A coal quality mutation control method and device based on an HP type medium-speed coal mill
By monitoring parameter changes in the HP-type medium-speed coal mill, the system automatically identifies sudden changes in coal quality and adjusts operating parameters, solving the problems of large errors in judging sudden changes in coal quality and high labor costs in existing technologies, thus improving the safety and economy of the unit.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUANENG NANJING JINLING POWER GENERATION
- Filing Date
- 2023-08-10
- Publication Date
- 2026-08-04
AI Technical Summary
Existing technologies cannot automatically identify sudden changes in coal quality in HP-type medium-speed coal mills, resulting in large errors in judgment, high labor costs, and poor unit safety.
By monitoring the temperature difference between the primary air inlet of the coal mill and the hot primary air outlet of the air preheater, the opening degree of the cold primary air in the coal mill, and the temperature at the mill outlet, corresponding function changes are set, and the coal quality changes are judged based on the incremental values, and the operating parameters of the coal mill are automatically adjusted.
It enables automatic identification of sudden changes in coal quality in coal mills, reduces labor costs, and improves the safety and economy of the unit.
Smart Images
Figure CN117563755B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of coal mill technology, and more specifically, to a method and equipment for controlling coal quality mutations based on an HP-type medium-speed coal mill. Background Technology
[0002] With the continuous increase in domestic thermal power generation capacity, the demand for high-quality thermal coal is growing daily, leading to a sustained rise in domestic coal prices. Economic coal types, especially high-quality thermal coal, have a significant price advantage, and blending these types has become one of the main profit-generating methods for domestic thermal power plants. However, the sudden changes in coal quality caused by blending have become a common occurrence in the operation of thermal power plants. High-moisture Indonesian coal is a typical economic coal type. This type of coal is characterized by low calorific value, high volatile matter, and high moisture content, which can significantly reduce the outlet temperature of the coal mill and easily lead to deflagration in the pulverizing system, thus affecting the economic efficiency of the unit and the safety of the pulverizing system to some extent.
[0003] In existing technologies, the determination of sudden changes in coal quality generally relies on the experience of staff for judgment. This not only leads to large errors in the judgment results, but also fails to guarantee timeliness, greatly increasing labor costs and safety risks to the unit.
[0004] Therefore, how to provide a method and equipment for controlling coal quality mutations based on HP-type medium-speed coal mills, so as to realize the automatic judgment of coal quality mutations, and automatically adjust the coal mill parameters according to the coal quality mutation situation, reduce labor costs, and improve the safety of the unit, is a technical problem that needs to be solved. Summary of the Invention
[0005] This invention provides a method and device for controlling coal quality mutations based on an HP-type medium-speed coal mill, to solve the problem that existing technologies cannot automatically identify coal quality mutations and make corresponding parameter adjustments. The method includes:
[0006] The sudden change in coal quality is determined based on the parameter information of the coal mill. The parameter information includes the difference between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, the opening degree of the cold primary air of the coal mill, and the outlet temperature of the mill.
[0007] The operating parameters of the coal mill are adjusted based on the aforementioned mutation.
[0008] In some specific embodiments, the method further includes determining the abrupt changes in coal quality based on parameter variation information of the coal mill, and the method also includes:
[0009] Let f1(t) be the function of the difference ΔT between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater as a function of time.
[0010] Let f2(t) be the function that describes the change of the primary air opening of the coal mill with time.
[0011] The function of mill outlet temperature changing with time is defined as f3(t);
[0012] The increments of f1(t), f2(t), and f3(t) at time t min are respectively the first increment g1(t), the second increment g2(t), and the third increment g3(t);
[0013] The abrupt changes in coal quality are determined based on the first, second, and third increments.
[0014] In some specific embodiments, g1(t) = f1(t) - f1(t-5), g2(t) = f2(t-1) - f2(t-6), and g3(t) = f3(t-4) - f3(t-9).
