Water treatment plant operation management method and operation management device

Abstract

This invention provides a method for operating and managing a water treatment plant that enables appropriate responses according to the degree of abnormality. [Solution] The operation management method for a water treatment plant includes the steps of acquiring a plurality of indicator values ​​that indicate the operating status of the water treatment device 10, and determining the degree of abnormality of the water treatment device 10 at a plurality of levels based on the acquired plurality of indicator values. The step of determining the degree of abnormality includes determining whether the degree of abnormality is at a predetermined level based on whether the acquired plurality of indicator values ​​satisfy predetermined conditions.

Description

Technical Field

[0001] The present invention relates to an operation management method and an operation management apparatus for a water treatment plant.

Background Art

[0002] In various plants such as power generation plants and water treatment plants, it is required to accurately grasp whether or not an abnormality has occurred in the plant and to take prompt response accordingly. For this reason, conventionally, operation management for monitoring the operating state of a plant has been performed based on measurement data from various measuring instruments. For example, Patent Document 1 describes an operation management method for a water treatment plant having a reverse osmosis membrane (RO membrane) module. In this method, the water permeability coefficient of the RO membrane is calculated based on various measurement data, and by comparing the calculated water permeability coefficient with the water permeability coefficient at the initial stage of operation, it is determined whether or not an abnormality such as fouling or deterioration has occurred in the RO membrane. A similar method is also described in Patent Document 2.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0004] Although the methods described in Patent Documents 1 and 2 are used to determine whether or not cleaning or replacement of the RO membrane is necessary, they do not evaluate the extent of abnormalities such as fouling and deterioration. Therefore, with the methods described in Patent Documents 1 and 2, for example, when the RO membrane is not fouled enough to require cleaning, such a state cannot be distinguished, so it is difficult to take appropriate measures according to the extent of the abnormality.

[0005] Therefore, the object of the present invention is to provide a water treatment plant operation management method and operation management device that can take appropriate action according to the degree of abnormality. [Means for solving the problem]

[0006] To achieve the above-mentioned objectives, the present invention provides a method for operating a water treatment plant having a water treatment device, comprising the steps of: acquiring a plurality of indicator values ​​indicating the operating state of the water treatment device; and determining the degree of abnormality of the water treatment device at a plurality of levels based on the acquired plurality of indicator values, wherein the step of determining the degree of abnormality includes determining whether the degree of abnormality is at a predetermined level based on whether the acquired plurality of indicator values ​​satisfy predetermined conditions.

[0007] Furthermore, the water treatment plant operation management device of the present invention is an operation management device for a water treatment plant having a water treatment device, and comprises an acquisition unit that acquires a plurality of indicator values ​​indicating the operating status of the water treatment device, and a determination unit that determines the degree of abnormality of the water treatment device at a plurality of levels based on the plurality of indicator values ​​acquired by the acquisition unit, wherein the determination unit determines whether the degree of abnormality is at a predetermined level based on whether the plurality of indicator values ​​acquired by the acquisition unit satisfy predetermined conditions. [Effects of the Invention]

[0008] As described above, according to the present invention, appropriate measures can be taken in a water treatment plant according to the degree of abnormality. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of a membrane separation apparatus according to one embodiment of the present invention. [Figure 2] This is a block diagram of an operation management device according to one embodiment of the present invention. [Figure 3] This is a flowchart of the contamination level determination process according to one embodiment of the present invention. [Figure 4]This is a flowchart of the degradation level determination process related to one embodiment of the present invention. [Figure 5] This is a flowchart of the contamination pattern estimation process according to one embodiment of the present invention. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. In this specification, contamination of a membrane separator, specifically fouling of a reverse osmosis membrane (RO membrane), is given as an example of an abnormality in a water treatment device monitored by the operation management device of the present invention. However, the present invention is not limited thereto, and may also include, for example, oxidative degradation of an ion exchange resin. Furthermore, this specification provides examples of specific indicator values ​​and conditions for determining the degree (including presence or absence) of an abnormality in a water treatment device, but these also do not limit the present invention.

[0011] Figure 1 is a schematic diagram of a membrane separation apparatus according to one embodiment of the present invention. It should be noted that the configuration of the membrane separation apparatus shown is merely an example and does not limit the present invention, and it goes without saying that it can be appropriately modified according to the purpose of use, application, and required performance of the apparatus.

