Control device, co2 recovery device, control method, and program

Abstract

Provided is a control method for a CO2 recovery device that achieves an economically efficient operation while controlling a controlled variable to a target value. A control device includes: a data acquisition unit that is configured to acquire operation data of a CO2 recovery device; a target value setting unit that is configured to set a target value of a parameter of a controlled object based on the operation data; a prediction model that is configured to simulate an operation and a state of the CO2 recovery device; an optimization calculation unit that is configured to calculate the manipulated variable that achieves an objective by optimization calculation in a case where the objective is to minimize a deviation between a predicted value of the parameter and the target value and to optimize a predicted value of an amount of heat to be supplied to a regeneration heater provided in a regeneration tower of the CO2 recovery device, while predicting the predicted value of the parameter when a predetermined manipulated variable is applied to the CO2 recovery device based on a prediction model that is configured to predict a state of the CO2 recovery device; and a control unit that is configured to control the CO2 recovery device based on the calculated manipulated variable.

Description

Control device, CO2 recovery device, control method and program

[0001] The present disclosure relates to a control device, ２ This disclosure claims priority to Japanese Patent Application No. 2024-061036, filed on April 4, 2024, the contents of which are incorporated herein by reference.

[0002] In Patent Document 1, CO ２ Concentration and CO ２ CO while controlling the recovery rate to the target value ２ Specifically, the method for operating the recovery system is to change the amount of circulating absorbent supplied to the absorption tower and the amount of saturated steam supplied to the regenerative heater of the regeneration tower, thereby reducing CO ２ Control to maintain the difference between the actual recovery rate and the target value within a predetermined range, and ２ This is a control method that simultaneously performs control to maintain the difference between the actual concentration value and the target value within a predetermined range. ２ Concentration and CO ２ The recovery rate is referred to as a control variable, and the amount of circulated lean absorbent supplied to the absorption tower and the amount of saturated steam supplied to the regenerative heater for controlling the control variable toward a target value are referred to as manipulated variables. ２ The manipulated variable for controlling the concentration, ２ A method for preventing interference of the manipulated variable for controlling the recovery rate is disclosed. ２ Concentration and CO ２ Although the recovery rate can be controlled to a target value, the economics of operation are not taken into consideration.

[0003] JP 2016-16392 A

[0004] CO that realizes economical operation while controlling the control amount to the target value ２ A method for controlling a recovery device is provided.

[0005] The present disclosure provides a control device, CO ２ A recovery device, a control method, and a program are provided.

[0006] According to one aspect of the present disclosure, the control device２ a data acquisition unit that acquires operation data of the recovery device; a target value setting unit that sets a target value of a parameter to be controlled based on the operation data; ２ A prediction model for predicting the state of the recovery device and a predetermined operation amount are ２ a prediction model for predicting a predicted value of the parameter when the parameter is applied to the recovery device, and minimizing a deviation between the predicted value of the parameter and the target value; ２ an optimization calculation unit that calculates the manipulated variable that achieves the objective by optimization calculation when the objective is to optimize a predicted value based on the prediction model of the heat quantity to be supplied to a regenerative heater provided in a regenerator of the recovery device; and ２ and a control unit that controls the recovery device.

[0007] According to one aspect of the present disclosure, CO ２ The recovery device includes an absorption tower, a regeneration tower, a regeneration heater provided in the regeneration tower, a pipe for delivering lean absorption liquid from the regeneration tower to the absorption tower, a valve provided in the pipe, and the above-mentioned control device.

[0008] According to one aspect of the present disclosure, the control method includes: ２ Operation data of the recovery device is acquired, and target values ​​of parameters to be controlled are set based on the operation data, and a predetermined manipulated variable is set to the CO ２ The predicted values ​​of the parameters when applied to the CO recovery device are ２ minimizing the deviation between the predicted value of the parameter and the target value while predicting the state of the recovery device based on a prediction model; ２ and optimizing a predicted value based on the prediction model of the amount of heat supplied to a regenerative heater provided in a regenerator of a recovery device, the operation amount for achieving the purpose is calculated by optimization calculation, and the CO ２ Control the recovery device.

[0009] According to one aspect of the present disclosure, the program ２Operation data of the recovery device is acquired, and target values ​​of parameters to be controlled are set based on the operation data, and a predetermined manipulated variable is set to the CO ２ The predicted values ​​of the parameters when applied to the CO recovery device are ２ minimizing the deviation between the predicted value of the parameter and the target value while predicting the state of the recovery device based on a prediction model; ２ and optimizing a predicted value based on the prediction model of the amount of heat supplied to a regenerative heater provided in a regenerator of a recovery device, the operation amount for achieving the purpose is calculated by optimization calculation, and the CO ２ A process for controlling the recovery device is executed.

[0010] The above-mentioned control device, CO ２ According to the recovery device, the control method, and the program, it is possible to control the control amount to a target value while taking into consideration the economic efficiency of CO ２ Control of the recovery device can be realized.

[0011] CO according to the embodiment ２ FIG. 1 is a schematic diagram showing an example of a recovery device. FIG. 2 is a block diagram showing an example of a control device according to an embodiment. FIG. 3 is a diagram showing an overview of control according to an embodiment. FIG. 4 is a first diagram explaining some control examples according to an embodiment. FIG. 5 is a second diagram explaining some control examples according to an embodiment. FIG. 6 is a diagram explaining an optimal operating point according to an embodiment. ２ FIG. 1 is a diagram showing an example of a test case for operating a recovery device. FIG. 2 is a first diagram showing an example of a control result when an optimal operating point is not taken into consideration according to the embodiment. FIG. 3 is a second diagram showing an example of a control result when an optimal operating point is not taken into consideration according to the embodiment. FIG. 4 is a diagram showing an example of a locus of operating points when an optimal operating point is taken into consideration according to the embodiment. FIG. 5 is a first diagram showing an example of a control result when an optimal operating point is taken into consideration according to the embodiment. FIG. 6 is a second diagram showing an example of a control result when an optimal operating point is taken into consideration according to the embodiment. ２ Fig. 2 is a flowchart showing an example of control of the recovery device Fig. 3 is a diagram showing an example of a hardware configuration of a control device according to an embodiment.

