Boiler combustion optimization system

Abstract

The invention provides a boiler combustion optimization system, and relates to the technical field of boiler combustion optimization, and the system comprises a parameter generation module which is used for generating actual combustion parameters according to the target generation power of a thermal power generating unit; the air supply control module obtains basic primary air flow and basic secondary air flow through an air volume prediction model based on the actual combustion parameters; the analysis and correction module is used for analyzing the dust deposition condition on the heating surface of the boiler and correcting the basic primary air flow and the basic secondary air flow; the data monitoring module is used for collecting actual smoke monitoring parameters of the boiler in the current operation state, and if any smoke monitoring parameter exceeds the allowable range, actual combustion parameters are regenerated; and the range control module is used for generating an allowable adjustment range of each parameter according to the boiler structure. The combustion process is corrected according to the accumulated dust on the heating surface of the boiler, the control accuracy of the combustion process of the boiler is improved, and therefore the stable combustion optimization effect is kept in different boiler states.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler combustion optimization, and particularly relates to a boiler combustion optimization system. Background Art

[0002] At present, thermal power generation is still the main source of electricity in China. The combustion optimization of boilers is an important technical means for thermal power units to achieve energy conservation and emission reduction. With the development of the informatization construction of the power industry, the thermal control systems of most combustion equipment in China are basically equipped with distributed control systems (DCS) to monitor and alarm during equipment operation, collect data, and achieve automatic control of the units.

[0003] In the existing combustion optimization systems, when performing combustion optimization, only input and output variables are often monitored, such as fuel flow rate, air flow rate, flue gas composition, etc., lacking the monitoring of the boiler state, such as the ash accumulation situation of the boiler. After the boiler has been used for a period of time, the actual optimization effect is difficult to reach the expected effect. Summary of the Invention

[0004] The present invention provides a boiler combustion optimization system to solve the defect in the prior art that there is a lack of monitoring of the boiler state, such as the ash accumulation situation of the boiler, and after the boiler has been used for a period of time, the actual optimization effect is difficult to reach the expected effect.

[0005] On the one hand, the present invention provides a boiler combustion optimization system, including:

[0006] A parameter generation module, configured to generate actual combustion parameters according to the target power generation of a thermal power unit, where the combustion parameters include: coal sample ratio, fuel composition, and input flow rate of the fuel;

[0007] An air supply control module, obtaining the basic primary air flow rate and the basic secondary air flow rate through an air volume prediction model based on the actual combustion parameters;

[0008] An analysis and correction module, configured to analyze the ash accumulation situation on the boiler heating surface and correct the basic primary air flow rate and the basic secondary air flow rate to obtain the actual primary air flow rate and the actual secondary air flow rate;

[0009] A data monitoring module, configured to collect the actual flue gas monitoring parameters of the boiler under the current operating state. If any one of the flue gas monitoring parameters exceeds the corresponding allowable range, the actual combustion parameters are regenerated;

[0010] A range control module, configured to generate the allowable adjustment ranges of the combustion parameters, the primary air flow rate, and the secondary air flow rate according to the boiler structure.

[0011] Preferably, the parameter generation module includes:

[0012] A target acquisition unit for acquiring the target power generation of a thermal power unit;

[0013] A fuel control unit for selecting a suitable actual coal blending plan and generating a corresponding fuel input flow rate, and generating actual combustion parameters.

[0014] Preferably, the fuel control unit includes:

[0015] A database establishment subunit for acquiring coal storage information and establishing a coal blending database by pre-configuring several preset coal blending plans based on the coal storage information;

[0016] A plan selection subunit for selecting the preset coal blending plan with the lowest cost price from the coal blending database as the pending coal blending plan based on the current tail gas treatment capacity;

[0017] A flow rate calculation subunit for calculating the fuel input flow rate based on the target power generation of the thermal power unit and the pending coal blending plan;

[0018] Among them, V m is the fuel input flow rate; P e is the target power generation of the thermal power unit; η is the thermal energy utilization rate of the thermal power unit; R m is the lower calorific value of the pending coal blending plan;

[0019] A flow rate verification unit for verifying whether the fuel input flow rate is within the allowable adjustment range. If the fuel input flow rate is within the allowable adjustment range, actual combustion parameters are generated according to the actual coal blending plan and the corresponding fuel input flow rate; otherwise, a new pending coal blending plan is selected.

