Adjustable speed linkage control method and system for air-cooled flush track

Abstract

The application discloses a kind of adjustable speed linkage control method and system of air-cooled flushing track, belong to the technical field of automatic cleaning control of direct air cooling system of thermal power plant. Among them, the control system includes data acquisition unit, storage unit, working condition determination unit, linkage control algorithm unit, execution output unit and monitoring feedback unit, data acquisition unit is connected with storage unit, working condition determination unit, linkage control algorithm unit are both connected with storage unit two-way communication, execution output unit is connected with storage unit, monitoring feedback unit is respectively connected with execution output unit, storage unit communication connection.This application realizes the intelligent speed regulation and water volume dynamic linkage of smooth deceleration in curved track, low-speed cleaning in heavy pollution area and large wind speed suppression by fusing track curvature, adaptive speed model of dirt thermal resistance and real-time wind speed, using coupled water pump frequency control model;Solve the technical problems of walking speed and flushing water volume fragmentation, lack of track geometry and environmental adaptive capability.

Description

Technical Field

[0001] This invention relates to the field of automatic cleaning control technology for direct air-cooled systems in thermal power plants, specifically to an adjustable speed linkage control method and system for air-cooled flushing tracks. Background Technology

[0002] In direct air-cooled systems of thermal power plants, air-cooled condensers rely on axial flow fans to force ventilation and cool the turbine exhaust. Since power plants are often built in windy and sandy areas, particulate matter in the air easily accumulates on the surface of the heat exchange fins, forming varying degrees of fouling. Fouling on the fins increases heat transfer resistance, leading to a decrease in unit vacuum, increased coal consumption, and negatively impacting the economic operation of the power plant. Currently, the industry commonly uses a track-mounted automatic cleaning trolley suspended from the top of the air-cooled island for periodic cleaning. Existing control technology typically employs an open-loop control method of "constant speed travel + constant frequency water pump," which has the following drawbacks:

[0003] 1. Due to the different thickness of dust accumulation on the fins, if the "constant speed walking + constant frequency water pump" mode is used for cleaning, some fins will not be completely cleaned of dust accumulation. At the same time, more water will be wasted when cleaning fins with less dust accumulation.

[0004] 2. Because the speed of the cleaning trolley is not linked to the water pump flow rate, if the cleaning trolley runs at a low speed, the water volume will be too large, resulting in waste; if the cleaning trolley runs at a high speed, the water volume will be too small, affecting the cleaning effect.

[0005] 3. When the cleaning trolley passes through a curve at its rated speed, it is prone to impact, which affects the stability of the equipment operation; when the ambient wind speed is too high, the water jet is prone to deflection, reducing the rinsing effect. Summary of the Invention

[0006] To address this, the present invention integrates an adaptive speed model that incorporates track curvature, dirt thermal resistance, and real-time wind speed, and employs a coupled water pump frequency control model to achieve intelligent speed regulation and dynamic water volume linkage for smooth deceleration on curves, low-speed cleaning in heavily soiled areas, and wind-induced speed suppression. This solves the technical problems of disconnect between walking speed and flushing water volume, and the lack of track geometry and environmental adaptability.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] An adjustable speed linkage control method and system for an air-cooled flushing track, comprising the following steps:

[0009] (S10) Data Acquisition: Acquire spatial location, track curvature, dirt thermal resistance, equipment status, and environmental perception; among which, spatial location includes the current precise position coordinates L of the cleaning trolley and the travel direction angle θ at the current position L of the cleaning trolley. dirThe orbital curvature includes the orbital curvature radius r(L) at the current position, and the fouling thermal resistance includes the fouling thermal resistance R of the air-cooled radiator surface corresponding to position L. f (L), Equipment status includes pipeline water pressure P and actual flow rate Q. act Environmental perception includes real-time wind speed v m and real-time wind direction θ m ;

[0010] (S20) Based on the data collected in step S10, a thermal performance judgment is made. The specific operation is as follows:

[0011] During long-term operation, the finned tube bundles of air-cooled radiators are affected by the deposition of particulate matter in the air, and a fouling layer gradually forms on their surface. The presence of this fouling layer directly increases the heat transfer resistance of the finned tube bundle, i.e., the fouling thermal resistance R. f (L) A thermal resistance higher than the cleanliness baseline indicates heavy dust accumulation and poor heat exchange, making it difficult to remove scale during constant-speed trolley flushing, thus reducing unit vacuum and operating economy. Therefore, the trolley speed needs to be adjusted according to the thermal resistance of the dirt: reduce the speed and extend the flushing time in heavily soiled areas, and maintain the normal speed in clean areas. The correction factor ω1 is applied only when the thermal resistance is higher than the cleanliness baseline R by the positive part operator. f0 It takes effect immediately; the weighting coefficient β has a range of 1.0 < β < 3.0, which can both amplify the speed adjustment range caused by dust accumulation and prevent large fluctuations in vehicle speed.

