Intelligent aeration system and aeration control method

Abstract

The invention relates to an intelligent aeration system and a control method, and belongs to the technical field of sewage treatment. The system comprises a clean water tank, an aeration tank, a data acquisition unit, a PLC control unit and an aeration unit. The system dynamically calculates the required DO set value by collecting the inlet water chemical oxygen demand, the clear water ammonia nitrogen concentration, the sludge concentration and the sewage temperature of sewage in real time, calculates the difference value between the actual DO value and the required DO set value, calculates the aeration amount needing to be adjusted, and finally adjusts the blast volume through the aeration unit. The problems that a traditional aeration system is high in energy consumption and low in control precision are solved, insufficient aeration or excessive aeration can be effectively avoided, and stable effluent quality is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and in particular to an intelligent aeration system and aeration control method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In wastewater treatment, aeration refers to the process of forcibly injecting air or oxygen into the wastewater during the biological treatment stage to promote the metabolic activity of microorganisms and decompose pollutants. As a core component of the entire wastewater treatment process, aeration accounts for 50%-70% of the overall energy consumption of a wastewater treatment plant, making it a key bottleneck restricting the industry's green and low-carbon development.

[0004] An aeration system is a system that uses automated control instruments and equipment, combined with aeration control strategies, to automatically and precisely regulate the aeration volume in the wastewater treatment process, so as to achieve stable effluent quality, energy saving and consumption reduction, and reduced human intervention.

[0005] The aeration systems commonly used in wastewater treatment plants currently have the following key problems: (1) High energy consumption: Traditional PID control uses a fixed air-water ratio, which leads to long-term high-load operation of the fan and high energy consumption per unit of COD removal.

[0006] (2) Low control accuracy: It relies on a fixed DO setting value and cannot adapt to fluctuations in influent load, which can easily lead to insufficient aeration and excessive aeration.

[0007] Meanwhile, current improvement schemes for aeration systems mainly include: U-tube model optimization and neural network control. However, U-tube model optimization requires well shut-in to obtain stable pressure data; neural network control relies on a large amount of training data, which is complex to deploy and has poor real-time performance.

[0008] Based on the above analysis, existing aeration systems have significant shortcomings in terms of control precision, control complexity, and energy consumption management. There is an urgent need for a more advanced, intelligent, and efficient aeration control system to overcome these technical obstacles and improve wastewater treatment efficiency and energy utilization efficiency. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides an intelligent aeration system and aeration control method. Through multi-parameter collaborative control, it achieves precision and intelligence in the aeration process, solving the core problems of traditional systems such as coarse control, high control complexity, and high energy consumption.

[0010] On the one hand, it provides an intelligent aeration system.

[0011] An intelligent aeration system, characterized in that the intelligent aeration system includes: a clear water tank, an aeration tank, a data acquisition unit, a PLC control unit, and an aeration unit; The clear water tank and the aeration tank are connected by an overflow pipe; The data acquisition unit collects real-time water quality parameters, including: influent chemical oxygen demand (COD), ammonia nitrogen concentration in clean water, sludge concentration, wastewater temperature, and actual dissolved oxygen (DO) value. The PLC control unit receives the collected real-time water quality parameters; The PLC control unit dynamically calculates the required DO setpoint based on real-time data collected from the wastewater influent chemical oxygen demand, ammonia nitrogen concentration in the clean water, sludge concentration, and wastewater temperature. Then, based on the difference between the actual DO value and the required DO setpoint, it calculates the aeration rate that needs to be adjusted and adjusts the blower volume through the aeration unit.

[0012] On the other hand, this application also provides an aeration control method for controlling the above-mentioned intelligent aeration system.

