A method for calibrating oxygen transfer coefficient of a biological aerated tank and related components

Abstract

This invention discloses a method and related components for calibrating the oxygen transfer coefficient of a biological aeration tank, relating to the field of environmental protection technology. This scheme utilizes a blower airflow regulation system and an online dissolved oxygen concentration monitor to achieve rapid online calibration of the oxygen transfer coefficient. Within a first preset time period, the blower airflow regulation system continuously delivers a fixed airflow to the aeration tank. The online dissolved oxygen concentration monitor collects first dissolved oxygen concentration data from the aeration tank at a first preset sampling period. Based on the collected first dissolved oxygen concentration data and a pre-designed optimization solution model, the oxygen transfer coefficient of the aeration tank is calibrated. Compared to existing calibration methods, this invention has advantages such as fewer input parameters, higher automation, and cost savings (i.e., no need to add dedicated calibration equipment), facilitating the commissioning and application of wastewater treatment plant aeration systems.

Description

Technical Field

[0001] This invention relates to the field of environmental protection technology, and in particular to a method for calibrating the oxygen transfer coefficient of a biological aeration tank and related components. Background Technology

[0002] Biological treatment is a commonly used process in wastewater treatment, and it is a complex biochemical process. Aeration (dissolved oxygen) control is a crucial step. The principle is to blow oxygen-containing gas into the aeration tank through aeration equipment, creating a favorable environment for the normal functioning of active microorganisms. Typically, the oxygen transfer coefficient is positively correlated with the air volume blown into the aeration tank, characterizing the amount of oxygen transferred from the gas phase to the liquid phase per unit time. To achieve accurate aeration rate calculation, it is necessary to model the oxygen transfer process, and the oxygen transfer coefficient is a key parameter in this model.

[0003] Currently, the calibration of oxygen transfer coefficients typically relies on specialized equipment to measure relevant data from wastewater samples in biological treatment tanks. This method is complex, time-consuming, and labor-intensive, and requires consideration of multiple parameters, such as the theoretical technical parameters provided by the aeration equipment, the saturated dissolved oxygen value under calibration conditions, and atmospheric pressure. Furthermore, the accuracy of the calibration results is difficult to match with actual aeration systems. Therefore, achieving rapid and efficient oxygen transfer coefficient calibration is crucial for achieving precise aeration. Summary of the Invention

[0004] The purpose of this invention is to provide a method and related components for calibrating the oxygen transfer coefficient of a biological aeration tank. The method utilizes a blower airflow regulation system and an online dissolved oxygen concentration monitor to quickly calibrate the oxygen transfer coefficient online. It is convenient to operate, saves manpower, requires fewer input parameters, has a high degree of automation, and is easy to implement and promote.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for calibrating the oxygen transfer coefficient of a biological aeration tank, comprising:

[0006] Within a first preset time period, the blower air volume regulation system continuously delivers a fixed air volume to the aeration tank;

[0007] Within the first preset time period, the dissolved oxygen concentration online monitoring instrument is controlled to collect the first dissolved oxygen concentration data of the aeration tank at a first preset sampling period;

[0008] The oxygen transfer coefficient of the aeration tank is determined based on the first dissolved oxygen concentration data and the pre-designed optimization solution model.

[0009] Preferably, the total number of the first dissolved oxygen concentration data is N, where N is an integer not less than 1 and N * the first preset sampling period is less than the first preset duration;

[0010] The oxygen transfer coefficient of the aeration tank is determined based on the first dissolved oxygen concentration data and the pre-designed optimization model, including:

[0011] The first dissolved oxygen concentration data are processed to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank.

[0012] A theoretical data sequence with the oxygen transfer coefficient as the parameter to be determined is determined based on the sampling time corresponding to each of the first dissolved oxygen concentration data. The total number of sampling times corresponding to each of the first dissolved oxygen concentration data is N, and the time interval between two adjacent sampling times is the first preset sampling period.

[0013] Based on the theoretical data sequence and the actual data sequence, an objective function with the oxygen transfer coefficient as the decision variable is established.

[0014] The objective function is optimized to obtain the oxygen transfer coefficient of the aeration tank.

[0015] Preferably, the first dissolved oxygen concentration data are processed to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank, including:

[0016] Based on the i-th first dissolved oxygen concentration data, the (i+1)-th first dissolved oxygen concentration data, the (i+2)-th first dissolved oxygen concentration data, and the first preset relationship, actual calibration data related to the oxygen transfer coefficient of the aeration tank are determined, where 1≤i≤N-2 and i is an integer, the total number of actual calibration data is N-2, and each of the actual calibration data forms the actual data sequence; N is specifically an integer greater than 2;

[0017] The first preset relation is:

[0018]

[0019] Wherein, A i C(t) represents the i-th actual calibration data. i ) indicates that at sampling time t i The first dissolved oxygen concentration data, C(t) i+1 ) indicates that at sampling time t i+1 The first dissolved oxygen concentration data, C(t) i+2 ) indicates that at sampling time t i+2 The first dissolved oxygen concentration data, and the t i+1 -t i =t i+2 -t i+1 = The first preset sampling period.