[0012] Determine the thermal resistance R of dirt on the surface of an air-cooled radiator f (L) Whether the thermal resistance threshold is exceeded. If it is exceeded, the travel speed of the cleaning trolley needs to be adjusted; otherwise, the travel speed remains unchanged. The adjusted travel speed of the cleaning trolley is calculated using the following formula:

[0013] V final (L) = V max ×ω1;

[0014] In the formula, V max The maximum design speed for the cleaning trolley is given; ω1 is a correction factor related to the thermal resistance of the dirt, calculated using the following formula:

[0015] ω1=[1+β(R f (L)-R f0 ) + ] -1 ;

[0016] In the formula, R f0 For the clean reference thermal resistance, (x) + β is the positive part operator, and β is the weighting coefficient of the surface fouling thermal resistance of the air-cooled radiator, with a value range of 1.0 < β < 3.0;

[0017] (S30) Based on the real-time target walking speed V calculated in step S20 final (L) The pump operating frequency f is calculated using a velocity-pressure-flow coupled pump frequency control model. ref The pump frequency control model is calculated using the following formula:

[0018] ;

[0019] In the formula, f0 is the fundamental frequency of the water pump; K p W is the PID proportional coefficient; s The flushing water volume is designed per unit area; D is the effective flushing coverage width; V final (L) represents the real-time target speed of the cleaning cart at position L; Q act P represents the actual flow rate of the pipeline in real time; P represents the real-time water pressure; P set The rated nozzle pressure is denoted by m; m is the nozzle flow characteristic index.

[0020] (S40) Output and Execution of Results: The water pump operating frequency f calculated in step S30 is output and executed. ref The output is sent to the frequency converter of the flushing water pump for execution.

[0021] In the above control method, in step S20, a geometric judgment is made based on the thermal judgment, and the specific operation is as follows:

[0022] The air-cooled washing track includes straight sections and curves. When the trolley travels at high speed through small-radius curves, it generates significant centrifugal force, leading to slippage, wear, derailment, and damage to the track support structure. The smaller the curve curvature, the lower the permissible speed. Therefore, the trolley speed is corrected based on the track curvature radius r(L), with automatic speed reduction on sharp curves to minimize centrifugal force. The geometric correction factor ω2 squares the inverse of the curvature, resulting in a significant speed reduction only on small-radius sharp curves, while having almost no impact on speed on straight sections and gentle curves.

[0023] If the radius of curvature r(L) of the track is greater than the curve determination threshold r set If the comparison results show that the cleaning trolley is running in a straight line, its speed will not be adjusted. Conversely, if the comparison results show that the cleaning trolley is running on a curve, its speed will be adjusted. The adjusted speed is calculated using the following formula:

[0024] V final =V max ×ω1×ω2;

[0025] In the formula, ω2 is a geometric correction factor related to the orbital curvature, which is calculated using the following formula:

[0026] ;

[0027] In the formula, α is the orbital curvature weighting coefficient, and its value ranges from 0.2 to 0.8.

[0028] The above control method, in step S20, performs an environmental judgment based on thermal and geometric judgments, as follows:

[0029] The air-cooled island is open and unobstructed, and strong winds can cause the washing water jet to deviate and atomization loss to increase, resulting in poor cleaning effect. Therefore, it is necessary to adjust the vehicle speed according to the real-time wind speed. In strong winds, the speed is reduced to prolong the jet action time and make up for the loss of effective water volume. The environmental correction factor ω3 achieves non-linear wind speed adjustment through the arctangent function, and the speed reduction magnitude tends to be stable in high wind speeds. Combined with the cosine value of the wind direction angle, the speed is greatly adjusted when the wind is tailwind, while the wind speed correction is weakened or canceled when the wind is crosswind or headwind, realizing adaptive speed control based on wind direction.

[0030] If the real-time wind speed is v m greater than the wind speed threshold v set If the wind direction is too high, the speed of the cleaning cart needs to be adjusted based on the angle between the wind direction and the direction of travel of the cleaning cart; the adjusted speed of the cleaning cart is calculated using the following formula.

