Intelligent sewage treatment control device based on water quality linkage feedback mechanism

Abstract

The invention relates to the technical field of sewage treatment, in particular to an intelligent sewage treatment control device based on a water quality linkage feedback mechanism, which comprises water quality monitoring equipment, a pH regulating tank, a mixing tank, a flocculation tank, pH value monitoring equipment, SS (suspended solids) monitoring equipment, an automatic dosing system and a PLC (programmable logic controller) control system, the water quality monitoring equipment is used for directly obtaining the pH value and the SS suspended matter concentration of tunnel sewage; the water quality monitoring equipment is used for adjusting the dosing amount of the system through the PLC control system so as to realize dynamic treatment of the tunnel sewage; the automatic dosing system is used for adding an acid-base saturated solution and a flocculant saturated solution into the pH regulating tank, the mixing tank and the flocculation tank; the PLC control system is used for controlling the automatic dosing system to automatically add chemicals and open and close pipeline valves by collecting the liquid level height of the regulating tank, the flow of a water inlet header pipe, the depth of an effluent weir tank, pH monitoring data and SS monitoring data of a water inlet of the pH regulating tank, and pH monitoring data and SS monitoring data of effluent of the flocculation tank.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an intelligent sewage treatment control device based on a water quality linkage feedback mechanism. Background Art

[0002] The main sources of tunnel construction wastewater are: ① gushing water generated when the tunnel passes through poor geology; ② wastewater generated during the construction process for dust reduction; ③ wastewater generated during shotcrete and grouting. Studies have shown that this type of wastewater has the characteristics of abnormal pH value, increased alkalinity, and extremely unstable water quality and quantity. At present, the process used by the tunnel entrance sewage treatment station is mainly pretreatment + acid-base neutralization + coagulation sedimentation + filtration. With the excavation of the tunnel, the sewage volume and water quality fluctuate greatly, and the effluent of the tunnel sewage treatment station is difficult to meet the discharge standards.

[0003] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0004] The purpose of the present invention is to provide an intelligent sewage treatment control device based on a water quality linkage feedback mechanism to solve the technical problems existing in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides an intelligent sewage treatment control device based on a water quality linkage feedback mechanism, which is characterized by comprising: Water quality monitoring equipment is used to directly obtain the pH value and SS suspended solids concentration of tunnel sewage; the water quality monitoring equipment is used to adjust the system dosage through the PLC control system to achieve dynamic treatment of tunnel sewage; pH adjustment tank, used to adjust the pH value of influent; Mixing tank, used for adding coagulants and as a place for sewage mixing reaction; Flocculation tank, used for adding coagulant aids and as a place for sewage flocculation and sedimentation reactions; pH value monitoring equipment, used to monitor the pH value of inlet and outlet water, suspended in the float valve at the inlet end and the weir trough at the outlet of the mixing tank; SS suspended matter monitoring equipment is used to monitor the SS suspended matter in the inlet and outlet water, and is suspended in the float valve at the inlet end and the weir trough at the outlet of the mixing tank; Automatic dosing system, used to add acid and alkali saturated solution and flocculant saturated solution to the pH adjustment tank, mixing tank and flocculation tank; The PLC control system controls the automatic dosing system to automatically add chemicals and open and close pipeline valves by collecting the liquid level height of the regulating tank, the flow rate of the water inlet main pipe, the depth of the water outlet weir, the pH monitoring data of the pH regulating tank inlet, the SS monitoring data, the pH monitoring data of the flocculation tank outlet, and the SS monitoring data.

[0006] Preferably, the hydraulic retention time of the pH adjustment tank is not less than 30 min; and the acid solution includes citric acid and oxalic acid.

[0007] Preferably, the hydraulic retention time of the mixing tank is not less than 30 min; and the coagulants include PAC and PFS.

[0008] Preferably, the hydraulic retention time of the flocculation tank is not less than 30 min; and the coagulant aid includes PAM.

[0009] Preferably, the parameter characteristics of the pH monitoring device are as follows: Range: 0~14pH, 0~80℃; Resolution: 0.01PH, ±0.1℃; Accuracy: ±0.1PH, ±0.2℃.

