Seawater desalination high-pressure pump with multi-information fusion regulation and control

Abstract

The invention provides a seawater desalination high-pressure pump with multi-information fusion regulation and control. The seawater desalination high-pressure pump comprises a power unit, a backflow pipeline, a valve, an operation parameter monitoring module, a time sequence analysis module and an intelligent control module. An inlet of the power unit is connected with the interior of the power unit through a return pipeline, and an outlet of the power unit is connected with the reverse osmosis membrane structure for generating fresh water; a valve is mounted on the return pipeline; the operation parameter monitoring module at least comprises a sensor and is used for detecting the outlet pressure and flow of the power unit and the current seawater temperature and salinity; the time sequence analysis module predicts the seawater temperature of the next time according to the current seawater temperature, weather forecast information and historical data; the intelligent control module regulates and controls the operation speed of the power unit and the opening degree of the valve according to the outlet pressure and flow of the power unit and the seawater temperature and salinity of the next time. The water production quality can be improved, and the system energy consumption can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of high-pressure pumps for seawater desalination, and specifically to a high-pressure pump for seawater desalination with multi-information fusion regulation and control. Background Art

[0002] With the increasingly severe global water shortage problem, seawater desalination, as an important way to obtain fresh water resources, is widely used in fields such as coastal city water supply, island domestic water supply guarantee, industrial production water supply, and water resource supplement in remote areas. In these application scenarios, there is an urgent need for the efficient and stable operation of seawater desalination equipment to achieve continuous and reliable fresh water output and meet the water use requirements of different fields.

[0003] Traditional high-pressure pumps mostly adopt a single-stage pressure regulation mechanism, which only relies on the single-dimensional regulation of the rotational speed of the power unit. When the seawater temperature, salinity, or working conditions change, single-stage regulation is difficult to quickly and accurately match the demand. Especially for large-scale seawater desalination high-pressure pumps, single-stage regulation is prone to excessive pressure fluctuations and flow regulation lags, thereby reducing the seawater desalination efficiency, increasing energy consumption, and making it difficult to finely adjust the pressure flexibly. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides a high-pressure pump for seawater desalination with multi-information fusion regulation and control, which solves the problems of flow regulation lag and unstable water quality in the single-stage pressure regulation mechanism of traditional high-pressure pumps, thereby improving the water production quality and reducing the system energy consumption.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A high-pressure pump for seawater desalination with multi-information fusion regulation and control includes a power unit, a return pipeline, a valve, an operating parameter monitoring module, a timing analysis module, and an intelligent control module;

[0007] The inlet of the power unit is connected to the inside of the power unit through the return pipeline, and the outlet of the power unit is connected to a reverse osmosis membrane structure for producing fresh water;

[0008] A valve is installed on the return pipeline; the operating parameter monitoring module includes at least one sensor for detecting the pressure and flow at the outlet of the power unit, the current seawater temperature and salinity; the timing analysis module predicts the seawater temperature at the next time according to the current seawater temperature, weather forecast information, and historical data;

[0009] The intelligent control module regulates the operating speed of the power unit and the opening degree of the valve according to the pressure and flow at the outlet of the power unit, the seawater temperature and salinity at the next time.

[0010] Furthermore, the power unit is a pump, and the outlet of the first two positive guide vanes of the pump is connected to the pump inlet through the return pipeline.

[0011] Furthermore, the operating parameter monitoring module includes a pressure sensor, a temperature sensor, a salinity sensor, and a flow sensor; the pressure sensor is used to monitor the outlet pressure of the power unit; the salinity sensor is used to monitor the salinity of the seawater at the inlet of the power unit; the temperature sensor is used to monitor the current seawater temperature.

[0012] Furthermore, the intelligent control module determines the outlet pressure of the power unit according to the expected water production flux of the reverse osmosis membrane structure, the seawater temperature and salinity at the next time;

[0013] The intelligent control module determines the operating speed of the future power unit according to the outlet pressure of the power unit, the rated pressure of the power unit, and the rated speed.

[0014] Furthermore, the intelligent control module determines the outlet pressure of the power unit according to the expected water production flux of the reverse osmosis membrane structure, the seawater temperature and salinity at the next time;

[0015] The intelligent control module determines the opening degree of the valve according to the difference between the outlet pressure of the power unit and the measured outlet pressure P s of the power unit.

