An intelligent circulation control system for secondary supply network based on residual chlorine decay model

Abstract

The present invention relates to the field of municipal water supply control technology, and in particular to a secondary water supply network intelligent circulation control system based on a residual chlorine attenuation model, including a domestic water tank, a supply network, a connecting pipe, a water supply pump group, a direct water supply pipe, a return pipe, a data acquisition module and a controller. The data acquisition module can collect key parameters such as the initial residual chlorine concentration of domestic water in the connecting pipe, the organic matter concentration in the water, the water temperature and the flow rate. The control module carried by the controller can establish a residual chlorine attenuation model in the secondary water supply network and the water tank, and its parameters cover the above-mentioned collected data. For the water age problem during the low-peak water use period at night, according to the flow meter and the water quality online instrument data, the model is used to calculate and compare the water age to decide whether to start the cycle. The present invention effectively solves the drawbacks of substandard residual chlorine at the end of the secondary water supply network and secondary chlorination, and ensures the water quality of the water supply through the intelligent recycling of residual chlorine, improves the safety and reliability of the secondary water supply, and has important practical value.

Description

Technical Field

[0001] The present invention relates to the technical field of municipal water supply control, and in particular to an intelligent circulation control system of a secondary water supply network based on a residual chlorine attenuation model. Background Art

[0002] At present, the three water quality detectors (residual chlorine, pH, and turbidity) installed in the water pump room usually only monitor the residual chlorine concentration of the water tank outlet pipe. In reality, even if the instrument shows that the residual chlorine meets the standard, it cannot accurately reflect the actual residual chlorine status of the tap water at the end of the secondary water supply network. This detection loophole makes it difficult to detect and effectively solve the hidden dangers of water quality at the end of the network in a timely manner.

[0003] Therefore, in order to solve the above problems, an intelligent circulation control system of the secondary supply network based on the residual chlorine attenuation model is proposed. Summary of the invention

[0004] The object of the present invention is to provide a secondary supply network intelligent circulation control system based on a residual chlorine attenuation model to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An intelligent circulation control system for a two-supply pipe network based on a residual chlorine attenuation model comprises a domestic water tank connected to a municipal water supply pipe, a supply pipe network connected to a building water supply pipe, a connecting pipe connecting the domestic water tank and the supply pipe network, and a water supply pump set arranged on the connecting pipe, a direct water supply pipe crossing the domestic water tank is arranged between the municipal water supply pipe and the connecting pipe, and a return pipe is arranged between the domestic water tank and the supply pipe network; and further comprises:

[0007] The data acquisition module includes a flow sensor and a water quality online monitoring sensor arranged on the connecting pipe. The data acquisition module collects the initial residual chlorine concentration of the domestic water in the connecting pipe. , water organic matter concentration TOC, water temperature T, flow rate ;

[0008] Controller, the controller is equipped with a control module, the control module includes:

[0009] The modeling module is used to establish the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank. The residual chlorine attenuation model of the secondary water supply network is based on the initial residual chlorine concentration. , water organic matter concentration TOC, water temperature T, flow rate As a parameter item, the formula of the residual chlorine attenuation model of the secondary water supply network is:

[0010] ,in, is a constant term, and its value is 1.77291. is the constant coefficient term of the initial residual chlorine concentration in the pipe network water, is the constant coefficient term of the organic matter concentration in the pipe network water, is the constant coefficient term of water temperature in the pipe network, is the constant coefficient term of water flow velocity in the pipe network, is the constant coefficient term of the square of the initial residual chlorine concentration in the pipe network water, is the constant coefficient of the square of the organic matter concentration in the pipe network water, is the constant coefficient of the square of the water temperature in the pipe network, is the constant coefficient of the square of the water velocity in the pipe network, is the residual chlorine attenuation coefficient of the secondary water supply network;

[0011] The residual chlorine attenuation model formula in the secondary water supply tank is:

[0012] , where A is a constant term, and its value is 0.024999, B is a constant coefficient term of the water temperature in the water tank, C is a constant coefficient term of the reciprocal of the initial residual chlorine concentration in the water tank, D is a constant coefficient term of the organic matter concentration in the water tank, E is a constant coefficient term of the ratio of the organic matter concentration in the water tank to the initial residual chlorine concentration, and F is a constant coefficient term of the square of the water temperature in the water tank. is the residual chlorine attenuation coefficient in the secondary water supply tank;

[0013] The control submodule receives the calculation results of the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank to determine whether the tap water of the end user meets the standard, and then controls the action of the electric valve module and the water supply pump group.

