Method and device for calculating water saving amount of demister of wet desulphurization system, electronic equipment and storage medium

Abstract

The invention relates to the technical field of control, in particular to a method and device for calculating the water saving amount of a demister of a wet desulfurization system, electronic equipment and a storage medium, the method is applied to a control unit in the wet desulfurization system, and a spraying area, a water collecting area and a demisting area are sequentially arranged in a desulfurization tower of the wet desulfurization system in the flue gas flowing direction. And at least one demister is arranged in the demisting area. According to the method for calculating the water-saving amount of the demister of the wet desulphurization system, the average water-saving amount is calculated by dynamically calculating the number of iterations and the single-time water-saving amount of cyclic utilization of flushing water in combination with the structural characteristics of a spraying area, a water collecting area and a demisting area in a desulphurization tower and the operation logic of a cyclic flushing water system, and the water-saving amount of the demister of the wet desulphurization system is calculated. Accurate quantification of the water saving amount and system optimization control are achieved, the water saving effect is quantified, data support is provided for system design, and meanwhile the water balance reliability of the desulfurization system is improved.

Description

Technical Field

[0001] The present invention relates to the field of control technology, and in particular to a method, device, electronic equipment and storage medium for calculating the water saving amount of a demister in a wet desulfurization system. Background Art

[0002] The demister is used in the wet flue gas desulfurization system to intercept slurry droplets in the flue gas to ensure that the smoke dust is discharged in compliance with the standards. The traditional flushing method uses process water (low solid matter, low soluble salt ions), but there is a problem of water waste.

[0003] In response to this phenomenon, existing technologies propose recycling flushing water to reduce resource waste, but lack a systematic method for calculating water savings, making it impossible to conduct quantitative analysis to optimize the wet flue gas desulfurization process, which is not conducive to improving water recycling efficiency. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a method, device, electronic equipment and storage medium for calculating the water saving of a demister in a wet flue gas desulfurization system.

[0005] In a first aspect, an embodiment of the present invention provides a method for calculating the water saving of a demister in a wet flue gas desulfurization system, which is applied to a control unit in the wet flue gas desulfurization system. A spraying area, a water collection area, and a demisting area are sequentially provided in a desulfurization tower of the wet flue gas desulfurization system along the flue gas flow direction. At least one demister is provided in the demisting area. A flushing assembly is provided above and below each demister, and the flushing assembly is connected to the outlet of a water supply pipeline through a water supply branch. The inlet of the water supply pipeline is connected to the outlet of a circulating flushing water tank, and the inlet of the circulating flushing water tank is connected to the water collection area through a water collection pipeline.

[0006] The method includes:

[0007] Obtain the process parameters of the wet desulfurization system;

[0008] Based on the process parameters, calculate the number of iterations of recycled flushing water and the amount of water saved per time;

[0009] The average water saving is calculated by combining the number of iterations of recycled flushing water and the amount of water saved per time.

[0010] In combination with the first aspect, the steps of calculating the number of iterations of recycling flushing water and the amount of water saved per time based on the process parameters include:

[0011] Calculate the instantaneous flushing water volume and average flushing water volume of the demister based on process parameters;

[0012] The critical droplet size is determined by combining the superficial tower velocity, droplet density, flue gas density and droplet Reynolds number in the demisting area;

[0013] Based on the amount of slurry droplets generated in the spray zone and the critical droplet size, the amount of slurry droplets removed by the mist eliminator is calculated;

[0014] Combined with the instantaneous flushing water volume, average flushing water volume, and the amount of slurry droplets removed by the demister, the number of recycled flushing water iterations and the amount of water saved per time that meet the preset requirements are calculated.

[0015] In combination with the first aspect, the process parameters include: diameter of the demisting area, demister layout parameters, flushing water valve layout parameters and nozzle layout parameters; flushing water valve layout parameters include: number of flushing valves, flushing time of a single flushing water valve, and flushing cycle of each layer of flushing water; nozzle layout parameters include: nozzle layout interval and single nozzle flow rate;

[0016] The steps for calculating the instantaneous flushing water volume and average flushing water volume of the mist eliminator based on the process parameters include:

[0017] Calculate the instantaneous flushing water volume based on the demisting area diameter and nozzle layout parameters;

[0018] The average flushing water volume is calculated based on the instantaneous flushing water volume, demister layout parameters, and flushing water valve layout parameters.

[0019] In combination with the first aspect, the step of determining the critical droplet size based on the superficial flow velocity, droplet density, flue gas density, and droplet Reynolds number in the demisting zone includes:

[0020] For each preset droplet flow state, obtain the droplet Reynolds number value range and critical particle size calculation rules corresponding to the droplet flow state;

[0021] The critical droplet size is calculated and predicted by combining the empty tower flow velocity, droplet density, flue gas density and critical particle size calculation rules in the demisting area;

[0022] Calculate the predicted droplet Reynolds number corresponding to the predicted critical droplet size;

[0023] The predicted droplet critical particle size whose predicted droplet Reynolds number is consistent with the droplet Reynolds number value range is determined as the target droplet critical particle size.

[0024] In combination with the first aspect, based on the amount of slurry droplets generated in the spray zone and the critical particle size of the droplets, the step of calculating the amount of slurry droplets removed by the demister includes:

[0025] Obtain the nozzle characteristic curve and demister separation efficiency curve of the preset spray zone;

[0026] Calculate the mass of the first droplet entering the demister based on the amount of slurry droplets generated in the spraying area and the nozzle characteristic curve of the spraying area;

[0027] For each particle size range, the corresponding cumulative mass percentage is read based on the nozzle characteristic curve of the spray zone to obtain the mass of the droplets in the particle size range entering the demister;

[0028] The amount of slurry droplets removed by the demister is calculated by combining the mass of droplets in all particle size ranges entering the demister and the demister separation efficiency for each particle size obtained by reading the demister separation efficiency curve.

[0029] In combination with the first aspect, the steps of calculating the number of iterations of recycled flushing water and the amount of water saved per time that meet preset requirements based on the instantaneous flushing water volume, the average flushing water volume, and the amount of slurry droplets removed by the demister include:

[0030] For each recycling flushing water operation, obtain the corresponding operating parameters of the recycling flushing water operation; the operating parameters include at least: the demister flushing water volume, the demister slurry droplet volume, the last recycling flushing water volume, the flushing water recovery rate, the solid content, and the content of each component in the aqueous solution;

[0031] Based on the operating parameters, calculate the values of multiple preset indicators of the recycling flushing water operation and record the single water saving amount;

[0032] Combined with the values of all preset indicators, the number of iterations of recycling flushing water is determined.

[0033] In combination with the first aspect, after the step of calculating the average water saving amount by combining the number of iterations of recycling flushing water and the single water saving amount, the method further includes:

[0034] Adjust the process water flow to the water supply line based on the average water savings.

[0035] In a second aspect, the present application further provides a device for calculating water savings of a demister in a wet desulfurization system, which is applied to a control unit in the wet desulfurization system. The desulfurization tower of the wet desulfurization system is provided with a spraying area, a water collection area, and a demisting area in sequence along the direction of flue gas flow, and at least one demister is provided in the demisting area; a flushing assembly is provided above and below each demister, and the flushing assembly is connected to the outlet of the water supply pipeline through a water supply branch; the inlet of the water supply pipeline is connected to the outlet of a circulating flushing water tank, and the inlet of the circulating flushing water tank is connected to the water collection area through a water collection pipeline; the device comprises:

[0036] An acquisition module is used to obtain process parameters of a wet desulfurization system;

[0037] The first calculation module is used to calculate the number of iterations of recycled flushing water and the amount of water saved per time based on process parameters;

[0038] The second calculation module is used to calculate the average water saving amount by combining the number of iterations of recycled flushing water and the single water saving amount.