[0012] The membrane separation device 10 is one of the water treatment devices that make up the water treatment plant, and has two RO membrane modules 11 and 12. Each RO membrane module 11 and 12 has at least one RO membrane element housed in a cylindrical vessel (pressure vessel). The number of vessels that make up each RO membrane module 11 and 12 is not particularly limited and may be one or multiple. The first RO membrane module 11 separates the raw water (water to be treated) into permeate and concentrated water, and the second RO membrane module 12 further separates the concentrated water from the first RO membrane module 11 into permeate and concentrated water. Hereinafter, the permeate and concentrated water separated by the first RO membrane module 11 will also be called "primary permeate" and "primary concentrated water," respectively, and the permeate and concentrated water separated by the second RO membrane module 12 will also be called "secondary permeate" and "secondary concentrated water," respectively.

[0013] The membrane separation device 10 has a plurality of lines L1 to L5 connected to the first and second RO membrane modules 11 and 12. Specifically, it has a water supply line L1 that supplies raw water to the first RO membrane module 11, a permeate line L2 that carries primary permeate water from the first RO membrane module 11, a concentrated water line L3 that carries primary concentrated water from the first RO membrane module 11 and supplies it to the second RO membrane module 12, a secondary permeate line L4 that carries secondary permeate water from the second RO membrane module 12 and merges it with the permeate line, and a drainage line L5 that carries secondary concentrated water from the second RO membrane module 12 and discharges it to the outside. Hereinafter, the primary permeate water after the secondary permeate water has merged will also be called "RO permeate water".

[0014] Furthermore, the membrane separation device 10 is provided in the water supply line L1 and has a pressurizing pump 13 that adjusts the pressure of the raw water supplied to the first RO membrane module 11. In addition, the membrane separation device 10 has a plurality of sensors 21a to 23d for detecting the operating state of the membrane separation device 10. Specifically, it has first and second conductivity sensors 21a and 21b, first to fourth pressure sensors 22a to 22d, and first to fourth flow sensors 23a to 23d.

[0015] The first conductivity sensor 21a is installed in the water supply line L1 and has the function of detecting the conductivity of raw water. The second conductivity sensor 21b is installed in the permeate line L2 downstream of the confluence with the secondary permeate line L4 and has the function of detecting the conductivity of RO permeate. The first pressure sensor 22a is installed in the water supply line L1 and has the function of detecting the pressure of raw water. The second pressure sensor 22b is installed in the permeate line L2 downstream of the confluence with the secondary permeate line L4 and has the function of detecting the pressure of RO permeate. The third pressure sensor 22c is installed in the concentrated water line L3 and has the function of detecting the pressure of primary concentrated water. The fourth pressure sensor 22d is installed in the drainage line L5 and has the function of detecting the pressure of secondary concentrated water. The first flow sensor 23a is installed in the water supply line L1 and has the function of detecting the flow rate of raw water. The second flow sensor 23b is installed in the permeate line L2 upstream of the confluence with the secondary permeate line L4 and has the function of detecting the flow rate of primary permeate. The third flow sensor 23c is installed in the secondary permeate line L4 and has the function of detecting the flow rate of secondary permeate. The fourth flow sensor 23d is installed in the drainage line L5 and has the function of detecting the flow rate of secondary concentrated water.

[0016] Figure 2 is a block diagram of an operation management device according to one embodiment of the present invention.

[0017] The operation management device 30 manages the operation of the membrane separation device 10 based on the detection results of the multiple sensors 21a to 23d described above, and includes an acquisition unit 31, a storage unit 32, a determination unit 33, and an output unit 34.

[0018] The acquisition unit 31 acquires a plurality of index values for determining the degree of contamination (fouling) and deterioration (oxidative deterioration) of the membrane separation device 10 from the conductivity sensor 21 (the first and second conductivity sensors 21a, 21b), the pressure sensor 22 (the first to fourth pressure sensors 22a to 22d), and the flow rate sensor 23 (the first to fourth flow rate sensors 23a to 23d). The acquisition unit 31 also acquires, from the pressure sensor 22, an index value for estimating the contamination pattern of the membrane separation device 10 (the combination of the presence or absence of contamination in the two RO membrane modules 11 and 12).