[0014] As a preferred solution, the electric valve module includes:

[0015] The electric valve A is arranged at the connection end of the domestic water tank and the municipal water supply pipe, and is used to control the water flow between the domestic water tank and the municipal water supply pipe;

[0016] The electric valve B provided at the connecting end of the domestic water tank and the connecting pipe is used to control the water flow between the domestic water tank and the connecting pipe;

[0017] The electric valve C provided on the direct water supply pipe is used to control the water flow of the direct water supply pipe;

[0018] The electric valve D provided on the return pipe is used to control the water flow of the return pipe.

[0019] As a preferred solution, the loop control logic of the control submodule is as follows:

[0020] During the nighttime low-peak water consumption period, the duration of the nighttime low-peak water consumption period is determined based on the water consumption data collected by the flow sensor. The residual chlorine value displayed by the water quality online monitoring sensor is used as the initial residual chlorine concentration of the secondary water supply network inlet water , according to the water age calculation formula, the allowable water age duration is obtained ,like , the circulation system is not turned on, otherwise the circulation system is turned on;

[0021] When the water tank and the secondary water supply network are operated in a circulation mode, when the circulation is started, the electric valve A and the electric valve B are closed, the electric valve C and the electric valve D are opened, the water supply pump group is running, and the circulation flow rate of the pump group is adjusted to 1m / s. The time from the start of the circulation to the completion is ,in, is the total length of the circulation pipeline, is the circulation flow rate, and the time interval from the time node after the cycle is completed to the arrival of the next peak water consumption period is recorded as After the cycle is completed, the water quality online monitoring sensor is read to show the residual chlorine concentration is , calculate again to get the safe water age ,like , the circulation is effective. Otherwise, the circulation system is turned on again. If it is still impossible to ensure that the calculated safe water age is greater than the actual water age of the pipe network, corresponding measures must be taken to replenish the residual chlorine in the water tank;

[0022] When the municipal water supply network is used to update the secondary water supply network water, when the circulation is started, the electric valve A and electric valve D are closed, and the electric valve B and electric valve C are opened. During the low-peak water consumption period at night, the water supply pump group directly pumps water from the municipal water supply network to ensure Less than the highest liquid level of the water tank, where: is the bottom area of ​​the water tank, is the water volume in the water tank before the cycle starts. is the water capacity of the network. The network circulation is based on the same circulation method as the water tank and secondary water supply network.

[0023] As a preferred solution, during the non-nighttime low-peak water usage period, electric valve B and electric valve C are closed under dynamic conditions, and the initial residual chlorine concentration after the nighttime low-peak water usage cycle is completed is recorded. The allowable water age under the current initial residual chlorine concentration is calculated based on the static pipe network water age calculation model. When the secondary pipe network water supply system is supplying water normally, the return pipe is in a static water state. The return pipe needs to open electric valve C before reaching the safe water age, circulate the stored water in the pipe back to the water tank and close electric valve C. Then, the current residual chlorine value of the water quality online monitoring sensor is immediately recorded separately to calculate the allowable safe water age of the return pipe. The period of opening electric valve C is to calculate the safe water age.

[0024] As a preferred solution, the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank are used to calculate the attenuation The method for calculating the residual chlorine concentration after a certain period of time is:

[0025] According to the formula Calculate attenuation Residual chlorine concentration in the secondary water supply network after , according to the formula Calculate attenuation Residual chlorine concentration in the secondary water supply tank after .