[0039] In a third aspect, the present application provides an electronic device, which includes a memory and a processor. The memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the above method.

[0040] In a fourth aspect, the present application provides a readable storage medium, in which computer program instructions are stored. When the computer program instructions are read and executed by a processor, the above-mentioned method is executed.

[0041] The embodiments of the present invention bring the following beneficial effects: the present application provides a method, device, electronic device, and storage medium for calculating the water saving of a demister in a wet desulfurization system. The method is applied to a control unit in a wet desulfurization system. A spraying area, a water collecting area, and a demisting area are sequentially arranged in the desulfurization tower of the wet desulfurization system along the direction of flue gas flow, and at least one demister is arranged in the demisting area; a flushing component is respectively provided above and below each demister, and the flushing component is connected to the outlet of the water supply pipeline through a water supply branch; the inlet of the water supply pipeline is connected to the outlet of the circulating flushing water tank, and the inlet of the circulating flushing water tank is connected to the water collecting area through a water collecting pipeline; the method includes: obtaining the process parameters of the wet desulfurization system; calculating the number of iterations of recycled flushing water and the water saving per time based on the process parameters; calculating the average water saving in combination with the number of iterations of recycled flushing water and the water saving per time.

[0042] The method for calculating the water saving of the demister in the wet flue gas desulfurization system proposed in the present invention combines the structural characteristics of the spraying area, water collection area and demisting area in the desulfurization tower with the operating logic of the circulating flushing water system. By dynamically calculating the number of iterations of the recycled flushing water and the single water saving, the accurate quantification of the water saving and system optimization control, and the quantified water saving effect are achieved, providing data support for system design, so as to improve the overall water balance efficiency of the desulfurization system.

[0043] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The objectives and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 A flow chart of a method for calculating water savings of a demister in a wet flue gas desulfurization system according to an embodiment of the present invention;

[0047] Figure 2 A schematic diagram of the combined principle of a wet desulfurization system provided by an embodiment of the present invention;

[0048] Figure 3 A schematic diagram of a nozzle atomization characteristic curve for a spray zone provided by an embodiment of the present invention;

[0049] Figure 4 A schematic diagram of a separation efficiency characteristic curve of a spray demister provided in an embodiment of the present invention;

[0050] Figure 5 A schematic diagram of the structure of a device for calculating water saving of a demister in a wet flue gas desulfurization system according to an embodiment of the present invention;

[0051] Figure 6 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

[0052] Reference numerals:

[0053] 1-desulfurization tower, 11-inlet, 12-outlet, 2-spraying area, 3-water collection area, 4-demist area, 5-flushing component, 6-water supply branch, 7-water supply pipeline, 8-circulating flushing water tank, 9-water collection pipeline;

[0054] 10-acquisition module, 20-first calculation module, 30-second calculation module;

[0055] 130 - processor, 131 - memory, 132 - bus, 133 - communication interface. DETAILED DESCRIPTION

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0057] To facilitate understanding of this embodiment, the following is a brief introduction to the technical terms used in this application.

[0058] Wet Flue Gas Desulfurization (WFGD) is a flue gas purification technology widely used in coal-fired power plants, metallurgy, chemical industry and other fields. It achieves efficient desulfurization through a chemical reaction between alkaline slurry and sulfur dioxide (SO) in the flue gas.

[0059] After introducing the technical terms involved in this application, the application scenarios and design concepts of the embodiments of this application are briefly introduced.

[0060] Although existing technologies have introduced a flushing water reuse and circulation mechanism to alleviate the problem of water resource consumption, its core defect is that a scientific method for calculating water savings has not been established, resulting in the inability to accurately measure the contribution of flushing water recovery to the system water balance (such as the water savings in a single cycle and the maximum number of iterations), which restricts the optimization direction of process parameters.

[0061] Based on this, the embodiments of the present application provide a method, device, electronic equipment, and storage medium for calculating the water saving of a demister in a wet flue gas desulfurization system.

[0062] Example 1

[0063] The present application provides a method for calculating the water saving of a demister in a wet desulfurization system, which is applied to a control unit in a wet desulfurization system. A spraying area 2, a water collecting area 3 and a demisting area 4 are sequentially provided in a desulfurization tower 1 of the wet desulfurization system along the direction of flue gas flow, and at least one demister is provided in the demisting area 4; a flushing assembly 5 is provided above and below each demister, and the flushing assembly 5 is connected to the outlet of the water supply pipeline 7 through a water supply branch 6; the inlet of the water supply pipeline 7 is connected to the outlet of a circulating flushing water tank 8, and the inlet of the circulating flushing water tank 8 is connected to the water collecting area 3 through a water collecting pipeline 9, as shown in Figure 2.

[0064] Combine Figure 1 As shown, the method includes:

[0065] S110, obtaining process parameters of the wet desulfurization system.

[0066] S120, based on the process parameters, calculate the number of iterations of recycled flushing water and the amount of water saved per time.

[0067] S130, calculating the average water saving amount by combining the number of iterations of recycling flushing water and the single water saving amount.

[0068] In this application, the solid content, soluble salt and chloride ion content of the recycled flushing water are iteratively calculated in combination with the pre-configured process parameters to quantify the water-saving effect, provide data support for system design, and improve the water balance reliability of the desulfurization system.

[0069] like Figure 2The wet desulfurization system shown includes a desulfurization tower 1, a circulating flushing water tank 8, and a water supply pipeline 7. The desulfurization tower 1 is provided with an inlet 11 at the lower part and an outlet 12 at the upper part. Inside the desulfurization tower 1, a spraying area 2, a water collection area 3 and a demisting area 4 are provided in sequence along the flue gas flow direction between the inlet 11 and the outlet 12. High-temperature flue gas enters the desulfurization tower 1 from the inlet 11, passes through the spraying area 2, the water collecting area 3 and the demisting area 4 in turn, and is discharged to the chimney from the upper outlet 12. The slurry is atomized into slurry droplets of different particle sizes by the nozzle of the spraying area 2 to react with SO2 in the flue gas. The large-particle droplets rely on their own gravity to overcome the resistance of the flue gas and fall back to the slurry pool at the bottom of the desulfurization tower 1. The slurry droplets with smaller particle sizes enter the demisting area 4 with the flue gas. Under the action of the demister in the demisting area 4, the droplets are removed by the inertial collision and interception of the multi-layer baffles (such as ridge type and tube type), thereby reducing the droplet content in the flue gas (such as the droplet concentration at the outlet 12 ≤75mg / m 3 ) to prevent the particulate matter content at the outlet of desulfurization tower 1 from exceeding the standard, causing environmental pollutants to fail to meet the standard.

[0070] The number of demisters in the demister area 4 can be adjusted according to actual usage requirements. A flushing assembly 5 is arranged above and below each demister. The flushing assembly 5 uses atomization at the end nozzle of the water supply branch 6 to periodically flush, remove sediment, and maintain the demister flux and efficiency. The flushing water carries the desulfurization slurry through the water collection area 3 for collection. The collected recycled liquid is then diverted to the circulating flushing water tank 8 through the water collection pipeline 9 for recycling and will be used for the next demister flushing.

[0071] As an operative approach, there is one demister, and in this case, two corresponding flushing assemblies 5 are connected to a water supply line 7 via a water supply branch line 6. The water supply line 7 is connected to the process water source and can also be connected to the outlet of a circulating flushing water tank 8. In other words, the water source for flushing the demister is either the process water source or the water recovered by the water collection area 3 and stored in the circulating flushing water tank 8. It should be noted that not all demister flushing water and deslurry droplets enter the circulating flushing water tank 8; a portion falls back into the slurry pool below the desulfurization tower 1.

