Microorganism monitoring in water treatment systems and intelligent ultraviolet sterilization system and method
By acquiring real-time data and dynamically adjusting the power of medium-pressure ultraviolet lamps, the problem of microbial fouling in the water treatment system was solved, achieving precise sterilization and equipment protection, and reducing operation and maintenance costs and energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHENGZHOU GAS POWER GENERATION CO LTD
- Filing Date
- 2025-12-31
- Publication Date
- 2026-06-02
Smart Images
Figure CN122126925A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of intelligent sterilization control technology, and more specifically, to a high-pressure microbial monitoring and ultraviolet intelligent sterilization system and method for water treatment systems. Background Technology
[0002] With the deepening of power market reform and the large-scale grid connection of new energy sources, thermal power units are playing an increasingly prominent role in supporting the grid's peak shaving and frequency regulation. The frequent start-up and shutdown of units has become the norm in the industry. Against this backdrop, the boiler feedwater treatment system, as a key auxiliary system to ensure the safe and economical operation of the units, directly affects the production efficiency and operation and maintenance costs of power generation companies. Modern water systems generally adopt membrane water treatment technologies such as ultrafiltration and reverse osmosis to achieve deep purification of raw water through multi-stage physical separation processes, so as to meet the strict requirements of high-parameter units for feedwater quality.
[0003] Existing water treatment systems have significant deficiencies in digital and intelligent control for preventing microbial fouling, a problem particularly severe under peak-shaving operation conditions. Specifically, when units frequently start and stop, the water treatment system operates intermittently, and the stagnant water inside the pipelines and membrane modules provides a suitable environment for microbial growth, leading to varying degrees of biofilm adhesion and pore blockage in the security filter, ultrafiltration membrane, and reverse osmosis membrane. This microbial fouling not only causes a continuous decline in membrane flux and a significant decrease in permeate yield but also accelerates membrane module aging and failure, forcing maintenance personnel to frequently replace filter cartridges and chemically clean the membrane system. Currently, the mainstream approach to solving this problem... The current method still relies on manual inspection and judgment and periodic addition of chemical disinfectants, lacking a digital program control mechanism based on real-time water quality monitoring data. This traditional model cannot adaptively adjust according to the system's operating conditions and the microbial growth potential, resulting in inherent drawbacks such as response lag, low control precision, and chemical residues. Furthermore, chemical disinfectants may cause oxidative damage to membrane materials. Due to the lack of intelligent monitoring, early warning, and closed-loop control methods, maintenance personnel find it difficult to implement precise disinfection interventions at the optimal time and location, ultimately leading to increased system energy consumption and high maintenance costs, which restricts the safe and economical operation of the water treatment system under the new situation of power grid peak shaving.
[0004] In view of this, the present invention proposes a high-pressure microbial monitoring and ultraviolet intelligent sterilization system and method for water treatment systems to solve the above problems. Summary of the Invention
[0005] To overcome the aforementioned deficiencies of the prior art and to achieve the above objectives, the present invention provides the following technical solution: a method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system, comprising: Step S1: Real-time acquisition of the instantaneous flow rate, inlet water temperature, instantaneous transmittance value, and current lamp power of the medium-pressure ultraviolet sterilizer in the current treatment section of the water treatment system; Step S2: Determine the microbial growth activity characteristic value based on the decrease magnitude and rate of decrease of the instantaneous transmittance value within adjacent collection cycles; obtain the sterilization intensity requirement level based on the combination relationship between the microbial growth activity characteristic value and the instantaneous flow rate. Step S3: Adjust the output power of the medium-pressure ultraviolet lamps according to the sterilization intensity requirement level to obtain the dynamic target power for the current collection cycle; determine the lamp power increase slope limit value according to the matching relationship between the dynamic target power and the inlet water temperature. Step S4: Determine the power adjustment damping coefficient based on the current operating power of the lamp tube and the changing trend of the inlet water temperature; obtain the actual power correction amount for the current acquisition cycle based on the power adjustment damping coefficient and the lamp tube power increase slope limit; and control the real-time output power of the medium-pressure ultraviolet lamp tube based on the dynamic target power and the actual power correction amount.
[0006] Furthermore, the method for determining the characteristic value of microbial growth activity includes: The difference between the instantaneous transmittance value of the current acquisition cycle and the instantaneous transmittance value of the previous acquisition cycle is calculated as the transmittance decrease. Based on the cumulative value of the transmittance decrease over three consecutive acquisition cycles, a transmittance attenuation cumulative index is obtained. Based on the degree of deviation between the instantaneous transmittance values of the current and previous acquisition cycles and the preset clean transmittance benchmark value, a transmittance deviation weighting factor is determined. The transmittance attenuation cumulative index is divided by the current instantaneous flow rate and multiplied by the transmittance deviation weighting factor to obtain the microbial growth activity characteristic value.
[0007] Furthermore, the step of obtaining the sterilization intensity requirement level based on the combination relationship between microbial growth activity characteristic values and instantaneous flow rate includes: The instantaneous flow rate is divided and adjusted to obtain flow ranges, each flow range corresponding to a basic dose coefficient; an activity correction coefficient is determined based on the magnitude of the microbial growth activity characteristic value; the basic dose coefficient of the flow range to which the current instantaneous flow rate belongs is multiplied by the activity correction coefficient to obtain a comprehensive dose requirement index; the comprehensive dose requirement index is compared with multiple preset dose threshold ranges to determine the corresponding sterilization intensity requirement level.