[0031] V final =V max ×ω1×ω2×ω3;

[0032] In the formula, ω3 is an environmental correction factor related to real-time wind speed and direction, which is calculated by the following formula:

[0033] ;

[0034] In the formula, v m V0 is the real-time wind speed, θ is the angle between the real-time wind direction and the direction of travel of the cleaning trolley, and γ is the environmental wind load weighting coefficient, with a value range of 0.1 < γ < 0.5.

[0035] The above control method, wherein the curve determination threshold r set The value range is 2.0m < r set <3.5m.

[0036] The above control method, wherein the real-time wind direction θ m The angle θ between the direction of travel of the cleaning trolley and the direction of travel is determined by the following formula:

[0037] θ=|θ m -θ dir |;

[0038] In the formula, θ dirTo determine the direction angle of travel at the current position L of the cleaning trolley; when θ≤90°, it is determined that the wind direction angle is within the influence range, and the wind load suppression strategy is activated; when θ>90°, it is determined that the wind direction angle is not within the influence range, and the wind load suppression strategy is not activated.

[0039] The above control method, wherein the wind speed threshold v set =6m / s, and the value range of the characteristic reference wind speed v0 is 2m / s < v0 < 5m / s.

[0040] The above control method, in step S40, also includes exception handling and safety protection:

[0041] (1) Sensor fault handling: When the signal of the anemometer, pressure transmitter or encoder is lost, the PLC will automatically lock the corresponding variable to the preset safety value and trigger an audible and visual alarm;

[0042] (2) Communication timeout handling: When the communication interruption between the PLC and the frequency converter exceeds 500ms, the PLC immediately outputs a stop command;

[0043] (3) Low water pressure protection: When P < 0.3 × P set After 5 seconds, immediately stop the cleaning cart from moving and turn off the flushing water pump.

[0044] The measured reference thermal resistance R of the clean finned tube bundle surface under the clean state described in the above control method. f0 =0.00029m²·K / W.

[0045] The above control method further includes a closed-loop feedback step: after step S40 is completed, the process returns to step S10 to re-execute data acquisition in order to continuously update the control commands and form a closed-loop control.

[0046] The adjustable speed linkage control system for the air-cooled flushing track includes:

[0047] The data acquisition unit is used to perform the data acquisition described in step S10: acquiring spatial location, track curvature, dirt thermal resistance, equipment status, and environmental perception.

[0048] The working condition determination unit is used to perform the data analysis and working condition determination described in step S20: perform working condition threshold analysis and logical discrimination on the data collected by the data acquisition unit, and calculate the real-time target walking speed step by step in the order of thermal correction factor ω1 having the highest priority, geometric correction factor ω2 having the second highest priority, and environmental correction factor ω3 having the lowest priority.

[0049] The linkage control algorithm unit is used to execute the adjustable speed linkage control described in step S30: based on the final target speed V calculated by the working condition determination unit. final(L), the pump operating frequency f is calculated using a pump frequency control model. ref ;

[0050] The execution output unit is used to perform the result output and execution described in step S40: outputting the target walking speed V calculated by the linkage control algorithm unit. final (L) is sent to the walking motor frequency converter, and the calculated water pump operating frequency f is used. ref The output is sent to the frequency converter of the flushing water pump for execution;

[0051] The storage unit is used to store the data collected by the data acquisition unit, the processing results of the working condition determination unit, and the calculation results of the linkage control algorithm unit;

[0052] The monitoring and feedback unit is used to collect the execution status of the execution output unit and feed it back to the storage unit;

[0053] The data acquisition unit is connected to the storage unit, the working condition judgment unit and the linkage control algorithm unit are both connected to the storage unit bidirectionally, the execution output unit is connected to the storage unit, and the monitoring feedback unit is connected to both the execution output unit and the storage unit.

[0054] The technical solution of the present invention achieves the following beneficial technical effects:

[0055] 1. By integrating track curvature, dirt thermal resistance and real-time wind speed into an adaptive speed model, intelligent speed regulation is achieved, which enables smooth deceleration on curves, low-speed cleaning in heavily soiled areas and speed suppression in windy weather. This solves the problems of poor flushing effect, easy derailment and water waste in constant speed walking mode. At the same time, through the speed-pressure-flow coupled water pump frequency control model, dynamic linkage matching between walking speed and flushing water volume is achieved.