[0012] Hereinafter, the CO２ The control method of the recovery device will be described with reference to the drawings. ２ An example of the schematic configuration of the recovery device 100 is shown in FIG. ２ The recovery system 100 includes a control device 10, an absorption tower 2, a regeneration tower 3, a heat exchanger 4, etc. Exhaust gas discharged from industrial combustion equipment such as a boiler or a gas turbine is cooled and then sent to the absorption tower 2 through a pipe 80. A flue gas measuring instrument 101 is provided on the pipe 80. The flue gas measuring instrument 101 measures the flow rate of the flue gas sent to the absorption tower 2 and the CO content in the flue gas. ２ The concentration is measured and the measured value is sent to the control device 10. The exhaust gas sent to the absorption tower 2 comes into contact with the absorbing liquid in the absorption tower 2, and the CO ２ is absorbed into the absorption liquid through a chemical reaction. ２ The absorbent that absorbed CO is called rich absorbent. ２ The exhaust gas after removal of CO is discharged to the outside of the system through a pipe 81. ２ A concentration meter 102 is provided. ２ The concentration meter 102 measures the CO ２ The concentration of CO ２ The concentration is transmitted to the control device 10. The rich absorbing solution is pressurized by the pump 21 and sent to the heat exchanger 4 through a pipe 53. In the heat exchanger 4, the rich absorbing solution is heated by the lean absorbing solution regenerated in the regenerator 3 and having a higher temperature than the rich absorbing solution, and is supplied to the regenerator 3 through a pipe 54.

[0013] The rich absorbing solution to be supplied to the regenerator 3 is supplied from the top of the regenerator 3 to the inside of the regenerator 3. The rich absorbing solution is converted into CO by an endothermic reaction inside the regenerator 3. ２ The rich absorbent supplied to the regeneration tower 3 releases CO while flowing down to the bottom of the tower. ２The absorption liquid is removed to form a semi-lean solution. A circulation line 31 is provided at the bottom of the regeneration tower 3, which circulates the absorption liquid that has flowed down to the tower bottom. A regeneration heater 33 is provided in this circulation line 31, which heats the absorption liquid. The regeneration heater 33 is, for example, an electric heater or a heat exchanger. In the case of an electric heater, the absorption liquid flowing through the circulation line 31 is heated by the heat of the electric heater and returned to the regeneration tower 3. In the case of a heat exchanger, for example, saturated steam or the like is supplied to the regeneration heater 33 through a pipe (not shown), and heat exchange occurs between the saturated steam supplied through this pipe and the absorption liquid flowing through the circulation line 31, and the absorption liquid flowing through the circulation line 31 is heated and returned to the regeneration tower 3. The semi-lean solution is circulated through the circulation line 31 and heated by the regeneration heater 33 to form a lean solution. In this way, almost all of the CO 2 is removed from the rich absorption liquid supplied to the regeneration tower 3 by the time it reaches the bottom of the regeneration tower 3. ２ The lean absorbing solution is an absorbing solution from which CO has been removed. The lean absorbing solution is pressurized by the pump 35 and sent to the heat exchanger 4 through the pipe 51. The lean absorbing solution sent to the heat exchanger 4 through the pipe 51 is cooled by the rich absorbing solution in the heat exchanger 4 and is supplied to the absorber 2 through the pipe 52. In this way, the absorbing solution circulates between the absorber 2 and the regenerator 3. From the top of the regenerator 3, CO released from the rich absorbing solution in the regenerator 3 is ２ The gas is discharged through a pipe 82. The pipe 82 contains CO ２ A gas measuring instrument 103 is provided. ２ The gas measuring instrument 103 measures the amount of CO emitted. ２ The gas flow rate and concentration of the gas are detected, and the detected gas flow rate and concentration are transmitted to the control device 10 .

[0014] A rich absorbent control valve 61 is provided in the pipe 54. The control device 10 controls the aperture of the rich absorbent control valve 61 to control the flow rate of the rich absorbent sent to the regenerator 3. The flow rate of the rich absorbent flowing through the pipe 54 is measured by a flow meter 71. The flow rate measured by the flow meter 71 is transmitted to the control device 10. A lean absorbent control valve 62 is provided in the pipe 52. The control device 10 controls the aperture of the lean absorbent control valve 62 to control the flow rate of the lean absorbent sent to the absorber 2. The flow rate of the lean absorbent flowing through the pipe 52 is measured by a flow meter 72. The flow rate measured by the flow meter 72 is transmitted to the control device 10. The control device 10 controls the heat input to the regenerative heater 33. For example, if the regenerative heater 33 is an electric heater, the control device 10 controls the output of the electric heater. When the regenerative heater 33 is a heat exchanger, the control device 10 controls the flow rate of saturated steam supplied to the regenerative heater 33 by controlling the opening of a saturated steam control valve (not shown) provided in a pipe that supplies saturated steam. A pump 21 that delivers rich absorbing liquid is provided in the pipe 53. The control device 10 controls the pump 21 to pressure-feed the rich absorbing liquid that accumulates in the lower part of the absorber 2 to the heat exchanger 4 and the regenerator 3 side. A pump 35 that delivers lean absorbing liquid is provided in the pipe 51. The control device 10 controls the pump 35 to pressure-feed the lean absorbing liquid that accumulates in the lower part of the regenerator 3 to the heat exchanger 4 and the absorber 2 side. The control device 10 controls the flow rate of the flue gas, the flue gas temperature, and the CO 2 in the flue gas measured by the flue gas measuring instrument 101. ２ Concentration, CO ２ CO measured by the concentration meter 102 ２ Concentration, CO ２ CO measured by the gas measuring instrument 103 ２ The gas flow rate and concentration of the gas are acquired, and based on this information, ２ Concentration and CO ２ The heat input to the regenerative heater 33 (for example, the output of the electric heater or the flow rate of saturated steam) is controlled so that the recovery rate reaches a predetermined target value.

[0015] 2 is a block diagram illustrating an example of the functions of the control device according to the embodiment. The control device 10 controls the CO ２ The control device 10 controls the recovery device 100. As shown in Fig. 2, the control device 10 includes a data acquisition unit 11, an operation amount calculation unit 12, a control unit 13, and a storage unit 14.

[0016] The data acquisition unit 11 acquires the flow rate and temperature of the exhaust gas measured by the exhaust gas measuring instrument 101 and the CO ２ Concentration, CO ２ CO measured by the concentration meter 102 ２ Concentration, CO ２ CO measured by the gas measuring instrument 103 ２ The data acquiring unit 11 acquires the gas flow rate and concentration of the gas, the flow rate of the rich absorbent measured by the flow meter 71, the flow rate of the lean absorbent measured by the flow meter 72, etc. The data acquiring unit 11 records the acquired measurement values ​​in the storage unit 14 in association with time.

