A method for controlling scaling of a slag removal system of a coal-fired unit

Abstract

The present invention relates to a method for controlling scaling in a coal-fired unit's slag removal system. Based on the quality characteristics of commonly used water and the leaching concentration of slag ions, the method measures the concentration rate of key ions that contribute to scaling in the slag removal machine. The method also calculates the initial overflow water volume and the corrected replenishment water volume to control the concentrations of several key ions in the slag water in the slag removal tank that affect scaling, thereby reducing scaling. The present invention has the beneficial effects of reducing chemical consumption, lowering the workload of manual descaling, slowing scaling rates, and rationally controlling water costs.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired unit slag removal, and more specifically, to a method for controlling scaling inhibition of a coal-fired unit slag removal system. Background Art

[0002] The operation of the slag removal system of a coal-fired unit directly affects the safety and reliability of the entire unit. Currently, most domestic slag removal systems use mechanical slag removal systems, which are specifically divided into two types: wet slag removal and dry slag removal.

[0003] The wet slag removal system mainly consists of two parts: slag conveying equipment and a slag scoop. A water-immersed scraper slag scoop is installed at the bottom of each boiler's cold ash hopper to continuously remove the bottom slag. The bottom slag discharged by the slag scoop is transported to the slag storage bin via a scraper slag conveyor with an inclined dewatering section. The slag is dehydrated in the inclined section, and the moisture content of the slag falling into the bin is generally ≤40%. The slag storage bin is equipped with a water separation element to further precipitate the water in the slag. The slag is then directly loaded into dump trucks and transported to the ash storage yard. Slag is a product of high-temperature combustion in boilers and contains alkaline oxidants. After entering the wet slag removal system, alkaline substances are dissolved in the water. The slag water has complex water quality and high salt content, which causes scaling on the surface of the heat exchanger, affecting the heat exchange of the slag water. There is a risk of slag water overheating, which threatens the safe and stable operation of the unit.

[0004] To solve this problem, existing methods include manual slag removal, pickling, or adding scale inhibitors. However, the operating costs of existing methods are high. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method for controlling scaling of a slag removal system of a coal-fired unit.

[0006] In a first aspect, a method for controlling scaling of a slag removal system of a coal-fired unit is provided, comprising:

[0007] Step 1: Calculate the amount of slag and water replenishment;

[0008] Step 2: Measure the leaching amount of each ion in the slag by solution leaching method, and measure the content of each ion in the common water replenishment by potentiometric titration and ion chromatography; the ions include OH - ions, CO3 2- ions, Mg 2+ ions, Ca 2+ ions and HCO3 - ion;

[0009] Step 3: Calculate the concentration of each ion brought into the slag based on the slag volume and water replenishment amount;

[0010] Step 4, calculating the amount of calcium carbonate and magnesium hydroxide carried into the slag skimmer cabin according to the concentration of each ion;

[0011] Step 5: setting the threshold concentrations of calcium carbonate and magnesium hydroxide so that the amount of calcium carbonate carried out of the slag scoop cabin is greater than or equal to the amount of calcium carbonate carried into the slag scoop cabin, and the amount of magnesium hydroxide carried out of the slag scoop cabin is greater than or equal to the amount of magnesium hydroxide carried into the slag scoop cabin;

[0012] Step 6: Calculate the economic efficiency based on the water price and select the appropriate water type;

[0013] Step 7: Dynamically monitor the ion concentration in the slag scoop cabin and adjust the water supply in time;

[0014] Step 8: After the overflow slag water enters the overflow tank, it is pumped into the desulfurization area slurry pool through the overflow water pump to serve as water for the desulfurization process. Preferably, in step 1, the calculation formula for the slag amount is:

[0015] M2=M1*10%

[0016] Among them, M2 represents the amount of slag, and M1 represents the amount of coal commonly used in a specific unit at full output, both in t / h;

[0017] The formula for calculating the amount of water replenishment is:

[0018] Q B =Q zs +Q Z +Q yl

[0019] Among them, Q B Indicates the amount of water replenishment, Q zs Indicates the amount of slag water, Q Z Indicates the amount of evaporated water, Q yl Indicates overflow water volume, unit is t / h.

