Flow measurement method and system for induced draft fan of pulverized coal fired boiler

Abstract

The embodiment of the invention provides a pulverized coal boiler induced draft fan flow measurement method and system.The method comprises the steps that the combustion smoke amount, the air leakage amount of an air pre-heater and the air leakage amount of a boiler body are obtained firstly, and the combustion smoke amount is obtained through calculation of operation parameters of a coal mill and a boiler; the air leakage amount of the air pre-heater is calculated according to the oxygen content of inlet flue gas and the oxygen content of outlet flue gas of the air pre-heater; the boiler body air leakage amount is obtained through calculation according to a boiler air leakage rate function obtained by fitting boiler historical data. And the total smoke flow is calculated according to the combustion smoke amount, the air leakage amount of the air pre-heater and the air leakage amount of the boiler body. By acquiring the equipment parameters of the induced draft fan and calculating the flow proportion of the induced draft fan according to the equipment parameters of the induced draft fan, the flue gas flow of the induced draft fan is output according to the flow proportion. According to the method, the flue gas flow can be calculated by measuring relatively accurate quantity, and the measurement precision can be improved, so that the problem of low accuracy of a flow parameter measurement result of the induced draft fan is solved.

Description

Technical Field

[0001] The present application relates to the technical field of fan flow measurement, and particularly to a method and system for measuring the flow of induced draft fans in pulverized coal boilers. Background Art

[0002] As a device applied to factory environments, a fan can generate gas flow in a specific direction during operation, thereby meeting the requirements of different processes for gas fluidity. During operation, a fan can generate operating parameters in multiple dimensions, such as flow parameters, power parameters, energy efficiency ratios, noise parameters, etc. These operating parameters can be detected and applied to industrial control systems to monitor the operating status of each fan in real time and meet the requirements of monitoring and early warning.

[0003] For example, the flow parameter is a key parameter of a fan and can be used to analyze the operating conditions and faults of the fan. The flow parameter, also known as the air volume parameter, refers to the volume of gas passing through the fan per unit time. When a fan is applied to a pulverized coal boiler device and serves as the induced draft fan of the pulverized coal boiler device, due to the large, compact, and complex structure of the inlet flue gas system of the induced draft fan, problems such as uneven distribution of the flue gas flow velocity across the flue gas cross-section and high turbulence intensity exist, resulting in difficulties in obtaining the flow parameter.

[0004] To obtain the flow parameter, a multi-point matrix flowmeter can be installed to measure the flow parameter and monitor the operating status of the fan. However, the multi-point matrix flowmeter has good monitoring effects for forced draft fans and primary fans. However, due to the poor operating environment of the induced draft fan of the pulverized coal boiler device and the fact that the gas flowing in the air supply space contains a large amount of dust and corrosive substances, the multi-point matrix flowmeter is prone to problems such as wear and corrosion by the dust-laden gas flow. Therefore, when using a multi-point matrix flowmeter to measure the flow parameter of the induced draft fan of the pulverized coal boiler device, data distortion is likely to occur, resulting in a low accuracy of the measurement result of the induced draft fan flow parameter. Summary of the Invention

[0005] In view of this, the embodiments of the present application provide a method and system for measuring the flow of induced draft fans in pulverized coal boilers to solve the problem of low accuracy of the measurement result of the induced draft fan flow parameter.

[0006] According to one aspect of the present application, there is provided a method for measuring the flow of an induced draft fan in a pulverized coal boiler, the method comprising:

[0007] Obtaining the combustion flue gas volume, the air preheater air leakage volume, and the boiler body air leakage volume;

[0008] Calculating the sum of the combustion flue gas volume, the air preheater air leakage volume, and the boiler body air leakage volume to generate the total flue gas flow;

[0009] Obtain the induced draft fan equipment parameters, where the induced draft fan equipment parameters include the motor current and the total fan pressure of at least two induced draft fans;

[0010] Calculate the flow rate ratio of the induced draft fan according to the induced draft fan equipment parameters;

[0011] Output the flue gas flow rate of the induced draft fan according to the flow rate ratio, where the flue gas flow rate is the product of the flow rate ratio and the total flue gas flow rate.

[0012] In some embodiments, the combustion flue gas volume is obtained by calculating based on the coal mill operation parameters and the steam parameters;

[0013] The air preheater air leakage volume is obtained by calculating based on the inlet flue gas oxygen content and the outlet flue gas oxygen content of the air preheater;

[0014] The boiler body air leakage volume is obtained by calculating according to the boiler air leakage rate function, and the boiler air leakage rate function is a fitting function obtained by performing fitting analysis on the boiler historical data.

[0015] In some embodiments, the method further includes:

[0016] Obtain the historical coal quality industrial analysis data within a preset detection period;

[0017] Perform multiple linear regression analysis on the historical coal quality industrial analysis data to obtain a coal quality parameter model;

[0018] Collect the unit operation parameters, where the unit operation parameters include the coal mill operation parameters and the steam parameters;

[0019] Based on the coal quality parameter model, calculate the combustion flue gas volume according to the unit operation parameters.

[0020] In some embodiments, performing multiple linear regression analysis on the historical coal quality industrial analysis data to obtain a coal quality parameter model includes:

[0021] According to the mass and energy conservation principle at the inlet and outlet of the coal mill, calculate the moisture content of the coal based on the coal mill operation parameters;

[0022] Perform multiple linear regression analysis on the historical coal quality industrial analysis data to obtain the first functional relationship between calorific value, moisture content, and ash content;

[0023] According to the first functional relationship and the moisture content, determine the second functional relationship between calorific value and ash content;

[0024] Based on the second functional relationship, calculate the third functional relationship between calorific value and volatile matter;

[0025] Construct the coal quality parameter model according to the principle that the total of fixed carbon, moisture, ash and volatile matter is a fixed value.

[0026] In some embodiments, based on the coal quality parameter model, calculate the combustion flue gas volume according to the unit operation parameters, including:

[0027] Set the calorific value of the input coal.

[0028] Perform proximate analysis of coal based on the calorific value of the input coal, and perform inverse balance calculation based on the results of proximate analysis of coal to obtain the first boiler efficiency.

[0029] Calculate the coal consumption and output heat according to the calorific value of the input coal, and perform direct balance calculation based on the coal consumption and output heat to obtain the second boiler efficiency.

[0030] Calculate the evaluation parameter, where the evaluation parameter is the difference between the first boiler efficiency and the second boiler efficiency.

[0031] Output the coal quality parameters based on the evaluation parameter.

[0032] In some embodiments, output the coal quality parameters based on the evaluation parameter, including:

[0033] Obtain a preset evaluation threshold.

[0034] If the evaluation parameter is less than the preset evaluation threshold, output the coal quality parameters, and calculate the combustion flue gas volume according to the coal quality parameters and the results of proximate analysis of coal.

[0035] If the evaluation parameter is greater than or equal to the preset evaluation threshold, modify the calorific value of the input coal.