[0020] Preferably, the air supply control module includes:

[0021] A model establishment unit for establishing an air volume prediction model;

[0022] A result output unit for sequentially inputting the actual combustion parameters into the air volume prediction model and automatically generating the basic primary air flow rate and the basic secondary air flow rate through the air volume prediction model.

[0023] Preferably, the fuel composition refers to the volatile matter, ash content, sulfur content, and nitrogen content of the coal sample. The model establishment subunit establishes the air volume prediction model based on the following method, including:

[0024] Step 1: Acquire several groups of historical combustion parameters of the boiler and the corresponding flue gas monitoring parameters;

[0025] Step 2: Screen out the historical combustion parameters with all flue gas monitoring parameters less than the preset screening threshold as the qualified data set;

[0026] Step 3: Based on the qualified data set, train the simulation model to generate an air volume prediction model.

[0027] Preferably, the analysis and correction module includes:

[0028] The ash accumulation monitoring unit is used to obtain the ash accumulation thickness of the boiler heating surface;

[0029] The alarm unit gives an ash cleaning alarm when the ash accumulation thickness of the boiler heating surface is greater than the preset dangerous ash accumulation thickness;

[0030] The judgment unit is used to judge whether the ash accumulation thickness of the boiler heating surface is greater than the preset influencing ash accumulation thickness. If the ash accumulation thickness of the boiler heating surface is greater than the preset influencing ash accumulation thickness, correct the basic primary air flow rate and the basic secondary air flow rate. Otherwise, use the basic primary air flow rate and the basic secondary air flow rate as the actual primary air flow rate and the actual secondary air flow rate;

[0031] The flow rate adjustment unit is used to correct the basic primary air flow rate and the basic secondary air flow rate to obtain the actual primary air flow rate and the actual secondary air flow rate;

[0032] The air volume verification unit is used to verify whether the actual primary air flow rate and the actual secondary air flow rate are within the corresponding allowable ranges. If both are within the corresponding allowable ranges, supply the primary air and the secondary air according to the actual primary air flow rate and the actual secondary air flow rate. Otherwise, perform auxiliary optimization;

[0033] The auxiliary optimization unit is used to execute the auxiliary optimization method.

[0034] Preferably, the flow rate adjustment unit obtains the actual primary air flow rate and the actual secondary air flow rate based on the following formula;

[0035] V f1 = V f10 [1 + k1(D s - D z )]; where, V f1 is the actual primary air flow rate; V f10 is the basic primary air flow rate; k1 is the influence coefficient of the ash accumulation thickness of the primary air; D s is the actual ash accumulation thickness of the boiler heating surface; D z is the preset influencing ash accumulation thickness;

[0036] V f2 = V f20 [1 + k2(D s - D z )]; where, V f2 is the actual secondary air flow rate; V f20 is the basic secondary air flow rate; k2 is the influence coefficient of the ash accumulation thickness of the secondary air; D sis the actual ash fouling thickness of the boiler heating surface; D z is the preset ash fouling thickness affecting factor.

[0037] Preferably, the auxiliary optimization method includes: introducing a combustion promoter or regenerating the actual combustion parameters. The auxiliary optimization unit includes:

[0038] A combustion promotion evaluation sub-unit, used to output a combustion promotion evaluation result, and the combustion promotion evaluation result includes achievable and unachievable;

[0039] A scheme selection sub-unit, used to select an auxiliary optimization scheme.

[0040] Preferably, the combustion promotion evaluation sub-unit includes:

[0041] A first parameter calculation block, used to calculate combustion promotion evaluation parameters, and the combustion promotion evaluation parameters include a first combustion promotion evaluation parameter and a second combustion promotion evaluation parameter;

[0042] wherein, T1 is the first combustion promotion evaluation parameter; V f10 is the basic primary air flow rate; V f1b is the upper limit value of the allowable range of the primary air flow rate; R1 is the preset maximum allowable overrun ratio of the primary air flow rate; is the floor function symbol;

[0043] wherein, T2 is the second combustion promotion evaluation parameter; V f20 is the basic secondary air flow rate; V f2b is the upper limit value of the allowable range of the secondary air flow rate; R2 is the preset maximum allowable overrun ratio of the secondary air flow rate;

[0044] A result output block, used to determine the combustion promotion evaluation result based on the combustion promotion evaluation parameters. If any one of the first combustion promotion evaluation parameter and the second combustion promotion evaluation parameter is greater than 0, the combustion promotion evaluation result is unachievable, otherwise the combustion promotion evaluation result is achievable.