[0026] It can be seen from the technical solution provided by the present invention that the intelligent circulation control system of the secondary supply network based on the residual chlorine attenuation model provided by the present invention has the following beneficial effects:

[0027] Ensure the safety of water quality: Through accurate residual chlorine attenuation model calculation and intelligent circulation control, it can effectively solve the problem of substandard residual chlorine in user tap water caused by long retention time of water in the secondary water supply network during low-peak water consumption at night, ensure that the tap water at the end of the secondary water supply always meets the water quality standards, reduce the health risks faced by residents due to drinking water with substandard residual chlorine, and effectively ensure the safety of people's livelihood;

[0028] Reduce the generation of disinfection by-products: Abandon the traditional secondary chlorination method, reduce the potential threat to residents' health from the source, and improve the safety and environmental protection of water supply;

[0029] Improve water resource utilization: Make full use of the residual chlorine in the municipal water supply network and domestic water tanks, and through a reasonable circulation control strategy, achieve effective renewal of water in the network, avoid waste of water resources, and improve the water resource utilization efficiency of the entire secondary water supply system;

[0030] Intelligent and precise control: The control module of the controller in the system can calculate and judge whether the tap water of the end user meets the standard in real time and accurately based on the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank, and accurately control the action of the electric valve module and the water supply pump group accordingly, thus realizing the intelligent management of the secondary water supply system and reducing manual intervention and operational errors;

[0031] Adapt to various working conditions: Whether it is the low-peak water use period at night or the non-night low-peak water use period, the system can adaptively adjust the operation mode and control strategy of the circulation system according to different water use characteristics and water quality changes; for example, during the low-peak water use period at night, the system can flexibly choose to circulate water between the water tank and the secondary water supply network or to update the water of the secondary water supply network through the municipal water supply network; during the non-night low-peak water use period, the system can effectively control the water age of the network to ensure stable and up-to-standard water supply, which greatly improves the applicability and reliability of the system;

[0032] Extend equipment service life: Through effective control of water quality and water flow, the corrosion and damage of impurities and residual chlorine changes in the water to water supply equipment are reduced, the service life of water supply pumps, pipelines, valves and other equipment is extended, the equipment maintenance cost and replacement frequency are reduced, and the overall economic benefits of the secondary water supply system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a schematic diagram of the overall structure of a secondary supply network intelligent circulation control system based on a residual chlorine attenuation model.

[0034] In the figure: 1. Municipal water supply pipe; 11. Direct water supply pipe; 12. Supply pipe network; 13. Return pipe; 14. Domestic water tank; 15. Building water supply pipe; 2. Electric valve A; 21. Electric valve B; 22. Electric valve C; 23. Electric valve D; 3. Water supply pump group; 31. Flow sensor; 4. Water quality online monitoring sensor; 5. Controller. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0037] like Figure 1 As shown, the embodiment of the present invention provides a two-supply pipe network intelligent circulation control system based on the residual chlorine attenuation model, including a domestic water tank 14 connected to a municipal water supply pipe 1, a supply pipe network 12 connected to a building water supply pipe 15, a connecting pipe connecting the domestic water tank 14 and the supply pipe network 12, and a water supply pump group 3 arranged on the connecting pipe, a direct water supply pipe 11 crossing the domestic water tank 14 is arranged between the municipal water supply pipe 1 and the connecting pipe, and a return pipe 13 is arranged between the domestic water tank 14 and the supply pipe network 12; and also includes:

[0038] The data acquisition module includes a flow sensor 31 and a water quality online monitoring sensor 4 arranged on the connecting pipe. The data acquisition module collects the initial residual chlorine concentration of the domestic water in the connecting pipe. , water organic matter concentration TOC, water temperature T, flow rate ;

[0039] Controller 5, controller 5 is equipped with a control module, the control module includes:

[0040] The modeling module is used to establish the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank. The residual chlorine attenuation model of the secondary water supply network is based on the initial residual chlorine concentration. , water organic matter concentration TOC, water temperature T, flow rate As a parameter item, the formula of the residual chlorine attenuation model of the secondary water supply network is:

[0041] ,in, is a constant term, and its value is 1.77291. is the constant coefficient term of the initial residual chlorine concentration in the pipe network water, is the constant coefficient term of the organic matter concentration in the pipe network water, is the constant coefficient term of water temperature in the pipe network, is the constant coefficient term of water flow velocity in the pipe network, is the constant coefficient term of the square of the initial residual chlorine concentration in the pipe network water, is the constant coefficient of the square of the organic matter concentration in the pipe network water, is the constant coefficient of the square of the water temperature in the pipe network, is the constant coefficient of the square of the water velocity in the pipe network, is the residual chlorine attenuation coefficient of the secondary water supply network;

