Remote monitoring method and system for membrane separation device

Abstract

A remote monitoring method and system for a membrane separation device are provided, which are capable of efficiently optimizing evaluation index values ​​such as power consumption. [Solution] A remote monitoring method for a membrane separation device that monitors the operating status of a membrane separation device (33) located at a remote site (30), in which a calculation method for calculating a target recovery rate at which the evaluation index value of the membrane separation device (33) is optimized according to the operating conditions is determined in advance, a planned evaluation index value is calculated from the target recovery rate calculated by the calculation method according to the acquired operating data and other operating conditions, and a performance evaluation index value is calculated from the actual recovery rate and other operating conditions, and information for changing at least the recovery rate is provided to the remote site (30) as operating information for reducing the discrepancy between the planned evaluation index value and the performance evaluation index value.

Description

[Technical Field]

[0001] The present invention relates to a remote monitoring method and system for a membrane separation device, for monitoring the operating status of a membrane separation device located at a remote site. [Background technology]

[0002] Conventionally, a remote monitoring method has been known in which the operating performance of each unit of a membrane separation device is received via the Internet and compared with standard performance based on product specifications, etc., to monitor whether performance has decreased by a certain level or more.

[0003] For example, Patent Document 1 proposes a maintenance service system in which a monitoring means for a membrane separation device of a customer who has signed a maintenance service contract is remotely operated by a computer at a remote central membrane monitoring center to collect measurement data, and correlation data previously stored in the computer at the central membrane monitoring center is referenced using the fluctuation trends of the collected measurement data as an index to determine the operating status of the membrane separation device, determine whether or not the membrane cartridge needs to be replaced, and deliver a new or regenerated membrane cartridge from a parts center.The correlation data is obtained in advance based on empirical rules, which represent the correlation between the filtration pressure, permeate volume, etc., and the operating status of the membrane filtration device, and there is room for improvement as a standard for each membrane separation device.

[0004] With the aim of making such improvements, Patent Document 2 proposes a remote monitoring system that, instead of using standard performance, uses performance obtained online from multiple user plants to calculate performance indicators such as power consumption, and uses distribution information of the calculation results to monitor deviations from the allowable range. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-58970 [Patent Document 2] Patent No. 4341950 Summary of the Invention [Problem to be solved by the invention]

[0006] However, because the quality of raw water, supply volume, etc. change constantly, membrane separation equipment and operating conditions are usually designed with a margin of error, resulting in a sacrifice of efficiency. Therefore, even if performance degradation is monitored from the early stages, as in Patent Document 1, it is difficult to further improve evaluation indicators such as power consumption. Furthermore, even when distribution information calculated from performance obtained online from multiple user plants is used, as in Patent Document 2, the membrane separation equipment and operating conditions are designed with a margin of error for each user plant, making it difficult to further improve evaluation indicators such as power consumption.

[0007] In addition, the method of controlling the operating conditions on-site depending on the operating state of the membrane separation device is premised on a design with a margin of error, and in order to further improve the evaluation index values ​​such as actual power consumption, it was necessary to more precisely calculate the planned evaluation index values ​​and compare the two.

[0008] Therefore, an object of the present invention is to provide a remote monitoring method and a remote monitoring system for a membrane separation apparatus that can efficiently optimize evaluation index values ​​such as power consumption. [Means for solving the problem]

[0009] That is, the present invention includes the following aspects.

[0010] [1] A method for remotely monitoring a membrane separation apparatus, which monitors the operating status of a membrane separation apparatus located at a remote site, A calculation method for calculating a target recovery rate at which the evaluation index value of the membrane separation device is optimized according to operating conditions is determined in advance, Calculating a planned evaluation index value from the target recovery rate calculated by the calculation method according to the acquired operating data and other operating conditions, and Calculate the performance evaluation index value from the actual recovery rate and other operating conditions, a remote monitoring method that provides the remote site with information for changing at least a recovery rate as operational information for reducing the discrepancy between the planned evaluation index value and the actual performance evaluation index value;

[0011] According to the remote monitoring method of the present invention, the acquired operating data can be used to improve operating conditions based on recovery rates so as to reduce the discrepancy between the planned evaluation index value calculated from the target recovery rate at which evaluation index values ​​such as power consumption are optimized, and the actual evaluation index value calculated from the actual recovery rate, thereby enabling the evaluation index values ​​to be optimized efficiently.

[0012] [2] The remote monitoring method according to [1], wherein the evaluation index value is an evaluation index value that reflects at least one of power consumption, cumulative permeation flow rate, or chemical usage amount.

[0013] Of the evaluation index values ​​of power consumption, integrated permeation flow rate, and chemical usage, it is desirable to reduce power consumption and chemical usage, and these can be effectively reduced by controlling operation based at least on the recovery rate.

[0014] [3] A remote monitoring method described in [1] or [2], which acquires the operating data multiple times within a certain period of time, calculates the planned evaluation index value and the actual evaluation index value, and provides information for changing at least the recovery rate as operating information for reducing the deviation within the certain period of time.

[0015] By calculating the planned evaluation index value and the actual evaluation index value within a certain period of time, periodic or irregular fluctuations in the water quality of the raw water, etc. are averaged out, making it possible to provide more appropriate operating information.

[0016] [4] The remote monitoring method according to any one of [1] to [3], wherein the operational data includes raw water data relating to the quality and supply amount of raw water.

[0017] The quality of the raw water is particularly prone to change, and the target recovery rate also fluctuates. Therefore, by calculating each evaluation index value in accordance with these, the evaluation index values ​​can be optimized more efficiently.

[0018] [5] The remote monitoring method according to any one of [1] to [4], wherein the potential deterioration of the operating conditions over time is reflected when calculating the planned evaluation index value and the actual performance evaluation index value.

[0019] By reflecting the deterioration over time of the potential operating conditions, it is possible to more accurately determine the recovery rate at which the evaluation index value becomes optimal.

