Energy-saving control method for cold standby operation of part corridor of MBR process of sewage treatment plant

Abstract

This invention discloses an energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant, relating to the field of wastewater treatment. The method includes: real-time monitoring of operating parameters of all operating sections in the MBR process system of the wastewater treatment plant; screening out sections that can be switched to cold standby operation without affecting the overall treatment effect based on the monitoring results; pre-treating the membrane modules in the screened cold standby sections to remove some contaminants attached to the membrane surface, and simultaneously adjusting the water flow state in the sections to match the initial state of cold standby. This invention ensures that the overall treatment effect of the system is not affected by real-time monitoring and screening of suitable sections for cold standby, accurately matching process requirements. Simultaneously, the pre-treatment of membrane modules and adjustment of water flow state can reduce contaminant adhesion to the membrane surface, protect membrane module performance, extend their service life, and achieve a smooth switchover through gradual adjustment of equipment operating status, avoiding the impact of sudden parameter changes on the system.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an energy-saving control method for cold standby operation of the MBR process corridor in a wastewater treatment plant. Background Technology

[0002] Cold standby operation of some MBR process corridors in wastewater treatment plants refers to suspending influent and aeration in some MBR corridors, maintaining only basic protection. This mode allows for flexible adjustment of treatment capacity based on influent load, reducing energy consumption and operation and maintenance costs, while ensuring that the backup corridors can be restarted at any time, improving the system's operational flexibility and stability.

[0003] Patent application No. 202011272457.X discloses a wastewater treatment control method based on MBR technology. The method includes: determining the number of MBR membranes operating in parallel based on a preset MBR unit-time treatment requirement and the unit-time treatment capacity of a single MBR membrane; setting up multiple MBR basic membrane groups in the MBR tank according to a specified on / off ratio of the MBR membranes and the number of parallel membranes, wherein the total unit-time treatment capacity of the multiple MBR basic membrane groups is greater than the MBR unit-time treatment requirement; controlling the multiple MBR basic membrane groups to take turns entering a pause period, and setting up additional MBR membrane groups in the MBR tank to replace the paused MBR basic membrane groups to perform MBR treatment; wherein, the method based on the specified on / off ratio of the MBR membranes... The method involves setting up multiple MBR basic membrane groups, including: rounding down the specified on / off time ratio of the MBR membranes to obtain an integer m, which is then used as the number of MBR basic membrane groups; dividing the number of parallel operations by the integer m to obtain the number of MBR membranes in each MBR basic membrane group. This application aims to solve the problem that "according to process control requirements, MBR membranes need to enter a certain pause period after continuous operation before they can start working again. Correspondingly, in order to cooperate with the above-mentioned on / off conditions of the MBR membranes, it is necessary to synchronously control the permeate pump of the MBR tank, the primary booster pump of the MBR permeate tank, and the secondary booster pump of the security filter according to the on / off status of the MBR membranes. Thus, the repeated on / off operation of multiple pumps will significantly reduce the service life of the pumps and result in significant energy consumption."

[0004] However, in the current scenario of cold standby operation control of the MBR process in wastewater treatment plants, the cold standby operation control of the corridor is only controlled by the decision-making of its associated basic parameters or is completely handed over to manual control. Its level of intelligence is low, and it is difficult to achieve good energy-saving goals through corridor cold standby.

[0005] Therefore, we propose an energy-saving control method for the cold standby operation of the MBR process corridor in a wastewater treatment plant. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the existing technology, the present invention provides an energy-saving control method for cold standby operation of the MBR process corridor in a wastewater treatment plant, which can effectively solve the problems of the existing technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions;

[0008] This invention discloses an energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant, comprising:

[0009] Real-time monitoring of operating parameters is conducted on all operating corridors in the wastewater treatment plant's MBR process system. Based on the monitoring results, corridors suitable for cold standby operation without affecting the overall treatment effect are selected. Membrane modules in the selected cold standby corridors undergo pretreatment to remove some contaminants adhering to the membrane surface, while the water flow within the corridors is adjusted to match the initial state for cold standby. Based on the wastewater treatment plant's MBR process system's water quality compliance requirements, treatment load demands, and the membrane module type and corridor volume characteristics of the cold standby corridors, key operating parameters are set for the corridors in cold standby mode, and these parameters are fed back to the control terminal of the wastewater treatment plant's MBR process system. Based on the cold standby operating parameters received by the control terminal, the system is gradually... The system adjusts the operating status of the influent, effluent, and aeration equipment in the standby corridor to smoothly switch it to standby operation mode. Continuous dynamic monitoring is performed on the corridor in standby mode. When operating parameters deviate from the set range or the overall requirements of the wastewater treatment plant's MBR process system change, the standby operating parameters are adjusted and fed back to the control terminal to maintain stable standby status. When it is necessary to put the standby corridor back into normal operation, recovery operating parameters are set according to the overall operating status of the wastewater treatment plant's MBR process system and sent to the control terminal. Combined with a pre-set recovery procedure, the operating parameters of the standby corridor and the status of the influent, effluent, and aeration equipment are gradually adjusted to smoothly restore the standby corridor to normal operation.

[0010] Furthermore, when selecting corridors that can be switched to cold standby operation without affecting the overall processing effect based on monitoring results, the following conditions must be met:

[0011] Based on preset sensors, the membrane flux, transmembrane pressure difference, mixed liquor suspended solids concentration, effluent chemical oxygen demand, and channel treatment load rate of each operating channel are monitored to assess the cold standby adaptability of each channel.

[0012]

[0013] In the formula: S represents the corridor cold standby adaptability; α, β, γ, δ, and ε are weighting coefficients; J max ΔP represents the design maximum membrane flux of the membrane module; J represents the sensed membrane flux; ΔP maxΔP is the maximum permissible transmembrane pressure difference for the membrane module; ΔP is the sensed transmembrane pressure difference; MLSS max MLSS represents the design upper limit for the concentration of mixed liquor suspended solids within the corridor; COD represents the sensed concentration of mixed liquor suspended solids. in Chemical oxygen demand (COD) of the influent to the corridor; out η is the perceived chemical oxygen demand (COD) of the effluent; η is the perceived corridor treatment load rate.

[0014] The sum of α, β, γ, δ, and ε is 1, and all of them are positive numbers;

[0015] After calculating S for each corridor, a cold standby adaptability threshold is set. All corridors with values ​​greater than the cold standby adaptability threshold are filtered out, and corridors that meet the following conditions are designated as cold standby corridors that can be switched to cold standby operation:

[0016] After the corridor stops operating, the total processing load rate of the remaining corridors in the system will still not exceed 90% of the designed total processing load rate;

[0017] If none of the corridors with a cold standby adaptability threshold meet the above conditions, it means that there are no cold standby corridors that can be switched to cold standby operation.

[0018] Furthermore, the pretreatment process for the selected membrane modules in the cooling preparation corridor is as follows:

[0019] The membrane module is backwashed using a pulse backwashing method. The backwash water is the effluent from the channel. The backwash pressure is controlled in the following sequence: initial pressure, gradient pressure increase, stable pressure, and gradient pressure decrease.

