Efficient magnetic suspension water chilling unit control system

Abstract

The invention relates to the technical field of automatic control, in particular to an efficient magnetic suspension water chilling unit control system which comprises a refrigerant flow monitoring module, a dynamic flow adjusting module, a start-stop delay judging module, a temperature gradient sensing module and a frequency self-adaptive adjusting module. According to the method, the temperature difference curve is established through real-time monitoring data, the refrigerant flow synchronism is analyzed, temperature difference abnormity can be accurately recognized, the refrigerant adjusting requirement is extracted, traditional threshold value judgment lag is avoided, the refrigerant flow is controlled in real time, fluctuation impact is buffered, and the adjusting precision is improved by dynamically adjusting the opening degree of the electronic expansion valve and the rotating speed of the circulating pump; the method has the advantages that starting and stopping conditions are accurately judged, misoperation is reduced, early positioning of thermal imbalance is achieved through temperature difference sensing of an evaporator, a compression cavity and a condenser and establishment of an internal temperature difference distribution diagram, energy efficiency reduction is avoided, the frequency of a frequency converter is adjusted according to temperature difference distribution, the optimal load is matched, frequency adaptivity and system load response are improved, and refrigeration cycle energy efficiency is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control, in particular to a high-efficiency magnetic suspension chiller control system. Background Art

[0002] The field of automation control technology encompasses the automated operation and management of industrial equipment, electromechanical systems, and energy devices. The core of this technology involves the real-time monitoring, automatic adjustment, and optimized control of system operating parameters through the establishment of control logic, thereby reducing manual intervention and improving operational efficiency and stability. The automation control technology system encompasses sensor signal acquisition, controller judgment and processing, actuator action output, and system feedback correction. Its application scope covers a wide range of industrial and civilian systems, including manufacturing, energy management, and building equipment control, and it is a critical foundation for efficient operation and intelligent management.

[0003] The high-efficiency magnetic levitation chiller control system is designed to achieve overall coordinated control of the magnetic levitation compressor refrigeration cycle by controlling refrigerant flow, compressor start-stop control, evaporator and condenser temperature adjustment, and system operating parameter determination, based on the operating characteristics of the magnetic levitation chiller. Specific technical aspects covered by this system include dynamically adjusting the compressor frequency based on the changing patterns of inlet and outlet water temperatures, using refrigerant flow control logic to match load fluctuations, switching multiple compressors to coordinated operation based on heat exchange efficiency, and setting the chiller's start-stop logic strategy under different operating conditions to ensure that all components work together within the set range to avoid overload and efficiency fluctuations.

[0004] Existing technologies for controlling magnetic levitation chillers commonly suffer from simplistic temperature difference analysis, delayed refrigerant flow regulation, crude start / stop decisions, slow internal thermal imbalance detection, and crude load-frequency matching. These issues lead to flow anomalies, increased system oscillation, frequent false start / stop triggering, and significant energy efficiency fluctuations under varying operating conditions. Traditional systems rely solely on the inlet and outlet water temperature difference to roughly infer load status, lacking in-depth understanding of the synchronization between flow changes and temperature difference curves. This can easily lead to delayed regulation and refrigerant control's inability to respond promptly to load fluctuations, resulting in frequent system oscillations and increased energy consumption. Most start / stop logic relies on static thresholds and lacks awareness of dynamic temperature fluctuation trends, leading to significant deviations in start / stop behavior under actual load fluctuations and compromising equipment reliability. Internal thermal imbalance detection relies solely on single-point temperature monitoring, failing to promptly identify potential local overheating hazards. Compressors operate in suboptimal thermal conditions for extended periods, exacerbating energy consumption and the risk of failure. Frequency adjustment strategies employ fixed logic or timed adjustments, ignoring the dynamic characteristics of load fluctuations. This causes the compressor's operating frequency to deviate from the actual load and reduces overall energy efficiency. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the embodiment of the present invention provides a high-efficiency magnetic suspension chiller control system. The technical solution is as follows:

[0006] A high-efficiency magnetic levitation chiller control system is provided, which includes:

[0007] The refrigerant flow monitoring module, based on the monitoring data of the magnetic levitation chiller, extracts real-time data from the chilled water inlet and outlet temperature sensors and the refrigerant flow sensor, compares the inlet and outlet water temperatures to form a temperature difference curve, analyzes the synchronization between the temperature difference curve and the refrigerant flow changes, screens the flow states where the temperature difference fluctuation exceeds the set range, and generates refrigerant flow adjustment instructions;

[0008] The dynamic flow regulation module calls the refrigerant flow regulation instruction, adjusts the opening of the electronic expansion valve and the speed of the refrigerant circulation pump, synchronously controls the refrigerant flow to the instruction required range, monitors the flow change trend after adjustment, and obtains the refrigerant flow adjustment state value;

[0009] The start-stop delay determination module calls the refrigerant flow adjustment state value, detects the chilled water outlet temperature fluctuation rate, compares the temperature fluctuation rate with the set start-stop gradient standard, selects the state where the fluctuation exceeds the standard, and obtains the start-stop trigger determination signal;

[0010] The temperature gradient sensing module calls the start-stop trigger judgment signal, extracts real-time data of the evaporator temperature detection point, the compression chamber temperature detection point, and the condenser temperature detection point, analyzes the temperature gradient changes of key parts inside the compressor, screens the temperature gradient abnormal range, and generates an internal temperature difference distribution map.

[0011] As a further solution of the present invention, the refrigerant flow regulation instruction includes a temperature difference fluctuation range, a refrigerant flow change characteristic, and a flow regulation target value; the refrigerant flow adjustment state value includes a flow adjustment amplitude, a flow adjustment stability, and a flow adjustment response rate; the start-stop trigger judgment signal includes a temperature fluctuation out-of-limit mark, a start-stop gradient change amplitude, and a start-stop warning trigger threshold; the internal temperature difference distribution map includes an evaporator temperature difference distribution characteristic, a compression chamber temperature difference distribution characteristic, and a condenser temperature difference distribution characteristic.

[0012] As a further solution of the present invention, the refrigerant flow monitoring module includes:

[0013] The temperature difference extraction submodule extracts the chilled water inlet and outlet temperature sensor data based on the monitoring data of the magnetic levitation chiller, identifies the same time points, calculates the inlet and outlet water temperature difference, extracts the temperature difference change rate within a continuous period, and generates the temperature difference change gradient value;

[0014] The load offset identification submodule calls the temperature difference change gradient value and the refrigerant flow sensor data, extracts inconsistent sections based on the comparison of the flow change amplitude and the temperature difference change direction in each time period, and marks the time period when the refrigerant flow and load fluctuation directions are opposite, thereby generating a flow load deviation section set;

[0015] The adjustment command generation submodule extracts the refrigerant flow and temperature gradient values of the corresponding time period based on the flow load deviation segment set, calculates the deviation from the set control interval, evaluates the degree of offset, and determines the adjustment amplitude and direction of the target flow in combination with the characteristic curve of the magnetic levitation compressor to generate a refrigerant flow adjustment instruction.

