Air-cooled high-efficiency anti-freezing innovative method based on intelligent monitoring

Abstract

This invention relates to the field of thermal power generation technology, and particularly to an innovative method for efficient antifreeze protection of air-cooled systems based on intelligent monitoring. The method includes the following steps: Step S1: Acquiring environmental parameters of the air-cooled tower, operating data of each operating sector, and power data of the unit; Step S2: Calculating the ratio of the time required for the water flow in each operating sector to cool to the freezing point to the actual residence time, based on the environmental parameters and the operating data, as the antifreeze safety margin for the corresponding operating sector; Step S3: Determining whether the antifreeze safety margin is lower than a set safety threshold; Step S4: Calculating the spatial distortion rate of the heat load based on the distribution differences of the antifreeze safety margins across all operating sectors; Step S5: Issuing frequency control commands with disturbance signals to the circulating water pumps based on an adjusted perturbation optimization algorithm. In this invention, by comprehensively calculating the antifreeze safety margin of each sector using environmental parameters and operating data, freezing and cracking accidents of the windward tube bundles under cold operating conditions are prevented.

Description

Technical Field

[0001] This invention relates to the field of thermal power generation technology, and in particular to an innovative method for efficient antifreeze air cooling based on intelligent monitoring. Background Technology

[0002] Indirect air-cooled systems are widely used for cold-end heat dissipation in thermal power generating units. In severe winter conditions accompanied by strong winds, air-cooled towers are highly susceptible to localized freezing and rupture of the cooling tube bundles. Existing conventional anti-freeze control strategies primarily rely on monitoring the average temperature of the main return water header. By setting a fixed safe temperature threshold, they trigger the synchronous closing of all tower louvers or the unified frequency increase of the circulating water pumps, thereby increasing the anti-freeze margin of the cooling water within the tube bundles and ensuring the basic operational safety of the unit.

[0003] Existing technologies rely on symmetrical regulation of the entire tower based on average temperature, without considering the asymmetry of spatial heat transfer caused by the ambient wind field. This fails to decouple the conflict between antifreeze and back pressure, forcing the system to sacrifice the overall heat dissipation potential of the tower in order to protect local antifreeze, significantly increasing exhaust back pressure and coal consumption. Furthermore, under asymmetrical operating conditions, any conventional energy-saving flow disturbance can easily penetrate the local safety threshold, causing irreversible freezing and cracking accidents in the windward tube bundles, and completely losing the unit's ability to operate under severe weather conditions. Summary of the Invention

[0004] To overcome the above shortcomings, this invention provides an innovative method for efficient antifreeze in air-cooled systems based on intelligent monitoring, aiming to improve the problem of the inability to decouple antifreeze from back pressure.

[0005] In a first aspect, the present invention provides the following technical solution: an innovative method for efficient antifreeze air cooling based on intelligent monitoring, comprising, Step S1: Obtain the environmental parameters of the air-cooled tower, the operating data of each operating sector, and the power data of the unit; Step S2: Based on the environmental parameters and the operating data, calculate the ratio of the time required for the water flow in each operating sector to cool down to the freezing point to the actual residence time, and use this as the antifreeze safety margin for the corresponding operating sector; Step S3: Determine whether the antifreeze safety margin is lower than the set safety threshold. If so, reduce the louver opening of the corresponding operating sector and increase the louver opening of the other operating sectors. Step S4: Calculate the heat load spatial distortion rate based on the distribution differences of the antifreeze safety margin of all operating sectors, and use the heat load spatial distortion rate to adjust the perturbation amplitude and perturbation period of the micro-perturbation optimization algorithm in real time. Step S5: Based on the adjusted perturbation optimization algorithm, a frequency control command with a perturbation signal is sent to the circulating water pump, and the basic operating frequency of the circulating water pump is adjusted according to the feedback of the change in the net output of the unit.

[0006] Preferably, in step S1, the step of obtaining the environmental parameters of the air-cooled tower, the operating data of each operating sector, and the power data of the unit includes: Obtain the ambient wind speed and ambient wind direction angle measured by the anemometer tower; Obtain the return water temperature and louver opening of each operating sector of the air-cooled tower; Obtain the current active power of the generator and the power consumption of the circulating water pump.

[0007] Preferably, in step S2, the step of calculating the ratio of the time required for the water flow in each operating sector to cool to the freezing point to the actual residence time, based on the environmental parameters and the operating data, as the antifreeze safety margin for the corresponding operating sector, includes: Based on the ambient wind speed, the ambient wind direction angle, and the installation orientation angle of each operating sector, the effective windward wind speed component of each operating sector is calculated. Based on the effective windward wind speed component and the return water temperature, the instantaneous cooling rate of the cooling water inside each operating sector is calculated. The theoretical time required for the cooling water to reach the freezing point at the instantaneous cooling rate is divided by the actual residence time of the cooling water flowing through the corresponding operating sector to obtain the antifreeze safety margin for each operating sector.

[0008] Preferably, in step S3, the step of determining whether the antifreeze safety margin is lower than a set safety threshold, and if so, reducing the louver opening of the corresponding operating sector and increasing the louver opening of the other operating sectors, includes: Real-time comparison of the antifreeze safety margin of each operating sector with the set antifreeze safety critical threshold; When the antifreeze safety margin of the operating sector on the windward side of each operating sector is less than or equal to the antifreeze safety critical threshold, the louver opening of the operating sector on the windward side is gradually reduced according to the preset step size. Calculate the reduction in air intake in the windward operating sector due to the reduced louver opening, and proportionally increase the louver opening in the leeward operating sector based on the reduced air intake to maintain the overall air intake balance of the air-cooled tower.

