A precise aeration air volume calculation system and an air volume control method thereof

Abstract

The present application relates to the technical field of sewage treatment, and particularly discloses a precise aeration air volume calculation system and an air volume control method thereof, which comprises a data acquisition unit, a data analysis unit and a fan control unit. The present application expands the applicability range of the aeration control method from the perspective of engineering application, and adjusts the control method of the aeration amount based on the influent conditions and process operation parameters of the sewage plant in real time, so that the control method can be applied to more application scenarios, thereby achieving the purposes of stable operation of the biochemical section aeration under variable influent conditions, on-demand aeration, and reduction of the operation cost.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a precise aeration air volume calculation system and an air volume control method thereof. Background Art

[0002] In this new era where synergistic efficiency improvements in pollution reduction and carbon reduction are key strategic priorities, the high-carbon-emission water treatment industry naturally has a responsibility. According to statistics, electricity and chemical dosing costs account for over 50% of treatment costs in existing urban wastewater treatment plants in my country. Therefore, while meeting emission standards, wastewater treatment plants urgently need to optimize operations to achieve energy conservation and consumption reduction goals. Precision aeration is a key measure for these plants to achieve energy conservation and consumption reduction.

[0003] Precision aeration is a control technology guided by on-demand aeration, designed to provide the oxygen required for the aerobic reaction of pollutants while reducing the aeration system's power consumption. Currently, control technologies capable of achieving on-demand aeration are based on a "feedforward + feedback" control logic. However, current patents related to precision aeration do not mention the detailed application of "feedforward" and "feedback" control, nor do they mention control methods in engineering applications. Due to the real-time variability of sewage plant influent in engineering applications, comprehensive control of sewage plant aeration is required to achieve true precision aeration. Summary of the Invention

[0004] The purpose of the present invention is to provide a precise aeration air volume calculation system and an air volume control method thereof, aiming to provide a detailed control method and application strategy for precise aeration engineering applications.

[0005] To achieve the above-mentioned purpose, the present invention adopts a precise aeration air volume calculation system, including a data acquisition unit, a data analysis unit, and a fan control unit. The data acquisition unit needs to collect data from an activated sludge oxygen consumption rate online meter, an oxygen transfer efficiency online meter, a dissolved oxygen meter, a sludge concentration meter, an inlet flow meter, an inlet COD online meter, an outlet COD online meter, a biochemical tank level meter, an inlet ammonia nitrogen online meter, an outlet ammonia nitrogen online meter, an inlet total nitrogen (Kjeldahl nitrogen) online meter, an outlet total nitrogen (Kjeldahl nitrogen) online meter, a biochemical tank thermometer and a thermal air flow meter; the data analysis unit includes a "feedforward" calculation subsystem and a "feedback" auxiliary calculation subsystem, and obtains a comprehensive air volume based on the comprehensive calculation of "feedforward" and "feedback"; the fan control unit feeds back the comprehensive air volume to the blower to dynamically control the air volume.

[0006] The present invention also provides an air volume control application method for a precise aeration air volume calculation system. This control application method can realize the integrated control of "feedforward" and "feedback" of the aeration system. The key to the calculation of the "feedforward" calculation subsystem is to propose a correction coefficient a value and a trend quantity N caused by nitrogen, and provide a calculation and use method thereof; the key to the application of the "feedback" auxiliary calculation subsystem is to divide the stability of the biochemical environment according to the fluctuation range of real-time DO, and then determine the comprehensive oxygen demand according to the correction coefficient a value. The method specifically includes the following steps:

[0007] The precise aeration air volume calculation system includes a data acquisition unit, a data analysis unit, and a fan control unit;

[0008] The data analysis unit should include the functions of the "feedforward" computing subsystem and the "feedback" auxiliary computing subsystem.

