Online water quality monitoring device and method for direct drinking water in pipelines

Abstract

The present invention belongs to the field of water purification technology, and specifically relates to an online water quality monitoring device and method for direct drinking water in a pipeline. The device includes at least four direct drinking water production devices in parallel and a processor connected to multiple detectors and multiple flow sensors. The water outlet pipe on each direct drinking water production device is connected to the water supply pipe via an intermediate connecting pipe. A detector and a flow sensor are respectively arranged on at least each water outlet pipe and on the upstream side of the water supply pipe. The processor can analyze and process the water quality detection signal obtained by the detector and the flow signal obtained by the flow sensor, respectively, to obtain water quality detection results and related flow statistics, and can make early warning judgments after further analyzing and processing the corresponding water quality detection results and flow statistics. The present invention can analyze and process water quality conditions and water output, etc., respectively, which helps to find direct drinking production devices that have been excessively damaged and prevent water filtration consumables from being replaced prematurely.

Description

Technical Field

[0001] The present invention belongs to the technical field of water purification, and in particular relates to an online water quality monitoring device and method for pipeline direct drinking water. Background Art

[0002] The TDS (total dissolved solids) value refers to the total amount of inorganic and organic matter dissolved in water, typically expressed in milligrams per liter (mg / L). The TDS value reflects the concentration of dissolved solids in water, including the total amount of inorganic salts and organic matter. TDS can be measured using a specialized TDS meter or conductivity meter. These devices measure the ion concentration in water and calculate the TDS value. The TDS value correlates well with water hardness and conductivity. Lower TDS values ​​indicate lower concentrations of ions such as Ca⁺, Mg⁺, Na⁺, and K⁺, and lower conductivity. Therefore, higher TDS values ​​indicate greater impurities in the water. Factors affecting the TDS value primarily depend on the type and amount of dissolved inorganic and organic matter in the water. Common inorganic compounds include carbonates, chlorides, sulfates, phosphates, and nitrates of calcium, manganese, sodium, and potassium. Organic compounds may include algae, bacteria, pesticides, and disinfectants. Therefore, in the process of direct drinking water production, testing the TDS value is the main detection indicator for judging the water quality.

[0003] Reference Figure 1 As shown, the direct drinking water system used in public places such as campuses and hospitals is equipped with multiple direct drinking water production devices 10 in parallel. The outlet pipes 20 of the multiple direct drinking water production devices 10 are connected to the water supply pipe 50 through a pipeline (i.e., an intermediate connecting pipe 40), ultimately delivering the direct drinking water to a plurality of water supply terminals. During the management and maintenance of the direct drinking water system, to ensure that the quality of the direct drinking water supplied to users meets health requirements, maintenance personnel are required to manually sample and test the TDS value of the direct drinking water at regular or irregular intervals. Based on the TDS value of the direct drinking water, they determine whether the direct drinking water production device 10 is operating normally and whether the filter element and other filter consumables of the direct drinking water production device 10 need to be replaced.

[0004] The daily water consumption in public places such as campuses and hospitals is relatively large and fluctuates significantly, which can easily cause differences between the actual conditions of water supply and water supply of each direct drinking water production device 10, resulting in large differences in the actual wear and tear status of each direct drinking water production device 10. The direct drinking water in the water supply pipe 50 is collected from the outlet pipes 20 of each direct drinking water production device 10. Due to the enrichment effect, the water quality of the direct drinking water in the water supply pipe 50 will be worse than the water quality of each outlet pipe 20 (for example, the TDS value will be relatively higher). When the water quality test result of the direct drinking water in the water supply pipe 50 exceeds the standard, it is impossible to clearly determine which one or more direct drinking water production devices 10 are responsible, so it is necessary to stop the operation of the entire system and centrally replace the water filter consumables of each direct drinking water production device 10. During this period, it is inevitable that a large number of filter consumables will be replaced prematurely, resulting in abnormally high operation and maintenance costs and serious waste of resources. If the water in the outlet pipe 20 of each direct drinking water production device 10 is sampled for testing at the same time, it will undoubtedly greatly increase the workload of the testers, and it still cannot effectively overcome the problem of a large number of filter consumables being replaced prematurely. Therefore, the control method of manually checking the water quality of direct drinking water at regular or irregular times is not suitable for the operation, shutdown, maintenance and control of direct drinking water production systems deployed in places such as campuses and hospitals that require large quantities of continuous water production. Summary of the Invention