[0045] Preferably, the scheme selection sub-unit includes:

[0046] A first judgment block. If the combustion promotion evaluation result is unachievable, the selection of the auxiliary optimization scheme is to regenerate the actual combustion parameters. Otherwise, calculate the selection evaluation parameter and select the auxiliary optimization scheme based on the selection evaluation parameter;

[0047] A second parameter calculation block, used to calculate the selection evaluation parameter;

[0048] wherein, P is the selection evaluation parameter; ln is the natural logarithm function with base e; e is the natural constant; V rThe required addition flow rate of the combustion improver; V0 is the unit flow rate; α and β are the weighted influence coefficients of the usage cost and the optimizable range respectively; B1 is the cost per unit volume of the combustion improver; t0 is the unit time; B2 is the cost per unit volume of the current coal blending scheme in use; V m is the fuel input flow rate corresponding to the current coal blending scheme in use; B3 is the cost per unit volume of the alternative coal blending scheme; V mx is the fuel input flow rate corresponding to the alternative coal blending scheme; B s is the preset cost difference reference value; M is the number of types of flue gas monitoring parameters; G i0 is the upper limit value of the allowable range of the i-th flue gas monitoring parameter; G i is the actual value of the i-th flue gas monitoring parameter; D s is the actual ash fouling thickness of the boiler heating surface; D z is the preset influence on the ash fouling thickness;

[0049] When the selected evaluation parameter is greater than the preset judgment threshold, the selection of the auxiliary optimization scheme is to regenerate the actual combustion parameters; otherwise, the selection of the auxiliary optimization scheme is to introduce the combustion improver.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The primary air flow rate and the secondary air flow rate are corrected according to the ash fouling on the boiler heating surface, thereby improving the air supply effect of the boiler, promoting the complete combustion of coal, and judging whether to regenerate the actual combustion parameters by monitoring the state of the flue gas. When the actual combustion state is excellent, there is no need to modify the actual combustion parameters, thereby reducing the number of modifications to the actual combustion parameters and ensuring the stability of the combustion state. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0053] Figure 1 is a schematic structural diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] To make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0055] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes, and do not particularly refer to the meaning of order or sequence, nor are they used to limit the present invention. They are merely used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions and technical features between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0056] Embodiment 1

[0057] An embodiment of the present invention provides a boiler combustion optimization system, including:

[0058] A parameter generation module, configured to generate actual combustion parameters according to the target power generation of a thermal power unit, where the combustion parameters include: coal sample ratio, fuel composition, and input flow rate of the fuel;

[0059] An air supply control module, configured to obtain a basic primary air flow rate and a basic secondary air flow rate through an air volume prediction model based on the actual combustion parameters;

[0060] An analysis and correction module, configured to analyze the ash accumulation on the boiler heating surface and correct the basic primary air flow rate and the basic secondary air flow rate to obtain an actual primary air flow rate and an actual secondary air flow rate;

[0061] A data monitoring module, configured to collect actual flue gas monitoring parameters of the boiler under the current operating state. If any flue gas monitoring parameter exceeds the corresponding allowable range, the actual combustion parameters are regenerated;

[0062] A range control module, configured to generate allowable adjustment ranges of the combustion parameters, the primary air flow rate, and the secondary air flow rate according to the boiler structure.

[0063] In this embodiment, the flue gas monitoring parameters include: exhaust gas temperature, fly ash combustible content, nitrogen oxide content in the flue gas, sulfide content in the flue gas, oxygen content in the flue gas, and carbon dioxide content in the flue gas.

[0064] In this embodiment, the primary air flow rate refers to the amount of air blown into the burner by the blower.

[0065] In this embodiment, the secondary air flow rate refers to the amount of air sent into the furnace to provide the oxygen required in the later stage of fuel combustion.

