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CN-116543846-B - Mixed coal blending combustion method and system for relieving ash slagging of heated area of boiler

CN116543846BCN 116543846 BCN116543846 BCN 116543846BCN-116543846-B

Abstract

The invention discloses a mixed coal blending combustion method and system for relieving ash slagging of a heated area of a boiler, which belongs to the technical field of mixed coal blending combustion, and the mixed coal blending combustion step of a coal-fired boiler is specially designed to focus on ash content, na 2 O and K 2 O content data in coal quality data of coal types, the method constructs a calculation model of the maximum alkali metal oxide equivalent value of the combustion boiler and the actual alkali metal oxide equivalent value of the coal, designs constraint conditions of the calculation model in the ash accumulation and slag formation of the coal-fired boiler, and accurately realizes the acquisition and adjustment of the blending and burning proportion of the mixed coal. The blending combustion method and system of the mixed coal are convenient in blending combustion steps and high in operability, can accurately realize blending combustion of the mixed coal in the coal-fired boiler, improve the accuracy of blending combustion control of the mixed coal, ensure the reliability of fuel combustion in the coal-fired boiler, improve the ash accumulation and slag formation degree of a heating surface of the boiler, reduce the shutdown overhaul times of the coal-fired boiler, ensure the reliability and stability of the work of the coal-fired boiler and reduce the operating economic cost of enterprises.

Inventors

  • YE RONG
  • ZHOU WEI
  • HE XIAOYAN
  • Zeng Mingshao

Assignees

  • 江西赣能股份有限公司

Dates

Publication Date
20260508
Application Date
20230424

Claims (9)

  1. 1. The coal blending and burning method for relieving ash and slag bonding in the heated area of the boiler is characterized by comprising the following steps: S1, acquiring design characteristic parameters of a coal-fired boiler and coal quality data of a designed coal, wherein the coal quality data comprises ash content, na 2 O content and K 2 O content; S2, calculating the maximum allowable alkali metal oxide equivalent value of the coal type used by the coal-fired boiler according to the coal quality data of the designed coal type The maximum alkali metal oxide equivalent value Is obtained by the following formula (1): (1) in the formula, Is the maximum alkali metal oxide equivalent value; the safety coefficient of the maximum allowable alkali metal oxide is 1-2; the percentage content of Na 2 O in the coal ash is designed; For designing the percentage content of K 2 O in the coal ash of the coal variety, 0.66 is the molar equivalent ratio of Na 2 O to K 2 O; ash content for designing coal types; The safety margin of the maximum allowable alkali metal oxide is between-20 and 20; s3, acquiring coal quality data of main combustion coal types when the coal-fired boiler is actually used, selecting at least one kind of blended combustion coal types with blending combustion potential with the main combustion coal types, and acquiring the coal quality data of each blended combustion coal type; The actual alkali metal oxide equivalent value J of the corresponding coal type is calculated by using the coal quality data of the coal type, and the calculation process is shown in the following formula (2): (2) in the formula, Is the actual alkali metal oxide equivalent value of coal type X; the percentage content of Na 2 O in the coal type X coal ash is as follows; the percentage content of K 2 O in the coal type X coal ash; ash for coal type X; s4, determining blending data of the main combustion coal types and the blending coal types according to actual alkali metal oxide equivalent values of the main combustion coal types and the blending coal types, and blending the main combustion coal types and a plurality of blending coal types before running according to the blending data to form mixed coal; s5, acquiring coal quality data of the mixed coal, and calculating the actual alkali metal oxide equivalent value of the mixed coal according to the formula (2) And further guiding and adjusting the relevant working conditions of the mixed coal blending combustion according to the calculation result to finish the mixed coal blending combustion process.
  2. 2. The method for blending and burning coal for relieving ash and slag bonding in a heated area of a boiler according to claim 1, wherein in step S4, the blending ratio of each coal type is calculated by the following formula (3): (3) in the formula, The actual alkali metal oxide equivalent value of the main combustion coal; 、 、...、 the actual alkali metal oxide equivalent value of the 1 st, 2 nd, & gt, y th blended coal species, y being an integer not less than 1; the blending proportion of the main combustion coal is 0.4-1.0; 、 、 for the blending ratio of the 1 st, 2 nd, and..the third blended coal seed of the y th blended coal seed, each mixing proportion is smaller than And is between 0 and 0.4 。
  3. 3. The method for blending and burning mixed coal for relieving ash and slag formation in heated area of boiler according to claim 1 or 2, wherein after obtaining coal quality data of mixed coal in step S5, the method is characterized by comprising the step of obtaining the maximum alkali metal oxide equivalent value of the coal-fired boiler And the actual alkali metal oxide equivalent value of the mixed coal Is the difference of (2) Judging the applicability level of the mixed coal relative to the coal-fired boiler, wherein, And the determination mode is as follows: When (when) When the temperature is more than 30, the ash deposition and slag bonding degree of the coal-fired boiler is very slight, and the grade is R 1 ; when 0< When the ash deposition and slag formation degree of the coal-fired boiler is less than or equal to 30, the grade R 2 ; When-30 < When the ash deposition and slag formation degree of the coal-fired boiler is less than or equal to 0, the grade R 3 ; When (when) In the time of-30 a, the method comprises the steps of, the ash deposition and slag formation degree of the coal-fired boiler is very serious, the product is denoted as R 4 .
  4. 4. The method for blending combustion of mixed coal for reducing ash slagging over a heated area of a boiler according to claim 3, wherein in step S5, the applicable grade of the mixed coal corresponding to the coal-fired boiler is adjusted to R 1 grade or R 2 grade.
  5. 5. The mixed coal blending combustion system is characterized in that the mixed coal blending combustion system completes the mixed coal blending combustion in a boiler according to the mixed coal blending combustion method for relieving ash slagging of the heated area of the boiler, which is disclosed by any one of claims 1-4, and comprises: The main combustion coal type storage bin is used for storing main combustion coal types of the boiler; At least one mixed coal seed storage bin for storing mixed coal seeds with mixed combustion potential with main combustion coal seeds; the coal-fired boiler is used for burning the mixed coal; The coal mixing device is respectively connected with the main combustion coal type storage bin and the at least one blending coal type storage bin and is used for respectively feeding the main combustion coal type and the corresponding blending coal type; And the mixed coal quality detection device is arranged corresponding to the conveying device and is used for acquiring mixed coal from the conveying device and detecting coal quality data of the mixed coal.
  6. 6. The blended coal blending combustion system of claim 5, further comprising a coal quality detection device; the coal quality detection device is arranged corresponding to each coal bin and is used for acquiring corresponding coal types from each coal bin and detecting coal quality data of the corresponding coal types.
  7. 7. The blended coal blending combustion system of claim 6, wherein the coal quality detection device and the blended coal quality detection device are the same detection device.
  8. 8. The coal blending combustion system of claim 6 or 7, further comprising a human interaction device; The manual interaction device is respectively connected with the coal mixing device, each coal quality detection device and each coal quality storage bin, and a coal quality data processing module capable of executing steps S2 and S3 is configured in the manual interaction device and is used for obtaining actual alkali metal oxide equivalent values of each coal type and the mixed coal and completing mixed coal blending combustion among the coal types.
  9. 9. The blended coal blending combustion system according to any one of claims 5-7, wherein the conveying device is a belt conveying mechanism; And/or The coal mixing device is a stirring coal mixing device.

