Rectification column air cooler system and control method thereof

Abstract

The application discloses a rectifying tower air cooler system and a control method thereof, and the system comprises an air cooler, an air cooler motor controller, an air cooler outlet temperature detection unit, an air cooler operation controller, an air cooler energy-saving optimization controller and a rectifying tower parameter acquisition unit; the air cooler energy-saving optimization controller is connected with the rectifying tower parameter acquisition unit, the air cooler motor controller, the air cooler outlet temperature detection unit and the air cooler operation controller respectively; the air cooler is connected with the air cooler motor controller and the air cooler outlet temperature detection unit respectively; the air cooler energy-saving optimization controller is used for generating total heat load of the air cooler and total heat exchange capacity of the air cooler according to material physical property variable data and temperature data, and transmitting the data to the air cooler operation controller and the air cooler motor controller. The application realizes accurate matching between heat exchange capacity of the air cooler and actual process load, effectively reduces system energy consumption under the premise of guaranteeing condensation effect.

Description

Technical Field

[0001] This invention relates to the field of heat transfer technology, and in particular to a distillation column air cooler system and its control method. Background Technology

[0002] Air coolers are among the most commonly used heat exchange devices in the petrochemical and oil and gas processing industries, primarily used for condensing and cooling high-temperature process fluids. Compared to traditional water-cooled equipment, air coolers utilize ambient air as the cooling medium, offering advantages such as low energy consumption, high airflow, high heat transfer rate, low vibration amplitude, low noise, and no need for additional cooling water. Therefore, air coolers are widely used in distillation column air cooler systems to ensure the smooth condensation of vaporous materials at the column top into a liquid phase, meeting process requirements while reducing energy consumption and improving the overall operating efficiency of the air cooler system.

[0003] Currently, existing technologies still have certain limitations in the optimized control of air coolers. Existing technologies mainly focus on the overall control technology of distillation columns, air cooler control technology (usually with fixed temperature settings), and improvements to the structure of air cooler equipment. They have not yet achieved systematic and intelligent control of air coolers, nor can they guarantee that the air cooler maintains a minimum energy consumption operating state under different operating conditions.

[0004] Existing air cooler systems suffer from the following main drawbacks: First, when environmental conditions (such as ambient temperature) change and the air cooler's regulation and control reach their limits, existing systems can only adjust the number of air coolers or control the outlet temperature separately, lacking coordinated optimization between the two. This prevents the air cooler from operating at its lowest energy consumption, thus increasing energy consumption. Second, changes in ambient temperature limit the air cooler's temperature regulation. Existing systems cannot utilize distillation column top reflux regulation to alleviate this limitation, reducing the operational flexibility and overall system stability.

[0005] This section is intended to provide background or context for the embodiments of the invention set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section. Summary of the Invention

[0006] This invention provides a distillation column air cooler system to achieve energy-saving optimization and adjustment of the number of air coolers in operation and the operating current of the motor, so as to improve the heat exchange efficiency of the system and reduce the system energy consumption.

[0007] The distillation column air cooler system includes: an air cooler, an air cooler motor controller, an air cooler outlet temperature detection unit, an air cooler operation controller, an air cooler energy-saving optimization controller, and a distillation column parameter acquisition unit;

[0008] The air cooler energy-saving optimization controller is connected to the distillation column parameter acquisition unit, the air cooler motor controller, the air cooler outlet temperature detection unit, and the air cooler operation controller, respectively.

[0009] The air cooler is connected to the air cooler motor controller and the air cooler outlet temperature detection unit, respectively;

[0010] The air cooler energy-saving optimization controller is used to receive material property variable data from the distillation column parameter acquisition unit and temperature data detected by the air cooler outlet temperature detection unit; generate the total heat load and total heat exchange of the air cooler based on the material property variable data and the temperature data, and transmit the total heat load and total heat exchange of the air cooler to the air cooler operation controller and the air cooler motor controller.

[0011] The air cooler operation controller determines the number of air coolers in operation and controls the number of air coolers in operation based on the total heat load and total heat exchange of the air cooler.

[0012] The air cooler motor controller determines the heat exchange of each operating air cooler based on the total heat load and total heat exchange of the air cooler, and controls the speed of the corresponding air cooler motor based on the heat exchange of each air cooler.

[0013] Furthermore, the air cooler energy-saving optimization controller includes:

[0014] The parameter acquisition module is used to acquire material property variable data and air property variable data of the air cooler; the air property variable data includes: the initial number of air coolers in operation and the operating current of the air cooler.

[0015] The total heat load determination module is used to determine the total heat load of the air cooler based on the material property variable data.

[0016] The total air flow rate determination module is used to determine the total air flow rate of the air cooler based on the initial number of air coolers in operation and the operating current of the air cooler.

[0017] The total heat exchange determination module is used to determine the total heat exchange of the air cooler based on the total air flow rate, the material property variable data, and the air property variable data.

[0018] Furthermore, the total heat load determination module is specifically used to determine the enthalpy of the top temperature, the enthalpy of the bubble point temperature, and the enthalpy of the subcooling temperature based on the top temperature, bubble point temperature, and the material temperature at the air cooler outlet, respectively; to determine the condensation heat of the material at the top of the column based on the enthalpy of the top temperature, the enthalpy of the bubble point temperature, the top flow rate, and the heat loss rate of the air cooler; to determine the subcooling heat of the material at the top of the column based on the enthalpy of the bubble point temperature, the enthalpy of the subcooling temperature, the top flow rate, and the heat loss rate of the air cooler; and to determine the total heat load of the air cooler based on the condensation heat and the subcooling heat.

[0019] Furthermore, the total air flow determination module is specifically used to determine the air flow of each operating air cooler based on the operating current through a motor characteristic model; and to obtain the total air flow by summing the initial number of operating air coolers and the air flow of each operating air cooler using a summation function.

[0020] Furthermore, the total heat exchange determination module includes:

[0021] The latent heat of natural convection determination unit is used to determine the latent heat of natural convection based on the condensation heat, the total heat load, and the air physical property variable data.

[0022] The logarithmic temperature difference determination unit is used to determine the logarithmic temperature difference under forced convection based on the supercooling heat, the latent heat of natural convection, the total air flow rate, and the air physical property variable data.

[0023] The total heat exchange determination unit is used to determine the total heat exchange of the air cooler based on the condensation heat, the latent heat of natural convection, the logarithmic temperature difference under forced convection, and the air property variable data.

[0024] Furthermore, the natural convection latent heat determination unit is specifically used to, in response to the air cooler being in a stopped state, determine the logarithmic temperature difference under natural convection based on the inlet material temperature, outlet material temperature, air inlet temperature, and air outlet temperature when the air cooler is in a stopped state; determine the heat transfer of the air cooler in a stopped state based on the natural convection heat transfer coefficient, the natural convection condensation heat transfer area, and the logarithmic temperature difference under natural convection; determine the total heat transfer of all air coolers in a stopped state based on the heat transfer of the air coolers in a stopped state, the total number of air coolers, and the initial number of air coolers in operation; and determine the natural convection latent heat based on the total heat transfer, the condensation heat, and the total heat load.

[0025] Furthermore, the logarithmic temperature difference determination unit is specifically used to determine the intermediate temperature of air in the subcooling stage based on the subcooling heat, the latent heat of natural convection, the total air flow rate, the air density, and the specific heat capacity of air; and in response to the air cooler being in operation, to determine the logarithmic temperature difference under forced convection based on the inlet material temperature of the air cooler, the outlet material temperature of the air cooler, the bubble point temperature, and the intermediate temperature.

[0026] Furthermore, the total heat exchange determination unit is specifically used to determine the heat transfer area required for material condensation under forced convection based on the condensation heat, the latent heat of natural convection, the condensation heat transfer coefficient, and the logarithmic temperature difference under forced convection; to determine the forced convection heat transfer area of ​​all air coolers in operation based on the bare tube area of ​​each air cooler and the initial number of operating units; and to determine the total heat exchange of the air cooler based on the subcooling heat transfer coefficient, the heat transfer area, the forced convection heat transfer area, the logarithmic temperature difference under forced convection, the total heat transfer, and the condensation heat.

[0027] Furthermore, the air cooler outlet temperature detection unit is used to detect the outlet temperature of the air cooler or the outlet temperature of the reflux tank, and transmit the temperature data to the air cooler energy-saving optimization controller.

[0028] Furthermore, the air cooler operation controller is also used to send the initial number of air coolers in operation to the air cooler energy-saving optimization controller.

[0029] Furthermore, the distillation column parameter acquisition unit is used to acquire material property variable data of the distillation column, wherein the material property variable data includes: column top flow rate, column top temperature, bubble point temperature and air cooler outlet material temperature, and sends the material property variable data to the air cooler energy-saving optimization unit.

[0030] This invention provides a method for controlling an air cooler in a distillation column, which optimizes the number of air coolers in operation and the operating current of the motor to improve the heat exchange efficiency of the system and reduce system energy consumption.

[0031] The control method for the air cooler of the distillation column is applied to the above-mentioned air cooler system of the distillation column, including:

[0032] Acquire material property data and air property data for the air cooler; air property data includes: the initial number of air coolers in operation and the operating current of the air cooler.

[0033] The total heat load of the air cooler is determined based on the material property variable data.

[0034] The total air flow rate of the air cooler is determined based on the initial number of air coolers in operation and the operating current of the air coolers.

[0035] The total heat exchange of the air cooler is determined based on the total air flow rate, the material property variable data, and the air property variable data.

