Variable frequency dehumidifier temperature regulation system with step protection and EEV cooperative control

Abstract

The application belongs to the technical field of dehumidifiers, and discloses a variable-frequency dehumidifier temperature regulation system with step protection and EEV cooperative control, which realizes gradual protection through a three-stage step protection mechanism and dynamic threshold correction design; when first-stage early warning, fine-tuning parameters maintain low-load operation, when second-stage regulation, linkage heat dissipation auxiliary function is forced to cool down, and when third-stage emergency protection, the circuit is cut off to stop, thereby avoiding the impact of direct stop on the compressor, EEV and other core components, and prolonging the service life of the equipment; the protection threshold is corrected in real time by a decision fault-tolerant module according to the environmental temperature and humidity and equipment load, thereby reducing protection false triggering; through EEV double-PID cooperative control and compression linkage closed-loop design, the temperature control precision and heat exchange efficiency are improved; the EEV regulation module adopts temperature deviation PID and overheating degree PID dynamic weighted adjustment, combined with temperature fluctuation prediction mode, thereby avoiding the situation of evaporator frosting and condenser heat exchange efficiency reduction.

Description

Technical Field

[0001] This invention belongs to the field of dehumidifier technology, specifically a variable frequency dehumidifier temperature control system with stepped protection and EEV collaborative control. Background Technology

[0002] Variable frequency dehumidifiers, with their advantages of low energy consumption, high dehumidification efficiency, and low operating noise, are widely used in homes, warehouses, laboratories, and agricultural product drying. Their core performance depends on the accuracy of temperature control, the stability of equipment operation, and the rationality of energy efficiency. Currently, the temperature control and protection systems of variable frequency dehumidifiers mainly suffer from the following technical problems: Existing temperature and humidity protection systems mostly use fixed threshold triggers, setting only a single temperature point as the protection condition without considering environmental humidity and equipment load. This makes it easy for protection actions to be falsely triggered or delayed, affecting the continuity of dehumidification and failing to fully guarantee equipment safety. Furthermore, protection actions are mostly direct shutdowns without tiered buffering, which can easily damage core components such as compressors and EEVs, shortening equipment lifespan.

[0003] As a core throttling component, the existing electronic expansion valve (EEV) uses a single superheat PID control for its opening adjustment, which is independent of the temperature control logic and disconnected from the compressor frequency regulation. This makes it unable to dynamically adapt to temperature deviations and protection levels. When the temperature fluctuates or the equipment enters a protection state, the EEV adjustment lags, which can easily lead to evaporator frosting, reduced condenser heat exchange efficiency, and exacerbate temperature control imbalance.

[0004] The existing system relies on a single ambient temperature sensor to collect data, without integrating parameters such as coil temperature and compressor discharge temperature. Furthermore, the compressor frequency adjustment step size is fixed, resulting in easy oscillation at low frequencies and lag in response at high frequencies, leading to large temperature fluctuations. At the same time, the temperature and humidity control logic is fragmented, directly shutting down the compressor after exiting the cooling mode, and requiring restarting if the humidity does not meet the standard, which further increases energy consumption due to frequent start-stop cycles. Summary of the Invention

[0005] The purpose of this invention is to provide a variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a variable frequency dehumidifier temperature control system including stepped protection and EEV coordinated control, comprising: Preferably, the multi-dimensional sensing module integrates an ambient temperature and humidity sensor, a coil temperature sensor, a compressor exhaust temperature sensor, an EEV inlet and outlet temperature difference sensor, and a variable frequency compressor current sensor. The ambient temperature and humidity sensor is used to collect real-time indoor temperature and humidity, the coil temperature sensor is used to continuously collect the evaporator and condenser coil temperatures to divide the operating cycle, the compressor exhaust temperature sensor is used to collect the compressor exhaust port temperature, the EEV inlet and outlet temperature difference sensor provides feedback on the EEV throttling effect, and the variable frequency compressor current sensor is used to assist in judging the equipment operating load. A dynamic sampling frequency adjustment mechanism is adopted. When the temperature fluctuation is ≤0.5℃, the sampling period is set to 5s. When the temperature fluctuation is >0.5℃ or the system enters the stepped protection state, the sampling period is shortened to 1s. At the same time, the collected data is filtered and noise-reduced to remove abnormal data. The collected real-time data is synchronously transmitted to the graded protection module, EEV control module and decision fault tolerance module.

[0007] Data transmission delay is ≤0.5s. Direct communication between modules is adopted to ensure that each functional module can synchronously execute control and protection actions based on real-time data, avoiding control imbalance caused by data lag.

[0008] Preferably, the graded protection module constructs a three-level tiered protection mechanism, which triggers corresponding protection actions based on real-time temperature and humidity, equipment load and other data collected by the multi-dimensional sensing module. The protection threshold of each level is dynamically corrected by the decision fault tolerance module according to the system operation data, and each level of protection is linked with the EEV control module and the compression linkage module to perform coordinated operations. The first-level early warning protection corresponds to scenarios where the temperature is close to the threshold and there is no risk of overload. When the ambient temperature, coil temperature or compressor exhaust temperature reaches the early warning threshold and the temperature fluctuation within the cycle meets the preset conditions, the system will not trigger a shutdown but will only send an early warning signal. The system will simultaneously instruct the EEV control module to fine-tune the EEV opening and the compression linkage module to control the variable frequency compressor to reduce the frequency, maintain the equipment operating at a low load, and continuously receive real-time data from the multi-dimensional sensing module to monitor temperature changes. The criteria for determining no overload risk are: the variable frequency compressor current is ≤80% of the rated current, the temperature difference between the EEV inlet and outlet is within the normal throttling range of 8-15℃, and the compressor exhaust temperature is ≤80℃. If all three conditions are met, it is determined that there is no overload risk.