[0013] S101: The data acquisition unit collects real-time water quality parameters, including: influent chemical oxygen demand (COD), ammonia nitrogen concentration in clean water, sludge concentration, wastewater temperature, and actual dissolved oxygen (DO) value. S102: The PLC control unit receives the collected real-time water quality parameters and performs analog-to-digital conversion and signal conditioning; S103: Calculate the required DO setpoint dynamically based on the influent chemical oxygen demand, ammonia nitrogen concentration in the clean water, sludge concentration, and wastewater temperature after signal conditioning. S104: The PLC control unit compares the calculated required DO setting value with the actual DO value, and adjusts the blower output air volume and aeration valve opening in real time according to the difference.

[0014] The above technical solution has the following advantages or beneficial effects: This invention collects the influent chemical oxygen demand (COD) and ammonia nitrogen concentration of wastewater in real time. Real-time water quality parameters such as sludge concentration, MLSS, and wastewater temperature are used to dynamically calculate the required DO setpoint, overcoming the limitations of traditional fixed DO setpoints. Based on the difference between the required DO setpoint and the actual DO value, the opening of the aeration valve and the air volume are adjusted in real time to avoid insufficient or excessive aeration, significantly reducing blower energy consumption.

[0015] This invention can detect the turbidity of water in the clear water tank and the flow rate of the overflow pipe in real time; when the turbidity of water in the clear water tank exceeds the threshold, an alarm is triggered, and the aeration / dosing strategy is adjusted in conjunction to ensure the quality of the effluent; when the flow rate of the overflow pipe is abnormal, the opening of the electric valve is automatically adjusted to maintain the stable operation of the system.

[0016] The invention also includes a mixer, which can effectively prevent sludge sedimentation and enhance gas-liquid mixing efficiency, thereby improving the uniformity of oxygen distribution. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of the intelligent aeration system of the present invention. Detailed Implementation

[0019] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the invention. The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] In this embodiment of the invention, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of this invention, "multiple" refers to two or more.

[0022] Example 1 This embodiment provides an intelligent aeration system, including: a clear water tank, an aeration tank, a data acquisition unit, a PLC control unit, and an aeration unit.

[0023] The data acquisition unit includes: an ammonia nitrogen detector, a COD detector, a temperature sensor, an MLSS detector, a DO sensor, and a turbidity detector.

[0024] The aeration unit includes: aeration disc, aeration valve, and blower.

[0025] The PLC control unit includes a data acquisition terminal, a data display window, and a control module. The control module includes a control unit based on the influent chemical oxygen demand, the concentration of ammonia nitrogen in the clean water, the sludge concentration, and the wastewater temperature.

[0026] Preferably, the intelligent aeration system also includes a flow meter and an electric regulating valve.

[0027] Preferably, the intelligent aeration system also includes a mixer.

[0028] like Figure 1 As shown, Figure 1 This is a schematic diagram of the intelligent aeration system based on PLC control of the present invention. In the figure, 1 is a clear water tank, 2 is an aeration tank, 3 is an ammonia nitrogen detector, 4 is a turbidity detector, 5 is a flow meter, 6 is an electric regulating valve, 7 is a COD detector, 8 is a temperature sensor, 9 is an MLSS detector, 10 is a DO sensor, 11 is a mixer blade, 12 is an aeration disc, 13 is a mixer, 14 is an aeration valve, 15 is a blower, and 16 is a PLC control unit.

[0029] In this application, the ammonia nitrogen detector, turbidity detector, flow meter, electric regulating valve, COD detector, MLSS detector, temperature sensor, DO sensor, mixer fan, aeration disc, mixer, aeration valve, blower, and data signal transmission line are all devices well known to those skilled in the art, and there are no special restrictions on their sources in this application.

[0030] The PLC control unit is a control system well known to those skilled in the art. Its data acquisition terminal includes a PLC communication module, a PLC analog input module (AI), a PLC analog output module (AO), a PLC digital input module (DI), and a PLC digital output module (DO).

[0031] Clear water tank 1 and aeration tank 2 are connected by an overflow pipe.