[0036] Further, the material property variables include: top temperature, bubble point temperature, air cooler outlet material temperature, top flow rate, and air cooler heat loss rate; determining the total heat load of the air cooler based on the material property variables includes:

[0037] Based on the column top temperature, bubble point temperature, and air cooler outlet material temperature, determine the enthalpy values ​​of the column top temperature, bubble point temperature, and subcooling temperature, respectively.

[0038] The condensation heat of the material at the top of the column is determined based on the enthalpy of the top temperature, the enthalpy of the bubble point temperature, the top flow rate, and the heat loss rate of the air cooler.

[0039] The subcooling heat of the material at the top of the column is determined based on the enthalpy of the bubble point temperature, the enthalpy of the subcooling temperature, the flow rate at the top of the column, and the heat loss rate of the air cooler.

[0040] The total heat load of the air cooler is determined based on the condensation heat and the subcooling heat.

[0041] Further, determining the total airflow of the air cooler based on the initial number of operating air coolers and the operating current of the air coolers includes:

[0042] The airflow rate of each operating air cooler is determined based on the operating current using a motor characteristic model.

[0043] The total air flow rate is obtained by summing the initial number of air coolers in operation and the air flow rate of each air cooler in operation using a summation function.

[0044] Furthermore, the air property variable data also includes: the inlet material temperature of the air cooler, the outlet material temperature of the air cooler, the air inlet temperature of the air cooler, the air outlet temperature of the air cooler, and the air outlet temperature of the air cooler when the air cooler is in a stopped state; the step of determining the total heat exchange of the air cooler based on the total air flow rate, the material property variable data, and the air property variable data includes:

[0045] The latent heat of natural convection is determined based on the condensation heat, the total heat load, and the air property variables.

[0046] Based on the supercooling heat, the latent heat of natural convection, the total air flow rate, and the air property variables, the logarithmic temperature difference under forced convection is determined.

[0047] The total heat exchange of the air cooler is determined based on the condensation heat, the latent heat of natural convection, the logarithmic temperature difference under forced convection, and the air property variables.

[0048] Furthermore, the air property variable data also includes: air cooler inlet material temperature, air cooler outlet material temperature, air inlet air cooler temperature, air outlet air cooler temperature when the air cooler is in a stopped state, natural convection heat transfer coefficient, natural convection condensation heat transfer area, and total number of air coolers; determining the latent heat of natural convection based on the condensation heat, the total heat load, and the air property variable data includes:

[0049] In response to the air cooler being in a stopped state, the logarithmic temperature difference under natural convection is determined based on the inlet material temperature of the air cooler, the outlet material temperature of the air cooler, the air inlet temperature of the air cooler, and the air outlet temperature of the air cooler when the air cooler is in a stopped state.

[0050] The heat transfer of the air cooler in a stopped state is determined based on the natural convection heat transfer coefficient, the natural convection condensation heat transfer area, and the logarithmic temperature difference under natural convection.

[0051] The total heat transfer of all air coolers in the stopped state is determined based on the heat transfer of the air coolers in the stopped state, the total number of air coolers, and the initial number of air coolers in operation.

[0052] The latent heat of natural convection is determined based on the total heat transfer, the condensation heat, and the total heat load.

[0053] Furthermore, the air property variable data also includes: air density, air specific heat capacity, and air outlet temperature of the air cooler; the step of determining the logarithmic temperature difference under forced convection based on the subcooling heat, the latent heat of natural convection, the total air flow rate, and the air property variable data includes:

[0054] The intermediate temperature of the air during the supercooling stage is determined based on the supercooling heat, the latent heat of natural convection, the total air flow rate, the air density, and the specific heat capacity of the air.

[0055] In response to the air cooler being in operation, the logarithmic temperature difference under forced convection is determined based on the inlet material temperature of the air cooler, the bubble point temperature, the air outlet temperature of the air cooler, and the intermediate temperature.

[0056] Furthermore, the air property variable data also includes: condensation heat transfer coefficient, the bare tube area of ​​each air cooler, and subcooling heat transfer coefficient; determining the total heat exchange of the air cooler based on the condensation heat, the latent heat of natural convection, the logarithmic temperature difference under forced convection, and the air property variable data includes:

[0057] Based on the condensation heat, the latent heat of natural convection, the condensation heat transfer coefficient, and the logarithmic temperature difference under forced convection, determine the heat transfer area required for material condensation under forced convection.

[0058] The forced convection heat transfer area of ​​all air coolers in operation is determined based on the tube area of ​​each air cooler and the initial number of operating units.

[0059] The total heat exchange of the air cooler is determined based on the subcooling heat transfer coefficient, the heat transfer area, the forced convection heat transfer area, the logarithmic temperature difference under forced convection, the total heat transfer, and the condensation heat.

[0060] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described distillation column air cooler control method.

[0061] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described distillation column air cooler control method.

[0062] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-described distillation column air cooler control method.

[0063] The distillation column air cooler system and its control method provided in this invention include an air cooler energy-saving optimization controller that dynamically calculates the total heat load of the distillation column air cooler system based on air and material property variable data. Simultaneously, the controller calculates the total air flow and total heat exchange of the air cooler under current operating conditions using a motor performance model and a heat exchange calculation model, thereby achieving real-time evaluation of the total heat exchange capacity of the air cooler. The air cooler motor controller and air cooler operation controller determine whether the number of air coolers currently in operation is redundant or insufficient, and whether the motor operating current is too high or too low, based on the comparison between the total heat load and the total heat exchange capacity. Based on this, they generate optimal start / stop control commands and current adjustment commands, achieving joint regulation of the number of air coolers in operation and the operating current. By precisely matching heat exchange demand with energy consumption, the air cooler energy-saving optimization controller effectively improves heat exchange efficiency and reduces ineffective power consumption in the distillation column air cooler system. Attached Figure Description

[0064] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0065] Figure 1 This is a schematic diagram of the structure of the distillation column air cooler system in an embodiment of the present invention;

[0066] Figure 2 This is a schematic diagram of the distillation column system in an embodiment of the present invention;

[0067] Figure 3 This is a schematic flowchart of a distillation column air cooler control method according to an embodiment of the present invention;

[0068] Figure 4 This is a schematic flowchart of a distillation column air cooler control method in another embodiment of the present invention;

[0069] Figure 5 This is a schematic flowchart of a distillation column air cooler control method in another embodiment of the present invention;

[0070] Figure 6 This is a schematic flowchart of a distillation column air cooler control method in another embodiment of the present invention;

[0071] Figure 7 This is a schematic flowchart of a distillation column air cooler control method in another embodiment of the present invention;

[0072] Figure 8 This is a schematic flowchart of a distillation column air cooler control method in another embodiment of the present invention;

[0073] Figure 9 This is a schematic flowchart of a distillation column air cooler control method in another embodiment of the present invention;

[0074] Figure 10 This is a schematic diagram of the physical structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0075] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0076] The information collected in the technical solution of this application is information and data authorized by the user or fully authorized by all parties. The collection, storage, use, processing, transmission, provision, disclosure and application of the relevant data all comply with the relevant laws, regulations and standards of the relevant countries and regions, necessary confidentiality measures have been taken, and they do not violate public order and good morals. Corresponding operation portals are provided for users to choose to authorize or refuse.

[0077] Provide users with corresponding operation entry points, allowing them to choose to agree to or reject the automated decision results; if the user chooses to reject, the process will proceed to the expert decision-making process.

[0078] To address the problems existing in current distillation column air cooler systems, such as: the inability to perform real-time calculations and dynamic adjustments based on total heat load, leading to inaccurate assessments of the air cooler's heat exchange capacity; the inability to accurately match the current number of operating air coolers with actual condensation demand, resulting in redundant energy consumption during air cooler operation; and the failure to fully utilize the heat exchange compensation capacity provided by natural convection when the air cooler is not in operation, thus resulting in high overall system energy consumption, this application proposes a distillation column air cooler system and its control method. This system can achieve efficient condensation of the column top gas, dynamically adapt to changes in condensation load, and effectively improve the heat exchange efficiency and energy-saving level of the air cooler system.

[0079] like Figure 1 As shown, the distillation column air cooler system 100 includes: an air cooler 101, an air cooler motor controller 102, an air cooler outlet temperature detection unit 103, an air cooler operation controller 104, an air cooler energy-saving optimization controller 105, and a distillation column parameter acquisition unit 106.

[0080] The air cooler energy-saving optimization controller 105 is connected to the air cooler motor controller 102, the air cooler outlet temperature detection unit 103, the air cooler operation controller 104, and the distillation column parameter acquisition unit 106, respectively.

[0081] The air cooler 101 is connected to the air cooler motor controller 102, the air cooler outlet temperature detection unit 103, and the air cooler operation controller 104, respectively.

[0082] The air cooler energy-saving optimization controller 105 receives temperature data detected by the air cooler outlet temperature detection unit 103 and material property variable data from the distillation column parameter acquisition unit 106. Based on the material property variable data and temperature data, it generates the total heat load and total heat exchange of the air cooler, and transmits these data to the air cooler motor controller 102 and the air cooler operation controller 104.

[0083] In this embodiment, the air cooler energy-saving optimization controller 105 receives material property variable data such as column top flow rate, column top temperature, and bubble point temperature collected by the distillation column parameter acquisition unit 106, and combines it with the air cooler outlet material temperature collected by the air cooler outlet temperature detection unit 103. It then calculates the condensing heat, subcooling heat, and total heat load of the air cooler using a built-in heat transfer calculation model. Based on the initial number of air coolers Nco and its corresponding operating current and other air property variable data, the total air flow rate of the air cooler is further determined using a motor performance model. The total heat transfer of the air cooler is then determined using the heat transfer calculation model, and the calculated total heat load and total heat transfer are sent to the air cooler motor controller 102 and the air cooler operation controller 104.