[0010] Preferably, the parameter characteristics of the SS suspended matter monitoring device are as follows: Range: 0~1000mg / L, 0~4000NTU; Resolution: 0.1 mg / L, 0.1 NTU; Accuracy: Indication error ±3%.

[0011] Preferably, the automatic dosing system comprises: an acid dosing metering pump, a PAC metering pump, a PAM metering pump and a drug stirring device.

[0012] Preferably, the PLC control system controls the automatic dosing system to automatically add reagents and open and close pipeline valves by collecting the liquid level height of the regulating tank, the flow rate of the water inlet main pipe, the depth of the water outlet weir, the pH monitoring data of the water inlet of the pH regulating tank, the SS monitoring data, the pH monitoring data of the flocculation tank outlet, and the SS monitoring data; the PLC control system is connected to a data analysis platform, and the data analysis platform is used to organize and analyze the data collected by the PLC control system, and feed it back to the PLC control system to perform acid-base neutralization and coagulation precipitation on the automatic dosing system.

[0013] Preferably, the algorithm steps of the PLC control system include: S1, Initialization: Set "Dosing Equipment" = Off; S2. Read monitoring values: read current pH value and SS suspended solids concentration; S3. Handle special situations: If the pH value and SS suspended solids concentration monitoring are continuously 0, enter the fault mode. If a fault occurs, set "dosing equipment" = fault and jump to step S6; S4. Determine whether to add medicine: If the pH value is greater than the set standard and the SS suspended solids concentration is greater than the set standard, turn on the "dosing equipment" and set "dosing equipment" = on; S5. Determine whether to stop adding medicine: If the pH value and SS suspended solids concentration reach the following parameters: Among them, pH value: pH>6, pH<9; Among them, SS suspended matter concentration: SS<70, Then turn off "dosing equipment", set "dosing equipment" = off; S6, log and feedback: record the current temperature and heater status in the log; if there is a fault, issue an alarm; S7: loop back to step S2, wait for the next monitoring cycle, and repeat the above process.

[0014] By adopting the above technical solution, the present invention has the following beneficial effects: The present invention takes the typical pollutants pH and SS of tunnel sewage as representatives, based on water quality monitoring equipment and PLC control system, through real-time online monitoring of water quality, online feedback mechanism, and dynamic adjustment of dosage, to achieve dynamic treatment of tunnel sewage, reduce the operating load of the tunnel sewage treatment station and reduce the dosage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A schematic diagram of an intelligent sewage treatment control device based on a water quality linkage feedback mechanism provided by an embodiment of the present invention; Icons: 1-PLC control system; 2-automatic dosing system; 3-pH sensor; 4-SS sensor. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0019] This embodiment provides an intelligent sewage treatment control device based on a water quality linkage feedback mechanism, characterized in that it includes: a water quality monitoring device, a pH adjustment tank, a mixing tank, a flocculation tank, a pH value monitoring device, a SS suspended matter monitoring device, an automatic dosing system 2 and a PLC control system 1; The water quality monitoring equipment is used to directly obtain the pH value and SS suspended solids concentration of tunnel sewage; the water quality monitoring equipment is used to adjust the system dosage through the PLC control system 1 to achieve dynamic treatment of tunnel sewage; Among them, the pH adjustment tank is used to adjust the pH value of the influent; Among them, the mixing tank is used for adding coagulants and as a place for sewage mixing reaction; Among them, the flocculation tank is used for adding coagulant aids and as a place for sewage to undergo flocculation and sedimentation reactions; Among them, the pH value monitoring equipment is used to monitor the pH value of the inlet and outlet water, and is suspended in the float valve at the inlet end and the weir tank at the outlet of the mixing tank; Among them, the SS suspended matter monitoring equipment is used to monitor the SS suspended matter in the inlet and outlet water, and is suspended in the float valve at the inlet end and the weir trough at the outlet of the mixing tank; Among them, the automatic dosing system 2 is used to add acid and alkali saturated solutions and flocculant saturated solutions to the pH adjustment tank, mixing tank and flocculation tank; Among them, the PLC control system 1 controls the automatic dosing system 2 to automatically add chemicals and open and close pipeline valves by collecting the liquid level height of the regulating tank, the flow rate of the water inlet main pipe, the depth of the water outlet weir, the pH monitoring data of the pH regulating tank inlet, the SS monitoring data, the pH monitoring data of the flocculation tank outlet, and the SS monitoring data.

