A method, device, and storage medium for controlling operation of an NDACC system

Abstract

The application discloses an NDACC system operation control method, device and equipment and a storage medium, and relates to the field of air cooling system operation control. The control method comprises the following steps: obtaining condensation flow data and supercooling degree data; adjusting the louvre opening degree corresponding to each cooling sector of the NDACC system according to the condensation flow data, so that the condensation amounts of each cooling unit are balanced; comparing the supercooling degree data with a preset supercooling degree threshold value; when the supercooling degree data exceeds the preset supercooling degree threshold value, preferentially increasing the scale of the vacuum pump put into use corresponding to the cooling sector; if the scale of the vacuum pump put into use reaches the maximum limit value and the supercooling degree data still exceeds the preset supercooling degree threshold value, adjusting the louvre opening degree corresponding to the cooling sector until the supercooling degree data falls back to the preset supercooling degree threshold value; and after the supercooling degree data falls back to the preset supercooling degree threshold value, restoring the louvre opening degree adjustment of the cooling sector, so that the cooling sector and the remaining cooling sectors maintain balanced condensation amounts.

Description

Technical Field

[0001] This invention relates to the field of operation control of coal-fired power plant air-cooled systems, and particularly to an NDACC system operation control method, device, equipment and storage medium. Background Technology

[0002] In the coal-rich but water-scarce coal-producing regions of northern my country, direct air-cooled systems (ACC) are widely used in the condensation stages of coal-fired power units due to their low water consumption. Natural draft direct air-cooled systems (NDACC) have been promoted for their low energy consumption and low noise. During winter operation, the combined effects of low temperature and ambient wind conditions cause uneven airflow into the cooling surfaces of NDACC systems, resulting in differences in airflow to different cooling units and consequently uneven distribution of steam condensation within each unit. To address this issue, existing technologies typically employ two types of control logic: one adjusts the opening of the corresponding louvers in each cooling unit to change the airflow and thus adjust the condensation rate, thereby controlling the system back pressure; the other monitors subcooling data and adjusts the operation of the vacuum pump or the louver opening in the corresponding area to keep the subcooling within a set range and prevent equipment damage.

[0003] However, when the system is adjusted using control logic targeting the system back pressure, the opening of the louvers in some cooling units may be adjusted to achieve a uniform distribution of condensation in each cooling unit. This adjustment process may cause the condensation intensity of some cooling units to exceed expectations, resulting in the subcooling in the corresponding area exceeding the safe range. This can lead to issues such as pipe freezing and corrosion, affecting the safe operation of the unit. When the system is adjusted using control logic targeting subcooling, the louvers in the corresponding area may be closed or the vacuum pump operation status may be adjusted to reduce the subcooling data in the excessive area. This adjustment process will change the condensation of the corresponding cooling unit, disrupting the existing condensation distribution between the cooling units. This will cause the system steam-side resistance to increase, the system back pressure to rise, and thus increase the unit's coal consumption for power generation, reducing the unit's operational economy.

[0004] In summary, during the winter operation of the unit, the ambient wind field and ambient temperature are in a state of continuous change. The two types of control logic will be frequently triggered with the change of operating conditions, causing the system operating state to fluctuate continuously. It is impossible to maintain a stable low back pressure operating state or to continuously ensure that the subcooling is within a safe range, thus affecting the operating stability of the unit under winter operating conditions. Summary of the Invention

[0005] To address the issues of uneven condensation flow distribution among cooling units and conflicts between overcooling protection and flow balancing control in existing NDACC systems during winter operation, this invention employs a collaborative control logic that combines flow regulation with graded control of overcooling protection. This prioritizes matching the vacuum pump's pumping capacity to address overcooling risks, and, combined with differentiated louver opening adjustment, achieves synergistic optimization of flow balancing and overcooling protection. This effectively mitigates the risk of pipe freezing and ensures economical and stable back pressure operation of the unit.

[0006] Based on this, in a first aspect of the present invention, a method for controlling the operation of an NDACC system is proposed. The NDACC system includes multiple cooling sectors, each cooling sector including a cooling unit, adjustable louvers corresponding to the cooling unit, and a vacuum pump group that is matched with the cooling sector and can be independently switched. The control method includes the following steps:

[0007] Acquire the condensate flow rate data of each cooling unit in the NDACC system, as well as the subcooling data corresponding to each cooling unit; wherein, the subcooling data includes at least one of condensate subcooling data and vacuum subcooling data;

[0008] Based on the condensation flow data, the opening of the louvers corresponding to each cooling sector of the NDACC system is adjusted to ensure that the condensation of each cooling unit is balanced.

[0009] The supercooling data is compared with a preset supercooling threshold. When the supercooling data exceeds the preset supercooling threshold, the vacuum pump operation scale of the corresponding cooling sector is increased first. If the supercooling data still exceeds the preset supercooling threshold after the vacuum pump operation scale reaches the maximum limit of the cooling sector, the louver opening of the corresponding cooling sector is adjusted until the supercooling data falls back to within the preset supercooling threshold.

[0010] Once the subcooling data of the corresponding cooling sector falls back to the preset subcooling threshold, the louver opening adjustment of that cooling sector is restored to maintain a balance in condensation between that cooling sector and the other cooling sectors.

[0011] Optionally, the control method may also include pre-control measures for overcooling risks:

[0012] Historical winter operating data of the NDACC system were obtained. The training dataset was constructed using historical condensate flow rate data, historical subcooling data, historical louver opening, historical vacuum pump operating data, historical system operating parameters, and historical external environmental parameters as input features, and the actual condensate flow rate and subcooling data of the corresponding time period as output labels.