[0015] In some specific embodiments, the abrupt change in coal quality is determined based on the first increment, the second increment, and the third increment, specifically as follows:
[0016] When at least two of the following conditions are met: the first increment is greater than the first threshold, the second increment is greater than the second threshold, and the third increment is greater than the third threshold, the mutation is a change from high-moisture Indonesian coal to ordinary coal.
[0017] When at least two of the following conditions are met: the first increment is less than the fourth threshold, the second increment is less than the fifth threshold, and the third increment is less than the sixth threshold, the mutation is a change from ordinary coal to high-moisture Indonesian coal.
[0018] Among them, the first threshold, the second threshold, and the third threshold are positive values, while the fourth threshold, the fifth threshold, and the sixth threshold are negative values.
[0019] In some specific embodiments, the operating parameters of the coal mill are adjusted based on the abrupt change, specifically as follows:
[0020] When the sudden change is from high-moisture Indonesian coal to ordinary coal, change the outlet temperature setting of the coal mill to 90℃ and the primary air volume offset setting to +15t / h.
[0021] When the sudden change is from ordinary coal to high-moisture Indonesian coal, change the outlet temperature setting of the coal mill to 60℃ and the primary air volume offset setting to +30t / h.
[0022] Accordingly, the present invention also proposes a coal quality mutation control device based on an HP-type medium-speed coal mill, the device comprising:
[0023] The determination module is used to determine the sudden change in coal quality based on the parameter information of the coal mill. The parameter information includes the difference between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, the opening degree of the cold primary air of the coal mill, and the outlet temperature of the mill.
[0024] The adjustment module is used to adjust the operating parameters of the coal mill based on the sudden change.
[0025] In some specific embodiments, the determining module is used to:
[0026] Let f1(t) be the function of the difference ΔT between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater as a function of time.
[0027] Let f2(t) be the function that describes the change of the primary air opening of the coal mill with time.
[0028] The function of mill outlet temperature changing with time is defined as f3(t);
[0029] The increments of f1(t), f2(t), and f3(t) at time t min are respectively the first increment g1(t), the second increment g2(t), and the third increment g3(t);
[0030] The abrupt changes in coal quality are determined based on the first, second, and third increments.
[0031] In some specific embodiments, g1(t) = f1(t) - f1(t-5), g2(t) = f2(t-1) - f2(t-6), and g3(t) = f3(t-4) - f3(t-9).
[0032] In some specific embodiments, the determining module is specifically used for:
[0033] When at least two of the following conditions are met: the first increment is greater than the first threshold, the second increment is greater than the second threshold, and the third increment is greater than the third threshold, the mutation is a change from high-moisture Indonesian coal to ordinary coal.
[0034] When at least two of the following conditions are met: the first increment is less than the fourth threshold, the second increment is less than the fifth threshold, and the third increment is less than the sixth threshold, the mutation is a change from ordinary coal to high-moisture Indonesian coal.
[0035] Among them, the first threshold, the second threshold, and the third threshold are positive values, while the fourth threshold, the fifth threshold, and the sixth threshold are negative values.
[0036] In some specific embodiments, the adjustment module is specifically used for:
[0037] When the sudden change is from high-moisture Indonesian coal to ordinary coal, change the outlet temperature setting of the coal mill to 90℃ and the primary air volume offset setting to +15t / h.
[0038] When the sudden change is from ordinary coal to high-moisture Indonesian coal, change the outlet temperature setting of the coal mill to 60℃ and the primary air volume offset setting to +30t / h.
[0039] By applying the above technical solutions, a method for controlling coal quality mutations based on an HP-type medium-speed coal mill is proposed. The method determines coal quality mutations based on the mill's parameter information, including the difference between the primary air temperature at the mill inlet and the hot primary air temperature at the air preheater outlet, the cold primary air opening degree of the mill, and the mill outlet temperature. Based on these mutations, the mill's operating parameters are adjusted. This real-time comparison of mill parameters determines coal quality mutations, and timely adjustments to operating parameters reduce labor costs, achieve automatic identification of coal quality mutations, and ensure unit safety. Attached Figure Description
[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0041] Figure 1 A schematic flowchart of a method for controlling coal quality mutations based on an HP-type medium-speed coal mill, as proposed in an embodiment of the present invention, is shown.
