A compressed air combined dehumidification system

Abstract

The present invention discloses a combined compressed air dehumidification system, including a refrigeration dehumidification unit, an adsorption dehumidification unit, a temperature and humidity control PLC system, and a fault diagnosis and maintenance module. The refrigeration dehumidification unit uses an evaporator to preliminarily dehumidify the compressed air, and the evaporator design and operating parameters are optimized by Fluent analysis software. The adsorption dehumidification unit uses activated alumina adsorbent, and the adsorption process is optimized by combining mathematical modeling with the Fluent model. The temperature and humidity control PLC system monitors and controls the temperature and humidity in real time, and adjusts the parameters of the two dehumidification units according to the working conditions. The fault diagnosis and maintenance module collects data through a sensor group, and the data analysis unit determines the fault, the alarm unit prompts, and the maintenance guidance unit provides operation suggestions. This system realizes efficient dehumidification, precise temperature and humidity control, and intelligent fault diagnosis and maintenance. It is energy-saving, highly adaptable and reliable, and is suitable for cold storage and other places with strict requirements on air humidity.

Description

Technical Field

[0001] The invention relates to the technical field of air treatment, and in particular to a compressed air combined dehumidification system. Background Art

[0002] In many industrial fields, such as cold storage, food processing, pharmaceuticals, and electronic manufacturing, precise control of air humidity is essential. Excessive humidity may cause products to deteriorate, equipment to rust and corrode, and microbial growth, which seriously affects product quality and production safety. Traditional dehumidification methods mainly include cooling dehumidification, adsorption dehumidification, and absorption dehumidification.

[0003] Cooling dehumidification removes water vapor by cooling the air to condense it into liquid water. However, this method has limited dehumidification efficiency in low-temperature and high-humidity environments, and the outlet dew point temperature fluctuates greatly, making it difficult to meet occasions with strict humidity requirements. Adsorption dehumidification uses adsorbents to absorb moisture in the air. Although the dehumidification effect is good, the adsorption capacity of the adsorbent is limited and requires frequent regeneration, which increases energy consumption and operating costs. Absorption dehumidification has problems such as the absorbent being volatile and corrosive.

