Selection system

Abstract

It is problematic that it is difficult for an inexperienced designer of equipment, when selecting an operating condition for a piece of equipment, to select an operating condition for which the variable cost of the equipment is low. This selection system (1) comprises an input unit (211), a first calculation unit (212), a second calculation unit (213), and a selection unit (214). The input unit (211) inputs a constraint relating to the operation of a piece of equipment as well as the specifications and production volume of a product manufactured by the equipment. The first calculation unit (212) automatically executes a simulation of the operation of the equipment and calculates an operating condition candidate satisfying the constraint and the specifications and production volume of the product. The second calculation unit (213) calculates a variable cost for when the equipment is operated in accordance with the candidate which is the calculation result of the first calculation unit (212). The selection unit (214) automatically compares the variable costs corresponding to a plurality of the candidates so as to select a first operating condition, which is an operating condition candidate having a low variable cost, from among the plurality of candidates.

Description

Selection System

[0001] Regarding the selection system.

[0002] As disclosed in Patent Document 1 (JP 2014-094938 A), there is a technique in which a designer of equipment such as a rectification column selects operating conditions of the equipment to produce a target product.

[0003] When an inexperienced equipment designer selects the operating conditions of the equipment, the method disclosed in Patent Document 1 has a problem in that it is difficult to select operating conditions that reduce the variable costs of the equipment.

[0004] A selection system according to a first aspect selects operating conditions for equipment with low costs, including variable costs of the equipment. The selection system includes an input unit, a first calculation unit, a second calculation unit, and a selection unit. The input unit inputs constraints related to the operation of the equipment, specifications of the product manufactured by the equipment, and the production volume of the product. The first calculation unit automatically executes a simulation of the operation of the equipment and calculates candidate operating conditions that satisfy the constraints, specifications, and production volume. The second calculation unit calculates the variable costs when the equipment is operated according to the candidates that are the calculation results of the first calculation unit. The selection unit repeatedly performs calculations by the first calculation unit and the second calculation unit. The selection unit automatically compares the variable costs corresponding to the multiple candidates and selects a first operating condition, which is a candidate operating condition with low variable costs, from the multiple candidates.

[0005] In the selection system according to the first aspect, the selection unit repeatedly performs calculations by the first calculation unit and the second calculation unit. The selection unit automatically compares variable costs corresponding to a plurality of candidates and selects, from the plurality of candidates, a first operating condition that is a candidate for an operating condition with low variable costs. As a result, the selection system can select operating conditions that will reduce the variable costs of the equipment, instead of an inexperienced equipment designer.

[0006] A second aspect of the selection system is the selection system of the first aspect, wherein the facility includes a fractionator that refines a feedstock to produce a product, and the operating conditions of the facility include at least one of the number of stages of the fractionator, the operating pressure, the feedstock feed stage, and the reflux amount.

[0007] A third aspect of the selection system is the selection system of the second aspect, wherein the equipment purifies the feedstock by extractive distillation, and the operating conditions of the equipment further include at least one of an extractant feed stage of the rectification column and an extractant flow rate.

[0008] A fourth aspect of the selection system is the selection system of the first aspect, in which the equipment includes a fractionator for purifying a raw material, a heater installed at the bottom of the fractionator, and a cooler installed at the top of the fractionator, and the variable costs include costs related to the raw material and utility costs for the heater and the cooler.

[0009] A fifth aspect of the selection system is the selection system of the fourth aspect, wherein the facility purifies the raw material by extractive distillation. The facility further includes an extractant cooler that cools the extractant. The variable costs further include costs related to the extractant and utility costs for the extractant cooler.

[0010] A sixth aspect of the present invention is a selection system according to any one of the first to fifth aspects, wherein the cost is a variable cost of the existing facility. The input unit further allows the user to input specifications of the facility.

[0011] A seventh aspect of the selection system is the selection system of any one of the first to fifth aspects, wherein the costs are the equipment installation cost and the variable cost of the equipment required to install the equipment. The first calculation unit automatically executes a simulation of the equipment operation to calculate candidate operating conditions that satisfy the constraints, specifications, and production volume, and candidate equipment specifications that satisfy the constraints, specifications, and production volume. The second calculation unit calculates the equipment installation cost and the variable cost when the equipment is operated in accordance with the candidates that are the calculation results of the first calculation unit. The selection unit repeatedly performs calculations by the first calculation unit and the second calculation unit. The selection unit automatically compares the equipment installation costs and variable costs corresponding to the multiple candidates, and selects, from the multiple candidates, second operating conditions that are candidate operating conditions and first equipment specifications that are candidate equipment specifications, which have the lowest total equipment installation cost and variable cost.

[0012] In the selection system of the seventh aspect, the selection unit repeatedly performs calculations by the first calculation unit and the second calculation unit. The selection unit automatically compares the equipment installation costs and variable costs corresponding to a plurality of candidates and selects, from the plurality of candidates, second operating conditions, which are candidate operating conditions, and first specifications, which are candidate equipment specifications, that have a low total of the equipment installation cost and variable costs. As a result, the selection system can select operating conditions that result in low equipment installation costs and variable costs, instead of an inexperienced equipment designer.

[0013] A selection system according to an eighth aspect is the selection system according to any one of the first to seventh aspects, wherein the input unit inputs a plurality of input items for the constraints, specifications, and production volume. The plurality of input items include required input items and optional input items.

[0014] A ninth aspect of the present invention relates to the selection system of the eighth aspect, wherein the input unit further allows the user to input a type of equipment. The input unit changes required input items for the constraints according to the input type of equipment.

[0015] A selection system according to a tenth aspect is a selection system according to any one of the first to ninth aspects, in which the selection unit selects the first operating conditions using an optimization algorithm that updates the operating conditions so as to reduce variable costs.

[0016] FIG. 1 is a schematic configuration diagram of equipment. FIG. 2 is a functional block diagram of a selection system. FIG. 3 is a diagram showing an overview of a calculation process of an objective function in the first embodiment. FIG. 4 is a diagram showing examples of types of equipment. FIG. 5 is a flowchart for explaining an example of the processing of the selection system in the first embodiment. FIG. 6 is a diagram showing an overview of a calculation process of an objective function in Modification 1B. FIG. 7 is a flowchart for explaining an example of the processing of the selection system in Modification 1B. FIG. 8 is a diagram showing an overview of a calculation process of an objective function in the second embodiment. FIG. 9 is a flowchart for explaining an example of the processing of the selection system in Modification 2B. FIG. 10 is a schematic configuration diagram of equipment that purifies a raw material by extractive distillation. FIG. 11 is a diagram showing examples of types of equipment that purify a raw material by extractive distillation.

[0017] First Embodiment (1) Overall Configuration The selection system 1 selects operating conditions for the facility 10 that minimize the cost of the facility 10. The facility 10 and the selection system 1 will be described in detail below.

[0018] (2) Detailed Configuration (2-1) Equipment The equipment 10 produces target products by distilling and purifying raw materials. Examples of the products include refrigerants (R32, R125, R22, R134a, R143a, R1234yf, R1234ze, R1233zd, E-1132, 1123, 152a), etchants (R23, R14, R41, R116, C318, HF), monomers (TFE, HFP (CFCF=CF), VDF (CF=CH)), chemical products (IF5, CVE (CFOCF=CF)), etc. FIG. 1 is a schematic diagram of the equipment 10. 1, the facility 10 mainly includes a rectification column 11, a reboiler 12 (heater), and a condenser 13 (cooler). The facility 10 is an existing facility.

[0019] The rectification tower 11 distills and refines the feedstock. In other words, the rectification tower 11 separates multiple compounds with different boiling points contained in the feedstock. The rectification tower 11 is formed with multiple stages 14. One of the multiple stages 14 is a feedstock feed stage 14a for supplying the feedstock into the rectification tower 11. Another of the multiple stages 14 is a side cut stage 14b for extracting a side cut liquid or a side cut gas from the rectification tower 11. The side cut liquid or the side cut gas extracted from the side cut stage 14b is stored in a side cut tank 18.