[0072] As another feasible way, there are two demisters, and in this case there are four corresponding flushing components 5; as another feasible way, there are multiple demisters, and in this case the ratio of the number of corresponding flushing components to the number of demisters is 2.

[0073] Combine Figure 2 As shown, in this embodiment, there are two demisters, and a flushing assembly 5 is arranged on the upper and lower sides of each demister. In actual application, the working principle of the flushing liquid recovery after flushing the demister is as follows:

[0074] During the first flushing, process water (which can be understood as good water with low solid phase and soluble salt ions) is used entirely. Each level of demister is equipped with upper and lower flushing components. Under the action of flushing water released by the nozzles of the flushing components, the slurry droplets attached to the surface of the demister follow the flushing water (the other part falls into the slurry pool at the bottom of the absorption tower) into the water collector of the water collection area 3, and then enter the circulating flushing water tank 8 through the water collection pipeline 9;

[0075] During the second flushing, the demister is first flushed with recycled flushing water (the water in the circulating flushing water tank 8), and the insufficient amount is supplemented with process water. At this time, part of the process water, the circulating flushing water, and the slurry attached to the surface of the demister enter the water collection area 3 and the circulating flushing water tank 8 again in a certain proportion;

[0076] Repeat the above process until the recycled flushing water fails to meet the flushing water requirements (wherein the flushing requirements are preset in the control unit, such as solid content, specified solubility factor range, etc.), stop releasing the recycled flushing water to act on the demister surface for flushing, and discharge the recycled flushing water.

[0077] In combination with the first aspect, step S120 includes:

[0078] S121, based on the process parameters, calculate the instantaneous flushing water volume and average flushing water volume of the demister.

[0079] S122, determine the critical droplet size based on the empty tower velocity, droplet density, flue gas density, and droplet Reynolds number in the demisting area.

[0080] S123, based on the amount of slurry droplets generated in the spraying area and the critical particle size of the droplets, calculate the amount of slurry droplets removed by the demister.

[0081] S124, combining the instantaneous flushing water volume, the average flushing water volume, and the amount of slurry droplets removed by the demister, calculates the number of iterations of recycled flushing water and the single water saving amount that meet the preset requirements.

[0082] In combination with the first aspect, the process parameters include: demisting area diameter, demisting device layout parameters, flushing water valve layout parameters and nozzle layout parameters; flushing water valve layout parameters include: number of flushing valves, flushing time of a single flushing water valve, and flushing cycle of each layer of flushing water; nozzle layout parameters include: nozzle layout interval and single nozzle flow rate.

[0083] Step S121 includes:

[0084] S1211, calculate the instantaneous flushing water volume based on the demisting area diameter and nozzle layout parameters.

[0085] S1212, calculate the average flushing water volume by combining the instantaneous flushing water volume, the demister layout parameters, and the flushing water valve layout parameters.

[0086] In this embodiment, the instantaneous flushing water volume refers to the volume or mass of flushing water consumed per unit time within the continuous flushing time range, and the unit is m 3 / h or kg / h.

[0087] Step S1211 includes: Where q is the instantaneous flushing water flow rate, in m 3 / h; D is the diameter of the demister area, in m; a is the distance from the blind plate to the end, in m; l0 is the spacing between the two pairs of nozzles in the upper and lower flushing assemblies corresponding to the demister, in m; q0 is the flow rate of a single nozzle in the flushing assembly, in m 3 / h.

[0088] The average flushing water volume refers to the volume or mass of flushing water consumed per unit time in a cycle (the time range from the start of the first flush to the start of the second flush, such as the start time of flushing is 0 minutes, flushing for 30 minutes, stopping for 90 minutes for the second flush, and the cycle is 2 hours). The unit is m 3 / h or kg / h.

[0089] Step S1212 includes: Where G is the average flushing water volume in kg / h; ρ is the flushing water density in kg / m 3 ; q is the instantaneous flushing water flow, unit is m 3 / h; N is the number of single-layer flushing water valves; t is the flushing time of a single valve, in hours; n is the number of flushing water layers; T i is the flushing cycle of the i-th layer of flushing water, in hours.

[0090] As an example, take the mist eliminator of a 300MW wet flue gas desulfurization system as an example. The absorption tower is equipped with a two-stage roof-type mist eliminator, four flushing layers, and five valves for the single-layer flushing water. The diameter of the mist eliminator area is 11.4m. The flushing water recovery rate of the upper three layers of mist eliminators is 90%. The solid content of the recycled flushing water is not higher than 4.5%, the chloride ion content is not higher than 1%, and the calcium sulfate solubility product factor is 9.6×10 -2 ; Calcium sulfite solubility product factor 7.2×10 -6 , running at 100% load.

[0091] At this time, process parameters can be obtained, such as the diameter of the demisting area D = 11.4m, the demister layout parameters (the demister is a two-stage ridge type), the flushing water valve layout parameters (including 5 flushing valves per layer, a total of 4 layers of flushing components, and a total of 20 flushing valves), and the nozzle layout parameters (the number of nozzles corresponds to the number of flushing valves). Combined with the design parameters of the wet desulfurization system, the blind plate sealing end distance a and the two pairs of nozzle layout intervals l0 in the upper flushing component and the lower flushing component corresponding to the demister are obtained, and then the instantaneous flushing water volume q is calculated based on step S1211, and then the average flushing water volume G is calculated based on step S1212.

[0092] In combination with the first aspect, step S122 includes:

[0093] S1221: For each preset droplet flow state, obtain the droplet Reynolds number value range and critical particle size calculation rule corresponding to the droplet flow state.

[0094] S1222: Calculate and predict the critical droplet size based on the empty tower velocity, droplet density, flue gas density, and critical particle size calculation rules within the demisting area.

[0095] S1223, calculating the predicted droplet Reynolds number corresponding to the predicted critical droplet size.

[0096] S1224: Determine the predicted droplet critical particle size whose predicted droplet Reynolds number is in accordance with the droplet Reynolds number value range as the target droplet critical particle size.

[0097] According to the working principle of the absorption tower, the slurry is transported to the spray layer by the slurry circulation pump, atomized by the nozzles in the spray area 2 and flows downward, and contacts the upward-flowing flue gas in countercurrent. The droplets of different particle sizes generated by the spray layer are affected by the flow of flue gas (affected by gravity, buoyancy and drag). The smaller droplets flow upward with the flue gas, and the larger droplets move downward. At a certain particle size, the gravity, buoyancy and drag are balanced, and this particle size is called the critical particle size.

[0098] According to the empty tower flue gas velocity, the droplet velocity of the critical particle size is equal to the empty tower flue gas velocity and in the opposite direction, that is, the flue gas velocity is upward and the droplet velocity of the critical particle size is downward.

[0099] Specifically, it is assumed that the droplet is in the Stokes region, that is, the droplet Reynolds number Re<2.

[0100] According to Stokes formula:

[0101] Among them, d r is the predicted critical droplet size, in m; v is the superficial velocity, in m / s; μ is the flue gas viscosity, in m 2 / s; g is the acceleration due to gravity, which is 9.8m2 / s; ρ1 is the droplet density, unit is kg / m 3 ρ g is the smoke density, in kg / m 3 .

[0102] According to the above formula, the critical droplet size d is calculated and predicted r Then, calculate the predicted critical droplet size d r The corresponding predicted droplet Reynolds number Re′:

[0103] Then, it is determined whether Re′ meets the preset droplet Reynolds number range in the Stokes region. If so, the calculated predicted droplet critical particle size d r As the target droplet critical particle size d; if not, it means the droplet is in the non-Stokes region, and the calculation is continued until the target droplet critical particle size d is obtained.