[0005] The present invention provides an online water quality monitoring device and method for piped direct drinking water, which can analyze and process the water quality status of the output water, the water quality status of the delivered water, the water output volume, the water delivery volume, etc. of each direct drinking water production device, respectively, and help to quickly and accurately find the direct drinking water production device that has been excessively damaged, and prevent the water filtration consumables from being replaced prematurely.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] The present application relates to an online water quality monitoring device for direct drinking water in a pipeline, comprising a plurality of direct drinking water production devices, detectors, flow sensors and processors respectively connected to the detectors and the flow sensors arranged in parallel.

[0008] The processor at least includes an alarm module, a parameter setting module, a storage module, an analysis and calculation module, a communication module and a display module.

[0009] The number of the direct drinking water production devices is four or more, and the water outlet pipes of each direct drinking water production device are connected to the water supply pipe via an intermediate connecting pipe. Furthermore, the detector for detecting water quality and the flow sensor for detecting water quantity are respectively provided on at least each water outlet pipe and on the upstream side of the water supply pipe.

[0010] The processor can analyze and process the water quality detection signal obtained by the detector and the flow signal obtained by the flow sensor respectively, obtain the real-time water quality detection results of each detector and related flow statistics, and make early warning judgments after further analyzing and processing the corresponding water quality detection results and flow statistics.

[0011] Optionally, a solenoid valve is respectively arranged on the water outlet pipe and downstream of the detector arranged thereon.

[0012] An electromagnetic valve is arranged on the water supply pipe at least downstream of the detector provided thereon.

[0013] The processor can at least control the on-off state of the solenoid valve according to the early warning judgment result, thereby realizing the switching control of the on-off state of the water outlet pipe and the switching control of the on-off state of the water supply pipe.

[0014] Optionally, the detector at least includes a TDS value detection module, and the detector can at least feed back TDS value detection data to the processor, and the processor analyzes and processes each received TDS value detection data.

[0015] The present application also relates to an online water quality monitoring method for piped drinking water based on any of the above-mentioned online water quality monitoring devices for piped drinking water, comprising the following steps.

[0016] Ⅰ. According to the selected standard value M, set the water supply warning threshold Mmax;

[0017] Among them, the standard value M can be selected with reference to the minimum required value of the direct drinking water (related) test results specified in national standards or industry standards, so that the water delivery warning threshold Mmax=a·M, where the value range of a is 0.9 to 0.999.

[0018] II. When the water supply warning threshold Mmax = 0.9M (i.e., when a is 0.9), the first warning threshold M1 and the second warning threshold M2 are selected;

[0019] When the sum of the detection results of the detectors installed on each water outlet pipe reaches 0.9M or more for the first time, and the detection result of the detector installed on the water supply pipe is less than 0.9M, the maximum value of the detection results in each water outlet pipe is used as the first warning threshold M1;

[0020] When the detection result of the detector installed on the water supply pipe exceeds 0.9M for the first time, the maximum value of the detection results in each water outlet pipe is used as the second warning threshold M2.

[0021] III. Determine the water redundancy ΔQ;

[0022] The average value of the total water supply Q of the water supply pipe during the period from the first warning threshold M1 to the second warning threshold M2 is divided by the number n of direct drinking water production devices as the water output redundancy ΔQ, that is:

[0023] Water outlet redundancy ΔQ = total water supply Q / n.

