Method and device for evaluating wet desulfurization limited load output and peak capacity

Abstract

The application discloses a wet desulfurization load limit output and peak capacity evaluation method and device, obtains desulfurization system online monitoring parameters and equipment design parameters, calculates real-time SO2 removal mass content based on flue gas flow and import and export SO2 concentration; combines slurry circulating pump operation parameters and slurry density to calculate real-time effective circulating slurry amount, determines CaCO3 actual supply amount according to limestone slurry related parameters and purity; splits and calculates desulfurization margins of slurry circulating pump and limestone slurry supply system and sums up total margin; calculates load margin and peak capacity based on total margin, current unit load and SO2 standard emission control concentration, judges whether to limit full load operation; if limited, deduces SO2 concentration limit value at desulfurization inlet and received base sulfur content control threshold value of coal at full load. The scheme realizes the balance of environmental protection standard and power generation benefit and peak regulation demand, and provides precise data support and guidance for safe and economic operation of the unit.

Description

Technical Field

[0001] This application relates to the cross-technical field of environmental protection and operation control of coal-fired power plants, and in particular to a method and device for assessing the load limiting output and peak capacity of wet desulfurization. Background Technology

[0002] Under the dual constraints of the "dual carbon" target and the ultra-low emission policy for thermal power units, coal-fired units must simultaneously meet peak-shaving needs and environmental compliance requirements. Limestone-gypsum wet desulfurization technology, with its advantages of high desulfurization efficiency and strong adaptability, has become the mainstream desulfurization configuration for coal-fired power plants. This technology uses a slurry circulation pump to deliver desulfurization slurry to fully contact the flue gas, utilizing the chemical reaction between CaCO3 in the limestone slurry and SO2 in the flue gas to achieve desulfurization. Its operational performance directly affects the unit's environmental compliance and power generation capacity.

[0003] However, existing technologies have significant limitations in practical applications. On the one hand, there is a lack of quantitative assessment models for desulfurization system output under high-load conditions, making it impossible to accurately predict the critical values ​​of desulfurization efficiency in different load ranges. When the unit operates at full capacity or exceeds capacity, factors such as a sudden increase in flue gas volume flow, the use of high-sulfur coal, or a decline in the quality of desulfurization slurry can easily lead to insufficient liquid-to-gas ratio, shortened slurry reaction time, and a significant drop in desulfurization efficiency, thereby triggering the risk of SO2 emissions exceeding standards. On the other hand, existing operation adjustment strategies mostly focus on low-load conditions. Under high loads, the control of parameters such as slurry pH value and circulating pump operation combinations mainly relies on manual experience, making it difficult to achieve an effective balance between meeting emission standards and unit output demands. To avoid environmental penalties, power plants are often forced to adopt passive measures to restrict high-load operation, resulting in both a loss of power generation benefits and a weakening of the unit's peak-shaving capacity. Existing technologies have not yet formed a complete, mechanism-based desulfurization system load limitation assessment method, which cannot provide accurate data support and operational guidance for the safe and economical operation of the unit. These technological gaps urgently need to be filled. Summary of the Invention

[0004] In view of this, this application provides a method and apparatus for assessing the load limitation and peak capacity of wet desulfurization, which mainly solves the problem that the existing technology lacks a quantitative assessment model for the output of wet desulfurization systems under high load conditions, and that the control of high load operating parameters relies on manual experience, which makes it easy for units to be forced to limit load due to excessive SO2 emissions, making it difficult to balance environmental compliance with power generation benefits and peak shaving needs.

[0005] According to one aspect of this application, a method for evaluating the load limiting output and peak capacity of wet desulfurization is provided, comprising: acquiring online monitoring parameters and equipment design parameters of the desulfurization system; calculating the current real-time SO2 mass content removed based on the collected data of flue gas flow rate at the desulfurization inlet and SO2 concentration at the desulfurization inlet and outlet; calculating the real-time effective circulating slurry volume of the desulfurization slurry circulation pump based on the collected parameters of the slurry circulation pump and the density parameters of the desulfurization slurry; and calculating the actual CaCO3 content of the desulfurization limestone slurry based on the collected parameters of the limestone slurry and the purity of the limestone. The actual supply volume is calculated; the desulfurization margin corresponding to the slurry circulation pump and the desulfurization margin corresponding to the limestone slurry supply system are calculated separately, and the total desulfurization margin of the desulfurization system is obtained by summing them up; based on the total desulfurization margin, the current unit load and the SO2 emission control concentration, the load margin and peak capacity of the unit are calculated, and it is determined whether the desulfurization system restricts the unit to operate at full load; if the desulfurization system restricts the unit to operate at full load, based on the total desulfurization margin and the unit design parameters, the limit value of SO2 concentration at the desulfurization inlet and the control threshold of sulfur content received from coal are derived when the unit is operating at full load.

