Biological pond aeration control method and system

Abstract

The application discloses a biological pool aeration control method and system, and the method comprises the following steps: acquiring the current ammonia nitrogen concentration, the current dissolved oxygen content and the user-set parameters collected by each biological pool; comparing the current ammonia nitrogen concentration with the set upper limit value and lower limit value of the ammonia nitrogen; if the current ammonia nitrogen concentration is greater than or equal to the set upper limit value, starting the air blower and controlling the working time length of the air blower according to the shortest aeration time; when the air blower is running, judging whether the ammonia nitrogen concentration decrease rate of each biological pool is consistent or whether the ammonia nitrogen concentration of each biological pool is consistent; if not, adopting a control strategy to control the air inlet valve to control the air inlet amount and adjust the ammonia nitrogen concentration of each biological pool; if the current ammonia nitrogen concentration is less than the set lower limit value, stopping the air blower and controlling the shutdown time length of the air blower according to the longest shutdown time. The method can timely, accurately and automatically control the aeration of the biological pool and reduce the artificial workload. Through the double protection of the shortest aeration time and the longest shutdown time, the effluent water quality can be continuously and stably discharged up to the standard.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a method and system for controlling aeration in a biological tank. Background Technology

[0002] A biological tank is a container used to cultivate and maintain the growth of organisms, commonly used in aquaculture, wastewater treatment, and bioreactors. In these applications, accurately controlling the dissolved oxygen concentration in the biological tank is crucial for maintaining the health and productivity of the organisms. Traditional wastewater treatment plant biological tank aeration systems rely excessively on the experience of technicians and manual operation. Many regions suffer from low levels of operational management and a shortage of professional personnel, making it impossible to adjust the aeration rate in a timely and effective manner. This results in inconsistent effluent quality and hinders the achievement of economic benefits. Currently, most wastewater treatment plants manually adjust the aeration rate. Due to the implementation of the Class A discharge standard, operators often over-aerate to ensure water quality meets the standard, leading to a significant increase in power consumption and wasted energy. Summary of the Invention

[0003] The purpose of this invention is to provide a method and system for controlling aeration in biological ponds, which can accurately and timely control aeration in biological ponds based on ammonia nitrogen concentration data and dissolved oxygen data, thereby making production operations more stable and ensuring that the effluent quality consistently meets discharge standards.

[0004] This invention is achieved through the following technical solution:

[0005] In a first aspect, an embodiment of the present invention provides a method for controlling aeration in a biological tank, comprising:

[0006] The system acquires the current ammonia nitrogen concentration, current dissolved oxygen content, and user-preset parameters collected from each biological tank. These parameters include the upper limit setting for ammonia nitrogen, the lower limit setting for ammonia nitrogen, the shortest aeration time, and the longest downtime.

[0007] Compare the current ammonia nitrogen concentration with the set upper and lower limits for ammonia nitrogen.

[0008] If the current ammonia nitrogen concentration is greater than or equal to the upper limit setting value of ammonia nitrogen, the blower is started and the working time of the blower is controlled according to the shortest aeration time. When the blower is running, it is determined whether the rate of decrease of ammonia nitrogen concentration in each biological tank is consistent or whether the concentration is consistent. If they are inconsistent, the control strategy is used to control the air intake valve to control the air intake volume and adjust the ammonia nitrogen concentration in each biological tank.

[0009] If the current ammonia nitrogen concentration is less than the lower limit set value, the blower will be stopped, and the blower shutdown time will be controlled according to the longest shutdown time.

[0010] Furthermore, the specific methods for adjusting the ammonia nitrogen concentration in each biological tank by controlling the air intake valve and regulating the air intake volume using a control strategy include:

[0011] The current ammonia nitrogen concentration, the target ammonia nitrogen concentration, and the initial ammonia nitrogen concentration are obtained, wherein the initial ammonia nitrogen concentration is the ammonia nitrogen concentration in the biological tank when the blower is turned on;

[0012] Calculate the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, target ammonia nitrogen concentration, and initial ammonia nitrogen concentration;

[0013] The average percentage of ammonia nitrogen remaining is calculated based on the percentage of ammonia nitrogen remaining in each biological tank.

[0014] Obtain airflow data in each biological pool, calculate the proportion of airflow in a single biological pool to the total airflow in all biological pools, and obtain the actual airflow proportion of a single biological pool.