[0056] 2. By monitoring and feedback the execution status to form a closed-loop control, and integrating a three-level safety protection mechanism of sensor fault lockout, communication timeout shutdown and low water pressure, the system achieves full-link closed-loop control and abnormal self-protection, improving the safety and reliability of system operation. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the working principle of the adjustable speed linkage control system for the hollow cold washing track in this invention.

[0058] Figure 2 This is a flowchart of the adjustable speed linkage control method for the hollow cold rinsing track in this invention. Detailed Implementation

[0059] The present invention will be further explained below with reference to examples.

[0060] like Figure 1As shown, the adjustable speed linkage control system for the air-cooled rinsing track in this invention includes a data acquisition unit, a storage unit, a working condition determination unit, a linkage control algorithm unit, an execution output unit, and a monitoring feedback unit. The data acquisition unit is communicatively connected to the storage unit, the working condition determination unit and the linkage control algorithm unit are bidirectionally communicatively connected to the storage unit, the execution output unit is communicatively connected to the storage unit, and the monitoring feedback unit is communicatively connected to both the execution output unit and the storage unit.

[0061] In this invention, the adjustable speed linkage control of the washing and cleaning trolley will be described in detail below.

[0062] Specifically, such as Figure 2 As shown, adjustable speed linkage control of the air-cooled rinsing track is achieved through the following steps:

[0063] (S10) Data Acquisition

[0064] The distributed sensor network performs synchronous acquisition of multi-dimensional raw signals, including spatial location, track curvature, dirt thermal resistance, equipment status, and environmental perception. The spatial location includes the precise coordinates L of the cleaning cart's current position and the travel direction angle θ at position L. dir The orbital curvature includes the orbital curvature radius r(L) at the current position, and the fouling thermal resistance includes the fouling thermal resistance R of the air-cooled radiator surface corresponding to position L. f (L), Equipment status includes pipeline water pressure P and actual flow rate Q. act Environmental perception includes real-time wind speed v m and real-time wind direction θ m ;

[0065] In this embodiment, the position coordinate L is obtained by real-time detection by the encoder, and the track curvature radius r(L) is obtained by mapping the track design parameters to the current position L; the thermal resistance R of the dirt on the surface of the air-cooled radiator is... f (L) The thermal resistance is obtained in real time by an online thermal resistance detection device. This device calculates the fouling thermal resistance in real time based on parameters such as the inlet and outlet air temperature, air volume, and heat exchange area of ​​the radiator, using the heat transfer equation. The larger the value, the more serious the dust accumulation on the fin surface, and the longer the required rinsing and residence time. The pipeline water pressure P is collected in real time by a pressure transmitter, and the actual flow rate Q... act Data is collected in real time by a flow meter; real-time ambient wind speed v m and real-time wind direction θ m Data is collected in real time by an anemometer;

[0066] (S20) Data analysis and operating condition determination

[0067] Perform operating condition threshold analysis and logical judgment on the data collected in step S10;

[0068] (S21) Thermal performance determination

[0069] During long-term operation, the finned tube bundles of air-cooled radiators are affected by the deposition of particulate matter in the air, and a fouling layer gradually forms on their surface. The presence of this fouling layer directly increases the heat transfer resistance of the finned tube bundle, i.e., the fouling thermal resistance R. f (L); When the fouling thermal resistance increases, it means that a thicker fouling layer has accumulated on the fin surface in that area, significantly reducing heat exchange efficiency. Conventional flushing cannot effectively remove the fouling, affecting the unit's vacuum level and operating economy; therefore, it is necessary to determine the appropriate fouling thermal resistance R. f The measured value of (L) is used to differentiate the walking speed of the cleaning cart;

[0070] Based on the thermal resistance R of the dirt on the surface of the air-cooled radiator obtained in step S10 f (L) Perform thermal performance assessment:

[0071] Determine the thermal resistance R of dirt on the surface of an air-cooled radiator f (L) Is it greater than the cleaning reference thermal resistance R? f0 If R f (L)>R f0 If the positive operator is activated, it indicates that there is dirt accumulation on the fin surface, and the speed of the cleaning trolley needs to be adjusted; otherwise, the speed of the cleaning trolley remains unchanged. When speed adjustment is required, the cleaning trolley speed after dirt correction is calculated using the following formula:

[0072] V final (L) = V max ×ω1;

[0073] In the formula, V max The maximum design speed for the cleaning trolley is given; ω1 is a correction factor related to the thermal resistance of the dirt, calculated using the following formula:

[0074] ω1=[1+β(R f (L)-R f0 ) + ] -1 ;

[0075] In the formula, R f0 As a baseline thermal resistance for cleaning, the measured baseline thermal resistance of the clean finned tube bundle surface in this embodiment is Rf0 = 0.00029 m²·K / W; (x) + β is the positive part operator, meaning it takes a value only when the value inside the parentheses is positive, otherwise it takes zero; β is the weighting coefficient of the thermal resistance of dirt on the surface of the air-cooled radiator, and its value range is 1.0 < β < 3.0;

[0076] In this embodiment, β is set to 2.0; a value greater than 1.0 ensures that the thermal resistance difference is effectively amplified and reflected in the speed adjustment, while a value less than 3.0 avoids drastic speed fluctuations caused by over-correction; the fouling thermal resistance R... f The larger (L) is, the smaller ω1 is, the greater the speed reduction, and the longer the rinsing residence time, to ensure that heavily soiled areas receive sufficient cleaning time; when R f (L)≤R f0 At that time, ω1=1, and no dirt compensation correction is applied to the walking speed;

[0077] (S22) Geometric determination

[0078] Based on the thermal judgment in step S21, a geometric judgment is further introduced. When the air-cooled flushing track is laid on top of the air-cooled island, it inevitably includes straight sections and curved sections to adapt to the equipment layout. When the cleaning trolley passes through a curved section with a small track curvature radius at a relatively high conventional travel speed, the cleaning trolley will be subjected to a large centrifugal force, posing a risk of lateral slippage or even derailment. At the same time, the impact load when passing through the curve will also cause fatigue damage to the track support structure. The smaller the track curvature radius r(L), the sharper the curve, the greater the centrifugal acceleration, and the lower the required safe passing speed. Therefore, it is necessary to make geometric constraint adjustments to the travel speed of the cleaning trolley based on the track curvature radius r(L) at the current position, and actively reduce the travel speed in sharp curves to reduce centrifugal force.

[0079] Based on the track curvature radius r(L) obtained in step S10 and the curve determination threshold r set The comparison is made, where the curve determination threshold r is... set The value range is 2.0m < r set <3.5m:

[0080] If the radius of curvature r(L) of the track is greater than the curve determination threshold r set If the direction of travel is straight, the cleaning trolley is determined to be in a straight-line running state, and no speed adjustment is made for the trolley; otherwise, the cleaning trolley is determined to be in a curved running state, and its speed needs to be adjusted. The geometrically corrected speed of the cleaning trolley is calculated using the following formula:

[0081] V final =V max ×ω1×ω2;

[0082] In the formula, ω2 is a geometric correction factor related to the orbital curvature, which is calculated using the following formula:

[0083] ;

[0084] In the formula, α is the orbital curvature weighting coefficient, and its value ranges from 0.2 to 0.8.

[0085] In this embodiment, α is set to 0.5; the expression for ω2 is the square of the reciprocal of the radius of curvature r(L), which results in a significant speed reduction effect on small-radius curves (large curvature), while the speed reduction effect on large-radius curves (small curvature) decays rapidly, achieving selective control that effectively reduces speed only on sharp curves; in the geometric correction activation state, the smaller r(L), the smaller ω2, and the greater the speed reduction, ensuring that the cleaning trolley passes through the curve area at a safe speed and avoiding derailment due to excessive centrifugal force; when r(L) > r set At this time, the geometric correction factor ω2 approaches 1 and has no substantial effect on walking speed;

[0086] (S23) Environmental assessment

[0087] Based on the thermal determination in step S21 and the geometric determination in step S22, an environmental determination is further introduced. Air-cooled islands are typically located in open areas outside the main power plant building, without tall buildings obstructing the view. When the ambient wind speed is high, the high-pressure water jet is deflected by lateral aerodynamic forces after being ejected from the nozzle. Part of the water jet deviates from the target fin surface, reducing the effective impact water volume. Simultaneously, the water jet fragmentation intensifies, atomization loss increases, and the cleaning effect significantly decreases. Therefore, it is necessary to consider the real-time wind speed v. m Environmentally adaptive adjustments were made to the walking speed of the cleaning trolley: the walking speed was actively reduced under strong wind conditions to increase the jet action time per unit area and compensate for the loss of effective rinsing water volume caused by jet deflection and atomization loss.