[0066] The beneficial effects of the above technical solutions are as follows:

[0067] The primary air flow rate and the secondary air flow rate are corrected according to the ash deposition on the boiler heating surface, so as to improve the air supply effect of the boiler, thereby promoting the complete combustion of coal. By monitoring the state of the flue gas, it is judged whether to regenerate the actual combustion parameters. In the case of excellent actual combustion state, there is no need to modify the actual combustion parameters, thus reducing the number of modifications to the actual combustion parameters and ensuring the stability of the combustion state.

[0068] Embodiment 2

[0069] On the basis of Embodiment 1, the parameter generation module includes:

[0070] A target acquisition unit for acquiring the target power generation of the thermal power unit;

[0071] A fuel control unit for selecting a suitable actual coal blending plan and generating the corresponding fuel input flow rate to generate actual combustion parameters.

[0072] Preferably, the fuel control unit includes:

[0073] A database establishment sub-unit for acquiring coal storage information and establishing a coal blending database by pre-configuring several preset coal blending plans based on the coal storage information;

[0074] A plan selection sub-unit for selecting the preset coal blending plan with the lowest cost price from the coal blending database as the pending coal blending plan based on the current tail gas treatment capacity;

[0075] A flow rate calculation sub-unit for calculating the fuel input flow rate based on the target power generation of the thermal power unit and the pending coal blending plan;

[0076] Among them, V m is the fuel input flow rate; P e is the target power generation of the thermal power unit; η is the thermal energy utilization rate of the thermal power unit; R m is the low calorific value of the pending coal blending plan;

[0077] A flow rate verification unit is used to verify whether the fuel input flow rate is within the allowable adjustment range. If the fuel input flow rate is within the allowable adjustment range, actual combustion parameters are generated based on the actual coal blending plan and the corresponding fuel input flow rate; otherwise, a pending coal blending plan is reselected.

[0078] In this embodiment, the thermal energy utilization rate of the thermal power unit is the proportion of the effective utilization of the chemical energy of the fuel during the process of converting fossil fuels (such as coal, natural gas, etc.) into electric energy in the thermal power plant. The thermal energy utilization rate of the thermal power unit is a preset value obtained based on pre - conducted test experiments.

[0079] In this embodiment, the coal material storage information includes the type of coal material, the price of coal material, and the corresponding coal material storage quantity.

[0080] In this embodiment, the lower calorific value refers to the heat released per unit mass of fuel when it is completely burned, after deducting the latent heat of vaporization of water vapor in the flue gas.

[0081] In this embodiment, the coal sample ratio refers to the doping ratio of different coal types in the fuel.

[0082] The beneficial effects of the above - mentioned technical solution are as follows:

[0083] By taking the coal blending plan selection order from low to high cost price, on the premise of ensuring the safe and stable operation of the power generation system and meeting the environmental protection parameters of flue gas emissions, it realizes reducing the price of incoming coal in thermal power plants, reducing the power generation cost, and improving the competitiveness of the enterprise. By verifying whether the input flow rate of the fuel is within the allowable adjustment range, it avoids the situation that the input flow rate of the fuel is too large and exceeds the maximum combustion speed of the boiler, resulting in incomplete combustion of some fuel and affecting the fuel utilization efficiency.

[0084] Embodiment 3

[0085] Based on any one of Embodiments 1 - 2, the air supply control module includes:

[0086] A model establishment unit is used to establish an air volume prediction model;

[0087] A result output unit is used to input the actual combustion parameters into the air volume prediction model in sequence, and automatically generate the basic primary air flow rate and the basic secondary air flow rate through the air volume prediction model.

[0088] Preferably, the fuel composition refers to the volatile matter, ash content, sulfur content, and nitrogen content of the coal sample. The model establishment subunit establishes the air volume prediction model based on the following method, including:

[0089] Step 1: Obtain several groups of historical combustion parameters of the boiler and the corresponding flue gas monitoring parameters;

[0090] Step 2: Screen out the historical combustion parameters where all flue gas monitoring parameters are less than the preset screening threshold as the qualified data set;

[0091] Step 3: Based on the qualified data set, perform simulation model training to generate a primary air flow prediction model.

[0092] The beneficial effects of the above technical solution are as follows:

[0093] By screening out the data with excellent combustion effects in the historical data as the qualified data set and performing model training based on the qualified data set to generate a primary air flow prediction model, it is ensured that the basic primary air flow and basic secondary air flow determined based on the output result of the primary air flow prediction model can maintain excellent combustion effects, improving the accuracy of the output result of the primary air flow prediction model and ensuring excellent combustion optimization effects.