[0019] Examples of the index values acquired by the acquisition unit 31 include the following. (1) Supply pressure of raw water to the membrane separation device 10 (detected value of the first pressure sensor 22a) (2) Standard water flow differential pressure of the membrane separation device 10 (Note 1) (3) Standard water flow differential pressure of the first RO membrane module 11 (Note 2) (4) Standard water flow differential pressure of the second RO membrane module 12 (Note 3) (5) RO permeate flow rate (sum of the detected value of the second flow rate sensor 23b and the detected value of the third flow rate sensor 23c) (6) Primary permeate flow rate (detected value of the second flow rate sensor 23b) (7) Secondary permeate flow rate (detected value of the third flow rate sensor 23c) (8) Standard RO permeate flow rate (Note 4) (9) Standard primary permeate flow rate (Note 5) (10) Standard secondary permeate flow rate (Note 6) (11) Flux of the membrane separation device 10 (value obtained by dividing the RO permeate flow rate by the total membrane area of the RO membrane elements) (12) Recovery rate of the membrane separation device 10 (percentage of the value obtained by dividing the RO permeate flow rate by the detected value of the first flow rate sensor 23a) (13) Desalination rate of the membrane separation device 10 (percentage of the value obtained by dividing the difference between the detected value of the first conductivity sensor 21a and the detected value of the second conductivity sensor 21b by the detected value of the first conductivity sensor 21a) (14) Primary concentrated water flow rate (difference between the detected value of the second flow rate sensor 23b and the detected value of the first flow rate sensor 23a) (15) Secondary concentrated water volume (detection value from the fourth flow sensor 23d) (16) Differential water pressure through the first RO membrane module 11 (the difference between the value detected by the third pressure sensor 22c and the value detected by the first pressure sensor 22a) (17) Water flow differential pressure of the second RO membrane module 12 (the difference between the detected value of the fourth pressure sensor 22d and the detected value of the third pressure sensor 22c)

[0020] (Note 1) The differential pressure of the membrane separator 10 (the difference between the detected value of the fourth pressure sensor 22d and the detected value of the first pressure sensor 22a) is converted to a differential pressure when the water flow rate on the primary side of the membrane separator 10 is at a standard value. (Note 2) The water flow differential pressure of the first RO membrane module 11 is converted to a differential pressure when the water flow rate on the primary side of the first RO membrane module 11 is at a standard value. (Note 3) The water flow differential pressure of the second RO membrane module 12 is converted to the differential pressure when the water flow rate on the primary side of the second RO membrane module 12 is at the standard value. (Note 4) The RO permeate volume is converted to a flow rate when the net drive pressure (NDP) and water temperature of the membrane separator 10 are at their respective reference values. (Note 5) The primary permeate rate is converted to a flow rate when the NDP and water temperature of the first RO membrane module 11 are at their respective reference values. (Note 6) The secondary permeate rate is converted to a flow rate when the NDP and water temperature of the second RO membrane module 12 are at their respective standard values. Note that the net driving pressure (NDP) referred to here is the actual pressure required to pass water from the primary side to the secondary side of the membrane, and corresponds to the pressure difference acting on both sides of the membrane.

[0021] The memory unit 32 stores reference values ​​for the indicator values ​​(1) to (11) and (16) to (17) described above. As reference values, the initial values ​​of each indicator value acquired by the acquisition unit 31 immediately after the start of use of each RO membrane, or the indicator values ​​acquired by the acquisition unit 31 after a certain period of time has elapsed since the start of use and the performance has stabilized (preferably their moving average values) are used. These are newly acquired by the acquisition unit 31 each time each RO membrane is replaced with a new one, and are stored and updated in the memory unit 32. The memory unit 32 also stores the judgment results and estimation results from the judgment unit 33.

[0022] The determination unit 33 determines the degree of contamination of the membrane separation device 10 at multiple levels based on the multiple indicator values ​​acquired by the acquisition unit 31. Specifically, the determination unit 33 determines whether the degree of contamination of the membrane separation device 10 is at a predetermined level based on whether the multiple indicator values ​​acquired by the acquisition unit 31 meet predetermined conditions. Whether the multiple indicator values ​​meet predetermined conditions is determined based on at least one of the following: whether the ratio of the indicator value to a reference value is within a predetermined range, whether the indicator value is within a predetermined range, and whether the indicator value is above a predetermined threshold.

[0023] Furthermore, if the determination unit 33 determines that the degree of contamination of the membrane separation device 10 is above a certain level, it determines the degree of deterioration of the membrane separation device 10 at one of several levels based on at least one index value acquired by the acquisition unit 31. Specifically, the determination unit 33 determines whether the degree of deterioration of the membrane separation device 10 is at a predetermined level based on whether at least one index value acquired by the acquisition unit 31 satisfies predetermined conditions. Whether at least one index value satisfies predetermined conditions is determined based on, for example, whether the ratio of the index value to a standard value is within a predetermined range, whether the index value is within a predetermined range, and whether the index value is above a predetermined threshold.