[0036] In some embodiments, the method further includes:

[0037] Obtain the boiler historical data and the combustion flue gas volume.

[0038] Perform parameter fitting on the boiler historical data to generate the boiler air leakage rate function.

[0039] Obtain the mill operation parameters, and calculate the boiler air leakage rate based on the mill operation parameters and the boiler air leakage rate function.

[0040] Calculate the product of the boiler air leakage rate and the combustion flue gas volume to obtain the boiler body air leakage volume.

[0041] In some embodiments, the method further includes:

[0042] Obtain the oxygen content of the flue gas at the inlet and outlet of the air preheater, where the oxygen content of the inlet flue gas is the volume fraction of oxygen at the inlet of the air preheater; the oxygen content of the outlet flue gas is the volume fraction of oxygen at the outlet of the air preheater;

[0043] Calculate the air leakage rate of the air preheater based on the oxygen content of the inlet flue gas and the oxygen content of the outlet flue gas;

[0044] Calculate the total gas volume of the boiler, where the total gas volume of the boiler is equal to the sum of the combustion flue gas volume and the air leakage volume of the boiler body;

[0045] Calculate the air leakage volume of the air preheater based on the total gas volume of the boiler, where the air leakage volume of the air preheater is the product of the total gas volume of the boiler and the air leakage rate of the air preheater.

[0046] In some embodiments, calculating the flow rate ratio of the induced draft fan according to the induced draft fan equipment parameters includes:

[0047] Read the motor current and the total fan pressure from the induced draft fan equipment parameters;

[0048] Calculate the total equipment current based on the motor currents of multiple induced draft fans, and calculate the total equipment wind pressure based on the total fan pressures of multiple induced draft fans;

[0049] Calculate the flow rate ratio of the induced draft fan based on the motor current, the total fan pressure, the total equipment current, and the total equipment wind pressure.

[0050] According to another aspect of the present application, there is provided a flow rate measurement system for an induced draft fan of a pulverized coal boiler, the system including a coal mill, a pulverized coal boiler, an induced draft fan, an air preheater, and a data processing device;

[0051] Wherein, the coal mill is configured to crush coal into pulverized coal and transport it to the pulverized coal boiler; the pulverized coal boiler is configured to burn the pulverized coal; the induced draft fan is configured to transport the flue gas generated during the pulverized coal combustion process in the pulverized coal boiler to the air preheater; the air preheater is configured to recover the waste heat in the flue gas to heat the air required for the combustion of the pulverized coal boiler;

[0052] The data processing device establishes a communication connection with at least one of the coal mill, the pulverized coal boiler, the induced draft fan, and the air preheater; the data processing device is further configured to:

[0053] Obtain the combustion flue gas volume, the air leakage volume of the air preheater, and the air leakage volume of the boiler body;

[0054] Calculate the sum of the combustion flue gas volume, the air leakage volume of the air preheater, and the air leakage volume of the boiler body to generate the total flue gas flow rate;

[0055] Obtain the parameters of the induced draft fan equipment, where the parameters of the induced draft fan equipment include the motor current and the total fan pressure of at least two induced draft fans;

[0056] Calculate the flow rate ratio of the induced draft fan according to the parameters of the induced draft fan equipment;

[0057] Output the flue gas flow rate of the induced draft fan according to the flow rate ratio, where the flue gas flow rate is the product of the flow rate ratio and the total flue gas flow rate.

[0058] According to another aspect of the present application, there is provided a computer device, including a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor. When the processor executes the program, the above-mentioned method for measuring the flow rate of the induced draft fan in a pulverized coal boiler is implemented.

[0059] According to still another aspect of the present application, there is provided a storage medium, on which a computer program is stored. When the program is executed by a processor, the above-mentioned method for measuring the flow rate of the induced draft fan in a pulverized coal boiler is implemented.

[0060] By means of the above technical solution, the embodiments of the present application provide a method and system for measuring the flow rate of the induced draft fan in a pulverized coal boiler. The method first obtains the combustion flue gas volume, the air preheater leakage air volume, and the boiler body leakage air volume. Among them, the combustion flue gas volume is obtained by calculating based on the operating parameters and steam parameters of the coal mill; the air preheater leakage air volume is calculated according to the oxygen content of the flue gas at the inlet and outlet of the air preheater; the boiler body leakage air volume is calculated according to the boiler air leakage rate function fitted from the historical data of the boiler. Then, the total flue gas flow rate is calculated according to the combustion flue gas volume, the air preheater leakage air volume, and the boiler body leakage air volume. By obtaining the parameters of the induced draft fan equipment and calculating the flow rate ratio of the induced draft fan according to the parameters of the induced draft fan equipment, the flue gas flow rate of the induced draft fan is output according to the flow rate ratio. The method can calculate the flue gas flow rate by using relatively accurately measured quantities, which can improve the measurement accuracy to solve the problem of low accuracy of the measurement result of the induced draft fan flow rate parameter.

[0061] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0063] Figure 1 It is a schematic structural diagram of the pulverized coal combustion process equipment provided by the embodiment of the present application;

[0064] Figure 2 Schematic flow diagram of the method for measuring the flow rate of the induced draft fan of the pulverized coal boiler provided by the embodiment of the present application;

[0065] Figure 3 Schematic flow diagram of calculating the flue gas flow rate of the induced draft fan provided by the embodiment of the present application;

[0066] Figure 4 Schematic flow diagram of outputting coal quality parameters provided by the embodiment of the present application;

[0067] Figure 5 Schematic structural diagram of the flow rate measurement system of the induced draft fan of the pulverized coal boiler provided by the embodiment of the present application;

[0068] Figure 6 Schematic structural diagram of the computer device provided by the embodiment of the present application. Detailed implementation manners

[0069] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0070] The method for measuring the flow rate of the induced draft fan of the pulverized coal boiler described in the embodiment of the present application can be applied to industrial scenarios with pulverized coal combustion processes. For example, thermal power plants, heating plants, coal chemical plants, industrial furnaces, etc. The pulverized coal combustion process is an efficient combustion technology. By grinding coal into fine powder and then burning it, the combustion efficiency can be improved and pollutant emissions can be reduced.

[0071] The pulverized coal combustion process may involve the coordinated operation of multiple devices. As Figure 1 shown, in some embodiments, the devices used in the pulverized coal combustion process include coal mills, pulverized coal boilers, induced draft fans, air preheaters, etc. Among them, the coal mill is a device that grinds raw coal into pulverized coal. Since the finer the particle size of the pulverized coal, the more complete the combustion and the higher the boiler efficiency, the coal mill can crush the raw coal into pulverized coal through mechanical grinding such as ball mills, roller mills or the air impact of fan coal mills. After the raw coal is processed into pulverized coal by the coal mill, the coal mill can transport the pulverized coal to the burner of the pulverized coal boiler through pipelines, conveyor belts, etc.