[0020] [6] A remote monitoring system for a membrane separation device that monitors the operating status of a membrane separation device located at a remote site, a communication means capable of transmitting and receiving information to and from the remote site, and an information processing device that processes the received information and outputs it to the communication means; The information processing device includes: A calculation method for calculating a target recovery rate at which the evaluation index value of the membrane separation device is optimized according to operating conditions is stored in advance, Calculating a planned evaluation index value from the target recovery rate calculated by the calculation method according to the operation data acquired by the communication means and other operation conditions, and Calculate the performance evaluation index value from the actual recovery rate and other operating conditions, A remote monitoring system wherein the communication means transmits to the remote site at least information for changing the recovery rate as operational information for reducing the discrepancy between the planned evaluation index value and the actual performance evaluation index value.

[0021] According to the remote monitoring system of the present invention, the acquired operating data can be used to improve operating conditions based on recovery rates so as to reduce the discrepancy between the planned evaluation index value calculated from the target recovery rate at which evaluation index values ​​such as power consumption are optimized, and the actual evaluation index value calculated from the actual recovery rate, thereby enabling the evaluation index values ​​to be optimized efficiently.

[0022] [7] The remote monitoring system according to [6], wherein the evaluation index value is an evaluation index value that reflects at least one of power consumption, cumulative permeation flow rate, or chemical usage amount.

[0023] Of the evaluation index values ​​of power consumption, integrated permeation flow rate, and chemical usage, it is desirable to reduce power consumption and chemical usage, and these can be effectively reduced by controlling operation based at least on the recovery rate.

[0024] [8] The information processing device acquires the operating data multiple times within a certain period of time, and calculates the planned evaluation index value and the actual performance evaluation index value; The remote monitoring system described in [6] or [7], wherein the communication means transmits at least information for changing the recovery rate as operating information for reducing the deviation within the certain period.

[0025] By calculating the planned evaluation index value and the actual evaluation index value within a certain period of time, periodic or irregular fluctuations in the quality of raw water, etc. are averaged out, making it possible to transmit more appropriate operating information.

[0026] [9] The remote monitoring system according to any one of [6] to [8], wherein the operational data includes raw water data relating to the quality and supply amount of raw water.

[0027] The quality of the raw water is particularly prone to change, and the target recovery rate also fluctuates. Therefore, by calculating each evaluation index value in accordance with these, the evaluation index values ​​can be optimized more efficiently.

[0028]

[10] The remote monitoring system described in any one of [6] to [9], wherein the information processing device reflects the deterioration of potential operating conditions over time when calculating the planned evaluation index value and the actual evaluation index value.

[0029] By reflecting the deterioration over time of the potential operating conditions, it is possible to more accurately determine the recovery rate at which the evaluation index value becomes optimal. [Effects of the Invention]

[0030] According to the present invention, it is possible to provide a remote monitoring method and a remote monitoring system for a membrane separation apparatus that can efficiently optimize evaluation index values ​​such as power consumption. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a block diagram illustrating an example of a remote monitoring system. [Figure 2A] 1 is a schematic diagram showing an example of a main part of a membrane separation device. FIG. [Figure 2B] 1 is a graph showing an example of calculation results of the relationship between recovery rate and required pressure when seawater (salt concentration 35 g / L) is desalinated using an RO membrane. [Figure 2C] 1 is a graph showing an example of calculation results of the relationship between recovery rate and specific power consumption when seawater (salt concentrations of 35 g / L and 20 g / L) is desalinated using an RO membrane. [Figure 2D] 1 is a graph showing an example of calculation results of the relationship between recovery rate and salt concentration of the permeate when seawater (salt concentrations of 35 g / L and 20 g / L) is desalinated using an RO membrane (rejection rates of 99.8% and 99.5%). [Figure 2E] 1 is a graph schematically showing a function for calculating a target recovery rate at which power consumption is optimized in accordance with the concentration of feed water, which is one of the operating conditions. [Figure 3] 10 is a flowchart illustrating an example of a processing flow by the remote monitoring system. [Figure 4A] 10 is a graph showing a schematic diagram of the change over time in the amount of power consumption per amount of permeated water in the case of actual performance evaluation index values ​​(solid line) and in the case of planned evaluation index values ​​(dotted line). [Figure 4B] This is a graph that schematically shows the change over time between the target recovery rate (dotted line) when calculating the planned evaluation index value and the actual recovery rate (solid line) when calculating the performance evaluation index value, depending on the concentration of solutes in the raw water (dashed line). [Figure 5A]10 is a graph showing a schematic diagram of the change over time in the amount of power consumption per amount of permeated water in the case of actual performance evaluation index values ​​(solid line) and in the case of planned evaluation index values ​​(dotted line). [Figure 5B] This is a graph that schematically shows the change over time between the actual recovery rate (solid line) when calculating the performance evaluation index value and the target recovery rate (dotted line) when calculating the planned evaluation index value, depending on the concentration of solutes in the raw water (dashed line). DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0033] (Remote monitoring method and remote monitoring system) The remote monitoring method of the present invention is a method for remotely monitoring a membrane separation apparatus that monitors the operating status of a membrane separation apparatus located at a remote site, and can be implemented using, for example, a remote monitoring system of the present invention as shown in Fig. 1. That is, as shown in Fig. 1, the remote monitoring system of the present invention includes a communication means 10 that can send and receive information to a remote site 30, and an information processing device 20 that processes the received information and outputs it to the communication means 10.

[0034] In the illustrated example, one remote site 30 and one remote monitoring system are connected via the network 13, but one remote monitoring system may be provided for multiple remote sites 30. When the remote monitoring method is implemented for multiple remote sites 30, information processing via the network 13 is performed for each remote site 30. Also, multiple remote monitoring systems may be provided for multiple remote sites 30. In this case as well, it is possible for the remote monitoring systems, etc., to share and use some information, such as a database of product information, software for information processing, etc.

[0035] Furthermore, the network 13 is not limited to a wide area network such as the Internet, but may be a local network such as an in-house LAN. The network 13 is not limited to wired connections, but may be partially or entirely wireless connections.

[0036] (Remote Site Equipment and Computational Fundamentals) 1, a membrane separation device 33, a control unit 32 for controlling the membrane separation device, and a communication means 31 for transmitting and receiving information to and from the remote monitoring system are provided at the remote site 30. A plurality of these may be provided for one communication means 31.

[0037] FIG. 2A shows a simplified configuration diagram of the main parts of the membrane separation device 33 in order to explain each parameter for calculating the evaluation index value.