[0020] The reboiler 12 is installed in the bottom 11b of the rectification column 11. The reboiler 12 heats the raw material by performing heat exchange between the raw material and a heat medium.

[0021] The condenser 13 is installed at the top 11t of the rectification column 11. The condenser 13 cools the vapor by performing heat exchange between the vaporized raw material and a heat medium. The condenser 13 is a vertical condenser.

[0022] When the raw material is supplied to the raw material feed stage 14a in the rectification column 11, a portion of the supplied raw material accumulates in the column bottom 11b, and the remainder flows out from the column bottom 11b. Of the raw material flowing out from the column bottom 11b, a portion is stored in the bottoms tank 19 as bottoms, and the remainder flows into the reboiler 12. The raw material flowing into the reboiler 12 is heated by the heat transfer medium to become steam. The steam flows into the column bottom 11b, rises in countercurrent contact with the raw material, and flows out from the column top 11t. The steam flowing out from the column top 11t flows into the condenser 13. The steam flowing into the condenser 13 is cooled by the heat transfer medium to become condensed liquid or uncondensed gas, which flows out from the condenser 13. A portion of the condensed liquid flowing out from the condenser 13 flows into the rectification column 11 as reflux liquid, and the remainder is stored in the distillation tank 17 as distillate or uncondensed gas.

[0023] (2-2) Selection System Fig. 2 is a functional block diagram of the selection system 1. As shown in Fig. 2, the selection system 1 includes a server device 2 and a user terminal 3. The server device 2 and the user terminal 3 are communicatively connected via a network NW. The network NW is, for example, the Internet, a LAN, or a WAN.

[0024] (2-2-1) Server Device The server device 2 selects operating conditions for the facility 10 that satisfy predetermined constraints and minimize the cost of the facility 10, based on input from the user terminal 3. In other words, the server device 2 is a device for solving an optimization problem in which, with the cost of the facility 10 as an objective function, operating conditions for the facility 10 are selected that satisfy predetermined constraints and minimize the value of the objective function.

[0025] Fig. 3 is a diagram showing an overview of the calculation process of the objective function in this embodiment. Fig. 3 shows the calculation process of the objective function when one operating condition of the equipment 10, which is a variable in the optimization problem, is selected from a search range of operating conditions of the equipment 10. The operating condition of the equipment 10 is automatically selected from the search range by an optimization algorithm.

[0026] As shown in flow F1, the server device 2 performs a model calculation of the rectification column 11 (hereinafter, sometimes referred to as a rectification column model calculation) based on the operating conditions of the equipment 10 selected from the search range and the specifications of the equipment 10 included in the input from the user terminal 3. After completing the rectification column model calculation, the server device 2 performs a model calculation of the heat exchanger (reboiler 12 and condenser 13) (hereinafter, sometimes referred to as a heat exchanger model calculation) based on the output of the rectification column model calculation and the specifications of the equipment 10, as shown in flow F2. After completing the heat exchanger model calculation, the server device 2 performs a flooding calculation of the condenser 13 (hereinafter, sometimes referred to as a vertical condenser flooding calculation) based on the output of the rectification column model calculation and the specifications of the equipment 10, as shown in flow F3. The vertical condenser flooding calculation is a calculation necessary because the condenser 13 is a vertical condenser. When the server device 2 completes the vertical condenser flooding calculation, as shown in flow F4, it determines whether the outputs of the rectification column model calculation, the heat exchanger model calculation, and the vertical condenser flooding calculation satisfy the constraints included in the input from the user terminal 3. If the constraints are satisfied, as shown in flow F5, the server device 2 calculates the cost of the facility 10 (hereinafter, sometimes referred to as cost calculation) based on the output of the rectification column model calculation and the specifications of the facility 10. When the server device 2 completes the cost calculation, as shown in flow F6, it sets the output of the cost calculation as the value of the objective function corresponding to the selected operating conditions of the facility 10.

[0027] As shown in FIG. 2 , the server device 2 includes a control and arithmetic device 21, a storage device 22, an input device 23, an output device 24, and a communication device 25. The control and arithmetic device 21 is a processor such as a CPU or a GPU. The storage device 22 is a storage medium such as a RAM, a ROM, or a HDD. The control and arithmetic device 21 reads programs for implementing functional blocks and performs predetermined arithmetic processing in accordance with the programs. Furthermore, the control and arithmetic device 21 can write arithmetic results to the storage device 22 and read information stored in the storage device 22 in accordance with the programs. In this embodiment, the storage device 22 particularly stores a process simulator 221, optimization software 222, and general spreadsheet software 223, which will be described later. The input device 23 is, for example, a keyboard and a mouse. The output device 24 is, for example, a monitor. The communication device 25 is a network interface device for communicating with the user terminal 3 via the network NW.

[0028] As shown in FIG. 2, the control and arithmetic device 21 has, as main functional blocks, an input unit 211, a first arithmetic unit 212, a second arithmetic unit 213, and a selection unit 214.

[0029] (2-2-1-1) Input Unit The input unit 211 allows a user to input, via the user terminal 3, constraints on the operation of the equipment 10, the specifications of the products manufactured by the equipment 10, and the production volume of the products manufactured by the equipment 10. The constraints on the operation of the equipment 10, the specifications of the products manufactured by the equipment 10, and the production volume of the products manufactured by the equipment 10 correspond to constraint conditions in the optimization problem. In this embodiment, the constraints on the operation of the equipment 10 include the upper limit of the flooding rate of the rectification tower 11, which is the output of the rectification tower model calculation; the lower limit (the outlet temperature of the heat medium of the condenser 13) of the outlet temperature of the fluid to be rectified in the condenser 13 (hereinafter, sometimes referred to as the top temperature of the rectification tower 11), which is the output of the rectification tower model calculation; the upper limit of the temperature of the bottom 11b of the rectification tower 11, which is the output of the rectification tower model calculation; the lower limit of the margin of the heat transfer area of ​​the condenser 13, which is the output of the heat exchanger model calculation; and the upper limit of the flooding rate of the condenser 13, which is the output of the vertical condenser flooding calculation. The product specifications include the product compound name, product purity, impurity concentration in the product, product recovery amount, product recovery rate, product loss flow rate, product loss rate, etc. The product production volume includes the target production volume for each component of the product, etc. The input unit 211 allows the user to input multiple input items for the constraints on the operation of the equipment 10, the product specifications, and the product production volume. The plurality of input items may include required input items and optional input items.

[0030] The input unit 211 also allows a user to input specifications of the equipment 10 via the user terminal 3. In this embodiment, the specifications of the equipment 10 include raw material feed conditions (amount, composition, pressure, temperature), current operating pressure, the number of stages of the rectification column 11, the column diameter of the rectification column 11, the packed length of the rectification column 11, the specifications of the packing of the rectification column 11 (material, type, etc.), the specifications of the condenser 13, the inlet pressure of the condenser 13, the inlet temperature of the heat medium of the condenser 13, the outlet temperature of the heat medium of the condenser 13, the fouling coefficients on each side of the shell and tube of the condenser 13, the film heat transfer coefficients on each side of the shell and tube of the condenser 13, the specifications of the tube of the condenser 13, the marginal cost of the product, the annual operating hours, and the utility costs of each device. The specifications of the equipment 10 may further include the type of heat medium of the reboiler 12 and the type of heat medium of the condenser 13.

[0031] Furthermore, in order to efficiently solve the optimization problem, the input unit 211 allows the user to input a search range for the operating conditions of the equipment 10 via the user terminal 3. The operating conditions of the equipment 10 include at least one of the number of stages of the distillation tower 11, the operating pressure of the distillation tower 11, the raw material feed stage 14a of the distillation tower 11, and the reflux amount of the distillation tower 11. The operating conditions of the equipment 10 may further include the distillate amount of the distillation tower 11, etc.