[0008] Furthermore, the step of adjusting the output power of the medium-pressure ultraviolet lamp in stages based on the sterilization intensity requirement level to obtain the dynamic target power for the current sampling period includes: The power output levels are preset, with each power output level corresponding to a sterilization intensity requirement range and a power reference value. When the sterilization intensity requirement level increases to a higher level, the dynamic target power is immediately switched to the power reference value of the corresponding higher power output level, and a one-time power boost pulse is added. When the sterilization intensity requirement level remains unchanged for more than a specified number of sampling cycles, the dynamic target power is locked at the power reference value of the current power output level. When the sterilization intensity requirement level decreases, the dynamic target power is allowed to switch down to the power reference value of the lower power output level after a delay of at least two sampling cycles.
[0009] Furthermore, determining the lamp power increase slope limit value based on the matching relationship between the dynamic target power and the inlet water temperature includes: Establish a mapping table between inlet water temperature and the maximum allowable power increase rate of the lamp tube; find the basic slope limit value in the corresponding mapping table based on the current inlet water temperature; when the inlet water temperature is lower than the preset low temperature threshold, multiply the basic slope limit value by the preset low temperature suppression coefficient; when the inlet water temperature is higher than the preset high temperature threshold, multiply the basic slope limit value by the preset high temperature relaxation coefficient; use the processed result as the lamp tube power increase slope limit value for the current acquisition cycle.
[0010] Furthermore, determining the power adjustment damping coefficient based on the changing trend of the current lamp operating power and the inlet water temperature includes: Calculate the direction and magnitude of inlet water temperature change within adjacent acquisition cycles; when the inlet water temperature shows a continuous upward trend and the magnitude of change exceeds the preset temperature rise threshold, set the power adjustment damping coefficient to the first damping value; when the inlet water temperature shows a continuous downward trend and the magnitude of change exceeds the preset temperature drop threshold, set the power adjustment damping coefficient to the second damping value; when the inlet water temperature change remains within the preset stable range for multiple consecutive acquisition cycles, gradually adjust the power adjustment damping coefficient to the third damping value; based on the direction of the difference between the current lamp working power and the dynamic target power, assign positive and negative signs to the selected damping coefficient to obtain the final power adjustment damping coefficient.
[0011] Furthermore, the step of obtaining the actual power correction amount for the current acquisition cycle based on the power adjustment damping coefficient and the lamp power increase slope limit includes: The difference between the dynamic target power and the current lamp operating power is used as the original power adjustment requirement. The original power adjustment requirement is limited in amplitude and direction based on the power adjustment damping coefficient to obtain the damped power adjustment amount. The damped power adjustment amount is converted into a power adjustment rate and compared with the lamp power increase slope limit value. The smaller value is taken as the maximum single-step adjustment amount allowed in the current acquisition cycle. After time unification processing of the maximum single-step adjustment amount according to the duration of the current acquisition cycle, the actual power correction amount is obtained.
[0012] Furthermore, the method for determining the additional one-time power boost pulse includes: The pulse amplitude is 10% to 20% of the power reference value corresponding to the higher power output level; the pulse duration is inversely proportional to the instantaneous flow rate and directly proportional to the microbial growth activity characteristic value; during the application of the power boost pulse, the constraint of the lamp power boost slope limit value is temporarily released; after the pulse ends, the constraint of the lamp power boost slope limit value is immediately restored and the lamp enters the normal power tracking state.
[0013] Furthermore, the method for dividing and adjusting the instantaneous flow includes: Initially, the entire flow range is divided into N flow intervals; the percentage of times each flow interval is actually triggered in the recent period is counted; adjacent flow intervals with a trigger percentage lower than the preset low-frequency threshold are merged; flow intervals with a trigger percentage higher than the preset high-frequency threshold are proportionally subdivided into M sub-intervals; the updated flow intervals and their corresponding basic dose coefficients take effect automatically at the start of the next acquisition cycle.
[0014] The water treatment system includes a high-pressure microbial monitoring and ultraviolet intelligent sterilization system, comprising: Multi-parameter acquisition module: Real-time acquisition of instantaneous flow rate, inlet water temperature, instantaneous transmittance value of the current treatment section of the water treatment system, and the current lamp power of the medium-pressure ultraviolet sterilizer; The grade assessment module determines the microbial growth activity characteristic value based on the decrease magnitude and rate of decrease of the instantaneous transmittance value within adjacent collection cycles; and obtains the sterilization intensity requirement level based on the combination relationship between the microbial growth activity characteristic value and the instantaneous flow rate. The graded decision module adjusts the output power of the medium-pressure ultraviolet lamps according to the sterilization intensity requirement level to obtain the dynamic target power for the current collection cycle; and determines the lamp power increase slope limit value according to the matching relationship between the dynamic target power and the inlet water temperature. Control execution module: Determines the power adjustment damping coefficient based on the current lamp working power and the changing trend of inlet water temperature; obtains the actual power correction amount for the current acquisition cycle based on the power adjustment damping coefficient and the lamp power increase slope limit; and controls the real-time output power of the medium-pressure ultraviolet lamp based on the dynamic target power and the actual power correction amount.