[0004] In addition, existing dehumidification systems often have problems such as inaccurate control, inability to monitor and adjust operating parameters in real time, and difficulty in fault diagnosis and maintenance. For example, when a system fails, it is difficult to quickly determine the location and cause of the failure, resulting in long downtime and huge losses to production. Moreover, with the continuous improvement of energy efficiency and production environment requirements, there is an urgent need for an efficient, stable and intelligent dehumidification system to meet the needs of industrial production. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention solves the technical problems by adopting a technical solution: a compressed air combined dehumidification system, comprising: A refrigeration and dehumidification unit is used for preliminary dehumidification of compressed air. The refrigeration and dehumidification unit includes an evaporator. The dehumidification process of the evaporator is simulated and studied by using Fluent analysis software, and different wet air intake speeds and evaporator parameters are analyzed to improve the dehumidification efficiency. The evaporator structure is simplified in design; The adsorption dehumidification unit is connected to the refrigeration dehumidification unit and is used to further dehumidify the air that has been preliminarily dehumidified. The adsorption dehumidification unit uses activated alumina as an adsorbent. By mathematically modeling the activated alumina adsorption dehumidification and combining it with the unidirectional flow porous medium model provided by Fluent, the UDF is used to realize the heat and mass transfer in the adsorption dehumidification process, and the adsorption dehumidification efficiency is optimized by changing the adsorbent-related parameters and the adsorption tower structure size; A temperature and humidity control PLC system, connected to the refrigeration dehumidification unit and the adsorption dehumidification unit, is used to monitor and control the temperature and humidity parameters of the entire dehumidification system in real time to ensure stable operation of the system and stable outlet dew point; A fault diagnosis and maintenance module is connected to the refrigeration and dehumidification unit, the adsorption dehumidification unit and the temperature and humidity control PLC system for performing fault diagnosis and maintenance operations on the system. The fault diagnosis and maintenance module includes: The sensor group is set inside the system to collect various data related to the system operation status, including temperature, humidity, pressure, air flow speed and equipment operation status information; A data analysis unit receives the data collected by the sensor group and compares and analyzes it with a preset normal operating parameter range to determine whether the system has a fault, and when abnormal data is detected, determines the fault type and possible fault location; An alarm unit connected to the data analysis unit, when the data analysis unit determines that there is a fault in the system, sends out a corresponding alarm signal, the alarm signal includes a visual alarm and an audible alarm; The maintenance guidance unit stores maintenance operation guides for different fault types. When a system fault occurs, the maintenance personnel are provided with corresponding maintenance operation suggestions according to the fault type determined by the data analysis unit. The maintenance operation process is as follows: Fault confirmation: After receiving the alarm signal, the maintenance personnel will first confirm the fault information, including checking the alarm type, fault location and related operating data to ensure the accuracy of the fault information; Operation guide acquisition: According to the fault type determined by the data analysis unit, the corresponding detailed maintenance operation guide is obtained from the maintenance guidance unit. The operation guide is presented in the form of pictures and texts or video tutorials to facilitate maintenance personnel to understand and operate; Safety measures preparation: Before carrying out maintenance operations, maintenance personnel should prepare appropriate safety protection equipment, such as gloves, goggles, and helmets, according to the fault type and system characteristics, and ensure that the system is in a safe shutdown state to prevent accidents during maintenance; Component inspection and repair: In accordance with the requirements of the maintenance operation guide, inspect the fault-related components to determine the specific cause of component damage or failure. For repairable components, such as sensor failure, valve blockage, etc., on-site repair is carried out. The repair process includes steps such as component disassembly, cleaning, replacement of damaged parts, reinstallation and commissioning; System parameter adjustment: If the fault is caused by abnormal system operating parameters, such as incorrect temperature and pressure setting values, the maintenance personnel will adjust the relevant parameters in the temperature and humidity control PLC system according to the operation guide, and conduct a short test run of the system after the adjustment to observe whether the system operation status returns to normal; Parts replacement: For parts that are severely damaged and cannot be repaired, such as compressor failure, adsorbent failure, etc., replace the parts according to the operating instructions. When replacing parts, ensure that the model and specifications of the new parts are consistent with the original parts, and install them strictly in accordance with the installation process requirements. After the installation is completed, perform necessary debugging and testing; System testing and verification: After completing component repair or replacement and parameter adjustment, conduct a comprehensive test on the system, including starting the system, observing whether the equipment is operating normally, checking whether the data collected by the sensor is within the normal range, and verifying whether the system's dehumidification effect and outlet dew point stability meet the design requirements by simulating actual operating conditions; Recording and feedback: During the maintenance operation, maintenance personnel record the fault phenomenon, maintenance measures, replacement parts information, test results, etc. in detail, and feedback the maintenance situation to the fault diagnosis and maintenance module. The data analysis unit organizes and analyzes this information to optimize system operating parameters, update fault diagnosis algorithms and maintenance operation guidelines, and improve system reliability and maintenance efficiency; The remote communication unit is used to communicate with external devices or a remote monitoring center. It can transmit the system's operating data and fault information to the remote monitoring center so that professional technicians can perform remote diagnosis and guide maintenance operations. It can also receive control instructions and system update information sent by the remote monitoring center to achieve remote maintenance and upgrades of the system.

[0006] Preferably, the refrigeration and dehumidification unit simulates the dehumidification process of the evaporator by using Fluent analysis software, comprising the following steps: Step 1: Based on the detailed mapping of the actual structure of the evaporator, the geometric parameters including the size of the heat exchange tube, the specifications of the fins and the arrangement method are obtained. A model consistent with the real object is created using 3D modeling software, and non-critical structural details are simplified. The constructed geometric model is imported into the Fluent pre-processing software. Unstructured grids are used for the complex flow areas inside the evaporator, and structured grids are used for regular areas. At the same time, grids are encrypted on the surface of the heat exchange tubes and in areas where the air flow changes dramatically. An accurate 3D geometric model of the evaporator is constructed to ensure that the grid quality meets the calculation requirements, that is, the grid distortion and orthogonality indicators are within the preset qualified range; Step 2: In Fluent software, select the Eulerian-Lagrangian model as the multiphase flow model of the air-water system, select the turbulence model according to the air flow characteristics in the evaporator, enable the energy equation and set the water vapor diffusion model based on Fick's law for the mass transfer process, where the mass transfer coefficient between water vapor and air is determined by precise experimental data or authoritatively verified empirical formulas, and accurately set the relevant parameters of each model; Step 3: Set the temperature, humidity, pressure and velocity parameters of the wet air entering the evaporator as the inlet boundary conditions, set the pressure outlet boundary conditions according to the overall pressure distribution and outlet position of the system, set the wall surface of the evaporator heat exchange tube as the coupled boundary condition and confirm the material properties of the heat exchange tube; Step 4: Calculate the density, specific heat capacity, and thermal conductivity of the moist air based on its temperature and humidity, create a custom moist air material and input it into Fluent, and set the material properties of the evaporator heat exchange tubes and fins, including density, specific heat capacity, and thermal conductivity; Step 5: Initialize the variables in the computational domain based on the inlet boundary conditions and the estimation of the initial state of the system, select the pressure-based solver, set the pressure-velocity coupling algorithm, discrete format and iteration step parameters, use a loose convergence standard and a large step size for the initial calculation, and gradually increase the standard and reduce the step size later; Step 6: Start the Fluent simulation calculation and monitor the changes in the residual curve. When the residuals of the continuity equation, momentum equation, and energy equation drop below the preset convergence standard and the distribution of key physical quantities is stable and the global parameters of import and export are balanced, the calculation is considered to be converged. If there is no convergence or abnormal situation, analyze and adjust; Step 7: After the calculation converges, use Fluent post-processing software to visualize the results, draw cloud maps, vector maps, and contour maps of temperature, humidity, and velocity physical quantities, calculate the evaporator dehumidification capacity and dehumidification efficiency performance indicators, and compare and verify with the empirical formula results. If there is a deviation, analyze the cause and correct the model; Step 8: Determine the optimization parameters based on the analysis results, change the parameter values ​​and re-simulate the calculation, compare the results of different parameter combinations to determine the optimal settings, improve the design if there are unreasonable aspects of the structure, re-model and mesh, and simulate the calculation to verify the improvement effect, and continuously iterate the optimization.