[0104] In this embodiment, the Allen region and the turbulent region are also included. The Allen region is the transition region from the laminar flow (Stokes region) to the turbulent flow region.

[0105] Among them, the value range of the droplet Reynolds number Re in the Allen zone is: 2≤Re<500, and the predicted critical droplet size d r The calculation formula is:

[0106] Among them, the range of the droplet Reynolds number Re in the turbulent zone is: 500≤Re, and the predicted critical droplet size d r The calculation formula is:

[0107] It is understood that in this embodiment, the control unit pre-stores multiple droplet flow states, one-to-one correspondences between the multiple droplet flow states and multiple droplet Reynolds number value ranges, and one-to-one correspondences between the multiple droplet flow states and multiple critical particle size calculation rules. In step S122, a predicted droplet critical particle size is first calculated based on different critical particle size calculation rules, and then a predicted droplet Reynolds number is calculated based on the calculated droplet critical particle size. Finally, the calculated predicted droplet Reynolds number is compared with the droplet Reynolds number value range corresponding to the droplet flow state to determine whether the aforementioned assumption is valid. If not, the droplet flow state is re-assumed and the aforementioned calculation and verification steps are repeated until the actual droplet flow state is determined, and a predicted droplet critical particle size is obtained whose predicted droplet Reynolds number meets the droplet Reynolds number value range. The predicted droplet critical particle size is used as the target droplet critical particle size.

[0108] It can be understood that the assumption, calculation and verification of each droplet flow state can be carried out simultaneously, or can be performed sequentially according to a preset operation priority, which is not limited here. During the sequential operation process, the operation can be terminated after the critical particle size of the target droplet is determined.

[0109] In combination with the first aspect, step S123 includes:

[0110] S1230: Obtain a nozzle characteristic curve and a demister separation efficiency curve of a preset spray zone.

[0111] S1231, calculating the mass of the first droplet entering the demister based on the amount of slurry droplets generated in the spraying zone and the nozzle characteristic curve of the spraying zone.

[0112] It is understood that the control unit pre-stores a nozzle characteristic curve. This nozzle characteristic curve may be obtained by the manufacturer based on manufacturing parameters and product testing, and the nozzle characteristic curve may be attached to the product manual or updated on the product website, so that the user can directly access it through the product manual or product website after purchasing the product. The nozzle characteristic curve may also be drawn during performance testing before use or obtained from other public documents, without limitation herein.

[0113] Figure 3 Schematic diagram of the nozzle atomization characteristic curve for spray zone 2 according to an embodiment of the present invention; the abscissa represents the droplet size generated by the nozzle in spray zone 2, and the ordinate represents the cumulative mass percentage of droplets larger than the critical separation size. For point A (d, η), the mass percentage of slurry droplets larger than the critical size d is η%, and the mass percentage of droplets entering the demister (which can only be droplets with a size smaller than d) is (100-η)%.

[0114] At this time, the calculation formula for the total slurry mass G' entering the demister is: Wherein, G0 is the total mass of slurry droplets entering the demister, in kg / h; η is the mass percentage of slurry droplets larger than the critical particle size d.

[0115] S1232: For each particle size range, the corresponding cumulative mass percentage is read based on the nozzle characteristic curve of the spray zone to obtain the mass of the droplets in the particle size range entering the demister.

[0116] Figure 4 Schematic diagram of the separation efficiency characteristic curve of the spray demister provided in an embodiment of the present invention; the horizontal axis is the particle size of the slurry droplets, and the vertical axis is the demister separation efficiency, that is, Figure 4 This curve shows that as the particle size of the slurry droplets increases, the separation efficiency of the demister changes. Similarly, this curve can also be directly obtained from public documents, such as the demister performance test text.

[0117] In obtaining Figure 4 After following the curve shown, find the minimum particle size value corresponding to 100% separation efficiency of the demister. When the slurry droplet particle size is greater than or equal to this particle size value, the demister separation efficiency is 100%. That is, this minimum particle size value is the critical particle size value.

[0118] Also for the i-th particle size interval [d i , d i+1 ], combined with Figure 4 Obtain the separation efficiency value corresponding to the particle size range, and then calculate the average separation efficiency. Read the corresponding average separation efficiency θ from the demister particle size-separation efficiency curve. i %, the amount of droplets removed by the demister for the i-th particle size interval (also the amount of slurry droplets entering the flushing water) The calculation formula is:

[0119] S1233, combining the mass of droplets in all particle size ranges entering the demister and the separation efficiency of the demister for each particle size, calculate the amount of slurry droplets removed by the demister.

[0120] Combined with the droplet removal amount corresponding to each particle size interval calculated in step S1232, all droplet removal amounts are summed to calculate the total droplet removal amount ΔG of the demister. The specific calculation formula is: Wherein, m is a positive integer.

[0121] It can be understood that the amount of droplets removed by the demister ΔG is also the amount of slurry droplets entering the circulating flushing water during the demister flushing cycle.

[0122] In combination with the first aspect, step S124 includes:

[0123] S1241, for each recycling flushing water operation, obtain the operating parameters corresponding to the recycling flushing water operation; the operating parameters include at least: the demister flushing water volume, the demister slurry droplet removal volume, the last recycling flushing water volume, the flushing water recovery rate, the solid content and the content of each component in the aqueous solution.

[0124] S1242: Calculate the values of multiple preset indicators of the recycling flushing water operation based on the operating parameters, and record the single water saving amount.

[0125] S1243, combining the values of all preset indicators, determining the number of iterations of recycling flushing water.

[0126] In this embodiment, the operating parameters include at least: the amount of demister flushing water, the amount of slurry droplets removed by the demister, the amount of flushing water recycled in the last cycle, the flushing water recovery rate, the solid content, the content of each component in the aqueous solution, the amount of slurry droplets removed by the demister, and the solid content of the slurry. It can be understood that the amount of demister flushing water can be collected by a flow meter; the flushing water recovery rate is determined by system design or actual measurement to reflect the flushing water recovery efficiency; the solid content is determined by the filtration and drying method to determine the proportion of solids in the process water; the content of each component in the aqueous solution is the mass fraction of each preset component in the water quality obtained through water quality analysis; the amount of slurry droplets removed by the demister is the total mass of slurry droplets actually intercepted by the demister (in kg / h); the solid content of the slurry is the mass of solid matter in the slurry droplets. In this embodiment, the preset components include at least:

[0127] As can be understood, based on the working principle in actual application, during the first flush, process water (which can be understood as high-quality water with low solids and soluble salt ions) is used. Under the action of flushing water released by the flushing nozzle of the flushing assembly, the slurry droplets adhering to the surface of the demister follow the flushing water (the other part falls into the slurry pool at the bottom of the absorption tower) into the water collector of the water collection area 3, and then enter the circulating flushing water tank 8 through the water collection pipeline 9.

[0128] During the second flushing, the demister is first flushed with recycled flushing water (the water in the circulating flushing water tank 8), and the insufficient amount is supplemented with process water. At this time, part of the process water, the circulating flushing water, and the slurry attached to the surface of the demister re-enter the water collection area 3, the water collection pipeline 9, and the circulating flushing water tank 8.

[0129] Repeat the above process until the recycled flushing water fails to meet the flushing water requirements (wherein the flushing requirements are preset in the control unit, such as solid content, specified solubility factor range, etc.), stop releasing the recycled flushing water to act on the demister surface for flushing, and discharge the recycled flushing water.

[0130] That is, the first flush uses process water as flushing water, the second flush uses process water and recycled flushing water... until the kth flush is completed, and the flushing water condition is not met, that is, it stops.