[0042] The residual chlorine attenuation model formula in the secondary water supply tank is:

[0043] , where A is a constant term, and its value is 0.024999, B is a constant coefficient term of the water temperature in the water tank, C is a constant coefficient term of the reciprocal of the initial residual chlorine concentration in the water tank, D is a constant coefficient term of the organic matter concentration in the water tank, E is a constant coefficient term of the ratio of the organic matter concentration in the water tank to the initial residual chlorine concentration, and F is a constant coefficient term of the square of the water temperature in the water tank. is the residual chlorine attenuation coefficient in the secondary water supply tank;

[0044] The control submodule receives the calculation results of the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank to determine whether the tap water of the end user meets the standard, and then controls the action of the electric valve module and the water supply pump group 3;

[0045] In this embodiment, the electric valve module includes:

[0046] The electric valve A2 provided at the connection end of the domestic water tank 14 and the municipal water supply pipe 1 is used to control the water flow between the domestic water tank 14 and the municipal water supply pipe 1;

[0047] The electric valve B21 provided at the end of the connection between the domestic water tank 14 and the connection pipe is used to control the water flow between the domestic water tank 14 and the connection pipe;

[0048] The electric valve C22 provided on the direct water supply pipe 11 is used to control the water flow of the direct water supply pipe;

[0049] The electric valve D23 disposed on the return pipe 13 is used to control the water flow of the return pipe 13 .

[0050] In this embodiment, the loop control logic of the control submodule is as follows:

[0051] During the low-peak water consumption period at night, the duration of the low-peak water consumption period at night is determined based on the water consumption data collected by the flow sensor 31. The residual chlorine value displayed by the water quality online monitoring sensor 4 is used as the initial residual chlorine concentration of the secondary water supply network inlet water , according to the water age calculation formula, the allowable water age duration is obtained ,like , the circulation system is not turned on, otherwise the circulation system is turned on;

[0052] When the water tank and the secondary water supply network are operated in a circulation mode, when the circulation is started, the electric valve A2 and the electric valve B21 are closed, the electric valve C22 and the electric valve D23 are opened, the water supply pump group 3 is running, and the circulation flow rate of the pump group is adjusted to 1m / s. The time from the start of the circulation to the completion is ,in, is the total length of the circulation pipeline, is the circulation flow rate, and the time interval from the time node after the cycle is completed to the arrival of the next peak water consumption period is recorded as After the cycle is completed, the water quality online monitoring sensor 4 shows the residual chlorine concentration is , calculate again to get the safe water age ,like , the circulation is effective. Otherwise, the circulation system is turned on again. If it is still impossible to ensure that the calculated safe water age is greater than the actual water age of the pipe network, corresponding measures must be taken to replenish the residual chlorine in the water tank;

[0053] When the municipal water supply network is used to update the secondary water supply network water, when the circulation is started, the electric valve A2 and the electric valve D23 are closed, the electric valve B21 and the electric valve C22 are opened, and the water supply pump group 3 directly pumps water from the municipal water supply network during the low-peak water consumption period at night to ensure Less than the highest liquid level of the water tank, where: is the bottom area of ​​the water tank, is the water volume in the water tank before the cycle starts. is the water capacity of the network. The network circulation is based on the same circulation method as the water tank and secondary water supply network.

[0054] In this embodiment, during the non-nighttime low-peak water usage period, the electric valve B21 and the electric valve C22 are closed under dynamic conditions, and the initial residual chlorine concentration after the nighttime low-peak water usage period cycle is completed is recorded, and the allowable water age under the current initial residual chlorine concentration is calculated according to the static pipe network water age calculation model. When the secondary pipe network water supply system is supplying water normally, the return pipe 13 is in a static water state, and the return pipe 13 needs to open the electric valve C22 before reaching the safe water age, circulate the stored water in the pipe back to the water tank and close the electric valve C22, and then immediately and separately record the current residual chlorine value of the water quality online monitoring sensor 4 to calculate the allowable safe water age of the return pipe 13, and the period of opening the electric valve C22 is to calculate the safe water age.