[0088] Based on the real-time environmental wind speed v obtained in step S10 m With wind speed threshold v set Compare and combine with real-time wind direction θ m The angle between the wind direction and the direction of travel of the cleaning trolley adjusts the speed of the cleaning trolley; specifically, the real-time wind direction θ m The angle θ between the wind speed and the direction of travel of the cleaning trolley is determined by the following formula, where the wind speed threshold v set =6m / s:

[0089] θ=|θ m -θ dir |;

[0090] In the formula, θ dir The direction angle of travel at the current position L of the cleaning trolley is determined. When θ ≤ 90°, the wind direction angle is considered to be within the influence range, and the wind load suppression strategy is activated. When θ > 90°, the wind direction angle is considered to be outside the influence range, and the wind load has a negligible impact on the washing effect, so the wind load suppression strategy is not activated. If v m >v setWhen θ≤90°, it is determined to be in wind-resistant mode, and the wind load suppression strategy is activated to adjust the travel speed of the cleaning trolley. The travel speed of the cleaning trolley after environmental correction is calculated by the following formula:

[0091] V final =V max ×ω1×ω2×ω3;

[0092] In the formula, ω3 is an environmental correction factor related to real-time wind speed and direction, which is calculated by the following formula:

[0093] ;

[0094] In the formula, v m θ is the real-time wind speed; v0 is the characteristic reference wind speed, with a value range of 2m / s < v0 < 5m / s; θ is the angle between the real-time wind direction and the direction of travel of the cleaning trolley; γ is the environmental wind load weighting coefficient, with a value range of 0.1 < γ < 0.5.

[0095] In this embodiment, γ is set to 0.3. Under the activated wind load suppression strategy (θ≤90°), the wind speed v m The larger the angle θ between the wind direction and the direction of travel, the smaller ω3, and the greater the speed reduction, in order to compensate for the loss of washing force caused by wind deflection; if v m ≤v set If θ > 90°, it is determined to be the normal mode, and the wind load suppression strategy is not activated, ω3 = 1;

[0096] (S30) Pump Frequency Control Model

[0097] The final target walking speed V is obtained after comprehensive correction by thermal correction factor ω1, geometric correction factor ω2 and environmental correction factor ω3 in step S20. final (L) The pump operating frequency f is calculated using a velocity-pressure-flow coupled pump frequency control model. ref The pump frequency control model is calculated using the following formula:

[0098] ;

[0099] In the formula, f0 is the fundamental frequency of the water pump; K p W is the PID proportional coefficient; s The flushing water volume is designed per unit area; D is the effective flushing coverage width; V final (L) represents the real-time target speed of the cleaning cart at position L; Q act P represents the actual flow rate of the pipeline in real time; P represents the real-time water pressure; P set The rated nozzle pressure is denoted by m; m is the nozzle flow characteristic index.

[0100] In this embodiment, the water pump's base frequency f0 = 30Hz, and the PID proportional coefficient K p =0.85 (dimensions: Hz / (m)) 3 / s), Design flushing water volume per unit area W s =2.5L / m 2 The effective coverage width for flushing is D=1.2m, and the rated nozzle pressure is P. set =8.0MPa, nozzle flow characteristic index m=0.5; after substituting the above parameters into the model, the pump operating frequency f ref It fluctuates within a small range around the fundamental frequency of 30Hz to achieve a precise match between walking speed and flushing water volume;

[0101] (S40) Result Output and Execution

[0102] The control command calculated in step S30 is converted into the actual action of the physical device. The PLC calculates the adaptive speed command V based on the adaptive speed command V calculated in step S20. final (L) Send a speed command to the frequency converter of the walking motor to drive the motor and adjust the output speed; at the same time, send the frequency command f calculated in step S30 to the frequency converter. ref The output is sent to the frequency converter of the flushing water pump to adjust the pump motor speed, so that the actual water supply flow rate follows the theoretical water demand in real time. Specifically, this includes:

[0103] (S41) The walking motor executes: The PLC executes the adaptive speed command V calculated in step S20. final (L) sends speed commands to the walking motor inverter via 4-20mA analog signal or fieldbus communication to drive the motor and adjust the output speed.

[0104] In this embodiment, 4mA corresponds to zero speed, 20mA corresponds to the maximum design speed Vmax, and the middle one corresponds linearly, with a broken wire detection function.