[0006] According to one aspect of this application, a wet desulfurization load limiting output and peak capacity assessment device is provided, characterized in that it is used to execute the wet desulfurization load limiting output and peak capacity assessment method, the device comprising a data acquisition unit, a parameter calculation unit, a margin calculation unit, a load assessment unit, a parameter derivation unit, and a data output unit; the data acquisition unit is used to establish bidirectional data interaction with the online monitoring equipment and database of the desulfurization system, and to collect and store online monitoring parameters and equipment design parameters in real time; the parameter calculation unit is used to call the data stored in the data acquisition unit to calculate the current real-time SO2 removal mass content, the real-time effective circulating slurry volume of the desulfurization slurry circulation pump, and the actual CaCO3 supply of the desulfurization limestone slurry; the margin calculation unit... The parameter calculation unit receives the output results from the parameter calculation unit, calculates the desulfurization margin corresponding to the slurry circulation pump and limestone slurry supply system separately, and summarizes them to obtain the total desulfurization margin. The load assessment unit receives the output results from the parameter calculation unit and the margin calculation unit, calculates the unit's load margin and peak capacity based on the total desulfurization margin, the current unit load, and the SO2 emission control concentration, and determines whether the desulfurization system restricts the unit from operating at full load. The parameter derivation unit receives the judgment result from the load assessment unit. When the desulfurization system restricts the unit from operating at full load, it derives the SO2 concentration limit value at the desulfurization inlet and the coal-based sulfur control threshold value based on the total desulfurization margin and the unit design parameters. The data output unit outputs the evaluation results.

[0007] By means of the above technical solution, this application provides a method and device for evaluating the load-limited output and peak capacity of wet desulfurization, which aims to solve the problems of existing technologies lacking quantitative evaluation models for desulfurization systems under high load conditions and relying on manual experience for high load parameter control, which leads to units being easily forced to limit load due to excessive SO2 emissions, making it difficult to balance environmental protection, power generation benefits and peak-shaving needs.

[0008] This application first obtains the online monitoring parameters of the desulfurization system (such as the flue gas flow rate at the desulfurization inlet, SO2 concentration at the inlet and outlet, and electrical parameters of the slurry circulation pump) and equipment design parameters (such as the design flow rate and rated power of the slurry circulation pump). Based on this data, the current real-time SO2 removal mass content is calculated first, and then the real-time effective circulating slurry volume of the desulfurization slurry circulation pump and the actual supply of CaCO3 in the limestone slurry are calculated separately. Subsequently, the desulfurization margin of the slurry circulation pump and the limestone slurry supply system are calculated separately and then summarized to obtain the total desulfurization margin. Combining the total desulfurization margin, the current unit load, and the SO2 emission control concentration to meet standards, the unit's load margin and peak capacity can be calculated, thereby determining whether the desulfurization system restricts the unit's full-load operation. If there is a restriction, the limit value of SO2 concentration at the desulfurization inlet and the control threshold of sulfur content received from coal during full-load operation will also be derived.

[0009] Simultaneously, this method also outputs key data such as load margin, peak capacity, and load limiting judgment results to various functional departments of the power plant and external related units. For example, it outputs SO2 concentration limits to the unit dispatching system to provide a basis for load adjustment and coal selection; it synchronizes load margin data to the power plant production management center and grid dispatching center to support operation and maintenance coordination and power generation plan optimization; and it outputs total desulfurization margin data to the desulfurization system operation and maintenance department to assist in equipment fault diagnosis and coal procurement strategy formulation.

[0010] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0011] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A schematic diagram of the architecture of this application is shown; Figure 2 A schematic diagram of the wet desulfurization load limiting and peak capacity assessment method of this application is shown; Figure 3A schematic diagram of the wet desulfurization load limiting and peak capacity assessment device of this application is shown. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all of them. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present application can be combined with each other.