[0009] Preferably, in step S4, the step of calculating the spatial distortion rate of heat load based on the distribution differences of the antifreeze safety margin of all operating sectors includes: Calculate the arithmetic mean of the freeze protection safety margins for all operating sectors of the air-cooled tower; Calculate the standard deviation of the freeze protection safety margin for all operating sectors of the air-cooled tower; Dividing the standard deviation by the arithmetic mean yields the heat load spatial distortion rate, which reflects the degree of uneven heat exchange inside the air-cooled tower.

[0010] Preferably, in step S4, the step of adjusting the perturbation amplitude of the micro-perturbation optimization algorithm in real time using the thermal load spatial distortion rate includes: Extract the basic perturbation amplitude of the perturbation optimization algorithm under steady-state conditions; Multiply the spatial distortion rate of the heat load by a preset attenuation coefficient to obtain the amplitude attenuation index; The basic disturbance amplitude is controlled to undergo negative exponential decay calculation according to the amplitude decay index to obtain the adjusted disturbance amplitude, so that the disturbance amplitude gradually decreases as the spatial distortion rate of the heat load increases.

[0011] Preferably, in step S4, the step of adjusting the perturbation period of the micro-perturbation optimization algorithm in real time using the thermal load spatial distortion rate includes: Extract the basic detection period of the perturbation optimization algorithm under steady-state conditions; Multiply the spatial distortion rate of the heat load by a preset time compensation coefficient to obtain the period extension ratio; The basic detection period is linearly amplified according to the period extension ratio to obtain the adjusted disturbance period, so that the disturbance period adaptively extends as the thermal load spatial distortion rate increases.

[0012] Preferably, in step S5, the step of issuing a frequency control command with a disturbance signal to the circulating water pump based on the adjusted perturbation optimization algorithm includes: The current basic operating frequency of the circulating water pump is used as the benchmark value; A sinusoidal disturbance signal is generated based on the adjusted disturbance amplitude and the adjusted disturbance period. The sinusoidal disturbance signal is superimposed on the reference value to generate the final frequency control command, which is then sent to the frequency converter of the circulating water pump.

[0013] Preferably, in step S5, the step of adjusting the basic operating frequency of the circulating water pump based on the feedback of changes in the unit's net output includes: Subtract the power consumption of the circulating water pump from the current active power of the generator to obtain the net output of the unit; Extract the component of the unit's net output that changes at the same frequency as the disturbance signal, and calculate the direction of the target gradient; If the direction of the target gradient is positive, then increase the base operating frequency of the circulating water pump; If the direction of the target gradient is negative, then the base operating frequency of the circulating water pump is reduced.

[0014] Secondly, the present invention provides the following technical solution: an innovative air-cooled high-efficiency antifreeze system based on intelligent monitoring, a data acquisition module, which acquires the environmental parameters of the air-cooled tower, the operating data of each operating sector, and the power data of the unit. The antifreeze margin calculation module calculates the ratio of the time required for the water flow in each operating sector to cool down to the freezing point to the actual residence time, based on the environmental parameters and the operating data, and uses this ratio as the antifreeze safety margin for the corresponding operating sector. The asymmetric control module for louvers determines whether the antifreeze safety margin is lower than the set safety threshold. If so, it reduces the louver opening of the corresponding operating sector and increases the louver opening of the other operating sectors. The optimization parameter adjustment module calculates the heat load spatial distortion rate based on the distribution differences of the antifreeze safety margin of all operating sectors, and uses the heat load spatial distortion rate to adjust the perturbation amplitude and perturbation period of the micro-perturbation optimization algorithm in real time. The variable frequency feedback control module sends frequency control commands with disturbance signals to the circulating water pump based on the adjusted micro-perturbation optimization algorithm, and adjusts the basic operating frequency of the circulating water pump according to the changes in the unit's net output.

[0015] The present invention has the following beneficial effects: 1. In this invention, the antifreeze safety margin of each sector is calculated by comprehensively considering environmental parameters and operating data, and the asymmetric louver control feature is triggered when the temperature is below the threshold. This changes the hysteresis that depends on the average temperature of the main pipe, cuts off the local supercooling source, and eliminates the freezing and cracking accident of the windward pipe bundle under cold conditions.

[0016] 2. In this invention, the spatial distortion rate of heat load formed by the differential distribution of antifreeze margin is extracted, and this feature is used to attenuate the disturbance amplitude and extend the disturbance period of the micro-perturbation optimization algorithm in real time. This ensures that the dynamic energy-saving disturbance of the circulating water pump will automatically converge under severe wind conditions and will not break through the local safety bottom line due to over-adjustment, thus solving the conflict between the optimization algorithm and antifreeze protection.

[0017] 3. In this invention, under the premise of using asymmetric louvers to transfer the cooling load to maintain the balance of the air intake of the entire tower, the basic operating frequency of the circulating water pump is dynamically adjusted in real time based on the micro-perturbation algorithm constrained by the distortion rate and combined with the unit's net output feedback. This enables the unit to lock the vacuum point and reduce the coal consumption for power generation even under extremely cold and asymmetric thermal conditions. Attached Figure Description

[0018] Figure 1 This is a flowchart of the innovative air-cooled high-efficiency antifreeze method based on intelligent monitoring proposed in this invention; Figure 2 This is a system module diagram of the innovative air-cooled high-efficiency antifreeze system based on intelligent monitoring proposed in this invention. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1 In the first embodiment of the present invention, the present invention provides an innovative method for efficient antifreeze air cooling based on intelligent monitoring, such as... Figure 1 As shown, it includes the following steps: Step S1: Obtain the environmental parameters of the air-cooled tower, the operating data of each operating sector, and the power data of the unit; In step S1, the steps of obtaining the environmental parameters of the air-cooled tower, the operating data of each operating sector, and the power data of the unit include: Obtain the ambient wind speed and ambient wind direction angle measured by the anemometer tower; Obtain the return water temperature and louver opening of each operating sector of the air-cooled tower; Obtain the current active power of the generator and the power consumption of the circulating water pump; Specifically, in step S1, the operation of obtaining the environmental parameters of the air-cooled tower is as follows: by using an independent anemometer located in the factory area or an anemometer installed on the top of the air-cooled tower, the ambient wind speed at the current moment is scanned and obtained in real time at a preset sampling period. and ambient wind angle Among them, the environmental wind direction angle Using true north as the zero-degree reference, the calculation is performed clockwise, with the value range being... to This parameter is used to determine the physical orientation coordinates of the windward and leeward sides of the air-cooled tower in three-dimensional space.

