JP5223154B2 - Temperature control method, temperature control device, and temperature control program - Google Patents

Description

  The present invention relates to temperature control of a reaction vessel, and more particularly to a temperature control method, a temperature control device, and a temperature control program for a reaction vessel in which temperature distribution is predicted to occur in the reaction vessel like a reaction tower.

  Conventionally, when it is desired to control a process such as a reaction system, model predictive control has been adopted to determine an operation amount. Model predictive control is a method for determining an operation amount so that a controlled amount in a process matches a target value. Various studies have been made on process control using such a method.

For example, in Patent Document 1, the operation amount for adjusting the purge gas flow rate of carbon monoxide (CO) in the process of the reaction system for hydroformylation of olefin is the actual CO partial pressure in the reaction vessel and the target CO partial pressure. As a technique to be determined by model predictive control based on the deviation from, the reaction is performed by comparing the detected CO partial pressure with the target value and adjusting the purge flow rate of the recycle gas extracted from the reaction vessel A technique for controlling the CO concentration in the container is disclosed.
JP-A-6-192158

  In the conventional model predictive control, when it is predicted that the reaction state will change in the reaction vessel, it is difficult to obtain good controllability for the temperature control in the reaction vessel by the model predictive control. It has been.

  That is, according to conventional model predictive control, for example, when determining an operation amount for controlling the temperature in the reaction vessel, a transfer function with the operation amount as an input and a calculated value of the temperature as an output, or a reaction system The manipulated variable is determined on the basis of a prediction model in which a measurable disturbance corresponding to the supply amount of the raw material to be input to is input and the calculated temperature value is output. However, even when using a predictive model with the manipulated variable or measurable disturbance as input as described above, particularly in a system in which the reaction state changes in the reaction vessel, good controllability is obtained. That is, accurate temperature control could not be performed.

  The present invention has been devised in view of such circumstances, and its purpose is to provide a temperature control method, a temperature control device, and a temperature control capable of ensuring good temperature controllability even when an unexpected disturbance such as a change in reaction state occurs. Is to provide a program.

  The temperature control method of the present invention is a temperature control method for controlling an operation amount for temperature control of a first part in a reaction vessel and a second part different from the first part. , The fluid flows in a direction from the second part toward the first part, and the computer stores the temperature of the first part in the reaction container in a storage device; and the second in the reaction container. Using the process model including the step of storing the temperature of the part in the storage device, the temperature of the first part and the temperature of the second part stored in the storage device, and the manipulated variable in the future Predicting the temperature of the first part and the temperature of the second part, generating an optimal control signal for the manipulated variable that is desirably temperature controlled, and outputting the generated control signal for the manipulated variable Step and run The process model includes a prediction model that predicts the temperature of the second part and the temperature of the first part, which are control quantities, directly from the manipulated variable, and the manipulated variable determines the second part. And a prediction model for predicting heat transfer to the first part.

  In the temperature control method of the present invention, the model used in the step of generating the control signal for the manipulated variable corresponds to a change in the supply amounts of the reaction raw material and the solvent to the reaction vessel in addition to the process model. A measurable disturbance model for predicting the temperature of the first part and the temperature of the second part, the measurable disturbance model being directly controlled by a control amount from the supply amounts of the reaction raw material and the solvent. A prediction model for predicting the temperature of the first part and the temperature of the second part, and a prediction representing heat transfer of the reaction raw material and the solvent through the second part to the first part Preferably including a model.

  Further, in the temperature control method of the present invention, the process model and the model based on the measurable disturbance model are input with values relating to the manipulated variable and the supply amounts of the reaction raw material and the solvent, and the temperature of the second part is determined. The first transfer function to be output, the temperature of the second part that is the output of the first transfer function, the manipulated value, and the value relating to the supply amount of the reaction raw material and the solvent are input, It is preferable that the transfer function includes a second transfer function that outputs the temperature of the first part as an output.

  The temperature control device of the present invention is a temperature control device that controls an operation amount for temperature control of a first portion in a reaction vessel and a second portion different from the first portion, Then, the fluid flows in the direction from the second part toward the first part, and a first input unit that receives an input of the temperature of the first part in the reaction container, and a second in the reaction container. A second input unit that receives an input of the temperature of the part, a temperature of the first part, a temperature of the second part, and a process model including the manipulated variable, and the first part in the future A signal generation unit that predicts the temperature of the second part and the temperature of the second part and generates a control signal of the optimum operation amount that is desirably temperature-controlled, and a signal output unit that outputs the control signal generated by the signal generation unit And the process model includes the operation. From the quantity, a prediction model for predicting the temperature of the second part and the temperature of the first part, which are control quantities, and the manipulated variable reach the first part via the second part. And a prediction model for predicting heat transfer.