[0020] Preferably, determining a theoretical data sequence with the oxygen transfer coefficient as the parameter to be determined based on the sampling time corresponding one-to-one with each of the first dissolved oxygen concentration data includes:

[0021] Based on the sampling time corresponding to each of the first dissolved oxygen concentration data and the second preset relationship, theoretical calibration data with the oxygen transfer coefficient as the parameter to be determined is determined; wherein, the total number of theoretical calibration data is N-2, and each of the theoretical calibration data forms the theoretical data sequence;

[0022] The second preset relation is:

[0023]

[0024] Wherein, the B i For the i-th theoretical calibration data, the K L a is the oxygen transfer coefficient, which is a parameter to be determined.

[0025] Preferably, based on the theoretical data sequence and the actual data sequence, an objective function is established with the oxygen transfer coefficient as the decision variable, including:

[0026] Based on the theoretical data sequence, the actual data sequence, and the third preset relation, an objective function is established with the oxygen transfer coefficient as the decision variable.

[0027] The objective function is:

[0028]

[0029] The optimization model established based on the objective function is as follows:

[0030] min D

[0031] Wherein, the decision variable of the objective function is the oxygen transfer coefficient K. L a, and the constraints of the objective function are:

[0032] K L a∈[K L a min ,K L a max ]

[0033] Wherein, K L a min The oxygen transfer coefficient K L The lower limit of the value of a, the K L a max The oxygen transfer coefficient K L The upper limit of the value of 'a'.

[0034] Preferably, the method for calibrating the oxygen transfer coefficient of the biological aeration tank further includes:

[0035] When the first preset time period is reached, the blower air volume regulation system is controlled to stop supplying the fixed air volume to the aeration tank;

[0036] Within a second preset time period, the dissolved oxygen concentration online monitoring instrument is controlled to collect the second dissolved oxygen concentration data of the aeration tank at a second preset sampling period;

[0037] The oxygen consumption rate of the aeration tank is determined based on the second dissolved oxygen concentration data and the pre-designed dissolved oxygen concentration-oxygen consumption rate calibration strategy.

[0038] Preferably, the total number of the second dissolved oxygen concentration data is M, where M is an integer greater than 1 and M * the second preset sampling period ≤ the second preset duration;

[0039] The oxygen consumption rate of the aeration tank is determined based on the second dissolved oxygen concentration data and a pre-designed dissolved oxygen concentration-oxygen consumption rate calibration strategy, including:

[0040] The difference between the (j+1)th and the jth second dissolved oxygen concentration data is denoted as ΔC. j+1 Where 1≤j≤M-1 and j is an integer; the total number of the differences is M-1.

[0041] Based on the second preset sampling period and each of the ΔC j+1 The oxygen consumption rate of the aeration tank is determined by the fourth preset relationship.

[0042] The fourth preset relation is:

[0043]

[0044] Wherein, OUR is the oxygen consumption rate, and ΔT is the second preset sampling period.

[0045] To address the aforementioned technical problems, the present invention also provides a calibration system for the oxygen transfer coefficient of a biological aeration tank, comprising:

[0046] The first control unit is used to control the blower air volume regulation system to continuously deliver a fixed air volume to the aeration tank within a first preset time period.

[0047] The second control unit is used to control the dissolved oxygen concentration online monitoring instrument to collect the first dissolved oxygen concentration data of the aeration tank at a first preset sampling period within the first preset time period.

[0048] The oxygen transfer coefficient determination unit is used to determine the oxygen transfer coefficient of the aeration tank based on the first dissolved oxygen concentration data and a pre-designed optimization solution model.

[0049] To address the aforementioned technical problems, the present invention also provides a device for calibrating the oxygen transfer coefficient of a biological aeration tank, comprising:

[0050] Memory, used to store computer programs;

[0051] A processor for performing the steps of the oxygen transfer coefficient calibration method for biological aeration tanks as described above.

[0052] To solve the above-mentioned technical problems, the present invention also provides an aeration tank control device, including a blower air volume adjustment system and an online dissolved oxygen concentration monitor, and also includes the oxygen transfer coefficient calibration device for biological aeration tank as described above.

[0053] The blower airflow regulation system is connected to the oxygen transfer coefficient calibration device of the biological aeration tank, and the dissolved oxygen concentration online monitoring instrument is connected to the oxygen transfer coefficient calibration device of the biological aeration tank.

