A total chlorine guarantee method and system for secondary water supply storage equipment based on water age control

Abstract

The present invention discloses a method and system for ensuring total chlorine in secondary water supply storage equipment based on water age control. The method includes: Step S1, select a number of reference secondary water supply storage equipment in the water supply area to be predicted for total chlorine in secondary water supply storage equipment, and obtain the total chlorine decay indexes of each reference secondary water supply storage equipment at different temperatures; Step S2, determine the general total chlorine decay index of each secondary water supply storage equipment in the current water supply area; Step S3, obtain the liquid level change data of the secondary water supply storage equipment to be measured, and according to the liquid level change data of the secondary water supply storage equipment to be measured and the general total chlorine decay index, use the pre-determined total chlorine prediction model to obtain the corresponding outlet total chlorine, and compare the predicted value with the measured value to determine the applicability of the model; Step S4, according to the outlet total chlorine target control value and the total chlorine prediction model, obtain the average water age as the control requirement for the secondary water supply storage equipment in this area.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary water supply in urban water supply pipe network systems, and particularly to a method and system for ensuring total chlorine in secondary water supply storage equipment based on water age control. Background Art

[0002] As an important link in urban residents' water supply, the rationality of the design and the later operation and maintenance management of secondary water supply have an important impact on the water quality at the faucet. And secondary water supply storage equipment, such as secondary water supply pools (tanks), is one of the important facilities in the secondary water supply process, mainly responsible for storing drinking water to adjust the contradiction between municipal water supply and users' water demand, so as to ensure the safety of users' water demand. However, water quality problems caused by secondary water supply pools (tanks) often occur.

[0003] The water quality problems brought by secondary water supply pools (tanks) mainly include metal oxides and harmful metal ions corroded by the material of the pool (tank) itself, pollution of water quality by chemical elements, and problems of moss, red worm breeding and bacterial reproduction caused by too long residence time. Total chlorine can inhibit the growth of bacteria in the pool (tank) and is an important indicator representing the water quality safety of secondary water supply. At present, there are many studies on the attenuation law of total chlorine in the water supply pipe network, but there are few studies on the variation law of total chlorine and water age in secondary water supply pools (tanks).

[0004] Therefore, there is an urgent need for an efficient and accurate prediction method for total chlorine in secondary water supply pools (tanks), which has important practical significance for effectively solving the water quality safety of the "last kilometer" of urban water supply. Summary of the Invention

[0005] To overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a method and system for ensuring total chlorine in secondary water supply storage equipment based on water age control, so as to achieve the purpose of accurately and efficiently ensuring that the total chlorine in secondary water supply pools (tanks) meets the requirements.

[0006] To achieve the above purpose, the present invention proposes a method for ensuring total chlorine in secondary water supply storage equipment based on water age control, including the following steps:

[0007] Step S1, select a number of reference secondary water supply storage equipment in the water supply area where the total chlorine of the secondary water supply storage equipment is to be predicted, obtain the total chlorine monitoring data of each reference secondary water supply storage equipment at different temperatures, and obtain the total chlorine attenuation index of each reference secondary water supply storage equipment at different temperatures by analyzing the change law of the total chlorine of the secondary water supply storage equipment;

[0008] Step S2, determine the general total chlorine attenuation index of each secondary water supply storage equipment in the current water supply area according to the total chlorine attenuation index of each reference secondary water supply storage equipment at different temperatures;

[0009] Step S3, obtain the liquid level change data of the secondary water supply storage equipment to be measured. According to the liquid level change data of the secondary water supply storage equipment to be measured and the general total chlorine decay index, use the pre-determined total chlorine prediction model to obtain the corresponding outlet total chlorine, and compare the outlet total chlorine obtained according to the total chlorine prediction model with the measured outlet total chlorine to determine the applicability of the total chlorine prediction model;

[0010] Step S4, according to the outlet total chlorine target control value and the total chlorine prediction model, obtain the average water age as the control requirement for the secondary water supply storage equipment in this area.

[0011] Preferably, in step S1, select several secondary water supply pools or water tanks with the worst conditions in the current water supply area as the reference secondary water supply storage equipment, install water quality monitoring equipment in each reference secondary water supply storage equipment, and then monitor the total chlorine monitoring data C at multiple moments under different temperatures through the water quality monitoring equipment installed in each reference secondary water supply storage equipment t , and use the multiple total chlorine monitoring data of each reference secondary water supply storage equipment at each temperature to obtain the total chlorine decay index of each reference secondary water supply storage equipment at different temperatures.

[0012] Preferably, in step S2, for the total chlorine decay indexes of each reference secondary water supply storage equipment obtained at different temperatures, select the maximum value of the total chlorine decay index as the general total chlorine decay index of each secondary water supply storage equipment in the current water supply area.