[0072] The pulverized coal boiler is a device that burns pulverized coal to generate high-temperature and high-pressure steam. In some embodiments, the pulverized coal boiler may include components such as a furnace, a burner, and a flue. The pulverized coal transported by the coal mill enters the pulverized coal boiler and can be sprayed into the furnace through the burner, so that the pulverized coal can burn rapidly at high temperature and release heat energy. The released heat energy can heat the heat transfer medium in the furnace and be converted into a high-temperature heat transfer medium. The high-temperature heat transfer medium is then transported to the heat supply end through pipelines to utilize the heat energy for energy conversion or heat transfer.

[0073] Taking a thermal power plant as an example, if the heat-conducting medium is water, after the pulverized coal boiler releases heat energy, the water in the furnace can be heated into high-pressure steam. The steam is then transported through a pipeline to the steam turbine to drive the rotation of the steam turbine, which in turn drives the generator to generate electricity, thus converting heat energy into electrical energy.

[0074] It can be seen that the input substances of the pulverized coal boiler are pulverized coal and air. After the combustion process, the output substances of the pulverized coal boiler are high-temperature heat-conducting medium and flue gas. The flue gas generated during the pulverized coal combustion process can be discharged through the flue. In addition, in order to meet the requirements of different pulverized coal combustion processes and improve the thermal efficiency of the pulverized coal combustion process, the pulverized coal boiler can also include other components such as water-cooled walls, superheaters, reheaters, economizers, etc. Among them, the water-cooled wall is the heating surface around the furnace, which can absorb the radiant heat in the furnace and heat the water into saturated steam; the superheater can heat the saturated steam into superheated steam to meet the requirements of the steam turbine for steam temperature; the reheater can reheat the steam discharged from the high-pressure cylinder of the steam turbine to increase the temperature and pressure of the steam; the economizer can utilize the waste heat of the flue gas at the tail of the boiler to preheat the feed water and improve the thermal efficiency of the boiler.

[0075] The air preheater, abbreviated as the air heater, is a device that uses the waste heat of the flue gas at the tail of the pulverized coal boiler to heat the air required for combustion. The air preheater can improve the combustion efficiency and reduce the flue gas discharge temperature. The combustion-supporting gases such as air required in the pulverized coal boiler combustion process can pass through the heat exchange surface of the air preheater to absorb the heat in the flue gas and heat the cold air. After the cold air is heated, it is sent into the boiler furnace through the forced draft fan for the combustion of pulverized coal. Therefore, the air preheater can provide the hot air required for the combustion of the pulverized coal boiler, and at the same time recover the waste heat in the flue gas and improve the system efficiency.

[0076] The induced draft fan can extract the flue gas generated during the combustion process of the pulverized coal substance, thereby maintaining the negative pressure in the furnace of the pulverized coal boiler and ensuring stable combustion. Since the induced draft fan can, through the suction effect, extract the high-temperature flue gas after combustion from the tail of the pulverized coal boiler, so that the flue gas is processed by flue gas post-treatment equipment such as air preheaters and dust collectors and finally discharged into the atmosphere, the operating state of the induced draft fan can directly affect the furnace pressure and combustion stability. If the induced draft fan fails, it will cause abnormal furnace pressure, affect the combustion efficiency and even lead to safety accidents.

[0077] To reduce the failure probability of the induced draft fan, real-time monitoring can be performed on the operation process of the induced draft fan, that is, by measuring the operation parameters of the induced draft fan during operation to determine whether the induced draft fan has operation failures and potential operation risks. In some embodiments, since the fan can generate operation parameters in multiple dimensions during operation, such as flow parameters, power parameters, energy efficiency ratio, noise parameters, etc. Therefore, these operation parameters can be measured by detection units such as sensors and applied to the industrial control system to monitor the operation status of each fan in real time and meet the monitoring and early warning requirements.

[0078] For example, the flow parameter, as a key parameter of the induced draft fan, can be used to analyze the operation conditions of the induced draft fan and the fan failure conditions. Among them, the flow parameter is also called the air volume parameter, which refers to the volume of gas passing through the fan per unit time. Since the induced draft fan is applied to the combustion process of the pulverized coal boiler, and the inlet flue gas system of the induced draft fan applied to the pulverized coal boiler is huge, compactly arranged, and complex in structure, resulting in problems such as uneven distribution of flue gas flow velocity and large turbulence intensity in the flue gas cross-section, so it is difficult to obtain the flow parameter.

[0079] In order to obtain the flow parameter, in some embodiments, the flow parameter can be measured by installing a multi-point matrix flowmeter to monitor the operation status of the induced draft fan. However, due to the poor operation environment of the induced draft fan of the pulverized coal boiler equipment and the gas flowing in the air supply space containing a large amount of dust and corrosive substances, the multi-point matrix flowmeter is prone to problems such as dust-laden gas flow abrasion and corrosion. Therefore, when using the multi-point matrix flowmeter to measure the flow parameter of the induced draft fan of the pulverized coal boiler equipment, data distortion is likely to occur, resulting in a low accuracy of the measurement result of the induced draft fan flow parameter.

[0080] To solve the problem of low accuracy of the measurement result of the induced draft fan flow parameter, some embodiments of the present application provide a method for measuring the flow of the induced draft fan of a pulverized coal boiler. The method can be applied to electronic devices with data processing capabilities, such as computers, mobile terminals, industrial control machines, servers, etc. For the sake of convenience of description, in the embodiments of the present application, the data processing device is uniformly used as the execution subject of the method. It should be understood that the method can select a suitable execution subject according to the specific application scenario, and the specific examples are not shown one by one in the embodiments of the present application. As Figure 2 shown, the method includes:

[0081] S101. Obtain the combustion flue gas volume, the air leakage volume of the air preheater, and the air leakage volume of the boiler body.

[0082] In the embodiments of the present application, in order to overcome the problem of inaccurate measurement results of the flowmeter, a quantity with relatively accurate measurement results is used to indirectly calculate the flue gas flow rate. The quantity with relatively accurate measurement results may include the combustion flue gas quantity, the air leakage quantity of the air preheater, and the air leakage quantity of the boiler body. Therefore, the data processing device can obtain the combustion flue gas quantity, the air leakage quantity of the air preheater, and the air leakage quantity of the boiler body.

[0083] Among them, the combustion flue gas quantity is used to characterize the flue gas quantity generated after pulverized coal burns in a pulverized coal boiler per unit time. The combustion flue gas quantity can be detected by a gas flow sensor arranged in the flue, or can be calculated from the operating parameters of the coal mill and the steam parameters.

[0084] As Figure 3 shown, in some embodiments, in order to obtain the combustion flue gas quantity, the data processing device can obtain the historical coal quality industrial analysis data within a preset detection period. Then perform multiple linear regression analysis on the historical coal quality industrial analysis data to obtain a coal quality parameter model. By collecting the unit operating parameters and based on the coal quality parameter model, calculate the combustion flue gas quantity according to the unit operating parameters. Among them, the unit operating parameters include the operating parameters of the coal mill and the steam parameters.

