Device for controlling a reverse osmosis membrane seawater desalination plant and method thereof

Abstract

An apparatus and method for controlling a reverse osmosis membrane seawater desalination plant are provided. The apparatus includes: a dissolved air flotation (DAF) unit for providing treated water obtained by treating seawater using DAF; an ultrafiltration (UF) unit comprising multiple ultrafiltration units each equipped with an ultrafiltration membrane, for performing an ultrafiltration process using the ultrafiltration membranes of the multiple ultrafiltration units to filter impurities remaining in the treated water; a reverse osmosis unit; an information collection unit; and a status processing unit.

Description

Technical Field

[0001] This invention relates to a plant control technology, and more particularly to an apparatus and method for controlling a reverse osmosis membrane desalination plant. Background Technology

[0002] In the pretreatment of seawater desalination projects, in order to remove suspended matter such as solids, it is necessary to use chemicals such as pH adjusters and coagulants at the front end of the dissolved air flotation (DAF) process. In traditional methods, injecting appropriate chemicals relies on sampling tests and the technical know-how of operators, making it difficult to control the process while reflecting the real-time changes in the state of the seawater and the state of the DAF back end process, which is the main engineering component.

[0003] Prior technology documents

[0004] Patent documents

[0005] (Patent Document 1) Korean Patent Publication No. 2019-0088180 (published on July 26, 2019) Summary of the Invention

[0006] The purpose of this invention is to provide an apparatus and method for controlling a reverse osmosis membrane seawater desalination plant.

[0007] To achieve the objectives described above, an apparatus for controlling a seawater desalination plant, according to a preferred embodiment of the present invention, includes: a dissolved air flotation (DAF) unit for providing treated water obtained by treating seawater using the DAF method; an ultrafiltration unit including multiple ultrafiltration units, each equipped with an ultrafiltration membrane, for performing an ultrafiltration (UF) process to filter impurities remaining in the treated water using the ultrafiltration membranes of the multiple ultrafiltration units; a reverse osmosis (RO) unit including multiple membrane stacks, each equipped with a reverse osmosis membrane, for performing a reverse osmosis (RO) process to filter impurities remaining in the treated water using the reverse osmosis membranes of the multiple membrane stacks; and an information collection unit for collecting data on the turbidity of the treated water, the residual iron (RI) of the treated water, and the differential pressure (DP) indicating the ultrafiltration process. The ultrafiltration differential pressure increase rate (increase rate of pressure) and the reverse osmosis differential pressure increase rate (increase rate of pressure) representing the increase rate of pressure difference in the reverse osmosis process are collected; and the state processing unit, by adjusting the amount of chemical agent injected into the seawater, maintains the ultrafiltration differential pressure increase rate and the reverse osmosis differential pressure increase rate below the preset reference values ​​while keeping the turbidity and the residual iron below the preset reference values.

[0008] The present invention is characterized in that: the state processing unit determines whether the turbidity of the treated water reaches or exceeds a preset reference value, and when the turbidity of the treated water reaches or exceeds the preset reference value, the turbidity of the treated water is lower than the preset reference value by adjusting the amount of chemical agent injected.

[0009] The present invention is characterized in that: when the turbidity of the treated water is lower than a preset reference value, the state processing unit determines whether the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference reach or exceed a preset reference value; when the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference reach or exceed a preset reference value, it determines whether the residual iron of the treated water reaches or exceeds a preset reference value; when the residual iron of the treated water reaches or exceeds a preset reference value, it changes the amount of chemical agent injected to make the residual iron of the treated water lower than a preset reference value.

[0010] The present invention is characterized in that: when the residual iron in the treated water is lower than a preset reference value, the state processing unit determines whether the increase rate of ultrafiltration pressure difference or the increase rate of reverse osmosis pressure difference reaches or exceeds a preset reference value; when the increase rate of ultrafiltration pressure difference or the increase rate of reverse osmosis pressure difference reaches or exceeds a preset reference value, the unit changes the amount of chemical agent injected to make the increase rate of ultrafiltration pressure difference and the increase rate of reverse osmosis pressure difference lower than the preset reference value.

[0011] The present invention is characterized in that: when the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference are lower than the preset benchmark values, the state processing unit gradually adjusts the chemical agent injection amount to the basic injection amount after waiting for a certain period of time.

[0012] The present invention is characterized in that the chemical agent comprises at least one of a hydrogen ion concentration regulator and a coagulant.

[0013] The present invention is characterized in that: the information collection unit collects pressure difference values ​​from the ultrafiltration unit during the calculation period of the ultrafiltration pressure difference increase rate, after a certain period of time has elapsed since the start of the filtration mode in which the ultrafiltration unit performs filtration, and before a certain period of time has elapsed since the start of the backwash mode or the chemical washing mode in which the ultrafiltration unit performs washing, and calculates the slope of the linear trend line of the collected pressure difference values ​​as the ultrafiltration pressure difference increase rate of the ultrafiltration unit.

[0014] The present invention is characterized in that: when the number of ultrafiltration units whose ultrafiltration differential pressure increase rate reaches or exceeds a certain set value reaches or exceeds a certain set value, the state processing unit determines that the ultrafiltration differential pressure increase rate has reached or exceeded a preset benchmark value.

[0015] The present invention is characterized in that: the information collection unit collects pressure difference values ​​from the membrane stack during a pre-set reverse osmosis pressure difference increase rate calculation period, divides the pre-set reverse osmosis pressure difference increase rate calculation period into unit time, and calculates the slope of the linear trend line of the pressure difference values ​​collected in each divided unit time as the reverse osmosis pressure difference increase rate.

[0016] The present invention is characterized in that: when the number of membrane stacks whose reverse osmosis pressure difference increase rate reaches or exceeds a certain set value, the state processing unit determines that the reverse osmosis pressure difference increase rate has reached or exceeded a preset benchmark value.