[0084] The air cooler energy-saving optimization controller 105 reacquires the temperature data from the air cooler outlet temperature detection unit 103 and the material property variable data from the distillation column parameter acquisition unit 106 in each control cycle, and redetermines the total heat load and total heat exchange of the air cooler, so as to dynamically adjust the number of air coolers in operation and the operating current of the motor.

[0085] The air cooler operation controller 104 determines the number of air coolers in operation and controls the number of air coolers in operation based on the total heat load and total heat exchange of the air coolers.

[0086] The air cooler motor controller 102 determines the heat exchange of each air cooler based on the total heat load and total heat exchange of the air cooler, and controls the speed of the corresponding air cooler motor based on the heat exchange of each air cooler.

[0087] In this embodiment, the air cooler operation controller 104 determines the optimal number of air coolers in operation based on a comparison between the currently calculated total heat load and the total heat exchange, thereby adjusting the initial number of operating air coolers Nco. When the total heat exchange is greater than or equal to the total heat load, it indicates that the current number of operating air coolers meets the condensation requirements. The air cooler operation controller 104 can maintain the current number of operating air coolers or further reduce the number of operating air coolers to achieve the goal of minimum energy consumption. When the total heat exchange is less than the total heat load, the air cooler operation controller 104 can increase the number of operating air coolers to improve the heat exchange capacity of the air coolers. In each control cycle, the air cooler operation controller 104 uses the updated number of operating air coolers as the new "initial number of operating air coolers Nco" for the next round of control cycle calculation, thereby forming an adaptive air cooler adjustment strategy.

[0088] The air cooler operation controller 104 is used to send a switch control signal (ON / OFF) to the motor switch inside the air cooler 101 to control the start and stop status of the motor, thereby adjusting the number of air coolers in operation.

[0089] The air cooler motor controller 102 controls the operating current of the motors inside the air cooler to regulate airflow. When the total heat exchange is greater than or equal to the total heat load, the air cooler motor controller 102 can reduce the operating current of each motor to decrease airflow output. When the total heat exchange is less than the total heat load, the air cooler motor controller 102 can increase the operating current of each motor to increase airflow output, thereby enhancing heat exchange capacity to meet condensation requirements.

[0090] The air cooler motor controller 102 sends control signals to the motor's frequency converter. The frequency converter adjusts its output frequency according to the control signals to adjust the motor speed. As the motor speed changes, its operating current also changes, thereby achieving dynamic adjustment of the motor load and heat exchange capacity.

[0091] In this embodiment of the invention, the air cooler motor controller and the air cooler operation controller compare the total heat exchange and total heat load of the air cooler in real time to determine whether there is redundancy or insufficiency in the number of air coolers currently in operation, and whether the motor operating current is too high or too low. Based on the judgment results, the air cooler operation controller can dynamically adjust the number of air coolers in operation, while the air cooler motor controller adjusts the corresponding operating current setpoint according to the heat exchange capacity required by each fan. Through this multi-factor dynamic judgment mechanism, not only is the response accuracy and control flexibility of the air cooler system improved during operation, but also ineffective energy consumption is significantly reduced, achieving the optimal energy-saving operation effect of the air cooler system while ensuring the condensation efficiency of the distillation column.

[0092] like Figure 2 As shown, in one embodiment, the distillation column system 200 includes a distillation column air cooler system 100, multiple flow meters A, multiple control valves C, a distillation column body E, multiple flow controllers FC, multiple level controllers LC and product purity controller AC, reflux tank RD and reboiler R. The above-mentioned devices are connected by connectors such as hoses and joints.

[0093] Feed line G1 connects to the feed inlet of distillation column body E. Flow meter A and regulating valve C are sequentially installed on feed line G1 along the material flow direction. Flow controller FC is connected to both flow meter A and regulating valve C, receiving the measured value from flow meter A and comparing it with a preset target flow rate. Flow controller FC uses a proportional-integral-derivative (PID) control algorithm to generate a control signal based on the comparison result and sends the control signal to regulating valve C to control the opening and closing degree of regulating valve C, thereby regulating the input flow rate of material F. Material F enters distillation column body E through feed line G1, where material separation occurs.

[0094] Specifically, when the measured value is greater than the target flow rate, the flow controller FC sends a valve closing signal to the regulating valve C, causing the regulating valve C to close appropriately, reducing the valve opening and thus decreasing the flow rate of material F. When the measured value is less than the target flow rate, the flow controller FC sends a valve opening signal to the regulating valve C, causing the regulating valve C to open appropriately, increasing the valve opening and thus increasing the flow rate of material F.

[0095] The outlet of distillation column E is connected to both the outlet pipeline G2 and the inlet of the reboiler R. A portion of the high-boiling-point bottom product enters the reboiler R, while the remaining portion is discharged from distillation column E as bottom product B. A regulating valve C is installed on the outlet pipeline G2, and a level controller LC at the bottom of the distillation column is connected to the regulating valve C. This controller reads the actual liquid level at the bottom of the distillation column in real time and compares it with the target liquid level. The level controller LC uses a proportional-integral-derivative (PID) control algorithm to generate a control signal based on the comparison result and sends the control signal to the regulating valve C to control the opening and closing degree of the regulating valve C, thereby regulating the output flow rate of the high-boiling-point bottom product B.

[0096] Specifically, when the actual liquid level is higher than the target liquid level, it indicates that there is too much liquid accumulation at the bottom of the column. The level controller LC sends a valve opening signal to the regulating valve C, appropriately increasing the opening of the regulating valve C to accelerate the discharge rate of product B from the bottom of the column, thereby lowering the liquid level. When the actual liquid level is lower than the target liquid level, the level controller LC sends a valve closing signal to the regulating valve C, appropriately decreasing the opening of the regulating valve C to slow down the discharge rate of product B from the bottom of the column, thus preventing the bottom of the column from drying out.

[0097] The feed inlet of the reboiler R is also connected to the feed line G3. On the feed line G3, a flow meter A and a regulating valve C are sequentially installed along the material flow direction. A flow controller FC is connected to flow meter A, regulating valve C, and product purity controller AC, respectively. It receives the measured value from flow meter A and compares the measured value with a preset target flow rate value. The flow controller FC uses a proportional-integral-derivative (PID) control algorithm to generate a control signal based on the comparison result and sends the control signal to regulating valve C to control the opening and closing degree of regulating valve C, thereby regulating the input flow rate of the heating medium Q.

[0098] Specifically, when the measured value is greater than the target flow rate, the flow controller FC sends a valve closing signal to the regulating valve C, causing the regulating valve C to close appropriately, reducing the valve opening and thus decreasing the flow rate of the heating medium Q. When the measured value is less than the target flow rate, the flow controller FC sends a valve opening signal to the regulating valve C, causing the regulating valve C to open appropriately, increasing the valve opening and thus increasing the flow rate of the heating medium Q.

[0099] Heating medium Q enters the reboiler R through feed line G3, where it exchanges heat with the high-boiling-point bottom product. A portion of the bottom product is vaporized and refluxes back to the distillation column as gaseous material V. The remaining unvaporized liquid bottom product is discharged from the drain port R1 of the reboiler R.

[0100] On the discharge pipeline G4, an air cooler 101, a reflux tank RD, and a regulating valve C are sequentially installed along the flow direction of the gaseous material. A level controller LC is connected to both the reflux tank RD and the regulating valve C to read the actual liquid level value of the reflux tank RD in real time and compare it with the target liquid level value. The level controller LC uses a proportional-integral-derivative (PID) control algorithm to generate a control signal based on the comparison result and sends the control signal to the regulating valve C to control the opening and closing degree of the regulating valve C, thereby regulating the output flow rate of the top product D.

[0101] Specifically, when the actual liquid level is higher than the target liquid level, it indicates that there is too much liquid accumulation in the reflux tank RD. The level controller LC sends a valve opening signal to the regulating valve C, appropriately increasing the opening of the regulating valve C to accelerate the discharge rate of the top product D, thereby lowering the liquid level. When the actual liquid level is lower than the target liquid level, the level controller LC sends a valve closing signal to the regulating valve C, appropriately decreasing the opening of the regulating valve C to slow down the discharge rate of the top product D, thus preventing the reflux tank RD from drying out.

[0102] The gaseous material at the top of the column enters the air cooler 101 through the discharge pipe G4. After condensation by heat exchange with air in the air cooler 101, it forms a liquid material. The condensed liquid material enters the reflux tank RD. Part of the liquid material is discharged as the top product D, and the other part of the liquid material L is returned to the distillation column body E through the reflux pipe G5.

[0103] On the return pipeline G5, a flow meter A and a regulating valve C are sequentially installed along the flow direction of the liquid material. A flow controller FC is connected to both flow meter A and regulating valve C to receive the measured value from flow meter A and compare it with a preset target flow rate value. The flow controller FC uses a proportional-integral-derivative (PID) control algorithm to generate a control signal based on the comparison result and sends the control signal to regulating valve C to control the opening and closing degree of regulating valve C, thereby regulating the return flow rate of the liquid material L.

[0104] Specifically, when the measured value is greater than the target flow rate, the flow controller FC sends a valve closing signal to the regulating valve C, causing the regulating valve C to close appropriately, reducing the valve opening and thus decreasing the flow rate of the liquid material L. When the measured value is less than the target flow rate, the flow controller FC sends a valve opening signal to the regulating valve C, causing the regulating valve C to open appropriately, increasing the valve opening and thus increasing the flow rate of the liquid material L.