[0054] This invention provides a method and related components for calibrating the oxygen transfer coefficient of a biological aeration tank. It utilizes a blower airflow regulation system and an online dissolved oxygen concentration monitor to achieve rapid online calibration of the oxygen transfer coefficient. Within a first preset time period, the blower airflow regulation system continuously delivers a fixed airflow to the aeration tank. The online dissolved oxygen concentration monitor collects first dissolved oxygen concentration data from the aeration tank at a first preset sampling period. Based on the collected first dissolved oxygen concentration data and a pre-designed optimization solution model, the oxygen transfer coefficient of the aeration tank is calibrated. Compared to existing calibration methods, this invention has advantages such as fewer input parameters, higher automation, and cost savings (i.e., no need to add dedicated calibration equipment), facilitating the commissioning and application of wastewater treatment plant aeration systems. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 A flowchart of a method for calibrating the oxygen transfer coefficient of a biological aeration tank provided by the present invention;

[0057] Figure 2 A dissolved oxygen concentration variation curve provided by the present invention;

[0058] Figure 3This is a schematic diagram of the structure of a biological aeration tank oxygen transfer coefficient calibration system provided by the present invention;

[0059] Figure 4 This is a schematic diagram of the structure of a biological aeration tank oxygen transfer coefficient calibration device provided by the present invention;

[0060] Figure 5 This is a schematic diagram of the structure of an aeration tank control device provided by the present invention. Detailed Implementation

[0061] The core of this invention is to provide a method and related components for calibrating the oxygen transfer coefficient of a biological aeration tank. The method utilizes a blower airflow regulation system and an online dissolved oxygen concentration monitor to quickly calibrate the oxygen transfer coefficient online. It is convenient to operate, saves manpower, requires fewer input parameters, has a high degree of automation, and is easy to implement and promote.

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] Please refer to Figure 1 , Figure 1 The flowchart illustrates a method for calibrating the oxygen transfer coefficient in a biological aeration tank, as provided by this invention.

[0064] The method for calibrating the oxygen transfer coefficient of the biological aeration tank includes:

[0065] S11: Within the first preset time period, control the blower air volume regulation system to continuously deliver a fixed air volume to the aeration tank;

[0066] S12: Within a first preset time period, control the online dissolved oxygen concentration monitor to collect the first dissolved oxygen concentration data of the aeration tank at a first preset sampling cycle.

[0067] S13: Determine the oxygen transfer coefficient of the aeration tank based on the first dissolved oxygen concentration data and the pre-designed optimization solution model.

[0068] In this embodiment, considering that the existing technology requires additional specialized equipment and involves complex procedures and high manpower costs to calibrate the oxygen transfer coefficient of an aeration tank, and that the calibration method requires multiple input parameters, resulting in an excessive reliance on the accuracy of parameter measurements, this application provides a method for calibrating the oxygen transfer coefficient of a biological aeration tank. This method enables online calibration of the oxygen transfer coefficient, is easy to operate, and readily applicable.

[0069] Specifically, this calibration method can be applied to a PLC (Programmable Logic Controller), which can send the acquired first dissolved oxygen concentration data to a host computer monitoring system for real-time monitoring of the first dissolved oxygen concentration data change curve. The blower airflow regulation system includes a blower, regulating valve, air flow meter, pressure transmitter, aeration head pipeline, etc. By adjusting the valve opening, the blower can blow a fixed volume of air into the aeration tank. Thus, within a first preset time period, the blower airflow regulation system is controlled to continuously deliver a fixed volume of air to the aeration tank, and the dissolved oxygen concentration online monitoring instrument is controlled to collect the first dissolved oxygen concentration data according to a first preset sampling period. It should be noted that the specific value of the first preset time period is not particularly limited here, but for the reliability of the calibration results, the preferred selection of the first preset time period should ensure that the dissolved oxygen concentration online monitoring instrument can collect a certain amount of first dissolved oxygen concentration data, that is, the first preset time period exceeds the first preset sampling period, and the setting of the first preset time period should not be too large to avoid dissolved oxygen concentration saturation.

[0070] Subsequently, an optimized solution model for calibrating the oxygen transfer coefficient was pre-designed. Based on the obtained first dissolved oxygen concentration data and the optimized solution model, the oxygen transfer coefficient of the aeration tank can be determined.

[0071] Furthermore, it is understood that the dissolved oxygen concentration online monitoring instrument can be controlled to collect the first dissolved oxygen concentration data of the aeration tank at a first preset sampling period. Of course, the first dissolved oxygen concentration data can also be collected once at different sampling times within the first preset duration, and the time interval between each sampling time is different. This application does not make any special limitation here, as long as the data acquisition logic for the first dissolved oxygen concentration data can be implemented.

[0072] It should also be noted that once the oxygen transfer coefficient is determined, it can be used indefinitely as long as the external environment does not change significantly; however, when the external environment changes significantly, it needs to be re-determined according to the method provided in this application.