[0085] The historical coal quality industrial analysis data is a data set constructed by analyzing the physical structure and chemical composition of the used pulverized coal and combining the measurement data of the pulverized coal combustion process. Therefore, in the historical coal quality industrial analysis data, it can include pulverized coal physical parameters, pulverized coal chemical parameters, and pulverized coal quality parameters. The coal quality parameters can include moisture (M ar ), ash (A ar ), volatile matter (V ar ), fixed carbon (F C ) and other main parameter indicators. The coal quality parameter model can be used to characterize the functional relationship between the coal quality parameters, the unit operating parameters, and the pulverized coal physical parameters and pulverized coal chemical parameters.

[0086] In order to construct the coal quality parameter model, the data processing device can obtain the historical coal quality industrial analysis data within a preset detection period. For example, if the preset detection period is half a year, the data processing device can obtain the historical coal quality industrial analysis data in the recent half year. After obtaining the historical coal quality industrial analysis data, the data processing device can perform multiple linear regression analysis based on the historical coal quality industrial analysis data and the corresponding operating parameters of the historical coal quality industrial analysis data to obtain the coal quality parameter model. Exemplarily, the independent variables of the coal quality parameter model include multiple variables used to characterize the unit operating parameters; the dependent variable of the coal quality parameter model includes variables used to characterize the coal quality parameters in multiple dimensions.

[0087] Therefore, in some embodiments, when the data processing device performs multiple linear regression analysis on the historical coal quality industrial analysis data, it may first calculate the moisture content of the coal based on the principle of mass and energy conservation at the inlet and outlet of the coal mill according to the operating parameters of the coal mill. Then, perform multiple linear regression analysis on the historical coal quality industrial analysis data to obtain the first functional relationship among calorific value, moisture, and ash. Then, according to the first functional relationship and the moisture content, determine the second functional relationship between calorific value and ash, and calculate the third functional relationship between calorific value and volatile matter based on the second functional relationship. Thus, construct the coal quality parameter model according to the principle that the total of fixed carbon, moisture, ash, and volatile matter is a fixed value.

[0088] For example, according to the mass and energy conservation at the inlet and outlet of the coal mill, the moisture content Mar in the coal can be calculated, that is, the calculation is performed according to the following formula of the mass and energy conservation principle at the inlet and outlet of the coal mill:

[0089] Q phrc +Q dbih +Q phlca +Q phg =Q weh +Q hc +Q dboh +Q cmhd ;

[0090] Wherein, Q phrc represents the physical heat of raw coal; Q dbih represents the heat brought in by the drying agent; Q phlca represents the physical heat of the leaked cold air; Q phg represents the physical heat generated by grinding; Q weh represents the heat of moisture evaporation; Q hc represents the heat for heating the coal material; Q dboh represents the heat carried out by the drying agent; Q cmhd represents the heat dissipation of the coal mill.

[0091] Performing multiple linear regression analysis on the historical coal quality industrial analysis data for nearly half a year can obtain the first functional relationship between calorific value and moisture and ash. Since the moisture content M ar in the coal can be calculated from the operating parameters of the coal mill, the relationship between calorific value and ash can be obtained. That is, the second functional relationship is:

[0092] Q net,ar =f(A ar , M ar );

[0093] Wherein, Q net,ar represents the net calorific value of the coal; Aar represents the ash content; Mar represents the moisture content.

[0094] Similarly, according to the multiple linear regression analysis, the relationship between calorific value, moisture, ash, and volatile matter can be obtained. Combining with the values calculated above, the relationship between calorific value and volatile matter can be obtained. That is, the third functional relationship is:

[0095] Q net,ar = f(A ar , M ar , V ar );

[0096] Among them, Q net,ar represents the calorific value; A ar represents the ash content; M ar represents the moisture content; V ar represents the volatile matter content.

[0097] The principle that the fixed carbon, moisture, ash, and total volatile matter are fixed values, that is:

[0098] F c + M ar + A ar + V ar = 1;

[0099] Among them, F c represents the fixed carbon amount; M ar represents the moisture content; A ar represents the ash content; V ar represents the volatile matter content.

[0100] According to the principle that the fixed carbon, moisture, ash, and total volatile matter are fixed values, after transforming the above formula, the functional relationship between fixed carbon and moisture, ash, and volatile matter can be obtained, that is: Fc = 1 - Mar - Aar - Var, that is, the coal quality parameter model is obtained.

[0101] After obtaining the coal quality parameter model, the data processing device can calculate the combustion flue gas volume based on the coal quality parameter model and according to the unit operation parameters, that is, as Figure 4 shown, in some embodiments, when the data processing device calculates the combustion flue gas volume based on the coal quality parameter model and according to the unit operation parameters, the input coal calorific value can be set first. Among them, the input coal calorific value is an input parameter for calculating the coal quality parameter model. For example, the input coal calorific value can be an assumed coal calorific value set according to actual measurement needs.

[0102] After setting the input coal calorific value, the data processing device can respectively perform coal quality industrial analysis based on the input coal calorific value, and calculate the coal consumption and output heat according to the input coal calorific value. Then, perform an inverse balance calculation based on the results of the coal quality industrial analysis to obtain the first boiler efficiency; and perform a direct balance calculation based on the coal consumption and output heat to obtain the second boiler efficiency.

[0103] After obtaining the first boiler efficiency and the second boiler efficiency, an evaluation parameter can also be calculated based on the first boiler efficiency and the second boiler efficiency. Among them, the evaluation parameter is the difference between the first boiler efficiency and the second boiler efficiency. The evaluation parameter can be used to determine the appropriate output coal quality parameter, that is, the data processing device can output the coal quality parameter based on the evaluation parameter.

[0104] That is, as Figure 4 shown, in some embodiments, outputting the coal quality parameter based on the evaluation parameter further includes: obtaining a preset evaluation threshold, and comparing the calculated evaluation parameter with the preset evaluation threshold. If the evaluation parameter is less than the preset evaluation threshold, output the coal quality parameter, and calculate the combustion flue gas volume according to the coal quality parameter and the coal quality proximate analysis result. If the evaluation parameter is greater than or equal to the preset evaluation threshold, modify the input coal calorific value.

[0105] After obtaining the coal quality parameter model, the data processing device can calculate the coal quality proximate analysis result when the pulverized coal calorific value is known. Among them, the coal quality proximate analysis result can include, when the current pulverized coal calorific value is known, inversely deducing the coal quality proximate analysis components. For example, the coal quality proximate analysis components can include heat loss due to flue gas discharge, heat loss due to incomplete combustion of gas, heat loss due to incomplete combustion of solid, heat dissipation loss, and physical heat loss of ash and slag. Among them, the heat loss due to flue gas discharge is the heat carried away by the boiler flue gas. It can be calculated according to the following formula:

[0106]

[0107] V gy = 0.98V gk +(α py -1)·V gk ;

[0108]

[0109] Among them, q2 is the heat loss due to flue gas discharge; V gk is the theoretical air volume required for combustion, V gy is the dry flue gas volume, V H2O is the volume of water in the flue gas; K is a calculation coefficient related to the fuel type, is the percentage of carbon content in ash and slag to the carbon content in coal, C fh is the carbon content in fly ash, C lz is the carbon content in slag, α py is the excess air coefficient of flue gas discharge, d k is the absolute humidity of ambient air, t py is the flue gas discharge temperature (°C); t0 is the reference temperature (which can be taken as 20°C).