  A temperature control program according to the present invention causes a computer to output a signal for controlling an operation amount for temperature control of a first part in a reaction vessel and a second part different from the first part. In the reaction vessel, the fluid flows in the direction from the second part toward the first part, and the temperature of the first part in the reaction container is transmitted to the computer. Storing in the storage device; storing the temperature of the second part in the reaction vessel in the storage device; and temperature of the first part and temperature of the second part stored in the storage device And predicting the temperature of the first part and the temperature of the second part in the future using a process model set in advance from the manipulated variable, and controlling the optimum manipulated variable for the desired manipulated temperature. The And a step of outputting the generated control signal of the manipulated variable, and the process model directly determines the temperature of the second part, which is a controlled variable, from the manipulated variable, and the first And a prediction model for predicting heat transfer from the second part to the first part through the second part.

  According to the present invention, when the reaction container is configured so that the fluid flows in the reaction container in the direction from the second part toward the first part, the temperature of the first part and the second part Optimum that is desirably temperature controlled by predicting the temperature of the first part and the temperature of the second part in the future using a process model that includes the temperature and the manipulated variable for temperature control of the first and second parts. A control signal with a large manipulated variable is generated and output.

In the present invention, the process model is obtained by predicting the temperature of the second part and the temperature of the first part, which are control amounts, directly from the manipulated variable, and the first part through the second part. And a prediction model for predicting heat transfer to the region.

  This shows the relationship between the manipulated variable and the controlled variable in multipoint temperature control of a reaction process that has a temperature distribution in the reaction vessel like a reaction tower and the fluid flows in the reaction vessel from the inlet direction to the outlet direction. The predicted model includes a predicted model that takes into account heat transfer between temperature detection parts due to flow.

  Therefore, even if an unexpected disturbance such as a change in the reaction state occurs in the reaction process, good temperature controllability can be obtained.

  Hereinafter, a reaction system in which an embodiment of a temperature control method of the present invention is realized will be described with reference to the drawings. In the following description, the same constituent elements are denoted by the same reference numerals in each drawing, and detailed description thereof will not be repeated.

  FIG. 1 is a diagram schematically showing the overall configuration of a reaction system in which an embodiment of the temperature control method of the present invention is realized. In the system of FIG. 1, a reaction tower is adopted as a reaction vessel, and a product is generated in the reaction tower by a chemical reaction between a first raw material and a second raw material.

  Referring to FIG. 1, in the system of the present embodiment, in reaction tower 100, a raw material is introduced from supply port 105 provided at the bottom of reaction tower 100. Specifically, when the first raw material and the second raw material react with each other in the process of the present embodiment to generate a product, the first raw material, the second raw material, and the solvent are mixed by the pump 75. Thereafter, it is introduced into the reaction tower 100 through the supply port 105. In the upper stage of the reaction tower 100, a discharge port 106 for taking out a product generated in the reaction tower 100 from the reaction tower 100 is provided.

  A control valve 42 for controlling the supply amount of the first raw material is provided in the path until the first raw material is introduced into the pump 75. Further, the flow rate of the first raw material in the route is detected by the flow rate sensor 41. The opening / closing operation of the path by the adjustment valve 42 is controlled by the flow rate adjustment unit 40. The detection output of the flow rate sensor 41 is input to the flow rate adjustment unit 40.

  A control valve 52 for controlling the supply amount of the second raw material is provided in the path until the second raw material is introduced into the pump 75. Further, the flow rate of the second raw material in the path is detected by the flow rate sensor 51. The opening / closing operation of the route by the control valve 52 is controlled by the flow rate adjusting unit 50. The detection output of the flow sensor 51 is input to the flow controller 50.

  A control valve 62 for controlling the supply amount of the solvent is provided in the path until the solvent is introduced into the pump 75. Further, the flow rate of the solvent in the path is detected by the flow rate sensor 61. The opening / closing operation of the path by the adjustment valve 62 is controlled by the flow rate adjustment unit 60. The detection output of the flow sensor 61 is input to the flow controller 60.