[0073] In summary, this application provides a method for calibrating the oxygen transfer coefficient in a biological aeration tank. It utilizes a blower airflow regulation system and an online dissolved oxygen concentration monitor to achieve rapid online calibration of the oxygen transfer coefficient. Compared with existing calibration methods, the method provided in this application has advantages such as fewer input parameters, higher degree of automation, and cost savings (i.e., no need to add special calibration equipment), which facilitates the commissioning and application of aeration systems in wastewater treatment plants.

[0074] Based on the above embodiments:

[0075] In a preferred embodiment, the total number of first dissolved oxygen concentration data is N, where N is an integer not less than 1 and N * first preset sampling period is less than first preset duration;

[0076] The oxygen transfer coefficient of the aeration tank is determined based on the first dissolved oxygen concentration data and a pre-designed optimization model, including:

[0077] The data on each first dissolved oxygen concentration were processed to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank.

[0078] The theoretical data sequence with oxygen transfer coefficient as the parameter to be determined is determined based on the sampling time corresponding to each first dissolved oxygen concentration data. The total number of sampling times corresponding to each first dissolved oxygen concentration data is N, and the time interval between two adjacent sampling times is the first preset sampling period.

[0079] Based on theoretical and actual data sequences, an objective function with oxygen transfer coefficient as the decision variable is established.

[0080] The objective function is optimized to obtain the oxygen transfer coefficient of the aeration tank.

[0081] This embodiment illustrates how to apply the first dissolved oxygen concentration data and a pre-designed optimization model to determine the oxygen transfer coefficient of the aeration tank. First, the first dissolved oxygen concentration data collected according to the first preset sampling period corresponds to different sampling times, but the time interval between each sampling time is the first preset sampling period.

[0082] Therefore, the first dissolved oxygen concentration data are processed to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank. The theoretical data sequence with the oxygen transfer coefficient as the undetermined parameter is determined according to the sampling time corresponding to each first dissolved oxygen concentration data. It can be seen that the theoretical calibration sequence is also related to the oxygen transfer coefficient of the aeration tank. Therefore, based on the theoretical data sequence and the actual data sequence, an objective function with the oxygen transfer coefficient as the decision variable can be established. The objective function is optimized and solved. When the objective function reaches its maximum value, the value of the corresponding decision variable is the oxygen transfer coefficient of the aeration tank.

[0083] It should be noted that the specific methods for optimizing the objective function here include, but are not limited to, greedy optimization algorithms and various intelligent optimization algorithms, and are not specifically limited here.

[0084] As a theoretical derivation, the following provides proof that there is indeed a correlation between actual data sequences and oxygen transfer coefficients:

[0085] Assuming the aeration tank can completely mix and react, and ignoring the effects of changes in influent flow rate and effluent dissolved oxygen on the system, the following simplified kinetic equation for dissolved oxygen concentration in the aeration tank (in continuous state) exists during the first preset time period:

[0086]

[0087] Here, C(t) represents the actual data sequence (in continuous state) within the first preset time period, which essentially still represents the dissolved oxygen concentration (unit: mg / L), K L a is the oxygen transfer coefficient (unit: / h), C S Let OUR be the saturated dissolved oxygen concentration (mg / L) in the aeration tank under the current environment, and let OUR be the oxygen consumption rate (mg / (Lh)). Therefore, according to the operating procedure, the first preset time is assumed to be expressed as [T]. on ,T off ], T on T represents the start time of the first preset duration. off Representing the end time of the first preset duration, solving the above differential equation yields the equation for the change in dissolved oxygen concentration within the first preset duration:

[0088]

[0089] Where, t∈[T] on ,T off C0 is a constant corresponding to the general solution of the differential equation, such as the dissolved oxygen concentration in the aeration tank when the oxygen transfer coefficient is 0. It is evident that the actual data sequence in the continuous state is indeed correlated with the oxygen transfer coefficient. It is easy to see that the actual data sequence in this application is essentially a discretized representation of the actual data sequence in the continuous state. Therefore, the actual data sequence in this application is indeed correlated with the oxygen transfer coefficient.

[0090] It is evident that by establishing the objective function and optimizing the solution as described above, the oxygen transfer coefficient can be reliably solved, facilitating its implementation and application.

[0091] As a preferred embodiment, the first dissolved oxygen concentration data are processed to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank, including:

[0092] Based on the i-th first dissolved oxygen concentration data, the (i+1)-th first dissolved oxygen concentration data, the (i+2)-th first dissolved oxygen concentration data, and the first preset relationship, the actual calibration data related to the oxygen transfer coefficient of the aeration tank are determined, where 1≤i≤N-2 and i is an integer, the total number of actual calibration data is N-2, and each actual calibration data forms an actual data sequence; N is specifically an integer greater than 2;

[0093] The first presupposed relation is:

[0094]

[0095] Among them, A i Let C(t) represent the i-th actual calibration data. i ) indicates that at sampling time t i The first dissolved oxygen concentration data, C(t) i+1 ) indicates that at sampling time t i+1 The first dissolved oxygen concentration data, C(t) i+2 ) indicates that at sampling time t i+2 The first dissolved oxygen concentration data, and t i+1 -t i =t i+2 -t i+1 = First preset sampling period.