[0024] Furthermore, if the determination unit 33 determines that the degree of contamination of the membrane separation device 10 is above a certain level, it estimates the contamination pattern of the membrane separation device 10 based on the two index values ​​acquired by the acquisition unit 31. Specifically, the determination unit 33 estimates which of several patterns the contamination of the membrane separation device 10 falls into, based on whether each index value satisfies predetermined conditions. Whether each index value satisfies predetermined conditions is determined, for example, based on whether the index value is above a standard value.

[0025] The output unit 34 outputs the determination result to an external device (e.g., a display) when the determination unit 33 has determined the degree of contamination or deterioration of the membrane separation device 10. At this time, the output unit 34 also outputs a message corresponding to the determined degree (level) of contamination or deterioration (e.g., information regarding chemical cleaning of the membrane separation device 10). In addition, the output unit 34 also outputs the estimation result to an external device (e.g., a display) when the determination unit 33 has estimated the contamination pattern of the membrane separation device 10. At this time, the output unit 34 also outputs a message corresponding to the estimated contamination pattern (e.g., information regarding membrane replacement of the membrane separation device 10).

[0026] Referring to the flowchart shown in Figure 3, an example of the contamination level determination process by the operation management device 30 will be explained. The contamination level determination process is a process that determines the degree of contamination of the membrane separation device 10 in multiple levels. In this embodiment, the degree of contamination is classified into five levels (levels 0 to 5), with level 0 being the lowest level of contamination and level 5 being the highest level of contamination.

[0027] When the contamination level determination process is started, the acquisition unit 31 acquires a first group of indicator values ​​(step S1). The first group of indicator values ​​is a group of indicator values ​​for determining whether or not the operating state of the membrane separation device 10 is stable, and it is preferable that it contains as many indicator values ​​as possible. Examples of such indicator values ​​include the indicator values ​​(1) to (15) above.

[0028] Next, the determination unit 33 determines whether the first set of index values ​​obtained in step S1 satisfies the first condition (step S2). The first condition is, for example, that all of the following conditions (A1) to (A15) are satisfied. (A1) The supply pressure of raw water to the membrane separator 10 is between 90% and 110% of the standard value. (A2) The standard water flow differential pressure of the membrane separator 10 is 90% or more but less than 150% of the standard value. (A3) The standard water flow differential pressure of the first RO membrane module 11 is 85% or more but less than 160% of the standard value. (A4) The standard water flow differential pressure of the second RO membrane module 12 is 85% or more but less than 160% of the standard value. (A5) RO permeate amount is 95% or more but less than 105% of the standard value. (A6) Primary permeate is 95% or more but less than 105% of the standard value. (A7) Secondary permeate is 90% or more but less than 110% of the standard value. (A8) Standard RO permeate is 95% or more but less than 105% of the standard value. (A9) Standard primary permeate is 95% or more but less than 110% of the standard value. (A10) Standard secondary permeate is 85% or more but less than 110% of the standard value. (A11) The flux of the membrane separation device 10 is between 95% and 105% of the standard value. (A12) The recovery rate of the membrane separation device 10 is 70% or more and less than 80%. (A13) The desalination rate of the membrane separation device 10 is 90% or higher. (A14) Primary concentrated water volume is equal to or greater than the minimum concentrated water volume. (A15) Secondary concentrated water volume is equal to or greater than the minimum concentrated water volume. Here, the minimum concentrated water flow rate in (A14) and (A15) above refers to the minimum flow rate of concentrated water that should be flowed into the concentrated water line L3 or the drainage line L5 in order to prevent membrane clogging due to fouling or scaling in each RO membrane module 11, 12. As an example, the minimum concentrated water flow rates in (A14) and (A15) above are 55 L / min and 70 L / min, respectively.

[0029] Then, in step S2, if it is determined that the first group of indicator values ​​satisfies the first condition, the degree of contamination of the membrane separation device 10 is determined to be level 0 (step S3). On the other hand, in step S2, if it is determined that the first group of indicator values ​​does not satisfy the first condition, the acquisition unit 31 acquires a second group of indicator values ​​(step S4). The second group of indicator values ​​is a group of indicator values ​​for detecting a state in which the operation of the membrane separation device 10 is stable but contamination is progressing to some extent, and it is preferable that it includes indicator values ​​that are easily affected when the degree of contamination of the membrane separation device 10 is mild. Examples of such indicator values ​​include the indicator values ​​(1) to (4) and (11) to (13) above.