[0009] The data acquisition unit needs to collect data from an activated sludge oxygen consumption rate online measuring instrument, an oxygen transfer efficiency online measuring instrument, a dissolved oxygen measuring instrument, a sludge concentration measuring instrument, an inlet flow meter, an inlet COD online measuring instrument, an effluent COD online measuring instrument, an inlet ammonia nitrogen online measuring instrument, an effluent ammonia nitrogen online measuring instrument, an inlet total nitrogen (Kjeldahl nitrogen) online measuring instrument, an effluent total nitrogen (Kjeldahl nitrogen) online measuring instrument, a biochemical tank level meter, a biochemical tank thermometer, and a thermal air flow meter;

[0010] Enter the control range of dissolved oxygen (DO L ,DO H );

[0011] Collecting data from various instruments through the data acquisition unit;

[0012] The feedforward calculation subsystem calculates oxygen demand for different scenarios based on the data acquired by the data acquisition unit. The oxygen demand calculation method for different scenarios is to use the acquired influent water quality and quantity and operation process parameters to calculate the oxygen demand for different scenarios according to different influent water volume changes and water quality load changes;

[0013] The feedback auxiliary calculation subsystem obtains the comprehensive oxygen demand based on the above-mentioned oxygen demand calculation results and combines the application methods of different dissolved oxygen environments, and converts the comprehensive oxygen demand into comprehensive air volume. The application method of different dissolved oxygen environments is to comprehensively calculate the oxygen demand calculation results of different scenarios according to the dissolved oxygen environment.

[0014] The fan control unit feeds back the integrated air volume to the blower, thereby dynamically controlling the air volume.

[0015] The method for the feedforward calculation subsystem to calculate oxygen demand in different scenarios is as follows:

[0016] The calculation formula of the oxygen demand is: S = a × (OUR × Vb × θ + N), where S is the aeration oxygen demand, kg / h; OUR is the activated sludge oxygen consumption rate g / (L·h); V is the effective volume of the aerobic tank, m 3 ; θ is the sensitivity factor, kg / h; b is the sensitivity factor correction coefficient, generally 1.5-1.7; N is the trend amount caused by nitrogen, kg / h; a is the correction coefficient related to the carbon and nitrogen in the inlet water.

[0017] Wherein, the calculation formula of the correction coefficient a is: Where, L C is the COD load at the current moment, gCOD / (gMLSS·d) or gCOD / (m 3 ·d); L Ct is the average COD load in the past t hours, gCOD / (gMLSS·d) or gCOD / (m 3 ·d); L N is the ammonia nitrogen load at the current moment, gNH3-N / (gMLSS·d) or gNH3-N / (m 3 ·d); L Nt The average ammonia nitrogen load in the past t hours is gNH3-N / (gMLSS·d) or gNH3-N / (m 3 d); X and Y are the coefficients of influence of influent COD and ammonia nitrogen on the aeration rate of the plant, respectively. They can be adjusted according to the site conditions. The value range of X and Y is 0-1.

[0018] The calculation formula of the trend quantity N is:

[0019] Where Q is the inlet water volume, m 3 / h; TN i is the total nitrogen in the influent, g / L; TKN i and TKN e Respectively, the total Kjeldahl nitrogen in the inlet and outlet, g / L, TKN i and TKN e You can take the empirical value TKN i =0.95×TN i , TKN e =0.2×TN e ;TON e is the nitrate nitrogen in the effluent, g / L, and the empirical value TON can be taken e =0.8×TN e , TN e is the total nitrogen in the effluent, g / L.

[0020] The calculation formula of the sensitivity factor θ is: Where, is the oxygen demand of the excess sludge, kg / h, For the current moment The instantaneous value of The time t hours before the current time The value range of t is 12 to 24 hours.

[0021] Wherein, the oxygen demand of the excess sludge The calculation formula is: Where Q 进水 is the inlet water volume, m 3 / h; COD i is the influent COD, g / L; COD e is the effluent COD, g / L; T is the water temperature of the biochemical pool, ℃.