[0007] Preferably, the parameters related to the activated alumina adsorbent in the adsorption dehumidification unit include the adsorbent filling amount and particle size, and the structural dimensions of the adsorption tower include tower height and diameter, and the adsorption dehumidification efficiency is optimized by changing these parameters.

[0008] Preferably, the temperature and humidity control PLC system can automatically adjust the operating parameters of the refrigeration dehumidification unit and the adsorption dehumidification unit according to the system operation conditions, including temperature, humidity, and pressure, and the adjustment steps are as follows: Step A1: continuously obtain the temperature, humidity and pressure operation data of the refrigeration dehumidification unit and the adsorption dehumidification unit through sensors arranged at various locations in the system, and transmit them to the PLC system; Step A2: The PLC system processes the collected data, calculates the current dehumidification effect index, compares it with the preset standard, determines whether the system operation status is normal, and determines whether the parameters need to be adjusted; Step A3: If adjustment is required, determine the adjustment strategy for the specific parameters of the refrigeration dehumidification unit and the adsorption dehumidification unit according to the deviation and the built-in algorithm; Step A4: The PLC system outputs control signals to the corresponding actuators to perform adjustment operations, and then re-evaluates the system status based on sensor feedback. If it does not meet expectations, repeat the above steps for optimization until the system runs stably. This ensures stable operation of the system and effectively solves the problem of outlet dew point fluctuations.

[0009] Preferably, the system is operated based on the cooling unit and its arrangement determined by the field simulation test of the 60m³ laboratory system set up in the company's factory. The effectiveness of the adsorption dehumidification unit is verified by mathematical model simulation analysis and physical model test. The specific verification method is as follows: Step B1: Based on the principles of adsorption thermodynamics and kinetics, combined with the characteristics of activated alumina adsorbent, a mathematical model of the adsorption dehumidification process is established to obtain simulation data of the performance of the adsorption dehumidification unit under different working conditions; Step B2: According to the structure and process requirements of the actual adsorption dehumidification unit, a small physical test model is built, equipped with high-precision temperature and humidity sensors and flow meter measurement equipment, and multiple groups of test conditions consistent with actual working conditions are set to obtain the measured performance data of the adsorption dehumidification unit under different working conditions in the physical model test; Step B3: compare the measured data obtained from the physical model test with the simulated data of the mathematical model point by point, calculate the deviation rate of each performance indicator, analyze the cause of the deviation, judge the accuracy of the mathematical model and the effectiveness of the adsorption dehumidification unit design, and output a comparison result report, including the deviation rate statistics of each performance indicator and the analysis of the cause of the deviation. If there is a problem with the effectiveness, go to step B4. If it is effective, end the verification process; Step B4: Based on the evaluation results of step B3, the assumptions, parameter values ​​and calculation methods of the mathematical model are corrected and optimized. After the mathematical model and physical model test device are adjusted and optimized, return to step B1 and re-perform simulation analysis and test verification until the effectiveness of the adsorption dehumidification unit is fully verified.

