A method for co-processing multi-source solid waste by using household garbage grate furnace

Abstract

The present application relates to a kind of method for disposing multiple-source solid waste by using domestic waste grate furnace, comprising (1) obtaining the optimal mixing ratio of mixed solid waste by multiple-source solid waste mixing ratio analysis technology;(2) converting the optimal mixing ratio into the optimal grab ratio by multiple-source solid waste partition coupling differential volume multi-grab bucket feeding technology;(3) comparing the optimal grab ratio with the actual grab ratio, adjusting the operation mode of primary air and grate by multiple-source solid waste mixing incineration control technology, and carrying out incineration.The present application can adapt to the change of fuel physical properties caused by the mixing of sludge, biogas residue and other municipal solid waste in the existing waste incineration grate furnace, and realize efficient incineration of multiple-source solid waste.

Description

Technical Field

[0001] This invention relates to the field of waste incineration technology, and in particular to a method for co-processing multiple sources of urban solid waste such as sludge and biogas residue using a grate furnace for municipal solid waste incineration. Background Technology

[0002] Currently, the number of publications on urban waste resource recovery worldwide is increasing year by year, and the rate of increase is accelerating. However, the number of publications on the use of grate furnaces for urban waste resource recovery and co-processing shows a downward trend. The reasons for this are as follows: 1. After long-term research, grate furnace incineration technology abroad has become relatively mature and meets application requirements; 2. Waste sorting work is well-implemented, and research has shifted towards more targeted approaches to waste types and higher resource recovery value. Furthermore, the distribution of major patent holders for waste incineration plants in the Derwent Innovations Index patent database shows that the number of patents held by each patent holder is relatively evenly distributed. Hitachi Zosen Corporation, which holds the most patents, owns less than 3% of the total. Other major patent holders include Alstom, Babcock & Wilcox, Mitsubishi Heavy Industries, and Takuma. Hitachi and Mitsubishi, ranking first and second respectively, utilize grate furnace technology from Von Roll (Switzerland) and Martin (Germany). It should be noted that while the patent distribution is relatively even, most patents belong to foreign companies, which aligns with the current situation where my country's waste grate furnace technology is heavily reliant on foreign technology.

[0003] With the introduction of grate furnace technology from companies such as Fengluo (Shanghai Kangheng) and Martin (Chongqing Sanfeng and Everbright International), domestic waste incineration and co-processing technologies have developed rapidly. However, most of these co-processing technologies target binary mixed systems, primarily using municipal sludge or biomass co-fired municipal solid waste. Research and applications targeting three or more types of municipal solid waste have not yet been reported. my country's urbanization process is rapid, and the sources of municipal solid waste are becoming increasingly complex. Therefore, multi-source waste co-processing will be one of the main development directions for waste incineration. However, due to the significant differences in the physical properties and quantities of multi-source waste, if the various processes of waste incineration are not scientifically managed, uneven and unstable combustion, or even incineration failure, may occur. Solving this problem can be achieved by clarifying the physical properties of the waste entering the furnace and the boiler combustion parameters, and by adjusting the waste feeding mode to meet design parameters such as grate combustion rate, bed thermal intensity, and combustion chamber volume heat load, thereby increasing the adaptability of grate furnace technology to the types and quantities of waste, making stable co-firing of multi-source waste possible.

[0004] Existing patents, such as CN114060826A, disclose an automatic combustion control method and control system for an incinerator. This system, through a preset module, optimizes the combustion process by adjusting combustion parameters, including primary air temperature, grate primary air volume, grate section speed, pusher running speed, and waste layer thickness, based on the calorific value of the waste. CN113701160A discloses an ACC automatic combustion control method for waste incineration plants. By estimating the physical properties of the waste entering the furnace, such as density and calorific value, and then using feedback to adjust the combustion control, it achieves complete combustion of waste, improves thermal efficiency, and reduces manual operation intensity while increasing the automatic input rate. CN113266833B discloses a combustion optimization method, system, and device for waste incinerators. Through a correlation model between CO concentration and combustion parameters obtained from historical data, coupled with O2 concentration, it optimizes the combustion system, improving the economic and environmental benefits of waste-to-energy plant operation. CN102927573B discloses an automatic combustion control system for a municipal solid waste incinerator. This system establishes control logic based on heat and material balance, and then adjusts the air distribution and grate operation mode to achieve the goal of high efficiency and low emissions.