[0032] In this embodiment, the acquisition / detection frequency of each structure in the data sampling unit can be set according to actual needs; in this embodiment, it is set to once every 30 minutes. The specific configuration of each structure in the data acquisition unit is as follows: Ammonia nitrogen detector 3 is installed in the clear water tank and collects ammonia nitrogen levels in the clear water through timed sampling. The ammonia nitrogen detector 3 communicates with the PLC communication module to transmit the measured ammonia nitrogen concentration in the clear water tank to the PLC data acquisition terminal.

[0033] Turbidity detector 4 is installed in the clear water tank, with its detection part extending into the tank to measure the turbidity of the water. Turbidity detector 4 is connected to the PLC analog input module via a data signal transmission line. The turbidity detector 4 outputs an analog signal, which is transmitted through the data signal transmission line and input to the PLC analog input module, thereby transmitting the measured turbidity information of the water in the clear water tank to the PLC data acquisition terminal.

[0034] The COD detector 7 is installed at the aeration tank and collects the chemical oxygen demand (COD) of the wastewater in the aeration tank at regular intervals. The COD detector 7 communicates with the PLC communication module to transmit the measured COD of the wastewater in the aeration tank to the PLC data acquisition terminal.

[0035] Temperature sensor 8 is installed in the aeration tank to measure the real-time temperature of the wastewater in the aeration tank through timed data acquisition. Temperature sensor 8 is connected to the PLC analog input module via a data signal transmission line. Temperature sensor 8 outputs an analog signal, which is transmitted through the data signal transmission line and input to the PLC analog input module, uploading the wastewater temperature detection data to the PLC data acquisition terminal.

[0036] The MLSS detector 9 is installed in the aeration tank and measures the sludge concentration (MLSS) of the wastewater in the aeration tank by periodic data acquisition. The MLSS detector 9 is connected to the PLC analog input module via a data signal transmission line. The MLSS detector 9 outputs an analog signal, which is transmitted through the data signal transmission line and input to the PLC analog input module, uploading the sludge concentration data of the wastewater to the PLC data acquisition terminal.

[0037] DO (dissolved oxygen) sensor 10 is installed in the aeration tank to detect the dissolved oxygen content of the wastewater in the aeration tank. DO sensor 9 is connected to the PLC analog input module via a data signal transmission line, outputting an analog signal which is transmitted through the data signal transmission line and input to the PLC analog input module, thus uploading the dissolved oxygen content of the wastewater to the PLC data acquisition terminal in real time.

[0038] The specific configuration of each structure in the aeration unit is as follows: The aeration disc 12 is located at the bottom of the aeration tank 2 and is connected to the aeration valve 14 through the aeration pipeline. Its function is to disperse compressed air into tiny bubbles.

[0039] The aeration valve 14 is located between the blower 15 and the aeration disc 12, and is connected to the PLC analog output module through a data signal transmission line. It receives the 0-100% opening command issued by the PLC control unit, controls the on / off state and flow rate of gas entering the aeration disc 11, and realizes precise control of the opening degree of the aeration valve.

[0040] The blower 15 is connected to the aeration valve 14 via a pipeline, and also connected to the PLC digital output module via a data signal transmission line. The function of the blower is to provide compressed air to the aeration tank and increase the survival rate of bacteria within the tank. In this embodiment, the blower can be either a variable frequency blower or a fixed frequency blower, which can be flexibly configured according to the actual needs of the system.

[0041] To ensure uniform oxygen distribution in the aeration tank, the aeration system of this invention also includes a mixer 13. The mixer 13 is connected to the PLC analog output module via a data signal transmission line to receive control commands from the PLC control unit. The mixer blades 11 of the mixer 13 are positioned in the wastewater of the aeration tank. The blade assembly of the mixer blades 11 is a three-bladed propeller structure. The rotating blades propel the wastewater to flow uniformly through the vortex effect. The blade angle and spacing are optimized through fluid dynamics design, effectively preventing sludge sedimentation and enhancing gas-liquid mixing efficiency, thereby improving the uniformity of oxygen distribution.