[0016] As a further solution of the present invention, the dynamic flow regulation module includes:

[0017] The instruction deconstruction submodule calls the target electronic expansion valve opening and refrigerant circulation pump speed parameters in the refrigerant flow adjustment instruction, combines the real-time operating parameters of the equipment, identifies the electronic expansion valve opening and circulation pump speed errors, selects the control items that need to be forced to be corrected, and obtains the adjustment instruction offset group;

[0018] The linkage control submodule calls the adjustment instruction offset group, adjusts the component execution value cycle by cycle, analyzes the adjustment efficiency change in combination with real-time flow feedback, selects effective adjustment combinations based on efficiency fluctuations, and generates a magnetic levitation compression state adjustment group;

[0019] The flow efficiency evaluation submodule calls the corresponding flow change cycle and compressor operating frequency in the magnetic levitation compression state adjustment group, compares them with the benchmark cooling efficiency value, determines the deviation, calculates the compression operating frequency offset trend value, identifies the compression efficiency change trend caused by magnetic levitation flow adjustment, and obtains the refrigerant flow adjustment state value.

[0020] As a further solution of the present invention, the compression operation frequency offset trend value adopts the formula:

[0021]

[0022] Among them, G represents the compression operation frequency deviation trend value, Q k represents the change in refrigerant flow rate of the magnetic levitation compression state adjustment group in the kth cycle, P k Represents the cooling output power generated by the compressor per unit time in the kth cycle, R k represents the deviation between the real-time operating efficiency and the standard operating efficiency of the compressor in the kth cycle, γ k represents the compressor load correction coefficient caused by the environmental disturbance factor in the kth cycle, F represents the collected mean value of the periodic compressor frequency response, λ represents the dynamic flow transfer lag correction value in the refrigerant pipe network system, and m represents the number of data segments in the current evaluation cycle.

[0023] As a further solution of the present invention, the start-stop delay determination module includes:

[0024] The magnetic disturbance monitoring submodule calls the refrigerant flow adjustment state value, collects the instantaneous gradient of the chilled water outlet temperature in real time, combines the magnetic bearing current fluctuation data, identifies the coupling coefficient between the temperature change rate and the magnetic flow disturbance, and obtains the magnetic suspension disturbance amount;

[0025] The gradient rotor judgment module loads the start-stop speed gradient threshold of the magnetic levitation unit based on the magnetic levitation disturbance amount, uses a sliding window algorithm to differentiate the temperature and speed correlation curve, extracts the continuous time period of speed fluctuation exceeding the limit, and generates the gradient exceeding limit interval;

[0026] The energy efficiency trigger submodule matches the current energy efficiency coefficient and load status of the magnetic levitation compressor according to the gradient overlimit interval, compares the preset energy efficiency attenuation threshold and start-stop protection logic, activates the decision nodes that meet multiple condition constraints in the interval, and obtains the start-stop trigger judgment signal.

[0027] As a further solution of the present invention, the temperature gradient sensing module includes:

[0028] The magnetic disturbance synchronization submodule calls the start-stop trigger determination signal, synchronizes the temperature detection point data of the evaporator, compression chamber, and condenser, associates the displacement of the magnetic suspension rotor with the temperature sampling timing, and generates a magnetic disturbance coupling gradient set;

[0029] Based on the magnetic perturbation coupling gradient set, the gradient coupling submodule identifies the correlation coefficient between the evaporator-compression chamber temperature gradient and the axial vibration of the magnetic bearing, extracts the sudden change value of the condenser temperature difference during the speed transition period, screens the operating segments that exceed the magnetic flow stability threshold, and generates the magnetic perturbation gradient anomaly domain;

[0030] The energy efficiency thermal state submodule analyzes the attenuation of the energy efficiency coefficient and heat exchange efficiency of the magnetic levitation compressor based on the magnetic disturbance gradient anomaly domain, calculates the total energy efficiency and heat exchange efficiency, maps the dynamic difference between the evaporator heat absorption rate and the condenser heat dissipation rate in the anomaly domain, and generates an internal temperature difference distribution map.

[0031] As a further solution of the present invention, the total energy efficiency and heat exchange efficiency are calculated using the formula:

[0032]

[0033] Among them, η represents the total energy efficiency and heat exchange efficiency, A i Represents the heat transfer coefficient of the i-th component, ΔT i represents the temperature difference of the i-th component, B i represents the heat exchange area of the i-th component, C i represents the discharge coefficient of the i-th component, Di represents the evaporator heat absorption rate of the i-th component, E i represents the condenser heat dissipation rate of the i-th component, and n represents the total number of components.

[0034] As a further solution of the present invention, the system further includes a frequency adaptive adjustment module:

[0035] The frequency adaptive adjustment module calls the internal temperature difference distribution map, analyzes the compressor load state and frequency matching, adjusts the compressor inverter output frequency, matches the operating frequency to the optimal load range, and obtains a control frequency adjustment execution record;

[0036] The control frequency adjustment execution record includes compressor frequency change record, load matching adjustment record, and frequency optimization matching interval.

[0037] As a further solution of the present invention, the frequency adaptive adjustment module includes:

[0038] The magnetic levitation load analysis submodule calls the internal temperature difference distribution map, extracts the dynamic relationship between the compressor rotor speed and the evaporator heat flux density, identifies the matching deviation between the magnetic levitation bearing resonant frequency and the current load, and obtains the dynamic coefficient of the magnetic levitation load;

[0039] The resonant frequency domain submodule maps the magnetic levitation bearing resonance suppression frequency band and the condenser heat dissipation efficiency correlation curve based on the magnetic levitation load dynamic coefficient, traverses the compressor operating frequency and the bearing vibration phase sensitive area, screens the frequency points where the matching deviation exceeds the magnetic levitation stability threshold, and generates the resonance suppression frequency band;

[0040] The energy efficiency frequency modulation submodule adjusts the inverter output frequency to the optimal range of the dynamic stiffness of the magnetic levitation bearing according to the resonance suppression frequency band, synchronously compresses the hysteresis compensation amount of the pressure gradient of the compression chamber and the frequency change, records the frequency adjustment amplitude and the magnetic levitation energy efficiency maintenance rate, and obtains the control frequency adjustment execution record.

[0041] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0042] By establishing a temperature differential curve based on real-time monitoring data and analyzing the synchronization of refrigerant flow rate changes, the system can accurately identify abnormal temperature differential fluctuations and effectively extract refrigerant adjustment demand indicators, avoiding the response lag caused by traditional single-threshold judgment. By dynamically adjusting the opening of the electronic expansion valve and the speed of the refrigerant circulation pump, the system synchronizes and controls the refrigerant flow in real time, effectively mitigating the impact of severe flow fluctuations on system stability and improving the sophistication and accuracy of regulation. Based on the adjusted flow rate status value and the judgment criteria for the chilled water outlet temperature fluctuation rate, the system can accurately identify critical changes in start-stop conditions, reducing the risk of false operation caused by the single, rough start-stop judgment method. By sensing the temperature gradient at multiple points in the evaporator, compression chamber, and condenser, a detailed internal temperature differential distribution map is established, enabling early detection of thermal imbalances within the compressor and avoiding energy efficiency degradation caused by local thermal imbalances. The system adjusts the compressor inverter output frequency based on the temperature differential distribution characteristics, matching the operating frequency to the optimal load range in real time. This significantly improves the adaptability of frequency regulation and the system's load response efficiency, ensuring a smoother overall refrigeration cycle and maximizing energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 Schematic diagram of a high-efficiency magnetic levitation chiller control system provided by an embodiment of the present invention;

[0045] Figure 2 Schematic diagram of the system framework of the present invention;

[0046] Figure 3 This is a flow chart of the refrigerant flow monitoring module in the present invention;

[0047] Figure 4 This is a flow chart of the dynamic flow regulation module in the present invention;

[0048] Figure 5 This is a flow chart of the start-stop delay determination module in the present invention;

[0049] Figure 6 This is a flow chart of the temperature gradient sensing module in the present invention;

[0050] Figure 7 This is a flow chart of the frequency adaptive adjustment module in the present invention. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0052] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as an "exemplary" in the present invention should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner. Furthermore, in the embodiments of the present invention, "and / or" can mean both or either of the two.