[0005] None of the aforementioned patents address the technological updates required for the co-processing of multi-source municipal solid waste, such as sludge and biogas residue. Therefore, there is an urgent need for a new method to co-process multi-source solid waste using a municipal solid waste incinerator grate. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a method for co-processing multi-source solid waste using a municipal solid waste incinerator grate. This invention employs multi-source solid waste co-firing ratio analysis technology, multi-source solid waste zone-coupled differential volume multi-grab bucket feeding technology, and multi-source solid waste co-firing and incineration control technology. This allows the method to adapt to changes in fuel physicochemical properties caused by co-firing municipal solid wastes such as sludge and biogas residue, achieving efficient incineration and disposal of multi-source solid waste.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] This invention provides a method for co-processing multi-source solid waste using a grate furnace in a municipal solid waste incinerator, the method comprising the following steps:

[0009] (1) Obtain the optimal co-firing ratio of co-firing solid waste through multi-source solid waste co-firing ratio analysis technology;

[0010] (2) The optimal co-firing ratio is converted into the optimal grab ratio by multi-grab bucket feeding technology with differential volume coupling of multi-source solid waste zoning;

[0011] (3) By comparing the optimal grab ratio and the actual grab ratio, the operation mode of the primary air and grate is adjusted through multi-source solid waste co-firing and incineration control technology to carry out incineration.

[0012] This invention employs multi-source solid waste co-firing ratio analysis technology, multi-source solid waste zone coupling differential volume multi-grab bucket feeding technology, and multi-source solid waste co-firing and incineration control technology, enabling it to adapt to changes in fuel physicochemical properties caused by co-firing of urban solid wastes such as sludge and biogas residue, thereby achieving efficient incineration and disposal of multi-source solid waste.

[0013] As a preferred technical solution of the present invention, the specific steps of the multi-source solid waste co-firing ratio analysis technology in step (1) include:

[0014] (1-1) Take co-fired solid waste and domestic waste and mix them quantitatively at a ratio of 1:0 to 0:1 to obtain a mixed sample;

[0015] (1-2) The mixed sample was tested using a thermogravimetric scanning calorimeter to obtain the combustion kinetic index; the combustion kinetic index includes the burnout rate index, flammability, and ignition stability index;

[0016] (1-3) Compare the combustion kinetic indices of each blended sample to obtain the optimal blending ratio YC;

[0017] (1-4) Based on the optimal blending ratio YC, industrial analysis was conducted on the co-firing of solid waste and municipal solid waste, and the optimal co-firing ratio calorific value QC and the threshold value QI of the co-firing ratio of waste into the furnace were calculated according to the analysis results. The calculation formulas are shown in Equation 1-2 respectively:

[0018] Formula 1;

[0019] In the formula: QS1 and QS2 are the dry basis calorific values ​​of co-fired solid waste 1 and 2, respectively; WCS1 and WCS2 are the moisture contents of co-fired solid waste 1 and 2, respectively.

[0020] Formula 2;

[0021] In the formula: QM is the calorific value of municipal solid waste; C is the proportion of solid waste mixed in with the incinerator.

[0022] It should be noted that in this invention, the maximum blending ratio is obtained by gradually increasing C from 1% and comparing the corresponding QI value with the required calorific value of the waste entering the furnace.

[0023] As a preferred technical solution of the present invention, the multi-source solid waste partitioned coupling differential volume multi-grab bucket feeding technology in step (2) includes multi-source waste partitioned waste pools and differential volume grab buckets;

[0024] Preferably, the multi-source waste zoning waste pool is provided with multi-source solid waste zoning and homogeneous mixing zone;

[0025] Preferably, the differential volume grab includes a large grab for municipal solid waste and a small grab for co-incinerating solid waste; the volume of the small grab for co-incinerating solid waste is 0.3-0.5 times that of the grab for municipal solid waste, for example, 0.3 times, 0.34 times, 0.38 times, 0.42 times, 0.46 times, 0.5 times, etc., but is not limited to the listed values, and other unlisted values ​​within the above range are also applicable.

[0026] As a preferred technical solution of the present invention, the specific steps of the multi-source solid waste partition coupling differential volume multi-grab bucket feeding technology in step (2) include:

[0027] (2-1) Based on the optimal co-firing ratio and the solid waste disposal requirements, calculate the initial grab bucket ratio and mix the waste into the furnace;

[0028] (2-2) Monitor the flue temperature, pollutant emission concentration of the flue gas emission online monitoring system, and actual steam quality of the boiler within a time period;

[0029] (2-3) Determine whether the flue temperature and pollutant emission concentration meet the standards; if they meet the standards, increase the number of high-calorific-value co-firing solid waste grabs to the initial grab ratio, calculate the calorific value of the waste entering the furnace, and reduce it to below the calorific value requirement of the waste entering the furnace and record the real-time steam quality.