[0030] Next, the determination unit 33 determines whether the second set of index values ​​obtained in step S4 satisfies the second condition (step S5). The second condition is, for example, that all of the following conditions (B1) to (B4) are met, or that any of the following conditions (B5) to (B8) are met, and any of the following conditions (B9) to (B11) are met. (B1) The supply pressure of raw water to the membrane separator 10 is between 90% and 110% of the standard value. (B2) The standard water flow differential pressure of the membrane separator 10 is 90% or more but less than 150% of the standard value. (B3) The standard water flow differential pressure of the first RO membrane module 11 is 80% or more but less than 150% of the standard value. (B4) The standard water flow differential pressure of the second RO membrane module 12 is 80% or more but less than 150% of the standard value. (B5) The supply pressure of raw water to the membrane separator 10 is between 90% and 120% of the standard value. (B6) The standard water flow differential pressure of the membrane separator 10 is 150% or more but less than 200% of the standard value. (B7) The standard water flow differential pressure of the first RO membrane module 11 is 160% or more but less than 180% of the standard value. (B8) The standard water flow differential pressure of the second RO membrane module 12 is 160% or more but less than 180% of the standard value. (B9) The flux of the membrane separation device 10 is between 95% and 105% of the standard value. (B10) The recovery rate of the membrane separation device 10 is 70% or more but less than 80%. (B11) Desalination rate of membrane separation device 10 is 90% or higher.

[0031] Then, in step S5, if it is determined that the second group of indicator values ​​satisfies the second condition, the degree of contamination of the membrane separation device 10 is determined to be level 1 (step S6). On the other hand, in step S5, if it is determined that the second group of indicator values ​​does not satisfy the second condition, the acquisition unit 31 acquires a third group of indicator values ​​(step S7). The third group of indicator values ​​is a group of indicator values ​​for determining whether or not contamination of the membrane separation device 10 is progressing, and it is preferable that it includes indicator values ​​that are easily affected when the degree of contamination of the membrane separation device 10 is mild to moderate. Examples of such indicator values ​​include the indicator values ​​(1) to (4) and (11) to (13) above.

[0032] Next, the determination unit 33 determines whether the third group of index values ​​obtained in step S7 satisfies the third condition (step S8). The third condition is, for example, that any of the following conditions (C1) to (C4) are met, and any of the following conditions (C5) to (C7) are met. (C1) The supply pressure of raw water to the membrane separator 10 is between 120% and 140% of the standard value. (C2) The standard water flow differential pressure of the membrane separator 10 is 200% or more but less than 250% of the standard value. (C3) The standard water flow differential pressure of the first RO membrane module 11 is 180% or more but less than 200% of the standard value. (C4) The standard water flow differential pressure of the second RO membrane module 12 is 180% or more but less than 200% of the standard value. (C5) The flux of the membrane separation device 10 is between 95% and 110% of the standard value. (C6) The recovery rate of the membrane separation device 10 is 70% or more but less than 80%. (C7) Desalination rate of membrane separation device 10 is 90% or higher.

[0033] Then, in step S8, if it is determined that the third group of indicator values ​​satisfies the third condition, the degree of contamination of the membrane separation device 10 is determined to be level 2 (step S9). On the other hand, in step S8, if it is determined that the third group of indicator values ​​does not satisfy the third condition, the acquisition unit 31 acquires a fourth group of indicator values ​​(step S10). The fourth group of indicator values ​​is a group of indicator values ​​for determining whether the contamination of the membrane separation device 10 has progressed further, and it is preferable that it includes indicator values ​​that are easily affected when the degree of contamination of the membrane separation device 10 is moderate to severe. Examples of such indicator values ​​include the indicator values ​​(1) to (5) and (11) above.

[0034] Next, the determination unit 33 determines whether the fourth group of index values ​​obtained in step S10 satisfies the fourth condition (step S11). The fourth condition is, for example, that any of the following conditions (D1) to (D4) are met, or that condition (D1) is met and either of the following conditions (D5) and (D6) are met. (D1) The supply pressure of raw water to the membrane separator 10 is 130% or more but less than 140% of the standard value. (D2) The standard water flow differential pressure of the membrane separator 10 is 250% or more but less than 300% of the standard value. (D3) The standard water flow differential pressure of the first RO membrane module 11 is 200% or more but less than 300% of the standard value. (D4) The standard water flow differential pressure of the second RO membrane module 12 is 200% or more but less than 300% of the standard value. (D5) RO permeate volume is 90% or more but less than 120% of the standard value. (D6) The flux of the membrane separation device 10 is between 90% and 95% of the standard value.