[0053] In the embodiments of the present invention, the terms "image" and "picture" may be used interchangeably. It should be noted that, when the distinction between them is not emphasized, their intended meanings are the same. The terms "of," "corresponding," and "corresponding" may be used interchangeably. It should be noted that, when the distinction between them is not emphasized, their intended meanings are the same.

[0054] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0055] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0056] The embodiment of the present invention provides a high-efficiency magnetic suspension chiller control system, such as Figure 1-2 The schematic diagram of the high-efficiency magnetic levitation chiller control system shown in the figure includes:

[0057] The refrigerant flow monitoring module, based on the monitoring data of the magnetic levitation chiller, extracts real-time data from the chilled water inlet temperature sensor, chilled water outlet temperature sensor, and refrigerant flow sensor, compares the inlet and outlet water temperatures to form a temperature difference curve, analyzes the synchronization between the temperature difference curve and the refrigerant flow rate changes, screens flow states where the temperature difference fluctuation exceeds the set range, identifies the refrigerant adjustment demand mark, and generates refrigerant flow adjustment instructions;

[0058] The dynamic flow regulation module calls the refrigerant flow regulation instruction, adjusts the opening of the electronic expansion valve and the speed of the refrigerant circulation pump, synchronously controls the refrigerant flow to the instruction required range, monitors the flow change trend after adjustment, and obtains the refrigerant flow adjustment status value;

[0059] The start-stop delay determination module calls the refrigerant flow adjustment status value, detects the chilled water outlet temperature fluctuation rate, compares the temperature fluctuation rate with the set start-stop gradient standard, selects states where the fluctuation exceeds the standard, identifies the start-stop decision trigger mark, and obtains the start-stop trigger determination signal;

[0060] The temperature gradient sensing module uses the start / stop trigger judgment signal to extract real-time data from the evaporator temperature detection points, the compression chamber temperature detection points, and the condenser temperature detection points. It analyzes the temperature gradient changes in key parts inside the compressor, screens for abnormal temperature gradient intervals, locates the thermal imbalance state inside the chiller, and generates an internal temperature difference distribution map.

[0061] The frequency adaptive adjustment module calls the internal temperature difference distribution map, analyzes the compressor load status and frequency matching, adjusts the compressor inverter output frequency, corresponds the operating frequency to the optimal load range, and obtains the control frequency adjustment execution record.

[0062] The refrigerant flow regulation instruction includes the temperature difference fluctuation range, the refrigerant flow change characteristics, and the flow regulation target value. The refrigerant flow adjustment status value includes the flow adjustment amplitude, the flow adjustment stability, and the flow adjustment response rate. The start-stop trigger judgment signal includes the temperature fluctuation limit mark, the start-stop gradient change amplitude, and the start-stop warning trigger threshold. The internal temperature difference distribution map includes the evaporator temperature difference distribution characteristics, the compression chamber temperature difference distribution characteristics, and the condenser temperature difference distribution characteristics. The control frequency adjustment execution record includes the compressor frequency change record, the load matching adjustment record, and the frequency optimization matching interval.

[0063] Specifically, if Figure 2 、 3 As shown, the refrigerant flow monitoring module includes:

[0064] The temperature difference extraction submodule extracts the chilled water inlet and outlet temperature sensor data based on the monitoring data of the magnetic levitation chiller, identifies the same time points, calculates the inlet and outlet water temperature difference, extracts the temperature difference change rate within a continuous period, and generates the temperature difference change gradient value;

[0065] The magnetic levitation chiller monitors the inlet and outlet water temperatures in real time. The data source is two temperature sensors. Whenever the unit is running, the inlet and outlet water temperatures are continuously recorded by the sensors and then uploaded in real time through the data acquisition system. By comparing the difference between the inlet and outlet water temperatures at the same time point, the instantaneous temperature difference is obtained. The real-time data of the temperature difference is recorded over time. During a longer operating cycle, the temperature difference will fluctuate. By calculating the rate of change of the temperature difference over a period of time, the speed and trend of the temperature difference change can be identified. The indicator will help identify the load changes or potential performance deviations of the chiller. For example, if the temperature difference increases rapidly within a certain period of time, it means that the cooling efficiency of the chiller has decreased or the system load has increased. The data is used to generate a temperature difference change gradient value, which represents the rate of temperature difference change. This value is the key basis for subsequent diagnosis and adjustment of the control strategy.

[0066] The load offset identification submodule uses the temperature difference gradient value and refrigerant flow sensor data to extract inconsistent sections based on the comparison of the flow change amplitude and the temperature difference change direction within each time period. It also marks the periods where the refrigerant flow and load fluctuation directions are opposite to each other, and generates a flow load deviation section set.

[0067] Data from the temperature gradient and refrigerant flow sensors is received. The magnitude of the flow change and the direction of the temperature difference are two key factors for each time period. The magnitude of the refrigerant flow change is obtained by real-time monitoring of the refrigerant flow sensor, and the flow value represents the amount of refrigerant flowing through the cooling system. When the temperature gradient value fluctuates significantly, the direction of the temperature difference is calculated and compared with the direction of the refrigerant flow. If the flow and temperature difference directions are inconsistent, for example, the flow decreases while the temperature difference increases, this indicates that the system load changes do not match the refrigerant flow changes. This phenomenon indicates that the system operation is drifting or unstable. In this case, the time period is marked as a deviation segment and aggregated into a flow-load deviation segment set for subsequent analysis and adjustment. For example, if the refrigerant flow decreases by 10% and the temperature difference increases by 15% during a certain period, this is identified as a load deviation and marked as a deviation segment for subsequent adjustment.

