A temperature control driving method for a distribution box circulating water cooling system

Abstract

The application provides a temperature control driving method for a power distribution box circulating water cooling system, comprising: obtaining the driving frequency of the water pump of the power distribution box circulating water cooling system, processing the driving frequency through fast Fourier transform to obtain the periodic variation amplitude of the cooling water flow; collecting the temperatures at the top air outlet and the bottom air inlet of the power distribution box body and calculating the vertical temperature difference, marking the height section of the power distribution box body whose vertical temperature difference exceeds the design heat dissipation limit value as a non-uniform heat dissipation height section; according to the heat exchange instability region, calling the stability boundary of the joint vibration bearing of the corresponding pipeline section, searching for the driving frequency set falling into the safety threshold interval in the amplitude corresponding relationship table, and determining the water pump driving frequency switching node; generating a variable frequency regulation instruction according to the water pump driving frequency switching node, driving the water pump to run, and making the cooling water flow maintain a steady laminar flow state in the heat exchange instability region.

Description

Technical Field

[0001] This invention relates to the field of information technology, and in particular to a temperature control drive method for a circulating water cooling system in a distribution box. Background Technology

[0002] As a key device in the power system for power distribution and circuit control, the distribution box integrates circuit breakers, busbars, and conductive circuits. During continuous operation, it generates heat due to resistance losses. The distribution box is filled with wires, switches, and copper busbars, all of which generate heat as long as they are powered on. With increasingly powerful equipment and increasingly crammed internal components, fans alone are no longer sufficient. Therefore, many distribution boxes utilize circulating water cooling for temperature reduction, similar to water cooling in a computer, providing good and even heat dissipation. Current temperature control logic is relatively straightforward: when a temperature rise is detected, the speed of the circulating water pump is increased, attempting to remove heat by increasing the coolant flow. However, the limited space inside the distribution box necessitates numerous bends and joints in the cooling pipes to reach the heat-generating components. While this strategy focuses on lowering the overall temperature level, its adjustment method does not fully consider the impact of pipe structure characteristics on flow stability, especially with rapid speed regulation under variable frequency drives. On the one hand, when the pump set frequently adjusts its speed or operates at high speed, the cooling medium experiences severe hydraulic impacts on the outside of bends and joint gaps. The repeated impact force acts on the weakest connection, inducing continuous micro-mechanical vibrations. Although the amplitude of such vibrations is extremely small and imperceptible to the naked eye, its long-term mechanism is similar to repeatedly shaking a not-fully-tightened bottle cap—the mating surfaces constantly undergo minute relative displacements and re-contacts, causing microscopic wear to gradually occur on the originally tightly fitted sealing rings or metal end faces, eventually forming gaps. Furthermore, the misalignment of joints caused by vibration can create steps or depressions inside the pipe, disrupting the original structure of the flow channel. Interfaces that were originally flush with the inner wall of the pipe become protruding or recessed into the flow channel due to misalignment, creating abrupt changes in the flow direction. When water flows through these raised steps, recessed gaps, and misaligned interfaces, the flow cannot maintain a stable laminar state; the liquid separates behind the steps, forming local backflow zones and vortices. Due to the dense piping and numerous joints within the distribution box, before the vortex generated by the first joint has disappeared, water flows into another downstream joint area, where new disturbances are superimposed on the residual disturbances, causing vortices and backflows to accumulate and interfere with each other. As a result, the flow state inside the pipe changes from orderly and gentle flow to violent turbulence. The flow velocity and pressure fluctuate randomly in both time and space, resembling the disorderly rolling of a boiling liquid—this is turbulence. In turbulent flow, some areas have excessively high flow velocities, with the liquid rapidly flowing over the heating surface without sufficient time for effective heat exchange; other areas form stagnation zones or backflow dead zones, where the heated liquid accumulates in place and cannot be replaced in time. This uneven flow directly damages the thermal boundary layer between the cooling medium and the heating wall, severely weakening the convective heat transfer capacity. If, under ideal conditions, 1 liter of coolant can remove 100 joules of heat, under actual conditions of turbulent flow, poor wall contact, and a damaged boundary layer, its effective heat transfer may drop to only 30 joules.At this point, the temperature of the mixed outlet water may only rise by 2°C because most pipe sections still maintain relatively normal flow and heat exchange; however, in localized areas near the joints, the surface temperature of the heating element may have risen by more than 20°C. Temperature sensors are typically installed at the main outlet pipe and measure the average temperature after mixing. This value cannot reflect the true thermal state of localized overheating points within the pipe, thus creating a temperature control blind spot and creating potential hazards such as insulation aging, contact overheating, and even escalation of the fault. Summary of the Invention

[0003] This invention provides a temperature control driving method for a circulating water cooling system in a distribution box, mainly comprising: The driving frequency of the water pump in the circulating water cooling system of the distribution box is obtained, and the driving frequency is processed by fast Fourier transform to obtain the periodic variation amplitude of the cooling water flow. Mechanical vibration signals of the joint are collected, and after removing environmental noise by bandpass filtering, the amplitude of the micro-vibration and the main frequency are extracted as mechanical state characterization quantities. An amplitude correspondence table is established based on the periodic variation amplitude of the cooling water flow and the mechanical state characterization quantities to delineate the stability boundary of the joint vibration load. The temperature at the top air outlet and bottom air inlet of the distribution box is collected and the vertical temperature difference is calculated. The height section of the box where the vertical temperature difference exceeds the design heat dissipation limit is marked as the uneven heat dissipation height section. Record the response time required for the flow meter reading to reach a steady state at the moment of water pump frequency switching, and determine the heat exchange instability area by combining the uneven heat dissipation height section; Based on the heat exchange instability region, retrieve the stability boundary of the joint vibration load of the corresponding pipeline section, search the amplitude correspondence table for the set of driving frequencies that fall within the preset safety margin range, and determine the pump driving frequency switching node. The variable frequency control command is generated based on the pump drive frequency switching node to drive the pump to maintain a stable laminar flow state of the cooling water in the heat exchange instability region.

[0004] Furthermore, the step of obtaining the driving frequency of the water pump in the circulating water cooling system of the distribution box, and processing the driving frequency through a fast Fourier transform to obtain the periodic variation amplitude of the cooling water flow, includes: Obtain the pump operation record and flow meter reading, and align the real-time drive frequency with the flow meter reading according to the acquisition time to obtain the drive frequency sequence and synchronous flow sequence; The continuous sampling intervals are divided according to the driving frequency sequence. The frequency components and corresponding amplitudes of each sampling interval are obtained by using fast Fourier transform. The non-zero frequency component with the largest amplitude is selected to obtain the main period of the cooling water flow. The synchronous flow rate sequence is divided according to the main period to obtain the average value of the difference between the maximum flow rate and the minimum flow rate in each period to obtain the periodic change amplitude of the cooling water flow.

[0005] Furthermore, the mechanical vibration signal of the acquired joint, after bandpass filtering to remove environmental noise, extracts the micro-amplitude vibration amplitude and dominant frequency as mechanical state characterization quantities. An amplitude correspondence table is established based on the periodic variation amplitude of the cooling water flow and the mechanical state characterization quantities to delineate the stability boundary of the joint vibration load, including: The sensor identification and mechanical vibration signal of the elbow and flange joint are acquired, and bandpass filtering is performed according to the preset passband. The difference between the maximum and minimum values ​​of the signal after bandpass filtering is taken as the amplitude of the micro-vibration. The non-zero frequency with the largest amplitude is extracted by fast Fourier transform as the main vibration frequency to obtain the mechanical state record. Based on the acquisition time of the mechanical state record, the periodic variation amplitude of the cooling water flow is matched, and the periodic variation amplitude, micro-vibration amplitude and main vibration frequency are recorded according to the sensor identification to obtain the amplitude correspondence table arranged according to the joint position. Obtain the upper limit of permissible vibration amplitude and the range of prohibited vibration frequencies for each joint from the pipeline structure file. Based on the amplitude correspondence table, filter the records that do not exceed the upper limit of permissible vibration amplitude and do not fall within the range of prohibited vibration frequencies to determine the vibration bearing stability boundary of the joint.