[0013] Based on the training dataset, the temporal neural network model and the gradient boosting tree model were trained respectively to obtain the flow-supercooling time series prediction model and the risk classification model.

[0014] The real-time collected system operation data is synchronously input into the flow-subcooling time series prediction model and risk classification model, and outputs the predicted value of condensing flow rate, the predicted value of subcooling, and the corresponding subcooling risk prediction results within a preset time period.

[0015] If the predicted subcooling value exceeds the preset subcooling threshold, and / or the risk classification model predicts that a subcooling risk will occur within a preset time period in the future, a pre-adjustment command is generated to pre-adjust the scale of vacuum pump operation and louver opening of the corresponding cooling sector. At the same time, based on the predicted condensation flow deviation, the louver opening adjustment command is corrected in advance.

[0016] Optionally, while acquiring condensate flow rate data and subcooling data, the real-time back pressure value of the NDACC system, the real-time load data of the unit, and the real-time temperature, wind speed, and wind direction data of the system's environment are also acquired simultaneously. The control method further includes correcting the adjustment command based on the real-time back pressure value of the system.

[0017] The economic back pressure operating range of the NDACC system is preset and then corrected based on ambient temperature and unit load data.

[0018] When the real-time back pressure value of the system is within the economic back pressure operating range, the control logic and control parameters of flow balance regulation and overcooling protection regulation remain unchanged.

[0019] When the real-time back pressure value of the system is less than the minimum value of the economic back pressure operating range, the opening of the louvers is increased and the preset overcooling threshold is lowered in the overcooling protection adjustment. At the same time, the allowable flow deviation range of each cooling unit is reduced in the flow balance adjustment.

[0020] When the real-time back pressure value of the system is greater than the maximum value of the economic back pressure operating range, the cooling sector that has triggered overcooling protection will still adjust the corresponding louver opening according to the overcooling protection adjustment logic, provided that it is not lower than the preset louver opening lockout lower limit. At the same time, the louver opening of other cooling sectors that have not triggered overcooling protection and whose overcooling data does not exceed the preset overcooling threshold will be increased, and the allowable flow deviation range of each cooling unit will be relaxed in the flow balance adjustment.

[0021] Optionally, adjusting the louver opening of each cooling sector of the NDACC system to balance the condensation of each cooling unit includes the following steps:

[0022] The louver opening is controlled by two levels: the cooling fan section and the cooling fan section itself.

[0023] Cooling fan zone hierarchy: Calculate the average condensation flow rate of all cooling fan zones. Based on the sector deviation value between the average condensation flow rate of each cooling fan zone and the average condensation flow rate of the whole system, adjust the basic opening reference value of all louvers in the corresponding cooling fan zone proportionally, and make the condensation flow rate deviation value between each cooling fan zone less than the first preset deviation threshold.

[0024] Cooling sector hierarchy: Calculate the sector average of the condensation flow rate of all cooling units in a single cooling sector, and divide the cooling units in the sector into high condensation capacity units, standard condensation capacity units, and low condensation capacity units;

[0025] For units with low condensation capacity, the opening adjustment step of the corresponding louver is increased proportionally to the flow deviation value;

[0026] For high condensation units, the opening adjustment step of the corresponding louver is reduced proportionally to the flow deviation value;

[0027] The standard condensation unit maintains the same opening reference value;

[0028] During the adjustment process, the average condensation flow rate of the entire sector is kept stable until the condensation flow rate deviation of all cooling units in the sector is less than the second preset deviation threshold, and the second preset deviation threshold is less than the first preset deviation threshold.

[0029] Optionally, the preset supercooling threshold includes a modified safety threshold, a warning threshold, and a limit threshold, with the values ​​of the three increasing sequentially.

[0030] Based on the comparison between supercooling data and supercooling thresholds, supercooling risk is divided into four levels: no risk, low risk, medium risk, and high risk, each triggering different control logic:

[0031] If the subcooling data is less than or equal to the safety threshold, it is determined to be risk-free, and the subcooling protection control is not triggered to maintain flow balance.

[0032] If the subcooling data is greater than the safety threshold but less than or equal to the warning threshold, it is judged as low risk, and the vacuum pump unit is put into initial operation.

[0033] If the subcooling data is greater than the warning threshold but less than or equal to the limit threshold, it is judged as medium risk, and the vacuum pump unit is put into medium-level operation.

[0034] If the subcooling data exceeds the limit threshold, it is judged as high risk, and the vacuum pump unit is put into full-load operation;

[0035] Based on ambient temperature and real-time unit load data, the safety threshold, warning threshold, and limit threshold are corrected. The lower the ambient temperature and the lower the unit load, the lower the corresponding threshold is adjusted accordingly.

[0036] Optionally, prioritizing the increase in the scale of vacuum pumps deployed in the corresponding cooling sector includes the following steps:

[0037] When a low-risk level is triggered, the required additional pumping capacity is calculated based on the difference between the subcooling data and the safety threshold. The corresponding number of vacuum pumps are started according to the minimum activation step size, and the operating frequency of the activated vacuum pumps is adjusted synchronously to match the total pumping capacity of the vacuum pump group with the subcooling deviation value.