[0020] It can be seen that by adding a regulating tank at the tunnel entrance and installing an automatic dosing device to pre-treat the sewage in the tunnel, on the one hand, the operating load of the tunnel sewage treatment station can be reduced, and the amount of chemicals added to the tunnel sewage treatment station can be reduced through precise dosing control, thereby reducing operating costs; on the other hand, the pretreatment in the tunnel entrance regulating tank provides a guarantee for the sewage treatment station to meet discharge standards.

[0021] In this embodiment, specifically, the water quality monitoring equipment includes: a pH sensor 3 and a SS sensor 4 .

[0022] In this embodiment, preferably, the hydraulic retention time of the pH adjustment tank is not less than 30 minutes; and the acid solution includes citric acid and oxalic acid.

[0023] In this embodiment, preferably, the hydraulic retention time of the mixing tank is not less than 30 minutes; and the coagulants include PAC and PFS.

[0024] In this embodiment, preferably, the hydraulic retention time of the flocculation tank is not less than 30 minutes; and the coagulant aid includes PAM.

[0025] In this embodiment, preferably, the parameter characteristics of the pH value monitoring device are as follows: Range: 0~14pH, 0~80℃; Resolution: 0.01PH, ±0.1℃; Accuracy: ±0.1PH, ±0.2℃.

[0026] In this embodiment, preferably, the parameter characteristics of the SS suspended matter monitoring device are as follows: Range: 0~1000mg / L, 0~4000NTU; Resolution: 0.1 mg / L, 0.1 NTU; Accuracy: Indication error ±3%.

[0027] In this embodiment, preferably, the automatic dosing system 2 includes: an acid dosing metering pump, a PAC metering pump, a PAM metering pump and a drug stirring device.

[0028] In this embodiment, preferably, the PLC control system 1 controls the automatic dosing system 2 to automatically add reagents and open and close pipeline valves by collecting the liquid level height of the regulating tank, the flow rate of the water inlet main pipe, the depth of the water outlet weir, the pH monitoring data of the water inlet of the pH regulating tank, the SS monitoring data, the pH monitoring data of the flocculation tank outlet, and the SS monitoring data; the PLC control system 1 is connected to a data analysis platform, and the data analysis platform is used to organize and analyze the data collected by the PLC control system 1, and feed it back to the PLC control system 1 to perform acid-base neutralization and coagulation precipitation on the automatic dosing system 2.

[0029] In this embodiment, preferably, the algorithm steps of the PLC control system 1 include: S1, Initialization: Set "Dosing Equipment" = Off; S2. Read monitoring values: read current pH value and SS suspended solids concentration; S3. Handle special situations: If the pH value and SS suspended solids concentration monitoring are continuously 0, enter the fault mode. If a fault occurs, set "dosing equipment" = fault and jump to step S6; S4. Determine whether to add medicine: If the pH value is greater than the set standard and the SS suspended solids concentration is greater than the set standard, turn on the "dosing equipment" and set "dosing equipment" = on; S5. Determine whether to stop adding medicine: If the pH value and SS suspended solids concentration reach the following parameters: Among them, pH value: pH>6, pH<9; Among them, SS suspended matter concentration: SS<70, Then turn off "Dosing Equipment", set "Dosing Equipment" = off; S6, log and feedback: record the current temperature and heater status in the log; if there is a fault, issue an alarm; S7, loop back to step S2, wait for the next monitoring cycle, and repeat the above process.

[0030] In this embodiment, the algorithm of the automatic dosing system adopts a PID algorithm model.

[0031] The PID algorithm model control principle is a control method that performs correction based on the output feedback of the output object. When the actual deviation from the plan is measured, it is corrected according to the rated value or standard. Specifically, in this embodiment, by deploying water quality monitoring sensors, the final monitored water quality results are fed back to the control line. According to the feedback results, the three control algorithms of proportion, integral, and differential coefficient are used to adjust the deviation and static error of the dosage, and dynamically and accurately determine the dosage, so that the treated sewage water quality is in a stable and standard state.