[0022] The oxygen demand calculation is based on the changes in water quantity and water quality load to form the following three calculation methods:

[0023] Calculation method 1:

[0024] When 0.999 <a<1.001,且水量变化小于5%,此时需氧量计算公式中a=1,N=0;

[0025] Calculation method 2:

[0026] When a is not within the range of (0.999, 1.001), or the change in influent flow is greater than 5%, if The correction coefficient a is the coefficient caused by the changes in carbon and nitrogen in the water quality. In this case, there is no need to increase the trend amount N of nitrogen, so N = 0;

[0027] Calculation method 3:

[0028] When a is not within the range of (0.999, 1.001), or the change in water flow is greater than 5%, if At this time, both the a value and the N value must be calculated.

[0029] The application method of the feed-back auxiliary calculation subsystem according to the air volume in different dissolved oxygen environments is as follows:

[0030] According to different dissolved oxygen environments, use the air volume application method to obtain the comprehensive air volume

[0031] Application method 1: When the real-time dissolved oxygen (DO L ,DO H )

[0032] At this time, the biochemical environment is relatively stable, and calculation method 1 is used;

[0033] Application method 2: When the real-time dissolved oxygen is less than DO L ;

[0034] When a≤1, use the comprehensive calculation of "A×Calculation Method 3+B×Calculation Method 2";

[0035] When a>1, use the comprehensive calculation of "A×Calculation Method 3+B×Calculation Method 1";

[0036] Application method 3: When the real-time dissolved oxygen is greater than DO H ;

[0037] When a≤1, use the comprehensive calculation of "A×calculation method 1+B×calculation method 2";

[0038] When a>1, use the comprehensive calculation of "A×calculation method 1+B×calculation method 2";

[0039] Among them, A and B represent the proportion of the two calculation methods in the comprehensive model, which can be modified according to project implementation.

[0040] Preferably, the calculation formula for converting the oxygen demand of the aerobic pool into the aeration amount is: Where Q 空气 is the required aeration volume, m 3 / h; S is the oxygen demand of the aerobic pool, kg / h; C S(20) is the saturated dissolved oxygen concentration under standard conditions, mg / L; α is the ratio of oxygen transfer rate between sewage and clean water, which is taken as 0.83; β is the ratio of saturated DO in sewage and clean water, which is taken as 0.95; ρ is the pressure correction coefficient, which is taken as 1.009; T is the water temperature, ℃; C S ( T ) is the average DO saturation in the aerobic pool at water temperature T, mg / L; C is the corrected value of DO in the aerobic pool, mg / L; E A is the oxygen utilization rate, %.

[0041] The present invention provides a precise aeration air volume calculation system and air volume control method thereof. The data acquisition unit collects data from various instruments. The data analysis unit's "feedforward" calculation subsystem and "feedback" auxiliary calculation subsystem perform a comprehensive calculation to obtain a comprehensive air volume based on the "feedforward" oxygen demand calculation method for different scenarios and the "feedback" application method for different dissolved oxygen environments. The fan control unit then feeds the comprehensive air volume back to the blower, thereby dynamically controlling the air volume. This method details the calculation and application of "feedforward" and "feedback" for precise aeration control, applicable to a wider range of application scenarios. This method achieves stable aeration operation in the biochemical section under variable inlet water conditions, aeration on demand, and reduced operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 It is a structural schematic diagram of a precise aeration air volume calculation system of the present invention.

[0044] Figure 2 It is a flow chart of the steps of an air volume control method of a precise aeration air volume calculation system of the present invention.