[0042] Figure 2 A schematic diagram of a coal quality mutation control device based on an HP-type medium-speed coal mill, as proposed in an embodiment of the present invention, is shown.
[0043] Figure 3 This invention provides a schematic diagram illustrating the parameter information change curves of a coal mill when the coal quality changes abruptly from high-moisture Indonesian coal to low-moisture ordinary coal, according to an embodiment of the present invention.
[0044] Figure 4 The diagram illustrates the parameter information change curves of a coal mill according to an embodiment of the present invention when the coal quality changes abruptly from low-moisture ordinary coal to high-moisture Indonesian coal or low-moisture ordinary coal. Detailed Implementation
[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0046] This invention, based on the actual situation of high-moisture Indonesian coal being blended into the boiler of an ultra-supercritical coal-fired power plant, analyzes the impact of this economical coal type on various parameters of an HP-type medium-speed mill. Since low calorific value, high volatile matter, and high moisture content are the main characteristics of this coal type, by comparing the effects of changes in volatile matter and moisture on various parameters of the HP-type medium-speed mill, the main parameters that this coal type may affect in the pulverizing system are identified. Based on the trend of parameter changes, an automatic detection and judgment logic for sudden changes in coal quality in the HP-type coal mill is designed and implemented.
[0047] Under the premise of being able to accurately judge the sudden change in coal quality in the pulverizing system, and based on the relevant regulations and operating experience of coal blending, the parameters of the HP medium-speed coal mill are adjusted accordingly to ensure the safety of blending high-moisture Indonesian coal, thereby improving the overall operating safety of the unit.
[0048] like Figure 1 As shown, this application proposes a method for controlling sudden changes in coal quality based on an HP-type medium-speed coal mill. The method includes the following steps:
[0049] Step S101: Determine the sudden change in coal quality based on the parameter information of the coal mill. The parameter information includes the difference between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, the opening degree of the cold primary air of the coal mill, and the outlet temperature of the mill.
[0050] In this embodiment, to automatically determine the sudden changes in coal quality, parameter information of the coal mill is collected for determination. The selection of these parameters should be based on the significant trend of change that occurs during the sudden change in coal quality, such as a continuous increase or a continuous decrease, which can be clearly judged. For the HP-type medium-speed coal mill, when grinding high-moisture Indonesian coal, the required drying output is greater, and the coal-air temperature at the coal mill outlet is often lower than that of other coal types. When the coal type in the coal mill changes from Indonesian coal to other high-calorific-value, low-moisture coal types, the coal-air temperature at the coal mill outlet will increase if the set value of the coal mill outlet temperature remains unchanged. Subsequently, under the automatic adjustment, the cold primary air damper will be opened wider to reduce the coal mill outlet temperature. At the same time, due to the increased proportion of cold air in the hot and cold primary air, the difference between the primary air temperature at the coal mill inlet and the hot primary air temperature at the air preheater outlet will also increase. Therefore, this scheme selects the difference between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, the opening degree of the cold primary air of the coal mill, and the mill outlet temperature. It should be noted that other parameter information that can be used to determine the sudden change in coal quality should also be within the protection scope of this scheme.
[0051] Meanwhile, to further ensure the accuracy of the judgment, ΔT, the coal mill outlet temperature, and the opening of the coal mill cold air damper will change in the initial stage of coal feeder operation. To prevent the influence of this period, this study selects data from 20 minutes after the coal mill is closed for logic construction.
[0052] To accurately determine abrupt changes in coal quality, in some embodiments of this application, the abrupt changes in coal quality are determined based on parameter change information of the coal mill. The method further includes:
[0053] Let f1(t) be the function of the difference ΔT between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater as a function of time.
[0054] Let f2(t) be the function that describes the change of the primary air opening of the coal mill with time.
