Sewage regulation-accident coupling system and method based on PLC automatic regulation and control

Abstract

The invention discloses a sewage regulation-accident coupling system and method based on PLC automatic regulation and control. Comprising an online monitoring system, an adjusting tank, an accident tank and a PLC control system, wherein water inlet pipes of the adjusting tank and the accident tank are connected with a sewage inlet pipe, and controlled valves are arranged on the water inlet pipes of the adjusting tank and the accident tank; the online monitoring system is used for monitoring the water quality of the sewage inlet pipe and outputting a monitoring result to the PLC control system; and the PLC control system outputs a control signal to the controlled valves on the water inlet pipes of the regulating tank and the accident tank according to a received result. The water inlet quality is monitored through the water inlet on-line monitoring system, water inlet electric valve switches of the adjusting tank and the accident tank are controlled through the PLC control system, and the accident response automation degree is high. The water outlet of the adjusting tank is controlled by the combination of the water outlet adjusting weir gate and the overflow adjusting weir gate, so that the stability of the water outlet amount is ensured, and a relatively large adjusting tank volume is not needed.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and more specifically to a sewage regulation-accident coupling system based on PLC automatic control. Background Art

[0002] During the discharge process, industrial wastewater changes with the production conditions, resulting in uneven water quality and unstable water quantity. Especially when there is an accident in production or there is a lot of rain, the water quality and water quantity of the wastewater change more greatly. This change will cause the wastewater treatment process to be abnormal, reduce the treatment effect, and fail to give full play to the design load of the treatment equipment. In order to make the treatment process work normally and not be affected by the changes in the peak flow or peak concentration of the wastewater, it is required that the wastewater has a relatively stable water volume and uniform water quality before treatment, and the water quality and water quantity must be adjusted.

[0003] At present, the traditional practice is to set up a regulating tank and an accident tank separately. Referring to the "Design Code for Treatment and Reuse of Chemical Industrial Wastewater" (GB 50684-2011), the volume of the regulating tank should be determined based on the influent water volume and water quality change data. When the data cannot be obtained, the volume of the regulating facility can be measured based on the 12-24h average hourly flow rate, and the volume of the accident tank can be measured based on the 8-12h average hourly flow rate. Based on this, in actual engineering design, the volume of the regulating tank and the accident tank is relatively large, which not only requires a large investment, but also occupies a large area, which restricts the overall design of the sewage treatment facility.

[0004] At the same time, in the current conventional design, the water outflow from the regulating tank is lifted by a water pump to achieve stable water outflow, which has high investment and operation costs. In addition, due to the large changes in water level, the operating point of the lifting pump is constantly changing, and it is still impossible to achieve absolute uniformity, which also affects the life of the lifting pump. At present, most accident pools are designed separately, and the degree of automation of accident response is low. When an accident is discovered, the sewage treatment system has been more or less impacted. Summary of the invention

[0005] In view of the above technical problems, the present invention provides a sewage regulation-accident coupling system based on PLC automatic control.

[0006] To achieve the above-mentioned purpose, the sewage regulation-accident coupling system based on PLC automatic control of the present invention includes an online monitoring system, a regulating tank, an accident tank, and a PLC control system; wherein the water inlet pipes of the regulating tank and the accident tank are connected to the sewage inlet pipe, and controlled valves are arranged on the water inlet pipes of the regulating tank and the accident tank; the online monitoring system is used to monitor the water quality of the sewage inlet pipe and output the monitoring results to the PLC control system; the PLC control system outputs control signals to the controlled valves on the water inlet pipes of the regulating tank and the accident tank according to the received results.

[0007] Furthermore, the online monitoring system samples the sewage in the sewage inlet pipe through a sampling pump; the waste sample liquid is discharged to the accident pool through a pipeline.

[0008] Furthermore, a stirrer and a liquid level meter are arranged in the regulating tank, and the signal of the liquid level meter is fed back to the PLC control system.