[0032] The input unit 211 also allows the user to input the type of equipment 10 via the user terminal 3. FIG. 4 is a diagram showing examples of types of equipment 10. The input unit 211 allows the user to input, for example, one type of equipment 10 from five types X1 to X4, Y1, and Y2 of equipment 10 shown in FIG. 4. Type X1 supplies raw material to the distillation column 111 and extracts uncondensed gas, a side cut liquid as a product, and bottoms from the distillation column 111. Type X2 supplies raw material to the distillation column 111 and extracts uncondensed gas, a side cut gas as a product, and bottoms from the distillation column 111. The type of equipment 10 shown in FIG. 1 corresponds to type X1 or type X2. Type X3 supplies raw material to the distillation column 111 and extracts a distillate as a product and bottoms from the distillation column 111. Type X4 supplies raw material to rectification column 111 and extracts uncondensed gas and bottoms as a product from rectification column 111. Types Y1 and Y2 have two rectification columns 111 and 112. Type Y1 supplies raw material to rectification column 111 and extracts uncondensed gas and bottoms from rectification column 111. Type Y1 supplies the bottoms extracted from rectification column 111 to rectification column 112 and extracts a distillate and bottoms as a product from rectification column 112. Type Y2 supplies raw material to rectification column 111 and extracts uncondensed gas and bottoms from rectification column 111. Type Y2 supplies the uncondensed gas extracted from rectification column 111 to rectification column 112 and extracts uncondensed gas and bottoms as a product from rectification column 112. The input unit 211 changes the input items of the operating conditions, constraints, and specifications of the equipment 10 according to the input type of the equipment 10. In particular, the input unit 211 changes the required input items for constraints related to the operation of the equipment 10 according to the input type of the equipment 10.

[0033] (2-2-1-2) First Calculation Unit The first calculation unit 212 automatically executes a simulation of the operation of the equipment 10 and calculates candidate operating conditions for the equipment 10 that satisfy the constraints (constraints on the operation of the equipment 10, specifications of the products manufactured by the equipment 10, and production volume of the products manufactured by the equipment 10).

[0034] First, the first calculation unit 212 performs a rectification column model calculation. Specifically, the first calculation unit 212 inputs the operating conditions of the equipment 10 selected from the search range and the specifications of the equipment 10 into the process simulator 221, and outputs the product specifications, the production volume of the product, the heat exchange amount of the reboiler 12, the heat exchange amount of the condenser 13, the flooding rate of the rectification column 11, the physical properties of the fluid rectified in the condenser 13 (the flow rate, specific gravity, and viscosity of the gas phase at the top 11t of the rectification column 11, and the flow rate, specific gravity, viscosity, and surface tension of the liquid phase flowing out from the condenser 13), the temperature at the top of the rectification column 11, the temperature at the bottom 11b of the rectification column 11, the composition distribution in the rectification column 11, the temperature distribution in the rectification column 11, the material balance, and the like (corresponding to flow F1 in FIG. 3 ). At this time, the specifications of the facility 10 input to the process simulator 221 include the raw material feed conditions (amount, composition, pressure, temperature), the current operating pressure, the number of stages in the rectification column 11, the column diameter of the rectification column 11, the packed length of the rectification column 11, and the specifications of the packing material in the rectification column 11. The process simulator 221 uses, for example, a process simulation tool such as PRO / II or ASPEN.

[0035] Next, the first calculation unit 212 performs a heat exchanger model calculation. Specifically, the first calculation unit 212 inputs the output of the rectification column model calculation and the specifications of the equipment 10 into the process simulator 221, and outputs the logarithmic mean temperature difference of the reboiler 12, the margin of the heat transfer area of ​​the condenser 13, the required heat transfer coefficient of the condenser 13, the inlet temperature of the fluid to be rectified in the condenser 13, the outlet temperature of the fluid to be rectified in the condenser 13, and the logarithmic mean temperature difference of the condenser 13, etc. (This corresponds to flow F2 in FIG. 3 ). At this time, the output of the rectification column model calculation input to the process simulator 221 includes the amount of heat exchanged by the reboiler 12 and the amount of heat exchanged by the condenser 13. The specifications of the equipment 10 to be input into the process simulator 221 include the specifications of the condenser 13, the inlet pressure of the condenser 13, the inlet temperature of the heat medium of the condenser 13, the outlet temperature of the heat medium of the condenser 13, the fouling coefficients on each side of the shell and tube of the condenser 13, and the film heat transfer coefficients on each side of the shell and tube of the condenser 13.

[0036] Next, the first calculation unit 212 performs a vertical condenser flooding calculation. Specifically, the first calculation unit 212 uses, for example, spreadsheet software 223 to calculate the flooding rate of the condenser 13 and other parameters from the output of the rectification column model calculation and the specifications of the equipment 10 using a predetermined relational expression (corresponding to flow F3 in FIG. 3 ). At this time, the output of the rectification column model calculation, which is input into the predetermined relational expression, includes the physical property values ​​of the fluid to be rectified in the condenser 13. The specifications of the equipment 10, which are input into the predetermined relational expression, include the specifications of the tube of the condenser 13.

[0037] Next, the first calculation unit 212 determines whether the outputs of the rectification column model calculation, the heat exchanger model calculation, and the vertical condenser flooding calculation satisfy the constraint conditions (corresponding to flow F4 in FIG. 3 ). Specifically, the first calculation unit 212 determines whether the flooding rate of the rectification column 11, which is the output of the rectification column model calculation, the top temperature of the rectification column 11, which is the output of the rectification column model calculation, the temperature of the bottom 11b of the rectification column 11, which is the output of the rectification column model calculation, the margin of the heat transfer area of ​​the condenser 13, which is the output of the heat exchanger model calculation, and the flooding rate of the condenser 13, which is the output of the vertical condenser flooding calculation, satisfy the constraint conditions included in the input from the user terminal 3, namely, the upper limit of the flooding rate of the rectification column 11, the lower limit of the top temperature of the rectification column 11, the upper limit of the temperature of the bottom 11b of the rectification column 11, the lower limit of the margin of the heat transfer area of ​​the condenser 13, and the upper limit of the flooding rate of the condenser 13, respectively. Furthermore, the first calculation unit 212 determines whether the product specifications and product production volume, which are the output of the rectification column model calculation, respectively satisfy the product specifications and product production volume in the constraint conditions included in the input from the user terminal 3. If the outputs of the rectification column model calculation, heat exchanger model calculation, and vertical condenser flooding calculation satisfy the constraint conditions, the first calculation unit 212 outputs the operating conditions of the equipment 10 used in the rectification column model calculation. If the outputs of the rectification column model calculation, heat exchanger model calculation, and vertical condenser flooding calculation do not satisfy the constraint conditions, the first calculation unit 212 performs the rectification column model calculation, heat exchanger model calculation, and vertical condenser flooding calculation using the operating conditions of the equipment 10 newly selected from the search range until the constraint conditions are satisfied.

[0038] (2-2-1-3) Second Calculation Unit The second calculation unit 213 uses, for example, spreadsheet software 223 to calculate the cost of the equipment 10 when it is operated in accordance with the candidate operating conditions of the equipment 10, which are the calculation results of the first calculation unit 212. In this embodiment, the cost of the equipment 10 is the variable cost of the equipment 10. The variable cost includes the cost of raw materials and the cost of utilities for the reboiler 12 and the condenser 13. The cost of raw materials is, for example, the cost of the product itself and the cost of product loss.

[0039] The second calculation unit 213 performs cost calculations. Specifically, the second calculation unit 213 calculates the variable costs of the equipment 10 using a predetermined relational expression based on the output of the rectification tower model calculation and the specifications of the equipment 10 (corresponding to flows F5 and F6 in FIG. 3). In this embodiment, the variable costs are calculated by "annual raw material loss + annual utility consumption cost." The annual raw material loss is calculated by "marginal cost of product × product loss flow rate × annual operating hours." The annual utility consumption cost is automatically calculated from the heat calculation results of the rectification tower model calculation. The annual utility consumption cost includes the annual steam cost of the reboiler 12 and the annual electricity cost of the condenser 13. The marginal cost of the product and the annual operating hours are also included in the specifications of the equipment 10.

[0040] (2-2-1-4) Selection Unit The selection unit 214 repeatedly performs the calculations by the first calculation unit 212 and the second calculation unit 213. The selection unit 214 automatically compares the costs corresponding to multiple candidates and selects a first operating condition, which is a candidate for an operating condition with a low cost, from the multiple candidates. The selection unit 214 selects the first operating condition using an optimization algorithm that updates the operating conditions so as to reduce the cost.