[0045] Figure 3 This is a data trend chart of actual aeration volume and dissolved oxygen control changes after 600 hours of continuous operation of aeration control according to Example 1 of the present invention. DETAILED DESCRIPTION

[0046] See also Figure 1 and Figure 3 The present invention provides a precise aeration air volume calculation system, comprising a data acquisition unit, a data analysis unit, and a fan control unit. The data acquisition unit needs to collect data from an activated sludge oxygen consumption rate online meter, an oxygen transfer efficiency online meter, a dissolved oxygen meter, a sludge concentration meter, an inlet flow meter, an inlet COD online meter, an outlet COD online meter, a biochemical tank level meter, an inlet ammonia nitrogen online meter, an outlet ammonia nitrogen online meter, an inlet total nitrogen (Kjeldahl nitrogen) online meter, an outlet total nitrogen (Kjeldahl nitrogen) online meter, a biochemical tank thermometer, and a thermal air flow meter; the data analysis unit comprises a "feedforward" calculation subsystem and a "feedback" auxiliary calculation subsystem, and obtains a comprehensive air volume based on the comprehensive calculation of "feedforward" and "feedback"; the fan control unit feeds the comprehensive air volume back to the blower to dynamically control the air volume.

[0047] See also Figure 2 The present invention also provides an air volume control method for a precise aeration air volume calculation system, comprising the following steps:

[0048] S1: Input the required control range of DO (DO L ,DO H );

[0049] S2: Collecting data from each instrument through the data acquisition unit;

[0050] S3: The feedforward calculation subsystem calculates oxygen demand in different scenarios based on the data acquired by the data acquisition unit;

[0051] S4: The feed-back auxiliary calculation subsystem obtains the comprehensive oxygen demand based on the above oxygen demand calculation result and the application method of different dissolved oxygen environments, and converts the comprehensive oxygen demand into the comprehensive air volume;

[0052] S5: The fan control unit feeds back the integrated air volume to the blower to dynamically control the air volume.

[0053] The method for the feedforward calculation subsystem to calculate oxygen demand in different scenarios is as follows:

[0054] The calculation formula of the oxygen demand is: S = a × (OUR × Vb × θ + N), where S is the aeration oxygen demand, kg / h; OUR is the activated sludge oxygen consumption rate g / (L·h); V is the volume of the aerobic tank, m 3 ; θ is the sensitivity factor, kg / h; b is the sensitivity factor correction coefficient, generally 1.5-1.7; N is the trend caused by nitrogen, kg / h; a is the correction coefficient related to the carbon and nitrogen in the influent. When the sludge age is less than 15 days, OUR can be corrected to: OUR 修正 =OUR×MLSS t / MLSS0.

[0055] The calculation formula of the correction coefficient a is: Where, L C is the COD load at the current moment, gCOD / (gMLSS·d) or gCOD / (m 3 ·d); L Ct is the average COD load in the past t hours, gCOD / (gMLSS·d) or gCOD / (m 3 ·d); L N is the ammonia nitrogen load at the current moment, gNH3-N / (gMLSS·d) or gNH3-N / (m 3 ·d); L NtThe average ammonia nitrogen load in the past t hours is gNH3-N / (gMLSS·d) or gNH3-N / (m 3 d); X and Y are the coefficients of influence of influent COD and ammonia nitrogen on the aeration rate of the plant, respectively. They can be adjusted according to the site conditions. The value range of X and Y is 0-1.

[0056] Among them, the water quality load can use sludge load or volume load, but the COD and ammonia nitrogen load expressions must be unified, that is, the calculation method of a uses sludge load or volume load.

[0057] The calculation formula of the trend quantity N is:

[0058] Where Q is the inlet water volume, m 3 / h; TN i is the total nitrogen in the influent, g / L; TKN i and TKN e Respectively, the total Kjeldahl nitrogen in the inlet and outlet, g / L, TKN i and TKN e You can take the empirical value TKN i =0.95×TN i , TKN e =0.2×TN e ;TON e is the nitrate nitrogen in the effluent, g / L, and the empirical value TON can be taken e =0.8×TN e , TN e is the total nitrogen in the effluent, g / L.

[0059] The calculation formula of the sensitivity factor θ is: Where, is the oxygen demand of the excess sludge, kg / h, Current moment The instantaneous value of The time t hours before the current time The value range of t is 12 to 24 hours.

[0060] Oxygen demand of the excess sludge The calculation formula is: Where Q 进水 is the inlet water volume, m 3 / h; COD i is the influent COD, g / L; COD e is the effluent COD, g / L; T is the water temperature of the biochemical pool, ℃.