[0020] After backwashing, a protective solution containing corrosion inhibitors and humectants of a preset concentration is introduced into the corridor, and the residence time of the protective solution in the corridor is not less than the shortest immersion time calculated based on the effective wetted area of ​​the membrane module.

[0021] Subsequently, the operating power and stirring direction of the stirring equipment in the corridor are adjusted so that the protective solution forms a low-speed circulating flow along the surface of the membrane module in the corridor, and the circulation flow rate is controlled within a preset range.

[0022] Furthermore, the setting phase of key operating parameters within the corridor under the cold standby state conforms to:

[0023] The minimum water quality assurance indicators for the effluent end of the cold standby corridor are set according to the water quality compliance requirements of the MBR process system of the wastewater treatment plant, including: effluent suspended solids concentration and effluent ammonia nitrogen concentration.

[0024] Calculate the maximum permissible outage load percentage for the standby cold storage corridor.

[0025] Q total Qremain These represent the total designed water treatment capacity of the MBR process system in the wastewater treatment plant and the total water treatment capacity of the remaining operating corridor under full load conditions, respectively.

[0026] The minimum maintenance parameters for the membrane modules in the cold standby state are set according to the membrane module type of the cold standby corridor, and the minimum retention volume V of the protective solution in the corridor in the cold standby state is calculated based on the corridor volume characteristics. min =σ×(V corridor ×a+S membrane ×b), σ represents the safety factor, V corridor S represents the effective volume of the corridor, 'a' represents the volume coverage coefficient, and S represents the effective volume of the corridor. membrane denoted by , b represents the total surface area of ​​the membrane module within the corridor, and b represents the minimum solution immersion volume required per unit membrane area. These are ultimately integrated to form a set of key operating parameters in the cold standby state. The set of key operating parameters includes the protective solution replacement cycle, membrane surface protection pressure, solution level within the corridor, and water quality monitoring frequency at the outlet.

[0027] Furthermore, the control operation that smoothly switches the cold standby corridor to cold standby operation mode is as follows:

[0028] The water inlet volume of the standby corridor is gradually reduced according to the preset water inlet adjustment gradient. After each reduction in water inlet volume, the water inlet volume is maintained for a preset duration until the water inlet volume drops to the preset water inlet flow rate corresponding to the standby state.

[0029] While adjusting the inflow rate, gradually reduce the outflow rate in a gradient synchronized with the inflow rate adjustment to ensure that the liquid level in the corridor is maintained within the preset fluctuation range. When the inflow rate stabilizes at the preset inflow rate, adjust the outflow rate to the cold standby outflow rate that matches the preset inflow rate.

[0030] Based on the aeration control requirements in the cold standby operation parameters, the aeration intensity of the aeration equipment is gradually reduced according to the preset aeration intensity adjustment gradient. After each adjustment of the aeration intensity, the dissolved oxygen concentration in the corridor is monitored. When the dissolved oxygen concentration in the corridor stabilizes within the preset dissolved oxygen range corresponding to the cold standby state, the aeration intensity adjustment is stopped to complete the switch to the cold standby operation mode.

[0031] Furthermore, when the operating parameters of the cold standby corridor deviate from the set range or the overall demand of the wastewater treatment plant's MBR process system changes, the operation of adjusting the cold standby operating parameters and feeding them back to the control terminal is as follows:

[0032] Determine the deviation evaluation index of the cold standby corridor operation status.

[0033] In the formula: n is the number of key parameters that need to be monitored in cold standby mode; X k X is the real-time monitoring value of the k-th parameter; k-setω is the set value for the k-th parameter; k The deviation weight coefficient for the k-th parameter;

[0034] A deviation threshold is set. If the real-time calculated D exceeds the deviation threshold, the parameter is determined to deviate from the set range. Based on the type and degree of deviation of the parameter, a corresponding cold standby operation parameter adjustment plan is generated. The adjustment range of the parameter in the adjustment plan is positively correlated with the D value.

[0035] When a change in overall system requirements is detected:

[0036] Changes in water demand: Calculate the difference between the total water demand processed by the system after the change and the current remaining processing capacity of the operating corridors. If the difference is greater than or equal to zero, calculate the maximum allowable recovery ratio of the cold standby corridors. m represents the total number of cold standby corridors, and ΔQ represents the difference between the total water treatment capacity of the system after the change and the treatment capacity of the currently remaining operating corridors. i-rated This represents the rated processing capacity of the i-th cold standby corridor. The influent flow rate of the cold standby corridor is then adjusted based on the κ value. If ΔQ < 0, the number of new cold standby corridors and the corresponding cold standby parameter baseline values ​​are reassessed.

[0037] Changes in effluent water quality standards: Based on the changes in the limits for total nitrogen, total phosphorus, and turbidity in the new standards, the monitoring thresholds for the effluent outlet of the cold standby corridor will be reset, and the pH value, reagent concentration, and solution replacement cycle benchmark value of the protective solution will be adjusted accordingly.

[0038] Compare the current operating parameters with the recalculated baseline values, and calculate the parameter adjustment amount ΔX. k =X k-new -X k-current X k-new X represents the new baseline value. k-current This represents the current parameter value, based on ΔX. k The absolute value of the parameter is used to generate parameter adjustment instructions in stages. The instructions include the adjustment direction, step size, and the required stabilization time after each adjustment, and are fed back to the control terminal for execution.

[0039] Furthermore, when it is necessary to put the cold standby corridor back into normal operation, the restoration operation parameters should be set according to the overall operating status of the wastewater treatment plant's MBR process system, and should comply with the following:

[0040] Collect overall system operation parameters, including: current processing load of remaining operating corridors, total system influent flow, system effluent water quality compliance rate, and historical recovery data of membrane modules;

[0041] Prioritize the restoration of cold standby corridors.

[0042] In the formula: λ1, λ2, λ3, and λ4 are weighting coefficients; ηremain Q represents the current processing load of the remaining operational corridors. in-total Q represents the total influent flow rate of the system. process The actual water volume processed by the system at present; γ reach The system's effluent water quality compliance rate; t cold The cold standby corridor has been in cold standby mode for a certain period of time; t cold-max This is the longest cold standby time allowed for this type of corridor;

[0043] Finally, the recovery order is determined by sorting the P values ​​of each cold standby corridor from largest to smallest. At the same time, based on the overall system operation parameters, target parameters for each stage of the recovery process are set, including the influent flow rate, aeration intensity, and membrane flux recovery rate in the initial recovery stage, forming a complete set of recovery operation parameters.

[0044] Among them, λ1, λ2, λ3, and λ4 are all positive numbers, and their sum is 1.

[0045] Furthermore, the recovery procedure includes:

[0046] The first stage of the recovery process: drain the protective solution in the corridor, with the draining rate controlled within the preset low-speed range. At the same time, start the membrane module preheating program, using a preheating liquid with the same temperature as the water during normal operation to circulate and preheat the membrane module, and the preheating time is not less than the shortest time required for the membrane module temperature to stabilize.