[0024] IV. Determine the initial value of the parameter α in the water discharge warning margin Q alarm;

[0025] The water discharge warning margin Q warning = α·water discharge redundancy ΔQ, where α is a positive rational number;

[0026] Find the water outlets whose water quality test results are greater than the first warning threshold M1 by the time the second warning threshold M2 is obtained in step II. Count the water output of each of these outlets from the time they first reach the first warning threshold M1 to the time they first reach the second warning threshold M2. Compare these water outputs with the water output redundancy ΔQ to determine whether any of the outlets has a water output greater than the water output redundancy ΔQ during this period.

[0027] i) If there is one, the ratio of the largest water output divided by the water output redundancy ΔQ is the initial value of α;

[0028] ii) If None, the initial value of α is taken as 1.

[0029] V. Modify the value of parameter α;

[0030] Gradually increase the value of a until the sum of the test results of each water outlet pipe and the test results of the water supply pipe are all less than the water supply warning threshold Mmax, and the value of a in the water supply warning threshold Mmax does not exceed 0.999; thereafter, continuously test the water output of each water outlet pipe during operation, calculate the subsequent water output of each water outlet pipe since the first warning threshold M1 is obtained, and compare the subsequent water output of each water outlet pipe with the water output warning margin Qwarn;

[0031] i) If the water quality test result of the water supply pipe exceeds the water supply warning threshold Mmax before the subsequent water output of each water outlet pipe reaches the water output warning margin Q, then the ratio of the maximum subsequent water output at that time divided by the water output redundancy ΔQ is used as the correction value of α, which is α'. When the subsequent water output of a water outlet pipe exceeds (α'·water output redundancy ΔQ), it is determined that the direct drinking water production device corresponding to the water outlet pipe needs to be maintained and replaced, that is, it is determined that the processing capacity of the corresponding direct drinking water production device has reached the standard / level that requires maintenance and replacement;

[0032] ii) If the water quality test result of the water supply pipe still does not exceed the water supply warning threshold Mmax when the subsequent water output of each water outlet pipe reaches the water output warning margin Q, then the water output of each water outlet pipe will continue to be tested until the water quality test result of the water supply pipe exceeds the water supply warning threshold Mmax; the ratio of the maximum subsequent water output at that time divided by the water output redundancy ΔQ is the correction value of α, which is α'', and when the subsequent water output of a certain water outlet pipe exceeds (α''·water output redundancy ΔQ), it is determined that the direct drinking water production device corresponding to the water outlet pipe needs to be maintained and replaced, that is, it is determined that the processing capacity of the corresponding direct drinking water production device has reached the standard / level that requires maintenance and replacement.

[0033] Optionally, in step I, the selected standard value M is a set value for TDS value and the unit of the set value is mg / L; the first warning threshold M1 and the second warning threshold M2 involved in step II are both readings for TDS value.

[0034] The beneficial effect of the present invention is that the present invention can analyze and process the water quality status of the outlet water, the water quality status of the delivery water, the water output, the water delivery, etc. of each direct drinking water production device respectively, so as to quickly and accurately find the direct drinking production device that causes the water quality to exceed the standard (such as the TDS value exceeds the standard), that is, it helps to achieve the purpose of quickly and accurately discovering the direct drinking production device that has been excessively damaged, to guide the precise shutdown and repair, and can overcome the problem of premature replacement of water filtration consumables on each direct drinking water production device, and help to improve the full utilization of each direct drinking water production device, and can reduce the operating cost of the direct drinking water system, and achieve the environmental protection purpose of saving resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the pipeline layout of the direct drinking water system in public places such as campuses.

[0036] Figure 2 This is a line graph of the TDS values ​​measured by the detectors installed on the water outlet pipe and the water supply pipe.

[0037] Figure 3 Schematic diagram of the logical process of the monitoring method.

[0038] In the figure: 10 direct drinking water production device; 20 water outlet pipe; 30 detector; 40 intermediate connecting pipe; 50 water supply pipe; 60 flow sensor; 70 solenoid valve. DETAILED DESCRIPTION

[0039] The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for understanding and reading by those familiar with this technology. They are not used to limit the conditions for implementation of the present invention and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, terms such as "upper", "lower", "front", "back", and "middle" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should also be considered as the scope of implementation of the present invention without substantially changing the technical content.