[0015] The percentage of ammonia nitrogen remaining in each biological tank was compared with the average percentage of ammonia nitrogen remaining.

[0016] If the remaining percentage of ammonia nitrogen in the biological tank is greater than the average remaining percentage of ammonia nitrogen, it indicates that the ammonia nitrogen in the biological tank is decreasing slowly. The actual gas volume percentage of the biological tank is increased by a set value to obtain the target gas volume percentage.

[0017] Within a set interval, the actual gas volume ratio of the biological tank is compared with the target gas volume ratio to obtain the comparison result. Based on the comparison result, the opening of the air inlet valve is controlled to achieve ammonia nitrogen balance in each biological tank.

[0018] Furthermore, the comparison results include less than and greater than or equal to. If the comparison result is less than, the opening of the intake valve is increased; if the comparison result is greater than or equal to, the opening of the intake valve is decreased.

[0019] Furthermore, the formula for calculating the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, target ammonia nitrogen concentration, and initial ammonia nitrogen concentration is as follows:

[0020] Remaining ammonia nitrogen percentage = (Current ammonia nitrogen concentration - Target ammonia nitrogen concentration) × 100 / (Initial ammonia nitrogen concentration - Target ammonia nitrogen concentration).

[0021] Furthermore, the parameters also include the blower differential pressure protection value. In the process of controlling the opening of the air inlet valve to achieve ammonia nitrogen balance in each biological tank based on the comparison results, the inlet and outlet pressures of the blower are obtained, and the inlet and outlet pressure difference is calculated. The inlet and outlet pressure difference is compared with the blower differential pressure protection value. When the inlet and outlet pressure difference is greater than or equal to the blower differential pressure protection value, the valve opening is automatically increased until the inlet and outlet pressure difference is lower than the blower differential pressure protection value or the valve reaches its maximum opening.

[0022] Furthermore, it also includes: during the process of ammonia nitrogen concentration decreasing in a certain biological tank, when the current dissolved oxygen content is greater than the preset value of dissolved oxygen content in the biological tank, controlling the air intake valve to reduce its opening.

[0023] Furthermore, the intake valve includes a main intake valve and branch intake valves.

[0024] Secondly, an embodiment of the present invention provides a biological tank aeration control system, comprising: a data acquisition module, a comparison module, and a blower control module;

[0025] The data acquisition module acquires the current ammonia nitrogen concentration, current dissolved oxygen content, and user-preset parameters collected from each biological tank. The parameters include the upper limit setting value for ammonia nitrogen, the lower limit setting value for ammonia nitrogen, the shortest aeration time, and the longest downtime.

[0026] The comparison module is used to compare the current ammonia nitrogen concentration with the set upper limit and lower limit values ​​for ammonia nitrogen.

[0027] The blower control module is used to start the blower when the current ammonia nitrogen concentration is greater than or equal to the upper limit setting value, and to control the working time of the blower according to the shortest aeration time. When the blower is running, it determines whether the rate of decrease of ammonia nitrogen concentration in each biological tank is consistent or whether the concentration is consistent. If they are inconsistent, a control strategy is used to control the air intake valve to control the air intake volume and adjust the ammonia nitrogen concentration in each biological tank. When the current ammonia nitrogen concentration is less than the lower limit setting value, the blower is controlled to stop, and the blower shutdown time is controlled according to the longest shutdown time.

[0028] Furthermore, the blower control module includes a control unit, which acquires the current ammonia nitrogen concentration, the target ammonia nitrogen concentration, and the initial ammonia nitrogen concentration, wherein the initial ammonia nitrogen concentration is the ammonia nitrogen concentration of the biological tank when the blower is turned on;

[0029] Calculate the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, target ammonia nitrogen concentration, and initial ammonia nitrogen concentration;

[0030] The average percentage of ammonia nitrogen remaining is calculated based on the percentage of ammonia nitrogen remaining in each biological tank.

[0031] Obtain airflow data in each biological pool, calculate the proportion of airflow in a single biological pool to the total airflow in all biological pools, and obtain the actual airflow proportion of a single biological pool.

[0032] The percentage of ammonia nitrogen remaining in each biological tank was compared with the average percentage of ammonia nitrogen remaining.

[0033] If the remaining percentage of ammonia nitrogen in the biological tank is greater than the average remaining percentage of ammonia nitrogen, it indicates that the ammonia nitrogen in the biological tank is decreasing slowly. The actual gas volume percentage of the biological tank is increased by a set value to obtain the target gas volume percentage.