[0047] The second stage of the recovery process: The feed rate is gradually increased according to the preset feed rate recovery gradient. After each increase in feed rate, the flow rate is maintained for a preset duration, and the membrane flux and transmembrane pressure difference are monitored simultaneously to ensure that the rate of change of both does not exceed the preset safe change range.

[0048] The third stage of the recovery process: When the influent flow rate is increased to 80% of the normal operating influent flow rate, the aeration intensity is gradually increased to the normal operating aeration intensity, and the effluent flow rate is adjusted to the normal operating effluent flow rate that matches the influent flow rate; when the membrane flux, transmembrane pressure difference, and effluent water quality are all stable within the normal operating parameter range and continue for the preset time, it is determined that the cold standby corridor has been smoothly restored to normal operating status.

[0049] Furthermore, during the operation of the cold standby corridor, its energy-saving benefits are simultaneously evaluated:

[0050] Real-time data collection of energy consumption from agitation equipment, solution replacement, and monitoring equipment during cold standby operation of the cold standby corridor; calculation of total energy consumption E during cold standby operation. cold =E mix +E change +E mon +E other E other This indicates the energy consumption of other auxiliary equipment during cold standby operation, which is manually entered by the user.

[0051] Calculate the theoretical energy consumption E of the corridor if it maintains normal operation. normal =E avg ×T×K,E avg This represents the historical energy consumption data of the corridor during normal operation over the past three complete operating cycles. The average total energy consumption per unit time under normal operating conditions is calculated. T represents the actual cold standby operating time of the corridor this time, and K represents the energy consumption correction factor.

[0052] The energy saving rate of the corridor during cold standby operation is:

[0053] Compared with the known prior art, the technical solution provided by this invention has the following beneficial effects:

[0054] This invention provides an energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant. During execution, this method uses real-time monitoring to select suitable sections for cold standby, ensuring the overall system treatment effect remains unaffected. It accurately matches process requirements and adjusts membrane module pretreatment and water flow conditions to reduce contaminant adhesion to the membrane surface, protect membrane module performance, and extend its service life. A gradual adjustment of equipment operating status achieves a smooth switchover, avoiding sudden parameter changes that could impact the system. Continuous dynamic monitoring and flexible adjustment of cold standby parameters ensure stable cold standby status and adaptability to system demand changes. Furthermore, recovery parameters and procedures are set according to the overall situation to ensure a smooth return to normal operation of the section, reducing recovery risks. Real-time assessment of energy-saving benefits is conducted, reducing equipment energy consumption through cold standby and comparing it with normal operating energy consumption to obtain the energy saving rate. Under the premise of ensuring wastewater treatment meets standards, this method effectively improves the economy and stability of process operation and reduces resource waste. Attached Figure Description

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

[0056] Figure 1 This is a schematic diagram of an energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant. Detailed Implementation

[0057] 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, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0058] The present invention will be further described below with reference to embodiments.

[0059] Example:

[0060] This embodiment presents an energy-saving control method for the cold standby operation of a section of the MBR process in a wastewater treatment plant, such as... Figure 1 As shown, it includes:

[0061] Real-time monitoring of operating parameters of all operating corridors in the MBR process system of the wastewater treatment plant is conducted, and corridors that can be switched to cold standby operation without affecting the overall treatment effect are selected based on the monitoring results.

[0062] When selecting corridors that can be switched to cold standby operation without affecting the overall processing effect based on monitoring results, the following criteria must be met:

[0063] Based on preset sensors, the membrane flux, transmembrane pressure difference, mixed liquor suspended solids concentration, effluent chemical oxygen demand, and channel treatment load rate of each operating channel are monitored to assess the cold standby adaptability of each channel.

[0064]

[0065] In the formula: S represents the corridor cold standby adaptability; α, β, γ, δ, and ε are weighting coefficients; J max ΔP represents the design maximum membrane flux of the membrane module; J represents the sensed membrane flux; ΔP max ΔP is the maximum permissible transmembrane pressure difference for the membrane module; ΔP is the sensed transmembrane pressure difference; MLSS max MLSS represents the design upper limit for the concentration of mixed liquor suspended solids within the corridor; COD represents the sensed concentration of mixed liquor suspended solids. in Chemical oxygen demand (COD) of the influent to the corridor; out η is the perceived chemical oxygen demand (COD) of the effluent; η is the perceived corridor treatment load rate.

[0066] The above formula integrates five core operating parameters: membrane flux, transmembrane pressure difference, mixed liquor suspended solids concentration, COD removal rate, and treatment load rate. It also introduces weighting coefficients to achieve scientific quantification of multi-dimensional indicators. Furthermore, it combines the constraint that the total treatment load rate of the remaining corridors in the system does not exceed 90% of the design value. This ensures that the selected corridors have the potential for cold standby while avoiding insufficient overall treatment capacity after cold standby, thus achieving a balance between the accuracy of cold standby corridor selection and system stability.

[0067] The sum of α, β, γ, δ, and ε is 1, and all are positive numbers. They follow the following rules: the larger the difference between the actual membrane flux and the maximum designed membrane flux of the membrane module, the larger the value of α, and vice versa; the same applies to β and γ. The higher the actual COD removal rate of the corridor, the larger the value of δ, and vice versa; the lower the actual treatment load rate of the corridor, the larger the value of ε, and vice versa.

[0068] After calculating S for each corridor, a cold standby adaptability threshold is set. All corridors with values ​​greater than the cold standby adaptability threshold are filtered out, and corridors that meet the following conditions are designated as cold standby corridors that can be switched to cold standby operation:

[0069] After the corridor stops operating, the total processing load rate of the remaining corridors in the system will still not exceed 90% of the designed total processing load rate;

[0070] If none of the corridors with a cold standby adaptability threshold meet the above conditions, it means that there are no cold standby corridors that can be switched to cold standby operation.

[0071] The membrane modules in the selected cold standby corridor are pretreated to remove some of the contaminants attached to the membrane surface, and the water flow in the corridor is adjusted to match the initial state of cold standby.

[0072] The pretreatment process for the membrane modules selected for cooling in the pre-cooling corridor is as follows:

[0073] The membrane module is backwashed using a pulse backwashing method. The backwash water is the effluent from the channel. The backwash pressure is controlled in the following sequence: initial pressure, gradient pressure increase, stable pressure, and gradient pressure decrease. The gradient pressure increase rate and gradient pressure decrease rate are both controlled within the ratio of the maximum allowable pressure fluctuation value specified by the membrane module manufacturer to the preset time interval. The preset time interval is determined based on the fatigue life test data of the membrane module material, so that the single pressure change is within the instantaneous pressure fluctuation threshold that the membrane module can withstand.

[0074] After backwashing, a protective solution containing corrosion inhibitors and humectants of a preset concentration is introduced into the corridor. The pH value of the protective solution is limited to the neutral to weakly alkaline range that is compatible with the membrane module material, the ion concentration is lower than the risk threshold of micropore blockage of the membrane module, and the residence time of the protective solution in the corridor is not less than the shortest immersion time calculated based on the effective wetted area of ​​the membrane module.