[0035] Then, in step S11, if it is determined that the fourth group of indicator values ​​satisfies the fourth condition, the degree of contamination of the membrane separation device 10 is determined to be level 3 (step S12). If it is determined that the fourth condition is not met, the degree of contamination of the membrane separation device 10 is determined to be level 4 (step S13).

[0036] In steps S3, S6, S9, and S12-S13, once the degree (level) of contamination of the membrane separation device 10 is determined, the output unit 34 outputs the determination result (step S14). At this time, in addition to the determination result, a message corresponding to the determined level of contamination is also output. Specifically, a message prompting confirmation of the operating status of the membrane separation device 10, for example, a message such as "Please check ***." (in the case of level 1) is also output. In addition, a message recommending the implementation of chemical cleaning, for example, a message such as "Please prepare for chemical cleaning." (in the case of contamination levels 2-3) or a message such as "Please perform chemical cleaning." (in the case of contamination level 4) is also output.

[0037] Next, it is determined whether the level of contamination of the membrane separation device 10, as determined in steps S3, S6, S9, and S12-S13, is level 2 or higher (step S15). If it is determined that the level of contamination is not level 2 or higher, the contamination level determination process ends. On the other hand, if it is determined that the level of contamination is level 2 or higher, the degradation level determination process is executed (step S16). The specific details of the degradation level determination process will be described later. Then, when the contamination pattern estimation process is executed (step S17), the contamination level determination process ends. The specific details of the contamination pattern estimation process will also be described later.

[0038] Here, an example of the degradation level determination process by the operation management device 30 will be explained with reference to the flowchart shown in Figure 4. The degradation level determination process is a process that determines the degree of degradation of the membrane separation device 10 in multiple levels. In this embodiment, the degree of degradation is classified into three levels (levels 0 to 2), with level 0 being the lowest level of degradation and level 2 being the highest level of degradation.

[0039] When the degradation level determination process is started, the acquisition unit 31 acquires a fifth group of indicator values ​​(step S21). The fifth group of indicator values ​​is a group of indicator values ​​for determining whether or not the degradation of the membrane separation device 10 is progressing, and it is preferable that it includes indicator values ​​that are easily affected when the degree of degradation of the membrane separation device 10 is moderate. Examples of such indicator values ​​include the indicator value in (13) above, i.e., the desalination rate of the membrane separation device 10.

[0040] Next, the determination unit 33 determines whether the fifth group of indicator values ​​obtained in step S21 satisfies the fifth condition (step S22). The fifth condition is, for example, that the desalination rate of the membrane separation device 10 is 87.5% or more and less than 90%.

[0041] Then, in step S22, if it is determined that the fifth group of indicator values ​​satisfies the fifth condition, the degree of deterioration of the membrane separator 10 is determined to be level 0 (step S23). On the other hand, in step S22, if it is determined that the fifth group of indicator values ​​does not satisfy the fifth condition, the acquisition unit 31 acquires the sixth group of indicator values ​​(step S24). The sixth group of indicator values ​​is a group of indicator values ​​for determining whether the deterioration of the membrane separator 10 is progressing further, and it is preferable that it includes indicator values ​​that are easily affected when the degree of deterioration of the membrane separator 10 is moderate to severe. Examples of such indicator values ​​include the indicator values ​​of (1), (5) and (13) above, namely the supply pressure of raw water to the membrane separator 10, the amount of RO permeate, and the desalination rate of the membrane separator 10.

[0042] Next, the determination unit 33 determines whether the sixth group of indicator values ​​obtained in step S24 satisfies the sixth condition (step S25). The sixth condition is, for example, that the supply pressure of raw water to the membrane separator 10 is 80% or less of the standard value and the RO permeate amount is 105% or more of the standard value, or that the desalination rate of the membrane separator 10 is 85% or more and less than 87.5%.

[0043] Then, in step S25, if it is determined that the sixth group of indicator values ​​satisfies the sixth condition, the degree of deterioration of the membrane separation device 10 is determined to be level 1 (step S26). If it is determined that the sixth condition is not met, the degree of deterioration of the membrane separation device 10 is determined to be level 2 (step S27).