[0021] The specific operation for obtaining the operating data of each operating sector is as follows: the heat dissipation tube bundle of the indirect air-cooled tower is equally divided in the circumferential spatial direction. Each independent operating sector, in which It is a positive integer, and is set to... Number the sectors The system is installed on the first... Temperature sensors at the main return water header of the heat sink bundle in each operating sector collect the return water temperature of that sector in real time. .

[0022] Simultaneously, the system obtains the first position by reading the analog position feedback signals of the louver actuators in each sector. The opening of the louvers in each operating sector Venetian blind opening The range of values ​​is defined as follows: to ,in This indicates that the louver blades are fully closed. This indicates that the louver blades are fully open for maximum ventilation.

[0023] The specific operation for obtaining the generator's electrical power data is as follows: The system reads the generator's current active power through the data interface of the electrical control system. and the current power consumption of the circulating water pump .

[0024] After extracting the aforementioned power data, the system calculates the unit's net output at the current moment using its built-in arithmetic logic unit. The formula for calculating the net output of the unit is as follows: ; In the formula, This indicates the net output of the unit at the current moment, in megawatts (MW). This indicates the current active power of the generator, measured in megawatts (MW). This indicates the current power consumption of the circulating water pump, in megawatts (MW). As the fundamental thermodynamic boundary input parameter for system operation, it provides a target evaluation benchmark based on net benefit feedback for the extreme value search algorithm in subsequent steps.

[0025] Step S2: Based on environmental parameters and operating data, calculate the ratio of the time required for the water flow in each operating sector to cool down to the freezing point to the actual residence time, which serves as the antifreeze safety margin for the corresponding operating sector; In step S2, the steps of calculating the ratio of the time required for the water flow to cool to the freezing point to the actual residence time in each operating sector, based on environmental parameters and operational data, and using this ratio as the antifreeze safety margin for the corresponding operating sector, include: The effective windward wind speed component of each operating sector is calculated based on the ambient wind speed, ambient wind direction angle, and installation orientation angle of each operating sector. By combining the effective windward wind speed component and the return water temperature, the instantaneous cooling rate of the cooling water inside each operating sector is calculated. The theoretical time required for cooling water to drop to the freezing point at an instantaneous cooling rate is divided by the actual residence time of the cooling water flowing through the corresponding operating sector to obtain the antifreeze safety margin for each operating sector. Specifically, the process of calculating the effective windward velocity component of each operating sector based on the ambient wind speed, ambient wind direction angle, and installation orientation angle of each operating sector is as follows: The system reads the preset sector geometric configuration parameters and calculates the effective windward velocity component of each operating sector. The geographic azimuth angle of the center normal of the outer surface of each operating sector is extracted as the installation orientation angle of that sector. Installation orientation angle Using true north as the zero-degree reference point, values ​​are incremented clockwise. The system's central processing unit obtains the ambient wind direction angle. With installation orientation angle The absolute value of the difference is calculated, and trigonometric function operations are performed.

[0026] No. Effective windward wind speed component of each operating sector The calculation formula is as follows: ; In the formula, Indicates the first The effective wind speed component of the operating sector is expressed in meters per second (m / s). This indicates the ambient wind speed, expressed in meters per second (m / s). Indicates the ambient wind direction angle, in degrees (°). ); Indicates the first The installation orientation angle of each operating sector, in degrees ( The system sets logical judgment conditions: when When the calculation result is less than or equal to zero, it indicates that... The sector is located in the leeward region of the environmental wind field and does not directly bear the dynamic pressure of the incoming wind. At this time, the system uses the effective windward wind speed component. The value is forcibly assigned to zero.

[0027] The specific operation for calculating the instantaneous cooling rate of cooling water within each operating sector, combining the effective windward velocity component and return water temperature, is as follows: the system calls the built-in tube bundle heat transfer empirical model. Based on the simplified logic of Newton's law of cooling, the cooling water temperature drop within the tubes is controlled by the external penetration wind speed and the temperature difference between the inside and outside of the tubes.

[0028] No. Instantaneous cooling rate of cooling water within each operating sector The calculation formula is as follows: ; In the formula, Indicates the first The instantaneous cooling rate of the cooling water within each operating sector, expressed in degrees Celsius per second (°C). ); This represents the heat transfer and cooling empirical coefficient of the heat dissipation tube bundle, which is pre-calibrated and stored inside the controller. Its value is determined by the tube bundle material, geometry, and aerodynamic characteristics. Indicates the first The effective wind speed component of the operating sector is expressed in meters per second (m / s). Indicates the first The return water temperature of each operating sector, in degrees Celsius. ).

[0029] The process of dividing the theoretical time required for cooling water to drop to the freezing point at an instantaneous cooling rate by the actual residence time of the cooling water flowing through the corresponding operating sector to obtain the antifreeze safety margin for each operating sector is as follows: The system presets a reference freezing point temperature threshold for the cooling water to undergo a solidification phase change. Utilizing return water temperature With freezing point temperature The difference is used as the available temperature reduction space.