[0038] When the medium risk level is triggered, 50% of the vacuum pumps in the cooling sector vacuum pump group will be started, and the operating frequency of the vacuum pumps in use will be increased to 70% of the rated frequency. At the same time, based on the real-time change data of subcooling, the number of vacuum pumps in use will be increased or decreased in steps of a single vacuum pump.

[0039] When a high-risk level is triggered, all vacuum pumps in the vacuum pump group of that cooling sector will be started to maximize the number of vacuum pumps in operation, and the frequency of all operating vacuum pumps will be increased to the rated frequency.

[0040] Optionally, adjusting the opening degree of the louvers for the corresponding cooling sector includes the following steps:

[0041] The cooling units within the cooling sector are divided into co-current cooling units and counter-current cooling units. The opening priority of the louvers corresponding to the co-current cooling units is set to be higher than that of the louvers corresponding to the counter-current cooling units.

[0042] When a high-risk level is triggered and the corresponding cooling sector vacuum pump unit is put into full load operation, if the subcooling data still has not fallen back to the safe threshold range, the opening of the louvers corresponding to the downstream cooling unit should be reduced by a preset fixed step size.

[0043] If the subcooling data still does not fall back to the safe threshold range after the louver opening of the downstream section is reduced to the preset lower limit, the louver opening of the corresponding cooling unit in the counter-current section will be reduced synchronously according to the preset step size.

[0044] In a second aspect of the invention, an NDACC system operation control device is provided for implementing the aforementioned control method, the device comprising:

[0045] The data acquisition module is used to acquire condensation flow rate data and subcooling data of each cooling unit in the NDACC system;

[0046] The flow control module is used to generate louver opening adjustment commands based on condensation flow data to control the condensation of each cooling unit to be balanced.

[0047] The subcooling control module is used to compare the subcooling data with the preset subcooling threshold and generate vacuum pump activation adjustment commands and louver subcooling protection adjustment commands.

[0048] The control module is used to restore the flow regulation of the corresponding cooling sector after the subcooling data falls back to within the subcooling threshold.

[0049] In a third aspect of the invention, an apparatus is provided that includes a processor and a memory;

[0050] The memory is used to store computer programs;

[0051] When the processor executes the computer program, it implements the aforementioned control method.

[0052] In a fourth aspect of the invention, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the aforementioned control method.

[0053] Compared with the above-mentioned background technology, the technical solution provided by the present invention has at least the following technical effects:

[0054] This invention achieves a balance in the condensation of each cooling unit by adjusting the opening of the louvers in each cooling sector based on condensation flow data. This alleviates the problem of uneven flow caused by differences in the ambient wind field and the heat exchange performance of the cooling units, thereby ensuring the consistency of the heat exchange conditions of each cooling unit.

[0055] When the system back pressure is higher than the economic operating range, this invention maintains the overcooling protection adjustment priority of the already triggered overcooling protection sectors while increasing the louver opening of the untriggered overcooling protection sectors. This achieves compensation and coordination between overcooling protection and economic back pressure control, thus avoiding weakening the antifreeze protection of the already triggered sectors and suppressing the continuous rise of the overall system back pressure.

[0056] This invention establishes a priority for overcooling protection regulation. When the overcooling exceeds the threshold, the scale of vacuum pump operation is adjusted first. This can address the risk of overcooling without changing the louver opening or disrupting the flow balance, thereby reducing the interference of overcooling protection regulation on the flow regulation of the cooling sector and solving the conflict between flow balance and overcooling protection.

[0057] This invention adopts the method of adjusting the louver opening only after the scale of vacuum pump operation reaches the limit, so as to control the risk of overcooling, avoid system back pressure fluctuations caused by frequent or large adjustments of louver opening, and thus ensure the stability of unit operation.

[0058] This invention restores the flow regulation of the corresponding cooling sector after the subcooling degree drops back to a preset subcooling degree threshold, which can achieve a smooth switch between subcooling protection and flow control of the cooling sector. This ensures the system's antifreeze safety during winter operation while also taking into account the economic efficiency of unit operation. Attached Figure Description

[0059] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0060] Figure 1 This is a flowchart of the NDACC system operation control method provided in an embodiment of the present invention. Detailed Implementation

[0061] The technical solutions of 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.

[0062] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0063] As described in the background section, during winter operation, the NDACC system experiences uneven airflow across its cooling surfaces due to the combined effects of low temperatures and ambient wind. This results in variations in airflow to different cooling units, leading to uneven distribution of vapor condensation within each unit. To address this system operation under these conditions, existing technologies typically employ two types of control logic. One approach adjusts the opening of the corresponding louvers for each cooling unit to change its airflow, thereby adjusting the condensation rate and controlling the system back pressure. The other approach monitors subcooling data and adjusts the operation of the vacuum pump in the corresponding area or the louver opening to keep the subcooling within a set range, preventing equipment damage.

[0064] However, when the system is adjusted using control logic targeting the system back pressure, the opening of the louvers in some cooling units may be adjusted to achieve a uniform distribution of condensation in each cooling unit. This adjustment process may cause the condensation intensity of some cooling units to exceed expectations, resulting in the subcooling in the corresponding area exceeding the safe range. This can lead to issues such as pipe freezing and corrosion, affecting the safe operation of the unit. When the system is adjusted using control logic targeting subcooling, the louvers in the corresponding area may be closed or the vacuum pump operation status may be adjusted to reduce the subcooling data in the excessive area. This adjustment process will change the condensation of the corresponding cooling unit, disrupting the existing condensation distribution between the cooling units. This will cause the system steam-side resistance to increase, the system back pressure to rise, and thus increase the unit's coal consumption for power generation, reducing the unit's operational economy.