[0006] Furthermore, the determination of the stability boundary for joint vibration bearing includes: Obtain the wall thickness, nominal diameter, bolt preload torque, and previous tightening records of elbow and flange joints. Compare the decrease in bolt preload torque relative to the initial value, classify the structural stiffness level according to the ratio of wall thickness to nominal diameter, and determine the position of easily loosened joints. Based on the position of the loose joint, the permissible vibration amplitude and prohibited frequency range that match the wall thickness, nominal diameter and bolt preload torque are retrieved from the preset structural load correspondence table to determine the upper limit of the micro-amplitude vibration amplitude and the prohibited frequency range of the main vibration frequency. The amplitude of the micro-vibration, the main frequency, the displacement of the joint, and the rebound of the fastener are arranged according to the periodic variation of the cooling water flow. When the amplitude of the micro-vibration reaches the upper limit of the amplitude of the micro-vibration or the main frequency enters the main frequency forbidden zone, the vibration bearing stability boundary is determined by the previous set of records in the previous fastening records according to the joint position.

[0007] Furthermore, the temperature at the top air outlet and bottom air inlet of the distribution box is collected, and the vertical temperature difference is calculated. Sections of the box height where the vertical temperature difference exceeds the design heat dissipation limit are marked as uneven heat dissipation height sections, including: The measured temperatures at the top air outlet and the bottom air inlet are obtained and paired according to the same acquisition time. The absolute value of the difference between the measured temperatures at the top air outlet and the bottom air inlet is taken to obtain the vertical temperature difference value. Obtain the design heat dissipation limit from the nameplate on the enclosure, compare the vertical temperature difference with the design heat dissipation limit, and if the vertical temperature difference exceeds the design heat dissipation limit, then use the installation height of the two temperature sensors installed on the top air outlet and the bottom air inlet as the upper and lower boundaries to determine the uneven heat dissipation height section.

[0008] Furthermore, the response time required for the flow meter reading to reach steady state at the moment of pump frequency switching is recorded. Combined with the uneven heat dissipation height range, the heat transfer instability region is determined, including: The pump frequency switching time and the flow meter reading after the pump frequency switching time are obtained. The change in adjacent readings is obtained according to the continuous sampling window. When the change in adjacent readings is continuously lower than the preset steady-state threshold, the response time is determined by the difference between the start time of the corresponding pump frequency window and the pump frequency switching time. If the response time exceeds the preset permitted time, the period between the pump frequency switching time and the start time of the steady-state window will be determined as the abnormal driving period. Based on the abnormal driving period, the pipeline topology and the height range of each pipe segment are retrieved, and pipe segments with overlapping heights are matched with uneven heat dissipation height segments to obtain height-mapped pipe segments. The flow duration is determined based on the length of each pipe segment and the corresponding flow rate. The abnormal driving period is traced back along the flow direction to obtain the time-traced pipe segment. If the pipe segment identifiers of the height-mapped pipe segment and the time-tracing pipe segment are consistent, the pipe segment is determined to be a heat exchange instability area.

[0009] Furthermore, the step of retrieving the stability boundary of the joint vibration load of the corresponding pipeline section based on the heat exchange instability region, searching the amplitude correspondence table for the set of driving frequencies falling within the preset safety margin range, and determining the pump drive frequency switching node includes: Based on the three-dimensional coordinate range of the heat exchange instability region, match the physical pipe segments that overlap in spatial range, retrieve the vibration bearing stability boundary of each joint in the physical pipe segment, extract the upper limit of the minimum micro-amplitude vibration value, and summarize the main vibration frequency forbidden zone. In the amplitude correspondence table, records whose micro-vibration amplitude does not exceed the minimum micro-vibration amplitude limit and whose main vibration frequency does not enter the main vibration frequency forbidden zone are selected. The safe driving frequency record is obtained by associating the driving frequency and flow meter reading according to the acquisition time. The required flow rate corresponding to the current heat dissipation load is read from the pre-established table of heat dissipation load and cooling water flow rate. The frequency with the smallest difference between the flow meter reading and the current drive frequency is selected from the safe drive frequency record and determined as the water pump drive frequency switching node.

[0010] Furthermore, the step of generating a frequency conversion adjustment command based on the water pump drive frequency switching node to drive the water pump to maintain a stable laminar flow state of the cooling water flow in the heat exchange instability region includes: The target drive frequency, switching time, and execution identifier are written into the pump drive frequency switching node to form a frequency conversion adjustment command, and the frequency conversion adjustment command is sent to the frequency conversion adjustment device to make the pump run at the target drive frequency. Obtain the inner diameter and flow meter reading of the pipe section corresponding to the heat exchange instability region, as well as the temperature of the insulation layer of the conductive circuit, and determine the flow velocity inside the pipe based on the inner diameter and flow meter reading; If the flow velocity inside the pipe is within a preset laminar flow velocity range and the temperature of the insulation layer is continuously within a preset stable temperature range, then the target driving frequency is maintained.

[0011] Furthermore, the step of generating a frequency conversion adjustment command based on the water pump drive frequency switching node to drive the water pump to maintain a stable laminar flow state of the cooling water flow in the heat exchange instability region includes: Obtain the difference between the current operating frequency and the target driving frequency of the water pump and the adjustment direction, divide the frequency range into gears according to the preset adjustment range, configure the dwell time for each frequency range, and obtain the geared frequency sequence from the current operating frequency to the target driving frequency. The water pumps are driven sequentially according to the frequency sequence to obtain the flow rate, inlet water temperature, outlet water temperature and the insulation layer temperature of the conductive circuit at the inlet, middle and outlet of the pipe section corresponding to the heat exchange instability area, thus obtaining a segmented operation record including the flow rate difference, outlet water temperature rise and insulation layer temperature.

[0012] Furthermore, the water pumps are driven sequentially according to the defined frequency sequence to obtain the flow velocity, inlet water temperature, outlet water temperature, and conductive circuit insulation layer temperature at the inlet, middle, and outlet of the pipe section corresponding to the heat exchange instability region. This yields a segmented operation record including the flow velocity difference, outlet water temperature rise, and insulation layer temperature, including: Based on the segmented operation records, if the flow velocity difference at the same frequency is continuously lower than the uniform threshold, the flow velocity at each sampling location is in the laminar flow velocity range, the effluent temperature rise is in the heat exchange temperature rise range, and the insulation layer temperature is in the stable temperature range, then the frequency is determined as the dwell operation point, and the insulation layer temperature stabilizes and the operation state is obtained.

[0013] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects: This invention discloses a temperature control drive method for a circulating water cooling system in a distribution box. Addressing the problem of abnormal insulation temperature caused by mechanical vibration of pipe joints and localized heat exchange instability due to flow fluctuations during long-term operation of the circulating water cooling system, the method employs a Fast Fourier Transform (FFT) to obtain the periodic variation characteristics of the cooling water flow. Simultaneously, high-frequency vibration signals from pipe elbow flange joints are acquired, and the amplitude of the vibration and the dominant frequency are extracted. Combined with structural parameters such as joint wall thickness, nominal diameter, and bolt preload torque, the vibration bearing stability boundaries of each joint are defined, thereby establishing a table corresponding to the amplitude of the water flow periodic variation and the mechanical vibration state. This invention identifies uneven heat dissipation sections by measuring the vertical temperature difference within the box. Combined with the abnormal flow response time characteristics during pump frequency switching, the heat dissipation anomalies are mapped to physical pipe sections, and the drive period is traced back. When two types of anomalies are located in the same pipe section, it is determined to be a heat exchange instability area. This invention retrieves the set of driving frequencies that fall within the safety threshold in the amplitude correspondence table based on the joint vibration bearing boundary corresponding to the region, selects the target frequency that satisfies both heat dissipation load and avoids mechanical vibration risk as the switching node, and generates frequency conversion adjustment commands to drive the water pump through a step-by-step climbing transition method, so that the cooling water flow maintains a stable laminar flow state in the unstable region, and finally achieves stable control of the temperature of the insulation layer of the conductive circuit. Attached Figure Description

[0014] Figure 1 This is a flowchart of a temperature control drive method for a circulating water cooling system in a distribution box according to the present invention.