[0010] Preferably, a humidity sensor is set at the outlet of the system to monitor the air humidity in real time, and the humidity data is transmitted to the PLC system as a basis for judgment and adjustment. According to the initial humidity, when the humidity is high, the refrigeration dehumidification unit is started first, and its ability to quickly reduce a large amount of water in the air is used for preliminary dehumidification. When the humidity is close to but has not reached the set range after refrigeration dehumidification, the adsorption dehumidification unit is started to give play to its advantage of further fine dehumidification of low-humidity air. The control system adjusts the operating parameters of the refrigeration dehumidification unit in real time according to the humidity monitoring data and the preset standard, such as evaporator temperature, cooling capacity, fan speed, etc., to optimize its dehumidification efficiency. At the same time, the parameters of the adsorption dehumidification unit are also adjusted, including adsorbent regeneration temperature, adsorption cycle, air flow rate, etc., to ensure that the adsorption effect is good and works in coordination with the refrigeration dehumidification unit. The parameter adjustments of the two units cooperate with each other to avoid conflicts or incoordination, such as ensuring that the air state at the outlet of the refrigeration dehumidification unit is suitable for the efficient operation of the adsorption dehumidification unit. Continuous monitoring and adjustment are carried out to achieve a dynamic balance between the working states of the refrigeration dehumidification unit and the adsorption dehumidification unit, ensuring that the dew point at the system outlet is stable within the set range. When responding to changes in working conditions (such as fluctuations in ambient temperature and humidity, changes in system load, etc.), the working modes and parameters of the two units can be automatically adjusted in a timely manner to maintain a stable dehumidification effect and meet the strict requirements of cold storage and other environments on air humidity.

[0011] With fault monitoring function, when a unit fails, it can detect and notify the control system in time. The control system can start the backup mechanism, such as switching to backup equipment or adjusting to single unit emergency operation mode, to minimize the impact of the fault on the overall dehumidification effect, and send out an alarm signal to notify maintenance personnel to carry out repairs.

[0012] Preferably, the sensor group in the fault diagnosis and maintenance module includes a temperature sensor, a humidity sensor, a pressure sensor, an air flow velocity sensor and an equipment status sensor, and the sensor group can accurately collect system operation data in real time.

[0013] Preferably, the data analysis unit uses intelligent algorithms to analyze the collected data, which can quickly and accurately determine the fault type and location, thereby improving the efficiency of fault diagnosis. The remote communication unit supports wireless communication technology to ensure stable and reliable data transmission between the system and the remote monitoring center.

[0014] The beneficial effects of the present invention are as follows: 1. The compressed air combined dehumidification system of the present invention combines the advantages of the refrigeration dehumidification unit and the adsorption dehumidification unit. The refrigeration dehumidification unit uses Fluent analysis software to accurately simulate the evaporator, optimizes the evaporator structure and operating parameters, and can quickly remove a large amount of moisture from the air and effectively reduce the air humidity. The adsorption dehumidification unit uses activated alumina adsorbent, and optimizes the adsorption process through mathematical modeling and combination with the Fluent model. It further finely dehumidifies the low-humidity air after refrigeration dehumidification to ensure that the outlet dew point is stable within the set range, greatly improving the overall dehumidification efficiency and meeting the strict requirements of cold storage and other environments with strict air humidity requirements.

[0015] 2. Temperature and humidity control The PLC system monitors and controls the temperature and humidity parameters of the entire dehumidification system in real time. Through the data collected by the sensor group, the PLC system can dynamically adjust the operating parameters of the refrigeration dehumidification unit and the adsorption dehumidification unit according to the actual working conditions, such as evaporator temperature, adsorbent regeneration temperature, fan speed, etc. This precise control ensures that the system can operate stably under different loads and environmental conditions, effectively solves the problem of outlet dew point fluctuations, provides a stable air humidity environment for industrial production, and is conducive to improving product quality and production efficiency.

[0016] 3. The setting of fault diagnosis and maintenance module provides a strong guarantee for the reliable operation of the system. The sensor group can comprehensively collect data related to the system operation status. The data analysis unit can timely and accurately judge whether there is a fault in the system by comparing it with the preset normal operating parameter range, and determine the fault type and possible fault location. The alarm unit quickly sends out visual and auditory alarm signals when a fault is detected, so that the operator can know and take corresponding measures in time. The maintenance guidance unit provides maintenance personnel with detailed operation guides, including equipment maintenance, component replacement, parameter adjustment, etc., which greatly shortens the troubleshooting and repair time, reduces maintenance costs, and improves system availability and maintenance efficiency.