[0094] Example 4

[0095] On the basis of any one of Examples 1 - 3, the analysis and correction module includes:

[0096] An ash deposition monitoring unit for obtaining the ash deposition thickness of the boiler heating surface;

[0097] An alarm unit for giving an ash cleaning alarm when the ash deposition thickness of the boiler heating surface is greater than the preset dangerous ash deposition thickness;

[0098] A judgment unit for judging whether the ash deposition thickness of the boiler heating surface is greater than the preset influencing ash deposition thickness. If the ash deposition thickness of the boiler heating surface is greater than the preset influencing ash deposition thickness, correct the basic primary air flow and basic secondary air flow, otherwise use the basic primary air flow and basic secondary air flow as the actual primary air flow and actual secondary air flow;

[0099] A flow rate adjustment unit for correcting the basic primary air flow and basic secondary air flow to obtain the actual primary air flow and actual secondary air flow;

[0100] A primary air flow verification unit for verifying whether the actual primary air flow and actual secondary air flow are within the corresponding allowable ranges. If both are within the corresponding allowable ranges, supply the primary air and secondary air according to the actual primary air flow and actual secondary air flow, otherwise, perform auxiliary optimization;

[0101] An auxiliary optimization unit for executing the auxiliary optimization method.

[0102] Preferably, the flow rate adjustment unit obtains the actual primary air flow and actual secondary air flow based on the following formula;

[0103] V f1 =V f10 [1 + k1(D s -Dz )]; where, V f1 is the actual primary air flow rate; V f10 is the basic primary air flow rate; k1 is the influence coefficient of the ash accumulation thickness of the primary air; D s is the actual ash accumulation thickness of the boiler heating surface; D z is the preset influence ash accumulation thickness;

[0104] V f2 = V f20 [1 + k2(D s - D z )]; where, V f2 is the actual secondary air flow rate; V f20 is the basic secondary air flow rate; k2 is the influence coefficient of the ash accumulation thickness of the secondary air; D s is the actual ash accumulation thickness of the boiler heating surface; D z is the preset influence ash accumulation thickness.

[0105] Preferably, the auxiliary optimization method includes: introducing a combustion improver or regenerating the actual combustion parameters, and the auxiliary optimization unit includes:

[0106] a combustion assistance evaluation sub-unit for outputting a combustion assistance evaluation result, and the combustion assistance evaluation result includes achievable and unachievable;

[0107] a scheme selection sub-unit for selecting an auxiliary optimization scheme.

[0108] In this embodiment, both the influence coefficient of the ash accumulation thickness of the primary air and the influence coefficient of the ash accumulation thickness of the secondary air are obtained by fitting after simulation experiments, and the values are both greater than 0 and less than 1.

[0109] In this embodiment, the combustion assistance evaluation result is an evaluation result of whether the method of introducing a combustion improver is feasible.

[0110] In this embodiment, the influence ash accumulation thickness is the minimum ash accumulation thickness when it will have a significant impact on the combustion effect.

[0111] The beneficial effects of the above technical solutions are;

[0112] By correcting the basic primary air flow rate and the basic secondary air flow rate based on the ash accumulation degree of the boiler heating surface, the primary air flow rate and the secondary air flow rate are adjusted according to the ash accumulation situation of the boiler, the fuel combustion efficiency is improved, the fuel reaches the preset combustion effect, and thus energy waste is reduced.

[0113] When the supply amounts of the primary air and the secondary air cannot reach the actual primary air flow rate and the actual secondary air flow rate, by adopting the auxiliary optimization method, the combustion effect inside the boiler is assisted and optimized, and the optimization degree of the combustion effect inside the boiler is improved.