[0105] The air cooler energy-saving optimization controller 105 is connected to the air cooler motor controller 102, the air cooler operation controller 104, the distillation column parameter acquisition unit 106, and the flow controller FC, respectively. The air cooler energy-saving optimization controller 105 receives material property variable data from the distillation column parameter acquisition unit 106 in real time, determines the total heat load and total heat exchange of the air cooler in real time based on the material property variable data, and transmits the total heat load and total heat exchange to the air cooler motor controller 102 and the air cooler operation controller 104. The air cooler 101 is connected to both the air cooler motor controller 102 and the air cooler operation controller 104. The air cooler operation controller 104 adjusts the number of air coolers 101 in operation in real time based on the total heat load and total heat exchange, while the air cooler motor controller 102 adjusts the operating current of the motor inside the air cooler 101 in real time based on the total heat load and total heat exchange.

[0106] In this embodiment of the invention, by installing flow meters, regulating valves, and flow controllers on the feed, discharge, and reflux pipelines, precise measurement and control of material flow rate is achieved, thereby ensuring the stability of the distillation operation in the distillation column system and the condensation effect of the top gas. Liquid level controllers are installed on the discharge pipelines of the bottom and top products, respectively, and combined with the liquid level changes in the reflux tank and reboiler, continuous adjustment of the liquid levels at the bottom and in the reflux tank is achieved, effectively preventing excessively high or low liquid levels and further ensuring the stable operation of the distillation column. Furthermore, the air cooler energy-saving optimization controller can receive material property variable data transmitted from the distillation column parameter acquisition unit in real time, and accurately calculate the total heat load required by the air cooler under the current operating conditions and its total heat exchange capacity through a built-in thermodynamic heat transfer model. The air cooler operation controller dynamically adjusts the number of air coolers in operation based on the difference between the total heat load and the total heat exchange capacity, preventing excessive energy waste due to too many air coolers or reduced condensation capacity due to insufficient configuration. At the same time, the air cooler motor controller can adjust the operating current of each motor according to the heat exchange requirements, thereby regulating the air flow rate and improving the heat exchange efficiency.

[0107] In one embodiment, the air cooler energy-saving optimization controller 105 includes a parameter acquisition module, a total heat load determination module, a total air flow determination module, and a total heat exchange determination module.

[0108] The parameter acquisition module is used to acquire material property variable data and air property variable data for the air cooler. The air property variable data includes: the initial number of air coolers in operation and the operating current of the air coolers.

[0109] Specifically, the parameter acquisition module collects material property variable data and air property variable data through various instruments and equipment in the distillation column system, the distillation column parameter acquisition unit 106, and the air cooler outlet temperature detection unit 103, and stores them respectively in the material property variable table (as shown in Table 1) and the air property variable table (as shown in Table 2). The various instruments and equipment include: flow meter A, flow controller FC, level controller LC, regulating valve C (or control valve), temperature sensor, air temperature probe, current sensor, motor frequency converter, and motor start / stop feedback switch, etc.

[0110] In one embodiment, the distillation column parameter acquisition unit 106 is used to acquire the column top flow rate Ftp, column top temperature Ttp, bubble point temperature Tbp, and air cooler outlet material temperature To, and send the above data to the air cooler energy-saving optimization controller 105.

[0111] Specifically, such as Figure 2 As shown, flow meter A is used to measure the flow rate at the top of the tower (Ftp), the flow rate of material F, and the flow rate of heating medium Q. Temperature sensors are used to measure the top temperature (Ttp), bubble point temperature (Tbp), material temperature at the air cooler inlet (Ti), and material temperature at the air cooler outlet (To). Air temperature probes are used to measure the air inlet temperature (Tairin), air outlet temperature (Tairout), and the air outlet temperature (Tairout_nc) when the air cooler is stopped. A current sensor is used to detect the motor's operating current (I). A motor frequency converter is used to control the motor's operating current (I) and frequency.

[0112] The material property variables collected by the above-mentioned instruments and equipment are stored in the material property variable table, as shown in Table 1:

[0113] variable name Physical meaning unit Ti air cooler inlet material temperature ℃ To Air cooler outlet material temperature ℃ Ttp Tower top temperature ℃ Tbp Bubble point temperature ℃ Ftp Tower top flow kg / h Hloss Air cooler heat loss rate ％

[0114] Table 1: Material Property Variables Table

[0115] The air physical property variables collected by the above-mentioned instruments and equipment are stored in the air physical property variable table, as shown in Table 2:

[0116]

[0117] Table 2: Air Property Variables Table

[0118] The total heat load determination module is used to determine the total heat load of the air cooler based on material property variable data.

[0119] In one embodiment, the total heat load determination module is specifically used to determine the enthalpy of the top temperature (Eptp), the enthalpy of the bubble point temperature (Epbp), and the enthalpy of the subcooling temperature (Epovc) based on the top temperature (Ttp), the bubble point temperature (Tbp), and the outlet material temperature (To) of the air cooler, respectively; to determine the condensation heat (Hcd) of the top material based on the enthalpy of the top temperature (Eptp), the enthalpy of the bubble point temperature (Epbp), the top flow rate (Ftp), and the heat loss rate (Hloss) of the air cooler; to determine the subcooling heat (Hoc) of the top material based on the enthalpy of the bubble point temperature (Epbp), the enthalpy of the subcooling temperature (Epovc), the top flow rate (Ftp), and the heat loss rate (Hloss) of the air cooler; and to determine the total heat load (Htotal_cl) of the air cooler based on the condensation heat (Hcd) and the subcooling heat (Hoc).

[0120] Specifically, the total heat load determination module calculates the enthalpy of the tower top temperature Eptp, the enthalpy of the bubble point temperature Eppp, and the enthalpy of the subcooling temperature Epovc according to formulas (1) to (3).

[0121] Eptp=f(Ttp) (1)

[0122] Epbp=f(Tbp) (2)

[0123] Epovc=f(To) (3)

[0124] Where Ttp is the top temperature of the column, Tbp is the bubble point temperature, To is the outlet material temperature of the air cooler; Eptp is the enthalpy of the top temperature of the column, Epbp is the enthalpy of the bubble point temperature, and Epovc is the enthalpy of the subcooling temperature, all in kJ / kg.

[0125] After the material at the top of the tower (i.e., high-temperature steam) enters the air cooler, it is cooled to the bubble point temperature. The condensation heat Hcd represents the heat released when the material condenses from the gas phase to the liquid phase. The total heat load determination module calculates the condensation heat Hcd according to formula (4).

[0126]

[0127] Where Ftp is the top flow rate, Eptp is the enthalpy of the top temperature, Epbp is the enthalpy of the bubble point temperature, and Hloss is the heat loss rate of the air cooler.

[0128] The subcooling heat Hoc represents the heat released when the material at the top of the tower is cooled from the bubble point temperature Tbp to the material temperature To at the outlet of the air cooler. The total heat load determination module calculates the subcooling heat Hoc according to formula (5).

[0129]

[0130] Where Ftp is the top flow rate, Epbp is the enthalpy of the bubble point temperature, EPOVC is the enthalpy of the subcooling temperature, and Hloss is the heat loss rate of the air cooler.

[0131] The total heat load determination module calculates the total heat load Htotal_cl of the air cooler according to formula (6).

[0132] Htotal_cl=Hcd+Hoc (6)

[0133] Where Hcd is the heat of condensation of the material at the top of the column, and Hoc is the heat of subcooling of the material at the top of the column.

[0134] The total air flow determination module is used to determine the total air flow of the air cooler based on the initial number of air coolers in operation and the operating current of the air cooler.

[0135] In one embodiment, the total air flow determination module is specifically used to determine the air flow Fair(i) of each operating air cooler based on the operating current I of the air cooler through a motor characteristic model; and to obtain the total air flow Fair_total of the air cooler by summing the initial number of operating air coolers Nco and the air flow of each operating air cooler through a summation function.

[0136] Specifically, the total air flow determination module detects the operating current I of the motor inside each operating air cooler through a current sensor, but this invention is not limited thereto.

[0137] The total air flow determination module calculates the air flow of each air cooler in operation according to formula (7).

[0138] Fair(i)=h(I) i=1,2,…,Nco (7)

[0139] Where I is the operating current of the air cooler, i is the i-th operating air cooler, h(i) is the motor characteristic model, and Nco is the initial number of operating air coolers. The initial number of operating air coolers, Nco, is preset.

[0140] The motor characteristic model can be obtained by establishing the motor performance curve through the air volume-current comparison table provided by the manufacturer, or by fitting the motor performance curve through the correspondence between the actual measured current and air volume. This invention is not limited to these methods.

[0141] The total air flow determination module calculates the air flow of each air cooler in a stopped state according to the following formula (8).

[0142] Fair(i)=0 i=Nco+1,…,Nc (8)

[0143] Where i is the number corresponding to the i-th air cooler that has stopped operating, Nco is the initial number of air coolers in operation, and Nc is the total number of air coolers.

[0144] The total air flow determination module calculates the total air flow of the air cooler, Fair_total, according to formula (9).

[0145]

[0146] Where i is the number corresponding to the i-th operating air cooler, Nco is the initial number of operating air coolers, and Fair(i) is the air flow rate of each operating air cooler.

[0147] The total heat exchange determination module is used to determine the total heat exchange of the air cooler based on the total air flow rate, material property variable data, and air property variable data.

[0148] In one embodiment, the total heat transfer determination module includes a natural convection latent heat determination unit, a logarithmic temperature difference determination unit, and a total heat transfer determination unit.