[0016] Furthermore, the intelligent control module determines the outlet pressure of the power unit at the future time t according to the expected water production flux of the reverse osmosis membrane structure, the seawater temperature and salinity at the next time, specifically:

[0017]

[0018] η t = f(T t , S)

[0019] In the formula: P t is the outlet pressure of the power unit at the future time t; η t is the seawater viscosity at the future time t; η ref is the reference seawater viscosity; J w is the expected water production flux of the reverse osmosis membrane structure; A is the water permeability coefficient of the membrane; i is the dissolution factor of the solute; S is the seawater salinity; ρ is the seawater density; R is the gas constant; T t is the absolute seawater temperature at the future time t; M is the average molar mass of the seawater; f(T t , S) represents the relationship between seawater temperature and salinity and seawater viscosity;

[0020] The intelligent control module determines the operating speed of the future power unit according to the outlet pressure of the power unit, the rated pressure of the power unit, and the rated speed, specifically as follows:

[0021]

[0022] In the formula: P N is the rated pressure of the power unit; n N is the rated speed of the power unit; n t is the speed of the power unit at the future time t.

[0023] Furthermore, the intelligent control module will obtain the speed n t of the power unit at the future time t, and take the minimum change rate of the pump speed as the target to obtain the pump speed curve of the power unit within the next T' hours, where t ∈ [1, …, T].

[0024] Furthermore, when the difference between the measured outlet pressure of the power unit and the outlet pressure P t of the power unit exceeds the threshold value, the intelligent control module controls the valve to adjust the opening degree V, and V = α p ·△P, where △P = P s -P t , and α p is the pressure response coefficient.

[0025] The beneficial effects of the present invention are as follows:

[0026] 1. For the high-pressure pump for seawater desalination with multi-information fusion regulation and control of the present invention, the intelligent control module regulates the operating speed of the power unit as the primary pressure regulation, and regulates the opening degree of the valve by the intelligent control module as the secondary pressure regulation. The primary pressure regulation adjusts the speed of the power unit in advance according to the current seawater temperature, salinity and future seawater temperature, and the secondary pressure regulation dynamically adjusts the valve opening degree according to the current seawater temperature, salinity and outlet pressure. The two cooperate with each other to form a two-stage pressure regulation system, which can flexibly respond to the fluctuations of pressure and flow under complex working conditions, significantly improve the stability and reliability of the seawater desalination system operation, and effectively guarantee the desalination efficiency and water production quality.

[0027] 2. For the high-pressure pump for seawater desalination with multi-information fusion regulation and control of the present invention, the time series analysis module realizes the accurate prediction of the change of seawater parameters. The fusion analysis module further integrates the data and prediction results to establish a multi-factor correlation model, providing a scientific decision-making basis for the intelligent control system, making the system have foresight, being able to predict potential problems in advance and actively adjust the operation strategy, reducing the probability of failure and extending the service life of the equipment.

[0028] 3. For the high-pressure pump for seawater desalination with multi-information fusion regulation and control of the present invention, the intelligent control module quickly responds to control the power unit and the valve according to the predicted seawater temperature, ensuring safe and stable operation even under extreme working conditions such as high salinity, guaranteeing the long-term efficient intelligent regulation ability of the system, and continuously optimizing the energy consumption and efficiency of the seawater desalination process. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. The drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, it is obvious that other drawings can also be obtained based on these drawings.

[0030] Figure 1 Schematic diagram of a high-pressure seawater desalination pump with multi-information fusion regulation according to the present invention.

[0031] Figure 2 System architecture diagram of the present invention.

[0032] Figure 3 Relationship diagram of each module of the present invention.

[0033] Figure 4 Curve of the rotational speed of the power unit at future time t.

[0034] Figure 5 Obtained the future pump speed curve with the minimum pump speed change rate as the target.

[0035] In the figure:

[0036] 1 - Power unit; 2 - Return pipeline; 3 - Valve. Specific implementation manners

[0037] The following will describe in detail the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0038] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0039] In the present invention, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] As Figure 1 and Figure 2 As shown, the high-pressure seawater desalination pump with multi-information fusion regulation of the present invention includes a power unit 1, a return pipeline 2, a valve 3, an operating parameter monitoring module, a timing analysis module, and an intelligent control module; the inlet of the power unit 1 is connected to the inside of the power unit 1 through the return pipeline 2, and the outlet of the power unit 1 is connected to a reverse osmosis membrane structure for generating fresh water; the valve 3 is installed on the return pipeline 2; the operating parameter monitoring module includes at least one sensor for detecting the outlet pressure and flow rate of the power unit 1, the current seawater temperature and salinity; the timing analysis module predicts the seawater temperature at the next time according to the current seawater temperature, weather forecast information, and historical data; the intelligent control module regulates the operating speed of the power unit 1 and the opening degree of the valve 3 according to the outlet pressure and flow rate of the power unit 1, the seawater temperature at the next time, and the salinity.