[0110] Heat loss q due to incomplete combustion of gas qt is the heat loss caused by combustible gases (such as CO) in the flue gas. Heat loss q due to incomplete combustion of gas qt can be calculated according to the following formula:

[0111] q3 = 0.032 × α py × CO × 100%;

[0112] where q3 is the heat loss due to incomplete combustion of gas; α py is the excess air coefficient at the smoke exhaust; CO is the volume percentage of carbon monoxide in the smoke exhaust.

[0113] Heat loss q due to incomplete combustion of solid gt is the heat loss caused by unburned carbon in fly ash and slag. Heat loss q due to incomplete combustion of solid gt can be calculated according to the following formula:

[0114]

[0115] where q4 is the heat loss due to incomplete combustion of solid; A ar is the ash content of the as-received coal entering the furnace (%); is the percentage of carbon content in slag to carbon content in coal; Q net,ar is the lower calorific value of the as-received coal entering the furnace (kJ / kg).

[0116] Heat dissipation loss q5 is the heat dissipated from the boiler furnace wall and pipes to the surrounding environment. The value range can be 0.8% - 3%.

[0117] Physical heat loss q6 of slag is relatively small, about 0.05%.

[0118] Therefore, based on the inverse balance calculation formula, the first boiler efficiency can be obtained, that is:

[0119] η f = 100% - (q2 + q3 + q4 + q5 + q6);

[0120] where η f is the first boiler efficiency; q2 is the heat loss of the exhaust gas; q3 is the heat loss due to incomplete combustion of gas; q4 is the heat loss due to incomplete combustion of solid; q5 is the heat dissipation loss; q6 is the physical heat loss of slag.

[0121] When calculating the first boiler efficiency, the coal consumption and output heat can also be calculated according to the calorific value of the input coal, and a direct balance calculation can be performed based on the coal consumption and output heat to obtain the second boiler efficiency. Among them, the direct balance method calculates the boiler efficiency by measuring the input heat and effective utilization heat of the boiler.

[0122] For example, the input heat of fuel Q can be determined according to the set input parameter of coal calorific value. s The input heat of fuel is the product of fuel consumption and the lower calorific value of fuel, i.e., Q s = fuel consumption × lower calorific value of fuel. Among them, the fuel consumption can be obtained through actual measurement; the lower calorific value of fuel can be obtained through coal quality analysis.

[0123] Then, the effective utilization heat Q is calculated based on the steam or hot water output of the boiler eu , that is, the heat output by the boiler. The effective utilization heat can be calculated according to the following formula:

[0124] Q eu = Q gr +Q re ;

[0125] Q gr = EV × (H gr -h gr );

[0126] Q re = RE × (H re -h re );

[0127] Among them, Q eu is the effective utilization heat, Q gr is the heat absorbed by the superheated steam of the boiler, Q re is the heat absorbed by the reheated steam of the boiler; EV is the evaporation capacity of the boiler, indicating the amount of steam generated by the boiler per hour; RE is the reheating evaporation capacity; H gr is the enthalpy value of the superheated steam, H re is the enthalpy value of the reheated steam, which can be obtained from the enthalpy-entropy diagram or steam table; h gr is the enthalpy value of the feed water, h re is the enthalpy value at the inlet of the reheated steam, which is also obtained from the enthalpy-entropy diagram.

[0128] After calculating the input heat of fuel Q s and the effective utilization heat Q eu , the ratio of the effective utilization heat Q eu to the input heat of fuel Q s can be calculated, and the second boiler efficiency η z can be obtained.

[0129] Based on the first boiler efficiency obtained by inverse balance calculation and the second boiler efficiency obtained by direct balance calculation, an evaluation parameter can be calculated, that is, the evaluation parameter is the difference between the first boiler efficiency and the second boiler efficiency, which is used to judge whether the calculated boiler efficiency conforms to the actual state. If the evaluation parameter η f -η z is less than the preset evaluation threshold ε, that is, ηf -η z When < ε, it is determined that the calculated boiler efficiency conforms to the actual state. Therefore, the coal quality parameters can be output, and the output coal quality parameters can be used to calculate the combustion flue gas volume Q1. If the evaluation parameter is greater than or equal to the preset evaluation threshold, that is, η f -η z ≥ ε, it indicates that the boiler efficiency calculated based on the current set calorific value of the input coal does not conform to the actual state. Therefore, the calorific value of the input coal can be modified, and the first boiler efficiency and the second boiler efficiency can be recalculated according to the above steps until η f -η z < ε and the coal quality parameters are output.

[0130] After calculating and outputting the coal quality parameters according to the coal quality parameter model, the data processing device can also calculate the combustion flue gas volume according to the coal quality parameters and the coal quality industrial analysis results. That is, in the case of known pulverized coal industrial analysis parameters, the flue gas volume Q1 generated by boiler combustion can be calculated according to industry standards such as DL / T904-2015.

[0131] Q1 = V gy + V H2O ;

[0132] Among them, V gy is the dry flue gas volume, and V H2O is the volume of water in the flue gas.

[0133] The boiler body air leakage rate is used to characterize the amount of gas leaked through the pulverized coal boiler during the pulverized coal combustion and flue gas emission processes. The boiler body air leakage rate can be obtained by calculating according to the boiler air leakage rate function, where the boiler air leakage rate function is a fitting function obtained by performing fitting analysis on the boiler historical data.

[0134] In some embodiments, in order to obtain the boiler body air leakage rate, the data processing device can first obtain the boiler historical data and the combustion flue gas volume, and perform parameter fitting on the boiler historical data to generate the boiler air leakage rate function.

[0135] Among them, the boiler historical data can be obtained through testing the pulverized coal boiler. The boiler historical data can include the operating parameters of the coal mill and the boiler air leakage rate measured during multiple test processes. Among them, the operating parameters of the coal mill can include output-related parameters, air volume and air pressure parameters, pulverized coal fineness and particle size parameters, operation control parameters, energy consumption and efficiency parameters, etc. By using one or more combinations of these parameters as independent variables and the boiler air leakage rate as the dependent variable for multiple linear fitting, the functional relationship between the boiler air leakage rate and the operating parameters of the coal mill, that is, the boiler air leakage rate function, can be determined.

