A PLC full-automatic on-line sampling control system and method for water quality

Abstract

The application discloses a kind of PLC full automation online sampling control system and method for water quality, including PLC control unit, sampling module, refrigeration module and fixed structure;Fixed structure adopts water-proof and rust-proof metal frame, and is detachably fixed to wall body or sampling point support;Sampling module includes water pump, filter and two worm special filter element connected in sequence;Filter element effective filtration pore size is 1-5 microns;PLC control unit is monitored the cumulative flow of sampling module in real time by flowmeter, and when reaching preset volume, automatically cut off water pump power supply;Refrigeration module is integrated with semiconductor refrigeration device and temperature sensor, for maintaining two worm special filter element storage bin temperature at 0-4 ℃.The application realizes whole process without personnel care, strict quantitative and automatic giardia lamblia and cryptosporidium full automation online sampling control system, realizes water sample automatic collection and processing, improves detection efficiency and accuracy, provides strong support for prevention and early warning of water quality parasitic disease.

Description

Technical Field

[0001] This invention relates to the field of water quality testing technology, and in particular to a PLC-based fully automated online sampling control system and method for water supply quality. Background Technology

[0002] According to the "Standards for Drinking Water Quality" and the "Standards for Urban Water Supply Quality," clear requirements are set for the detection of Giardia lamblia and Cryptosporidium in treated water. Currently, two main sampling methods are used for testing treated water: one involves sampling personnel collecting up to 100 liters of water at the sampling point and bringing it back to the laboratory for enrichment and filtration. This process is not only time-consuming and labor-intensive but also consumes significant space and time resources in the sampling vehicle and laboratory. Furthermore, because it is difficult to maintain a constant refrigeration temperature of 0-4 degrees Celsius during transportation and storage, the parasite activity or morphological changes in the sample may decrease, thus affecting the accuracy of the experimental results.

[0003] Another method is on-site sampling. Using a portable, dedicated on-site sampling device, 100L of water sample is filtered at the sampling point, concentrated on the filter cartridge, and then refrigerated and brought back to the laboratory. While this reduces the hassle of transporting water samples to some extent, existing equipment still has shortcomings in terms of automation and portability. For example, sampling personnel need to carry bulky sampling devices to the site for filtration, consuming manpower and resources and limiting the flexibility of sampling locations. Furthermore, since existing equipment cannot achieve automatic collection, the sampling process still requires human supervision, undoubtedly increasing labor and time costs. Therefore, an automated and intelligent sampling control system is urgently needed to solve these problems. Summary of the Invention

[0004] To address at least one of the aforementioned technical problems, this invention provides a PLC-based fully automated online sampling control system and method for water supply quality.

[0005] In a first aspect, the present invention provides a PLC-based fully automated online sampling and control system for water supply quality, the system comprising:

[0006] PLC control unit, sampling module, refrigeration module and fixed structure;

[0007] The fixing structure adopts a waterproof and rust-proof metal frame, which can be detachably fixed to the wall or sampling point bracket;

[0008] The sampling module includes a water pump, a filter, and a special filter cartridge for two insects connected in sequence; the effective filtration pore size of the filter cartridge is 1-5 micrometers.

[0009] The PLC control unit monitors the cumulative flow of the sampling module in real time through the flow meter, and automatically cuts off the power to the water pump when the cumulative flow reaches the preset volume.

[0010] The refrigeration module integrates a semiconductor refrigeration device and a temperature sensor to maintain the temperature of the two insect-specific filter cartridge storage compartment at 0-4℃.

[0011] In one embodiment, the refrigeration module adopts a double-layer vacuum insulation structure, with a phase change energy storage material layer on the outer layer, which can continuously maintain a low-temperature environment for more than 8 hours in the event of a power outage.

[0012] In one embodiment, the two-insect-specific filter cartridge is made of polycarbonate material with a porosity greater than 85% and an effective filtration area greater than 200cm².

[0013] In one embodiment, the PLC control unit integrates a wireless communication module for remote parameter setting, status monitoring, and abnormal alarm functions.

[0014] In one embodiment, the fixing structure is equipped with a multi-directional adjustment bracket, allowing the sampling control system to adjust the installation angle within a vertical range of ±15°.

[0015] In one embodiment, the refrigeration module also integrates a temperature control enrichment module, which has a vacuum-jacketed filter chamber, a built-in compressor cooling chip and a phase change material layer, and initiates graded temperature control based on the temperature data of the sampled water quality.