[0017] The operation amount calculation unit 12 calculates the CO ２ concentration and / or CO ２ The operation amount calculation unit 12 calculates an operation amount such that the difference between the measured value of the recovery rate and a predetermined target value (reference value) falls within a predetermined range. ２ concentration and CO ２ Not only does it bring the recovery rate closer to the target value, but it also reduces the heater heat input Q in Alternatively, the operation amount may be calculated to optimize the flow rate WL of the lean absorbent. in represents the amount of heat given to the regenerative heater 33, and can be controlled by adjusting the output of the electric heater or the flow rate of saturated steam. The lean absorbent flow rate WL can be optimized by adjusting the opening of the lean absorbent control valve 62, etc. The manipulated variable calculation unit 12 includes a target value setting unit 121, a prediction model 122, and an optimization calculation unit 123.

[0018] The target value setting unit 121 determines the control amount (CO ２ Concentration, CO ２ Recovery rate) and operation amount (flow rate WL of lean absorbent supplied to the absorption tower, heater heat input Q inFor example, the target value setting unit 121 sets a target value for CO ２ CO depending on the flow rate and temperature of the exhaust gas supplied to the recovery device 100 ２ Concentration target value and CO ２ Target recovery rate, CO ２ Heat input Q of the heater at the optimum operating point according to the flow rate and temperature of the exhaust gas supplied to the recovery device 100 in The target values ​​of the CO ２ The target value may be calculated in advance using a simulator (which may be a prediction model 122 described later) that simulates the operation of the recovery device 100. Alternatively, the target value setting unit 121 may have a simulator, and ２ Parameters such as the flow rate and temperature of the exhaust gas acquired by the data acquisition unit 11 during operation of the recovery device 100 may be input into the simulator, and the respective target values ​​may be calculated.

[0019] The prediction model 122 is ２ The prediction model 122 is a simulator that simulates the operation of the recovery device 100 when the device is operated, and predicts the state of the plant that will occur as a result of the operation. ２ It is composed of a number of physical models that explain the phenomena that occur within the recovery device 100. Most of the physical models are described using nonlinear mathematical expressions. An example of a physical model is shown below. This physical model takes into account the properties and mass transfer coefficient of the absorption liquid, the concentrations of gas and liquid, and the temperature distribution in the direction of flow within the vessel. The gas contains CO ２ , N ２ , O ２ , H in the liquid ２ O, N ２ , amine absorbent, etc. t is time, i is the identification number of the gas and liquid components, j is the number of divisions in the flow direction of the gas and liquid components (the areas created by dividing the absorption tower 2 etc. at cross sections perpendicular to the flow direction of the gas or liquid are considered as "elements," and the state of the gas and liquid is modeled based on the chemical changes that occur in each element. The number of divisions refers to the number of elements in this case), F j L (t) is the liquid flow rate [kg / s], x i,j(t) is the liquid mass composition [weight fraction], M i is the molecular weight [kg / kg-mol], d z is the length in the flow direction per element [m], M cpj is the heat capacity [J / K], C j PL (t) is liquid specific velocity [J / kg K], γ i (t) is the reaction heat [J / kg], Q ex If (t) is the heat transfer rate between the gas and the liquid [J / s], the liquid holdup U i,j (t) [kg] and liquid temperature T j L (t)[K] are calculated using the following formula (1).

[0020]

[0021] k Gi,j (t) is the mass transfer coefficient [kg-mol / (s m2 Pa)], which is a function of temperature, liquid composition, etc., j is the gas / liquid contact area [m2], p i,j (t) is the partial pressure of the gas [Pa], p i,j * If (t) is the equilibrium partial pressure [Pa], which is a function of temperature, liquid composition, etc., then CO ２ and H ２ Mass transfer rate of O m i,j (t) [kg-mol / s] is calculated using the following formula (2).

[0022]

[0023] F j G is the gas flow rate [kg-mol / s], y i,j If (t) is the gas composition [molar fraction], the gas mass balance is calculated using the following equation (3):

[0024]

[0025] C j PG If (t) is the gas specific velocity [J / kg-mol K], the gas temperature T j G (t) is calculated from the gas side heat balance using the following equation (4).

[0026]

[0027] Online moment-by-moment CO ２ For use in controlling the capture system 100, the predictive model 122 includes a high-speed CO ２ It is required to be able to predict the state of the recovery device 100. Therefore, in the prediction model 122, the 10,000 or more parameters used in the physical model constituting the prediction model 122 are reduced in dimension to about several hundred parameters so as to enable high-speed calculations while maintaining prediction accuracy. The reduction in dimension is achieved by approximating the coefficients of the absorption reaction and equilibrium reaction with polynomials and adjusting the number of divisions. The CO ２ It has been confirmed that the simulation results of the gas flow rate and the like accurately match the measured values ​​in the actual plant. For example, the prediction model 122 in and the lean absorbent flow rate WL are given as inputs, ２ Concentration, CO ２ Predict recovery rates, etc.

[0028] The optimization calculation unit 123 uses the prediction model 122 to calculate the CO ２ CO when the recovery device 100 is controlled ２ The controlled variable such as concentration is predicted, and the manipulated variable is set to achieve the target value of the controlled variable, or the heater heat input Q is set to achieve the target value of the controlled variable. in For example, the optimization calculation unit 123 calculates the operation amount by optimization calculation, which can realize the optimal operating point by optimizing the flow rate WL of the lean absorbent and the flow rate WL of the refrigerant. ２ The state of the recovery device 100 is predicted by the prediction model 122, and the CO ２The manipulated variable that minimizes the sum of the differences between the predicted values ​​of control variables such as recovery rate and their target values ​​is calculated as the optimal solution. For example, the C / GMRES method is used to search for a solution in the optimization calculation. When the C / GMRES method is used, the manipulated variable is calculated without iterative calculation by tracking the change in the optimal solution, so that the solution can be calculated efficiently and quickly. By reducing the number of parameters in the prediction model 122 and performing calculations using the C / GMRES method, the manipulated variable that is the solution can be calculated quickly. This allows the CO ２ It is possible to realize real-time control and online control of the recovery device 100. For example, ２ Even in a situation where the operating load of the recovery device 100 changes rapidly, the CO ２ The recovery device 100 can be controlled.

[0029] The control unit 13 calculates the CO ２ For example, the control unit 13 controls the recovery device 100. ２ concentration and CO ２ Achieving the target recovery rate while reducing the heater heat input Q in The opening degree of the lean absorbent adjusting valve 62 and the like is controlled so that the lean absorbent flow rate WL can be optimized.