  In the reaction tower 100, a temperature sensor 71 for detecting an upper temperature in the reaction tower 100 and a temperature sensor 72 for detecting an intermediate temperature are provided.

  The reaction tower 100 is provided with supply ports 101, 102, 103, 104 from the upper stage to the lower stage. Steam is introduced into the reaction tower 100 from a steam supply source via supply ports 101, 102, 103, 104 in order to adjust the temperature in the reaction tower 100. The total amount of steam supplied to the supply ports 101 and 102 is detected by the flow sensor 21 and adjusted by the control valve 22. The detection output of the flow rate sensor 21 is input to the flow rate adjustment unit 20, and the degree of opening and closing of the adjustment valve 22 is controlled by the flow rate adjustment unit 20. The total amount of steam supplied to the supply ports 103 and 104 is detected by the flow sensor 31 and adjusted by the control valve 32. The detection output of the flow rate sensor 31 is input to the flow rate adjustment unit 30, and the degree of opening and closing of the adjustment valve 32 is controlled by the flow rate adjustment unit 30.

  In this specification, the steam appropriately introduced into the upper supply port (supply ports 101 and 102) of the reaction tower 100 is referred to as “upper steam”, and the lower supply port (103, The steam introduced into the reaction tower 100 via 104) is referred to as “lower steam”. The upper steam amount is detected by the flow sensor 21, and the lower steam amount is detected by the flow sensor 31.

  The system according to the present embodiment shown in FIG. 1 includes a control device 10 for determining an upper steam supply amount, a lower steam supply amount, and the like. The control device 10 uses the target values of the flow rate adjustment units 20 and 30 as operation variables, the flow rate measurement values of the flow rate adjustment units 40, 50, and 60 as disturbance variables, and the measurement values of the temperature sensors 71 and 72 as control variables.

FIG. 2 schematically shows the configuration of the system shown in FIG.
Referring to FIG. 2, the control device 10 includes a CPU (central processing unit) that controls the operation of the control device 10 as a whole. The CPU 11 exchanges data with various devices inside and outside the control device 10 via an input / output device (I / O) 12. The CPU 11 includes a control signal generation unit 11A that generates target values for the flow rate adjustment units 20 and 30 in order to control the supply amount of steam as described above.

  The control device 10 also includes a RAM 15 (random access memory) that functions as a work area for the CPU 11, a hard disk (HD) 13 that stores various data such as programs executed by the CPU 11, and external information such as a keyboard. An input unit 16 that receives input, a media drive 14 that reads and writes information on a recording medium 140 that can be attached to and detached from the control device 10, a display unit 18 that displays processing contents of the CPU 11, and the CPU 11 executes various processes. A database 17 for storing data to be used is included.

  The CPU 11 can execute a program recorded on the HD 13 or can execute a program recorded on the recording medium 140. In addition, a program recorded on the recording medium 140 can be installed in the HD 13, and a program downloaded from the network via the I / O 12 can be installed.

  In the present embodiment, the control device 10 controls the upper steam amount and the lower steam amount using a model predictive control algorithm. Specifically, the values corresponding to the upper steam amount, the lower steam amount, and the supply amounts of the first raw material, the second raw material, and the solvent are input, and the detected temperature (upper temperature) of the temperature sensor 71 in the reaction tower 100 or the temperature sensor. Assuming a prediction model that outputs the detected temperature (middle temperature) of 72, the upper steam amount and the lower steam amount at which the temperature predicted by the prediction model is a desirable temperature target value are calculated, and the flow rate adjustment units 20, 30 A control signal that is a target value of is output. FIG. 3 shows a block diagram of a transfer function used in the control device 10.

  FIG. 3A shows a block diagram of a transfer function regarding the upper stage steam amount, the lower stage steam amount, the middle stage temperature, and the upper stage temperature, and FIG. 3B shows the supply amount of the first raw material and the second raw material amount. The block diagram of the transfer function regarding the supply amount, the supply amount of the solvent, the middle stage temperature, and the upper stage temperature is shown.