[0034] Within a set interval, the actual gas volume ratio of the biological tank is compared with the target gas volume ratio to obtain the comparison result. Based on the comparison result, the opening of the air inlet valve is controlled to achieve ammonia nitrogen balance in each biological tank.

[0035] Furthermore, the comparison results include less than and greater than or equal to. If the comparison result is less than, the opening of the intake valve is increased; if the comparison result is greater than or equal to, the opening of the intake valve is decreased.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] This invention provides a biological tank aeration control method and system. The automatic start / stop of the blower utilizes primary control of ammonia nitrogen concentration and secondary control of dissolved oxygen content. The blower's start / stop is automatically controlled based on the upper and lower limits of ammonia nitrogen concentration in the biological tank. When the blower is running, if the rate of ammonia nitrogen concentration decrease is inconsistent across different biological tanks, or if the current ammonia nitrogen concentrations are inconsistent, the air intake valve is automatically adjusted to control the air intake, thereby ensuring a consistent rate of ammonia nitrogen concentration decrease across all biological tanks. This allows for timely, accurate, and automatic control of biological tank aeration, resulting in more stable production operations and reduced manual workload. By setting dual protection mechanisms for minimum aeration time and maximum shutdown time, the effluent water quality consistently meets discharge standards. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered 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. In the drawings:

[0039] Figure 1 A flowchart of an aeration control method for a biological pond provided in the first embodiment of the present invention;

[0040] Figure 2 This is a structural block diagram of a biological pond aeration control system provided in another embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0042] Example 1

[0043] like Figure 1 As shown, the first embodiment of the present invention provides an aeration control method for a biological pond, which is applicable to the aeration control system for a biological pond provided in the embodiments of the present invention, and includes:

[0044] The system acquires the current ammonia nitrogen concentration, current dissolved oxygen content, and user-preset parameters for each biological tank. These parameters include the upper limit setting value for ammonia nitrogen, the lower limit setting value for ammonia nitrogen, the target ammonia nitrogen concentration, the shortest aeration time, the longest downtime, and the blower differential pressure protection value.

[0045] Compare the current ammonia nitrogen concentration with the upper limit setting and the lower limit setting for ammonia nitrogen;

[0046] If the current ammonia nitrogen concentration is greater than or equal to the upper limit setting value of ammonia nitrogen, the blower is started and the working time of the blower is controlled according to the shortest aeration time. When the blower is running, it is determined whether the rate of decrease of ammonia nitrogen concentration in each biological tank is consistent or whether the concentration is consistent. If they are inconsistent, the control strategy is used to control the air intake valve to control the air intake volume and adjust the ammonia nitrogen concentration in each biological tank.

[0047] If the current ammonia nitrogen concentration is less than the lower limit set value, the blower will be stopped, and the blower shutdown time will be controlled according to the longest shutdown time.

[0048] Ammonia nitrogen concentration is collected in the biological treatment tank using an ammonia nitrogen sensor. The number of ammonia nitrogen sensors can be set to one or more depending on the actual situation. If one sensor is installed, the current ammonia nitrogen concentration, the upper limit setting value, and the lower limit setting value are the ammonia nitrogen concentration data collected by the sensor. If multiple sensors are installed, the current ammonia nitrogen concentration, the upper limit setting value, and the lower limit setting value are the average value obtained by averaging the collected ammonia nitrogen data. In this embodiment, the start and stop of the blower are controlled according to the upper and lower limits of ammonia nitrogen in the biological treatment tank. When the current ammonia nitrogen concentration is greater than or equal to the upper limit setting value, the blower is started, and the working time of the blower is controlled according to the shortest aeration time. When the current ammonia nitrogen concentration is less than the lower limit setting value, the blower is stopped, and the downtime of the blower is controlled according to the longest downtime. During the operation of the blower, if the rate of decrease of ammonia nitrogen concentration in the biological treatment tank is not consistent or the concentration is not consistent, a control strategy is used to control the air intake valve to control the air intake volume, so that the ammonia nitrogen concentration in each biological treatment tank reaches a balance. The minimum aeration time and maximum shutdown time are set according to actual production needs. These two parameters provide dual protection for the effluent quality, ensuring consistently stable and compliant discharge. The air inlet valves include a main inlet valve and branch inlet valves. Control modes are available in main control mode and branch control mode, selectable based on actual requirements. In main control mode, if the ammonia nitrogen concentration decreases at inconsistent rates or levels in the biological tanks, the main inlet valves of each biological tank will automatically adjust to achieve a uniform ammonia nitrogen concentration decrease rate. In branch control mode, the branch inlet valves on each biological tank are automatically adjusted in conjunction with auxiliary adjustment of the main inlet valve to achieve a uniform ammonia nitrogen concentration decrease rate across all biological tanks. Comparatively, branch control mode offers more precise control.