[0068] The adjustment command generation submodule extracts the refrigerant flow rate and temperature gradient values for the corresponding period based on the flow load deviation segment set, calculates the deviation from the set control interval, evaluates the degree of deviation, and determines the adjustment amplitude and direction of the target flow rate in combination with the magnetic levitation compressor characteristic curve to generate the refrigerant flow adjustment command;

[0069] Based on the identified flow load deviation range, the refrigerant flow rate and temperature gradient values within that range are extracted, and the deviation between the current value and the set control range is calculated. The control range is set based on the unit's ideal operating conditions or established design standards. The deviation is calculated by comparing the actual refrigerant flow rate with the predetermined control flow rate. If the deviation is large, the current operating condition is considered unsatisfactory and adjustment is required. For example, if the set refrigerant flow rate is 10 tons / hour and the actual flow rate is 8 tons / hour, the deviation is -2 tons / hour. The temperature gradient value is also considered in the evaluation, and the magnitude and direction of the adjustment are calculated based on the magnitude of the temperature difference. The magnetic levitation compressor characteristic curve plays a key role. This curve reflects the compressor's performance under different operating conditions and can determine how to adjust the refrigerant flow rate in the current operating deviation. For example, if the compressor characteristic curve shows that the compressor efficiency decreases when the flow rate decreases, the refrigerant flow rate can be increased to restore load matching. The generated refrigerant flow adjustment command is transmitted to the chiller for execution, adjusting the refrigerant flow rate to restore system balance.

[0070] Specifically, if Figure 2 、 4As shown, the dynamic flow regulation module includes:

[0071] The instruction deconstruction submodule calls the target electronic expansion valve opening and refrigerant circulation pump speed parameters in the refrigerant flow control instruction, combines them with the real-time operating parameters of the equipment, identifies the errors in the electronic expansion valve opening and circulation pump speed, selects the control items that need to be forced to correct, and obtains the adjustment instruction offset group;

[0072] The refrigerant flow control instructions use the target electronic expansion valve opening and refrigerant circulation pump speed parameters. These parameters play a crucial role in chillers: the expansion valve controls the refrigerant flow, while the circulation pump controls the refrigerant's circulation rate. Real-time operating parameters such as flow, temperature, and pressure are collected and compared with the target parameters. By calculating the error between the expansion valve opening and the pump speed—the difference between the current expansion valve opening and the target opening, and the deviation between the current and set circulation pump speeds—the submodule can identify excessive errors. For example, if the target expansion valve opening is 50% but the actual opening is 55%, or the target circulation pump speed is 1500 rpm but the actual speed is 1400 rpm, these deviations are flagged and control items requiring mandatory correction are identified. Control items are corrected when the error exceeds a certain threshold. For example, the expansion valve opening and pump speed need to be adjusted to approach the target values. This process generates a control instruction offset group, indicating which adjustments the equipment needs to make.

[0073] The linkage control submodule calls the adjustment instruction offset group to adjust the component execution value cycle by cycle, and analyzes the change in adjustment efficiency based on real-time flow feedback. It selects effective adjustment combinations based on efficiency fluctuations and generates a magnetic levitation compression state adjustment group.

[0074] The previously generated adjustment command offset group is processed. Using this offset group, the execution values of various components in the chiller are adjusted cycle by cycle. The adjustment process analyzes the efficiency changes after the adjustments based on real-time flow feedback data, which reflects the actual operating status of the chiller. When making adjustments, attention is not only focused on the target settings for each component, but also on the overall performance of the equipment. Specifically, if the deviation between the refrigerant flow rate and the target value gradually decreases within a certain cycle and the chiller efficiency improves, the adjustment is considered effective. Conversely, if the flow feedback data shows no efficiency improvement, the current adjustment strategy needs to be re-optimized. By analyzing the efficiency fluctuations of different adjustment cycles, the most effective adjustment combination can be screened, namely the optimal expansion valve opening and pump speed combination. This combination contributes to stable system operation. Effective adjustment combinations are summarized as magnetic levitation compression state adjustment groups for subsequent equipment control and optimization.

[0075] The flow efficiency evaluation submodule calls the corresponding flow change cycle and compressor operating frequency in the magnetic levitation compression state adjustment group, compares them with the benchmark cooling efficiency value, determines the deviation, calculates the compression operating frequency offset trend value, identifies the compression efficiency change trend caused by magnetic levitation flow adjustment, and obtains the refrigerant flow adjustment state value;

[0076] To evaluate whether the magnetic levitation compressor maintains efficient operation in the adjusted state, data corresponding to the flow change cycle is extracted from the magnetic levitation compression state adjustment group. The flow change cycle reflects the changing trend of the refrigerant flow over a period of time. The operating frequency of the compressor is also extracted and compared with the benchmark cooling efficiency value. The benchmark cooling efficiency value is a standard value set through experiments or design, representing the operating efficiency under ideal conditions. If, during the comparison process, it is found that the deviation between the actual efficiency of the compressor and the benchmark value exceeds the preset range, then it means that the operating state of the compressor has changed adversely. In order to further analyze the trend of compressor operation, the offset trend value of the compressor operating frequency is calculated. This trend value reflects the frequency change trend of the compressor over a period of time. If the offset trend value shows that the frequency is gradually decreasing, it means that the compression efficiency change trend caused by the magnetic levitation flow adjustment is affecting the performance of the compressor, thereby causing the system efficiency to decrease. The refrigerant flow adjustment state value is obtained. This value is used to indicate whether the refrigerant flow adjustment has successfully restored the ideal operating state of the system;

[0077] Compress the operating frequency deviation trend value using the formula:

[0078]

[0079] Among them, G represents the compression operation frequency deviation trend value, Q k represents the change in refrigerant flow rate of the magnetic levitation compression state adjustment group in the kth cycle, P k Represents the cooling output power generated by the compressor per unit time in the kth cycle, R k represents the deviation between the real-time operating efficiency and the standard operating efficiency of the compressor in the kth cycle, γ k represents the compressor load correction coefficient caused by the environmental disturbance factor in the kth cycle, F represents the average value of the collected periodic compressor frequency response, λ represents the dynamic flow transfer lag correction value in the refrigerant pipe network system, and m represents the number of data segments in the current evaluation cycle;

[0080] The compression operating frequency offset trend value represents the change in the compressor's operating frequency caused by refrigerant flow regulation within a specific cycle. This value is calculated based on the combined influence of multiple factors, including refrigerant flow change, cooling output power, compressor operating efficiency, environmental disturbance factor, frequency response mean, and flow lag correction value. When the offset value is large, it means that refrigerant flow regulation has a significant impact on the operation of the compressor, which may cause the difference between the compressor operating frequency and the standard setting value to increase, thereby affecting the efficiency and energy consumption performance of the system. By calculating this value, the compression efficiency change trend caused by magnetic suspension flow regulation can be monitored and identified in real time, providing an important basis for subsequent adjustment and optimization.