[0131] In this embodiment, the recycled flushing water is divided into pure water, soluble salts and solid phase. The recycled flushing water can be regarded as a mixture of the recovered part of the process water, the slurry droplets and the last recycled flushing water.

[0132] In summary, it can be seen that each recycling flushing water operation requires the execution of steps S1241-1242 for obtaining operating parameters, calculating the values of preset indicators, and calculating the single water saving amount.

[0133] For the first recycling flushing water operation, S1242 specifically includes:

[0134] A1. Calculate the total process water volume, process water solids volume, process water aqueous solution volume, and the volume of each component entering the circulating flushing water tank based on the demister flushing water volume, flushing water recovery rate, solid content, and the content of each component in the aqueous solution.

[0135] Specifically, the total process water volume G′1 entering the water receiving pipeline 9 for the first time is calculated using the following formula: G1′=G×τ; wherein G is the demister flushing water volume in kg / h; τ is the demister flushing water recovery rate.

[0136] For example, G = 18497 kg / h, τ = 67.5%, then the calculated G′1 = 18497×τ≈12485 kg / h.

[0137] Calculate the solid phase amount G' of the process water entering the water receiving pipeline 9 for the first time 1,s , calculated as follows: G′ 1,s =G×τ×ξ′; where ξ′ is the solid content of process water.

[0138] For example, ξ′=15%, combined with the above example, G′ 1,s =18497×67.5%×0.55%≈68.67kg / h.

[0139] Calculate the amount of process water solution G' that enters the water receiving pipeline 9 for the first time 1,l , where the amount of aqueous solution refers to the amount of ion-containing liquid after solid removal, which is calculated using the following formula: G′ 1,l =G×τ×(1-ξ′).

[0140] Combined with the above example, G′ 1,l =18497×67.5%×(1-0.55%)≈12416.8kg / h.

[0141] Calculate the amount of the i-th preset component in the process water entering the water receiving pipeline 9 for the first time, wherein, in combination with the above example, the preset components include at least: Ca 2+ 、 Cl - In this embodiment, the preset components are the four preset components mentioned above, and the four preset components are numbered. At this time, the value range of i is 1-4. The specific calculation is as follows: G′ 1,i =G×τ×(1-ξ′)×ω′ i ; where G′ 1,i The amount of the i-th preset component entering the water receiving pipeline 9 in the first cycle operation, in kg / h; ω′ i is the mass fraction of the i-th preset component.

[0142] For example,

[0143] Combining the above examples,

[0144] A2. Based on the amount of slurry droplets removed by the demister (the amount of slurry droplets remaining in the demister after deducting the amount of slurry droplets escaping from the amount of slurry droplets entering and leaving the demister), the flushing water recovery rate, the solid content of the slurry and the concentration of each component in the aqueous solution, calculate the total amount of slurry droplets entering the water collection pipeline 9, the amount of solid phase matter in the slurry droplets, the amount of slurry droplet aqueous solution and the amount of each component.

[0145] Calculate the total slurry droplet volume G″1 entering the water collection pipeline 9 for the first time using the following formula: G″1 = ΔG×τ; where ΔG is the slurry droplet volume removed by the demister, in kg / h; τ is the demister flushing water recovery rate.

[0146] For example, ΔG=3322 kg / h. Combined with the above example, G″1=3322×67.5%≈2242 kg / h.

[0147] Calculate the amount of solid matter G" of the slurry droplets entering the water receiving pipeline 9 for the first time 1,s , calculated as follows: G″ 1,s =ΔG×τ×ξ″; where ξ″ is the solid content of the slurry droplet.

[0148] For example, ξ″=15%. Combined with the above example, G″ 1,s =3322×67.5%×15%≈336kg / h. Calculate the amount of slurry dripping water solution G" entering the water receiving pipe 9 for the first time 1,l , where the amount of aqueous solution refers to the amount of ion-containing liquid after solid removal, and is specifically calculated using the following formula: G″ 1,l =ΔG×τ×(1-ξ"").

[0149] Combined with the above example, G″ 1,l =3322×67.5%×(1-15%)≈1906kg / h.

[0150] Calculate the amount G″ of the i-th preset component in the slurry dripping water solution entering the water receiving pipeline 9 for the first time 1,i , combined with the above examples, the preset components include at least: In this embodiment, the preset components are the four preset components mentioned above, and the four preset components are numbered. At this time, the value range of i is 1-4. The specific calculation is as follows: G" 1,i =ΔG×τ×(1-ξ″)×ω″ i ; Among them, G″ 1,iThe amount of the i-th preset component entering the water receiving pipeline 9 in the first cycle operation, in kg / h; ω″ i is the mass fraction of the i-th preset component.

[0151] For example,

[0152] Combining the above examples,

[0153] A3, combined with the calculation of the total process water volume, process water solid phase volume, process water aqueous solution volume and the volume of each component, total slurry drop volume, slurry drop solid phase volume, slurry drop aqueous solution volume and the volume of each component, as well as the circulating water volume and the volume of each circulating component entering the water receiving pipeline 9, calculate the total amount of recycled flushing water, the amount of recycled flushing water solid phase volume, the amount of recycled flushing water aqueous solution, the volume of each component in the recycled flushing water aqueous solution, the solid content of the recycled flushing water and the content of each component in the recycled flushing water aqueous solution.

[0154] During the first cycle operation (no flushing water is recovered from the circulating flushing water tank 8), the total circulating flushing water volume G″′0 entering the water receiving pipe 9 for the first time is 0; the solid phase volume G″′ of the circulating flushing water entering the water receiving pipe 9 for the first time is 1,s = 0; the amount of flushing water solution G"' entering the water receiving pipe 9 for the first time 0,l = 0; the amount of the i-th preset component G″′ in the flushing water solution entering the water receiving pipeline 9 for the first time 0,i =0.

[0155] Therefore, the total amount of flushing water G used in the first cycle is calculated as follows: 1,c :G 1,c =(G+ΔG)×τ=G′1+G″1;

[0156] The solid phase amount G of the first recycled flushing water is calculated as follows: 1,s :G 1,s =(G×ξ′+ΔG×ξ″)×τ;

[0157] The amount of flushing water solution G used in the first cycle is calculated as follows: 1,l :G 1,l =(G×(1-ξ′)+ΔG×(1-ξ″))×τ;

[0158] Calculate the amount of each component G in the first recycled flushing water solution using the following formula: 1,i :G 1,i =(G×(1-ξ′)×ωi ′+ΔG×(1-ξ″)×ω″ i )×τ;

[0159] The solid content of the first recycled flushing water ξ1 is calculated using the following formula:

[0160] The content of each component of the first recycled flushing water solution ω is calculated using the following formula: 1,i :

[0161] Combined with the above example, G 1,c =(18497+3322)×67.5%=12485+2242=14727kg / h; G 1,s =(18497×0.55%+3322×15%)×67.5%≈405.02kg / h; G 1,l =[18497×(1-0.55%)+3322×(1-15%)]×67.5%≈14322.8kg / h;

[0162] The same calculation

[0163]

[0164] Similarly, calculation

[0165] Then, based on the working principle of the system, the second flushing method of the demister is: the first circulating flushing water is used to flush the demister first, and the insufficient part is flushed with process water. Therefore, S1242 specifically includes:

[0166] B1. Calculate the total process water volume, process water solids volume, process water aqueous solution volume and the volume of each component entering the water collection pipeline 9 for the second time based on the demister flushing water volume, the total amount of flushing water recycled in the previous cycle, the amount of slurry drops removed by the demister, the flushing water recovery rate, the solid content and the concentration of each component in the aqueous solution.