  FIG. 3A shows a transfer function 301 having the upper stage steam amount as an input and the middle stage temperature as an output, and a transfer function 302 having the lower stage steam amount as an input and the middle stage temperature as an output. In FIG. 3A, the transfer function 303 with the upper steam amount as an input and the upper temperature as an output, the transfer function 304 with the lower steam amount as an input and the upper temperature as an output, and the transfer function 301 and the transfer function 302 are shown. A transfer function 305 is shown in which the middle stage temperature, which is the output of, is input and the upper stage temperature is the output.

  FIG. 3B shows a transfer function 311 with the supply amount of the first raw material as input and the middle stage temperature as output, a transfer function 312 with the supply amount of solvent as input and the middle stage temperature as output, and the second raw material A transfer function 313 is shown in which the supply amount is input and the middle stage temperature is output. In FIG. 3B, the transfer function 314 that receives the supply amount of the second raw material and outputs the upper stage temperature, and the middle stage temperature that is the output of the transfer functions 311, 312, and 313, and the upper stage temperature are input. A transfer function 315 is output.

  In the present embodiment, transfer functions 301 to 305 and 311 to 315 are set for the process shown in FIG. 1, and an upper steam amount and a lower steam amount in which the middle stage temperature and the upper stage temperature are desirably controlled are realized. As described above, the target values of the flow rate adjusters 20 and 30 are determined. In the transfer functions described in FIGS. 3A and 3B, “s” is a Laplace transformer, and “e” is the base of the natural logarithm.

  FIG. 7 shows a block diagram of a transfer function employed in a control algorithm according to a conventional method as a comparison of the control algorithm employed in the present embodiment.

  If the conventional method as shown in FIG. 7 is followed, transfer functions 901 to 910 are set for the process shown in FIG. 1, and the upper steam amount and the lower steam amount in which the middle temperature and the upper temperature are desirably controlled. So that the target values of the flow rate adjusting units 20 and 30 are determined.

  The transfer function 901 has an input as the upper steam amount and an output as the upper temperature. The transfer function 902 has an input as the upper steam amount and an output as the intermediate temperature. The transfer function 903 has an input as a lower steam amount and an output as an upper temperature. The transfer function 904 uses an input as a lower steam amount and an output as an intermediate temperature. The transfer function 905 uses the first raw material as an input and outputs the upper stage temperature as an output. The transfer function 906 uses the first raw material as an input and outputs the middle stage temperature as an output. The transfer function 907 receives the solvent as an input and outputs the upper temperature as an output. The transfer function 908 takes the solvent as an input and the middle stage temperature as an output. The transfer function 909 uses the second raw material as an input and outputs the upper stage temperature as an output. The transfer function 910 uses the second raw material as an input and outputs the middle stage temperature as an output. That is, according to the conventional method, as a model of the control algorithm, all operation variables (upper steam amount and lower steam amount) and disturbance variables (first raw material supply amount, second raw material supply amount, and solvent supply amount). ) And a transfer function (transfer functions 901 to 910) that outputs all control variables (upper temperature and intermediate temperature). According to the conventional method, a prediction model is assumed for the upper stage temperature and the middle stage temperature independently of each other.

  On the other hand, in the control algorithm employed in the present embodiment as shown in FIG. 3, the set transfer function is a combination reflecting the temperature dependency in the reaction tower 100.

  Specifically, in the reaction tower 100, heat propagation occurs due to the movement of substances, and the direction is from the middle stage where the temperature sensor 72 is arranged to the upper stage where the temperature sensor 71 is arranged. It is thought that.

  Of the transfer functions set in the present embodiment, those having the upper stage temperature as an output include those whose input is the middle stage temperature (transfer functions 305 and 315).

  As a result, at the stage where a change (such as a change in the reaction state of the compound) occurring in the reaction tower 100 is detected as a change in the middle temperature, the influence of the change can be reflected as a predicted value of the upper temperature. In the present embodiment, a transfer function 303 with the upper steam amount as an input, a transfer function 304 with the lower steam amount as an input, and a transfer function 314 with the second raw material as an input are adopted as models for the upper temperature. Yes. Of the compounds (first raw material and second raw material) to be reacted in the reaction tower 100 of the present embodiment, the first raw material is assumed to be liquid in the temperature environment in the reaction tower 100. In addition, for the second raw material, it is assumed that a gas is generated by the reaction under the temperature environment. Further, not only the steam (upper stage steam) introduced through the supply ports 101 and 102 but also the steam introduced through the supply ports 103 and 104 directly affects the temperature detected by the temperature sensor 71. It is also possible to give.

