaction-separation structure according to claim 2, characterized in that, The constraint conditions of the mathematical optimization design model of the methanol production system include: the inlet mass balance constraint of the methanol production system, the relationship constraint between the performance index of the methanol production system and the feed flow rate of the reaction-separation structure, the maximum load constraint of the unit equipment in the methanol production system, the upper and lower operation limits constraint of the reaction-separation structure, the quantity constraint of the reaction-separation structure, the number constraint of the reactors in the reaction-separation structure, and the methanol product demand constraint of the reaction-separation structure; among them, the unit equipment includes coolers, heaters and separators.

5. The optimization design method of the methanol production system based on the reconstruction of the reaction-separation structure according to claim 4, characterized in that The inlet mass balance constraint of the methanol production system is: （6） Among them, q t is the period t The total feed flow rate provided to the methanol production system inward, T is the total number of cycles; The relationship constraint between the performance index of the methanol production system and the feed flow rate of the reaction-separation structure is: （7） （8） （9） （10） Among them, d j,m,t is the methanol production of the reaction-separation structure selected for the t th time within the cycle m ; j The methanol production; and are respectively the loads of cold utility and hot utility required for the reaction-separation structure selected for the t th time within the cycle m ; j The loads of cold utility and hot utility required; is the feed flow rate of the t th separator of the reaction-separation structure selected for the m th time within the cycle j ; n The feed flow rate of the separator; z j,m,t is a binary variable indicating whether the reaction-separation structure t is selected for the j th time within the cycle m ; f j,m,t is the feed flow rate of the reaction-separation structure selected for the t th time within the cycle m ; j The feed flow rate; g d , g cu , g hu , g s are respectively functions of the independent variables , and the dependent variables , , and ; J is the type of reaction-separation structure; M is the number of times the same reaction-separation structure is selected within the cycle t , and T is the total number of cycles; The relationship constraint between the performance index of the methanol production system and the feed flow rate of the reaction-separation structure is obtained by fitting the process simulation data of the methanol production system.

6. The optimization design method of the methanol production system based on the reconstruction of the reaction-separation structure according to claim 4, characterized in that The maximum load constraint of the unit equipment in the methanol production system is: （11） （12） （13） Among them, , and respectively represent the maximum loads of the cooler, heater, and separator over all cycles; and are respectively the loads of cold utility and hot utility required for the reaction-separation structure t selected for the m th time in cycle j ; is the feed flow rate of the t th separator in the reaction-separation structure m selected for the j th time in cycle n .

7. The optimization design method of the methanol production system based on the reconstruction of the reaction-separation structure according to claim 4, wherein The upper and lower operation limits constraint of the reaction-separation structure is: （14） Among them, z j,m,t is a binary variable representing the period t the reaction-separation structure within j the m th selection or not; ψlow j and ψup j are respectively the lower and upper limits of the feed flow rate for the normal operation of the reaction-separation structure j ; f j,m,t is the period t the m th selected reaction-separation structure j feed flow rate; J is the type of reaction-separation structure; M is the number of times the same reaction-separation structure is selected within the period t ; T is the total number of periods; The quantity constraint of the reaction-separation structure is: （15） The number constraint of the reactors in the reaction-separation structure is: （16） Among them, is the number of reactors of the reaction-separation structure j , and is the maximum value of the number of reactors in the methanol production system; ​ The methanol product demand constraint of the reaction-separation structure is: （17） Wherein, d j,m,t is the methanol production amount of the reaction-separation structure t selected for the m th time within the cycle, j and d low is the minimum product demand required by the methanol production system.

8. An optimization design operating system for a methanol production system based on reaction-separation structure reconstruction, characterized in that, It includes: A data acquisition module for obtaining the total feed flow rate of the methanol production system; A calculation module for using the total feed flow rate of the methanol production system as the input, solving the mathematical optimization design model of the methanol production system, and obtaining the reconstruction plan of the reaction-separation structure and the feed flow rate distribution plan; the feed flow rate distribution plan refers to the distribution plan of the total feed flow rate of the methanol production system among different reaction-separation structures; the optimization objective of the mathematical optimization design model of the methanol production system is to maximize the annualized profit.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the optimization design method of the methanol production system based on the reconstruction of the reaction-separation structure according to any one of claims 2 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the optimization design method of the methanol production system based on the reconstruction of the reaction-separation structure according to any one of claims 2 to 7.

Images