[0032] The control law of the PID algorithm model is as follows: ; in: u(t)— The output of the controller is the regulated variable, such as the flow rate of a dosing pump or the opening of a solenoid valve.

[0033] e(t) —The error at the current moment, that is, the difference between the expected value and the actual value.

[0034] K p 、K i 、K d are the coefficients of proportional, integral, and differential respectively.

[0035] — represents the integral of the error.

[0036] — represents the differential of the error.

[0037] Proportional link: The proportional link can proportionally reflect the deviation signal of the control system. Once the deviation occurs, the control action is immediately taken to reduce the deviation. The output u(t) of the proportional controller is proportional to the input deviation e(t), which can quickly reflect the deviation and thus reduce the deviation, but it cannot eliminate the static error.

[0038] Integral link: The function of the integral link is mainly to eliminate static error and improve the system's error-free degree. The strength of the integral effect. The existence of the integral control effect is related to the existence time of the deviation e(t). As long as there is a deviation in the system, the integral link will continue to work, integrating the input deviation, so that the output of the controller and the opening of the actuator will continue to change, and a control effect will be generated to reduce the deviation.

[0039] Differential link: The function of the differential link is to reflect the changing trend of the deviation signal and to introduce an effective early correction signal into the system before the value of the deviation signal becomes too large, thereby speeding up the system's action speed and reducing the adjustment time.

[0040] Parameter determination: When determining the parameters of the PID controller, the parameters of the controller can be adjusted iteratively multiple times using the experimental method based on the qualitative relationship between the parameters of the controller and the dynamic performance and steady-state performance of the system. The specific steps are as follows: S1. Define control objectives pH value control target: The outlet pH value is set to pH>6 and pH<9.

[0041] Suspended solids concentration control target: effluent suspended solids concentration SS<70.

[0042] S2. Design PID controller ① pH value PID controller Input: pH value of inlet water quality (monitored in real time by sensor).

[0043] Set point: Target pH, pH>6, pH<9.

[0044] Output: Amount of acid and base saturated solution added.

[0045] ②Suspended matter concentration PID controller Input: Influent suspended solids concentration (monitored in real time by sensors).

[0046] Set point: Target suspended solids concentration, SS<70.

[0047] Output: The amount of flocculant saturated solution added.

[0048] S3. Adjust PID parameters ① pH value PID parameter adjustment Proportional (P) Parameters: Initial Settings Kp is a small value, such as 0.1. Gradually increase K p , until the system begins to oscillate slightly, and then reduce it appropriately to find a balance point that neither causes oscillation nor responds quickly.

[0049] Integral (I) Parameters: Initial Settings K i If the system responds too slowly or oscillates, reduce K i .

[0050] Derivative (D) parameters: Initial settings K d If the system starts to oscillate, reduce K d .

[0051] ②Suspended matter concentration PID parameter adjustment: Same as pH value PID parameter adjustment.

[0052] S4. Feedback control ① pH value control: Use a sensor to monitor the pH value of the effluent water. According to the output of the PID controller, adjust the amount of acid and alkali saturated solution added.

[0053] ② Suspended matter concentration control: Use sensors to monitor the suspended matter concentration of the effluent water. According to the output of the PID controller, adjust the amount of flocculant saturated solution added.

[0054] In summary: The present invention takes the typical pollutants pH and SS of tunnel sewage as representatives, based on water quality monitoring equipment and PLC control system, through real-time online monitoring of water quality, online feedback mechanism, and dynamic adjustment of dosage, to achieve dynamic treatment of tunnel sewage, reduce the operating load of the tunnel sewage treatment station and reduce the dosage.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An intelligent sewage treatment control device based on water quality linkage feedback mechanism, characterized in that: include: Water quality monitoring equipment is used to directly obtain the pH value and SS suspended solids concentration of tunnel sewage; the water quality monitoring equipment is used to adjust the system dosage through the PLC control system to achieve dynamic treatment of tunnel sewage; pH adjustment tank, used to adjust the pH value of influent; Mixing tank, used for adding coagulants and as a place for sewage mixing reaction; Flocculation tank, used for adding coagulant aids and as a place for sewage flocculation and sedimentation reactions; pH value monitoring equipment, used to monitor the pH value of inlet and outlet water, suspended in the float valve at the inlet end and the weir trough at the outlet of the mixing tank; SS suspended matter monitoring equipment is used to monitor the SS suspended matter in the inlet and outlet water, and is suspended in the float valve at the inlet end and the weir trough at the outlet of the mixing tank; Automatic dosing system, used to add acid and alkali saturated solution and flocculant saturated solution to the pH adjustment tank, mixing tank and flocculation tank; The PLC control system controls the automatic dosing system to automatically add chemicals and open and close pipeline valves by collecting the liquid level height of the regulating tank, the flow rate of the water inlet main pipe, the depth of the water outlet weir, the pH monitoring data of the pH regulating tank inlet, the SS monitoring data, the pH monitoring data of the flocculation tank outlet, and the SS monitoring data.

