Intelligent regulation and control supply system for wastewater reuse

Abstract

The invention discloses a wastewater reuse intelligent regulation and control supply system which comprises a clean water tank, a reuse water pump set, a low-power motor, a high-power motor, a pressure sensor, a flow sensor, a frequency converter, a PLC and a communication module. The reuse water pump set comprises at least four water pumps and is driven by a low-power motor and a high-power motor. The PLC executes the following control logics: pressure-flow cooperative control: when the pipe network pressure P is less than or equal to 0.4 MPa and the flow Q is less than or equal to 3m < 3 > / h, starting a single low-power motor; when Qgt; starting a high-power motor, and starting a system integrated energy recovery module to capture braking energy when the high-power motor is shut down; dynamic efficiency optimization: based on a formula psi = k1 * delta P + k2 * ln (Q / Qth), the motor operation mode is adjusted, k1 and k2 are weight coefficients, and Qth = 3m < 3 > / h; and emergency response: when P is less than or equal to 0.1 MPa or the flow exceeds the limit, the small motor is forcibly started for pressurization, the start and stop of the equipment realize immediate response, and the problem of teletransmission pressure lag is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a wastewater reuse intelligent control and supply system. Background Art

[0002] In the field of industrial circulating water treatment, traditional water supply systems generally adopt start-stop control or constant pressure frequency conversion technology based on fixed pressure thresholds, which have prominent problems such as response lag, high energy consumption, and large equipment loss. Existing systems mostly rely on a single pressure feedback signal. When the water consumption in the pipeline network suddenly changes, the pressure regulation delay often exceeds 20 seconds, resulting in poor water supply stability. At the same time, the frequent start-stop of industrial frequency pumps not only causes more than 30% energy waste, but also accelerates mechanical wear of equipment.

[0003] In addition, traditional systems lack intelligent prediction capabilities and are unable to dynamically adjust operating strategies based on changes in water demand. The pressure fluctuation range usually exceeds ±0.15MPa. Although some improvement schemes have adopted dual-pump switching control, there are still defects such as rigid control parameters and insufficient coordination of multiple physical quantities. It is difficult to meet the comprehensive needs of modern industry for rapid response (<5 seconds), high-precision control (±0.05MPa) and energy saving and high efficiency (η>80%) of water supply systems. Summary of the Invention

[0004] In view of the above-mentioned defects of existing control parameters being solidified and insufficient coordination of multiple physical quantities, it is difficult to meet the comprehensive needs of modern industry for water supply systems with rapid response (<5 seconds), high-precision control (±0.05MPa) and energy saving and high efficiency (η>80%). The present invention is proposed.

[0005] Therefore, the object of the present invention is to provide a wastewater reuse intelligent control supply system.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a wastewater reuse intelligent control supply system, comprising:

[0007] Clean water tank, reuse water pump group, low-power motor, high-power motor, pressure sensor, flow sensor, frequency converter, PLC controller and communication module;

[0008] The reuse water pump group comprises at least four water pumps, which are driven by a low-power motor and a high-power motor respectively;

[0009] The PLC controller executes the following control logic:

[0010] Pressure-flow coordinated control: When the pipe network pressure P≤0.4MPa and the flow rate Q≤3m 3 / h, start a single low-power motor; when Q>3m 3 / h and the small motor frequency fsmall≥fset for 10 seconds, the high-power motor is started. When the high-power motor is turned off, the system integrated energy recovery module is started to capture braking energy;

[0011] Dynamic performance optimization: Based on the formula Ψ=k1·ΔP+k2·ln(Q / Q th ), adjust the motor operation mode, where k1 and k2 are weight coefficients, Q th =3m 3 / h;

[0012] Emergency response: When P≤0.1MPa or the flow exceeds the limit, the small motor is forced to start to increase the pressure.

[0013] As a preferred solution of the wastewater reuse intelligent control supply system of the present invention, the power ratio of the small power motor to the large power motor is 1:3 to 1:5, and the starting frequency f of the large motor is 大 , 启动 =0.8·f 小，max , where f 小，max It is the maximum frequency of small motor.