[0017] 4. Through the simulation optimization of the evaporator of the refrigeration dehumidification unit and the parameter adjustment of the adsorbent and structure of the adsorption dehumidification unit, the system reduces energy consumption while ensuring the dehumidification effect. For example, the reasonable evaporator structure and operating parameter settings reduce the energy consumption of the compressor, and the optimized adsorbent parameters and adsorption tower structure improve the adsorption efficiency and reduce the frequency of adsorbent regeneration, thereby achieving energy saving and consumption reduction. In addition, the system further optimizes the overall performance of the system and improves energy utilization efficiency based on the cold air unit and its layout determined by the laboratory simulation test, which meets the requirements of modern industry for energy conservation and emission reduction.

[0018] 5. The dehumidification system of the present invention can adapt to the dehumidification requirements under different working conditions and environmental conditions. Whether in high humidity, low temperature environment or in the case of large humidity fluctuations, the system can stably output dry air that meets the requirements through the coordinated work of the two dehumidification units and the intelligent control of the PLC system. At the same time, the reasonable design of each component of the system and the existence of the fault diagnosis and maintenance module improve the reliability and stability of the system, reduce the risk of production interruption due to equipment failure, and provide a reliable air dehumidification solution for industrial production. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses. Embodiment 1

[0020] According to the steps in claim 2, the evaporator is mapped in detail, and after obtaining the geometric parameters, a three-dimensional model is created and imported into Fluent for meshing and other operations. Select the appropriate model and parameter settings to complete the simulation research and optimization design of the refrigeration and dehumidification unit. According to the optimization results, purchase the evaporator, compressor, condenser, throttling device and other components of corresponding specifications and assemble them in the factory. After the installation is completed, perform a preliminary electrical connection and pipeline connection inspection to ensure that there are no leaks and connection errors.

[0021] Start the refrigeration and dehumidification unit and run it for a period of time under no-load conditions to observe the operating status of each component, such as whether the compressor starts smoothly and whether there is abnormal frost on the evaporator surface. At the same time, use the temperature sensor and pressure sensor installed at the inlet and outlet of the evaporator to monitor the temperature and pressure changes of the inlet and outlet air, and preliminarily judge whether the operation of the refrigeration and dehumidification unit meets expectations. For example, under the conditions of an ambient temperature of 25°C and a relative humidity of 60%, the evaporator inlet air temperature should be around 25°C. After refrigeration and dehumidification, the outlet air temperature should be significantly reduced, such as to 5-10°C, and the pressure change should be within the normal range.

[0022] According to claim 3, determine the filling amount, particle size and structural dimensions of the activated alumina adsorbent. Purchase suitable activated alumina adsorbent and load it into the adsorption tower to ensure uniform loading. Build an adsorbent regeneration device, connect it to the adsorption tower and debug it. Install temperature and humidity sensors and pressure sensors at the inlet and outlet of the adsorption tower to monitor parameter changes during the adsorption process. In the test of the adsorption dehumidification unit running alone, air with a certain humidity (such as 80% relative humidity) and temperature (such as 30°C) is passed into the adsorption tower at a set flow rate (such as 2m / s) to monitor the changes in outlet air humidity. At the beginning, the outlet air humidity should gradually decrease, and when the adsorbent reaches adsorption saturation, the outlet air humidity will tend to stabilize. Record the time from the start of adsorption to adsorption saturation, as well as the outlet air humidity at saturation, and compare them with the theoretical calculated value to preliminarily evaluate the performance of the adsorption dehumidification unit.

[0023] According to the system design requirements, connect the temperature and humidity sensors, pressure sensors and other data acquisition devices to the data acquisition module of the PLC system to ensure normal signal transmission. Write a control algorithm program in the PLC system, and set the initial control parameters and preset standards according to the steps in claim 4, such as the outlet air humidity setting value of 40% ± 5%.

[0024] Conduct communication tests to check whether the PLC system can accurately receive the data collected by the sensor and display it on the human-machine interface. At the same time, test whether the control signal output by the PLC system can correctly control the actuators in the refrigeration dehumidification unit and the adsorption dehumidification unit (such as the start and stop of the compressor, fan speed adjustment, etc.). For example, by manually changing the temperature or humidity value collected by the sensor, observe whether the PLC system can send corresponding control signals according to the preset algorithm, such as adjusting the cooling capacity of the evaporator or the working status of the adsorbent regeneration device.