[0081] Refrigerant flow change Q k :This parameter indicates the change in refrigerant flow rate of the magnetic levitation compression state adjustment group during the kth cycle. The refrigerant flow rate is monitored by the refrigerant flow sensor and collected by the flow meter. This value is expressed in cubic meters per minute (m3 / min). 3 / min). In practical applications, the pressure difference and temperature data based on the compressor inlet and outlet can be calculated through the state equation. For example, assuming that the refrigerant flow change in the first cycle is Q1 = 0.15m 3 / min;

[0082] The cooling output power P generated by the compressor operation per unit time k : This parameter represents the cooling output power of the compressor in the kth cycle. The cooling output of the compressor is obtained by calculating the condensing temperature, evaporating temperature and the performance parameters of the compressor. The cooling output power can be obtained by consulting the compressor performance curve or directly measuring it with a flow meter and temperature sensor. Assume that the cooling output power of the compressor in the first cycle is P1 = 10kW;

[0083] The deviation value η between the compressor's real-time operating efficiency and the standard operating efficiency k : This parameter represents the deviation between the actual efficiency of the compressor in the kth cycle and the standard efficiency. The standard efficiency is based on the design data provided by the manufacturer, while the actual efficiency is calculated based on the actual operating data of the compressor. The actual efficiency is estimated by monitoring the current, voltage and power consumption of the compressor and compared with the standard efficiency. Assume that the efficiency deviation value of the first cycle is η1 = 0.03 (3% deviation);

[0084] Compressor load correction factor γ caused by environmental disturbance factors k : This parameter represents the compressor load correction factor caused by environmental factors (such as temperature and humidity). The environmental sensor monitors the environmental conditions and calculates the disturbance factor, which affects the cooling output and energy efficiency of the compressor. Assume that the environmental disturbance factor in the first cycle is γ1 = 0.05;

[0085] Periodic compressor frequency response mean F: This parameter represents the frequency response mean of the compressor within a specific period, obtained through frequency analysis or vibration monitoring system. Assume that the periodic frequency response mean is F = 60Hz;

[0086] Dynamic flow transfer hysteresis correction value λ in the refrigerant pipe network system: This parameter represents the correction value caused by flow hysteresis in the refrigerant pipe network system. By monitoring the delay between flow change and time, the hysteresis correction value can be obtained. Assume that the hysteresis correction value of the refrigerant pipe network is λ = 0.02m 3 / min;

[0087] Enter the parameter value:

[0088] The results show that the operating frequency of the compressor shifts by 4.27 Hz in the current cycle, reflecting the trend of compression efficiency change caused by magnetic levitation flow regulation.

[0089] Specifically, if Figure 2 、 5 As shown, the start-stop delay determination module includes:

[0090] The magnetic disturbance monitoring submodule calls the refrigerant flow adjustment state value, collects the instantaneous gradient of the chilled water outlet temperature in real time, and combines it with the magnetic bearing current fluctuation data to identify the coupling coefficient between the temperature change rate and the magnetic flow disturbance, thereby obtaining the magnetic suspension disturbance value.

[0091] Based on the refrigerant flow rate, the state value is adjusted and real-time acquisition of the instantaneous gradient of the chilled water outlet temperature begins. The temperature gradient is the rate of temperature change per unit time. Using the temperature sensor installed in the real-time monitoring device, the temperature change at the chilled water outlet is captured and the temperature change rate is calculated. The system also monitors magnetic bearing current fluctuation data. Current fluctuation is caused by the adjustment of the magnetic bearing during operation of the magnetic levitation compressor. By comparing the temperature change rate and current fluctuation, the coupling coefficient between the two can be identified. The coupling coefficient reflects the relationship between temperature change and current fluctuation. If the temperature change rate is high and the current fluctuation is large, it indicates that the system is unstable and magnetic flow disturbance exists. By calculating the relationship between temperature and current fluctuation, the magnetic levitation disturbance value can be obtained. This is a quantitative indicator that indicates the degree of system performance fluctuation caused by magnetic flow disturbance. For example, if the instantaneous temperature gradient is 0.5°C / min and the current fluctuation is 0.1A during a certain period of time, the submodule can use its built-in algorithm to calculate a magnetic levitation disturbance value, which reflects the current operating status of the system.

[0092] The gradient rotor judgment module is based on the magnetic levitation disturbance amount, loads the magnetic levitation unit start-stop speed gradient threshold, uses the sliding window algorithm to differentiate the temperature and speed correlation curve, extracts the continuous time period of speed fluctuation exceeding the limit, and generates the gradient limit interval;

[0093] Based on the calculated magnetic levitation disturbance, a start-stop speed gradient threshold is applied. This threshold is used to determine whether the current speed change exceeds a predetermined range. In practice, the start-stop speed gradient threshold is set to a fixed range, such as ±200 rpm. This means that speed changes exceeding this range are considered excessive fluctuations. A sliding window algorithm is used to differentiate the temperature-speed correlation curve, calculating the relationship between temperature and speed changes. This process involves smoothing and differential calculations of the temperature and speed data to extract the trend of speed fluctuations. If the speed fluctuation amplitude exceeds the preset gradient threshold within a certain period of time, the sliding window algorithm identifies that period as a speed fluctuation exceeding the limit. For example, if the speed change exceeds the ±200 rpm threshold and lasts for a certain period of time (e.g., more than 5 minutes), the period is marked as a gradient exceeding the limit. This helps identify speed instability caused by temperature fluctuations or disturbances in the chiller, providing a basis for subsequent adjustments.

[0094] The energy efficiency trigger submodule matches the current energy efficiency coefficient of the magnetic levitation compressor with the load status according to the gradient over-limit interval, compares it with the preset energy efficiency attenuation threshold and start-stop protection logic, activates the decision nodes that meet multiple condition constraints within the interval, and obtains the start-stop trigger judgment signal;

[0095] When handling a gradient overrun interval, the system first checks the current energy efficiency coefficient (EEC) and load status of the magnetic levitation compressor. The EEC refers to the amount of electrical energy consumed per unit of cooling output, while the load status refers to the load currently being applied to the compressor. For example, if the EEC is 2.5kWh / Ton and the load status is 80%, the compressor's energy efficiency is considered ideal. This is then compared to the preset EEC degradation threshold and the start-stop protection logic. The EEC degradation threshold is set as a percentage. For example, if the EEC exceeds a preset threshold (e.g., 3.0kWh / Ton), the compressor's operating efficiency has decreased, necessitating the activation of the start-stop protection logic. The start-stop protection logic determines whether to shut down or restart the compressor based on the current load status and EEC. For example, if the system detects a high load and an EEC exceeding a preset threshold within a gradient overrun interval, and that the EEC has fluctuated significantly over time, it activates a decision node that satisfies multiple constraints to determine whether a start-stop operation is necessary. A start-stop trigger determination signal is then output to execute the system's start-stop control decision, thereby protecting the compressor system from unstable operating conditions.

[0096] Specifically, if Figure 2 、 6 As shown, the temperature gradient sensing module includes:

[0097] The magnetic disturbance synchronization submodule calls the start-stop trigger judgment signal, synchronizes the temperature detection point data of the evaporator, compression chamber, and condenser, associates the magnetic suspension rotor displacement with the temperature sampling timing, and generates a magnetic disturbance coupling gradient set;

[0098] First, the system receives a start / stop trigger signal, which is analyzed and used to determine the start / stop decision. It then synchronizes temperature data from the evaporator, compression chamber, and condenser. These data are collected from temperature sensors in key locations, providing real-time temperature information for each component. In actual operation, the evaporator controls the refrigerant's heat absorption, the compression chamber compresses the refrigerant, and the condenser releases the heat through heat dissipation. Therefore, temperature fluctuations are crucial to system stability. After synchronizing these temperature data, the system then combines this with the magnetically suspended rotor displacement, which reflects rotor deflection during operation and provides key indicators of vibration and load. Based on this data and the temperature sampling time series, a relationship between temperature and rotor displacement is established, generating a magnetic perturbation coupling gradient set. This gradient set further understands the interaction between temperature changes and rotor displacement, providing a basis for system tuning. For example, if the rotor displacement fluctuates significantly during a certain period of time, coupled with significant changes in evaporator temperature, this indicates that the system is experiencing some type of disturbance. Analyzing the coupling between temperature and rotor displacement can reveal the underlying relationship between these changes.