[0049] Specifically, the methods for adjusting the ammonia nitrogen concentration in each biological tank by controlling the air intake valve and regulating the air intake volume using a control strategy include:

[0050] The current ammonia nitrogen concentration, the target ammonia nitrogen concentration, and the initial ammonia nitrogen concentration are obtained, wherein the initial ammonia nitrogen concentration is the ammonia nitrogen concentration in the biological tank when the blower is turned on;

[0051] Calculate the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, target ammonia nitrogen concentration, and initial ammonia nitrogen concentration;

[0052] The average percentage of ammonia nitrogen remaining is calculated based on the percentage of ammonia nitrogen remaining in each biological tank.

[0053] Obtain airflow data in each biological pool, calculate the proportion of airflow in a single biological pool to the total airflow in all biological pools, and obtain the actual airflow proportion of a single biological pool.

[0054] The percentage of ammonia nitrogen remaining in each biological tank was compared with the average percentage of ammonia nitrogen remaining.

[0055] If the remaining percentage of ammonia nitrogen in the biological tank is greater than the average remaining percentage of ammonia nitrogen, it indicates that the ammonia nitrogen in the biological tank is decreasing slowly. The actual gas volume percentage of the biological tank is increased by a set value to obtain the target gas volume percentage.

[0056] Within a set interval, the actual gas volume ratio of the biological tank is compared with the target gas volume ratio to obtain the comparison result. Based on the comparison result, the opening of the air inlet valve is controlled to achieve ammonia nitrogen balance in each biological tank.

[0057] The formula for calculating the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, target ammonia nitrogen concentration, and initial ammonia nitrogen concentration is as follows:

[0058] Remaining ammonia nitrogen percentage = (Current ammonia nitrogen concentration - Target ammonia nitrogen concentration) × 100 / (Initial ammonia nitrogen concentration - Target ammonia nitrogen concentration).

[0059] Specifically, when the blower is turned on, the initial ammonia nitrogen concentration in each series of biological tanks is recorded. During a waiting period after the blower is turned on (temporarily 20 minutes), the system makes no adjustments. After the waiting period, the percentage of remaining ammonia nitrogen (PCT) is estimated every 15 minutes. The percentage of remaining ammonia nitrogen refers to the ratio of the current ammonia nitrogen concentration to the target ammonia nitrogen concentration. For example: when the blower is turned on, the initial ammonia nitrogen concentration of series 2 is 7, and the target ammonia nitrogen concentration is 3. If at a certain moment the current ammonia nitrogen concentration of series 2 is 6, then:

[0060] The remaining percentage of ammonia nitrogen = (6-3)×100 / (7-3) = 75.

[0061] If its current ammonia nitrogen concentration rises to 8,

[0062] The remaining percentage of ammonia nitrogen = (8-3)×100 / (7-3) = 125.

[0063] The gas flow rate in each biological tank can be measured using the installed gas flow meters. The total gas flow rate is obtained by adding the gas flow rates in each biological tank. The specific calculation method is as follows:

[0064] Total gas volume = Gas volume of #1 + Gas volume of #2 + Gas volume of #3;

[0065] 2# Actual gas volume percentage = 2# gas volume × 100 / total gas volume.

[0066] The average ammonia nitrogen percentage is calculated based on the remaining percentage of ammonia nitrogen in all biological tanks. The remaining percentage of ammonia nitrogen in each biological tank is then compared with the average. If the remaining percentage of ammonia nitrogen in a biological tank is greater than the average, it indicates that the ammonia nitrogen in that biological tank is decreasing at a slower rate. The actual gas volume percentage of that biological tank is then increased by a set value to obtain the target gas volume percentage. Conversely, the actual gas volume percentage of the biological tank is decreased.