[0014] As a preferred solution of the wastewater reuse intelligent control supply system of the present invention, the PLC controller has a built-in PID algorithm to adjust the output frequency of the frequency converter, control the pressure fluctuation range ΔP≤±0.05MPa, and the flow sampling period T 采样 ≤1 second.

[0015] As a preferred solution of the wastewater reuse intelligent control and supply system of the present invention, the reuse water pump group adopts a redundant configuration, two of the four water pumps are driven by low power and two are driven by high power. When any one fails, the system automatically switches to the backup pump and triggers an audible and visual alarm.

[0016] As a preferred solution of the wastewater reuse intelligent control supply system of the present invention, the communication module supports remote monitoring and uploads real-time data including pressure P, flow Q, motor frequency f and health index H, where the health index H is calculated by the formula H = 1-e -λ·(t故障 / t总) Calculation, λ is the equipment aging coefficient.

[0017] As a preferred solution of the wastewater reuse intelligent control supply system of the present invention, the clean water tank is provided with a liquid level sensor. When the liquid level L≤L 安全 When the water pump is stopped and water replenishment is started, the water replenishment flow rate Q 补水 =k3·(L 安全 -L), k3 is the proportional coefficient.

[0018] As a preferred solution of the wastewater reuse intelligent control supply system of the present invention, the pressure sensor and flow sensor are explosion-proof, with a protection level ≥ IP67, and the data is processed by Kalman filtering, with a filtering equation where α=0.7.

[0019] As a preferred solution of the wastewater reuse intelligent control supply system of the present invention, the system integrates an energy recovery module, and when the large motor brakes, the recovered energy E recovery = η·1 / 2Iω 2 , where η is the efficiency coefficient, I is the moment of inertia, and ω is the angular velocity.

[0020] As a preferred solution of the wastewater reuse intelligent control supply system of the present invention, the PLC controller predicts the peak water consumption through historical data, and the prediction model is Q 预测 =Q 均值 +β·ΔQ 趋势 , β is the trend weight coefficient.

[0021] As a preferred solution of the wastewater reuse intelligent control supply system of the present invention, the frequency converter supports multi-mode operation, including:

[0022] Constant pressure mode: maintain P = 0.8 MPa;

[0023] Boost mode: When P≤0.4MPa, the frequency is linearly increased to the maximum;

[0024] Energy saving mode: when Q≤1m 3 / h, the frequency drops to a minimum of 20Hz.

[0025] The beneficial effects of the present invention are: the supply is intelligently changed as the water demand changes, the start and stop of the equipment realizes instant response, and the problem of remote pressure lag is avoided. The entire system adopts PID intelligent control in combination with parameters such as pressure, flow, and frequency. Various detection signals interact intelligently with the control center and are executed according to the designed logic. At the same time, fault alarms and status displays are reported to the background operation supervisor in real time, achieving the goals of reducing staff, increasing efficiency, and energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 This is a connection diagram of a wastewater reuse intelligent control supply system of the present invention.

[0028] Figure 2 This is a logical flow diagram of a wastewater reuse intelligent control supply system of the present invention. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0032] Furthermore, the present invention is described in detail with reference to schematic diagrams. For ease of illustration, when describing the embodiments of the present invention, cross-sectional views illustrating device structures may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, the three-dimensional dimensions of length, width, and depth should be included.

[0033] Example

[0034] Reference Figure 1 - Figure 2 , an embodiment of the present invention provides a wastewater reuse intelligent control supply system, which includes a clean water tank, a reuse water pump group, a low-power motor, a high-power motor, a pressure sensor, a flow sensor, a frequency converter, a PLC controller and a communication module;

[0035] The reuse water pump group includes at least four water pumps, which are driven by a small power motor and a large power motor respectively;