[0016] In one embodiment, the PLC control unit further integrates a dynamic adjustment module for:

[0017] Establish a turbidity-flow rate mapping table to classify turbidity values ​​into different levels and match them with corresponding flow rates;

[0018] Monitor changes in turbidity levels, and use a preset acceleration to gradually change the flow rate when the turbidity level changes.

[0019] In one embodiment, the dynamic adjustment module is further configured to generate a dynamic differential pressure compensation value based on the actual flow rate and the preset flow rate, so as to correct the pump operating parameters during subsequent sampling.

[0020] Secondly, the present invention also provides a PLC-based fully automated online sampling control method for water supply quality, applied to a PLC-based fully automated online sampling control system for water supply quality as described in any one of the first aspects, the method comprising:

[0021] Set sampling parameters, including the target sampling volume and the maximum allowable flow rate;

[0022] The sampling parameters are sent to the PLC control unit, which automatically starts the water pump, allowing water to flow through the filter to enrich the two insects; the filter cartridge storage compartment is maintained at 0-4℃ throughout the process.

[0023] Real-time monitoring of flow data; automatically adjusts pump power when instantaneous flow exceeds maximum allowable flow.

[0024] When the accumulated flow reaches the preset flow rate, the water pump is automatically shut off and the solenoid valve is triggered to cut off the pipeline; a sampling log is generated, which includes sampling time, water temperature, flow curve and equipment status parameters.

[0025] In one embodiment, the method further includes:

[0026] The system automatically sends sampling logs to the remote monitoring platform. If the filter element clogging coefficient is detected to exceed the preset value, a maintenance alarm is issued simultaneously.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] In this embodiment, the fixing structure adopts a waterproof and rust-proof metal frame, which can adapt to different usage environments, especially humid or corrosive environments, effectively extending the service life of the system. Simultaneously, its detachable design allows the system to be easily installed on a wall or sampling point bracket, facilitating installation and subsequent system maintenance, relocation, or repositioning. The water pump, filter, and two-insect-specific filter cartridge in the sampling module are connected sequentially, forming an efficient sampling process. The water pump provides stable power, ensuring the smooth entry of water samples into the sampling system; the filter pre-filters out large particulate impurities, protecting the subsequent two-insect-specific filter cartridge and extending its service life; the two-insect-specific filter cartridge has an effective filtration pore size of 1-5 micrometers, accurately capturing the target microorganisms (two insects) in the water, ensuring the accuracy and effectiveness of sampling. The PLC control unit monitors the cumulative flow of the sampling module in real time through a flow meter, automatically cutting off the water pump power when the cumulative flow reaches a preset volume. This function achieves automated control of the sampling process, avoiding errors and uncertainties that may be caused by manual operation, ensuring the accuracy of the sample volume each time, and improving the reliability and comparability of the sampling data. The refrigeration module integrates a semiconductor refrigeration device and a temperature sensor, enabling real-time monitoring and maintenance of the temperature within the two-parasite filter cartridge preservation chamber at 0-4℃. Within this temperature range, the microorganisms (two parasites) in the water maintain a relatively stable state, reducing their growth, reproduction, and death, thus ensuring sample quality and providing a reliable foundation for subsequent detection and analysis. The temperature sensor allows the refrigeration module to automatically adjust the operating status of the semiconductor refrigeration device based on actual temperature conditions, achieving intelligent temperature control. This intelligent adjustment not only ensures temperature stability but also effectively reduces energy consumption and improves the system's energy efficiency.

[0029] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the background art, the accompanying drawings used in the embodiments of the present invention or the background art will be described below.

[0031] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to illustrate the technical solutions of this disclosure.

[0032] Figure 1 A schematic diagram of a PLC-based fully automated online sampling control system for water supply quality provided in an embodiment of the present invention;

[0033] Figure 2 for Figure 1 Schematic diagram of the structure of the medium-refrigeration module 300;

[0034] Figure 3 for Figure 1 A schematic diagram of the sub-modules of the PLC control unit 100;

[0035] Figure 4 This is a flowchart illustrating a fully automated online sampling and control method for water supply quality using a PLC, as provided in an embodiment of the present invention. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, 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.