[0065] Based on this, the present invention proposes an NDACC system operation control method, which is applied to a natural ventilation direct air cooling system (NDACC).

[0066] The NDACC system includes multiple cooling sectors distributed along the circumference of the tower. Each cooling sector includes multiple sets of cooling units arranged in parallel and counter-current sections. Each cooling unit has an adjustable louver on its inlet side. Each cooling sector is equipped with an independently switchable vacuum pump group. The vacuum pump group is connected to the cooling unit of the corresponding cooling sector to adjust the content of non-condensable gas in the cooling unit, thereby adjusting the condensation heat transfer intensity of the cooling unit.

[0067] The NDACC system also includes a data acquisition unit and actuators. The data acquisition unit includes at least a flow sensor, a temperature sensor, a pressure sensor, and a wind speed and direction sensor. The temperature sensor includes at least a steam-side temperature acquisition unit for acquiring the steam temperature or steam saturation temperature of the cooling unit, a condensate temperature acquisition unit for acquiring the condensate outlet temperature, a vacuum temperature acquisition unit for acquiring the vacuum branch temperature, and an ambient temperature acquisition unit for acquiring the ambient temperature. The data acquisition unit is used to acquire data on the condensate flow rate, steam temperature or steam saturation temperature, condensate outlet temperature, vacuum temperature, real-time system back pressure, unit load, ambient temperature, and ambient wind speed and direction. The actuators include at least an electric actuator for the louvers and a frequency converter control mechanism for the vacuum pump, used to receive control commands and adjust the louver opening, the number of vacuum pumps in operation, and their operating frequency accordingly.

[0068] Figure 1 This is a flowchart of the NDACC system operation control method provided by the present invention, such as... Figure 1 As shown, the NDACC system operation control method provided by the present invention specifically includes the following steps:

[0069] Step 1: Obtain the condensate flow rate data of each cooling unit in the NDACC system, as well as the corresponding subcooling data for each cooling unit. The subcooling data includes at least one of the following: condensate subcooling data and vacuum subcooling data.

[0070] In a preferred implementation, the data acquisition unit synchronously acquires system-wide operating data at a preset acquisition frequency of once per second. The acquired data includes at least the real-time condensate flow rate data of each cooling unit, the steam saturation temperature at the corresponding pressure, the condensate outlet temperature, and the vacuum temperature. Based on the difference between the steam saturation temperature and the condensate outlet temperature, the condensate subcooling data of the corresponding cooling unit is calculated. Based on the difference between the steam saturation temperature and the vacuum temperature, the vacuum subcooling data of the corresponding cooling unit or cooling sector is calculated. The condensate subcooling data and the vacuum subcooling data are combined and input into the overcooling protection adjustment logic as subcooling data. Furthermore, when either the condensate subcooling data or the vacuum subcooling data exceeds its corresponding preset subcooling threshold, it is determined that the subcooling data of the corresponding cooling sector exceeds the preset subcooling threshold, and the corresponding level of overcooling protection adjustment is triggered.

[0071] As an optional implementation method, while acquiring condensate flow rate data and subcooling data, the real-time back pressure value of the NDACC system, the real-time load data of the unit, and the real-time temperature, wind speed and wind direction data of the system environment are acquired simultaneously.

[0072] Step 2: Based on the condensation flow data, adjust the louver opening of each cooling sector of the NDACC system to ensure that the condensation of each cooling unit is balanced.

[0073] Furthermore, as a preferred embodiment, the louver opening is adjusted through two levels within the cooling fan zone and the cooling fan zone itself, specifically including the following steps:

[0074] Cooling fan zone adjustment level: Calculate the average condensing flow rate of all cooling fan zones in the entire system. Based on the sector deviation value between the average condensing flow rate of each cooling fan zone and the average condensing flow rate of the entire system, adjust the basic opening reference value of all louvers in the corresponding cooling fan zone proportionally to the deviation value, so that the condensing flow rate deviation value between each cooling fan zone is less than a first preset deviation threshold. The first preset deviation threshold is set according to the unit's operating conditions and historical operating data; in this embodiment, the first preset deviation threshold is set to 10%.

[0075] Adjustment level within a cooling sector: Calculate the sector average of the condensation flow rate of all cooling units within a single cooling sector. Based on the unit deviation between the condensation flow rate of each cooling unit and the sector average, divide the cooling units within the sector into high condensation capacity units, standard condensation capacity units, and low condensation capacity units.

[0076] For units with low condensation capacity, the opening adjustment step of the corresponding louver is increased proportionally to the unit flow deviation value.

[0077] For high condensation units, the opening adjustment step of the corresponding louver is reduced proportionally to the unit flow deviation value.

[0078] The standard condensation unit maintains the current opening reference value.

[0079] During the above adjustment process, the average condensation flow rate of the cooling sector is kept stable until the condensation flow rate deviation of all cooling units in the sector is less than the second preset deviation threshold. The second preset deviation threshold is less than the first preset deviation threshold. In this embodiment, the second preset deviation threshold is set to 5%.

[0080] As an optional implementation, during the two-level adjustment process, the windward cooling sector is simultaneously identified based on real-time collected environmental wind speed and direction data. When the windward cooling sector shows a risk of overcooling or the overcooling data shows an increasing trend, the adjustment step size of the louvers in the overcooling protection adjustment of the windward cooling sector is amplified and corrected to improve the response speed of the windward overcooling protection and reduce the risk of pipe freezing.