[0096] This embodiment describes how to process the acquired first dissolved oxygen concentration data. The specific processing method has been explained above and will not be repeated here. It can be seen that by establishing the change logic of the above three adjacent points, the actual data sequence related to the oxygen transfer coefficient of the aeration tank can be determined simply and reliably.

[0097] As a preferred embodiment, a theoretical data sequence with the oxygen transfer coefficient as the parameter to be determined is determined based on the sampling time corresponding one-to-one with each first dissolved oxygen concentration data, including:

[0098] Based on the sampling time corresponding to each first dissolved oxygen concentration data and the second preset relationship, theoretical calibration data with oxygen transfer coefficient as the parameter to be determined are determined; wherein, the total number of theoretical calibration data is N-2, and each theoretical calibration data constitutes a theoretical data sequence;

[0099] The second presupposed relation is:

[0100]

[0101] Among them, B i For the i-th theoretical calibration data, K L 'a' represents the oxygen transfer coefficient, which is a parameter to be determined.

[0102] This embodiment demonstrates how to determine theoretical calibration data with the oxygen transfer coefficient as the parameter to be determined based on the sampling time corresponding one-to-one with each of the first dissolved oxygen concentration data. The specific processing method has been explained above and will not be repeated here. It can be seen that, through the above execution logic, the oxygen transfer coefficient is ensured to be a parameter to be determined in the theoretical data sequence, which facilitates the subsequent establishment of the objective function.

[0103] As a preferred embodiment, based on theoretical data sequences and actual data sequences, an objective function with the oxygen transfer coefficient as the decision variable is established, including:

[0104] An objective function with oxygen transfer coefficient as the decision variable is established based on theoretical data sequence, actual data sequence and third preset relation.

[0105] The objective function is:

[0106]

[0107] The optimization model based on the objective function is as follows:

[0108] min D

[0109] The decision variable of the objective function is the oxygen transfer coefficient K. L a, and the constraints of the objective function are:

[0110] K L a∈[K L a min ,K L a max ]

[0111] Among them, K L a min Oxygen transfer coefficient K L The lower bound of the value of a, K L a max Oxygen transfer coefficient K L The upper limit of the value of 'a'.

[0112] This embodiment illustrates how to establish the objective function and the corresponding optimization model. The decision variable of the optimization model is the oxygen transfer coefficient, and the constraints are as described above, and will not be repeated here. It should be noted that the oxygen transfer coefficient K here... L The lower and upper limits of the value of 'a' can be set according to the actual application.

[0113] It should also be noted that the method of establishing an objective function with the oxygen transfer coefficient as the decision variable based on the theoretical data sequence and the actual data sequence is not limited to the one mentioned above. For example, an objective function with the oxygen transfer coefficient as the decision variable can also be established based on the cosine similarity function for the theoretical data sequence and the actual data sequence. No special limitation is made here.

[0114] As can be seen, through the above execution logic, based on N-2 sets of theoretical calibration data and actual calibration data, the difference between each theoretical calibration data and actual calibration data is reliably guaranteed to be minimized, and the value of the corresponding decision variable at this time is determined to be the oxygen transfer coefficient, with high calibration accuracy.

[0115] As a preferred embodiment, the method for calibrating the oxygen transfer coefficient of a biological aeration tank further includes:

[0116] When the first preset time is reached, the blower air volume regulation system stops supplying a fixed amount of air to the aeration tank;

[0117] Within a second preset time period, the dissolved oxygen concentration online monitoring instrument is controlled to collect the second dissolved oxygen concentration data of the aeration tank at a second preset sampling cycle;

[0118] The oxygen consumption rate of the aeration tank is determined based on the second dissolved oxygen concentration data and the pre-designed dissolved oxygen concentration-oxygen consumption rate calibration strategy.

[0119] In this embodiment, the inventors further considered that in the prior art, in order to determine the oxygen consumption rate during the aeration cessation phase, it is usually necessary to add an additional respiration rate meter for detection, which brings additional costs. Therefore, the method in this application may further include: when the first preset time period is reached, controlling the blower air volume regulation system to stop delivering a fixed air volume to the aeration tank, that is, stopping aeration in preparation for calibrating the oxygen consumption rate; within the second preset time period, controlling the dissolved oxygen concentration online monitoring instrument to collect the second dissolved oxygen concentration data of the aeration tank at a second preset sampling period; specifically, the second preset sampling period here may be the same as or different from the first preset sampling period mentioned above, and is not limited here; and it is understood that the dissolved oxygen concentration online monitoring instrument can be controlled to collect the second dissolved oxygen concentration data of the aeration tank at the second preset sampling period, and of course, the second dissolved oxygen concentration data can also be collected once at different sampling times within the second preset time period with different time intervals between the sampling times. This application does not make any special limitations here, as long as the data acquisition logic for the second dissolved oxygen concentration data can be implemented.