[0037] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] Please see Figure 1 , Figure 1 This is a schematic diagram of a PLC-based fully automated online sampling control system for water supply quality, provided as an embodiment of the present invention. Figure 1 As shown, the system includes:

[0039] PLC control unit 100, sampling module 200, refrigeration module 300 and fixed structure 400;

[0040] The fixing structure 400 adopts a waterproof and rust-proof metal frame, which can be detachably fixed to the wall or sampling point bracket;

[0041] The sampling module 200 includes a water pump, a filter, and a special filter cartridge for two insects connected in sequence; the effective filtration pore size of the filter cartridge is 1-5 micrometers.

[0042] The PLC control unit 100 monitors the cumulative flow of the sampling module 200 in real time through the flow meter, and automatically cuts off the power supply to the water pump when the cumulative flow reaches the preset volume.

[0043] The refrigeration module 300 integrates a semiconductor refrigeration device and a temperature sensor to maintain the temperature of the two insect-specific filter cartridge storage compartment at 0-4℃.

[0044] First, select a suitable installation location based on actual sampling requirements, such as a wall or sampling point bracket. Secure the fixed structure 400, composed of a waterproof and rust-proof metal frame, to the selected location using detachable methods (such as bolts or clips). This detachable design facilitates subsequent system maintenance, relocation, or replacement. Install the sampling module 200, PLC control unit, and refrigeration module 300 onto the fixed structure 400 according to design requirements. Ensure all modules are securely installed to prevent vibration or shaking from affecting the normal operation of the system.

[0045] Connect the water pump, filter, and dedicated filter cartridge for Giardia lamblia in sequence. Connect the water pump inlet to the water supply pipe, using the pump's suction to introduce the water sample into the sampling system. Connect the water pump outlet to the filter inlet; the filter removes large particles from the water sample, protecting the dedicated filter cartridge. Connect the filter outlet to the dedicated filter cartridge's inlet; the dedicated filter cartridge has an effective pore size of 1-5 micrometers, precisely capturing the target microorganisms in the water, namely Giardia lamblia and Cryptosporidium.

[0046] The PLC control unit 100 is connected to the power control terminal of the water pump via a control signal line to control the pump's start and stop. Simultaneously, a flow meter is installed on the pipe of the sampling module 200, transmitting flow data to the PLC control unit via a signal line. The two-insect special filter cartridge is placed in the storage compartment of the refrigeration module 300, which provides a stable low-temperature storage environment for the cartridge. A temperature sensor transmits the temperature data within the storage compartment to the PLC control unit via a signal line; the PLC control unit 100 controls the start and stop of the semiconductor refrigeration device via a control signal line. The overall water flow direction is: from the water pump outlet to the filter inlet, then to the filter outlet, and finally to the two-insect special filter cartridge inlet.

[0047] After the sampling control system is activated, the water pump starts working, introducing water samples from the water supply pipe into the sampling module 200. The water sample passes sequentially through a filter and a special filter cartridge for the two worms. Large particulate impurities in the water are filtered out by the filter, while the target microorganisms (two worms) are captured by the special filter cartridge. Simultaneously, the flow meter monitors the cumulative flow of the sampling module 200 in real time and transmits the flow data to the PLC control unit 100. When the cumulative flow reaches a preset volume, the PLC control unit 100 receives a signal from the flow meter and automatically cuts off the power to the water pump, stopping sampling. This ensures the accuracy of the sample volume for each sampling, improving the reliability and comparability of the sampling data. A temperature sensor monitors the temperature inside the storage chamber of the special filter cartridge in real time and transmits the temperature data to the PLC control unit 100. When the temperature inside the storage chamber exceeds 4°C, the PLC control unit 100 activates the semiconductor cooling device to lower the temperature inside the storage chamber; when the temperature inside the storage chamber falls below 0°C, the PLC control unit 100 stops the semiconductor cooling device to prevent excessively low temperatures from affecting sample quality. Through this intelligent control, the temperature inside the storage chamber is maintained between 0-4°C, ensuring sample quality.

[0048] See Figure 2 In one embodiment, the refrigeration module 300 adopts a double-layer vacuum insulation structure, with a phase change energy storage material layer on the outer layer, which can continuously maintain a low-temperature environment for more than 8 hours in the event of a power outage.