[0009] Furthermore, the regulating tank is provided with a water outlet regulating weir gate, and the outlet water is connected to the next processing unit.

[0010] Furthermore, the regulating tank is provided with an overflow regulating weir gate, and the overflow sewage is discharged to the accident tank through a pipeline.

[0011] Furthermore, a mixer and a liquid level meter are arranged in the accident pool, and the signal of the liquid level meter is fed back to the PLC control system.

[0012] Furthermore, a lifting pump is provided at the outlet of the accident pool, and the outlet of the lifting pump is lifted to the regulating pool through a pipeline.

[0013] Furthermore, an overflow water inlet electric valve is provided on the discharge pipe of the overflow sewage.

[0014] To achieve the above object, the sewage regulation-accident coupling method based on PLC automatic control of the present invention is implemented based on the above sewage regulation-accident coupling system based on PLC automatic control, and the method includes the following water quality adjustment steps:

[0015] The online monitoring system monitors the water quality of the sewage inlet pipe in real time:

[0016] If the inlet water quality meets the design requirements, open the regulating tank inlet electric valve, close the accident tank inlet electric valve, and the sewage enters the regulating tank;

[0017] If the inlet water quality does not meet the design requirements, the regulating tank inlet electric valve is closed, the accident tank inlet electric valve is opened, and the sewage enters the accident tank.

[0018] Furthermore, the method further comprises the following water volume adjustment step:

[0019] Calculate the outflow flow rate based on the water level Z0 of the regulating pool and the opening height Z1 of the outflow regulating weir gate;

[0020]

[0021] Among them, m is the discharge coefficient, b is the weir width, and H = Z0-Z1 is the water head on the weir;

[0022] 1) When the outflow rate is greater than the designed water volume, adjust the overflow regulating weir gate height Z2 downward to make the outflow rate equal to the designed water volume;

[0023] 2) When the outflow rate is less than the designed water volume, adjust the overflow regulating weir gate height Z2 upward to make the outflow rate equal to the designed water volume;

[0024] 3) When the overflow regulating weir gate is completely closed, the outflow flow is still less than the design water volume, indicating that the inflow flow is less than the design water volume; start the emergency pool lift pump to counter-compensate the peak overflow volume to ensure the stability of the outflow of regulating pool 2.

[0025] The technical solution provided by the present invention has the following beneficial effects:

[0026] (1) The present invention monitors the inlet water quality through an inlet water online monitoring system and controls the inlet electric valve switches of the regulating tank and the accident tank through a PLC control system, and the accident response has a high degree of automation.

[0027] (2) The effluent from the regulating pool of the present invention is controlled by a combination of an effluent regulating weir gate and an overflow regulating weir gate, thereby ensuring a stable effluent volume without the need to set up a larger regulating pool capacity.

[0028] (3) The effluent from the regulating tank of the present invention does not need to be lifted by a water pump, and the operating cost is relatively low.

[0029] (4) The present invention will greatly reduce the construction investment of current conventional designs and significantly reduce the floor space. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the process of the present invention.

[0031] Among them, 1 is the online monitoring system, 101 is the sampling pump; 2 is the regulating tank, 201 is the regulating tank water inlet electric valve, 202 is the regulating tank mixer, 203 is the water outlet regulating weir gate, 204 is the overflow regulating weir gate, 205 is the regulating tank liquid level gauge; 3 is the accident tank, 301 is the accident tank water inlet electric valve, 302 is the accident tank mixer, 303 is the accident tank overflow water inlet electric valve, 304 is the accident tank lifting pump, 205 is the accident tank liquid level gauge; 4 is the PLC control system. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0035] Example 1

[0036] like Figure 1 The sewage regulation-accident coupling system based on PLC automatic control proposed by the present invention shown includes an online monitoring system 1, a regulation tank 2, an accident tank 3, and a PLC control system 4.