[0120] Therefore, a dissolved oxygen concentration-oxygen consumption rate calibration strategy was pre-designed. Based on the obtained second dissolved oxygen concentration data and the pre-designed dissolved oxygen concentration-oxygen consumption rate calibration strategy, the oxygen consumption rate of the aeration tank can be determined.

[0121] It should be noted that the second dissolved oxygen concentration data measured here is related to the oxygen consumption rate. As a theoretical derivation, the following explains the proof that there is indeed a correlation between the second dissolved oxygen concentration data and the oxygen consumption rate:

[0122] Based on the simplified dissolved oxygen concentration kinetic equation of the aeration tank in the above embodiment, it is assumed that the second preset duration can be expressed as [T off ,T end ], T off T represents the start time of the second preset duration. end Let represent the end time of the second preset time period. Solving the differential equation yields the equation for the change in dissolved oxygen concentration during the second preset time period (in a continuous state):

[0123] C(t)=C Toff -OUR*(tT off )

[0124] Where OUR is the oxygen consumption rate (unit: mg / (Lh)), C(t) represents the dissolved oxygen concentration data within the second preset time period (in continuous state), and t∈[T] off ,T end ], C Toff A constant corresponding to the general solution of a differential equation, for example, can be T. off The dissolved oxygen concentration in the aeration tank at any given time. It is evident that the dissolved oxygen concentration data under continuous conditions within the second preset time period is indeed correlated with the oxygen consumption rate. It is easy to understand that the second dissolved oxygen concentration data in this application is essentially a discrete representation of the dissolved oxygen concentration data under continuous conditions. Therefore, the second dissolved oxygen concentration data in this application is indeed correlated with the oxygen consumption rate.

[0125] It should also be noted that there is no specific limitation on the value of the second preset duration. However, for the reliability of the calibration results, the preferred choice of the second preset duration should ensure that the dissolved oxygen concentration online monitor can collect a certain amount of second dissolved oxygen concentration data, that is, the second preset duration exceeds the duration of the second preset sampling period.

[0126] In addition, please refer to Figure 2 , Figure 2 Based on the above embodiments, a dissolved oxygen concentration curve is provided, obtained by collecting first dissolved oxygen concentration data within a first preset time period and second dissolved oxygen concentration data within a second preset time period. The horizontal axis represents time in hours, and the vertical axis represents dissolved oxygen concentration data in mg / L. The T value mentioned above is also indicated here. on T off and T end .

[0127] It is evident that this method can reliably determine the oxygen consumption rate of the aeration tank without requiring an additional respiration rate meter, thus reducing costs and facilitating practical application.

[0128] In a preferred embodiment, the total number of second dissolved oxygen concentration data is M, where M is an integer greater than 1 and M * second preset sampling period ≤ second preset duration;

[0129] The oxygen consumption rate of the aeration tank is determined based on the second dissolved oxygen concentration data and a pre-designed dissolved oxygen concentration-oxygen consumption rate calibration strategy, including:

[0130] The difference between the (j+1)th and the jth second dissolved oxygen concentration data is denoted as ΔC. j+1 Where 1≤j≤M-1 and j is an integer; the total number of differences is M-1.

[0131] Based on the second preset sampling period, each ΔC j+1 The oxygen consumption rate of the aeration tank is determined by the fourth preset relationship.

[0132] The fourth pre-defined relation is:

[0133]

[0134] Where OUR is the oxygen consumption rate and ΔT is the second preset sampling period.

[0135] This embodiment demonstrates how to determine the oxygen consumption rate of the aeration tank based on the second dissolved oxygen concentration data and a pre-designed dissolved oxygen concentration-oxygen consumption rate calibration strategy. The specific processing method has been explained above and will not be repeated here. It is evident that the oxygen consumption rate of the aeration tank can be determined simply and reliably through the above execution logic.

[0136] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of a biological aeration tank oxygen transfer coefficient calibration system provided by the present invention.

[0137] This biological aeration tank oxygen transfer coefficient calibration system includes:

[0138] The first control unit 21 is used to control the blower air volume regulation system to continuously deliver a fixed air volume to the aeration tank within a first preset time period.

[0139] The second control unit 22 is used to control the dissolved oxygen concentration online monitoring instrument to collect the first dissolved oxygen concentration data of the aeration tank at a first preset sampling period within a first preset time period.

[0140] The oxygen transfer coefficient determination unit 23 is used to determine the oxygen transfer coefficient of the aeration tank based on the first dissolved oxygen concentration data and the pre-designed optimization solution model.