[0040] like Figure 1 The illustrated device for online drinking water quality monitoring includes multiple drinking water production devices 10 arranged in parallel, multiple detectors 30, multiple flow sensors 60, and a processor connected to each detector 30 and each flow sensor 60. The outlet pipe 20 of each drinking water production device 10 is connected to a water supply pipe 50 via an intermediate connecting pipe 40.

[0041] The processor at least includes an alarm module, a parameter setting module, a storage module, an analysis and calculation module, a communication module and a display module, wherein the display module and / or the parameter setting module respectively contain or share an input terminal.

[0042] The detector 30 at least includes a TDS value detection module. The detector 30 can at least feed back the TDS value detection results to the processor, and the processor analyzes and processes each received TDS value detection result.

[0043] A detector 30 for detecting water quality and a flow sensor 60 for detecting water quantity are installed on at least each water outlet pipe 20 and upstream of the water supply pipe 50. The detector 30 can feed back its real-time water quality test results (TDS test results) to the processor, and can perform statistical calculations on the water production flow rate (water production volume) of each water outlet pipe 20 and the water delivery flow rate (water delivery volume) of the water supply pipe 50, and issue an early warning after performing relevant analysis and processing.

[0044] Solenoid valves 70 are respectively disposed on the water outlet pipes 20, downstream of the detectors 30 disposed thereon. Solenoid valves 70 are also disposed on the water supply pipes 50, at least downstream of the detectors 30 disposed thereon. The processor can control the on / off status of each solenoid valve 70 based on the analysis and judgment results, thereby enabling separate switching control of the on / off status of each water outlet pipe 20 and the on / off status of the water supply pipe 50.

[0045] The processor can analyze and process the water quality detection signal obtained by the detector 30 and the flow signal obtained by the flow sensor 60 respectively, and obtain the real-time water quality detection results of each detector 30 (detected at different time points) and the relevant flow statistics (for a specific time period and a specific pipeline). After further analyzing and processing the corresponding water quality detection results and flow statistics, the processor can make an early warning judgment.

[0046] A method for monitoring the quality of direct drinking water in a pipeline based on any of the above-mentioned direct drinking water in a pipeline online water quality monitoring device comprises the following steps (taking the TDS value of direct drinking water as an example), which can be referred to Figure 3 .

[0047] Ⅰ. According to the selected standard value M (regarding the TDS value), the water supply warning threshold Mmax of the TDS value of the water quality at the upstream inlet of the water supply pipe 50 is set;

[0048] Referring to the requirements of the national standard GB5749-2022 "Sanitary Standards for Drinking Water", the minimum TDS content of direct drinking water is 1000 mg / L, and the standard value M can be selected as 1000 mg / L, or 900 mg / L, or 500 mg / L, etc., and the water supply warning threshold Mmax=a·M, where a is 0.9 to 0.99.

[0049] II. When the water supply warning threshold Mmax = 0.9M (ie, when a takes the minimum value of 0.9), the first warning threshold M1 and the second warning threshold M2 about the water outlet pipe 20 are selected;

[0050] When the sum of the TDS value water quality test results (hereinafter referred to as the test result) of the detectors 30 corresponding to the respective water outlet pipes 20 initially (obtained by the test) reaches 0.9M or more, and the TDS value water quality test result (hereinafter referred to as the test result) of the detector 30 corresponding to the water supply pipe 50 is less than 0.9M, the maximum test result (i.e., the maximum reading) in each of the water outlet pipes 20 at that time is used as the first warning threshold M1;

[0051] When the detection result of the detector 30 corresponding to the water supply pipe 50 exceeds 0.9M for the first time (detection result), the value of the maximum detection result (ie, the maximum reading) in each water outlet pipe 20 at that time is used as the second warning threshold M2.

[0052] III. Determine the water redundancy ΔQ;

[0053] The average value obtained by dividing the total water supply Q of the water supply pipe 50 by the number n of the direct drinking water production devices 10 during the period from obtaining the first warning threshold M1 to obtaining the second warning threshold M2 is used as the water output redundancy ΔQ, that is:

[0054] Water outlet redundancy ΔQ = total water supply Q / n.