Description

Mixed coal blending combustion method and system for relieving ash slagging of heated area of boiler Technical Field The invention belongs to the technical field of mixed coal blending and sintering, and particularly relates to a mixed coal blending and sintering method and system for relieving ash and slag bonding in a heated area of a boiler. Background As is well known, the development of modern society still relies heavily on traditional fossil energy sources, and about 74% of total energy consumption worldwide is statistically derived from primary energy sources such as coal, oil, and gas. In recent years, the consumption total amount of coal, petroleum, natural gas, primary power and other energy sources breaks through 40 hundred million tons of standard coal in China, wherein the coal accounts for about 60% of the consumption total amount of the energy sources. In the future, coal still occupies a very important dominant position in the energy consumption fields of power production, chemical industry and the like for a quite long time. Power station boilers and industrial boilers in China are usually mainly coal-fired, and the coal consumption of the power station boilers and the industrial boilers often deviates from the designed coal types. Under the general condition, the power coal has poor quality, high ash content, high sulfur content and the like, and is easy to form the conditions of pollution, ash accumulation, slag formation, corrosion, abrasion and the like of a heating surface of the boiler. The problems of ash accumulation and slag bonding on the heating surface of the coal-fired boiler are common, and if the problems of ash accumulation and slag bonding on the heating surface of the coal-fired boiler cannot be solved properly, the efficiency of the boiler is reduced, the combustion is deteriorated, and even accidents such as flameout, shutdown and overhaul of the boiler are caused. It is found that the high alkaline element (Na, K, etc.) coal is easier to generate serious ash deposition and slag formation problems in the actual combustion and utilization process, and the Na 2 O and K 2 O content in the alkali metal oxide are often the most main factors causing the ash deposition and slag formation of the boiler. How to alleviate the ash deposition and slag formation of high-alkali coal is an actual engineering problem to be solved currently. The mixed coal blending combustion is one of important ways for solving the problems of shortage of fuel supply, complex and changeable coal types of the coal-fired power station boilers in China and improving the running safety, economy and environmental protection of units. However, most of the power plants in China mainly adopt different coal types to perform mixed combustion by experience at present, randomness and uncertainty are high, and in addition, on-site operators have insufficient knowledge of the combustion state in the furnace, adverse effects on unreasonable proportion mixed combustion are not timely reflected, the boiler is difficult to operate in the optimal combustion state when facing complex and changeable coal types, not only is resource waste caused, but also serious ash accumulation and slag formation of the boiler are extremely easy to occur. Disclosure of Invention Aiming at one or more of the defects or improvement demands of the prior art, the invention provides a coal blending and burning method and system for relieving ash slagging of a heated area of a boiler, which can effectively relieve ash accumulation and slagging of a heated surface of the boiler, improve the burning quality of fire coal and ensure that the boiler operates in a better burning state. In order to achieve the above object, according to one aspect of the present invention, there is provided a coal blending and firing method for reducing ash slagging in a heated area of a boiler, comprising the steps of: S1, acquiring design characteristic parameters of a coal-fired boiler and coal quality data of a designed coal, wherein the coal quality data comprises ash content, na 2 O content and K 2 O content; S2, calculating the maximum allowable alkali metal oxide equivalent value of the coal type used by the coal-fired boiler according to the coal quality data of the designed coal type The maximum alkali metal oxide equivalent valueIs obtained by the following formula (1): (1) in the formula, Is the maximum alkali metal oxide equivalent value; the safety coefficient of the maximum allowable alkali metal oxide is 1-2; the percentage content of Na 2 O in the coal ash is designed; For designing the percentage content of K 2 O in the coal ash of the coal variety, 0.66 is the molar equivalent ratio of Na 2 O to K 2 O; ash content for designing coal types; The safety margin of the maximum allowable alkali metal oxide is between-20 and 20; s3, acquiring coal quality data of main combustion coal types when the coal-fired boiler is actually used, selecting at least