[0013] To gain a comprehensive understanding of the proposed solution, its structure will be introduced first. (See also...) Figure 1This is a system architecture diagram for assessing the load limiting output and peak capacity of wet desulfurization systems in coal-fired power plants. The desulfurization system is the object of assessment, serving as the data source and providing basic parameters for the assessment system. Specifically, the online monitoring equipment and database of the desulfurization system collect and output two types of key data in real time: one type is online monitoring parameters, including dynamic data reflecting the real-time operating status of the system, such as the flue gas flow rate at the desulfurization inlet, SO2 concentration at the desulfurization inlet and outlet, electrical parameters of the slurry circulation pump (such as current and voltage), desulfurization slurry density, and limestone slurry supply; the other type is equipment design parameters, such as the design circulation flow rate of the slurry circulation pump, rated power, absorption tower cross-sectional area, and unit capacity, reflecting the inherent attributes of the equipment. These parameters together constitute the basis for the calculation and analysis of the assessment system. The assessment system, as the main body responsible for the assessment, is the core processing link of this application scheme. After obtaining the aforementioned parameters from the desulfurization system, it calculates the total real-time SO2 removal volume, effective circulating slurry volume, and actual CaCO3 supply volume according to specific algorithm formulas. It then breaks down the desulfurization margin of the slurry circulation pump and the limestone slurry supply system, ultimately obtaining the total desulfurization margin, unit load margin, and peak capacity. It also determines whether there are load limiting conditions; if so, it derives the SO2 concentration limit and the coal sulfur control threshold, forming a complete assessment result. The various functional departments of the power plant and external related units, as the main bodies implementing the optimization strategy, are the application ends of the assessment results. The data output by the evaluation system, such as load margin, peak capacity, and load limiting judgment results, will provide the unit dispatching system with a basis for load adjustment, provide cross-departmental collaborative support for the power plant production management center, and provide a reference for the power grid dispatching center to optimize regional power generation plans. Meanwhile, data such as total desulfurization margin, sub-item margin, and effective circulating slurry volume can assist the desulfurization system operation and maintenance department in conducting equipment fault diagnosis, and the coal management department in formulating procurement and blending strategies. At the same time, it can provide basic data for third-party technical service agencies to conduct desulfurization system performance diagnosis and modification scheme design. Ultimately, it can achieve data support for evaluation, evaluation guidance for optimization, and support for the safe and economical operation of the unit.

[0014] This application addresses the issue of excessive emissions and load limitations in wet desulfurization systems of coal-fired power plants under high-load conditions. Based on online monitoring parameters and equipment design parameters, it quantifies and calculates real-time SO2 removal, effective circulating slurry volume, and CaCO3 supply to understand the system's current status. It further breaks down the desulfurization margin of the slurry circulation pump and limestone slurry supply system and summarizes the total margin to calculate the unit's load margin and peak capacity. This clarifies the limitations of the desulfurization system under full-load operation and derives the SO2 concentration limit at the desulfurization inlet and the sulfur content control threshold of the coal received at full load. This forms a complete logic of data acquisition, parameter calculation, margin assessment, load judgment, and threshold derivation, filling the technical gap in quantitative performance evaluation of desulfurization systems under high-load conditions and providing support for environmental compliance and safe and economical operation of the unit.

[0015] See Figure 2 The diagram illustrates the wet desulfurization load limit and peak capacity assessment method of this application. This wet desulfurization load limit and peak capacity assessment method includes the following steps S201-S206.

[0016] S201: Obtain online monitoring parameters and equipment design parameters of the desulfurization system.

[0017] Online monitoring parameters refer to data that can be collected in real time during the operation of the desulfurization system. These include data such as the flue gas flow rate at the desulfurization inlet, SO2 concentration at the desulfurization inlet and outlet, electrical parameters of the slurry circulation pump, desulfurization slurry density, desulfurization slurry supernatant density, limestone slurry density, limestone slurry supply rate, limestone purity, slurry level in the absorption tower, current unit load, and unit coal consumption. These parameters are typically acquired in real time through sensors and monitoring instruments installed on the corresponding equipment or pipelines, providing a direct reflection of the system's current operating status. Equipment design parameters, on the other hand, are inherent parameters determined during the design and manufacturing of the desulfurization system and related equipment. These include the design volumetric flow rate, rated power, operating voltage, and power factor of the slurry circulation pump; the cross-sectional area of ​​the absorption tower; the unit capacity; limestone density; and the opening degree of the limestone slurry supply pump. These parameters can be obtained from the equipment's technical specifications, design drawings, or the power plant's equipment archives.

[0018] S202: Based on the collected flue gas flow rate at the desulfurization inlet and SO2 concentration data at the desulfurization inlet and outlet, calculate the current real-time SO2 removal mass content.

[0019] Specifically, by using the real-time monitored flue gas flow rate at the desulfurization inlet and combining it with the SO2 concentration difference between the desulfurization inlet and outlet, the actual SO2 mass content removed by the current desulfurization system can be obtained through a certain conversion relationship. The key is to quantify the total amount of SO2 removed based on the changes in flue gas flow rate and concentration.