[0030] Theoretical time required for cooling water to cool to freezing point The calculation method is to divide the temperature drop range by the instantaneous cooling rate of the corresponding sector. Simultaneously, the system extracts the cooling water volume parameters based on the circulating water pump flow rate and the internal volume of the tube bundle during the first stage. The time consumed by a single physical flow within a single operating sector bundle is defined as the actual dwell time. .

[0031] No. Freeze safety margin for each operating sector The final comprehensive calculation formula is as follows: ; In the formula, Indicates the first The anti-freeze safety margin of each operating sector is output as a dimensionless value. Indicates the first The return water temperature of each operating sector, in degrees Celsius. ); This indicates the physical freezing point temperature threshold of the cooling water, which is set to 0 degrees Celsius under normal operating conditions. ); Indicates the first The instantaneous cooling rate of each operating sector, expressed in degrees Celsius per second (°C). ); This indicates the actual residence time of cooling water in the corresponding operating sector, in seconds. The calculated set of matrices. The data will be stored in the controller's random access memory as the direct data basis for determining the driving mechanism of the louver asymmetric actuator in subsequent steps.

[0032] Step S3: Determine whether the antifreeze safety margin is lower than the set safety threshold. If so, reduce the louver opening of the corresponding operating sector and increase the louver opening of the other operating sectors. In step S3, determining whether the antifreeze safety margin is lower than the set safety threshold, and if so, reducing the louver opening of the corresponding operating sector and increasing the louver opening of the other operating sectors includes: Real-time comparison of the antifreeze safety margin of each operating sector with the set antifreeze safety critical threshold; When the antifreeze safety margin of the operating sector on the windward side is less than or equal to the antifreeze safety critical threshold, the louver opening of the operating sector on the windward side is gradually reduced according to the preset step size. Calculate the reduction in air intake in the windward operating sector due to the reduced louver opening, and proportionally increase the louver opening in the leeward operating sector based on the reduced air intake to maintain the overall air intake balance of the air-cooled tower. Specifically, the real-time comparison of the freeze protection margin of each operating sector with the set freeze protection threshold is performed as follows: the system controller pre-writes a dimensionless freeze protection threshold into the read-only memory. This threshold is jointly calibrated using historical extreme values ​​of environmental meteorology and physical freeze resistance limit test data of the cooling water pipe bundle. The controller extracts the calculated freeze protection safety margin for each operating sector at a set clock cycle. And through the internal comparator, it performs numerical comparison operations one by one to confirm the value of the first value. One operating sector Is it less than or equal to? .

[0033] When the antifreeze safety margin of the operating sector facing the wind is less than or equal to the antifreeze safety critical threshold, the specific operation of gradually reducing the louver opening of the operating sector facing the wind according to the preset step size is as follows: If the comparator output signal indicates And based on the effective windward wind speed component in step S2 Determine the first Each operating sector is located on the windward side of the air-cooled tower. The system's central processing unit generates control commands and sends step-by-step closing signals to the electric or pneumatic actuators of the louvers in that sector.

[0034] The system is preset with a fixed step size for closing the blinds. . No. The iterative update formula for the louver opening degree of each windward operating sector is as follows: ; In the formula, Indicates the current control cycle number The louver opening setting value of each windward operating sector is limited to a range of 0% to 100% by the underlying physical execution constraint. Indicates the number of the previous control cycle Actual feedback value of the louver opening degree of each windward operating sector; This indicates the preset step size for closing the blinds.

[0035] The specific operation of calculating the reduced air intake volume of the windward operating sector due to the reduced louver opening, and proportionally increasing the louver opening of the leeward operating sector based on the reduced air intake volume to maintain the overall air intake balance of the air-cooled tower is as follows: The system has a built-in air intake volume reduction evaluation logic, which calculates the absolute change in air intake volume caused by the sector located on the windward side that has performed the reduction action.

[0036] Reduction in total air intake at the windward side The calculation formula is as follows: ; In the formula, This represents the decrease in total air intake at the windward side, expressed in cubic meters per second. ); This represents the set of sectors that are on the windward side and whose antifreeze safety margin triggers the lower threshold. This represents the constant of the airflow resistance coefficient of the louver inlet, which is determined in advance by the system. Indicates the first The effective physical ventilation cross-sectional area of ​​each operating sector louver is in square meters. ); This indicates the step length of the small movement when closing the blinds; Indicates the first The effective windward wind speed component of each operating sector, in meters per second (m / s). ).

[0037] Subsequently, the system traverses the sector status table to identify the current effective wind speed component on the windward side. The operating sectors are categorized into sets of leeward or crosswind compensation sectors. The system will reduce the total air intake on the windward side by [value]. According to set The physical ventilation cross-sectional area ratio of each sector is allocated, and the first sector is calculated. Each leeward or crosswind sector needs to compensate for the increased louver opening step. .

[0038] No. The formula for compensating and updating the louver opening of a sector on the leeward or crosswind side is as follows: ; In the formula, Indicates the current control cycle number The control system locks the upper limit physical dead zone threshold of the louver opening setting value of each leeward or crosswind operating sector to 100%. Indicates the number of the previous control cycle Feedback value of louver opening degree for each leeward or crosswind operating sector; Indicates allocation to the first The louver opening action step of each sector is controlled. The controller synchronously drives the louver actuators on the windward and leeward sides to maintain the algebraic sum of the global air mass flow rate of the air-cooled tower at zero change.