[0041] Specifically, the selection unit 214 inputs the operating conditions of the equipment 10 (variables in the optimization problem) calculated by the first calculation unit 212 and the cost of the equipment 10 (objective function in the optimization problem) corresponding to the operating conditions calculated by the second calculation unit 213 to the optimization software 222. Each time the selection unit 214 inputs the operating conditions to the optimization software 222, the selection unit 214 selects, as candidates for new operating conditions of the equipment 10, operating conditions of the equipment 10 within a search range that are expected to result in a smaller value of the objective function, output from the optimization software 222. The optimization software 222 may use, for example, commercially available tools such as modeFRONTIER, Optimus, and Isight. The optimization algorithm used may be a general optimization algorithm that employs, for example, a global search method such as a genetic algorithm or a local search method such as a gradient method.

[0042] (2-2-1-5) Output Unit The output unit 215 outputs the optimal operating conditions of the equipment 10 corresponding to the smallest objective function value, selected by the selection unit 214, to the user terminal 3. The output unit 215 may further output the output of the rectification column model calculation, the output of the heat exchanger model calculation, the output of the vertical condenser flooding calculation, and the output of the cost calculation, using the optimal operating conditions of the equipment 10, to the user terminal 3.

[0043] (2-2-2) User Terminal The user terminal 3 is a general-purpose personal computer. The user terminal 3 has processors such as a CPU and a GPU, and storage devices such as a RAM, a ROM, and an HDD. The user terminal 3 also has a keyboard, a mouse, and the like for inputting information. The user terminal 3 also has a display for displaying information. The user terminal 3 also has a network interface device for connecting to the network NW. The user terminal 3 also has general applications such as a web browser and a mailer installed.

[0044] A user accesses the server device 2 from a user terminal 3 via the network NW and inputs specifications and the like of the facility 10. The user terminal 3 also displays the optimal operating conditions and the like of the facility 10 output by the server device 2.

[0045] (3) Processing An example of processing performed by the selection system 1 in this embodiment will be described with reference to the flowchart of FIG.

[0046] As shown in step S1, the selection system 1 prompts the user to input the type of equipment 10 via the user terminal 3, and further prompts the user to input constraints, specifications of the equipment 10, and a search range for the operating conditions of the equipment 10 according to the type of equipment 10.

[0047] After completing step S1, the selection system 1 performs a rectification column model calculation based on the operating conditions of the equipment 10 selected from the search range and the specifications of the equipment 10, as shown in step S2.

[0048] After completing step S2, the selection system 1 performs a heat exchanger model calculation based on the output of the rectification column model calculation and the specifications of the equipment 10, as shown in step S3.

[0049] After completing step S3, the selection system 1 performs a vertical condenser flooding calculation in step S4 based on the output of the rectification column model calculation and the specifications of the facility 10. Note that the selection system 1 may perform the heat exchanger model calculation in step S3 and the vertical condenser flooding calculation in step S4 in parallel.

[0050] After completing step S4, the selection system 1 determines whether the outputs of the rectification column model calculation, the heat exchanger model calculation, and the vertical condenser flooding calculation satisfy the constraint conditions, as shown in step S5. If the constraint conditions are satisfied, the process proceeds to step S6. If the constraint conditions are not satisfied, the process returns to step S2, and the selection system 1 performs the rectification column model calculation, the heat exchanger model calculation, and the vertical condenser flooding calculation using the operating conditions of the equipment 10 newly selected from the search range.

[0051] When the selection system 1 proceeds from step S5 to step S6, it performs a cost calculation for the equipment 10 based on the output of the fractionator model calculation and the specifications of the equipment 10, and sets the output of the cost calculation as the value of the objective function.

[0052] After completing step S6, the selection system 1 inputs the operating conditions of the equipment 10 and the value of the objective function corresponding to those operating conditions into the optimization software 222, as shown in step S7, and selects the operating conditions of the equipment 10 within the search range that are expected to result in a smaller value of the objective function output from the optimization software 222 as candidates for the operating conditions of the new equipment 10.

[0053] After completing step S7, the selection system 1 determines, as shown in step S8, whether or not the operating conditions of the equipment 10 have been selected a predetermined number of times using the optimization software 222. If the operating conditions of the equipment 10 have been selected a predetermined number of times, the process proceeds to step S9. If the operating conditions of the equipment 10 have not been selected a predetermined number of times, the process returns to step S2, and the selection system 1 performs a rectification column model calculation, a heat exchanger model calculation, and a vertical condenser flooding calculation using the operating conditions of the equipment 10 selected using the optimization software 222.

[0054] When the selection system 1 proceeds from step S8 to step S9, it outputs to the user terminal 3 the optimal operating conditions of the equipment 10 corresponding to the minimum value of the objective function.

[0055] (4) Features (4-1) Conventionally, there is a technique in which a designer of equipment such as a rectification column selects the operating conditions of the equipment to manufacture a target product. When an inexperienced designer of equipment selects the operating conditions of the equipment, there is a problem in the conventional technique that it is difficult to select operating conditions that will reduce the variable costs of the equipment. Furthermore, even when an experienced designer of equipment selects the operating conditions of the equipment, there is a problem in that it is difficult to select operating conditions that will minimize the variable costs of the equipment.

[0056] The selection system 1 of this embodiment selects operating conditions for the equipment 10 that have low costs, including the variable costs of the equipment 10. The selection system 1 includes an input unit 211, a first calculation unit 212, a second calculation unit 213, and a selection unit 214. The input unit 211 inputs constraints on the operation of the equipment 10, the specifications of the product manufactured by the equipment 10, and the production volume of the product. The first calculation unit 212 automatically executes a simulation of the operation of the equipment 10 and calculates candidate operating conditions that satisfy the constraints on the operation of the equipment 10, the specifications of the product manufactured by the equipment 10, and the production volume of the product manufactured by the equipment 10. The second calculation unit 213 calculates the variable costs when the equipment is operated in accordance with the candidates that are the calculation results of the first calculation unit 212. The selection unit 214 causes the first calculation unit 212 and the second calculation unit 213 to repeatedly perform calculations. The selection unit 214 automatically compares the variable costs corresponding to the plurality of candidates and selects a first operating condition, which is a candidate for an operating condition with a low variable cost, from the plurality of candidates.

[0057] In the selection system 1 of this embodiment, the selection unit 214 repeatedly performs calculations by the first calculation unit 212 and the second calculation unit 213. The selection unit 214 automatically compares variable costs corresponding to multiple candidates and selects a first operating condition, which is a candidate operating condition with low variable costs, from the multiple candidates. As a result, the selection system 1 can select operating conditions that will reduce the variable costs of the facility 10, instead of an inexperienced designer of the facility 10. Furthermore, the selection system 1 can select operating conditions that will minimize the variable costs of the facility 10, instead of an experienced designer of the facility 10.

[0058] (4-2) In the selection system 1 of this embodiment, the equipment 10 includes a rectification column 11 that refines a raw material to produce a product. The operating conditions of the equipment 10 include at least one of the number of stages of the rectification column 11, the operating pressure of the rectification column 11, the raw material feed stage 14a of the rectification column 11, and the reflux amount of the rectification column 11.

[0059] (4-3) In the selection system 1 of this embodiment, the facility 10 includes a fractionator 11 that refines the raw material, a reboiler 12 installed in the bottom 11b of the fractionator 11, and a condenser 13 installed in the top 11t of the fractionator 11. The variable costs of the facility 10 include costs related to the raw material and utility costs for the reboiler 12 and condenser 13.

[0060] (4-4) In the selection system 1 of this embodiment, the cost is the variable cost of the existing facility 10. The input unit 211 further allows the specification of the facility 10 to be input.

[0061] (4-5) In the selection system 1 of this embodiment, the input unit 211 prompts the user to input a plurality of input items for constraints on the operation of the equipment 10, specifications of the product to be manufactured by the equipment 10, and the production volume of the product to be manufactured by the equipment 10. The plurality of input items include required input items and optional input items.

