Aeration combined control energy-saving device and sewage treatment system

Abstract

The application relates to an aeration combined control energy-saving device and a sewage treatment system, wherein the aeration combined control energy-saving device comprises an anoxic zone and an aerobic zone, the anoxic zone is provided with an aeration stirring module, and the aerobic zone is provided with an oxygenation aeration module; a centrifugal fan is connected with a main air supply pipe, the main air supply pipe is connected with an anoxic air supply branch pipe and an aerobic air supply branch pipe, a main air supply valve is arranged on the main air supply pipe, an anoxic air supply valve and an aerobic air supply valve are arranged on the anoxic air supply branch pipe and the aerobic air supply branch pipe respectively; a control module is arranged, an inlet water ammonia nitrogen on-line monitor and a redox potential instrument are arranged in the anoxic zone, outlet water ammonia nitrogen on-line monitors and dissolved oxygen on-line monitors are arranged in the aerobic zone, and the centrifugal fan, the main air supply valve, the anoxic air supply valve, the aerobic air supply valve, the inlet water ammonia nitrogen on-line monitor, the redox potential instrument, the outlet water ammonia nitrogen on-line monitor and the dissolved oxygen on-line monitor are electrically connected with the control module.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment technology, and more specifically, to an energy-saving device for combined aeration control and a wastewater treatment system. Background Technology

[0002] Currently, a large proportion of municipal wastewater treatment plants in my country still use oxidation ditch technology. This technology removes pollutants such as total phosphorus (TP) and phosphate from wastewater through anaerobic phosphorus release and aerobic phosphorus uptake, and removes difficult-to-treat pollutants such as total nitrogen and ammonia nitrogen through anoxic denitrification and aerobic nitrification. However, the oxygenation and mixing equipment in oxidation ditches is mostly surface aerators. Due to their long service life and severe aging, the oxygenation efficiency of these surface aerators has significantly decreased. This has led to various problems in wastewater treatment plants, including high energy consumption, low water quality, high chemical dosage, and substandard effluent quality. More and more wastewater treatment plants are starting to improve their aeration methods, switching from surface aeration to bottom aeration, which greatly improves oxygenation efficiency and saves energy from surface aerators. However, due to the addition of a large number of mixing and stirring equipment such as flow promoters and agitators after the upgrade, the overall energy consumption has not been significantly reduced.

[0003] Meanwhile, some municipal wastewater treatment plants use multi-stage AO biological tank treatment processes. These processes separate the anoxic and aerobic zones using partitions, and achieve uniform mixing in the anoxic zone by adding partitions and creating flow deflections. In the aerobic zone, aeration is achieved through bottom aeration. However, in actual operation, the mixing effect of the partitions is poor, leading to sludge accumulation at the bottom of the tank, reducing the effective volume of the anoxic zone, and increasing the risk of exceeding effluent quality standards. Furthermore, the amount of carbon source required also increases significantly.

[0004] Currently, commonly used aeration blowers are centrifugal blowers such as air-suspended blowers and magnetic levitation blowers. These blowers deliver air through pipelines to the aeration devices at the bottom of the oxidation ditch, providing sufficient oxygen to the wastewater and achieving a conversion from surface aeration to bottom aeration. This improves aeration efficiency and saves operating costs by replacing high-energy-consuming surface aerators with energy-efficient blowers. However, because centrifugal blowers use high-speed impeller rotation for aeration, it is difficult to frequently change blower parameters and adjust blower speed. This can lead to situations where, when the influent water quality is good, the airflow is too high, increasing dissolved oxygen in the water, consuming organic carbon sources, and increasing the dosage of chemicals. Therefore, centrifugal blowers cannot quickly adjust their speed to adjust the airflow according to changes in influent water quality, thus easily resulting in over-aeration and wasted energy.

[0005] The oxidation ditch propeller and agitator have excessive energy consumption, increasing power consumption. The multi-stage AO biological tank has poor mixing effect due to the baffle wall, which increases the risk of effluent not meeting standards. In addition, the blower has excessive aeration, which increases the power consumption of the blower and consumes carbon source, increasing the cost of chemicals. Summary of the Invention

[0006] The purpose of this application is to provide an energy-saving device for combined aeration control and a wastewater treatment system that can solve the above-mentioned technical problems.

[0007] To achieve the above objectives, in a first aspect, the present invention provides an aeration combined control energy-saving device, including an anoxic zone and an aerobic zone, wherein an aeration stirring module is provided in the anoxic zone and an oxygenation aeration module is provided in the aerobic zone.