[0055] In this embodiment, the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank are used to calculate the attenuation The method for calculating the residual chlorine concentration after a certain period of time is:

[0056] According to the formula Calculate attenuation Residual chlorine concentration in the secondary water supply network after , according to the formula Calculate attenuation Residual chlorine concentration in the secondary water supply tank after .

[0057] In this embodiment, the data acquisition module plays a key role in the intelligent circulation control system of the secondary supply network based on the residual chlorine attenuation model. It provides important data support for the precise control of the entire system; specifically:

[0058] Sensor settings and data collection content: The data collection module includes a flow sensor 31 and a water quality online monitoring sensor 4 set on the connecting pipe; it mainly collects the initial residual chlorine concentration of domestic water inside the connecting pipe , water organic matter concentration TOC, water temperature T, flow rate v and other data; these data are the basic parameters for establishing the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank; for example, in the residual chlorine attenuation model of the secondary water supply network, the initial residual chlorine concentration, organic matter concentration in the water, water temperature, flow rate and other parameters directly affect the calculation of the coefficients in the model and the prediction of residual chlorine attenuation;

[0059] Importance of data collection: Accurate collection of this data enables the system to more accurately evaluate the attenuation of residual chlorine in the secondary water supply network and water tanks; by real-time monitoring of this data, the system can adjust the circulation control strategy in a timely manner according to different working conditions and water quality conditions to ensure that the tap water quality of end users meets the standards; for example, during the low-peak water consumption period at night, the system can determine whether to start the circulation system and how to perform the circulation operation based on the water consumption data collected by the flow sensor and the residual chlorine value displayed by the online water quality monitoring sensor, thereby effectively ensuring water supply safety and stable water quality.

[0060] The present invention will be further described below in conjunction with specific embodiments:

[0061] Example 1: System infrastructure construction and operation

[0062] In this embodiment, a complete set of two-supply pipe network intelligent circulation control system based on residual chlorine attenuation model is constructed; the domestic water tank 14 connected to the municipal water supply pipe 1 is made of food-grade stainless steel with a volume of 50 cubic meters. Its water inlet is connected to the municipal water supply pipe 1 through a pipe, and a check valve is installed to prevent water backflow; the supply pipe network 12 connected to the building water supply pipe 15 is composed of corrosion-resistant polyethylene pipes, and the pipe diameter is designed to be DN100 according to the building water consumption to ensure stable water supply pressure; the connecting pipe connecting the domestic water tank 14 and the supply pipe network 12 is a galvanized steel pipe with a length of 10 meters. The water supply pump group 3 installed on the connecting pipe has a power of 10kW, which can provide sufficient power to drive water circulation;

[0063] The diameter of the direct water supply pipe 11 between the municipal water supply pipe 1 and the connecting pipe is DN80, and an electric valve C22 is provided, which can be quickly opened in emergency water supply or special working conditions to realize the municipal water supply directly supplying water to the supply network 12; the diameter of the return pipe 13 between the domestic water tank 14 and the supply network 12 is DN65, and an electric valve D23 is installed, so that the water in the supply network 12 can be returned to the domestic water tank 14 for circulation treatment when needed;

[0064] The flow sensor 31 in the data acquisition module adopts an electromagnetic flow sensor with an accuracy of ±0.5%, which can accurately measure the flow rate and flow data of the water in the connecting pipe; the water quality online monitoring sensor 4 integrates advanced electrochemical sensors and optical sensors, which can monitor the initial residual chlorine concentration of domestic water in the connecting pipe in real time. , water organic matter concentration TOC, water temperature T, flow rate v, the measurement accuracy is ±0.05mg / L, ±0.1mg / L, ±0.5℃, ±0.05m / s respectively, meeting the system's high-precision requirements for water quality data;

[0065] The controller 5 uses a high-performance industrial control computer. In the control module, the modeling submodule models and optimizes the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank based on a large amount of experimental data and machine learning algorithms; for example, by analyzing and training 100 sets of water quality data in different seasons and regions, the model parameters are continuously adjusted to make the model prediction accuracy reach more than 90%; the control submodule determines whether the tap water of the end user meets the standard according to the model calculation results and the preset water quality standard, and then accurately controls the action of the electric valve module and the water supply pump group 3;

