Desalted water treatment system based on pressure feedback regulation

Abstract

The invention relates to the technical field of desalted water treatment, in particular to a desalted water treatment system based on pressure feedback regulation. Comprising an ultrafiltration subsystem, a reverse osmosis subsystem, a mixed bed subsystem and a scheduling cooperation module, wherein the ultrafiltration subsystem comprises an ultrafiltration sensing module and an ultrafiltration adjusting module; the reverse osmosis subsystem comprises a reverse osmosis sensing module and a reverse osmosis adjusting module; the mixed bed subsystem comprises a mixed bed sensing module and a mixed bed adjusting module; the problems that the regeneration process cannot be continuously carried out, shutdown operation is needed, and the continuous water production capacity of the system is affected due to the fact that procedure collaboration cannot be achieved in regeneration circulation of all devices are solved. A PID feedback regulation mechanism is established through data extraction and processing, and parameter negative feedback regulation of each device in a production process is realized; and a composite control model for quick response and adjustment is established, and the dosage of the control agent and the water pressure of the circulating pump are dynamically adjusted.

Description

Technical Field

[0001] The invention relates to the technical field of desalted water treatment, and in particular to a desalted water treatment system based on pressure feedback regulation. Background Art

[0002] Demineralized water is an important industrial water. Ensuring the quality of demineralized water is of great significance to the safe operation of industrial production. The safe and efficient operation of the demineralized water system is a reliable guarantee for water production in water plants. At present, there are two main types of demineralized water production systems in my country, namely reverse osmosis system + mixed bed and reverse osmosis system + EDI (electrodeionization technology). Most of them are reverse osmosis system + mixed bed technology. The main process is raw water → raw water booster pump → self-cleaning filter → ultrafiltration device → precision filter → reverse osmosis device → mixed bed → effluent. Ultrafiltration technology is a membrane separation technology developed in recent years based on material science. Ultrafiltration technology has been widely used in the fields of industrial wastewater treatment such as electricity, steel, and chemical industry. At present, the research on ultrafiltration devices focuses on technical means such as increasing membrane water production and reducing costs. The patented "Constant Flow Ultrafiltration Method and Equipment" of the Ecological and Environmental Research Center of the Chinese Academy of Sciences mainly reduces the filtration resistance of the membrane, extends the reverse cleaning cycle, simplifies the operation procedures, and increases the water production of the membrane by adjusting the opening method of the circulating pump. The reverse osmosis process uses the filtering principle of the reverse osmosis membrane to drive the membrane to separate the solvent from the solution with pressure, effectively removing salt ions and most organic matter in the water, ensuring that the effluent quality meets the national standards and meets the actual production needs of the enterprise. After a long period of development, the membrane flux of my country's reverse osmosis membrane has increased several times, and the most advanced reverse osmosis desalination rate has reached more than 99%. The technical principle of the mixed bed is ion exchange, which is a commonly used process for desalination. The effluent quality is stable and the pretreatment requirements are simple. It has now been widely used in the field of industrial water treatment in my country.

[0003] However, the existing desalted water treatment technology still has many shortcomings and limitations. For example, in the production process of the desalted water treatment system, multiple regeneration and circulation processes are often involved. The process coordination cannot be achieved in the regeneration cycle of each equipment, resulting in the regeneration process cannot be carried out continuously and the system needs to be shut down, which affects the system's continuous water production capacity.

[0004] Secondly, the existing desalted water treatment system involves parameter adjustment of various valves and devices, which is relatively complex to operate and requires high skills of operators. In actual production, the adjustment and setting of many parameters require human experience and judgment. There is no composite control model for rapid response and adjustment, and no negative feedback system is established to meet the challenges of optimizing the control of reagent dosage and circulating pump water pressure regulation.

[0005] Therefore, it is necessary to propose a desalted water treatment system based on pressure feedback regulation to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to solve the problems existing in the background technology, and propose a desalinated water treatment system based on pressure feedback regulation;

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A desalted water treatment system based on pressure feedback regulation comprises an ultrafiltration subsystem, a reverse osmosis subsystem, a mixed bed subsystem and a scheduling coordination module, wherein the ultrafiltration subsystem comprises an ultrafiltration sensing module and an ultrafiltration regulating module; the reverse osmosis subsystem comprises a reverse osmosis sensing module and a reverse osmosis regulating module; and the mixed bed subsystem comprises a mixed bed sensing module and a mixed bed regulating module.

[0009] The ultrafiltration sensing module obtains the temperature T of the plate heat exchanger, the liquid level C1 in the ultrafiltration water tank, and the pressure P in the ultrafiltration backwash pump at every preset time interval t.

[0010] The reverse osmosis sensing module obtains the water inlet flow Q1 of the precision filter, the liquid level C2 and the conductivity ρ of the liquid in the fresh water tank at every preset time interval t.

[0011] The mixed bed sensing module obtains the conductivity ρ2 of the water entering the mixed ion exchanger at a preset time interval t, and outputs the conductivity ρ3 of the water in the mixed ion exchanger and the desalted water flow rate Q2 flowing into the desalted water tank. The conductivity difference Δρ between the water entering the mixed ion exchanger and the water outputting the mixed ion exchanger is calculated by the formula Δρ=ρ2-ρ1.

[0012] As a preferred embodiment of the present invention, the ultrafiltration sensing module, the reverse osmosis sensing module and the mixed bed sensing module generate two-dimensional data images about eight groups of time according to the collected data, including temperature-time diagram, liquid level-time diagram, pressure-time diagram, flow-time diagram, liquid level-time diagram, conductivity-time diagram, conductivity difference-time diagram and desalted water flow-time diagram.

[0013] Furthermore, for the eight groups of images, the cumulative deviation, relative deviation and deviation change rate of each data are obtained through data extraction and calculation.

[0014] The data extraction and calculation process is specifically as follows:

[0015] Retrieve the preset data fluctuation range limits corresponding to each group of images, including the fluctuation upper limit XMax and the lower limit XMin; obtain the area of ​​the part above the upper limit of the data fluctuation in the eight groups of images respectively, and record it as the cumulative positive deviation; obtain the area of ​​the part below the lower limit of the data fluctuation in the eight groups of images respectively, and record it as the cumulative negative deviation; record the difference between the cumulative positive deviation and the cumulative negative deviation as the cumulative deviation e1(X).