[0061] The oxygen demand calculation forms the following three calculation methods according to the changes in water quantity and water quality load:

[0062] Calculation method 1:

[0063] When 0.999 <a<1.001,且水量变化小于5%,此时需氧量计算公式中a=1,N=0;

[0064] Calculation method 2:

[0065] When a is not within the range of (0.999, 1.001), or the change in influent flow is greater than 5%, if The correction coefficient a is the coefficient caused by the changes in carbon and nitrogen in the water quality. In this case, there is no need to increase the trend amount N of nitrogen, so N = 0;

[0066] Calculation method 3:

[0067] When a is not within the range of (0.999, 1.001), or the change in influent flow is greater than 5%, if At this time, both the a value and the N value must be calculated.

[0068] The application method of the feed-back auxiliary calculation subsystem according to the air volume in different dissolved oxygen environments is as follows:

[0069] According to different dissolved oxygen environments, use the air volume application method to obtain the comprehensive air volume;

[0070] Application method 1: When the real-time dissolved oxygen (DO L ,DO H )

[0071] At this time, the biochemical environment is relatively stable, and calculation method 1 is used;

[0072] Application method 2: When the real-time dissolved oxygen is less than DO L ;

[0073] When a≤1, use the comprehensive calculation of "A×Calculation Method 3+B×Calculation Method 2";

[0074] When a>1, use the comprehensive calculation of "A×Calculation Method 3+B×Calculation Method 1";

[0075] Application method 3: When the real-time dissolved oxygen is greater than DO H ;

[0076] When a≤1, use the comprehensive calculation of "A×calculation method 1+B×calculation method 2";

[0077] When a>1, use the comprehensive calculation of "A×calculation method 1+B×calculation method 2";

[0078] Among them, A and B represent the proportion of the two calculation methods in the comprehensive model, which can be modified according to project implementation.

[0079] Preferably, the calculation formula for converting the oxygen demand of the aerobic pool into the aeration amount is: Where Q 空气 is the required aeration volume, m 3 / h; S is the oxygen demand of the aerobic pool, kg / h; C S(20) is the saturated dissolved oxygen concentration under standard conditions, mg / L; α is the ratio of oxygen transfer rate between sewage and clean water, which is taken as 0.83; β is the ratio of saturated DO in sewage and clean water, which is taken as 0.95; ρ is the pressure correction coefficient, which is taken as 1.009; T is the water temperature, ℃; C S ( T ) is the average DO saturation in the aerobic pool at water temperature T, mg / L; C is the corrected value of DO in the aerobic pool, mg / L; E A is the oxygen utilization rate, %.

[0080] The first embodiment of the present invention:

[0081] A domestic sewage treatment plant with a daily water treatment capacity of 15,000-20,000 tons uses A 2 O process, the influent COD fluctuation range is 80-550mg / L, the influent ammonia nitrogen fluctuation range is 5-55mg / L, and the influent total nitrogen fluctuation range is 15-90mg / L. Since the plant is adjacent to a slaughterhouse, it often has high ammonia nitrogen and high total nitrogen influent.

[0082] The sewage treatment plant is equipped with online monitoring and detection equipment such as activated sludge oxygen consumption rate online measuring instrument, oxygen transfer efficiency online measuring instrument, dissolved oxygen measuring instrument, sludge concentration measuring instrument, inlet flow meter, inlet COD online measuring instrument, inlet ammonia nitrogen online measuring instrument, inlet TN online measuring instrument, effluent COD online measuring instrument, effluent ammonia nitrogen online measuring instrument, effluent TN online measuring instrument, biochemical pool level meter, biochemical pool thermometer, etc.; thermal air flow meter and air regulating valve are installed on the aeration pipe.

[0083] Connect all the above instruments and blowers to the precise aeration air volume calculation system.

[0084] The plant is aerated controlled according to the control method of the present invention.