[0136] Obtain the operating parameters of the coal mill again, and calculate the air leakage rate of the boiler based on the operating parameters of the coal mill and the boiler air leakage rate function. That is, after obtaining the current operating parameters of the coal mill, the operating parameters of the coal mill can be input into the boiler air leakage rate function, so as to calculate the boiler air leakage rate λ under the current operating parameters of the coal mill. Then calculate the product of the boiler air leakage rate and the combustion flue gas volume to obtain the air leakage volume of the boiler body. That is, according to the boiler historical test data, the boiler air leakage rate λ can be obtained, then the air leakage volume Q2 of the boiler body = λ × Q1.

[0137] The air leakage volume of the air preheater is used to characterize the air volume leaked from the air preheater during the process of using the waste heat of the flue gas at the tail of the pulverized coal boiler to heat the air required for combustion. The air leakage volume of the air preheater can be obtained by calculating the oxygen content of the flue gas at the inlet and the oxygen content of the flue gas at the outlet of the air preheater.

[0138] In some embodiments, in order to calculate the air leakage volume of the air preheater, the data processing device can obtain the oxygen content of the flue gas at the inlet and the oxygen content of the flue gas at the outlet of the air preheater. Among them, the oxygen content of the inlet flue gas is the volume fraction of oxygen at the inlet of the air preheater; the oxygen content of the outlet flue gas is the volume fraction of oxygen at the outlet of the air preheater.

[0139] After obtaining the oxygen content of the flue gas at the inlet and the oxygen content of the flue gas at the outlet of the air preheater, calculate the air leakage rate of the air preheater according to the oxygen content of the inlet flue gas and the oxygen content of the outlet flue gas, and then calculate the total boiler gas volume and calculate the air leakage volume of the air preheater according to the total boiler gas volume. Among them, the total boiler gas volume is equal to the sum of the combustion flue gas volume and the air leakage volume of the boiler body. The air leakage volume of the air preheater is the product of the total boiler gas volume and the air leakage rate of the air preheater.

[0140] That is, the data processing device can obtain the oxygen content of the flue gas at the inlet of the air preheater and the oxygen content of the flue gas at the outlet After that, according to the oxygen content of the inlet flue gas and the oxygen content of the outlet flue gas Calculate the air leakage rate of the air preheater, that is:

[0141]

[0142] Among them, η lv is the air leakage rate of the air preheater; is the volume fraction of oxygen at the outlet of the air preheater, is the volume fraction of oxygen at the inlet of the air preheater.

[0143] Based on the above formula, the air leakage rate η of the air preheater is calculated lv After that, the data processing device can calculate the air leakage volume Q3 of the air preheater based on the combustion flue gas volume Q1 and the air leakage volume Q2 of the boiler body, that is:

[0144] Q3 = (Q1 + Q2) × η lv ;

[0145] Wherein, Q3 is the air leakage rate of the air preheater; Q1 is the combustion flue gas volume; Q2 is the air leakage rate of the boiler body; η lv is the air leakage rate of the air preheater.

[0146] S102. Calculate the sum of the combustion flue gas volume, the air leakage rate of the air preheater, and the air leakage rate of the boiler body to generate the total flue gas flow rate.

[0147] After obtaining the combustion flue gas volume Q1, the air leakage rate Q2 of the boiler body, and the air leakage rate Q3 of the air preheater, the data processing device can calculate the total flue gas flow rate Q according to the combustion flue gas volume Q1, the air leakage rate Q2 of the boiler body, and the air leakage rate Q3 of the air preheater. Wherein, the total flue gas flow rate Q is the sum of the combustion flue gas volume Q1, the air leakage rate Q2 of the boiler body, and the air leakage rate Q3 of the air preheater. That is:

[0148] Q = Q1 + Q2 + Q3;

[0149] Wherein, Q is the total flue gas flow rate; Q1 is the combustion flue gas volume; Q2 is the air leakage rate of the boiler body; Q3 is the air leakage rate of the air preheater.

[0150] S103. Obtain the induced draft fan equipment parameters.

[0151] Wherein, the induced draft fan equipment parameters include the motor current and the total fan pressure of at least two induced draft fans. According to the number of induced draft fans used in the pulverized coal boiler, the induced draft fan equipment parameters suitable for the number of induced draft fans can be obtained. For example, when two induced draft fans, namely induced draft fan A and induced draft fan B, are provided on the pulverized coal boiler, the induced draft fan equipment parameters corresponding to induced draft fan A and induced draft fan B can be obtained respectively.

[0152] The induced draft fan equipment parameters can be a parameter set including the motor current and the total fan pressure of the induced draft fan. Wherein, the motor current refers to the current value passing through the motor winding during the operation of the induced draft fan motor, and the motor current can reflect the load condition of the motor. The total fan pressure refers to the total pressure difference between the outlet and the inlet of the fan, which is the sum of the static pressure and the dynamic pressure. The total fan pressure can reflect the ability of the fan to overcome the system resistance.

[0153] In some embodiments, the induced draft fan equipment parameters can be obtained according to information such as the equipment model. For example, when building a set of pulverized coal combustion process equipment, the induced draft fan equipment model used in the pulverized coal boiler can be obtained, and a database of the induced draft fan equipment model can be constructed. In the constructed database, the induced draft fan equipment model and the induced draft fan equipment parameters can be set, and an association relationship can be established. Then, when obtaining the induced draft fan equipment parameters, the data processing device can extract the equipment parameters from the database based on the induced draft fan equipment model, and parse the motor current and the total fan pressure from the equipment parameters.

[0154] In some embodiments, the induced draft fan equipment parameters can also be obtained through real-time detection by sensors. For example, to detect the motor current of the induced draft fan, a current sensor, such as a clamp ammeter, a motor control cabinet, a data acquisition system, etc., can be installed in the power supply circuit of the induced draft fan. Similarly, to detect the total fan pressure of the induced draft fan, pressure sensors can be installed at the inlet and outlet of the fan, or a pitot tube can be used to measure the dynamic pressure and static pressure at the inlet and outlet of the fan, or an anemometer can be used to measure the wind speed at the inlet and outlet of the fan. When it is necessary to obtain the induced draft fan equipment parameters, the data processing device can send data acquisition instructions to the current sensor, pressure sensor, etc., and the current sensor and pressure sensor can measure the motor current and total fan pressure in response to the data acquisition instructions, thereby obtaining the induced draft fan equipment parameters.

[0155] S104, calculating the flow ratio of the induced draft fan according to the induced draft fan equipment parameters;

[0156] After obtaining the induced draft fan equipment parameters, the data processing device can calculate the flow ratio corresponding to each induced draft fan based on the induced draft fan equipment parameters. The flow ratio is used to represent the load ratio of the induced draft fan to the flue gas. The larger the flow ratio, the greater the flue gas flow corresponding to the induced draft fan.

[0157] In some embodiments, to calculate the flow ratio, the data processing device may read the motor current and the fan total pressure from the induced draft fan equipment parameters when calculating the flow ratio of the induced draft fan based on the induced draft fan equipment parameters. The device total current is then calculated based on the motor currents of the multiple induced draft fans, and the device total pressure is calculated based on the fan total pressures of the multiple induced draft fans. The flow ratio of the induced draft fan is thereby calculated based on the motor current, the fan total pressure, the device total current, and the device total pressure.