[0037] Among them, the online monitoring system 1 uses the sampling pump 101 to sample and monitor the influent COD, ammonia nitrogen, total nitrogen, total phosphorus, pH and other indicators, and the waste sample liquid is discharged to the accident pool 3; the online monitoring system 1 feeds back the detection results to the PLC control system 4.

[0038] The regulating pool 2 is provided with an electric valve 201 for water inlet; the accident pool 3 is provided with an electric valve 301 for water inlet;

[0039] The PLC control system 4 includes an input module, a logic operation module and an output module. The input module receives signals from external devices such as the online monitoring system 1, sensors, switches, buttons, etc., and processes the signals accordingly; the logic operation module performs logic operations on the processed signals; and the output module sends control signals to external devices such as actuators, motors, valves, etc.

[0040] Example 2

[0041] Based on the above embodiment, the PLC control system 4, the sewage regulation-accident coupling control logic is:

[0042] After detection by the online monitoring system 1, if the inlet water quality meets the design requirements, the electric inlet valve 201 of the regulating tank 2 is opened, the electric inlet valve 301 of the accident tank is closed, and the sewage enters the regulating tank 2;

[0043] If the inlet water quality does not meet the design requirements, the regulating tank inlet electric valve 201 is closed, the accident tank inlet electric valve 301 is opened, and the sewage enters the accident tank 3.

[0044] Example 3

[0045] On the basis of the above embodiment, a stirrer 202 and a liquid level meter 205 are arranged inside the regulating tank 2 , and the signal of the liquid level meter 205 is fed back to the PLC control system 4 .

[0046] Example 4

[0047] On the basis of the above-mentioned embodiment, the regulating pool 2 is provided with a water outlet regulating weir gate 203, and the water outlet is connected to the next processing unit.

[0048] Example 5

[0049] On the basis of the above-mentioned embodiment, the regulating pool 2 is provided with an overflow regulating weir gate 204 , and the overflow sewage is connected to the accident pool 3 .

[0050] Example 6

[0051] On the basis of the above embodiment, a stirrer 302 is arranged inside the accident pool 3; a liquid level meter is also arranged inside the accident pool 3, and the signal is fed back to the PLC control system.

[0052] Example 7

[0053] On the basis of the above-mentioned embodiment, a lifting pump 304 is provided for the outlet water of the accident pool 3 to lift the water to the regulating pool 2 .

[0054] Example 8

[0055] On the basis of the above-mentioned embodiment, the accident pool 3 is provided with an overflow water inlet electric valve 303 .

[0056] Example 9

[0057] Based on the above embodiment, the PLC control system 4, the sewage regulation-accident coupling control logic also includes:

[0058] Water volume control

[0059] The outflow rate is calculated based on the water level Z0 of the regulating pool 2 and the opening height Z1 of the outflow regulating weir gate 203 .

[0060]

[0061] Among them, m is the flow coefficient, b is the weir width, and H=Z0-Z1 is the water head on the weir (Z1 must be greater than the design water level of the next treatment unit + head loss).

[0062] 1) When the outflow flow is greater than the designed water volume, the height Z2 of the overflow regulating weir gate 204 is adjusted downward to make the outflow flow equal to the designed water volume;

[0063] 2) When the outflow flow is less than the designed water volume, the height Z2 of the overflow regulating weir gate 204 is adjusted upward to make the outflow flow equal to the designed water volume;

[0064] 3) When the overflow regulating weir gate 204 is completely closed, the outflow is still less than the designed water volume, indicating that the inflow is less than the designed water volume. At this time, the accident pool lift pump 304 is started to counter-fill the peak overflow to ensure the stable outflow of the regulating pool 2.

[0065] It should be noted that the above description is only a possible specific implementation of the present invention and should not be regarded as limiting. For example, all connecting pipes must be installed with necessary valves; all PLC control execution units, such as valves, weir gates, etc., can be electric or pneumatic; the indicators monitored by the online monitoring system are not limited to the indicators described; the water outlet regulating weir gate and the overflow regulating weir gate can be designed in other forms. Therefore, the present invention is not limited to possible specific implementations, and various changes can be made within the scope of knowledge possessed by ordinary technicians in this field without departing from the purpose of the present invention. Many other changes and modifications that do not depart from the concept and scope of the present invention should be regarded as the scope of protection of the present invention.