[0020] S203: Based on the collected parameters of the slurry circulation pump and the density parameters of the desulfurization slurry, calculate the real-time effective circulating slurry volume of the desulfurization slurry circulation pump; based on the collected parameters of the limestone slurry and the purity of the limestone, calculate the actual supply of CaCO3 to the desulfurization limestone slurry.

[0021] When calculating the real-time effective circulating slurry volume, the design circulation flow rate of each operating slurry circulation pump is first considered. Then, combined with parameters such as operating current, voltage, rated power, and power factor, as well as the density of desulfurization slurry and supernatant, the circulation slurry volume reduction coefficient of each pump is calculated. This is used to correct the design flow rate, and finally, the total real-time effective circulating slurry volume of all operating pumps is obtained. This process takes into account the actual operating status of the pumps and the influence of the slurry's own characteristics on the effective slurry volume. When calculating the actual supply of CaCO3, the solid content of the limestone slurry is first calculated based on parameters such as the density of the limestone slurry. Then, combined with the limestone slurry supply volume and limestone purity, the actual supply of CaCO3 participating in the desulfurization reaction can be obtained. The key is to clarify the actual quantity of effective reactive components in the limestone slurry.

[0022] S204: Separately calculate the desulfurization margin corresponding to the slurry circulation pump and the desulfurization margin corresponding to the limestone slurry supply system, and summarize them to obtain the total desulfurization margin of the desulfurization system.

[0023] First, margin calculations were performed separately for the slurry circulation pump and the limestone slurry supply system. For the slurry circulation pump, its additional SO2 removal capacity was calculated based on its operating status, reduction coefficient, and other parameters; this is the desulfurization margin corresponding to the slurry circulation pump. For the limestone slurry supply system, its additional SO2 removal potential was calculated based on parameters such as the solids content of the limestone slurry, the supply volume, and the residence time; this is the desulfurization margin corresponding to the limestone slurry supply system. Finally, these two margins were added together to obtain the total desulfurization margin of the desulfurization system.

[0024] S205: Based on the total desulfurization margin, current unit load, and SO2 emission control concentration, calculate the unit's load margin and peak capacity, and determine whether the desulfurization system restricts the unit from operating at full load.

[0025] Based on the total desulfurization margin, and combined with data such as the current unit load, desulfurization inlet flue gas flow rate, and SO2 emission control concentration, the additional load margin that the unit can add is calculated. This load margin is then added to the current unit load, while also considering the unit capacity, to determine the unit's peak capacity. If the peak capacity reaches the unit capacity, it indicates that the desulfurization system will not restrict the unit's full-load operation; if the peak capacity is lower than the unit capacity, it indicates that the desulfurization system has limitations on full-load operation.

[0026] S206: If the desulfurization system restricts the unit to full-load operation, based on the total desulfurization margin and the unit design parameters, derive the SO2 concentration limit at the desulfurization inlet and the coal-based sulfur control threshold when the unit is running at full load.

[0027] When it is determined that the desulfurization system restricts the unit from operating at full load, the maximum SO2 concentration limit that the desulfurization inlet can withstand under full load operation is derived using parameters such as total desulfurization margin, current unit load, flue gas flow rate at the desulfurization inlet, unit capacity, and SO2 emission control concentration. Then, combined with data such as the maximum SO2 concentration at the desulfurization inlet, flue gas flow rate, and unit coal consumption, the corresponding coal-based sulfur control threshold is further calculated, providing a basis for selecting appropriate sulfur-containing coal and achieving full-load emission compliance.

[0028] Those skilled in the art understand that in the operation assessment and management of wet desulfurization systems in coal-fired power plants, the accurate output and targeted transmission of relevant quantitative assessment data are crucial to ensuring the safe, environmentally friendly, and economical operation of the unit and the collaborative work of multiple parties. Therefore, in practice, simultaneously outputting the results of load margin, peak capacity, and load limitation assessments along with one or more of the following: real-time SO2 removal content, effective circulating slurry volume, actual CaCO3 supply, total desulfurization margin, and individual desulfurization margins, can provide intuitive and accurate quantitative data for various functional departments within the power plant and external related units. This allows all parties to clearly understand the core status of the desulfurization system and unit operation, providing data support for subsequent decision-making.