[0020] As a preference, in step 2, the slag is leached to remove OH - The ion concentration is recorded as C1, and the slag leaching CO3 2- The ion concentration is recorded as C2, and the Mg leached from the slag is 2+ The ion concentration is recorded as C3, and the slag leaching Ca 2+ The ion concentration is recorded as C4; and the water OH - The ion concentration is recorded as C ’ 1. Replenish water with CO3 2- The ion concentration is recorded as C ’ 2. Rehydration Mg 2+ The ion concentration is recorded as C ’ 3. Rehydration Ca 2+ The ion concentration is recorded as C ’ 4. Replenish water with HCO3 - The ion concentration is recorded as C ’ 5. The unit is g / kg.

[0021] Preferably, in step 3, OH - The ion enrichment rate of ions is expressed as a = M2·C1+Q B ·C ’ 1; CO3 2 The ion enrichment rate of ions is expressed as b = M2·C2+Q B ·C ’ 2;Mg 2+ The ion enrichment rate of ions is expressed as c = M2·C3 + Q B ·C ’ 3; Ca 2+ The ion enrichment rate of ions is expressed as d = M2·C4+Q B ·C ’ 4; HCO3 - The ion enrichment rate of ions is expressed as e = Q B ·C ’ 5.

[0022] Preferably, in step 4, the ion enrichment rates of the ions are compared, and the amount of calcium carbonate brought into the slag skimmer cabin is expressed as MIN(b, d); in addition, if a≤e, there is no magnesium hydroxide, otherwise the amount of magnesium hydroxide brought into the slag skimmer cabin is expressed as MIN(ae, c).

[0023] As a preference, in step 5, the amount of calcium carbonate carried out of the slag machine cabin is expressed as (Q yl +Q zs )·α, α is the threshold concentration of calcium carbonate, unit is mg / L; the amount of magnesium hydroxide carried out by the slag machine cabin is expressed as (Q yl +Q zs )·β, β is the threshold concentration of magnesium hydroxide, the unit is mg / L.

[0024] As a preference, in step 6, the water supply includes industrial water, desalted water and RO effluent water, and the water fee is calculated as follows: water fee = Q B Corresponding water prices.

[0025] Preferably, in step 7, a continuous flow analysis technique is used to perform colorimetric analysis, measuring the absorbance of the sample and the alkalinity indicator at a specific wavelength, and calculating the alkalinity of the actual water sample by comparing it with a standard substance of known alkalinity; and calculating HCO3 by the alkalinity Ao of methyl orange and the alkalinity Ap of phenolphthalein. - , OH - , CO3 2- Ion concentration, Ca is directly measured using a calcium ion selective electrode method 2+ and Mg 2+ Ion concentration: if it deviates from the acceptable concentration, increase the water replenishment and overflow flow.

[0026] In a second aspect, a coal-fired unit slag removal system is provided, which is used to implement the coal-fired unit slag removal system scaling control method described in any one of the first aspects, comprising: a slag bin 1, a slag scoop cabin 2, an overflow tank 3, and a desulfurization area slurry tank 4 connected in sequence;

[0027] Among them, the slag scoop cabin 2 is provided with a potentiometric titrator 7 and an overflow port, and is connected to the overflow tank 3 through the overflow port; the overflow tank 3 is provided with a pipeline, and the overflow slag water is transported to the desulfurization area slurry tank 4 through a flow meter 5 and a water pump 6.

[0028] The beneficial effects of the present invention are as follows: the present invention monitors the concentrations of anions and cations online through a scaling factor control method, assesses the possibility of scaling, can reduce the consumption of reagents, reduce the workload of manual scaling removal, and slow down the scaling rate; in addition, the present invention reasonably controls the water cost by adjusting the water replenishment amount through online calculation and feedback. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural diagram of the slag removal system of a coal-fired unit;

[0030] Figure 2 This is a flow chart of a method for controlling scaling of a slag removal system of a coal-fired unit;

[0031] Figure 3 This is the flow chart for judging the ion concentration in the slag scoop cabin;

[0032] Figure 4 This is a schematic diagram of the slag removal system slag picker cabin;

[0033] Figure 5 Schematic diagram of ion dissolution of slag sample;

[0034] Figure 6 It is a schematic diagram of the structure rate of the slag removal system;

[0035] Explanation of the reference numerals: slag bin 1, slag scoop cabin 2, overflow pool 3, desulfurization area slurry pool 4, flow meter 5, water pump 6, potentiometric titrator 7. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the following examples. The following examples are provided only to facilitate understanding of the present invention. It should be noted that, without departing from the principles of the present invention, it is possible for a person skilled in the art to make various modifications to the present invention, and such improvements and modifications fall within the scope of the claims of the present invention.