[0036] Among them, the clear water tank is equipped with a liquid level sensor, which is connected to the PLC through a 4-20mA signal, and the water outlet is connected to the inlet of the reuse water pump group through a pipe; the reuse water pump group has two small-power motors and two high-power motors installed in parallel, each motor is directly connected to the water pump through a coupling, and the water outlet is connected to the main pipeline of the pipe network system; the pressure sensor is installed at the bifurcation of the main pipeline of the pipe network, and the flow sensor is installed on the pump group outlet main pipe, both of which are connected to the PLC through the RS485 bus; the frequency converter corresponds to the motor and is connected to the PLC digital / analog IO module through hard wiring; the PLC controller is the core control unit, connected to the frequency converter through PROFIBUS-DP, and is used to integrate the PID control algorithm and health prediction model; the system energy recovery module is directly connected to the braking end of the high-power motor and is connected in parallel to the frequency converter energy storage unit through the DC bus; the communication module is an embedded industrial switch that supports ModbusTCP / IP and is connected to the central control room monitoring platform through optical fiber.

[0037] The PLC controller executes the following control logic:

[0038] Pressure-flow coordinated control: When the pipe network pressure P≤0.4MPa and the flow rate Q≤3m 3 / h, start a single low-power motor; when Q>3m 3 / h and small motor frequency f 小 When ≥f is set to last for 10 seconds, the high-power motor is started, and when the high-power motor is turned off, the system integrated energy recovery module is started to capture braking energy;

[0039] Dynamic performance optimization: Based on the formula Ψ=k1·ΔP+k2·ln(Q / Q th ), adjust the motor operation mode, where k1 and k2 are weight coefficients, Q th =3m 3 / h;

[0040] Emergency response: When P≤0.1MPa or the flow exceeds the limit, the small motor is forced to start to increase the pressure.

[0041] Among them, the pipe network pressure P is used to determine whether the system needs to be pressurized or depressurized. It is the core control parameter and directly determines the motor start and stop logic;

[0042] Among them, flow Q is the real-time water flow, and the coordinated regulation with pressure is the threshold basis for triggering the switching of large and small motors (such as Q>3m 3 / h to start the large motor);

[0043] Among them, f 小 、f 大 :The operating frequency of small / large motor is the basis for inverter adjustment. When the frequency exceeds the limit, the linkage is triggered (such as f 小 ≥45Hz to start large motors);

[0044] Among them, Ψ is the symbol of the dynamic control efficiency index, which is a comprehensive evaluation of the system's response capability. The higher the value, the better the control (the threshold is set at 0.8);

[0045] Specifically, the power ratio of the small power motor to the large power motor is 1:3 to 1:5, and the starting frequency f of the large motor is 大，启动 =0.8·f 小，max , where f 小，max It is the maximum frequency of small motor;

[0046] Among them, f 小，max It is the maximum frequency allowed for small motors (such as 50Hz) and is used to limit small motor overload and protect equipment. 大，启动 The motor starting frequency is set to 40 Hz to ensure smooth switching and avoid current shock.

[0047] Furthermore, the PLC controller has a built-in PID algorithm to adjust the inverter output frequency, control the pressure fluctuation range ΔP≤±0.05MPa, and the flow sampling period Tsampling≤1 second;

[0048] Among them, the allowable pressure fluctuation range of ΔP≤±0.05MPa enables the PID algorithm to adjust the target and ensure pressure stability, and high-frequency sampling is performed during the flow sampling period to reduce control lag.

[0049] Furthermore, the reused water pump group adopts a redundant configuration. Two of the four water pumps are driven by low power and two are driven by high power. When any one fails, the system automatically switches to the backup pump and triggers an audible and visual alarm.

[0050] Furthermore, the communication module supports remote monitoring and real-time upload of data including pressure P, flow Q, motor frequency f and health index H, where the health index H is given by the formula H = 1-e -λ·(t故障 / t总) Calculation, λ is the equipment aging coefficient; among them, the equipment health (0-1) is used to predict the failure risk, and H<0.2 triggers an alarm.

[0051] Furthermore, the clean water tank is equipped with a liquid level sensor. When the liquid level L≤L 安全 When the water pump is stopped and water replenishment is started, the water replenishment flow rate Q 补水 =k3·(L 安全 -L), k3 is the proportional coefficient;

[0052] Among them, when the liquid level L≤L 安全 When the clear water tank level safety threshold (unit: m) is used to prevent the pump body from idling and damaging, the water flow rate Q 补水 It is used to dynamically adjust the amount of water added to avoid liquid level fluctuations.