[0167] It can be understood that when this is the second time to recycle the flushing water, the total amount of flushing water recycled in the last cycle is the total amount of flushing water recycled in the first cycle G 1,c .

[0168] Specifically, the total process water volume G2′ entering the water receiving pipeline 9 for the second time is calculated using the following formula:

[0169] G2′=(GG1,c )×τ;

[0170] Among them, G is the demister flushing water volume, unit is kg / h; G 1,c is the total amount of flushing water recycled for the first time; τ is the demister flushing water recovery rate.

[0171] Calculate the solid phase amount G' of the process water entering the water receiving pipeline 9 for the second time 2,s , calculated as follows: G′ 2,s =(GG 1,c )×τ×ξ′; where ξ′ is the solid content of process water.

[0172] Calculate the amount of process water solution G' entering the water receiving pipeline 9 for the second time 2,l , where the amount of aqueous solution refers to the amount of ion-containing liquid after solid removal, which is calculated using the following formula: G 2,l =(GG 1,c )×τ×(1-ξ′).

[0173] Calculate the amount of the i-th preset component G′ in the process water entering the water receiving pipeline 9 for the second time 2,i , calculated as follows: G′ 2,i =(GG 1,c )×τ×(1-ξ′)×ω′ i ; Among them, ω′ i is the mass fraction of the i-th preset component.

[0174] B2. Based on the amount of slurry droplets removed by the demister (the amount of slurry droplets remaining in the demister after deducting the amount of slurry droplets escaping from the amount of slurry droplets entering and leaving the demister), the flushing water recovery rate, the solid content of the slurry and the concentration of each component in the aqueous solution, calculate the total amount of slurry droplets entering the water collection pipeline 9, the amount of solid phase in the slurry droplets, the amount of aqueous solution in the slurry droplets and the amount of each component.

[0175] Understandably, under established operating conditions, the volume of slurry droplets removed by the demister remains constant. This is due to the combined effects of the volume of slurry droplets generated by the spray layer, the size distribution of the slurry droplets entering the demister, and the demister's efficiency in removing slurry droplets of varying sizes. Therefore, the volume of slurry droplets entering the water collection line 9 and its component contents (such as solids and soluble salt ion concentrations) remain the same each time as during the first cycle, demonstrating the system's material balance characteristics under stable operating conditions.

[0176] Specifically, the total slurry drop volume G"2 entering the water receiving pipeline 9 for the second time is calculated using the following formula: G"2 = G"1.

[0177] Calculate the amount of solid matter G" of the slurry droplets entering the water receiving pipe 9 for the second time 2,s , calculated as follows: G" 2,s =G"1,s .

[0178] Calculate the amount of slurry dripping solution G entering the water receiving pipe 9 for the second time 2,l , where the amount of aqueous solution refers to the amount of ion-containing liquid after solid removal, and is calculated using the following formula: G" 2,l =G" 1,l .

[0179] Calculate the amount of the i-th preset component G in the slurry dripping water solution entering the water receiving pipeline 9 for the second time 2,i , calculated as follows: G" 2,i =G" 1,i .

[0180] B3, calculate the product of the second circulating flushing water volume and the flushing water recovery rate to obtain the second circulating water volume entering the water receiving pipeline 9.

[0181] G″′2=G 1,c ×τ; where G″′2 is the total circulating flushing water volume entering the water receiving pipeline 9 for the second time, in kg / h.

[0182] G″′ 2,s =G 1,s ×τ; where G″′ 2,s It is the amount of solid matter in the circulating flushing water entering the water receiving pipeline 9 for the second time, in kg / h.

[0183] G″′ 2,l =G 1,l ×τ; where G″′ 2,s The volume of the circulating flushing water solution entering the water receiving pipeline 9 for the second time, in kg / h.

[0184] G″′ 2,i =G 1,i ×τ; where G″′ 2,s The amount of the preset component i in the circulating flushing water solution entering the water receiving pipeline 9 for the second time, in kg / h.

[0185] Therefore, the total amount of flushing water used in the second cycle is G 2,c , calculated using the following formula:

[0186] G 2,c =G2′+G″2+G″′2;

[0187] Second cycle of flushing water solid matter G 2,s , calculated using the following formula: G 2,s =G2′ ,s +G″ 2,s +G″′ 2,s ;

[0188] The amount of flushing water solution used in the second cycle G 2,l , calculated using the following formula: G 2,l =G2′ ,l +G″ 2,l +G″′ 2,l ;

[0189] The amount of each component in the second recycling flushing water solution G 2,i , calculated using the following formula: G 2,i =G′ 2,i +G″ 2,i +G″′ 2,i ;

[0190] The solid content ξ2 of the second recycled flushing water is calculated using the following formula:

[0191] The content of the i-th preset component of the second recycled flushing water solution is calculated using the following formula:

[0192] Then, according to its working principle, the operation continues. In the k-th recycling flushing water operation, the k-th demister flushing method is: preferentially use the recycled flushing water recovered in the k-1th time to flush the demister, and use process water to flush the demister for the remaining amount. Therefore, step S142 specifically includes:

[0193] K1, calculate the total process water volume, process water solid phase volume, process water aqueous solution volume and the volume of each component entering the water receiving pipeline 9 for the kth time based on the demister flushing water volume, the total amount of flushing water recycled in the last cycle, the demister slurry droplet volume, the flushing water recovery rate, the solid content and the concentration of each component in the aqueous solution.

[0194] It can be understood that the "total amount of flushing water used in the last cycle" at this time is: the total amount of flushing water used in the k-1th cycle G k-1,c .

[0195] Therefore, the total process water volume G′ entering the circulating flushing water tank 8 for the kth time k , calculated as follows: G′ k =(GG k-1,c )×τ; where G k-1,c The total amount of flushing water recycled for the k-1th time, in kg / h.

[0196] Calculate the solid phase amount G′ of the process water entering the water receiving pipeline 9 for the kth time k,s , calculated as follows: G′ k,s =(GG k-1,c )×τ×ξ′.

[0197] Calculate the amount of process water solution G′ entering the water receiving pipeline 9 for the kth time k,l , where the amount of aqueous solution refers to the amount of ion-containing liquid after solid removal, which is calculated using the following formula: G′ k,l =(GG k-1,c )×τ×(1-ξ′).

[0198] Calculate the amount G′ of the i-th preset component in the process water entering the water receiving pipeline 9 for the kth time k,i , calculated as follows: G′ k,i =(GG k-1,c )×τ×(1-ξ′)×ω i ′.

[0199] K2, based on the amount of slurry drops removed by the demister, the recovery rate of flushing water, the solid content of the slurry and the concentration of each component in the aqueous solution, calculate the total slurry droplet amount, the amount of solid phase in the slurry droplet, the amount of aqueous solution in the slurry droplet and the amount of each component entering the water collection pipeline 9.

[0200] Specifically, calculate the total slurry drop volume G" entering the water receiving pipeline 9 for the kth time k , calculated as follows: G″ k =G″1.

[0201] Calculate the solid phase amount G" of the slurry droplet entering the water receiving pipeline 9 for the kth time k,s , calculated as follows: G″ k,s =G″ 1,s .

[0202] Calculate the amount of slurry dripping water solution G entering the water receiving pipeline 9 for the kth time k " ,l , where the amount of aqueous solution refers to the amount of ion-containing liquid after solid removal, and is specifically calculated using the following formula: G″ k,l =G″ 1,l .

[0203] Calculate the amount G″ of the i-th preset component in the slurry dripping water solution entering the water receiving pipeline 9 for the kth time k,i , calculated as follows: G″′ k,i =G″ 1,i .

[0204] B3, calculate the product of the k-1th circulating flushing water volume and the flushing water recovery rate to obtain the kth circulating water volume entering the water receiving pipeline 9.