[0042] Flow meter 5 is installed at the overflow pipes of the clear water tank and the aeration tank. Its function is to provide feedback based on the real-time flow rate from the outlet of the aeration tank to the inlet of the clear water tank. Flow meter 5 is connected to the PLC analog input module via a data signal transmission line. Flow meter 5 outputs an analog signal, which is transmitted through the data signal transmission line and input to the PLC analog input module, uploading the detected flow data to the PLC data acquisition terminal.

[0043] The electric regulating valve 6 is installed at the overflow pipe of the clear water tank and the aeration tank, and is located after the flow meter, closer to the aeration tank. Its function is to control the valve opening and stabilize the flow rate. The electric regulating valve 6 communicates with the PLC communication module, and the PLC control unit uses the communication module to control its opening.

[0044] The specific settings for the PLC control unit are as follows: The PLC control unit includes a data acquisition terminal, a data display window, and a control module.

[0045] The data acquisition terminal includes a PLC communication module, a PLC analog input module (AI), a PLC analog output module (AO), a PLC digital input module (DI), and a PLC digital output module (DO). The PLC analog input module is connected to the turbidity detector 4, flow meter 5, temperature sensor 8, MLSS detector 9, DO sensor 10, and mixer 13 via data signal transmission lines. The PLC digital output module is connected to the aeration valve 14 and blower 15 via data signal transmission lines.

[0046] The PLC control unit receives various real-time water quality parameters through the PLC analog input module and PLC communication module, including: the ammonia nitrogen concentration in the clean water measured by the ammonia nitrogen detector 3, the chemical oxygen demand (COD) of the wastewater measured by the COD detector 7, the temperature of the wastewater in the aeration tank measured by the temperature sensor 8, the sludge concentration measured by the MLSS detector 9, and the actual DO value of the wastewater detected by the DO sensor 10.

[0047] The control module dynamically calculates the required DO setpoint based on real-time monitoring values ​​of influent chemical oxygen demand (COD), ammonia nitrogen concentration in purified water, sludge concentration, and wastewater temperature. The specific formula is as follows:

[0048] COD refers to the influent chemical oxygen demand of wastewater, expressed in mg / L. The concentration of ammonia nitrogen in the clean water is mg / L; MLSS is the sludge concentration is g / L; and T is the wastewater temperature is °C.

[0049] After calculating the required DO setpoint, the PLC control unit compares the actual DO value measured by DO sensor 10 with the required DO setpoint. Based on the difference, it calculates the aeration rate that needs to be adjusted and then outputs a signal through the PLC analog output module to adjust the blower volume through the aeration unit, i.e., adjusting the opening of aeration valve 14 and the blower volume output by blower 15. Since the aeration rate calculated based on the difference and the blower volume adjusted through the aeration unit may vary in actual systems, this invention does not limit the specific adjustment method. Those skilled in the art can derive specific adjustment methods based on the aeration discs and valves, combined with the PLC control unit.

[0050] The intelligent aeration system of this invention can dynamically calculate the required DO setpoint based on real-time monitoring values ​​of influent chemical oxygen demand, ammonia nitrogen concentration in clean water, sludge concentration, and wastewater temperature, thereby adjusting the aeration rate and ensuring the accuracy and stability of aeration control.

[0051] Turbidity detector 4 monitors the turbidity of the water in the clear water tank in real time. The PLC control unit receives the detected turbidity value. If the detected turbidity exceeds the preset effluent water quality standard threshold, the PLC control unit determines that the effluent water quality does not meet the standard and immediately triggers an alarm signal. Simultaneously, this information is fed back to the PLC control module as an auxiliary reference for adjusting the aeration strategy. By increasing aeration intensity, adjusting stirring, and adding chemicals, the treatment effect can be optimized. The preset effluent water quality standard threshold is a value set by those skilled in the art based on actual needs.