[0158] For example, after obtaining the equipment parameters of induced draft fan A and induced draft fan B, the motor current I and fan total pressure P can be extracted from the equipment parameters respectively, that is, the motor current of induced draft fan A is I A , the total fan pressure of induced draft fan A is P A ; The motor current of induced draft fan B is I B , the total fan pressure of induced draft fan B is P B Then, according to the motor current of induced draft fan A and induced draft fan B, I A and I B Calculate the total current of the device (I A +I B ). And according to the total fan pressure P of induced draft fan A and induced draft fan B A and P B Calculate the total wind pressure of the equipment (P A +P B ).

[0159] Then, according to the motor currents and the total pressures of the two induced draft fans, calculate the flow rate ratio of the two induced draft fans according to the following formula, that is:

[0160]

[0161] where ζ A is the flow rate ratio of induced draft fan A; I A is the motor current of induced draft fan A; P A is the total pressure of induced draft fan A; I B is the motor current of induced draft fan B; P B is the total pressure of induced draft fan B.

[0162]

[0163] where ζ B is the flow rate ratio of induced draft fan B; I A is the motor current of induced draft fan A; P A is the total pressure of induced draft fan A; I B is the motor current of induced draft fan B; P B is the total pressure of induced draft fan B.

[0164] S105. Output the flue gas flow rate of the induced draft fan according to the flow rate ratio.

[0165] After calculating the flow rate ratio of the induced draft fan, the data processing device can calculate and output the flue gas flow rate of the induced draft fan according to the flow rate ratio. Among them, the flue gas flow rate is the product of the flow rate ratio and the total flue gas flow rate, that is:

[0166]

[0167] where Q A is the flue gas flow rate of induced draft fan A; ζ A is the flow rate ratio of induced draft fan A; Q is the total flue gas flow rate.

[0168]

[0169] where Q B is the flue gas flow rate of induced draft fan B; ζ B is the flow rate ratio of induced draft fan B; Q is the total flue gas flow rate.

[0170] By applying the technical solutions of the above embodiments, based on the method for measuring the flow rate of the induced draft fan of the pulverized coal boiler provided in the above embodiments, the data processing device can calculate the flue gas volume Q1 generated by boiler combustion by using the operating parameters of the coal mill, steam parameters, etc., and fit the boiler air leakage rate function by using the boiler historical test report to calculate the air leakage volume Q2 of the boiler body, and calculate the air leakage volume Q3 of the air preheater by using the oxygen content at the inlet and outlet of the air preheater. Then, the above flue gas volume and air leakage volume are summed to obtain the total flue gas volume. Finally, the flue gas flow rate distribution ratio of the two induced draft fans is calculated according to parameters such as the motor current and the total fan pressure of multiple induced draft fans, so as to obtain the flue gas flow rate of each induced draft fan. The method can calculate the flue gas flow rate by using relatively accurate measured quantities, improve the measurement accuracy, and solve the problem of low accuracy of the measurement results of the induced draft fan flow rate parameters.

[0171] In some embodiments, as a specific implementation of the method for measuring the flow rate of the induced draft fan of the pulverized coal boiler described in the above embodiments, some embodiments of the present application further provide a system for measuring the flow rate of the induced draft fan of the pulverized coal boiler, as Figure 5 shown, the system includes a coal mill, a pulverized coal boiler, an induced draft fan, an air preheater, and a data processing device; wherein, the coal mill is configured to crush coal into pulverized coal and transport it to the pulverized coal boiler; the pulverized coal boiler is configured to burn the pulverized coal; the induced draft fan is configured to transport the flue gas generated during the pulverized coal combustion process in the pulverized coal boiler to the air preheater; the air preheater is configured to recover the waste heat in the flue gas to heat the air required for the combustion of the pulverized coal boiler.

[0172] The data processing device establishes a communication connection with at least one of the coal mill, the pulverized coal boiler, the induced draft fan, and the air preheater; the data processing device is further configured to:

[0173] Obtain the combustion flue gas volume, the air leakage volume of the air preheater, and the air leakage volume of the boiler body;

[0174] Calculate the sum of the combustion flue gas volume, the air leakage volume of the air preheater, and the air leakage volume of the boiler body to generate the total flue gas flow rate;

[0175] Obtain the induced draft fan equipment parameters, where the induced draft fan equipment parameters include the motor current and the total fan pressure of at least two induced draft fans;

[0176] Calculate the flow rate ratio of the induced draft fan according to the induced draft fan equipment parameters;

[0177] Output the flue gas flow rate of the induced draft fan according to the flow rate ratio, where the flue gas flow rate is the product of the flow rate ratio and the total flue gas flow rate.

[0178] By applying the technical solutions of the above embodiments, the embodiments of the present application provide a flow measurement system for an induced draft fan of a pulverized coal boiler. The data processing device of the system can first obtain the combustion flue gas volume, the air leakage volume of the air preheater, and the air leakage volume of the boiler body. Among them, the combustion flue gas volume is calculated based on the operating parameters of the coal mill and the steam parameters; the air leakage volume of the air preheater is calculated based on the oxygen content of the flue gas at the inlet and the oxygen content of the flue gas at the outlet of the air preheater; the air leakage volume of the boiler body is calculated based on the boiler air leakage rate function fitted from the historical data of the boiler. Then, the total flue gas flow is calculated based on the combustion flue gas volume, the air leakage volume of the air preheater, and the air leakage volume of the boiler body. By obtaining the parameters of the induced draft fan device and calculating the flow ratio of the induced draft fan according to the parameters of the induced draft fan device, the flue gas flow of the induced draft fan is output according to the flow ratio. The system can calculate the flue gas flow by using relatively accurate measured quantities, which can improve the measurement accuracy to solve the problem of low accuracy of the measurement result of the flow parameter of the induced draft fan.

[0179] It should be noted that for other corresponding descriptions of each functional unit involved in the flow measurement system for the induced draft fan of the pulverized coal boiler provided by the embodiments of the present application, reference can be made to the corresponding descriptions in the flow measurement method for the induced draft fan of the pulverized coal boiler provided by the above embodiments, which will not be elaborated here.

[0180] As Figure 6 shown, the embodiments of the present application also provide a computer device, which can specifically be a personal computer, a server, a network device, etc. The computer device includes a bus, a processor, a memory, and a communication interface, and may further include an input / output interface and a display device. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store location information. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the steps in the method embodiments are implemented.

[0181] Those skilled in the art can understand that the structure of the above computer device is only a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components, or combine some components, or have different component arrangements.

[0182] In one embodiment, a computer-readable storage medium is also provided. The computer-readable storage medium may be non-volatile or volatile, and stores a computer program. When the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0183] In one embodiment, a computer program product is also provided, including a computer program which, when executed by a processor, implements the steps in the above method embodiments.