[0099] The gradient coupling submodule identifies the correlation coefficient between the evaporator-compression chamber temperature gradient and the axial vibration of the magnetic bearing based on the magnetic perturbation coupling gradient set, extracts the sudden change in the condenser temperature difference during the speed transition period, screens the operating segments that exceed the magnetic flow stability threshold, and generates the magnetic perturbation gradient anomaly domain.

[0100] The correlation coefficient between the temperature gradient between the evaporator and compression chamber and the axial vibration of the magnetic bearing is analyzed. The temperature gradient refers to the temperature difference between the evaporator and compression chamber. A large temperature gradient indicates uneven energy transfer or a mechanical fault, while the axial vibration of the magnetic bearing can reveal vibration problems in the system caused by load changes or mechanical imbalance. By comprehensively analyzing these two parameters, the presence of instability factors is further determined. Sudden changes in the condenser temperature difference during speed transitions are extracted. Speed transitions occur when the load changes rapidly, and the condenser temperature difference changes significantly during these times, providing the system with timely feedback on load changes. After selecting time periods, the system determines whether anomalies exist based on a set magnetic flux stability threshold. If the temperature gradient and vibration exceed the preset thresholds during certain operating segments, the segment is identified as an anomaly and marked as a magnetic disturbance gradient anomaly domain. This helps accurately locate potential fault areas and facilitates further corrective or adjustment measures. For example, if the temperature difference between the evaporator and compression chamber suddenly changes during a speed transition, and the vibration data also shows an abnormal range, this period will be marked as an anomaly for subsequent analysis and processing.

[0101] The energy efficiency thermal state submodule analyzes the attenuation of the energy efficiency coefficient and heat exchange efficiency of the magnetic levitation compressor based on the magnetic disturbance gradient anomaly domain, calculates the total energy efficiency and heat exchange efficiency, maps the dynamic difference between the evaporator heat absorption rate and the condenser heat dissipation rate within the anomaly domain, and generates an internal temperature difference distribution map.

[0102] The energy efficiency coefficient (EEC) and heat exchange efficiency degradation of a magnetic levitation compressor are analyzed. The EEC is measured by the amount of electrical energy consumed per unit of cooling output. As the system continues to operate, the EEC will degrade if abnormal disturbances occur. The heat exchange efficiency measures the heat exchange capacity of the evaporator and condenser under different operating conditions. When the system experiences an abnormal magnetic disturbance gradient, these two parameters are affected. The system's total energy efficiency and heat exchange efficiency are calculated to further analyze the energy efficiency trend during operation. If the system is in an abnormal region, the energy efficiency will fluctuate significantly. To assess performance in this region, the dynamic difference between the evaporator's heat absorption rate and the condenser's heat dissipation rate is mapped. This difference reflects the system's heat exchange capacity. A large difference indicates an imbalance in the heat exchange process, leading to reduced energy efficiency. The data is used to generate an internal temperature difference distribution map. This map shows the temperature differences between various parts of the system and whether there are excessive temperature differences, providing a visual basis for further adjustments and maintenance. For example, in a section with abnormal magnetic disturbance gradient, if the evaporator's heat absorption rate is 3kW, while the condenser's heat dissipation rate is only 2.5kW, the difference of 0.5kW indicates that the heat exchange is unbalanced. The map will visually display the difference to help detect and adjust system performance.

[0103] The total energy efficiency and heat exchange efficiency are calculated using the formula:

[0104]

[0105] Among them, η represents the total energy efficiency and heat exchange efficiency, A i Represents the heat transfer coefficient of the i-th component, ΔT i represents the temperature difference of the i-th component, B i represents the heat exchange area of the i-th component, C i represents the discharge coefficient of the i-th component, D i represents the evaporator heat absorption rate of the i-th component, E i represents the condenser heat dissipation rate of the i-th component, and n represents the total number of components;

[0106] Total energy efficiency and heat exchange efficiency are indicators that measure the overall energy efficiency and heat exchange efficiency of the system. They represent the heat transfer efficiency of each component within the system under certain operating conditions. This coefficient is calculated by considering factors such as the heat transfer coefficient, temperature difference, heat exchange area, flow coefficient, evaporator heat absorption rate, and condenser heat dissipation rate of each sub-module, and combining their impact on the heat exchange process. Higher total energy efficiency and heat exchange efficiency mean that the system is more efficient in heat transfer and energy utilization, indicating that the system can achieve better heat exchange effects with less energy consumption. Total energy efficiency and heat exchange efficiency are one of the key parameters for evaluating and optimizing system operating performance.

[0107] A i is the heat transfer coefficient of the i-th component, which indicates the heat exchange efficiency between each component and the fluid. It is obtained through actual testing or calculation of heat conduction model, and the unit is W / m 2 K, the heat transfer coefficient, is calculated based on parameters such as coolant type, flow state, and surface roughness;

[0108] ΔT i Represents the temperature difference of the i-th component, indicating the temperature difference of the fluid at both ends of the component, in K. This parameter is obtained by measuring the temperature of the coolant inlet and outlet through the temperature sensor, ΔT i The measurement is based on the temperature difference collected by the temperature sensor, assuming that ΔT i 15K;

[0109] B i is the heat exchange area of the ith component, in m 2 , which is calculated from the geometric dimensions of the component, including parameters such as pipe length, diameter and heat transfer surface area, B i The value is obtained by measuring or calculating the heat exchange area of the component, assuming that B i 20m 2 ;

[0110] C i is the flow coefficient of the ith component, indicating the fluid flow efficiency, in m 3 / s·K, this value is calculated based on the flow rate, viscosity, density and other parameters of the fluid, C i The flow coefficient is calculated based on the flow state of the fluid in the component, assuming that C i 0.3m 3 / s·K;

[0111] D i is the heat absorption rate of the evaporator of the i-th component, in W. This value is obtained by monitoring the flow sensor and temperature sensor, and represents the heat transferred by the evaporator during the heat absorption process;

[0112] E i is the heat dissipation rate of the condenser of the i-th component, in W. This value is calculated based on the temperature change and flow data of the condenser, and represents the heat released by the condenser;

[0113] During the calculation process, the parameters of each component are first quantified: A i The calculation basis is the heat conduction model of the fluid. In specific applications, based on the heat exchanger material and fluid conditions, the value is 500W / m 2 K;

[0114] D i and E i Represent the heat of the evaporator and condenser respectively, assuming that D i =3000W, E i =2800W;

[0115] Substituting the values into the formula, we get:

[0116] First calculate the fractional part:

[0117] Then calculate the square root part:

[0118] Next, multiply the values: 1250·14.14=17675;

[0119] If we assume that multiple components are considered and n is 3, then: η = 3·17675 = 53025;

[0120] The calculated η=53025W is the total energy efficiency and heat exchange efficiency of the system.