[0052] Flow meter 5 monitors the water flow in the overflow pipe between the clear water tank and the aeration tank in real time. The PLC control unit receives the detected water flow value. If an abnormal flow is detected, the PLC control unit immediately triggers an alarm signal and sends a command to the electric regulating valve through the PLC communication module to dynamically adjust its opening to maintain the stability of the system flow or attempt to clear the blockage.

[0053] The regulating valve 6 is directly controlled by the PLC control unit. In response to abnormal signals from the flow meter 5, it adjusts its opening to stabilize the flow rate.

[0054] Example 2 This embodiment provides a method for aeration control using the intelligent aeration system of Embodiment 1 described above, including the following steps: S101: The data acquisition unit collects real-time water quality parameters, including: influent chemical oxygen demand (COD), ammonia nitrogen concentration in clean water, sludge concentration, wastewater temperature, and actual dissolved oxygen (DO) value. S102: The PLC control unit receives the collected real-time water quality parameters and performs analog-to-digital conversion and signal conditioning; S103: Calculate the required DO setpoint dynamically based on the influent chemical oxygen demand, ammonia nitrogen concentration in the clean water, sludge concentration, and wastewater temperature after signal conditioning. S104: The PLC control unit compares the calculated required DO setting value with the actual DO value, and adjusts the blower output air volume and aeration valve opening in real time according to the difference.

[0055] In step S101, the data acquisition unit refers to an ammonia nitrogen detector, a COD detector, a temperature sensor, an MLSS detector, and a DO sensor. The ammonia nitrogen detector measures the ammonia nitrogen concentration in the clean water; the COD detector measures the chemical oxygen demand (COD) of the wastewater; the temperature sensor measures the real-time temperature of the wastewater in the aeration tank; the MLSS detector measures the sludge concentration; and the DO sensor detects the actual DO value of the wastewater in the aeration tank. In this embodiment, the acquisition / detection frequency of each structure in the data sampling unit can be set according to actual needs; in this embodiment, it is set to once every 30 minutes.

[0056] Step S102 specifically includes: S102-1: The PLC control unit receives the collected real-time water quality parameters and converts the analog signals into digital signals.

[0057] S102-2: Signal conditioning is performed on the real-time water quality parameters after analog-to-digital conversion. Specifically, Savitzky-Golay filtering is used for filtering, with the window width set to 15 and the polynomial order set to 3. The filtered real-time water quality parameters are then standardized, with Min-Max normalized to the [0,1] interval.

[0058] Step S103 specifically includes: The PLC control unit dynamically calculates the required DO setpoint based on real-time water quality parameters. The specific formula is as follows:

[0059] COD stands for Chemical Oxygen Demand of Influent, expressed in mg / L. Ammonia nitrogen concentration is expressed in mg / L; MLSS is expressed in g / L; and T is expressed in °C.

[0060] Step S104 specifically includes: After the PLC control unit calculates the required DO setting value, it first compares the actual DO value measured by the DO sensor 10 with the required DO setting value, calculates the aeration volume that needs to be adjusted based on the difference, and then outputs a signal through the PLC analog output module to adjust the opening degree of the aeration valve 14 and the blower volume output by the blower 15.

[0061] The descriptions of each embodiment in the above embodiments have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0062] The proposed system can be implemented in other ways. For example, the system embodiments described above are merely illustrative, and the division of modules described above is only a logical functional division. In actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed.

Claims

1. An intelligent aeration system, characterized in that, The intelligent aeration system includes: a clear water tank, an aeration tank, a data acquisition unit, a PLC control unit, and an aeration unit; The clear water tank and the aeration tank are connected by an overflow pipe; The data acquisition unit collects real-time water quality parameters, including: influent chemical oxygen demand (COD), ammonia nitrogen concentration in clean water, sludge concentration, wastewater temperature, and actual dissolved oxygen (DO) value. The PLC control unit receives the collected real-time water quality parameters; The PLC control unit dynamically calculates the required DO setpoint based on real-time collected values ​​of influent chemical oxygen demand, ammonia nitrogen concentration in clean water, sludge concentration, and wastewater temperature; then, based on the difference between the actual DO value and the required DO setpoint, it calculates the aeration rate that needs to be adjusted and adjusts the blower volume through the aeration unit.