[0015] The technical effects and advantages of the pressure-controlled microbial monitoring and ultraviolet intelligent sterilization system and method in the water treatment system of this invention are as follows: This invention directly reflects the activity level of microbial growth and reproduction in water by measuring the instantaneous decrease in transmittance value and its rate of decrease. By combining transmittance deviation weighting factors and instantaneous flow rate, it obtains characteristic values of microbial growth activity, achieving real-time quantitative monitoring of microbial growth potential and overcoming the response lag problem of traditional manual inspection. By acquiring the required sterilization intensity levels, sterilization intervention decisions can be adaptively adjusted according to system operating conditions, avoiding the inherent drawbacks of periodically adding chemical disinfectants that cannot adapt to intermittent peak-shaving conditions. Based on the sterilization intensity required levels, the medium-pressure ultraviolet lamps are graded to obtain dynamic target power. At high levels, an additional power boost pulse is added for rapid response; at low levels, the power is delayed and reduced to prevent microbial rebound, thus achieving a balance between sterilization intensity and microbial growth. Precise dynamic matching of sterilization levels; determining the lamp power increase slope limit value based on the inlet water temperature, suppressing the power increase rate at low temperatures to avoid thermal shock, and appropriately relaxing the increase sterilization response speed at high temperatures, protecting the lamps and extending the equipment's service life while ensuring sterilization timeliness; determining the power adjustment damping coefficient based on temperature change trends to limit the amplitude and direction of the power adjustment process, making the power output smooth and stable and avoiding fatigue damage to the lamps caused by frequent fluctuations; using medium-pressure ultraviolet physical sterilization to replace chemical sterilizers, eliminating the risk of chemical residues and the hidden danger of oxidation damage to membrane materials, combined with closed-loop control of real-time power correction to achieve precise sterilization intervention at the optimal time, thereby reducing system operating energy consumption and maintenance costs, and improving the safe and economical operation capability of the water treatment system under the new situation of power grid peak shaving. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the high-pressure microbial monitoring and ultraviolet intelligent sterilization method in the water treatment system of the present invention; Figure 2 This is a schematic diagram of the high-pressure microbial monitoring and ultraviolet intelligent sterilization system in the water treatment system of the present invention. Detailed Implementation
[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0018] Example 1 Please see Figure 1 As shown, the method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in the water treatment system of this embodiment includes: Step S1: Real-time acquisition of the instantaneous flow rate, inlet water temperature, instantaneous transmittance value, and current lamp power of the medium-pressure ultraviolet sterilizer in the current treatment section of the water treatment system.
[0019] With the deepening of power market reform, the frequent start-up and shutdown of thermal power units has led to the intermittent operation of water treatment systems. The stagnant water inside pipelines and membrane modules provides a suitable environment for microbial growth. Current technologies rely on manual inspections and periodic addition of chemical disinfectants, lacking a digital program control mechanism based on real-time water quality monitoring data, and are unable to adaptively adjust according to system operating conditions. Therefore, this solution first establishes a comprehensive real-time data acquisition system to provide a data foundation for subsequent intelligent sterilization control.
[0020] In this embodiment, the water treatment system includes a security filter section, an ultrafiltration membrane section, and a reverse osmosis membrane section, each equipped with an independent data acquisition device. Instantaneous flow rate is obtained through electromagnetic flowmeters installed in the inlet pipes of each treatment section, with a range of 0 to 500 cubic meters per hour; inlet water temperature is obtained through platinum resistance temperature sensors installed at the inlet, with a range of 0 to 50 degrees Celsius; instantaneous transmittance is obtained through online ultraviolet transmittance analyzers installed in each treatment section, with a range of 0% to 100%; and the current lamp power of the medium-pressure ultraviolet sterilizer is obtained through the power feedback signal from the lamp power module.
[0021] In this embodiment, the data acquisition cycle is set to 30 seconds. When the thermal power unit is operating during peak shaving, the load change rate is usually 1% to 3% of the rated load per minute. The 30-second acquisition cycle can capture the water volume fluctuations caused by load changes in a timely manner, while avoiding the consumption of system resources due to excessively frequent acquisition. In addition, the changes in light transmittance caused by microbial growth usually appear on the minute level. The 30-second acquisition cycle can effectively track the dynamic trend of light transmittance changes.
[0022] It should be noted that in other embodiments of the present invention, the acquisition cycle can be adjusted according to the actual scale and control precision requirements of the water treatment system. For example, for a small water treatment system, the acquisition cycle can be extended to 60 seconds, and for a system with high precision control requirements, the acquisition cycle can be shortened to 15 seconds.
[0023] Step S2: Determine the microbial growth activity characteristic value based on the decrease magnitude and rate of decrease of the instantaneous transmittance value within adjacent collection cycles; obtain the sterilization intensity requirement level based on the combination relationship between the microbial growth activity characteristic value and the instantaneous flow rate.
[0024] When microorganisms proliferate in water, they produce colonies and metabolic products. These substances absorb and scatter ultraviolet light, leading to a decrease in water transmittance. The magnitude and rate of this decrease directly reflect the level of microbial activity. Existing technologies rely on manual inspections to assess microbial growth potential, which suffers from inherent drawbacks such as response lag. Therefore, this solution achieves quantitative monitoring of microbial growth potential by analyzing transmittance changes in real time.
[0025] Specifically, methods for determining the characteristic values of microbial growth activity include: First, calculate the difference between the instantaneous transmittance value of the current acquisition cycle and the instantaneous transmittance value of the previous acquisition cycle, as the transmittance decrease. Let the current acquisition cycle be the [number]th [cycle]. The instantaneous transmittance value is recorded as for each cycle. The instantaneous transmittance value of the previous acquisition cycle is recorded as follows: The amount of light transmittance decreases. .when A positive value indicates a decrease in light transmittance. A negative value indicates an increase in transmittance. Secondly, the cumulative transmittance decay index is obtained based on the cumulative value of the decrease in transmittance over three consecutive sampling periods. (Transmittance decay cumulative index) The transmittance fluctuations in a single sampling period may be affected by instantaneous disturbances in water quality, leading to misjudgments. The cumulative value of three consecutive periods can effectively filter out random fluctuations while maintaining sensitivity to microbial growth trends.