[0013] Preferably, the total chlorine prediction model is:

[0014]

[0015] Wherein, C is the average total chlorine concentration of the influent water of the secondary water supply water tank (pool), C' is the average total chlorine concentration of the outlet water of the secondary water supply water tank (pool). When used for water age control, C' is the outlet total chlorine target control value, a is the ratio of the difference between the liquid level for closing the valve and stopping water replenishment and the liquid level for opening the valve and replenishing water of the secondary water supply storage equipment to the liquid level for closing the valve and stopping water replenishment, that is, the ratio of the water replenishment volume X to the effective volume V, k is the general total chlorine decay index; q is the average hourly water consumption of residents corresponding to the outlet of the secondary water supply storage equipment, and V is the effective volume of the secondary water supply storage equipment to be measured.

[0016] Preferably, in step S3, monitor the liquid level change data of the secondary water supply storage device to be measured, obtain the effective volume of the secondary water supply storage device to be measured, the ratio of the difference between the liquid level for closing the valve and stopping water replenishment and the liquid level for opening the valve and replenishing water of the secondary water supply storage device to be measured to the liquid level for closing the valve and stopping water replenishment, monitor and obtain the average hourly water consumption q of the residents corresponding to the outlet of the secondary water supply storage device, and combine the general total chlorine decay index k obtained in step S2 and the total chlorine concentration at the inlet of the secondary water supply storage device to be measured. Use the total chlorine prediction model to obtain the total chlorine concentration C' at the outlet of the secondary water supply storage device to be measured, and compare the calculated value with the monitored value to determine the applicability of the total chlorine prediction model.

[0017] Preferably, in step S4, when the judgment result is that the total chlorine prediction model meets the applicability, use the outlet total chlorine target control value as the average total chlorine concentration C' at the outlet of the secondary water supply storage device, obtain the average water age according to the total chlorine prediction model, and thus adjust the effective volume of the secondary water supply storage device in this area according to the result.

[0018] To achieve the above object, the present invention also provides a total chlorine guarantee system for a secondary water supply storage device based on water age control, including:

[0019] A reference device total chlorine analysis module, which is used to select several reference secondary water supply storage devices in the water supply area for total chlorine prediction of the secondary water supply storage device, obtain the total chlorine monitoring data of each reference secondary water supply storage device at different temperatures, and obtain the total chlorine decay index of each reference secondary water supply storage device at different temperatures by analyzing the total chlorine change law of the secondary water supply storage device;

[0020] A general total chlorine decay index determination module, which is used to determine the general total chlorine decay index of each secondary water supply storage device in the current water supply area according to the total chlorine decay index of each reference secondary water supply storage device at different temperatures;

[0021] A total chlorine prediction module, which is used to obtain the liquid level change data of the secondary water supply storage device to be measured, and according to the liquid level change data of the secondary water supply storage device to be measured and the general total chlorine decay index, use the pre-determined total chlorine prediction model to obtain the corresponding total chlorine at the outlet, and compare the obtained predicted value with the measured value to determine the applicability of the total chlorine prediction model.

[0022] A total chlorine guarantee module, which is used to, after judging that the total chlorine prediction model meets the applicability, obtain the average water age as the control requirement of the current secondary water supply storage device to be measured according to the outlet total chlorine target control value and the total chlorine prediction model, so as to obtain the regulation basis for the current area.

[0023] Preferably, the total chlorine prediction module compares the obtained predicted value with the measured value to judge the accuracy, determines the applicability of the total chlorine prediction model according to the accuracy. After judging that the total chlorine prediction model meets the applicability, the total chlorine guarantee module substitutes the outlet total chlorine target control value into the total chlorine prediction model to obtain the average water age as the regional control target, and adjusts the effective volume V of the secondary water supply storage equipment in the current area accordingly.

[0024] Preferably, the reference equipment total chlorine analysis module selects several secondary water supply pools or water tanks with the worst conditions in the current water supply area as the reference secondary water supply storage equipment, installs water quality monitoring equipment in each reference secondary water supply storage equipment, and then monitors the total chlorine monitoring data C at multiple moments under different temperatures through the water quality monitoring equipment installed in each reference secondary water supply storage equipment. t The total chlorine decay index of each reference secondary water supply storage equipment at different temperatures is obtained by using the multiple total chlorine monitoring data of each reference secondary water supply storage equipment at each temperature.

[0025] Preferably, the total chlorine prediction model is:

[0026]

[0027] Wherein, C is the average total chlorine concentration of the influent water of the secondary water supply water tank (pool), C' is the average total chlorine concentration of the outlet of the secondary water supply water tank (pool). When used for water age control, C' is the outlet total chlorine target control value, a is the ratio of the difference between the liquid level for closing the valve and stopping water replenishment and the liquid level for opening the valve and replenishing water in the secondary water supply storage equipment to the liquid level for closing the valve and stopping water replenishment, that is, the ratio of the water replenishment volume X to the effective volume V, k is the general total chlorine decay index; q is the average hourly water consumption of residents corresponding to the outlet of the secondary water supply storage equipment, and V is the effective volume of the secondary water supply storage equipment to be determined.