[0105] (S42) Flushing water pump execution: The PLC will execute the frequency command f calculated in step S30. ref The output is sent to the frequency converter of the flushing water pump to adjust the speed of the water pump motor, so that the actual water supply flow rate follows the theoretical water demand in real time. The execution of the walking motor and the execution of the flushing water pump form a "speed-flow" linkage mechanism, and the water pump frequency is adjusted synchronously when the speed of the cleaning trolley changes.

[0106] (S43) Monitoring and Data Recording: The host computer monitoring system (SCADA / HMI) displays the real-time position L and operating status of the cleaning trolley, real-time speed and flow curves, water pressure P, and wind speed v. m and the thermal resistance of dirt R f (L) and other parameters;

[0107] (S44) Abnormal handling and safety protection

[0108] (1) Sensor failure: When the signal of the anemometer, pressure transmitter or encoder is lost, the PLC will automatically lock the corresponding variable to the preset safety value and trigger an audible and visual alarm;

[0109] (2) Communication timeout: If the communication interruption between the PLC and the frequency converter exceeds 500ms, the PLC will immediately output a stop command;

[0110] (3) Low water pressure: When P < 0.3 × P set If the cycle continues for 5 seconds, immediately stop the cleaning trolley from moving and turn off the water pump;

[0111] After execution, return to step S10 to form a closed-loop control.

[0112] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this application.

Claims

1. A method and system for adjustable speed linkage control of an air-cooled flushing track, characterized in that, Control can be achieved through the following steps: (S10) Data Acquisition: Acquire spatial location, track curvature, dirt thermal resistance, equipment status, and environmental perception; among which, spatial location includes the current precise position coordinates L of the cleaning trolley and the travel direction angle θ at the current position L of the cleaning trolley. dir The orbital curvature includes the orbital curvature radius r(L) at the current position, and the fouling thermal resistance includes the fouling thermal resistance R of the air-cooled radiator surface corresponding to position L. f (L), Equipment status includes pipeline water pressure P and actual flow rate Q. act Environmental perception includes real-time wind speed v m and real-time wind direction θ m ; (S20) Based on the data collected in step S10, a thermal performance judgment is made. The specific operation is as follows: Determine the thermal resistance R of dirt on the surface of an air-cooled radiator f (L) Whether the thermal resistance threshold is exceeded. If it is exceeded, the travel speed of the cleaning trolley needs to be adjusted; otherwise, the travel speed remains unchanged. The adjusted travel speed of the cleaning trolley is calculated using the following formula: V final (L)=V max ×ω1; In the formula, V max The maximum design speed for the cleaning trolley is given; ω1 is a correction factor related to the thermal resistance of the dirt, calculated using the following formula: ω1=[1+β(R f (L)-R f0 ) + ] -1 ; In the formula, R f0 For the clean reference thermal resistance, (x) + β is the positive part operator, and β is the weighting coefficient of the surface fouling thermal resistance of the air-cooled radiator, with a value range of 1.0 < β < 3.0; (S30) Based on the real-time target walking speed V calculated in step S20 final (L) The pump operating frequency f is calculated using a velocity-pressure-flow coupled pump frequency control model. ref The pump frequency control model is calculated using the following formula: ； In the formula, f0 is the fundamental frequency of the water pump; K p W is the PID proportional coefficient; s The flushing water volume is designed per unit area; D is the effective flushing coverage width; V final (L) represents the real-time target speed of the cleaning cart at position L; Q act P represents the actual flow rate of the pipeline in real time; P represents the real-time water pressure; P set The rated nozzle pressure is denoted by m; m is the nozzle flow characteristic index. (S40) Output and Execution of Results: The water pump operating frequency f calculated in step S30 is output and executed. ref The output is sent to the frequency converter of the flushing water pump for execution.

2. The adjustable speed linkage control method and system for an air-cooled flushing track according to claim 1, characterized in that, In step S20, a geometric judgment is made based on the thermal judgment, and the specific operation is as follows: If the radius of curvature r(L) of the track is greater than the curve determination threshold r set If the direction of travel is straight, the cleaning cart is determined to be in a straight line, and its speed is not adjusted. Conversely, if the direction of travel is curved, the cleaning cart is determined to be in a curved line, and its speed is adjusted. The adjusted speed is calculated using the following formula: V final =V max ×ω1×ω2; In the formula, ω2 is a geometric correction factor related to the orbital curvature, which is calculated using the following formula: ； In the formula, α is the orbital curvature weighting coefficient, and its value ranges from 0.2 to 0.