[0026] Then, based on the degree of deviation between the instantaneous transmittance values of the current and previous acquisition cycles and the preset clean transmittance benchmark value, a transmittance deviation weighting factor is determined. (Preset clean transmittance benchmark value) The value is set at 95%, determined based on the typical transmittance level of the pretreated raw water entering the membrane system. Even a slight decrease in transmittance close to the cleanliness baseline should raise concern, as this could be an early sign of microbial growth. When transmittance is significantly below the cleanliness baseline, the system is already contaminated, and further decreases require a stronger sterilization response. The transmittance deviation weighting factor is calculated by calculating the transmittance deviation for each current sampling period. Deviation of transmittance from the previous collection cycle Transmittance deviates from weighting factor .
[0027] Finally, the cumulative transmittance decay index is divided by the current instantaneous flow rate and then multiplied by the transmittance deviation weighting factor to obtain the characteristic value of microbial growth activity. Dividing by the instantaneous flow rate serves the purpose that: when the flow rate is high, the water residence time in the pipeline is short, and the impact on microbial growth is relatively weak; when the flow rate is low, the water residence time is long, and even with the same decrease in transmittance, the threat of microbial growth is higher; through flow rate normalization, the characteristic value of microbial growth activity can accurately reflect the degree of microbial growth activity per unit volume of water.
[0028] Methods for obtaining the required sterilization intensity level include: First, the instantaneous flow rate is divided and adjusted to obtain flow ranges, each corresponding to a basic dosage coefficient. In this embodiment, the entire flow range (0 to 500 cubic meters per hour) is initially divided into N flow ranges, where N is set to 5. The reason for this setting is that too few zones cannot reflect the differentiated sterilization requirements under different flow conditions, while too many zones increase system complexity and have obvious boundary effects; 5 zones can cover typical operating conditions of the water treatment system, such as shutdown, low load, medium load, high load, and full load, which is in line with the actual characteristics of peak-shaving operation of thermal power units.
[0029] The initial flow rate ranges are divided as follows: Range 1: 0 to 100 cubic meters per hour, corresponding to a base dose coefficient of 1.5; Range 2: 100 to 200 cubic meters per hour, corresponding to a base dose coefficient of 1.2; Range 3: 200 to 300 cubic meters per hour, corresponding to a base dose coefficient of 1.0; Range 4: 300 to 400 cubic meters per hour, corresponding to a base dose coefficient of 0.9; Range 5: 400 to 500 cubic meters per hour, corresponding to a base dose coefficient of 0.8. At low flow rates, the water residence time in the pipes and membrane modules is extended, allowing microorganisms more time to attach and multiply, requiring a higher bactericide dose; at high flow rates, the water flows rapidly, making it difficult for microorganisms to attach effectively, requiring a relatively lower bactericide dose.
[0030] The method for dynamically adjusting flow ranges in this embodiment is as follows: First, the percentage of actual triggers for each flow range within a recent period (set as 24 hours, corresponding to a typical peak-shaving cycle for thermal power units) is statistically analyzed. Second, adjacent flow ranges with a trigger percentage lower than a preset low-frequency threshold (set as 5%, meaning the number of triggers in that range within 24 hours is less than 5% of the total number of data collections) are merged, and the merged flow range uses the weighted average of the original base dose coefficients for each range. Third, flow ranges with a trigger percentage higher than a preset high-frequency threshold (set as 40%, meaning the number of triggers in that range within 24 hours exceeds 40% of the total number of data collections) are proportionally subdivided into M sub-ranges, where M is set to 2. The sub-ranges are then linearly interpolated based on the original base dose coefficients. The updated flow ranges and their corresponding base dose coefficients automatically take effect at the start of the next data collection cycle. Through dynamic adjustment of flow ranges, the system can adapt to the flow distribution characteristics under different operating modes, improving the targeting of sterilization control.
[0031] Secondly, the activity correction coefficient is determined based on the magnitude of the microbial growth activity characteristic value. In this embodiment, the grading rules for the activity correction coefficient are as follows: when the microbial growth activity characteristic value is less than 0.0001, the activity correction coefficient is 0.8; when the microbial growth activity characteristic value is between 0.0001 and 0.0002, the activity correction coefficient is 1.0; when the microbial growth activity characteristic value is between 0.0002 and 0.0003, the activity correction coefficient is 1.2; when the microbial growth activity characteristic value is between 0.0003 and 0.0005, the activity correction coefficient is 1.5; and when the microbial growth activity characteristic value is greater than 0.0005, the activity correction coefficient is 2.0. The grading rules are based on the statistical analysis of actual operating data: the characteristic value of microbial growth activity is usually less than 0.0001 during normal operation, between 0.0001 and 0.0003 during light pollution, between 0.0003 and 0.0005 during moderate pollution, and greater than 0.0005 during heavy pollution.
[0032] Then, the basic dose coefficient of the current instantaneous flow range is multiplied by the activity correction coefficient to obtain the comprehensive dose demand index.
[0033] Finally, the corresponding sterilization intensity requirement level is determined by comparing the comprehensive dose requirement index with multiple preset dose threshold ranges. This embodiment sets five sterilization intensity requirement levels: Level 1 (lowest) when the comprehensive dose requirement index is less than 0.8, Level 2 when it is between 0.8 and 1.2, Level 3 when it is between 1.2 and 1.6, Level 4 when it is between 1.6 and 2.4, and Level 5 (highest) when it is greater than 2.4.