[0030] The storage unit 14 stores data such as the data acquired by the data acquisition unit 11 and the target value set by the target value setting unit 121. ２ It stores various information necessary for controlling the recovery device 100.

[0031] FIG. 3 shows an outline of the control by the control device 10. d (Measured disturbance) in FIG. 3 is, for example, CO ２ The disturbance d is the flow rate and temperature of the exhaust gas supplied to the recovery device 100. The disturbance d is given to the Static Optimizer 201 and the Plant 205. When the Static Optimizer 201 receives the disturbance d, it generates a Reference. The Reference is, for example, a target value of a controlled variable and an manipulated variable. For example, the Static Optimizer 201 calculates the CO ２ concentration target value, CO２ Target value of recovery amount, heater heat input Q according to disturbance d in and a target value of the lean absorbent flow rate WL according to the disturbance d. The Static Optimizer 201 provides the generated Reference to the Dynamic Optimizer 202. The Dynamic Optimizer 202 searches for manipulated variables Mv that can achieve the received Reference through optimization calculations. Specifically, the Dynamic Optimizer 202 provides a certain manipulated variable Mv to the Model 203, compares the controlled variables Cv predicted by the Model 203 with the target values, and evaluates the manipulated variable Mv provided to the Model 203. The Dynamic Optimizer 202 repeats this process to search for an appropriate manipulated variable Mv. The manipulated variable Mv is a variable that represents the heater heat input Q in (for example, the opening of a valve that adjusts the output of an electric heater or the flow rate of saturated steam), and the lean absorbent flow rate WL (for example, the opening of the lean absorbent control valve 62). When an appropriate manipulated variable Mv is found, the plant 205 is controlled by the manipulated variable Mv. As a result of controlling the plant 205 by the manipulated variable Mv, ２ Concentration and CO ２ A measured value y, such as a recovery rate, is measured. The Estimator 204 calculates the difference between the measured value y and the estimated value ye (estimated measurements) of the controlled variable predicted by the Model 203 when the same manipulated variable Mv as that applied to the Plant 205 is applied to the Model 203, calculates a state s of the Model 203 that compensates for the difference, and corrects the Model 203 by the amount of the state s so that the actual state of the Plant 205 can be accurately simulated. The Static Optimizer 201 corresponds to the target value setting unit 121 in FIG. 2. The Model 203 corresponds to the prediction model 122 in FIG. 2. The Dynamic Optimizer 202 corresponds to the optimization calculation unit 123 in FIG. 2.

[0032] Next, several control examples will be described with reference to Figures 4 and 5. (1) Conventional Control For comparison, an example of conventional control will be described. In conventional control, for example, the heater heat input Q in and a command value for the lean absorbent flow rate WL, and feedforward control is performed by providing the command value to the plant. In conventional control, control using NMCP is not performed. Next, an example of control utilizing NMCP according to this embodiment will be described.

[0033] (2) 1 input 1 output In the 1 input 1 output, the heater heat input Q is used as the manipulated variable. in The CO at the outlet of regeneration tower 3 is used as the control quantity. ２ The flow rate is used. The prediction model 122 uses the heater heat input Q in Giving CO ２ Heat input Q to the heater that can control the flow rate to the target value in is calculated by optimization calculation. A command value is calculated for the lean absorbent flow rate WL, and the command value is calculated based on the CO ２ Feed-forward control is performed to output to the recovery device 100. ２ Flow rate and CO ２ The relationship between the recovery rate and the CO at the outlet of the regeneration tower can be expressed by the following formula (A): ２ The flow rate is adjusted to the target value. ２ As a recovery rate, CO ２ Recovery rate is CO ２ This means approaching the target recovery rate. ２ Recovery rate = (CO at the outlet of the regeneration tower ２ flow rate) / (exhaust gas flow rate at the inlet of the absorber 2 × CO in the exhaust gas at the outlet of the absorber 2 ２ Concentration) ... (A) CO at the outlet of the regeneration tower of formula (A) ２ The flow rate includes CO ２ The value measured by the gas measuring instrument 103 can be used for the exhaust gas flow rate at the inlet of the absorption tower 2, and the value measured by the exhaust gas measuring instrument 101 can be used for the CO ２ The concentrations include CO ２ The value measured by the densitometer 102 can be used.

[0034] An example of an evaluation function in optimization calculation is shown in formula (1) in Fig. 5. In formula (1) in Fig. 5, x represents the control amount, and as shown in the "X (control amount)" column in the table in Fig. 5, x in the case of one input and one output is x = [X6 regen Q in ] Ｔ In equation (1) of FIG. ｒｅｆ represents the target value (reference value) of the controlled variable, and x ｒｅｆ = [X6 regen_ref 0 (zero)] Ｔ Similarly, u in equation (1) in FIG. 5 represents the manipulated variable, and as shown in the column "U (NMPC manipulated variable)" in the table in FIG. 5, u in the case of one input and one output is expressed as u=[dQ in / dt] Ｔ t is time, and the T in t+T is T=T ｆ (1-e －αｔ ) is the value calculated by T ｆ is the prediction horizon, α is the acceleration gain. The superscript T is the transposed vector, u is the manipulated variable, Q in is the heater heat input, WL ｉｎ is the flow rate of the lean absorbent supplied from the regeneration tower 3 to the absorption tower 2, X6 ｒｅｇｅｎ is the CO at the outlet of regeneration tower 3 ２ Flow rate (CO ２ Measurement value of gas measuring instrument 103), X6 ｒｅｇｅｎ＿ｒｅｆ is the exhaust gas flow rate to the absorber 2 × CO at the inlet of the absorber 2 ２ Concentration x CO ２ where Sf is a value calculated using the target value of the recovery rate, Q is a weighting coefficient for the state, and R is a weighting coefficient for control. The optimization calculation unit 123 calculates u that minimizes the value of formula (1) in FIG. 5. In the case of one input and one output, as is clear from the definition of x and formula (1) in FIG. 5, which is the evaluation function, the CO ２ Flow rate prediction and CO ２ Minimize deviation from target value of flow rate (CO ２ Recovery rate and CO ２ The control amount that minimizes the deviation from the target value of the recovery rate and the heater heat input Q in Here, CO ２ Flow rate prediction and CO ２ The objective was to minimize the deviation from the target value of the flow rate.２ Predicted concentration and CO ２ It may be configured to minimize deviations from a target concentration value.