[0066] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0068] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A sewage regulation-accident coupling system based on PLC automatic control, characterized in that: It includes an online monitoring system, a regulating tank, an accident tank, and a PLC control system; wherein, the water inlet pipes of the regulating tank and the accident tank are connected to the sewage inlet pipe, and controlled valves are provided on the water inlet pipes of the regulating tank and the accident tank; the online monitoring system is used to monitor the water quality of the sewage inlet pipe and output the monitoring results to the PLC control system; the PLC control system outputs control signals to the controlled valves on the water inlet pipes of the regulating tank and the accident tank according to the received results.

2. The sewage regulation-accident coupling system based on PLC automatic control according to claim 1 is characterized in that: The online monitoring system samples the sewage in the sewage inlet pipe through a sampling pump; the waste sample liquid is discharged to the accident pool through a pipeline.

3. The sewage regulation-accident coupling system based on PLC automatic control according to claim 1 is characterized in that: A stirrer and a liquid level gauge are provided in the regulating tank, and the liquid level gauge signal is fed back to the PLC control system.

4. The sewage regulation-accident coupling system based on PLC automatic control according to claim 1 is characterized in that: The regulating tank is provided with a water outlet regulating weir gate, and the outlet water is connected to the next processing unit.

5. The sewage regulation-accident coupling system based on PLC automatic control according to claim 1 is characterized in that: The regulating pool is provided with an overflow regulating weir gate, and the overflow sewage is discharged to the accident pool through a pipeline.

6. The sewage regulation-accident coupling system based on PLC automatic control according to claim 1 is characterized in that: A mixer and a liquid level gauge are provided in the accident pool, and the liquid level gauge signal is fed back to the PLC control system.

7. The sewage regulation-accident coupling system based on PLC automatic control according to claim 1 is characterized in that: A lifting pump is provided for the outlet of the accident pool, and the outlet of the lifting pump is lifted to the regulating pool through a pipeline.

8. The sewage regulation-accident coupling system based on PLC automatic control according to claim 5 is characterized in that: An overflow water inlet electric valve is provided on the discharge pipe of the overflow sewage.

9. A sewage regulation-accident coupling method based on PLC automatic control, characterized in that: The method is implemented based on the sewage regulation-accident coupling system based on PLC automatic control as claimed in claim 1, and the method includes the following water quality adjustment steps: The online monitoring system monitors the water quality of the sewage inlet pipe in real time: If the inlet water quality meets the design requirements, open the regulating tank inlet electric valve, close the accident tank inlet electric valve, and the sewage enters the regulating tank; If the inlet water quality does not meet the design requirements, close the regulating tank inlet electric valve, open the accident tank inlet electric valve, and the sewage enters the accident tank.

10. The sewage regulation-accident coupling method based on PLC automatic control according to claim 9, characterized in that: The method further comprises the following water volume adjustment step: Calculate the outflow flow rate based on the water level Z0 of the regulating pool and the opening height Z1 of the outflow regulating weir gate; (Designed as non-submerged rectangular weir) Where m is the discharge coefficient, b is the weir width, and H = Z0-Z1 is the water head above the weir; 1) When the outflow rate is greater than the design water volume, adjust the overflow regulating weir gate height Z2 downward to make the outflow rate equal to the design water volume; 2) When the outflow rate is less than the designed water volume, adjust the overflow weir gate height Z2 upwards to make the outflow rate equal to the designed water volume; 3) When the overflow regulating weir gate is completely closed, the outflow rate is still less than the design water volume, indicating that the inflow rate is less than the design water volume; Start the emergency pool lift pump to counter-compensate the peak overflow volume to ensure the stable water output of regulating pool 2.

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