[0034] Step S3: Adjust the output power of the medium-pressure ultraviolet lamps according to the sterilization intensity requirement level to obtain the dynamic target power for the current collection cycle; determine the lamp power increase slope limit value according to the matching relationship between the dynamic target power and the inlet water temperature.
[0035] Existing technologies rely on periodic addition of chemical disinfectants, which cannot adaptively adjust to the microbial growth potential, and these chemical disinfectants may cause oxidative damage to the membrane material. This solution employs medium-pressure ultraviolet physical sterilization technology, achieving precise sterilization through graded adjustment of the lamp output power. Simultaneously, considering the impact of inlet water temperature on the thermal stress state of the lamps, a power increase slope limit is set to protect the lamp equipment.
[0036] Specifically, this embodiment pre-sets five power output levels, each corresponding to a sterilization intensity requirement range and a power reference value: the first level corresponds to the first-level sterilization intensity requirement, with a power reference value of 30% of the lamp's rated power; the second level corresponds to the second level, with a power reference value of 50% of the rated power; the third level corresponds to the third level, with a power reference value of 70% of the rated power; the fourth level corresponds to the fourth level, with a power reference value of 85% of the rated power; and the fifth level corresponds to the fifth level, with a power reference value of 100% of the rated power. In this embodiment, the rated power of the medium-pressure ultraviolet lamp is 3000 watts, so the power reference values for each level are 900 watts, 1500 watts, 2100 watts, 2550 watts, and 3000 watts, respectively.
[0037] When the sterilization intensity requirement level increases to a higher level, the dynamic target power is immediately switched to the power reference value of the corresponding higher power output level, and a one-time power boost pulse is applied. The purpose of the additional power boost pulse is: when increased microbial growth is detected, high-intensity ultraviolet irradiation needs to be applied in a short period of time to quickly inhibit microbial reproduction and prevent further spread of contamination; pulsed high-power output is more energy-efficient than continuous high-power operation, while achieving rapid sterilization.
[0038] The power boost pulse is determined as follows: the pulse amplitude is set to 10% to 20% of the power reference value corresponding to the higher power output level. In this embodiment, 15% is used as the standard pulse amplitude. The pulse duration is inversely proportional to the instantaneous flow rate (the water residence time is longer when the flow rate is low, requiring a longer pulse duration) and directly proportional to the microbial growth activity characteristic value (high activity requires a longer period of high-intensity sterilization). The calculation formula is: pulse duration = reference duration × (reference flow rate / current instantaneous flow rate) × (microbial growth activity characteristic value / reference activity characteristic value), where the reference duration is set to 60 seconds, the reference flow rate is set to 200 cubic meters per hour, and the reference activity characteristic value is set to 0.0002. During the application of the power boost pulse, the constraint of the lamp power boost slope limit value is temporarily released to ensure that the pulse can quickly reach the target amplitude. After the pulse ends, the constraint of the lamp power boost slope limit value is immediately restored and the normal power tracking state is entered.
[0039] When the sterilization intensity requirement level remains unchanged for more than the specified number of sampling cycles, the dynamic target power will be locked at the power reference value of the current power output level. The specified number of sampling cycles is set to 10 cycles (i.e., 5 minutes). If the sterilization intensity requirement level remains unchanged for 5 consecutive minutes, it indicates that the system has entered a stable operating state. At this time, locking the power at the reference value can avoid unnecessary power fluctuations and extend the lamp life.
[0040] When the required sterilization intensity level decreases, the dynamic target power should be allowed to switch down to the lower power output level reference value only after a delay of at least two sampling cycles. The purpose of delaying the switch is that microbial growth has certain periodic fluctuation characteristics, and a brief decrease in activity may be a trough in the fluctuation rather than a true mitigation of pollution. Delaying the switch by two cycles (60 seconds) can effectively avoid premature reduction of sterilization power due to misjudgment, which could lead to a rebound in microorganisms.
[0041] The inlet water temperature affects the thermal stress state of the medium-pressure ultraviolet lamp: at low temperatures, the lamp is in a relatively cold state, and a rapid increase in power will cause excessive thermal stress in the quartz sleeve of the lamp, affecting the lamp's lifespan or even causing it to break; at high temperatures, the lamp is already in a relatively hot state, and the change in thermal stress is relatively gradual, so the power increase rate can be appropriately accelerated to improve the sterilization response speed.
[0042] This embodiment establishes a mapping table between inlet water temperature and the maximum allowable power increase rate of the lamp tube as follows: water temperature of 5 degrees Celsius corresponds to a basic slope limit of 50 watts per second; water temperature of 10 degrees Celsius corresponds to 80 watts per second; water temperature of 15 degrees Celsius corresponds to 120 watts per second; water temperature of 20 degrees Celsius corresponds to 160 watts per second; water temperature of 25 degrees Celsius corresponds to 200 watts per second; water temperature of 30 degrees Celsius corresponds to 240 watts per second; and water temperature of 35 degrees Celsius corresponds to 280 watts per second. For water temperature values not listed in the mapping table, the corresponding basic slope limit value is obtained using a linear interpolation method.
[0043] After finding the basic slope limit value in the corresponding mapping table based on the current inlet water temperature, the following adjustments are made: When the inlet water temperature is lower than the preset low temperature threshold (set to 10 degrees Celsius, which is determined based on the typical lower limit of the operating temperature of the medium-pressure ultraviolet lamp), the basic slope limit value is multiplied by the preset low temperature suppression coefficient of 0.6 to further reduce the power boost rate and protect the lamp in the low temperature state; when the inlet water temperature is higher than the preset high temperature threshold (set to 30 degrees Celsius, which is determined based on the typical upper limit of the operating temperature of the medium-pressure ultraviolet lamp), the basic slope limit value is multiplied by the preset high temperature relaxation coefficient of 1.3 to accelerate the power boost rate and improve the sterilization response speed; the processed result is used as the lamp power boost slope limit value for the current collection cycle.