[0015] Figure 2 This is a schematic diagram of a temperature control drive method for a circulating water cooling system in a distribution box according to the present invention.

[0016] Figure 3 This is another schematic diagram of a temperature control drive method for a circulating water cooling system in a distribution box according to the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings. The described embodiments are merely some embodiments of the present invention.

[0018] like Figures 1-3 The temperature control drive method for a circulating water cooling system in a distribution box, as described in this embodiment, may specifically include: S101. Obtain the driving frequency of the water pump in the circulating water cooling system of the distribution box, and process the driving frequency through fast Fourier transform to obtain the periodic variation amplitude of the cooling water flow.

[0019] Acquire pump operation records and flow meter readings. Align the real-time drive frequency with the flow meter readings according to the acquisition time, and discard records during pump start-up and shutdown to obtain a drive frequency sequence and a synchronous flow sequence. Divide the continuous sampling intervals according to the drive frequency sequence, and use Fast Fourier Transform to obtain the frequency components and corresponding amplitudes of each sampling interval. Select the non-zero frequency component with the largest amplitude to obtain the main period of the cooling water flow. Divide the synchronous flow sequence according to the main period, obtain the difference between the maximum and minimum flow rates in each period, and average the differences for each period to obtain the periodic variation amplitude of the cooling water flow.

[0020] In one embodiment, the circulating water cooling device in the distribution box is powered by a solar power unit and a lithium battery power unit. A frequency converter records the water pump drive frequency, operating status, and recording time, while a flow meter records the instantaneous flow rate of the circulating pipeline and the acquisition time. The records are written to the local storage area according to a unified time reference.

[0021] Specifically, data from the stable operation period of the water pump is extracted from the operation records. Start-up records where the drive frequency rises from zero to the operating frequency, and stop records where the operating frequency falls back to zero, are not included in period identification. The remaining records are arranged according to the acquisition time to obtain a drive frequency sequence. For cases where the acquisition intervals of the flow meter and the frequency converter are inconsistent, the drive frequency recording time is used as the alignment time, and the flow meter reading with the smaller time distance is selected. When the alignment time is between two readings, the corresponding flow rate is determined based on the time distance between the two readings and the alignment time, resulting in a synchronous flow sequence. "Two readings" refers to the two flow meter records in the flow meter's recording sequence that are closest to a certain drive frequency recording time (alignment time) on the time axis, located before and after that time, respectively. Further, sampling intervals are divided according to the continuity of the operation records. When the time interval between adjacent records exceeds the preset acquisition interval, or when the water pump's operating state changes, the interval is truncated at the corresponding position. The drive frequency records within each sampling interval remain continuous; intervals with a recording length less than the preset length are not processed.

[0022] In one possible implementation, the average driving frequency of each sampling interval is subtracted from the driving frequency of that interval to obtain a frequency change sequence. A Fast Fourier Transform (FFT) is then used to obtain each frequency component and its corresponding amplitude. The zero-frequency component represents the average level of the interval and is not considered a periodic component. The frequency component with the largest amplitude is selected as the dominant frequency from the remaining frequency components, and the main period of the cooling water flow is determined based on the repetition duration corresponding to this dominant frequency. The main period represents the duration of the repeated changes in circulating flow caused by pump frequency regulation. Based on the main period, a synchronous flow sequence is divided from the start of the sampling interval. Each complete period forms a flow record group; records with a duration less than one main period at the end of the sampling interval are not included. For each flow record group, the maximum and minimum flow rates are read, and the difference between them is taken as the flow change amplitude for that period.

[0023] For example, when the same sampling interval contains multiple complete cycles, the flow rate change amplitude of each cycle is obtained sequentially, and then the average value of the flow rate change amplitude is taken to obtain the cycle change amplitude of the sampling interval. When different sampling intervals have the same main cycle, the corresponding cycle change amplitudes are summarized according to the recording time.

[0024] It should be noted that the periodic variation amplitude corresponds to the periodic fluctuations of the cooling water flow during the stable operation of the water pump, and does not include instantaneous flow rate changes during start-up and shutdown. The records include the start and end times of the sampling interval, the main period, the maximum flow rate within the period, the minimum flow rate within the period, and the periodic variation amplitude.

[0025] S102. Collect the mechanical vibration signal of the joint, remove environmental noise by bandpass filtering, and extract the amplitude of the micro-vibration and the main frequency as mechanical state characterization quantities. Establish an amplitude correspondence table between the periodic change amplitude of the cooling water flow and the mechanical state characterization quantities according to the acquisition time, and delineate the stability boundary of the joint vibration load.

[0026] Sensor identifiers and mechanical vibration signals from elbows and flange joints are acquired. Bandpass filtering is performed according to a preset passband, and the difference between the maximum and minimum values ​​of the filtered signal is taken as the micro-amplitude vibration amplitude. Fast Fourier Transform is used to extract the non-zero frequency with the largest amplitude as the dominant frequency, resulting in a mechanical state record. The periodic variation amplitude of the cooling water flow is matched to the acquisition time of the mechanical state record. The periodic variation amplitude, micro-amplitude vibration amplitude, and dominant frequency are recorded according to the sensor identifiers, resulting in an amplitude correspondence table arranged by joint position. The permissible vibration amplitude upper limit and prohibited frequency range for each joint are obtained from the pipeline structure file. Records that do not exceed the amplitude upper limit and do not fall within the prohibited frequency range are selected based on the amplitude correspondence table. The vibration bearing stability boundary of the joint is determined based on the value range of each characteristic quantity in the record.

[0027] In one embodiment, high-frequency accelerometers are fixed to the outer arc surface of the elbows and the outer wall of the flange joints of the circulating water cooling pipeline in the distribution box. Each high-frequency accelerometer is equipped with a unique sensor identifier, which is associated with and stored in relation to the joint position, joint type, pipeline route, and installation direction, thereby distinguishing the mechanical vibration signals generated by different joints.

[0028] Specifically, the high-frequency accelerometer continuously records acceleration changes according to a unified acquisition clock. For elbows, the acquisition direction can be set along the pipeline axial direction and the elbow radial direction; for flange joints, the acquisition direction can be set along the pipeline axial direction and the flange end face normal direction. The acquired values ​​in each direction are arranged according to the acquisition time to form the original vibration sequence of the corresponding joint. Furthermore, based on the vibration of the housing fan and external equipment acquired during the pump's shutdown period, the frequency range of the main distribution of environmental noise is determined; based on the frequency distribution of joint vibration during the pump's stable operation, the frequency range of retained joint mechanical vibration is determined. The lower limit of the bandpass filter is higher than the low-frequency housing sway frequency, and the upper limit is lower than the sensor's high-frequency electrical noise frequency, so that the filtered vibration sequence retains the vibration components caused by water flow impact and slight displacement of the joint.

[0029] In one possible implementation, the filtered vibration sequence is divided into continuous sampling intervals. Each sampling interval has the same start and end times as the statistical interval for the periodic variation amplitude of the cooling water flow. If there are sensor interruptions, missing connector position identifiers, or pump start-stop switching within a sampling interval, that sampling interval is discarded, and the connector vibration record during continuous pump operation is retained.