[0041] The power unit 1 described in the present invention includes a motor and a multi-stage centrifugal pump. In one embodiment of the present invention, the return pipeline 2 connects the pump outlet pipeline and the pump inlet pipeline; in another embodiment of the present invention, the return pipeline 2 connects the outlet surfaces of the first two positive guide vanes before the pump outlet and the pump inlet pipeline, which can prevent the concentrated brine intercepted by the reverse osmosis membrane from flowing back through the return pipeline.

[0042] The operating parameter monitoring module includes a pressure sensor, a temperature sensor, a salinity sensor, and a flow sensor; the pressure sensor is used to monitor the outlet pressure of the power unit 1; the flow sensor is used to monitor the outlet flow of the power unit 1; the salinity sensor is used to monitor the salinity of the seawater at the inlet of the power unit 1; the temperature sensor is used to monitor the current seawater temperature.

[0043] The timing analysis module predicts the seawater temperature at the next time according to the current seawater temperature, weather forecast information, and historical data. The timing analysis module analyzes the data through a long short-term memory (LSTM) network model and predicts the seawater temperature. The training method of this LSTM network model is as follows: Collect meteorological temperature data and seawater temperature data monitored by the temperature sensor, with a sampling interval of 10 minutes and a collection duration of 8 hours as one group; Use each group of data as input and the seawater temperature data at the last moment of each group as output, and train the neural network model using the LSTM method; The obtained LSTM network model can predict the future seawater temperature by recursive method with a time step of 10 minutes according to the meteorological temperature data and the past seawater temperature data. The timing analysis module combines and preprocesses the temperature data monitored by the temperature sensor and the past / current seawater temperature in the historical database through an adaptive filtering algorithm, and uses it to predict the seawater temperature within the next 8 hours. The timing analysis module is a common prediction model existing in the market.

[0044] As Figure 3 shown, the intelligent control module determines the outlet pressure of the power unit 1 according to the expected water production flux of the reverse osmosis membrane structure, the seawater temperature and salinity at the future time t; specifically:

[0045] The expression of the water production flux of the reverse osmosis membrane:

[0046]

[0047] In the formula: C is the salt concentration (mol / m 3 ), and the conversion relationship with the seawater salinity S is:

[0048] The relationship between the seawater viscosity and temperature and salinity:

[0049] η t = f(T t , S)

[0050] P can be solved to obtain:

[0051]

[0052] In the formula: P t is the outlet pressure of the power unit 1 at the future time t, in Pa; η t is the seawater viscosity at the future time t; ηref is the reference viscosity of seawater, η ref = 0.891×10 -3 Pa·s; J w is the expected water production flux of the reverse osmosis membrane structure, m / s; A is the water permeability coefficient of the membrane, L / (m 2 ·h·bar), in the embodiment, A = 0.96L / (m 2 ·h·bar); i is the dissolution factor of the solute, i≈2 for NaCl; S is the seawater salinity; ρ is the seawater density, kg / m 3 ; R is the gas constant, taking R = 8.134J / (mol·K); T t is the absolute temperature of seawater at the future time t, K; M is the average molar mass of seawater, kg / mol;

[0053] The relationship between seawater viscosity and temperature and salinity is η t = f(T t , S), which can be obtained through multiple experiments. Similar to the fact that the viscosity of water is different at different temperatures, this can be obtained by referring to material manuals or data.

[0054] The intelligent control module determines the future operating speed of the power unit 1 according to the outlet pressure of the power unit 1, the rated pressure of the power unit 1, and the rated speed, specifically as follows:

[0055]

[0056] In the formula: P N is the rated pressure of the power unit 1; n N is the rated speed of the power unit 1; n t is the speed of the power unit 1 at the future time t.

[0057] The intelligent control module will obtain the speeds n t of the power unit 1 at several future times t, and obtain the pump speed curve of the power unit 1 within the next T' hours with the minimum pump speed change rate as the goal, t ∈ [1,..., T']. In the embodiment, T' is 8 hours, and 8 hours can be equally divided into several parts, or divided into 0.2h, 0.5h, 1h, 2h, 4h, 8h.