[0114] Example 5

[0115] Based on Example 4, the combustion-supporting evaluation subunit includes:

[0116] The first parameter calculation block is used to calculate the combustion-supporting evaluation parameters, and the combustion-supporting evaluation parameters include the first combustion-supporting evaluation parameter and the second combustion-supporting evaluation parameter;

[0117] Among them, T1 is the first combustion-supporting evaluation parameter; V f10 is the basic primary air flow rate; V f1b is the upper limit value of the allowable range of the primary air flow rate; R1 is the maximum allowable overrun ratio of the preset primary air flow rate; is the floor function symbol;

[0118] Among them, T2 is the second combustion-supporting evaluation parameter; V f20 is the basic secondary air flow rate; V f2b is the upper limit value of the allowable range of the secondary air flow rate; R2 is the maximum allowable overrun ratio of the preset secondary air flow rate;

[0119] The result output block is used to determine the combustion-supporting evaluation result based on the combustion-supporting evaluation parameters. If any one of the first combustion-supporting evaluation parameter and the second combustion-supporting evaluation parameter is greater than 0, the combustion-supporting evaluation result is unachievable, otherwise the combustion-supporting evaluation result is achievable.

[0120] Preferably, the scheme selection subunit includes:

[0121] The first judgment block. If the combustion-supporting evaluation result is unachievable, the selection of the auxiliary optimization scheme is to regenerate the actual combustion parameters. Otherwise, calculate the selection evaluation parameters and select the auxiliary optimization scheme based on the selection evaluation parameters;

[0122] The second parameter calculation block is used to calculate the selection evaluation parameters;

[0123] Among them, P is the selection evaluation parameter; ln is the natural logarithm function with base e; e is the natural constant; V r is the required addition flow rate of the combustion improver; V0 is the unit flow rate; α and β are the weighted influence coefficients of the usage cost and the optimizable range respectively; B1 is the cost per unit volume of the combustion improver; t0 is the unit duration; B2 is the cost per unit volume of the current coal blending scheme used; V m is the fuel input flow rate corresponding to the current coal blending scheme used; B3 is the cost per unit volume of the alternative coal blending scheme; V mx is the fuel input flow rate corresponding to the alternative coal blending scheme; B s is the preset cost difference reference value; M is the number of types of flue gas monitoring parameters; G i0is the upper limit value of the allowable range of the i-th flue gas monitoring parameter; G i is the actual value of the i-th flue gas monitoring parameter; D s is the actual ash fouling thickness of the boiler heating surface; D z is the preset influence ash fouling thickness;

[0124] When the selected evaluation parameter is greater than the preset judgment threshold, the selection of the auxiliary optimization scheme is to regenerate the actual combustion parameters, otherwise the selection of the auxiliary optimization scheme is to inject a combustion improver.

[0125] In this embodiment, the cost difference benchmark value is the preset cost benchmark value used to judge the cost difference degree between injecting a combustion improver and regenerating the actual combustion parameters.

[0126] In this embodiment, the maximum allowable overrun ratio of the primary air flow rate refers to the ratio within which the primary air flow rate exceeds the upper limit value of the allowable range of the primary air flow rate, and the combustion effect can be achieved by adding a combustion improver. The maximum allowable overrun ratio of the primary air flow rate is obtained by analyzing the experimental results after a simulation experiment.

[0127] In this embodiment, the maximum allowable overrun ratio of the secondary air flow rate refers to the ratio within which the secondary air flow rate exceeds the upper limit value of the allowable range of the secondary air flow rate, and the combustion effect can be achieved by adding a combustion improver. The maximum allowable overrun ratio of the secondary air flow rate is obtained by analyzing the experimental results after a simulation experiment.

[0128] In this embodiment, the required injection flow rate of the combustion improver is estimated by the staff according to an empirical formula, and the empirical formula is obtained by fitting the experimental data obtained from experiments.

[0129] The beneficial effects of the above technical solutions are:

[0130] By calculating the combustion improver evaluation parameter, it is determined whether the method of injecting a combustion improver can achieve the target combustion effect, thereby determining the feasibility of the method of injecting a combustion improver, avoiding the situation that the expected combustion effect cannot be achieved after choosing the method of injecting a combustion improver, and further providing an intuitive judgment basis for the selection of the auxiliary optimization method, improving the accuracy of the selection of the auxiliary optimization method.