[0038] The membrane separation device 33 basically comprises a pre-pressurization measuring instrument 41 that measures the pressure of the feed water before pressurization, a pressure pump 42 that pressurizes the feed water, a feed water measuring instrument 43 that measures the concentration and flow rate of the feed water after pressurization, a separation membrane module 44 that separates the feed water into permeate and concentrated water, a permeate measuring instrument 45 that measures the concentration and flow rate of the permeate, and a concentrated water measuring instrument 46 that measures the concentration and flow rate of the concentrated water. In addition, control valves, on-off valves, switching valves, tanks, circulation channels, etc. may be provided as necessary.

[0039] Examples of separation membranes used in the separation membrane module 44 include RO membranes, NF membranes, and UF membranes, and one or more membrane elements equipped with these separation membranes are housed in a pressure-resistant container. Compared to other separation membranes, RO membranes, NF membranes, and the like treat large amounts of water at high pressure, so the proportion of costs due to power consumption is high, and improvements in this area are desired.

[0040] For such a membrane separation device 33, the following relationship holds when the feed water flow rate is Qf, the permeate flow rate is Qp, the concentrate flow rate is Qr, the feed water concentration is Cf, the permeate concentration is Cp, the concentrate concentration is Cr, the recovery rate is Rp, the salt permeability is SP, and the rejection rate is Rej. Water balance of membrane system: Qf=Qp+Qr Mass balance of membrane system: QfxCf=QpxCp+QrxCr Recovery rate: Rp=Qp / Qf Salt permeability: SP=(Cp / ((Cf+Cr) / 2))x100 Interdiction rate: Rej=100-SP

[0041] In the present invention, the relationship between the power consumption and recovery rate of the membrane separation device 33 is important, so we will explain the relationship between the recovery rate and power consumption when producing a certain amount of water in a seawater desalination process using an RO membrane as an example.

[0042] When operating RO (reverse osmosis) membranes for seawater desalination, there is a close relationship between the recovery rate and the required power (energy consumption) to obtain a certain amount of freshwater. The relationship between recovery rate and permeate volume is such that, while increasing the recovery rate will result in more freshwater being obtained from the same amount of feedwater, the salt concentration of the remaining concentrated water (brine) will increase.

[0043] Because RO membranes require pressure that exceeds the osmotic pressure, it is necessary to consider the increase in the salt concentration of the concentrated water and the osmotic pressure. Increasing the recovery rate causes a rapid increase in the salt concentration of the feed water, which increases the required pressure and power consumption.

[0044] For example, if seawater (approximately 35 g / L, osmotic pressure approximately 27 bar) is treated at a recovery rate of 50%, the brine side will be concentrated to approximately 70 g / L, and the osmotic pressure will be close to 40 bar, which will increase the power required for the high-pressure pump.

[0045] Regarding the relationship between energy consumption and recovery rate, at low recovery rates (e.g., 30%), brine concentration is gradual and the required pressure is relatively low, but a large amount of seawater must be supplied to obtain the same amount of freshwater. On the other hand, at high recovery rates (e.g., over 50%), concentration progresses and the required pressure increases, increasing the risk of membrane fouling and scaling, and requiring more power for the high-pressure pump.

[0046] Figure 2B shows the relationship between the recovery rate and the required pressure when desalination of seawater (salt concentration 35 g / L) using an RO membrane. Figure 2C shows the relationship between the recovery rate and the specific power consumption when desalination of seawater (salt concentrations 35 g / L and 20 g / L) using an RO membrane. Here, the specific power consumption is the power consumption per unit of permeate volume.

[0047] This model assumes a seawater concentration of 35 g / L (osmotic pressure approximately 27 bar), estimates the osmotic pressure from the average salt concentration (logarithmic average) on the membrane surface, and evaluates the required driving pressure = average osmotic pressure + NDP 5 bar + pressure loss 2 bar. The assumed parameters and calculation formulas are as follows. For comparison, Figure 2C also shows the case of a seawater concentration of 20 g / L.

[0048]

number

[0049] As shown in Figure 2B, as the recovery rate R increases, the concentration of seawater increases, the average osmotic pressure increases, and the required pressure also increases. However, even if the required pressure increases, the increase in the amount of permeate water is greater than the degree of increase, so as shown in Figure 2C, the higher the recovery rate R, the smaller the specific power consumption. Also, as shown in Figure 2C, the higher the salt concentration of the feed water, the higher the required pressure, so when comparing at the same recovery rate R, the higher the salt concentration of the feed water, the greater the specific power consumption.

[0050] On the other hand, the salinity of the permeate changes depending on the recovery rate R. Figure 2D shows the relationship between recovery rate and salinity of the permeate when seawater (salt concentrations of 35 g / L and 20 g / L) is desalinated using an RO membrane (rejection rates of 99.8% and 99.5%). The underlying parameters and calculation formula are as follows:

[0051]

number

[0052] As shown in Figure 2D, the higher the recovery rate, the higher the bulk average salinity, resulting in a higher permeate salinity even at the same rejection rate. In other words, a feedwater with a salinity of 20 g / L will have a lower permeate salinity than a feedwater with a salinity of 35 g / L at the same recovery rate and rejection rate.

[0053] Therefore, when membrane separating feed water with a constant concentration to produce a constant amount of permeate water with a concentration below a certain level, the higher the recovery rate, the lower the power consumption, but since the concentration of the permeate water increases, in order to keep the concentration below a certain level and reduce power consumption, it is effective to increase the recovery rate until the concentration of the permeate water reaches its upper limit. Furthermore, since the concentration of the permeate water is affected by the concentration of the feed water, if the concentration of the feed water fluctuates, it is effective in reducing power consumption to increase the recovery rate in accordance with the fluctuation until the concentration of the permeate water reaches its upper limit.