[0044] In steps S23, S26-S27, the degree (level) of deterioration of the membrane separation device 10 is determined, and the output unit 34 outputs the determination result (step S28). At this time, in addition to the determination result, a message corresponding to the determined level of deterioration is also output. Specifically, a message recommending membrane replacement is output, such as "Please prepare a new membrane." (for level 1) or "Please replace with a new membrane." (for level 2). Once the determination result is output, the deterioration level determination process is completed.

[0045] Next, an example of the contamination pattern estimation process by the operation management device 30 will be described with reference to the flowchart shown in Figure 5. The contamination pattern estimation process is a process for estimating the form of contamination of the membrane separation device 10, and specifically, it is a process for estimating which of several patterns it falls under. In this embodiment, four contamination patterns are possible, which are combinations of the presence or absence of contamination of the first RO membrane module 11 and the presence or absence of contamination of the second RO membrane module 12.

[0046] When the contamination pattern estimation process is started, the acquisition unit 31 acquires an index value for determining the degree of contamination of the first RO membrane module 11 (step S31). The index value acquired at this time may be, for example, the index value of (16) above, i.e., the water flow differential pressure of the first RO membrane module 11.

[0047] Next, the determination unit 33 determines whether the index value obtained in step S31 satisfies the seventh condition (step S32). The seventh condition is, for example, that the water flow differential pressure of the first RO membrane module 11 is equal to or greater than the reference value. The reference value in this case is the moving average value of the water flow differential pressure over a certain period (for example, 10 days) after the RO membrane's performance stabilizes immediately after the start of use.

[0048] Then, if it is determined in step S32 that the index value satisfies the seventh condition, the acquisition unit 31 acquires an index value for determining the degree of contamination of the second RO membrane module 12 (step S33). An example of the index value acquired at this time is the index value in (17) above, that is, the differential water flow pressure of the second RO membrane module 12.

[0049] Next, the determination unit 33 determines whether the index value obtained in step S33 satisfies the eighth condition (step S34). The eighth condition is, for example, that the water flow differential pressure of the second RO membrane module 12 is equal to or greater than the reference value. The reference value in this case is the moving average value over a certain period (for example, 10 days) after the performance stabilizes immediately after the start of use of each RO membrane.

[0050] Then, in step S34, if it is determined that the index value satisfies the eighth condition, the contamination pattern of the membrane separator 10 is determined to be pattern A (step S35). If it is determined that the eighth condition is not met, the contamination pattern of the membrane separator 10 is determined to be pattern B (step S36). Pattern A is a state in which the differential water flow pressure of the first and second RO membrane modules 11 and 12 is both rising. Pattern B is a state in which the differential water flow pressure of the first RO membrane module 11 is rising.

[0051] On the other hand, if it is determined in step S32 that the index value does not satisfy the seventh condition, the acquisition unit 31 acquires the same index value as acquired in step S33 (step S37), and the determination unit 33 determines whether the index value satisfies the eighth condition using the same method as in step S34 (step S38). If it is determined that the index value satisfies the eighth condition, the contamination pattern of the membrane separation device 10 is determined to be pattern C (step S39), and if it is determined that the eighth condition is not satisfied, the contamination pattern of the membrane separation device 10 is determined to be pattern D (step S40). Pattern C is a state in which the water flow differential pressure of the second RO membrane module 12 is rising. Pattern D is a state in which the water flow differential pressure of the first and second RO membrane modules 11 and 12 is not rising.

[0052] In steps S35-S36 and S39-S40, once the pattern of contamination of the membrane separation device 10 is estimated, the output unit 34 outputs the estimation result (step S41). At this time, in addition to the estimation result, a message corresponding to the estimated contamination pattern is also output. Specifically, a message recommending the type of chemical to be used during chemical cleaning, based on the cause of contamination inferred from the estimated contamination pattern, is output, for example, "When performing chemical cleaning, we recommend using ***." Once the estimation result is output, the contamination pattern estimation process is completed.

[0053] As described above, according to this embodiment, a plurality of pre-set indicator values ​​are acquired for each level, depending on the degree (level) of abnormality such as contamination in the membrane separation device 10. Then, based on whether the acquired indicator values ​​meet predetermined conditions, it is determined whether the degree of abnormality is at a predetermined level. This makes it possible to accurately evaluate the degree of abnormality in the membrane separation device 10 and to take appropriate action according to the degree of abnormality. Note that contamination (fouling) of the membrane separation device 10 occurs due to a combination of factors, such as the quality of the raw water and the conditions of the pretreatment. Therefore, for example, the indicator values ​​that are most susceptible to the effects of a high degree of contamination may differ depending on the configuration of the water treatment plant including the membrane separation device 10. Accordingly, it is preferable that the plurality of indicator values ​​acquired for each level determination are not limited to those exemplified in the embodiment described above, but are appropriately set according to the actual plant configuration.