[0121] Specifically, if Figure 2 、 7 As shown, the frequency adaptive adjustment module includes:

[0122] The magnetic levitation load analysis submodule uses the internal temperature difference distribution map to extract the dynamic relationship between the compressor rotor speed and the evaporator heat flux density, identify the matching deviation between the magnetic levitation bearing resonant frequency and the current load, and obtain the dynamic coefficient of the magnetic levitation load;

[0123] First, an internal temperature difference distribution map is obtained. This map reflects the temperature differences in various areas inside the equipment, which helps to determine changes in the system's cooling efficiency. Based on the data, the dynamic relationship between the compressor rotor speed and the evaporator heat flux density is extracted. The rotor speed refers to the rotation speed of the compressor in the chiller, while the evaporator heat flux density represents the heat flow through the evaporator per unit time. By observing the relationship between the two at different time points, the interaction between the compressor and the evaporator can be revealed. When the rotor speed is higher, the evaporator heat flux density is higher, indicating that the cooling effect is more significant. Based on the relationship, the matching deviation between the resonant frequency of the magnetic bearing and the current load will be identified. The resonant frequency is the natural frequency of the magnetic bearing. When the load resonates with this frequency, it will cause system instability. By analyzing the deviation, a magnetic levitation load dynamic coefficient can be calculated to indicate the degree of influence of the system load on the vibration of the magnetic bearing. For example, under certain working conditions, the compressor speed is 1500rpm and the evaporator heat flux density is 3.0kW / m 2 The system will calculate the relationship between the rotational speed and the heat flux density based on the data, and further analyze the vibration characteristics of the magnetic bearing under the current load to evaluate the stability of the system.

[0124] The resonant frequency domain submodule maps the correlation curve between the magnetic bearing resonance suppression frequency band and the condenser heat dissipation efficiency based on the dynamic coefficient of the magnetic levitation load. It traverses the sensitive areas between the compressor operating frequency and the bearing vibration phase, screens the frequency points where the matching deviation exceeds the magnetic levitation stability threshold, and generates the resonance suppression frequency band.

[0125] The compressor's operating status is analyzed based on the dynamic coefficient of the magnetic levitation load, and the resonance suppression frequency band of the magnetic bearing is mapped. This frequency range effectively avoids resonance. Within this range, bearing vibration is effectively controlled, preventing damage to the equipment. A correlation curve between the condenser's heat dissipation efficiency and the frequency band is also mapped. The condenser's heat dissipation efficiency reflects the system's ability to transfer heat from the refrigerant to the environment. By comparing the condenser's heat dissipation efficiency with the resonance suppression frequency band, it is possible to identify frequency points that contribute to improved condenser heat exchange efficiency. The system then traverses the sensitive regions between the compressor's operating frequency and the bearing's vibration phase. This process is determined by analyzing the relationship between the bearing's vibration mode and speed changes at different frequencies. If the vibration amplitude at a certain frequency point is large and mismatched with the load, resulting in instability, the system selects frequencies where the matching deviation exceeds the magnetic levitation stability threshold. For example, if the bearing's vibration amplitude exceeds a predetermined range (e.g., exceeding 0.5mm) within a certain operating frequency band, this frequency point is marked as abnormal, and a corresponding resonance suppression frequency band is generated for subsequent frequency adjustment and equipment protection.

[0126] The energy efficiency frequency modulation submodule adjusts the inverter output frequency to the optimal range of the dynamic stiffness of the magnetic levitation bearing according to the resonance suppression frequency band, synchronizes the hysteresis compensation of the compression chamber pressure gradient and frequency change, records the frequency adjustment amplitude and magnetic levitation energy efficiency maintenance rate, and obtains the control frequency adjustment execution record;

[0127] The inverter output frequency is adjusted to the optimal range of the magnetic bearing's dynamic stiffness. This range is the frequency range where bearing vibration amplitude is minimized and system operation is most stable. Dynamic stiffness refers to the bearing's ability to suppress vibration during operation. By adjusting the inverter output frequency, the bearing is kept in optimal condition, thereby improving system stability. The system also simultaneously adjusts the pressure gradient in the compression chamber and takes into account the hysteresis compensation for frequency changes. This hysteresis compensation reflects the time difference in system response after frequency adjustment. By compensating for this time difference, the system can quickly stabilize. The frequency adjustment amplitude and magnetic levitation energy efficiency maintenance rate are recorded. The frequency adjustment amplitude represents the change in the inverter output frequency, while the magnetic levitation energy efficiency maintenance rate indicates the system's ability to maintain energy efficiency after the frequency adjustment. For example, if the inverter output frequency is adjusted from 50Hz to 55Hz and the energy efficiency maintenance rate reaches 95%, the adjusted system efficiency is relatively ideal. All data is recorded to generate a control frequency adjustment execution log.

[0128] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A high-efficiency magnetic levitation chiller control system, characterized in that: The system comprises: The refrigerant flow monitoring module, based on the monitoring data of the magnetic levitation chiller, extracts real-time data from the chilled water inlet and outlet temperature sensors and the refrigerant flow sensor, compares the inlet and outlet water temperatures to form a temperature difference curve, analyzes the synchronization between the temperature difference curve and the refrigerant flow changes, screens the flow states where the temperature difference fluctuation exceeds the set range, and generates refrigerant flow adjustment instructions; The dynamic flow regulation module calls the refrigerant flow regulation instruction, adjusts the opening of the electronic expansion valve and the speed of the refrigerant circulation pump, synchronously controls the refrigerant flow to the instruction required range, monitors the flow change trend after adjustment, and obtains the refrigerant flow adjustment state value; The start-stop delay determination module calls the refrigerant flow adjustment state value, detects the chilled water outlet temperature fluctuation rate, compares the temperature fluctuation rate with the set start-stop gradient standard, selects the state where the fluctuation exceeds the standard, and obtains the start-stop trigger determination signal; The temperature gradient sensing module calls the start-stop trigger judgment signal, extracts real-time data of the evaporator temperature detection point, the compression chamber temperature detection point, and the condenser temperature detection point, analyzes the temperature gradient changes of key parts inside the compressor, screens the temperature gradient abnormal range, and generates an internal temperature difference distribution map.

2. The high-efficiency magnetic levitation chiller control system according to claim 1 is characterized in that: The refrigerant flow regulation instruction includes the temperature difference fluctuation range, the refrigerant flow change characteristics, and the flow regulation target value. The refrigerant flow adjustment status value includes the flow adjustment amplitude, the flow adjustment stability, and the flow adjustment response rate. The start-stop trigger judgment signal includes the temperature fluctuation out-of-limit mark, the start-stop gradient change amplitude, and the start-stop warning trigger threshold. The internal temperature difference distribution map includes the evaporator temperature difference distribution characteristics, the compression chamber temperature difference distribution characteristics, and the condenser temperature difference distribution characteristics.