[0055] The function of mill outlet temperature changing with time is defined as f3(t);
[0056] The increments of f1(t), f2(t), and f3(t) at time t min are respectively the first increment g1(t), the second increment g2(t), and the third increment g3(t);
[0057] The abrupt changes in coal quality are determined based on the first, second, and third increments.
[0058] In this embodiment, the function f1(t) represents the difference ΔT between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, the function f2(t) represents the change of the cold primary air opening of the coal mill, and the function f3(t) represents the change of the mill outlet temperature. The increment values of these three parameters at time t min are analyzed to determine whether the coal type ground by the coal mill changes from ordinary coal to high-moisture Indonesian coal, or from high-moisture Indonesian coal to ordinary coal.
[0059] To ensure accurate judgment of coal quality mutation, in some embodiments of this application, g1(t) = f1(t) - f1(t-5), g2(t) = f2(t-1) - f2(t-6), and g3(t) = f3(t-4) - f3(t-9).
[0060] In this embodiment, when all three parameters show significant changes, it can be basically determined that the coal quality has changed. Since parameter changes are a continuous process, the time span for selecting the changes in the three parameters in the automatic logic judgment should not be too short, nor too long to provide timely judgment. Through analysis of the parameters in actual operation, we believe a 5-minute time span is appropriate, i.e., the parameter change at the current moment = (parameter value at the current moment) - (parameter value 5 minutes ago). In actual operation, judging coal quality changes solely based on a single variable may lead to misjudgments (e.g., temperature feedback failure, cold air opening feedback failure, etc.). Because the changes in these three parameters are causally related, the increase in each parameter value does not occur synchronously. Therefore, to automatically judge coal quality changes, a certain delay is needed for the three parameters to achieve simultaneous judgment. Based on a comparison of actual data, we propose the following solution:
[0061] Let f1(t) be the function representing the difference ΔT between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, f2(t) be the function representing the change in the opening degree of the cold primary air in the coal mill, and f3(t) be the function representing the change in the mill outlet temperature. Let g1(t), g2(t), and g3(t) be the increments of these three parameters at time t min, respectively. Then:
[0062] g1(t) = f1(t) - f1(t-5)
[0063] g2(t)=f2(t-1)-f2(t-6)
[0064] g3(t)=f3(t-4)-f3(t-9)
[0065] By using the above processing, the changes in the three parameters can be considered simultaneously in the automatic judgment logic, thus avoiding misjudgment.
[0066] Step S102: Adjust the operating parameters of the coal mill based on the sudden change.
[0067] In this embodiment, after determining a sudden change in coal quality, the various operating parameters of the HP medium-speed coal mill will be adjusted to a level suitable for the current coal type, so as to ensure the economy of the HP medium-speed coal mill when burning ordinary coal and the safety when burning high-moisture Indonesian coal.
[0068] To determine the abrupt changes in coal quality, in the specific implementation of this application, the abrupt changes in coal quality are determined based on the first increment, the second increment, and the third increment, specifically as follows:
[0069] When at least two of the following conditions are met: the first increment is greater than the first threshold, the second increment is greater than the second threshold, and the third increment is greater than the third threshold, the mutation is a change from high-moisture Indonesian coal to ordinary coal.
[0070] When at least two of the following conditions are met: the first increment is less than the fourth threshold, the second increment is less than the fifth threshold, and the third increment is less than the sixth threshold, the mutation is a change from ordinary coal to high-moisture Indonesian coal.
[0071] Among them, the first threshold, the second threshold, and the third threshold are positive values, while the fourth threshold, the fifth threshold, and the sixth threshold are negative values.
[0072] In this embodiment, because Indonesian coal has a much higher moisture content than other coal types, a larger share of drying output is required, and the pulverized coal outlet temperature of the pulverizer is often lower than that of other coal types. When the coal type in the pulverizer changes from Indonesian coal to other high-calorific-value, low-moisture ordinary coal types, the pulverized coal outlet temperature of the pulverizer will increase if the pulverizer outlet temperature setpoint remains unchanged. Subsequently, under automatic adjustment, the cold primary air damper will be opened wider to reduce the pulverizer outlet temperature. At the same time, due to the increased proportion of cold air in the hot and cold primary air, the difference between the pulverizer inlet primary air temperature and the air preheater outlet hot primary air temperature will also increase (the difference between the pulverizer inlet primary air temperature and the air preheater outlet hot primary air temperature is defined as ΔT (°C) below, i.e., ΔT = air preheater outlet hot primary air temperature - pulverizer inlet primary air temperature).