[0067] Then, every 2 minutes for 15 minutes, the actual gas volume percentage of each biological tank is compared with the target gas volume percentage. If the actual gas volume percentage is less than the target gas volume percentage, the opening of the air inlet valve is increased; if the actual gas volume percentage is greater than or equal to the target gas volume percentage, the opening of the air inlet valve is decreased, ensuring that the valve opening is within the limits (lower limit tentatively set at 25%, upper limit at 98%). This process continuously brings the residual ammonia nitrogen removal percentage of each biological tank closer to an average, achieving ammonia nitrogen balance in each biological tank.

[0068] In the process of controlling the opening of the air inlet valve to achieve ammonia-nitrogen balance in each biological tank based on the comparison results, the inlet and outlet pressures of the blower are acquired, and the inlet and outlet pressure difference is calculated. This inlet and outlet pressure difference is compared with the blower's differential pressure protection value. When the inlet and outlet pressure difference is greater than or equal to the blower's differential pressure protection value, the valve opening is automatically increased until the inlet and outlet pressure difference falls below the blower's differential pressure protection value or the valve reaches its maximum opening. By setting the blower's differential pressure protection value, the normal operation of the blower can be protected.

[0069] During the decrease of ammonia nitrogen concentration in a biological tank, when it reaches a low level, the current dissolved oxygen content may rise. If the current dissolved oxygen content exceeds a preset value for dissolved oxygen content in the biological tank, the system will automatically control the air inlet valve to reduce its opening, thereby reducing the actual gas volume ratio in the biological tank and preventing the current dissolved oxygen content from rising too high. In this embodiment, the judgment is performed every 15 minutes.

[0070] This invention provides a biological tank aeration control method. The automatic start / stop of the blower utilizes primary control of ammonia nitrogen concentration and secondary control of dissolved oxygen content. The blower's start / stop is automatically controlled based on the upper and lower limits of the ammonia nitrogen concentration in the biological tank. When the blower is running, if the rate of ammonia nitrogen concentration decrease is inconsistent across different biological tanks, or if the current ammonia nitrogen concentrations are inconsistent, the air intake valve is automatically adjusted to control the air intake, thereby ensuring a consistent rate of ammonia nitrogen concentration decrease across all biological tanks. This allows for timely, accurate, and automatic control of biological tank aeration, resulting in more stable production operations and reduced manual workload. By setting dual protection mechanisms for minimum aeration time and maximum shutdown time, the effluent water quality consistently meets discharge standards.

[0071] Example 2

[0072] like Figure 2As shown in another embodiment of the present invention, an aeration control system for a biological tank includes: a data acquisition module, a comparison module, and a blower control module. The data acquisition module acquires the current ammonia nitrogen concentration, current dissolved oxygen content, and user-preset parameters collected from each biological tank. The parameters include an upper limit setting value for ammonia nitrogen, a lower limit setting value for ammonia nitrogen, a minimum aeration time, and a maximum downtime. The comparison module compares the current ammonia nitrogen concentration with the set upper limit setting value and lower limit setting value. The blower control module controls the blower to start when the current ammonia nitrogen concentration is greater than or equal to the upper limit setting value, and controls the blower's operating time according to the minimum aeration time. While the blower is running, it determines whether the rate of decrease in ammonia nitrogen concentration in each biological tank is consistent or whether the concentration levels are consistent. If they are inconsistent, a control strategy is used to control the air intake valve to adjust the air intake volume and regulate the ammonia nitrogen concentration in each biological tank. When the collected ammonia nitrogen concentration is less than the lower limit setting value, it controls the blower to stop, and controls the blower's downtime according to the maximum downtime.

[0073] The blower control module includes a control unit, which acquires the current ammonia nitrogen concentration, the target ammonia nitrogen concentration, and the initial ammonia nitrogen concentration, wherein the initial ammonia nitrogen concentration is the ammonia nitrogen concentration in the biological tank when the blower is turned on;

[0074] Calculate the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, target ammonia nitrogen concentration, and initial ammonia nitrogen concentration;

[0075] The average percentage of ammonia nitrogen remaining is calculated based on the percentage of ammonia nitrogen remaining in each biological tank.

[0076] Obtain airflow data in each biological pool, calculate the proportion of airflow in a single biological pool to the total airflow in all biological pools, and obtain the actual airflow proportion of a single biological pool.

[0077] The percentage of ammonia nitrogen remaining in each biological tank was compared with the average percentage of ammonia nitrogen remaining.