[0029] Providing the SO2 concentration limits and the controlled threshold for sulfur content in coal received by the generator set to the unit dispatch system is of great significance. These two parameters clearly define the maximum SO2 concentration that the desulfurization inlet can withstand and the upper limit of sulfur content in coal received by the generator set when operating at full load. Based on this data, the unit dispatch system can scientifically adjust the unit load distribution, rationally select suitable coal types, or optimize the operating parameters of the desulfurization system, thereby mitigating the risk of SO2 emissions exceeding standards during full-load operation from the source and ensuring that the unit meets environmental protection requirements while generating electricity efficiently.

[0030] The results of load margin, peak capacity, and load shedding assessments must be simultaneously transmitted to the power plant's production management center and the power grid dispatch center. Based on this data, the power plant's production management center can coordinate the operation and maintenance of the desulfurization system, as well as the procurement and allocation of coal. The power grid dispatch center, in turn, can use this data to optimize the regional power grid's power generation plan, rationally allocate peak power supply tasks, and avoid insufficient unit output due to desulfurization system limitations, thus affecting grid stability and achieving efficient coordination between power plant operation and power grid dispatch.

[0031] It is particularly important to provide targeted data on total desulfurization margin, individual desulfurization margin, real-time SO2 removal content, effective circulating slurry volume, and actual CaCO3 supply to the desulfurization system operation and maintenance department, coal management department, or third-party technical service providers. The desulfurization system operation and maintenance department can use this data to troubleshoot equipment malfunctions, such as determining if the slurry circulation pump has reduced efficiency or is clogged, and optimize operating parameters. The coal management department can use this data to formulate scientific coal procurement plans and blending strategies, selecting coal with sulfur content and other indicators that meet requirements. Third-party technical service providers can use this data to conduct desulfurization system performance diagnostics, design targeted modification schemes, and verify the modification effects, comprehensively improving the operational stability and efficiency of the desulfurization system.

[0032] Therefore, in one implementation, after step S206 above, the following processing flow is also included: Simultaneously outputting one or more of the following: load margin, peak capacity, load limit judgment result, real-time SO2 removal mass content, effective circulating slurry volume, actual CaCO3 supply, total desulfurization margin, and individual desulfurization margin, providing quantitative assessment basis for various functional departments of the power plant and external related units; Specifically, outputting the SO2 concentration limit value and the coal-based sulfur control threshold to the unit dispatching system as the basis for unit load adjustment, coal selection, or desulfurization system operating parameter optimization, ensuring that SO2 emissions reach the required level when the unit is operating at full load. The system will simultaneously output the load margin, peak capacity, and load limitation judgment results to the power plant production management center and the power grid dispatch center as the basis for coordinating desulfurization operation and maintenance, coal management, unit dispatch, regional power grid power generation plan optimization, and / or peak power supply task allocation. It will also output the total desulfurization margin, the desulfurization margin of individual components, the real-time SO2 removal mass content, the effective circulating slurry volume, and the actual CaCO3 supply to the desulfurization system operation and maintenance department, the coal management department, or a third-party technical service organization as the basis for equipment fault diagnosis, operating parameter optimization, coal procurement, blending strategy formulation, desulfurization system performance diagnosis, retrofit design, and / or retrofit effect verification.

[0033] As can be seen, this application addresses the technical problem of excessive SO2 emissions and forced load limiting in wet desulfurization systems of coal-fired power plants under high-load conditions. Firstly, by integrating online monitoring parameters and equipment design parameters, a precise quantitative assessment model is constructed. This model can accurately calculate key indicators such as real-time SO2 removal volume, effective circulating slurry volume, and actual CaCO3 supply, clearly understanding the current operating status of the desulfurization system. This fills the gap in existing technologies for quantitative assessment of desulfurization system output under high-load conditions and overcomes the limitations of previous reliance on manual experience. Secondly, by separately calculating the desulfurization margin of the slurry circulation pump and limestone slurry supply system, and summing the total margin, the unit load margin and peak capacity can be accurately quantified. This clarifies whether the desulfurization system is limited to full-load operation, providing a clear basis for unit load adjustment. This avoids the loss of power generation benefits caused by blindly limiting load to circumvent environmental penalties, while ensuring SO2 emission compliance, achieving a balance between environmental requirements and power generation benefits. Furthermore, when the desulfurization system experiences load limitations, the solution can derive the SO2 concentration limit at the desulfurization inlet and the basic sulfur content control threshold of the coal during full-load operation of the unit. This provides targeted guidance for coal selection and optimization of desulfurization system operating parameters, helping power plants achieve full-load emission compliance through scientific adjustments. Simultaneously, the various quantitative data output by the solution can be provided to relevant units such as the power plant's production management center, grid dispatch center, and desulfurization system operation and maintenance department. This provides strong support for coordinating desulfurization operation and maintenance, coal management, unit dispatch, and optimization of regional grid power generation plans, comprehensively improving the operational safety, economy, and environmental friendliness of coal-fired units, enhancing their peak-shaving capacity, and adapting to the "dual carbon" targets and ultra-low emission requirements of thermal power units.