  Therefore, in the present embodiment, the transfer function having the upper stage temperature as an output is not only the one having the middle stage temperature as an input (transfer functions 305 and 315), but also the temperature sensor 72 after being introduced into the reaction tower 100. The difference between the time until reaching the temperature sensor 71 and the time until reaching the temperature sensor 71 is relatively short, and it is considered that there is substantially no difference between the timing contributing to the change in the middle temperature and the timing contributing to the change in the upper temperature. For these, a transfer function (transfer functions 303, 304, and 314) having those as inputs and the upper temperature as an output is employed. Thus, the construction of a control algorithm including a minimum transfer function in accordance with the actual situation of the process shown in FIG. 1 is realized.

  In the present embodiment described above, predictive control is performed on the upper steam amount and the lower steam amount using the control algorithm as shown in FIG.

  Here, the result of the control based on the control algorithm shown in FIG. 3 is shown together with the result of the control based on the control algorithm of FIG. 7 shown as a reference.

  FIG. 4 is a diagram illustrating the behavior when the setting is changed to increase the target value for the upper stage temperature by 1 ° C. FIG. FIG. 4A shows the measurement results of the upper stage temperature and the middle stage temperature from the start to 240 minutes after the start. FIG. 4B shows changes in the upper steam amount and the lower steam amount after 240 minutes from the start.

  First, referring to FIG. 4A, a group of graphs is described on the upper side, and a group of graphs is also described on the lower side. The upper one-dot chain line indicates the target value for the upper stage temperature. That is, FIG. 4 (A) shows that the target temperature has been changed to increase by 1 ° C. 60 minutes after the start.

  In FIG. 4A, a pair of solid lines and a broken line graph are shown on the upper side, and a pair of solid lines and a broken line graph are shown on the lower side. In the upper pair of graphs, a solid line indicates a change in the upper temperature when the control based on FIG. 3 is executed, and a broken line indicates a change in the upper temperature when the control according to FIG. 7 is executed. Is shown. In the lower set of graphs, the solid line indicates the change in the middle stage temperature when the control according to FIG. 3 is executed, and the broken line indicates the time when the control according to FIG. 7 is executed. The change in the middle temperature is shown. The lower one-dot chain line indicates the target value for the middle temperature.

  In FIG. 4B, a group of graphs is shown on the upper side, and a group of graphs is shown on the lower side. In the upper group of graphs, the solid line indicates the change in the upper steam amount (the detection output of the flow sensor 21) when the control according to FIG. 3 is executed, and the broken line indicates the control according to FIG. It shows the change in the upper steam amount when executed.

  In the lower group of graphs, a solid line indicates a change in the lower steam amount (detected output of the flow sensor 31) when the control of FIG. 3 is executed, and a broken line indicates the control of FIG. This shows the change in the amount of steam at the bottom.

  When the target value for the upper stage temperature is changed so as to increase by 1 ° C. as indicated by a one-dot chain line on the upper side of FIG. 4 (A) 60 minutes after the start, it is shown in FIG. 4 (B) accordingly. As can be seen, the upper steam amount increases when either of the controls in FIGS. 3 and 7 is executed. In addition, the lower steam amount starts decreasing from 60 minutes after the start, and converges to a constant value around 80 minutes after the start.

  Referring to FIG. 4A, in response to the change in the upper steam amount and the lower steam amount as described above, with regard to the upper temperature, even if any of the controls in FIG. 3 and FIG. From around 65 minutes, the upper temperature starts to rise. When any control is executed, the target value is reached around 140 minutes after the start and then substantially coincides with the target value.

  The middle temperature started to increase slightly around 65 minutes after the start, but then decreased to change to match the target value (lower one-dot chain line) for the middle temperature.

  As described above with reference to FIGS. 4A and 4B, even when the target value for the upper stage temperature is changed, the control algorithm employed in the present embodiment shown in FIG. Based on the control, temperature control substantially equivalent to that of a system using a control algorithm according to the conventional method shown in FIG. 7 is realized.