[0008] Centrifugal fan, the centrifugal fan is connected to an air supply main pipe, the air supply main pipe is connected to an oxygen-deficient air supply branch pipe and an aerobic air supply branch pipe respectively, an air supply main valve is installed on the air supply main pipe, and an oxygen-deficient air supply valve and an aerobic air supply valve are installed on the anoxic air supply branch pipe and the aerobic air supply branch pipe respectively.

[0009] The control module is equipped with an online ammonia nitrogen monitor and an oxidation-reduction potential meter in the anoxic zone, and an online ammonia nitrogen monitor and an online dissolved oxygen monitor in the aerobic zone. The centrifugal fan, main air supply valve, anoxic air supply valve, aerobic air supply valve, online ammonia nitrogen monitor, oxidation-reduction potential meter, online ammonia nitrogen monitor, and online dissolved oxygen monitor are all electrically connected to the control module.

[0010] In an optional implementation, the anoxic zone is also equipped with an ultrasonic sludge interface meter for real-time monitoring of the sludge level in the anoxic zone, and the ultrasonic sludge interface meter is electrically connected to the control module.

[0011] In an optional embodiment, the aeration and mixing module includes multiple independently configured aeration and mixing units, each of which includes an anoxic distribution pipe connected in parallel to the anoxic air supply branch pipe.

[0012] In an optional implementation, an oxygen-deficient distribution pipe and an oxygen-deficient air supply branch pipe are provided with an oxygen-deficient air supply branch valve, and a time relay is installed on the oxygen-deficient air supply branch valve. The oxygen-deficient air supply branch valve and the time relay are electrically connected to the control module.

[0013] In an optional embodiment, each aeration and mixing unit includes multiple anoxic aeration pipes, which are horizontally arranged at the bottom of the anoxic zone, and multiple aeration holes are evenly distributed at intervals at the bottom of the anoxic aeration pipes. An ultrasonic sludge interface meter is installed at the top of the anoxic aeration pipes.

[0014] In an optional embodiment, a distribution branch pipe is provided between the anoxic distribution pipe and the anoxic aeration pipe, the anoxic aeration pipe is welded to the bottom of the distribution branch pipe, a connecting flange is provided between the distribution branch pipe and the anoxic distribution pipe, and a triangular bracket is provided at the connecting flange.

[0015] In an optional embodiment, a traction rope is also provided between the distribution branch pipe and the hypoxia distribution pipe, with one end of the traction rope tied to the distribution branch pipe and the other end tied to the part of the distribution branch pipe located below the connecting flange.

[0016] In an optional implementation, a calorific value gas flow meter is installed on both the main air supply pipe and the aerobic air supply branch pipe, and the calorific value gas flow meter is electrically connected to the control module.

[0017] In an optional embodiment, the main air supply valve, the anoxic air supply valve, and the aerobic air supply valve include solenoid valves with adjustable opening, and the anoxic air supply branch valve includes a two-position switch valve.

[0018] Secondly, the present invention provides a wastewater treatment system, including a biological tank and an aeration combined control energy-saving device according to any of the foregoing embodiments, wherein the anoxic zone and the aerobic zone include multiple sets of units arranged in the biological tank.

[0019] By installing an aeration and mixing module in the anoxic zone, excess air volume in the aerobic zone can be distributed to the aeration and mixing module in the anoxic zone, and aeration and mixing can be carried out in the form of aeration at the bottom of the anoxic zone. This solves the problem of easy sludge accumulation in multi-stage AO biological tanks through wall mixing and stirring, eliminates the energy consumption required for mixing by the pusher and agitator in the existing oxidation ditch, and effectively avoids the situation of increased reagent dosage due to over-aeration in the aerobic zone.

[0020] By connecting the control module with the centrifugal fan, different air valves, and online monitoring instruments in the anoxic and aerobic zones, the combined control of aeration and aeration can be achieved, reducing the energy loss of the centrifugal fan. By distributing the excess aeration air volume from the aerobic zone to the anoxic zone for aeration and aeration, the problem of excessive dissolved oxygen in the aerobic zone and consumption of carbon source is solved, as well as the problem of high energy consumption and poor effect of mixing and aeration in the anoxic zone. This not only saves the amount of carbon source added to the biological tank but also reduces the power consumption.

[0021] The combined control energy-saving system in this invention reduces the operating costs of chemicals and electricity for water plants while ensuring that the effluent meets discharge standards, thus achieving the goal of energy conservation and consumption reduction. At the same time, the aeration and mixing module facilitates equipment inspection and maintenance during actual operation, thereby extending the service life of the equipment.

[0022] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the plan layout of the anoxic and aerobic zones in this application;

[0025] Figure 2 This is a side view of the aeration and mixing module in this application.

[0026] Figure 3 This diagram shows the coordination relationship between the centrifugal fan, the anoxic air supply branch pipe, the aerobic air supply branch pipe, and the control valve.