[0054] As described above, the configuration of the membrane separation device 10 is not limited to that shown in the figures. For example, the second RO membrane module 12 may further process the permeate from the first RO membrane module 11. Also, the membrane separation device 10 is not limited to having two RO membrane modules 11 and 12. For example, it may have a single RO membrane module. However, RO membrane fouling is particularly likely to occur in the downstream RO membrane when concentrated water from the upstream RO membrane is processed by the downstream RO membrane. Therefore, the operation management method of this embodiment is particularly useful when the second RO membrane module 12 processes concentrated water from the first RO membrane module 11, as shown in the figures. [Explanation of Symbols]

[0055] 10 Membrane separation equipment 11. First RO membrane module 12. Second RO membrane module 13. Pressure pump 21 Conductivity Sensor 21, 21a~21b Conductivity Sensor 22, 22a~22d Pressure Sensor 23, 23a~23d Flow Sensor 30 Operation Management Device 31 Acquisition Department 32 Storage section 33 Judgment section 34 Output section L1 Water supply line L2 Permeable Water Line L3 Concentrated Water Line L4 Secondary Permeate Water Line L5 drainage line

Claims

1. A method for operating and managing a water treatment plant equipped with a water treatment device, A step of obtaining multiple indicator values ​​that show the operating status of the water treatment device, The process includes determining the degree of abnormality of the water treatment device at multiple levels based on the multiple indicator values ​​obtained, A method for operating and managing a water treatment plant, wherein the step of determining the degree of the abnormality includes determining whether the degree of the abnormality is at a predetermined level based on whether the acquired plurality of indicator values ​​satisfy predetermined conditions.

2. The water treatment apparatus has at least one reverse osmosis membrane that separates the water to be treated into permeate and concentrated water. The method for operating and managing a water treatment plant according to claim 1, wherein the plurality of indicator values ​​are a plurality of indicator values ​​indicating the state of the at least one reverse osmosis membrane, and the abnormality is contamination of the at least one reverse osmosis membrane.

3. The method for operating and managing a water treatment plant according to claim 2, wherein the at least one reverse osmosis membrane includes a first reverse osmosis membrane and a second reverse osmosis membrane for treating concentrated water or permeate from the first reverse osmosis membrane.

4. A method for operating and managing a water treatment plant according to claim 2 or 3, further comprising the step of outputting a message corresponding to the determined degree of contamination.

5. If it is determined that the degree of contamination of the at least one reverse osmosis membrane is above a certain level, the step is to obtain at least one index value indicating the state of the at least one reverse osmosis membrane. The process further includes determining the degree of deterioration of the at least one reverse osmosis membrane at multiple levels based on the at least one index value obtained, The method for operating and managing a water treatment plant according to claim 2 or 3, wherein the step of determining the degree of deterioration includes determining whether the degree of deterioration is at a predetermined level based on whether or not the at least one index value satisfies a predetermined condition.

6. A method for operating and managing a water treatment plant according to claim 5, further comprising the step of outputting a message corresponding to the determined degree of deterioration.

7. If it is determined that the degree of contamination of at least one reverse osmosis membrane is above a certain level, the process involves obtaining an index value indicating the state of the first reverse osmosis membrane and an index value indicating the state of the second reverse osmosis membrane. A method for operating and managing a water treatment plant according to claim 3, further comprising the step of estimating a contamination pattern that combines the presence or absence of contamination of the first reverse osmosis membrane and the presence or absence of contamination of the second reverse osmosis membrane based on the acquired index values.

8. A method for operating and managing a water treatment plant according to claim 7, comprising the step of outputting a message corresponding to the estimated contamination pattern.

9. An operation and management system for a water treatment plant having a water treatment device, An acquisition unit that acquires multiple indicator values ​​indicating the operating status of the water treatment apparatus, The system includes a determination unit that determines the degree of abnormality of the water treatment device at multiple levels based on a plurality of indicator values ​​obtained by the acquisition unit, The determination unit determines whether the degree of the abnormality is at a predetermined level based on whether a plurality of indicator values ​​obtained by the acquisition unit meet predetermined conditions, and is an operation management device for a water treatment plant.

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