[0039] Step S4: Calculate the heat load spatial distortion rate based on the distribution differences of the antifreeze safety margin of all operating sectors, and use the heat load spatial distortion rate to adjust the perturbation amplitude and perturbation period of the micro-perturbation optimization algorithm in real time. In step S4, the step of calculating the spatial distortion rate of heat load based on the distribution differences of the antifreeze safety margin in all operating sectors includes: Calculate the arithmetic mean of the freeze protection safety margins for all operating sectors of the air-cooled tower; Calculate the standard deviation of the freeze protection safety margin for all operating sectors of the air-cooled tower; Dividing the standard deviation by the arithmetic mean yields the heat load spatial distortion rate, which reflects the degree of uneven heat exchange inside the air-cooled tower. In step S4, the step of adjusting the perturbation amplitude of the micro-perturbation optimization algorithm in real time using the spatial distortion rate of thermal load includes: Extract the basic perturbation amplitude of the perturbation optimization algorithm under steady-state conditions; Multiply the spatial distortion rate of the heat load by the preset attenuation coefficient to obtain the amplitude attenuation index; The amplitude of the control base disturbance is calculated by negative exponential decay according to the amplitude decay index to obtain the adjusted disturbance amplitude, so that the disturbance amplitude gradually decreases as the spatial distortion rate of the heat load increases; In step S4, the step of adjusting the perturbation period of the micro-perturbation optimization algorithm in real time using the spatial distortion rate of the thermal load includes: Extract the basic detection period of the perturbation optimization algorithm under steady-state conditions; Multiply the spatial distortion rate of the heat load by the preset time compensation coefficient to obtain the period extension ratio; The control base detection period is linearly amplified according to the period extension ratio to obtain the adjusted disturbance period, so that the disturbance period adaptively extends with the increase of the thermal load spatial distortion rate. Specifically, based on the differences in the distribution of freeze protection safety margins across all operating sectors, the process for calculating the spatial distortion rate of heat load is as follows: The system extracts the freeze protection safety margin data matrix for each operating sector and calculates the arithmetic mean of the freeze protection safety margins for all operating sectors of the air-cooled tower. (Arithmetic mean) The calculation formula is as follows: ; In the formula, This represents the arithmetic mean of the freeze protection margins for all operating sectors; Indicates the total number of running sectors Indicates the first The freeze protection margin for each operating sector.

[0040] Subsequently, the system controller extracts the deviation between the freeze protection safety margin of each operating sector and the arithmetic mean, and calculates the standard deviation of the freeze protection safety margin for all operating sectors of the air-cooled tower. The calculation formula is as follows: ; In the formula, This represents the standard deviation of the freeze protection margin for all operating sectors; Indicates the total number of operating sectors; Indicates the first The freeze protection margin for each operating sector; The arithmetic mean of the safety margin for frost protection.

[0041] The system's built-in arithmetic logic unit divides the calculated standard deviation by the arithmetic mean, outputting the heat load spatial distortion rate, which reflects the degree of heat transfer unevenness within the air-cooled tower. Heat Load Spatial Distortion Rate The calculation formula is as follows: ; In the formula, This represents the spatial distortion rate of the heat load, and is a dimensionless parameter. This represents the standard deviation of the freeze protection margin for all operating sectors; This represents the arithmetic mean of the freeze protection margins for all operating sectors.

[0042] In step S4, the specific operation of adjusting the disturbance amplitude of the perturbation optimization algorithm in real time using the thermal load spatial distortion rate is as follows: the system controller extracts the pre-set basic disturbance amplitude of the perturbation optimization algorithm corresponding to the steady-state operating condition from its internal memory. This basic disturbance amplitude is represented by the initial frequency step change sent by the controller to the circulating water pump frequency converter.

[0043] The system's central processing unit reads the set amplitude attenuation coefficient, multiplies it by the thermal load spatial distortion rate, and generates an amplitude attenuation exponent. The system's basic control disturbance amplitude is then calculated using a negative exponential attenuation method based on the amplitude attenuation exponent to obtain the adjusted disturbance amplitude. Adjusted disturbance amplitude The calculation formula is as follows: ; In the formula, This indicates the adjusted disturbance amplitude, in Hertz (Hz). ); This represents the basic perturbation amplitude of the perturbation optimization algorithm under steady-state conditions, in Hertz (Hz). ); is the base of the natural logarithm; This represents the preset amplitude attenuation coefficient, which is a dimensionless constant. This represents the spatial distortion rate of the heat load. The above calculations cause the disturbance amplitude of the system output to gradually decrease as the spatial distortion rate of the heat load increases.

[0044] In step S4, the specific operation of adjusting the perturbation period of the perturbation optimization algorithm in real time using the thermal load spatial distortion rate is as follows: the system extracts the basic detection period of the perturbation optimization algorithm under steady-state conditions. This basic detection period is defined as the time interval between two adjacent perturbation actions.

[0045] The system reads a preset time compensation coefficient, multiplies the spatial distortion rate of the heat load by this coefficient, and calculates the period extension ratio. The system then linearly amplifies the basic detection period according to this period extension ratio to obtain the adjusted disturbance period. Adjusted disturbance period The calculation formula is as follows: ; In the formula, This indicates the adjusted disturbance period, in seconds. ); This represents the basic detection period of the perturbation optimization algorithm under steady-state conditions, in seconds. ); This represents the preset time compensation coefficient, which is a dimensionless constant. This represents the spatial distortion rate of the heat load. The above calculation causes the disturbance period executed by the system to adaptively lengthen as the spatial distortion rate of the heat load increases.

[0046] Step S5: Based on the adjusted perturbation optimization algorithm, a frequency control command with a perturbation signal is sent to the circulating water pump, and the basic operating frequency of the circulating water pump is adjusted according to the feedback of the change in the net output of the unit. In step S5, the step of issuing a frequency control command with a disturbance signal to the circulating water pump based on the adjusted perturbation optimization algorithm includes: The current basic operating frequency of the circulating water pump is used as the benchmark value; Based on the adjusted disturbance amplitude and the adjusted disturbance period, a sinusoidal disturbance signal is generated; The sinusoidal disturbance signal is superimposed on the reference value to generate the final frequency control command and send it to the frequency converter of the circulating water pump. In step S5, the step of adjusting the basic operating frequency of the circulating water pump based on the feedback of changes in the unit's net output includes: Subtract the power consumption of the circulating water pump from the current active power of the generator to obtain the net output of the unit; Extract the component of the unit's net output that changes at the same frequency as the disturbance signal, and calculate the direction of the target gradient; If the direction of the target gradient is positive, then increase the base operating frequency of the circulating water pump; If the direction of the target gradient is negative, then reduce the base operating frequency of the circulating water pump; Specifically, the process of issuing frequency control commands with disturbance signals to the circulating water pump based on the adjusted perturbation optimization algorithm is as follows: The system extracts the current basic operating frequency of the circulating water pump as a reference value. The signal generator built into the controller generates a sinusoidal disturbance signal that varies continuously with time based on the adjusted disturbance amplitude and the adjusted disturbance period calculated in step S4.