[0149] The natural convection latent heat determination unit is used to determine the natural convection latent heat Hair_nc_lh based on the condensation heat Hcd, the total heat load Htotal_cl, and air property variable data.

[0150] In one embodiment, the latent heat determination unit for natural convection is specifically used to determine the logarithmic temperature difference ΔTln_oc_nc under natural convection in response to the air cooler being in a stopped state, based on the inlet material temperature Ti, the outlet material temperature To, the air inlet temperature Tairin, and the air outlet temperature Tairin when the air cooler is in a stopped state; determine the heat transfer Hovc of the air cooler in a stopped state based on the natural convection heat transfer coefficient Uoc_nc, the natural convection condensation heat transfer area Acd_nc, and the logarithmic temperature difference ΔTln_oc_nc under natural convection; determine the total heat transfer Hair_nc of all air coolers in a stopped state based on the heat transfer Hovc of the air cooler in a stopped state, the total number of air coolers Nc, and the initial number of air coolers in operation Nco; step 704: determine the latent heat of natural convection Hair_nc_lh based on the total heat transfer Hovc, the condensation heat Hcd, and the total heat load Htotal_cl.

[0151] Specifically, when the air cooler is in a stopped state, the latent heat determination unit of natural convection calculates the logarithmic temperature difference ΔTln_oc_nc of the air cooler under natural convection according to formula (10).

[0152]

[0153] Where Ti is the inlet material temperature of the air cooler, Tairout_nc is the air outlet temperature of the air cooler when the air cooler is in a stopped state, To is the outlet material temperature of the air cooler, and Tairin is the air inlet temperature of the air cooler.

[0154] The latent heat determination unit for natural convection calculates the heat transfer Hovc of the air cooler under natural convection when it is in a stopped state according to formula (11).

[0155]

[0156] Where Uoc_nc is the natural convection heat transfer coefficient, Acd_nc is the natural convection condensation heat transfer area, and △Tln_oc_nc is the logarithmic temperature difference of the air cooler under natural convection.

[0157] The natural convection latent heat determination unit further calculates the total heat transfer of all air coolers in the stopped state, Hair_nc, according to formula (12).

[0158] Hair_nc=Hovc*(Nc-Nco) (12)

[0159] Where Hovc is the heat transfer of the air cooler when it is stopped, Nc is the total number of air coolers, and Nco is the initial number of air coolers in operation.

[0160] The latent heat of natural convection is determined by calculating the latent heat of natural convection Hair_nc_lh according to formula (13).

[0161]

[0162] Where Hair_nc is the total heat transfer of all air coolers that are in a stopped state; Hcd is the heat of condensation of the material at the top of the tower; and Htotal_cl is the total heat load of the air coolers.

[0163] The logarithmic temperature difference determination unit is used to determine the logarithmic temperature difference ΔTln_cd under forced convection based on the subcooling heat Hoc, natural convection latent heat Hair_nc_lh, total air flow Fair_total, and air property variables.

[0164] In one embodiment, the logarithmic temperature difference determination unit is specifically used to determine the intermediate temperature Tairovc of air in the subcooling stage based on the subcooling heat Hoc, the latent heat of natural convection Hair_nc_lh, the total air flow rate Fair_total, the air density ρ, and the air specific heat capacity Cpair; and in response to the air cooler being in operation, to determine the logarithmic temperature difference ΔTln_cd under forced convection based on the inlet material temperature Ti of the air cooler, the bubble point temperature Tbp, the air outlet temperature Tairout of the air cooler, and the intermediate temperature Tairovc.

[0165] Specifically, the logarithmic temperature difference determination unit calculates the intermediate temperature Tairovc of the air side in the supercooled stage according to the following formula (14).

[0166]

[0167] Where Hoc is the subcooling heat of the material at the top of the tower, Hair_nc_lh is the latent heat of free convection, Fair_total is the total air flow rate of the air cooler, Cpair is the specific heat capacity of air, ρ is the air density, and Tairin is the temperature of the air entering the air cooler.

[0168] The logarithmic temperature difference determination unit calculates the logarithmic temperature difference ΔTln_cd of the air cooler under forced convection according to formula (15).

[0169]

[0170] Where Ti is the inlet material temperature of the air cooler, Tairout is the air outlet temperature of the air cooler, Tbp is the bubble point temperature, and Tairovic is the intermediate temperature of the air during the subcooling stage.

[0171] The total heat transfer determination unit is used to determine the total heat transfer of the air cooler, Hair_total, based on the condensation heat Hcd, the latent heat of natural convection Hair_nc_lh, the logarithmic temperature difference ΔTln_cd under forced convection, and air property variable data.

[0172] In one embodiment, the total heat exchange determination unit is specifically used to determine the heat transfer area Acd required for material condensation under forced convection based on the condensation heat Hcd, the latent heat of natural convection Hair_nc_lh, the condensation heat transfer coefficient Ucd, and the logarithmic temperature difference ΔTln_cd under forced convection; to determine the forced convection heat transfer area Afc of all air coolers in operation based on the bare tube area Aair_p of each air cooler and the initial number of air coolers in operation Nco; and to determine the total heat exchange Hair_total of the air cooler based on the subcooling heat transfer coefficient Uoc, the heat transfer area Acd, the forced convection heat transfer area Afc, the logarithmic temperature difference ΔTln_cd under forced convection, the total heat transfer Hair_nc, and the condensation heat Hcd.

[0173] Specifically, the total heat exchange determination unit calculates the heat transfer area Acd required for material condensation according to formula (16).

[0174]

[0175] Where Hcd is the condensation heat of the material at the top of the column, Hair_nc_lh is the latent heat of natural convection, Ucd is the condensation heat transfer coefficient, and ΔTln_cd is the logarithmic temperature difference under forced convection.

[0176] The total heat exchange determination unit calculates the forced convection heat exchange area Afc of all air coolers in operation according to formula (17).

[0177] Afc = Aair_p * Nco (17)

[0178] Where: Aair_p is the tube area of ​​each air cooler, and Nco is the initial number of air coolers in operation.

[0179] The total heat exchange determination unit calculates the total heat exchange of the air cooler, Hair_total, according to formula (18).

[0180]

[0181] Where Uoc is the subcooling heat transfer coefficient, Afc is the forced convection heat transfer area of ​​all operating air coolers, Acd is the heat transfer area required for material condensation under forced convection, △Tln_cd is the logarithmic temperature difference under forced convection, Hair_nc is the total heat transfer of all air coolers in a stopped state, and Hcd is the condensation heat of the material at the top of the tower.

[0182] In one embodiment, the air cooler outlet temperature detection unit 103 is used to detect the outlet temperature of the air cooler or the outlet temperature of the reflux tank, and transmit the temperature data to the air cooler energy-saving optimization controller 105.

[0183] Specifically, such as Figure 2 As shown, the air cooler outlet temperature detection unit 103 is used to detect the outlet temperature of the material on the discharge pipeline G4 before it leaves the air cooler 101 and enters the reflux tank RD, or to detect the outlet temperature of the material after it leaves the reflux tank RD. The air cooler outlet temperature detection unit 103 sends the outlet temperature of the air cooler 101 or the outlet temperature of the reflux tank RD as the air cooler outlet material temperature To to the air cooler energy-saving optimization controller 105. The air cooler energy-saving optimization controller 105 calculates the total heat load Htotal_cl and the total heat exchange of the air cooler Hair_total based on the new data.

[0184] In one embodiment, the air cooler operation controller 104 is also used to send the initial number of air coolers Nco to the air cooler energy-saving optimization controller 105.

[0185] Specifically, in the first control cycle, the air cooler operation controller 104 sends the initial number of air coolers operating, Nco, to the air cooler energy-saving optimization controller 105. This allows the air cooler energy-saving optimization controller 105 to determine the total airflow (Fair_total) of the air cooler based on the initial number of operating units, Nco, using a motor performance model. Furthermore, based on the initial number of operating units, Nco, the air cooler energy-saving optimization controller 105 determines the total heat exchange (Hair_total) of the air cooler using a heat exchange calculation model. The air cooler operation controller 104 compares the total heat load (Htotal_cl) calculated by the air cooler energy-saving optimization controller 105 for the first control cycle with the total heat exchange (Hair_total), and determines the optimal number of air coolers to operate based on the comparison result, thus updating the "initial number of operating units, Nco" for the next control cycle.

[0186] In this embodiment of the invention, the air cooler energy-saving optimization controller dynamically calculates the total heat load of the distillation column air cooler system based on air and material property variable data. Simultaneously, the controller calculates the total air flow and total heat exchange of the air cooler under current operating conditions using a motor performance model and a heat exchange calculation model, thereby achieving real-time evaluation of the air cooler's total heat exchange capacity. The air cooler motor controller and air cooler operation controller determine whether the number of operating air coolers is redundant or insufficient, and whether the motor operating current is too high or too low, based on the comparison between the total heat load and the total heat exchange capacity. Based on this, they generate optimal start / stop control commands and current adjustment commands, achieving joint regulation of the number of operating air coolers and their operating current. By precisely matching heat exchange demand with energy consumption, the air cooler energy-saving optimization controller effectively improves heat exchange efficiency and reduces ineffective power consumption in the distillation column air cooler system.

[0187] This invention also provides a method for controlling a distillation column air cooler, which is applied to the aforementioned distillation column air cooler system. The main body executing this method is an air cooler energy-saving optimization controller, as described in the following embodiments.

[0188] like Figure 3 As shown, the distillation column air cooler control method includes steps 301 to 304.