[0027] Figure 4 A schematic diagram of the control logic for a combined control energy-saving system;

[0028] Figure 5 Diagram showing the coordination relationship between the oxygen-deficient distribution pipe and the oxygen-deficient supply air branch pipe;

[0029] Figure 6 Diagram showing the coordination relationship between the anoxic distribution pipe, the anoxic air supply branch pipe, and the anoxic aeration pipe.

[0030] Figure 7 This is a schematic diagram of the structure of an oxygen-deficient aeration pipe.

[0031] icon:

[0032] A - Hypoxic zone; B - Aerobic zone;

[0033] 1-Aeration and mixing module; 2-Oxygenation aeration module; 3-Centrifugal fan; 4-Main air supply pipe; 5-Anoxic air supply branch pipe; 6-Aerobic air supply branch pipe; 7-Main air supply valve; 8-Anoxic air supply valve; 9-Aerobic air supply valve; 10-Influent ammonia nitrogen online monitor; 11-Oxidation-reduction potential meter; 12-Effluent ammonia nitrogen online monitor; 13-Dissolved oxygen online monitor; 14-Ultrasonic sludge interface meter; 15-Anoxic distribution pipe; 16-Anoxic air supply branch valve; 17-Anoxic aeration pipe; 18-Aeration hole; 19-Distribution branch pipe; 20-Connecting flange; 21-Triangular bracket; 22-Traction rope; 23-Calorific value gas flow meter. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] The aeration combined control energy-saving device in this application is mainly used for the treatment of sewage in biological tanks. Specifically, through necessary structures and monitoring instruments, the control system controls the regulating valves and centrifugal fans on each air supply pipeline, distributing excess air volume in the aerobic zone to the aeration and stirring modules in the anoxic zone. This eliminates the need for power-consuming propellers and stirrers, reducing energy consumption. At the same time, it avoids the situation where the dosage of chemicals needs to be increased due to over-aeration in the aerobic zone, thus achieving the fundamental goal of energy saving and consumption reduction.

[0038] See Figure 1 The aeration combined control energy-saving device in this application includes anoxic zone A and aerobic zone B. An aeration and stirring module 1 is installed in anoxic zone A, and an oxygenation and aeration module 2 is installed in aerobic zone B.

[0039] The aeration and mixing module 1 in the anoxic zone A achieves zero power consumption for mixing. By distributing the excess air volume in the aerobic zone B to the anoxic zone A, it can impact and mix the bottom sludge in the form of aeration at the bottom of the anoxic zone A, while simultaneously mixing the wastewater in the anoxic zone A, thereby realizing the aeration and mixing function.

[0040] By setting up the aeration and mixing module 1, the air can effectively mix the sewage. At the same time, the downward aeration holes 18 blow away the sludge accumulated at the bottom of the sand tank, preventing the formation of bottom sludge in the anoxic zone A and ensuring the effective volume of the anoxic zone A.

[0041] Combination Figures 2-4 The joint control energy-saving system also includes a centrifugal fan 3 and a control module. The centrifugal fan 3 is connected to a main air supply pipe 4. The main air supply pipe 4 is connected to anoxic air supply branch pipe 5 and aerobic air supply branch pipe 6 respectively. A main air supply valve 7 is installed on the main air supply pipe 4. Anoxic air supply valve 8 and aerobic air supply valve 9 are installed on the anoxic air supply branch pipe 5 and the aerobic air supply branch pipe 6 respectively.

[0042] The anoxic zone A is equipped with an online ammonia nitrogen monitor 10 and an oxidation-reduction potential meter 11, while the aerobic zone B is equipped with an online ammonia nitrogen monitor 12 and an online dissolved oxygen monitor 13. The centrifugal fan 3, the main air supply valve 7, the anoxic air supply valve 8, the aerobic air supply valve 9, the online ammonia nitrogen monitor 10, the oxidation-reduction potential meter 11, the online ammonia nitrogen monitor 12, and the online dissolved oxygen monitor 13 are all electrically connected to the control module.

[0043] The anoxic zone A is also equipped with an ultrasonic sludge interface instrument 14 for real-time monitoring of the sludge level in the anoxic zone A. The ultrasonic sludge interface instrument 14 is electrically connected to the control module.

[0044] The control module includes a joint control system, which is responsible for coordinating the oxygen supply in the hypoxic zone A and the aerobic zone B, and also for adjusting the output air volume of the centrifugal fan 3.

[0045] For the anoxic zone A, an ultrasonic sludge interface meter 14 is installed in the anoxic zone A to monitor the sludge level in the anoxic zone A in real time and feed it back to the joint control system to adjust the valve opening degree, opening frequency and time of the anoxic air supply valve 8 of the aeration and mixing module 1.