[0062] (4-6) In the selection system 1 of this embodiment, the input unit 211 further prompts the user to input the type of equipment 10. The input unit 211 changes the required input items for the constraints on the operation of the equipment 10, depending on the input type of equipment 10.

[0063] (4-7) In the selection system 1 of this embodiment, the selection unit 214 selects the first operating conditions using an optimization algorithm that updates the operating conditions of the equipment 10 so that the variable costs of the equipment 10 are reduced.

[0064] (5) Modifications (5-1) Modification 1A In this embodiment, the server device 2 performed a rectification column model calculation. However, the server device 2 may add a simulation of a reaction process to the rectification column model calculation. The simulation of the reaction process calculates, for example, the raw material feed conditions in the specifications of the equipment 10, which are one of the inputs of the rectification column model calculation. In this case, the server device 2 selects operating conditions of the equipment 10 that minimize the sum of the variable costs obtained from the output of the rectification column model calculation and the variable costs obtained from the output of the simulation of the reaction process.

[0065] Furthermore, the server device 2 may select the operating conditions of the reactor and the equipment 10 such that the total cost of the variable cost of the reactor and the variable cost of the distillation column 11 is minimized.

[0066] (5-2) Modification 1B In this embodiment, the server device 2 calculates the value of the objective function after determining whether the constraint conditions are satisfied. However, the determination of whether the constraint conditions are satisfied may be realized by including a term related to the constraint conditions in the objective function.

[0067] FIG. 6 is a diagram showing an overview of the calculation process of the objective function in this modified example. As shown in FIG. 6, the objective function is the sum of the cost of the equipment 10 and a term related to the constraint conditions. Unlike FIG. 3, after completing the vertical condenser flooding calculation of flow F3, the server device 2 performs cost calculation based on the output of the rectification column model calculation and the specifications of the equipment 10, as shown in flow F4'. After completing the cost calculation, the server device 2 substitutes the outputs of the rectification column model calculation, the heat exchanger model calculation, and the vertical condenser flooding calculation, as well as the constraint conditions included in the input from the user terminal 3, into the term related to the constraint conditions of the objective function, as shown in flow F5', and further substitutes the cost of the equipment 10, which is the output of the cost calculation, into the objective function to calculate the value of the objective function.

[0068] The constraint-related term is the sum of a term indicating a constraint on the flooding rate of the rectification column 11, which is an output of the rectification column model calculation, a term indicating a constraint on the top temperature of the rectification column 11, which is an output of the rectification column model calculation, a term indicating a constraint on the temperature of the column bottom 11b of the rectification column 11, which is an output of the rectification column model calculation, a term indicating a constraint on the margin of the heat transfer area of ​​the condenser 13, which is an output of the heat exchanger model calculation, a term indicating a constraint on the flooding rate of the condenser 13, which is an output of the vertical condenser flooding calculation, a term indicating a constraint on the product specifications, and a term indicating a constraint on the production volume of the product. Each of the constraint-related terms is configured so that the value of the term itself becomes smaller as the respective constraint is satisfied. In other words, the value of the objective function becomes smaller as the respective constraint is satisfied. For example, the term indicating the constraint condition regarding the flooding rate of the distillation tower 11 is configured so that the value of the term becomes smaller as the flooding rate of the distillation tower 11, which is the output of the distillation tower model calculation, falls within a specified range. Selecting the operating conditions of the equipment 10 that minimize such an objective function corresponds to selecting the operating conditions of the equipment 10 that satisfy the constraint condition and minimize the cost of the equipment 10.

[0069] 7 is a flowchart illustrating an example of the processing of the selection system 1 in this modified example. Unlike in FIG. 5, after completing step S4, the selection system 1, as shown in step S5', calculates the cost of the equipment 10 based on the output of the rectification column model calculation and the specifications of the equipment 10. After completing step S5', the selection system 1, as shown in step S6', substitutes the outputs of the rectification column model calculation, the heat exchanger model calculation, the vertical condenser flooding calculation, and the cost calculation, as well as the constraints included in the input from the user terminal 3, into an objective function to calculate a value of the objective function.

[0070] (5-3) Modification 1C The equipment 10 may purify the raw material by extractive distillation to produce the target product. The following mainly describes the differences from this embodiment. Other than the details described in this modification, the equipment is basically the same as this embodiment.

[0071] 12 is a schematic diagram of equipment 10 for purifying a raw material by extractive distillation. As shown in FIG. 12, equipment 10 mainly includes rectification columns 311 and 312, reboilers 321 and 322, condensers 331 and 332, and a condenser 333 (extractant cooler).

[0072] A plurality of stages 341, 342 are formed in the rectification columns 311, 312. One of the plurality of stages 341 is a raw material feed stage 341a for supplying raw material into the rectification column 311. Another one of the plurality of stages 341 is an extractant feed stage 341b for supplying an extractant into the rectification column 311. Another one of the plurality of stages 342 is a bottoms feed stage 342a for supplying bottoms flowing out from the rectification column 311 into the rectification column 312.

[0073] The reboiler 321 is installed in the bottom 311b of the rectification column 311. The reboiler 321 heats the raw material and the extractant by performing heat exchange between the raw material and the extractant and a heat medium.

[0074] The condenser 331 is installed at the top 311t of the rectification column 311. The condenser 331 cools the vapor by performing heat exchange between the vaporized raw material and a heat medium. The condenser 331 is a vertical condenser.

[0075] When the raw material is supplied to the raw material feed stage 341a in the rectification column 311 and the extractant is supplied to the extractant feed stage 341b in the rectification column 311, a portion of the supplied raw material and extractant accumulates in the column bottom 311b, while the remainder flows out from the column bottom 311b. Of the raw material and extractant that flow out from the column bottom 311b, a portion flows into the bottoms feed stage 342a in the rectification column 312 as bottoms, and the remainder flows into the reboiler 321. The raw material and extractant that flow into the reboiler 321 are heated by a heat transfer medium and become steam. The steam flows into the column bottom 311b, rises in countercurrent contact with the raw material and extractant, and flows out from the column top 311t. The steam that flows out from the column top 311t flows into the condenser 331. The vapor that has flowed into the condenser 331 is cooled by the heat medium to become a condensed liquid or uncondensed gas, which then flows out of the condenser 331. A portion of the condensed liquid that has flowed out of the condenser 331 flows into the distillation column 311 as reflux liquid, and the remainder is stored in the distillation tank 37 as a distillate or uncondensed gas.

[0076] The reboiler 322 is installed in the bottom 312b of the rectification column 312. The reboiler 322 heats the raw material and the extractant by performing heat exchange between the raw material and the extractant and a heat medium.

[0077] The condenser 332 is installed at the top 312t of the rectification column 312. The condenser 332 cools the vapor by performing heat exchange between the vaporized raw material and a heat medium.

[0078] When the bottoms (feedstock and extractant) flowing out of the rectification column 311 are supplied to the bottoms feed stage 342a in the rectification column 312, a portion of the supplied feedstock and extractant accumulates in the column bottom 312b, while the remainder flows out from the column bottom 312b. Of the feedstock and extractant flowing out from the column bottom 312b, the extractant is stored in the bottoms tank 39 as bottoms, and the feedstock and extractant flow into the reboiler 322. The feedstock and extractant flowing into the reboiler 322 are heated by a heat transfer medium to become steam. The steam flows into the column bottom 312b, rises in countercurrent contact with the feedstock and extractant, and flows out from the column top 312t. The steam flowing out from the column top 312t flows into the condenser 332. The steam flowing into the condenser 332 is cooled by the heat transfer medium to become condensed liquid or uncondensed gas, which flows out from the condenser 332. A portion of the condensate flowing out from the condenser 332 flows into the rectification column 312 as reflux liquid, and the remainder is stored in the distillate tank 38 as distillate or uncondensed gas.

[0079] The condenser 333 cools the extractant stored in the bottoms tank 39 by heat exchange between the extractant and a heat transfer medium. The cooled extractant is supplied to the extractant feed stage 341b in the distillation column 311. In other words, the equipment 10 recycles the extractant by supplying the extractant recovered from the distillation column 312 to the distillation column 311.