[0131] When calculating the selection evaluation parameters, first determine the degree of cost change caused by using the combustion improver by considering the influence degree of the cost increase of two auxiliary optimization methods, and then determine the difficulty of realizing the optimization of using the combustion improver by calculating the combustible optimization range of adding the combustion improver and the estimated flow rate of adding the combustion improver. By comprehensively considering the degree of cost change caused by using the combustion improver and the difficulty of realizing the optimization, and then correcting the above calculation results according to the current ash accumulation thickness, the selection evaluation parameters are obtained, providing an intuitive judgment basis for the selection of the auxiliary optimization method and reducing the difficulty of selecting the auxiliary optimization method.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A boiler combustion optimization system, characterized in that, Including: A parameter generation module, configured to generate actual combustion parameters according to the target power generation of a thermal power unit, where the combustion parameters include: coal sample ratio, fuel composition, and fuel input flow rate; An air supply control module, configured to obtain a basic primary air flow rate and a basic secondary air flow rate through an air volume prediction model based on the actual combustion parameters; An analysis and correction module, configured to analyze the ash fouling condition on the boiler heating surface and correct the basic primary air flow rate and the basic secondary air flow rate to obtain the actual primary air flow rate and the actual secondary air flow rate; A data monitoring module, configured to collect actual flue gas monitoring parameters of the boiler under the current operating state. If any flue gas monitoring parameter exceeds the corresponding allowable range, the actual combustion parameters are regenerated; A range control module, configured to generate allowable adjustment ranges of the combustion parameters, the primary air flow rate, and the secondary air flow rate according to the boiler structure.

2. The boiler combustion optimization system according to claim 1, wherein The parameter generation module includes: A target acquisition unit, configured to acquire the target power generation of the thermal power unit; A fuel control unit, configured to select a suitable actual coal blending plan and generate a corresponding fuel input flow rate, and generate actual combustion parameters.

3. The boiler combustion optimization system according to claim 2, wherein, The fuel control unit includes: A database establishment subunit, configured to acquire coal storage information and establish a coal blending database with a number of preset coal blending plans preconfigured based on the coal storage information; A plan selection subunit, configured to select the preset coal blending plan with the lowest cost price from the coal blending database as the pending coal blending plan based on the current tail gas treatment capacity; A flow rate calculation subunit, configured to calculate the fuel input flow rate based on the target power generation of the thermal power unit and the pending coal blending plan; Among them, V m is the fuel input flow rate; P e is the target power generation of the thermal power unit; η is the thermal energy utilization rate of the thermal power unit; R m is the lower calorific value of the pending coal blending scheme; A flow rate verification unit, configured to verify whether the fuel input flow rate is within the allowable adjustment range. If the fuel input flow rate is within the allowable adjustment range, actual combustion parameters are generated according to the actual coal blending plan and the corresponding fuel input flow rate. Otherwise, the pending coal blending plan is reselected.

4. A boiler combustion optimization system according to claim 1, characterized in that The air supply control module includes: A model establishment unit, configured to establish an air volume prediction model; A result output unit, configured to sequentially input the actual combustion parameters into the air volume prediction model, and automatically generate a basic primary air flow rate and a basic secondary air flow rate through the air volume prediction model.

5. The boiler combustion optimization system according to claim 4, wherein, The fuel composition refers to the volatile matter, ash content, sulfur content, and nitrogen content of the coal sample. The model establishment subunit establishes the air volume prediction model based on the following method, including: Step 1: Acquire a number of groups of historical combustion parameters of the boiler and the corresponding flue gas monitoring parameters; Step 2: Screen out the historical combustion parameters where each flue gas monitoring parameter is less than a preset screening threshold as the qualified data set; Step 3: Train a simulation model based on the qualified data set to generate an air volume prediction model.

6. The boiler combustion optimization system according to claim 1, characterized in that The analysis and correction module includes: An ash fouling monitoring unit, configured to acquire the ash fouling thickness of the boiler heating surface; An alarm unit, configured to give an ash cleaning alarm when the ash fouling thickness of the boiler heating surface is greater than a preset dangerous ash fouling thickness; A judgment unit, configured to judge whether the ash fouling thickness of the boiler heating surface is greater than a preset influencing ash fouling thickness. If the ash fouling thickness of the boiler heating surface is greater than the preset influencing ash fouling thickness, the basic primary air flow rate and the basic secondary air flow rate are corrected. Otherwise, the basic primary air flow rate and the basic secondary air flow rate are used as the actual primary air flow rate and the actual secondary air flow rate. A flow rate adjustment unit for correcting the basic primary air flow rate and the basic secondary air flow rate to obtain the actual primary air flow rate and the actual secondary air flow rate; An air volume verification unit for verifying whether the actual primary air flow rate and the actual secondary air flow rate are within the corresponding allowable ranges. If both are within the corresponding allowable ranges, the supply of primary air and the supply of secondary air are carried out according to the actual primary air flow rate and the actual secondary air flow rate; otherwise, auxiliary optimization is performed; An auxiliary optimization unit for executing an auxiliary optimization method.