[0046] For aerobic zone B, the valve opening of aerobic air supply valve 9 of aerobic zone B oxygenation module 2 is adjusted according to the dissolved oxygen online monitoring instrument 13 of aerobic zone B; the influent ammonia nitrogen concentration is monitored in real time by the influent ammonia nitrogen online monitoring instrument 10 at the front end of the biological tank, and the influent ammonia nitrogen concentration is fed back to the joint control system. According to the deviation of the influent ammonia nitrogen concentration from the design value, which is the ammonia nitrogen concentration after the sewage treatment is qualified, the blower is uniformly adjusted to achieve the optimal air volume, and the main air supply valve 7 is adjusted to the optimal air volume opening.

[0047] Under the premise of stabilizing the blower air volume, the effluent ammonia nitrogen concentration is monitored and fed back in real time by the online ammonia nitrogen monitor 12. The valve opening and closing status of the anoxic air supply valve 8 of the aeration and stirring module 1 is adjusted to control the aeration and oxygenation of the aerobic zone B, thereby reducing the consumption of carbon sources in the wastewater by excessive aeration. This method can save carbon source reagents and electricity consumption.

[0048] The aeration and mixing module 1 includes multiple independently set aeration and mixing units. Each aeration and mixing unit includes an oxygen-deficient distribution pipe 15, which is connected in parallel to the oxygen-deficient air supply branch pipe 5.

[0049] An oxygen-deficient distribution pipe 15 and an oxygen-deficient air supply branch pipe 5 are provided with an oxygen-deficient air supply branch valve 16. A time relay is installed on the oxygen-deficient air supply branch valve 16. The oxygen-deficient air supply branch valve 16 and the time relay are electrically connected to the control module.

[0050] The valve opening frequency of the aeration and mixing module 1 is linked to the angle of the sludge level height monitored by the ultrasonic sludge interface instrument 14 in the anoxic zone A. In order to accurately control the mixing time and frequency of the aeration and mixing module 1, a time relay is installed on the anoxic air supply branch valve 16 between the anoxic distribution pipe 15 and the anoxic air supply branch pipe 5 in each aeration and mixing unit. According to the data monitored by the ultrasonic sludge interface instrument 14 in each anoxic zone A and the aeration and mixing air volume, the opening time and opening frequency of the anoxic air supply branch valve 16 are dynamically adjusted, which not only ensures the mixing effect of aeration and mixing, but also reduces the valve wear caused by frequent opening of the anoxic air supply branch valve 16.

[0051] See Figures 5-7 Each aeration and mixing unit includes multiple anoxic aeration pipes 17, which are horizontally arranged at the bottom of the anoxic zone A. Multiple aeration holes 18 are evenly distributed at the bottom of the anoxic aeration pipes 17, allowing air to be sprayed out from the anoxic aeration pipes 17 through the aeration holes 18. This ensures the mixing effect of the wastewater in the anoxic zone A and prevents the sedimentation of bottom sludge in the anoxic zone A. An ultrasonic sludge interface meter 14 is installed above the anoxic aeration pipes 17, which can monitor the height of the sludge below the anoxic aeration pipes 17 in real time.

[0052] A vertical distribution branch pipe 19 is provided between the anoxic distribution pipe 15 and the anoxic aeration pipe 17. Air is supplied to the anoxic aeration pipe 17 through the distribution branch pipe 19, and then discharged through the aeration hole 18 for aeration and stirring.

[0053] The anoxic aeration pipe 17 is welded to the bottom of the distribution branch pipe 19, and the anoxic aeration pipe 17 is connected to the lumen of the distribution branch pipe 19. A connecting flange 20 is provided between the distribution branch pipe 19 and the anoxic distribution pipe 15 to facilitate the detachable connection between the anoxic distribution pipe 15 and the distribution branch pipe 19, which is convenient for later maintenance and replacement.

[0054] Both the distribution branch pipe 19 and the anoxic aeration pipe 17 are made of stainless steel, which effectively prevents corrosion of the aeration pipes by municipal sewage and extends their service life. Because the anoxic aeration pipe 17 experiences significant vibration during bottom aeration and mixing, a triangular bracket 21 is added at the welding position between the distribution branch pipe 19 and the connecting flange 20. The triangular bracket 21 consists of two brackets, one vertically and one vertically, with both ends connected to the flange and the distribution branch pipe 19, respectively. This serves to reinforce the flange and vertically support the distribution branch pipe 19.

[0055] The distribution branch pipe 19 is a DN25 stainless steel pipe, and the anoxic aeration pipe 17 is a DN40 stainless steel pipe. To ensure the aeration and mixing effect, an aeration hole 18 with a diameter of 6mm is reserved every 100mm in the anoxic aeration pipe 17 for downward aeration and mixing.