[0075] Subsequently, the operating power and stirring direction of the stirring equipment in the corridor were adjusted so that the protective solution formed a low-speed circulating flow along the surface of the membrane module in the corridor. The circulating flow rate was controlled within a preset range, which was determined through previous tests. It was necessary to simultaneously meet the dual requirements of avoiding the redeposition of pollutants that had been loosened on the membrane surface and reducing the energy consumption of the stirring equipment, thereby completing the adjustment of the water flow state in the corridor to the initial state of cold standby.

[0076] Based on the water quality compliance requirements and treatment load demand of the wastewater treatment plant's MBR process system, as well as the membrane module type and volume characteristics of the standby corridor, key operating parameters in the corridor under standby conditions are set, and the set parameters are fed back to the control terminal of the wastewater treatment plant's MBR process system.

[0077] During the setting phase of key operating parameters within the corridor in cold standby mode, the following shall apply:

[0078] The minimum water quality assurance indicators for the effluent end of the cold standby corridor are set according to the water quality compliance requirements of the MBR process system of the wastewater treatment plant, including: effluent suspended solids concentration and effluent ammonia nitrogen concentration.

[0079] Calculate the maximum permissible outage load percentage for the standby cold storage corridor.

[0080] Q total Q remain These represent the total designed water treatment capacity of the MBR process system in the wastewater treatment plant and the total water treatment capacity of the remaining operating corridor under full load conditions, respectively.

[0081] The minimum maintenance parameters for the membrane modules in the cold standby state are set according to the membrane module type of the cold standby corridor, and the minimum retention volume V of the protective solution in the corridor in the cold standby state is calculated based on the corridor volume characteristics. min =σ×(V corridor ×a+S membrane ×b), σ represents the safety factor, V corridor S represents the effective volume of the corridor, 'a' represents the volume coverage coefficient, and S represents the effective volume of the corridor. membrane 'b' represents the total surface area of ​​the membrane module in the corridor, and 'b' represents the minimum solution immersion volume required per unit membrane area. These are ultimately integrated to form a set of key operating parameters in the cold standby state. The set of key operating parameters includes the protective solution replacement cycle, membrane surface protection pressure, solution level in the corridor, and water quality monitoring frequency at the outlet.

[0082] For the calculation of minimum stock, this formula comprehensively considers the effective volume of the corridor, the volume coverage factor, the total surface area of ​​the membrane module, the minimum solution wetting volume per unit membrane area, and the safety factor. The volume coverage factor is dynamically adjusted according to the complexity of the bottom structure of the corridor, the risk of pollutant residue, and the solution evaporation rate. The minimum solution wetting volume per unit membrane area is determined in combination with the membrane module material, pore size, and experimentally verified wetting characteristics. The safety factor is flexibly changed with the solution evaporation rate and the degree of irregularity of the membrane module shape. Through multi-parameter collaborative calculation, it ensures that the protective solution can completely wet the surface of the membrane module to achieve the protective effect, while avoiding resource waste and increased energy consumption caused by excessive solution. At the same time, it addresses potential risks such as solution evaporation and membrane module shape differences, ensuring the stable performance of the membrane module during cold standby.

[0083] The minimum maintenance parameters include membrane surface protection pressure, minimum solution replacement cycle, and solution level in the corridor based on V. min The calculated safety factor σ≥1 increases with the evaporation rate of the protective solution and the irregularity of the membrane module shape, and decreases with the decrease of the evaporation rate of the protective solution and the regularity of the membrane module shape; the volume coverage factor a∈[0.3~0.7] increases when the bottom structure of the corridor is complex, the risk of bottom pollutant residue is high, or the evaporation rate is fast during the liquid accumulation period, and decreases when the bottom structure of the corridor is simple, the risk of bottom pollutant residue is low, or the evaporation rate is slow during the liquid accumulation period; the minimum solution wetting volume b required per unit membrane area is determined based on the material, pore size, and membrane fiber arrangement density of the membrane module to be cooled and prepared, combined with the wetting characteristic data of this type of membrane module verified by experiments, and must match the requirement of full surface wetting of the membrane module without dead corners;

[0084] Based on the cold standby operation parameters received by the control terminal, the operation status of the water inlet, water outlet and aeration equipment of the cold standby corridor is gradually adjusted so that the cold standby corridor can be smoothly switched to the cold standby operation mode.

[0085] The control operation to smoothly switch the cold standby corridor to cold standby operation mode is as follows:

[0086] The water inlet volume of the standby corridor is gradually reduced according to the preset water inlet adjustment gradient. After each reduction in water inlet volume, the water inlet volume is maintained for a preset duration until the water inlet volume drops to the preset water inlet flow rate corresponding to the standby state.

[0087] While adjusting the inflow rate, gradually reduce the outflow rate in a gradient synchronized with the inflow rate adjustment to ensure that the liquid level in the corridor is maintained within the preset fluctuation range. When the inflow rate stabilizes at the preset inflow rate, adjust the outflow rate to the cold standby outflow rate that matches the preset inflow rate.

[0088] Based on the aeration control requirements in the cold standby operation parameters, the aeration intensity of the aeration equipment is gradually reduced according to the preset aeration intensity adjustment gradient. After each adjustment of the aeration intensity, the dissolved oxygen concentration in the corridor is monitored. When the dissolved oxygen concentration in the corridor stabilizes within the preset dissolved oxygen range corresponding to the cold standby state, the aeration intensity adjustment is stopped to complete the cold standby operation mode switch.

[0089] Continuous dynamic monitoring is carried out on the corridors in cold standby operation. When the operating parameters are detected to deviate from the set range or the overall demand of the sewage treatment plant MBR process system changes, the cold standby operating parameters are adjusted and fed back to the control terminal to maintain the stability of the cold standby status.

[0090] When the operating parameters of the cold standby corridor deviate from the set range or the overall requirements of the wastewater treatment plant's MBR process system change, the operation of adjusting the cold standby operating parameters and feeding them back to the control terminal is as follows:

[0091] Determine the deviation evaluation index of the cold standby corridor operation status.

[0092] In the formula: n is the number of key parameters that need to be monitored in cold standby mode; X k X is the real-time monitoring value of the k-th parameter; k-set ω is the set value for the k-th parameter; k The deviation weight coefficient for the k-th parameter;

[0093] The above formula calculates the deviation between the real-time values ​​and set values ​​of each key monitoring parameter and assigns corresponding deviation weight coefficients to different parameters, thereby achieving a comprehensive quantitative assessment of the cold standby corridor's operating status. Its design logic focuses on the core control objectives during the cold standby process, and highlights the impact of key parameters through weight allocation. When the deviation exceeds the threshold, abnormal parameters and their impact can be quickly identified, providing a precise basis for the formulation of subsequent parameter adjustment plans, avoiding the limitations of single parameter monitoring, and ensuring that the cold standby status is always within a controllable range.