[0017] To achieve the objectives described above, a preferred embodiment of the present invention is provided for controlling a seawater desalination plant, comprising: a chemical agent treatment unit for injecting a chemical agent into seawater; and an information collection unit for collecting data on the turbidity of the treated water obtained by treating the seawater using dissolved air flotation (DAF), the residual iron (RI) of the treated water, the increase rate of the ultrafiltration differential pressure (DP) indicating the increase rate of the differential pressure during ultrafiltration (UF) for filtering impurities remaining in the treated water, and the increase rate of the differential pressure during reverse osmosis (RO) for filtering impurities remaining in the treated water. The reverse osmosis pressure difference increase rate is collected during the pressure difference increase rate in the Osmosis process; and the state processing unit compares the turbidity of the treated water, the residual iron in the treated water, the ultrafiltration pressure difference increase rate, and the reverse osmosis pressure difference increase rate with preset reference values ​​for the turbidity, the residual iron, the ultrafiltration pressure difference increase rate, and the reverse osmosis pressure difference increase rate, respectively. By controlling the chemical agent processing unit, the injection amount of the chemical agent is adjusted so that the turbidity and the residual iron are maintained below the preset reference values, while the ultrafiltration pressure difference increase rate and the reverse osmosis pressure difference increase rate are also maintained below the preset reference values.

[0018] The present invention is characterized in that: the state processing unit determines whether the turbidity of the treated water reaches or exceeds a preset reference value, and when the turbidity of the treated water reaches or exceeds the preset reference value, the turbidity of the treated water is lower than the preset reference value by adjusting the amount of chemical agent injected.

[0019] The present invention is characterized in that: when the turbidity of the treated water is lower than a preset reference value, the state processing unit determines whether the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference reach or exceed a preset reference value; when the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference reach or exceed a preset reference value, it determines whether the residual iron of the treated water reaches or exceeds a preset reference value; when the residual iron of the treated water reaches or exceeds a preset reference value, it changes the amount of chemical agent injected to make the residual iron of the treated water lower than a preset reference value.

[0020] The present invention is characterized in that: when the residual iron in the treated water is lower than a preset reference value, the state processing unit determines whether the increase rate of ultrafiltration pressure difference or the increase rate of reverse osmosis pressure difference reaches or exceeds a preset reference value; when the increase rate of ultrafiltration pressure difference or the increase rate of reverse osmosis pressure difference reaches or exceeds a preset reference value, the unit changes the amount of chemical agent injected to make the increase rate of ultrafiltration pressure difference and the increase rate of reverse osmosis pressure difference lower than the preset reference value.

[0021] The present invention is characterized in that: when the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference are lower than the preset benchmark values, the state processing unit gradually adjusts the chemical agent injection amount to the basic injection amount after waiting for a certain period of time.

[0022] To achieve the objectives described above, a preferred embodiment of the present invention is used to control a seawater desalination plant, comprising: a data collection unit collecting data on the turbidity of treated water obtained by treating seawater using dissolved air flotation (DAF), the residual iron (RI) of the treated water, the increase rate of the ultrafiltration differential pressure (DP) during ultrafiltration (UF) for filtering impurities remaining in the treated water, and the increase rate of the reverse osmosis (RO) process for filtering impurities remaining in the treated water. The steps include: collecting the rate of increase in pressure difference during the Osmosis process, specifically the rate of increase in reverse osmosis pressure difference; and comparing the turbidity of the treated water, the residual iron in the treated water, the rate of increase in ultrafiltration pressure difference, and the rate of increase in reverse osmosis pressure difference with preset reference values ​​for the turbidity, the residual iron, the rate of increase in ultrafiltration pressure difference, and the rate of increase in reverse osmosis pressure difference, respectively, by adjusting the amount of chemical agent injected into the seawater, thereby maintaining the turbidity and the residual iron at a level below the preset reference values ​​while also maintaining the rate of increase in ultrafiltration pressure difference and the rate of increase in reverse osmosis pressure difference at a level below the preset reference values.

[0023] The step of adjusting the injection amount of the chemical agent includes: a step of determining whether the turbidity of the treated water reaches or exceeds a preset reference value by the state processing unit; and a step of adjusting the injection amount of the chemical agent by the state processing unit to make the turbidity of the treated water lower than the preset reference value when the turbidity of the treated water reaches or exceeds the preset reference value.

[0024] The method, after the step of determining whether the turbidity of the treated water reaches or exceeds a preset reference value, further includes: when the turbidity of the treated water is lower than a preset reference value, the state processing unit determines whether the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference reach or exceed a preset reference value; when the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference reach or exceed a preset reference value, the state processing unit determines whether the residual iron of the treated water reaches or exceeds a preset reference value; and when the residual iron of the treated water reaches or exceeds a preset reference value, the state processing unit changes the amount of chemical agent injected to make the residual iron of the treated water lower than a preset reference value.

[0025] The method, after the step of determining whether the residual iron in the treated water reaches or exceeds a preset benchmark value, further includes: when the residual iron in the treated water is lower than a preset benchmark value, the state processing unit determines whether the increase rate of ultrafiltration pressure difference or the increase rate of reverse osmosis pressure difference reaches or exceeds a preset benchmark value; and when the increase rate of ultrafiltration pressure difference or the increase rate of reverse osmosis pressure difference reaches or exceeds a preset benchmark value, the state processing unit changes the injection amount of chemical agent to make the increase rate of ultrafiltration pressure difference and the increase rate of reverse osmosis pressure difference lower than the preset benchmark value.

[0026] The method, after determining whether the increase rate of ultrafiltration pressure differential or the increase rate of reverse osmosis pressure differential reaches or exceeds a preset benchmark value, further includes: when the increase rate of ultrafiltration pressure differential or the increase rate of reverse osmosis pressure differential is lower than the preset benchmark value, the state processing unit waits for a certain period of time; and the state processing unit gradually adjusts the chemical agent injection amount to a basic injection amount.

[0027] The present invention is characterized in that the chemical agent comprises at least one of a hydrogen ion concentration regulator and a coagulant.