[0030] Specifically, within each sampling interval, the maximum and minimum acceleration values ​​of the filtered vibration sequence are read, and the difference between them is taken as the micro-amplitude vibration amplitude. The micro-amplitude vibration amplitude characterizes the overall range of the joint's reciprocating vibration within that sampling interval. For multi-directional acquisition records, the axial and radial micro-amplitude vibration amplitudes are obtained separately, and the larger one is taken as the micro-amplitude vibration amplitude of the joint.

[0031] Preferably, a Fast Fourier Transform is performed on the filtered vibration sequence to obtain multiple non-zero frequencies and their corresponding spectral amplitudes. After excluding zero-frequency components, the frequency with the largest spectral amplitude is selected as the master oscillation frequency. If the difference in spectral amplitude between two adjacent frequencies is less than a preset identification difference, the frequency with a more stable correspondence to the periodic component of the water pump drive frequency is selected as the master oscillation frequency according to the following method: For each candidate frequency, its ratio to the drive frequency is calculated, and the ratio is rounded to the nearest integer multiple, which is recorded as the theoretical multiple relationship. Within 10 consecutive sampling periods, the actual ratio of the candidate frequency to the drive frequency is calculated, and the absolute value of the deviation between the actual ratio and the theoretical multiple relationship is calculated. The average of the 10 deviation values ​​is taken as the stability index of the candidate frequency. The smaller the stability index value, the more stable the correspondence. The frequency with the smallest stability index is selected as the master oscillation frequency. The micro-amplitude vibration amplitude and the master oscillation frequency together constitute the mechanical state record. Based on a unified acquisition clock, the periodic variation amplitude of the cooling water flow is matched according to the acquisition interval of the mechanical state record. During matching, the start and end times of the acquisition interval, sensor identifier, connector position, periodic change amplitude, micro-vibration amplitude and main frequency are read and written into the amplitude correspondence table in the form of one connector position corresponding to one set of records.

[0032] For example, when the same joint exhibits different cooling water flow periodic variation amplitudes across multiple continuous acquisition intervals, the corresponding mechanical state records are arranged from low to high according to the periodic variation amplitude. If adjacent records have the same periodic variation amplitude, they are arranged according to the acquisition time. This establishes a step-by-step correspondence between the degree of cooling water flow fluctuation and the joint vibration response in the amplitude correspondence table. Further, the connection type, wall thickness, nominal diameter, fastening method, and permissible vibration amplitude upper limit for each joint are read from the pipeline structure file, along with the vibration-prohibited frequency range adjacent to the joint's inherent vibration. For elbow connections, the permissible vibration amplitude upper limit is determined based on the elbow wall thickness and fixing spacing; for flange joints, the permissible vibration amplitude upper limit is determined based on the flange thickness and bolt preload status.

[0033] In one embodiment, the mechanical state records in the amplitude correspondence table are checked one by one. If the amplitude of the minor vibration does not exceed the upper limit of the permissible vibration amplitude of the corresponding joint, and the dominant vibration frequency does not fall within the prohibited vibration frequency range of the corresponding joint, the record is marked as a stable record. The stable records of the same joint are summarized, and the continuous range of values ​​of the cooling water flow period variation amplitude, minor vibration amplitude, and dominant vibration frequency is taken to determine the vibration bearing stability boundary of the joint.

[0034] Another way to determine the vibration bearing stability boundary is to obtain the wall thickness, nominal diameter and bolt preload torque of the pipe elbows and flange joints, identify the joint positions that are prone to loosening during long-term operation, determine the upper limit of the micro-vibration amplitude and the forbidden zone of the main vibration frequency that each position can withstand, and incorporate the joint displacement and fastener springback under different cooling water flow cycle changes to form the vibration bearing stability boundary.

[0035] Obtain the wall thickness, nominal diameter, bolt preload torque, and previous tightening records for elbow and flange joints. Compare the decrease in bolt preload torque relative to the initial value, and classify the structural stiffness level according to the ratio of wall thickness to nominal diameter to determine the position of easily loosened joints. Based on the position of easily loosened joints, look up the permissible vibration amplitude and prohibited frequency range that match the wall thickness, nominal diameter, and bolt preload torque in the preset structural load correspondence table to determine the upper limit of micro-vibration amplitude and the prohibited range of dominant vibration frequency. Arrange the micro-vibration amplitude, dominant vibration frequency, joint displacement, and fastener rebound of the easily loosened joint positions according to the periodic variation amplitude of cooling water flow. When the vibration amplitude reaches the upper limit of micro-vibration amplitude or the dominant vibration frequency enters the prohibited range of dominant vibration frequency, determine the vibration load stability boundary according to the joint position based on the previous set of records.

[0036] In one implementation, the joint position, wall thickness, nominal diameter and connection type of each elbow and flange joint are retrieved from the design file of the circulating water cooling pipeline, and the initial preload torque, re-inspection preload torque and recording time of the corresponding bolts are retrieved from the assembly record and the previous maintenance record to form a structural record arranged by joint position.

[0037] Specifically, the wall thickness is taken as the minimum design thickness of the pressure-bearing part of the joint, and the nominal diameter is taken as the nominal diameter of the corresponding pipe section. The structural stiffness level is classified according to the ratio of wall thickness to nominal diameter; under the same connection type, joints with a lower ratio are classified into lower structural stiffness levels. Furthermore, for each joint location, the pre-tightening torque of each re-inspection is arranged according to the recording time, and the degree of retention of the pre-tightening torque of each re-inspection relative to the initial pre-tightening torque is read, using the initial pre-tightening torque as a benchmark. When multiple consecutive records show a decreasing trend, a pre-tightening torque decay record for that joint location is formed.

[0038] In one possible implementation, a correspondence matching is performed between the structural stiffness level and the preload torque decay record. If a joint with a lower structural stiffness level exhibits a continuous torque decrease, or if the same joint repeatedly falls below a preset torque holding threshold within adjacent inspection cycles, that joint is identified as an easily loosened joint. For each easily loosened joint, a permissible vibration amplitude is retrieved from a preset structural load correspondence table. This table records data based on pipeline design load, joint connection type, wall thickness, nominal diameter, and assembly preload torque, with each set of structural attributes corresponding to a permissible vibration amplitude that allows the joint to remain in a tightened state.

[0039] It should be noted that the prohibited vibration frequency range is determined based on the natural frequency of the joint: this natural frequency is read from the pipeline's factory vibration inspection record, and then, using this frequency as the center, it is expanded to both sides according to a preset deviation to define the prohibited vibration range. The natural frequency is read from the pipeline's factory vibration inspection record; using this natural frequency as the center, it is expanded to both sides according to a preset frequency deviation to form the prohibited vibration frequency range for the corresponding joint. The permissible vibration amplitude constitutes the upper limit of the micro-amplitude vibration amplitude, and the prohibited vibration frequency range constitutes the prohibited vibration frequency range.

[0040] For example, if the natural frequency of a connector is 120Hz and the preset frequency deviation is ±10%, then the vibration-prohibited frequency range is 108Hz to 132Hz, and the main vibration frequency components within this range should be avoided.

[0041] Specifically, according to the acquisition interval corresponding to the periodic variation amplitude of the cooling water flow, filtered mechanical vibration signals of the same joint position are read. The mechanical vibration signals are integrated twice over time, and baseline drift in the integration curve is removed using a Butterworth high-pass filter to obtain the displacement curve of the joint relative to its initial position. The high-pass filter uses a 4th-order Butterworth structure, with a cutoff frequency set to 0.1 to 0.3 times the fundamental frequency of the cooling water flow variation. When the cooling water flow variation period is 10 seconds, the cutoff frequency is set to 0.01 Hz to 0.03 Hz. The difference between the maximum and minimum values ​​of the displacement curve within one cooling water flow variation period is taken as the joint displacement corresponding to that period. Further, the peak displacement and the residual displacement at the end of the period are read from the displacement curve, and the difference between the two is taken as the fastener springback. That is, fastener springback = peak displacement - residual displacement at the end of the period. The joint displacement represents the overall movement range of the joint under hydraulic disturbance, and the fastener springback represents the distance the bolted connection recovers from its maximum offset position to its original tightened position.