[0056] The anoxic distribution pipe 15 is specifically a DN80 carbon steel pipe. Each anoxic distribution pipe 15 is connected to 3 anoxic aeration pipes 17. The main purpose is to prevent the bottom distribution pipes from being connected in series, which can easily cause air pipe blockage.

[0057] Meanwhile, to facilitate timely maintenance of the bottom aeration and mixing pipes and prevent blockages in the air pipes that would necessitate water shut-off for cleaning and disrupt the normal operation of the wastewater treatment plant, the anoxic distribution pipe 15 and the distribution branch pipe 19 are connected using flanges and stainless steel bolts for easy disassembly. To prevent the bolts from loosening and the anoxic distribution pipe 15 and distribution branch pipe 19 from separating during aeration and mixing due to intense vibrations, a traction rope 22 is installed between the distribution branch pipe 19 and the anoxic distribution pipe 15. One end of the traction rope 22 is tied to the distribution branch pipe 19, and the other end is tied to the part of the distribution branch pipe 19 located below the connecting flange 20.

[0058] The traction rope 22 is specifically a stainless steel traction rope 22, which is corrosion resistant. The stainless steel traction rope 22 can be used to make a secondary connection and fixation between the distribution branch pipe 19 and the anoxic distribution pipe 15. Even if the distribution branch pipe 19 is detached from the anoxic distribution pipe 15 due to vibration, the connection effect of the traction rope 22 can prevent the distribution branch pipe 19 from falling to the bottom of the pool, reducing unnecessary trouble for subsequent inspection and maintenance.

[0059] Combination Figures 3-4 The control of the joint control energy-saving system in this invention is mainly reflected in the following aspects:

[0060] The valve opening of the aerobic air supply valve 9 in the aerobic zone B oxygenation module 2 and the angle of the dissolved oxygen concentration monitored by the dissolved oxygen online monitoring instrument 13 are linked and adjusted. By monitoring the dissolved oxygen concentration in aerobic zone B in real time and feeding it back to the joint control system, the joint control system controls the valve opening of the aerobic air supply valve 9 to adjust the amount of oxygen supplied to aerobic zone B.

[0061] The angles of the aeration and mixing module 1 and the oxygenation and aeration module 2, in conjunction with the influent ammonia nitrogen online monitoring instrument 10 and the effluent ammonia nitrogen online monitoring instrument 12, mainly include the following aspects:

[0062] 1) Stabilize the fan airflow based on the ammonia nitrogen concentration of the influent and effluent:

[0063] By directly inputting commonly used data such as aerobic tank volume, safety factor, total sludge production rate coefficient, and half-rate constant of nitrogen in nitrification into the joint control energy-saving system of this invention, and by real-time detecting variable parameters such as ammonia nitrogen concentration and temperature of influent and effluent through online detection instruments, the detection data is transmitted to the joint control system. At the same time, the real-time output air volume value of the blower is calculated according to formula (1), and the actual air volume parameter of the blower is adjusted by adjusting the calculated blower air volume, so as to realize the energy-saving and efficient control operation of the blower air volume.

[0064] Fan air volume

[0065] Q—Centrifugal fan output air volume (m³) 3 / min);

[0066] Na — Difference in ammonia nitrogen concentration between influent and effluent (mg / L);

[0067] V — Volume of the aerobic zone (pond) (m³) 3 );

[0068] X—Average concentration of suspended solids in the mixed liquor of the bioreactor (gMLSS / L), taken as 5;

[0069] F – Safety factor, taken as 1.5;

[0070] Yt——Total sludge yield coefficient (kgMLSS / kgBOD5), set to 1;

[0071] Kn—the half-rate constant of nitrogen in nitrification (mg / L), taken as 0.4;

[0072] T – Water temperature (°C).

[0073] Meanwhile, in order to reduce the frequent adjustment of centrifugal fan 3 and affect its service life, a database needs to be formed in the joint control energy-saving system to collect data on fan air volume. The fan air volume under the condition of 80% guarantee rate is taken as the commonly used air volume value during stable operation. At the same time, this air volume value should also correspond to the ammonia nitrogen concentration of the inlet and outlet water being within the 80% guarantee rate. The maximum ammonia nitrogen concentration is taken as the limit value. If the online monitoring data of the ammonia nitrogen concentration of the inlet and outlet water exceeds the limit value, the fan air volume is recalculated by formula (1). This process is repeated until the optimal fan air volume value is finally found through data accumulation.

[0074] 2) After stabilizing the fan air volume Q, adjust the valve opening of the aerobic air supply valve 9 of the aerobic aeration module 2 according to the dissolved oxygen concentration in the aerobic zone B. At the same time, feed back the ammonia nitrogen concentration in the effluent to the joint control system to further adjust the valve opening of each section.