[0009] Level 2 control protection is for scenarios where the temperature exceeds the limit and there is a slight overload. When the temperature continues to rise and reaches the control threshold, and the equipment running time meets the preset conditions, the EEV control module is instructed to adjust the EEV opening according to the gradient, the compression linkage module will reduce the frequency of the variable frequency compressor, and the condenser heat dissipation auxiliary function will be activated to force the temperature to drop. If the temperature does not drop within 30 seconds, it will enter Level 3 protection. The criteria for judging a slight overload are: the variable frequency compressor current is in the range of 80%-100% of the rated current, the temperature difference between the EEV inlet and outlet is ≥15℃ and ≤20℃, and the compressor exhaust temperature is in the range of 80℃-90℃. If all three conditions are met, it is judged as a slight overload.

[0010] The heat dissipation auxiliary function is achieved by turning on the auxiliary cooling fan on the condenser side. The fan speed is dynamically adjusted according to the condenser coil temperature: 70% of the rated speed when the coil temperature is 60-63℃, 90% of the rated speed when it is 63-65℃, 100% of the rated speed when it is ≥65℃, and the auxiliary fan is turned off when the temperature drops below 58℃.

[0011] The Level 3 emergency protection is designed for scenarios involving severely excessive temperatures and heavy overloads. When the temperature reaches the emergency threshold, or when an abnormal current or EEV jamming occurs, the system immediately instructs the compression linkage module to stop the variable frequency compressor and the EEV control module to close the EEV opening to cut off the heat exchange circuit. At the same time, the protection trigger information is fed back to the decision-making fault-tolerant module, which records the protection trigger time, trigger cause, and the temperature and humidity data at that time. After the temperature drops to the safety threshold, the decision-making fault-tolerant module instructs all relevant modules to start restart testing. After confirming that there are no abnormalities, the system will resume operation.

[0012] The criteria for judging severe overload are: the inverter compressor current is greater than 100% of the rated current, the temperature difference between the EEV inlet and outlet is greater than 20℃, and the compressor discharge temperature is greater than 90℃. If any one of these conditions is met, it is judged as severe overload and triggers the three-level emergency protection.

[0013] Preferably, the EEV control module receives temperature control commands from the decision-tolerance module and protection level signals from the graded protection module. It then dynamically adjusts the EEV opening based on multi-dimensional data collected by the multi-dimensional sensing module, including temperature and humidity, and the temperature difference between the EEV inlet and outlet. A dual-algorithm control system, employing both temperature deviation PID and overheat PID algorithms, dynamically switches adjustment weights according to different operating scenarios to ensure the temperature remains stable within a set threshold range. Under stepped protection conditions, it receives protection level commands from the graded protection module. In level one warning mode, it prioritizes overheat adjustment; in level two control mode, it simultaneously strengthens the coordinated adjustment of temperature deviation and overheat. When the temperature fluctuates rapidly, it activates a predictive adjustment mode based on temperature change data collected by the multi-dimensional sensing module, adjusting the EEV opening in advance. The prediction time window is set to 3 seconds. Based on the slope of temperature change within the past 3 seconds, the subsequent temperature trend is predicted, and the adjustment range is 1.2 times that of the normal adjustment range to ensure timely intervention before the temperature fluctuation expands.

[0014] The EEV control module and the compression linkage module achieve real-time linkage, synchronously receiving the collaborative instructions from the decision fault tolerance module. When the compressor frequency increases, the EEV opening is increased synchronously; when the compressor frequency decreases, the EEV opening is decreased synchronously. The adjustment parameters are fed back to the data optimization module in real time.

[0015] Preferably, the compression linkage module receives temperature control commands from the decision fault tolerance module and protection action commands from the graded protection module, forming a collaborative closed loop with the EEV control module to dynamically adjust the operating frequency of the variable frequency compressor. Simultaneously, it receives data such as equipment load and exhaust temperature collected by the multi-dimensional sensing module. A dynamic step-size adjustment mechanism matching temperature deviation and load is adopted. Based on the temperature deviation data fed back by the multi-dimensional sensing module, when the temperature deviation is ≥1℃, the frequency adjustment step size is set to 5Hz / s; when the temperature deviation is <1℃, the adjustment step size is reduced to 1Hz / s. At the same time, a preset compressor resonant frequency range is established, and when the frequency approaches the preset compressor resonant frequency range, the resonant frequency point is automatically skipped. The compression linkage module is linked in real time with the graded protection module and the EEV control module. It responds to the protection commands of each level of the graded protection module. When the first level warning occurs, the compressor frequency is reduced, and the opening degree of the EEV control module is finely adjusted. The frequency reduction is 5Hz, which is reduced to 80% of the current frequency (not lower than 30Hz). The frequency is maintained until the temperature drops below the warning threshold. During secondary control, the compressor further reduces its frequency to work with the EEV control module to balance the system load; it further reduces the frequency by 10Hz, or to 60% of the current frequency (not lower than 30Hz), working in conjunction with EEV opening adjustment and heat dissipation auxiliary functions; in case of emergency protection, it immediately triggers a shutdown action; when the temperature rises back to the normal range, it gradually increases the frequency based on the humidity data fed back by the multi-dimensional sensing module, and parameters such as operating frequency and start / stop status are synchronously fed back to the data optimization module.