[0028] Compared with the prior art, the total chlorine guarantee method and system for secondary water supply storage equipment based on water age control of the present invention can determine the relationship between the total chlorine at the outlet of the secondary water supply pool (tank) and the water age by using the liquid level change data and the total chlorine decay index of the secondary water supply pool (tank) to be predicted with a pre-established total chlorine prediction model, which can provide theoretical support for adjusting the operating water level of the pool (tank) and shortening the water age of the pool (tank) on the premise of ensuring the water use safety of users, and has a small prediction error and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the step flow chart of the total chlorine guarantee method for secondary water supply storage equipment based on water age control of the present invention;

[0030] Figure 2 is the schematic diagram of the liquid level change of the secondary water supply storage equipment under the control of the liquid level valve;

[0031] Figure 3 It is a diagram showing the total chlorine attenuation at different temperatures in a specific embodiment of the present invention;

[0032] Figure 4 It is a diagram showing the equalization hypothesis of the water replenishment interval for liquid level control water replenishment during the model derivation process in the present invention;

[0033] Figure 5 It is a comparison diagram between the measured value and the model calculated value of the total chlorine concentration at the outlet of Pool A in a specific embodiment of the present invention;

[0034] Figure 6 It is a system structure diagram of a total chlorine guarantee system for a secondary water supply storage device based on water age control in the present invention. Specific Embodiments

[0035] The following describes the embodiments of the present invention through specific examples in combination with the drawings. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific examples, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] Figure 1 It is a step flow chart of a total chlorine guarantee method for a secondary water supply storage device based on water age control in the present invention. As Figure 3 shown, a total chlorine guarantee method for a secondary water supply storage device based on water age control in the present invention includes the following steps:

[0037] Step S1, select a number of reference secondary water supply storage devices in the water supply area where the total chlorine of the secondary water supply storage device is to be predicted, obtain the total chlorine monitoring data of each reference secondary water supply storage device at different temperatures, and analyze the total chlorine change law of the secondary water supply storage device to obtain the total chlorine attenuation index of each reference secondary water supply storage device at different temperatures.

[0038] In a specific embodiment of the present invention, the secondary water supply storage device is a secondary water supply pool (tank). Select a number of secondary water supply pools (tanks) with the worst performance as reference secondary water supply storage devices. The secondary water supply pools (tanks) with the worst performance can be those secondary water supply pools (tanks) whose service life exceeds the specified years, or those with more complaints, or those with more severe internal corrosion. By statistically analyzing the total chlorine change law of the secondary water supply pool (tank), the attenuation law of total chlorine in the water supply pipe network shows an exponential change:

[0039] C t =Ce -kt

[0040] Among them, C tIt represents the value of chlorine in the water supply network at time t, with the unit of mg / L. C represents the initial chlorine value in the water supply network, with the unit of mg / L; k represents the total chlorine decay index.

[0041] In a specific embodiment of the present invention, select 3 - 5 secondary water supply reservoirs (tanks) with poor conditions in a selected area (here, the area generally refers to an area where the influent chlorine concentration is similar as the current water supply area. For example, within 3 kilometers from the water plant can be considered as one area, and 3 - 6 kilometers is another area, and so on) as reference secondary water supply reservoirs (tanks), such as secondary water supply reservoirs (tanks) with poor conditions (such as those with poor materials like concrete structures, older ages, and more problems like red worms complained by residents). By installing liquid level control valves in each reference secondary water supply reservoir (tank) and installing water quality monitoring equipment (such as on - line water quality monitors) on the inlet and outlet pipes of the reservoir (tank), then monitor the total chlorine monitoring data C at multiple moments under different temperatures through the water quality monitoring equipment installed in each reference secondary water supply reservoir (tank). t , and use the multiple total chlorine monitoring data of each reference secondary water supply reservoir (tank) at each temperature to obtain the total chlorine decay index of each reference secondary water supply reservoir (tank) at different temperatures, as Figure 3 shown.

[0042] Step S2: Determine the general total chlorine decay index of each secondary water supply storage device in the current water supply area according to the total chlorine decay indices of each reference secondary water supply storage device at different temperatures.

[0043] In a specific embodiment of the present invention, for the total chlorine decay indices of each obtained reference secondary water supply reservoir (tank) at different temperatures, select the maximum value of the total chlorine decay index as the general total chlorine decay index of each secondary water supply reservoir (tank) in the current water supply area, that is, obtain the fastest total chlorine decay coefficient at high temperatures as the general total chlorine decay index of each secondary water supply reservoir (tank).

[0044] Step S3: Obtain the liquid level change data of the secondary water supply storage device to be measured. According to the liquid level change data of the secondary water supply storage device to be measured and the general total chlorine decay index, use the pre - determined total chlorine prediction model to obtain the corresponding outlet total chlorine, and compare the outlet total chlorine obtained according to the total chlorine prediction model with the measured outlet total chlorine to determine the applicability of the total chlorine prediction model.