[0035] (3) 2 inputs, 2 outputs In 2 input, 2 output control, the heater heat input Q is used as the manipulated variable. in and the lean absorbent flow rate WL are used, and the CO ２ Flow rate and CO emitted from absorber 2 ２ The prediction model 122 uses the heater heat input Q in and the lean absorbent flow rate WL are given, and CO ２ Flow rate and CO ２ Heat input Q to the heater that can control the concentration to each target value in and the lean absorbent flow rate WL are calculated by optimization calculation. ２ The concentrations include CO ２ The value measured by the densitometer 102 can be used. The evaluation function is the formula (1) in FIG. 5. Unlike the case of one input and one output, the control amount x is expressed as x = [X6 regen Q in Y6 abso ] Ｔ x ｒｅｆ is x as shown in the table of FIG. ｒｅｆ = [X6 regen_ref 0 Y6 abso_ref ] Ｔ As shown in the "U (NMPC manipulated variable)" column of the table in FIG. 5, u is expressed as u = [dQ in / dt,dWLin / dt] Ｔ In the case of two inputs and two outputs, ２ Flow rate prediction and CO ２ Minimize deviation from the target value of flow rate and reduce CO ２ Predicted concentration and CO ２ The manipulated variable that minimizes the deviation from the target concentration value and minimizes itself is the heater heat input Q. in Calculate.

[0036] (4) Two-input, two-output operation with the optimum operating point taken into consideration In the two-input, two-output operation with the optimum operating point taken into consideration, the heater heat input Q is used as the manipulated variable. in and the lean absorbent flow rate WL are used, and the CO ２Flow rate and CO emitted from absorber 2 ２ The concentration is then calculated. ２ Flow rate and CO ２ Not only does it control the concentration to the respective target value, but also the heater heat input Q in The heater heat input Q is calculated so that the difference between the predicted value of the lean absorbent flow rate WL and the predicted value of the lean absorbent flow rate WL and the respective optimal operating points is minimized. in and the lean absorbent flow rate WL are calculated by optimization calculation. The evaluation function is the formula (1) in Figure 5. Unlike the case of two inputs and two outputs, the control amount x is x = [X6 regen Q in Y6 abso W.L. in ] Ｔ x ｒｅｆ is x ｒｅｆ = [X6 regen_ref Q in_ref Y6 abso_ref W.L. in_ref ] Ｔ u is similar to two inputs and two outputs.

[0037] (Optimal Operating Point) Next, the optimal operating point will be described. Fig. 6 shows the optimal operating point and the CO ２ The vertical axis of the graph in FIG. 6 shows an example of the locus of operating points when the recovery device is operated. in The graph 600 shows the CO2 emissions at various CO2 ratios when the exhaust gas flow rate is rated. ２ Heat input Q of the heater at the operating point of the recovery device 100 in Graph 601 shows the relationship between the CO concentration and the lean absorbent flow rate WL. ２ Heat input Q of the heater at the operating point of the recovery device 100 in Graph 602 shows the relationship between the CO 2 concentration and the lean absorbent flow rate WL when the exhaust gas flow rate is 60%. ２ Heat input Q of the heater at the operating point of the recovery device 100 in Graphs 600 to 602 show the relationship between CO ２As input parameters of the simulator of the recovery device 100 (for example, it may be the prediction model 122), values ​​of rated, 80%, and 60% are given for the exhaust gas flow rate, and the CO ２ Concentration and CO ２ The operating state that achieves the target value of the recovery rate is simulated, and while maintaining that operating state, the lean absorbent flow rate WL and the heater heat input Q when the lean absorbent flow rate WL is varied are calculated. in The optimum operating point is a graph plotting the relationship between CO ２ Concentration and CO ２ While achieving the target recovery rate, the heater heat input Q in is the operating point at which the ratio of the heater heat input to the lean absorbent solution flow rate to the lean absorbent solution is minimum. For the rated graph 600, the value of the heater heat input and the lean absorbent solution flow rate corresponding to point 60a is the optimal operating point. Similarly, for the rated graph 601, the value of the heater heat input to the heater and the lean absorbent solution flow rate corresponding to point 61a is the optimal operating point, and for the rated graph 602, the value of the heater heat input to the heater and the lean absorbent solution flow rate corresponding to point 62a is the optimal operating point.

[0038] CO ２ The target recovery rate was set at 75%, and CO ２ Graphs 63 to 65 in FIG. 6 show the loci of operating points obtained when an operation simulation was performed in which the exhaust gas flow rate supplied to the recovery device 100 was reduced from the rated flow rate to 60% at a rate of 10% / min, maintained at that state for a while, and then increased to the rated flow rate at the same rate. The values ​​for the rate of change of the exhaust gas flow rate and the rate of reduction (10% / min and 60%, respectively) are merely examples and are not intended to be limiting. Graph 63 shows the locus of operating points obtained when the above-mentioned (1) conventional control was performed while the exhaust gas flow rate was changed under the above conditions. Graph 65 shows the locus of operating points obtained when the above-mentioned (2) one-input, one-output control was performed while the exhaust gas flow rate was similarly changed. Graph 64 shows the locus of operating points obtained when the above-mentioned (3) two-input, two-output control was performed while the exhaust gas flow rate was changed under the same conditions. In this example, the simulation was performed using a certain operating point based on the operation of the actual machine as the starting condition. As shown in FIG. 6, in each case, the heater heat input Q was lower than the optimal operating point.in is maintained at a high level.

[0039] (Control Results When the Optimal Operating Point is Not Considered) Figures 8A and 8B show examples of simulation results when the optimal operating point is not considered. Figure 8A shows the results of the controlled variables. The vertical axis of graphs 801 to 803 is CO ２ The graph 801 shows the CO concentration in the conventional control. ２ The graph 802 shows the transition of the concentration of CO ２ The graph 803 shows the transition of the concentration of CO ２ The graphs 801a, 802a, and 803a show the target values, and the graphs 801b, 802b, and 803b show the control results. ２ The density overshoot is large. In the two-input, two-output configuration, the overshoot is suppressed.

[0040] The vertical axis of graphs 804 to 806 in FIG. 8A is CO ２ The graph 804 shows the flow rate and the horizontal axis shows time. ２ The graph 805 shows the transition of the flow rate, and the graph 806 shows the transition of the flow rate. ２ The graph 806 shows the transition of the flow rate, and the graph 807 shows the transition of the flow rate. ２ The graphs 804a, 805a, and 806a show the target values, and the graphs 804b, 805b, and 806b show the control results. (1) In conventional control, there are time periods when there is a slight deviation between the target value and the control value, but in (2) one input, one output, and (3) two inputs, two outputs, control is achieved almost exactly as targeted.