[0016] Preferably, the decision-making fault-tolerant module incorporates an intelligent decision-making algorithm that integrates multi-dimensional information such as temperature deviation from the multi-dimensional sensing module, opening data from the EEV control module, frequency data from the compression linkage module, and protection status from the graded protection module. This allows for real-time assessment of the system's operating status, dynamic correction of the three-level protection thresholds of the graded protection module, and adjustment parameters of the EEV control module and the compression linkage module. Furthermore, it constructs a fault type database and, by comparing the real-time operating data transmitted by each module with preset simulation model parameters, predicts abnormal situations in the multi-dimensional sensing module, EEV control module, and compression linkage module, and sends early warning signals to the human-machine monitoring module in advance. A fault-tolerance mechanism is set up so that when a sensor fails, data from other relevant sensors in the multi-dimensional sensing module are automatically called for replacement calculations. When the EEV is slightly stuck, the EEV control module is instructed to adjust the adjustment step size and force the EEV to move. The criteria for determining mild EEV jamming are as follows: after the EEV is instructed to adjust its opening, the actual opening deviates from the target opening by ≥5% and ≤10% for two consecutive sampling cycles. If the deviation does not reach this range or the deviation is >10%, it is determined to be severe jamming.

[0017] Adjust the step size to 1.5 times the normal step size. The normal step size is 3%-5% each time. After driving 3 times in a row, check the opening deviation. If the deviation is ≤3%, restore the normal step size. If it still exceeds the standard, trigger the severe jamming fault protection.

[0018] When a fault cannot heal itself, the instruction hierarchical protection module activates the corresponding protection status, while recording the fault data and feeding it back to the human-machine monitoring module and the data optimization module.

[0019] If a single module fails to transmit valid data for five consecutive sampling cycles, or transmits data that exceeds the preset simulation model parameter range for three consecutive sampling cycles, the module is deemed abnormal.

[0020] Preferably, the data optimization module collects sampling data from the multi-dimensional sensing module, protection action records from the graded protection module, opening adjustment data from the EEV control module, frequency operation data from the compression linkage module, fault records and control command data from the decision fault tolerance module, and operation records from the human-machine monitoring module. It then uses algorithms to analyze and optimize the tiered protection threshold, EEV control parameters, and compressor frequency adjustment strategy. A built-in data storage unit is available to store at least one year's worth of system operation data. Machine learning algorithms are used to analyze the stored data and uncover the correlation between temperature fluctuations, EEV adjustment, compressor operation, and energy consumption. The system regularly optimizes parameters such as the three-level protection threshold of the graded protection module, the dual PID adjustment weight of the EEV control module, and the frequency adjustment step size of the compression linkage module. The optimized parameters are synchronously fed back to the decision fault tolerance module, which then updates the control strategies of each corresponding module. At the same time, it supports importing operating data from different application scenarios through the human-machine monitoring module to optimize relevant parameters.

[0021] The optimized parameters take effect in a "hot" manner, without requiring a system restart. After the decision-making fault tolerance module updates the parameters, they are immediately sent to the corresponding modules. The new parameters overwrite the old parameters and are executed immediately. If the optimized parameters cause system fluctuations, i.e., the temperature deviation is >1℃, the system will automatically roll back to the previous valid parameters to ensure stable operation.

[0022] In addition to fixed-period optimization, when the system triggers Level 3 protection ≥ 2 times or the same fault type warning ≥ 5 times in a single operation, a temporary optimization process is immediately initiated to quickly calibrate the control parameters to adapt to the current operating environment.

[0023] Preferably, the human-machine monitoring module receives system operating status, fault information, and real-time operating parameters of each module from the decision-making fault-tolerant module. It also enables manual control commands to be linked with each functional module. Equipped with a local touchscreen display, it displays real-time temperature and humidity data from the multi-dimensional sensing module, protection status of the graded protection module, EEV opening degree of the EEV control module, compressor frequency of the compression linkage module, system runtime, and fault records from the decision-making fault-tolerant module. It supports manual adjustment of parameters such as set temperature, protection threshold of the graded protection module, and adjustment sensitivity of the EEV control module. Manual operation commands are sent to the decision-making fault-tolerant module, which then forwards them to the corresponding functional modules for execution. The EEV sensitivity adjustment has 5 levels. Level 1 is the lowest sensitivity with a 1-second response delay, and Level 5 is the highest sensitivity with a 0.2-second response delay. The adjustment is synchronized to the EEV control module in real time after the level is switched.

[0024] It has a built-in wireless communication module, which supports remote connection to a mobile APP or monitoring platform to remotely view the operating status of each module, send control commands, and receive fault warnings and protection action reminders forwarded by the decision-making fault-tolerant module; it also supports fault data export. The system has multiple preset modes, such as home, laboratory, warehouse, and agricultural product drying. After switching, the system automatically calls the corresponding control parameters and protection thresholds that have been optimized by the data optimization module.