[0053] Furthermore, the pressure sensor and flow sensor are explosion-proof, with a protection level of ≥IP67, and the data is processed by Kalman filtering, and the filtering equation Where α = 0.7, and Kalman filtering is used to eliminate sensor noise and improve the reliability of pressure data.

[0054] Furthermore, the system integrates an energy recovery module. When the large motor brakes, the recovered energy Erecovery = η·1 / 2Iω 2 , where η is the efficiency coefficient, I is the moment of inertia, and ω is the angular velocity, which can achieve quantitative energy-saving effects, improve overall energy efficiency, and reduce operating costs.

[0055] Furthermore, the PLC controller predicts the peak water consumption through historical data, and the prediction model is Q 预测 =Q 均值 +β·ΔQ 趋势 , β is the trend weight coefficient, which is used to adjust the motor operation mode in advance.

[0056] Furthermore, in constant pressure mode: maintain P = 0.8 MPa;

[0057] Boost mode: When P≤0.4MPa, the frequency is linearly increased to the maximum;

[0058] Energy saving mode: when Q≤1m 3 / h, the frequency drops to a minimum of 20Hz, which is the lowest frequency in energy-saving mode. It can be used to force frequency reduction at low flow rates to reduce energy consumption.

[0059] When filtering and prediction coefficients can be used to enhance data reliability and control foresight.

[0060] Operation process, 1. Check before system startup:

[0061] S1. Hardware confirmation: Check the liquid level in the clean water tank (L≥L safety threshold); verify the mechanical connection status of the reuse water pump group (4 pumps: 2 low-power + 2 high-power); ensure that the RS485 communication between the pressure / flow sensor (IP67 explosion-proof type) and the PLC is normal; test the PROFIBUS-DP connection and hard-wired signal between the inverter and the PLC.

[0062] S2, software initialization: PLC loads PID control parameters (ΔP≤±0.05MPa target); sets dynamic performance formula weights (k1, k2) and flow threshold (Qth=3m 3 / h); enable Kalman filter (α=0.7) to process sensor data.

[0063] 2. Run the control process:

[0064] S1. Pressure-flow coordinated control: real-time monitoring; collecting pipe network pressure P (after filtering) and flow Q (sampling period T ≤ 1 second);

[0065] S2, pattern judgment;

[0066] Low load mode (P≤0.4MPa and Q≤3m 3 / h): Start a single low-power motor, and the inverter adjusts the frequency f as small as PID;

[0067] High load mode (Q>3m 3 / h and fmin ≥ fset for 10 seconds): Start the high-power motor, the initial frequency value fmax = 0.8·f 小，max ; Trigger the energy recovery module when the low-power motor is turned off (capture E recovery = η·1 / 2Iω 2 );

[0068] S3. Emergency response: If P≤0.1MPa or Q exceeds the limit, the small motor will be forced to start to increase the pressure.

[0069] S4. Dynamic performance optimization: Calculate performance index Ψ=k1·ΔP+k2·ln(Q / Q th ): When Ψ≥0.8, maintain the current mode; when Ψ<0.8, switch the motor combination (such as increasing / decreasing high-power motors).

[0070] S5. Redundancy and health management: real-time monitoring of health index H = 1-e -λ·(t故障 / t总) :When H<0.2, the standby pump is switched and the sound and light alarm is triggered; the faulty pump is marked as waiting for repair

[0071] 3. Energy saving and predictive control:

[0072] S1, Energy recovery: When the large motor brakes, the DC bus feeds energy back to the inverter energy storage unit.

[0073] S2. Water consumption forecast: PLC based on Q 预测 =Q 均值 +β·ΔQ 趋势 Adjust the motor mode in advance.

[0074] S3, Operation mode switch:

[0075]

[0076]

[0077] 4. Exception handling process

[0078] S1, abnormal liquid level (L≤L 安全 ): Pause the water pump and start water replenishment (Q 补水 =k3·(L安全 -L).

[0079] S2, sensor failure: enable backup sensor or switch to historical data prediction mode.