[0045] In a specific embodiment of the present invention, the derivation process of the total chlorine prediction model is as follows: Assume that the water replenishment cycle is T, and T is a constant. The product of the difference between the water shut-off and replenishment stop level and the opening level of the valve and the bottom area is the water replenishment volume, denoted as X. The product of the opening level of the valve for water replenishment and the bottom area is the water storage volume, denoted as Y. The ratio of the difference between the water shut-off and replenishment stop level and the opening level of the valve to the water shut-off and replenishment stop level (the ratio of the water replenishment volume X to the effective volume V) is a, and a = X / (X + Y); the ratio of the opening level of the valve for water replenishment to the water shut-off and replenishment stop level (the ratio of the water storage volume Y to the effective volume V) is b, and b = Y / (X + Y).

[0046] The first water supply cycle:

[0047] Assume that when the secondary water supply pool (tank) is initially at the water shut-off and replenishment stop level after being put into operation, the pool (tank) is at a high water level, and the total chlorine concentration at this time is C.

[0048] After T time, the water level drops to the opening level of the valve for water replenishment, and it is at a low water level. At this time, the total chlorine concentration in the pool (tank) is:

[0049] Ce -kT

[0050] The second water supply cycle:

[0051] Assume that the total chlorine concentration of the replenished water is the same as the initial total chlorine concentration, both being C. At the end of the first water supply cycle, water replenishment starts until the water shut-off and replenishment stop level. The pool (tank) is at a high water level. At this time, the total chlorine concentration is:

[0052] aC + bCe -kT

[0053] After another T time, when the water level drops to the opening level of the valve for water replenishment, the pool (tank) is at a low water level, and the total chlorine concentration decreases to:

[0054] (aC + bCe -kT )e -kT = aCe -kT + bCe -2kT

[0055] The nth water supply cycle:

[0056] By analogy, at the nth water shut-off and replenishment stop level, the pool (tank) is at a high water level. At this time, the total chlorine concentration in the pool (tank) can be expressed as:

[0057] aC(1 + be -kT + b 2 e -2kT +... + b n-2 e -(n-2)kT ) + b n-1 Ce -(n-1)kT

[0058] Among them, n is greater than or equal to 2.

[0059] After another T time, when the liquid level drops to the valve-opening water replenishment level, the water tank (cistern) is at a low liquid level, and the total chlorine concentration decreases to:

[0060]

[0061] When n approaches infinity, (be -kT ) n-2 and b n-1 Ce -nkT both approach 0. At this time, the total chlorine concentration in the water tank (cistern) is:

[0062]

[0063] This is the lowest total chlorine value of the water tank. If the controlled lowest total chlorine value meets the target value C', it meets the requirements.

[0064] Assume that the initial full water level of the secondary water supply tank (cistern) and the total chlorine concentration C of the influent water are known quantities. The actual average value at the end of the pipe network in this area can be taken as a parameter and substituted. Then the total chlorine prediction model is:

[0065]

[0066] By transforming, we get:

[0067]

[0068] Assume that when the water consumption of residents is uniform within a period of time, the average hourly water consumption corresponding to the outlet of the water tank (cistern) can be set as q, and the effective volume of the water tank (cistern) is V. Then the water replenishment cycle T is:

[0069]

[0070] Substituting into the above formula, the water age control requirements are obtained:

[0071]

[0072] Among them, C is the total chlorine concentration of the influent water of the secondary water supply tank (cistern), with the unit of mg / L; C' is the average total chlorine concentration at the outlet of the secondary water supply tank (cistern), with the unit of mg / L. When used for water age control, C' is the target control value of the total chlorine at the outlet; a is the ratio of the difference between the valve-closing stop and water replenishment level and the valve-opening water replenishment level of the secondary water supply tank (cistern) to the valve-closing stop and water replenishment level, that is, the ratio of the water replenishment volume X to the effective volume v; k is the total chlorine decay rate; q is the average hourly water consumption of residents corresponding to the outlet of the water tank (cistern), with the unit of m 3 / h; V is the effective volume of the secondary water supply tank (cistern), with the unit of m 3 , and V / q represents the average water age.