[0081] Step 3: Compare the supercooling data with the preset supercooling threshold. When the supercooling data exceeds the preset supercooling threshold, prioritize increasing the vacuum pump operation scale of the corresponding cooling sector. If the supercooling data still exceeds the preset supercooling threshold after the vacuum pump operation scale reaches the maximum limit of the cooling sector, adjust the louver opening of the corresponding cooling sector until the supercooling data falls back to within the preset supercooling threshold.

[0082] As a preferred implementation, the preset supercooling threshold includes a dynamically corrected safety threshold, a warning threshold, and a limit threshold, with the values ​​of the three increasing sequentially.

[0083] Based on the comparison between supercooling data and supercooling threshold, supercooling risk is divided into four levels: no risk, low risk, medium risk, and high risk, which trigger different control logics accordingly.

[0084] Specifically, if the supercooling data is less than or equal to the safety threshold, it is determined to be risk-free, and the supercooling protection control is not triggered, maintaining the flow balance adjustment logic.

[0085] If the subcooling data is greater than the safety threshold but less than or equal to the warning threshold, it is judged as low risk, and the vacuum pump group is put into initial operation and adjustment.

[0086] If the subcooling data is greater than the warning threshold but less than or equal to the limit threshold, it is judged as medium risk, and the vacuum pump group is put into medium-level operation and adjustment is performed.

[0087] If the subcooling data exceeds the limit threshold, it is judged as high risk, and the vacuum pump unit is put into full-load operation for adjustment.

[0088] In this embodiment, the safety threshold, warning threshold, and limit threshold are dynamically corrected based on ambient temperature and real-time unit load data. The lower the ambient temperature and the lower the unit load, the lower the corresponding threshold is adjusted accordingly, so that the subcooling threshold matches the actual operating conditions of the system.

[0089] In this embodiment, the correction direction of the supercooling threshold can be determined according to the operating conditions of the system. Specifically, when the ambient temperature is lower than the preset low temperature threshold, or when the system enters the winter anti-freeze operation mode, the system is determined to be in a low temperature anti-freeze condition. At this time, the risk of supercooling and pipe freezing is high. The safety threshold, warning threshold, and limit threshold are adjusted synchronously as the ambient temperature decreases and the real-time load of the unit decreases, so as to trigger the supercooling protection in advance.

[0090] When the ambient temperature is higher than the preset high temperature threshold, or when the system enters the summer high temperature operation mode, the system is determined to be in a high temperature non-antifreeze condition. At this time, the system control objective is to maintain heat exchange capacity and economic back pressure. The safety threshold, warning threshold and limit threshold are simultaneously adjusted upward or restored to the high temperature condition reference value to reduce the false triggering of the overcooling protection adjustment and avoid unnecessary closing of the louvers, which would lead to an increase in system back pressure.

[0091] In this embodiment, the scale of vacuum pumps deployed in the corresponding cooling sector is increased first, specifically including the following steps:

[0092] When a low-risk level is triggered, the required additional pumping capacity is calculated based on the difference between the subcooling data and the safety threshold. The corresponding number of vacuum pumps are started according to the minimum activation step size, and the operating frequency of the activated vacuum pumps is adjusted synchronously to match the total pumping capacity of the vacuum pump group with the subcooling deviation value.

[0093] When the medium risk level is triggered, 50% of the vacuum pumps in the cooling sector vacuum pump group will be started, and the operating frequency of the vacuum pumps will be increased to 70% of the rated frequency. At the same time, based on the real-time change data of subcooling, the number of vacuum pumps put into operation will be increased or decreased in steps of a single vacuum pump to adjust the pumping capacity.

[0094] When a high-risk level is triggered, all vacuum pumps in the vacuum pump group of the cooling sector will be started, so that the scale of vacuum pumps put into operation reaches the maximum limit of the cooling sector, and the frequency of all operating vacuum pumps will be increased to the rated frequency.

[0095] As an optional implementation method, during the commissioning of vacuum pumps, a polling start-stop method is used to match the cumulative running time of each vacuum pump, so that the deviation of the cumulative running time of each vacuum pump in the same sector is less than a preset time threshold, thereby avoiding long-term continuous operation of a single vacuum pump and extending the service life of the equipment.

[0096] In this embodiment, when the vacuum pump operation reaches the maximum limit of the cooling sector, and the subcooling data still exceeds the preset subcooling threshold, the opening of the louvers in the corresponding cooling sector is adjusted, specifically including the following steps:

[0097] The cooling units within the cooling sector are divided into co-current cooling units and counter-current cooling units according to the heat exchange process. The opening priority of the louvers corresponding to the co-current cooling units is set to be higher than that of the louvers corresponding to the counter-current cooling units.

[0098] When a high-risk level is triggered and the corresponding cooling sector vacuum pump unit is put into full load operation, if the subcooling data still has not fallen back to the safe threshold range, the opening of the louvers corresponding to the downstream cooling unit is closed first according to the preset fixed step size, and the real-time changes of subcooling data are collected simultaneously. Subcooling is checked once after each step size adjustment is completed.

[0099] If the subcooling data still does not fall back to the safe threshold range after the louver opening of the downstream section is reduced to the preset lower limit, the louver opening of the corresponding cooling unit in the counter-flow section will be reduced synchronously according to the preset step size.

[0100] As an optional implementation, during the adjustment of the louver opening, based on the real-time difference between the subcooling data and the safety threshold, the PID controller calculates the fine adjustment amount of the louver opening and corrects the opening adjustment step size.