[0055] IV. Determine the initial value of the parameter α in the water discharge warning margin Q alarm;

[0056] The water discharge warning margin Q warning = α·water discharge redundancy ΔQ, where α is a positive rational number;

[0057] Find each water outlet pipe 20 whose water quality test result is greater than the first warning threshold M1 by the time the second warning threshold M2 is obtained in step II, calculate the water flow rate of each of these water outlet pipes 20 from the time they first reach the first warning threshold M1 to the time they first reach the second warning threshold M2, and compare these water flow rates with the water flow margin ΔQ to determine whether the water flow rate of one or more water outlet pipes 20 exceeds the water flow margin ΔQ.

[0058] i) If yes, then the ratio of the maximum water flow value of each water outlet pipe 20 whose water flow value is greater than the water flow redundancy ΔQ divided by the water flow redundancy ΔQ is used as the initial value of α, that is, at that time:

[0059] α=(maximum water output value) / (water output redundancy ΔQ);

[0060] ii) If None, the initial value of α is taken as 1.

[0061] V. Gradually modify the value of parameter α;

[0062] Gradually increase the value of a until the sum of the test results of each water outlet pipe 20 and the test result of the water supply pipe 50 are all less than the (updated) water supply warning threshold value Mmax; thereafter, continuously detect the water flow of each water outlet pipe 20 during operation, calculate the subsequent water flow (value) of each water outlet pipe 20 after obtaining the first warning threshold value M1 in step II, and compare the subsequent water flow of each water outlet pipe 20 with the water flow warning margin Qwarn;

[0063] i) If the water quality test result of the water supply pipe 50 exceeds the (updated) water supply warning threshold Mmax before the subsequent water output of each water outlet pipe 20 reaches the water output warning margin Q, then the ratio of the maximum subsequent water output at that time divided by the water output redundancy ΔQ is used as the correction value of α, namely α', that is, α' = (maximum subsequent water output) / (water output redundancy ΔQ); and when the subsequent water output of each water outlet pipe 20 exceeds (α'·water output redundancy ΔQ), it is determined that the filter consumables of the direct drinking water production device 10 corresponding to the water outlet pipe 20 need to be maintained and replaced, that is, it is determined that the processing capacity of the corresponding direct drinking water production device 10 has reached the standard / level requiring maintenance and replacement;

[0064] ii) If, when the subsequent water output of each water outlet pipe 20 reaches the water output warning margin Q alarm, the water quality detection result of the water supply pipe 50 still does not exceed the (updated) water output warning threshold Mmax, then the water output of each water outlet pipe 20 will continue to be detected until the water quality detection result of the water supply pipe 50 exceeds the (updated) water output warning threshold Mmax; then the ratio of the maximum subsequent water output at that time divided by the water output redundancy ΔQ is the correction value of α and is α'', that is, α''=(maximum subsequent water output) / (water output redundancy ΔQ); and when the subsequent water output of each water outlet pipe 20 exceeds (α''·water output redundancy ΔQ), it is determined that the filter consumables of the direct drinking water production device 10 corresponding to the water outlet pipe 20 need to be maintained and replaced, that is, it is determined that the processing capacity of the corresponding direct drinking water production device 10 has reached the standard / level that requires maintenance and replacement.

[0065] Obviously, the value of the "maximum subsequent water output" in step V i) is smaller than the value of the "maximum subsequent water output" in step V ii). The "maximum subsequent water output" in i) can be defined as the first maximum subsequent water output, and the "maximum subsequent water output" in ii) can be defined as the second maximum subsequent water output. The second maximum subsequent water output is greater than the first maximum subsequent water output.