[0025] According to claims 1 and 8, a sensor group consisting of a temperature sensor, a humidity sensor, a pressure sensor, an air flow velocity sensor, and an equipment status sensor is installed to ensure that the sensor installation position is accurate and can accurately collect the operating data of each key part of the system. The sensor group is connected to the data analysis unit of the fault diagnosis and maintenance module, and a communication test is performed to ensure that the data transmission is correct. When the system is initialized, the data analysis unit analyzes the initial data collected by the sensor to determine whether each sensor is working properly, such as whether the temperature sensor displays a reasonable ambient temperature value, whether the pressure sensor is within the normal pressure range, etc. At the same time, check whether the alarm unit can work properly, for example, by simulating a fault signal (such as disconnecting a sensor line) and observing whether the alarm unit can send out visual (such as flashing indicator lights) and auditory (such as buzzer sounds) alarm signals in time. Check whether the fault type and maintenance operation guide stored in the maintenance guidance unit are complete and accurate. Embodiment 2

[0026] When the system is running as a whole, compressed air with a certain humidity (such as 70% relative humidity) and temperature (such as 28°C) is passed into the refrigeration and dehumidification unit for preliminary dehumidification. According to claim 7, the humidity sensor at the outlet monitors the air humidity in real time and transmits the data to the PLC system. When the humidity is high (such as higher than 60%), the PLC system controls the refrigeration and dehumidification unit to operate at full capacity according to the preset algorithm, such as increasing the compressor frequency to enhance the refrigeration effect and reducing the evaporator temperature. The air after refrigeration and dehumidification enters the adsorption dehumidification unit for further dehumidification. The PLC system also monitors the humidity changes at the inlet and outlet of the adsorption dehumidification unit. When the humidity after refrigeration and dehumidification is close to but has not reached the set range (such as 40%-45%), the adsorption dehumidification unit is started, and the parameters such as the adsorbent regeneration cycle are dynamically adjusted according to the humidity changes during the adsorption process. For example, if the outlet humidity drops slowly, the adsorbent regeneration cycle can be appropriately shortened to improve the adsorption efficiency of the adsorbent.

[0027] During the whole process, the temperature and humidity control PLC system continuously monitors the temperature and humidity parameters of the system, as well as the operating status parameters of the refrigeration dehumidification unit and the adsorption dehumidification unit (such as compressor power, adsorption tower pressure difference, etc.), to ensure that the system operates stably and the outlet dew point is stable within the set range (such as -5℃-0℃). At the same time, the fault diagnosis and maintenance module collects system operation data in real time for fault monitoring.

[0028] After running for a period of time, collect the operating data recorded by the temperature and humidity control PLC system, including the operating parameters of the refrigeration dehumidification unit and the adsorption dehumidification unit under different working conditions, the outlet air humidity and temperature change curves, etc. Analyze these data to evaluate the overall dehumidification performance and stability of the system. For example, if it is found that the outlet dew point fluctuates greatly under certain working conditions, further analysis is conducted to determine whether it is caused by the unstable cooling capacity of the refrigeration dehumidification unit or the poor adsorption effect of the adsorption dehumidification unit.

[0029] According to the analysis results, the system is optimized. If the problem is with the refrigeration dehumidification unit, refer to the steps of the refrigeration dehumidification unit simulation study in claim 2, adjust and optimize the parameters of the evaporator and other components, such as changing the evaporator fin structure to improve the heat exchange efficiency, and then re-run the system and monitor the effect. For the adsorption dehumidification unit, according to the method for verifying the effectiveness of the adsorption dehumidification unit in claim 6, check whether the adsorbent performance has decreased. If necessary, replace the adsorbent or adjust the adsorption tower structure size, and verify and optimize again.

[0030] At the same time, the control algorithm of the temperature and humidity control PLC system is optimized. According to the actual operation data, the set values ​​and adjustment strategies of the control parameters are adjusted so that the system can respond to changes in working conditions more quickly and accurately, and improve the dehumidification efficiency and stability. For example, under conditions where the humidity changes rapidly, the sampling frequency and control response time of the PLC system are optimized to ensure that the system can adjust the operating parameters in a timely manner.

[0031] During the operation of the system, suppose the compressor fails, such as the motor overheating. The sensor group in the fault diagnosis and maintenance module, such as the temperature sensor monitoring the compressor casing temperature is too high, the current sensor detecting the motor current abnormality, etc., collects relevant data and transmits it to the data analysis unit. The data analysis unit determines the fault type as the compressor overheating fault according to the preset fault judgment logic, and determines that the possible fault location is the compressor motor part.

[0032] The alarm unit immediately sends out visual (such as the compressor fault indicator in the control room lights up) and auditory (such as the alarm rings) alarm signals to notify the operator. At the same time, the maintenance guidance unit provides maintenance personnel with corresponding maintenance operation suggestions based on the type of fault, such as checking whether the compressor cooling fan is running normally, whether the lubrication system is faulty, whether the motor winding is short-circuited, etc., and gives corresponding maintenance steps and precautions.