[0028] In this invention, the amount of chemicals injected into the seawater can be adjusted to maintain the turbidity and residual iron of the treated water below preset benchmark values, while simultaneously keeping the increase rates of ultrafiltration and reverse osmosis pressure differentials below preset benchmark values. This allows for optimization of the chemical injection amount in a seawater desalination plant based on changes in influent water quality and the plant's status. This facilitates stable operation and management of downstream processes and reduces operational costs. Attached Figure Description

[0029] Figure 1This is a schematic diagram illustrating the configuration of an apparatus for controlling a reverse osmosis membrane seawater desalination plant to which embodiments of the present invention are applicable.

[0030] Figure 2 This is a flowchart illustrating a method for controlling a reverse osmosis membrane seawater desalination plant to which embodiments of the present invention apply.

[0031] Figure 3 This is a schematic diagram illustrating a computing device to which embodiments of the present invention are applied. Detailed Implementation

[0032] This invention can be modified in various ways and has multiple embodiments. Specific embodiments will be illustrated and described in detail below. However, this is not intended to limit the invention to a particular implementation, but rather it should be understood that the invention includes all modifications, equivalents, and substitutions within the scope of the inventive concept and technology.

[0033] The terminology used in this invention is for illustrative purposes only and is not intended to limit the invention. Singular words / phrases may also have plural meanings unless the context clearly indicates otherwise. In this invention, terms such as "comprising" or "having" are used only to indicate the presence of features, numbers, steps, actions, constituent elements, components, or combinations thereof described in the specification, and should not be construed as excluding the possibility of the presence or addition of one or more other features, numbers, steps, actions, constituent elements, components, or combinations thereof.

[0034] Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same reference numerals are used wherever possible to denote the same constituent elements in the drawings. Furthermore, detailed descriptions related to well-known functions and structures that may obscure the essence of the invention will be omitted. For the same reason, some constituent elements in the drawings may be enlarged, omitted, or simplified in their illustration.

[0035] First, an apparatus for controlling a reverse osmosis membrane seawater desalination plant, according to an embodiment of the present invention, will be described in detail. Figure 1 This is a schematic diagram illustrating the configuration of an apparatus for controlling a reverse osmosis membrane seawater desalination plant to which embodiments of the present invention are applicable. See also... Figure 1 A reverse osmosis membrane seawater desalination plant according to an embodiment of the present invention includes: a dissolved air flotation (DAF) device 10, an ultrafiltration (UF) device 20, a reverse osmosis (RO) device 30, and a control device 40.

[0036] The dissolved air flotation unit 10 is used to provide dissolved air suspension (DAF) treated water (hereinafter referred to as "treated water") obtained by treating seawater according to the dissolved air flotation (DAF) method.

[0037] The ultrafiltration device 20 includes multiple ultrafiltration units, each equipped with an ultrafiltration membrane. The ultrafiltration device 20 performs an ultrafiltration (UF) process, which uses the ultrafiltration membranes of the multiple ultrafiltration units to filter impurities remaining in the treated water. The ultrafiltration device 20 filters impurities remaining in the treated water by passing it through the ultrafiltration membranes of the multiple ultrafiltration units.

[0038] The reverse osmosis unit 30 includes multiple membrane stacks, each equipped with a reverse osmosis membrane. The reverse osmosis unit 30 performs a reverse osmosis (RO) process, which uses the multiple membrane stacks to filter impurities remaining in the treated water. The reverse osmosis unit 30 passes treated water through the multiple membrane stacks of reverse osmosis membranes, thereby filtering out residual impurities using the reverse osmosis principle.

[0039] The control device 40, applicable to embodiments of the present invention, is used to control the injection amount of chemical agents used in the pretreatment process of a seawater desalination plant. Specifically, chemical agents such as pH adjusters (e.g., H2SO4) and coagulants (e.g., FeCl3) are used in seawater desalination plant treatment. Therefore, it is necessary to derive the optimal chemical agent injection amount in the dissolved air flotation (DAF) process. However, the chemical agent injection amount also affects the differential pressure (DP) of the ultrafiltration unit 20 and the reverse osmosis unit 30 used to perform the downstream processes, namely ultrafiltration (UF) and reverse osmosis (RO). Therefore, the control device 40, applicable to embodiments of the present invention, is used to perform control to adjust the chemical agent injection amount, thereby optimizing the dissolved air flotation (DAF) process while maintaining the differential pressure (DP) of the ultrafiltration unit 20 and the reverse osmosis unit 30 below a reference value. In embodiments of the present invention, the control to adjust the chemical agent injection amount refers to increasing or decreasing the injection amount based on the basic chemical agent injection amount. The control device 40 described above includes an information collection unit 100, a status processing unit 200, and a chemical agent processing unit 300.

[0040] The information collection unit 100 is used to collect water quality information related to dissolved air flotation (DAF) treated water (hereinafter referred to as "treated water") and differential pressure information indicating changes in differential pressure (DP) during ultrafiltration (UF) and reverse osmosis (RO) processes. The water quality information includes the turbidity (Tutb) and residual iron (RI) of the treated water. The differential pressure information includes the UF differential pressure increase rate and the RO differential pressure increase rate. The UF differential pressure increase rate refers to the differential pressure increase rate of the ultrafiltration unit 20, and the RO differential pressure increase rate refers to the differential pressure increase rate of the reverse osmosis unit 30; these will be explained in more detail later.