[0044] For example, when the inlet water temperature is 8 degrees Celsius, the basic slope limit value obtained by linear interpolation is 68 watts per second. Since it is 10 degrees Celsius below the low temperature threshold, after multiplying by the low temperature suppression coefficient of 0.6, the lamp power increase slope limit value is 40.8 watts per second.
[0045] Step S4: Determine the power adjustment damping coefficient based on the current working power of the lamp and the changing trend of the inlet water temperature; obtain the actual power correction amount for the current acquisition cycle based on the power adjustment damping coefficient and the lamp power increase slope limit; and control the real-time output power of the medium-pressure ultraviolet lamp based on the dynamic target power and the actual power correction amount to achieve precise physical killing of microorganisms in the water treatment system.
[0046] Existing technologies lack intelligent closed-loop control mechanisms, making it difficult for maintenance personnel to implement precise sterilization interventions at the optimal time. This solution achieves smooth and stable power output control through dual constraints of power adjustment damping coefficient and slope limit value, avoiding fatigue damage to lamps caused by frequent fluctuations, while ensuring timely sterilization response.
[0047] The trend of inlet water temperature reflects the dynamic characteristics of the system's heat load: when the temperature rises rapidly, it indicates that the system's heat load is increasing. At this time, the thermal stress margin of the lamp is reduced, and the damping coefficient needs to be increased to limit the power adjustment range; when the temperature drops rapidly, it indicates that the system's heat load is decreasing, and the lamp is in the cooling process. Similarly, the damping coefficient needs to be increased to avoid thermal shock caused by sudden power changes; when the temperature is stable, the thermal stress state of the lamp is stable, and the damping coefficient can be reduced to accelerate the power tracking speed.
[0048] The method for determining the power adjustment damping coefficient in this embodiment is as follows: First, calculate the direction and magnitude of inlet water temperature changes within adjacent data collection periods. (Water temperature change amount) The direction of change is from The sign of the symbol is determined, and the range of change is... The absolute value of.
[0049] Then, the base value of the power adjustment damping coefficient is determined according to the following rules: When the inlet water temperature shows a continuous upward trend (ΔTemp is positive for three consecutive cycles) and the change exceeds the preset temperature rise threshold (set at 0.5 degrees Celsius per cycle, meaning a temperature rise exceeding 0.5 degrees Celsius within 30 seconds indicates a rapid increase in system heat load), the power adjustment damping coefficient is set to the first damping value of 0.4. This value is set based on the principle that during rapid temperature increases, the power adjustment should be limited to 40% of the original demand to prevent damage to the lamps from the accumulated heat load.
[0050] When the inlet water temperature shows a continuous downward trend (for three consecutive cycles) When all values are negative and the change exceeds the preset temperature drop threshold (set to 0.5 degrees Celsius per cycle), the power adjustment damping coefficient is set to the second damping value of 0.5. The reason for this value being slightly higher than the first damping value is that the lamp is in the cooling process when the temperature drops, and the risk of thermal shock is relatively lower than when the temperature rises, so the power adjustment range can be appropriately relaxed.
[0051] When the inlet water temperature variation remains within a preset stable range (±0.2 degrees Celsius per cycle) for multiple consecutive sampling cycles (set to 5 cycles, i.e., 2.5 minutes), the power adjustment damping coefficient is gradually adjusted to the third damping value of 0.9. The gradual adjustment method is as follows: change the current damping coefficient by 0.1 in each cycle until it reaches 0.9. When the temperature is stable, the lamp's thermal stress state is good, and power adjustment is almost unrestricted to ensure rapid sterilization response.
[0052] Finally, based on the direction of the difference between the current lamp operating power and the dynamic target power, the selected damping coefficient is assigned a positive or negative sign to obtain the final power adjustment damping coefficient. When the dynamic target power is greater than the current lamp operating power (power needs to be increased), the damping coefficient is positive; when the dynamic target power is less than the current lamp operating power (power needs to be reduced), the damping coefficient is negative.
[0053] Furthermore, methods for obtaining the actual power correction amount include: First, the difference between the dynamic target power and the current lamp operating power is used as the initial power adjustment requirement. Let the dynamic target power be... The current operating power of the lamp is The original power adjustment requirement .
[0054] Secondly, based on the power adjustment damping coefficient, the original power adjustment demand is limited in amplitude and direction to obtain the damped power adjustment amount. Damped power adjustment amount ,in The damping coefficient is adjusted for power, and its absolute value is used for amplitude limitation. The sign of the damping coefficient is already included. middle.
[0055] Then, the damped power adjustment amount is converted into a power adjustment rate, which is compared with the lamp power increase slope limit value, and the smaller value is taken as the maximum single-step adjustment amount allowed in the current acquisition cycle. Specifically, the damped power adjustment amount is divided by the current acquisition cycle duration to obtain the damped power adjustment rate. ,in, This represents the current acquisition cycle duration. The damped power adjustment rate is compared with the lamp power increase slope limit, and the smaller value is taken as the maximum single-step adjustment rate. The purpose of taking the smaller value is: when the damped adjustment rate exceeds the lamp's maximum allowable power increase rate, the slope limit is used to prevent excessively rapid power changes from causing thermal shock damage to the lamp; when the damped adjustment rate is lower than the slope limit, the damped adjustment rate is used to achieve smooth power tracking.