[0033] Maintenance personnel conduct inspections and repairs based on the recommendations of the maintenance guidance unit. If the cooling fan fails, repair or replace the fan; if the lubrication system fails, add or replace the lubricant; if the motor winding is short-circuited, the motor may need to be replaced. After the repair is completed, restart the compressor and observe the system operation status. The fault diagnosis and maintenance module continues to monitor the system operation to ensure that the system returns to normal operation. If the fault is more complex, maintenance personnel can use the remote communication unit (if available) to transmit detailed fault information to the remote monitoring center, seek remote diagnosis and guidance from professional technicians, and speed up the fault repair process.

[0034] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A compressed air combined dehumidification system, characterized in that: include: A refrigeration and dehumidification unit is used to preliminarily dehumidify the compressed air. The refrigeration and dehumidification unit includes an evaporator. The dehumidification process of the evaporator is simulated and studied by using Fluent analysis software, and different wet air intake speeds and evaporator parameters are analyzed; The adsorption dehumidification unit is connected to the refrigeration dehumidification unit and is used to further dehumidify the air that has been preliminarily dehumidified. The adsorption dehumidification unit uses activated alumina as an adsorbent, and mathematically models the adsorption dehumidification of activated alumina and combines it with the unidirectional flow porous medium model provided by Fluent, and uses UDF to realize heat and mass transfer in the adsorption dehumidification process; A temperature and humidity control PLC system, connected to the refrigeration dehumidification unit and the adsorption dehumidification unit, is used to monitor and control the temperature and humidity parameters of the entire dehumidification system in real time; A fault diagnosis and maintenance module is connected to the refrigeration and dehumidification unit, the adsorption dehumidification unit and the temperature and humidity control PLC system for performing fault diagnosis and maintenance operations on the system. The fault diagnosis and maintenance module includes: The sensor group is set inside the system to collect various data related to the system operation status, including temperature, humidity, pressure, air flow speed and equipment operation status information; A data analysis unit receives the data collected by the sensor group and compares and analyzes it with a preset normal operating parameter range to determine whether the system has a fault, and when abnormal data is detected, determines the fault type and possible fault location; An alarm unit connected to the data analysis unit, when the data analysis unit determines that there is a fault in the system, sends out a corresponding alarm signal, the alarm signal includes a visual alarm and an audible alarm; The maintenance guidance unit stores maintenance operation guides for different fault types. When a system fault occurs, the maintenance personnel are provided with corresponding maintenance operation suggestions according to the fault type determined by the data analysis unit.

2. The compressed air combined dehumidification system according to claim 1, characterized in that: The refrigeration and dehumidification unit simulates the dehumidification process of the evaporator by using Fluent analysis software, including the following steps: Step 1: Based on the detailed mapping of the actual structure of the evaporator, the geometric parameters including the size of the heat exchange tube, the specifications of the fins and the arrangement method are obtained. A model consistent with the real object is created using 3D modeling software, and non-critical structural details are simplified. The constructed geometric model is imported into the Fluent pre-processing software. Unstructured grids are used for the complex flow areas inside the evaporator, and structured grids are used for regular areas. At the same time, grids are encrypted on the surface of the heat exchange tube and in areas where the air flow changes dramatically, so as to construct an accurate 3D geometric model of the evaporator. Step 2: In Fluent software, select the Eulerian-Lagrangian model as the multiphase flow model of the air-water system, select the turbulence model according to the air flow characteristics in the evaporator, enable the energy equation and set the water vapor diffusion model based on Fick's law for the mass transfer process; Step 3: Set the temperature, humidity, pressure and velocity parameters of the wet air entering the evaporator as the inlet boundary conditions, set the pressure outlet boundary conditions according to the overall pressure distribution and outlet position of the system, set the wall surface of the evaporator heat exchange tube as the coupled boundary condition and confirm the material properties of the heat exchange tube; Step 4: Calculate the density, specific heat capacity, and thermal conductivity of the moist air based on its temperature and humidity, create a custom moist air material and input it into Fluent, and set the material properties of the evaporator heat exchange tubes and fins, including density, specific heat capacity, and thermal conductivity; Step 5: Initialize the variables in the computational domain based on the inlet boundary conditions and the estimation of the initial state of the system, select the pressure-based solver, set the pressure-velocity coupling algorithm, discrete format and iteration step parameters, use a loose convergence standard and a large step size for the initial calculation, and gradually increase the standard and reduce the step size later; Step 6: Start the Fluent simulation calculation and monitor the changes in the residual curve. When the residuals of the continuity equation, momentum equation, and energy equation drop below the preset convergence standard and the distribution of key physical quantities is stable and the global parameters of import and export are balanced, the calculation is considered to have converged. Step 7: After the calculation converges, use Fluent post-processing software to visualize the results, draw cloud maps, vector maps, and contour maps of temperature, humidity, and velocity physical quantities, calculate the evaporator dehumidification capacity and dehumidification efficiency performance indicators, and compare and verify with the empirical formula results. If there is a deviation, analyze the cause and correct the model; Step 8: Determine the optimization parameters based on the analysis results, change the parameter values ​​and re-simulate the calculation, compare the results of different parameter combinations to determine the optimal settings, improve the design if there are unreasonable aspects of the structure, re-model and mesh, and simulate the calculation to verify the improvement effect, and continuously iterate the optimization.