  FIG. 5 is a diagram showing the behavior when the supply amounts of the first raw material, the second raw material, and the solvent, which are measurable disturbances in the system shown in FIG. 1, are changed. Specifically, FIG. 5A shows changes in the upper temperature (upper graph) and the middle temperature (lower graph), and FIG. 5B shows the upper steam amount (upper graph) in each system. ) And the lower steam amount (lower graph), and FIG. 5C shows changes in the supply amounts of the first raw material, the second raw material, and the solvent to the reaction tower 100 (flow rate sensor 41). , 51, 61). 5A and 5B, the solid line is a graph of a system in which the control algorithm of FIG. 3 is adopted, and the broken line is a graph of a system in which the control algorithm of FIG. 7 is adopted. .

  First, referring to FIG. 5C, it is shown that the supply amounts (per unit time) of the first raw material, the second raw material, and the solvent have increased at 60 minutes after the start. In the present embodiment, it is assumed that the reaction in which the first raw material and the second raw material react to produce a product is an endothermic reaction.

  As shown in FIG. 5 (B), as shown in FIG. 5 (B), the upper steam in the system according to any of the control algorithms of FIG. 3 and FIG. 7 according to the increase in the supply amount of the first raw material, the second raw material and the solvent. The amount and the amount of lower steam are changing.

  Further, as shown in FIG. 5A, although the middle stage temperature is not affected by the increase in the supply amount of the first raw material, the second raw material, and the solvent, the upper stage temperature is 60 From the time point of the minute, the lower temperature starts to decrease in any system. Note that the upper stage temperature then rises as the upper stage steam amount increases as shown in FIG. 5B, and returns to the target value indicated by the alternate long and short dash line.

  As described above with reference to FIGS. 5A to 5C, the supply amounts of the first raw material, the second raw material, and the solvent to the reaction tower 100 are increased, and the endothermic reaction in the reaction tower 100 is increased. Even in the case of acceleration, the control according to the present embodiment in accordance with the control algorithm shown in FIG. 3 is equivalent to the control according to the conventional control algorithm shown in FIG. The middle stage temperature can be controlled.

  FIG. 6 shows the behavior in the system shown in FIG. 1 when an unexpected disturbance occurs in the reaction tower 100 that affects the intermediate temperature. Specifically, FIG. 6A shows changes in the upper stage temperature (upper graph) and the middle stage temperature (lower graph), and FIG. 6B shows changes in the upper and lower steam amounts. Show. 6A and 6B, the solid line is a graph of the system in which the control algorithm of FIG. 3 is adopted, and the broken line is a graph of the system in which the control algorithm of FIG. 7 is adopted. The alternate long and short dash line indicates the target temperature for each of the upper stage temperature and the middle stage temperature.

  In FIG. 6A, the magnitude of the disturbance is indicated by a two-dot chain line. Specifically, when none of the control by the control algorithm shown in FIG. 3 and FIG. 7 is applied and left as it is, the middle stage temperature is 80 minutes after the start with respect to the temperature up to the start 60 minutes. It is shown that a disturbance that raises the temperature by 1 ° C. was applied.

  With reference to FIG. 6B, in the model shown in FIG. 7, the lower steam amount decreases slightly at the point of 60 minutes after the start due to the introduction of the disturbance as described above, while the upper steam amount is slightly higher. It is rising late.

  On the other hand, in the model of the present embodiment shown in FIG. 3, both the upper steam amount and the lower steam amount are decreased after 60 minutes from the start, and the lower steam amount is a value around the end after the decrease is completed. The upper steam amount has converged after rising again.

  Referring to FIG. 6 (A), the middle stage temperature is temporarily increased due to a disturbance from 60 minutes after the start in both the case of following the model of FIG. 3 and the case of the model of FIG. And converges to the target value indicated by the alternate long and short dash line.

  On the other hand, for the upper stage temperature, when the model shown in FIG. 3 is adopted, the temperature rise is suppressed by a temperature rise of 0.25 ° C., while the model shown in FIG. 7 is adopted. In this case, a temperature increase of 0.5 ° C. occurs.

  In the model shown in FIG. 7, since the heat transfer from the middle temperature to the upper temperature is not reflected in the model, the increase in the middle temperature is not reflected in the prediction of the change in the upper temperature. For this reason, the control signal output to the flow rate adjusting unit 20 and the flow rate adjusting unit 30 is intended to lower only the middle stage temperature. This corresponds to the fact that the broken line for the lower steam amount in FIG. 6B greatly decreases from 60 minutes to 80 minutes after the start.