[0016] For the temperature data point (t, X) obtained within the last preset time interval t, the formula Calculate the relative deviation e2(X) corresponding to each image; by formula Calculate the deviation change rate e3(X) corresponding to each image, where X=T, C1, P, Q1, C2, ρ, Q2 and Δρ.

[0017] As a preferred embodiment of the present invention, data fusion is performed on the cumulative deviation, relative deviation and deviation change rate extracted from each image to obtain control parameters δ1, δ2, δ3, δ4, δ5, δ6, δ7 and δ8. The data fusion process is specifically as follows:

[0018] By formula Calculate control parameters δ1, δ2 and δ3;

[0019] By formula Calculate control parameters δ4, δ5 and δ6;

[0020] By formula The control parameters δ7 and δ8 are calculated, where λ1, λ2 and λ3 are all preset weight factors.

[0021] As a preferred embodiment of the present invention, the mapped control parameters are obtained by normalization processing, including mapped control parameter one f(δ1), mapped control parameter two f(δ2), mapped control parameter three f(δ3), mapped control parameter four f(δ4), mapped control parameter five f(δ5), mapped control parameter six f(δ6), mapped control parameter seven f(δ7) and mapped control parameter eight f(δ8), and the specific process is as follows:

[0022] For the obtained control parameters δ1, δ2 and δ3, their specific values ​​are mapped to between -3 and 3, and the mapping function is: Where int is a rounding symbol, for example, int(2.6)=2; where δ1Max, δ2Max, δ3Max are the upper limits of fluctuations of the control parameters δ1, δ2, and δ3, respectively; where δ1Min, δ2Min, δ3Min are the lower limits of fluctuations of the control parameters δ1, δ2, and δ3, respectively;

[0023] For the obtained control parameters δ4, δ5 and δ6, their specific values ​​are mapped to between 0 and 100, and the mapping function is: Among them, δ4Max, δ5Max, δ6Max are the fluctuation upper limits of the control parameters δ4, δ5 and δ6 respectively; among them, δ4Min, δ5Min, δ6Min are the fluctuation lower limits of the control parameters δ4, δ5 and δ6 respectively;

[0024] For control parameters δ7 and δ8, their specific values ​​are mapped to between -3 and 3. The mapping function is: Among them, δ7Max and δ8Max are the fluctuation upper limits of control parameters δ7 and δ8 respectively; among them, δ7Min and δ8Min are the fluctuation lower limits of control parameters δ7 and δ8 respectively.

[0025] As a preferred embodiment of the present invention, the ultrafiltration regulating module, the reverse osmosis regulating module and the mixed bed regulating module perform numerical judgment, data fusion and targeted data execution according to the mapped control parameters, specifically:

[0026] In the ultrafiltration subsystem:

[0027] The ultrafiltration adjustment module performs numerical judgment on the mapped control parameter one f(δ1) and the control parameter two f(δ2) to generate the valve opening instruction parameter ε1; performs data fusion on the mapped control parameter two f(δ2) and the mapped control parameter three f(δ3) to generate the backwash instruction parameter ε2;

[0028] As a preferred embodiment of the present invention, the temperature control and adjustment operation is performed according to the generated valve opening instruction parameter ε1, specifically:

[0029] First, the valve opening instruction parameter is subjected to the first numerical determination to determine whether the value of ε1 is greater than the preset threshold value 0. If so, the second numerical determination is performed; if not, the steam valve is closed and the temperature control adjustment is terminated.

[0030] In the second numerical determination, it is determined whether the value of ε1 is greater than or equal to the preset threshold value 5. If so, the steam valve is opened and maintained for 10 seconds. Then the value of ε1 is reduced by one and the second numerical determination is returned to form a loop until the value of ε1 is negative in the second numerical determination, and the loop is exited; if not, the steam valve is opened and maintained for 10 seconds, and then the valve is closed and the temperature control adjustment is ended.

[0031] As a preferred embodiment of the present invention, the ultrafiltration backwash operation is performed according to the specific value of the backwash instruction parameter ε2, specifically:

[0032] If the value of the backwash instruction parameter ε2 is greater than or equal to the preset maximum threshold ε2Max, a first backwash instruction is sent to the ultrafiltration backwash pump. When the value of the backwash instruction parameter ε2 is less than the maximum threshold ε2Max and greater than or equal to the minimum threshold ε2Min, a second backwash instruction is sent to the ultrafiltration backwash pump.

[0033] The first backwash instruction is specifically: turn on the ultrafiltration backwash pump and start the pump timing, and pump the ultrafiltration water output by the ultrafiltration device from the ultrafiltration water pool back into the input end of the ultrafiltration device at a preset first head H1 and a first pump shaft speed n1 to perform ultrafiltration backwashing. When the pump timing reaches the preset first pump start time T1, turn off the ultrafiltration backwash pump.

[0034] The second backwash instruction is specifically: turn on the ultrafiltration backwash pump and start the pump timing, and pump the ultrafiltration water output by the ultrafiltration device from the ultrafiltration water pool back into the input end of the ultrafiltration device at the preset second head H2 and second pump shaft speed n2 to perform ultrafiltration backwashing. When the pump timing reaches the preset second pump start time T2, turn off the ultrafiltration backwash pump.

[0035] In terms of specific values, the first head H1 of the ultrafiltration backwash pump is greater than the second head H2; the first pump shaft speed n1 of the ultrafiltration backwash pump is greater than the second pump shaft speed n2; the first pump start time T1 is greater than the second pump start time T2.

[0036] In the reverse osmosis subsystem:

[0037] The reverse osmosis regulation module obtains the reverse osmosis instruction parameter ε3 through data fusion.