[0205] G″′ k =G k-1,c ×τ; where G″′ k is the total circulating flushing water volume entering the water receiving pipeline 9 for the kth time, in kg / h; G k-1,cThe total circulating flushing water volume entering the water receiving pipeline 9 for the k-1th time, in kg / h.

[0206] G″′ k,s =G k-1,s ×τ; where G″′ k,s G is the amount of solid matter in the circulating flushing water entering the water receiving pipeline 9 for the kth time, in kg / h; k-1,s The solid matter content of the circulating flushing water entering the water receiving pipeline 9 for the k-1th time, in kg / h.

[0207] G″′ k,l =G k-1,l ×τ; where G″′ k,s is the amount of circulating flushing water solution entering the water receiving pipeline 9 for the kth time, in kg / h; G k-1,l The amount of circulating flushing water solution entering the water receiving pipeline 9 for the k-1th time, in kg / h.

[0208] G″′ 2,i =G k-1,i ×τ; where G″′ 2,s The amount of the preset component in the i-th circulating flushing water solution entering the water receiving pipeline 9 for the kth time, in kg / h; G k-1,i The amount of the i-th preset component in the circulating flushing water solution entering the water receiving pipeline 9 for the k-1th time, in kg / h.

[0209] Therefore, the total amount of flushing water used in the kth cycle G k , calculated using the following formula: G k,c =G′ k +G″ k +G″′ k .

[0210] Solid matter amount G of the flushing water used in the kth cycle k,s , calculated using the following formula: G k,s =G′ k,s +G″′ k,s +G″′ k,s .

[0211] The amount of flushing water solution used in the kth cycle G k,l , calculated using the following formula: G k,l =G′ k,l +G″ k,l +G″′ k,l .

[0212] The amount of each component G in the kth recycled flushing water solution k,i , calculated using the following formula: G k,i =G′ k,i +G″k,i +G″′ k,i .

[0213] Solid content of the kth recycled flushing water ξ k , calculated using the following formula:

[0214] The content of the i-th preset component of the k-th recycled flushing water solution is calculated using the following formula:

[0215] In combination with the first aspect, step S1243 includes:

[0216] S12431, combining the values of all preset indicators, determining whether there are abnormal indicators;

[0217] If so, execute step S12432; if not, execute step S12433.

[0218] S12432, determine the number of times the previous flushing water recycling operation is performed as the number of flushing water recycling iterations.

[0219] S12433, execute the next number of recycling flushing water operations until an abnormality indicator is obtained, and determine the number of recycling flushing water iterations.

[0220] It is understandable that, based on step S1242, the values of multiple preset indicators for each recycling flushing water operation can be calculated, wherein the preset indicators include but are not limited to solid content, soluble salt concentration (such as calcium sulfate and calcium sulfite solubility product factor) and chloride ion content. Then, step S1243 determines whether there are abnormal indicators among the multiple preset indicators. Specifically, an indicator allowable range is set for each preset indicator, for example, the solid content should be ≤4.5%, the calcium sulfate volume fraction should be ≤0.096, and the calcium sulfite volume fraction should be ≤7.2×10 -6 . If any preset indicator exceeds the allowable range of the indicator, it is considered that an abnormal indicator has occurred. At this time, step S12432 is executed and the number of iterations of the recycled flushing water is based on the number of effective recycling flushing water operations (i.e., the k-1th time). This can maximize the water-saving effect while avoiding water quality deterioration. Finally, step S1244 calculates the average water saving of the system based on the determined target number of cycles by accumulating the water saving of each cycle, and then calculates the water saving of the demister flushing water (the water saving of a single flushing water). At the same time, the number of cycles and the amount of water discharged when the abnormal termination occurs are recorded to support subsequent water balance optimization.

[0221] Among them, if all the preset indicators are within the allowable range of the indicators, it is considered that no abnormal indicators have appeared. At this time, step S12433 is executed to perform the next recycling flushing water operation and calculate again until abnormal indicators appear to determine the number of recycling flushing water iterations.

[0222] Specifically, a solid content threshold ζ0 is preset. In this embodiment, ζ0=4.5%. When the solid content is less than or equal to 4.5%, if the detected solid content is greater than 4.5%, the solid content is determined to be an abnormal indicator.

[0223] In this embodiment, the allowable range of soluble salt crystallization in the recycled flushing water is also preset, specifically:

[0224]

[0225]

[0226] in, The mass fraction of calcium ions in the recycled flushing water; is the mass fraction of sulfate in the recycled flushing water; is the mass fraction of sulfite in the recycled flushing water; KS1 is the solubility product factor of calcium sulfate under the condition that the temperature of the recycled flushing water is T, and KS2 is the solubility product factor of calcium sulfite under the condition that the temperature of the recycled flushing water is T. In this embodiment, KS1 = 0.096, KS2 = 7.2 × 10 -6 It is understandable that if the above formula is not satisfied, the crystallization of soluble salts in the recycled flushing water is determined to be an abnormal indicator.

[0227] In this embodiment, a chloride ion mass fraction threshold value in the recycled flushing water is also preset. When the calculated chloride ion mass fraction in the recycled flushing water is greater than the preset chloride ion mass fraction threshold value, the chloride ion mass fraction is determined to be an abnormal indicator.

[0228] It is understandable that the allowable range of the above indicators can be adjusted according to the actual configuration, process parameters and operating conditions of the wet flue gas desulfurization system. This is only an example and not a limitation. In the above example, the solid content of the recycled flushing water is not higher than 4.5%, the chloride ion content is not higher than 1%, and the calcium sulfate solubility product factor is 9.6×10 -2 ; Calcium sulfite solubility product factor 7.2×10 -6 , the water saving under 100% load is calculated as follows", in this example, ζ0 = 4.5%, the chloride ion mass fraction threshold is 1%, KS1 = 0.096, KS2 = 7.2×10 -6 .

[0229] Step S1244 specifically includes:

[0230] Calculate using the following formula: in, is the average water saving, in kg / h; G i,c is the recycled flushing water volume of the i-th recycled flushing water operation, in kg / h; k is a positive integer greater than 1.

[0231] In this embodiment, the present invention utilizes the existing demister flushing water recycling tank 8. By quantitatively analyzing the amount of slurry droplets generated in the spray layer and the demister flushing water parameters, combined with the system's operating mechanism, a method for calculating the water savings from flushing water recycling and reuse is constructed. This method not only provides a theoretical basis for the optimized design of the demister flushing water recovery process but can also be integrated into desulfurization system water balance analysis, effectively improving water recycling efficiency and possessing significant application value in achieving water-saving operational optimization of the desulfurization process.

[0232] In combination with the first aspect, after step S130, the method further includes:

[0233] S140: Adjust the process water volume to the water supply pipeline based on the average water saving volume.

[0234] After calculating the average water saving amount in step S130, the valve opening adjustment signal of the water supply pipeline is calculated based on the difference between the average water saving amount and the real-time process water consumption, so as to adjust the process water replenishment amount through a control unit such as a PID controller, which is conducive to improving the degree of automation.

[0235] On the second aspect, the embodiment of the present application also provides a device for calculating the water saving of a demister in a wet desulfurization system, which is applied to a control unit in a wet desulfurization system. A spraying area 2, a water collecting area 3 and a demisting area 4 are sequentially provided in the desulfurization tower of the wet desulfurization system along the direction of flue gas flow, and at least one demister is provided in the demisting area 4; a flushing assembly 5 is provided above and below each demister, and the flushing assembly 5 is connected to the outlet of the water supply pipe 7 through a water supply branch 6; the inlet of the water supply pipe 7 is connected to the outlet of the circulating flushing water tank 8, and the inlet of the circulating flushing water tank 8 is connected to the water collecting area 3 through a water collecting pipe 9. Combined with Figure 5 As shown, the device includes: an acquisition module 10, a first calculation module 20 and a second calculation module 30.