[0094] A deviation threshold is set. If the real-time calculated D exceeds the deviation threshold, the parameter is determined to deviate from the set range. Based on the type and degree of deviation of the parameter, a corresponding cold standby operation parameter adjustment plan is generated. The adjustment range of the parameter in the adjustment plan is positively correlated with the D value.

[0095] When a change in overall system requirements is detected:

[0096] Changes in water demand: Calculate the difference between the total water demand processed by the system after the change and the current remaining processing capacity of the operating corridors. If the difference is greater than or equal to zero, calculate the maximum allowable recovery ratio of the cold standby corridors. m represents the total number of cold standby corridors, and ΔQ represents the difference between the total water treatment capacity of the system after the change and the treatment capacity of the currently remaining operating corridors. i-ratedThis represents the rated processing capacity of the i-th cold standby corridor. The influent flow rate of the cold standby corridor is then adjusted based on the κ value. If ΔQ < 0, the number of new cold standby corridors and the corresponding cold standby parameter baseline values ​​are reassessed.

[0097] Changes in effluent water quality standards: Based on the changes in the limits for total nitrogen, total phosphorus, and turbidity in the new standards, the monitoring thresholds for the effluent outlet of the cold standby corridor will be reset, and the pH value, reagent concentration, and solution replacement cycle benchmark value of the protective solution will be adjusted accordingly.

[0098] Compare the current operating parameters with the recalculated baseline values, and calculate the parameter adjustment amount ΔX. k =X k-new -X k-current X k-new X represents the new baseline value. k-current This represents the current parameter value, based on ΔX. k The absolute value of the parameter is used to generate parameter adjustment instructions in stages. The instructions include the adjustment direction, step size, and the required stabilization time after each adjustment step, and are fed back to the control terminal for execution.

[0099] Wherein, the deviation weight coefficient ω of the kth parameter k The value follows Furthermore, the value of this parameter is determined based on its impact on the operational stability of the cold standby corridor, the performance protection of the membrane module, and the subsequent restoration to normal operation. The parameter with the greater impact on these objectives has a higher ω value. k The larger the value, the smaller the value. Changes in overall system requirements include changes in water treatment volume requirements and changes in effluent water quality standards.

[0100] When it is necessary to put the cold standby corridor back into normal operation, the restoration operation parameters are set according to the overall operation status of the sewage treatment plant's MBR process system and sent to the control terminal. The operation parameters of the cold standby corridor and the status of the influent, effluent and aeration equipment are gradually adjusted in conjunction with the preset restoration program so that the cold standby corridor can be smoothly restored to normal operation.

[0101] When it is necessary to put the cold standby corridor back into normal operation, the restoration operation parameters should be set according to the overall operating status of the wastewater treatment plant's MBR process system, and should comply with the following:

[0102] Collect overall system operation parameters, including: current processing load of remaining operating corridors, total system influent flow, system effluent water quality compliance rate, and historical recovery data of membrane modules;

[0103] Prioritize the restoration of cold standby corridors.

[0104] In the formula: λ1, λ2, λ3, and λ4 are weighting coefficients; η remain Q represents the current processing load of the remaining operational corridors.in-total Q represents the total influent flow rate of the system. process The actual water volume processed by the system at present; γ reach The system's effluent water quality compliance rate; t cold The cold standby corridor has been in cold standby mode for a certain period of time; t cold-max This is the longest cold standby time allowed for this type of corridor;

[0105] The above formula integrates four key factors: the remaining operating corridor treatment load, the difference between the total system influent flow and the actual treated water volume, the system effluent water quality compliance rate, and the cold standby corridor's cold standby time. The weight coefficients of each factor are dynamically set according to their impact on system operation. Through the weighted calculation of multi-dimensional indicators, the recovery order of cold standby corridors is quantitatively sorted to ensure that the corridors most critical to alleviating system operating pressure and improving treatment efficiency are restored first, avoiding blind recovery order and optimizing the overall system operating efficiency.

[0106] Finally, the recovery order is determined by sorting the P values ​​of each cold standby corridor from largest to smallest. At the same time, based on the overall system operation parameters, target parameters for each stage of the recovery process are set, including the influent flow rate, aeration intensity, and membrane flux recovery rate in the initial recovery stage, forming a complete set of recovery operation parameters.

[0107] Among them, λ1, λ2, λ3, and λ4 are all positive numbers, and their sum is 1. λ1 is larger when the current processing load of the remaining operating corridor is closer to the full load, and smaller when it is closer to the full load. λ2 is larger when the difference between the total influent flow rate and the current actual processing flow rate is larger, and smaller when it is smaller. λ3 is larger when the effluent quality compliance rate of the system is lower, and smaller when it is higher. λ4 is larger when the cold standby corridor is close to its maximum allowable cold standby time, and smaller when it is lower.

[0108] The recovery process includes:

[0109] The first stage of the recovery process: drain the protective solution in the corridor, with the draining rate controlled within the preset low-speed range. At the same time, start the membrane module preheating program, using a preheating liquid with the same temperature as the water during normal operation to circulate and preheat the membrane module, and the preheating time is not less than the shortest time required for the membrane module temperature to stabilize.

[0110] The second stage of the recovery process: The feed rate is gradually increased according to the preset feed rate recovery gradient. After each increase in feed rate, the flow rate is maintained for a preset duration, and the membrane flux and transmembrane pressure difference are monitored simultaneously to ensure that the rate of change of both does not exceed the preset safe change range.

[0111] The third stage of the recovery process: When the influent flow rate is increased to 80% of the normal operating influent flow rate, the aeration intensity is gradually increased to the normal operating aeration intensity, while the effluent flow rate is adjusted to the normal operating effluent flow rate that matches the influent flow rate; when the membrane flux, transmembrane pressure difference, and effluent water quality are all stable within the normal operating parameter range and continue for the preset time, it is determined that the cold standby corridor has been smoothly restored to normal operating status.

[0112] When the cold standby corridor is in operation, its energy-saving benefits should be evaluated simultaneously:

[0113] Real-time data collection of energy consumption from agitation equipment, solution replacement, and monitoring equipment during cold standby operation of the cold standby corridor; calculation of total energy consumption E during cold standby operation. cold =E mix +E change +E mon +E other E other This indicates the energy consumption of other auxiliary equipment during cold standby operation, which is manually entered by the user.

[0114] Calculate the theoretical energy consumption E of the corridor if it maintains normal operation. normal =E avg ×T×K,E avg This represents the historical energy consumption data of the corridor during normal operation over the past three complete operating cycles. The average total energy consumption per unit time under normal operating conditions is calculated. T represents the actual cold standby operating time of the corridor this time, and K represents the energy consumption correction factor.

[0115] It should be noted that the three complete running cycles are defined by the user, such as setting 72 hours as a complete running cycle;

[0116] The above formula is based on historical energy consumption data of the corridor within the last three complete operating cycles, with the deviation between the designed processing load and the actual processing load before cold standby not exceeding ±10%. It calculates the average total energy consumption per unit time, and then combines the actual cold standby duration and energy consumption correction coefficient to obtain the theoretical energy consumption if the corridor maintains normal operation. It eliminates the influence of load difference on energy consumption calculation through historical data screening conditions and energy consumption correction coefficient, making the theoretical energy consumption comparable to the actual cold standby energy consumption, and providing an accurate reference standard for energy saving rate calculation.