[0038] As a preferred embodiment of the present invention, the reverse osmosis flushing operation is performed according to the specific value of the backwash instruction parameter ε3, specifically:

[0039] If the value of the backwash instruction parameter ε3 is greater than or equal to the preset maximum threshold ε3Max, a first reverse osmosis instruction is sent to the reverse osmosis flushing pump. When the value of the backwash instruction parameter ε3 is less than the maximum threshold ε3Max and greater than or equal to the minimum threshold ε3Min, a second reverse osmosis instruction is sent to the reverse osmosis flushing pump.

[0040] The first reverse osmosis instruction is specifically: turn on the reverse osmosis flushing pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at a preset first head H1 and a first pump shaft speed n1 to perform reverse osmosis flushing. When the pump timing reaches the preset first pump start time T1, turn off the reverse osmosis flushing pump.

[0041] The second reverse osmosis instruction is specifically: turn on the reverse osmosis flushing pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at the preset second head H2 and second pump shaft speed n2 to perform reverse osmosis flushing. When the pump timing reaches the preset second pump start time T2, turn off the reverse osmosis flushing pump.

[0042] In terms of specific values, the first head H1 is greater than the second head H2; the first pump shaft speed n1 is greater than the second pump shaft speed n2; and the first pump start time T1 is greater than the second pump start time T2.

[0043] As a preferred embodiment of the present invention, the dosage of the dosing system is optimized and adjusted according to the control parameter δ6 corresponding to the conductivity, specifically:

[0044] The normalized control parameter 6f(δρ) is numerically fuzzy processed, and the formula is Calculate the dosing execution parameter ε4, where A is the preset conductivity model constant, B is the preset flux constant, and ε4Max is the preset maximum dosage of the agent. Adjust the dosage to ε4 at every preset time interval t;

[0045] In the mixed bed subsystem:

[0046] The mixed bed adjustment module performs numerical judgment on the normalized control parameters f(δ7) and f(δ8) to generate the regeneration instruction parameter ε5.

[0047] The switch of the fresh water pump is adjusted according to the specific value of the regeneration instruction parameter ε5, specifically:

[0048] If the value of the regeneration instruction parameter ε5 is greater than or equal to the preset maximum threshold ε5Max, a first reverse osmosis instruction is sent to the fresh water pump. When the value of the regeneration instruction parameter ε5 is less than the maximum threshold ε5Max and greater than or equal to the minimum threshold ε5Min, a second reverse osmosis instruction is sent to the fresh water pump.

[0049] The first reverse osmosis instruction is specifically: turn on the fresh water pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at a preset first head H1 and a first pump shaft speed n1 to perform reverse osmosis flushing. When the pump timing reaches the preset first pump start time T1, turn off the fresh water pump.

[0050] The second reverse osmosis instruction is specifically: turn on the fresh water pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at the preset second head H2 and second pump shaft speed n2 to perform reverse osmosis flushing. When the pump timing reaches the preset second pump start time T2, turn off the fresh water pump.

[0051] In terms of specific values, the first head H1 is greater than the second head H2; the first pump shaft speed n1 is greater than the second pump shaft speed n2; and the first pump start time T1 is greater than the second pump start time T2.

[0052] As a preferred embodiment of the present invention, the coordinated scheduling module realizes the process coordination and error control of the ultrafiltration subsystem, the reverse osmosis subsystem and the mixed bed subsystem by adjusting the water pump parameters, specifically:

[0053] The control parameter δ2 is obtained from the ultrafiltration subsystem; the control parameters δ4 and δ5 are obtained from the reverse osmosis subsystem; and the control parameter δ8 is obtained from the mixed bed subsystem.

[0054] By formula Calculate the overall balance factor S(1,2,3). S(1,2) is the balance factor of the ultrafiltration subsystem and the reverse osmosis subsystem; S(2,3) is the balance factor of the reverse osmosis subsystem and the mixed bed subsystem.

[0055] When the overall balance factor S(1,2,3) is greater than the preset threshold S(1,2,3)MAX, the balance factors S(1,2) and S(2,3) are numerically judged. The specific process is as follows:

[0056] If the value of the balance factor S(1,2) is greater than the preset threshold value S(1,2)Max, the first head and the first pump shaft speed of the backwash pump are increased.

[0057] If the value of the balance factor S(2,3) is greater than the preset threshold value S(2,3)Max, the first head and the first pump shaft speed of the reverse osmosis high-pressure flushing pump are increased.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] In the regeneration cycle of each device, process coordination is often not achieved, resulting in the regeneration process being unable to proceed continuously and requiring shutdown operations, which affects the system's continuous water production capacity.

[0060] Secondly, the existing desalted water treatment system involves parameter adjustment of various valves and devices, which is relatively complex to operate and requires high skills of operators. In actual production, the adjustment and setting of many parameters require human experience and judgment. There is no composite control model for rapid response and adjustment, and no negative feedback system is established to meet the challenges of optimizing the control of reagent dosage and circulating pump water pressure regulation.

[0061] (1) The present invention realizes process coordination and error control of the ultrafiltration subsystem, the reverse osmosis subsystem and the mixed bed subsystem through the coordinated scheduling module and the adjustment of the pump parameters, thereby solving the problem that the process coordination cannot be achieved in the regeneration cycle of each device, resulting in the regeneration process being unable to proceed continuously and requiring shutdown operation, which affects the continuous water production capacity of the system;

[0062] (2) The present invention establishes a PID feedback adjustment mechanism through data extraction and processing of the ultrafiltration sensing module, the reverse osmosis sensing module and the mixed bed sensing module, thereby realizing negative feedback adjustment of parameters of each device in the production process; a fast-response and adjustable composite control model is established to dynamically adjust the dosage of the control agent and the water pressure of the circulating pump; BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to facilitate the understanding of those skilled in the art, the present invention is further described below with reference to the accompanying drawings:

[0064] Figure 1 is a flow chart of the method of the present invention;

[0065] Figure 2 It is a schematic diagram of a data image of the present invention;

[0066] Figure 3 It is a schematic diagram of the temperature control and adjustment process of the present invention;

[0067] Figure 4 This is a schematic diagram of the scheduling coordination of the present invention. DETAILED DESCRIPTION

[0068] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] See also Figure 1 As shown, a desalted water treatment system based on pressure feedback regulation includes an ultrafiltration subsystem, a reverse osmosis subsystem, a mixed bed subsystem and a scheduling coordination module, wherein the ultrafiltration subsystem includes an ultrafiltration sensing module and an ultrafiltration regulation module; the reverse osmosis subsystem includes a reverse osmosis sensing module and a reverse osmosis regulation module; the mixed bed subsystem includes a mixed bed sensing module and a mixed bed regulation module.