[0049] First, the inner and outer layers of the refrigeration module 300 are fabricated separately. The inner layer uses a material with good thermal conductivity, such as stainless steel, to ensure that the cooling effect of the semiconductor refrigeration device can be effectively transferred to the storage compartment. The outer layer uses a high-strength, heat-insulating material, such as glass fiber reinforced plastic. The inner and outer layers are assembled together, and a vacuum is created using a specialized process to form a double-layer vacuum insulation structure, reducing heat conduction and convection. A suitable phase change energy storage material (such as eutectic salt phase change material) can be selected for the phase change energy storage material layer, which is then encapsulated in a sealed container or sheet. The encapsulated phase change energy storage material is then evenly laid on the inner wall of the outer layer, ensuring a tight bond with the double-layer vacuum insulation structure. The fabricated refrigeration module 300 is integrated into the entire PLC-based fully automated online sampling and control system for water quality. Following the previously described connection relationships, the temperature sensor, semiconductor refrigeration device, and PLC control unit are connected to ensure normal communication and collaborative operation of all components. Meanwhile, the special filter cartridge storage compartment for the two insects is placed in a suitable position in the refrigeration module 300 to ensure that it is in a good low-temperature storage environment.

[0050] In practical applications, sudden power outages may occur. This embodiment employs a double-layer vacuum insulation structure and a phase change energy storage material layer, enabling the refrigeration module 300 to maintain a low-temperature environment for over 8 hours after a power outage. This provides ample time for water sample preservation; even during prolonged power outages, the temperature inside the two-insect filter cartridge preservation chamber remains between 0 and 4°C, effectively preventing the growth, reproduction, or death of microorganisms (two insects) in the water due to temperature increases, thus ensuring sample quality and the accuracy of test results. The double-layer vacuum insulation structure significantly reduces heat transfer, lowering the energy consumption of the semiconductor refrigeration device. The phase change energy storage material layer absorbs and stores cold energy during the refrigeration process and releases it during power outages, further assisting in maintaining the low-temperature environment and reducing dependence on external energy sources. This design makes the refrigeration module 300 more energy-efficient during normal operation, reducing operating costs.

[0051] Furthermore, the stable low-temperature environment not only benefits sample preservation but also protects the internal equipment of the refrigeration module 300 (such as semiconductor refrigeration devices and temperature sensors). This reduces damage to the equipment caused by temperature fluctuations, lowers the equipment failure rate, extends the equipment's lifespan, and reduces maintenance and replacement costs.

[0052] In one embodiment, the two-insect-specific filter cartridge is made of polycarbonate material with a porosity greater than 85% and an effective filtration area greater than 200cm².

[0053] In manufacturing polycarbonate filter cartridges, specific molding processes are employed to create cartridges specifically designed for insects. Common methods include phase inversion and stretching. Taking phase inversion as an example, polycarbonate is dissolved in a suitable solvent to form a homogeneous solution. This solution is then extruded through a specific mold or coated onto a support material, and subsequently placed in a coagulation bath where the solvent and coagulant exchange, causing the polycarbonate to solidify and form a filter cartridge with a porous structure. During the molding process, process parameters such as solution concentration, coagulation bath composition, temperature, and time are controlled to adjust the porosity and pore size of the filter cartridge, ensuring a porosity greater than 85% and an effective filtration pore size of 1-5 micrometers.

[0054] The manufactured two-insect-specific filter cartridge is integrated into the sampling module 200. Following the connection method of the sampling module 200, the inlet of the filter cartridge is connected to the outlet of the filter, ensuring a tight and airtight connection to prevent water sample leakage. Simultaneously, the filter cartridge is installed in a suitable position to ensure smooth sampling.

[0055] Because the porosity of the two-insect-specific filter cartridge is greater than 85%, it means that there are a large number of pores inside the cartridge, providing more channels for water sample flow. During sampling, the water sample can pass through the cartridge more smoothly, reducing water flow resistance and improving sampling efficiency. At the same time, the high porosity also increases the contact area between the cartridge and the water sample, giving the target microorganisms (two-insects) in the water a greater chance of being captured by the cartridge, thus improving filtration efficiency and accuracy. The effective filtration area is greater than 200 cm², providing more space for the filtration process. A larger filtration area can process more water samples per unit time, further increasing the sampling speed. Moreover, the large filtration area results in a longer cartridge lifespan because, for the same sampling volume, the contaminant load per unit area is relatively small, reducing the risk of cartridge clogging and extending the cartridge replacement cycle.

[0056] In addition, polycarbonate material has good chemical stability and mechanical properties. It is resistant to most chemicals and can maintain stable performance in different water quality environments. It will not be corroded or dissolved by the chemical components in the water sample, ensuring the reliability and durability of the filter element.