[0047] Sine wave disturbance signal The calculation formula is as follows: ; In the formula, express The sinusoidal perturbation signal at time t, measured in Hertz (Hz). ); This indicates the adjusted disturbance amplitude, in Hertz (Hz). ); This indicates the adjusted disturbance period, in seconds. ); This represents the runtime variable, in seconds. ).

[0048] Subsequently, the system's internal arithmetic adder directly superimposes the aforementioned sinusoidal disturbance signal onto the reference value of the basic operating frequency, generating the final frequency control command. The system then sends this command in real time to the frequency converter of the circulating water pump in the field via the industrial communication bus.

[0049] Frequency control command The calculation formula is as follows: ; In the formula, This indicates the frequency control command issued to the inverter, in Hertz (Hz). ); This represents the baseline operating frequency of the circulating water pump, in Hertz (Hz). ); This indicates a sinusoidal disturbance signal. After receiving this command signal, the frequency converter drives the circulating water pump motor to operate at a frequency with superimposed tiny fluctuations, causing a corresponding periodic physical disturbance in the cooling water flow rate within the pipe network.

[0050] In step S5, the specific process of adjusting the basic operating frequency of the circulating water pump based on the feedback of changes in the unit's net output is as follows: The system synchronously collects the current active power data of the generator and the power consumption data of the circulating water pump. The arithmetic logic unit inside the system subtracts the power consumption of the circulating water pump from the current active power of the generator to calculate the current net output of the unit.

[0051] The system controller is equipped with a bandpass filter and a synchronous demodulation module, which receives continuous net power output signals from the unit as data input. This module extracts the variation components in the net power output signal that have the same frequency as the sinusoidal disturbance signal and performs integration to calculate the direction of the target gradient.

[0052] target gradient The calculation formula is as follows: ; In the formula, This represents the calculated target gradient; Indicates time The net output of the unit, in megawatts (MW). ); This indicates the adjusted disturbance period, in seconds. ); This is the time variable for integration.

[0053] The system is based on the target gradient The algebraic symbols determine the direction of the target gradient and drive the optimization update of the base operating frequency. When the comparator inside the controller determines the target gradient... When the direction of the target gradient is positive, it indicates that the increase in the current circulating water pump frequency has led to an increase in the unit's net output. The system sends a stepping command to the frequency converter to increase the base operating frequency of the circulating water pump.

[0054] When the comparator determines the target gradient When the target gradient is in the negative direction, it indicates that the increase in the current circulating water pump frequency has led to a decrease in the unit's net output. The system sends a stepping command to the frequency converter to lower the base operating frequency of the circulating water pump.

[0055] The formula for updating the basic operating frequency is as follows: ; In the formula, This represents the baseline operating frequency for the next cycle, expressed in Hertz (Hz). ); This represents the baseline operating frequency value for the current cycle, in Hertz (Hz). ); This represents the system's pre-set frequency update step size constant, in Hertz (Hz). ); The sign function representing the target gradient, when When the value is 1, The value is -1. Through the above closed-loop iterative calculation, the system controls the basic operating frequency of the circulating water pump to approach the extreme point of the unit's net output.

[0056] Example 2: Under strong winds during winter, uneven wind distribution in air-cooled towers leads to spatial asymmetry in the heat load of the cooling tube bundles. Existing control systems only perform global adjustments based on the average return water temperature, failing to address localized overcooling and creating a risk of cooling water freezing on the windward side of the tube bundles. Furthermore, conventional frequency converter optimization, when adjusting the overall flow rate, can easily cause local critical tube bundles to drop to freezing points, making it impossible to achieve optimal net output while ensuring freeze protection for each sector. To address these issues, this invention provides an innovative, intelligently monitored, high-efficiency freeze protection system for air-cooled towers, the structure of which is as follows... Figure 2 As shown. The specific implementation process of this system is as follows: The data acquisition module acquires environmental parameters of the air-cooled tower, operating data of each operating sector, and electrical power data of the unit. The freeze protection margin calculation module calculates the ratio of the time required for the water flow to cool to the freezing point to the actual residence time in each operating sector based on environmental parameters and operating data, and uses this ratio as the freeze protection safety margin for the corresponding operating sector. The asymmetric control module for louvers determines whether the antifreeze safety margin is lower than the set safety threshold. If so, it reduces the louver opening of the corresponding operating sector and increases the louver opening of the other operating sectors. The optimization parameter adjustment module calculates the heat load spatial distortion rate based on the distribution differences of the antifreeze safety margin of all operating sectors, and uses the heat load spatial distortion rate to adjust the perturbation amplitude and perturbation period of the micro-perturbation optimization algorithm in real time. The variable frequency feedback control module sends frequency control commands with disturbance signals to the circulating water pump based on the adjusted micro-perturbation optimization algorithm, and adjusts the basic operating frequency of the circulating water pump according to the changes in the unit's net output.