[0041] FIG. 8B shows the relationship between the manipulated variable and CO ２ The results of the recovery rate are shown. The vertical axis of graphs 807 to 809 represents the lean absorbent flow rate WL, and the horizontal axis represents time. Graphs 807b to 809b respectively represent (1) the transition of the lean absorbent flow rate WL under conventional control, (2) the transition of the lean absorbent flow rate WL under one input and one output, and (3) the transition of the lean absorbent flow rate WL under two inputs and two outputs.

[0042] The vertical axis of graphs 810 to 812 is the heater heat input Q in The horizontal axis represents time. in Graphs 810b to 812b respectively show the target values ​​of (1) the heater heat input Q under conventional control in (2) Heat input Q of heater with one input and one output in (3) Heat input Q of heater with 2 inputs and 2 outputs in In either case, the heater heat input Q in has remained above the target value.

[0043] The vertical axis of graphs 813 to 815 is CO ２ The graphs 813bb to 815b show the recovery rate and the horizontal axis shows time, respectively. ２ (2) CO recovery rate with one input and one output ２ (3) CO recovery rate with two inputs and two outputs ２ The transition of the recovery rate is shown below. (2) The transient change is smallest in the case of one input and one output.

[0044] (Control Results When Optimal Operating Point is Considered) Next, an example of control when the optimal operating point is considered will be described. FIG. 9 shows an example of the trajectory of the operating point when the optimal operating point is considered. For (1) conventional control, (2) one-input, one-output, and (3) two-input, two-output, the optimal operating point was considered by setting the operating point at the start of operation to the optimal operating point 60a. Graphs 91, 92, and 93 shown in FIG. 9 show the trajectories of the operating point when the exhaust gas flow rate shown in FIG. 7 is changed by performing (1) conventional control, (2) one-input, one-output, and (3) two-input, two-output control, respectively. Looking at the trajectories in FIG. 9, it is clear that an operating point closer to the optimal operating point can be achieved compared to the case of FIG. 6. In contrast, graph 94 shows the trajectory of the operating point when (4) two-input, two-output control considering the optimal operating point is performed. It can be seen from comparison with graphs 91 to 93 that an ideal trajectory of the operating point is achieved.

[0045] 10A and 10B show an example of the simulation results when the optimal operating point is taken into consideration. Fig. 10A shows the results of the controlled variables. The vertical axis of graphs 817 to 820 is CO ２ The graph 817 shows the CO concentration in the conventional control. ２ The graph 818 shows the transition of the concentration of CO ２ The graph 819 shows the transition of the concentration of CO ２ The graph 820 shows the transition of the CO concentration at two inputs and two outputs considering the optimal operating point. ２ (4) The most accurate CO concentration is obtained when two inputs and two outputs are used, taking into account the optimal operating point. ２ The target concentration was achieved.

[0046] The vertical axis of graphs 821 to 824 is CO ２ The horizontal axis represents the flow rate, and the horizontal axis represents time. ２ Graphs 821b to 824b show the CO2 values ​​for (1) conventional control, (2) one input and one output, (3) two inputs and two outputs, and (4) two inputs and two outputs with the optimal operating point taken into consideration. ２ The flow rate control results are shown. In both cases, control was achieved almost exactly as targeted.

[0047] FIG. 10B shows the relationship between the manipulated variable and CO ２ The results of the recovery rate are shown. The vertical axis of graphs 825 to 828 indicates the lean absorbent flow rate WL, and the horizontal axis indicates time. Graphs 825b to 828b respectively show the trends in (1) the lean absorbent flow rate WL under conventional control, (2) the lean absorbent flow rate with one input and one output, (3) the lean absorbent flow rate WL with two inputs and two outputs, and (4) the lean absorbent flow rate WL with two inputs and two outputs taking the optimal operating point into consideration. Graph 828a shows the trends in the optimal operating point.

[0048] The vertical axis of graphs 829 to 832 is the heater heat input Q in The horizontal axis represents time. in Graph 832c shows the transition of the optimum operating point (target value when the exhaust gas flow rate is 60%).

[0049] The vertical axis of graphs 833 to 836 is CO ２ The graphs 833b to 836b show the recovery rate and the horizontal axis shows time, respectively. ２ (2) CO recovery rate with one input and one output ２ (3) CO recovery rate with two inputs and two outputs ２ (4) CO2 recovery rate with two inputs and two outputs considering the optimal operating point ２ The transition of the recovery rate is shown. (4) The transient change is smallest in the case of two inputs and two outputs, taking into account the optimal operating point.

[0050] The above results can be summarized as follows: (a) By setting the initial value of the operating point near the optimal operating point, the unit CO ２ Heat input Q per flow rate in (b) CO ２ In order to suppress concentration overshoot, two-input, two-output control (3) or (4) is necessary. (c) From the viewpoint of controllability and economy, (4) two-input, two-output control considering the optimal operating point is optimal. (d) Even with control (2) to (3), controllability and economy can be improved compared to conventional control (1). By adjusting the weighting coefficients (Q, R) in equation (1) in Figure 5, control according to the plant operation objectives, such as whether to prioritize economy or controllability, becomes possible.

[0051] (Operation) Next, the operation of the control device 10 will be described. ２ 1 is a flowchart showing an example of control of a recovery device. Information on which control method to adopt, (2) one input, one output, (3) two inputs, two outputs, or (4) two inputs, two outputs taking into account the optimal operating point, is input in advance to the control device 10 and set in the storage unit 14. First, the data acquisition unit 11 acquires the flow rate, temperature, and CO2 content of the exhaust gas measured by the exhaust gas measuring instrument 101. ２ Concentration, CO ２ CO measured by the concentration meter 102 ２ Concentration, CO ２ CO measured by the gas measuring instrument 103 ２ The gas flow rate and concentration of the gas are acquired (step S1).

[0052] Next, the target value setting unit 121 sets a target value (reference value) (step S2). ２ concentration and / or CO ２ For example, the storage unit 14 stores the CO ２ Target values ​​for concentration and CO ２ A setting table in which target values ​​for the recovery rate are set is registered, and the target value setting unit 121 calculates the CO recovery rate based on this setting table and the exhaust gas flow rate and exhaust gas temperature acquired in step S1. ２ Target concentration and CO ２ (4) When two-input, two-output control is performed in consideration of the optimum operating point, the target value setting unit 121 sets the optimum operating point according to the flow rate of the exhaust gas (or the flow rate and temperature of the exhaust gas). ２ Target concentration and CO ２ For each target value of the recovery rate, data on the operating points at various flow rates of exhaust gas, as shown in FIG. 6, is registered. ２ Concentration and CO ２ The target value setting unit 121 refers to the data corresponding to the target value of the recovery rate and reads the optimum operating point corresponding to the exhaust gas flow rate acquired in step S1. The target value setting unit 121 sets the optimum operating point (the lean absorption liquid flow rate WL and the heater heat input Q in ) is set as the target value of the manipulated variable.