[0080] (5-3-1) Input Unit The input unit 211 allows the user to input constraints on the operation of the equipment 10, which are related to the rectification towers 311 and 312, the reboilers 321 and 322, and the condensers 331 to 333, the specifications of the products manufactured by the equipment 10, and the production volume of the products manufactured by the equipment 10. In particular, the input unit 211 allows the user to input the recovery purity of the extractant in the rectification tower 312 and the recovery rate of the extractant in the rectification tower 312 as constraints on the operation of the equipment 10.

[0081] The input unit 211 also allows the user to input specifications of the equipment 10 related to the rectification columns 311 and 312, the reboilers 321 and 322, and the condensers 331 to 333. In particular, the input unit 211 allows the user to input, as a specification of the equipment 10, the temperature of the extractant supplied to the extractant feed stage 341b in the rectification column 311.

[0082] The input unit 211 also prompts the user to input search ranges for the operating conditions of the equipment 10 related to the rectification columns 311 and 312, the reboilers 321 and 322, and the condensers 331 to 333. The operating conditions of the equipment 10 further include at least one of the extractant feed stage 341b of the rectification column 311 and the extractant flow rate of the rectification column 311. The operating conditions of the equipment 10 may further include the temperature of the extractant supplied to the extractant feed stage 341b in the rectification column 311. In this case, the input unit 211 prompts the user to input a search range for the extractant temperature, instead of inputting the extractant temperature as a specification of the equipment 10.

[0083] The input unit 211 also prompts the user to input the type of equipment 10 related to the rectification columns 311 and 312, the reboilers 321 and 322, and the condensers 331 to 333. FIG. 13 is a diagram showing examples of types of equipment 10 that purify a raw material by extractive distillation. The input unit 211 prompts the user to input, for example, one type of equipment 10 from the two types of equipment 10, Y1-A and Y1-B, shown in FIG. 13. In type Y1-A, the raw material and the extractant are supplied to the rectification column 311, and impurities (uncondensed gas or distillate) and bottoms (product, extractant, etc.) are extracted from the rectification column 311. The bottoms extracted from the rectification column 311 are supplied to the rectification column 312, and the product, etc. (uncondensed gas or distillate) and extractant are extracted from the rectification column 312. The extractant removed (recovered) from rectification column 312 is cooled by condenser 333 and supplied again to rectification column 311. In type Y1-B, the raw material and extractant are supplied to rectification column 311, and products, etc. (uncondensed gas or distillate) and bottoms (impurities, extractant, etc.) are removed from rectification column 311. The bottoms removed from rectification column 311 are supplied to rectification column 312, and impurities (uncondensed gas or distillate) and extractant are removed from rectification column 312. The extractant removed (recovered) from rectification column 312 is cooled by condenser 333 and supplied again to rectification column 311.

[0084] (5-3-2) First Calculation Unit The first calculation unit 212 performs a rectification tower model calculation for the rectification towers 311 and 312 based on the operating conditions of the equipment 10 selected from the search range and the specifications of the equipment 10 included in the input from the user terminal 3. After completing the rectification tower model calculation, the first calculation unit 212 performs a heat exchanger model calculation for the reboilers 321 and 322 and the condensers 331 to 333 based on the output of the rectification tower model calculation and the specifications of the equipment 10. After completing the heat exchanger model calculation, the first calculation unit 212 performs a vertical condenser flooding calculation for the condenser 331 based on the output of the rectification tower model calculation and the specifications of the equipment 10. After completing the vertical condenser flooding calculation, the first calculation unit 212 determines whether the outputs of the rectification tower model calculation, the heat exchanger model calculation, and the vertical condenser flooding calculation satisfy the constraints included in the input from the user terminal 3.

[0085] (5-3-3) Second Calculation Unit When the constraint conditions are satisfied, the second calculation unit 213 calculates the cost of the equipment 10 based on the output of the rectification column model calculation and the specifications of the equipment 10. The cost of the equipment 10 is the variable cost of the equipment 10. The variable cost further includes the cost of the extractant and the cost of utilities for the condenser 333. For example, the variable cost is calculated by "annual raw material loss + annual extractant loss + annual utility cost." The annual extractant loss is calculated by "marginal cost of extractant × extractant loss flow rate × annual operating time." The annual utility cost is automatically calculated from the heat calculation results of the rectification column model calculation. The annual utility cost includes the cost of steam consumed annually by the reboilers 321 and 322 and the cost of electricity consumed annually by the condensers 331 to 333.

[0086] (5-4) Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0087] Second Embodiment The following mainly describes the differences from the first embodiment. The second embodiment is basically the same as the first embodiment except for the details described in the second embodiment.

[0088] (1) Overall Configuration In the first embodiment, the equipment 10 was an existing equipment. In the present embodiment, the equipment 10 is a newly constructed equipment. In this case, the variables in the optimization problem include not only the operating conditions of the equipment 10 but also some of the specifications of the equipment 10 (hereinafter, sometimes referred to as the specification conditions of the equipment 10). The specification conditions of the equipment 10 include the number of stages of the rectification tower 11, the tower diameter of the rectification tower 11, the packed length of the rectification tower 11, and the specifications of the packing of the rectification tower 11 (hereinafter, the group of items constituting the specifications of the equipment 10 excluding the group of items constituting the specification conditions of the equipment 10, which is a part of these, will be referred to as the "specifications of the equipment 10").

[0089] (2) Detailed Configuration (2-1) Equipment Equipment 10 is a newly constructed equipment.

[0090] (2-2) Selection System (2-2-1) Server Device The server device 2 selects operating conditions and specification conditions for the facility 10 that satisfy predetermined constraints and minimize the cost of the facility 10, based on input from the user terminal 3. In other words, the server device 2 is a device for solving an optimization problem in which, with the cost of the facility 10 as an objective function, the server device 2 selects operating conditions and specification conditions for the facility 10 that satisfy predetermined constraints and minimize the value of the objective function.

[0091] 8 is a diagram illustrating an outline of the calculation process of the objective function in this embodiment, in which one operating condition of the equipment 10 and one specification condition of the equipment 10, which are variables in the optimization problem, are selected from the search range of the operating condition of the equipment 10 and one specification condition of the equipment 10, respectively.

[0092] As shown in flow F11, the server device 2 performs a FLASH calculation based on the specifications of the equipment 10 included in the input from the user terminal 3. After completing the FLASH calculation, the server device 2 performs a rectification column model calculation based on the operating conditions of the equipment 10 selected from the search range, the specification conditions of the equipment 10 selected from the search range, and the specifications of the equipment 10 included in the input from the user terminal 3, as shown in flow F12. After completing the rectification column model calculation, the server device 2 determines whether the output of the rectification column model calculation satisfies the constraint conditions included in the input from the user terminal 3, as shown in flow F13. If the constraint conditions are satisfied, the server device 2 performs a cost calculation based on the output of the rectification column model calculation, the specification conditions of the selected equipment 10, and the specifications of the equipment 10, as shown in flow F14. After completing the cost calculation, the server device 2 sets the output of the cost calculation as the value of the objective function corresponding to the operating conditions of the selected equipment 10 and the specification conditions of the equipment 10, as shown in flow F15.

[0093] (2-2-1-1) Input Unit The input unit 211 allows the user to input the type of equipment 10 via the user terminal 3, and further allows the user to input constraints (constraints on the operation of the equipment 10, specifications of the product to be manufactured by the equipment 10, production volume of the product to be manufactured by the equipment 10), specifications of the equipment 10, search range of operating conditions of the equipment 10, and search range of specification conditions of the equipment 10 according to the type of equipment 10.

[0094] (2-2-1-2) First Calculation Unit The first calculation unit 212 automatically executes a simulation of the operation of the equipment 10, and calculates candidate operating conditions for the equipment 10 that satisfy the constraints on the operation of the equipment 10, the specifications of the products to be manufactured by the equipment 10, and the production volume of the products to be manufactured by the equipment 10, and candidate specification conditions for the equipment 10 that satisfy the constraints on the operation of the equipment 10, the specifications of the products to be manufactured by the equipment 10, and the production volume of the products to be manufactured by the equipment 10.