[0054] This relationship allows the calculation of a target recovery rate at which power consumption is optimized. However, the function used to calculate the target recovery rate varies depending on the underlying design conditions. Figure 2E shows a schematic diagram of a function used to calculate a target recovery rate at which power consumption is optimized, based on the concentration of the feedwater, one of the operating conditions. This function varies depending on the underlying design conditions. For example, as shown in Figure 2E, this function may be a function like that used under design condition D1, or a function like that used under design condition D2, which has a smaller effect on the concentration of the feedwater. Furthermore, as in design condition D3, the allowable recovery rate may be limited to a certain level due to operating conditions that prioritize reducing power consumption. As with design conditions D1 to D3, the function used to calculate the target recovery rate varies depending on the underlying equipment, design conditions, and other operating conditions. However, as described below, a calculation method (e.g., the function shown in Figure 2E) for calculating the target recovery rate at which the evaluation index value of the membrane separation device 33 is optimized depending on the operating conditions can be determined using simulation software, etc., making the present invention applicable to a wide range of equipment, design conditions, and other operating conditions.

[0055] Some or all of the operating data relating to the above parameters can be acquired by the remote monitoring system via the communication means 31. In the present invention, the target recovery rate is calculated according to the acquired operating data, and the planned evaluation index value and the actual performance evaluation index value are calculated from the target recovery rate and other operating conditions, but the other operating conditions also include operating data relating to these parameters.

[0056] The acquired operating data preferably includes raw water data including the quality and supply amount of raw water, but the raw water data may also be raw water data including the quality and supply amount of feed water supplied to the separation membrane module 44. Furthermore, in cases where pretreatment is performed, the raw water data may also be raw water data including the quality and supply amount of raw water from a more upstream side.

[0057] The quality of the raw water is at least one of the following: pH, BOD, COD, TOC, SS, turbidity, oil content, concentration of surfactant components, TDS, electric conductivity, concentration of each ion, saturation of scale components, temperature, color, general aerobic bacteria, sulfate reducing bacteria, etc., but it is preferable to include at least one or more concentration-related factors.

[0058] The raw water data may be numerical data on water quality and supply volume, but may also be secondary data processed at the remote site 30 or data obtained by converting signals from measuring instruments into digital form.

[0059] The membrane separation device 33 is provided with an individual or overall control unit 32 for controlling its operation, and the raw water data may be transmitted to the communication means 31 via the control unit 32. The control unit 32 usually controls the recovery rate and the like of the membrane separation device 33 within the range of design values.

[0060] The membrane separation device 33 may be provided with a supply device for a scale inhibitor or a bactericide (not shown), and the water supplied to the separation membrane module 44 may contain these chemicals.

[0061] The separation membrane module 44 of the membrane separation device 33 generally has a structure in which one or more membrane elements (membrane units) are housed in series in a vessel. In the membrane separation device 33, the separation membrane modules 44 may be provided in parallel or may be connected in two or more stages.

[0062] The above-mentioned parameters may be determined for each separation membrane module 44, for each membrane element, or for a group of multiple separation membrane modules 44.

[0063] (Outline of information processing device and processing) 1, the information processing device 20 includes an input / output unit 21 that inputs and outputs signals to and from the communication means 10, a calculation unit 22 that performs calculations, a storage unit 23 that stores information for performing calculations, and a control unit 24 that controls these. The information processing device 20 is not particularly limited, and a personal computer, a dedicated server, or the like can be used.

[0064] 3 shows a flowchart of an example of processing by the information processing device 20. The remote monitoring method of the present invention can be implemented by processing by the information processing device 20 and the like in accordance with this flowchart.

[0065] The information processing device 20 stores in advance a calculation method for calculating, according to the operating conditions, the target recovery rate at which the evaluation index value of the membrane separation device 33 is optimized. At this time, the calculation method can be stored in the memory unit 23 within the information processing device 20, but it can also be stored in an external server or the like.

[0066] When determining the calculation method, each calculation method is determined according to the type of evaluation index value, and the target recovery rate at which the evaluation index value is optimized can be calculated according to the operating conditions. For example, using simulation software capable of calculating the operating status of the membrane separation device 33, the evaluation index value can be calculated in advance from set operating conditions so as to cover many operating conditions under conditions that are premised on product information, etc., and the calculation can be made into a database or by automatic calculation software so that the recovery rate at which the evaluation index value is optimized can be output as the target recovery rate when operating data is input.

[0067] It is also possible to perform multivariate analysis based on such a database to create a correlation function for calculating a target recovery rate from operational data, and when operational data is input, to output the recovery rate at which the evaluation index value becomes optimal as the target recovery rate. Furthermore, it is also possible to output the recovery rate at which the evaluation index value becomes optimal from the operational data as the target recovery rate calculated by automatic calculation software.

[0068] As preparation for carrying out this method of calculating the target recovery rate, a process for determining more specific operating conditions is carried out in step S1 for inputting product information, etc., and step S2 for pre-operation planning. Note that as product information, a database that associates product numbers with performance data may be created in advance, so that performance data can be read by inputting the product number.

[0069] Next, step S3 acquires information about the start of operation, which initiates step S4 of acquiring operating data. Operating data may be acquired immediately after the start of operation, or a waiting period may be allowed until the membrane separation device 33 stabilizes. In step S4 of acquiring operating data, operating data is acquired at regular time intervals. The interval between acquisitions of operating data is, for example, 5 to 1,440 minutes, with 60 to 720 minutes being preferred in consideration of the stabilization time that reflects fluctuations in operating conditions. When acquiring operating data multiple times within a certain period, the acquisition period of operating data is, for example, 24 to 720 hours, with 72 to 240 hours being preferred in consideration of the effectiveness of operation monitoring based on continuous data. The operating data is sequentially stored as a data set for each parameter, which is read out as needed and used for subsequent calculations.

[0070] Furthermore, the information processing device 20 calculates a planned evaluation index value from the target recovery rate calculated by the calculation method according to the operation data acquired by the communication means 10 and other operation conditions, and also calculates a performance evaluation index value from the actual recovery rate calculated according to the operation data acquired by the communication means 10 and other operation conditions. Such calculations can be performed by the calculation unit 22 using a program stored in the memory unit 23, for example.

[0071] The program in question can be a customized version of the automatic monitoring software for operational data provided by separation membrane manufacturers for more detailed monitoring. Automatic monitoring software measures operational data (pressure, water volume, water quality) of RO membranes and other equipment in actual plants, acquires the measured data, automatically graphs it to show operational progress, and provides advice on operational conditions based on the data. Hydranautics' Hydra$AVE is an example of such automatic monitoring software, and is available from Hydranautics.