[0034] The following are specific embodiments of the solution proposed in this application.

[0035] The first step is to calculate the current SO2 mass content removed in real time by the limestone wet flue gas desulfurization system.

[0036] (1) : Total amount of SO2 removed so far, kg / h; : Flue gas flow rate at desulfurization inlet (standard dry), m 3 / h, monitoring parameters; SO2 concentration at the desulfurization inlet (standard dry), mg / m³ 3 Monitoring parameters; SO2 concentration at desulfurization outlet (standard dry), mg / m³ 3 Monitoring parameters.

[0037] The second step, assessment of the current status of desulfurization performance, direction 1: calculate the real-time circulating slurry volume of the current desulfurization slurry circulation pump.

[0038] (2) (3) : The design volumetric flow rate of the circulating slurry for the i-th slurry circulation pump, in m³ 3 / h, equipment design parameters; Number of slurry circulation pumps in operation; : Circulating slurry volume reduction coefficient. In actual operation, the effective slurry volume of the slurry circulation pump will be reduced due to the following two main factors: (1) The pump may not be able to operate at the rated power due to its own equipment problems (blockage, detachment, cavitation, etc.); (2) The presence of soluble salts in the desulfurization slurry reduces the effective solid content that can participate in the desulfurization reaction, so it is necessary to calculate the actual circulating slurry volume.

[0039] : The total effective circulating slurry volume of the current slurry circulation pump, in m 3 / h; : Operating current of the i-th slurry circulation pump, A, monitoring parameter; Operating voltage (V) of the i-th slurry circulation pump; equipment design parameters; : Rated power of the i-th slurry circulation pump, kW, equipment design parameters; Power factor, dimensionless, equipment design parameter; Desulfurization slurry density, kg / m³ 3 Monitoring parameters; Density of desulfurization slurry supernatant, kg / m³ 3 Monitoring parameters; A judgment function. Because the pump's shutdown current may not return to zero, this judgment function is set up to determine whether the pump has stopped: if the judgment condition... The pump is in the start state, and the return value is If the judgment condition is not met, the pump is in a closed state and the return value is 0.

[0040] The third step, the second direction of the current status assessment of desulfurization performance, is to calculate the current supply of desulfurization limestone slurry.

[0041] (4) (5) Limestone slurry density, kg / m³ 3 Monitoring parameters; Limestone slurry solids content, % Limestone density, kg / m³ 3 The default value is 2750.

[0042] Limestone purity, monitoring parameters; Limestone slurry supply volume, m 3 / h, monitoring parameters; The desulfurization limestone slurry provides CaCO3 content, kg / h.

[0043] The fourth step is to calculate the current SO2 removal margin of the desulfurization system.

[0044] (6) (7) (8) (9) (10) : Reduction coefficient for circulating slurry margin calculation, dimensionless; : Cross-sectional area of ​​the absorption tower, m 2 Equipment design parameters; : Slurry level in the absorption tower, m, monitoring parameter; : Slurry residence time, h, equipment design parameter; Limestone slurry supply pump opening degree, equipment design parameters; Limestone slurry desulfurization allowance, kg / h; Desulfurization margin of slurry circulation pump, kg / h; Total desulfurization margin, kg / h.

[0045] The fifth step is to assess the current desulfurization system's limited unit load output and peak capacity. (11)

[0046] SO2 emission control concentration of the unit, mg / m³ 3 ; Load margin, in MW; Current unit load, MW, monitoring parameters; Peak capacity of the unit, in MW; Unit capacity, MW, equipment design parameters.

[0047] when When this condition is met, it indicates that the current desulfurization system can meet the requirements for full-load power generation; when... When this time, it indicates that the current desulfurization system is operating under conditions that limit full-load power generation; at this time, the maximum load limit is [value missing]. .

[0048] Step 6: Suggestions for adjusting the operation of wet desulfurization.

[0049] When wet desulfurization is subject to load limiting, in order to achieve full-load operation of the unit, the SO2 concentration at the desulfurization inlet / sulfur content of coal must be reduced to achieve full-load emission compliance.