[0025] The beneficial effects of this invention are as follows: 1. This invention achieves progressive protection through a three-level tiered protection mechanism and dynamic threshold correction design; the first level of early warning fine-tunes parameters to maintain low-load operation, the second level of regulation links the heat dissipation auxiliary function to force cooling, and the third level of emergency protection cuts off the circuit to shut down, avoiding the impact of direct shutdown on core components such as the compressor and EEV, and extending the equipment life; the protection threshold is corrected in real time by the decision fault tolerance module according to the ambient temperature and humidity and equipment load, reducing false triggering of protection, ensuring the continuity of the dehumidification process, and adapting to the stable operation needs of multiple scenarios such as home and warehouse.

[0026] 2. This invention improves temperature control accuracy and heat exchange efficiency through EEV dual PID collaborative control and compression linkage closed-loop design. The EEV control module adopts dynamic weighted adjustment of temperature deviation PID and superheat PID, combined with temperature fluctuation prediction mode, to avoid evaporator frosting and condenser heat exchange efficiency reduction. It is linked in real time with the compression linkage module, and the EEV opening is adjusted synchronously when the compressor frequency increases / decreases to ensure accurate matching between heat exchange system flow and equipment load. The compressor adopts a dynamic step size adjustment mechanism to skip the resonant frequency range, solving the problems of low-frequency oscillation and high-frequency response lag, reducing operating noise and energy consumption, and achieving dual optimization of temperature control and energy saving.

[0027] 3. This invention achieves full-scenario adaptive control through a collaborative design of multi-dimensional perception, decision-making fault tolerance, and data optimization. The multi-dimensional perception module integrates five types of sensors, dynamically adjusts the sampling frequency, and purifies the data to provide a basis for control. The decision-making fault tolerance module has a fault prediction and alternative operation mechanism. When sensors fail or the EEV experiences slight lag, it can self-heal through data substitution or step size adjustment to ensure system stability. The data optimization module uses machine learning to discover operating patterns, periodically iterates protection thresholds and control strategies, and supports the import of multi-scenario data to adapt to differentiated needs. The temperature and humidity collaborative control logic avoids frequent start-stop after the cooling mode is exited, further reducing energy consumption. Combined with the local and remote operation functions of the human-machine monitoring module, it improves ease of use and operation and maintenance efficiency. Attached Figure Description

[0028] Figure 1 This is the overall system flowchart of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1 As shown, this embodiment of the invention provides a variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control, including: The multi-dimensional sensing module integrates an ambient temperature and humidity sensor, a coil temperature sensor, a compressor exhaust temperature sensor, an EEV inlet and outlet temperature difference sensor, and a variable frequency compressor current sensor. The ambient temperature and humidity sensor is used to collect real-time indoor temperature and humidity. The coil temperature sensor is used to continuously collect the evaporator and condenser coil temperatures to divide the operating cycle. The compressor exhaust temperature sensor is used to collect the compressor exhaust port temperature. The EEV inlet and outlet temperature difference sensor provides feedback on the EEV throttling effect. The variable frequency compressor current sensor is used to assist in judging the equipment operating load. The ambient temperature and humidity sensors have an accuracy of ±0.3℃ for temperature and ±2%RH for humidity; the coil temperature sensor has an accuracy of ±0.2℃; the compressor exhaust temperature sensor has an accuracy of ±0.5℃; the EEV inlet and outlet temperature difference sensor has an accuracy of ±0.1℃; and the variable frequency compressor current sensor has an accuracy of ±0.5%FS, ensuring the reliability of the collected data.

[0031] A dynamic sampling frequency adjustment mechanism is adopted. When the temperature fluctuation is ≤0.5℃, the sampling period is set to 5s. When the temperature fluctuation is >0.5℃ or the system enters the stepped protection state, the sampling period is shortened to 1s to avoid data lag. At the same time, the collected data is filtered and noise-reduced to remove abnormal data, thereby ensuring data accuracy. The collected real-time data is synchronously transmitted to the graded protection module, EEV control module and decision fault tolerance module.

[0032] The filtering and noise reduction adopts the moving average filtering method, taking the average of 5 consecutive sampling points as the valid data; the outlier removal adopts the 3σ criterion. When a single sample data exceeds ±3 times the standard deviation of the mean of the parameter over the past 20 sampling periods, it is judged as outlier data and removed to ensure the stability of the data transmitted to each module.

[0033] The graded protection module constructs a three-level tiered protection mechanism. Based on real-time temperature and humidity, equipment load and other data collected by the multi-dimensional sensing module, corresponding protection actions are triggered. The protection threshold of each level is dynamically corrected by the decision fault tolerance module according to the system operation data. Moreover, each level of protection is linked with the EEV control module and the compression linkage module to perform coordinated operations, so as to realize progressive protection of early warning, control and shutdown. The first-level early warning protection corresponds to scenarios where the temperature is close to the threshold and there is no risk of overload. When the ambient temperature, coil temperature, or compressor exhaust temperature reaches the early warning threshold, such as an ambient temperature of 35°C and a coil temperature of 55°C, and the temperature fluctuation within the cycle meets the preset conditions, the system will not trigger a shutdown but will only send an early warning signal. The system will simultaneously instruct the EEV control module to fine-tune the EEV opening and the compression linkage module to control the frequency converter compressor to reduce its frequency, maintain the equipment operating at a low load, and continuously receive real-time data from the multi-dimensional sensing module to monitor temperature changes. The preset condition is "temperature fluctuation within the cycle ≤ 0.8℃", the cycle is based on the operating cycle collected by the coil temperature sensor (default 10s / cycle), and the fluctuation amplitude is calculated as the difference between the highest and lowest temperatures within the cycle.