[0066] Through the piped drinking water online water quality monitoring device involved in this application, each detector 30 regularly detects the water quality of each water outlet pipe 20 and the water quality of the water supply pipe 50 at the same time, and the following can be obtained: Figure 2 The TDS value line graph shown in FIG. 1 , wherein S0 is a TDS value line graph of the water outlet pipe 20 obtained by detecting the water quality of the water outlet pipe 20 ( Figure 2The figure only shows the TDS value test results for one water outlet pipe 20. In actual operation, the TDS value line graph for all water outlet pipes 20 should be displayed. S1 is the TDS value line graph for the water supply pipe 50, obtained by testing the water quality of the water supply pipe 50. It can be seen that the TDS value on line S1 at the same (test) time point is always higher than the TDS value on line S0. For new equipment, the initial sum of the test results (values) on each water outlet pipe 20 and the test results (values) on the water supply pipe 50 will be far lower than the (original / original) set water supply warning threshold Mmax, which is 0.9 times the standard value M. During operation, as the filtering capacity of the direct drinking water production device 10 gradually weakens, the test results (values) on each water outlet pipe 20 will tend to gradually increase. Furthermore, because the wear and tear status / extent of each direct drinking water production device 10 inevitably varies during operation, the differences between the test results (values) on the water outlet pipes 20 corresponding to each direct drinking water production device 10 will tend to gradually increase, ultimately causing the maximum test result value across all water outlet pipes 20 to increasingly deviate from their average. When setting the initial / original water delivery warning threshold Mmax for the water delivery pipe 50, the number of direct drinking water production devices 10 must be considered. Extensive testing revealed that when there are four or more direct drinking water production devices 10, the sum of the test results (values) on each water outlet pipe 20 will most likely first exceed the initially set water delivery warning threshold Mmax, followed by the test result (value) on the water delivery pipe 50. Therefore, a related method has been developed.

[0067] In summary, the present invention can comprehensively analyze the water quality conditions of the outlet water and the water quality conditions of the water supply of multiple direct drinking water production devices 10 to quickly and accurately find the direct drinking water production device that causes the water quality to exceed the standard (TDS value exceeds the standard) or quickly and accurately find the direct drinking water production device that has been excessively damaged, guide the precise shutdown and repair, and help overcome the problem of too many water filtration consumables being replaced prematurely, thereby improving the full utilization of each direct drinking water production device 10, reducing the operating cost of the direct drinking water system, and achieving the environmental protection purpose of saving resources. Therefore, the present invention effectively overcomes some practical problems in the prior art and has high utilization value and use significance.

[0068] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. The present invention can be improved in many aspects without violating the overall concept. Those skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed by the present invention shall be covered by the claims of the present invention.

Claims

1. An online water quality monitoring device for direct drinking water in a pipeline, comprising a plurality of direct drinking water production devices (10), a detector (30) and a flow sensor (60) arranged in parallel; the outlet pipe (20) on each direct drinking water production device (10) is connected to the water supply pipe (50) via an intermediate connecting pipe (40); and is characterized in that: The number of the direct drinking water production devices (10) is four or more; The detector (30) for detecting water quality and the flow sensor (60) for detecting water volume are respectively provided on at least each water outlet pipe (20) and on the upstream side of the water supply pipe (50); It also includes a processor connected to the detector (30) and the flow sensor (60), respectively, and the processor includes at least an alarm module, a parameter setting module, a storage module, an analysis and calculation module, a communication module and a display module; The processor can analyze and process the water quality detection signal obtained by the detector (30) and the flow signal obtained by the flow sensor (60) respectively, obtain the real-time water quality detection results of each detector (30) and related flow statistics, and make early warning judgments after further analyzing and processing the corresponding water quality detection results and flow statistics; The detector (30) at least contains a TDS value detection module, and the detector (30) can at least feed back TDS value detection data to the processor, and the processor analyzes and processes each received TDS value detection data.

2. The online water quality monitoring device for piped drinking water according to claim 1 is characterized in that: A solenoid valve (70) is respectively arranged on the water outlet pipe (20) and downstream of the detector (30) arranged thereon; a solenoid valve (70) is respectively arranged on the water supply pipe (50) and downstream of at least the detector (30) arranged thereon; the processor can at least control the on-off state of the solenoid valve (70) according to the early warning judgment result, thereby realizing switching control of the on-off state of the water outlet pipe (20) and realizing switching control of the on-off state of the water supply pipe (50).