[0080] S3, Communication interruption: PLC caches data locally and synchronizes it to the central control room after recovery.

[0081] 5. Shutdown and maintenance

[0082] S1, normal shutdown: gradually reduce the frequency to stop all motors; turn off the DC bus of the energy recovery module.

[0083] S2. Maintenance inspection: Analyze the historical data of health index H and formulate maintenance plan; calibrate sensor and inverter parameters.

[0084] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A wastewater reuse intelligent control supply system, characterized by: include, Clean water tank, reuse water pump group, low-power motor, high-power motor, pressure sensor, flow sensor, frequency converter, PLC controller and communication module; The reuse water pump group comprises at least four water pumps, which are driven by a low-power motor and a high-power motor respectively; The PLC controller executes the following control logic: Pressure-flow coordinated control: When the pipe network pressure P≤0.4MPa and the flow rate Q≤3m 3 / h, start a single low-power motor; when Q>3m 3 / h and small motor frequency f 小 When the setting of ≥f lasts for 10 seconds, the high-power motor is started, and when the high-power motor is turned off, the system integrated energy recovery module is started to capture braking energy; Dynamic performance optimization: Based on the formula Ψ=k1·ΔP+k2·ln(Q / Q th ), adjust the motor operation mode, where k1 and k2 are weight coefficients, Q th =3m 3 / h; Emergency response: When P≤0.1MPa or the flow exceeds the limit, the small motor is forced to start to increase the pressure.

2. The wastewater reuse intelligent control and supply system according to claim 1 is characterized by: The power ratio of the low-power motor to the high-power motor is 1:3 to 1:5, and the starting frequency of the high-power motor is f 大，启动 =0.8·f 小，max , where f 小，max It is the maximum frequency of small motor.

3. The wastewater reuse intelligent control and supply system according to claim 2 is characterized by: The PLC controller has a built-in PID algorithm to adjust the output frequency of the frequency converter, control the pressure fluctuation range ΔP≤±0.05MPa, and the flow sampling period T sampling ≤1 second.

4. The wastewater reuse intelligent control supply system according to claim 2 or 3, characterized in that: The reuse water pump group adopts a redundant configuration. Two of the four water pumps are driven by low power and two are driven by high power. When any one of them fails, the system automatically switches to the backup pump and triggers an audible and visual alarm.

5. The wastewater reuse intelligent control and supply system according to claim 4 is characterized by: The communication module supports remote monitoring and real-time upload of data including pressure P, flow Q, motor frequency f and health index H, where the health index H is calculated by the formula H = 1-e -λ·(t故障 / t总) Calculation, λ is the equipment aging coefficient.

6. The wastewater reuse intelligent control and supply system according to claim 5 is characterized by: The clean water tank is equipped with a liquid level sensor. When the liquid level L≤L 安全 When the water pump is stopped and water replenishment is started, the water replenishment flow rate Q 补水 =k3·(L 安全 -L), k3 is the proportional coefficient.

7. The wastewater reuse intelligent control and supply system according to claim 6 is characterized by: The pressure sensor and flow sensor are explosion-proof, with protection level ≥ IP67, and the data are processed by Kalman filtering, and the filtering equation Where α = 0.

7.

8. The wastewater reuse intelligent control and supply system according to claim 1 is characterized by: The system integrates an energy recovery module. When the large motor brakes, the recovered energy Erecovery = η·1 / 2Iω 2 , where η is the efficiency coefficient, I is the moment of inertia, and ω is the angular velocity.

9. The wastewater reuse intelligent control and supply system according to claim 8, characterized in that: The PLC controller predicts the peak water consumption through historical data, and the prediction model is: Q 预测 =Q 均值 +β·ΔQ 趋势 , where β is the trend weight coefficient.

10. The wastewater reuse intelligent control and supply system according to claim 9, characterized in that: The inverter supports multi-mode operation, including: Constant pressure mode: maintain P = 0.8 MPa; Boost mode: When P≤0.4MPa, the frequency is linearly increased to the maximum; Energy saving mode: when Q≤1m 3 / h, the frequency drops to a minimum of 20Hz.

Images