[0101] Simultaneously, based on the real-time back pressure value of the system, a lower limit for louver opening is set. When the real-time back pressure value of the system is greater than the preset upper back pressure value, the cooling sector that has triggered overcooling protection will continue to reduce the corresponding louver opening according to the overcooling protection adjustment logic, provided that it is not lower than the preset lower limit for louver opening. At the same time, in other cooling sectors that have not triggered overcooling protection and whose overcooling data is within the safe threshold range, the corresponding louver opening is increased according to the back pressure deviation value to improve the heat exchange capacity of the entire system and make the system back pressure fall back to the economic back pressure operating range. During the compensation opening adjustment process, the overcooling data of each cooling sector is checked in real time. If the overcooling data of any cooling sector exceeds the corresponding threshold, the opening increase of that cooling sector is stopped or it is switched to overcooling protection adjustment.

[0102] Step 4: When the subcooling data of the corresponding cooling sector falls back to the preset subcooling threshold, restore the louver opening adjustment of the cooling sector to maintain a balance of condensation between the cooling sector and the other cooling sectors.

[0103] In this embodiment, when the supercooling data of the corresponding cooling sector remains within the safe threshold range for a preset stable time, a supercooling protection exit gradient command is generated. Following the opposite direction to the commissioning sequence, the operating frequency of the vacuum pump is first gradually reduced by a preset step size, and then the vacuum pumps commissioned during the supercooling protection period are gradually shut down by a single vacuum pump as the step size.

[0104] During the adjustment of vacuum pump operating parameters, the opening of the louvers in the cooling sector is gradually restored according to the preset gradient. Each time the vacuum pump adjustment is completed, the opening of the louvers is restored accordingly to avoid a rebound in the subcooling data.

[0105] During the recovery process of the vacuum pump and louver opening, the condensation flow data of each cooling unit in the cooling sector is monitored in real time, and the louver opening of the other cooling sectors is adjusted in reverse to ensure that the condensation flow deviation of all cooling units in the whole system is always maintained within the preset range.

[0106] Once the vacuum pump unit returns to its operating state before the overcooling protection is triggered, and the louver opening returns to the reference opening corresponding to the flow balance adjustment, the priority of the overcooling protection adjustment is completely released, and the entire system returns to flow balance adjustment.

[0107] As an optional implementation, the control method of the present invention further includes correcting the adjustment command based on the real-time back pressure value of the system, specifically including the following steps:

[0108] The economic back pressure operating range of the NDACC system is preset, and the economic back pressure operating range is dynamically corrected based on ambient temperature and unit load data.

[0109] When the real-time back pressure value of the system is within the economic back pressure operating range, the control logic and control parameters of flow balance regulation and overcooling protection regulation remain unchanged.

[0110] When the real-time back pressure value of the system is less than the minimum value of the economic back pressure operating range, the opening of the louvers is increased and the preset overcooling threshold is lowered in the overcooling protection adjustment. At the same time, the allowable flow deviation range of each cooling unit is reduced in the flow balance adjustment.

[0111] When the real-time back pressure value of the system is greater than the maximum value of the economic back pressure operating range, the cooling sector that has triggered overcooling protection will still adjust the corresponding louver opening according to the overcooling protection adjustment logic, provided that it is not lower than the preset louver opening lockout lower limit. At the same time, the louver opening of other cooling sectors that have not triggered overcooling protection and whose overcooling data does not exceed the preset overcooling threshold will be increased, and the allowable flow deviation range of each cooling unit will be relaxed in the flow balance adjustment.

[0112] As another optional implementation, the control method of the present invention further includes a supercooling risk pre-control step, specifically including the following steps:

[0113] Historical winter operating data of the NDACC system were obtained. The training dataset was constructed using historical condensate flow rate data, historical subcooling data, historical louver opening, historical vacuum pump operating data, historical system operating parameters, and historical external environmental parameters as input features, and the actual condensate flow rate and subcooling data of the corresponding time period as output labels.

[0114] Based on the training dataset, the temporal neural network model and the gradient boosting tree model were trained respectively to obtain the flow-supercooling time series prediction model and the risk classification model.

[0115] The real-time collected system operation data is synchronously input into the flow-subcooling time series prediction model and risk classification model, and outputs the predicted value of condensing flow rate, the predicted value of subcooling, and the corresponding subcooling risk prediction results within a preset time period.

[0116] If the predicted subcooling value exceeds the preset subcooling threshold, or if the risk classification model predicts that a subcooling risk will occur within a preset time period, a pre-adjustment command will be generated in advance to pre-adjust the scale of vacuum pump operation and louver opening of the corresponding cooling sector. At the same time, based on the predicted condensation flow deviation, the louver opening adjustment command will be corrected in advance to avoid the occurrence of subcooling risk and flow imbalance.

[0117] Furthermore, the two models are incrementally trained daily based on the newly added operational data, and the model parameters are updated. At the same time, the fusion weight of the two models' output results is dynamically adjusted based on the deviation between the model's prediction accuracy and the actual operational results.

[0118] The present invention also provides an NDACC system operation control device for implementing the above-mentioned NDACC system operation control method. The device includes a data acquisition module, a flow control module, a subcooling control module, and a regulation module.