[0095] First, the first calculation unit 212 performs a FLASH calculation. Specifically, the first calculation unit 212 calculates a search range for the operating pressure of the distillation column 11 included in the operating conditions of the equipment 10 based on the raw material feed conditions and the like included in the specifications of the equipment 10 (corresponding to flow F11 in FIG. 8 ).

[0096] Next, the first calculation unit 212 inputs the operating conditions of the equipment 10 selected from the search range, the specification conditions of the equipment 10 selected from the search range, and the specifications of the equipment 10 into the process simulator 221, and performs a rectification column model calculation (corresponding to flow F12 in Figure 8).

[0097] Next, the first calculation unit 212 determines whether the output of the rectification column model calculation satisfies the constraint conditions (corresponding to flow F13 in FIG. 8 ). If the output of the rectification column model calculation does not satisfy the constraint conditions, the first calculation unit 212 performs the rectification column model calculation using the operating conditions of the equipment 10 newly selected from the search range and the specification conditions of the equipment 10 until the constraint conditions are satisfied.

[0098] (2-2-1-3) Second Calculation Unit The second calculation unit 213 performs cost calculations. The cost of the equipment 10 in this embodiment is the equipment installation cost required to install the equipment 10 and the variable cost of the equipment 10. The second calculation unit 213 calculates the equipment installation cost and the variable cost of the equipment 10 when it is operated in accordance with the candidate that is the calculation result of the first calculation unit 212, from the output of the distillation column model calculation, the specification conditions of the equipment 10, and the specifications of the equipment 10, using a predetermined relational expression (corresponding to flows F14 and F15 in FIG. 8 ).

[0099] The equipment installation cost is calculated by (cost of rectification tower 11 + cost of reboiler 12 + cost of condenser 13) ÷ number of years for depreciation of equipment 10. The cost of rectification tower 11 is calculated using a predetermined relational expression based on the diameter of rectification tower 11, the packed length of rectification tower 11, etc. The cost of reboiler 12 is calculated using a predetermined relational expression based on the heat exchange amount of reboiler 12, etc. The cost of condenser 13 is calculated using a predetermined relational expression based on the heat exchange amount of condenser 13, etc. In this case, the diameter of rectification tower 11 and the packed length of rectification tower 11 are included in the specification conditions of equipment 10. In addition, the heat exchange amount of reboiler 12 and the heat exchange amount of condenser 13 are included in the output of the rectification tower model calculation.

[0100] (2-2-1-4) Selection Unit The selection unit 214 repeatedly performs the calculations by the first calculation unit 212 and the second calculation unit 213. The selection unit 214 automatically compares the equipment installation costs and variable costs corresponding to a plurality of candidates, and selects, from the plurality of candidates, second operating conditions, which are candidates for operating conditions, and first specification conditions, which are candidates for specification conditions, that have the lowest totals of the equipment installation costs and variable costs.

[0101] Specifically, the selection unit 214 inputs the operating conditions and specification conditions of the equipment 10 (variables in the optimization problem) calculated by the first calculation unit 212, and the cost of the equipment 10 corresponding to the operating conditions and specification conditions (objective function in the optimization problem) calculated by the second calculation unit 213, to the optimization software 222. The selection unit 214 selects, as candidates for new operating conditions and specification conditions of the equipment 10, operating conditions and specification conditions of the equipment 10 within a search range that are expected to result in a smaller value of the objective function, which are output from the optimization software 222 each time data is input to the optimization software 222.

[0102] (3) Processing An example of processing performed by the selection system 1 in this embodiment will be described with reference to the flowchart of FIG.

[0103] As shown in step S11, the selection system 1 prompts the user to input the type of equipment 10 via the user terminal 3, and further prompts the user to input constraints, specifications of the equipment 10, a search range for the operating conditions of the equipment 10, and a search range for the specification conditions of the equipment 10, depending on the type of equipment 10.

[0104] After completing step S11, the selection system 1 performs a FLASH calculation based on the specifications of the equipment 10, as shown in step S12.

[0105] After completing step S12, the selection system 1 performs a fractionation tower model calculation based on the operating conditions and specification conditions of the equipment 10 selected from the search range, and the specifications of the equipment 10, as shown in step S13.

[0106] After completing step S13, the selection system 1 determines whether the output of the rectification column model calculation satisfies the constraint conditions, as shown in step S14. If the constraint conditions are satisfied, the process proceeds to step S15. If the constraint conditions are not satisfied, the process returns to step S13, and the selection system 1 performs a rectification column model calculation using the operating conditions and specification conditions of the equipment 10 newly selected from the search range.

[0107] When the selection system 1 proceeds from step S14 to step S15, it performs a cost calculation for the equipment 10 based on the output of the fractionator model calculation, the specification conditions of the selected equipment 10, and the specifications of the equipment 10, and uses the output of the cost calculation as the value of the objective function.

[0108] After completing step S15, the selection system 1 inputs the operating conditions and specification conditions of the equipment 10, and the value of the objective function corresponding to the operating conditions and specification conditions, into the optimization software 222, as shown in step S16, and selects the operating conditions and specification conditions of the equipment 10 within the search range that are output from the optimization software 222 and that are expected to result in a smaller value of the objective function, as candidate operating conditions and candidate specification conditions of the new equipment 10.

[0109] After completing step S16, the selection system 1 determines, as shown in step S17, whether the operating conditions and specification conditions of the equipment 10 have been selected a predetermined number of times using the optimization software 222. If the operating conditions and specification conditions of the equipment 10 have been selected a predetermined number of times, the process proceeds to step S18. If the operating conditions and specification conditions of the equipment 10 have not been selected a predetermined number of times, the process returns to step S13, and the selection system 1 performs a rectification column model calculation using the operating conditions and specification conditions of the equipment 10 selected using the optimization software 222.

[0110] When the selection system 1 proceeds from step S17 to step S18, it outputs to the user terminal 3 the optimal operating conditions of the equipment 10 and the specification conditions of the equipment 10 that correspond to the minimum value of the objective function.

[0111] (4) Features (4-1) In the selection system 1 of this embodiment, the costs are the equipment installation cost required to install the equipment 10 and the variable cost of the equipment 10. The first calculation unit 212 automatically executes a simulation of the operation of the equipment 10, and calculates candidate operating conditions that satisfy constraints on the operation of the equipment 10, the specifications of the products manufactured by the equipment 10, and the production volume of the products manufactured by the equipment 10, as well as candidate specification conditions for the equipment 10 that satisfy the constraints on the operation of the equipment 10, the specifications of the products manufactured by the equipment 10, and the production volume of the products manufactured by the equipment 10. The second calculation unit 213 calculates the equipment installation cost and the variable cost when the equipment is operated in accordance with the candidates that are the calculation results of the first calculation unit 212. The selection unit 214 causes the first calculation unit 212 and the second calculation unit 213 to repeatedly perform calculations. The selection unit 214 automatically compares the equipment installation costs and variable costs corresponding to the multiple candidates, and selects, from the multiple candidates, the second operating conditions, which are candidates for operating conditions, and the first specification conditions, which are candidates for specification conditions, that have the lowest total of the equipment installation costs and variable costs.

[0112] In the selection system 1 of this embodiment, the selection unit 214 repeatedly causes the first calculation unit 212 and the second calculation unit 213 to perform calculations. The selection unit 214 automatically compares the equipment installation costs and variable costs corresponding to multiple candidates and selects, from the multiple candidates, second operating conditions, which are candidate operating conditions, and first specification conditions, which are candidate specification conditions, that have a low total of the equipment installation costs and variable costs. As a result, the selection system 1 can select operating conditions and specification conditions that will reduce the equipment installation costs and variable costs, instead of an inexperienced designer of the equipment 10. Furthermore, the selection system 1 can select operating conditions and specification conditions that will minimize the equipment installation costs and variable costs, instead of an experienced designer of the equipment 10.