[0073] like Figure 1As shown, with the horizontal axis at 10 minutes as the reference, the curves from top to bottom represent the outlet temperature, coal quantity, current, cold air opening degree, and temperature change, respectively. When the coal changes abruptly from high-moisture Indonesian coal to low-moisture ordinary coal, around the 7-minute mark, due to the change in coal quality, the mill outlet temperature begins to show a significant upward trend. After a brief delay, the cold air damper opening increases, and subsequently, ΔT also increases. Therefore, in this scheme, when the abrupt change occurs from high-moisture Indonesian coal to ordinary coal, the first increment is greater than the first threshold, the second increment is greater than the second threshold, and the third increment is greater than the third threshold; that is, all parameters show an upward trend. To further ensure the accuracy of the judgment, when two of these parameters are satisfied, the abrupt change can be determined as a change from high-moisture Indonesian coal to ordinary coal.
[0074] Correspondingly, when the coal type in the pulverizer changes from other high-calorific-value, low-moisture coal to high-moisture Indonesian coal, the pulverizer outlet air-coal temperature will decrease if the pulverizer outlet temperature setpoint remains unchanged. Subsequently, under automatic regulation, the cold primary air damper will be closed to increase the pulverizer outlet temperature. At the same time, as the proportion of cold air in the hot and cold primary air decreases, the difference between the pulverizer inlet primary air temperature and the air preheater outlet hot primary air temperature will also decrease (the difference between the pulverizer inlet primary air temperature and the air preheater outlet hot primary air temperature is defined as ΔT (°C) below, i.e., ΔT = air preheater outlet hot primary air temperature - pulverizer inlet primary air temperature). Figure 3 The coal type inside the coal mill was changed from a high-volatile, low-moisture coal to Indonesian coal.
[0075] like Figure 4 As shown, with the horizontal axis representing 10 minutes, the parameters from top to bottom are: outlet temperature, coal quantity, temperature variable, current, and cold air opening. These parameters represent the changes in various operating parameters of the coal mill during the abrupt change from high-volatile, low-moisture coal to Indonesian coal. Around the 7-minute mark, due to the change in coal quality, the mill outlet temperature begins to show a significant downward trend. After a brief delay, the cold air damper opening decreases, and subsequently, ΔT also decreases. When all three parameters show a significant decrease, it can be basically determined that the coal quality has changed. Therefore, in this scheme, when the abrupt change is from ordinary coal to high-moisture Indonesian coal, the first increment is less than the fourth threshold, the second increment is less than the fifth threshold, and the third increment is less than the sixth threshold; that is, all parameters show a downward trend. To further ensure the accuracy of the judgment, when two of these parameters are satisfied, the abrupt change can be determined as a change from ordinary coal to high-moisture Indonesian coal.
[0076] To ensure the stable operation of the unit, in some embodiments of this application, the operating parameters of the coal mill are adjusted based on the aforementioned abrupt changes, specifically as follows:
[0077] When the sudden change is from high-moisture Indonesian coal to ordinary coal, change the outlet temperature setting of the coal mill to 90℃ and the primary air volume offset setting to +15t / h.
[0078] When the sudden change is from ordinary coal to high-moisture Indonesian coal, change the outlet temperature setting of the coal mill to 60℃ and the primary air volume offset setting to +30t / h.