[0057] In one embodiment, the PLC control unit 100 integrates a wireless communication module for remote parameter setting, status monitoring, and abnormal alarm functions.

[0058] Connect the selected wireless communication module to the PLC control unit via a suitable interface (such as a serial port or Ethernet interface) to ensure a secure connection and stable signal transmission. Simultaneously, equip the wireless communication module with the necessary antennas to enhance signal strength and coverage. This method allows operators to set and adjust system operating parameters remotely via a terminal without being physically present on-site, significantly saving time and labor costs.

[0059] When the system malfunctions, it can promptly send alarm information to remote terminals, enabling relevant personnel to quickly learn about the fault and respond. This helps reduce the impact of the fault on the system and minimize losses. For example, when the temperature of the refrigeration module 300 exceeds the normal range, the system will immediately issue an alarm, reminding operators to check the refrigeration equipment in time to prevent samples from being damaged due to excessive temperature. After a fault occurs, operators can obtain detailed operating data of the system through remote terminals for remote diagnosis and analysis, which helps to quickly locate the cause of the fault, develop effective maintenance plans, and shorten the fault handling time.

[0060] In one embodiment, the fixing structure 400 is equipped with a multi-directional adjustment bracket, allowing the sampling control system to adjust the installation angle within a vertical range of ±15°.

[0061] First, fix the waterproof and rust-proof metal frame fixing structure 400 to the wall or sampling point bracket using a detachable method (such as bolts or clips) as described previously. Install the multi-directional adjustment bracket onto the fixing structure 400, ensuring a secure connection. Welding, bolting, or other methods can be used, but the connection points must undergo rigorous strength testing to prevent loosening during use. Install the sampling module 200, PLC control unit 100, and refrigeration module 300 onto the fixing structure 400 according to design requirements, ensuring correct and stable connections between modules. Based on actual sampling needs and site conditions, loosen the locking device of the multi-directional adjustment bracket and adjust the vertical angle of the sampling control system to achieve a suitable installation angle, within ±15°. After adjustment, tighten the locking device to ensure the angle is fixed.

[0062] After completing the angle adjustment, the entire sampling control system was thoroughly debugged, and the operation of each module was checked to ensure that the system was working properly. At the same time, the locking of the multi-directional adjustment bracket was checked to ensure that the angle would not change during system operation.

[0063] Preferably, in actual water quality sampling sites, installation space and terrain conditions can vary widely. In some places, walls or supports are not perfectly vertical or horizontal. Equipped with a multi-directional adjustable support, the sampling control system can adjust its angle according to the actual site conditions, thus adapting to different installation environments and ensuring smooth installation and use. By adjusting the system's installation angle, the sampling location and direction can be better selected. For example, at sampling points with irregular water flow directions, adjusting the angle allows the sampling module 200 to more accurately collect representative water samples, improving sampling accuracy and reliability.

[0064] Thus, a proper installation angle allows the sampling module 200 to better withstand the impact of water flow during sampling. By adjusting the angle, water flows into the sampling module 200 in a more suitable manner, reducing the impact and wear on system components, thereby improving system performance stability and service life. Furthermore, a suitable installation angle helps ensure coordinated operation between the sampling module 200, the PLC control unit, and the refrigeration module 300. For example, placing the connecting pipe between the sampling module 200 and the refrigeration module 300 in a more optimal position reduces pipe bends and resistance, ensuring smooth flow of water samples into the refrigeration module 300 and improving the overall operating efficiency of the system.

[0065] In one embodiment, the refrigeration module 300 also integrates a temperature control enrichment module, which has a vacuum-jacketed filter compartment, a built-in compressor cooling chip and a phase change material layer, and initiates graded temperature control based on the temperature data of the sampled water quality.

[0066] A filter chamber with a vacuum jacket is fabricated. The vacuum jacket effectively reduces heat transfer and provides good insulation. The filter chamber can be made of materials such as stainless steel to ensure its strength and corrosion resistance. A compressor cooling plate and a phase change material layer are installed inside the filter chamber. The compressor cooling plate, as the main cooling component, is responsible for lowering the temperature inside the filter chamber; the phase change material layer absorbs and stores cold energy during the cooling process and releases it when needed, thus stabilizing the temperature. A temperature control enrichment module is connected to the compressor cooling plate and temperature sensor to ensure that the temperature control enrichment module can accurately acquire temperature data and control the operation of the compressor cooling plate.