[0053] Next, the optimization calculation unit 123 sets an evaluation function (step S3). The optimization calculation unit 123 calculates x and x in equation (1) of FIG. ｒｅｆ , u are set to values ​​corresponding to one of the control methods: (2) one input, one output; (3) two inputs, two outputs; or (4) two inputs, two outputs taking into account the optimal operating point; and predetermined values ​​are set for the weighting coefficients Sf, Q, and R.

[0054] Next, the optimization calculation unit 123 executes optimization calculation (step S4). The optimization calculation unit 123 uses the prediction model 122 to calculate CO ２Recovery rate (CO emitted from regeneration tower 3) ２ flow rate) and CO ２ The manipulated variables are calculated so that the target concentration value can be achieved (or, in addition, so that operation at the optimum operating point can be realized). In the optimization calculation, the C / GMRES method can be used. This makes it possible to calculate the manipulated variables that minimize the value of the evaluation function set in step S3 in a relatively short calculation time. The manipulated variables are the lean absorbent flow rate WL and the heater heat input Q in The optimization calculation unit 123 outputs the manipulated variable calculated by the optimization calculation to the control unit 13.

[0055] Next, the control unit 13 controls the actual machine using the manipulated variable calculated by the optimization calculation (step S5). For example, the control unit 13 calculates the opening degree of the lean absorbent adjustment valve 62 based on the lean absorbent flow rate WL calculated in step S4, and controls the lean absorbent adjustment valve 62 with the calculated opening degree. For example, the control unit 13 controls the actual machine using the manipulated variable calculated in step S4. in Based on this, the output of the electric heater and the opening of the valve provided in the pipe that supplies saturated steam to the regenerative heater 33 are calculated, and the electric heater is controlled by the calculated output, and the valve is controlled by the calculated opening.

[0056] (Effects) As described above, the nonlinear model predictive control (NMPC) of this embodiment reduces CO ２ While controlling the control amount of the recovery device to the target value, ２ In particular, by providing an optimal operating point as a reference and operating the CO recovery system in accordance with the reference, it is possible to achieve both controllability and economic efficiency. ２ Control to optimize recovery rate and CO ２ Interference in the control for optimizing the concentration can be adjusted by the weight R of the controlled variable, so there is no need to worry about interference. By reducing the dimension of the prediction model and performing optimization calculations using the C / GMRES method, it is possible to shorten the update period to, for example, 1 second and the prediction time to several minutes (for example, 5 minutes), and the CO ２ This allows for real-time control of the recovery device, thereby improving controllability during transient changes in the plant, for example.

[0057] 12 is a diagram showing an example of the hardware configuration of a control device according to each embodiment. A computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905. The above-described control device 10 is implemented in the computer 900. The above-described functions are stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage device 903, loads it into the main storage device 902, and executes the above-described processing in accordance with the program. The CPU 901 allocates a storage area in the main storage device 902 in accordance with the program. The CPU 901 allocates a storage area in the auxiliary storage device 903 for storing data being processed in accordance with the program.

[0058] A program for implementing all or part of the functions of the control device 10 may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed to perform processing by each functional unit. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. If a WWW system is used, the term "computer system" also includes the homepage provision environment (or display environment). The term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, as well as storage devices such as hard disks built into the computer system. If the program is distributed to the computer 900 via a communication line, the computer 900 may load the program into the main storage device 902 and execute the processing described above. The program may be for implementing part of the functions described above, or may be capable of implementing the functions described above in combination with a program already stored in the computer system.

[0059] In another embodiment, the control device 10 may include a custom large-scale integrated circuit (LSI) such as a programmable logic device (PLD) in addition to or instead of the above configuration. Examples of PLDs include programmable array logic (PAL), generic array logic (GAL), complex programmable logic device (CPLD), and field programmable gate array (FPGA). In this case, some or all of the functions realized by the processor may be realized by the integrated circuit.

[0060] As described above, several embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as defined in the claims, as well as in the scope and spirit of the invention.

[0061] <Additional Notes> The control device and CO ２ The recovery device, the control method, and the program can be understood, for example, as follows.

[0062] (1) The control device according to the first aspect is ２ a data acquisition unit that acquires operation data (such as exhaust gas flow rate) of the recovery device; a target value setting unit that sets target values ​​of parameters to be controlled based on the operation data; ２ A prediction model that simulates the operation and state of the recovery device and a predetermined operation variable are used to calculate the CO ２ a prediction model for predicting a predicted value of the parameter when the parameter is applied to the recovery device, and minimizing a deviation between the predicted value of the parameter and the target value; ２an optimization calculation unit that calculates the manipulated variable that achieves the objective by optimization calculation, and that optimizes a predicted value based on the prediction model of the amount of heat supplied to a regenerative heater provided in a regenerator of the recovery device, and ２ and a control unit for controlling the recovery device. This allows for economical CO recovery while controlling the control amount to a target value. ２ Control of the recovery device can be realized.

[0063] (2) A control device according to a second aspect is the control device of (1), and performs the optimization calculation using the C / GMRES method. This allows the optimization calculation to be performed at high speed, and CO ２ Real-time control of the recovery device can be achieved.

[0064] (3) A control device according to a third aspect is the control device according to (1) to (2), wherein the optimization calculation unit is configured to calculate the CO discharged from the regeneration tower. ２ The optimization calculation is performed with the objectives of minimizing the deviation between the predicted value and the target value of the flow rate and minimizing the amount of heat. ２ While bringing the flow rate closer to the target value, the heater heat input Q in It is possible to realize a control that minimizes

[0065] (4) A control device according to a fourth aspect is the control device according to (1) to (2), wherein the optimization calculation unit is configured to calculate the CO discharged from the regeneration tower. ２ Minimizing the deviation between the predicted value and the target value of the flow rate; ２ CO emitted from the absorption tower of the recovery unit ２ The optimization calculation is performed with the objectives of minimizing the deviation between the predicted value and the target value of the CO concentration and minimizing the amount of heat. ２ Concentration and CO ２ While bringing the recovery rate closer to the target value, the heater heat input Q in It is possible to realize a control that minimizes

[0066] (5) A control device according to a fifth aspect is the control device according to (1) to (2), wherein the optimization calculation unit is configured to calculate the CO discharged from the regeneration tower.２ Minimizing the deviation between the predicted value and the target value of the flow rate; ２ CO emitted from the absorption tower of the recovery unit ２ The optimization calculation is performed with the objectives of minimizing the deviation between the predicted value and the target value of the concentration of the lean absorbent, minimizing the deviation between the predicted value and the target value of the flow rate of the lean absorbent supplied from the regeneration tower to the absorption tower, and minimizing the deviation between the predicted value and the target value of the amount of heat. This enables control that is both economical and easy to control.