[0056] Finally, after time-homogenization processing of the maximum single-step adjustment amount based on the current acquisition cycle duration, the actual power correction amount is obtained. The specific method for time-homogenization is as follows: multiply the maximum single-step adjustment rate by the current acquisition cycle duration, convert the rate dimension (watts per second) to the power dimension (watts), and obtain the actual allowable power correction amount within the current acquisition cycle. ,in This is a sign function; it outputs 1 when the input is positive and -1 when the input is negative, ensuring that the power correction direction is consistent with the original adjustment requirement. The significance of time-uniform processing lies in the fact that the acquisition cycle length may differ under different operating conditions (for example, the acquisition cycle may be longer when the system is busy). By multiplying the adjustment rate by the actual acquisition cycle length, it ensures that the power correction amount is proportional to time, making the power adjustment process consistent and predictable in the time dimension.
[0057] The current lamp operating power is added to the actual power correction amount to obtain the lamp target output power for the next acquisition cycle. This is then sent as a control command to the power module of the medium-voltage ultraviolet lamp to achieve real-time adjustment of the lamp output power.
[0058] Through the above methods, this solution achieves quantitative analysis of microbial growth potential based on real-time water quality monitoring data and intelligent closed-loop control of the output power of medium-pressure ultraviolet lamps. It overcomes the inherent drawbacks of traditional manual inspection and periodic chemical sterilization modes, such as response lag and low control accuracy. The physical sterilization method eliminates the risk of oxidative damage to membrane materials by chemical sterilizers. Power grading adjustment and damping control extend the service life of lamp equipment, thereby reducing system operating energy consumption and maintenance costs, and improving the safe and economical operation capability of the water treatment system under the new situation of power grid peak shaving.
[0059] Example 2 Please see Figure 2 As shown, for parts not described in detail in this embodiment, please refer to the description in Embodiment 1. A high-pressure microbial monitoring and ultraviolet intelligent sterilization system for a water treatment system is provided, including: Multi-parameter acquisition module: Real-time acquisition of instantaneous flow rate, inlet water temperature, instantaneous transmittance value of the current treatment section of the water treatment system, and the current lamp power of the medium-pressure ultraviolet sterilizer; The grade assessment module determines the microbial growth activity characteristic value based on the decrease magnitude and rate of decrease of the instantaneous transmittance value within adjacent collection cycles; and obtains the sterilization intensity requirement level based on the combination relationship between the microbial growth activity characteristic value and the instantaneous flow rate. The graded decision module adjusts the output power of the medium-pressure ultraviolet lamps according to the sterilization intensity requirement level to obtain the dynamic target power for the current collection cycle; and determines the lamp power increase slope limit value according to the matching relationship between the dynamic target power and the inlet water temperature. Control execution module: Determines the power adjustment damping coefficient based on the current lamp working power and the changing trend of inlet water temperature; obtains the actual power correction amount for the current acquisition cycle based on the power adjustment damping coefficient and the lamp power increase slope limit; and controls the real-time output power of the medium-pressure ultraviolet lamp based on the dynamic target power and the actual power correction amount.
[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system, characterized in that, include: Step S1: Real-time acquisition of the instantaneous flow rate, inlet water temperature, instantaneous transmittance value, and current lamp power of the medium-pressure ultraviolet sterilizer in the current treatment section of the water treatment system; Step S2: Determine the microbial growth activity characteristic value based on the decrease magnitude and rate of decrease of the instantaneous transmittance value within adjacent collection cycles; obtain the sterilization intensity requirement level based on the combination relationship between the microbial growth activity characteristic value and the instantaneous flow rate. Step S3: Adjust the output power of the medium-pressure ultraviolet lamps according to the sterilization intensity requirement level to obtain the dynamic target power for the current collection cycle; determine the lamp power increase slope limit value according to the matching relationship between the dynamic target power and the inlet water temperature. Step S4: Determine the power adjustment damping coefficient based on the current operating power of the lamp tube and the changing trend of the inlet water temperature; Based on the power adjustment damping coefficient and the lamp power increase slope limit, the actual power correction amount for the current acquisition cycle is obtained. The real-time output power of the medium-pressure ultraviolet lamp is controlled based on the dynamic target power and the actual power correction.
2. The method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system according to claim 1, characterized in that, The methods for determining the characteristic values of microbial growth activity include: The difference between the instantaneous transmittance value of the current acquisition cycle and the instantaneous transmittance value of the previous acquisition cycle is calculated as the transmittance decrease. Based on the cumulative value of the transmittance decrease over three consecutive acquisition cycles, a transmittance attenuation cumulative index is obtained. Based on the degree of deviation between the instantaneous transmittance values of the current and previous acquisition cycles and the preset clean transmittance benchmark value, a transmittance deviation weighting factor is determined. The transmittance attenuation cumulative index is divided by the current instantaneous flow rate and multiplied by the transmittance deviation weighting factor to obtain the microbial growth activity characteristic value.
3. The method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system according to claim 2, characterized in that, The method of obtaining the sterilization intensity requirement level based on the combination relationship between microbial growth activity characteristic values and instantaneous flow rate includes: The instantaneous flow rate is divided and adjusted to obtain flow ranges, each flow range corresponding to a basic dose coefficient; an activity correction coefficient is determined based on the magnitude of the microbial growth activity characteristic value; the basic dose coefficient of the flow range to which the current instantaneous flow rate belongs is multiplied by the activity correction coefficient to obtain a comprehensive dose requirement index; the comprehensive dose requirement index is compared with multiple preset dose threshold ranges to determine the corresponding sterilization intensity requirement level.