[0041] Furthermore, the status processing unit 200 receives water quality information, namely the turbidity (Turb) and residual iron (RI) of the treated water, and pressure difference information, namely the increase rate of ultrafiltration (UF) pressure difference and the increase rate of reverse osmosis (RO) pressure difference, from the information collection unit 100. It compares these information with reference values ​​and adjusts the amount of chemical reagent injected accordingly. This optimizes the dissolved air flotation (DAF) treatment while maintaining the pressure difference (DP) of the ultrafiltration unit 20 and the reverse osmosis unit 30 below the reference value. Specifically, when the pressure difference (DP) of the ultrafiltration unit 20 and the reverse osmosis unit 30 reaches or exceeds the reference value, the status processing unit 200 defines it as an abnormal state (FB_ABNORMAL_1, FB_ABNORMAL_2, FB_ABNORMAL_3). While maintaining the turbidity (Turb) and residual iron (RI) of the treated water below the reference value, it adjusts the amount of chemical reagent injected to stabilize the pressure difference (DP) of the ultrafiltration unit 20 and the reverse osmosis unit 30 below the reference value. Furthermore, after the pressure difference (DP) of the ultrafiltration unit 20 and the reverse osmosis unit 30 stabilizes below the reference value, the state processing unit 200 gradually adjusts the chemical agent injection amount back to the basic injection amount while continuously checking whether it has re-entered an abnormal state.

[0042] The chemical agent treatment unit 300 can inject chemical agents into seawater before dissolved air flotation (DAF) treatment, and can increase or decrease the amount of chemical agent injected from the basic injection amount or inject the basic injection amount according to the control of the state treatment unit 200.

[0043] Next, we will explain in more detail the method for calculating the increase rate of ultrafiltration (UF) pressure differential and the increase rate of reverse osmosis (RO) pressure differential and determining whether an abnormal state exists by comparing them with the baseline value.

[0044] The ultrafiltration (UF) process is performed in three modes: filtration mode (Filtration Mode), backwash (BW) mode (Backwashing Mode), and chemically enhanced backwash (CEB) mode (Chemical Enhanced Backwash Mode), which washes the ultrafiltration membrane with a detergent. After repeating the filtration mode (e.g., 30 times) for a certain number of times (e.g., 30 minutes) and the backwash mode (e.g., 3 minutes), the chemically enhanced backwash mode (e.g., 70 minutes) is performed. The period for calculating the ultrafiltration differential pressure increase rate is from the start of the filtration mode and the start of the other modes (BW Mode or CEB Mode) for a certain period of time (e.g., 1 minute) before the start of the other modes. The information collection unit 100 can calculate the ultrafiltration differential pressure increase rate of multiple ultrafiltration units using the differential pressure values ​​collected from multiple ultrafiltration units during the period for calculating the ultrafiltration differential pressure increase rate. The rate of increase of ultrafiltration differential pressure for one of a plurality of ultrafiltration units can be calculated in the manner described below. Specifically, the information collection unit 100 calculates the slope of a linear trend line of differential pressure values ​​collected from the ultrafiltration unit during the period of calculating the rate of increase of ultrafiltration differential pressure as the rate of increase of ultrafiltration differential pressure (e.g., the value of 'a' in y = ax + b). The rate of increase of ultrafiltration differential pressure as described above is provided to the status processing unit 200. The status processing unit 200 can determine that the rate of increase of ultrafiltration differential pressure (slope of the linear trend line) has reached or exceeded a predetermined reference value when the number of ultrafiltration units for which the rate of increase of ultrafiltration differential pressure (the slope of the linear trend line) calculated by the information collection unit 100 reaches or exceeds a specific set value (e.g., 0.15).

[0045] The reverse osmosis (RO) process is performed in two modes: a filtration mode (performing reverse osmosis filtration) and a chemical in-place (CIP) mode (performing washing). As described above, the RO process involves repeatedly performing a filtration mode for a certain period (e.g., 3 months) followed by a washing mode for a certain period (e.g., 2 days). The time for calculating the reverse osmosis differential pressure increase rate is preset during the period when the reverse osmosis unit 30 performs the filtration mode. The information collection unit 100 can calculate the reverse osmosis differential pressure increase rate of multiple membrane stacks using the differential pressure values ​​collected from multiple membrane stacks during the period for calculating the reverse osmosis differential pressure increase rate of all membrane stacks in the reverse osmosis unit 30. The reverse osmosis differential pressure increase rate of a single membrane stack can be calculated in the manner described below. That is, after dividing a pre-set calculation time for the reverse osmosis differential pressure increase rate (e.g., 1000 minutes) into unit time periods (e.g., 50 minutes), the slope of the linear trend line of the differential pressure value collected from the corresponding membrane stack in each unit time period (a in y = ax + b) is calculated as the reverse osmosis differential pressure increase rate of the corresponding membrane stack. The reverse osmosis differential pressure increase rate described above is provided to the status processing unit 200. The status processing unit 200 can determine that the reverse osmosis differential pressure increase rate exceeds a pre-set reference value when the number of membrane stacks whose reverse osmosis differential pressure increase rate (the slope of the linear trend line of the differential pressure value) exceeds a specific set value (e.g., 0.05) exceeds a specific set value (e.g., 4 out of 8).

[0046] Next, a method for controlling a reverse osmosis membrane seawater desalination plant, according to embodiments of the present invention, will be described in more detail. Figure 2 This is a flowchart illustrating a method for controlling a reverse osmosis membrane seawater desalination plant to which embodiments of the present invention apply.

[0047] See Figure 2 The information collection unit 100 continuously collects water quality information of the treated water obtained by dissolved air flotation (DAF) and differential pressure information indicating the changes in differential pressure (DP) during the ultrafiltration (UF) and reverse osmosis (RO) processes during step S110, and provides this information to the state processing unit 200. The water quality information includes the turbidity and residual iron (RI) of the treated water. The differential pressure information includes the increase rate of the ultrafiltration (UF) differential pressure and the increase rate of the reverse osmosis (RO) differential pressure.

[0048] In step S120, the status processing unit 200 determines whether the turbidity of the treated water has reached or exceeded a preset reference value. Based on the determination result of step S120, if the turbidity of the treated water is lower than the preset reference value, the status processing unit 200 executes step S130. Conversely, if based on the determination result of step S120, if the turbidity of the treated water reaches or exceeds the preset reference value, the status processing unit 200 executes step S160.