[0189] Step 301: Obtain the material property variable data and air property variable data of the air cooler. The air property variable data includes: the initial number of air coolers in operation, Nco, and the operating current, I, of the air cooler.

[0190] Specifically, material property variable data and air property variable data are collected through various instruments and equipment in the distillation column system, the distillation column parameter acquisition unit 106, and the air cooler outlet temperature detection unit 103, and stored in the material property variable table (as shown in Table 1) and the air property variable table (as shown in Table 2), respectively. The various instruments and equipment include: flow meter A, flow controller FC, level controller LC, regulating valve C (or control valve), temperature sensor, air temperature probe, level gauge, current sensor, motor frequency converter, speed feedback sensor, motor start / stop feedback switch, and pressure transmitter, etc.

[0191] Data measured by instruments and equipment can be read from the Distributed Control System (DCS), while other physical property data (such as air cooler heat loss rate Hloss, air density ρ, and air specific heat capacity Cpair) can be found in chemical handbooks or read from online process models.

[0192] like Figure 2 As shown, flow meter A measures the flow rate at the top of the column (Ftp), the flow rate of the material (F), and the flow rate of the heating medium (Q). Flow controller FC controls the flow rate at the feed inlet of the distillation column (E) and the reboiler. Level controller LC controls the liquid level in the distillation column and reflux tank. Control valve C (or regulating valve) controls the flow rate in the feed, discharge, and reflux lines. Level gauges measure the liquid levels in the reflux tank, the bottom of the distillation column, and the reboiler. Temperature sensors measure the top temperature (Ttp), bubble point temperature (Tbp), air cooler inlet material temperature (Ti), and air cooler outlet material temperature (To). Air temperature probes measure the air inlet temperature (Tairin), air outlet temperature (Tairout), and air outlet temperature (Tairout_nc) when the air cooler is stopped. A current sensor detects the motor's operating current (I). The motor inverter controls the motor's operating current (I) and frequency. A speed feedback sensor detects the actual motor speed. The motor start / stop feedback switch is used to detect whether the air cooler is in operation.

[0193] The material property variables collected by the above-mentioned instruments and equipment are stored in the material property variable table, as shown in Table 1:

[0194] variable name Physical meaning unit Ti air cooler inlet material temperature ℃ To Air cooler outlet material temperature ℃ Ttp Tower top temperature ℃ Tbp Bubble point temperature ℃ Ftp Tower top flow kg / h Hloss Air cooler heat loss rate ％

[0195] Table 1: Material Property Variables Table

[0196] The air physical property variables collected by the above-mentioned instruments and equipment are stored in the air physical property variable table, as shown in Table 2:

[0197]

[0198] Table 2: Air Property Variables Table

[0199] Step 302: Determine the total heat load of the air cooler based on the material property variable data.

[0200] like Figure 4 As shown, in one embodiment, step 302 includes steps 401 to 404.

[0201] Step 401: Based on the column top temperature Ttp, bubble point temperature Tbp, and air cooler outlet material temperature To, determine the enthalpy of the column top temperature Eptp, the enthalpy of the bubble point temperature Epbp, and the enthalpy of the subcooling temperature Epovc, respectively.

[0202] Specifically, the enthalpy of the top temperature Eptp, the enthalpy of the bubble point temperature Epbp, and the enthalpy of the supercooled temperature Epovc are calculated according to formulas (1) to (3).

[0203] Eptp=f(Ttp) (1)

[0204] Epbp=f(Tbp) (2)

[0205] Epovc=f(To) (3)

[0206] Where Ttp is the top temperature of the column, Tbp is the bubble point temperature, To is the outlet material temperature of the air cooler; Eptp is the enthalpy of the top temperature of the column, Epbp is the enthalpy of the bubble point temperature, and Epovc is the enthalpy of the subcooling temperature, all in kJ / kg.

[0207] Step 402: Determine the condensation heat Hcd of the material at the top of the column based on the enthalpy of the column top temperature Eptp, the enthalpy of the bubble point temperature Epbp, the column top flow rate Ftp, and the heat loss rate of the air cooler Hloss.

[0208] Specifically, the material at the top of the tower (i.e., high-temperature steam) enters the air cooler and is cooled to its bubble point temperature. The heat of condensation, Hcd, represents the heat released when the material condenses from the gas phase to the liquid phase, and its calculation formula is as follows:

[0209]

[0210] Where Ftp is the top flow rate, Eptp is the enthalpy of the top temperature, Epbp is the enthalpy of the bubble point temperature, and Hloss is the heat loss rate of the air cooler.

[0211] Step 403: Determine the subcooling heat Hoc of the material at the top of the column based on the enthalpy of the bubble point temperature Epbp, the enthalpy of the subcooling temperature Epovc, the flow rate at the top of the column Ftp, and the heat loss rate of the air cooler Hloss.

[0212] Specifically, the subcooling heat Hoc represents the heat released when the material at the top of the column is cooled from its bubble point temperature Tbp to the material temperature To at the outlet of the air cooler. Its calculation formula is as follows:

[0213]

[0214] Where Ftp is the top flow rate, Epbp is the enthalpy of the bubble point temperature, EPOVC is the enthalpy of the subcooling temperature, and Hloss is the heat loss rate of the air cooler.

[0215] Step 404: Determine the total heat load Htotal_cl of the air cooler based on the condensation heat Hcd and the subcooling heat Hoc.

[0216] Specifically, the total heat load Htotal_cl of the air cooler is calculated according to formula (6).

[0217] Htotal_cl=Hcd+Hoc (6)

[0218] Where Hcd is the heat of condensation of the material at the top of the column, and Hoc is the heat of subcooling of the material at the top of the column.

[0219] Step 303: Determine the total air flow rate of the air cooler based on the initial number of air coolers in operation and the operating current of the air cooler.

[0220] like Figure 5 As shown, in one embodiment, step 303 includes steps 501 to 502.

[0221] Step 501: Determine the air flow rate Fair(i) of each operating air cooler based on the operating current I of the air cooler using the motor characteristic model.

[0222] Specifically, the operating current I of the motor inside each operating air cooler is detected by a current sensor, but this invention is not limited thereto.

[0223] When the air cooler is in operation, the internal motor drives the fan to rotate, transferring the heat of the material to the air through forced convection, i.e., forced convection heat transfer. The air flow rate of each air cooler in operation is calculated according to formula (7).

[0224] Fair(i)=h(I) i=1,2,…,Nco (7)

[0225] Where I is the operating current of the air cooler, i is the i-th operating air cooler, h(I) is the motor characteristic model, and Nco is the initial number of operating air coolers. The initial number of operating air coolers, Nco, is preset.

[0226] The motor characteristic model can be obtained by establishing the motor performance curve through the air volume-current comparison table provided by the manufacturer, or by fitting the motor performance curve through the correspondence between the actual measured current and air volume. This invention is not limited to these methods.

[0227] When the air cooler is not in operation, the internal motor stops driving the fan. The density difference caused by the temperature difference drives the fluid to flow spontaneously, forming a natural convection process, so that the material transfers heat to the air, i.e., natural convection heat transfer. Calculate the air flow rate of each air cooler in the stopped state according to formula (8).

[0228] Fair(i)=0 i=Nco+1,…,Nc (8)

[0229] Where i is the number corresponding to the i-th air cooler that has stopped operating, Nco is the initial number of air coolers in operation, and Nc is the total number of air coolers.

[0230] Step 502: Based on the initial number of air coolers Nco and the air flow rate of each air cooler, sum them using a summation function to obtain the total air flow rate of the air coolers Fair_total.

[0231] Specifically, the total air flow of the air cooler, Fair_total, is calculated according to the following formula (9).

[0232]

[0233] Where i is the number corresponding to the i-th operating air cooler, Nco is the initial number of operating air coolers, and Fair(i) is the air flow rate of each operating air cooler.

[0234] Step 304: Determine the total heat exchange of the air cooler based on the total air flow rate Fair_total, material property variable data, and air property variable data.

[0235] like Figure 6 As shown, in one embodiment, step 304 includes steps 601 to 603.

[0236] Step 601: Determine the latent heat of natural convection Hair_nc_lh based on the condensation heat Hcd, total heat load Htotal_cl, and air property variable data.

[0237] like Figure 7 As shown, in one embodiment, step 601 includes steps 701 to 704.

[0238] Step 701: In response to the air cooler being in a stopped state, determine the logarithmic temperature difference ΔTln_oc_nc under natural convection based on the inlet material temperature Ti, the outlet material temperature To, the air inlet temperature Tairin, and the air outlet temperature Tairin when the air cooler is in a stopped state.

[0239] Specifically, when the air cooler is in a stopped state, the motor inside the air cooler stops driving the fan to rotate, and the air undergoes natural convection heat transfer during the condensation stage. The logarithmic temperature difference ΔTln_oc_nc of the air cooler under natural convection is calculated according to formula (10).

[0240]

[0241] Where Ti is the inlet material temperature of the air cooler, Tairout_nc is the air outlet temperature of the air cooler when the air cooler is in a stopped state, To is the outlet material temperature of the air cooler, and Tairin is the air inlet temperature of the air cooler.

[0242] Step 702: Determine the heat transfer Hovc of the air cooler in the off-line state based on the natural convection heat transfer coefficient Uoc_nc, the natural convection condensation heat transfer area Acd_nc, and the logarithmic temperature difference ΔTln_oc_nc under natural convection.

[0243] Specifically, when the air cooler is in a stopped state, the motor inside the air cooler stops driving the fan to rotate, and the air undergoes natural convection heat transfer during the subcooling stage. The heat transfer Hovc of the air cooler under natural convection in the stopped state is calculated according to formula (11).