[0072] In step S6 for calculating the recovery rate, the target recovery rate and the actual recovery rate are calculated based on the acquired operating data, but step S5 of data analysis may be performed to determine the need for membrane cleaning and membrane replacement (including changing the loading position).In this case, standardization processing may be performed to improve the accuracy of the calculation of the recovery rate.

[0073] Next, based on the calculated recovery rate, step S7 is performed to calculate evaluation index values, which include planned evaluation index values ​​and actual evaluation index values, and then step S8 is performed to compare these evaluation index values.

[0074] The information processing device 20 is required to output information to the communication means 10 to be transmitted to the remote site 30, and outputs at least information for changing the recovery rate as operational information for reducing the discrepancy between the calculated planned evaluation index value and the actual evaluation index value.

[0075] In the example shown in FIG. 3, step S9 for adjusting the operating conditions is executed, and information for changing the recovery rate as information for controlling the operating conditions is fed back to the remote site 30, and step S4 for acquiring operating data is executed again.

[0076] The above process will be explained in more detail below.

[0077] (Evaluation index value) The evaluation index value is preferably an evaluation index value that reflects at least one of the power consumption, the cumulative permeation flow rate, or the amount of chemicals used by the membrane separation apparatus 33. The cost due to power consumption accounts for a large proportion of the total operating cost of the membrane separation apparatus 33, and the total operating cost can be effectively reduced by reducing the power consumption or the total power consumption per cumulative permeation flow rate, which directly affects the power consumption. In addition, the cost due to chemical usage accounts for the second largest proportion of the total operating cost of the membrane separation apparatus 33, and therefore, using the amount of chemical usage as the evaluation index value will be highly effective in reducing the total operating cost.

[0078] The majority of the power consumption of the membrane separation device 33, especially in the case of one using an RO membrane, is due to the pressure pump 42 (high-pressure pump). Power consumption = supply pressure x supply water volume x pump efficiency x operating time It can be calculated as follows.

[0079] The cumulative permeation flow rate (cumulative permeate flow rate) of the membrane separation device 33 is an index of how much the separation membrane is actually used, Accumulated permeation flow rate = permeation water volume [L / min.] x operating time [h] It can be calculated as follows.

[0080] Regarding the amount of chemicals used, for example, in the case of scale inhibitors, the amount of chemicals added is determined by (1) the amount of concentrated water (or amount of water supplied) and recovery rate treated with an RO membrane, etc., and (2) the saturation level of ions that contribute to scale formation contained in the concentrated water. Specifically, Saturation of ions that contribute to scale formation in concentrated water = (Saturation of ions that contribute to scale components in raw water × (1 / (1 - recovery rate))) - (Saturation of ions that contribute to scale components in permeated water) × recovery rate × (1 / (1 - recovery rate))) Amount of chemical used = Chemical concentration required to suppress scale components according to the saturation level of ions that contribute to scale formation in concentrated water × Concentrated water flow rate It can be calculated as follows.

[0081] In addition, in the case of disinfectants, the amount of chemicals to be added is determined based on the flow rate of raw water treated by RO membranes, etc. Amount of chemical used = supply water flow rate x target amount added It can be calculated as follows.

[0082] (Calculation method for target recovery rate and actual recovery rate) The information processing device 20 stores in advance a calculation method for calculating the target recovery rate at which the evaluation index value of the membrane separation device 33 is optimized according to the operating conditions, and after steps S1, S2, and S4, the target recovery rate is calculated in step S6. Note that the case where the potential deterioration over time of the operating conditions is reflected will be described separately.

[0083] For example, if one of the operating conditions is that the permeate concentration of a specific solute is within a predetermined range and a predetermined total amount of permeate is obtained, the amount of raw water supplied is constant and the water quality changes, and the evaluation index value is power consumption (hereinafter referred to as "Precondition 1"), the target recovery rate can be calculated as follows.

[0084] Power consumption = supply pressure x supply water volume x pump efficiency x operating time. The pump efficiency is input in step S1 and the supply water volume is obtained in step S4. Therefore, once the supply pressure is determined and the operating time is decided, the power consumption value can be calculated as an evaluation index value.

[0085] In addition, the power consumption per volume of permeated water is Power consumption per volume of permeated water = supply pressure × supply water volume × pump efficiency × operating time ÷ permeated water volume = supply pressure ÷ (recovery rate ÷ 100) × pump efficiency × operating time Similarly, the power consumption value per permeate amount can be calculated as the evaluation index value.

[0086] The solute rejection rate (removal rate) of the separation membrane module 44 of the membrane separation device 33 is determined by product information, so the solute concentration in the permeate can be determined primarily once the solute concentration in the raw water and the recovery rate are determined. Once the recovery rate is determined, the operating time required to obtain a predetermined total amount of permeate is determined because the amount of water supplied is constant. In addition, once the recovery rate is determined, the supply pressure is also determined. Therefore, under the above assumptions, once the solute concentration in the raw water and the recovery rate are determined, the solute concentration in the permeate and power consumption can be determined.

[0087] Such calculations can be performed using simulation software. By varying the solute concentration in the raw water and the recovery rate, the relationship between these parameters, the solute concentration in the permeate, and power consumption is calculated, and a database is created of the relationship between the solute concentration in the raw water and the recovery rate when power consumption is optimized (e.g., minimized) within the permeate concentration range. This recovery rate becomes the target recovery rate. The relationship between the solute concentration in the raw water and the recovery rate when power consumption is optimized (e.g., minimized) is, for example, as shown in Figure 2E.

[0088] The database can be used directly to obtain the solute concentration in the raw water, which is the operating data, in step S4, and the target recovery rate can be calculated based on this and other operating conditions. Alternatively, the database can be used to create a correlation function to obtain the solute concentration in the raw water, which is the operating data, in step S4, and the target recovery rate can be calculated based on this and other operating conditions.

[0089] When calculating the target recovery rate, it is possible to determine a calculation method that will allow the recovery rate at which the evaluation index value is optimized to be obtained from the expected water quality range of the raw water, such as the maximum, minimum, and average concentrations of each ion, the combination of maximum, minimum, and average values ​​of pH and temperature, the expected amount of water supplied, and operating conditions other than the recovery rate.