[0050] (13) (14) Maximum SO2 concentration at the desulfurization inlet when the unit is at full load, mg / m³ 3 ; The maximum sulfur content control threshold based on coal consumption when the unit is at full load, % Current coal consumption of the unit, t / h, monitoring parameters.

[0051] See Figure 3 This application illustrates a wet desulfurization load limit output and peak capacity assessment device provided in an embodiment of the present application. The device is used to execute the aforementioned wet desulfurization load limit output and peak capacity assessment method. The device includes a data acquisition unit, a parameter calculation unit, a margin calculation unit, a load assessment unit, a parameter derivation unit, and a data output unit; wherein... The data acquisition unit is used to establish bidirectional data interaction with the online monitoring equipment and database of the desulfurization system, and to collect and store online monitoring parameters and equipment design parameters in real time. The parameter calculation unit is used to call the data stored in the data acquisition unit to calculate the current real-time SO2 mass content, the real-time effective circulating slurry volume of the desulfurization slurry circulation pump, and the actual supply of CaCO3 to the desulfurization limestone slurry. The margin calculation unit is used to receive the output results of the parameter calculation unit, split the calculation of the desulfurization margin corresponding to the slurry circulation pump and the limestone slurry supply system, and summarize to obtain the total desulfurization margin. The load assessment unit is used to receive the output results of the parameter calculation unit and the margin calculation unit, and calculate the load margin and peak capacity of the unit based on the total desulfurization margin, the current unit load and the SO2 emission control concentration to determine whether the desulfurization system restricts the unit from operating at full load. The parameter derivation unit is used to receive the judgment result of the load assessment unit. When the desulfurization system restricts the unit to run at full load, based on the total desulfurization margin and the unit design parameters, it derives the SO2 concentration limit value at the desulfurization inlet and the coal-based sulfur control threshold value when the unit is running at full load. The data output unit is used to output the evaluation results.

[0052] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for evaluating the limited load output and peak capacity of wet desulfurization processes, characterized in that, include: Obtain online monitoring parameters and equipment design parameters of the desulfurization system; Based on the collected data on flue gas flow rate at the desulfurization inlet and SO2 concentration at the desulfurization inlet and outlet, the current real-time SO2 mass content is calculated. Based on the collected parameters of the slurry circulation pump and the density parameters of the desulfurization slurry, the real-time effective circulating slurry volume of the desulfurization slurry circulation pump is calculated; based on the collected parameters of the limestone slurry and the purity of the limestone, the actual supply of CaCO3 to the desulfurization limestone slurry is calculated. The desulfurization margin corresponding to the slurry circulation pump and the desulfurization margin corresponding to the limestone slurry supply system are calculated separately, and the total desulfurization margin of the desulfurization system is obtained by summing them up. Based on the total desulfurization margin, current unit load, and SO2 emission control concentration, calculate the unit's load margin and peak capacity to determine whether the desulfurization system restricts the unit from operating at full load. If the desulfurization system restricts the unit to operate at full load, based on the total desulfurization margin and the unit design parameters, the SO2 concentration limit at the desulfurization inlet and the coal-based sulfur control threshold are derived when the unit is operating at full load.

2. The method according to claim 1, characterized in that, Also includes: The load margin, peak capacity, load limit judgment results, and one or more of the following parameters—real-time SO2 removal content, effective circulating slurry volume, actual CaCO3 supply, total desulfurization margin, and individual desulfurization margin—will be simultaneously output to provide quantitative assessment basis for various functional departments of the power plant and external related units; among which... The SO2 concentration limit and the coal-based sulfur content control threshold are output to the unit dispatching system as the basis for unit load adjustment, coal selection or desulfurization system operation parameter optimization, to ensure that SO2 emissions meet the standards when the unit is running at full load. The load margin, peak capacity, and load limitation judgment results are simultaneously output to the power plant production management center and the power grid dispatch center as the basis for coordinating desulfurization operation and maintenance, coal-fired power management, unit dispatch, regional power grid power generation plan optimization, and / or peak power supply task allocation. The total desulfurization margin, the desulfurization margin of each component, the real-time SO2 removal mass content, the effective circulating slurry volume, and the actual CaCO3 supply will be output to the desulfurization system operation and maintenance department, the coal management department, or a third-party technical service organization as the basis for equipment fault diagnosis, operating parameter optimization, coal procurement, blending strategy formulation, desulfurization system performance diagnosis, modification scheme design, and / or modification effect verification.