[0057] Specifically, the data acquisition module connects to the wind measurement equipment deployed within the plant area, scanning and acquiring the ambient wind speed and direction angle in real time at a preset sampling period. The data acquisition module also collects the return water temperature of the operating sector in real time via temperature sensors installed at the main return water header of the cooling pipe bundle. Simultaneously, the data acquisition module reads the position feedback analog signals of the louver actuators in each sector to obtain the louver opening degree of the operating sector. Finally, the data acquisition module reads the current active power of the generator and the current power consumption of the circulating water pump through the data interface of the electrical control system, extracts the power data, and performs subtraction to obtain the current net output of the unit.

[0058] The freeze protection margin calculation module reads preset sector geometric configuration parameters and extracts the geographical azimuth angle of the center normal of the outer surface of the operating sector as the installation orientation angle. The module obtains the absolute value of the difference between the ambient wind direction angle and the installation orientation angle and performs trigonometric function calculations, combining this with the ambient wind speed to calculate the effective windward wind speed component for each operating sector. Combining the effective windward wind speed component and the return water temperature, the module calculates the instantaneous cooling rate of the cooling water inside each operating sector based on a preset tube bundle heat transfer empirical model. The module uses the difference between the return water temperature and the freezing point temperature threshold divided by the instantaneous cooling rate to obtain the theoretical time required for the cooling water to cool to the freezing point. Simultaneously, it extracts the time consumed by a single physical flow of cooling water inside the tube bundle as the actual residence time, and divides the required theoretical time by the actual residence time to obtain the freeze protection safety margin for the corresponding operating sector.

[0059] The asymmetric control module for the louvers extracts the antifreeze safety margin according to a set clock cycle and performs a value comparison calculation with the antifreeze safety critical threshold one by one. When the antifreeze safety margin of the operating sector on the windward side is less than or equal to the antifreeze safety critical threshold, the asymmetric control module sends a step-down signal to the louver actuator of that sector, gradually reducing the louver opening of the windward operating sector according to a preset step size. The asymmetric control module calculates the absolute airflow change caused by the closing action for each sector, summarizing the total reduction in airflow on the windward side. The asymmetric control module identifies operating sectors where the effective windward wind speed component is zero as compensation sectors, allocates the total reduction in airflow on the windward side according to the proportion of the physical ventilation cross-sectional area of ​​each compensation sector, determines the required increase in louver opening step size for each compensation sector, and drives the louver actuator of the compensation sector to increase the opening size, maintaining the overall airflow balance of the air-cooled tower.

[0060] The optimization parameter adjustment module calculates the arithmetic mean of the freeze protection safety margins for all operating sectors of the air-cooled tower, and extracts the standard deviation from each freeze protection safety margin. Dividing the standard deviation by the arithmetic mean, the module outputs the heat load spatial distortion rate, reflecting the degree of heat transfer unevenness within the air-cooled tower. The module also extracts the base disturbance amplitude of the micro-perturbation optimization algorithm under steady-state conditions, multiplies the heat load spatial distortion rate by a preset attenuation coefficient to generate an amplitude attenuation index, and controls the base disturbance amplitude to undergo negative exponential attenuation according to the amplitude attenuation index to obtain the adjusted disturbance amplitude. Finally, the module extracts the base detection period of the micro-perturbation optimization algorithm, multiplies the heat load spatial distortion rate by a preset time compensation coefficient to obtain the period extension ratio, and controls the base detection period to undergo linear amplification according to the period extension ratio to obtain the adjusted disturbance period.

[0061] The frequency conversion feedback control module extracts the current base operating frequency of the circulating water pump as a reference value. Based on the adjusted disturbance amplitude and period, it generates a sinusoidal disturbance signal that continuously varies over time. The module superimposes this sinusoidal disturbance signal onto the reference value to generate the final frequency control command, which is then sent to the frequency converter of the circulating water pump. The module calculates the unit's net output by subtracting the circulating water pump's power consumption from the generator's current active power. It extracts the component with the same frequency as the sinusoidal disturbance signal from the unit's net output signal and performs integration to calculate the direction of the target gradient. When the target gradient is positive, the module sends a step command to the frequency converter to increase the circulating water pump's base operating frequency; when the target gradient is negative, it sends a step command to decrease the circulating water pump's base operating frequency.

[0062] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An innovative method for efficient antifreeze air cooling based on intelligent monitoring, characterized in that: include: Step S1: Obtain the environmental parameters of the air-cooled tower, the operating data of each operating sector, and the power data of the unit; Step S2: Based on the environmental parameters and the operating data, calculate the ratio of the time required for the water flow in each operating sector to cool down to the freezing point to the actual residence time, and use this as the antifreeze safety margin for the corresponding operating sector; Step S3: Determine whether the antifreeze safety margin is lower than the set safety threshold. If so, reduce the louver opening of the corresponding operating sector and increase the louver opening of the other operating sectors. Step S4: Calculate the heat load spatial distortion rate based on the distribution differences of the antifreeze safety margin of all operating sectors, and use the heat load spatial distortion rate to adjust the perturbation amplitude and perturbation period of the micro-perturbation optimization algorithm in real time. Step S5: Based on the adjusted perturbation optimization algorithm, a frequency control command with a perturbation signal is sent to the circulating water pump, and the basic operating frequency of the circulating water pump is adjusted according to the feedback of the change in the net output of the unit.

2. The innovative method for efficient antifreeze air cooling based on intelligent monitoring according to claim 1, characterized in that, In step S1, the step of acquiring the environmental parameters of the air-cooled tower, the operating data of each operating sector, and the power data of the unit includes: Obtain the ambient wind speed and ambient wind direction angle measured by the anemometer tower; Obtain the return water temperature and louver opening of each operating sector of the air-cooled tower; Obtain the current active power of the generator and the power consumption of the circulating water pump.