3. The high-efficiency magnetic levitation chiller control system according to claim 1 is characterized in that: The refrigerant flow monitoring module includes: The temperature difference extraction submodule extracts the chilled water inlet and outlet temperature sensor data based on the monitoring data of the magnetic levitation chiller, identifies the same time points, calculates the inlet and outlet water temperature difference, extracts the temperature difference change rate within a continuous period, and generates the temperature difference change gradient value; The load offset identification submodule calls the temperature difference change gradient value and the refrigerant flow sensor data, extracts inconsistent sections based on the comparison of the flow change amplitude and the temperature difference change direction in each time period, and marks the time period when the refrigerant flow and load fluctuation directions are opposite, thereby generating a flow load deviation section set; The adjustment command generation submodule extracts the refrigerant flow and temperature gradient values of the corresponding time period based on the flow load deviation segment set, calculates the deviation from the set control interval, evaluates the degree of offset, and determines the adjustment amplitude and direction of the target flow in combination with the characteristic curve of the magnetic levitation compressor to generate a refrigerant flow adjustment instruction.

4. The high-efficiency magnetic levitation chiller control system according to claim 3 is characterized in that: The dynamic flow regulation module includes: The instruction deconstruction submodule calls the target electronic expansion valve opening and refrigerant circulation pump speed parameters in the refrigerant flow adjustment instruction, combines the real-time operating parameters of the equipment, identifies the electronic expansion valve opening and circulation pump speed errors, selects the control items that need to be forced to be corrected, and obtains the adjustment instruction offset group; The linkage control submodule calls the adjustment instruction offset group, adjusts the component execution value cycle by cycle, analyzes the adjustment efficiency change in combination with real-time flow feedback, selects effective adjustment combinations based on efficiency fluctuations, and generates a magnetic levitation compression state adjustment group; The flow efficiency evaluation submodule calls the corresponding flow change cycle and compressor operating frequency in the magnetic levitation compression state adjustment group, compares them with the benchmark cooling efficiency value, determines the deviation, calculates the compression operating frequency offset trend value, identifies the compression efficiency change trend caused by magnetic levitation flow adjustment, and obtains the refrigerant flow adjustment state value.

5. The high-efficiency magnetic levitation chiller control system according to claim 4 is characterized in that: The compression operation frequency deviation trend value adopts the formula: Among them, G represents the compression operation frequency deviation trend value, Q k represents the change in refrigerant flow rate of the magnetic levitation compression state adjustment group in the kth cycle, P k Represents the cooling output power generated by the compressor per unit time in the kth cycle, R k represents the deviation between the real-time operating efficiency and the standard operating efficiency of the compressor in the kth cycle, γ k represents the compressor load correction coefficient caused by the environmental disturbance factor in the kth cycle, F represents the collected mean value of the periodic compressor frequency response, λ represents the dynamic flow transfer lag correction value in the refrigerant pipe network system, and m represents the number of data segments in the current evaluation cycle.

6. The high-efficiency magnetic levitation chiller control system according to claim 4 is characterized in that: The start-stop delay determination module includes: The magnetic disturbance monitoring submodule calls the refrigerant flow adjustment state value, collects the instantaneous gradient of the chilled water outlet temperature in real time, combines the magnetic bearing current fluctuation data, identifies the coupling coefficient between the temperature change rate and the magnetic flow disturbance, and obtains the magnetic suspension disturbance amount; The gradient rotor judgment module loads the start-stop speed gradient threshold of the magnetic levitation unit based on the magnetic levitation disturbance amount, uses a sliding window algorithm to differentiate the temperature and speed correlation curve, extracts the continuous time period of speed fluctuation exceeding the limit, and generates the gradient exceeding limit interval; The energy efficiency trigger submodule matches the current energy efficiency coefficient and load status of the magnetic levitation compressor according to the gradient overlimit interval, compares the preset energy efficiency attenuation threshold and start-stop protection logic, activates the decision nodes that meet multiple condition constraints in the interval, and obtains the start-stop trigger judgment signal.

7. The high-efficiency magnetic levitation chiller control system according to claim 6, characterized in that: The temperature gradient sensing module includes: The magnetic disturbance synchronization submodule calls the start-stop trigger determination signal, synchronizes the temperature detection point data of the evaporator, compression chamber, and condenser, associates the displacement of the magnetic suspension rotor with the temperature sampling timing, and generates a magnetic disturbance coupling gradient set; Based on the magnetic perturbation coupling gradient set, the gradient coupling submodule identifies the correlation coefficient between the evaporator-compression chamber temperature gradient and the axial vibration of the magnetic bearing, extracts the sudden change value of the condenser temperature difference during the speed transition period, screens the operating segments that exceed the magnetic flow stability threshold, and generates the magnetic perturbation gradient anomaly domain; The energy efficiency thermal state submodule analyzes the attenuation of the energy efficiency coefficient and heat exchange efficiency of the magnetic levitation compressor based on the magnetic disturbance gradient anomaly domain, calculates the total energy efficiency and heat exchange efficiency, maps the dynamic difference between the evaporator heat absorption rate and the condenser heat dissipation rate in the anomaly domain, and generates an internal temperature difference distribution map.

8. The high-efficiency magnetic levitation chiller control system according to claim 7, characterized in that: The total energy efficiency and heat exchange efficiency are calculated using the formula: Among them, η represents the total energy efficiency and heat exchange efficiency, A i Represents the heat transfer coefficient of the i-th component, ΔT i represents the temperature difference of the i-th component, B i Represents the heat exchange area of the i-th component, C i represents the discharge coefficient of the i-th component, D i represents the evaporator heat absorption rate of the i-th component, E i represents the condenser heat dissipation rate of the i-th component, and n represents the total number of components.

9. The high-efficiency magnetic levitation chiller control system according to claim 1, characterized in that: The system also includes a frequency adaptive adjustment module: The frequency adaptive adjustment module calls the internal temperature difference distribution map, analyzes the compressor load state and frequency matching, adjusts the compressor inverter output frequency, matches the operating frequency to the optimal load range, and obtains a control frequency adjustment execution record; The control frequency adjustment execution record includes compressor frequency change record, load matching adjustment record, and frequency optimization matching interval.

10. The high-efficiency magnetic levitation chiller control system according to claim 9, characterized in that: The frequency adaptive adjustment module includes: The magnetic levitation load analysis submodule calls the internal temperature difference distribution map, extracts the dynamic relationship between the compressor rotor speed and the evaporator heat flux density, identifies the matching deviation between the magnetic levitation bearing resonant frequency and the current load, and obtains the dynamic coefficient of the magnetic levitation load; The resonant frequency domain submodule maps the magnetic levitation bearing resonance suppression frequency band and the condenser heat dissipation efficiency correlation curve based on the magnetic levitation load dynamic coefficient, traverses the compressor operating frequency and the bearing vibration phase sensitive area, screens the frequency points where the matching deviation exceeds the magnetic levitation stability threshold, and generates the resonance suppression frequency band; The energy efficiency frequency modulation submodule adjusts the inverter output frequency to the optimal range of the dynamic stiffness of the magnetic levitation bearing according to the resonance suppression frequency band, synchronously compresses the hysteresis compensation amount of the pressure gradient of the compression chamber and the frequency change, records the frequency adjustment amplitude and the magnetic levitation energy efficiency maintenance rate, and obtains the control frequency adjustment execution record.

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