3. The method according to claim 1, characterized in that, The current SO2 mass content removed in real time is calculated using the following formula: ， in, This represents the total amount of SO2 removed so far. The flue gas flow rate at the desulfurization inlet. The SO2 concentration at the desulfurization inlet. This refers to the SO2 concentration at the desulfurization outlet.

4. The wet desulfurization load assessment method according to claim 1, characterized in that, The real-time effective circulating slurry volume of the desulfurization slurry circulation pump is calculated using the following formula: ， The circulating slurry volume reduction coefficient is calculated using the following formula: ； in, The design volumetric flow rate of the circulating slurry for the i-th slurry circulation pump is given. The number of slurry circulation pumps in operation; This is the coefficient for reducing the amount of circulating slurry. This represents the total effective circulating slurry volume of the current slurry circulation pump. Let be the operating current of the i-th slurry circulation pump. Let be the operating voltage of the i-th slurry circulation pump. Let be the rated power of the i-th slurry circulation pump; For power factor, The density of the desulfurization slurry, This refers to the density value of the supernatant of the desulfurization slurry. For a judgment function, if the judgment condition is... The pump is in the start state, and the return value is If the judgment condition is not met, the pump is in a closed state and the return value is 0.

5. The method according to claim 1, characterized in that, The actual supply of CaCO3 is calculated using the following formula: ； The solid content of the limestone slurry is calculated using the following formula: ； in, The density of limestone slurry, This refers to the solids content of the limestone slurry. The density of limestone, For limestone purity, For limestone slurry supply volume, Provides CaCO3 content for desulfurized limestone slurry.

6. The method according to claim 1, characterized in that, The total desulfurization margin is obtained by summing the following formulas: ； The desulfurization margin corresponding to the slurry circulation pump is calculated using the following formula: ； The desulfurization margin corresponding to the limestone slurry supply system is calculated using the following formula: ； in, For the total desulfurization margin, For the desulfurization margin of the slurry circulation pump, Provide a margin for desulfurization of limestone slurry. Calculate the reduction factor for circulating slurry margin. Adjust the opening of the limestone slurry supply pump. This refers to the residence time of the slurry.

7. The method according to claim 1, characterized in that, The load margin is calculated using the following formula: ， Peak capacity is calculated using the following formula: ； in, As a load margin, For the current unit load, To ensure SO2 emissions meet standards, control concentrations. For the peak capacity of the unit, This refers to the unit capacity.

8. The method according to claim 1, characterized in that, The SO2 concentration limit at the desulfurization inlet when the unit is running at full load is derived using the following formula: ， in, This represents the maximum SO2 concentration at the desulfurization inlet when the unit is at full load. This is the maximum sulfur content control threshold for coal received at full load. This represents the current coal consumption of the unit.

9. The method according to claim 8, characterized in that, The sulfur content control threshold for coal received is derived using the following formula: ； in, The sulfur content control threshold for coal is determined by the amount of sulfur received. The SO2 generation coefficient, The SO2 generation coefficient is determined based on the coal combustion mechanism and actual industrial operating data, representing the current coal consumption of the unit.

10. A device for evaluating the limited load output and peak capacity of wet desulfurization processes, characterized in that, The device is used to perform the wet desulfurization load limiting output and peak capacity assessment method according to any one of claims 1-9, and the device includes a data acquisition unit, a parameter calculation unit, a margin calculation unit, a load assessment unit, a parameter derivation unit and a data output unit. The data acquisition unit is used to establish bidirectional data interaction with the online monitoring equipment and database of the desulfurization system, and to collect and store online monitoring parameters and equipment design parameters in real time. The parameter calculation unit is used to call the data stored in the data acquisition unit to calculate the current real-time SO2 mass content, the real-time effective circulating slurry volume of the desulfurization slurry circulation pump, and the actual supply of CaCO3 to the desulfurization limestone slurry. The margin calculation unit is used to receive the output results of the parameter calculation unit, split the calculation of the desulfurization margin corresponding to the slurry circulation pump and the limestone slurry supply system, and summarize to obtain the total desulfurization margin. The load assessment unit is used to receive the output results of the parameter calculation unit and the margin calculation unit, and calculate the load margin and peak capacity of the unit based on the total desulfurization margin, the current unit load and the SO2 emission control concentration to determine whether the desulfurization system restricts the unit from operating at full load. The parameter derivation unit is used to receive the judgment result of the load assessment unit. When the desulfurization system restricts the unit to run at full load, based on the total desulfurization margin and the unit design parameters, it derives the SO2 concentration limit value at the desulfurization inlet and the coal-based sulfur control threshold value when the unit is running at full load. The data output unit is used to output the evaluation results.

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