[0085] The plant's influent COD, influent ammonia nitrogen and total nitrogen fluctuate greatly, and high ammonia nitrogen and high total nitrogen influent are often present, so comprehensive control of the three application methods is required.

[0086] Since the sludge age of the plant is maintained at 18-20 days for a long time and the sludge concentration changes little, the volume load algorithm is used to calculate the a value, and the value range of X and Y is 0.4-0.6.

[0087] The plant's DO control range (DO L ,DO H ), generally selected in the range of 0.9-1.5 mg / L.

[0088] Application method 1: When the real-time dissolved oxygen (DO L ,DO H )

[0089] At this time, the biochemical environment is relatively stable, and calculation method 1 is used.

[0090] Application method 2: When the real-time dissolved oxygen is less than DO L ;

[0091] When a≤1, use the comprehensive calculation of A×calculation method 3+B×calculation method 2;

[0092] The value range of A is 0.1-0.3, and the value range of B is 0.7-0.9;

[0093] When a>1, use the comprehensive calculation of A×calculation method 3+B×calculation method 1;

[0094] The value range of A is 0.1-0.3, and the value range of B is 0.7-0.9;

[0095] Application method 3: When the real-time dissolved oxygen is greater than DO H ;

[0096] When a≤1, use the comprehensive calculation of A×calculation method 1+B×calculation method 2;

[0097] The value range of A is 0.4-0.6, and the value range of B is 0.4-0.6;

[0098] When a>1, use the comprehensive calculation of A×calculation method 1+B×calculation method 2;

[0099] The value range of A is 0.6-0.8, and the value range of B is 0.2-0.4;

[0100] The plant applied the integrated control of application method 1, application method 2 and application method 3. After aeration control, the dissolved oxygen remained stable within the control range of more than 85%. The gas-water ratio of the sewage plant was maintained within the range of 3.0-3.5, and the effluent stably reached the Class A standard in GB18918-2002, achieving the purpose of stabilizing the dissolved oxygen in the aerobic tank and saving energy and reducing consumption.

[0101] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of the rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A precise aeration air volume calculation system, characterized in that the precise aeration air volume calculation system includes a data acquisition unit, a data analysis unit, and a fan control unit; the data acquisition unit needs to collect data from an on-line measuring instrument for the oxygen consumption rate of activated sludge, an on-line measuring instrument for oxygen transfer efficiency, a dissolved oxygen measuring instrument, a sludge concentration measuring instrument, an influent flowmeter, an on-line measuring instrument for influent COD, an on-line measuring instrument for effluent COD, a biochemical tank liquid level gauge, an on-line measuring instrument for influent ammonia nitrogen, an on-line measuring instrument for effluent ammonia nitrogen, an on-line measuring instrument for influent total nitrogen, an on-line measuring instrument for effluent total nitrogen, a biochemical tank thermometer, and a thermal air flowmeter; the data analysis unit includes a "feedforward" calculation subsystem and a "feedback" auxiliary calculation subsystem, and obtains the comprehensive air volume through the comprehensive calculation of "feedforward" and "feedback"; the fan control unit feeds back the comprehensive air volume to the blower to dynamically control the air volume; A precise aeration air volume control method includes the following steps: Enter the DO demand control range (DO L ,DO H ); Collect data from each instrument through the data acquisition unit; The feedforward calculation subsystem calculates the oxygen demand in different scenarios based on the data obtained by the data acquisition unit. The oxygen demand calculation method for different scenarios is to calculate the oxygen demand in different scenarios according to different influent water volume changes and water quality load changes by using the obtained influent water quality and quantity and operation process parameters respectively; The feedback auxiliary calculation subsystem obtains the comprehensive oxygen demand based on the above oxygen demand calculation results and combines the application methods in different dissolved oxygen environments, and converts the comprehensive oxygen demand into the comprehensive air volume. The application method in different dissolved oxygen environments is to comprehensively calculate the oxygen demand calculation results in different scenarios according to the dissolved oxygen environment; The fan control unit feeds back the comprehensive air volume to the blower to dynamically control the air volume; The calculation formula of the oxygen demand is: , where S is the aeration oxygen demand, kg / h; OUR is the activated sludge oxygen consumption rate, g / (L∙h); V is the effective volume of the aerobic tank, m 3 ; θ is the sensitivity factor, kg / h; b is the sensitivity factor correction coefficient, generally 1.5-1.7; N is the trend caused by nitrogen, kg / h; a is the correction coefficient related to the carbon and nitrogen in the influent; The calculation formula of the correction coefficient a is: , where is the COD load at the current moment, gCOD / (gMLSS∙d) or gCOD / (m 3 ∙d); is the average COD load in the past t hours, gCOD / (gMLSS∙d) or gCOD / (m 3 ∙d); is the ammonia nitrogen load at the current moment, gNH3-N / (gMLSS∙d) or gNH3-N / (m 3 ∙d); The average ammonia nitrogen load in the past t hours is gNH3-N / (gMLSS∙d) or gNH3-N / (m 3 ∙d); X and Y are the coefficients of influence of influent COD and ammonia nitrogen on the aeration rate of the plant, respectively. They can be adjusted according to the site conditions. The value range of X and Y is 0-1; The calculation formula for the trend quantity N is: , where Q is the inlet water volume, m 3 / h; TN i is the total nitrogen in the influent, g / L; TKN i and TKN e Respectively, the total Kjeldahl nitrogen in the inlet and outlet, g / L, TKN i and TKN e Experience points can be obtained separately , ;TON e Nitrate nitrogen in effluent, g / L, can be taken as empirical value , TN e is the total nitrogen in the effluent, g / L.