[0073] Specifically, in this step, the liquid level change data of the secondary water supply tank (or cistern) to be measured is obtained. For example, when the liquid level drops to the valve-opening water replenishment level, the secondary water supply tank (or cistern) to be measured is at a low liquid level, that is, the stored water volume is Y. When the water replenishment reaches the valve-closing stop-replenishment level, the secondary water supply tank (or cistern) to be measured is at a high liquid level, and the effective volume V of the secondary water supply tank (or cistern) at this time is obtained. At this time, the water replenishment volume is X, then the proportion a of the water replenishment volume of the secondary water supply tank (or cistern) is a = X / (X + Y). The average hourly water consumption q of residents corresponding to the outlet of the water tank (or cistern) is obtained through monitoring. Finally, based on the obtained effective volume V of the secondary water supply tank (or cistern), the proportion a of the water replenishment volume of the secondary water supply tank (or cistern), the average hourly water consumption q of residents corresponding to the outlet of the water tank (or cistern), and the general total chlorine decay index k, and combined with the total chlorine concentration of the inlet water of the secondary water supply tank (or cistern) to be measured, the average total chlorine concentration C' at the outlet of the secondary water supply tank (or cistern) is obtained by using the above total chlorine prediction model.

[0074] Finally, the obtained predicted value (i.e., the average total chlorine concentration C' at the outlet of the secondary water supply tank (or cistern) obtained by the total chlorine prediction model) is compared with the measured value to judge the accuracy, and the applicability of the total chlorine prediction model is determined according to the accuracy. That is, if the accuracy meets the requirements, it can be judged that the total chlorine prediction model meets the applicability.

[0075] It has been proven by experiments that as Figure 5 shown, the coincidence degree between the outlet total chlorine concentration value obtained by the water quality monitoring equipment and the outlet total chlorine concentration value obtained by the present invention through this total chlorine prediction model is extremely high, meeting the applicability.

[0076] Step S4, according to the outlet total chlorine target control value and the total chlorine prediction model, the average water age is obtained as the control requirement for the secondary water supply storage equipment in this area. That is to say, when the judgment result is that the total chlorine prediction model meets the applicability, the outlet total chlorine target control value is used as the average total chlorine concentration C' at the outlet of the secondary water supply tank (or cistern). According to the total chlorine prediction model, the average water age V / q is obtained, and thus the effective volume of the secondary water supply storage equipment in this area is adjusted according to the result.

[0077] Figure 6 This is the system structure diagram of a total chlorine guarantee system for secondary water supply storage equipment based on water age control according to the present invention. As Figure 6 shown, a total chlorine guarantee system for secondary water supply storage equipment based on water age control according to the present invention includes:

[0078] A reference equipment total chlorine analysis module 501, which is used to select several reference secondary water supply storage equipment in the water supply area where the total chlorine of the secondary water supply storage equipment is to be predicted, obtain the total chlorine monitoring data of each reference secondary water supply storage equipment at different temperatures, and obtain the total chlorine decay index of each reference secondary water supply storage equipment at different temperatures by analyzing the total chlorine change law of the secondary water supply storage equipment.

[0079] In a specific embodiment of the present invention, the secondary water supply storage device is a secondary water supply pool (tank). Several secondary water supply pools (tanks) with poor performance are selected as reference secondary water supply storage devices. The secondary water supply pools (tanks) with poor performance may be those that have been in use for more than the specified number of years. By statistically analyzing the variation law of total chlorine in the secondary water supply pool (tank), the attenuation law of total chlorine in the water supply pipe network shows an exponential change:

[0080] C t = Ce -kt

[0081] wherein, C t represents the value of chlorine in the water supply pipe network at time t, with the unit of mg / L, C represents the initial chlorine value in the water supply pipe network, with the unit of mg / L; k represents the total chlorine attenuation index.

[0082] In a specific embodiment of the present invention, secondary water supply pools (tanks) with poor conditions in 3-5 communities in the selected area are selected as reference secondary water supply pools (tanks). By installing water quality monitoring equipment (such as an on-line water quality monitor) in each reference secondary water supply pool (tank), and then monitoring the total chlorine monitoring data C t at multiple moments under different temperatures through the water quality monitoring equipment installed in each reference secondary water supply pool (tank), and transmitting it to the total chlorine analysis module 501 of the reference device. The total chlorine analysis module 501 of the reference device obtains the total chlorine attenuation index of each reference secondary water supply pool (tank) at different temperatures by acquiring multiple total chlorine monitoring data of each reference secondary water supply pool (tank) at each temperature.

[0083] The general total chlorine attenuation index determination module 502 is used to determine the general total chlorine attenuation index of each secondary water supply storage device in the current water supply area according to the total chlorine attenuation index of each reference secondary water supply storage device at different temperatures.

[0084] In a specific embodiment of the present invention, for the total chlorine attenuation index of each reference secondary water supply pool (tank) obtained at different temperatures, the general total chlorine attenuation index determination module 502 selects the maximum value of the total chlorine attenuation index as the general total chlorine attenuation index of each secondary water supply pool (tank) in the current water supply area, that is, obtains the fastest total chlorine attenuation coefficient at high temperature as the general total chlorine attenuation index of each secondary water supply pool (tank).

[0085] The total chlorine prediction module 503 is used to obtain the liquid level change data of the secondary water supply storage device to be measured, and according to the liquid level change data of the secondary water supply storage device to be measured and the general total chlorine attenuation index, obtain the corresponding outlet total chlorine by using a pre-determined total chlorine prediction model, and compare the obtained predicted value with the measured value to determine the applicability of the total chlorine prediction model.