[0030] (2-4) If the temperature of a flue is below standard but the pollutant emission concentration is within standard, the auxiliary combustion system shall be turned on and the number of low-calorific-value garbage grabs shall be reduced; if the pollutant emission concentration is below standard, the control parameters of the environmental protection island shall be adjusted, and if it is still below standard, the co-combustion shall be stopped.

[0031] (2-5) Compare the real-time steam flow rate under different grab bucket ratios, and determine the grab bucket ratio at the maximum steam flow rate as the optimal grab bucket ratio.

[0032] It should be noted that, in step (2-2) of this invention, a time period refers to twice the residence time of the waste on the grate; and in this invention, monitoring the temperature of a flue gas duct refers to monitoring whether the temperature of a flue gas duct meets the national standard requirements for flue gas temperature.

[0033] It should be noted that after obtaining the optimal co-incineration ratio, the optimal grab bucket ratio search method will be input to obtain the executable optimal grab bucket ratio. First, waste from different sources will be stored in separate zones. In order to accurately control the proportion of waste to be co-incinerated, and because the amount to be disposed of is relatively small compared to municipal solid waste, and because it has a high moisture content, it needs to be transported from the zoned waste storage area to the mixing and homogenizing zone using smaller, more airtight grab buckets.

[0034] As a preferred technical solution of the present invention, the calculation formula for calculating the calorific value of the waste fed into the furnace in step (2-3) is shown in Equation 3:

[0035] Formula 3;

[0036] In the formula: S1 and S2 are the proportions of co-fired solid waste 1 and 2, respectively; QI is the dry basis calorific value of the waste fed into the furnace; QM is the dry basis calorific value of municipal solid waste; QS1 and QS2 are the dry basis calorific values ​​of co-fired solid waste 1 and 2, respectively; WCS1 and WCS2 are the moisture contents of co-fired solid waste 1 and 2, respectively.

[0037] As a preferred technical solution of the present invention, the specific steps of the multi-source solid waste co-incineration control technology in step (3) include:

[0038] (3-1) Determine the calorific value type of the waste fed into the furnace based on the amount of steam generated per ton of waste within a time period;

[0039] (3-2) Select the primary air and grate operation mode parameters according to the type of waste fed into the furnace;

[0040] (3-3) Compare the optimal grab ratio and the actual grab ratio, and adjust the operating parameters of the primary air, feeding and combustion grate according to the adjustment method of primary air and grate operation mode;

[0041] (3-4) Input the adjusted operating mode parameters into the automatic combustion control system for execution;

[0042] (3-5) During the adjustment process described in step (3-3), the flue gas temperature and the pollutant emission values ​​of the end flue gas emission online monitoring system are monitored in real time; if the flue gas temperature exceeds the standard, the auxiliary combustion system is turned on; if the pollutant emission values ​​of the end flue gas emission online monitoring system exceed the standard, the environmental protection island equipment parameters are adjusted.

[0043] It should be noted that the method for selecting the primary air and grate operation mode parameters in step (3-2) of this invention is as follows: the calorific value type of the waste is determined based on the ratio of the steam mass generated by the boiler to the amount of waste incinerated in the boiler within a time period (the residence time of the waste on the grate). When the SRM is greater than or equal to 2.3, it is determined to be normal waste (N); otherwise, it is determined to be low-calorific-value waste (L). When it is determined to be low-calorific-value waste, the technology needs to be coupled with the auxiliary combustion system during implementation to avoid the temperature of the dioxin incineration zone being lower than the corresponding standard requirements.

[0044] It should be noted that, based on the primary strategy, this invention will further adjust the strategy by combining the target steam flow rate and combustion conditions with the multi-source solid waste grate and primary air operation mode adjustment method to calculate the primary air volume and grate operating speed. In this adjustment, the sludge and biogas residue mixing ratio influencing factors MP and MG will be introduced to tune the operating parameters, aiming to achieve stable combustion and reduce pollutant concentration emissions.