  On the other hand, in the model of FIG. 3 according to the present embodiment, heat transfer from the middle temperature to the upper temperature is reflected in the model. As a result, the upper steam amount is controlled so as to increase thereafter, although it is temporarily decreased immediately after the disturbance is input. This corresponds to the fact that the solid line of the upper steam amount in FIG. 6 (B) decreases from 60 minutes to 75 minutes after the start and then increases from 75 minutes to 90 minutes.

  That is, in the model of the present embodiment shown in FIG. 3, the heat transfer from the middle stage temperature to the upper stage temperature is reflected in the model, so that the rise in the upper stage temperature is predicted as the middle stage temperature rises, and is temporarily The upper steam amount is lowered and the upper steam temperature is predicted to decrease due to the lower steam amount being lowered, and the upper steam amount is increased (returned) from 75 minutes to 90 minutes after the start as described above. .

  As described above with reference to FIG. 4 to FIG. 6, the prediction model employed in the present embodiment is a diagram for changing the target value and changing the supply amount of measurable disturbance (raw material and solvent). 7 can be realized, and in addition, as described with reference to FIG. 6, when an unexpected change such as a change in the reaction state in the reaction tower 100 occurs. The change can be regarded as a change in the middle temperature, and the change can be reflected in the prediction of the upper temperature. Thereby, as explained with reference to FIG. 6A in particular, the controllability of the upper stage temperature can be made favorable.

  In the present embodiment described above, in order to adjust the temperature of the first part (temperature sensor 71) and the second part (temperature sensor 72) in the reaction vessel (reaction tower 100), the control device 10 includes: The control signal is transmitted to the flow rate adjusting units 20 and 30. The control signal is generated by the control signal control unit 11A of the CPU 11. The control signal generation unit 11A generates a control signal based on a control algorithm using the prediction model shown in FIG. The CPU 11 transmits the generated control signal to the flow rate adjustment units 20 and 30 via the I / O 12.

  In the present embodiment, a reaction tower is shown in which a plurality of temperature measurement points are arranged in the vertical direction, and the fluid moving direction in the reaction tower is from top to bottom. The process for realizing the control method of the invention is not limited to the case where the reaction is performed in such a reaction column. For example, in a reaction vessel configured to move a fluid from left to right, temperature sensors 71 and 72 for detecting the temperature inside the reaction vessel are arranged. The present invention can also be applied to the case where the temperature at the right position is also detected.

  In the present embodiment described above, a future first model is used by using a process model including the temperatures of the first part and the second part of the reaction tower and the manipulated variables (target values of the flow rate control units 20 and 30). The temperature of the part and the temperature of the second part are predicted, and the control signal with the optimum operation amount is generated.

  As shown in FIG. 3, the process model is a prediction model (transfer functions 301 and 302) that predicts the temperature of the second part and the temperature of the first part, which are directly controlled quantities, from the manipulated variable. , 303, 304) and a prediction model (transfer function 305) for predicting heat transfer from the manipulated variable through the second part to the first part.

  Further, in the present embodiment, as a feedforward model used for prediction of the temperature of the first part and the second temperature, the first part corresponds to a change in the supply amount of the reaction raw material and the solvent to the reaction vessel. And a measurable disturbance model that predicts the temperature of the second part and the temperature of the second part. The measurable disturbance model includes a predictive model (transfer functions 311, 312, 313, which predicts the temperature of the first part and the second part, which are control quantities, directly from the supply amounts of the reaction raw material and the solvent. 314) and a prediction model (transfer function 315) representing heat transfer from the reaction raw material and the solvent through the second part to the first part.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows typically the whole structure of the system by which one Embodiment of the temperature control method of this invention is applied. It is a figure which shows typically the structure of the system shown by FIG. (A) is a block diagram of a transfer function according to the present embodiment regarding the upper stage steam amount, the lower stage steam amount, the middle stage temperature, and the upper stage temperature, and (B) is the supply of the first raw material, the second raw material, and the solvent. It is a block diagram of the transfer function according to this embodiment regarding quantity, middle temperature, and upper temperature. It is a figure which shows the behavior of the system in the control according to the control algorithm of FIG. 3, and the control according to the control algorithm of FIG. It is a figure which shows the behavior of the system in the control according to the control algorithm of FIG. 3, and the control according to the control algorithm of FIG. It is a figure which shows the behavior of the system in the control according to the control algorithm of FIG. 3, and the control according to the control algorithm of FIG. It is a block diagram of the transfer function employ | adopted in the control algorithm according to the conventional method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Control apparatus, 11 CPU, 11A Control signal generation part, 12 I / O, 13 HD, 14 Media drive, 15 RAM, 16 input part, 17 Database, 18 Display part, 20, 3040, 50, 60 Flow volume adjustment part, 21, 31, 41, 51, 61 Flow rate sensor, 22, 32, 42, 52, 62 Control valve, 71, 72 Temperature sensor, 75 Pump, 100 Reaction tower, 101-105 Supply port, 106 Discharge port, 140 Recording medium , 301-305, 311-315, 901-910 transfer functions.