[0042] In one embodiment, each group of structural attributes in the structural load-bearing correspondence table corresponds to three parameters: the upper limit of permissible vibration amplitude, the range of prohibited vibration frequencies, and the range of permissible displacement. The permissible displacement range is determined based on the yield strength of the joint material and the safety factor, with a typical value of 0.05 mm to 0.2 mm. Records of the same easily loosened joint position are arranged from low to high according to the variation amplitude of the cooling water flow cycle. Each record includes the micro-vibration amplitude, the dominant vibration frequency, the joint displacement, and the fastener springback. When the micro-vibration amplitude does not reach the upper limit of permissible vibration amplitude, the dominant vibration frequency does not enter the prohibited vibration frequency range, the joint displacement does not exceed the permissible displacement range, and the fastener springback is greater than the residual displacement, the record is marked as a stable record. A fastener springback greater than the residual displacement indicates that elastic recovery is dominant, and the fastener maintains good elasticity. Let the springback be Δr and the residual displacement be Δp. When Δr is greater than Δp, the fastening force can be maintained. If any condition is not met, the record is marked as an out-of-bounds record, and the adjacent stable record before the out-of-bounds record is selected as the critical record.

[0043] Preferably, for each easily loosened joint position, the cooling water flow cycle variation amplitude, micro-vibration amplitude, main vibration frequency, joint displacement and fastener springback in the critical records are summarized and stored separately according to the joint position. The value range corresponding to each critical record forms the vibration bearing stability boundary arranged according to the joint position.

[0044] S103. Collect the temperatures at the top air outlet and bottom air inlet of the distribution box and calculate the vertical temperature difference. Mark the height section of the box where the vertical temperature difference exceeds the design heat dissipation limit as the uneven heat dissipation height section.

[0045] The measured temperatures at the top air outlet and bottom air inlet are obtained and paired according to the same acquisition time. The absolute value of the difference between the measured temperatures at the top air outlet and the bottom air inlet is taken to obtain the vertical temperature difference value. The design heat dissipation limit is obtained from the cabinet nameplate. The vertical temperature difference value is compared with the design heat dissipation limit value. If the vertical temperature difference value exceeds the design heat dissipation limit value, the installation height of the two temperature sensors is used as the upper and lower boundaries to determine the uneven heat dissipation height segment.

[0046] In one embodiment, the top air outlet temperature sensor is installed within the hot air exhaust path, and the bottom air inlet temperature sensor is installed within the external air intake path. Both temperature sensors record temperature and acquisition time using the same sampling period, and the measured temperatures at the top air outlet and bottom air inlet are paired based on the acquisition time. For records with inconsistent acquisition times, two records with a time interval not exceeding a preset synchronization time difference are selected to form a temperature recording group.

[0047] Specifically, for each temperature recording group, the measured temperatures at the top air outlet and bottom air inlet are read, and the absolute value of the difference between the two temperatures is taken as the vertical temperature difference. During continuous data collection, multiple vertical temperature differences can be arranged according to a preset statistical period. Records during periods when the temperature sensor is disconnected or the cabinet door is open are discarded, and temperature records during periods when the distribution box is normally powered on and the cabinet is closed are retained. Further, the design heat dissipation limit is read from the nameplate of the distribution box or the corresponding equipment parameter record, and the vertical temperature difference is compared item by item. If the vertical temperature difference exceeds the design heat dissipation limit, the installation heights of the top air outlet temperature sensor and the bottom air inlet temperature sensor are read, and the cabinet space between the two installation heights is used as the upper and lower boundaries to determine the uneven heat dissipation height segment.

[0048] S104. Record the response time required for the flow meter reading to enter a steady state at the moment of water pump frequency switching. If the response time is abnormal, map the uneven heat dissipation height section to a physical pipe section and backtrack the drive period corresponding to the abnormal response time to the pipe section. When the pipe section mapped from the uneven heat dissipation height section is the same pipe section as the pipe section backtracked from the abnormal response time, the pipe section is determined to be a heat exchange instability area.

[0049] The system acquires the pump frequency switching time and the flow meter reading after the switching time. It obtains the change in adjacent readings within a continuous sampling window. When the change in adjacent readings is continuously lower than a preset steady-state threshold, the response time is determined by the difference between the start time of the corresponding pump frequency window and the pump frequency switching time. If the response time exceeds a preset permissible time, the period between the pump frequency switching time and the start time of the steady-state window is defined as the abnormal driving period. Based on the abnormal driving period, the system retrieves the pipeline topology and the height range of each pipe segment. It matches pipe segments with overlapping heights in areas of uneven heat dissipation to obtain height-mapped pipe segments. The system determines the flow duration based on the length of each pipe segment and the corresponding flow rate. It then traces back the abnormal driving period along the flow direction to obtain the time-traced pipe segment. The system compares the pipe segment identifiers of the height-mapped pipe segment and the time-traced pipe segment. If the identifiers match, the pipe segment is determined to be a heat exchange instability region. The system reads the start and end coordinates of the pipe segment from the pipeline topology to obtain the three-dimensional coordinate range of the heat exchange instability region.

[0050] In one embodiment, the frequency converter records the pump drive frequency and the time of frequency switching, while the flow meter records the instantaneous flow rate of the circulating cooling water and the acquisition time according to a fixed sampling period. The drive frequency record and the flow meter reading use a unified clock marker, so that each frequency switch corresponds to a set of flow records before and after the switch.

[0051] Specifically, starting from the pump frequency switching moment, the flow meter readings after the switching are arranged according to continuous sampling windows. For each continuous sampling window, the absolute value of the difference between adjacent flow meter readings is obtained sequentially. When the absolute value of the difference reaches a preset number of times and is always lower than a preset steady-state threshold, the first continuous sampling window that meets the condition is determined as the steady-state window. Further, the start time of the steady-state window is read, and the time interval between the start time and the pump frequency switching moment is used as the response duration. If no steady-state window that meets the condition appears after the frequency switching, the response duration is determined by the end time of the preset observation period, and the flow response corresponding to this frequency switching is marked as not having entered a steady state.

[0052] In one possible implementation, the permitted duration is obtained from the commissioning records of the water pump and corresponding pipelines. These records document the normal response duration range corresponding to different frequency switching amplitudes when the pipeline connections are intact and the cooling water flow is stable. Based on the drive frequency before and after the frequency switch, the upper limit of the normal response duration range is read as the permitted duration. If the response duration exceeds the permitted duration, the abnormal drive period is determined by the time interval between the frequency switching moment and the start of the steady-state window.

[0053] Specifically, the pipeline topology records the connection relationships between pumps, branch points, elbows, flange joints, heat exchange pipe sections, junction points, and flow meters according to the flow direction of the circulating cooling water. Adjacent connection points form a physical pipe section. Each physical pipe section is assigned a pipe section identifier, and its starting point coordinates, ending point coordinates, length, inner diameter, and height range within the distribution box are recorded. Based on this pipeline topology, the upper and lower boundary heights of the uneven heat dissipation height zone are read and compared item by item with the height range of each physical pipe section. When the height range of a physical pipe section overlaps with the uneven heat dissipation height zone, the physical pipe section is recorded as a candidate pipe section. From the candidate pipe sections, the pipe section with the larger overlap length is selected to obtain the height-mapped pipe section. Furthermore, for each physical pipe section in the pipeline topology, the required flow time of cooling water through that pipe section is determined based on the internal volume of the pipe section and the average flow rate during the abnormal drive period. The internal volume V of the pipe section is calculated using the cylinder volume formula based on the pipe section length L and inner diameter D. The average flow rate Q during the abnormal drive period is obtained by summing all flow meter readings during that period and dividing by the number of readings. The flow duration T is calculated using T=V / Q, which is the internal volume of the pipe section divided by the average flow rate during the abnormal drive period. For example, if the volume of a pipe section is 0.5 cubic meters and the average flow rate during the abnormal drive period is 0.1 cubic meters per second, then the flow duration of that pipe section is 5 seconds.