[0045] As a preferred technical solution of the present invention, after comparing the optimal grab bucket ratio and the actual grab bucket ratio in step (3-3), the calculation formula for the primary air volume PF is shown in Equation 4:

[0046] Equation 4;

[0047] In the formula: FRM is the primary wind coefficient, with a value ranging from 3 to 7 Nm. 3 / ton of waste; WM is the amount of waste fed into the furnace; MP is the adjustment coefficient, with a value range of 1~1.1.

[0048] It should be noted that the primary air volume calculation method in this invention is as follows: First, the amount of waste fed into the furnace is adjusted by the difference between the set steam production (SS) and the actual steam flow rate (RS). Then, the initial primary air volume is determined by coupling the secondary air or circulating flue gas flow rate. Within one waste grate residence time cycle, when the ratio of biogas residue to sludge grab bucket is equal to the optimal grab bucket ratio, MP remains unchanged at 1; otherwise, MP will be adjusted within the range of 1-1.1, and the air volume will increase accordingly.

[0049] As a preferred technical solution of the present invention, after comparing the optimal grab ratio and the actual grab ratio in step (3-3), the formula for calculating the feeding grate movement speed GV is shown in Equation 5:

[0050] Formula 5;

[0051] In the formula: TD is the total stroke required for the feeding grate to advance per hour; AT is the total time required for the feeding grate per hour excluding the forward movement; MG is the adjustment coefficient, with a value range of 0.9~1.

[0052] It should be noted that the calculation method for the feeding grate speed in this invention is as follows: First, the total hourly stroke of the feeding grate is calculated based on the amount of waste fed into the furnace, combined with the thickness and density of the material layer on the grate. Then, the grate operating frequency is determined by combining the stroke of a single grate section. Finally, after subtracting the time for grate retraction and dwell time, the grate operating speed is obtained. Within one waste grate dwell time cycle, when the actual grab ratio is not equal to the optimal grab ratio, MG will be adjusted within the range of 0.9-1. The subsequent grate operating speed will be reduced by no more than 20% from the original speed.

[0053] As a preferred technical solution of the present invention, the calculation formula for the grate operating speed GVL after comparing the optimal grab ratio and the actual grab ratio in step (3-3) is shown in Equation 6:

[0054] Formula 6;

[0055] In the formula: GVO is the basic grate operating speed; ML is the adjustment coefficient, with a value range of 0.8~1.

[0056] As a preferred technical solution of the present invention, in step (3-3) adjusting the operating mode parameters of primary air, feeding and combustion grate, the calculation formulas for the amount of waste entering the furnace WM, the total stroke TD required for the feeding grate to advance per hour, and the total time AT required for the feeding grate per hour excluding the forward movement are respectively shown in Equations 7-9:

[0057] Formula 7;

[0058] In the formula: SS is the set steam flow rate; RS is the actual steam flow rate; SRM is the steam production per ton of waste;

[0059] Formula 8;

[0060] Where: DWM is the density of the waste fed into the furnace; SWM is the cross-sectional area of ​​the waste pushed by the feeding grate;

[0061] Equation 9;

[0062] In the formula: ST is the time the feeding grate needs to stay after each forward movement; BT is the time the feeding grate needs to retreat after each forward movement; SD is the forward stroke of the feeding grate each time.

[0063] Compared with the prior art, the present invention has at least the following beneficial effects:

[0064] This invention employs multi-source solid waste co-firing ratio analysis technology, multi-source solid waste zone coupling differential volume multi-grab bucket feeding technology, and multi-source solid waste co-firing and incineration control technology, enabling it to adapt to changes in fuel physicochemical properties caused by co-firing of urban solid wastes such as sludge and biogas residue, thereby achieving efficient incineration and disposal of multi-source solid waste. Attached Figure Description

[0065] Figure 1 This is a schematic diagram of a device for co-processing multi-source solid waste using a grate furnace incinerator for municipal solid waste, provided by the present invention.

[0066] The components include: 1. Multi-source waste zoned waste pits; 2. Differential volume grab buckets; 3. Adjustable segmented grate and its air supply system; 4. Flue gas emission monitoring system (CEMS); 5. Feeding grate; 6. Flue; and 7. Waste heat boiler.

[0067] Figure 2 This is a flowchart of a method for co-processing multi-source solid waste using a municipal solid waste incinerator grate furnace, as provided by the present invention.

[0068] Figure 3This is a schematic diagram of the multi-source waste partitioning waste pool in the multi-source solid waste partitioning coupling differential volume multi-grab bucket feeding technology of the present invention.

[0069] Figure 4 This is a process flow diagram of the multi-source solid waste co-firing ratio analysis technology in this invention.