3. The innovative method for efficient antifreeze air cooling based on intelligent monitoring according to claim 2, characterized in that, In step S2, the step of calculating the ratio of the time required for the water flow in each operating sector to cool to the freezing point to the actual residence time, based on the environmental parameters and the operating data, as the antifreeze safety margin for the corresponding operating sector, includes: Based on the ambient wind speed, the ambient wind direction angle, and the installation orientation angle of each operating sector, the effective windward wind speed component of each operating sector is calculated. Based on the effective windward wind speed component and the return water temperature, the instantaneous cooling rate of the cooling water inside each operating sector is calculated. The theoretical time required for the cooling water to reach the freezing point at the instantaneous cooling rate is divided by the actual residence time of the cooling water flowing through the corresponding operating sector to obtain the antifreeze safety margin for each operating sector.

4. The innovative method for efficient antifreeze air cooling based on intelligent monitoring according to claim 1, characterized in that, In step S3, the step of determining whether the antifreeze safety margin is lower than the set safety threshold, and if so, reducing the louver opening of the corresponding operating sector and increasing the louver opening of the other operating sectors, includes: Real-time comparison of the antifreeze safety margin of each operating sector with the set antifreeze safety critical threshold; When the antifreeze safety margin of the operating sector on the windward side of each operating sector is less than or equal to the antifreeze safety critical threshold, the louver opening of the operating sector on the windward side is gradually reduced according to the preset step size. Calculate the reduction in air intake in the windward operating sector due to the reduced louver opening, and proportionally increase the louver opening in the leeward operating sector based on the reduced air intake to maintain the overall air intake balance of the air-cooled tower.

5. The innovative method for efficient antifreeze air cooling based on intelligent monitoring according to claim 1, characterized in that, In step S4, the step of calculating the spatial distortion rate of heat load based on the distribution differences of the antifreeze safety margin of all operating sectors includes: Calculate the arithmetic mean of the freeze protection safety margins for all operating sectors of the air-cooled tower; Calculate the standard deviation of the freeze protection safety margin for all operating sectors of the air-cooled tower; Dividing the standard deviation by the arithmetic mean yields the heat load spatial distortion rate, which reflects the degree of uneven heat exchange inside the air-cooled tower.

6. The innovative method for efficient antifreeze air cooling based on intelligent monitoring according to claim 1, characterized in that, In step S4, the step of adjusting the perturbation amplitude of the micro-perturbation optimization algorithm in real time using the thermal load spatial distortion rate includes: Extract the basic perturbation amplitude of the perturbation optimization algorithm under steady-state conditions; Multiply the spatial distortion rate of the heat load by a preset attenuation coefficient to obtain the amplitude attenuation index; The basic disturbance amplitude is controlled to undergo negative exponential decay calculation according to the amplitude decay index to obtain the adjusted disturbance amplitude, so that the disturbance amplitude gradually decreases as the spatial distortion rate of the heat load increases.

7. The innovative method for efficient antifreeze air cooling based on intelligent monitoring according to claim 1, characterized in that, In step S4, the step of adjusting the perturbation period of the micro-perturbation optimization algorithm in real time using the thermal load spatial distortion rate includes: Extract the basic detection period of the perturbation optimization algorithm under steady-state conditions; Multiply the spatial distortion rate of the heat load by a preset time compensation coefficient to obtain the period extension ratio; The basic detection period is linearly amplified according to the period extension ratio to obtain the adjusted disturbance period, so that the disturbance period adaptively extends as the thermal load spatial distortion rate increases.

8. The innovative method for efficient antifreeze air cooling based on intelligent monitoring according to claim 6, characterized in that, In step S5, the step of issuing a frequency control command with a disturbance signal to the circulating water pump based on the adjusted perturbation optimization algorithm includes: The current basic operating frequency of the circulating water pump is used as the benchmark value; A sinusoidal disturbance signal is generated based on the adjusted disturbance amplitude and the adjusted disturbance period. The sinusoidal disturbance signal is superimposed on the reference value to generate the final frequency control command, which is then sent to the frequency converter of the circulating water pump.

9. The innovative method for efficient antifreeze air cooling based on intelligent monitoring according to claim 1, characterized in that, In step S5, the step of adjusting the basic operating frequency of the circulating water pump based on the feedback of changes in the unit's net output includes: Subtract the power consumption of the circulating water pump from the current active power of the generator to obtain the net output of the unit; Extract the component of the unit's net output that changes at the same frequency as the disturbance signal, and calculate the direction of the target gradient; If the direction of the target gradient is positive, then increase the base operating frequency of the circulating water pump; If the direction of the target gradient is negative, then the base operating frequency of the circulating water pump is reduced.

10. An innovative air-cooled high-efficiency antifreeze system based on intelligent monitoring, characterized in that: The system for the innovative air-cooled high-efficiency antifreeze method based on intelligent monitoring according to any one of claims 1-9 comprises: The data acquisition module acquires environmental parameters of the air-cooled tower, operating data of each operating sector, and electrical power data of the unit. The antifreeze margin calculation module calculates the ratio of the time required for the water flow in each operating sector to cool down to the freezing point to the actual residence time, based on the environmental parameters and the operating data, and uses this ratio as the antifreeze safety margin for the corresponding operating sector. The asymmetric control module for louvers determines whether the antifreeze safety margin is lower than the set safety threshold. If so, it reduces the louver opening of the corresponding operating sector and increases the louver opening of the other operating sectors. The optimization parameter adjustment module calculates the heat load spatial distortion rate based on the distribution differences of the antifreeze safety margin of all operating sectors, and uses the heat load spatial distortion rate to adjust the perturbation amplitude and perturbation period of the micro-perturbation optimization algorithm in real time. The variable frequency feedback control module sends frequency control commands with disturbance signals to the circulating water pump based on the adjusted micro-perturbation optimization algorithm, and adjusts the basic operating frequency of the circulating water pump according to the changes in the unit's net output.

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