[0244]

[0245] Where Uoc_nc is the natural convection heat transfer coefficient, Acd_nc is the natural convection condensation heat transfer area, and △Tln_oc_nc is the logarithmic temperature difference of the air cooler under natural convection.

[0246] Step 703: Determine the total heat transfer Hair_nc of all air coolers in the stopped state based on the heat transfer Hovc of the air coolers in the stopped state, the total number of air coolers Nc, and the initial number of air coolers in operation Nco.

[0247] Specifically, the heat transfer Hovc of an air cooler in a stopped state under natural convection is calculated according to the above steps, and the total heat transfer Hair_nc of all air coolers in a stopped state is calculated according to formula (12).

[0248] Hair_nc=Hovc*(Nc-Nco) (12)

[0249] Where Hovc is the heat transfer of the air cooler when it is stopped, Nc is the total number of air coolers, and Nco is the initial number of air coolers in operation.

[0250] Step 704: Determine the latent heat of natural convection Hair_nc_lh based on the total heat transfer Hovc, condensation heat Hcd, and total heat load Htotal_cl.

[0251] Specifically, a portion of the condensation heat Hcd released by the material during the condensation stage can be dissipated by the air cooler, which is in a stopped state, i.e., through the natural flow of air. This portion of heat dissipation is the latent heat of natural convection, Hair_nc_lh, and its calculation formula is as follows:

[0252]

[0253] Where Hair_nc is the total heat transfer of all air coolers that are in a stopped state; Hcd is the heat of condensation of the material at the top of the tower; and Htotal_cl is the total heat load of the air coolers.

[0254] Step 602: Determine the logarithmic temperature difference ΔTln_cd under forced convection based on the subcooling heat Hoc, natural convection latent heat Hair_nc_lh, total air flow Fair_total, and air property variables.

[0255] like Figure 8 As shown, step 602 includes steps 801 to 802.

[0256] Step 801: Determine the intermediate temperature Tairovc of the air during the supercooling stage based on the supercooling heat Hoc, the latent heat of natural convection Hair_nc_lh, the total air flow rate Fair_total, the air density ρ, and the air specific heat capacity Cpair.

[0257] Specifically, the temperature of the air entering the air cooler from the natural environment is Tairin. After the air exchanges heat with the liquid material, the air temperature rises. The average temperature of the air during the entire process is the intermediate temperature Tairovc of the air side in the subcooling stage. The intermediate temperature Tairovc of the air side in the subcooling stage is calculated according to the following formula (14).

[0258]

[0259] Where Hoc is the subcooling heat of the material at the top of the tower, Hair_nc_lh is the latent heat of free convection, Fair_total is the total air flow rate of the air cooler, Cpair is the specific heat capacity of air, ρ is the air density, and Tairin is the temperature of the air entering the air cooler.

[0260] Step 802: In response to the air cooler being in operation, determine the logarithmic temperature difference ΔTln_cd under forced convection based on the inlet material temperature Ti, bubble point temperature Tbp, air outlet temperature Tairout, and intermediate temperature Tairovic of the air cooler.

[0261] Specifically, when the air cooler is in operation, the motor inside the air cooler drives the fan to rotate so that the air undergoes forced convection heat transfer during the condensation stage. The logarithmic temperature difference ΔTln_cd of the air cooler under forced convection is calculated according to formula (15).

[0262]

[0263] Where Ti is the inlet material temperature of the air cooler, Tairout is the air outlet temperature of the air cooler, Tbp is the bubble point temperature, and Tairovic is the intermediate temperature of the air during the subcooling stage.

[0264] Step 603: Determine the total heat transfer of the air cooler, Hair_total, based on the condensation heat Hcd, the latent heat of natural convection Hair_nc_lh, the logarithmic temperature difference ΔTln_cd under forced convection, and the air property variables.

[0265] like Figure 9 As shown, step 603 includes steps 901 to 903.

[0266] Step 901: Determine the heat transfer area Acd required for material condensation under forced convection based on the condensation heat Hcd, the latent heat of natural convection Hair_nc_lh, the condensation heat transfer coefficient Ucd, and the logarithmic temperature difference ΔTln_cd under forced convection.

[0267] Specifically, according to the above steps, the condensation heat Hcd released by the material during the condensation process is partially dissipated by the air cooler that is not in operation, and the other part needs to be dissipated by the air cooler that is in operation. Before calculating this dissipated heat, the heat transfer area Acd required for material condensation needs to be calculated according to formula (16).

[0268]

[0269] Where Hcd is the condensation heat of the material at the top of the column, Hair_nc_lh is the latent heat of natural convection, Ucd is the condensation heat transfer coefficient, and ΔTln_cd is the logarithmic temperature difference under forced convection.

[0270] Step 902: Determine the forced convection heat transfer area Afc of all air coolers in operation based on the tube area Aair_p of each air cooler and the initial number of air coolers in operation Nco.

[0271] Specifically, the forced convection heat transfer area Afc of all air coolers in operation is calculated according to formula (17).

[0272] Afc = Aair_p * Nco (17)

[0273] Where: Aair_p is the tube area of ​​each air cooler, and Nco is the initial number of air coolers in operation.

[0274] Step 903: Determine the total heat transfer of the air cooler, Hair_total, based on the subcooling heat transfer coefficient Uoc, heat transfer area Acd, forced convection heat transfer area Afc, logarithmic temperature difference ΔTln_cd under forced convection, total heat transfer Hair_nc, and condensation heat Hcd.

[0275] Specifically, the total heat exchange of the air cooler, Hair_total, is calculated according to formula (18).

[0276]

[0277] Where Uoc is the subcooling heat transfer coefficient, Afc is the forced convection heat transfer area of ​​all operating air coolers, Acd is the heat transfer area required for material condensation under forced convection, △Tln_cd is the logarithmic temperature difference under forced convection, Hair_nc is the total heat transfer of all air coolers in a stopped state, and Hcd is the condensation heat of the material at the top of the tower.

[0278] In this embodiment of the invention, a heat transfer calculation model based on thermodynamics and heat transfer principles is constructed to accurately predict the heat transfer capacity of the air cooler. This model acquires material and air property data to calculate the enthalpy of the vapor phase at the top of the tower, the enthalpy of the liquid phase at the bubble point, and the enthalpy of the liquid in the subcooled state. This allows for the accurate determination of the latent heat (i.e., condensation heat) released by the material during the condensation stage and the sensible heat (i.e., subcooling heat) released during the subcooling stage. The sum of these two constitutes the total heat load that the air cooler needs to handle, providing an optimization target for subsequent air cooler operation control. The total air flow rate of the air cooler can be calculated using a motor performance model, and the intermediate temperature of the air during the subcooling stage can be estimated accordingly. Furthermore, the logarithmic mean temperature difference between the forced convection section and the natural convection section can be determined, thereby accurately assessing the heat transfer driving force between the air and the material. Based on the logarithmic mean temperature difference of the natural convection section, the effective compensating heat provided by natural airflow for the condensation task under the condition that the air cooler is not in operation is calculated. This heat is then used to correct the actual forced heat exchange area required during the condensation stage, thereby effectively avoiding over-operation of the air cooler and reducing the system's power consumption. Finally, by comparing the heat exchange area provided by the currently operating air cooler with the area required for condensation, and combining the heat exchange capabilities of forced convection and natural convection, the total heat exchange capacity of the air cooler system under the current configuration is comprehensively calculated, thereby improving the overall heat exchange efficiency of the system and effectively reducing the power consumption of the air cooler.

[0279] Figure 10 This is a schematic diagram of the physical structure of an electronic device provided in an embodiment of the present invention, such as... Figure 10 As shown, the electronic device 1000 includes: a processor 1001, a memory 1002, and a bus 1003.

[0280] The processor 1001 and the memory 1002 communicate with each other via the bus 1003.

[0281] The processor 1001 is used to call program instructions in the memory 1002 to execute the methods provided in the above-described method embodiments.

[0282] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described distillation column air cooler control method.

[0283] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-described distillation column air cooler control method.

[0284] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0285] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0286] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0287] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0288] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A distillation column air cooler system, characterized in that, include: Air cooler, air cooler motor controller, air cooler outlet temperature detection unit, air cooler operation controller, air cooler energy-saving optimization controller, and distillation column parameter acquisition unit; The air cooler energy-saving optimization controller is connected to the distillation column parameter acquisition unit, the air cooler motor controller, the air cooler outlet temperature detection unit, and the air cooler operation controller, respectively. The air cooler is connected to the air cooler motor controller and the air cooler outlet temperature detection unit, respectively; The air cooler energy-saving optimization controller is used to receive material property variable data from the distillation column parameter acquisition unit and temperature data detected by the air cooler outlet temperature detection unit; generate the total heat load and total heat exchange of the air cooler based on the material property variable data and the temperature data, and transmit the total heat load and total heat exchange of the air cooler to the air cooler operation controller and the air cooler motor controller. The air cooler operation controller determines the number of air coolers in operation and controls the number of air coolers in operation based on the total heat load and total heat exchange of the air cooler. The air cooler motor controller determines the heat exchange of each operating air cooler based on the total heat load and total heat exchange of the air cooler, and controls the speed of the corresponding air cooler motor based on the heat exchange of each air cooler.