[0075] See Figure 4 In the logic control, the angle of the output stable air volume of the centrifugal fan 3 is dynamically adjusted. The ammonia nitrogen concentration of the influent and effluent is monitored in real time by the online monitoring instrument of ammonia nitrogen concentration in the influent and effluent to determine the total oxygen demand of the biological tank. The joint control system controls the operation of the centrifugal fan 3. By adjusting the speed of the centrifugal fan 3 and the SV value of the output air volume, the initial fan air volume is determined, and then the initial oxygen supply of the fan is derived.

[0076] During the aeration process in the biological tank, the opening of the aerobic air supply valve 9 in the aerobic zone B is adjusted based on the dissolved oxygen parameters detected by the dissolved oxygen online monitoring instrument 13. Furthermore, the aerobic oxygen demand of the biological tank is verified by combining the values ​​of the ammonia nitrogen concentration in the influent and effluent of the biological tank with the values ​​of the online monitoring instrument. This also participates in the adjustment of the aerobic air supply valve 9. Since the ammonia nitrogen concentration in the influent and effluent is fixed during a specific treatment process, the stable air volume of the centrifugal fan 3 can be determined by adjusting the above-mentioned factors.

[0077] From the perspective of controlling whether to turn on aeration and stirring, the first thing to consider is whether the oxygen in the stable output of centrifugal fan 3 meets the supply requirements of aerobic zone B.

[0078] When the aerobic oxygen demand is greater than the initial oxygen supply of the blower, the electric valve of the anoxic air supply valve 8 in the anoxic zone A is closed. When the aerobic oxygen demand continues to be greater than the initial oxygen supply of the blower, the control of the centrifugal blower 3 to maintain a stable output air volume is restored. The aerobic oxygen demand of the biological tank is verified based on the values ​​of the online monitoring instrument for ammonia nitrogen concentration in the influent and effluent of the biological tank, and then the opening of the aerobic air supply valve 9 is adjusted to increase.

[0079] Based on the control of anoxic zone A, when the aerobic oxygen demand is less than the initial oxygen demand of centrifugal fan 3, the anoxic air supply valve 8 of anoxic zone A is opened, and the opening degree of the anoxic air supply valve 8 of anoxic zone A is controlled and adjusted by the data of oxidation-reduction potential meter 11 and the real-time data of ultrasonic sludge interface meter 14.

[0080] After stabilizing the fan airflow, the valve opening of the aerobic air supply valve 9 in each aerobic zone B needs to be adjusted to determine the optimal aeration rate for each aerobic zone B. This is mainly achieved by feeding back the online dissolved oxygen concentration data of each aerobic zone B to the integrated control system. Based on the correlation between dissolved oxygen concentration and aeration rate (see Equation 2), the aeration airflow value of aerobic zone B under the corresponding dissolved oxygen conditions is calculated. Simultaneously, to precisely adjust the aeration rate of aerobic zone B, calorific value gas flow meters 23 are installed on both the main air supply pipe 4 and the aerobic air supply branch pipe 6, and these flow meters 23 are electrically connected to the integrated control system. The online monitoring data from the calorific value gas flow meters 23 is fed back to the integrated control system to adjust the valve opening of the aerobic air supply valve 9.

[0081] Dissolved oxygen concentration q1=k*Gs*0.28*EA (2)

[0082] q1 — Dissolved oxygen concentration (mg / L);

[0083] k — constant;

[0084] Gs—Aeration rate (m³ / s) under standard conditions (0.1 MPa, 20℃) 3 / h);

[0085] 0.28 — Oxygen content per cubic meter of air under standard conditions (kgO2 / m³) 3 );

[0086] EA – Oxygen utilization rate of aeration disc (%), generally taken as 23%.

[0087] Meanwhile, in order to determine the optimal dissolved oxygen concentration for each aerobic zone B, it is necessary to establish an online monitoring database for dissolved oxygen concentration and influent and effluent ammonia nitrogen concentration. By determining the dissolved oxygen concentration control value for each aerobic zone B when the difference between influent and effluent ammonia nitrogen concentration is the largest, the optimal dissolved oxygen concentration value and the optimal aeration rate for different aerobic zones B can be determined.

[0088] 3) Adjust the opening frequency and opening time of the aeration and stirring module 1 according to the feedback of the influent ammonia nitrogen concentration, and at the same time adjust the valve opening of the aerobic air supply valve 9 of the oxygenation aeration module 2. Adjust the valve opening of the anoxic air supply valve 8 of the oxygenation aeration module 2 according to the feedback of the effluent ammonia nitrogen concentration.