[0086] In a specific embodiment of the present invention, it is necessary to first determine the total chlorine prediction model, and the derivation process of the total chlorine prediction model is as follows:

[0087] Statistically analyze the liquid level change law of the secondary water supply water tank (box), and obtain the makeup water volume of the water tank (box), the difference between the liquid level at which the valve is closed to stop makeup and the liquid level at which the valve is opened to make up water as a ratio of the liquid level at which the valve is closed to stop makeup (the makeup water volume X accounts for the effective volume V), and the makeup water cycle.

[0088] Analyze the liquid level change law of the secondary water supply water tank (box). Assume that the makeup water cycle is T, and T is a constant. The makeup water volume is X, the stored water volume is Y, the proportion of the makeup water volume in the total water volume is a, a = X / (X + Y); the proportion of the stored water volume in the total water volume is b, b = Y / (X + Y).

[0089] The first water supply cycle:

[0090] Assume that when the secondary water supply water tank (box) is initially at the liquid level where the valve is closed to stop makeup after being put into operation, the water tank (box) is at a high liquid level, and the total chlorine concentration at this time is C.

[0091] After T moments, the liquid level drops to the liquid level where the valve is opened to make up water and is at a low liquid level. At this time, the total chlorine concentration in the water tank (box) is:

[0092] Ce -kT

[0093] The second water supply cycle:

[0094] Assume that the total chlorine concentration of the makeup water is the same as the initial total chlorine concentration, both are C. At the end of the first water supply cycle, the makeup water starts until the liquid level where the valve is closed to stop makeup, and the water tank (box) is at a high liquid level. At this time, the total chlorine concentration is:

[0095] aC + bCe -kT

[0096] After another T moments, when the liquid level drops to the liquid level where the valve is opened to make up water, the water tank (box) is at a low liquid level, and the total chlorine concentration is reduced to:

[0097] (aC + bCe -kT )e -kT = aCe -kT + bCe -2kT

[0098] The nth water supply cycle:

[0099] By analogy, at the nth time when the valve is closed to stop makeup, the water tank (box) is at a high liquid level. At this time, the total chlorine concentration in the water tank (box) can be expressed as:

[0100] aC(1 + be -kT + b 2 e -2kT +... + bn-2 e -(n-2)kT ) + b n-1 Ce -(n-1)kT

[0101] where n is greater than or equal to 2.

[0102] After another T moments, when the liquid level drops to the liquid level for valve opening and water replenishment, the water tank (cistern) is at a low liquid level, and the total chlorine concentration decreases to:

[0103]

[0104] When n approaches infinity, (be -kT ) n-2 and b n-1 Ce -nkT both approach 0. At this time, the total chlorine concentration in the water tank (cistern) is:

[0105]

[0106] This is the lowest total chlorine value of the water tank. If the controlled lowest total chlorine value meets the target value, then C' meets the requirements.

[0107] Assume that the initial full water level of the secondary water supply tank (cistern) and the total chlorine concentration C of the influent water are known quantities. In practice, the average value at the end of the pipe network in this area can be taken as a parameter and substituted. Then the total chlorine prediction model is:

[0108]

[0109] By transformation, we get:

[0110]

[0111] Assume that when the water consumption of residents is uniform within a period of time, the average hourly water consumption corresponding to the outlet of the water tank (cistern) can be set as q, and the effective volume of the water tank (cistern) is V. Then the water replenishment cycle T is:

[0112]

[0113] Substitute the above formula to obtain the requirements for water age control:

[0114]

[0115] Wherein, C is the total chlorine concentration at the inlet of the secondary water supply tank (pool), with the unit of mg / L; C' is the average total chlorine concentration at the outlet of the secondary water supply tank (pool), with the unit of mg / L. When used for water age control, C' is the target control value of the total chlorine at the outlet; a is the ratio of the difference between the liquid level for closing the valve to stop water replenishment and the liquid level for opening the valve to replenish water in the secondary water supply tank (pool) to the liquid level for closing the valve to stop water replenishment, that is, the ratio of the water replenishment volume X to the effective volume v; k is the total chlorine decay rate; q is the average hourly water consumption of residents corresponding to the outlet of the tank (pool), with the unit of m 3 / h; V is the effective volume of the secondary water supply pool (tank), with the unit of m 3 , and V / q represents the average water age.