[0037] Example 1:

[0038] The wet slag removal system of a coal-fired unit is fed with circulating water. After complete combustion, the coal slag falls into a slag scoop filled with circulating water. A heat exchanger is used to cool the slag water, maintaining a temperature of approximately 50°C. The system is overflow-free, and water replenishment is currently controlled based on liquid level. Evaporation of water causes ions dissolved in the coal slag to continuously concentrate in the slag water, leading to severe scaling in the heat exchanger and on the inner walls of the slag scoop, impacting the heat exchange efficiency and causing the risk of slag water overheating. This impacts the continuous and stable operation of the slag removal system and threatens the safe operation of the unit.

[0039] The purpose of the present invention is to solve the problem of scaling on the inner wall of the heat exchanger and the slag remover cabin, reduce the operating cost investment caused by manpower and chemicals, and provide a coal-fired unit slag removal system, such as Figure 1 As shown, it includes: a slag bin 1, a slag scoop cabin 2, an overflow pool 3 and a desulfurization area slurry pool 4 which are connected in sequence;

[0040] Among them, the slag scoop cabin 2 is provided with a potentiometric titrator 7 and an overflow port, and is connected to the overflow tank 3 through the overflow port; the overflow tank 3 is provided with a pipeline, and the overflow slag water is transported to the desulfurization area slurry tank 4 through a flow meter 5 and a water pump 6.

[0041] Example 2:

[0042] The coal-fired unit slag removal system provided in Example 1 is used to monitor the slag water Ca in the slag removal machine cabin 2 online through the potentiometric titrator 7. 2+ , Mg 2+ ,HCO3 - , OH - , CO3 2- Since the solubility of MgCO3 in water is similar to that of CaCO3, but the solubility of MgCO3 is greater than that of CaCO3 under the same conditions, for most water containing both MgCO3 and CaCO3, any condition that reduces the solubility of MgCO3 and CaCO3 will first form CaCO3 scale. - Will react with HCO3 - The reaction produces CO3 2- , if OH - If there is excess, it will react with Mg in the slag water. 2+ Mg(OH)2 is formed, so the scale in the slag removal machine is mainly composed of calcium carbonate and magnesium hydroxide. The present invention creates a method for inhibiting scaling control in the slag removal system of a coal-fired unit based on the solubility of the main inorganic salts in the slag water and the concentration of four ions.

[0043] Specifically, if Figure 2 As shown, the method includes the following steps:

[0044] Step 1: Calculate the amount of slag and water replenishment.

[0045] In step 1, the calculation formula of the slag amount is:

[0046] M2=M1*10%

[0047] Among them, M2 represents the amount of slag, and M1 represents the amount of coal commonly used in a specific unit at full output, both in t / h;

[0048] The formula for calculating the amount of water replenishment is:

[0049] Q B =Q zs +Q Z +Q yl

[0050] Among them, Q B Indicates the amount of water replenishment, Q zs Indicates the amount of slag water, Q Z Indicates the amount of evaporated water, Q yl Indicates overflow water volume, unit is t / h.

[0051] Step 2: Measure the leaching amount of each ion in the slag by solution leaching method, and measure the content of each ion in the common water replenishment by potentiometric titration and ion chromatography; the ions include OH - ions, CO3 2- ions, Mg 2+ ions, Ca 2+ ions and HCO3 - ion.

[0052] In step 2, the slag is leached to remove OH - The ion concentration is recorded as C1, and the slag leaching CO3 2- The ion concentration is recorded as C2, and the Mg leached from the slag is 2+ The ion concentration is recorded as C3, and the slag leaching Ca 2+ The ion concentration is recorded as C4; and the water OH - The ion concentration is recorded as C ’ 1. Replenish water with CO3 2- The ion concentration is recorded as C ’ 2. Rehydration Mg 2+ The ion concentration is recorded as C ’ 3. Rehydration Ca 2+ The ion concentration is recorded as C ’ 4. Replenish water with HCO3 - The ion concentration is recorded as C ’ 5. The unit is g / kg.

[0053] Step 3: Calculate the concentration of each ion brought into the slag based on the slag volume and water replenishment volume.