[0089] After determining the optimal airflow value of the blower and the optimal aeration rate of each aerobic zone B, in order to utilize the airflow of centrifugal blower 3 more efficiently and reduce over-aeration in aerobic zone B, the excess airflow can be used for mixing in the anoxic tank. The opening time of the aeration mixing module 1 can be adjusted by the influent ammonia nitrogen concentration value. If the online monitoring value of the influent ammonia nitrogen concentration is lower than the value of the 60% guarantee rate of influent ammonia nitrogen concentration in the database, it indicates that the influent ammonia nitrogen concentration is low, the influent water quality is good, and excessive aeration is not required for nitrification. In order to make more effective use of the excess air, the anoxic air supply valve 8 of the aeration mixing module 1 in anoxic zone A can be opened to aerate and mix anoxic zone A.

[0090] Meanwhile, in order to reduce the alteration of the hypoxic environment in hypoxic zone A due to over-aeration, it is necessary to monitor the online oxidation-reduction potential meter 11 in hypoxic zone A in real time. If the online oxidation-reduction potential value is higher than +200mV, the aeration and stirring of hypoxic zone A should be stopped.

[0091] If the online monitoring value of influent ammonia nitrogen concentration is between 60% and 80% of the guaranteed value of influent ammonia nitrogen concentration in the database, it indicates that the influent ammonia nitrogen concentration is slightly low and the aeration rate of the blower is slightly high. The valve opening of the anoxic air supply valve 8 in anoxic zone A can be adjusted to perform micro-aeration and stirring in anoxic zone A. On the one hand, this reduces excessive aeration and consumption of available carbon source in aerobic zone B. On the other hand, it utilizes the excess aeration to perform micro-aeration in the aeration and stirring area, preventing the anoxic aeration pipe 17 from being easily blocked by the sludge at the bottom of the pool if it is not aerated for a long time.

[0092] In addition, to prevent the aeration pipe 17 at the bottom of the tank from being blocked and affecting the performance of the aeration and mixing module 1, an ultrasonic sludge interface meter 14 is installed in the sludge-prone area of ​​the anoxic section to monitor the sludge height at the bottom of the tank in real time. If the sludge deposition height at the bottom of the tank exceeds 0.5m, the valve of the aeration and mixing module 1 will start to aerate and mix.

[0093] Meanwhile, to improve the ammonia nitrogen removal capacity of aerobic zone B, the valve opening of the anoxic air supply valve 8 in aeration and mixing module 1 needs to be adjusted based on the online monitoring values ​​of influent and effluent ammonia nitrogen concentrations. If the difference between influent and effluent ammonia nitrogen concentrations is higher than the 90% guarantee rate of the influent and effluent concentration difference in the database, it indicates that the concentration of ammonia nitrogen pollutants in the influent is too high. Therefore, the aeration rate in aerobic zone B needs to be increased to promote nitrification. Thus, the valve opening of the anoxic air supply valve 8 in aeration and mixing module 1 needs to be reduced until the effluent ammonia nitrogen concentration is lower than the 60% guarantee rate value of the effluent ammonia nitrogen concentration in the database.

[0094] The linkage adjustment between the aeration and mixing module 1 and the oxygenation module 2, along with the influent ammonia nitrogen online monitoring instrument 10 and the effluent ammonia nitrogen online monitoring instrument 12, is the core of this application and enables the linkage control between aeration and mixing and oxygenation.

[0095] The integrated control system offers several control modes, including feedback control and manual mode. When manual control is required, it can be switched to manual mode, granting operators the authority to directly input relevant setpoints from the central control room and monitor the overall operation of the control system.

[0096] The main air supply valve 7, the anoxic air supply valve 8, and the aerobic air supply valve 9 are all solenoid valves with adjustable opening. The anoxic air supply branch valve 16 includes a two-position switch valve, which can easily adjust the opening of the main air supply valve 7, the anoxic air supply valve 8, and the aerobic air supply valve 9, and facilitate the control of the on / off of aeration and mixing in the individual aeration and mixing unit.

[0097] The present invention also provides a wastewater treatment system, including a biological tank and the above-mentioned aeration combined control energy-saving device. The anoxic zone A and aerobic zone B include multiple sets of units installed in the biological tank. The total air supply of the multiple sets of anoxic zone A and aerobic zone B is controlled by the main air supply valve 7.

[0098] The wastewater treatment system effectively saves energy and reduces consumption, as well as the dosage of carbon source agents. Before the control, four flow boosters were installed in anoxic zone A, each with a power of 7.5 kW. Operating 24 hours a day, the daily electricity consumption was 7.5 * 4 * 24 * 0.8 = 576 kWh, and the annual electricity cost was 576 * 0.7 * 365 = 147,168 yuan. After the control, the flow boosters were discontinued, and aeration and mixing were used instead. Aeration and mixing only consume a portion of the excess aerobic aeration air, with approximately zero electricity consumption. Therefore, compared to before the control, daily electricity consumption was reduced by 576 kWh, and annual electricity costs were reduced by approximately 147,000 yuan.