[0184] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data that have been authorized by the user or fully authorized by all parties.

[0185] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above method embodiments.

[0186] Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memory can include Read-Only Memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc.

[0187] Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0188] The database involved in the embodiments provided in this application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on blockchain, etc., and is not limited thereto. The processor involved in the embodiments provided in this application can be a general-purpose processor, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., and is not limited thereto.

[0189] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0190] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A method for measuring the flow rate of an induced draft fan in a pulverized coal boiler, characterized in that, The method includes: Obtaining the combustion flue gas volume, the air preheater air leakage volume, and the boiler body air leakage volume; Calculating the sum of the combustion flue gas volume, the air preheater air leakage volume, and the boiler body air leakage volume to generate the total flue gas flow rate; Obtaining the induced draft fan equipment parameters, where the induced draft fan equipment parameters include the motor current and the fan total pressure of at least two induced draft fans; Calculating the flow rate ratio of the induced draft fan according to the induced draft fan equipment parameters; Outputting the flue gas flow rate of the induced draft fan according to the flow rate ratio, where the flue gas flow rate is the product of the flow rate ratio and the total flue gas flow rate.

2. The method according to claim 1, wherein The combustion flue gas volume is obtained by calculating based on the coal mill and boiler operation parameters; The air preheater air leakage volume is obtained by calculating according to the inlet flue gas oxygen content and the outlet flue gas oxygen content of the air preheater; The boiler body air leakage volume is obtained by calculating according to the boiler air leakage rate function, and the boiler air leakage rate function is a fitting function obtained by performing fitting analysis on the boiler historical data.

3. The method according to claim 2, wherein The method further includes: Obtaining the historical coal quality industrial analysis data within a preset detection period; Performing multiple linear regression analysis on the historical coal quality industrial analysis data to obtain a coal quality parameter model; Collecting the unit operation parameters, where the unit operation parameters include the coal mill operation parameters and the steam parameters; Calculating the combustion flue gas volume based on the unit operation parameters based on the coal quality parameter model.

4. The method according to claim 3, characterized in that, Performing multiple linear regression analysis on the historical coal quality industrial analysis data to obtain a coal quality parameter model, including: Calculating the moisture content of the coal based on the coal mill inlet and outlet mass and energy conservation principle based on the coal mill operation parameters; Performing multiple linear regression analysis on the historical coal quality industrial analysis data to obtain the first functional relationship between calorific value, moisture, and ash; Determining the second functional relationship between calorific value and ash according to the first functional relationship and the moisture content; Calculating the third functional relationship between calorific value and volatile matter based on the second functional relationship; Constructing the coal quality parameter model according to the principle that the total of fixed carbon, moisture, ash, and volatile matter is a fixed value.

5. The method according to claim 3, characterized in that, Calculating the combustion flue gas volume based on the unit operation parameters based on the coal quality parameter model, including: Setting the calorific value of the input coal; Performing coal quality industrial analysis based on the input coal calorific value, and performing inverse balance calculation based on the coal quality industrial analysis result to obtain the first boiler efficiency; Calculating the coal consumption and output heat according to the input coal calorific value, and performing direct balance calculation based on the coal consumption and output heat to obtain the second boiler efficiency; Calculating an evaluation parameter, where the evaluation parameter is the difference between the first boiler efficiency and the second boiler efficiency; Outputting coal quality parameters based on the evaluation parameter.

6. The method according to claim 5, wherein Outputting coal quality parameters based on the evaluation parameter, including: Obtaining a preset evaluation threshold; If the evaluation parameter is less than the preset evaluation threshold, outputting coal quality parameters, and calculating the combustion flue gas volume according to the coal quality parameters and the coal quality industrial analysis result; If the evaluation parameter is greater than or equal to the preset evaluation threshold, modifying the input coal calorific value.

7. The method according to claim 2, wherein The method further includes: Obtaining the boiler historical data and the combustion flue gas volume; Perform parameter fitting on the historical data of the boiler to generate the air leakage rate function of the boiler; Obtain the operating parameters of the coal mill, and calculate the air leakage rate of the boiler based on the operating parameters of the coal mill and the air leakage rate function of the boiler; Calculate the product of the air leakage rate of the boiler and the combustion flue gas volume to obtain the air leakage volume of the boiler body.

8. The method according to claim 2, wherein The method further includes: Obtain the inlet flue gas oxygen content and the outlet flue gas oxygen content of the air preheater, where the inlet flue gas oxygen content is the volume fraction of oxygen at the inlet of the air preheater; the outlet flue gas oxygen content is the volume fraction of oxygen at the outlet of the air preheater; Calculate the air leakage rate of the air preheater according to the inlet flue gas oxygen content and the outlet flue gas oxygen content; Calculate the total gas volume of the boiler, where the total gas volume of the boiler is equal to the sum of the combustion flue gas volume and the air leakage volume of the boiler body; Calculate the air leakage volume of the air preheater according to the total gas volume of the boiler, where the air leakage volume of the air preheater is the product of the total gas volume of the boiler and the air leakage rate of the air preheater.

9. The method according to claim 1, wherein Calculate the flow rate ratio of the induced draft fan according to the induced draft fan equipment parameters, including: Read the motor current and the fan total pressure from the induced draft fan equipment parameters; Calculate the total equipment current according to the motor currents of multiple induced draft fans, and calculate the total equipment air pressure according to the fan total pressures of multiple induced draft fans; Calculate the flow rate ratio of the induced draft fan based on the motor current, the fan total pressure, the total equipment current and the total equipment air pressure.

10. A flow measurement system for an induced draft fan of a pulverized coal boiler, characterized in that, The system includes a coal mill, a pulverized coal boiler, an induced draft fan, an air preheater and a data processing device; Wherein, the coal mill is configured to crush coal into pulverized coal and transport it to the pulverized coal boiler; the pulverized coal boiler is configured to burn the pulverized coal; the induced draft fan is configured to transport the flue gas generated during the pulverized coal combustion process in the pulverized coal boiler to the air preheater; the air preheater is configured to recover the waste heat in the flue gas to heat the air required for the combustion of the pulverized coal boiler; The data processing device establishes a communication connection with at least one of the coal mill, the pulverized coal boiler, the induced draft fan and the air preheater; the data processing device is further configured to: Obtain the combustion flue gas volume, the air leakage volume of the air preheater and the air leakage volume of the boiler body; Calculate the sum of the combustion flue gas volume, the air leakage volume of the air preheater and the air leakage volume of the boiler body to generate the total flue gas flow rate; Obtain the induced draft fan equipment parameters, where the induced draft fan equipment parameters include the motor currents and the fan total pressures of at least two induced draft fans; Calculate the flow rate ratio of the induced draft fan according to the induced draft fan equipment parameters; Output the flue gas flow rate of the induced draft fan according to the flow rate ratio, where the flue gas flow rate is the product of the flow rate ratio and the total flue gas flow rate.

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