[0049] In step S130, the state processing unit 200 determines whether the increase rate of ultrafiltration (UF) pressure differential and the increase rate of reverse osmosis (RO) pressure differential have reached or exceeded a preset reference value. Based on the determination result of step S130, the state processing unit 200 executes step S140 when the increase rate of ultrafiltration (UF) pressure differential and the increase rate of reverse osmosis (RO) pressure differential reach or exceed the preset reference value. Conversely, based on the determination result of step S130, the state processing unit 200 executes step S230 when the increase rate of ultrafiltration (UF) pressure differential or the increase rate of reverse osmosis (RO) pressure differential is lower than the preset reference value.

[0050] In step S140, the state processing unit 200 determines whether the residual iron (RI) in the treated water reaches or exceeds a preset reference value. Based on the determination result of step S140, if the residual iron (RI) in the treated water reaches or exceeds the preset reference value, the state processing unit 200 executes step S180. Conversely, based on the determination result of step S140, if the residual iron (RI) in the treated water is below the preset reference value, the state processing unit 200 executes step S150.

[0051] In step S150, the state processing unit 200 determines whether the increase rate of ultrafiltration (UF) pressure differential or the increase rate of reverse osmosis (RO) pressure differential has reached or exceeded a preset reference value. Based on the determination result of step S150, the state processing unit 200 executes step S200 when the increase rate of ultrafiltration (UF) pressure differential or the increase rate of reverse osmosis (RO) pressure differential reaches or exceeds the preset reference value. Conversely, based on the determination result of step S150, the state processing unit 200 executes step S230 when the increase rate of ultrafiltration (UF) pressure differential or the increase rate of reverse osmosis (RO) pressure differential is lower than the preset reference value.

[0052] As described above, when the turbidity of the treated water reaches or exceeds a preset reference value (S120), the first abnormal state (FB_ABNORMAL_1) procedure of step S160 will be executed. That is, the state processing unit 200 will adjust the amount of chemical agent injected in step S160 to make the turbidity of the treated water lower than the preset reference value. Specifically, the state processing unit 200 will increase or decrease the injection amounts of F bias (e.g., FeCl3 injection amount) and S bias (e.g., H2SO4 injection amount).

[0053] Next, the status processing unit 200 will confirm in step S170 whether the turbidity of the treated water has reached or exceeded a preset reference value. Based on the confirmation result of step S170, if the turbidity of the treated water still reaches or exceeds the preset reference value, the status processing unit 200 will execute step S220. Conversely, based on the confirmation result of step S170, if the turbidity of the treated water is lower than the preset reference value, the status processing unit 200 will execute step S130.

[0054] Furthermore, as described above, when the turbidity of the treated water is lower than a preset reference value (S120), the increase rate of ultrafiltration (UF) pressure difference and the increase rate of reverse osmosis (RO) pressure difference reach or exceed preset reference values ​​(S130), and the residual iron (RI) of the treated water reaches or exceeds a preset reference value (S140), the second abnormal state (FB_ABNORMAL_2) procedure of step S180 will be executed. That is, the state processing unit 200 will adjust the amount of chemical agent injected in step S180 so that the residual iron (RI) of the treated water is lower than the preset reference value. That is, the state processing unit 200 will increase or decrease the injection amount of F bias (e.g., FeCl3 injection amount) and S bias (e.g., H2SO4 injection amount).

[0055] Next, the status processing unit 200 will reconfirm in step S190 whether the residual iron (RI) of the treated water has reached or exceeded a preset reference value. Based on the confirmation result of step S190, if the residual iron (RI) of the treated water still reaches or exceeds the preset reference value, the status processing unit 200 will execute step S220. Conversely, based on the confirmation result of step S190, if the residual iron (RI) of the treated water drops below the preset reference value, step S200 will be executed.

[0056] Furthermore, as described above, when the turbidity of the treated water is lower than a preset reference value (S120), the increase rate of ultrafiltration (UF) pressure differential and the increase rate of reverse osmosis (RO) pressure differential reach or exceed preset reference values ​​(S130), the residual iron (RI) of the treated water is lower than a preset reference value (S140), or the increase rate of ultrafiltration (UF) pressure differential or the increase rate of reverse osmosis (RO) pressure differential exceeds a preset reference value (S150), the third abnormal state (FB_ABNORMAL_3) procedure of step S200 will be executed. That is, the state processing unit 200 will adjust the amount of chemical agent injected in step S200 so that the increase rate of ultrafiltration (UF) pressure differential or the increase rate of reverse osmosis (RO) pressure differential reaches or falls below a preset reference value. That is, the state processing unit 200 will increase or decrease the injection amount of F bias (e.g., FeCl3 injection amount) and S bias (e.g., H2SO4 injection amount).

[0057] Next, the status processing unit 200 will confirm in step S210 whether the increase rate of ultrafiltration (UF) pressure differential and the increase rate of reverse osmosis (RO) pressure differential have reached or exceeded a preset reference value. Based on the confirmation result of step S210, the status processing unit 200 will execute step S220 if the increase rate of ultrafiltration (UF) pressure differential and the increase rate of reverse osmosis (RO) pressure differential exceed the preset reference value. Conversely, based on the confirmation result of step S210, the status processing unit 200 will execute step S230 if either the increase rate of ultrafiltration (UF) pressure differential or the increase rate of reverse osmosis (RO) pressure differential is lower than the preset reference value.

[0058] In step S220, if the abnormal state cannot be resolved after processing the first to third abnormal states (FB_ABNORMAL_1, FB_ABNORMAL_2, FB_ABNORMAL_3), the state processing unit 200 will identify it as an uncontrollable state (FB_OUTOFCONTROL). In step S220, the state processing unit 200 will generate an alarm and switch to a mode where the user directly controls the factory, i.e., manual control mode.