[0034] Level 2 control protection is for scenarios where the temperature exceeds the limit and there is a slight overload. When the temperature continues to rise and reaches the control threshold, such as an ambient temperature of 38°C and a coil temperature of 60°C, and the equipment running time meets the preset conditions, the EEV control module is instructed to adjust the EEV opening according to the gradient, the compression linkage module will reduce the frequency of the variable frequency compressor, and the condenser heat dissipation auxiliary function will be activated to force the temperature to drop. If the temperature does not drop within 30 seconds, it will enter Level 3 protection. The preset condition is "the temperature exceeds the standard and the operation continues for ≥10 seconds". The timer starts from the moment when the multi-dimensional sensing module detects that the temperature first reaches the control threshold. If the temperature does not recover to the safe range for 10 seconds, the secondary control action is triggered.

[0035] The gradient adjustment rule is as follows: each adjustment of the EEV opening is 5% (based on the maximum opening as 100%), with an adjustment interval of 2 seconds, and the cumulative adjustment shall not exceed 3 times; if the temperature does not drop after 3 adjustments, the adjustment range shall be increased to 8% each time until the temperature reaches the standard or the level 3 protection is triggered.

[0036] The maximum opening degree of the EEV is defined as the valve opening degree when the electronic expansion valve is fully open, corresponding to 100% of the valve core stroke. At this time, the flow rate of the heat exchange system reaches its maximum value. This reference value is determined by calibration before the equipment leaves the factory and stored in the parameter library of the EEV control module.

[0037] The Level 3 emergency protection is designed for scenarios involving severely excessive temperatures and heavy overloads. When the temperature reaches the emergency threshold, such as an ambient temperature of 42°C and a coil temperature of 65°C, or when faults such as abnormal current or EEV jamming occur, the system immediately instructs the compression linkage module to control the variable frequency compressor to stop and the EEV control module to close the EEV opening to cut off the heat exchange circuit. At the same time, the protection trigger information is fed back to the decision-making fault-tolerant module, which records the protection trigger time, trigger cause, and the temperature and humidity data at that time. After the temperature drops to the safe threshold, the decision-making fault-tolerant module instructs all relevant modules to start restart testing. After confirming that there are no abnormalities, the system will resume operation in a coordinated manner to avoid damage to the core components of the equipment.

[0038] The protection thresholds for different application scenarios can be adjusted based on the baseline values. The baseline value for home scenarios is ±1℃, for laboratory scenarios (high precision requirements) it is ±0.5℃, for warehousing scenarios it is ±2℃, and for agricultural and sideline product drying scenarios it is ±3℃. After adjustment, the data optimization module needs to be used for synchronous calibration.

[0039] The restart testing process is as follows: First, check whether the data of each sensor in the multi-dimensional sensing module are within the normal range. Second, verify whether the EEV opening adjustment response is smooth (the deviation between the command opening and the actual opening is ≤2%). Third, test whether the compressor runs under no-load for 3 seconds without any abnormalities (the frequency is stable at 30Hz and the current fluctuation is ≤3%). If all three steps are passed, normal operation is gradually restored according to the humidity data. If any step is abnormal, the shutdown state is maintained and the fault record is updated.

[0040] The fine-tuning range is ±3% each time (based on the maximum opening of EEV as 100%). After each adjustment, maintain for 5 seconds to observe the temperature change. If the temperature is still close to the threshold, it can be fine-tuned again. The cumulative fine-tuning range shall not exceed 10% of the total opening to avoid over-adjustment that may cause system fluctuations.

[0041] The EEV control module receives temperature control commands from the decision fault tolerance module and protection level signals from the graded protection module. It combines multi-dimensional data such as temperature and humidity and temperature difference between EEV inlet and outlet collected by the multi-dimensional sensing module to dynamically adjust the opening of EEV, thereby achieving coordination with the temperature control, step protection, and compression linkage modules to improve temperature control accuracy and heat exchange efficiency. A dual-algorithm control system employs temperature deviation PID and superheat PID, dynamically switching adjustment weights according to different operating scenarios to ensure temperature stability within the set threshold range. The switching rules for the dual PID adjustment weights are as follows: during normal operation, the temperature deviation PID weight is 0.6 and the superheat PID weight is 0.4; when the temperature fluctuation rate is 0.5-1℃ / s, both weights are 0.5; when the temperature fluctuation rate is ≥1℃ / s, the temperature deviation PID weight is 0.7 and the superheat PID weight is 0.3; during the first-level warning of the stepped protection, the superheat PID weight is 0.7 and the temperature deviation PID weight is 0.3; during the second-level control, the temperature deviation PID weight is 0.6 and the superheat PID weight is 0.4.

[0042] In the stepped protection state, it receives protection level instructions from the graded protection module. During the first-level warning, it focuses on superheat regulation to avoid evaporator frosting and condenser overheating. During the second-level regulation, it simultaneously strengthens the coordinated regulation of temperature deviation and superheat to quickly balance the heat exchange system. When the temperature fluctuates rapidly, such as when the ambient temperature changes at a rate ≥1℃ / s, it starts the predictive regulation mode based on the temperature change data collected by the multi-dimensional sensing module to adjust the EEV opening in advance and avoid regulation lag. The EEV control module and the compression linkage module are linked in real time. They synchronously receive the collaborative instructions from the decision fault tolerance module. When the compressor frequency increases, the EEV opening is increased synchronously. When the compressor frequency decreases, the EEV opening is decreased synchronously to ensure that the heat exchange system flow matches the compressor load. The adjustment parameters are fed back to the data optimization module in real time.