2. The intelligent aeration system as described in claim 1, characterized in that, It also includes a mixer; the mixer is connected to a PLC control unit; the mixer blades are placed in the wastewater of the aeration tank; the mixer blade assembly is a three-bladed propeller structure.

3. The intelligent aeration system as described in claim 1, characterized in that, The data acquisition unit includes: an ammonia nitrogen detector, a COD detector, a temperature sensor, an MLSS detector, and a DO sensor; The ammonia nitrogen detector is installed in the clear water tank to collect the ammonia nitrogen concentration of the clear water and is connected to the PLC control unit. The COD detector is installed at the aeration tank to collect the chemical oxygen demand (COD) of the wastewater in the aeration tank and is connected to the PLC control unit. The temperature sensor is installed in the aeration tank to collect the wastewater temperature and is connected to the PLC control unit. The MLSS detector is installed in the aeration tank to collect sludge concentration and is connected to the PLC control unit for signal transmission. The DO sensor is installed in the aeration tank to collect the actual DO value of the wastewater.

4. The intelligent aeration system as described in claim 3, characterized in that, The data acquisition unit also includes a turbidity detector; The turbidity detector is installed in the clear water tank and is connected to the PLC control unit. Its detection part extends into the clear water tank. If the turbidity exceeds the preset threshold of the effluent water quality standard, the PLC control unit determines that the effluent water quality does not meet the standard and immediately triggers an alarm signal.

5. The intelligent aeration system as described in claim 1, characterized in that, It also includes flow meters and electric regulating valves; The flow meter is installed at the overflow pipe of the clear water tank and the aeration tank to detect the water flow rate in the overflow pipe between the clear water tank and the aeration tank, and is connected to the PLC control unit signal. The electric regulating valve is installed at the overflow pipe of the clear water tank and the aeration tank, and is located behind the flow meter on the side close to the aeration tank, and is connected to the PLC control unit. If the flow meter detects an abnormal flow rate, the PLC control unit immediately triggers an alarm signal and sends a command to the electric regulating valve through the PLC communication module to dynamically adjust its opening.

6. The intelligent aeration system as described in claim 1, characterized in that, Based on real-time data collection of influent chemical oxygen demand (COD), ammonia nitrogen concentration in treated water, sludge concentration, and wastewater temperature, the required DO setpoint is dynamically calculated. Specifically: COD refers to the chemical oxygen demand of the influent. 1 represents the ammonia nitrogen concentration in the clean water; MLSS represents the sludge concentration; T represents the wastewater temperature.

7. The intelligent aeration system as described in claim 1, characterized in that, The aeration unit includes an aeration disc, an aeration valve, and a blower.

8. The intelligent aeration system as described in claim 7, characterized in that, The method of adjusting the air volume through the aeration unit specifically involves adjusting the opening of the aeration valve and the air volume output by the blower to regulate the air volume.

9. An aeration control method, characterized in that, Includes the following steps: S101: The data acquisition unit collects real-time water quality parameters, including: influent chemical oxygen demand (COD), ammonia nitrogen concentration in clean water, sludge concentration, wastewater temperature, and actual dissolved oxygen (DO) value. S102: The PLC control unit receives the collected real-time water quality parameters and performs analog-to-digital conversion and signal conditioning; S103: Calculate the required DO setpoint dynamically based on the influent chemical oxygen demand, ammonia nitrogen concentration in the clean water, sludge concentration, and wastewater temperature after signal conditioning. S104: The PLC control unit compares the calculated required DO setting value with the actual DO value, and adjusts the blower output air volume and aeration valve opening in real time according to the difference.

10. The aeration control method as described in claim 9, characterized in that, The signal conditioning process involves using Savitzky-Golay filtering to filter the real-time water quality parameters after analog-to-digital conversion, and then standardizing the filtered real-time water quality parameters.

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