[0070] First embodiment:

[0071] Negative feedback regulation of ultrafiltration backwash is achieved through PID control of the ultrafiltration subsystem.

[0072] The hardware equipment in the ultrafiltration subsystem includes a plate heat exchanger, an ultrafiltration device, an ultrafiltration water tank and an ultrafiltration backwash pump.

[0073] The ultrafiltration subsystem includes an ultrafiltration sensing module and an ultrafiltration regulating module.

[0074] The ultrafiltration sensing module obtains the temperature T of the plate heat exchanger, the liquid level C1 in the ultrafiltration water tank, and the pressure P in the ultrafiltration backwash pump at every preset time interval t.

[0075] Three sets of data points of temperature, liquid level and pressure changing with time are recorded respectively, including temperature data points (t, T), liquid level data points (t, C1) and pressure data points (t, P), and then three sets of data images are generated, including temperature-time graph, liquid level-time graph and pressure-time graph.

[0076] See also Figure 2 As shown, data extraction is performed for the three groups of data images, and the preset data fluctuation range limits corresponding to each image are retrieved, including the upper temperature limit TMax, the upper liquid level limit C1Max, and the upper pressure limit PMax; the lower limit of the data fluctuation range is retrieved, including the lower temperature limit TMin, the upper liquid level limit C1Min, and the upper pressure limit PMin. The areas exceeding the upper temperature limit, the upper liquid level limit, and the upper pressure limit are obtained in the three groups of images respectively, and recorded as the cumulative deviation positive amount; the areas below the lower temperature limit, the lower liquid level limit, and the lower pressure limit are obtained in the three groups of images respectively, and recorded as the cumulative deviation negative amount, and the difference between the cumulative deviation positive amount and the cumulative deviation negative amount is recorded as the cumulative deviation amount e1.

[0077] The accumulated deviations e1(T), e1(C1) and e1(C1) corresponding to the temperature T, the liquid level C1 and the pressure P are calculated respectively.

[0078] To extract data, for the temperature data point (t, T), liquid level data point (t, C1) and pressure data point (t, P) obtained within the last preset time interval t, the formula Calculate the relative deviations e2(T), e2(C1) and e2(P) corresponding to temperature, liquid level and pressure, using the formula Calculate the deviation change rates e3(T), e3(C1) and e3(P) corresponding to temperature, liquid level and pressure. The control parameters δ1, δ2 and δ3 are calculated, where λ1, λ2 and λ3 are all preset weight factors.

[0079] Furthermore, the obtained control parameters δ1, δ2 and δ3 are normalized, and their specific values ​​are mapped to between -3 and 3. The mapping function is: Where int is the rounding symbol, for example, int(2.6) = 2; where δ1Max, δ2Max, δ3Max are the upper limits of fluctuations of control parameters δ1, δ2 and δ3 respectively; where δ1Min, δ2Min, δ3Min are the lower limits of fluctuations of control parameters δ1, δ2 and δ3 respectively.

[0080] The ultrafiltration adjustment module performs numerical judgment on the mapped control parameter one f(δ1) and control parameter two f(δ2) to generate the valve opening instruction parameter ε1. The specific judgment conditions are shown in Table 1:

[0081] Table 1

[0082]

[0083]

[0084] See also Figure 3As shown, the temperature control valve is temperature-controlled and adjusted according to the specific value of the valve opening instruction parameter ε1, specifically:

[0085] First, the valve opening instruction parameter is subjected to the first numerical determination to determine whether the value of ε1 is greater than the preset threshold value 0. If so, the second numerical determination is performed; if not, the steam valve is closed and the temperature control adjustment is terminated.

[0086] In the second numerical determination, it is determined whether the value of ε1 is greater than or equal to the preset threshold value 5. If so, the steam valve is opened and maintained for 10 seconds. Then the value of ε1 is reduced by one and the second numerical determination is returned to form a loop until the value of ε1 is negative in the second numerical determination, and the loop is exited; if not, the steam valve is opened and maintained for 10 seconds, and then the valve is closed and the temperature control adjustment is ended.

[0087] It should be noted that if the opening and closing time of the steam valve of the plate heat exchanger is set to a fixed value, there will be a lag in the regulation effect when the water volume changes, affecting the temperature control effect of the plate heat exchanger. This process is designed to comprehensively consider the flow and temperature data, and ensure that the water entering the ultrafiltration equipment has a constant temperature through negative feedback regulation of temperature, protect the safety of the pipeline and ultrafiltration system, and meet the use conditions of the ultrafiltration device.

[0088] The backwash instruction parameter ε2 is calculated by the formula ε2=K1×f(δ2)+K2×f(δ3), where k1 and k2 are preset influencing factors.

[0089] The ultrafiltration backwash operation is performed according to the specific value of the backwash instruction parameter ε2, specifically:

[0090] If the value of the backwash instruction parameter ε2 is greater than or equal to the preset maximum threshold ε2Max, a first backwash instruction is sent to the ultrafiltration backwash pump. When the value of the backwash instruction parameter ε2 is less than the maximum threshold ε2Max and greater than or equal to the minimum threshold ε2Min, a second backwash instruction is sent to the ultrafiltration backwash pump.

[0091] The first backwash instruction is specifically: turn on the ultrafiltration backwash pump and start the pump timing, and pump the ultrafiltration water output by the ultrafiltration device from the ultrafiltration water pool back into the input end of the ultrafiltration device at a preset first head H1 and a first pump shaft speed n1 to perform ultrafiltration backwashing. When the pump timing reaches the preset first pump start time T1, turn off the ultrafiltration backwash pump.