2. The intelligent sewage treatment control device based on water quality linkage feedback mechanism according to claim 1 is characterized in that: The hydraulic retention time of the pH adjustment pool is not less than 30 minutes; the acid solution includes citric acid and oxalic acid.

3. The intelligent sewage treatment control device based on water quality linkage feedback mechanism according to claim 1 is characterized in that: The hydraulic retention time of the mixing tank is not less than 30 minutes; the coagulants include PAC and PFS.

4. The intelligent sewage treatment control device based on water quality linkage feedback mechanism according to claim 1 is characterized in that: The hydraulic retention time of the flocculation tank is not less than 30 minutes; the coagulant aid includes PAM.

5. The intelligent sewage treatment control device based on water quality linkage feedback mechanism according to claim 1 is characterized in that: The parameter characteristics of the pH monitoring device are as follows: Range: 0~14pH, 0~80℃; Resolution: 0.01PH, ±0.1℃; Accuracy: ±0.1PH, ±0.2℃.

6. The intelligent sewage treatment control device based on water quality linkage feedback mechanism according to claim 1 is characterized in that: The parameter characteristics of the SS suspended matter monitoring equipment are as follows: Range: 0~1000mg / L, 0~4000NTU; Resolution: 0.1 mg / L, 0.1 NTU; Accuracy: Indication error ±3%.

7. The intelligent sewage treatment control device based on water quality linkage feedback mechanism according to claim 1 is characterized in that: The automatic dosing system includes: an acid dosing metering pump, a PAC metering pump, a PAM metering pump and a drug stirring device.

8. The intelligent sewage treatment control device based on water quality linkage feedback mechanism according to claim 1 is characterized in that: The PLC control system controls the automatic dosing system to automatically add reagents and open and close pipeline valves by collecting the liquid level height of the regulating tank, the flow rate of the water inlet main pipe, the depth of the water outlet weir, the pH monitoring data of the water inlet of the pH regulating tank, the SS monitoring data, the pH monitoring data of the water outlet of the flocculation tank, and the SS monitoring data; the PLC control system is connected to the data analysis platform, and the data analysis platform is used to organize and analyze the data collected by the PLC control system, and feed it back to the PLC control system to perform acid-base neutralization and coagulation precipitation on the automatic dosing system.

9. The intelligent sewage treatment control device based on water quality linkage feedback mechanism according to claim 1 is characterized in that: The algorithm steps of the PLC control system include: S1, Initialization: Set "Dosing Equipment" = Off; S2. Read monitoring values: read current pH value and SS suspended solids concentration; S3. Handle special situations: If the pH value and SS suspended solids concentration monitoring are continuously 0, enter the fault mode. If a fault occurs, set "dosing equipment" = fault and jump to step S6; S4. Determine whether to add medicine: If the pH value is greater than the set standard and the SS suspended solids concentration is greater than the set standard, turn on the "dosing equipment" and set "dosing equipment" = on; S5. Determine whether to stop adding medicine: If the pH value and SS suspended solids concentration reach the following parameters: Among them, pH value: pH>6, pH<9; Among them, SS suspended matter concentration: SS<70, Then turn off "dosing equipment", set "dosing equipment" = off; S6, log and feedback: record the current temperature and heater status in the log; if there is a fault, issue an alarm; S7: loop back to step S2, wait for the next monitoring cycle, and repeat the above process.

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