[0058] The intelligent control module determines the outlet pressure of the power unit 1 according to the expected water production flux of the reverse osmosis membrane structure, the seawater temperature and salinity at the next time;

[0059] The intelligent control module determines the opening of the valve 3 according to the difference between the outlet pressure of the power unit 1 and the measured outlet pressure P s of the power unit 1.

[0060] When the difference between the measured outlet pressure P of the power unit 1 s - the outlet pressure P of the power unit 1 t exceeds the threshold value, the intelligent control module controls the valve 3 to adjust the opening V, and V = α p ·△P, where △P = P s - P t , and α p is the pressure response coefficient.

[0061] Regarding the regulation of the operating speed of the power unit by the intelligent control module as the primary pressure regulation, and the regulation of the opening of the valve by the intelligent control module as the secondary pressure regulation. The primary pressure regulation adjusts the rotational speed of the power unit ahead of time according to the current seawater temperature, salinity and future seawater temperature. The secondary pressure regulation dynamically adjusts the valve opening according to the current seawater temperature, salinity and outlet pressure. The two cooperate with each other to form a two-stage pressure regulation system, which can flexibly respond to the fluctuations of pressure and flow under complex working conditions, significantly improve the stability and reliability of the seawater desalination system operation, and effectively ensure the desalination efficiency and water production quality.

[0062] In the embodiment, assume a certain type of high-pressure seawater desalination, the seawater density is ρ = 1.02×10 3 kg / m 3 , the average molar mass of seawater salts is M = 58 g / mol, the expected water production flux J w = 1×10 -5 m / s, the pressure response coefficient of the valve 3 is α p = 50% / MPa; at the current moment t = 0, the measured current and future 8-hour seawater temperatures are shown in Table 1, and the inlet salinity is 30‰;

[0063] Table 1 Predicted future 8-hour seawater temperature at t = 0 in the embodiment

[0064]

[0065] The intelligent control module determines the outlet pressure and the required rotational speed of the power unit 1 according to the expected water production flux of the reverse osmosis membrane structure, the seawater temperature and salinity at the future t moment in Table 1, as shown in Table 2. After multi-objective optimization, the obtained rotational speed curve is as Figure 4 shown.

[0066] Table 2 Required rotational speed predicted for the future 8 hours at t = 0 in the embodiment

[0067]

[0068] At t = 0, the rotational speed is the actual rotational speed of 2229 rpm. After multi-objective optimization, as Figure 4 shown, the intelligent control module is based on Figure 4As a result, the power unit 1 accelerates to 2,262 rpm within 0.2 h; the difference between the outlet pressure Ps of the power unit 1 and the pump outlet pressure P0 measured at t = 0 is less than the threshold value, so the valve opening is 0.

[0069] After one cycle, at the current time t = 0.2 h, the seawater temperatures for the current and the next 8 hours are measured as shown in Table 3, and the inlet salinity is 30‰; the intelligent control module determines the outlet pressure and the required rotational speed of the power unit 1 according to the expected water production flux of the reverse osmosis membrane structure, the seawater temperature and salinity at the next t moment in Table 1, as shown in Table 4. After multi-objective optimization, the obtained rotational speed curve is as Figure 5 shown.

[0070] Table 3 Predicted seawater temperatures for the next 8 hours at t = 0.2 h in the embodiment

[0071]

[0072] Table 4 Required rotational speeds for the next 8 hours predicted at t = 0.2 h in the embodiment

[0073]

[0074] At t = 0.2, the rotational speed is the actual rotational speed of 2,229 rpm. The intelligent control module controls the power unit 1 to accelerate to 2,275 rpm within 0.4 h according to the Figure 5 result; at t = 0.2, the actually measured outlet pressure Ps = 6.46 Mpa, and △P = 6.46 - 6.30 = 0.13 MPa, which is greater than the threshold value (0.1 MPa). Then V = α p ·△P = 6.5%, and this signal is sent to control the opening of the valve 3. During the above process, since it is predicted that the water temperature will start to drop rapidly after 0.2 h to 0.5 h, the rotational speed of the power unit is increased in advance during the period of 0 to 0.2 h, so that the change rate of the rotational speed of the power unit is significantly reduced (as Figure 5 shown), and this control method is beneficial to improving the service life of the high-pressure pump for large-scale seawater desalination and reducing energy consumption.