[0092] The second backwash instruction is specifically: turn on the ultrafiltration backwash pump and start the pump timing, and pump the ultrafiltration water output by the ultrafiltration device from the ultrafiltration water pool back into the input end of the ultrafiltration device at the preset second head H2 and second pump shaft speed n2 to perform ultrafiltration backwashing. When the pump timing reaches the preset second pump start time T2, turn off the ultrafiltration backwash pump.

[0093] In terms of specific values, the first head H1 of the ultrafiltration backwash pump is greater than the second head H2; the first pump shaft speed n1 of the ultrafiltration backwash pump is greater than the second pump shaft speed n2; the first pump start time T1 is greater than the second pump start time T2.

[0094] It should be noted that this process is designed to open the ultrafiltration backwash pump when the water pressure drops and the flow rate is large to pump the incompletely filtered ultrafiltration water back into the ultrafiltration device to ensure that the ultrafiltration water is fully filtered.

[0095] Second embodiment:

[0096] Negative feedback regulation of the reverse osmosis cycle is achieved through PID control of the reverse osmosis subsystem.

[0097] The hardware equipment in the reverse osmosis subsystem includes a precision filter, a reverse osmosis high-pressure flushing pump, a fresh water tank and a dosing system.

[0098] The reverse osmosis subsystem includes a reverse osmosis sensing module and a reverse osmosis regulating module.

[0099] The reverse osmosis sensing module obtains the water inlet flow Q1 of the precision filter, the liquid level C2 and the conductivity ρ of the liquid in the fresh water tank at every preset time interval t.

[0100] Three sets of data points of water inflow Q1, liquid level C2 and conductivity ρ changing with time are recorded respectively, including flow data point (t, Q1), liquid level data point (t, C2) and conductivity data point (t, ρ). Then, three sets of data images are generated according to the three sets of data points, including flow-time graph, liquid level-time graph and conductivity-time graph.

[0101] Data extraction is performed on the three groups of data images, and the preset data fluctuation range limits corresponding to each image are retrieved, including the flow upper limit Q1Max, the liquid level upper limit C2Max, and the conductivity upper limit ρMax; the lower limit of the data fluctuation range is retrieved, including the flow lower limit Q1Min, the liquid level lower limit C2Min, and the conductivity lower limit ρMin. The areas exceeding the flow upper limit, the liquid level upper limit, and the conductivity upper limit are obtained in the three groups of images respectively, and recorded as the cumulative positive deviation; the areas below the flow lower limit, the liquid level lower limit, and the conductivity lower limit are obtained in the three groups of images respectively, and recorded as the cumulative negative deviation, and the difference between the cumulative positive deviation and the cumulative negative deviation is recorded as the cumulative deviation. The cumulative deviations e1(Q1), e1(C2), and e1(ρ) corresponding to the flow Q1, liquid level C2, and conductivity ρ are calculated respectively.

[0102] Data extraction is performed. For the flow data point (t, Q1), liquid level data point (t, C2) and conductivity data point (t, ρ) obtained within the last preset time interval t, the formula Calculate the relative deviations e2(Q1), e2(C2) and e2(ρ) corresponding to flow, liquid level and conductivity, and use the formula Calculate the deviation change rates e3(Q1), e3(C2) and e3(ρ) corresponding to temperature, liquid level and pressure. The control parameters δ4, δ5 and δ6 are calculated, where λ1, λ2 and λ3 are all preset weight factors.

[0103] Furthermore, the obtained control parameters δ4, δ5 and δ6 are normalized, and their specific values ​​are mapped to between 0 and 100. The mapping function is: Where int is the rounding down symbol, for example, int(2.6) = 2; where δ4Max, δ5Max, δ6Max are the upper limits of fluctuations of control parameters δ4, δ5 and δ6 respectively; where δ4Min, δ5Min, δ6Min are the lower limits of fluctuations of control parameters δ4, δ5 and δ6 respectively.

[0104] The reverse osmosis regulation module calculates the reverse osmosis instruction parameter ε3 by the formula: ε3 = K3×f(δ4)+K4×f(δ5), where k3 and k4 are preset weight factors.

[0105] The reverse osmosis flushing operation is performed according to the specific value of the backwash instruction parameter ε3, specifically:

[0106] If the value of the backwash instruction parameter ε3 is greater than or equal to the preset maximum threshold ε3Max, a first reverse osmosis instruction is sent to the reverse osmosis flushing pump. When the value of the backwash instruction parameter ε3 is less than the maximum threshold ε3Max and greater than or equal to the minimum threshold ε3Min, a second reverse osmosis instruction is sent to the reverse osmosis flushing pump.

[0107] The first reverse osmosis instruction is specifically: turn on the reverse osmosis flushing pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at a preset first head H1 and a first pump shaft speed n1 to perform reverse osmosis flushing. When the pump timing reaches the preset first pump start time T1, turn off the reverse osmosis flushing pump.

[0108] The second reverse osmosis instruction is specifically: turn on the reverse osmosis flushing pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at the preset second head H2 and second pump shaft speed n2 to perform reverse osmosis flushing. When the pump timing reaches the preset second pump start time T2, turn off the reverse osmosis flushing pump.

[0109] In terms of specific values, the first head H1 is greater than the second head H2; the first pump shaft speed n1 is greater than the second pump shaft speed n2; and the first pump start time T1 is greater than the second pump start time T2.

[0110] Furthermore, the dosage of the dosing system is optimized and adjusted according to the control parameter δ6 corresponding to the conductivity, specifically:

[0111] The normalized control parameter 6f(δρ) is numerically fuzzy processed, and the formula is Calculate the dosing execution parameter ε4, where A is the preset conductivity model constant, B is the preset flux constant, and ε4Max is the preset maximum dosage of the agent.

[0112] At every preset time interval t, the dosage is adjusted to ε4.

[0113] It should be noted that the dosing system uses ammonia to adjust the pH value of desalted water. When the pH value is adjusted to near 7, the positive or negative charge in the desalted water will remain in a smaller range, and the conductivity of the desalted water is low. On the contrary, when the pH value of the desalted water is too high or too low, the concentration of charged ions in the desalted water is high and the conductivity is high. Therefore, the conductivity can indirectly reflect whether the pH value of the desalted water is adjusted to an appropriate range.