[0090] On the other hand, in order to calculate the actual recovery rate under the above-mentioned Precondition 1, the information processing device 20 acquires the raw water supply rate and permeate rate, which are the operating data, in step S4, and calculates the actual recovery rate from the relationship of recovery rate: Rp = Qp / Qf in step S6. Also, when operation is performed at a predetermined recovery rate at the time of design, the recovery rate at the time of design can be used as the actual recovery rate.

[0091] (Calculation of evaluation index values) The information processing device 20 calculates a planned evaluation index value from the target recovery rate calculated by the calculation method according to the operation data acquired by the communication means 10 and other operation conditions, and also calculates a performance evaluation index value from the actual recovery rate and other operation conditions. The actual recovery rate may be calculated according to the operation data acquired by the communication means 10.

[0092] When calculating the planned evaluation index value, the planned evaluation index value is calculated in step S7 from the target recovery rate calculated in step S6 using the calculation method described above, and other operating conditions, such as the operating conditions entered in step S1 and the operating data acquired in step S4.

[0093] For example, when calculating a power consumption value as a planning evaluation index value under the above-mentioned precondition 1, the power consumption value as a planning evaluation index value can be calculated as follows.

[0094] For example, power consumption per unit time = supply pressure × supply water volume × pump efficiency, and since the pump efficiency is input in step S1 and the supply water volume is acquired in step S4, once the supply pressure is determined, the power consumption per unit time can be calculated, and by integrating this over a certain period, the power consumption value can be calculated as the planning evaluation index value. Also, instead of the power consumption per unit time, the power consumption per volume of permeate water produced may be calculated.

[0095] The target recovery rate is calculated according to changes in the solute concentration in the raw water. Once the target recovery rate is determined, the permeate volume can be determined because the feed water volume is constant. This permeate volume also changes, but by integrating it over a certain period of time, the operating time required to obtain a specified total volume of permeate is determined. In addition, once the target recovery rate is determined, the supply pressure is determined, and the power consumption per unit time can be calculated. Therefore, under the above assumptions, once the solute concentration in the raw water is determined, the power consumption within a certain period of time can be determined.

[0096] Such calculations can be performed by customizing the automated monitoring software for more detailed monitoring while acquiring operational data, and then calculating the calculated target recovery rate.

[0097] On the other hand, when calculating the performance evaluation index value, the performance evaluation index value for a certain period is calculated in step S7 from the actual recovery rate calculated in step S6 as described above, and other operating conditions such as the operating conditions input in step S1 and the operating data acquired in step S4.

[0098] For example, when calculating a power consumption value as a performance evaluation index value under the above-mentioned precondition 1, the power consumption value as a performance evaluation index value can be calculated as follows.

[0099] Power consumption = supply pressure x supply water volume x pump efficiency x operating time. The pump efficiency is input in step S1, and the supply pressure and supply water volume are obtained in step S4. Therefore, once the operating time is determined, the power consumption value can be calculated as a performance evaluation index value within a certain period of time.

[0100] Regarding the operating time, since the amount of water supplied is constant, once the actual recovery rate is determined, the operating time required to obtain a predetermined total amount of permeate is determined. Therefore, under the above assumptions, once the actual recovery rate is determined, the amount of power consumption within a certain period of time is determined.

[0101] Such calculations can be performed using the results of calculations performed using automatic monitoring software for operational data.

[0102] Figure 4A shows the change over time in power consumption per unit volume of permeate for the actual performance index (solid line) and the planned performance index (dotted line). Figure 4B shows the change over time in the target recovery rate (dotted line) when the planned performance index value is calculated and the actual recovery rate (solid line) when the actual performance index value is calculated, depending on the solute concentration in the raw water (dashed line). The planned performance index value can be calculated from the relationship between the operating conditions and the target recovery rate, as shown in Figure 2E.

[0103] For example, as shown in Fig. 4B, when the solute concentration in the raw water is low, the target recovery rate, which allows for a further reduction in power consumption per volume of permeate, becomes higher, and when the target recovery rate is high, as shown in Fig. 4A, the planned evaluation index value for power consumption per volume of permeate can be reduced, but because the actual recovery rate is set low as in Fig. 4B, the actual evaluation index value for power consumption per volume of permeate becomes high. Therefore, by bringing the actual recovery rate closer to the target recovery rate, it is possible to further reduce the discrepancy between the planned evaluation index value and the actual evaluation index value.

[0104] The operating conditions other than the recovery rate that are used in the series of calculations include the "product number of the membrane module (membrane element) used," "initial performance of the membrane module used," "number of years of operation of the membrane used," "coefficient of change in permeate volume over time of the membrane used," "coefficient of change in blocking performance over time of the membrane used," and "coefficient of change in differential pressure over time of the membrane used."

[0105] (Comparison of evaluation index values) The information processing device 20 outputs information to the communication means 10 to be transmitted to the remote site 30, and for this purpose, step S8 of comparing the evaluation index values ​​is executed. For example, in the example shown in Fig. 4A, the actual evaluation index value is worse than the planned evaluation index value (high power consumption), and as shown in Fig. 4B, the actual recovery rate can be lowered to reduce the discrepancy between the planned evaluation index value and the actual evaluation index value. As operating information for this purpose, at least information for changing the recovery rate is output.

[0106] Examples of information for changing the recovery rate include the recovery rate itself, the amount of permeate, the supply pressure, etc. Furthermore, while these pieces of information may only be information about increases and decreases, it is preferable that they be quantitative. For example, information for quantitatively changing the recovery rate may include outputting a control value equivalent to 50 to 100% of the difference between the actual recovery rate and the target recovery rate at the point when the difference between the two is smallest within a certain period of time, or outputting a control value equivalent to 50 to 100% of the average value of the difference between the actual recovery rate and the target recovery rate.

[0107] (Adjusting operating conditions) In step S9 of adjusting the operating conditions, the communication means 10 transmits to the remote site 30 at least information for changing the recovery rate as operating information for reducing the discrepancy between the planned evaluation index value and the actual performance evaluation index value.