[0054] In one embodiment, the upstream physical pipe segments are read sequentially in the opposite direction of the cooling water flow, starting from the pipe segment where the flow meter is located, and the corresponding flow duration is accumulated segment by segment. When the accumulated flow duration covers the abnormal drive period, the last physical pipe segment included in the accumulation is determined as the time period backtracking pipe segment. When parallel branches exist, backtracking is performed along each branch, and the overlap duration between the flow duration of the backtracking pipe segment of each branch and the abnormal drive period is calculated. The ratio of the overlap duration to the total duration of the abnormal drive period is used as the overlap index. When the overlap is greater than or equal to 0.6, it is determined to be a high overlap, and the physical pipe segment corresponding to that branch is retained as the time period backtracking pipe segment. If the overlap of multiple branches meets the standard, the branch with the highest overlap is selected; if the overlap is equal, the pipe segment corresponding to the branch with the larger flow rate is selected.

[0055] It should be noted that the height-mapped pipe segment reflects the spatial location of the uneven heat dissipation section of the enclosure, while the time-tracing pipe segment reflects the propagation location of the abnormal flow response in the pipeline. The pipe segment identifiers of the height-mapped pipe segment and the time-tracing pipe segment are read and compared. If the pipe segment identifiers are the same, the corresponding physical pipe segment is identified as the heat exchange instability area; if the pipe segment identifiers are different, no heat exchange instability area record is formed.

[0056] Preferably, the starting and ending three-dimensional coordinates of the heat exchange instability region are read from the pipeline topology, and the spatial range occupied by the pipe segment is determined in combination with the inner diameter of the pipe segment. The three-dimensional coordinates are based on a preset reference point at the bottom of the distribution box as the origin, and the positions of the pipe segment along the width, depth, and height directions of the box are recorded respectively to obtain the three-dimensional coordinate range of the heat exchange instability region.

[0057] S105. Based on the heat exchange instability region, retrieve the stability boundary of the joint vibration load of the corresponding pipeline section, search the set of driving frequencies that fall within the safe threshold range in the amplitude correspondence table, and determine the switching node of the water pump driving frequency.

[0058] Based on the three-dimensional coordinate range of the heat exchange instability region, matching the spatially overlapping physical pipe segments, the vibration bearing stability boundary of each joint within the physical pipe segment is retrieved. The upper limit of the lowest micro-amplitude vibration is taken, and the main vibration frequency forbidden zone is summarized. Records in the amplitude correspondence table that do not exceed the lower limit of the lowest micro-amplitude vibration and whose main vibration frequency does not enter the main vibration frequency forbidden zone are selected. The safe drive frequency record is obtained by associating the drive frequency and flow meter reading at the acquisition time. The required flow rate corresponding to the current heat dissipation load is read from the pre-established heat dissipation load and cooling water flow rate correspondence table. The frequency in the safe drive frequency record that has a flow meter reading not lower than the required flow rate and has the smallest difference between the flow meter reading and the current drive frequency is selected as the pump drive frequency switching node.

[0059] In one implementation, the spatial range formed by the three-dimensional coordinates of the starting point and the ending point of the heat exchange instability region, as well as the pipe segment diameter, is read. The pipe segment identifier, starting point coordinates, ending point coordinates, and outer diameter of each physical pipe segment are then read from the pipeline topology. The two spatial ranges are compared for overlap, and physical pipe segments with continuous overlapping intervals are identified as the target physical pipe segments.

[0060] Specifically, when the target physical pipe section crosses multiple bends or flange joints, the joint position of each joint is read according to the connection order in the pipeline topology, and the corresponding vibration bearing stability boundary is retrieved based on the joint position. Each vibration bearing stability boundary includes the upper limit of permissible micro-amplitude vibration, the no-go zone of the dominant frequency, and the corresponding range of cooling water flow cycle variation. Further, the upper limits of permissible micro-amplitude vibration for each joint within the target physical pipe section are compared, and the lowest value is taken as the upper limit of permissible micro-amplitude vibration for the pipe section. The no-go zones of the dominant frequency for each joint are summarized according to frequency range; when frequency ranges overlap, they are merged into continuous no-go zones, thus obtaining the common vibration bearing range of the target physical pipe section.

[0061] In one possible implementation, records corresponding to each joint within the target physical pipe section are read from an amplitude correspondence table. These records include the acquisition time, cooling water flow cycle variation amplitude, micro-vibration amplitude, dominant frequency, and pump drive frequency. If the micro-vibration amplitude does not exceed the upper limit of the permissible micro-vibration amplitude for the pipe section, and the dominant frequency does not fall within any consecutive restricted areas, the corresponding record is marked as a safe vibration record. Based on these safe vibration records, flowmeter readings associated with the same acquisition time are grouped according to the pump drive frequency. When multiple flowmeter readings correspond to the same drive frequency, readings during pump start-up / shutdown periods and periods before the flow reaches a steady state are discarded. The average of the remaining readings is then taken as the stable flow rate corresponding to that drive frequency, forming a safe drive frequency record.

[0062] Specifically, the current heat dissipation load is obtained by summing the heat generated by the circuit breakers, busbars, and conductive circuits within the distribution box during the current operating period. The operating period is divided according to the actual operating conditions of the distribution box, with current data collected every 15 minutes as one time period. The heat generated by the circuit breaker is obtained by multiplying the measured current by the contact resistance; the heat generated by the busbar is calculated by multiplying the busbar resistance by the square of the current; and the heat generated by the conductive circuit is determined by multiplying the total resistance of the circuit by the square of the current. The heat dissipation load Q is the direct sum of the heat generated by the three types of components, i.e., Q = Qbreak + Qbus + Qcircuit. Taking a certain distribution box as an example, if the measured heat generated by the circuit breaker is 120 watts, the heat generated by the busbar is 80 watts, and the heat generated by the conductive circuit is 50 watts, then the current heat dissipation load is 250 watts. A pre-established table corresponding to the heat dissipation load and cooling water flow rate records the required cooling water flow rate according to the rated load range of the distribution box. The cooling water flow rate corresponding to the load range into which the current heat dissipation load falls is read as the required flow rate.

[0063] Preferably, the current driving frequency of the water pump is read, the absolute value of the difference between each driving frequency in the candidate driving frequency set and the current driving frequency is calculated, and the driving frequency with the smallest absolute difference is selected. If multiple identical differences exist, the driving frequency with the lower stable flow rate is selected, and the water pump driving frequency switching node is determined.

[0064] S106. Generate frequency conversion adjustment command according to the water pump drive frequency switching node, drive the water pump to run so that the cooling water flow maintains a stable laminar flow state in the heat exchange instability region.

[0065] The target drive frequency, switching time, and execution identifier are written into the pump drive frequency switching node to form a frequency conversion adjustment command, which is then sent to the frequency conversion adjustment device to make the pump operate at the target drive frequency. The inner diameter, flow meter reading, and conductive circuit insulation layer temperature of the pipe section corresponding to the heat exchange instability region are obtained. The flow velocity inside the pipe is determined based on the inner diameter and flow meter reading. If the flow velocity inside the pipe is within a preset laminar flow velocity range and the insulation layer temperature is continuously within a preset stable temperature range, the target drive frequency is maintained.

[0066] In one implementation, the target drive frequency corresponding to the water pump drive frequency switching node is read, and the switching time, water pump identifier, and execution identifier are written to form a frequency conversion adjustment command. After receiving the frequency conversion adjustment command, the frequency conversion adjustment device adjusts the output frequency to the target drive frequency and records the actual drive frequency and execution time. After the actual drive frequency reaches the target drive frequency, the water pump delivers cooling water according to the corresponding speed.