[0066] During the operation of the system, taking a certain community as an example, when the low-peak water consumption period arrives at night, the flow sensor 31 detects a significant decrease in water consumption. At this time, the system automatically starts the water age calculation program; the residual chlorine value displayed by the water quality online monitoring sensor 4 is used as the initial residual chlorine concentration of the secondary water supply network inlet water Assuming that its value is 0.5 mg / L, water temperature T is 15°C, organic matter concentration TOC in water is 1 mg / L, flow velocity v is 0.2 m / s, the allowable water age is calculated by combining the residual chlorine attenuation model of the secondary water supply network. 10 hours; if the low-peak water consumption period at night is For 8 hours, due to > , the system determines that there is no need to start the circulation system and continues to maintain normal water supply status.

[0067] Example 2: Water tank and pipe network circulation mode operation

[0068] When the secondary water supply system in a certain area needs to start the circulation between the water tank and the secondary water supply network during the low-peak water consumption period at night, the system operates according to the following process; when starting the circulation, the electric valve A2 and the electric valve B21 are quickly closed to prevent unnecessary water flow interference between the domestic water tank 14 and the municipal water supply pipe 1 and the connecting pipe; the electric valve C22 and the electric valve D23 are opened at the same time, the water supply pump group 3 is started and the circulation flow rate is adjusted to 1m / s; assuming that the total length L of the circulation pipeline is 50 meters, according to the formula The calculated time from the start of the cycle to its completion is 50 seconds;

[0069] During the circulation process, the water quality online monitoring sensor 4 continuously monitors the water quality changes; after the circulation is completed, the water quality online monitoring sensor 4 reads the residual chlorine concentration. , assuming that its value is 0.4 mg / L, the safe water age is calculated again based on the current water quality parameters and the residual chlorine attenuation model of the secondary water supply network The time interval from the time point after the cycle is completed to the next peak water consumption period is recorded as , assuming 6 hours, due to > , the system determines that this cycle is valid and maintains the current state and waits for the next monitoring;

[0070] If it is found in subsequent monitoring that it is always impossible to ensure that the calculated safe water age is greater than the actual water age of the pipe network, for example, after multiple cycles, the safe water age continues to shorten to 5 hours, while the actual water age increases to 7 hours, the system will trigger an alarm signal and start the backup plan; at this time, an appropriate amount of sodium hypochlorite solution can be added to the domestic water tank 14 through automatic control for secondary chlorination, or the water replenishment time and flow rate of the municipal water supply pipe 1 to the domestic water tank 14 can be adjusted to make full use of the residual chlorine in the municipal water supply network to control the residual chlorine in the water tank within a suitable concentration range to ensure water supply safety;

[0071] Example 3: Municipal pipe network update pipe network water mode operation

[0072] Under another working condition, when the municipal water supply network is used to update the water in the secondary water supply network, the system operates as follows; when the cycle is started, the electric valve A2 and the electric valve D23 are closed, the electric valve B21 and the electric valve C22 are opened, and the water supply pump group 3 directly pumps water from the municipal water supply network during the low-peak water consumption period at night; assuming that the bottom area of ​​the water tank is For 10 square meters, the water volume in the water tank before the cycle starts The water capacity of the pipe network is 30 cubic meters. is 20 cubic meters, and the calculation ensures Smaller than the highest liquid level of the water tank to prevent the water tank from overflowing;

[0073] During the network circulation process, the water age and residual chlorine attenuation are calculated based on the water quality data monitored by the online water quality monitoring sensor 4 and the flow data monitored by the flow sensor 31, in the same principle as the water tank and the secondary water supply network circulation method; for example, during one circulation process, the initial residual chlorine concentration is 0.6mg / L, water temperature T is 18℃, organic matter concentration TOC in water is 1.2mg / L, flow rate v is 0.3m / s. After a period of circulation, the circulation effect is judged based on the comparison between model calculation and actual monitoring. If the residual chlorine concentration remains within the safe range after circulation and the water age meets the requirements, the circulation mode will continue to be maintained. If an abnormal situation occurs, such as the residual chlorine concentration drops too fast or the water age is too long, the system will adjust the circulation parameters in time or switch to other operating modes to ensure that the secondary water supply quality is stable and meets the standards.