2. The precise aeration air volume calculation system according to claim 1, characterized in that The calculation formula of the sensitivity factor θ is: , where φ is the oxygen demand of excess sludge, kg / h, φ0 is the instantaneous value of φ at the current moment, φ t is the average value of φ in the period t hours before the current time, where t ranges from 12 to 24 hours; the calculation formula for the oxygen demand φ of the excess sludge is: , where Q 进水 is the inlet water volume, m 3 / h; COD i is the influent COD, g / L; COD e is the effluent COD, g / L; T is the water temperature of the biochemical pool, ℃.

3. The precise aeration air volume calculation system according to claim 2, characterized in that the oxygen demand calculation forms the following three calculation methods according to the changes in water volume and water quality load: Calculation method 1: When 0.999 < a < 1.001 and the water volume change is less than 5%, at this time a = 1 and N = 0 in the oxygen demand calculation formula; Calculation method 2: When a is not within the range of (0.999, 1.001), or the change in influent flow is greater than 5%, if , the correction coefficient a is the coefficient caused by the changes in carbon and nitrogen in the water quality. At this time, there is no need to increase the trend amount N of nitrogen, so N=0; Calculation method 3: When a is not within the range of (0.999, 1.001), or the change in influent flow is greater than 5%, if , at this time, both the a value and the N value need to be calculated.

4. The precise aeration air volume calculation system according to claim 3, characterized in that According to different dissolved oxygen environments, use the air volume application method to obtain the comprehensive air volume; Application method 1: When the real-time dissolved oxygen is within the range of (DOL, DOH); At this time, the biochemical environment is relatively stable, and calculation method 1 is adopted; Application method 2: When the real-time dissolved oxygen is less than DOL; When a ≤ 1, use the comprehensive calculation of "A × calculation method 3 + B × calculation method 2"; When a > 1, use the comprehensive calculation of "A × calculation method 3 + B × calculation method 1"; Application method 3: When the real-time dissolved oxygen is greater than DOH; When a ≤ 1, use the comprehensive calculation of "A × calculation method 1 + B × calculation method 2"; When a > 1, use the comprehensive calculation of "A × calculation method 1 + B × calculation method 2"; Among them, A and B represent the proportion of the two calculation methods in the comprehensive model, which can be modified according to project implementation.

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