[0114] Third embodiment:

[0115] The negative feedback regulation of the mixed bed desalted water regeneration cycle is achieved through the PID control of the mixed bed subsystem.

[0116] The hardware equipment in the mixed bed subsystem includes a mixed ion exchanger, a fresh water pump and a desalted water tank.

[0117] The mixed bed subsystem comprises a mixed bed sensing module and a mixed bed regulating module.

[0118] The mixed bed sensing module obtains the conductivity ρ2 of the water entering the mixed ion exchanger at every preset time interval t, and outputs the conductivity ρ3 of the water in the mixed ion exchanger and the desalted water flow rate Q2 flowing into the desalted water tank.

[0119] Furthermore, the conductivity difference Δρ between the water entering the mixed ion exchanger and the water exiting the mixed ion exchanger is calculated by the formula Δρ=ρ2-ρ1.

[0120] Two groups of data points of conductivity difference and desalted water flow are recorded respectively, including conductivity difference data points (t, Δρ) and desalted water flow data points (t, Q2), and then two groups of data images are generated according to the two groups of data points, including conductivity difference-time graph and desalted water flow-time graph.

[0121] Data extraction is performed on the two sets of data images, and the preset data fluctuation range limits corresponding to each image are retrieved, including the conductivity difference upper limit ΔρMax and the flow upper limit Q2Max; the lower limit of the data fluctuation range is retrieved, including the conductivity difference lower limit ΔρMin and the flow upper and lower limits Q2Min. The areas exceeding the conductivity difference upper limit and the flow upper limit are obtained in the two sets of images respectively, and recorded as the cumulative positive deviation; the areas below the conductivity difference lower limit and the flow lower limit are obtained in the two sets of images respectively, and recorded as the cumulative negative deviation, and the difference between the cumulative positive deviation and the cumulative negative deviation is recorded as the cumulative deviation. The cumulative deviations e1(Δρ) and e1(Q2) corresponding to the conductivity difference Δρ and the flow Q2 are calculated respectively.

[0122] To extract data, for the conductivity difference data point (t, Δρ) and flow data point (t, Q2) obtained within the last preset time interval t, the formula Calculate the relative deviation e2(Δρ) and e2(Q2) corresponding to the conductivity difference and flow rate, and use the formula Calculate the conductivity difference and the deviation change rate corresponding to the flow rate e3(Δρ) and e3(Q2). The control parameters δ7 and δ8 are calculated, where λ1, λ2 and λ3 are all preset weight factors.

[0123] Furthermore, the control parameters δ7 and δ8 are numerically normalized, and their specific values ​​are mapped to between -3 and 3. The mapping function is: Where int is the rounding symbol; where δ7Max and δ8Max are the upper limits of the fluctuation of the control parameters δ7 and δ8 respectively; where δ7Min and δ8Min are the lower limits of the fluctuation of the control parameters δ7 and δ8 respectively.

[0124] The mixed bed adjustment module makes a numerical judgment on the normalized control parameters f(δ7) and f(δ8) to generate the regeneration instruction parameter ε5. The specific judgment conditions are shown in Table 2:

[0125] Table 2

[0126]

[0127] The switch of the fresh water pump is adjusted according to the specific value of the regeneration instruction parameter ε5, specifically:

[0128] If the value of the regeneration instruction parameter ε5 is greater than or equal to the preset maximum threshold ε5Max, a first reverse osmosis instruction is sent to the fresh water pump. When the value of the regeneration instruction parameter ε5 is less than the maximum threshold ε5Max and greater than or equal to the minimum threshold ε5Min, a second reverse osmosis instruction is sent to the fresh water pump.

[0129] The first reverse osmosis instruction is specifically: turn on the fresh water pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at a preset first head H1 and a first pump shaft speed n1 to perform reverse osmosis flushing. When the pump timing reaches the preset first pump start time T1, turn off the fresh water pump.

[0130] The second reverse osmosis instruction is specifically: turn on the fresh water pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at the preset second head H2 and second pump shaft speed n2 to perform reverse osmosis flushing. When the pump timing reaches the preset second pump start time T2, turn off the fresh water pump.

[0131] In terms of specific values, the first head H1 is greater than the second head H2; the first pump shaft speed n1 is greater than the second pump shaft speed n2; and the first pump start time T1 is greater than the second pump start time T2.

[0132] Fourth embodiment:

[0133] See also Figure 4 As shown, the present invention further provides a scheduling coordination module, including the PID control functions described in the first, second and third embodiments, and the coordinated scheduling module realizes the process coordination and error control of the ultrafiltration subsystem, the reverse osmosis subsystem and the mixed bed subsystem by adjusting the water pump parameters, specifically:

[0134] The control parameter δ2 is obtained from the ultrafiltration subsystem; the control parameters δ4 and δ5 are obtained from the reverse osmosis subsystem; and the control parameter δ8 is obtained from the mixed bed subsystem.

[0135] By formula Calculate the overall balance factor S(1,2,3). S(1,2) is the balance factor of the ultrafiltration subsystem and the reverse osmosis subsystem; S(2,3) is the balance factor of the reverse osmosis subsystem and the mixed bed subsystem.

[0136] It should be noted that the overall balance factor quantifies the degree of balance between the inlet and outlet water rates of the ultrafiltration subsystem, reverse osmosis subsystem, and mixed bed subsystem.

[0137] When the overall balance factor S(1,2,3) is greater than the preset threshold S(1,2,3)MAX, the balance factors S(1,2) and S(2,3) are numerically judged. The specific process is as follows:

[0138] If the value of the balance factor S(1,2) is greater than the preset threshold value S(1,2)Max, the first head and the first pump shaft speed of the backwash pump are increased; if the value of the balance factor S(2,3) is greater than the preset threshold value S(2,3)Max, the first head and the first pump shaft speed of the reverse osmosis high-pressure flushing pump are increased.