[0099] Before the adjustment, due to the poor flow deflection effect of the partition wall, the effective volume of the anoxic tank in a single biological tank was reduced by 1509 m³. 3 The sludge volume in the anoxic tank was 31% of the total volume, reducing denitrification time and decreasing the retention time in the anoxic tank from 5.80 hours to 3.98 hours. Denitrification efficiency weakened, leading to an increase in carbon source dosage to approximately 80 ppm. The carbon source dosage was 80 * 40000 / 1000000 = 3.2 t / d, and the carbon source reagent cost was 3.2 * 1300 = 4160 yuan / d. After adjustment, the sludge accumulation at the bottom of the anoxic tank decreased significantly, restoring the effective tank volume to 4829 m³. The retention time in the anoxic tank returned to 5.8 hours, and the carbon source dosage was significantly reduced to approximately 40 ppm, resulting in a carbon source dosage of 1.6 t / d and a carbon source reagent cost of 2080 yuan / d. Therefore, compared to before adjustment, the daily reagent dosage was reduced by 1.6 t / d, saving an annual carbon source reagent cost of 2080 * 365 = 759,200 yuan.

[0100] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0101] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An aeration combined control energy saving device, characterized by, It includes an anoxic zone and an aerobic zone. The anoxic zone is equipped with an aeration and stirring module, and the aerobic zone is equipped with an oxygenation and aeration module. A centrifugal fan is connected to a main air supply pipe, which is connected to an anoxic air supply branch pipe and an aerobic air supply branch pipe respectively. A main air supply valve is installed on the main air supply pipe, and an anoxic air supply valve and an aerobic air supply valve are installed on the anoxic air supply branch pipe and the aerobic air supply branch pipe respectively. The control module includes an online ammonia nitrogen monitor and an oxidation-reduction potential meter in the anoxic zone, and an online ammonia nitrogen monitor and an online dissolved oxygen monitor in the aerobic zone. The centrifugal fan, the main air supply valve, the anoxic air supply valve, the aerobic air supply valve, the online ammonia nitrogen monitor, the oxidation-reduction potential meter, the online ammonia nitrogen monitor, and the online dissolved oxygen monitor are all electrically connected to the control module. The aeration and mixing module includes multiple independently set aeration and mixing units. Each set of aeration and mixing units includes an anoxic distribution pipe, which is connected in parallel to the anoxic air supply branch pipe. An oxygen-deficient distribution pipe is provided between the oxygen-deficient air supply branch pipe and the oxygen-deficient air supply branch pipe. A time relay is installed on the oxygen-deficient air supply branch valve. The oxygen-deficient air supply branch valve and the time relay are respectively electrically connected to the control module. The anoxic zone is also equipped with an ultrasonic sludge interface meter for real-time monitoring of the sludge level in the anoxic zone. Each aeration and mixing unit includes multiple anoxic aeration pipes. The anoxic aeration pipes are horizontally arranged at the bottom of the anoxic zone, and multiple aeration holes are evenly distributed at intervals at the bottom of the anoxic aeration pipes. The ultrasonic sludge interface meter is located at the top of the anoxic aeration pipes. The ultrasonic sludge interface instrument is electrically connected to the control module. A distribution branch pipe is provided between the anoxic distribution pipe and the anoxic aeration pipe. The anoxic aeration pipe is welded to the bottom of the distribution branch pipe. A connecting flange is provided between the distribution branch pipe and the anoxic distribution pipe. A triangular bracket is provided at the connecting flange.

2. The aeration combined control energy saving device according to claim 1, characterized in that, A traction rope is also provided between the distribution branch pipe and the hypoxia distribution pipe. One end of the traction rope is tied to the distribution branch pipe, and the other end is tied to the part of the distribution branch pipe located below the connecting flange.

3. The aeration combined control energy saving device according to claim 1, characterized in that, Both the main air supply pipe and the aerobic air supply branch pipe are equipped with calorific value gas flow meters, which are electrically connected to the control module.

4. The aeration combined control energy saving device according to claim 1, characterized in that, The main air supply valve, the anoxic air supply valve, and the aerobic air supply valve all include solenoid valves with adjustable opening degrees, and the anoxic air supply branch valve includes a two-position switch valve.

5. A sewage treatment system comprising a biological tank and the aeration combined control energy-saving device according to any one of claims 1-4, characterized in that, The anoxic zone and the aerobic zone comprise multiple units disposed within the biological tank.

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