[0067] A temperature sensor is installed at a suitable location in the sampling module 200 to monitor the temperature of the sampled water in real time. The temperature sensor is connected to the temperature control enrichment module via a signal line to transmit temperature data. The temperature control enrichment module is integrated with a PLC control unit, enabling the PLC control unit to receive data from the temperature control enrichment module and perform control according to a preset program. Parameters for graded temperature control are set through programming, such as the cooling intensity and operating time corresponding to different temperature ranges.

[0068] During system operation, temperature sensors collect real-time temperature data of the sampled water and transmit it to the temperature control and enrichment module. The module analyzes the temperature data to determine which preset temperature range the current water temperature falls within. Based on the analysis results, the module activates corresponding tiered temperature control strategies. For example, when the sampled water temperature is high, the module controls the compressor cooling element to operate at higher power to quickly reduce the temperature inside the filter chamber; when the temperature approaches the preset suitable temperature range, the cooling power is reduced to maintain temperature stability. Simultaneously, the phase change material layer absorbs cold energy during the cooling process and releases it when the cooling power is reduced or stopped, further stabilizing the temperature.

[0069] This embodiment demonstrates that the tiered temperature control function automatically adjusts the cooling intensity based on the actual temperature of the sampled water, ensuring that the temperature within the storage chamber of the two-parasite filter cartridge remains within a suitable range of 0-4℃, thus improving the system's adaptability to different water temperatures. Precise temperature control effectively reduces the impact of temperature fluctuations on the sample, ensuring the target microorganisms (two parasites) in the water are in a relatively stable environment, reducing their growth, reproduction, and death, thereby improving sample preservation quality and providing more reliable samples for subsequent detection and analysis. The tiered temperature control strategy adjusts the cooling power according to the actual temperature, avoiding the drawbacks of traditional cooling methods that operate at maximum power under all circumstances, achieving on-demand cooling. The vacuum-jacketed filter chamber and the phase change material layer work together to effectively reduce the influence of external temperature on the temperature inside the filter chamber, minimizing temperature fluctuations. Simultaneously, the tiered temperature control strategy ensures that the compressor cooling elements operate under suitable conditions, avoiding prolonged high-load operation, reducing equipment wear and the probability of malfunctions, extending equipment lifespan, and lowering maintenance costs.

[0070] See Figure 3 In one embodiment, the PLC control unit 100 further integrates a dynamic adjustment module 101, used for:

[0071] Establish a turbidity-flow rate mapping table to classify turbidity values ​​into different levels and match them with corresponding flow rates;

[0072] Monitor changes in turbidity levels, and use a preset acceleration to gradually change the flow rate when the turbidity level changes.

[0073] Specifically, based on the collected turbidity data, the turbidity values ​​are divided into different levels. For example, turbidity values ​​can be divided into three levels: low, medium, and high, each corresponding to a turbidity range. The specific level division can be adjusted according to actual needs and experimental data. For each turbidity level, the experimental data is analyzed to determine the optimal sampling flow rate. This flow rate should ensure sampling efficiency while preventing the filter cartridge from experiencing a decrease in filtration effect due to excessive flow rate, and also preventing wasted sampling time due to excessive flow rate. The turbidity levels and corresponding flow rates are recorded to form a turbidity-flow rate mapping table. The established turbidity-flow rate mapping table is stored in the dynamic adjustment module 101 of the PLC control unit. The turbidity sensor is connected to the PLC control unit 100, enabling the PLC control unit to acquire the turbidity value of the water sample in real time.

[0074] During system operation, the turbidity sensor monitors the turbidity value of the water sample in real time and transmits the turbidity data to the dynamic adjustment module 101 of the PLC control unit. The dynamic adjustment module 101 determines the current turbidity level according to a preset turbidity level classification standard. When a change in the turbidity level is detected, the dynamic adjustment module 101 gradually increases the flow rate using a preset acceleration. For example, if the turbidity value changes from a low level to a medium level, the dynamic adjustment module 101 will gradually increase the sampling flow rate according to a preset acceleration until it reaches the flow rate corresponding to the medium level turbidity. This avoids sudden changes in flow rate from adversely affecting the sampling process and the filter element.