[0117] Among them, E avg The energy consumption includes the energy consumption of aeration equipment, inlet pump, outlet pump, mixing equipment and routine maintenance of membrane modules during normal operation. The data is selected and statistically analyzed based on the condition that the deviation between the design treatment load of the corridor during normal operation and the actual treatment load of the corridor before cold standby does not exceed ±10%. The energy consumption correction coefficient K∈[0.9,1.1]. When the deviation between the overall system treatment load during cold standby and the average treatment load of the corridor during historical normal operation is ≤±5%, K=1. When the deviation exceeds ±5%, K is corrected by ±0.05.

[0118] The energy saving rate of the corridor during cold standby operation is:

[0119] The method described in the above embodiments can accurately select stop corridors, smoothly switch to cold standby after pretreatment of the protective membrane components, dynamically adjust cold standby parameters to ensure stability, and smoothly switch back during recovery. At the same time, it can evaluate energy-saving benefits in real time, significantly reduce operating energy consumption, ensure that sewage treatment meets standards, improve the system's operational flexibility and economy, reduce equipment wear, extend membrane component life, and achieve efficient and energy-saving operation while ensuring treatment effect.

[0120] Referring to the method in the above embodiments, an application example of this method is described:

[0121] The wastewater treatment plant in Town X adopts the MBR process and is designed to treat 50,000 m³ of wastewater per day. 3 A total of 6 parallel operating corridors are set up, and the maximum membrane flux of each corridor membrane module is designed to be 25 L / (m²). 2 •h), the maximum permissible transmembrane pressure difference is 30 kPa, and the design upper limit for the mixed liquor suspended solids concentration is 8000 mg / L. During periods of low influent load in summer, a cool-standby corridor should be selected to achieve energy-saving operation.

[0122] First, real-time parameter monitoring was conducted on the six operating channels to obtain data on membrane flux, transmembrane pressure difference, mixed liquor suspended solids concentration, influent and effluent chemical oxygen demand, and treatment load rate for each channel. Based on the cold standby adaptability evaluation method and the weighting coefficients (the weighting coefficients for membrane flux and transmembrane pressure difference were set to 0.3 due to the large difference between actual and design values; the weighting coefficient for COD removal rate was set to 0.25 due to the actual removal rate reaching 92%; and the weighting coefficient for treatment load rate was set to 0.15 due to the actual load rate being only 65%), the cold standby adaptability of channels 3 and 5 was calculated to be 0.82 and 0.78, respectively. A cold standby adaptability threshold of 0.75 was set, and both met the requirements. Further calculation showed that after stopping channels 3 or 5, the total treatment load rates of the remaining channels in the system were 82% and 85%, respectively, both not exceeding 90% of the designed total treatment load rate. Therefore, channel 3 was ultimately determined as the cold standby channel.

[0123] Subsequently, the membrane module of corridor No. 3 underwent pretreatment: pulse backwashing was employed, using the corridor's effluent as backwash water. The backwash pressure was controlled as follows: initial pressure 0.1 MPa, gradually increasing to 0.25 MPa (increase rate 0.05 MPa / min), stabilizing for 3 minutes, and then gradually decreasing to 0.1 MPa (decrease rate 0.05 MPa / min). After backwashing, a protective solution containing 2% corrosion inhibitor and 1.5% humectant was introduced, with the solution pH controlled at 7.5-8.0, ion concentration at 200 mg / L, and residence time at 30 minutes. Simultaneously, the stirring equipment power was adjusted to 1.5 kW, and the stirring direction was clockwise, creating a low-speed circulating flow of 0.2 m / s to adjust the water flow state.

[0124] Based on system requirements, key parameters for cold standby were set as follows: effluent suspended solids concentration ≤ 5 mg / L, effluent ammonia nitrogen concentration ≤ 1.5 mg / L; the calculated maximum allowable downtime load percentage was 18%; based on the membrane module type, the membrane surface protection pressure was set at 0.12 MPa, and the minimum solution replacement cycle at 7 days; combined with the effective volume of the corridor being 500 m³ / h... 3 A safety factor of 1.2, a volume coverage factor of 0.5, and a minimum solution wetting volume per unit membrane area of ​​0.02 m³ are used. 3 / m 2 (Total membrane surface area 8000m²) 2 The minimum retention capacity of the protective solution was calculated to be 60m³. 3 The final set of cold standby parameters was determined as follows: protective solution replacement cycle of 7 days, membrane surface protection pressure of 0.12 MPa, solution level in the channel of 1.2 m, and water quality monitoring frequency at the outlet of 4 times / day, which was then fed back to the control terminal.

[0125] Following the cold standby switchover procedure, the water inflow into Corridor No. 3 was gradually reduced: from the initial 800m... 3 / h decreases by 100m per step 3 / h, maintain the gradient adjustment for 20 minutes until it drops to 200m 3 / h; Simultaneously reduce the outflow rate to ensure that the liquid level fluctuation is ≤±0.1m, and finally stabilize the outflow rate at 200m³ / h. 3 / h. Aeration intensity from 3m 3 / (m 2 •h) Decrease by 0.5m per step 3 / (m 2 •h) Monitor the gradient adjustment of dissolved oxygen until dissolved oxygen stabilizes at 2-3 mg / L, and complete the cold standby switchover.

[0126] During the cold standby period, dynamic monitoring was conducted on Corridor No. 3. On the 5th day, the solution level was monitored to have dropped to 1.1m (set value 1.2m), and the deviation evaluation index was calculated to be 0.15 (set threshold 0.2), which was within the range. On the 10th day, the system's water treatment capacity increased to 48,000 m³.3 / d, calculations show that one cold standby corridor needs to be restored, and the baseline value for the inlet flow rate of corridor No. 3 is reset to 750m³. 3 / h, increasing by 50m per step 3 Adjust the water inflow rate by setting the command to / h and maintain for 15 minutes.

[0127] After 15 days of cold standby operation, Corridor No. 3 needs to be restored to normal operation. Data collected from the system: The remaining corridor is currently operating at 92% capacity, with a total inflow of 48,000 m³ / h. 3 / d, actual treated water volume 45,000 m³ 3 / d, effluent quality compliance rate 95%, Corridor No. 3 has been in cold standby for 15 days (maximum allowable cold standby is 20 days). The calculated restoration priority score is 0.88 (no other cold standby corridors), therefore Corridor No. 3 is prioritized for restoration. Follow the restoration procedure: first, with a 0.5m... 3 The protective solution is discharged at a rate of / min, while the membrane module is preheated for 40min using a 25℃ preheating liquid circulation system; then the membrane module is raised by 50m per step. 3 The feed rate was gradually increased at a rate of 600 m³ / h for 20 minutes, while simultaneously monitoring membrane flux and transmembrane pressure differential to ensure the rate of change remained within a safe range. 3 / h (normal flow rate 750m) 3 When the aeration rate is 80% (per hour), the aeration intensity will be increased to 3m. 3 / (m 2 •h), the water output was adjusted to 600m³. 3 / h; After continuous monitoring for 8 hours, the membrane flux, transmembrane pressure difference, and effluent water quality all remained stable within the normal range, indicating that normal operation had been restored.