[0116] Specifically, the total chlorine prediction module 503 obtains the liquid level change data of the secondary water supply pool (tank) to be measured. For example, when the liquid level drops to the liquid level for opening the valve to replenish water, the secondary water supply pool (tank) to be measured is at a low liquid level, that is, the stored water volume Y. When the water is replenished to the liquid level for closing the valve to stop water replenishment, the secondary water supply pool (tank) to be measured is at a high liquid level, and the effective volume V of the secondary water supply pool (tank) at this time is obtained. At this time, the water replenishment volume is X, then the ratio a of the water replenishment volume of the secondary water supply tank (pool) is a = X / (X + Y). By monitoring, the average hourly water consumption q of residents corresponding to the outlet of the tank (pool) is obtained. Finally, based on the obtained effective volume V of the secondary water supply pool (tank), the ratio a of the water replenishment volume of the secondary water supply tank (pool), the average hourly water consumption q of residents corresponding to the outlet of the tank (pool), and the general total chlorine decay index k, and combined with the total chlorine concentration at the inlet of the secondary water supply pool (tank) to be measured, the average total chlorine concentration C' at the outlet of the secondary water supply tank (pool) is obtained by using the above total chlorine prediction model.

[0117] Finally, the obtained predicted value (that is, the average total chlorine concentration C' at the outlet of the secondary water supply tank (pool) obtained by the total chlorine prediction module) is compared with the measured value to judge the accuracy, and the applicability of the total chlorine prediction model is determined according to the accuracy. That is, if the accuracy meets the requirements, it can be judged that the total chlorine prediction model meets the applicability.

[0118] It has been proved by experiments that as Figure 5 shown, the coincidence degree between the total chlorine concentration value at the outlet obtained by using the water quality monitoring equipment and the total chlorine concentration value at the outlet obtained by the present invention through this total chlorine prediction model is extremely high, meeting the applicability.

[0119] The total chlorine guarantee module 504 is used to, after judging that the total chlorine prediction model meets the applicability, obtain the average water age as the control requirement for the secondary water supply storage equipment in this area according to the outlet total chlorine target control value and the total chlorine prediction model, so as to obtain the regulation basis for the current area.

[0120] Specifically, when the judgment result shows that the total chlorine prediction model meets the applicability, the total chlorine guarantee module 504 takes the outlet total chlorine target control value as the average total chlorine concentration C' at the outlet of the secondary water supply water tank (pool), obtains the average water age V / q according to the total chlorine prediction model, and thus adjusts the effective volume of the secondary water supply storage equipment in this area according to the result.

[0121] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person skilled in the art can modify and change the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of the right to protection of the present invention shall be as listed in the claims.

Claims

1. A method for ensuring total chlorine in secondary water supply storage equipment based on water age control, comprising the following steps: Step S1, select a number of reference secondary water supply storage equipment in the water supply area to be predicted for total chlorine in secondary water supply storage equipment, obtain the total chlorine monitoring data of each reference secondary water supply storage equipment at different temperatures, and obtain the total chlorine decay index of each reference secondary water supply storage equipment at different temperatures by analyzing the total chlorine change law of secondary water supply storage equipment; Step S2, determine the general total chlorine decay index of each secondary water supply storage equipment in the current water supply area according to the total chlorine decay index of each reference secondary water supply storage equipment at different temperatures obtained; Step S3, obtain the liquid level change data of the secondary water supply storage equipment to be measured, and according to the liquid level change data of the secondary water supply storage equipment to be measured and the general total chlorine decay index, use the pre-determined total chlorine prediction model to obtain the corresponding outlet total chlorine, and compare the outlet total chlorine obtained according to the total chlorine prediction model with the measured outlet total chlorine to determine the applicability of the total chlorine prediction model; The total chlorine prediction model is: Wherein, C is the average total chlorine concentration of the influent water of the secondary water supply equipment, C' is the average total chlorine concentration of the outlet water of the secondary water supply equipment. When used for water age control, C' is the target control value of the outlet total chlorine. a is the ratio of the difference between the liquid level for closing the valve to stop water replenishment and the liquid level for opening the valve to replenish water in the secondary water supply storage equipment to the liquid level for closing the valve to stop water replenishment, that is, the ratio of the water replenishment volume X to the effective volume V. k is the general total chlorine decay index; q is the average hourly water consumption of residents corresponding to the outlet of the secondary water supply storage equipment, and V is the effective volume of the secondary water supply storage equipment to be measured; Step S4: According to the target control value of the total chlorine at the outlet and the total chlorine prediction model, obtain the average water age as the control requirement for the secondary water supply storage equipment in this area. Specifically, when the judgment result is that the total chlorine prediction model meets the applicability, use the target control value of the total chlorine at the outlet as the average total chlorine concentration C' at the outlet of the secondary water supply storage equipment, and obtain the average water age according to the total chlorine prediction model. Adjust the effective volume of the secondary water supply storage equipment in this area. The average water age is calculated as follows:

2. The total chlorine guarantee method for secondary water supply storage equipment based on water age control according to claim 1, characterized in that: In step S1, several secondary water supply storage tanks or water tanks with the worst conditions are selected as reference secondary water supply storage devices in the current water supply area. Water quality monitoring devices are installed in each reference secondary water supply storage device, and then total chlorine monitoring data C at multiple moments under different temperatures are obtained through the water quality monitoring devices installed in each reference secondary water supply storage device. t , and the total chlorine decay indices of each reference secondary water supply storage device at different temperatures are obtained by using the multiple total chlorine monitoring data of each reference secondary water supply storage device at each temperature.