[0043] The compression linkage module receives temperature control commands from the decision fault tolerance module and protection action commands from the graded protection module, forming a collaborative closed loop with the EEV control module to dynamically adjust the operating frequency of the variable frequency compressor. At the same time, it receives data such as equipment load and exhaust temperature collected by the multi-dimensional sensing module to ensure accurate temperature control, reduce energy consumption, reduce component wear, and avoid the risk of frequency oscillation and resonance. A dynamic step-size adjustment mechanism matching temperature deviation and load is adopted. Based on the temperature deviation data fed back by the multi-dimensional sensing module, when the temperature deviation is ≥1℃, the frequency adjustment step size is set to 5Hz / s to quickly approach the set temperature; when the temperature deviation is <1℃, the adjustment step size is reduced to 1Hz / s to avoid temperature overshoot. At the same time, the compressor resonant frequency range is preset (calibrated according to the equipment model). When the frequency approaches the preset compressor resonant frequency range, the resonant frequency point is automatically skipped to avoid increased operating noise and mechanical wear of components. Resonance frequency range calibration method: Within the compressor's rated frequency range (30-120Hz), perform a frequency sweep test with a step size of 5Hz, and record the frequency range corresponding to an operating noise ≥60dB or vibration amplitude ≥0.5mm / s. This is the resonance frequency range. After calibration, it needs to be stored in the parameter library of the compressor linkage module.

[0044] The rated frequency range of 30-120Hz is the design operating range of the compressor, of which 30-50Hz is the low frequency band, 50-100Hz is the medium frequency band, and 100-120Hz is the high frequency band. The dynamic step size adjustment mechanism of different frequency bands remains consistent to ensure stable operation across the entire frequency band.

[0045] The compression linkage module works in real time with the graded protection module and the EEV control module, responding to protection commands at each level of the graded protection module. During a level one warning, the compressor frequency is reduced, and the opening degree of the EEV control module is finely adjusted. During level two control, the compressor frequency is further reduced, working with the EEV control module to balance the system load. During emergency protection, a shutdown action is immediately triggered. When the temperature rises back to the normal range, the frequency is gradually increased based on the humidity data fed back by the multi-dimensional sensing module to avoid frequent start-stop, balancing dehumidification efficiency and energy consumption control. Parameters such as operating frequency and start-stop status are synchronously fed back to the data optimization module.

[0046] The gradual frequency increase rule is as follows: starting from the lowest operating frequency (30Hz), if the humidity does not meet the standard, the frequency is increased by 3Hz every 5 seconds; when the humidity is close to the set value (difference ≤3%RH), the frequency is increased by 1Hz every 5 seconds until the target frequency is reached or the humidity meets the standard, so as to avoid temperature fluctuations caused by excessive frequency increase.

[0047] The decision-making fault-tolerant module incorporates an intelligent decision-making algorithm that integrates multi-dimensional information such as temperature deviation from the multi-dimensional sensing module, opening data from the EEV control module, frequency data from the compression linkage module, and protection status from the graded protection module. It then uses this information to judge the system's operating status in real time and dynamically correct the three-level protection thresholds of the graded protection module and the control parameters of the EEV control module and the compression linkage module. When the data from the multi-dimensional sensing module meets the criteria of "temperature deviation ≤ 0.3℃ + humidity deviation ≤ 1%RH + compressor current fluctuation ≤ 5%" for three consecutive sampling cycles, the system is considered to be operating stably. When the data from a single module is abnormal (exceeding the normal range by 20%) for two consecutive sampling cycles, an early warning is triggered. If the abnormality persists for five consecutive sampling cycles without improvement, the alternative operation mechanism is activated, prioritizing the use of redundant sensor data or default control parameters.

[0048] A fault type database is constructed. By comparing the real-time operating data transmitted by each module with the preset simulation model parameters, abnormal situations of the multi-dimensional sensing module (sensor failure), EEV control module (EEV stagnation), and compression linkage module (compressor failure) are predicted, and early warning signals are sent to the human-machine monitoring module in advance. Imported data should be in CSV format. Core fields must include: ambient temperature, ambient humidity, coil temperature, compressor discharge temperature, EEV opening, compressor frequency, protection action records, and operating energy consumption. Data sampling interval should be ≤5s. After import, the data optimization module will automatically align with the time axis for analysis.

[0049] The fault type database includes core fault categories: sensor faults (open circuit, short circuit, data drift), EEV faults (mild jamming, severe jamming, no opening response), compressor faults (no frequency response, abnormal resonance, excessive current), and communication faults (inter-module data transmission interruption, delay exceeding 1 second). Each fault corresponds to a preset warning signal and preliminary handling instructions.