[0119] The data acquisition module is used to acquire condensation flow rate data and subcooling data of each cooling unit in the NDACC system, and transmit the acquired data to the flow control module and the subcooling control module. In an optional implementation, the data acquisition module is also used to synchronously acquire the real-time back pressure value of the system, the real-time load data of the unit, the ambient temperature, wind speed and wind direction data, and transmit them to the corresponding modules.

[0120] The flow control module is used to generate louver opening adjustment commands based on condensation flow data. Through two-level adjustment between and within sectors, it controls the balanced distribution of condensation in each cooling unit.

[0121] The subcooling control module compares the subcooling data with the preset subcooling threshold, determines the subcooling risk level, generates vacuum pump activation adjustment commands and louver subcooling protection adjustment commands, and locks the execution priority of the subcooling protection adjustment to be higher than the flow balance adjustment.

[0122] The control module is used to execute the subcooling protection gradient exit logic after the subcooling data falls back to the preset subcooling threshold, release the priority of subcooling protection regulation, restore the flow balance regulation of the corresponding cooling sector, and maintain a balanced distribution of condensation in the entire system.

[0123] As an optional implementation, the device also includes a pre-control module, which is used to run the trained flow-supercooling time series prediction model and risk classification model to generate supercooling risk prediction results and pre-adjustment instructions to achieve pre-control of supercooling risk.

[0124] The present invention also provides a device, including a processor and a memory; the memory is used to store a computer program; the processor is used to execute the computer program to implement the above-described NDACC system operation control method.

[0125] Specifically, the device also includes a communication interface, input / output interfaces, and a communication bus. The processor, memory, communication interface, and input / output interfaces communicate with each other via the communication bus. The input / output interfaces are used to connect external devices, acquire operating data, and issue control commands to the actuators.

[0126] The memory may include various media capable of storing program code, such as random access memory, read-only memory, disk or optical disk. The computer program stored thereon can be loaded and executed by a processor to implement all or part of the steps of the NDACC system operation control method in this embodiment.

[0127] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the aforementioned NDACC system operation control method. This computer-readable storage medium includes various media capable of storing program code, such as a USB flash drive, portable hard drive, read-only memory, random access memory, magnetic disk, or optical disk.

[0128] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0129] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A method for controlling the operation of an NDACC system, wherein the NDACC system includes multiple cooling sectors, each cooling sector includes a cooling unit, adjustable louvers corresponding to the cooling unit, and a vacuum pump unit that is matched with the cooling sector and can be independently switched on and off, characterized in that, The control method includes the following steps: Acquire the condensate flow rate data of each cooling unit in the NDACC system, as well as the subcooling data corresponding to each cooling unit; wherein, the subcooling data includes at least one of condensate subcooling data and vacuum subcooling data; Based on the condensation flow data, the opening of the louvers corresponding to each cooling sector of the NDACC system is adjusted to ensure that the condensation of each cooling unit is balanced. The supercooling data is compared with a preset supercooling threshold. When the supercooling data exceeds the preset supercooling threshold, the vacuum pump operation scale of the corresponding cooling sector is increased first. If the supercooling data still exceeds the preset supercooling threshold after the vacuum pump operation scale reaches the maximum limit of the cooling sector, the louver opening of the corresponding cooling sector is adjusted until the supercooling data falls back to within the preset supercooling threshold. Once the subcooling data of the corresponding cooling sector falls back to the preset subcooling threshold, the louver opening adjustment of that cooling sector is restored to maintain a balance in condensation between that cooling sector and the other cooling sectors.

2. The control method according to claim 1, characterized in that, It also includes steps for preventing and controlling the risk of overcooling: Historical winter operating data of the NDACC system were obtained. The training dataset was constructed using historical condensate flow rate data, historical subcooling data, historical louver opening, historical vacuum pump operating data, historical system operating parameters, and historical external environmental parameters as input features, and the actual condensate flow rate and subcooling data of the corresponding time period as output labels. Based on the training dataset, the time-series neural network model and the gradient boosting tree model were trained respectively to obtain the flow-supercooling time-series prediction model and the risk classification model. The real-time collected system operation data is synchronously input into the flow-subcooling time series prediction model and risk classification model, and outputs the predicted value of condensing flow rate, the predicted value of subcooling, and the corresponding subcooling risk prediction results within a preset time period. If the predicted subcooling value exceeds the preset subcooling threshold, and / or the risk classification model predicts that a subcooling risk will occur within a preset time period in the future, a pre-adjustment command is generated to pre-adjust the scale of vacuum pump operation and louver opening of the corresponding cooling sector. At the same time, based on the predicted condensation flow deviation, the louver opening adjustment command is corrected in advance.

3. The control method according to claim 1, characterized in that, While acquiring condensate flow rate data and subcooling data, the real-time back pressure value of the NDACC system, the real-time load data of the unit, and the real-time temperature, wind speed, and wind direction data of the system's environment are also acquired simultaneously. The control method further includes correcting the adjustment command based on the real-time back pressure value of the system. The economic back pressure operating range of the NDACC system is preset and then corrected based on ambient temperature and unit load data. When the real-time back pressure value of the system is within the economic back pressure operating range, the control logic and control parameters of flow balance regulation and overcooling protection regulation remain unchanged. When the real-time back pressure value of the system is less than the minimum value of the economic back pressure operating range, the opening of the louvers is increased and the preset overcooling threshold is lowered in the overcooling protection adjustment. At the same time, the allowable flow deviation range of each cooling unit is reduced in the flow balance adjustment. When the real-time back pressure value of the system is greater than the maximum value of the economic back pressure operating range, the cooling sector that has triggered overcooling protection will still adjust the corresponding louver opening according to the overcooling protection adjustment logic, provided that it is not lower than the preset louver opening lockout lower limit. At the same time, the louver opening of other cooling sectors that have not triggered overcooling protection and whose overcooling data does not exceed the preset overcooling threshold will be increased, and the allowable flow deviation range of each cooling unit will be relaxed in the flow balance adjustment.