[0074] Example 4: Non-nighttime low-peak water consumption control

[0075] During the non-nighttime low-peak water consumption period, the system is in a dynamic operation state; for example, during the daytime peak water consumption period, the electric valve B21 and the electric valve C22 remain closed to ensure that the water supply pressure is stable to supply water to the building; when the water consumption trough period comes, the system records the initial residual chlorine concentration after the cycle of the nighttime low-peak water consumption period is completed, assuming it is 0.45 mg / L, and calculates the allowable water age under the current initial residual chlorine concentration according to the static pipe network water age calculation model; when the system is supplying water normally, the return pipe 13 pipeline is in a static water state. After a period of monitoring, when it is determined that the return pipe 13 is about to reach the safe water age, the system automatically opens the electric valve C22, circulates the stored water in the pipe back to the water tank and closes the electric valve C22; then immediately and separately records the current residual chlorine value of the water quality online monitoring sensor 4, recalculates the allowable safe water age of the return pipe 13, and uses this as a basis to determine the next opening cycle of the electric valve C22 to ensure that the water quality in the pipe network is always in a good state, avoiding problems such as insufficient residual chlorine or deterioration of water quality due to excessive water age;

[0076] Through the above multiple embodiments, the operation process and control strategy of the secondary water supply network intelligent circulation control system based on the residual chlorine attenuation model under different working conditions are demonstrated in detail, which fully reflects the effectiveness and stability of the system and can effectively solve the problems of residual chlorine attenuation and water quality assurance in the secondary water supply process; in practical applications, the system can be further optimized and adjusted according to different water supply scenarios and water quality conditions to meet diverse needs.

[0077] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dual-supply pipe network intelligent circulation control system based on a residual chlorine attenuation model, comprising a domestic water tank (14) connected to a municipal water supply pipe (1), a supply pipe network (12) connected to a building water supply pipe (15), a connecting pipe connecting the domestic water tank (14) and the supply pipe network (12), and a water supply pump group (3) arranged on the connecting pipe, characterized in that: A direct water supply pipe (11) is arranged between the municipal water supply pipe (1) and the connecting pipe and crosses the domestic water tank (14); a return pipe (13) is arranged between the domestic water tank (14) and the supply pipe network (12); and further comprising: A data acquisition module, comprising a flow sensor (31) and a water quality online monitoring sensor (4) arranged on the connecting pipe, wherein the data acquisition module acquires the initial residual chlorine concentration of the domestic water in the connecting pipe , water organic matter concentration TOC, water temperature T, flow rate ; A controller (5), wherein the controller (5) is equipped with a control module, and the control module comprises: A modeling submodule for establishing a residual chlorine decay model for a secondary water supply network and a residual chlorine decay model in a secondary water supply tank; A control submodule, the control submodule receives calculation results of the residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank to determine whether the tap water of the end user meets the standard, and then controls the operation of the electric valve module and the water supply pump group (3); The electric valve module comprises: An electric valve A (2) provided at the connection end between the domestic water tank (14) and the municipal water supply pipe (1) is used to control the water flow between the domestic water tank (14) and the municipal water supply pipe (1); An electric valve B (21) provided at the end of the connection between the domestic water tank (14) and the connection pipe, for controlling the water flow between the domestic water tank (14) and the connection pipe; An electric valve C (22) provided on the direct water supply pipe (11) for controlling the water flow of the direct water supply pipe; An electric valve D (23) provided on the return pipe (13) for controlling the flow of water in the return pipe (13); The loop control logic of the control submodule is as follows: During the nighttime low-peak water consumption period, the duration of the nighttime low-peak water consumption period is determined based on the water consumption data collected by the flow sensor (31). The residual chlorine value displayed by the water quality online monitoring sensor (4) is used as the initial residual chlorine concentration of the secondary water supply network inlet water. , according to the water age calculation formula, the allowable water age duration is obtained ,like , the circulation system is not turned on, otherwise the circulation system is turned on; When the water tank and the secondary water supply network are operated in a circulation mode, when the circulation is started, the electric valve A (2) and the electric valve B (21) are closed, the electric valve C (22) and the electric valve D (23) are opened, the water supply pump group (3) is running, and the circulation flow rate of the pump group is adjusted to 1m / s. The time from the start of the circulation to the completion is ,in, is the total length of the circulation pipeline, and the time interval from the time node after the circulation is completed to the arrival of the next peak water consumption period is recorded as After the cycle is completed, the water quality online monitoring sensor (4) is read and the residual chlorine concentration is , calculate again to get the safe water age ,like , the circulation is effective. Otherwise, the circulation system is turned on again. If it is still impossible to ensure that the calculated safe water age is greater than the actual water age of the pipe network, corresponding measures must be taken to replenish the residual chlorine in the water tank; When the municipal water supply network is used to update the secondary water supply network water, when the circulation is started, the electric valve A (2) and the electric valve D (23) are closed, and the electric valve B (21) and the electric valve C (22) are opened. During the low-peak water consumption period at night, the water supply pump group (3) directly pumps water from the municipal water supply network to ensure Less than the highest liquid level of the water tank, where: is the bottom area of ​​the water tank, is the water volume in the water tank before the cycle starts. is the water capacity of the network. The network circulation is based on the same circulation method as the water tank and secondary water supply network.