3. A method for monitoring the online quality of drinking water in a pipeline based on the online water quality monitoring device for drinking water in a pipeline according to claim 1, characterized in that The steps include: Ⅰ. Set the water supply warning threshold Mmax according to the selected standard value M; The water supply warning threshold Mmax=a·M, where the value range of a is 0.9 to 0.999; II. When the water supply warning threshold Mmax = 0.9M, the first warning threshold M1 and the second warning threshold M2 are selected; When the sum of the detection results of the detectors (30) corresponding to each water outlet pipe (20) reaches 0.9M or more, and the detection result of the detector (30) corresponding to the water supply pipe (50) is less than 0.9M, the maximum value of the detection result in the water outlet pipe (20) is used as the first warning threshold value M1; When the detection result of the detector (30) corresponding to the water supply pipe (50) exceeds 0.9M, the maximum value of the detection results in each water outlet pipe (20) is used as the second warning threshold value M2; III. Determine the water redundancy ΔQ; The average value obtained by dividing the total amount of water Q delivered by the water delivery pipe (50) by the number n of direct drinking water production devices (10) during the period from obtaining the first warning threshold M1 to obtaining the second warning threshold M2 is used as the water output redundancy ΔQ; IV. Determine the initial value of the parameter α in the water discharge warning margin Q alarm; The water discharge warning margin Q warning = α·water discharge redundancy ΔQ, where α is a positive rational number; Find out the water outlet pipes (20) whose water quality test results are greater than the first warning threshold M1 before the second warning threshold M2 is obtained, count the water output of these water outlet pipes (20) from the time they first reach the first warning threshold M1 to the time they first reach the second warning threshold M2, and compare these water outputs with the water output redundancy ΔQ to determine whether there is a situation in which the water output of any of the water outlet pipes (20) during this period is greater than the water output redundancy ΔQ; i) If there is one, the ratio of the largest water output divided by the water output redundancy ΔQ is the initial value of α; ii) If not, the initial value of α is 1; V. Modify the value of parameter α; Gradually increase the value of a until the sum of the detection results of each water outlet pipe (20) and the detection result of the water supply pipe (50) are all less than the water supply warning threshold value Mmax; thereafter, continuously detect the water output of each water outlet pipe (20) during operation, and calculate the subsequent water output of each water outlet pipe (20) since the first warning threshold value M1 is obtained, and compare the subsequent water output of each water outlet pipe (20) with the water output warning margin Q warning respectively; i) If the water quality test result of the water supply pipe (50) exceeds the water supply warning threshold value Mmax before the subsequent water output of each water outlet pipe (20) reaches the water output warning margin Q warning; then the ratio obtained by dividing the maximum subsequent water output by the water output redundancy ΔQ at that time is the correction value of α and is α', and when the subsequent water output of a certain water outlet pipe (20) exceeds α'·water output redundancy ΔQ, it is determined that the direct drinking water production device (10) corresponding to the water outlet pipe (20) needs to be maintained and replaced; ii) If the water quality test result of the water supply pipe (50) does not exceed the water supply warning threshold value Mmax when the subsequent water output of each water outlet pipe (20) reaches the water output warning margin Q warning, then until the water quality test result of the water supply pipe (50) exceeds the water supply warning threshold value Mmax; the ratio obtained by dividing the maximum subsequent water output by the water output redundancy ΔQ at that time is the correction value of α and is α'', and when the subsequent water output of a certain water outlet pipe (20) exceeds α''·water output redundancy ΔQ, it is determined that the direct drinking water production device (10) corresponding to the water outlet pipe (20) needs to be maintained and replaced.

4. The method for online water quality monitoring of piped drinking water according to claim 3, characterized in that: In step I, the selected standard value M is a set value for the TDS value and the unit of the set value is mg / L; The first warning threshold M1 and the second warning threshold M2 involved in step II are both readings of TDS values.

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