[0128] Energy efficiency assessment shows that during the cold standby period of Corridor No. 3, the energy consumption of the mixing equipment is 120 kWh, the energy consumption of solution replacement is 80 kWh, the energy consumption of monitoring equipment is 30 kWh, and the energy consumption of other auxiliary equipment is 50 kWh, for a total energy consumption of 280 kWh. The average total energy consumption per unit time during normal operation of the corridor is 45 kWh / h, and the theoretical energy consumption for 15 days (360h) of cold standby is 15,300 kWh (energy consumption correction factor 1.0). The final calculated energy saving rate during cold standby operation is 98.2%.

[0129] In summary, the methods described in the above embodiments, during execution, ensure that the overall system treatment effect is not affected by real-time monitoring and screening of suitable corridors for cold standby. They can accurately match process requirements, and at the same time, the pretreatment of membrane modules and adjustment of water flow status can reduce the adhesion of pollutants on the membrane surface, protect the performance of membrane modules, and extend their service life. Furthermore, the gradual adjustment of equipment operating status achieves a smooth switch, avoiding the impact of sudden parameter changes on the system. Continuous dynamic monitoring and flexible adjustment of cold standby parameters ensure the stability of the cold standby state and adapt to changes in system requirements. In addition, recovery parameters and procedures are set according to the overall situation to enable the corridor to smoothly return to normal operation, reduce recovery risks, and evaluate energy-saving benefits in real time. By reducing equipment energy consumption through cold standby and comparing it with the energy consumption during normal operation, the energy saving rate is obtained. Under the premise of ensuring that wastewater treatment meets standards, the economic efficiency and stability of process operation are effectively improved, and resource waste is reduced.

[0130] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant, characterized in that, include: Real-time monitoring of operating parameters of all operating corridors in the MBR process system of the wastewater treatment plant is conducted, and corridors that can be switched to cold standby operation without affecting the overall treatment effect are selected based on the monitoring results. The membrane modules in the selected cold standby corridor are pretreated to remove some of the contaminants attached to the membrane surface, and the water flow in the corridor is adjusted to match the initial state of cold standby. Based on the water quality compliance requirements and treatment load demand of the wastewater treatment plant's MBR process system, as well as the membrane module type and volume characteristics of the standby corridor, key operating parameters in the corridor under standby conditions are set, and the set parameters are fed back to the control terminal of the wastewater treatment plant's MBR process system. Based on the cold standby operation parameters received by the control terminal, the operation status of the water inlet, water outlet and aeration equipment of the cold standby corridor is gradually adjusted so that the cold standby corridor can be smoothly switched to the cold standby operation mode. Continuous dynamic monitoring is carried out on the corridors in cold standby operation. When the operating parameters are detected to deviate from the set range or the overall demand of the sewage treatment plant MBR process system changes, the cold standby operating parameters are adjusted and fed back to the control terminal to maintain the stability of the cold standby status. When it is necessary to put the cold standby corridor back into normal operation, the restoration operation parameters are set according to the overall operation status of the wastewater treatment plant's MBR process system and sent to the control terminal. The operation parameters of the cold standby corridor and the status of the influent, effluent and aeration equipment are gradually adjusted in conjunction with the preset restoration program so that the cold standby corridor can be smoothly restored to normal operation.

2. The energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant according to claim 1, characterized in that, When selecting corridors that can be switched to cold standby operation without affecting the overall processing effect based on monitoring results, the following conditions must be met: Based on preset sensors, the membrane flux, transmembrane pressure difference, mixed liquor suspended solids concentration, effluent chemical oxygen demand, and channel treatment load rate of each operating channel are monitored to assess the cold standby adaptability of each channel. In the formula: S represents the corridor cold standby adaptability; α, β, γ, δ, and ε are weighting coefficients; J max ΔP represents the design maximum membrane flux of the membrane module; J represents the sensed membrane flux; ΔP max ΔP is the maximum permissible transmembrane pressure difference for the membrane module; ΔP is the sensed transmembrane pressure difference; MLSS max MLSS represents the design upper limit for the concentration of mixed liquor suspended solids within the corridor; COD represents the sensed concentration of mixed liquor suspended solids. in Chemical oxygen demand (COD) of the influent to the corridor; out η is the perceived chemical oxygen demand (COD) of the effluent; η is the perceived corridor treatment load rate. The sum of α, β, γ, δ, and ε is 1, and all of them are positive numbers; After calculating S for each corridor, a cold standby adaptability threshold is set. All corridors with values ​​greater than the cold standby adaptability threshold are filtered out, and corridors that meet the following conditions are designated as cold standby corridors that can be switched to cold standby operation: After the corridor stops operating, the total processing load rate of the remaining corridors in the system will still not exceed 90% of the designed total processing load rate; If none of the corridors with a cold standby adaptability threshold meet the above conditions, it means that there are no cold standby corridors that can be switched to cold standby operation.

3. The energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant according to claim 1, characterized in that, The pretreatment process for the membrane modules selected for cooling in the pre-cooling corridor is as follows: The membrane module is backwashed using a pulse backwashing method. The backwash water is the effluent from the channel. The backwash pressure is controlled in the following sequence: initial pressure, gradient pressure increase, stable pressure, and gradient pressure decrease. After backwashing, a protective solution containing corrosion inhibitors and humectants of a preset concentration is introduced into the corridor, and the residence time of the protective solution in the corridor is not less than the shortest immersion time calculated based on the effective wetted area of ​​the membrane module. Subsequently, the operating power and stirring direction of the stirring equipment in the corridor are adjusted so that the protective solution forms a low-speed circulating flow along the surface of the membrane module in the corridor, and the circulation flow rate is controlled within a preset range.

4. The energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant according to claim 1, characterized in that, The setting phase of key operating parameters within the corridor under cold standby conditions shall conform to: The minimum water quality assurance indicators for the effluent end of the cold standby corridor are set according to the water quality compliance requirements of the MBR process system of the wastewater treatment plant, including: effluent suspended solids concentration and effluent ammonia nitrogen concentration. Calculate the maximum permissible outage load percentage for the standby cold storage corridor. Q total Q remain These represent the total designed water treatment capacity of the MBR process system in the wastewater treatment plant and the total water treatment capacity of the remaining operating corridor under full load conditions, respectively. The minimum maintenance parameters for the membrane modules in the cold standby state are set according to the membrane module type of the cold standby corridor, and the minimum retention volume V of the protective solution in the corridor in the cold standby state is calculated based on the corridor volume characteristics. min =σ×(V corridor ×a+S membrane ×b), σ represents the safety factor, V corridor S represents the effective volume of the corridor, 'a' represents the volume coverage coefficient, and S represents the effective volume of the corridor. membrane denoted by , b represents the total surface area of ​​the membrane module within the corridor, and b represents the minimum solution immersion volume required per unit membrane area. These are ultimately integrated to form a set of key operating parameters in the cold standby state. The set of key operating parameters includes the protective solution replacement cycle, membrane surface protection pressure, solution level within the corridor, and water quality monitoring frequency at the outlet.