[0059] Conversely, step S230 involves waiting in a waiting state (FB_NORMAL_STANDBY) after processing the first to third abnormal states (FB_ABNORMAL_1, FB_ABNORMAL_2, FB_ABNORMAL_3) to see if the system can return to the normal state. In this waiting state (FB_NORMAL_STANDBY), the state processing unit 200 checks whether the system is normal or not at intervals of a specific time (e.g., 5 minutes).

[0060] Next, the state processing unit 200 will execute the recovery state (FB_NORMAL_ACTION) procedure in step S240, thereby gradually adjusting the chemical agent injection amount to the basic injection amount. That is, the injection amount will be increased or decreased so that the F bias (FeCl3 additional injection amount) and S bias (H2SO4 additional injection amount) reach the basic injection amount.

[0061] Next, the status processing unit 200 will confirm in step S250 whether the increase rate of ultrafiltration (UF) differential pressure and the increase rate of reverse osmosis (RO) differential pressure have reached or fallen below a reference value. Based on the confirmation result of step S250, the status processing unit 200 will execute step S260 if the increase rate of ultrafiltration (UF) differential pressure and the increase rate of reverse osmosis (RO) differential pressure reach or fall below a preset reference value. Conversely, based on the confirmation result of step S250, the status processing unit 200 will return to step S120 if either the increase rate of ultrafiltration (UF) differential pressure or the increase rate of reverse osmosis (RO) differential pressure exceeds a preset reference value. Step S260 is a fully restored normal state (FB_NORMAL), at which point the status processing unit 200 will maintain the automatic control mode (DCO AutoControl Mode).

[0062] Figure 3 This is a schematic diagram illustrating a computing device to which an embodiment of the present invention is applied. The computing device TN100 may be any device described in this specification (e.g., a device for controlling a reverse osmosis seawater desalination plant, etc.).

[0063] exist Figure 3 In some embodiments, the computing device TN100 may include at least one processor TN110, a transceiver device TN120, and a memory TN130. Furthermore, the computing device TN100 may also include a storage device TN140, an input interface device TN150, and an output interface device TN160, etc. The components included in the computing device TN100 can be connected and communicate with each other via a bus TN170.

[0064] Processor TN110 can execute at least one program command stored in memory TN130 and storage device TN140. Processor TN110 can refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor capable of executing the methods applicable to embodiments of the present invention. Processor TN110 can implement steps, processes, and methods related to embodiments applicable to the present invention. Processor TN110 can control various components of computing device TN100.

[0065] The memory TN130 and the storage device TN140 can respectively store various information related to the operation of the processor TN110. The memory TN130 and the storage device TN140 can be composed of at least one of volatile storage medium and non-volatile storage medium. For example, the memory TN130 can be composed of at least one of read-only memory (ROM) and random access memory (RAM).

[0066] The TN120 transceiver can transmit or receive wired or wireless signals. The TN120 can also perform communication by connecting to a network.

[0067] Furthermore, the various methods applicable to embodiments of the present invention as described above can be implemented as a program form readable by various computing devices and recorded in a computer-readable recording medium. The recording medium may include program instructions, data files, and data structures, either individually or in combination. The program instructions recorded in the recording medium may be specifically designed for the present invention or may be known and usable by those skilled in the art of computer software. For example, the recording medium includes specially configured hardware devices capable of storing and executing program instructions, such as magnetic media (e.g., hard disks, floppy disks, and magnetic tapes), optical media (e.g., CD-ROMs and DVDs), magneto-optical media (e.g., floppy disks), read-only memory (ROM), random access memory (RAM), and flash memory. Examples of software instructions include not only machine language code generated by a compiler but also high-level language code executable in a computer, such as an interpreter. The hardware device may be configured to operate through one or more software modules to perform the actions of the embodiments, or vice versa.

[0068] An embodiment of the present invention has been described above. However, those skilled in the art can make various modifications and alterations to the present invention by adding, changing, deleting, or supplementing the constituent elements without departing from the spirit of the present invention as set forth in the claims. Such modifications and alterations are also included within the scope of the claims of the present invention.

Claims

1. A device for controlling a seawater desalination plant, characterized in that, include: Dissolved air flotation unit, used to provide treated water obtained by treating seawater using the dissolved air flotation method; An ultrafiltration apparatus includes multiple ultrafiltration units, each equipped with an ultrafiltration membrane, for performing an ultrafiltration process that uses the ultrafiltration membranes of the multiple ultrafiltration units to filter impurities remaining in the treated water. A reverse osmosis device includes multiple membrane stacks, each equipped with a reverse osmosis membrane, for performing a reverse osmosis process that uses the reverse osmosis membranes of the multiple membrane stacks to filter impurities remaining in the treated water. The information collection unit is used to collect the turbidity of the treated water, the residual iron in the treated water, the ultrafiltration differential pressure increase rate (representing the rate of increase in differential pressure during the ultrafiltration process), and the reverse osmosis differential pressure increase rate (representing the rate of increase in differential pressure during the reverse osmosis process); and, The state processing unit adjusts the injection amount of the chemical agent into the seawater to maintain the turbidity and residual iron below preset reference values, while simultaneously maintaining the increase rate of ultrafiltration pressure differential and the increase rate of reverse osmosis pressure differential below preset reference values; and The information collection unit, During the calculation period of the increase rate of ultrafiltration differential pressure, after a certain period of time has elapsed since the start of the filtration mode performed by the ultrafiltration unit and before a certain period of time has elapsed since the start of either the backwash mode or the chemical washing mode performed by the ultrafiltration unit, The pressure difference value is collected from the ultrafiltration unit, and the slope of the linear trend line of the collected pressure difference value is calculated as the ultrafiltration pressure difference increase rate of the ultrafiltration unit. The state processing unit, When the number of ultrafiltration units whose ultrafiltration differential pressure increase rate reaches a certain set value or more reaches a certain set value or more. The increase rate of ultrafiltration differential pressure was determined to have reached or exceeded the preset benchmark value; The information collection unit, The pressure differential value is collected from the membrane stack during the pre-set reverse osmosis pressure differential increase rate calculation period. The calculation period for the pre-set reverse osmosis pressure differential increase rate is divided into unit time periods, and the slope of the linear trend line of the pressure differential value collected in each unit time period is calculated as the reverse osmosis pressure differential increase rate. The state processing unit, When the number of membrane stacks whose reverse osmosis pressure differential increase rate reaches a certain set value or more, The rate of increase in reverse osmosis pressure differential was determined to have reached or exceeded the pre-set benchmark value.