[0075] Furthermore, by establishing a turbidity-flow rate mapping table, the system can automatically adjust the sampling flow rate according to the actual turbidity value of the water sample, making the sampling process more adaptable to different water quality conditions. In water samples with high turbidity, appropriately reducing the flow rate ensures that the filter cartridge has sufficient time to filter impurities, improving the filtration effect; in water samples with low turbidity, increasing the flow rate shortens the sampling time and improves sampling efficiency. Using a preset, gradually varying flow rate avoids interference from sudden changes in flow rate during the sampling process. The smooth change in flow rate makes the flow of the water sample in the filter cartridge more stable, reducing problems such as filter cartridge clogging or uneven filtration caused by sudden changes in flow rate, thereby ensuring the stability and accuracy of the sampling quality.

[0076] Therefore, proper flow rate adjustment can reduce filter cartridge wear. In cases of high turbidity, reducing the flow rate can prevent excessive impurities from quickly accumulating on the filter cartridge, extending its lifespan; in cases of low turbidity, increasing the flow rate can fully utilize the filter cartridge's filtration capacity without putting excessive pressure on it.

[0077] In one embodiment, the dynamic adjustment module 101 is further configured to generate a dynamic differential pressure compensation value based on the actual flow rate and the preset flow rate, so as to correct the pump operating parameters during subsequent sampling.

[0078] ;

[0079] In the formula, This is the dynamic differential pressure compensation value. The adjustment factor represents the adjustment intensity coefficient of the flow deviation, which is determined by experiments or system debugging, and usually takes a value range of 0.5-2. These represent the actual flow rate and the set flow rate, respectively. Larger responses are strongly influenced by flow deviations, allowing for rapid correction but potentially triggering oscillations. A smaller value indicates a smoother correction, resulting in a more stable system but a slower response time.

[0080] For example, the system sets the traffic. Actual measured flow rate proportionality coefficient Substituting into the above formula, we can calculate the result. ,because A negative value indicates insufficient flow. Therefore, the PLC control unit 100 will increase the water pump speed to adjust the subsequent sampling flow rate to:

[0081] ;

[0082] Therefore, the compensated flow rate approaches the target value, avoiding a decrease in sampling efficiency due to filter clogging.

[0083] See Figure 4 In one embodiment, the present invention also provides a PLC-based fully automated online sampling control method for water supply quality, the method comprising:

[0084] S10. Set sampling parameters, including target sampling volume and maximum allowable flow rate;

[0085] Input the following parameters through the human-machine interface: target sampling volume, maximum allowable flow rate, and sampling period interval; the system will automatically load historically optimal parameters, such as when turbidity is detected. At that time, the system will automatically Reduced by 20%.

[0086] S20. The sampling parameters are sent to the PLC control unit 100, and the water pump is automatically started, so that the water flows through the filter to complete the enrichment of the two insects; the filter cartridge storage chamber is maintained at 0-4℃ throughout the process.

[0087] One hour before sampling, the semiconductor cooling system is activated, and the filter compartment temperature is controlled in a closed-loop manner using a temperature sensor to maintain it at 2±1℃. If the ambient temperature... Pre-cooling refrigerant is injected in advance to enhance cooling.

[0088] S30. Real-time monitoring of flow data; automatically adjusts pump power when instantaneous flow exceeds the maximum allowable flow.

[0089] After the PLC sends the start command, the solenoid valve opens first, and after a 0.5s delay, the micro centrifugal pump starts. The inlet water passes through a stainless steel pre-filter to intercept impurities larger than 100μm, then enters the two-insect enrichment filter membrane, and finally flows into the flow meter detection end. The filter cartridge chamber adopts a double-layer vacuum insulation structure, with the interlayer filled with aerogel insulation material. When the surface temperature of the filter membrane... When the semiconductor cooling chip is activated, the power consumption is... When the temperature At this time, the chamber heating resistor (500Ω) is activated to prevent icing and damage to the filter membrane.

[0090] S40. When the accumulated flow reaches the preset flow, the water pump is automatically shut off and the solenoid valve is triggered to cut off the pipeline; a sampling log is generated, which includes sampling time, water temperature, flow curve and equipment status parameters.

[0091] When the cumulative flow reaches the preset flow rate, the system enters fine-tuning mode. As the flow rate decreases, the pump stops first, and then the solenoid valve closes after a 2-second delay to prevent siphoning. The storage format can be a CSV file containing the following fields: timestamp, water temperature (°C), instantaneous flow rate (L / min), cumulative volume (L), filter element temperature (°C), and alarm code. Flow curve recording: Flow data is saved every minute, generating a line graph embedded in a PDF report.