[0141] For an introduction to the oxygen transfer coefficient calibration system for biological aeration tanks provided in this invention, please refer to the embodiments of the above-described oxygen transfer coefficient calibration method for biological aeration tanks; further details will not be repeated here.

[0142] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of a biological aeration tank oxygen transfer coefficient calibration device provided by the present invention.

[0143] The parameter calibration device includes:

[0144] Memory 31 is used to store computer programs;

[0145] Processor 32 is used to perform the steps of the oxygen transfer coefficient calibration method for biological aeration tanks as described above.

[0146] For a description of the oxygen transfer coefficient calibration device for biological aeration tanks provided in this invention, please refer to the embodiments of the above-described oxygen transfer coefficient calibration method for biological aeration tanks; it will not be repeated here.

[0147] It should be noted that the processor 32 here includes, but is not limited to, PLCs, etc., and is not limited here.

[0148] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of an aeration tank control device provided by the present invention.

[0149] The aeration tank control equipment includes a blower air volume regulation system 41 and a dissolved oxygen concentration online monitoring instrument 43, and also includes a biological aeration tank oxygen transfer coefficient calibration device 42 as described above.

[0150] The blower air volume regulation system 41 is connected to the oxygen transfer coefficient calibration device 42 of the biological aeration tank, and the dissolved oxygen concentration online monitoring instrument 43 is connected to the oxygen transfer coefficient calibration device 42 of the biological aeration tank.

[0151] For a description of the aeration tank control equipment provided in this invention, please refer to the above-described embodiment of the oxygen transfer coefficient method for biological aeration tanks; it will not be repeated here.

[0152] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0153] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0154] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for calibrating the oxygen transfer coefficient of a biological aeration tank, characterized in that, include: Within a first preset time period, the blower air volume regulation system continuously delivers a fixed air volume to the aeration tank; Within the first preset time period, the dissolved oxygen concentration online monitoring instrument is controlled to collect the first dissolved oxygen concentration data of the aeration tank at a first preset sampling period; The oxygen transfer coefficient of the aeration tank is determined based on the first dissolved oxygen concentration data and the pre-designed optimization solution model. The total number of the first dissolved oxygen concentration data is N, where N is an integer not less than 1 and N * the first preset sampling period is less than the first preset duration; The step of determining the oxygen transfer coefficient of the aeration tank based on the first dissolved oxygen concentration data and a pre-designed optimization model includes: The first dissolved oxygen concentration data are processed to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank. A theoretical data sequence with the oxygen transfer coefficient as the parameter to be determined is determined based on the sampling time corresponding to each of the first dissolved oxygen concentration data. The total number of sampling times corresponding to each of the first dissolved oxygen concentration data is N, and the time interval between two adjacent sampling times is the first preset sampling period. Based on the theoretical data sequence and the actual data sequence, an objective function with the oxygen transfer coefficient as the decision variable is established. The objective function is optimized and solved to obtain the oxygen transfer coefficient of the aeration tank; The step of processing each of the first dissolved oxygen concentration data to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank includes: Based on the i-th first dissolved oxygen concentration data, the (i+1)-th first dissolved oxygen concentration data, the (i+2)-th first dissolved oxygen concentration data, and the first preset relationship, actual calibration data related to the oxygen transfer coefficient of the aeration tank are determined, where 1≤i≤N-2 and i is an integer, the total number of actual calibration data is N-2, and each of the actual calibration data forms the actual data sequence; N is specifically an integer greater than 2; The first preset relation is: ； Among them, the This represents the i-th actual calibration data. Indicates at the sampling time The first dissolved oxygen concentration data, Indicates at the sampling time The first dissolved oxygen concentration data, Indicates at the sampling time The first dissolved oxygen concentration data, and the =The first preset sampling period.

2. The method for calibrating the oxygen transfer coefficient of a biological aeration tank as described in claim 1, characterized in that, Based on the sampling time corresponding one-to-one with each of the first dissolved oxygen concentration data, a theoretical data sequence is determined with the oxygen transfer coefficient as the parameter to be determined, including: Based on the sampling time corresponding to each of the first dissolved oxygen concentration data and the second preset relationship, theoretical calibration data with the oxygen transfer coefficient as the parameter to be determined is determined; wherein, the total number of theoretical calibration data is N-2, and each of the theoretical calibration data forms the theoretical data sequence; The second preset relation is: ； Among them, the For the i-th theoretical calibration data, the The oxygen transfer coefficient is a parameter to be determined.