[0054] In step 3, as shown in Table 1, OH - The ion enrichment rate of ions is expressed as a = M2·C1+Q B ·C’ 1; CO3 2 The ion enrichment rate of ions is expressed as b = M2·C2+Q B ·C ’ 2;Mg 2+ The ion enrichment rate of ions is expressed as c = M2·C3 + Q B ·C ’ 3; Ca 2+ The ion enrichment rate of ions is expressed as d = M2·C4+Q B ·C ’ 4; HCO3 - The ion enrichment rate of ions is expressed as e = Q B ·C ’ 5.

[0055] Table 1

[0056] ion Slag leaching capacity kg / h Water intake kg / h Ion enrichment rate <![CDATA[OH - ]]> <![CDATA[M2·C1]]> <![CDATA[Q B ·C ’ 1]]> <![CDATA[a=M2·C1+Q B ·C ’ 1]]> <![CDATA[CO3 2- ]]> <![CDATA[M2·C2]]> <![CDATA[Q B ·C ’ 2]]> <![CDATA[b=M2·C2+Q B ·C ’ 2]]> <![CDATA[Mg 2+ ]]> <![CDATA[M2·C3]]> <![CDATA[Q B ·C ’ 3]]> <![CDATA[c=M2·C3+Q B ·C ’ 3]]> <![CDATA[Ca 2+ ]]> <![CDATA[M2·C4]]> <![CDATA[Q B ·C ’ 4]]> <![CDATA[d=M2·C4+Q B ·C ’ 4]]> <![CDATA[HCO3 - ]]> / <![CDATA[Q B ·C5]]> <![CDATA[e=Q B ·C5]]>

[0057] Step 4: Calculate the amount of calcium carbonate and magnesium hydroxide carried into the slag skimmer cabin based on the concentrations of the ions.

[0058] In step 4, the ion enrichment rates of various ions are compared, and the amount of calcium carbonate brought into the slag skimmer cabin is expressed as MIN(b, d). Generally speaking, b is less than d. In addition, if a≤e, there is no magnesium hydroxide, otherwise the amount of magnesium hydroxide brought into the slag skimmer cabin is expressed as MIN(ae, c).

[0059] Step 5: setting the threshold concentrations of calcium carbonate and magnesium hydroxide so that the amount of calcium carbonate carried out of the slag skimmer cabin is greater than or equal to the amount of calcium carbonate carried into the slag skimmer cabin, and the amount of magnesium hydroxide carried out of the slag skimmer cabin is greater than or equal to the amount of magnesium hydroxide carried into the slag skimmer cabin.

[0060] In step 5, the amount of calcium carbonate carried out by the slag remover is expressed as (Q yl +Q zs )·α, α is the threshold concentration of calcium carbonate, unit is mg / L; the amount of magnesium hydroxide carried out by the slag machine cabin is expressed as (Q yl +Q zs )·β, β is the threshold concentration of magnesium hydroxide, the unit is mg / L.

[0061] Theoretically, when (overflow water volume + slag water volume) * acceptable concentration of calcium carbonate ≥ calcium carbonate enrichment rate, and (overflow water volume + slag water volume) * acceptable concentration of magnesium hydroxide ≥ magnesium hydroxide enrichment rate, there is no continuous scaling of calcium carbonate and magnesium hydroxide, which can be expressed as:

[0062] (Q yl +Q zs )·α≥MIN(b,d)&(Q yl +Qzs )·β≥MIN(ae,c)

[0063] Step 6: Calculate the economic efficiency based on the water price and select the appropriate water replenishment type.

[0064] In step 6, the water supply includes industrial water, desalted water and RO effluent water, etc. Select one water supply and repeat steps 2 to 5 to obtain Q B Value, water fee = Q B Compare the corresponding water prices and obtain the lowest cost water replenishment.

[0065] Step 7: Dynamically monitor the ion concentration in the slag skimmer cabin and adjust the water replenishment in a timely manner.

[0066] In step 7, continuous flow analysis technology is used to complete colorimetric analysis. The absorbance value of the sample and alkalinity indicator mixture is measured at a specific wavelength. The alkalinity of the actual water sample is calculated by comparing it with a standard substance with known alkalinity. HCO3 is calculated using the alkalinity of methyl orange Ao and the alkalinity of phenolphthalein Ap. - , OH - , CO3 2- Ion concentration, such as Figure 3 As shown, the calcium ion selective electrode method was used to directly measure Ca 2+ and Mg 2+ Ion concentration: if it deviates from the acceptable concentration, increase the water replenishment and overflow flow.