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3. The adjustable speed linkage control method and system for an air-cooled flushing track according to claim 2, characterized in that, In step S20, an environmental assessment is performed based on the thermal and geometric assessments. The specific steps are as follows: If the real-time wind speed is v m greater than the wind speed threshold v set If the wind direction is too high, the speed of the cleaning cart needs to be adjusted based on the angle between the wind direction and the direction of travel of the cleaning cart; the adjusted speed of the cleaning cart is calculated using the following formula. V final =V max ×ω1×ω2×ω3; In the formula, ω3 is an environmental correction factor related to real-time wind speed and direction, which is calculated by the following formula: ； In the formula, v m V0 is the real-time wind speed, θ is the angle between the real-time wind direction and the direction of travel of the cleaning trolley, and γ is the environmental wind load weighting coefficient, with a value range of 0.1 < γ < 0.

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4. The adjustable speed linkage control method and system for an air-cooled flushing track according to claim 3, characterized in that, The curve determination threshold r set The value range is 2.0m < r set <3.5m.

5. The adjustable speed linkage control method and system for an air-cooled flushing track according to claim 3, characterized in that, The real-time wind direction θ m The angle θ between the direction of travel of the cleaning trolley and the direction of travel is determined by the following formula: θ=|θ m -θ dir |; In the formula, θ m Real-time wind direction angle; θ dir To determine the direction angle of travel at the current position L of the cleaning trolley; when θ≤90°, it is determined that the wind direction angle is within the influence range, and the wind load suppression strategy is activated; when θ>90°, it is determined that the wind direction angle is not within the influence range, and the wind load suppression strategy is not activated.

6. The adjustable speed linkage control method and system for an air-cooled flushing track according to claim 3, characterized in that, The wind speed threshold v set =6m / s, and the value range of the characteristic reference wind speed v0 is 2m / s < v0 < 5m / s.

7. The adjustable speed linkage control method and system for an air-cooled flushing track according to claim 1, characterized in that, Step S40 also includes exception handling and security protection: (1) Sensor fault handling: When the signal of the anemometer, pressure transmitter or encoder is lost, the PLC will automatically lock the corresponding variable to the preset safety value and trigger an audible and visual alarm; (2) Communication timeout handling: When the communication interruption between the PLC and the frequency converter exceeds 500ms, the PLC immediately outputs a stop command; (3) Low water pressure protection: When P < 0.3 × P set After 5 seconds, immediately stop the cleaning cart from moving and turn off the flushing water pump.

8. The adjustable speed linkage control method and system for an air-cooled flushing track according to claim 1, characterized in that, The measured reference thermal resistance R of the clean finned tube bundle surface in a clean state. f0 =0.00029m²·K / W.

9. The adjustable speed linkage control method and system for an air-cooled flushing track according to claim 1, characterized in that, The method also includes a closed-loop feedback step: after step S40 is completed, the process returns to step S10 to re-execute data acquisition in order to continuously update the control commands and form a closed-loop control.

10. A speed-adjustable linkage control system for an air-cooled flushing track, characterized in that, include: The data acquisition unit is used to perform the data acquisition described in step S10: acquiring spatial location, track curvature, dirt thermal resistance, equipment status, and environmental perception. The working condition determination unit is used to perform the data analysis and working condition determination described in step S20: perform working condition threshold analysis and logical discrimination on the data collected by the data acquisition unit, and calculate the real-time target walking speed step by step in the order of thermal correction factor ω1 having the highest priority, geometric correction factor ω2 having the second highest priority, and environmental correction factor ω3 having the lowest priority. The linkage control algorithm unit is used to execute the adjustable speed linkage control described in step S30: based on the final target speed V calculated by the working condition determination unit. final (L), the pump operating frequency f is calculated using a pump frequency control model. ref ; The execution output unit is used to perform the result output and execution described in step S40: outputting the target walking speed V calculated by the linkage control algorithm unit. final (L) is sent to the walking motor frequency converter, and the calculated water pump operating frequency f is used. ref The output is sent to the frequency converter of the flushing water pump for execution; The storage unit is used to store the data collected by the data acquisition unit, the processing results of the working condition determination unit, and the calculation results of the linkage control algorithm unit; The monitoring and feedback unit is used to collect the execution status of the execution output unit and feed it back to the storage unit; The data acquisition unit is connected to the storage unit, the working condition judgment unit and the linkage control algorithm unit are both connected to the storage unit bidirectionally, the execution output unit is connected to the storage unit, and the monitoring feedback unit is connected to both the execution output unit and the storage unit.

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