[0139] It should be understood that the terms "include" and "comprising" used in the specification and claims of the present disclosure indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0140] It should also be understood that the terms used in this disclosure are only for the purpose of describing specific embodiments and are not intended to limit the disclosure. As used in this disclosure and the claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in this disclosure and the claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations;

[0141] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A desalted water treatment system based on pressure feedback regulation, comprising an ultrafiltration sensing module, a reverse osmosis sensing module, a mixed bed sensing module and a scheduling coordination module, characterized in that: The ultrafiltration sensing module, the reverse osmosis sensing module and the mixed bed sensing module respectively collect various data in the operation process of the desalted water treatment system at preset time intervals, and generate eight groups of two-dimensional data images about time according to the collected data, including temperature-time diagram, liquid level-time diagram, pressure-time diagram, flow-time diagram, liquid level-time diagram, conductivity-time diagram, conductivity difference-time diagram and desalted water flow-time diagram; through data extraction, data fusion and normalization processing in the image, the mapped control parameter one f(δ1), the mapped control parameter two f(δ2), the mapped control parameter three f(δ3), the mapped control parameter four f(δ4), the mapped control parameter five f(δ5), the mapped control parameter six f(δ6), the mapped control parameter seven f(δ7) and the mapped control parameter eight f(δ8) are obtained; The collaborative scheduling module realizes collaborative control of the processes of the ultrafiltration subsystem, reverse osmosis subsystem and mixed bed subsystem through data analysis and water pump regulation.

2. A desalted water treatment system based on pressure feedback regulation according to claim 1, characterized in that: It also includes an ultrafiltration regulating module, a reverse osmosis regulating module and a mixed bed regulating module; The ultrafiltration adjustment module, the reverse osmosis adjustment module and the mixed bed adjustment module perform numerical judgment, data fusion and targeted data execution according to the mapped control parameters.

3. A desalted water treatment system based on pressure feedback regulation according to claim 1, characterized in that: The data during the operation of the salt water treatment system include: The temperature T of the plate heat exchanger, the liquid level C1 in the ultrafiltration water tank, the pressure P in the ultrafiltration backwash pump, the water inlet flow Q1 of the precision filter, the liquid level C2 in the fresh water tank, the conductivity ρ, the conductivity ρ2 of the water entering the mixed ion exchanger, the conductivity ρ3 of the water outputting the mixed ion exchanger, the desalted water flow Q2 flowing into the desalted water tank and the conductivity difference Δρ; wherein the conductivity difference Δρ is calculated by the formula Δρ=ρ2-ρ1; wherein ρ1 is the conductivity of the water entering the mixed ion exchanger; wherein ρ2 is the conductivity of the water outputting the mixed ion exchanger.

4. A desalted water treatment system based on pressure feedback regulation according to claim 1, characterized in that: The data extraction and calculation process is specifically as follows: Retrieve the preset data fluctuation range limit values ​​corresponding to each group of images, including the fluctuation upper limit XMax and the lower limit XMin; obtain the area of ​​the part above the data fluctuation upper limit in the eight groups of images respectively, record it as the cumulative positive deviation, obtain the area of ​​the part below the data fluctuation lower limit in the eight groups of images respectively, record it as the cumulative negative deviation, and record the difference between the cumulative positive deviation and the cumulative negative deviation as the cumulative deviation e1(X); For the temperature data point (t, X) obtained within the last preset time interval t, the formula Calculate the relative deviation e2(X) corresponding to each image; by formula Calculate the deviation change rate e3(X) corresponding to each image, where X = T, C1, P, Q1, C2, ρ, Q2 and Δρ; Data fusion and normalization are performed on the cumulative deviation, relative deviation and deviation change rate of each group of data.

5. A desalted water treatment system based on pressure feedback regulation according to claim 4, characterized in that: The specific process of data fusion and normalization for the cumulative deviation, relative deviation and deviation change rate of each group of data is as follows: By formula Calculate control parameters δ1, δ2 and δ3; By formula Calculate control parameters δ4, δ5 and δ6; By formula Calculate control parameters δ7 and δ8, where λ1, λ2 and λ3 are all preset weight factors; For the obtained control parameters δ1, δ2 and δ3, their specific values ​​are mapped to between -3 and 3, and the mapping function is: Where int is a rounding symbol, for example, int(2.6)=2; where δ1Max, δ2Max, δ3Max are the upper limits of fluctuations of the control parameters δ1, δ2, and δ3, respectively; where δ1Min, δ2Min, δ3Min are the lower limits of fluctuations of the control parameters δ1, δ2, and δ3, respectively; For the obtained control parameters δ4, δ5 and δ6, their specific values ​​are mapped to between 0 and 100, and the mapping function is: Among them, δ4Max, δ5Max, δ6Max are the fluctuation upper limits of the control parameters δ4, δ5 and δ6 respectively; among them, δ4Min, δ5Min, δ6Min are the fluctuation lower limits of the control parameters δ4, δ5 and δ6 respectively; For the control parameters δ7 and δ8, their specific values ​​are mapped to between -3 and 3; the mapping function is: Among them, δ7Max and δ8Max are the fluctuation upper limits of control parameters δ7 and δ8 respectively; among them, δ7Min and δ8Min are the fluctuation lower limits of control parameters δ7 and δ8 respectively.

6. A desalted water treatment system based on pressure feedback regulation according to claim 1, characterized in that: The specific process of the collaborative scheduling module to achieve collaborative control of the ultrafiltration subsystem, reverse osmosis subsystem and mixed bed subsystem through data analysis and water pump regulation is as follows: Obtain control parameter δ2 from the ultrafiltration subsystem; obtain control parameters δ4 and δ5 from the reverse osmosis subsystem; obtain control parameter δ8 from the mixed bed subsystem; By formula Calculate the overall balance factor S(1,2,3); where S(1,2) is the balance factor of the ultrafiltration subsystem and the reverse osmosis subsystem; where S(2,3) is the balance factor of the reverse osmosis subsystem and the mixed bed subsystem; When the overall balance factor S(1,2,3) is greater than the preset threshold value S(1,2,3)MAX, a numerical judgment is performed on the balance factors S(1,2) and S(2,3). If the value of the balance factor S(1,2) is greater than the preset threshold value S(1,2)Max, the first head and the first pump shaft speed of the backwash pump are increased; if the value of the balance factor S(2,3) is greater than the preset threshold value S(2,3)Max, the first head and the first pump shaft speed of the reverse osmosis high-pressure flushing pump are increased.