[0070] Figure 5 This is a flowchart illustrating the logic of the multi-source solid waste partitioning coupling differential volume multi-grab bucket feeding technology in this invention.

[0071] Figure 6 This is a logic flowchart of the multi-source solid waste co-incineration control technology in this invention.

[0072] Figure 7 This is a logical flowchart of the operation mode of the primary air and grate in this invention.

[0073] Figure 8 This is a graph showing the changes in flammability and ignition stability index with the dosage in this invention. Detailed Implementation

[0074] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0075] Example 1

[0076] This embodiment provides a method for co-processing multi-source solid waste using a municipal solid waste incinerator grate furnace. The apparatus used in this method is as follows: Figure 1 As shown, the system includes a multi-source waste zoning waste pit 1, a differential volume grab bucket 2, an adjustable segmented grate and its air supply system 3, a flue gas emission monitoring system (CEMS) 4, a feeding grate 5, a primary flue 6, and a waste heat boiler 7. The key parameters monitored in the system are collected from the flue gas temperature in the primary flue 6, the pollutant emission concentration in the CEMS 4, and the real-time steam volume in the waste heat boiler 7. The overall flowchart of the method is shown below. Figure 2 As shown;

[0077] Taking a 750t / d waste incineration plant as an example, the solid waste to be co-processed in this project is mainly urban sludge and anaerobic residue from kitchen waste;

[0078] The method includes the following steps:

[0079] (1) Obtain the optimal co-firing ratio of co-firing solid waste through multi-source solid waste co-firing ratio analysis technology;

[0080] (2) The optimal co-firing ratio is converted into the optimal grab ratio by multi-grab bucket feeding technology with differential volume coupling of multi-source solid waste zoning;

[0081] (3) By comparing the optimal grab ratio with the actual grab ratio, the operation mode of the primary air and grate is adjusted through multi-source solid waste co-firing and incineration control technology to carry out incineration;

[0082] The process flow diagram of the multi-source solid waste co-firing ratio analysis technology is as follows: Figure 4 As shown, the specific steps include:

[0083] (1-1) Take co-fired solid waste and domestic waste and mix them quantitatively at a ratio of 1:0 to 0:1 to obtain a mixed sample;

[0084] (1-2) The mixed sample was analyzed using a thermogravimetric scanning calorimeter to obtain combustion kinetic indices, such as... Figure 8 As shown; the combustion kinetics indices include burnout rate index, flammability, and ignition stability index;

[0085] (1-3) By comparing the combustion kinetic indices of each blended sample, the optimal blending ratio YC for co-firing solid waste is obtained; (Comprehensive) Figure 8 The optimal blending ratio that can be obtained from the combustibility index and ignition stability characteristics is the No. 4 blending ratio condition, which corresponds to a blending ratio of 3 (sludge):7 (biogas residue).

[0086] (1-4) Based on the optimal blending ratio YC, industrial analysis was conducted on the co-firing of solid waste and municipal solid waste, and the optimal co-firing ratio calorific value QC and the threshold value QI of the co-firing ratio of waste into the furnace were calculated according to the analysis results. The calculation formulas are shown in Equation 1-2 respectively:

[0087] Formula 1;

[0088] In the formula: QS1 and QS2 are the dry basis calorific values ​​of co-fired solid waste 1 and 2, respectively; WCS1 and WCS2 are the moisture contents of co-fired solid waste 1 and 2, respectively.

[0089] Formula 2;

[0090] In the formula: QM is the calorific value of municipal solid waste; C is the proportion of solid waste mixed in with the incinerator;

[0091] The multi-source solid waste partitioned coupling differential volume multi-grab bucket feeding technology includes a multi-source waste partitioned waste pool and differential volume grab buckets; a schematic diagram of the multi-source waste partitioned waste pool is shown below. Figure 3 As shown;

[0092] The multi-source waste zoning waste pool is equipped with multi-source solid waste zoning and homogeneous mixing zone; the differential volume grab bucket includes a large grab bucket for domestic waste and a small grab bucket for co-incinerated solid waste; the volume of the small grab bucket for co-incinerated solid waste is 0.5 times that of the large grab bucket for domestic waste;

[0093] The logic flowchart of the multi-source solid waste partitioning coupling differential volume multi-grab bucket feeding technology is as follows: Figure 5 As shown, the specific steps include:

[0094] (2-1) Based on the optimal co-firing ratio and the solid waste disposal requirements, calculate the initial grab bucket ratio and mix the waste into the furnace;

[0095] (2-2) Monitor the flue temperature, pollutant emission concentration of the flue gas emission online monitoring system, and actual steam quality of the boiler within a time period;

[0096] (2-3) Determine whether the flue temperature and pollutant emission concentration meet the standards; if they meet the standards, increase the number of high-calorific-value co-firing solid waste grabs to the initial grab ratio, calculate the calorific value of the waste entering the furnace, and reduce it to below the calorific value requirement of the waste entering the furnace and record the real-time steam quality.