[0075] It should be understood that although this specification is described according to each embodiment, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0076] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiments or changes made without departing from the technical spirit of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-pressure pump for seawater desalination with multi-information fusion control, characterized in that, It includes a power unit (1), a reflux pipeline (2), a valve (3), an operating parameter monitoring module, a timing analysis module, and an intelligent control module; The inlet of the power unit (1) is internally connected to the power unit (1) through the reflux pipeline (2), and the outlet of the power unit (1) is connected to a reverse osmosis membrane structure for generating fresh water; A valve (3) is installed on the reflux pipeline (2); the operating parameter monitoring module includes at least one sensor for detecting the outlet pressure and flow rate of the power unit (1), the current seawater temperature and salinity; the timing analysis module predicts the seawater temperature at the next time according to the current seawater temperature, weather forecast information, and historical data; The intelligent control module regulates the operating speed of the power unit (1) and the opening degree of the valve (3) according to the outlet pressure and flow rate of the power unit (1), the seawater temperature at the next time, and the salinity.

2. The high-pressure pump for seawater desalination with multi-information fusion control according to claim 1, characterized in that, The power unit (1) is a pump, and the outlet of the first two positive guide vanes of the pump is connected to the pump inlet through the reflux pipeline (2).

3. The high-pressure pump for seawater desalination with multi-information fusion control according to claim 1, characterized in that, The operating parameter monitoring module includes a pressure sensor, a temperature sensor, and a salinity sensor; the pressure sensor is used to monitor the outlet pressure of the power unit (1); the salinity sensor is used to monitor the seawater salinity at the inlet of the power unit (1); the temperature sensor is used to monitor the current seawater temperature.

4. The high-pressure pump for seawater desalination with multi-information fusion control according to claim 1, characterized in that, The intelligent control module determines the outlet pressure of the power unit (1) according to the desired water production flux of the reverse osmosis membrane structure, the seawater temperature at the next time, and the salinity; The intelligent control module determines the future operating speed of the power unit (1) according to the outlet pressure of the power unit (1), the rated pressure and rated speed of the power unit (1).

5. The high-pressure pump for seawater desalination with multi-information fusion control according to claim 1, characterized in that, The intelligent control module determines the outlet pressure of the power unit (1) according to the desired water production flux of the reverse osmosis membrane structure, the seawater temperature at the next time, and the salinity; The intelligent control module determines the opening degree of the valve (3) according to the difference between the outlet pressure of the power unit (1) and the actually measured outlet pressure P of the power unit (1). s ​ 6. The high-pressure pump for seawater desalination with multi-information fusion control according to claim 4 or 5, characterized in that The intelligent control module determines the outlet pressure of the power unit (1) at the future time t according to the desired water production flux of the reverse osmosis membrane structure, the seawater temperature at the next time, and the salinity, specifically: η t = f(T t , S) Where: P t is the outlet pressure of the power unit (1) at future time t; η t is the seawater viscosity at future time t; η ref is the reference seawater viscosity; J w is the desired water production flux of the reverse osmosis membrane structure; A is the water permeability coefficient of the membrane; i is the dissolution factor of the solute; S is the seawater salinity; ρ is the seawater density; R is the gas constant; T t is the absolute seawater temperature at future time t; M is the average molar mass of seawater; f(T t , S) represents the relationship between seawater temperature and salinity and seawater viscosity; The intelligent control module determines the future operating speed of the power unit (1) according to the outlet pressure of the power unit (1), the rated pressure and rated speed of the power unit (1), specifically as follows: Where: P N is the rated pressure of the power unit (1); n N is the rated speed of the power unit (1); n t is the speed of the power unit (1) at the future time t.

7. The high-pressure pump for seawater desalination with multi-information fusion control according to claim 6, characterized in that, The intelligent control module obtains the rotational speed n of the power unit (1) at the future time t t , and with the minimum pump speed change rate as the target, obtains the pump speed curve of the power unit (1) within the next T' hours, where t ∈ [1, …, T'].

8. The high-pressure pump for seawater desalination with multi-information fusion control according to claim 5, characterized in that, At time t, the measured outlet pressure P of the power unit (1) s - The outlet pressure P of the power unit (1) t When the difference exceeds the threshold, the intelligent control module controls the valve (3) to adjust the opening V, where V = α p ·△P, and △P = P s - P t , and α p is the pressure response coefficient.

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