7. An optimized boiler combustion system according to claim 6, characterized in that, The flow rate adjustment unit obtains the actual primary air flow rate and the actual secondary air flow rate based on the following formula; V f1 = V f10 [1 + k1(D s - D z )]; Among them, V f1 is the actual primary air flow rate; V f10 is the basic primary air flow rate; k1 is the influence coefficient of the ash deposition thickness of the primary air; D s is the actual ash deposition thickness of the boiler heating surface; D z is the preset ash deposition thickness for influence; V f2 = V f20 [1 + k2(D s - D z )]; where V f2 is the actual secondary air flow rate; V f20 is the basic secondary air flow rate; k2 is the influence coefficient of the secondary air ash deposition thickness; D s is the actual ash deposition thickness of the boiler heating surface; D z is the preset influence ash deposition thickness.

8. The boiler combustion optimization system according to claim 6, characterized in that, The auxiliary optimization method includes: introducing a combustion improver or regenerating actual combustion parameters. The auxiliary optimization unit includes: A combustion assistance evaluation sub-unit for outputting a combustion assistance evaluation result, where the combustion assistance evaluation result includes achievable and unachievable; A solution selection sub-unit for selecting an auxiliary optimization solution.

9. The boiler combustion optimization system according to claim 8, wherein The combustion assistance evaluation sub-unit includes: A first parameter calculation block for calculating combustion assistance evaluation parameters, where the combustion assistance evaluation parameters include a first combustion assistance evaluation parameter and a second combustion assistance evaluation parameter; Among them, T1 is the first combustion-supporting evaluation parameter; V f10 is the basic primary air flow rate; V f1b is the upper limit value of the allowable range of the primary air flow rate; R1 is the preset maximum allowable over-limit ratio of the primary air flow rate; is the floor function symbol; Among them, T2 is the second combustion-supporting evaluation parameter; V f20 is the basic secondary air flow rate; V f2b is the upper limit value of the allowable range of the secondary air flow rate; R2 is the maximum allowable over-limit ratio of the preset secondary air flow rate; A result output block for determining the combustion assistance evaluation result based on the combustion assistance evaluation parameters. If any one of the first combustion assistance evaluation parameter and the second combustion assistance evaluation parameter is greater than 0, the combustion assistance evaluation result is unachievable; otherwise, the combustion assistance evaluation result is achievable.

10. A boiler combustion optimization system according to claim 8, characterized in that, The solution selection sub-unit includes: A first judgment block. If the combustion assistance evaluation result is unachievable, the selection of the auxiliary optimization solution is to regenerate the actual combustion parameters; otherwise, the selection evaluation parameters are calculated, and the auxiliary optimization solution is selected based on the selection evaluation parameters; A second parameter calculation block for calculating the selection evaluation parameters; where P is the selected evaluation parameter; ln is the logarithmic function with base e; e is the natural constant; V r is the required addition flow rate of the combustion improver; V0 is the unit flow rate; α and β are the weighted influence coefficients of the usage cost and the optimizable range respectively; B1 is the cost per unit volume of the combustion improver; t0 is the unit time duration; B2 is the cost per unit volume of the current coal blending scheme in use; V m is the fuel input flow rate corresponding to the current coal blending scheme in use; B3 is the cost per unit volume of the alternative coal blending scheme; V mx is the fuel input flow rate corresponding to the alternative coal blending scheme; B s is the preset cost difference reference value; M is the number of types of flue gas monitoring parameters; G i0 is the upper limit value of the allowable range of the i-th flue gas monitoring parameter; G i is the actual value of the i-th flue gas monitoring parameter; D s is the actual ash fouling thickness of the boiler heating surface; D z is the preset influence ash fouling thickness; When the selection evaluation parameter is greater than a preset judgment threshold, the selection of the auxiliary optimization solution is to regenerate the actual combustion parameters; otherwise, the selection of the auxiliary optimization solution is to introduce a combustion improver.

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