3. A total chlorine guarantee method for a secondary water supply storage device based on water age control according to claim 2, characterized in that: In step S2, for the total chlorine decay index of each reference secondary water supply storage equipment at different temperatures obtained, select the maximum value of the total chlorine decay index as the general total chlorine decay index of each secondary water supply storage equipment in the current water supply area.

4. The total chlorine guarantee method for the secondary water supply storage equipment based on water age control according to claim 3, characterized in that, In step S3, monitor the liquid level change data of the secondary water supply storage equipment to be measured, obtain the effective volume of the secondary water supply storage equipment to be measured, the ratio of the difference between the liquid level for closing the valve to stop water replenishment and the liquid level for opening the valve to replenish water in the secondary water supply storage equipment to the liquid level for closing the valve to stop water replenishment, monitor and obtain the average hourly water consumption q of residents corresponding to the outlet of the secondary water supply storage equipment, and combine the general total chlorine decay index k obtained in step S2 and the influent total chlorine concentration of the secondary water supply storage equipment to be measured, and use the total chlorine prediction model to obtain the average total chlorine concentration C' of the outlet of the secondary water supply storage equipment to be measured, and compare the calculated value with the monitored value to determine the applicability of the total chlorine prediction model.

5. A system for ensuring total chlorine in secondary water supply storage equipment based on water age control, comprising: A reference equipment total chlorine analysis module, which is used to select a number of reference secondary water supply storage equipment in the water supply area to be predicted for total chlorine in secondary water supply storage equipment, obtain the total chlorine monitoring data of each reference secondary water supply storage equipment at different temperatures, and obtain the total chlorine decay index of each reference secondary water supply storage equipment at different temperatures by analyzing the total chlorine change law of secondary water supply storage equipment; A general total chlorine decay index determination module, which is used to determine the general total chlorine decay index of each secondary water supply storage device in the current water supply area according to the total chlorine decay indices of each reference secondary water supply storage device at different temperatures; A total chlorine prediction module, which is used to obtain the liquid level change data of the secondary water supply storage device to be measured, and according to the liquid level change data of the secondary water supply storage device to be measured and the general total chlorine decay index, use the pre-determined total chlorine prediction model to obtain the corresponding outlet total chlorine, and compare the obtained predicted value with the measured value, so as to determine the applicability of the total chlorine prediction model; A total chlorine guarantee module, which is used to, after judging that the total chlorine prediction model meets the applicability, obtain the average water age as the control requirement of the current secondary water supply storage device to be measured according to the outlet total chlorine target control value and the total chlorine prediction model, so as to obtain the regulation basis of the current area.

6. The total chlorine guarantee system for secondary water supply storage equipment based on water age control according to claim 5, characterized in that: The total chlorine prediction module compares the obtained predicted value with the measured value to judge the accuracy, and determines the applicability of the total chlorine prediction model according to the accuracy. After judging that the total chlorine prediction model meets the applicability, the total chlorine guarantee module substitutes the outlet total chlorine target control value into the total chlorine prediction model to obtain the average water age as the regional control target, and adjusts the effective volume V of the secondary water supply storage device in the current area accordingly.

7. The total chlorine guarantee system for secondary water supply storage equipment based on water age control according to claim 5, characterized in that: The total chlorine analysis module of the reference device selects several secondary water supply pools or water tanks with the worst conditions in the current water supply area as reference secondary water supply storage devices, installs water quality monitoring devices in each reference secondary water supply storage device, and then monitors the total chlorine monitoring data C at multiple moments under different temperatures through the water quality monitoring devices installed in each reference secondary water supply storage device. t , and uses the multiple total chlorine monitoring data of each reference secondary water supply storage device at each temperature to obtain the total chlorine decay index of each reference secondary water supply storage device at different temperatures.

8. The total chlorine guarantee system for secondary water supply storage equipment based on water age control according to claim 5, characterized in that, The total chlorine prediction model is: Wherein, C is the average total chlorine concentration of the influent water of the secondary water supply water tank (pool), C' is the average total chlorine concentration of the outlet of the secondary water supply water tank (pool), and when used for water age control, C' is the outlet total chlorine target control value, a is the ratio of the difference between the liquid level for closing the valve to stop replenishing water and the liquid level for opening the valve to replenish water of the secondary water supply storage device to the liquid level for closing the valve to stop replenishing water, that is, the ratio of the replenishing water volume X to the effective volume V, k is the general total chlorine decay index; q is the average hourly water consumption of the residents corresponding to the outlet of the secondary water supply storage device, and V is the effective volume of the secondary water supply storage device to be measured.

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