Claims (5)

A temperature control method for controlling an operation amount for temperature control of a first part in a reaction vessel and a second part different from the first part,
In the reaction vessel, the fluid flows in a direction from the second part toward the first part,
Computer
Storing the temperature of the first part in the reaction vessel in a storage device;
Storing the temperature of the second part in the reaction vessel in the storage device;
Using the process model including the temperature of the first part and the temperature of the second part stored in the storage device and the manipulated variable, the temperature of the first part and the second part in the future Generating a control signal of the optimum manipulated variable that is desirably temperature controlled;
Outputting the generated control signal of the manipulated variable,
The process model is
A prediction model for predicting the temperature of the second part and the temperature of the first part, which are control quantities, directly from the manipulated variable ;
Before SL via the second portion and a prediction model for predicting the heat transfer leading to the first portion, the temperature control method. In addition to the process model, the model used in the step of generating the operation amount control signal corresponds to a change in the supply amount of the reaction raw material and the solvent to the reaction vessel, and the temperature of the first part and the Including a measurable disturbance model that predicts the temperature of the second site;
The measurable disturbance model is
A prediction model for predicting the temperature of the first part and the temperature of the second part, which are control amounts, directly from the supply amounts of the reaction raw material and the solvent;
The temperature control method according to claim 1, further comprising: a prediction model representing heat transfer of the reaction raw material and the solvent through the second portion to the first portion. The model by the process model and the measurable disturbance model is
A first transfer function having the manipulated variable and a value related to the supply amount of the reaction raw material and the solvent as inputs and a temperature of the second part as an output;
The temperature of the second part, which is the output of the first transfer function, the manipulated variable, and the value relating to the supply amount of the reaction raw material and the solvent are input, and the temperature of the first part is output. The temperature control method of Claim 2 comprised by the transfer function containing the 2nd transfer function to do. A temperature control device for controlling an operation amount for temperature control of a first part in a reaction vessel and a second part different from the first part,
In the reaction vessel, the fluid flows in a direction from the second part toward the first part,
A first input unit for receiving an input of the temperature of the first part in the reaction vessel;
A second input unit for receiving an input of the temperature of the second part in the reaction vessel;
A process model including the temperature of the first part and the temperature of the second part and the manipulated variable is used to predict the temperature of the first part and the temperature of the second part in the future. A signal generation unit for generating a control signal of the optimum operation amount to be temperature controlled;
A signal output unit that outputs the control signal generated by the signal generation unit,
The process model is
A prediction model for predicting the temperature of the second part and the temperature of the first part, which are control quantities, directly from the manipulated variable ;
Before SL via the second portion and a prediction model for predicting the heat transfer leading to the first portion, the temperature control device. A temperature control program for causing a computer to output a signal for controlling an operation amount for temperature control of a first part in a reaction vessel and a second part different from the first part,
In the reaction vessel, the fluid flows in a direction from the second part toward the first part,
On the computer,
Storing the temperature of the first part in the reaction vessel in a storage device;
Storing the temperature of the second part in the reaction vessel in a storage device;
Using the process model preset from the temperature of the first part and the temperature of the second part stored in the storage device and the manipulated variable, the temperature of the first part and the first part Predicting the temperature of the two parts and generating a control signal of the optimum manipulated variable that is desirably temperature controlled;
Outputting the generated control signal of the manipulated variable,
The process model is
A prediction model for predicting the temperature of the second part, which is a control amount, directly from the manipulated variable, and the temperature of the first part ;
And a prediction model for predicting the heat transfer leading to the first portion through the front Stories second portion, the temperature control program.

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