[0108] This is received by communication means 31 at remote site 30, and control unit 32 adjusts the operating conditions of membrane separation device 33. This changes the recovery rate of membrane separation device 33, making it possible to reduce the discrepancy between the planned evaluation index value and the actual evaluation index value.

[0109] The results of adjusting the operating conditions twice are shown in Figures 5A and 5B. Figure 5A shows the change over time in the amount of power consumed per unit volume of permeate for the actual performance index (solid line) and the planned performance index (dotted line). Figure 5B also shows the change over time in the actual recovery rate (solid line) when the actual performance index value is calculated and the target recovery rate (dotted line) when the planned performance index value is calculated, depending on the solute concentration in the raw water (dashed line).

[0110] 5A and 5B, by adjusting the operating conditions, the actual recovery rate gradually approaches the target recovery rate, and as a result, the difference between the planned evaluation index value and the actual performance evaluation index value can be gradually reduced. As a result, for example, by further reducing the power consumption per permeate amount, the power consumption required to obtain a predetermined amount of permeate can be further reduced.

[0111] (Data Analysis) After the step S4 of acquiring the driving data, the information processing device 20 can also execute a step S of analyzing data to determine the degree of deterioration of the driving situation based on the driving data. Also, based on this, it is possible to modify the calculation method of the target recovery rate.

[0112] In this case, the degree of deterioration of the operating conditions can be determined by introducing at least one of the indicators of standardized water permeability Qn, standardized salt permeability SPn, and standardized differential pressure ΔPn, which are calculated from the initial and current values ​​of the operating data.

[0113] The standardized permeability Qn is calculated by standardizing the current permeate rate using the rate of change over time of the net effective pressure (NDP) and the rate of change over time of the temperature conversion factor (TCF), and is calculated as follows: Standardized permeability Qn = Current permeate rate × Initial NDP ÷ Current NDP × Initial TCF ÷ Current TCF. In this formula, NDP is the net effective pressure, and is calculated as NDP = Operating pressure - Osmotic pressure (osmotic pressure is proportional to concentration), and TCF is the temperature conversion factor, and is calculated as TCF = EXP(Kex(1 / (298)-(1 / (273+To)))) Ke = 2,700, and To is the water temperature [°C].

[0114] The standardized salt permeability SPn is the current salt permeability standardized by the rate of change over time of the permeate volume and the rate of change over time of the temperature conversion factor TCF, and is calculated as follows: Standardized salt permeability SPn = current salt permeability × current permeate volume ÷ initial permeate volume × initial TCF ÷ current TCF.

[0115] The standardized differential pressure ΔPn is the current differential pressure standardized by the rate of change over time of the pressure loss based on the average flow rate in the vessel and the water temperature, and is calculated as follows: Standardized differential pressure ΔPn = Current differential pressure × (Initial average flow rate in the vessel)^1.4 ÷ (Current average flow rate in the vessel)^1.4 × (1 + 0.01 (To-25)), and the average flow rate in the vessel = (Amount of supplied water + Amount of concentrated water) / 2.

[0116] When QPn, SPn, and ΔPn deteriorate, for example, when they deteriorate (change) by 20%, it is possible to determine the need for membrane cleaning or membrane replacement (including changing the loading position).In addition, when determining the calculation method for the target recovery rate, it is also possible to set an upper limit for the recovery rate and modify the calculation method.

[0117] (Calculation reflecting deterioration over time) The information processing device 20 can reflect the potential deterioration of the driving condition over time when calculating the planned evaluation index value and the actual performance evaluation index value. Such processing can also be performed in the data analysis step S5.

[0118] In this case, three indices, namely, standardized permeability Qn, standardized salt permeability SPn, and standardized differential pressure ΔPn, which are calculated from the initial and current values ​​of the operating conditions, can be introduced to reflect the deterioration of the potential operating conditions over time.

[0119] Specifically, the standardized parameters are used when determining a calculation method for calculating, in advance, a target recovery rate at which the evaluation index value of the membrane separation device 33 is optimized according to the operating conditions. Also, the standardized parameters are used when calculating the planned evaluation index value.

[0120] When calculating the performance evaluation index value from the actual recovery rate and other operating conditions, standardized parameters are not used. However, since the actual recovery rate and other operating conditions reflect the actual deterioration of the operating conditions over time, it is possible to adjust the operating conditions more accurately by comparing the performance evaluation index value calculated in this manner with the planned evaluation index value calculated using standardized parameters and determining the deviation between the two.

[0121] (Other embodiments) (1) In the previous embodiment, an example was shown in which the evaluation index value was an evaluation index value reflecting the amount of power consumption. However, even if the evaluation index value is the cumulative permeation flow rate or the amount of chemical usage, the planned evaluation index value can be calculated from the target recovery rate calculated in accordance with the operating data acquired in the same manner and other operating conditions, and the actual evaluation index value can be calculated from the actual recovery rate and other operating conditions.

[0122] That is, it can be calculated by the formula: cumulative permeation flow rate = permeate water volume [L / min.] × operating time [h]. Since the permeate water volume is determined once the recovery rate is determined, a calculation method for calculating the target recovery rate at which the cumulative permeation flow rate is optimized according to the operating conditions can be determined in advance. Once the target recovery rate is calculated according to the acquired operating data, the cumulative permeation flow rate, which is the planned evaluation index value, can be calculated from the target recovery rate and other operating conditions. This can be compared with the cumulative permeation flow rate, which is the actual evaluation index value calculated from the actual recovery rate and other operating conditions, to determine the deviation.

[0123] (2) Furthermore, the amount of chemical usage, for example, in the case of a scale inhibitor, is calculated as follows: chemical concentration required to suppress scale components in the concentrate, which corresponds to the saturation level of ions that contribute to scale formation in the concentrate, multiplied by the concentrate flow rate. The saturation level of ions that contribute to scale formation in the concentrate = (saturation level of ions that contribute to scale components in the raw water × (1 / (1 - recovery rate))) - (saturation level of ions that contribute to scale components in the permeate) × recovery rate × (1 / (1 - recovery rate)). Once the recovery rate is determined, a calculation method can be determined based on the operating data to calculate a target recovery rate that optimizes the amount of chemical usage in accordance with the operating conditions. Once the target recovery rate is calculated based on the acquired operating data, the amount of chemical usage, which is the planned evaluation index value, can be calculated from the target recovery rate and other operating conditions. This can then be compared with the amount of chemical usage, which is the actual evaluation index value calculated from the actual recovery rate and other operating conditions, to determine any discrepancy.