[0097] (2-4) If the temperature of a flue is below standard but the pollutant emission concentration is within standard, the auxiliary combustion system shall be turned on and the number of low-calorific-value garbage grabs shall be reduced; if the pollutant emission concentration is below standard, the control parameters of the environmental protection island shall be adjusted, and if it is still below standard, the co-combustion shall be stopped.

[0098] (2-5) Compare the real-time steam flow rate under different grab bucket ratios, and determine the grab bucket ratio at the maximum steam flow rate as the optimal grab bucket ratio;

[0099] By comparing the steam flow rates corresponding to different grab bucket ratios, the optimal grab bucket ratio under the current operating mode is 5 large grab buckets for municipal solid waste (30 tons): 1 small grab bucket for co-firing solid waste (3 tons): 1 large grab bucket (6 tons of biogas residue), with a grab bucket ratio of 6:1.

[0100] The formula for calculating the calorific value of the waste fed into the furnace is shown in Equation 3:

[0101] Formula 3;

[0102] In the formula: S1 and S2 are the proportions of co-fired solid waste 1 and 2, respectively; QI is the dry basis calorific value of the waste fed into the furnace; QM is the dry basis calorific value of municipal solid waste; QS1 and QS2 are the dry basis calorific values ​​of co-fired solid waste 1 and 2, respectively; WCS1 and WCS2 are the moisture contents of co-fired solid waste 1 and 2, respectively.

[0103] The logic flowchart of the multi-source solid waste co-incineration control technology is as follows: Figure 6 As shown, the specific steps include:

[0104] (3-1) Determine the calorific value type of the waste fed into the furnace based on the amount of steam per ton of waste within a time period; select the basic control strategy for air supply and grate based on the calorific value type, and see Table 1 and Table 2 for specific strategies; Table 1 corresponds to the grate furnace system with a single grate angle tilted upwards; Table 2 corresponds to other systems; the combustion section in the table can be divided into two control sections, and the air distribution and residence time ratio of the two sections are both 0.48:0.52, with the former being the combustion section grate closer to the drying section;

[0105] (3-2) Select the primary air and grate operation mode parameters according to the type of waste fed into the furnace;

[0106] (3-3) Compare the optimal grab ratio and the actual grab ratio, and adjust the operating parameters of the primary air, feeding and combustion grate according to the adjustment method of primary air and grate operation mode;

[0107] (3-4) Input the adjusted operating mode parameters into the automatic combustion control system for execution;

[0108] (3-5) During the adjustment process described in step (3-3), the flue gas temperature and the pollutant emission values ​​of the end flue gas emission online monitoring system are monitored in real time; if the flue gas temperature exceeds the standard, the auxiliary combustion system is turned on; if the pollutant emission values ​​of the end flue gas emission online monitoring system exceed the standard, the environmental protection island equipment parameters are adjusted.

[0109] Table 1

[0110]

[0111] Table 2

[0112]

[0113] The method for calculating the primary air volume PF after comparing the optimal grab-bucket ratio and the actual grab-bucket ratio in step (3-3) is as follows: Figure 7 As shown, the calculation formula is as shown in Equation 4:

[0114] Equation 4;

[0115] In the formula: FRM is the primary wind coefficient, with a value ranging from 3 to 7 Nm. 3 / ton of waste; WM is the amount of waste fed into the furnace; MP is the adjustment coefficient, with a value range of 1~1.1;

[0116] The calculation method for the feeding grate speed GV after comparing the optimal grab ratio and the actual grab ratio in step (3-3) is as follows: Figure 7 As shown, the calculation formula is as shown in Equation 5:

[0117] Formula 5;

[0118] Where: TD is the total stroke required for the feeding grate to advance per hour; AT is the total time required for the feeding grate per hour excluding the forward movement; MG is the adjustment coefficient, with a value range of 0.9~1;

[0119] After comparing the optimal grab ratio and the actual grab ratio as described in step (3-3), the formula for calculating the grate operating speed GVL is shown in Equation 6:

[0120] Formula 6;

[0121] In the formula: GVO is the basic grate operating speed; ML is the adjustment coefficient, with a value range of 0.8 to 1;

[0122] The values ​​of adjustment coefficients MP, MG, and ML obtained based on actual combustion effects are shown in Table 3.