4. The control method according to claim 1, characterized in that, Adjusting the louver opening of each cooling sector of the NDACC system to balance the condensation of each cooling unit includes the following steps: The louver opening is controlled by two levels: the cooling fan section and the cooling fan section itself. Cooling fan zone hierarchy: Calculate the average condensation flow rate of all cooling fan zones. Based on the sector deviation value between the average condensation flow rate of each cooling fan zone and the average condensation flow rate of the whole system, adjust the basic opening reference value of all louvers in the corresponding cooling fan zone proportionally, and make the condensation flow rate deviation value between each cooling fan zone less than the first preset deviation threshold. Cooling sector hierarchy: Calculate the sector average of the condensation flow rate of all cooling units in a single cooling sector, and divide the cooling units in the sector into high condensation capacity units, standard condensation capacity units, and low condensation capacity units; For units with low condensation capacity, the opening adjustment step of the corresponding louver is increased proportionally to the flow deviation value; For high condensation units, the opening adjustment step of the corresponding louver is reduced proportionally to the flow deviation value; The standard condensation unit maintains the same opening reference value; During the adjustment process, the average condensation flow rate of the entire sector is kept stable until the condensation flow rate deviation of all cooling units in the sector is less than the second preset deviation threshold, and the second preset deviation threshold is less than the first preset deviation threshold.

5. The control method according to claim 1, characterized in that, The preset supercooling threshold includes a modified safety threshold, a warning threshold, and a limit threshold, with the values ​​of the three increasing sequentially. Based on the comparison between supercooling data and supercooling thresholds, supercooling risk is divided into four levels: no risk, low risk, medium risk, and high risk, each triggering different control logic: If the subcooling data is less than or equal to the safety threshold, it is determined to be risk-free, and the subcooling protection control is not triggered to maintain flow balance. If the subcooling data is greater than the safety threshold but less than or equal to the warning threshold, it is judged as low risk, and the vacuum pump unit is put into initial operation. If the subcooling data is greater than the warning threshold but less than or equal to the limit threshold, it is judged as medium risk, and the vacuum pump unit is put into medium-level operation. If the subcooling data exceeds the limit threshold, it is judged as high risk, and the vacuum pump unit is put into full-load operation; The safety threshold, warning threshold, and limit threshold are adjusted based on ambient temperature and real-time unit load data. The lower the ambient temperature and the lower the unit load, the lower the corresponding threshold is adjusted accordingly.

6. The control method according to claim 5, characterized in that, The step of prioritizing increasing the operational capacity of vacuum pumps in the corresponding cooling sector includes the following steps: When a low-risk level is triggered, the required additional pumping capacity is calculated based on the difference between the subcooling data and the safety threshold. The corresponding number of vacuum pumps are started according to the minimum activation step size, and the operating frequency of the activated vacuum pumps is adjusted synchronously to match the total pumping capacity of the vacuum pump group with the subcooling deviation value. When the medium risk level is triggered, 50% of the vacuum pumps in the cooling sector vacuum pump group will be started, and the operating frequency of the vacuum pumps in use will be increased to 70% of the rated frequency. At the same time, based on the real-time change data of subcooling, the number of vacuum pumps in use will be increased or decreased in steps of a single vacuum pump. When a high-risk level is triggered, all vacuum pumps in the vacuum pump group of that cooling sector will be started to maximize the number of vacuum pumps in operation, and the frequency of all operating vacuum pumps will be increased to the rated frequency.

7. The control method according to claim 5, characterized in that, Adjusting the opening degree of the louvers for the corresponding cooling sector includes the following steps: The cooling units within the cooling sector are divided into co-current cooling units and counter-current cooling units. The opening priority of the louvers corresponding to the co-current cooling units is set to be higher than that of the louvers corresponding to the counter-current cooling units. When a high-risk level is triggered and the corresponding cooling sector vacuum pump unit is put into full load operation, if the subcooling data still has not fallen back to the safe threshold range, the opening of the louvers corresponding to the downstream cooling unit should be reduced by a preset fixed step size. If the subcooling data still does not fall back to the safe threshold range after the louver opening of the downstream section is reduced to the preset lower limit, the louver opening of the corresponding cooling unit in the counter-current section will be reduced synchronously according to the preset step size.

8. A control device for the operation of an NDACC system, characterized in that, The apparatus for implementing the control method as described in any one of claims 1 to 7 comprises: The data acquisition module is used to acquire condensation flow rate data and subcooling data of each cooling unit in the NDACC system; The flow control module is used to generate louver opening adjustment commands based on condensation flow data to control the condensation of each cooling unit to be balanced. The subcooling control module is used to compare the subcooling data with the preset subcooling threshold and generate vacuum pump activation adjustment commands and louver subcooling protection adjustment commands. The control module is used to restore the flow regulation of the corresponding cooling sector after the subcooling data falls back to within the subcooling threshold.

9. A device, characterized in that, Including processor and memory; The memory is used to store computer programs; When the processor executes the computer program, it implements the control method as described in any one of claims 1 to 7.

10. 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 control method as described in any one of claims 1 to 7.

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