[0079] In this embodiment, after determining that the coal quality in the pulverizer has changed to high-moisture Indonesian coal, the pulverizer outlet temperature setpoint is automatically changed to 60°C to prevent excessively high outlet air-coal temperature from causing deflagration of the Indonesian coal. The primary air volume offset setpoint is also changed to +30t / h to increase the primary air volume and reduce the possibility of coal dust deposition. After determining that the coal quality in the pulverizer has changed to ordinary coal, the pulverizer outlet temperature setpoint is automatically changed to 90°C to minimize the amount of cold primary air used in the pulverizer. The primary air volume offset setpoint is also changed to +15t / h to reduce primary air fan power consumption and improve boiler economy.
[0080] To prevent sudden changes in coal quantity caused by manual coal feeding, this logic is set to operate only when the automatic coal quantity offset of the coal feeder remains unchanged and the manual coal quantity feedback remains unchanged.
[0081] By applying the above technical solutions, a method for controlling coal quality mutations based on an HP-type medium-speed coal mill is proposed. The method determines coal quality mutations based on the mill's parameter information, including the difference between the primary air temperature at the mill inlet and the hot primary air temperature at the air preheater outlet, the cold primary air opening degree of the mill, and the mill outlet temperature. Based on these mutations, the mill's operating parameters are adjusted. This real-time comparison of mill parameters determines coal quality mutations, and timely adjustments to operating parameters reduce labor costs, achieve automatic identification of coal quality mutations, and ensure unit safety.
[0082] This application also proposes a coal quality mutation control device based on an HP-type medium-speed coal mill, such as... Figure 2 As shown, the device includes:
[0083] The determination module 10 is used to determine the sudden change in coal quality based on the parameter information of the coal mill. The parameter information includes the difference between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, the opening degree of the cold primary air of the coal mill, and the outlet temperature of the mill.
[0084] The adjustment module 20 is used to adjust the operating parameters of the coal mill based on the sudden change.
[0085] In the specific application scenario of this application, the determining module is used for:
[0086] Let f1(t) be the function of the difference ΔT between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater as a function of time.
[0087] Let f2(t) be the function that describes the change of the primary air opening of the coal mill with time.
[0088] The function of mill outlet temperature changing with time is defined as f3(t);
[0089] The increments of f1(t), f2(t), and f3(t) at time t min are respectively the first increment g1(t), the second increment g2(t), and the third increment g3(t);
[0090] The abrupt changes in coal quality are determined based on the first, second, and third increments.
[0091] In the specific application scenario of this application, g1(t) = f1(t) - f1(t-5), g2(t) = f2(t-1) - f2(t-6), and g3(t) = f3(t-4) - f3(t-9).
[0092] In the specific application scenario of this application, the determining module is specifically used for:
[0093] When at least two of the following conditions are met: the first increment is greater than the first threshold, the second increment is greater than the second threshold, and the third increment is greater than the third threshold, the mutation is a change from high-moisture Indonesian coal to ordinary coal.
[0094] When at least two of the following conditions are met: the first increment is less than the fourth threshold, the second increment is less than the fifth threshold, and the third increment is less than the sixth threshold, the mutation is a change from ordinary coal to high-moisture Indonesian coal.
[0095] Among them, the first threshold, the second threshold, and the third threshold are positive values, while the fourth threshold, the fifth threshold, and the sixth threshold are negative values.
[0096] In the specific application scenario of this application, the adjustment module is specifically used for:
[0097] When the sudden change is from high-moisture Indonesian coal to ordinary coal, change the outlet temperature setting of the coal mill to 90℃ and the primary air volume offset setting to +15t / h.
[0098] When the sudden change is from ordinary coal to high-moisture Indonesian coal, change the outlet temperature setting of the coal mill to 60℃ and the primary air volume offset setting to +30t / h.
[0099] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0100] In this invention, unless otherwise explicitly specified and limited, the terms "entering," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0101] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0102] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.