2. The system according to claim 1, characterized in that, The air cooler energy-saving optimization controller includes: The parameter acquisition module is used to acquire material property variable data and air property variable data of the air cooler; the air property variable data includes: the initial number of air coolers in operation and the operating current of the air cooler. The total heat load determination module is used to determine the total heat load of the air cooler based on the material property variable data. The total air flow rate determination module is used to determine the total air flow rate of the air cooler based on the initial number of air coolers in operation and the operating current of the air cooler. The total heat exchange determination module is used to determine the total heat exchange of the air cooler based on the total air flow rate, the material property variable data, and the air property variable data.

3. The system according to claim 2, characterized in that, The total heat load determination module is specifically used to determine the enthalpy of the top temperature, the enthalpy of the bubble point temperature, and the enthalpy of the subcooling temperature based on the top temperature, bubble point temperature, and the outlet material temperature of the air cooler, respectively; to determine the condensation heat of the material at the top of the column based on the enthalpy of the top temperature, the enthalpy of the bubble point temperature, the top flow rate, and the heat loss rate of the air cooler; to determine the subcooling heat of the material at the top of the column based on the enthalpy of the bubble point temperature, the enthalpy of the subcooling temperature, the top flow rate, and the heat loss rate of the air cooler; and to determine the total heat load of the air cooler based on the condensation heat and the subcooling heat.

4. The system according to claim 2, characterized in that, The total airflow determination module is specifically used to determine the airflow of each operating air cooler based on the operating current and the motor characteristic model. The total air flow rate is obtained by summing the initial number of air coolers in operation and the air flow rate of each air cooler in operation using a summation function.

5. The system according to claim 2, characterized in that, The total heat exchange determination module includes: The latent heat of natural convection determination unit is used to determine the latent heat of natural convection based on the condensation heat, the total heat load, and the air property variable data. The logarithmic temperature difference determination unit is used to determine the logarithmic temperature difference under forced convection based on the supercooling heat, the latent heat of natural convection, the total air flow rate, and the air physical property variable data. The total heat exchange determination unit is used to determine the total heat exchange of the air cooler based on the condensation heat, the latent heat of natural convection, the logarithmic temperature difference under forced convection, and the air property variable data.

6. The system according to claim 5, characterized in that, The natural convection latent heat determination unit is specifically used to, in response to the air cooler being in a stopped state, determine the logarithmic temperature difference under natural convection based on the inlet material temperature, outlet material temperature, air inlet temperature, and air outlet temperature when the air cooler is in a stopped state; determine the heat transfer of the air cooler in a stopped state based on the natural convection heat transfer coefficient, the natural convection condensation heat transfer area, and the logarithmic temperature difference under natural convection; determine the total heat transfer of all air coolers in a stopped state based on the heat transfer of the air coolers in a stopped state, the total number of air coolers, and the initial number of air coolers in operation; and determine the natural convection latent heat based on the total heat transfer, the condensation heat, and the total heat load.

7. The system according to claim 6, characterized in that, The logarithmic temperature difference determination unit is specifically used to determine the intermediate temperature of air in the subcooling stage based on the subcooling heat, the latent heat of natural convection, the total air flow rate, the air density, and the specific heat capacity of air; and in response to the air cooler being in operation, to determine the logarithmic temperature difference under forced convection based on the inlet material temperature of the air cooler, the outlet material temperature of the air cooler, the bubble point temperature, and the intermediate temperature.

8. The system according to claim 5, characterized in that, The total heat exchange determination unit is specifically used to determine the heat transfer area required for material condensation under forced convection based on the condensation heat, the latent heat of natural convection, the condensation heat transfer coefficient, and the logarithmic temperature difference under forced convection; to determine the forced convection heat transfer area of ​​all air coolers in operation based on the bare tube area of ​​each air cooler and the initial number of operating units; and to determine the total heat exchange of the air cooler based on the subcooling heat transfer coefficient, the heat transfer area, the forced convection heat transfer area, the logarithmic temperature difference under forced convection, the total heat transfer, and the condensation heat.

9. The system according to claim 1, characterized in that, The air cooler outlet temperature detection unit is used to detect the outlet temperature of the air cooler or the outlet temperature of the reflux tank, and transmit the temperature data to the air cooler energy-saving optimization controller.

10. The system according to claim 1, characterized in that, The air cooler operation controller is also used to send the initial number of air coolers in operation to the air cooler energy-saving optimization controller.

11. The system according to claim 1, characterized in that, The distillation column parameter acquisition unit is used to acquire material property variable data of the distillation column, wherein the material property variable data includes: column top flow rate, column top temperature, bubble point temperature and air cooler outlet material temperature, and sends the material property variable data to the air cooler energy saving optimization unit.

12. A method for controlling an air cooler in a distillation column, characterized in that, Applied to the distillation column air cooler system according to any one of claims 1-11, comprising: Acquire material property data and air property data for the air cooler; air property data includes: the initial number of air coolers in operation and the operating current of the air cooler. The total heat load of the air cooler is determined based on the material property variable data. The total air flow rate of the air cooler is determined based on the initial number of air coolers in operation and the operating current of the air coolers. The total heat exchange of the air cooler is determined based on the total air flow rate, the material property variable data, and the air property variable data.

13. The method according to claim 12, characterized in that, The material property variables include: top temperature, bubble point temperature, air cooler outlet material temperature, top flow rate, and air cooler heat loss rate; determining the total heat load of the air cooler based on the material property variables includes: Based on the column top temperature, bubble point temperature, and air cooler outlet material temperature, determine the enthalpy values ​​of the column top temperature, bubble point temperature, and subcooling temperature, respectively. The condensation heat of the material at the top of the column is determined based on the enthalpy of the top temperature, the enthalpy of the bubble point temperature, the top flow rate, and the heat loss rate of the air cooler. The subcooling heat of the material at the top of the column is determined based on the enthalpy of the bubble point temperature, the enthalpy of the subcooling temperature, the flow rate at the top of the column, and the heat loss rate of the air cooler. The total heat load of the air cooler is determined based on the condensation heat and the subcooling heat.

14. The method according to claim 13, characterized in that, The step of determining the total air flow rate of the air cooler based on the initial number of operating air coolers and the operating current of the air coolers includes: The airflow rate of each operating air cooler is determined based on the operating current using a motor characteristic model. The total air flow rate is obtained by summing the initial number of air coolers in operation and the air flow rate of each air cooler in operation using a summation function.

15. The method according to claim 14, characterized in that, The air property variable data also includes: the inlet material temperature of the air cooler, the outlet material temperature of the air cooler, the air inlet temperature of the air cooler, the air outlet temperature of the air cooler, and the air outlet temperature of the air cooler when the air cooler is in a stopped state; the determination of the total heat exchange of the air cooler based on the total air flow rate, the material property variable data, and the air property variable data includes: The latent heat of natural convection is determined based on the condensation heat, the total heat load, and the air property variables. Based on the supercooling heat, the latent heat of natural convection, the total air flow rate, and the air property variables, determine the logarithmic temperature difference under forced convection; The total heat exchange of the air cooler is determined based on the condensation heat, the latent heat of natural convection, the logarithmic temperature difference under forced convection, and the air property variables.

16. The method according to claim 15, characterized in that, The air property variable data also includes: air cooler inlet material temperature, air cooler outlet material temperature, air inlet air cooler temperature, air outlet air cooler temperature when the air cooler is stopped, natural convection heat transfer coefficient, natural convection condensation heat transfer area, and total number of air coolers; determining the latent heat of natural convection based on the condensation heat, the total heat load, and the air property variable data includes: In response to the air cooler being in a stopped state, the logarithmic temperature difference under natural convection is determined based on the inlet material temperature of the air cooler, the outlet material temperature of the air cooler, the air inlet temperature of the air cooler, and the air outlet temperature of the air cooler when the air cooler is in a stopped state. The heat transfer of the air cooler in a stopped state is determined based on the natural convection heat transfer coefficient, the natural convection condensation heat transfer area, and the logarithmic temperature difference under natural convection. The total heat transfer of all air coolers in the stopped state is determined based on the heat transfer of the air coolers in the stopped state, the total number of air coolers, and the initial number of air coolers in operation. The latent heat of natural convection is determined based on the total heat transfer, the condensation heat, and the total heat load.

17. The method according to claim 16, characterized in that, The air property variable data also includes: air density, air specific heat capacity, and air outlet temperature of the air cooler; determining the logarithmic temperature difference under forced convection based on the subcooling heat, the latent heat of natural convection, the total air flow rate, and the air property variable data includes: The intermediate temperature of the air during the supercooling stage is determined based on the supercooling heat, the latent heat of natural convection, the total air flow rate, the air density, and the specific heat capacity of the air. In response to the air cooler being in operation, the logarithmic temperature difference under forced convection is determined based on the inlet material temperature of the air cooler, the bubble point temperature, the air outlet temperature of the air cooler, and the intermediate temperature.

18. The method according to claim 17, characterized in that, The air property variable data also includes: condensation heat transfer coefficient, the bare tube area of ​​each air cooler, and subcooling heat transfer coefficient; determining the total heat exchange of the air cooler based on the condensation heat, the latent heat of natural convection, the logarithmic temperature difference under forced convection, and the air property variable data includes: Based on the condensation heat, the latent heat of natural convection, the condensation heat transfer coefficient, and the logarithmic temperature difference under forced convection, determine the heat transfer area required for material condensation under forced convection. The forced convection heat transfer area of ​​all air coolers in operation is determined based on the tube area of ​​each air cooler and the initial number of operating units. The total heat exchange of the air cooler is determined based on the subcooling heat transfer coefficient, the heat transfer area, the forced convection heat transfer area, the logarithmic temperature difference under forced convection, the total heat transfer, and the condensation heat.

19. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 12 to 18.

20. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 12 to 18.

21. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 12 to 18.

Images