[0123] Table 3

[0124]

[0125] In step (3-3), the calculation formulas for the amount of waste fed into the furnace (WM), the total stroke (TD) required for the feeding grate to advance per hour, and the total time (AT) required for the feeding grate per hour excluding the forward movement are shown in Equations 7-9, respectively:

[0126] Formula 7;

[0127] In the formula: SS is the set steam flow rate; RS is the actual steam flow rate; SRM is the steam production per ton of waste;

[0128] Formula 8;

[0129] Where: DWM is the density of the waste fed into the furnace; SWM is the cross-sectional area of ​​the waste pushed by the feeding grate;

[0130] Equation 9;

[0131] In the formula: ST is the time the feeding grate needs to stay after each forward movement; BT is the time the feeding grate needs to retreat after each forward movement; SD is the forward stroke of the feeding grate each time.

[0132] In summary, this invention provides a method for co-processing multi-source solid waste using a municipal solid waste incinerator grate. By employing multi-source solid waste co-firing ratio analysis technology, multi-source solid waste zone coupling differential volume multi-grab bucket feeding technology, and multi-source solid waste co-firing and incineration control technology, it can adapt to the changes in fuel physicochemical properties caused by the co-firing of urban solid waste such as sludge and biogas residue, thereby achieving efficient incineration and disposal of multi-source solid waste.

[0133] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for co-processing multi-source solid waste using a grate furnace in a municipal solid waste incinerator, characterized in that, The method includes the following steps: (1) Obtain the optimal co-firing ratio of co-firing solid waste through multi-source solid waste co-firing ratio analysis technology; (2) The optimal co-firing ratio is converted into the optimal grab ratio by multi-grab bucket feeding technology with differential volume coupling of multi-source solid waste zoning; (3) By comparing the optimal grab ratio and the actual grab ratio, the operation mode of the primary air and grate is adjusted through multi-source solid waste co-firing and incineration control technology to carry out incineration.

2. The method according to claim 1, characterized in that, The specific steps of the multi-source solid waste co-combustion ratio analysis technology described in step (1) include: (1-1) Take co-fired solid waste and domestic waste and mix them quantitatively at a ratio of 1:0 to 0:1 to obtain a mixed sample; (1-2) The mixed sample was tested using a thermogravimetric scanning calorimeter to obtain the combustion kinetic index; the combustion kinetic index includes the burnout rate index, flammability, and ignition stability index; (1-3) Compare the combustion kinetic indices of each blended sample to obtain the optimal blending ratio YC; (1-4) Based on the optimal blending ratio YC, industrial analysis was conducted on the co-firing of solid waste and municipal solid waste, and the optimal co-firing ratio calorific value QC and the threshold value QI of the co-firing ratio of waste into the furnace were calculated according to the analysis results. The calculation formulas are shown in Equation 1-2 respectively: Formula 1; In the formula: QS1 and QS2 are the dry basis calorific values ​​of co-fired solid waste 1 and 2, respectively; WCS1 and WCS2 are the moisture contents of co-fired solid waste 1 and 2, respectively. Formula 2; In the formula: QM is the calorific value of municipal solid waste; C is the proportion of solid waste mixed in with the incinerator.

3. The method according to claim 1 or 2, characterized in that, The multi-source solid waste partitioned coupling differential volume multi-grab bucket feeding technology described in step (2) includes multi-source waste partitioned waste pools and differential volume grab buckets; Preferably, the multi-source waste zoning waste pool is provided with multi-source solid waste zoning and homogeneous mixing zone; Preferably, the differential volume grab includes a large grab for municipal solid waste and a small grab for co-incinerating solid waste; the volume of the small grab for co-incinerating solid waste is 0.3-0.5 times that of the grab for municipal solid waste.