2. According to claim 1, a dual supply network intelligent circulation control system based on the residual chlorine attenuation model is characterized in that: The residual chlorine attenuation model of the secondary water supply network is based on the initial residual chlorine concentration , water organic matter concentration TOC, water temperature T, flow rate As a parameter item, the formula of the residual chlorine attenuation model of the secondary water supply network is: ,in, is a constant term, and its value is 1.77291. is the constant coefficient term of the initial residual chlorine concentration in the pipe network water, is the constant coefficient term of the organic matter concentration in the pipe network water, is the constant coefficient term of water temperature in the pipe network, is the constant coefficient term of water flow velocity in the pipe network, is the constant coefficient term of the square of the initial residual chlorine concentration in the pipe network water, is the constant coefficient of the square of the organic matter concentration in the pipe network water, is the constant coefficient term of the square of the water temperature in the pipe network, is the constant coefficient of the square of the water velocity in the pipe network, is the residual chlorine attenuation coefficient of the secondary water supply network; The residual chlorine attenuation model formula in the secondary water supply tank is: , where A is a constant term, and its value is 0.024999, B is a constant coefficient term of the water temperature in the water tank, C is a constant coefficient term of the reciprocal of the initial residual chlorine concentration in the water tank, D is a constant coefficient term of the organic matter concentration in the water tank, E is a constant coefficient term of the ratio of the organic matter concentration in the water tank to the initial residual chlorine concentration, and F is a constant coefficient term of the square of the water temperature in the water tank. It is the residual chlorine attenuation coefficient in the secondary water supply tank.

3. According to claim 2, a dual supply network intelligent circulation control system based on the residual chlorine attenuation model is characterized in that: During the non-nighttime low-peak water consumption period, the electric valve B (21) and the electric valve C (22) are closed under dynamic working conditions, and the initial residual chlorine concentration after the cycle of the nighttime low-peak water consumption period is completed is recorded. The allowable water age under the current initial residual chlorine concentration is calculated based on the static pipe network water age calculation model. When the secondary pipe network water supply system is supplying water normally, the return pipe (13) is in a static water state. The return pipe (13) needs to open the electric valve C (22) before reaching the safe water age, circulate the stored water in the pipe back to the water tank and close the electric valve C (22). Then, the current residual chlorine value of the water quality online monitoring sensor (4) is immediately recorded separately to calculate the allowable safe water age of the return pipe (13). The period of opening the electric valve C (22) is the calculation of the safe water age.

4. According to claim 3, a dual supply network intelligent circulation control system based on a residual chlorine attenuation model is characterized in that: The residual chlorine attenuation model of the secondary water supply network and the residual chlorine attenuation model in the secondary water supply tank are used to calculate the attenuation. The method for calculating the residual chlorine concentration after a certain period of time is: According to the formula Calculate attenuation Residual chlorine concentration in the secondary water supply network after , according to the formula Calculate attenuation Residual chlorine concentration in the secondary water supply tank after .

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