Claims
1. A method for controlling sudden changes in coal quality based on an HP-type medium-speed coal mill, characterized in that, The method includes: The sudden change in coal quality is determined based on the parameter information of the coal mill. The parameter information includes the difference between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, the opening degree of the cold primary air of the coal mill, and the outlet temperature of the mill. The operating parameters of the coal mill are adjusted based on the aforementioned sudden change. The method for determining abrupt changes in coal quality based on parameter variation information of the coal mill further includes: Let f1(t) be the function of the difference ΔT between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater as a function of time. Let f2(t) be the function that describes the change of the primary air opening of the coal mill with time. The function of mill outlet temperature changing with time is defined as f3(t); The increments of f1(t), f2(t), and f3(t) at time t min are respectively the first increment g1(t), the second increment g2(t), and the third increment g3(t); The abrupt changes in coal quality are determined based on the first, second, and third increments; Specifically, determining the abrupt changes in coal quality based on the first increment, the second increment, and the third increment involves: When at least two of the following conditions are met: the first increment is greater than the first threshold, the second increment is greater than the second threshold, and the third increment is greater than the third threshold, the mutation is a change from high-moisture Indonesian coal to ordinary coal. When at least two of the following conditions are met: the first increment is less than the fourth threshold, the second increment is less than the fifth threshold, and the third increment is less than the sixth threshold, the mutation is a change from ordinary coal to high-moisture Indonesian coal. Among them, the first threshold, the second threshold and the third threshold are positive values, while the fourth threshold, the fifth threshold and the sixth threshold are negative values.
2. The method according to claim 1, characterized in that, g1(t)=f1(t)-f1(t-5), g2(t)=f2(t-1)-f2(t-6), g3(t)=f3(t-4)-f3(t-9).
3. The method according to claim 1, characterized in that, The operating parameters of the coal mill are adjusted based on the aforementioned abrupt change, specifically as follows: When the sudden change is from high-moisture Indonesian coal to ordinary coal, change the outlet temperature setting of the coal mill to 90℃ and the primary air volume offset setting to +15t / h. When the sudden change is from ordinary coal to high-moisture Indonesian coal, change the outlet temperature setting of the coal mill to 60℃ and the primary air volume offset setting to +30t / h.
4. A coal quality mutation control device based on an HP-type medium-speed coal mill, characterized in that, The device includes: The determination module is used to determine the sudden change in coal quality based on the parameter information of the coal mill. The parameter information includes the difference between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater, the opening degree of the cold primary air of the coal mill, and the outlet temperature of the mill. An adjustment module is used to adjust the operating parameters of the coal mill based on the sudden change. The determining module is used for: Let f1(t) be the function of the difference ΔT between the primary air temperature at the inlet of the coal mill and the hot primary air temperature at the outlet of the air preheater as a function of time. Let f2(t) be the function that describes the change of the primary air opening of the coal mill with time. The function of mill outlet temperature changing with time is defined as f3(t); The increments of f1(t), f2(t), and f3(t) at time t min are respectively the first increment g1(t), the second increment g2(t), and the third increment g3(t); The abrupt changes in coal quality are determined based on the first, second, and third increments; Specifically, the determining module is used for: When at least two of the following conditions are met: the first increment is greater than the first threshold, the second increment is greater than the second threshold, and the third increment is greater than the third threshold, the mutation is a change from high-moisture Indonesian coal to ordinary coal. When at least two of the following conditions are met: the first increment is less than the fourth threshold, the second increment is less than the fifth threshold, and the third increment is less than the sixth threshold, the mutation is a change from ordinary coal to high-moisture Indonesian coal. Among them, the first threshold, the second threshold and the third threshold are positive values, while the fourth threshold, the fifth threshold and the sixth threshold are negative values.
5. The device as described in claim 4, characterized in that, g1(t)=f1(t)-f1(t-5), g2(t)=f2(t-1)-f2(t-6), g3(t)=f3(t-4)-f3(t-9).
6. The device as described in claim 4, characterized in that, The adjustment module is specifically used for: When the sudden change is from high-moisture Indonesian coal to ordinary coal, change the outlet temperature setting of the coal mill to 90℃ and the primary air volume offset setting to +15t / h. When the sudden change is from ordinary coal to high-moisture Indonesian coal, change the outlet temperature setting of the coal mill to 60℃ and the primary air volume offset setting to +30t / h.