4. The method according to any one of claims 1-3, characterized in that, The specific steps of the multi-source solid waste zone coupling differential volume multi-grab bucket feeding technology described in step (2) include: (2-1) Based on the optimal co-firing ratio and the solid waste disposal requirements, calculate the initial grab bucket ratio and mix the waste into the furnace; (2-2) Monitor the flue temperature, pollutant emission concentration of the flue gas emission online monitoring system, and actual steam quality of the boiler within a time period; (2-3) Determine whether the flue temperature and pollutant emission concentration meet the standards; if they meet the standards, increase the number of high-calorific-value co-firing solid waste grabs to the initial grab ratio, calculate the calorific value of the waste entering the furnace, and reduce it to below the calorific value requirement of the waste entering the furnace and record the real-time steam quality. (2-4) If the temperature of a flue is below standard but the pollutant emission concentration is within standard, the auxiliary combustion system shall be turned on and the number of low-calorific-value garbage grabs shall be reduced; if the pollutant emission concentration is below standard, the control parameters of the environmental protection island shall be adjusted, and if it is still below standard, the co-combustion shall be stopped. (2-5) Compare the real-time steam flow rate under different grab bucket ratios, and determine the grab bucket ratio at the maximum steam flow rate as the optimal grab bucket ratio.

5. The method according to claim 4, characterized in that, The formula for calculating the calorific value of the waste fed into the furnace in step (2-3) is shown in Equation 3: Formula 3; In the formula: S1 and S2 are the proportions of co-fired solid waste 1 and 2, respectively; QI is the dry basis calorific value of the waste fed into the furnace; QM is the dry basis calorific value of municipal solid waste; QS1 and QS2 are the dry basis calorific values ​​of co-fired solid waste 1 and 2, respectively; WCS1 and WCS2 are the moisture contents of co-fired solid waste 1 and 2, respectively.

6. The method according to any one of claims 1-5, characterized in that, The specific steps of the multi-source solid waste co-incineration control technology described in step (3) include: (3-1) Determine the calorific value type of the waste fed into the furnace based on the amount of steam generated per ton of waste within a time period; (3-2) Select the primary air and grate operation mode parameters according to the type of waste fed into the furnace; (3-3) Compare the optimal grab ratio and the actual grab ratio, and adjust the operating parameters of the primary air, feeding and combustion grate according to the adjustment method of primary air and grate operation mode; (3-4) Input the adjusted operating mode parameters into the automatic combustion control system for execution; (3-5) During the adjustment process described in step (3-3), the flue gas temperature and the pollutant emission values ​​of the end flue gas emission online monitoring system are monitored in real time; if the flue gas temperature exceeds the standard, the auxiliary combustion system is turned on; if the pollutant emission values ​​of the end flue gas emission online monitoring system exceed the standard, the environmental protection island equipment parameters are adjusted.

7. The method according to any one of claims 1-6, characterized in that, After comparing the optimal grab-bucket ratio and the actual grab-bucket ratio as described in step (3-3), the formula for calculating the primary air volume PF is shown in Equation 4: Equation 4; In the formula: FRM is the primary wind coefficient, with a value ranging from 3 to 7 Nm. 3 / ton of waste; WM is the amount of waste fed into the furnace; MP is the adjustment coefficient, with a value range of 1~1.

1.

8. The method according to any one of claims 1-7, characterized in that, After comparing the optimal grab ratio and the actual grab ratio as described in step (3-3), the formula for calculating the feed grate speed GV is shown in Equation 5: Formula 5; In the formula: TD is the total stroke required for the feeding grate to advance per hour; AT is the total time required for the feeding grate per hour excluding the forward movement; MG is the adjustment coefficient, with a value range of 0.9~1.

9. The method according to any one of claims 1-8, characterized in that, After comparing the optimal grab ratio and the actual grab ratio as described in step (3-3), the formula for calculating the grate operating speed GVL is shown in Equation 6: Formula 6; In the formula: GVO is the basic grate operating speed; ML is the adjustment coefficient, with a value range of 0.8~1.

10. The method according to any one of claims 1-9, characterized in that, In step (3-3), the calculation formulas for the amount of waste fed into the furnace (WM), the total stroke (TD) required for the feeding grate to advance per hour, and the total time (AT) required for the feeding grate per hour excluding the forward movement are shown in Equations 7-9, respectively: Formula 7; In the formula: SS is the set steam flow rate; RS is the actual steam flow rate; SRM is the steam production per ton of waste; Formula 8; Where: DWM is the density of the waste fed into the furnace; SWM is the cross-sectional area of ​​the waste pushed by the feeding grate; Equation 9; In the formula: ST is the time the feeding grate needs to stay after each forward movement; BT is the time the feeding grate needs to retreat after each forward movement; SD is the forward stroke of the feeding grate each time.

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