[0092] In one embodiment, the method further includes:

[0093] The system automatically sends sampling logs to the remote monitoring platform. If the filter element clogging coefficient is detected to exceed the preset value, a maintenance alarm is issued simultaneously.

[0094] The system detects the congestion coefficient to determine whether the congestion is mild or severe. When there is mild congestion, an SMS reminder can be sent. If there is severe congestion, a shutdown protection mechanism needs to be triggered and a work order is pushed. The system automatically generates a maintenance work order and assigns it to the nearest maintenance personnel.

[0095] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

Claims

1. A PLC-based fully automated online sampling and control system for water supply quality, characterized in that, The system includes: PLC control unit, sampling module, refrigeration module and fixed structure; The fixing structure adopts a waterproof and rust-proof metal frame, which can be detachably fixed to the wall or sampling point bracket; The sampling module includes a water pump, a filter, and a special filter cartridge for two insects connected in sequence; the effective filtration pore size of the filter cartridge is 1-5 micrometers. The PLC control unit monitors the cumulative flow of the sampling module in real time through the flow meter, and automatically cuts off the power to the water pump when the cumulative flow reaches the preset volume. The refrigeration module integrates a semiconductor refrigeration device and a temperature sensor to maintain the temperature of the two insect-specific filter cartridge storage compartment at 0-4℃. The PLC control unit also integrates a dynamic adjustment module for: Establish a turbidity-flow rate mapping table to classify turbidity values ​​into different levels and match them with corresponding flow rates; Monitor changes in turbidity levels, and use a preset acceleration to gradually change the flow rate when the turbidity level changes; The dynamic adjustment module is also used to generate a dynamic differential pressure compensation value based on the actual flow rate and the preset flow rate, so as to correct the pump operating parameters during subsequent sampling, including: ； In the formula, This is the dynamic differential pressure compensation value. The adjustment factor represents the adjustment intensity coefficient of the flow deviation, which is determined by experiments or system debugging, and usually takes a value range of 0.5-2. These represent the actual flow rate and the set flow rate, respectively.

2. The PLC-based fully automated online sampling control system for water supply quality according to claim 1, characterized in that, The refrigeration module adopts a double-layer vacuum insulation structure, with a phase change energy storage material layer on the outer layer, which can maintain a low-temperature environment for more than 8 hours in the event of a power outage.

3. The PLC-based fully automated online sampling control system for water supply quality according to claim 1, characterized in that, The two-insect-specific filter cartridge is made of polycarbonate with a porosity greater than 85% and an effective filtration area greater than 200cm².

4. The PLC-based fully automated online sampling control system for water supply quality according to claim 1, characterized in that, The PLC control unit integrates a wireless communication module for remote parameter setting, status monitoring, and abnormal alarm functions.

5. The PLC-based fully automated online sampling control system for water supply quality according to claim 1, characterized in that, The fixed structure is equipped with a multi-directional adjustable bracket, which allows the sampling control system to adjust the installation angle within a vertical range of ±15°.

6. The PLC-based fully automated online sampling control system for water supply quality according to claim 1, characterized in that, The refrigeration module also integrates a temperature control enrichment module, a filter chamber with a vacuum jacket, a built-in compressor cooling chip and a phase change material layer, and initiates graded temperature control based on the temperature data of the sampled water quality.

7. A PLC-based fully automated online sampling control method for water supply quality, applied to the PLC-based fully automated online sampling control system for water supply quality as described in any one of claims 1-6, characterized in that, The method includes: Set sampling parameters, including the target sampling volume and the maximum allowable flow rate; The sampling parameters are sent to the PLC control unit, which automatically starts the water pump, allowing water to flow through the filter to enrich the two insects; the filter cartridge storage compartment is maintained at 0-4℃ throughout the process. Real-time monitoring of flow data; automatically adjusts pump power when instantaneous flow exceeds maximum allowable flow. When the accumulated flow reaches the preset flow rate, the water pump is automatically shut off and the solenoid valve is triggered to cut off the pipeline; a sampling log is generated, which includes sampling time, water temperature, flow curve and equipment status parameters.

8. The PLC-based fully automated online sampling and control method for water supply quality according to claim 7, characterized in that, The method further includes: The system automatically sends sampling logs to the remote monitoring platform. If the filter element clogging coefficient is detected to exceed the preset value, a maintenance alarm is issued simultaneously.

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