[0067] (6) CO according to the sixth aspect ２ The recovery device includes an absorption tower, a regeneration tower, a regeneration heater provided in the regeneration tower, a pipe for delivering lean absorption liquid from the regeneration tower to the absorption tower, a valve provided in the pipe, and a control device described in (1) to (5).

[0068] (7) The control method according to the seventh aspect is ２ Operation data of the recovery device is acquired, and target values ​​of parameters to be controlled are set based on the operation data, and a predetermined manipulated variable is set to the CO ２ The predicted values ​​of the parameters when applied to the CO recovery device are ２ minimizing the deviation between the predicted value of the parameter and the target value while making predictions based on a prediction model that simulates the operation and state of the recovery device; ２ and optimizing a predicted value based on the prediction model of the amount of heat supplied to a regenerative heater provided in a regenerator of a recovery device, the operation amount for achieving the purpose is calculated by optimization calculation, and the CO ２ Control the recovery device.

[0069] (8) A program according to an eighth aspect includes: ２ Operation data of the recovery device is acquired, and target values ​​of parameters to be controlled are set based on the operation data, and a predetermined manipulated variable is set to the CO ２ The predicted values ​​of the parameters when applied to the CO recovery device are ２minimizing the deviation between the predicted value of the parameter and the target value while making predictions based on a prediction model that simulates the operation and state of the recovery device; ２ and optimizing a predicted value based on the prediction model of the amount of heat supplied to a regenerative heater provided in a regenerator of a recovery device, the operation amount for achieving the purpose is calculated by optimization calculation, and the CO ２ A process for controlling the recovery device is executed.

[0070] The above-mentioned control device, CO ２ According to the recovery device, the control method, and the program, it is possible to control the control amount to a target value while taking into consideration the economic efficiency of CO ２ Control of the recovery device can be realized.

[0071] DESCRIPTION OF SYMBOLS 2: Absorption tower 3: Regeneration tower 4: Heat exchanger 10: Control device 11: Data acquisition unit 12: Operation amount calculation unit 121: Target value setting unit 122: Prediction model 123: Optimization calculation unit 13: Control unit 14: Memory unit 21: Pump 31: Circulation line 33: Regenerative heater 51, 52, 53, 54: Piping 61: Rich absorbent control valve 62: Lean absorbent control valve 71, 72: Flowmeter 100: CO ２ Recovery device 101...exhaust gas measuring instrument 102...CO ２ Concentration meter 103...CO ２ Gas measuring instrument 900: Computer 901: CPU 902: Main storage device 903: Auxiliary storage device 904: Input / output interface 905: Communication interface

Claims

1. CO ２ a data acquisition unit that acquires operation data of the recovery device; a target value setting unit that sets a target value of a parameter to be controlled based on the operation data; ２ A prediction model for predicting the state of the recovery device, and a predetermined operation amount for the CO ２ a prediction model for predicting a predicted value of the parameter when the parameter is applied to the recovery device, and minimizing a deviation between the predicted value of the parameter and the target value; ２ an optimization calculation unit that calculates the manipulated variable that achieves the objective by optimization calculation when the objective is to optimize a predicted value based on the prediction model of the amount of heat supplied to a regenerative heater provided in a regenerator of the recovery device; ２ A control device comprising: a control unit that controls the recovery device.

2. The control device according to claim 1, wherein the optimization calculation is performed using a C / GMRES method.

3. The optimization calculation unit calculates the CO emitted from the regeneration tower. ２ The control device according to claim 1 or 2, wherein the optimization calculation is performed with the objectives of minimizing the deviation between the predicted value and the target value of the flow rate and minimizing the amount of heat.

4. The optimization calculation unit calculates the CO emitted from the regeneration tower. ２ Minimizing the deviation between the predicted value and the target value of the flow rate; ２ CO emitted from the absorption tower of the recovery unit ２ 3. The control device according to claim 1, wherein the optimization calculation is performed with the objectives of minimizing the deviation between the predicted value and the target value of the concentration of the compound and minimizing the amount of heat.

5. The optimization calculation unit calculates the CO emitted from the regeneration tower. ２ Minimizing the deviation between the predicted value and the target value of the flow rate; ２ CO emitted from the absorption tower of the recovery unit ２ 3. The control device according to claim 1, wherein the optimization calculation is performed with the objectives of minimizing a deviation between the predicted value and the target value of the concentration of 6. A CO2 absorbing system comprising an absorption tower, a regeneration tower, a regeneration heater provided in the regeneration tower, a pipe for sending lean absorbent from the regeneration tower to the absorption tower, a valve provided in the pipe, and the control device according to claim 1 or 2. ２ Recovery device.

7. CO ２ Acquire operating data of the recovery device, set target values ​​of parameters to be controlled based on the operating data, and adjust a predetermined manipulated variable to the CO ２ The predicted values ​​of the parameters when applied to the CO recovery device are ２ minimizing the deviation between the predicted value of the parameter and the target value while predicting the state of the recovery device based on a prediction model; ２ The object of the present invention is to optimize a predicted value based on the prediction model of the amount of heat supplied to a regenerative heater provided in a regenerator of a recovery device, and to calculate the manipulated variable that achieves the object by optimization calculation, and ２ A control method for controlling a recovery device.

8. On the computer, ２ Acquire operating data of the recovery device, set target values ​​of parameters to be controlled based on the operating data, and adjust a predetermined manipulated variable to the CO ２ The predicted values ​​of the parameters when applied to the CO recovery device are ２ minimizing the deviation between the predicted value of the parameter and the target value while predicting the state of the recovery device based on a prediction model; ２ The object of the present invention is to optimize a predicted value based on the prediction model of the amount of heat supplied to a regenerative heater provided in a regenerator of a recovery device, and to calculate the manipulated variable that achieves the object by optimization calculation, and ２ A program for executing a process for controlling the recovery device.