5. The energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant according to claim 1, characterized in that, The control operation that smoothly switches the cold standby corridor to cold standby operation mode is as follows: The water inlet volume of the standby corridor is gradually reduced according to the preset water inlet adjustment gradient. After each reduction in water inlet volume, the water inlet volume is maintained for a preset duration until the water inlet volume drops to the preset water inlet flow rate corresponding to the standby state. While adjusting the inflow rate, gradually reduce the outflow rate in a gradient synchronized with the inflow rate adjustment to ensure that the liquid level in the corridor is maintained within the preset fluctuation range. When the inflow rate stabilizes at the preset inflow rate, adjust the outflow rate to the cold standby outflow rate that matches the preset inflow rate. Based on the aeration control requirements in the cold standby operation parameters, the aeration intensity of the aeration equipment is gradually reduced according to the preset aeration intensity adjustment gradient. After each adjustment of the aeration intensity, the dissolved oxygen concentration in the corridor is monitored. When the dissolved oxygen concentration in the corridor stabilizes within the preset dissolved oxygen range corresponding to the cold standby state, the aeration intensity adjustment is stopped to complete the switch to the cold standby operation mode.

6. The energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant according to claim 1, characterized in that, When the operating parameters of the cold standby corridor deviate from the set range or the overall requirements of the wastewater treatment plant's MBR process system change, the operation of adjusting the cold standby operating parameters and feeding them back to the control terminal is as follows: Determine the deviation evaluation index of the cold standby corridor operation status. In the formula: n is the number of key parameters that need to be monitored in cold standby mode; X k X is the real-time monitoring value of the k-th parameter; k-set ω is the set value for the k-th parameter; k The deviation weight coefficient for the k-th parameter; A deviation threshold is set. If the real-time calculated D exceeds the deviation threshold, the parameter is determined to deviate from the set range. Based on the type and degree of deviation of the parameter, a corresponding cold standby operation parameter adjustment plan is generated. The adjustment range of the parameter in the adjustment plan is positively correlated with the D value. When a change in overall system requirements is detected: Changes in water demand: Calculate the difference between the total water demand processed by the system after the change and the current remaining processing capacity of the operating corridors. If the difference is greater than or equal to zero, calculate the maximum allowable recovery ratio of the cold standby corridors. m represents the total number of cold standby corridors, and ΔQ represents the difference between the total water treatment capacity of the system after the change and the treatment capacity of the currently remaining operating corridors. i-rated This represents the rated processing capacity of the i-th cold standby corridor. The influent flow rate of the cold standby corridor is then adjusted based on the κ value. If ΔQ < 0, the number of new cold standby corridors and the corresponding cold standby parameter baseline values ​​are reassessed. Changes in effluent water quality standards: Based on the changes in the limits for total nitrogen, total phosphorus, and turbidity in the new standards, the monitoring thresholds for the effluent outlet of the cold standby corridor will be reset, and the pH value, reagent concentration, and solution replacement cycle benchmark value of the protective solution will be adjusted accordingly. Compare the current operating parameters with the recalculated baseline values, and calculate the parameter adjustment amount ΔX. k =X k-new -X k-current X k-new X represents the new baseline value. k-current This represents the current parameter value, based on ΔX. k The absolute value of the parameter is used to generate parameter adjustment instructions in stages. The instructions include the adjustment direction, step size, and the required stabilization time after each adjustment, and are fed back to the control terminal for execution.

7. The energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant according to claim 1, characterized in that, When it is necessary to put the cold standby corridor back into normal operation, the restoration operation parameters should be set according to the overall operating status of the wastewater treatment plant's MBR process system, and should comply with the following: Collect overall system operation parameters, including: current processing load of remaining operating corridors, total system influent flow, system effluent water quality compliance rate, and historical recovery data of membrane modules; Prioritize the restoration of cold standby corridors. In the formula: λ1, λ2, λ3, and λ4 are weighting coefficients; η remain Q represents the current processing load of the remaining operational corridors. in-total Q represents the total influent flow rate of the system. process The actual water volume processed by the system at present; γ reach The system's effluent water quality compliance rate; t cold The cold standby corridor has been in cold standby mode for a certain period of time; t cold-max This is the longest cold standby time allowed for this type of corridor; Finally, the recovery order is determined by sorting the P values ​​of each cold standby corridor from largest to smallest. At the same time, based on the overall system operation parameters, target parameters for each stage of the recovery process are set, including the influent flow rate, aeration intensity, and membrane flux recovery rate in the initial recovery stage, forming a complete set of recovery operation parameters. Among them, λ1, λ2, λ3, and λ4 are all positive numbers, and their sum is 1.

8. The energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant according to claim 1, characterized in that, The recovery procedure includes: The first stage of the recovery process: drain the protective solution in the corridor, with the draining rate controlled within the preset low-speed range. At the same time, start the membrane module preheating program, using a preheating liquid with the same temperature as the water during normal operation to circulate and preheat the membrane module, and the preheating time is not less than the shortest time required for the membrane module temperature to stabilize. The second stage of the recovery process: The feed rate is gradually increased according to the preset feed rate recovery gradient. After each increase in feed rate, the flow rate is maintained for a preset duration, and the membrane flux and transmembrane pressure difference are monitored simultaneously to ensure that the rate of change of both does not exceed the preset safe change range. The third stage of the recovery process: When the influent flow rate is increased to 80% of the normal operating influent flow rate, the aeration intensity is gradually increased to the normal operating aeration intensity, and the effluent flow rate is adjusted to the normal operating effluent flow rate that matches the influent flow rate; when the membrane flux, transmembrane pressure difference, and effluent water quality are all stable within the normal operating parameter range and continue for the preset time, it is determined that the cold standby corridor has been smoothly restored to normal operating status.

9. The energy-saving control method for cold standby operation of a section of the MBR process in a wastewater treatment plant according to claim 1, characterized in that, When the cold standby corridor is in operation, its energy-saving benefits will be evaluated simultaneously: Real-time data collection of energy consumption from agitation equipment, solution replacement, and monitoring equipment during cold standby operation of the cold standby corridor; calculation of total energy consumption E during cold standby operation. cold =E mix +E change +E mon +E other E other This indicates the energy consumption of other auxiliary equipment during cold standby operation, which is manually entered by the user. Calculate the theoretical energy consumption E of the corridor if it maintains normal operation. normal =E avg ×T×K,E avg This represents the historical energy consumption data of the corridor during normal operation over the past three complete operating cycles. The average total energy consumption per unit time under normal operating conditions is calculated. T represents the actual cold standby operating time of the corridor this time, and K represents the energy consumption correction factor. The energy saving rate of the corridor during cold standby operation is:

Images