[0113] (5) Modifications (5-1) Modification 2A In this embodiment, the server device 2 performed a rectification column model calculation. However, the server device 2 may add a simulation of a reaction process to the rectification column model calculation. The simulation of the reaction process calculates, for example, the raw material feed conditions in the specifications of the equipment 10, which are one of the inputs of the rectification column model calculation. In this case, the server device 2 selects operating conditions of the equipment 10 that minimize the sum of the variable costs obtained from the output of the rectification column model calculation and the variable costs obtained from the output of the simulation of the reaction process.

[0114] Furthermore, the server device 2 may select the operating conditions of the reactor and the equipment 10 and the specification conditions of the reactor and the equipment 10 so that the total cost of the variable cost and the equipment installation cost of the reactor and the variable cost and the equipment installation cost of the distillation column 11 is minimized.

[0115] (5-2) Modification 2B In this embodiment, the server device 2 calculates the value of the objective function after determining whether the constraint conditions are satisfied. However, the determination of whether the constraint conditions are satisfied may be realized by including a term related to the constraint conditions in the objective function.

[0116] Fig. 10 is a diagram showing an overview of the calculation process of the objective function in this modified example. As shown in Fig. 10, the objective function is the sum of the cost of the equipment 10 and a term related to the constraint conditions. Unlike Fig. 8, after completing the rectification tower model calculation of flow F12, the server device 2 performs cost calculation based on the output of the rectification tower model calculation, the specification conditions of the equipment 10, and the specifications of the equipment 10, as shown in flow F13'. After completing the cost calculation, the server device 2 substitutes the output of the rectification tower model calculation and the constraint conditions included in the input from the user terminal 3 into the term related to the constraint conditions of the objective function, and further substitutes the cost of the equipment 10, which is the output of the cost calculation, into the objective function to calculate the value of the objective function, as shown in flow F14'.

[0117] 11 is a flowchart illustrating an example of the processing of the selection system 1 in this modified example. Unlike in FIG. 9, after completing step S13, the selection system 1, as shown in step S14′, calculates the cost of the equipment 10 based on the output of the rectification column model calculation, the specification conditions of the selected equipment 10, and the specifications of the equipment 10. After completing step S14′, the selection system 1 substitutes the output of the rectification column model calculation and the cost calculation, and the constraint conditions included in the input from the user terminal 3 into an objective function to calculate a value of the objective function, as shown in step S15′.

[0118] (5-3) Modification 2C The equipment 10 may purify the raw material by extractive distillation to produce the target product. The following mainly describes the differences between this embodiment and Modification 1C of the first embodiment. Other than the details described in this modification, this modification is basically the same as this embodiment and Modification 1C of the first embodiment.

[0119] (5-3-1) Input Unit The input unit 211 allows the user to input constraints (constraints related to the operation of the equipment 10, specifications of the products manufactured by the equipment 10, and production volumes of the products manufactured by the equipment 10) related to the rectification towers 311, 312, the reboilers 321, 322, and the condensers 331 to 333, the specifications of the equipment 10, the search range for the operating conditions of the equipment 10, the search range for the specification conditions of the equipment 10, and the type of the equipment 10. In particular, the specification conditions of the equipment 10 include the number of stages of the rectification towers 311, 312, the tower diameters of the rectification towers 311, 312, the packed lengths of the rectification towers 311, 312, and the specifications of the packing materials of the rectification towers 311, 312.

[0120] (5-3-2) First Calculation Unit The first calculation unit 212 performs a FLASH calculation based on the specifications of the equipment 10. After completing the FLASH calculation, the first calculation unit 212 performs a rectification column model calculation based on the operating conditions of the equipment 10 selected from the search range, the specification conditions of the equipment 10 selected from the search range, and the specifications of the equipment 10. After completing the rectification column model calculation, the first calculation unit 212 determines whether the output of the rectification column model calculation satisfies the constraint conditions.

[0121] (5-3-3) Second Calculation Unit When the constraint conditions are satisfied, the second calculation unit 213 performs cost calculation based on the output of the rectification column model calculation, the specification conditions of the selected equipment 10, and the specifications of the equipment 10. The cost of the equipment 10 is the equipment installation cost required to install the equipment 10 and the variable cost of the equipment 10. The equipment installation cost is calculated by "(cost of the rectification columns 311, 312 + cost of the reboilers 321, 322 + cost of the condensers 331 to 333) ÷ number of years for depreciation of the equipment 10."

[0122] (5-4) Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0123] 1 Selection system 10 Equipment 11, 111, 112, 311, 312 Rectification column 11b, 311b, 312b Tower bottom 11t, 311t, 312t Tower top 12, 321, 322 Reboiler (heater) 13, 331, 332 Condenser (cooler) 14a, 341a Raw material feed stage 211 Input unit 212 First calculation unit 213 Second calculation unit 214 Selection unit 333 Condenser (extractant cooler) 341b Extractant feed stage

[0124] JP 2014-094938 A

Claims

1. A selection system (1) for selecting operating conditions of a facility (10) that has low costs, including variable costs, comprising: an input unit (211) for inputting constraints on the operation of the facility, specifications of a product to be manufactured by the facility, and a production volume of the product; A first calculation unit (212) that automatically executes a simulation of the operation of the facility and calculates candidates for operation conditions that satisfy the constraints, the specifications, and the production volume; A second calculation unit (213) that calculates the variable cost when operating according to the candidate that is a calculation result of the first calculation unit; a selection unit (214) that repeatedly performs a calculation by the first calculation unit and a calculation by the second calculation unit, automatically compares the variable costs corresponding to a plurality of the candidates, and selects a first operating condition that is a candidate for an operating condition having a low variable cost from among the plurality of candidates; Equipped with Selection system (1).

2. The facility includes a fractionator (11, 111, 112, 311, 312) for purifying a raw material to produce the product, The operating conditions of the facility include at least one of the number of stages of the distillation column, the operation pressure, the raw material feed stage (14a, 341a), and the reflux amount; A selection system (1) according to claim 1.

3. The facility purifies the feedstock by extractive distillation; The operating conditions of the system further include at least one of the extractant feed stage (341b) of the rectification column and the extractant flow rate. Selection system (1) according to claim 2.

4. The facility includes a fractionation column (11, 111, 112, 311, 312) for purifying a raw material, a heater (12, 321, 322) installed in a column bottom (11b, 311b, 312b) of the fractionation column, and a cooler (13, 331, 332) installed in a column top (11t, 311t, 312t) of the fractionation column, The variable costs include costs for raw materials and utilities for the heater and the cooler. A selection system (1) according to claim 1.

5. The facility purifies the feedstock by extractive distillation; The equipment includes an extractant cooler (333) for cooling the extractant; Further comprising: The selection system (1) according to claim 4, wherein the variable costs further include a cost for the extractant and a cost of utilities for the extractant cooler.

6. The cost is a variable cost of the existing facility, The input unit further causes a specification of the equipment to be input. Selection system (1) according to any of the preceding claims.

7. The cost is an equipment installation cost required for installing the equipment and a variable cost of the equipment, The first calculation unit automatically executes a simulation of operation of the equipment, and calculates candidate operating conditions that satisfy the constraints, the specifications, and the production volume, and candidate specifications of the equipment that satisfy the constraints, the specifications, and the production volume; The second calculation unit calculates the equipment introduction cost and the variable cost when operating according to the candidate that is a calculation result of the first calculation unit, the selection unit repeatedly performs the calculation by the first calculation unit and the calculation by the second calculation unit, automatically compares the equipment installation cost and the variable cost corresponding to the plurality of candidates, and selects, from the plurality of candidates, a second operating condition which is a candidate for an operating condition, and a first specification of the equipment which is a candidate for a specification of the equipment, which have a lower total of the equipment installation cost and the variable cost. Selection system (1) according to any of the preceding claims.

8. the input unit causes a plurality of input items to be input for the constraints, the specifications, and the production volume; The plurality of input items include required input items and optional input items. Selection system (1) according to any of the preceding claims.

9. The input unit includes: Furthermore, the type of the equipment is input, changing the required input items for the constraints according to the input type of the equipment; Selection system (1) according to claim 8.

10. The selection unit selects the first operating condition by an optimization algorithm that updates the operating condition so as to reduce the variable cost. Selection system (1) according to any of the preceding claims.