3. The method for calibrating the oxygen transfer coefficient of a biological aeration tank as described in claim 2, characterized in that, Based on the theoretical data sequence and the actual data sequence, an objective function is established with the oxygen transfer coefficient as the decision variable, including: Based on the theoretical data sequence, the actual data sequence, and the third preset relation, an objective function is established with the oxygen transfer coefficient as the decision variable. The objective function is: ； The optimization model established based on the objective function is as follows: ； Wherein, the decision variable of the objective function is the oxygen transfer coefficient. And the constraints of the objective function are: ； Among them, the The oxygen transfer coefficient The lower limit of the value, the The oxygen transfer coefficient The upper limit of the possible values.

4. The method for calibrating the oxygen transfer coefficient of a biological aeration tank as described in any one of claims 1 to 3, characterized in that, The method for calibrating the oxygen transfer coefficient of the biological aeration tank also includes: When the first preset time period is reached, the blower air volume regulation system is controlled to stop supplying the fixed air volume to the aeration tank; Within a second preset time period, the dissolved oxygen concentration online monitoring instrument is controlled to collect the second dissolved oxygen concentration data of the aeration tank at a second preset sampling period; The oxygen consumption rate of the aeration tank is determined based on the second dissolved oxygen concentration data and the pre-designed dissolved oxygen concentration-oxygen consumption rate calibration strategy.

5. The method for calibrating the oxygen transfer coefficient of a biological aeration tank as described in claim 4, characterized in that, The total number of the second dissolved oxygen concentration data is M, where M is an integer greater than 1 and M * the second preset sampling period ≤ the second preset duration; The oxygen consumption rate of the aeration tank is determined based on the second dissolved oxygen concentration data and a pre-designed dissolved oxygen concentration-oxygen consumption rate calibration strategy, including: The difference between the (j+1)th and the jth second dissolved oxygen concentration data is denoted as [the value of the difference]. Where 1≤j≤M-1 and j is an integer; the total number of the differences is M-1. Based on the second preset sampling period, each of the above The oxygen consumption rate of the aeration tank is determined by the fourth preset relationship. The fourth preset relation is: ； in, The oxygen consumption rate is... This is the second preset sampling period.

6. A calibration system for the oxygen transfer coefficient of a biological aeration tank, characterized in that, include: The first control unit is used to control the blower air volume regulation system to continuously deliver a fixed air volume to the aeration tank within a first preset time period. The second control unit is used to control the dissolved oxygen concentration online monitoring instrument to collect the first dissolved oxygen concentration data of the aeration tank at a first preset sampling period within the first preset time period. The oxygen transfer coefficient determination unit is used to determine the oxygen transfer coefficient of the aeration tank based on the first dissolved oxygen concentration data and the pre-designed optimization solution model. The total number of the first dissolved oxygen concentration data is N, where N is an integer not less than 1 and N * the first preset sampling period is less than the first preset duration; The oxygen transfer coefficient determination unit is specifically used for: The first dissolved oxygen concentration data are processed to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank; a theoretical data sequence with the oxygen transfer coefficient as the parameter to be determined is determined according to the sampling time corresponding to each of the first dissolved oxygen concentration data, wherein the total number of sampling times corresponding to each of the first dissolved oxygen concentration data is N and the time interval between two adjacent sampling times is the first preset sampling period; an objective function with the oxygen transfer coefficient as the decision variable is established based on the theoretical data sequence and the actual data sequence; the objective function is optimized and solved to obtain the oxygen transfer coefficient of the aeration tank; The step of processing each of the first dissolved oxygen concentration data to determine the actual data sequence related to the oxygen transfer coefficient of the aeration tank includes: Based on the i-th first dissolved oxygen concentration data, the (i+1)-th first dissolved oxygen concentration data, the (i+2)-th first dissolved oxygen concentration data, and the first preset relationship, actual calibration data related to the oxygen transfer coefficient of the aeration tank are determined, where 1≤i≤N-2 and i is an integer, the total number of actual calibration data is N-2, and each of the actual calibration data forms the actual data sequence; N is specifically an integer greater than 2; The first preset relation is: ； Among them, the This represents the i-th actual calibration data. Indicates at the sampling time The first dissolved oxygen concentration data, Indicates at the sampling time The first dissolved oxygen concentration data, Indicates at the sampling time The first dissolved oxygen concentration data, and the =The first preset sampling period.

7. A device for calibrating the oxygen transfer coefficient of a biological aeration tank, characterized in that, include: Memory, used to store computer programs; A processor for performing the steps of the method for calibrating the oxygen transfer coefficient of a biological aeration tank as described in any one of claims 1 to 5.

8. An aeration tank control device, characterized in that, It includes a blower air volume regulation system and an online dissolved oxygen concentration monitoring instrument, and also includes the oxygen transfer coefficient calibration device for the biological aeration tank as described in claim 7; The blower airflow regulation system is connected to the oxygen transfer coefficient calibration device of the biological aeration tank, and the dissolved oxygen concentration online monitoring instrument is connected to the oxygen transfer coefficient calibration device of the biological aeration tank.

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