[0067] Specifically, the inner diameter of the physical pipe section corresponding to the heat exchange instability region is retrieved, and the flow meter reading after the water pump is running is read. The internal flow cross-sectional area of ​​the pipe section is determined based on the inner diameter, and the flow velocity inside the pipe is obtained by dividing the flow meter reading by the flow cross-sectional area. The flow velocity inside the pipe is compared with a pre-recorded laminar flow velocity range. If the flow velocity inside the pipe is continuously within the laminar flow velocity range, the cooling water flow in the heat exchange instability region is determined to be in a stable laminar flow state. Further, the temperature of the insulating layer of the conductive circuit near the heat exchange instability region is read, and the temperature records are arranged according to continuous sampling time. If the insulating layer temperature is within a preset stable temperature range, and the change between adjacent temperature records is continuously lower than a preset temperature fluctuation threshold, the target driving frequency is maintained; if any condition is not met, the confirmation of the target driving frequency as a stable operating frequency is stopped.

[0068] Extract the range of difference between the current operating frequency and the target driving frequency of the water pump, transition in stages according to each stage not exceeding the preset ramp-up range, and set the dwell time for each stage. Evaluate the uniformity of the flow velocity and the rise in outlet water temperature in the heat exchange instability zone during the transition period. After the water flow state changes from turbulent to stable laminar flow, determine the frequency as the dwell point to obtain the operating state where the temperature of the insulation layer of the conductive circuit stabilizes.

[0069] The difference between the current operating frequency and the target driving frequency of the water pump, along with the adjustment direction, is obtained. Frequency levels are divided according to a preset adjustment range, and a dwell time is configured for each frequency level, resulting in a frequency sequence pointing from the current operating frequency to the target driving frequency. The water pump is driven sequentially according to this frequency sequence. The flow velocity, inlet water temperature, outlet water temperature, and insulation layer temperature of the pipe section corresponding to the heat exchange instability region are obtained at the inlet, middle, and outlet, resulting in a segmented operation record including the flow velocity difference, outlet water temperature rise, and insulation layer temperature. Based on this segmented operation record, if the flow velocity difference at the same frequency is continuously lower than the uniform threshold, the flow velocity at each sampling location is within the laminar flow velocity range, the outlet water temperature rise is within the heat exchange temperature rise range, and the insulation layer temperature is within the stable temperature range, then this frequency is determined as the dwell operation point, and the insulation layer temperature stabilizes.

[0070] In one implementation, the current operating frequency of the water pump and the target driving frequency are read, and their magnitudes are compared. If the target driving frequency is higher than the current operating frequency, the adjustment direction is determined to be frequency increase; if the target driving frequency is lower than the current operating frequency, the adjustment direction is determined to be frequency decrease. The absolute value of the difference between the two constitutes the frequency range to be adjusted.

[0071] Specifically, the upper limit of the single-level adjustment amplitude is read from the preset record of the frequency converter, and the frequency range to be adjusted is continuously divided according to the adjustment direction. The frequency difference between adjacent frequency levels does not exceed the upper limit of the single-level adjustment amplitude, and the final frequency level is consistent with the target drive frequency, thereby obtaining a segmented frequency sequence. Further, a residence time is configured for each frequency level in the segmented frequency sequence. The residence time at least covers the flow time of cooling water from the water pump outlet to the outlet of the pipe section corresponding to the heat exchange instability area, and covers the response time required for the flow meter reading to enter the stable fluctuation range, so that each frequency level corresponds to a complete flow and temperature acquisition range.

[0072] In one possible implementation, the variable frequency drive adjusts the pump's operating frequency sequentially according to the defined frequency range. Each time a frequency range is entered, the corresponding dwell time is maintained, and the actual drive frequency, start and end times of the range, and flow meter reading are recorded simultaneously. If the actual drive frequency has not reached the current frequency range, the flow rate and temperature records for that range are not included in the flow regime determination.

[0073] Specifically, flow velocity records are acquired at the inlet, middle, and outlet of the pipe section corresponding to the heat exchange instability region. Each sampling location can be equipped with a flow detection unit, or the flow velocity can be obtained based on the local flow rate and the cross-sectional area of ​​the pipe section at the same time. The average flow velocity at each sampling location within the same speed range is read, and the difference between the maximum and minimum average flow velocities is used as the flow velocity difference value. Based on the flow velocity records, the inlet water temperature and outlet water temperature of the pipe section are simultaneously acquired, and the outlet water temperature rise is obtained by subtracting the inlet water temperature from the outlet water temperature. When the flow velocity difference value is continuously lower than a preset uniformity threshold, and the flow velocities at the inlet, middle, and outlet are all within the laminar flow velocity range corresponding to the pipe diameter, the current speed range is marked as a stable flow speed range.

[0074] For example, for each stable flow level, the corresponding outlet water temperature rise and the temperature of the conductive circuit insulation layer are continuously read. If the outlet water temperature rise is within the preset heat exchange temperature rise range, it indicates that the cooling water has completed the specified degree of heat absorption in the pipe section; if the insulation layer temperature is within the preset stable temperature range, and the change between adjacent temperature records is continuously lower than the preset temperature fluctuation threshold, the level is marked as a temperature stabilization level.

[0075] Preferably, the frequency range that first meets all the judgment conditions along the adjustment direction is selected from the temperature stabilization ranges, and this range is maintained for an additional observation period. If the flow velocity difference, flow velocity at each sampling location, water temperature rise, and insulation layer temperature all remain within the corresponding ranges during the additional observation period, then this frequency is determined as the dwell operating point, and the operating state of the conductive circuit insulation layer temperature stabilization is obtained.

[0076] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A temperature control driving method for a circulating water cooling system in a distribution box, characterized in that, include: The driving frequency of the water pump in the circulating water cooling system of the distribution box is obtained, and the driving frequency is processed by fast Fourier transform to obtain the periodic variation amplitude of the cooling water flow. Mechanical vibration signals of the joint are collected, and after removing environmental noise by bandpass filtering, the amplitude of the micro-vibration and the main frequency are extracted as mechanical state characterization quantities. An amplitude correspondence table is established based on the periodic variation amplitude of the cooling water flow and the mechanical state characterization quantities to delineate the stability boundary of the joint vibration load. The temperature at the top air outlet and bottom air inlet of the distribution box is collected and the vertical temperature difference is calculated. The height section of the box where the vertical temperature difference exceeds the design heat dissipation limit is marked as the uneven heat dissipation height section. Record the response time required for the flow meter reading to reach a steady state at the moment of water pump frequency switching, and determine the heat exchange instability area by combining the uneven heat dissipation height section; Based on the heat exchange instability region, retrieve the stability boundary of the joint vibration load of the corresponding pipeline section, search the amplitude correspondence table for the set of driving frequencies that fall within the preset safety margin range, and determine the pump driving frequency switching node. The variable frequency control command is generated based on the pump drive frequency switching node to drive the pump to maintain a stable laminar flow state of the cooling water in the heat exchange instability region.

2. The temperature control drive method for a circulating water cooling system in a distribution box according to claim 1, characterized in that, The process of obtaining the driving frequency of the water pump in the circulating water cooling system of the distribution box, and processing the driving frequency through a fast Fourier transform to obtain the periodic variation amplitude of the cooling water flow, includes: Obtain the pump operation record and flow meter reading, and align the real-time drive frequency with the flow meter reading according to the acquisition time to obtain the drive frequency sequence and synchronous flow sequence; The continuous sampling intervals are divided according to the driving frequency sequence. The frequency components and corresponding amplitudes of each sampling interval are obtained by using fast Fourier transform. The non-zero frequency component with the largest amplitude is selected to obtain the main period of the cooling water flow. The synchronous flow rate sequence is divided according to the main period to obtain the average value of the difference between the maximum flow rate and the minimum flow rate in each period to obtain the periodic change amplitude of the cooling water flow.