7. A desalted water treatment system based on pressure feedback regulation according to claim 2, characterized in that: The specific process of the ultrafiltration adjustment module for numerical judgment, data fusion and targeted data execution is as follows: The mapped control parameter one f(δ1) and the mapped control parameter two f(δ2) are numerically judged to generate the valve opening instruction parameter ε1; the mapped control parameter two f(δ2) and the mapped control parameter three f(δ3) are data-fused to generate the backwash instruction parameter ε2; The temperature control and adjustment operation is performed according to the generated valve opening instruction parameter ε1. First, the valve opening instruction parameter is subjected to the first numerical determination to determine whether the value of ε1 is greater than the preset threshold value 0; if so, the second numerical determination is performed; if not, the steam valve is closed and the temperature control and adjustment is terminated; In the second numerical determination, it is determined whether the value of ε1 is greater than or equal to the preset threshold value 5; if so, the steam valve is opened and maintained for 10 seconds; then the value of ε1 is reduced by one and the second numerical determination is returned to form a loop until the value of ε1 is negative in the second numerical determination, and the loop is exited; if not, the steam valve is opened and maintained for 10 seconds, and then the valve is closed and the temperature control adjustment is ended; Perform ultrafiltration backwash operation according to the specific value of the backwash instruction parameter ε2. If the value of the backwash instruction parameter ε2 is greater than or equal to the preset maximum threshold ε2Max, send a first backwash instruction to the ultrafiltration backwash pump; when the value of the backwash instruction parameter ε2 is less than the maximum threshold ε2Max and greater than or equal to the minimum threshold ε2Min, send a second backwash instruction to the ultrafiltration backwash pump; The first backwash instruction is specifically: turn on the ultrafiltration backwash pump and start the pump timing, pump the ultrafiltration water output by the ultrafiltration device from the ultrafiltration water pool back into the input end of the ultrafiltration device at a preset first head H1 and a first pump shaft speed n1 to perform ultrafiltration backwashing; when the pump timing reaches the preset first pump start time T1, turn off the ultrafiltration backwash pump; The second backwash instruction is specifically: turn on the ultrafiltration backwash pump and start the pump timing, pump the ultrafiltration water output by the ultrafiltration device from the ultrafiltration water pool back into the input end of the ultrafiltration device at a preset second head H2 and a second pump shaft speed n2 to perform ultrafiltration backwashing; when the pump timing reaches the preset second pump start time T2, turn off the ultrafiltration backwash pump; In terms of specific values, the first head H1 of the ultrafiltration backwash pump is greater than the second head H2; the first pump shaft speed n1 of the ultrafiltration backwash pump is greater than the second pump shaft speed n2; the first pump start time T1 is greater than the second pump start time T2.

8. A desalted water treatment system based on pressure feedback regulation according to claim 2, characterized in that: The specific process of the reverse osmosis regulation module for numerical judgment, data fusion and targeted data execution is as follows: The reverse osmosis instruction parameter ε3 is obtained by data fusion, and the reverse osmosis flushing operation is performed according to the specific value of the backwash instruction parameter ε3. If the value of the backwash instruction parameter ε3 is greater than or equal to the preset maximum threshold ε3Max, a first reverse osmosis instruction is sent to the reverse osmosis flushing pump; when the value of the backwash instruction parameter ε3 is less than the maximum threshold ε3Max and greater than or equal to the minimum threshold ε3Min, a second reverse osmosis instruction is sent to the reverse osmosis flushing pump; The first reverse osmosis instruction is specifically: turn on the reverse osmosis flushing pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at a preset first head H1 and a first pump shaft speed n1 to perform reverse osmosis flushing; when the pump timing reaches the preset first pump start time T1, turn off the reverse osmosis flushing pump; The second reverse osmosis instruction is specifically: turn on the reverse osmosis flushing pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at a preset second head H2 and second pump shaft speed n2 to perform reverse osmosis flushing; when the pump timing reaches the preset second pump start time T2, turn off the reverse osmosis flushing pump; In terms of specific values, the first head H1 is greater than the second head H2; the first pump shaft speed n1 is greater than the second pump shaft speed n2; the first pump start time T1 is greater than the second pump start time T2; According to the control parameter δ6 corresponding to the conductivity, the dosage of the dosing system is optimized and adjusted, and the normalized control parameter δ6f(δρ) is numerically fuzzy processed. Calculate the dosing execution parameter ε4, where A is the preset conductivity model constant, B is the preset flux constant, and ε4Max is the preset maximum agent dosage; adjust the dosage to ε4 at every preset time interval t.

9. A desalted water treatment system based on pressure feedback regulation according to claim 2, characterized in that: The specific process of the mixed bed adjustment module to perform numerical judgment, data fusion and targeted data execution is as follows: Perform numerical judgment on the normalized control parameters f(δ7) and f(δ8) to generate the regeneration command parameter ε5; The switch of the fresh water pump is adjusted according to the specific value of the regeneration instruction parameter ε5, specifically: If the value of the regeneration instruction parameter ε5 is greater than or equal to the preset maximum threshold ε5Max, a first reverse osmosis instruction is sent to the fresh water pump; when the value of the regeneration instruction parameter ε5 is less than the maximum threshold ε5Max and greater than or equal to the minimum threshold ε5Min, a second reverse osmosis instruction is sent to the fresh water pump; The first reverse osmosis instruction is specifically: turn on the fresh water pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at a preset first head H1 and a first pump shaft speed n1 to perform reverse osmosis flushing; when the pump timing reaches the preset first pump start time T1, turn off the fresh water pump; The second reverse osmosis instruction is specifically: turn on the fresh water pump and start the pump timing, pump the fresh water output by the reverse osmosis device from the fresh water tank back into the input end of the reverse osmosis device at a preset second head H2 and second pump shaft speed n2 for reverse osmosis flushing; when the pump timing reaches the preset second pump start time T2, turn off the fresh water pump.

Images