2. The apparatus for controlling a seawater desalination plant according to claim 1, characterized in that: The state processing unit, Determine whether the turbidity of the treated water reaches or exceeds a preset benchmark value. When the turbidity of the treated water reaches or exceeds a preset reference value, By adjusting the amount of the chemical agent injected. This ensures that the turbidity of the treated water is lower than a preset benchmark value.

3. The apparatus for controlling a seawater desalination plant according to claim 2, characterized in that: The state processing unit, When the turbidity of the treated water is lower than a preset reference value, Determine whether the increase rate of the ultrafiltration pressure differential and the increase rate of the reverse osmosis pressure differential reach or exceed a preset benchmark value. When the increase rate of ultrafiltration pressure differential and the increase rate of reverse osmosis pressure differential reach or exceed a preset benchmark value, Determine whether the residual iron in the treated water reaches or exceeds a preset benchmark value. When the residual iron in the treated water reaches or exceeds a preset benchmark value, By changing the amount of chemical agent injected, the residual iron in the treated water is made to be lower than a preset benchmark value.

4. The apparatus for controlling a seawater desalination plant according to claim 3, characterized in that: The state processing unit, When the residual iron in the treated water is lower than a preset benchmark value, Determine whether the increase rate of the ultrafiltration pressure differential or the increase rate of the reverse osmosis pressure differential reaches or exceeds a preset benchmark value. When the increase rate of the ultrafiltration pressure differential or the increase rate of the reverse osmosis pressure differential reaches or exceeds a preset benchmark value, By changing the amount of chemical agent injected, the increase rate of ultrafiltration pressure differential and the increase rate of reverse osmosis pressure differential are made lower than preset benchmark values.

5. The apparatus for controlling a seawater desalination plant according to claim 4, characterized in that: When the increase rate of ultrafiltration pressure differential and the increase rate of reverse osmosis pressure differential are lower than preset benchmark values, The state processing unit, After waiting for a certain period of time Gradually reduce the amount of chemical agent injected to the basic injection amount.

6. The apparatus for controlling a seawater desalination plant according to claim 1, characterized in that: The chemical agent, It includes at least one of a hydrogen ion concentration regulator and a coagulant.

7. An apparatus for controlling a seawater desalination plant, characterized in that, include: Chemical treatment unit, used to inject chemicals into seawater; The information collection unit is used to collect the turbidity of the treated water obtained by treating the seawater according to the dissolved air flotation method, the residual iron in the treated water, the ultrafiltration differential pressure increase rate (indicating the increase rate of the differential pressure during the ultrafiltration process for filtering impurities remaining in the treated water), and the reverse osmosis differential pressure increase rate (indicating the increase rate of the differential pressure during the reverse osmosis process for filtering impurities remaining in the treated water); and, The state processing unit compares the turbidity of the treated water, the residual iron in the treated water, the increase rate of ultrafiltration pressure difference, and the increase rate of reverse osmosis pressure difference with preset reference values ​​for these parameters, respectively. By controlling the chemical agent processing unit, the injection amount of the chemical agent is adjusted to maintain both the turbidity and residual iron below the preset reference values, and simultaneously maintain the increase rates of ultrafiltration pressure difference and reverse osmosis pressure difference below the preset reference values. The information collection unit, During the calculation period of the increase rate of ultrafiltration differential pressure, after a certain period of time has elapsed since the start of a filtration mode performed by the ultrafiltration unit and before a certain period of time has elapsed since the start of a backwash mode or a chemical washing mode performed by the ultrafiltration unit, The pressure difference value is collected from the ultrafiltration unit, and the slope of the linear trend line of the collected pressure difference value is calculated as the ultrafiltration pressure difference increase rate of the ultrafiltration unit. The state processing unit, When the number of ultrafiltration units whose ultrafiltration differential pressure increase rate reaches a certain set value or more reaches a certain set value or more. The increase rate of ultrafiltration differential pressure was determined to have reached or exceeded the preset benchmark value; The information collection unit, The pressure differential value is collected from the membrane stack during the pre-set reverse osmosis pressure differential increase rate calculation period. The calculation period for the pre-defined reverse osmosis pressure differential increase rate is divided into unit time intervals, and the slope of the linear trend line of the pressure differential values ​​collected in each unit time interval is calculated as the reverse osmosis pressure differential increase rate; and The state processing unit, When the number of membrane stacks whose reverse osmosis pressure differential increase rate reaches a certain set value or more, The rate of increase in reverse osmosis pressure differential was determined to have reached or exceeded the pre-set benchmark value.

8. The apparatus for controlling a seawater desalination plant according to claim 7, characterized in that: The state processing unit, Determine whether the turbidity of the treated water reaches or exceeds a preset benchmark value. When the turbidity of the treated water reaches or exceeds a preset reference value, By adjusting the amount of the chemical agent injected. This ensures that the turbidity of the treated water is lower than a preset benchmark value.

9. The apparatus for controlling a seawater desalination plant according to claim 8, characterized in that: The state processing unit, When the turbidity of the treated water is lower than a preset reference value, Determine whether the increase rate of the ultrafiltration pressure differential and the increase rate of the reverse osmosis pressure differential reach or exceed a preset benchmark value. When the increase rate of ultrafiltration pressure differential and the increase rate of reverse osmosis pressure differential reach or exceed a preset benchmark value, Determine whether the residual iron in the treated water reaches or exceeds a preset benchmark value. When the residual iron in the treated water reaches or exceeds a preset benchmark value, By changing the amount of chemical agent injected, the residual iron in the treated water is made to be lower than a preset benchmark value.