[0067] Step 8: After the overflow slag water enters the overflow tank, it is pumped into the desulfurization area slurry pool by the overflow water pump to serve as water for the desulfurization process. The overflow slag water contains calcium and magnesium ions and is weakly alkaline, which has no effect on the desulfurization system.

[0068] The present invention takes into account that the ions that affect scaling are mainly calcium ions, magnesium ions, carbonate ions, and hydroxide ions. Therefore, according to the quality characteristics of commonly used water and the leaching concentration of slag ions, the enrichment rate of key ions that cause scaling of the slag remover is measured, the initial overflow water volume is calculated, and the scaling rate is evaluated. The corrected water replenishment amount is also calculated to control the concentrations of several key ions that affect scaling in the slag water in the slag remover cabin, thereby reducing the amount of scaling.

[0069] Example 3:

[0070] The slag collecting machine cabin volume of a power plant slag removal system is 140 cubic meters, the slag input is 2.74t / h, the circulating water replenishment is 2.17t / h, the evaporation loss is 0.69t / h, the slag output is 4.22t / h, and the water content is 35%. Figure 4 The quality of commonly used water is shown in Table 2, and the dissolution of slag ions is shown in Figure 5 , carbonate dissolution 39mg / L, hydroxide 10mg / L, calcium ion 260mg / L, magnesium ion 6mg / L.

[0071] Table 2

[0072]

[0073] Changing the makeup water to demineralized water and increasing the overflow rate, as shown in Table 3, assuming an acceptable calcium carbonate concentration of 450 mg / L and an acceptable magnesium hydroxide concentration of 8 mg / L, yields a demineralized makeup rate of 4.17 t / h and an overflow rate of 2 t / h. At a cost of 10 yuan / t for demineralized water, this translates to a cost of 21.7 yuan / h.

[0074] Table 3

[0075]

[0076] Replace the make-up water with circulating water and increase the overflow rate, as shown in Table 4. Assuming the acceptable calcium carbonate concentration is 450 mg / L and the acceptable magnesium hydroxide concentration is 8 mg / L, the calculated circulating water make-up rate is 6.17 t / h and the overflow rate is 4 t / h. At a circulating water cost of 4 yuan / t, the cost is 24.7 yuan / h.

[0077] Table 4

[0078]

[0079] After comparison, it is found that the circulating water can be used as the make-up water and the scale inhibition method of the slag removal system is more economical.

[0080] After adopting this method, the structure rate of the slag removal system is as follows: Figure 6 As shown, it is the acceptable range.

[0081] Example 4:

[0082] Based on Example 3, the make-up water was changed to industrial water and overflow was increased. As shown in Table 5, the acceptable concentration of calcium carbonate was set at 450 mg / L and the acceptable concentration of magnesium hydroxide was set at 8 mg / L. The calculated industrial water make-up rate was 6.17 t / h and the overflow rate was 4 t / h. At 5 yuan / t for industrial water, the cost was 30.9 yuan / h. By comparison, the economic efficiency of using industrial water was not as good as that of circulating water.

[0083] Table 5

[0084]