[0236] The acquisition module 10 is used to obtain process parameters of the wet desulfurization system.

[0237] The first calculation module 20 is used to calculate the number of iterations of recycling flushing water and the amount of water saved per time based on the process parameters.

[0238] The second calculation module 30 is used to calculate the average water saving amount by combining the number of iterations of recycling flushing water and the single water saving amount.

[0239] In a third aspect, the present application provides an electronic device, Figure 6 As shown, the electronic device includes a memory 131 and a processor 130. The memory 131 is used to store computer programs, and the processor 130 runs the computer programs to enable the electronic device to perform the above method.

[0240] Further, combined with Figure 6 The electronic device shown further includes a bus 132 and a communication interface 133 , and the processor 130 , the communication interface 133 and the memory 131 are connected via the bus 132 .

[0241] The memory 131 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk storage. The communication connection between the system network element and at least one other network element is achieved through at least one communication interface 133 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used. The bus 132 may be an ISA bus, a PCI bus, or an EISA bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0242] The processor 130 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by hardware integrated logic circuits in the processor 130 or by software instructions. The processor 130 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in conjunction with the embodiments of the present invention can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in memory 131, and processor 130 reads information in memory 131 and, in conjunction with its hardware, completes the steps of the method of the aforementioned embodiment.

[0243] In a fourth aspect, an embodiment of the present application provides a readable storage medium, in which computer program instructions are stored. When the computer program instructions are read and executed by a processor, the above-mentioned method is executed.

[0244] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems and devices can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0245] In addition, in the description of the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0246] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0247] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0248] Finally, it should be noted that the above embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for calculating water saving of a demister in a wet flue gas desulfurization system, characterized in that: A control unit applied to a wet flue gas desulfurization system, wherein a desulfurization tower of the wet flue gas desulfurization system is provided with a spraying area, a water collection area, and a demisting area in sequence along the flue gas flow direction, wherein the demisting area is provided with at least one demister; a flushing assembly is provided above and below each demister, respectively, and the flushing assembly is connected to the outlet of a water supply pipeline via a water supply branch; the inlet of the water supply pipeline is connected to the outlet of a circulating flushing water tank, and the inlet of the circulating flushing water tank is connected to the water collection area via a water collection pipeline; The method comprises: Obtaining process parameters of the wet desulfurization system; Based on the process parameters, the number of iterations of recycled flushing water and the amount of water saved per time are calculated; The average water saving is calculated based on the number of iterations of the recycled flushing water and the single water saving.

2. The method according to claim 1, characterized in that The steps of calculating the number of iterations of recycling flushing water and the amount of water saved per time based on the process parameters include: Based on the process parameters, calculating the instantaneous flushing water volume and the average flushing water volume of the demister; Determining the critical droplet size based on the superficial flow velocity, droplet density, flue gas density, and droplet Reynolds number in the demisting zone; Calculating the amount of slurry droplets removed by the mist eliminator based on the amount of slurry droplets generated in the spray zone and the critical particle size of the droplets; Combined with the instantaneous flushing water volume, the average flushing water volume, and the amount of slurry droplets removed by the demister, the number of iterations of recycled flushing water and the single water saving amount that meet the preset requirements are calculated.

3. The method according to claim 2, characterized in that The process parameters include: demisting area diameter, demisting device layout parameters, flushing water valve layout parameters and nozzle layout parameters; the flushing water valve layout parameters include: number of flushing valves, flushing time of a single flushing water valve, and flushing cycle of each layer of flushing water; the nozzle layout parameters include: nozzle layout interval and single nozzle flow rate; The step of calculating the instantaneous flushing water volume and the average flushing water volume of the demister based on the process parameters comprises: Calculating instantaneous flushing water volume based on the demisting area diameter and the nozzle arrangement parameters; The average flushing water volume is calculated based on the instantaneous flushing water volume, the demister layout parameters, and the flushing water valve layout parameters.

4. The method according to claim 2, characterized in that The step of determining the critical droplet size based on the superficial flow velocity, droplet density, flue gas density, and droplet Reynolds number in the demisting zone comprises: For each preset droplet flow state, obtaining the droplet Reynolds number value range and critical particle size calculation rule corresponding to the droplet flow state; Calculate and predict the critical droplet size by combining the superficial flow velocity, droplet density, flue gas density and the critical particle size calculation rule in the demisting area; Calculating a predicted droplet Reynolds number corresponding to the predicted critical droplet size; The predicted droplet critical particle size whose predicted droplet Reynolds number is consistent with the droplet Reynolds number value range is determined as the target droplet critical particle size.

5. The method according to claim 2, characterized in that The step of calculating the amount of slurry droplets removed by the mist eliminator based on the amount of slurry droplets generated in the spray zone and the critical particle size of the droplets comprises: Obtain the nozzle characteristic curve and demister separation efficiency curve of the preset spray zone; Calculating the mass of the first droplets entering the demister according to the amount of slurry droplets generated in the spraying zone and the nozzle characteristic curve of the spraying zone; For each particle size interval, the corresponding cumulative mass percentage is read based on the nozzle characteristic curve of the spray zone to obtain the mass of the droplets in the particle size interval entering the demister; The amount of slurry droplets removed by the demister is calculated by combining the mass of all droplets in the particle size range entering the demister and the demister separation efficiency for each particle size obtained by reading the demister separation efficiency curve.

6. The method according to claim 2, characterized in that The step of calculating the number of iterations of recycled flushing water and the amount of water saved per time that meet preset requirements based on the instantaneous flushing water volume, the average flushing water volume, and the amount of slurry droplets removed by the demister comprises: For each recycling flushing water operation, obtain the operating parameters corresponding to the recycling flushing water operation; the operating parameters include at least: the amount of demister flushing water, the amount of slurry droplets removed by the demister, the total amount of flushing water recycled in the previous operation, the flushing water recovery rate, the solid content, and the content of each component in the aqueous solution; Based on the operating parameters, calculating the values of a plurality of preset indicators of the recycling flushing water operation and recording the single water saving amount; Combined with the values of all preset indicators, the number of iterations of recycling flushing water is determined.

7. The method according to claim 1, characterized in that After calculating the average water saving amount based on the number of iterations of recycling flushing water and the single water saving amount, the method further includes: The amount of process water flowing to the water supply pipeline is adjusted based on the average water saving amount.

8. A device for calculating water saving of a mist eliminator in a wet flue gas desulfurization system, characterized in that: A control unit applied to a wet flue gas desulfurization system, wherein a desulfurization tower of the wet flue gas desulfurization system is provided with a spraying area, a water collection area, and a demisting area in sequence along the flue gas flow direction, wherein the demisting area is provided with at least one demister; a flushing assembly is provided above and below each demister, respectively, and the flushing assembly is connected to the outlet of a water supply pipeline via a water supply branch; the inlet of the water supply pipeline is connected to the outlet of a circulating flushing water tank, and the inlet of the circulating flushing water tank is connected to the water collection area via a water collection pipeline; The device comprises: An acquisition module, used for acquiring process parameters of the wet desulfurization system; A first calculation module is used to calculate the number of iterations of recycling flushing water and the amount of water saved per time based on the process parameters; The second calculation module is used to calculate the average water saving amount by combining the number of iterations of recycling flushing water and the single water saving amount.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to perform the method according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores computer program instructions, and when the computer program instructions are read and executed by a processor, the method according to any one of claims 1 to 7 is executed.

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