10. The apparatus for controlling a seawater desalination plant according to claim 9, characterized in that: The state processing unit, When the residual iron in the treated water is lower than a preset benchmark value, Determine whether the increase rate of the ultrafiltration pressure differential or the increase rate of the reverse osmosis pressure differential reaches or exceeds a preset benchmark value. When the increase rate of the ultrafiltration pressure differential or the increase rate of the reverse osmosis pressure differential reaches or exceeds a preset benchmark value, By changing the amount of chemical agent injected, the increase rate of ultrafiltration pressure differential and the increase rate of reverse osmosis pressure differential are made lower than preset benchmark values.

11. The apparatus for controlling a seawater desalination plant according to claim 10, characterized in that: When the increase rate of ultrafiltration pressure differential and the increase rate of reverse osmosis pressure differential are lower than preset benchmark values, The state processing unit, After waiting for a certain period of time Gradually reduce the amount of chemical agent injected to the basic injection amount.

12. A method for controlling a seawater desalination plant, characterized in that, include: The step of collecting information by the information collection unit is as follows: turbidity of the treated water obtained by treating seawater by dissolved air flotation, residual iron in the treated water, ultrafiltration differential pressure increase rate (representing the increase rate of differential pressure during the ultrafiltration process for filtering impurities remaining in the treated water), and reverse osmosis differential pressure increase rate (representing the increase rate of differential pressure during the reverse osmosis process for filtering impurities remaining in the treated water). as well as, The process involves a state processing unit comparing the turbidity of the treated water, the residual iron in the treated water, the increase rate of ultrafiltration pressure difference, and the increase rate of reverse osmosis pressure difference with preset reference values ​​for each of these parameters. By adjusting the amount of chemical agent injected into the seawater, the process aims to maintain both the turbidity and residual iron levels below the preset reference values, while simultaneously maintaining the increase rates of ultrafiltration pressure difference and reverse osmosis pressure difference below the preset reference values. The information collection unit, During the calculation period of the increase rate of ultrafiltration differential pressure, after a certain period of time has elapsed since the start of a filtration mode performed by the ultrafiltration unit and before a certain period of time has elapsed since the start of a backwash mode or a chemical washing mode performed by the ultrafiltration unit, The pressure differential values ​​are collected from the ultrafiltration unit, and the slope of the linear trend line of the collected pressure differential values ​​is calculated as the rate of increase of the ultrafiltration pressure differential of the ultrafiltration unit; and The state processing unit, When the number of ultrafiltration units whose ultrafiltration differential pressure increase rate reaches a certain set value or more reaches a certain set value or more. The increase rate of ultrafiltration differential pressure was determined to have reached or exceeded the preset benchmark value; The information collection unit, The pressure differential value is collected from the membrane stack during the pre-set reverse osmosis pressure differential increase rate calculation period. The calculation period for the pre-set reverse osmosis pressure differential increase rate is divided into unit time periods, and the slope of the linear trend line of the pressure differential value collected in each unit time period is calculated as the reverse osmosis pressure differential increase rate. The state processing unit, When the number of membrane stacks whose reverse osmosis pressure differential increase rate reaches a certain set value or more, The rate of increase in reverse osmosis pressure differential was determined to have reached or exceeded the pre-set benchmark value.

13. The method for controlling a seawater desalination plant according to claim 12, characterized in that: The step of adjusting the injection amount of the chemical agent includes: The step of determining whether the turbidity of the treated water reaches or exceeds a preset reference value by the status processing unit; and, When the turbidity of the treated water reaches or exceeds a preset reference value, the step of adjusting the injection amount of the chemical agent by the state processing unit to make the turbidity of the treated water lower than the preset reference value.

14. The method for controlling a seawater desalination plant according to claim 13, characterized in that: After the step of determining whether the turbidity of the treated water reaches or exceeds a preset benchmark value, the method further includes: When the turbidity of the treated water is lower than a preset reference value, the state processing unit determines whether the increase rate of the ultrafiltration pressure difference and the increase rate of the reverse osmosis pressure difference reach or exceed the preset reference value. When the increase rate of the ultrafiltration pressure differential and the increase rate of the reverse osmosis pressure differential reach or exceed a preset reference value, the state processing unit determines whether the residual iron in the treated water reaches or exceeds a preset reference value; and, When the residual iron in the treated water reaches or exceeds a preset benchmark value, the residual iron in the treated water is reduced to below the preset benchmark value by changing the amount of chemical agent injected by the state processing unit.

15. The method for controlling a seawater desalination plant according to claim 14, characterized in that: After the step of determining whether the residual iron in the treated water reaches or exceeds a preset benchmark value, the method further includes: When the residual iron in the treated water is lower than a preset benchmark value, the state processing unit determines whether the increase rate of the ultrafiltration pressure differential or the increase rate of the reverse osmosis pressure differential reaches or exceeds a preset benchmark value; and, When the increase rate of ultrafiltration differential pressure or the increase rate of reverse osmosis differential pressure reaches or exceeds a preset reference value, the step of changing the injection amount of chemical agent by the state processing unit to make the increase rate of ultrafiltration differential pressure or the increase rate of reverse osmosis differential pressure lower than the preset reference value.

16. The method for controlling a seawater desalination plant according to claim 15, characterized in that: After determining whether the increase rate of the ultrafiltration pressure differential or the increase rate of the reverse osmosis pressure differential reaches or exceeds a preset benchmark value, the method further includes: When the increase rate of ultrafiltration pressure differential and the increase rate of reverse osmosis pressure differential are lower than preset benchmark values, The step of waiting for a certain period of time by the state processing unit; and, The step of gradually adjusting the amount of chemical agent injected to the basic injection amount by the state processing unit.

17. The method for controlling a seawater desalination plant according to claim 12, characterized in that: The chemical agent, It includes at least one of a hydrogen ion concentration regulator and a coagulant.

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