3. The compressed air combined dehumidification system according to claim 1, characterized in that: The parameters related to the activated alumina adsorbent in the adsorption dehumidification unit include the adsorbent filling amount and particle size, and the structural dimensions of the adsorption tower include tower height and diameter.

4. The compressed air combined dehumidification system according to claim 1, characterized in that: The temperature and humidity control PLC system can automatically adjust the operating parameters of the refrigeration dehumidification unit and the adsorption dehumidification unit according to the system operation conditions, including temperature, humidity, and pressure. The adjustment steps are as follows: Step A1: continuously obtain the temperature, humidity and pressure operation data of the refrigeration dehumidification unit and the adsorption dehumidification unit through sensors arranged at various locations in the system, and transmit them to the PLC system; Step A2: The PLC system processes the collected data, calculates the current dehumidification effect index, compares it with the preset standard, determines whether the system operation status is normal, and determines whether the parameters need to be adjusted; Step A3: If adjustment is required, determine the adjustment strategy for the specific parameters of the refrigeration dehumidification unit and the adsorption dehumidification unit according to the deviation and the built-in algorithm; Step A4: The PLC system outputs control signals to the corresponding actuators to perform adjustment operations, and then re-evaluates the system status based on sensor feedback. If the system status does not meet expectations, the above steps are repeated for optimization until the system runs stably.

5. The compressed air combined dehumidification system according to claim 1, characterized in that: The system is based on the operation of the cooling units and their layout determined by on-site simulation tests in a 60m³ laboratory system set up in the factory.

6. The compressed air combined dehumidification system according to claim 1, characterized in that: The effectiveness of the adsorption dehumidification unit is verified by mathematical model simulation analysis and physical model test. The specific verification method is as follows: Step B1: Based on the principles of adsorption thermodynamics and kinetics, combined with the characteristics of activated alumina adsorbent, a mathematical model of the adsorption dehumidification process is established to obtain simulation data of the performance of the adsorption dehumidification unit under different working conditions; Step B2: According to the structure and process requirements of the actual adsorption dehumidification unit, a small physical test model is built, equipped with high-precision temperature and humidity sensors and flow meter measurement equipment, and multiple groups of test conditions consistent with actual working conditions are set to obtain the measured performance data of the adsorption dehumidification unit under different working conditions in the physical model test; Step B3: compare the measured data obtained from the physical model test with the simulated data of the mathematical model point by point, calculate the deviation rate of each performance indicator, analyze the cause of the deviation, judge the accuracy of the mathematical model and the effectiveness of the adsorption dehumidification unit design, and output a comparison result report, including the deviation rate statistics of each performance indicator and the analysis of the cause of the deviation. If there is a problem with the effectiveness, go to step B4. If it is effective, end the verification process; Step B4: Based on the evaluation results of step B3, the assumptions, parameter values ​​and calculation methods of the mathematical model are corrected and optimized. After the mathematical model and physical model test device are adjusted and optimized, return to step B1 and re-perform simulation analysis and test verification until the effectiveness of the adsorption dehumidification unit is fully verified.

7. The compressed air combined dehumidification system according to claim 1, characterized in that: A humidity sensor is set at the system outlet to monitor the air humidity in real time and transmit the humidity data to the PLC system as a basis for judgment and adjustment. According to the initial humidity conditions, when the humidity is high, the refrigeration dehumidification unit is started first to use its ability to quickly reduce a large amount of water in the air for initial dehumidification. When the humidity is close to but has not reached the set range after refrigeration dehumidification, the adsorption dehumidification unit is started to give full play to its advantage of further fine dehumidification of low-humidity air. The control system adjusts the operating parameters of the refrigeration dehumidification unit in real time according to the humidity monitoring data and preset standards. At the same time, the parameters of the adsorption dehumidification unit are also adjusted.

8. The compressed air combined dehumidification system according to claim 1, characterized in that: The sensor group in the fault diagnosis and maintenance module includes a temperature sensor, a humidity sensor, a pressure sensor, an air flow velocity sensor and an equipment status sensor.