[0078] If the remaining percentage of ammonia nitrogen in the biological tank is greater than the average remaining percentage of ammonia nitrogen, it indicates that the ammonia nitrogen in the biological tank is decreasing slowly. The actual gas volume percentage of the biological tank is increased by a set value to obtain the target gas volume percentage.

[0079] Within a set interval, the actual gas volume ratio of the biological tank is compared with the target gas volume ratio to obtain the comparison result. Based on the comparison result, the opening of the air inlet valve is controlled to achieve ammonia nitrogen balance in each biological tank.

[0080] The comparison results include less than and greater than or equal to. If the comparison result is less than, the opening of the intake valve is increased; if the comparison result is greater than or equal to, the opening of the intake valve is decreased.

[0081] This invention provides an aeration control system for a biological tank. The automatic start / stop of the blower utilizes primary control of ammonia nitrogen concentration and secondary control of dissolved oxygen content. The blower's start and stop are automatically controlled based on the upper and lower limits of ammonia nitrogen concentration in the biological tank. When the blower is running, if the rate of ammonia nitrogen concentration decrease is inconsistent across different biological tanks, or if the current ammonia nitrogen concentrations in different biological tanks are inconsistent, the air intake valve will automatically adjust to control the air intake, thereby ensuring a consistent rate of ammonia nitrogen concentration decrease across all biological tanks. This allows for timely, accurate, and automatic control of aeration in the biological tank, resulting in more stable production operations and reduced manual workload. By setting dual protections for the shortest aeration time and the longest shutdown time, the effluent water quality consistently meets discharge standards.

[0082] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling aeration in a biological tank, characterized in that, include: The system acquires the current ammonia nitrogen concentration, current dissolved oxygen content, and user-preset parameters collected from each biological tank. These parameters include the upper limit setting for ammonia nitrogen, the lower limit setting for ammonia nitrogen, the shortest aeration time, and the longest downtime. Compare the current ammonia nitrogen concentration with the set upper and lower limits for ammonia nitrogen. If the current ammonia nitrogen concentration is greater than or equal to the upper limit setting value of ammonia nitrogen, the blower is started and the working time of the blower is controlled according to the shortest aeration time. When the blower is running, it is determined whether the rate of decrease of ammonia nitrogen concentration in each biological tank is consistent or whether the concentration is consistent. If they are inconsistent, the control strategy is used to control the air intake valve to control the air intake volume and adjust the ammonia nitrogen concentration in each biological tank. The specific method for adjusting the ammonia nitrogen concentration in each biological tank by controlling the air intake valve using a control strategy includes: The current ammonia nitrogen concentration, the target ammonia nitrogen concentration, and the initial ammonia nitrogen concentration are obtained, wherein the initial ammonia nitrogen concentration is the ammonia nitrogen concentration in the biological tank when the blower is turned on; Calculate the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, target ammonia nitrogen concentration, and initial ammonia nitrogen concentration; The formula for calculating the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, the target ammonia nitrogen concentration, and the initial ammonia nitrogen concentration is as follows: Remaining ammonia nitrogen percentage = (Current ammonia nitrogen concentration - Target ammonia nitrogen concentration) × 100 / (Initial ammonia nitrogen concentration - Target ammonia nitrogen concentration); The average percentage of ammonia nitrogen remaining is calculated based on the percentage of ammonia nitrogen remaining in each biological tank. Obtain airflow data in each biological pool, calculate the proportion of airflow in a single biological pool to the total airflow in all biological pools, and obtain the actual airflow proportion of a single biological pool. The percentage of ammonia nitrogen remaining in each biological tank was compared with the average percentage of ammonia nitrogen remaining. If the remaining percentage of ammonia nitrogen in the biological tank is greater than the average remaining percentage of ammonia nitrogen, it indicates that the ammonia nitrogen in the biological tank is decreasing slowly. The actual gas volume percentage of the biological tank is increased by a set value to obtain the target gas volume percentage. Within a set interval, the actual gas volume ratio of the biological tank is compared with the target gas volume ratio to obtain the comparison result. Based on the comparison result, the opening of the air inlet valve is controlled to achieve ammonia nitrogen balance in each biological tank. If the current ammonia nitrogen concentration is less than the lower limit set value, the blower is controlled to stop, and the blower shutdown time is controlled according to the longest shutdown time.