[0050] A fault-tolerant mechanism is set up so that when a certain sensor fails, data from other relevant sensors in the multi-dimensional sensing module are automatically called for replacement calculation. For example, when the ambient temperature sensor fails, the ambient temperature is calculated by combining the coil temperature with the exhaust temperature. When the EEV is slightly stuck, the EEV control module is instructed to adjust the adjustment step size to force the EEV to move. The ambient temperature calculation logic is as follows: Ambient temperature ≈ Coil temperature - (Compressor exhaust temperature - Coil temperature) × 0.35. The calculation result is considered valid if the deviation from the historical ambient temperature of the same period is ≤1℃. If it exceeds the deviation, the default ambient temperature value of the same scenario stored in the data optimization module will be called.

[0051] When a fault cannot heal itself, the instruction hierarchical protection module activates the corresponding protection status, while recording the fault data and feeding it back to the human-machine monitoring module and the data optimization module.

[0052] The data optimization module collects sampling data from the multi-dimensional sensing module, protection action records from the graded protection module, opening adjustment data from the EEV control module, frequency operation data from the compression linkage module, fault records and control command data from the decision fault tolerance module, and operation records from the human-machine monitoring module. It then uses algorithms to analyze and optimize the tiered protection threshold, EEV control parameters, and compressor frequency adjustment strategy. The parameter iteration cycle is set to once a week by default, but can be manually adjusted to once every 3 days or once every 15 days through the human-machine monitoring module. The machine learning algorithm adopts the gradient boosting tree (GBT) algorithm, which focuses on the correlation analysis of temperature fluctuation amplitude, EEV adjustment, compressor frequency and unit energy consumption. The optimization process retains the most recent 3 historical parameters and supports backtracking recovery.

[0053] The built-in data storage unit can store at least one year of system operation data. Machine learning algorithms are used to analyze the stored data to uncover the correlation between temperature fluctuations, EEV regulation, compressor operation and energy consumption. The data storage unit has a capacity of ≥16GB and supports a data cyclic overwrite mechanism. When the storage capacity is full, it automatically overwrites the oldest running data. It also supports manual export of historical data backups, and the export format is compatible with CSV and Excel, which is convenient for offline analysis.

[0054] Regularly optimize parameters such as the three-level protection threshold of the graded protection module, the dual PID adjustment weight of the EEV control module, and the frequency adjustment step size of the compression linkage module, for example, once a week. The optimized parameters are synchronously fed back to the decision fault tolerance module, which updates the control strategies of each corresponding module to make the system adapt to different ambient temperatures and humidity and different dehumidification needs, such as high-precision temperature control and energy-saving dehumidification. It also supports importing operational data from different application scenarios through the human-machine monitoring module, optimizing relevant parameters, and improving the system's versatility. For example, when applied to the drying of agricultural and sideline products, it can automatically optimize temperature control parameters and protection thresholds according to the temperature and humidity requirements of the dried materials, taking into account both drying effect and equipment safety.

[0055] Imported data should be in CSV format. Core fields must include: ambient temperature, ambient humidity, coil temperature, compressor discharge temperature, EEV opening, compressor frequency, protection action records, and operating energy consumption. Data sampling interval should be ≤5s. After import, the data optimization module will automatically align with the time axis for analysis.

[0056] The human-machine monitoring module receives system operating status, fault information, and real-time operating parameters of each module from the decision-making fault-tolerant module. It also enables manual control commands to be linked with various functional modules. Equipped with a local touchscreen display, it shows real-time temperature and humidity data from the multi-dimensional sensing module, the protection status (normal, warning, control, emergency protection) of the graded protection module, the EEV opening of the EEV control module, the compressor frequency of the compression linkage module, system runtime, and fault records from the decision-making fault-tolerant module. It supports manual adjustment of parameters such as the set temperature (adjustment range 5℃-35℃), the protection threshold of the graded protection module (adjustable ±2℃ from factory settings), and the adjustment sensitivity of the EEV control module. Manual operation commands are sent to the decision-making fault-tolerant module, which then forwards them to the corresponding functional modules for execution. The touch display is a ≥5-inch color LCD screen with a resolution of ≥800×480, a touch response latency of ≤0.3s, and the screen brightness supports automatic adjustment (100-500cd / m² corresponding to an ambient light intensity of 30-1000 lux) to ensure clear visibility in different scenarios.

[0057] It has a built-in wireless communication module (WiFi / Bluetooth) that supports remote connection to a mobile APP or monitoring platform, enabling remote viewing of the operating status of each module, sending control commands, and receiving fault warnings and protection action reminders forwarded by the decision-making fault-tolerant module; it also supports fault data export, which facilitates maintenance personnel to analyze the cause of faults and optimize maintenance solutions. WiFi communication uses the IEEE 802.11n protocol with a communication distance of ≤100m (unobstructed environment); Bluetooth communication uses the BLE 5.0 protocol with a communication distance of ≤10m; remote control command transmission delay is ≤2s, and data refresh frequency is ≥1 time / s to ensure real-time remote operation.