Claims

1. A method for controlling scaling of a slag removal system of a coal-fired unit, characterized in that: include: Step 1: Calculate the slag amount and water replenishment amount; in step 1, the calculation formula of the slag amount is: M2=M1*10% Among them, M2 represents the amount of slag, and M1 represents the amount of coal commonly used in a specific unit at full output, both in t / h; The formula for calculating the amount of water replenishment is: Q B =Q zs +Q Z +Q yl Among them, Q B Indicates the amount of water replenishment, Q zs Indicates the amount of slag water, Q Z Indicates the amount of evaporated water, Q yl Indicates overflow water volume, the unit is t / h; Step 2: Measure the leaching amount of each ion in the slag by solution leaching method, and measure the content of each ion in the common water replenishment by potentiometric titration and ion chromatography; the ions include OH - ions, CO3 2- ions, Mg 2+ ions, Ca 2+ ions and HCO3 - ions; in step 2, the slag is leached to remove OH - The ion concentration is recorded as C1, and the slag leaching CO3 2- The ion concentration is recorded as C2, and the Mg leached from the slag is 2+ The ion concentration is recorded as C3, and the slag leaching Ca 2+ The ion concentration is recorded as C4; and the water OH - The ion concentration is recorded as C ’ 1. Replenish water CO3 2- The ion concentration is recorded as C ’ 2. Rehydration Mg 2+ The ion concentration is recorded as C ’ 3. Rehydration Ca 2+ The ion concentration is recorded as C ’ 4. Replenish water with HCO3 - The ion concentration is recorded as C ’ 5. The unit is g / kg; Step 3: Calculate the concentration of each ion brought into the slag based on the amount of slag and the amount of water added; In step 3, OH - The ion enrichment rate of ions is expressed as a = M2·C1+Q B ·C ’ 1; CO3 2 The ion enrichment rate of ions is expressed as b = M2·C2+Q B ·C ’ 2;Mg 2+ The ion enrichment rate of ions is expressed as c = M2·C3 + Q B ·C ’ 3; Ca 2+ The ion enrichment rate of ions is expressed as d = M2·C4+Q B ·C ’ 4; HCO3 - The ion enrichment rate of ions is expressed as e = Q B ·C ’ 5; Step 4: Calculate the amount of calcium carbonate and magnesium hydroxide carried into the slag skimmer cabin according to the concentrations of the ions. In step 4, compare the ion enrichment rates of the ions, and express the amount of calcium carbonate carried into the slag skimmer cabin as MIN(b, d). In addition, if a≤e, there is no magnesium hydroxide; otherwise, express the amount of magnesium hydroxide carried into the slag skimmer cabin as MIN(ae, c). Step 5: setting the threshold concentrations of calcium carbonate and magnesium hydroxide so that the amount of calcium carbonate carried out of the slag scoop cabin is greater than or equal to the amount of calcium carbonate carried into the slag scoop cabin, and the amount of magnesium hydroxide carried out of the slag scoop cabin is greater than or equal to the amount of magnesium hydroxide carried into the slag scoop cabin; Step 6: Calculate the economic efficiency based on the water price and select the appropriate water supply type; Step 7: Dynamically monitor the ion concentration in the slag scoop cabin and adjust the water supply in time; Step 8: After the overflow slag water enters the overflow tank, it is pumped into the slurry pool in the desulfurization area through the overflow water pump to serve as water for the desulfurization process.

2. The method for controlling scaling of a slag removal system of a coal-fired unit according to claim 1, characterized in that: In step 5, the amount of calcium carbonate carried out by the slag remover is expressed as (Q yl +Q zs )·α, α is the threshold concentration of calcium carbonate, unit is mg / L; the amount of magnesium hydroxide carried out by the slag machine cabin is expressed as (Q yl +Q zs )·β, β is the threshold concentration of magnesium hydroxide, the unit is mg / L.

3. The method for controlling scaling of a slag removal system of a coal-fired unit according to claim 2, characterized in that: In step 6, the water supply includes industrial water, desalted water and RO effluent water. The water fee is calculated as follows: Water fee = Q B Corresponding water prices.

4. The method for controlling scaling of a slag removal system of a coal-fired unit according to claim 3, characterized in that: In step 7, continuous flow analysis technology is used to complete colorimetric analysis. The absorbance value of the sample and alkalinity indicator mixture is measured at a specific wavelength. The alkalinity of the actual water sample is calculated by comparing it with a standard substance with known alkalinity. HCO3 is calculated using the alkalinity of methyl orange Ao and the alkalinity of phenolphthalein Ap. - , OH - , CO3 2- Ion concentration, Ca is directly measured using a calcium ion selective electrode method 2+ and Mg 2+ Ion concentration: if it deviates from the acceptable concentration, increase the water replenishment and overflow flow.

5. A coal-fired unit slag removal system, characterized in that: The method for controlling scaling inhibition of a slag removal system of a coal-fired unit according to any one of claims 1 to 4 comprises: a slag bin (1), a slag scoop cabin (2), an overflow tank (3) and a desulfurization area slurry tank (4) connected in sequence; The slag scoop cabin (2) is provided with a potentiometric titrator (7) and an overflow port, and is connected to an overflow tank (3) through the overflow port; the overflow tank (3) is provided with a pipeline, and the overflow slag water is transported to the desulfurization area slurry tank (4) through a flow meter (5) and a water pump (6).

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