3. The temperature control drive method for a circulating water cooling system in a distribution box according to claim 1, characterized in that, The mechanical vibration signal of the acquired joint is filtered to remove environmental noise, and the amplitude of the small vibration and the dominant frequency are extracted as mechanical state characteristics. An amplitude correspondence table is established based on the periodic variation amplitude of the cooling water flow and the mechanical state characteristics to define the stability boundary of the joint vibration load, including: The sensor identification and mechanical vibration signal of the elbow and flange joint are acquired, and bandpass filtering is performed according to the preset passband. The difference between the maximum and minimum values ​​of the signal after bandpass filtering is taken as the amplitude of the micro-vibration. The non-zero frequency with the largest amplitude is extracted by fast Fourier transform as the main vibration frequency to obtain the mechanical state record. Based on the acquisition time of the mechanical state record, the periodic variation amplitude of the cooling water flow is matched, and the periodic variation amplitude, micro-vibration amplitude and main vibration frequency are recorded according to the sensor identification to obtain the amplitude correspondence table arranged according to the joint position. Obtain the upper limit of permissible vibration amplitude and the range of prohibited vibration frequencies for each joint from the pipeline structure file. Based on the amplitude correspondence table, filter the records that do not exceed the upper limit of permissible vibration amplitude and do not fall within the range of prohibited vibration frequencies to determine the vibration bearing stability boundary of the joint.

4. The temperature control drive method for a circulating water cooling system in a distribution box according to claim 1, characterized in that, The defined stability boundary for joint vibration bearing includes: Obtain the wall thickness, nominal diameter, bolt preload torque, and previous tightening records of elbow and flange joints. Compare the decrease in bolt preload torque relative to the initial value, classify the structural stiffness level according to the ratio of wall thickness to nominal diameter, and determine the position of easily loosened joints. Based on the position of the loose joint, the permissible vibration amplitude and prohibited frequency range that match the wall thickness, nominal diameter and bolt preload torque are retrieved from the preset structural load correspondence table to determine the upper limit of the micro-amplitude vibration amplitude and the prohibited frequency range of the main vibration frequency. The amplitude of the micro-vibration, the main frequency, the displacement of the joint, and the rebound of the fastener are arranged according to the periodic variation of the cooling water flow. When the amplitude of the micro-vibration reaches the upper limit of the amplitude of the micro-vibration or the main frequency enters the main frequency forbidden zone, the vibration bearing stability boundary is determined by the previous set of records in the previous fastening records according to the joint position.

5. The temperature control drive method for a circulating water cooling system in a distribution box according to claim 1, characterized in that, The temperature at the top air outlet and bottom air inlet of the distribution box is collected, and the vertical temperature difference is calculated. Sections of the box height where the vertical temperature difference exceeds the design heat dissipation limit are marked as uneven heat dissipation height sections, including: The measured temperatures at the top air outlet and the bottom air inlet are obtained and paired according to the same acquisition time. The absolute value of the difference between the measured temperatures at the top air outlet and the bottom air inlet is taken to obtain the vertical temperature difference value. Obtain the design heat dissipation limit from the nameplate on the enclosure, compare the vertical temperature difference with the design heat dissipation limit, and if the vertical temperature difference exceeds the design heat dissipation limit, then use the installation height of the two temperature sensors installed on the top air outlet and the bottom air inlet as the upper and lower boundaries to determine the uneven heat dissipation height section.

6. The temperature control drive method for a circulating water cooling system in a distribution box according to claim 1, characterized in that, Record the response time required for the flow meter reading to reach steady state at the moment of pump frequency switching. Combine this with the uneven heat dissipation height range to determine the heat transfer instability region, including: The pump frequency switching time and the flow meter reading after the pump frequency switching time are obtained. The change in adjacent readings is obtained according to the continuous sampling window. When the change in adjacent readings is continuously lower than the preset steady-state threshold, the response time is determined by the difference between the start time of the corresponding pump frequency window and the pump frequency switching time. If the response time exceeds the preset permitted time, the period between the pump frequency switching time and the start time of the steady-state window will be determined as the abnormal driving period. Based on the abnormal driving period, the pipeline topology and the height range of each pipe segment are retrieved, and pipe segments with overlapping heights are matched with uneven heat dissipation height segments to obtain height-mapped pipe segments. The flow duration is determined based on the length of each pipe segment and the corresponding flow rate. The abnormal driving period is traced back along the flow direction to obtain the time-traced pipe segment. If the pipe segment identifiers of the height-mapped pipe segment and the time-tracing pipe segment are consistent, the pipe segment is determined to be a heat exchange instability area.

7. The temperature control drive method for a circulating water cooling system in a distribution box according to claim 1, characterized in that, The process involves retrieving the stability boundary of the joint vibration load of the corresponding pipeline section based on the heat exchange instability region, searching the amplitude correspondence table for the set of driving frequencies falling within the preset safety margin range, and determining the pump drive frequency switching node, including: Based on the three-dimensional coordinate range of the heat exchange instability region, match the physical pipe segments that overlap in spatial range to determine the safe drive frequency record; The required flow rate corresponding to the current heat dissipation load is read from the pre-established table of heat dissipation load and cooling water flow rate. The frequency with the smallest difference between the flow meter reading and the current drive frequency is selected from the safe drive frequency record and determined as the water pump drive frequency switching node.

8. The temperature control drive method for a circulating water cooling system in a distribution box according to claim 1, characterized in that, The step of generating a frequency conversion adjustment command based on the water pump drive frequency switching node to drive the water pump to maintain a stable laminar flow state of the cooling water in the heat exchange instability region includes: The target drive frequency, switching time, and execution identifier are written into the pump drive frequency switching node to form a frequency conversion adjustment command, and the frequency conversion adjustment command is sent to the frequency conversion adjustment device to make the pump run at the target drive frequency. Obtain the inner diameter and flow meter reading of the pipe section corresponding to the heat exchange instability region, as well as the temperature of the insulation layer of the conductive circuit, and determine the flow velocity inside the pipe based on the inner diameter and flow meter reading; If the flow velocity inside the pipe is within a preset laminar flow velocity range and the temperature of the insulation layer is continuously within a preset stable temperature range, then the target driving frequency is maintained.

9. The temperature control drive method for a circulating water cooling system in a distribution box according to claim 1, characterized in that, The step of generating a frequency conversion adjustment command based on the water pump drive frequency switching node to drive the water pump to maintain a stable laminar flow state of the cooling water in the heat exchange instability region includes: Obtain the difference between the current operating frequency and the target driving frequency of the water pump and the adjustment direction, divide the frequency range into gears according to the preset adjustment range, configure the dwell time for each frequency range, and obtain the geared frequency sequence from the current operating frequency to the target driving frequency. The water pumps are driven sequentially according to the frequency sequence to obtain the flow rate, inlet water temperature, outlet water temperature and the insulation layer temperature of the conductive circuit at the inlet, middle and outlet of the pipe section corresponding to the heat exchange instability area, thus obtaining a segmented operation record including the flow rate difference, outlet water temperature rise and insulation layer temperature.

10. A temperature control driving method for a circulating water cooling system in a distribution box according to claim 9, characterized in that, The pumps are driven sequentially according to the defined frequency sequence to obtain the flow velocity, inlet water temperature, outlet water temperature, and conductive circuit insulation layer temperature at the inlet, middle, and outlet of the pipe section corresponding to the heat exchange instability region. This yields a segmented operation record including the flow velocity difference, outlet water temperature rise, and insulation layer temperature, including: Based on the segmented operation records, if the flow velocity difference at the same frequency is continuously lower than the uniform threshold, the flow velocity at each sampling location is in the laminar flow velocity range, the effluent temperature rise is in the heat exchange temperature rise range, and the insulation layer temperature is in the stable temperature range, then the frequency is determined as the dwell operation point, and the insulation layer temperature stabilizes and the operation state is obtained.

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