[0058] The system offers multiple preset modes, including home, laboratory, warehouse, and agricultural product drying. After switching modes, the system automatically calls the corresponding optimized control parameters and protection thresholds from the data optimization module, eliminating the need for repeated manual adjustments and improving the system's practicality and convenience.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A variable frequency dehumidifier temperature control system including stepped protection and EEV coordinated control, characterized in that, include: Multi-dimensional sensing module: integrates multi-dimensional sensors to acquire the environmental and equipment operating parameters required for system operation, processes the collected data using a dynamic sampling and data processing mechanism, and then synchronously transmits it to the core functional module; Hierarchical protection module: Based on the data provided by the sensing module, a progressive hierarchical protection mechanism is constructed. It can dynamically adjust the protection threshold according to the system operation data, link relevant modules to perform corresponding protection operations, and realize progressive protection of early warning, control and shutdown. EEV control module: Receives command signals from relevant modules, combines them with parameters collected by the multi-dimensional sensing module, and uses a dual-algorithm collaborative control mechanism to dynamically adjust the opening of the electronic expansion valve, and works in conjunction with relevant modules to ensure that the heat exchange system flow rate matches the equipment operating load; Compression linkage module: Receives command signals from relevant modules, combines data from the multi-dimensional sensing module to dynamically adjust the operating frequency of the variable frequency compressor, and forms a collaborative closed loop with the EEV control module; Decision-making fault-tolerant module: Receives the operating data transmitted by each functional module, judges the system operating status and protection level and sends coordinated control instructions. It has fault prediction and fault tolerance functions and can start the alternative operation mechanism and record feedback fault data when a single module is abnormal. Data optimization module: Collects and analyzes operational data from each module, periodically iterates and optimizes system protection thresholds and control parameters, and synchronously feeds back to the decision-making fault-tolerant module to update control strategies; Human-Machine Monitoring Module: Visualizes system operation information, supports local and remote control operations, and allows for the export of fault data.

2. The variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control according to claim 1, characterized in that, The multi-dimensional sensing module integrates environmental temperature and humidity sensors, coil temperature sensors, compressor exhaust temperature sensors, EEV inlet and outlet temperature difference sensors, and variable frequency compressor current sensors. Each sensor collects corresponding environmental and equipment operating parameters. The dynamic sampling and data processing mechanism can achieve filtering and noise reduction, abnormal data removal, and the sampling frequency can be dynamically adjusted according to temperature fluctuations and system protection status. The processed real-time data is synchronously transmitted to the hierarchical protection module, EEV control module, and decision fault tolerance module.

3. The variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control according to claim 2, characterized in that, The hierarchical protection module constructs a three-level tiered protection mechanism. The protection threshold is dynamically adjusted by the decision-tolerance module based on system operation data. Each level of protection is linked with the EEV control module and the compression linkage module to perform coordinated operations. The first-level early warning protection is triggered when the temperature approaches the threshold and there is no risk of overload. It sends an early warning signal and instructs relevant modules to fine-tune parameters to maintain low-load operation. The second-level control protection is triggered when the temperature exceeds the standard and there is a slight overload. It instructs relevant modules to adjust parameters in a gradient and activate the heat dissipation auxiliary function. The Level 3 emergency protection immediately cuts off the heat exchange circuit and shuts down the machine when the temperature exceeds the limit or an equipment malfunction occurs. It records relevant data and, once the temperature drops to the safe threshold, instructs the relevant modules to start restart detection.

4. The variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control according to claim 3, characterized in that, The EEV control module receives command signals from the decision-tolerance module and the graded protection module, and combines them with multi-dimensional parameters collected by the multi-dimensional sensing module to dynamically adjust the opening of the electronic expansion valve through dual-algorithm collaborative control. In the stepped protection state, it can adjust the adjustment priority according to the protection level, and can also activate the predictive adjustment mode when the temperature fluctuates rapidly. The EEV control module is linked with the compression linkage module in real time, synchronously responds to the command of the decision-tolerance module, and the adjustment parameters are fed back to the data optimization module in real time.

5. The variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control according to claim 4, characterized in that, The compression linkage module and the EEV control module form a collaborative closed loop. Based on the instructions of the decision-tolerance module and the graded protection module, as well as the data from the multi-dimensional sensing module, a dynamic step size adjustment mechanism matching the temperature deviation and load is adopted to dynamically adjust the operating frequency of the variable frequency compressor. It can automatically skip the compressor resonance frequency range, respond to protection instructions at all levels to adjust the operating status, and gradually increase the frequency when the temperature rises back to the normal range, combined with humidity data. The operating parameters are synchronously fed back to the data optimization module.

6. The variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control according to claim 5, characterized in that, The decision-making fault-tolerant module incorporates an intelligent decision-making algorithm, integrates the operating data of each module, judges the system operating status in real time, and dynamically corrects the protection threshold and control parameters; it also constructs a fault type database, which can predict module anomalies and send early warnings. A fault-tolerant mechanism is set up to activate alternative operation mechanisms or remedial measures when sensor failure or mild EEV lag occurs. When the fault cannot heal itself, the corresponding protection is triggered and the fault data is recorded and fed back.

7. The variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control according to claim 6, characterized in that, The data optimization module collects the operating data and operation records of each module, analyzes and mines the operating patterns through algorithms, and regularly optimizes the protection threshold, control parameters and adjustment strategies. The optimized parameters are synchronously updated to the decision fault tolerance module. It has a built-in data storage unit that supports importing running data from different application scenarios to optimize corresponding parameters.

8. The variable frequency dehumidifier temperature control system with stepped protection and EEV coordinated control according to claim 7, characterized in that, The human-machine monitoring module is equipped with a local touch screen display, which displays the operating parameters, protection status and fault records of each module in real time, and supports manual adjustment of relevant parameters. It has a built-in wireless communication module, which supports remote viewing, control, receiving fault alerts, and exporting fault data. Multiple application modes are preset, and the corresponding optimization parameters and protection thresholds are automatically applied after switching.

Images