2. The aeration control method for a biological tank according to claim 1, characterized in that, The comparison result includes less than and greater than or equal to. If the comparison result is less than, the opening of the intake valve is increased; if the comparison result is greater than or equal to, the opening of the intake valve is decreased.

3. The aeration control method for a biological tank according to claim 1, characterized in that, The parameters also include the blower differential pressure protection value. In the process of controlling the opening of the air inlet valve to achieve ammonia nitrogen balance in each biological tank according to the comparison results, the inlet and outlet pressures of the blower are obtained, and the inlet and outlet pressure difference is calculated. The inlet and outlet pressure difference is compared with the blower differential pressure protection value. When the inlet and outlet pressure difference is greater than or equal to the blower differential pressure protection value, the valve opening is automatically increased until the inlet and outlet pressure difference is lower than the blower differential pressure protection value or the valve reaches the maximum opening.

4. The aeration control method for a biological tank according to claim 1, characterized in that, Also includes: During the process of ammonia nitrogen concentration decreasing in a certain biological tank, when the current dissolved oxygen content is greater than the preset value of dissolved oxygen content in the biological tank, the air intake valve is controlled to reduce its opening.

5. The aeration control method for a biological tank according to any one of claims 1-4, characterized in that, The intake valve includes a main intake valve and branch intake valves.

6. A biological tank aeration control system, characterized in that, include: Data acquisition module, comparison module, and fan control module; The data acquisition module acquires the current ammonia nitrogen concentration, current dissolved oxygen content, and user-preset parameters collected from each biological tank. The parameters include the upper limit setting value for ammonia nitrogen, the lower limit setting value for ammonia nitrogen, the shortest aeration time, and the longest downtime. The comparison module is used to compare the current ammonia nitrogen concentration with the set upper limit and lower limit values ​​for ammonia nitrogen. The blower control module is used to start the blower when the current ammonia nitrogen concentration is greater than or equal to the upper limit set value, and to control the working time of the blower according to the shortest aeration time. When the blower is running, it determines whether the rate of decrease of ammonia nitrogen concentration in each biological tank is consistent or whether the concentration is consistent. If they are inconsistent, a control strategy is used to control the air intake valve to control the air intake volume and adjust the ammonia nitrogen concentration in each biological tank. When the current ammonia nitrogen concentration is less than the lower limit set value, the blower is controlled to stop, and the blower shutdown time is controlled according to the longest shutdown time. The blower control module includes a control unit, which acquires the current ammonia nitrogen concentration, the target ammonia nitrogen concentration, and the initial ammonia nitrogen concentration, wherein the initial ammonia nitrogen concentration is the ammonia nitrogen concentration of the biological tank when the blower is turned on. Calculate the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, target ammonia nitrogen concentration, and initial ammonia nitrogen concentration; The formula for calculating the remaining percentage of ammonia nitrogen in each biological tank based on the current ammonia nitrogen concentration, the target ammonia nitrogen concentration, and the initial ammonia nitrogen concentration is as follows: Remaining ammonia nitrogen percentage = (Current ammonia nitrogen concentration - Target ammonia nitrogen concentration) × 100 / (Initial ammonia nitrogen concentration - Target ammonia nitrogen concentration); Calculate the average ammonia nitrogen remaining percentage based on the ammonia nitrogen remaining percentage of each biological tank; obtain the air flow data in each biological tank, calculate the proportion of air flow in a single biological tank to the total air flow of all biological tanks, and obtain the actual air volume proportion of a single biological tank. The percentage of ammonia nitrogen remaining in each biological tank was compared with the average percentage of ammonia nitrogen remaining. If the remaining percentage of ammonia nitrogen in the biological tank is greater than the average remaining percentage of ammonia nitrogen, it indicates that the ammonia nitrogen in the biological tank is decreasing slowly. The actual gas volume percentage of the biological tank is increased by a set value to obtain the target gas volume percentage. Within a set interval, the actual gas volume ratio of the biological tank is compared with the target gas volume ratio to obtain the comparison result. Based on the comparison result, the opening of the air inlet valve is controlled to achieve ammonia nitrogen balance in each biological tank.

7. The biological tank aeration control system according to claim 6, characterized in that, The comparison results include less than and greater than or equal to. If the comparison result is less than, the opening of the intake valve is increased; if the comparison result is greater than or equal to, the opening of the intake valve is decreased.

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