[0124] (3) In the previous embodiment, an example was shown in which product information for a new (unused) product was used as product information. However, the present invention can also be implemented for offline washed products by utilizing their performance information (rejection rate, permeate volume, differential pressure).

[0125] (4) In the previous embodiment, an example was shown in which the operating conditions of one separation membrane module were used as the operating conditions of the membrane separation apparatus. However, it is also possible to use the operating conditions of two or more separation membrane modules to determine in advance a calculation method for calculating the target recovery rate of each separation membrane module at which the evaluation index value of the membrane separation apparatus is optimized according to the operating conditions, and calculate a planned evaluation index value from the target recovery rate calculated using the calculation method according to the acquired operating data of each separation membrane module and other operating conditions, and to calculate a performance evaluation index value from the actual recovery rate of each separation membrane module and other operating conditions.

[0126] (5) In the previous embodiment, Precondition 1 was that the amount of raw water supplied was constant. However, even if the amount of raw water supplied fluctuates, it is possible to determine the method for calculating the target recovery rate and calculate the planned evaluation index value and the actual evaluation index value in a similar manner.

[0127] In other words, a calculation method for calculating the target recovery rate at which the evaluation index value of the membrane separation device is optimized based on operating conditions including the amount of water supplied is determined in advance, and the planned evaluation index value is calculated from the target recovery rate calculated using the calculation method based on the acquired operating data including the amount of water supplied and other operating conditions, and the actual evaluation index value is calculated from the actual recovery rate and other operating conditions.

[0128] (6) In the above embodiment, when providing information for changing at least the recovery rate to the remote site, control information for adjusting the operating conditions is transmitted to the remote site via the same network. However, the method of providing information does not have to be a method of directly adjusting the operating conditions. Examples of such information providing methods include sending information by email, outputting to a website, outputting by dedicated software, etc. [Explanation of symbols]

[0129] 10. Means of communication 13 Network 20 Information processing equipment 33 Membrane separation equipment 44 Separation membrane module

Claims

1. A remote monitoring method for a membrane separation apparatus that monitors the operating status of a membrane separation apparatus located at a remote site, comprising: The recovery rate of the membrane separation device is defined as the value obtained by dividing the permeate flow rate by the feed water flow rate, The evaluation index value is defined as information including one or more selected from the power consumption of the membrane separation device, the integrated permeation flow rate, and the amount of scale inhibitor or bactericide used; The recovery rate at which the evaluation index value is optimized is defined as a target recovery rate, A calculation method for calculating the target recovery rate is determined in advance according to the operating conditions of the membrane separation device, Calculating a target recovery rate using the calculation method according to the operating data of the membrane separation device acquired from the remote site, and calculating a planning evaluation index value from the calculated target recovery rate and operating conditions other than the recovery rate; A performance evaluation index value is calculated from an actual recovery rate according to the operating data of the membrane separation device acquired from the remote site and operating conditions other than the actual recovery rate; a remote monitoring method that provides the remote site with at least information for changing a recovery rate as operational information for reducing the discrepancy between the planned evaluation index value and the actual performance evaluation index value;

2. 2. The remote monitoring method according to claim 1, wherein the operating data is acquired multiple times within a certain period of time, the planned evaluation index value and the actual evaluation index value are calculated, and at least information for changing the recovery rate is provided as operating information for reducing the deviation within the certain period of time.

3. The remote monitoring method of claim 1 , wherein the operational data includes raw water data relating to raw water concentration and supply rate.

4. 2. The remote monitoring method of claim 1, wherein when calculating the planned evaluation index value and the actual evaluation index value, at least one of the indexes of standardized permeability Qn, standardized salt permeability SPn, and standardized differential pressure ΔPn, which are calculated from the initial value and current value of the operating data, is introduced to reflect the deterioration of the potential operating condition over time.

5. A remote monitoring system for a membrane separation apparatus that monitors the operating status of a membrane separation apparatus located at a remote site, The recovery rate of the membrane separation device is defined as the value obtained by dividing the permeate flow rate by the feed water flow rate, The evaluation index value is defined as information including one or more selected from the power consumption of the membrane separation device, the integrated permeation flow rate, and the amount of scale inhibitor or bactericide used; The recovery rate at which the evaluation index value is optimized is defined as a target recovery rate, a communication means capable of transmitting and receiving information to and from the remote site, and an information processing device that processes the received information and outputs it to the communication means; The information processing device includes: a storage unit that stores in advance a calculation method for calculating the target recovery rate according to the operating conditions of the membrane separation device; Calculating a target recovery rate using the calculation method according to the operational data of the membrane separation device acquired from the remote site by the communication means, and calculating a planning evaluation index value from the calculated target recovery rate and operational conditions other than the recovery rate; and a calculation unit that calculates a performance evaluation index value from an actual recovery rate according to the operation data of the membrane separation device acquired from the remote site by the communication means and operation conditions other than the actual recovery rate; A remote monitoring system wherein the communication means transmits to the remote site at least information for changing the recovery rate as operational information for reducing the discrepancy between the planned evaluation index value and the actual performance evaluation index value.

6. the information processing device acquires the operation data a plurality of times within a certain period of time, and calculates the planned evaluation index value and the actual performance evaluation index value; 6. The remote monitoring system according to claim 5, wherein said communication means transmits at least information for changing said recovery rate as the operational information for reducing the deviation within said fixed period.

7. The remote monitoring system of claim 5 , wherein the operational data includes raw water data relating to raw water concentration and supply rate.

8. The remote monitoring system of claim 5, wherein the information processing device, when calculating the planned evaluation index value and the actual evaluation index value, introduces at least one index of standardized permeability Qn, standardized salt permeability SPn, and standardized differential pressure ΔPn, which are calculated from the initial value and current value of the operating data, to reflect deterioration of the potential operating condition over time.

Images