4. The method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system according to claim 3, characterized in that, The step of adjusting the output power of the medium-pressure ultraviolet lamp in stages based on the sterilization intensity requirement level to obtain the dynamic target power for the current sampling period includes: The power output levels are preset, with each power output level corresponding to a sterilization intensity requirement range and a power reference value. When the sterilization intensity requirement level increases to a higher level, the dynamic target power is immediately switched to the power reference value of the corresponding higher power output level, and a one-time power boost pulse is added. When the sterilization intensity requirement level remains unchanged for more than a specified number of sampling cycles, the dynamic target power is locked at the power reference value of the current power output level. When the sterilization intensity requirement level decreases, the dynamic target power is allowed to switch down to the power reference value of the lower power output level after a delay of at least two sampling cycles.
5. The method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system according to claim 4, characterized in that, The step of determining the lamp power increase slope limit value based on the matching relationship between dynamic target power and inlet water temperature includes: Establish a mapping table between inlet water temperature and the maximum allowable power increase rate of the lamp tube; find the basic slope limit value in the corresponding mapping table based on the current inlet water temperature; when the inlet water temperature is lower than the preset low temperature threshold, multiply the basic slope limit value by the preset low temperature suppression coefficient; when the inlet water temperature is higher than the preset high temperature threshold, multiply the basic slope limit value by the preset high temperature relaxation coefficient; use the processed result as the lamp tube power increase slope limit value for the current acquisition cycle.
6. The method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system according to claim 5, characterized in that, The determination of the power adjustment damping coefficient based on the changing trend of the current lamp operating power and the inlet water temperature includes: Calculate the direction and magnitude of inlet water temperature change within adjacent acquisition cycles; when the inlet water temperature shows a continuous upward trend and the magnitude of change exceeds the preset temperature rise threshold, set the power adjustment damping coefficient to the first damping value; when the inlet water temperature shows a continuous downward trend and the magnitude of change exceeds the preset temperature drop threshold, set the power adjustment damping coefficient to the second damping value; when the inlet water temperature change remains within the preset stable range for multiple consecutive acquisition cycles, gradually adjust the power adjustment damping coefficient to the third damping value; based on the direction of the difference between the current lamp working power and the dynamic target power, assign positive and negative signs to the selected damping coefficient to obtain the final power adjustment damping coefficient.
7. The method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system according to claim 6, characterized in that, The method of obtaining the actual power correction amount for the current acquisition cycle based on the power adjustment damping coefficient and the lamp power increase slope limit includes: The difference between the dynamic target power and the current lamp operating power is used as the original power adjustment requirement. The original power adjustment requirement is limited in amplitude and direction based on the power adjustment damping coefficient to obtain the damped power adjustment amount. The damped power adjustment amount is converted into a power adjustment rate and compared with the lamp power increase slope limit value. The smaller value is taken as the maximum single-step adjustment amount allowed in the current acquisition cycle. After time unification processing of the maximum single-step adjustment amount according to the duration of the current acquisition cycle, the actual power correction amount is obtained.
8. The method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system according to claim 7, characterized in that, The method for determining the additional one-time power boost pulse includes: The pulse amplitude is 10% to 20% of the power reference value corresponding to the higher power output level; the pulse duration is inversely proportional to the instantaneous flow rate and directly proportional to the microbial growth activity characteristic value; during the application of the power boost pulse, the constraint of the lamp power boost slope limit value is temporarily released; after the pulse ends, the constraint of the lamp power boost slope limit value is immediately restored and the lamp enters the normal power tracking state.
9. The method for high-pressure microbial monitoring and ultraviolet intelligent sterilization in a water treatment system according to claim 8, characterized in that, The methods for dividing and adjusting instantaneous flow include: Initially, the entire flow range is divided into N flow intervals; the percentage of times each flow interval is actually triggered in the recent period is counted; adjacent flow intervals with a trigger percentage lower than the preset low-frequency threshold are merged; flow intervals with a trigger percentage higher than the preset high-frequency threshold are proportionally subdivided into M sub-intervals; the updated flow intervals and their corresponding basic dose coefficients take effect automatically at the start of the next acquisition cycle.
10. A high-pressure microbial monitoring and ultraviolet intelligent sterilization system for a water treatment system, used to implement the high-pressure microbial monitoring and ultraviolet intelligent sterilization method for a water treatment system as described in any one of claims 1 to 9, characterized in that, include: Multi-parameter acquisition module: Real-time acquisition of instantaneous flow rate, inlet water temperature, instantaneous transmittance value of the current treatment section of the water treatment system, and the current lamp power of the medium-pressure ultraviolet sterilizer; The rating assessment module determines the characteristic value of microbial growth activity based on the magnitude and rate of decrease in the instantaneous value of transmittance within adjacent collection cycles. Based on the combination relationship between the characteristic value of microbial growth activity and instantaneous flow rate, the required level of sterilization intensity is obtained; The graded decision module adjusts the output power of the medium-pressure ultraviolet lamps according to the sterilization intensity requirement level to obtain the dynamic target power for the current collection cycle; and determines the lamp power increase slope limit value according to the matching relationship between the dynamic target power and the inlet water temperature. Control execution module: Determines the power adjustment damping coefficient based on the changing trend of the current lamp working power and the inlet water temperature; Based on the power adjustment damping coefficient and the lamp power increase slope limit, the actual power correction amount for the current acquisition cycle is obtained. The real-time output power of the medium-pressure ultraviolet lamp is controlled based on the dynamic target power and the actual power correction.